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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * The User Datagram Protocol (UDP).
8 *
9 * Authors: Ross Biro
10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
12 * Alan Cox, <alan@lxorguk.ukuu.org.uk>
13 * Hirokazu Takahashi, <taka@valinux.co.jp>
14 *
15 * Fixes:
16 * Alan Cox : verify_area() calls
17 * Alan Cox : stopped close while in use off icmp
18 * messages. Not a fix but a botch that
19 * for udp at least is 'valid'.
20 * Alan Cox : Fixed icmp handling properly
21 * Alan Cox : Correct error for oversized datagrams
22 * Alan Cox : Tidied select() semantics.
23 * Alan Cox : udp_err() fixed properly, also now
24 * select and read wake correctly on errors
25 * Alan Cox : udp_send verify_area moved to avoid mem leak
26 * Alan Cox : UDP can count its memory
27 * Alan Cox : send to an unknown connection causes
28 * an ECONNREFUSED off the icmp, but
29 * does NOT close.
30 * Alan Cox : Switched to new sk_buff handlers. No more backlog!
31 * Alan Cox : Using generic datagram code. Even smaller and the PEEK
32 * bug no longer crashes it.
33 * Fred Van Kempen : Net2e support for sk->broadcast.
34 * Alan Cox : Uses skb_free_datagram
35 * Alan Cox : Added get/set sockopt support.
36 * Alan Cox : Broadcasting without option set returns EACCES.
37 * Alan Cox : No wakeup calls. Instead we now use the callbacks.
38 * Alan Cox : Use ip_tos and ip_ttl
39 * Alan Cox : SNMP Mibs
40 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support.
41 * Matt Dillon : UDP length checks.
42 * Alan Cox : Smarter af_inet used properly.
43 * Alan Cox : Use new kernel side addressing.
44 * Alan Cox : Incorrect return on truncated datagram receive.
45 * Arnt Gulbrandsen : New udp_send and stuff
46 * Alan Cox : Cache last socket
47 * Alan Cox : Route cache
48 * Jon Peatfield : Minor efficiency fix to sendto().
49 * Mike Shaver : RFC1122 checks.
50 * Alan Cox : Nonblocking error fix.
51 * Willy Konynenberg : Transparent proxying support.
52 * Mike McLagan : Routing by source
53 * David S. Miller : New socket lookup architecture.
54 * Last socket cache retained as it
55 * does have a high hit rate.
56 * Olaf Kirch : Don't linearise iovec on sendmsg.
57 * Andi Kleen : Some cleanups, cache destination entry
58 * for connect.
59 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
60 * Melvin Smith : Check msg_name not msg_namelen in sendto(),
61 * return ENOTCONN for unconnected sockets (POSIX)
62 * Janos Farkas : don't deliver multi/broadcasts to a different
63 * bound-to-device socket
64 * Hirokazu Takahashi : HW checksumming for outgoing UDP
65 * datagrams.
66 * Hirokazu Takahashi : sendfile() on UDP works now.
67 * Arnaldo C. Melo : convert /proc/net/udp to seq_file
68 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
69 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind
70 * a single port at the same time.
71 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
72 * James Chapman : Add L2TP encapsulation type.
73 */
74
75#define pr_fmt(fmt) "UDP: " fmt
76
77#include <linux/uaccess.h>
78#include <asm/ioctls.h>
79#include <linux/memblock.h>
80#include <linux/highmem.h>
81#include <linux/swap.h>
82#include <linux/types.h>
83#include <linux/fcntl.h>
84#include <linux/module.h>
85#include <linux/socket.h>
86#include <linux/sockios.h>
87#include <linux/igmp.h>
88#include <linux/inetdevice.h>
89#include <linux/in.h>
90#include <linux/errno.h>
91#include <linux/timer.h>
92#include <linux/mm.h>
93#include <linux/inet.h>
94#include <linux/netdevice.h>
95#include <linux/slab.h>
96#include <net/tcp_states.h>
97#include <linux/skbuff.h>
98#include <linux/proc_fs.h>
99#include <linux/seq_file.h>
100#include <net/net_namespace.h>
101#include <net/icmp.h>
102#include <net/inet_hashtables.h>
103#include <net/ip_tunnels.h>
104#include <net/route.h>
105#include <net/checksum.h>
106#include <net/xfrm.h>
107#include <trace/events/udp.h>
108#include <linux/static_key.h>
109#include <linux/btf_ids.h>
110#include <trace/events/skb.h>
111#include <net/busy_poll.h>
112#include "udp_impl.h"
113#include <net/sock_reuseport.h>
114#include <net/addrconf.h>
115#include <net/udp_tunnel.h>
116#if IS_ENABLED(CONFIG_IPV6)
117#include <net/ipv6_stubs.h>
118#endif
119
120struct udp_table udp_table __read_mostly;
121EXPORT_SYMBOL(udp_table);
122
123long sysctl_udp_mem[3] __read_mostly;
124EXPORT_SYMBOL(sysctl_udp_mem);
125
126atomic_long_t udp_memory_allocated;
127EXPORT_SYMBOL(udp_memory_allocated);
128
129#define MAX_UDP_PORTS 65536
130#define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
131
132static int udp_lib_lport_inuse(struct net *net, __u16 num,
133 const struct udp_hslot *hslot,
134 unsigned long *bitmap,
135 struct sock *sk, unsigned int log)
136{
137 struct sock *sk2;
138 kuid_t uid = sock_i_uid(sk);
139
140 sk_for_each(sk2, &hslot->head) {
141 if (net_eq(sock_net(sk2), net) &&
142 sk2 != sk &&
143 (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
144 (!sk2->sk_reuse || !sk->sk_reuse) &&
145 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
146 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
147 inet_rcv_saddr_equal(sk, sk2, true)) {
148 if (sk2->sk_reuseport && sk->sk_reuseport &&
149 !rcu_access_pointer(sk->sk_reuseport_cb) &&
150 uid_eq(uid, sock_i_uid(sk2))) {
151 if (!bitmap)
152 return 0;
153 } else {
154 if (!bitmap)
155 return 1;
156 __set_bit(udp_sk(sk2)->udp_port_hash >> log,
157 bitmap);
158 }
159 }
160 }
161 return 0;
162}
163
164/*
165 * Note: we still hold spinlock of primary hash chain, so no other writer
166 * can insert/delete a socket with local_port == num
167 */
168static int udp_lib_lport_inuse2(struct net *net, __u16 num,
169 struct udp_hslot *hslot2,
170 struct sock *sk)
171{
172 struct sock *sk2;
173 kuid_t uid = sock_i_uid(sk);
174 int res = 0;
175
176 spin_lock(&hslot2->lock);
177 udp_portaddr_for_each_entry(sk2, &hslot2->head) {
178 if (net_eq(sock_net(sk2), net) &&
179 sk2 != sk &&
180 (udp_sk(sk2)->udp_port_hash == num) &&
181 (!sk2->sk_reuse || !sk->sk_reuse) &&
182 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
183 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
184 inet_rcv_saddr_equal(sk, sk2, true)) {
185 if (sk2->sk_reuseport && sk->sk_reuseport &&
186 !rcu_access_pointer(sk->sk_reuseport_cb) &&
187 uid_eq(uid, sock_i_uid(sk2))) {
188 res = 0;
189 } else {
190 res = 1;
191 }
192 break;
193 }
194 }
195 spin_unlock(&hslot2->lock);
196 return res;
197}
198
199static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot)
200{
201 struct net *net = sock_net(sk);
202 kuid_t uid = sock_i_uid(sk);
203 struct sock *sk2;
204
205 sk_for_each(sk2, &hslot->head) {
206 if (net_eq(sock_net(sk2), net) &&
207 sk2 != sk &&
208 sk2->sk_family == sk->sk_family &&
209 ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
210 (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) &&
211 (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
212 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
213 inet_rcv_saddr_equal(sk, sk2, false)) {
214 return reuseport_add_sock(sk, sk2,
215 inet_rcv_saddr_any(sk));
216 }
217 }
218
219 return reuseport_alloc(sk, inet_rcv_saddr_any(sk));
220}
221
222/**
223 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
224 *
225 * @sk: socket struct in question
226 * @snum: port number to look up
227 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
228 * with NULL address
229 */
230int udp_lib_get_port(struct sock *sk, unsigned short snum,
231 unsigned int hash2_nulladdr)
232{
233 struct udp_hslot *hslot, *hslot2;
234 struct udp_table *udptable = sk->sk_prot->h.udp_table;
235 int error = 1;
236 struct net *net = sock_net(sk);
237
238 if (!snum) {
239 int low, high, remaining;
240 unsigned int rand;
241 unsigned short first, last;
242 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
243
244 inet_get_local_port_range(net, &low, &high);
245 remaining = (high - low) + 1;
246
247 rand = prandom_u32();
248 first = reciprocal_scale(rand, remaining) + low;
249 /*
250 * force rand to be an odd multiple of UDP_HTABLE_SIZE
251 */
252 rand = (rand | 1) * (udptable->mask + 1);
253 last = first + udptable->mask + 1;
254 do {
255 hslot = udp_hashslot(udptable, net, first);
256 bitmap_zero(bitmap, PORTS_PER_CHAIN);
257 spin_lock_bh(&hslot->lock);
258 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
259 udptable->log);
260
261 snum = first;
262 /*
263 * Iterate on all possible values of snum for this hash.
264 * Using steps of an odd multiple of UDP_HTABLE_SIZE
265 * give us randomization and full range coverage.
266 */
267 do {
268 if (low <= snum && snum <= high &&
269 !test_bit(snum >> udptable->log, bitmap) &&
270 !inet_is_local_reserved_port(net, snum))
271 goto found;
272 snum += rand;
273 } while (snum != first);
274 spin_unlock_bh(&hslot->lock);
275 cond_resched();
276 } while (++first != last);
277 goto fail;
278 } else {
279 hslot = udp_hashslot(udptable, net, snum);
280 spin_lock_bh(&hslot->lock);
281 if (hslot->count > 10) {
282 int exist;
283 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum;
284
285 slot2 &= udptable->mask;
286 hash2_nulladdr &= udptable->mask;
287
288 hslot2 = udp_hashslot2(udptable, slot2);
289 if (hslot->count < hslot2->count)
290 goto scan_primary_hash;
291
292 exist = udp_lib_lport_inuse2(net, snum, hslot2, sk);
293 if (!exist && (hash2_nulladdr != slot2)) {
294 hslot2 = udp_hashslot2(udptable, hash2_nulladdr);
295 exist = udp_lib_lport_inuse2(net, snum, hslot2,
296 sk);
297 }
298 if (exist)
299 goto fail_unlock;
300 else
301 goto found;
302 }
303scan_primary_hash:
304 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 0))
305 goto fail_unlock;
306 }
307found:
308 inet_sk(sk)->inet_num = snum;
309 udp_sk(sk)->udp_port_hash = snum;
310 udp_sk(sk)->udp_portaddr_hash ^= snum;
311 if (sk_unhashed(sk)) {
312 if (sk->sk_reuseport &&
313 udp_reuseport_add_sock(sk, hslot)) {
314 inet_sk(sk)->inet_num = 0;
315 udp_sk(sk)->udp_port_hash = 0;
316 udp_sk(sk)->udp_portaddr_hash ^= snum;
317 goto fail_unlock;
318 }
319
320 sk_add_node_rcu(sk, &hslot->head);
321 hslot->count++;
322 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
323
324 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
325 spin_lock(&hslot2->lock);
326 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
327 sk->sk_family == AF_INET6)
328 hlist_add_tail_rcu(&udp_sk(sk)->udp_portaddr_node,
329 &hslot2->head);
330 else
331 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
332 &hslot2->head);
333 hslot2->count++;
334 spin_unlock(&hslot2->lock);
335 }
336 sock_set_flag(sk, SOCK_RCU_FREE);
337 error = 0;
338fail_unlock:
339 spin_unlock_bh(&hslot->lock);
340fail:
341 return error;
342}
343EXPORT_SYMBOL(udp_lib_get_port);
344
345int udp_v4_get_port(struct sock *sk, unsigned short snum)
346{
347 unsigned int hash2_nulladdr =
348 ipv4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
349 unsigned int hash2_partial =
350 ipv4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);
351
352 /* precompute partial secondary hash */
353 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
354 return udp_lib_get_port(sk, snum, hash2_nulladdr);
355}
356
357static int compute_score(struct sock *sk, struct net *net,
358 __be32 saddr, __be16 sport,
359 __be32 daddr, unsigned short hnum,
360 int dif, int sdif)
361{
362 int score;
363 struct inet_sock *inet;
364 bool dev_match;
365
366 if (!net_eq(sock_net(sk), net) ||
367 udp_sk(sk)->udp_port_hash != hnum ||
368 ipv6_only_sock(sk))
369 return -1;
370
371 if (sk->sk_rcv_saddr != daddr)
372 return -1;
373
374 score = (sk->sk_family == PF_INET) ? 2 : 1;
375
376 inet = inet_sk(sk);
377 if (inet->inet_daddr) {
378 if (inet->inet_daddr != saddr)
379 return -1;
380 score += 4;
381 }
382
383 if (inet->inet_dport) {
384 if (inet->inet_dport != sport)
385 return -1;
386 score += 4;
387 }
388
389 dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if,
390 dif, sdif);
391 if (!dev_match)
392 return -1;
393 if (sk->sk_bound_dev_if)
394 score += 4;
395
396 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
397 score++;
398 return score;
399}
400
401static u32 udp_ehashfn(const struct net *net, const __be32 laddr,
402 const __u16 lport, const __be32 faddr,
403 const __be16 fport)
404{
405 static u32 udp_ehash_secret __read_mostly;
406
407 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret));
408
409 return __inet_ehashfn(laddr, lport, faddr, fport,
410 udp_ehash_secret + net_hash_mix(net));
411}
412
413static struct sock *lookup_reuseport(struct net *net, struct sock *sk,
414 struct sk_buff *skb,
415 __be32 saddr, __be16 sport,
416 __be32 daddr, unsigned short hnum)
417{
418 struct sock *reuse_sk = NULL;
419 u32 hash;
420
421 if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) {
422 hash = udp_ehashfn(net, daddr, hnum, saddr, sport);
423 reuse_sk = reuseport_select_sock(sk, hash, skb,
424 sizeof(struct udphdr));
425 }
426 return reuse_sk;
427}
428
429/* called with rcu_read_lock() */
430static struct sock *udp4_lib_lookup2(struct net *net,
431 __be32 saddr, __be16 sport,
432 __be32 daddr, unsigned int hnum,
433 int dif, int sdif,
434 struct udp_hslot *hslot2,
435 struct sk_buff *skb)
436{
437 struct sock *sk, *result;
438 int score, badness;
439
440 result = NULL;
441 badness = 0;
442 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
443 score = compute_score(sk, net, saddr, sport,
444 daddr, hnum, dif, sdif);
445 if (score > badness) {
446 result = lookup_reuseport(net, sk, skb,
447 saddr, sport, daddr, hnum);
448 /* Fall back to scoring if group has connections */
449 if (result && !reuseport_has_conns(sk, false))
450 return result;
451
452 result = result ? : sk;
453 badness = score;
454 }
455 }
456 return result;
457}
458
459static struct sock *udp4_lookup_run_bpf(struct net *net,
460 struct udp_table *udptable,
461 struct sk_buff *skb,
462 __be32 saddr, __be16 sport,
463 __be32 daddr, u16 hnum)
464{
465 struct sock *sk, *reuse_sk;
466 bool no_reuseport;
467
468 if (udptable != &udp_table)
469 return NULL; /* only UDP is supported */
470
471 no_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_UDP,
472 saddr, sport, daddr, hnum, &sk);
473 if (no_reuseport || IS_ERR_OR_NULL(sk))
474 return sk;
475
476 reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum);
477 if (reuse_sk)
478 sk = reuse_sk;
479 return sk;
480}
481
482/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
483 * harder than this. -DaveM
484 */
485struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
486 __be16 sport, __be32 daddr, __be16 dport, int dif,
487 int sdif, struct udp_table *udptable, struct sk_buff *skb)
488{
489 unsigned short hnum = ntohs(dport);
490 unsigned int hash2, slot2;
491 struct udp_hslot *hslot2;
492 struct sock *result, *sk;
493
494 hash2 = ipv4_portaddr_hash(net, daddr, hnum);
495 slot2 = hash2 & udptable->mask;
496 hslot2 = &udptable->hash2[slot2];
497
498 /* Lookup connected or non-wildcard socket */
499 result = udp4_lib_lookup2(net, saddr, sport,
500 daddr, hnum, dif, sdif,
501 hslot2, skb);
502 if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED)
503 goto done;
504
505 /* Lookup redirect from BPF */
506 if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
507 sk = udp4_lookup_run_bpf(net, udptable, skb,
508 saddr, sport, daddr, hnum);
509 if (sk) {
510 result = sk;
511 goto done;
512 }
513 }
514
515 /* Got non-wildcard socket or error on first lookup */
516 if (result)
517 goto done;
518
519 /* Lookup wildcard sockets */
520 hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
521 slot2 = hash2 & udptable->mask;
522 hslot2 = &udptable->hash2[slot2];
523
524 result = udp4_lib_lookup2(net, saddr, sport,
525 htonl(INADDR_ANY), hnum, dif, sdif,
526 hslot2, skb);
527done:
528 if (IS_ERR(result))
529 return NULL;
530 return result;
531}
532EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
533
534static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
535 __be16 sport, __be16 dport,
536 struct udp_table *udptable)
537{
538 const struct iphdr *iph = ip_hdr(skb);
539
540 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
541 iph->daddr, dport, inet_iif(skb),
542 inet_sdif(skb), udptable, skb);
543}
544
545struct sock *udp4_lib_lookup_skb(const struct sk_buff *skb,
546 __be16 sport, __be16 dport)
547{
548 const struct iphdr *iph = ip_hdr(skb);
549
550 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
551 iph->daddr, dport, inet_iif(skb),
552 inet_sdif(skb), &udp_table, NULL);
553}
554
555/* Must be called under rcu_read_lock().
556 * Does increment socket refcount.
557 */
558#if IS_ENABLED(CONFIG_NF_TPROXY_IPV4) || IS_ENABLED(CONFIG_NF_SOCKET_IPV4)
559struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
560 __be32 daddr, __be16 dport, int dif)
561{
562 struct sock *sk;
563
564 sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport,
565 dif, 0, &udp_table, NULL);
566 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
567 sk = NULL;
568 return sk;
569}
570EXPORT_SYMBOL_GPL(udp4_lib_lookup);
571#endif
572
573static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk,
574 __be16 loc_port, __be32 loc_addr,
575 __be16 rmt_port, __be32 rmt_addr,
576 int dif, int sdif, unsigned short hnum)
577{
578 struct inet_sock *inet = inet_sk(sk);
579
580 if (!net_eq(sock_net(sk), net) ||
581 udp_sk(sk)->udp_port_hash != hnum ||
582 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
583 (inet->inet_dport != rmt_port && inet->inet_dport) ||
584 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) ||
585 ipv6_only_sock(sk) ||
586 !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
587 return false;
588 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif, sdif))
589 return false;
590 return true;
591}
592
593DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key);
594void udp_encap_enable(void)
595{
596 static_branch_inc(&udp_encap_needed_key);
597}
598EXPORT_SYMBOL(udp_encap_enable);
599
600void udp_encap_disable(void)
601{
602 static_branch_dec(&udp_encap_needed_key);
603}
604EXPORT_SYMBOL(udp_encap_disable);
605
606/* Handler for tunnels with arbitrary destination ports: no socket lookup, go
607 * through error handlers in encapsulations looking for a match.
608 */
609static int __udp4_lib_err_encap_no_sk(struct sk_buff *skb, u32 info)
610{
611 int i;
612
613 for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
614 int (*handler)(struct sk_buff *skb, u32 info);
615 const struct ip_tunnel_encap_ops *encap;
616
617 encap = rcu_dereference(iptun_encaps[i]);
618 if (!encap)
619 continue;
620 handler = encap->err_handler;
621 if (handler && !handler(skb, info))
622 return 0;
623 }
624
625 return -ENOENT;
626}
627
628/* Try to match ICMP errors to UDP tunnels by looking up a socket without
629 * reversing source and destination port: this will match tunnels that force the
630 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
631 * lwtunnels might actually break this assumption by being configured with
632 * different destination ports on endpoints, in this case we won't be able to
633 * trace ICMP messages back to them.
634 *
635 * If this doesn't match any socket, probe tunnels with arbitrary destination
636 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
637 * we've sent packets to won't necessarily match the local destination port.
638 *
639 * Then ask the tunnel implementation to match the error against a valid
640 * association.
641 *
642 * Return an error if we can't find a match, the socket if we need further
643 * processing, zero otherwise.
644 */
645static struct sock *__udp4_lib_err_encap(struct net *net,
646 const struct iphdr *iph,
647 struct udphdr *uh,
648 struct udp_table *udptable,
649 struct sock *sk,
650 struct sk_buff *skb, u32 info)
651{
652 int (*lookup)(struct sock *sk, struct sk_buff *skb);
653 int network_offset, transport_offset;
654 struct udp_sock *up;
655
656 network_offset = skb_network_offset(skb);
657 transport_offset = skb_transport_offset(skb);
658
659 /* Network header needs to point to the outer IPv4 header inside ICMP */
660 skb_reset_network_header(skb);
661
662 /* Transport header needs to point to the UDP header */
663 skb_set_transport_header(skb, iph->ihl << 2);
664
665 if (sk) {
666 up = udp_sk(sk);
667
668 lookup = READ_ONCE(up->encap_err_lookup);
669 if (lookup && lookup(sk, skb))
670 sk = NULL;
671
672 goto out;
673 }
674
675 sk = __udp4_lib_lookup(net, iph->daddr, uh->source,
676 iph->saddr, uh->dest, skb->dev->ifindex, 0,
677 udptable, NULL);
678 if (sk) {
679 up = udp_sk(sk);
680
681 lookup = READ_ONCE(up->encap_err_lookup);
682 if (!lookup || lookup(sk, skb))
683 sk = NULL;
684 }
685
686out:
687 if (!sk)
688 sk = ERR_PTR(__udp4_lib_err_encap_no_sk(skb, info));
689
690 skb_set_transport_header(skb, transport_offset);
691 skb_set_network_header(skb, network_offset);
692
693 return sk;
694}
695
696/*
697 * This routine is called by the ICMP module when it gets some
698 * sort of error condition. If err < 0 then the socket should
699 * be closed and the error returned to the user. If err > 0
700 * it's just the icmp type << 8 | icmp code.
701 * Header points to the ip header of the error packet. We move
702 * on past this. Then (as it used to claim before adjustment)
703 * header points to the first 8 bytes of the udp header. We need
704 * to find the appropriate port.
705 */
706
707int __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
708{
709 struct inet_sock *inet;
710 const struct iphdr *iph = (const struct iphdr *)skb->data;
711 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
712 const int type = icmp_hdr(skb)->type;
713 const int code = icmp_hdr(skb)->code;
714 bool tunnel = false;
715 struct sock *sk;
716 int harderr;
717 int err;
718 struct net *net = dev_net(skb->dev);
719
720 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
721 iph->saddr, uh->source, skb->dev->ifindex,
722 inet_sdif(skb), udptable, NULL);
723
724 if (!sk || udp_sk(sk)->encap_type) {
725 /* No socket for error: try tunnels before discarding */
726 if (static_branch_unlikely(&udp_encap_needed_key)) {
727 sk = __udp4_lib_err_encap(net, iph, uh, udptable, sk, skb,
728 info);
729 if (!sk)
730 return 0;
731 } else
732 sk = ERR_PTR(-ENOENT);
733
734 if (IS_ERR(sk)) {
735 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
736 return PTR_ERR(sk);
737 }
738
739 tunnel = true;
740 }
741
742 err = 0;
743 harderr = 0;
744 inet = inet_sk(sk);
745
746 switch (type) {
747 default:
748 case ICMP_TIME_EXCEEDED:
749 err = EHOSTUNREACH;
750 break;
751 case ICMP_SOURCE_QUENCH:
752 goto out;
753 case ICMP_PARAMETERPROB:
754 err = EPROTO;
755 harderr = 1;
756 break;
757 case ICMP_DEST_UNREACH:
758 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
759 ipv4_sk_update_pmtu(skb, sk, info);
760 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
761 err = EMSGSIZE;
762 harderr = 1;
763 break;
764 }
765 goto out;
766 }
767 err = EHOSTUNREACH;
768 if (code <= NR_ICMP_UNREACH) {
769 harderr = icmp_err_convert[code].fatal;
770 err = icmp_err_convert[code].errno;
771 }
772 break;
773 case ICMP_REDIRECT:
774 ipv4_sk_redirect(skb, sk);
775 goto out;
776 }
777
778 /*
779 * RFC1122: OK. Passes ICMP errors back to application, as per
780 * 4.1.3.3.
781 */
782 if (tunnel) {
783 /* ...not for tunnels though: we don't have a sending socket */
784 goto out;
785 }
786 if (!inet->recverr) {
787 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
788 goto out;
789 } else
790 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
791
792 sk->sk_err = err;
793 sk_error_report(sk);
794out:
795 return 0;
796}
797
798int udp_err(struct sk_buff *skb, u32 info)
799{
800 return __udp4_lib_err(skb, info, &udp_table);
801}
802
803/*
804 * Throw away all pending data and cancel the corking. Socket is locked.
805 */
806void udp_flush_pending_frames(struct sock *sk)
807{
808 struct udp_sock *up = udp_sk(sk);
809
810 if (up->pending) {
811 up->len = 0;
812 up->pending = 0;
813 ip_flush_pending_frames(sk);
814 }
815}
816EXPORT_SYMBOL(udp_flush_pending_frames);
817
818/**
819 * udp4_hwcsum - handle outgoing HW checksumming
820 * @skb: sk_buff containing the filled-in UDP header
821 * (checksum field must be zeroed out)
822 * @src: source IP address
823 * @dst: destination IP address
824 */
825void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
826{
827 struct udphdr *uh = udp_hdr(skb);
828 int offset = skb_transport_offset(skb);
829 int len = skb->len - offset;
830 int hlen = len;
831 __wsum csum = 0;
832
833 if (!skb_has_frag_list(skb)) {
834 /*
835 * Only one fragment on the socket.
836 */
837 skb->csum_start = skb_transport_header(skb) - skb->head;
838 skb->csum_offset = offsetof(struct udphdr, check);
839 uh->check = ~csum_tcpudp_magic(src, dst, len,
840 IPPROTO_UDP, 0);
841 } else {
842 struct sk_buff *frags;
843
844 /*
845 * HW-checksum won't work as there are two or more
846 * fragments on the socket so that all csums of sk_buffs
847 * should be together
848 */
849 skb_walk_frags(skb, frags) {
850 csum = csum_add(csum, frags->csum);
851 hlen -= frags->len;
852 }
853
854 csum = skb_checksum(skb, offset, hlen, csum);
855 skb->ip_summed = CHECKSUM_NONE;
856
857 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
858 if (uh->check == 0)
859 uh->check = CSUM_MANGLED_0;
860 }
861}
862EXPORT_SYMBOL_GPL(udp4_hwcsum);
863
864/* Function to set UDP checksum for an IPv4 UDP packet. This is intended
865 * for the simple case like when setting the checksum for a UDP tunnel.
866 */
867void udp_set_csum(bool nocheck, struct sk_buff *skb,
868 __be32 saddr, __be32 daddr, int len)
869{
870 struct udphdr *uh = udp_hdr(skb);
871
872 if (nocheck) {
873 uh->check = 0;
874 } else if (skb_is_gso(skb)) {
875 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
876 } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
877 uh->check = 0;
878 uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb));
879 if (uh->check == 0)
880 uh->check = CSUM_MANGLED_0;
881 } else {
882 skb->ip_summed = CHECKSUM_PARTIAL;
883 skb->csum_start = skb_transport_header(skb) - skb->head;
884 skb->csum_offset = offsetof(struct udphdr, check);
885 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
886 }
887}
888EXPORT_SYMBOL(udp_set_csum);
889
890static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4,
891 struct inet_cork *cork)
892{
893 struct sock *sk = skb->sk;
894 struct inet_sock *inet = inet_sk(sk);
895 struct udphdr *uh;
896 int err;
897 int is_udplite = IS_UDPLITE(sk);
898 int offset = skb_transport_offset(skb);
899 int len = skb->len - offset;
900 int datalen = len - sizeof(*uh);
901 __wsum csum = 0;
902
903 /*
904 * Create a UDP header
905 */
906 uh = udp_hdr(skb);
907 uh->source = inet->inet_sport;
908 uh->dest = fl4->fl4_dport;
909 uh->len = htons(len);
910 uh->check = 0;
911
912 if (cork->gso_size) {
913 const int hlen = skb_network_header_len(skb) +
914 sizeof(struct udphdr);
915
916 if (hlen + cork->gso_size > cork->fragsize) {
917 kfree_skb(skb);
918 return -EINVAL;
919 }
920 if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) {
921 kfree_skb(skb);
922 return -EINVAL;
923 }
924 if (sk->sk_no_check_tx) {
925 kfree_skb(skb);
926 return -EINVAL;
927 }
928 if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
929 dst_xfrm(skb_dst(skb))) {
930 kfree_skb(skb);
931 return -EIO;
932 }
933
934 if (datalen > cork->gso_size) {
935 skb_shinfo(skb)->gso_size = cork->gso_size;
936 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
937 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
938 cork->gso_size);
939 }
940 goto csum_partial;
941 }
942
943 if (is_udplite) /* UDP-Lite */
944 csum = udplite_csum(skb);
945
946 else if (sk->sk_no_check_tx) { /* UDP csum off */
947
948 skb->ip_summed = CHECKSUM_NONE;
949 goto send;
950
951 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
952csum_partial:
953
954 udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
955 goto send;
956
957 } else
958 csum = udp_csum(skb);
959
960 /* add protocol-dependent pseudo-header */
961 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
962 sk->sk_protocol, csum);
963 if (uh->check == 0)
964 uh->check = CSUM_MANGLED_0;
965
966send:
967 err = ip_send_skb(sock_net(sk), skb);
968 if (err) {
969 if (err == -ENOBUFS && !inet->recverr) {
970 UDP_INC_STATS(sock_net(sk),
971 UDP_MIB_SNDBUFERRORS, is_udplite);
972 err = 0;
973 }
974 } else
975 UDP_INC_STATS(sock_net(sk),
976 UDP_MIB_OUTDATAGRAMS, is_udplite);
977 return err;
978}
979
980/*
981 * Push out all pending data as one UDP datagram. Socket is locked.
982 */
983int udp_push_pending_frames(struct sock *sk)
984{
985 struct udp_sock *up = udp_sk(sk);
986 struct inet_sock *inet = inet_sk(sk);
987 struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
988 struct sk_buff *skb;
989 int err = 0;
990
991 skb = ip_finish_skb(sk, fl4);
992 if (!skb)
993 goto out;
994
995 err = udp_send_skb(skb, fl4, &inet->cork.base);
996
997out:
998 up->len = 0;
999 up->pending = 0;
1000 return err;
1001}
1002EXPORT_SYMBOL(udp_push_pending_frames);
1003
1004static int __udp_cmsg_send(struct cmsghdr *cmsg, u16 *gso_size)
1005{
1006 switch (cmsg->cmsg_type) {
1007 case UDP_SEGMENT:
1008 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u16)))
1009 return -EINVAL;
1010 *gso_size = *(__u16 *)CMSG_DATA(cmsg);
1011 return 0;
1012 default:
1013 return -EINVAL;
1014 }
1015}
1016
1017int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size)
1018{
1019 struct cmsghdr *cmsg;
1020 bool need_ip = false;
1021 int err;
1022
1023 for_each_cmsghdr(cmsg, msg) {
1024 if (!CMSG_OK(msg, cmsg))
1025 return -EINVAL;
1026
1027 if (cmsg->cmsg_level != SOL_UDP) {
1028 need_ip = true;
1029 continue;
1030 }
1031
1032 err = __udp_cmsg_send(cmsg, gso_size);
1033 if (err)
1034 return err;
1035 }
1036
1037 return need_ip;
1038}
1039EXPORT_SYMBOL_GPL(udp_cmsg_send);
1040
1041int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1042{
1043 struct inet_sock *inet = inet_sk(sk);
1044 struct udp_sock *up = udp_sk(sk);
1045 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
1046 struct flowi4 fl4_stack;
1047 struct flowi4 *fl4;
1048 int ulen = len;
1049 struct ipcm_cookie ipc;
1050 struct rtable *rt = NULL;
1051 int free = 0;
1052 int connected = 0;
1053 __be32 daddr, faddr, saddr;
1054 __be16 dport;
1055 u8 tos;
1056 int err, is_udplite = IS_UDPLITE(sk);
1057 int corkreq = READ_ONCE(up->corkflag) || msg->msg_flags&MSG_MORE;
1058 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1059 struct sk_buff *skb;
1060 struct ip_options_data opt_copy;
1061
1062 if (len > 0xFFFF)
1063 return -EMSGSIZE;
1064
1065 /*
1066 * Check the flags.
1067 */
1068
1069 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
1070 return -EOPNOTSUPP;
1071
1072 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
1073
1074 fl4 = &inet->cork.fl.u.ip4;
1075 if (up->pending) {
1076 /*
1077 * There are pending frames.
1078 * The socket lock must be held while it's corked.
1079 */
1080 lock_sock(sk);
1081 if (likely(up->pending)) {
1082 if (unlikely(up->pending != AF_INET)) {
1083 release_sock(sk);
1084 return -EINVAL;
1085 }
1086 goto do_append_data;
1087 }
1088 release_sock(sk);
1089 }
1090 ulen += sizeof(struct udphdr);
1091
1092 /*
1093 * Get and verify the address.
1094 */
1095 if (usin) {
1096 if (msg->msg_namelen < sizeof(*usin))
1097 return -EINVAL;
1098 if (usin->sin_family != AF_INET) {
1099 if (usin->sin_family != AF_UNSPEC)
1100 return -EAFNOSUPPORT;
1101 }
1102
1103 daddr = usin->sin_addr.s_addr;
1104 dport = usin->sin_port;
1105 if (dport == 0)
1106 return -EINVAL;
1107 } else {
1108 if (sk->sk_state != TCP_ESTABLISHED)
1109 return -EDESTADDRREQ;
1110 daddr = inet->inet_daddr;
1111 dport = inet->inet_dport;
1112 /* Open fast path for connected socket.
1113 Route will not be used, if at least one option is set.
1114 */
1115 connected = 1;
1116 }
1117
1118 ipcm_init_sk(&ipc, inet);
1119 ipc.gso_size = READ_ONCE(up->gso_size);
1120
1121 if (msg->msg_controllen) {
1122 err = udp_cmsg_send(sk, msg, &ipc.gso_size);
1123 if (err > 0)
1124 err = ip_cmsg_send(sk, msg, &ipc,
1125 sk->sk_family == AF_INET6);
1126 if (unlikely(err < 0)) {
1127 kfree(ipc.opt);
1128 return err;
1129 }
1130 if (ipc.opt)
1131 free = 1;
1132 connected = 0;
1133 }
1134 if (!ipc.opt) {
1135 struct ip_options_rcu *inet_opt;
1136
1137 rcu_read_lock();
1138 inet_opt = rcu_dereference(inet->inet_opt);
1139 if (inet_opt) {
1140 memcpy(&opt_copy, inet_opt,
1141 sizeof(*inet_opt) + inet_opt->opt.optlen);
1142 ipc.opt = &opt_copy.opt;
1143 }
1144 rcu_read_unlock();
1145 }
1146
1147 if (cgroup_bpf_enabled(BPF_CGROUP_UDP4_SENDMSG) && !connected) {
1148 err = BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk,
1149 (struct sockaddr *)usin, &ipc.addr);
1150 if (err)
1151 goto out_free;
1152 if (usin) {
1153 if (usin->sin_port == 0) {
1154 /* BPF program set invalid port. Reject it. */
1155 err = -EINVAL;
1156 goto out_free;
1157 }
1158 daddr = usin->sin_addr.s_addr;
1159 dport = usin->sin_port;
1160 }
1161 }
1162
1163 saddr = ipc.addr;
1164 ipc.addr = faddr = daddr;
1165
1166 if (ipc.opt && ipc.opt->opt.srr) {
1167 if (!daddr) {
1168 err = -EINVAL;
1169 goto out_free;
1170 }
1171 faddr = ipc.opt->opt.faddr;
1172 connected = 0;
1173 }
1174 tos = get_rttos(&ipc, inet);
1175 if (sock_flag(sk, SOCK_LOCALROUTE) ||
1176 (msg->msg_flags & MSG_DONTROUTE) ||
1177 (ipc.opt && ipc.opt->opt.is_strictroute)) {
1178 tos |= RTO_ONLINK;
1179 connected = 0;
1180 }
1181
1182 if (ipv4_is_multicast(daddr)) {
1183 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
1184 ipc.oif = inet->mc_index;
1185 if (!saddr)
1186 saddr = inet->mc_addr;
1187 connected = 0;
1188 } else if (!ipc.oif) {
1189 ipc.oif = inet->uc_index;
1190 } else if (ipv4_is_lbcast(daddr) && inet->uc_index) {
1191 /* oif is set, packet is to local broadcast and
1192 * uc_index is set. oif is most likely set
1193 * by sk_bound_dev_if. If uc_index != oif check if the
1194 * oif is an L3 master and uc_index is an L3 slave.
1195 * If so, we want to allow the send using the uc_index.
1196 */
1197 if (ipc.oif != inet->uc_index &&
1198 ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk),
1199 inet->uc_index)) {
1200 ipc.oif = inet->uc_index;
1201 }
1202 }
1203
1204 if (connected)
1205 rt = (struct rtable *)sk_dst_check(sk, 0);
1206
1207 if (!rt) {
1208 struct net *net = sock_net(sk);
1209 __u8 flow_flags = inet_sk_flowi_flags(sk);
1210
1211 fl4 = &fl4_stack;
1212
1213 flowi4_init_output(fl4, ipc.oif, ipc.sockc.mark, tos,
1214 RT_SCOPE_UNIVERSE, sk->sk_protocol,
1215 flow_flags,
1216 faddr, saddr, dport, inet->inet_sport,
1217 sk->sk_uid);
1218
1219 security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));
1220 rt = ip_route_output_flow(net, fl4, sk);
1221 if (IS_ERR(rt)) {
1222 err = PTR_ERR(rt);
1223 rt = NULL;
1224 if (err == -ENETUNREACH)
1225 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
1226 goto out;
1227 }
1228
1229 err = -EACCES;
1230 if ((rt->rt_flags & RTCF_BROADCAST) &&
1231 !sock_flag(sk, SOCK_BROADCAST))
1232 goto out;
1233 if (connected)
1234 sk_dst_set(sk, dst_clone(&rt->dst));
1235 }
1236
1237 if (msg->msg_flags&MSG_CONFIRM)
1238 goto do_confirm;
1239back_from_confirm:
1240
1241 saddr = fl4->saddr;
1242 if (!ipc.addr)
1243 daddr = ipc.addr = fl4->daddr;
1244
1245 /* Lockless fast path for the non-corking case. */
1246 if (!corkreq) {
1247 struct inet_cork cork;
1248
1249 skb = ip_make_skb(sk, fl4, getfrag, msg, ulen,
1250 sizeof(struct udphdr), &ipc, &rt,
1251 &cork, msg->msg_flags);
1252 err = PTR_ERR(skb);
1253 if (!IS_ERR_OR_NULL(skb))
1254 err = udp_send_skb(skb, fl4, &cork);
1255 goto out;
1256 }
1257
1258 lock_sock(sk);
1259 if (unlikely(up->pending)) {
1260 /* The socket is already corked while preparing it. */
1261 /* ... which is an evident application bug. --ANK */
1262 release_sock(sk);
1263
1264 net_dbg_ratelimited("socket already corked\n");
1265 err = -EINVAL;
1266 goto out;
1267 }
1268 /*
1269 * Now cork the socket to pend data.
1270 */
1271 fl4 = &inet->cork.fl.u.ip4;
1272 fl4->daddr = daddr;
1273 fl4->saddr = saddr;
1274 fl4->fl4_dport = dport;
1275 fl4->fl4_sport = inet->inet_sport;
1276 up->pending = AF_INET;
1277
1278do_append_data:
1279 up->len += ulen;
1280 err = ip_append_data(sk, fl4, getfrag, msg, ulen,
1281 sizeof(struct udphdr), &ipc, &rt,
1282 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1283 if (err)
1284 udp_flush_pending_frames(sk);
1285 else if (!corkreq)
1286 err = udp_push_pending_frames(sk);
1287 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1288 up->pending = 0;
1289 release_sock(sk);
1290
1291out:
1292 ip_rt_put(rt);
1293out_free:
1294 if (free)
1295 kfree(ipc.opt);
1296 if (!err)
1297 return len;
1298 /*
1299 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1300 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1301 * we don't have a good statistic (IpOutDiscards but it can be too many
1302 * things). We could add another new stat but at least for now that
1303 * seems like overkill.
1304 */
1305 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1306 UDP_INC_STATS(sock_net(sk),
1307 UDP_MIB_SNDBUFERRORS, is_udplite);
1308 }
1309 return err;
1310
1311do_confirm:
1312 if (msg->msg_flags & MSG_PROBE)
1313 dst_confirm_neigh(&rt->dst, &fl4->daddr);
1314 if (!(msg->msg_flags&MSG_PROBE) || len)
1315 goto back_from_confirm;
1316 err = 0;
1317 goto out;
1318}
1319EXPORT_SYMBOL(udp_sendmsg);
1320
1321int udp_sendpage(struct sock *sk, struct page *page, int offset,
1322 size_t size, int flags)
1323{
1324 struct inet_sock *inet = inet_sk(sk);
1325 struct udp_sock *up = udp_sk(sk);
1326 int ret;
1327
1328 if (flags & MSG_SENDPAGE_NOTLAST)
1329 flags |= MSG_MORE;
1330
1331 if (!up->pending) {
1332 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
1333
1334 /* Call udp_sendmsg to specify destination address which
1335 * sendpage interface can't pass.
1336 * This will succeed only when the socket is connected.
1337 */
1338 ret = udp_sendmsg(sk, &msg, 0);
1339 if (ret < 0)
1340 return ret;
1341 }
1342
1343 lock_sock(sk);
1344
1345 if (unlikely(!up->pending)) {
1346 release_sock(sk);
1347
1348 net_dbg_ratelimited("cork failed\n");
1349 return -EINVAL;
1350 }
1351
1352 ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
1353 page, offset, size, flags);
1354 if (ret == -EOPNOTSUPP) {
1355 release_sock(sk);
1356 return sock_no_sendpage(sk->sk_socket, page, offset,
1357 size, flags);
1358 }
1359 if (ret < 0) {
1360 udp_flush_pending_frames(sk);
1361 goto out;
1362 }
1363
1364 up->len += size;
1365 if (!(READ_ONCE(up->corkflag) || (flags&MSG_MORE)))
1366 ret = udp_push_pending_frames(sk);
1367 if (!ret)
1368 ret = size;
1369out:
1370 release_sock(sk);
1371 return ret;
1372}
1373
1374#define UDP_SKB_IS_STATELESS 0x80000000
1375
1376/* all head states (dst, sk, nf conntrack) except skb extensions are
1377 * cleared by udp_rcv().
1378 *
1379 * We need to preserve secpath, if present, to eventually process
1380 * IP_CMSG_PASSSEC at recvmsg() time.
1381 *
1382 * Other extensions can be cleared.
1383 */
1384static bool udp_try_make_stateless(struct sk_buff *skb)
1385{
1386 if (!skb_has_extensions(skb))
1387 return true;
1388
1389 if (!secpath_exists(skb)) {
1390 skb_ext_reset(skb);
1391 return true;
1392 }
1393
1394 return false;
1395}
1396
1397static void udp_set_dev_scratch(struct sk_buff *skb)
1398{
1399 struct udp_dev_scratch *scratch = udp_skb_scratch(skb);
1400
1401 BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long));
1402 scratch->_tsize_state = skb->truesize;
1403#if BITS_PER_LONG == 64
1404 scratch->len = skb->len;
1405 scratch->csum_unnecessary = !!skb_csum_unnecessary(skb);
1406 scratch->is_linear = !skb_is_nonlinear(skb);
1407#endif
1408 if (udp_try_make_stateless(skb))
1409 scratch->_tsize_state |= UDP_SKB_IS_STATELESS;
1410}
1411
1412static void udp_skb_csum_unnecessary_set(struct sk_buff *skb)
1413{
1414 /* We come here after udp_lib_checksum_complete() returned 0.
1415 * This means that __skb_checksum_complete() might have
1416 * set skb->csum_valid to 1.
1417 * On 64bit platforms, we can set csum_unnecessary
1418 * to true, but only if the skb is not shared.
1419 */
1420#if BITS_PER_LONG == 64
1421 if (!skb_shared(skb))
1422 udp_skb_scratch(skb)->csum_unnecessary = true;
1423#endif
1424}
1425
1426static int udp_skb_truesize(struct sk_buff *skb)
1427{
1428 return udp_skb_scratch(skb)->_tsize_state & ~UDP_SKB_IS_STATELESS;
1429}
1430
1431static bool udp_skb_has_head_state(struct sk_buff *skb)
1432{
1433 return !(udp_skb_scratch(skb)->_tsize_state & UDP_SKB_IS_STATELESS);
1434}
1435
1436/* fully reclaim rmem/fwd memory allocated for skb */
1437static void udp_rmem_release(struct sock *sk, int size, int partial,
1438 bool rx_queue_lock_held)
1439{
1440 struct udp_sock *up = udp_sk(sk);
1441 struct sk_buff_head *sk_queue;
1442 int amt;
1443
1444 if (likely(partial)) {
1445 up->forward_deficit += size;
1446 size = up->forward_deficit;
1447 if (size < (sk->sk_rcvbuf >> 2) &&
1448 !skb_queue_empty(&up->reader_queue))
1449 return;
1450 } else {
1451 size += up->forward_deficit;
1452 }
1453 up->forward_deficit = 0;
1454
1455 /* acquire the sk_receive_queue for fwd allocated memory scheduling,
1456 * if the called don't held it already
1457 */
1458 sk_queue = &sk->sk_receive_queue;
1459 if (!rx_queue_lock_held)
1460 spin_lock(&sk_queue->lock);
1461
1462
1463 sk->sk_forward_alloc += size;
1464 amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1);
1465 sk->sk_forward_alloc -= amt;
1466
1467 if (amt)
1468 __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT);
1469
1470 atomic_sub(size, &sk->sk_rmem_alloc);
1471
1472 /* this can save us from acquiring the rx queue lock on next receive */
1473 skb_queue_splice_tail_init(sk_queue, &up->reader_queue);
1474
1475 if (!rx_queue_lock_held)
1476 spin_unlock(&sk_queue->lock);
1477}
1478
1479/* Note: called with reader_queue.lock held.
1480 * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch
1481 * This avoids a cache line miss while receive_queue lock is held.
1482 * Look at __udp_enqueue_schedule_skb() to find where this copy is done.
1483 */
1484void udp_skb_destructor(struct sock *sk, struct sk_buff *skb)
1485{
1486 prefetch(&skb->data);
1487 udp_rmem_release(sk, udp_skb_truesize(skb), 1, false);
1488}
1489EXPORT_SYMBOL(udp_skb_destructor);
1490
1491/* as above, but the caller held the rx queue lock, too */
1492static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb)
1493{
1494 prefetch(&skb->data);
1495 udp_rmem_release(sk, udp_skb_truesize(skb), 1, true);
1496}
1497
1498/* Idea of busylocks is to let producers grab an extra spinlock
1499 * to relieve pressure on the receive_queue spinlock shared by consumer.
1500 * Under flood, this means that only one producer can be in line
1501 * trying to acquire the receive_queue spinlock.
1502 * These busylock can be allocated on a per cpu manner, instead of a
1503 * per socket one (that would consume a cache line per socket)
1504 */
1505static int udp_busylocks_log __read_mostly;
1506static spinlock_t *udp_busylocks __read_mostly;
1507
1508static spinlock_t *busylock_acquire(void *ptr)
1509{
1510 spinlock_t *busy;
1511
1512 busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log);
1513 spin_lock(busy);
1514 return busy;
1515}
1516
1517static void busylock_release(spinlock_t *busy)
1518{
1519 if (busy)
1520 spin_unlock(busy);
1521}
1522
1523int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
1524{
1525 struct sk_buff_head *list = &sk->sk_receive_queue;
1526 int rmem, delta, amt, err = -ENOMEM;
1527 spinlock_t *busy = NULL;
1528 int size;
1529
1530 /* try to avoid the costly atomic add/sub pair when the receive
1531 * queue is full; always allow at least a packet
1532 */
1533 rmem = atomic_read(&sk->sk_rmem_alloc);
1534 if (rmem > sk->sk_rcvbuf)
1535 goto drop;
1536
1537 /* Under mem pressure, it might be helpful to help udp_recvmsg()
1538 * having linear skbs :
1539 * - Reduce memory overhead and thus increase receive queue capacity
1540 * - Less cache line misses at copyout() time
1541 * - Less work at consume_skb() (less alien page frag freeing)
1542 */
1543 if (rmem > (sk->sk_rcvbuf >> 1)) {
1544 skb_condense(skb);
1545
1546 busy = busylock_acquire(sk);
1547 }
1548 size = skb->truesize;
1549 udp_set_dev_scratch(skb);
1550
1551 /* we drop only if the receive buf is full and the receive
1552 * queue contains some other skb
1553 */
1554 rmem = atomic_add_return(size, &sk->sk_rmem_alloc);
1555 if (rmem > (size + (unsigned int)sk->sk_rcvbuf))
1556 goto uncharge_drop;
1557
1558 spin_lock(&list->lock);
1559 if (size >= sk->sk_forward_alloc) {
1560 amt = sk_mem_pages(size);
1561 delta = amt << SK_MEM_QUANTUM_SHIFT;
1562 if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) {
1563 err = -ENOBUFS;
1564 spin_unlock(&list->lock);
1565 goto uncharge_drop;
1566 }
1567
1568 sk->sk_forward_alloc += delta;
1569 }
1570
1571 sk->sk_forward_alloc -= size;
1572
1573 /* no need to setup a destructor, we will explicitly release the
1574 * forward allocated memory on dequeue
1575 */
1576 sock_skb_set_dropcount(sk, skb);
1577
1578 __skb_queue_tail(list, skb);
1579 spin_unlock(&list->lock);
1580
1581 if (!sock_flag(sk, SOCK_DEAD))
1582 sk->sk_data_ready(sk);
1583
1584 busylock_release(busy);
1585 return 0;
1586
1587uncharge_drop:
1588 atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1589
1590drop:
1591 atomic_inc(&sk->sk_drops);
1592 busylock_release(busy);
1593 return err;
1594}
1595EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb);
1596
1597void udp_destruct_sock(struct sock *sk)
1598{
1599 /* reclaim completely the forward allocated memory */
1600 struct udp_sock *up = udp_sk(sk);
1601 unsigned int total = 0;
1602 struct sk_buff *skb;
1603
1604 skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue);
1605 while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) {
1606 total += skb->truesize;
1607 kfree_skb(skb);
1608 }
1609 udp_rmem_release(sk, total, 0, true);
1610
1611 inet_sock_destruct(sk);
1612}
1613EXPORT_SYMBOL_GPL(udp_destruct_sock);
1614
1615int udp_init_sock(struct sock *sk)
1616{
1617 skb_queue_head_init(&udp_sk(sk)->reader_queue);
1618 sk->sk_destruct = udp_destruct_sock;
1619 return 0;
1620}
1621EXPORT_SYMBOL_GPL(udp_init_sock);
1622
1623void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len)
1624{
1625 if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) {
1626 bool slow = lock_sock_fast(sk);
1627
1628 sk_peek_offset_bwd(sk, len);
1629 unlock_sock_fast(sk, slow);
1630 }
1631
1632 if (!skb_unref(skb))
1633 return;
1634
1635 /* In the more common cases we cleared the head states previously,
1636 * see __udp_queue_rcv_skb().
1637 */
1638 if (unlikely(udp_skb_has_head_state(skb)))
1639 skb_release_head_state(skb);
1640 __consume_stateless_skb(skb);
1641}
1642EXPORT_SYMBOL_GPL(skb_consume_udp);
1643
1644static struct sk_buff *__first_packet_length(struct sock *sk,
1645 struct sk_buff_head *rcvq,
1646 int *total)
1647{
1648 struct sk_buff *skb;
1649
1650 while ((skb = skb_peek(rcvq)) != NULL) {
1651 if (udp_lib_checksum_complete(skb)) {
1652 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS,
1653 IS_UDPLITE(sk));
1654 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
1655 IS_UDPLITE(sk));
1656 atomic_inc(&sk->sk_drops);
1657 __skb_unlink(skb, rcvq);
1658 *total += skb->truesize;
1659 kfree_skb(skb);
1660 } else {
1661 udp_skb_csum_unnecessary_set(skb);
1662 break;
1663 }
1664 }
1665 return skb;
1666}
1667
1668/**
1669 * first_packet_length - return length of first packet in receive queue
1670 * @sk: socket
1671 *
1672 * Drops all bad checksum frames, until a valid one is found.
1673 * Returns the length of found skb, or -1 if none is found.
1674 */
1675static int first_packet_length(struct sock *sk)
1676{
1677 struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue;
1678 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1679 struct sk_buff *skb;
1680 int total = 0;
1681 int res;
1682
1683 spin_lock_bh(&rcvq->lock);
1684 skb = __first_packet_length(sk, rcvq, &total);
1685 if (!skb && !skb_queue_empty_lockless(sk_queue)) {
1686 spin_lock(&sk_queue->lock);
1687 skb_queue_splice_tail_init(sk_queue, rcvq);
1688 spin_unlock(&sk_queue->lock);
1689
1690 skb = __first_packet_length(sk, rcvq, &total);
1691 }
1692 res = skb ? skb->len : -1;
1693 if (total)
1694 udp_rmem_release(sk, total, 1, false);
1695 spin_unlock_bh(&rcvq->lock);
1696 return res;
1697}
1698
1699/*
1700 * IOCTL requests applicable to the UDP protocol
1701 */
1702
1703int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
1704{
1705 switch (cmd) {
1706 case SIOCOUTQ:
1707 {
1708 int amount = sk_wmem_alloc_get(sk);
1709
1710 return put_user(amount, (int __user *)arg);
1711 }
1712
1713 case SIOCINQ:
1714 {
1715 int amount = max_t(int, 0, first_packet_length(sk));
1716
1717 return put_user(amount, (int __user *)arg);
1718 }
1719
1720 default:
1721 return -ENOIOCTLCMD;
1722 }
1723
1724 return 0;
1725}
1726EXPORT_SYMBOL(udp_ioctl);
1727
1728struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
1729 int noblock, int *off, int *err)
1730{
1731 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1732 struct sk_buff_head *queue;
1733 struct sk_buff *last;
1734 long timeo;
1735 int error;
1736
1737 queue = &udp_sk(sk)->reader_queue;
1738 flags |= noblock ? MSG_DONTWAIT : 0;
1739 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1740 do {
1741 struct sk_buff *skb;
1742
1743 error = sock_error(sk);
1744 if (error)
1745 break;
1746
1747 error = -EAGAIN;
1748 do {
1749 spin_lock_bh(&queue->lock);
1750 skb = __skb_try_recv_from_queue(sk, queue, flags, off,
1751 err, &last);
1752 if (skb) {
1753 if (!(flags & MSG_PEEK))
1754 udp_skb_destructor(sk, skb);
1755 spin_unlock_bh(&queue->lock);
1756 return skb;
1757 }
1758
1759 if (skb_queue_empty_lockless(sk_queue)) {
1760 spin_unlock_bh(&queue->lock);
1761 goto busy_check;
1762 }
1763
1764 /* refill the reader queue and walk it again
1765 * keep both queues locked to avoid re-acquiring
1766 * the sk_receive_queue lock if fwd memory scheduling
1767 * is needed.
1768 */
1769 spin_lock(&sk_queue->lock);
1770 skb_queue_splice_tail_init(sk_queue, queue);
1771
1772 skb = __skb_try_recv_from_queue(sk, queue, flags, off,
1773 err, &last);
1774 if (skb && !(flags & MSG_PEEK))
1775 udp_skb_dtor_locked(sk, skb);
1776 spin_unlock(&sk_queue->lock);
1777 spin_unlock_bh(&queue->lock);
1778 if (skb)
1779 return skb;
1780
1781busy_check:
1782 if (!sk_can_busy_loop(sk))
1783 break;
1784
1785 sk_busy_loop(sk, flags & MSG_DONTWAIT);
1786 } while (!skb_queue_empty_lockless(sk_queue));
1787
1788 /* sk_queue is empty, reader_queue may contain peeked packets */
1789 } while (timeo &&
1790 !__skb_wait_for_more_packets(sk, &sk->sk_receive_queue,
1791 &error, &timeo,
1792 (struct sk_buff *)sk_queue));
1793
1794 *err = error;
1795 return NULL;
1796}
1797EXPORT_SYMBOL(__skb_recv_udp);
1798
1799int udp_read_sock(struct sock *sk, read_descriptor_t *desc,
1800 sk_read_actor_t recv_actor)
1801{
1802 int copied = 0;
1803
1804 while (1) {
1805 struct sk_buff *skb;
1806 int err, used;
1807
1808 skb = skb_recv_udp(sk, 0, 1, &err);
1809 if (!skb)
1810 return err;
1811 used = recv_actor(desc, skb, 0, skb->len);
1812 if (used <= 0) {
1813 if (!copied)
1814 copied = used;
1815 kfree_skb(skb);
1816 break;
1817 } else if (used <= skb->len) {
1818 copied += used;
1819 }
1820
1821 kfree_skb(skb);
1822 if (!desc->count)
1823 break;
1824 }
1825
1826 return copied;
1827}
1828EXPORT_SYMBOL(udp_read_sock);
1829
1830/*
1831 * This should be easy, if there is something there we
1832 * return it, otherwise we block.
1833 */
1834
1835int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
1836 int flags, int *addr_len)
1837{
1838 struct inet_sock *inet = inet_sk(sk);
1839 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
1840 struct sk_buff *skb;
1841 unsigned int ulen, copied;
1842 int off, err, peeking = flags & MSG_PEEK;
1843 int is_udplite = IS_UDPLITE(sk);
1844 bool checksum_valid = false;
1845
1846 if (flags & MSG_ERRQUEUE)
1847 return ip_recv_error(sk, msg, len, addr_len);
1848
1849try_again:
1850 off = sk_peek_offset(sk, flags);
1851 skb = __skb_recv_udp(sk, flags, noblock, &off, &err);
1852 if (!skb)
1853 return err;
1854
1855 ulen = udp_skb_len(skb);
1856 copied = len;
1857 if (copied > ulen - off)
1858 copied = ulen - off;
1859 else if (copied < ulen)
1860 msg->msg_flags |= MSG_TRUNC;
1861
1862 /*
1863 * If checksum is needed at all, try to do it while copying the
1864 * data. If the data is truncated, or if we only want a partial
1865 * coverage checksum (UDP-Lite), do it before the copy.
1866 */
1867
1868 if (copied < ulen || peeking ||
1869 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
1870 checksum_valid = udp_skb_csum_unnecessary(skb) ||
1871 !__udp_lib_checksum_complete(skb);
1872 if (!checksum_valid)
1873 goto csum_copy_err;
1874 }
1875
1876 if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
1877 if (udp_skb_is_linear(skb))
1878 err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
1879 else
1880 err = skb_copy_datagram_msg(skb, off, msg, copied);
1881 } else {
1882 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
1883
1884 if (err == -EINVAL)
1885 goto csum_copy_err;
1886 }
1887
1888 if (unlikely(err)) {
1889 if (!peeking) {
1890 atomic_inc(&sk->sk_drops);
1891 UDP_INC_STATS(sock_net(sk),
1892 UDP_MIB_INERRORS, is_udplite);
1893 }
1894 kfree_skb(skb);
1895 return err;
1896 }
1897
1898 if (!peeking)
1899 UDP_INC_STATS(sock_net(sk),
1900 UDP_MIB_INDATAGRAMS, is_udplite);
1901
1902 sock_recv_ts_and_drops(msg, sk, skb);
1903
1904 /* Copy the address. */
1905 if (sin) {
1906 sin->sin_family = AF_INET;
1907 sin->sin_port = udp_hdr(skb)->source;
1908 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1909 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1910 *addr_len = sizeof(*sin);
1911
1912 BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk,
1913 (struct sockaddr *)sin);
1914 }
1915
1916 if (udp_sk(sk)->gro_enabled)
1917 udp_cmsg_recv(msg, sk, skb);
1918
1919 if (inet->cmsg_flags)
1920 ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off);
1921
1922 err = copied;
1923 if (flags & MSG_TRUNC)
1924 err = ulen;
1925
1926 skb_consume_udp(sk, skb, peeking ? -err : err);
1927 return err;
1928
1929csum_copy_err:
1930 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
1931 udp_skb_destructor)) {
1932 UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1933 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1934 }
1935 kfree_skb(skb);
1936
1937 /* starting over for a new packet, but check if we need to yield */
1938 cond_resched();
1939 msg->msg_flags &= ~MSG_TRUNC;
1940 goto try_again;
1941}
1942
1943int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
1944{
1945 /* This check is replicated from __ip4_datagram_connect() and
1946 * intended to prevent BPF program called below from accessing bytes
1947 * that are out of the bound specified by user in addr_len.
1948 */
1949 if (addr_len < sizeof(struct sockaddr_in))
1950 return -EINVAL;
1951
1952 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr);
1953}
1954EXPORT_SYMBOL(udp_pre_connect);
1955
1956int __udp_disconnect(struct sock *sk, int flags)
1957{
1958 struct inet_sock *inet = inet_sk(sk);
1959 /*
1960 * 1003.1g - break association.
1961 */
1962
1963 sk->sk_state = TCP_CLOSE;
1964 inet->inet_daddr = 0;
1965 inet->inet_dport = 0;
1966 sock_rps_reset_rxhash(sk);
1967 sk->sk_bound_dev_if = 0;
1968 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) {
1969 inet_reset_saddr(sk);
1970 if (sk->sk_prot->rehash &&
1971 (sk->sk_userlocks & SOCK_BINDPORT_LOCK))
1972 sk->sk_prot->rehash(sk);
1973 }
1974
1975 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1976 sk->sk_prot->unhash(sk);
1977 inet->inet_sport = 0;
1978 }
1979 sk_dst_reset(sk);
1980 return 0;
1981}
1982EXPORT_SYMBOL(__udp_disconnect);
1983
1984int udp_disconnect(struct sock *sk, int flags)
1985{
1986 lock_sock(sk);
1987 __udp_disconnect(sk, flags);
1988 release_sock(sk);
1989 return 0;
1990}
1991EXPORT_SYMBOL(udp_disconnect);
1992
1993void udp_lib_unhash(struct sock *sk)
1994{
1995 if (sk_hashed(sk)) {
1996 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1997 struct udp_hslot *hslot, *hslot2;
1998
1999 hslot = udp_hashslot(udptable, sock_net(sk),
2000 udp_sk(sk)->udp_port_hash);
2001 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
2002
2003 spin_lock_bh(&hslot->lock);
2004 if (rcu_access_pointer(sk->sk_reuseport_cb))
2005 reuseport_detach_sock(sk);
2006 if (sk_del_node_init_rcu(sk)) {
2007 hslot->count--;
2008 inet_sk(sk)->inet_num = 0;
2009 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
2010
2011 spin_lock(&hslot2->lock);
2012 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
2013 hslot2->count--;
2014 spin_unlock(&hslot2->lock);
2015 }
2016 spin_unlock_bh(&hslot->lock);
2017 }
2018}
2019EXPORT_SYMBOL(udp_lib_unhash);
2020
2021/*
2022 * inet_rcv_saddr was changed, we must rehash secondary hash
2023 */
2024void udp_lib_rehash(struct sock *sk, u16 newhash)
2025{
2026 if (sk_hashed(sk)) {
2027 struct udp_table *udptable = sk->sk_prot->h.udp_table;
2028 struct udp_hslot *hslot, *hslot2, *nhslot2;
2029
2030 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
2031 nhslot2 = udp_hashslot2(udptable, newhash);
2032 udp_sk(sk)->udp_portaddr_hash = newhash;
2033
2034 if (hslot2 != nhslot2 ||
2035 rcu_access_pointer(sk->sk_reuseport_cb)) {
2036 hslot = udp_hashslot(udptable, sock_net(sk),
2037 udp_sk(sk)->udp_port_hash);
2038 /* we must lock primary chain too */
2039 spin_lock_bh(&hslot->lock);
2040 if (rcu_access_pointer(sk->sk_reuseport_cb))
2041 reuseport_detach_sock(sk);
2042
2043 if (hslot2 != nhslot2) {
2044 spin_lock(&hslot2->lock);
2045 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
2046 hslot2->count--;
2047 spin_unlock(&hslot2->lock);
2048
2049 spin_lock(&nhslot2->lock);
2050 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
2051 &nhslot2->head);
2052 nhslot2->count++;
2053 spin_unlock(&nhslot2->lock);
2054 }
2055
2056 spin_unlock_bh(&hslot->lock);
2057 }
2058 }
2059}
2060EXPORT_SYMBOL(udp_lib_rehash);
2061
2062void udp_v4_rehash(struct sock *sk)
2063{
2064 u16 new_hash = ipv4_portaddr_hash(sock_net(sk),
2065 inet_sk(sk)->inet_rcv_saddr,
2066 inet_sk(sk)->inet_num);
2067 udp_lib_rehash(sk, new_hash);
2068}
2069
2070static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2071{
2072 int rc;
2073
2074 if (inet_sk(sk)->inet_daddr) {
2075 sock_rps_save_rxhash(sk, skb);
2076 sk_mark_napi_id(sk, skb);
2077 sk_incoming_cpu_update(sk);
2078 } else {
2079 sk_mark_napi_id_once(sk, skb);
2080 }
2081
2082 rc = __udp_enqueue_schedule_skb(sk, skb);
2083 if (rc < 0) {
2084 int is_udplite = IS_UDPLITE(sk);
2085
2086 /* Note that an ENOMEM error is charged twice */
2087 if (rc == -ENOMEM)
2088 UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS,
2089 is_udplite);
2090 else
2091 UDP_INC_STATS(sock_net(sk), UDP_MIB_MEMERRORS,
2092 is_udplite);
2093 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
2094 kfree_skb(skb);
2095 trace_udp_fail_queue_rcv_skb(rc, sk);
2096 return -1;
2097 }
2098
2099 return 0;
2100}
2101
2102/* returns:
2103 * -1: error
2104 * 0: success
2105 * >0: "udp encap" protocol resubmission
2106 *
2107 * Note that in the success and error cases, the skb is assumed to
2108 * have either been requeued or freed.
2109 */
2110static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
2111{
2112 struct udp_sock *up = udp_sk(sk);
2113 int is_udplite = IS_UDPLITE(sk);
2114
2115 /*
2116 * Charge it to the socket, dropping if the queue is full.
2117 */
2118 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
2119 goto drop;
2120 nf_reset_ct(skb);
2121
2122 if (static_branch_unlikely(&udp_encap_needed_key) && up->encap_type) {
2123 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
2124
2125 /*
2126 * This is an encapsulation socket so pass the skb to
2127 * the socket's udp_encap_rcv() hook. Otherwise, just
2128 * fall through and pass this up the UDP socket.
2129 * up->encap_rcv() returns the following value:
2130 * =0 if skb was successfully passed to the encap
2131 * handler or was discarded by it.
2132 * >0 if skb should be passed on to UDP.
2133 * <0 if skb should be resubmitted as proto -N
2134 */
2135
2136 /* if we're overly short, let UDP handle it */
2137 encap_rcv = READ_ONCE(up->encap_rcv);
2138 if (encap_rcv) {
2139 int ret;
2140
2141 /* Verify checksum before giving to encap */
2142 if (udp_lib_checksum_complete(skb))
2143 goto csum_error;
2144
2145 ret = encap_rcv(sk, skb);
2146 if (ret <= 0) {
2147 __UDP_INC_STATS(sock_net(sk),
2148 UDP_MIB_INDATAGRAMS,
2149 is_udplite);
2150 return -ret;
2151 }
2152 }
2153
2154 /* FALLTHROUGH -- it's a UDP Packet */
2155 }
2156
2157 /*
2158 * UDP-Lite specific tests, ignored on UDP sockets
2159 */
2160 if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
2161
2162 /*
2163 * MIB statistics other than incrementing the error count are
2164 * disabled for the following two types of errors: these depend
2165 * on the application settings, not on the functioning of the
2166 * protocol stack as such.
2167 *
2168 * RFC 3828 here recommends (sec 3.3): "There should also be a
2169 * way ... to ... at least let the receiving application block
2170 * delivery of packets with coverage values less than a value
2171 * provided by the application."
2172 */
2173 if (up->pcrlen == 0) { /* full coverage was set */
2174 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n",
2175 UDP_SKB_CB(skb)->cscov, skb->len);
2176 goto drop;
2177 }
2178 /* The next case involves violating the min. coverage requested
2179 * by the receiver. This is subtle: if receiver wants x and x is
2180 * greater than the buffersize/MTU then receiver will complain
2181 * that it wants x while sender emits packets of smaller size y.
2182 * Therefore the above ...()->partial_cov statement is essential.
2183 */
2184 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
2185 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n",
2186 UDP_SKB_CB(skb)->cscov, up->pcrlen);
2187 goto drop;
2188 }
2189 }
2190
2191 prefetch(&sk->sk_rmem_alloc);
2192 if (rcu_access_pointer(sk->sk_filter) &&
2193 udp_lib_checksum_complete(skb))
2194 goto csum_error;
2195
2196 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
2197 goto drop;
2198
2199 udp_csum_pull_header(skb);
2200
2201 ipv4_pktinfo_prepare(sk, skb);
2202 return __udp_queue_rcv_skb(sk, skb);
2203
2204csum_error:
2205 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
2206drop:
2207 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
2208 atomic_inc(&sk->sk_drops);
2209 kfree_skb(skb);
2210 return -1;
2211}
2212
2213static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2214{
2215 struct sk_buff *next, *segs;
2216 int ret;
2217
2218 if (likely(!udp_unexpected_gso(sk, skb)))
2219 return udp_queue_rcv_one_skb(sk, skb);
2220
2221 BUILD_BUG_ON(sizeof(struct udp_skb_cb) > SKB_GSO_CB_OFFSET);
2222 __skb_push(skb, -skb_mac_offset(skb));
2223 segs = udp_rcv_segment(sk, skb, true);
2224 skb_list_walk_safe(segs, skb, next) {
2225 __skb_pull(skb, skb_transport_offset(skb));
2226
2227 udp_post_segment_fix_csum(skb);
2228 ret = udp_queue_rcv_one_skb(sk, skb);
2229 if (ret > 0)
2230 ip_protocol_deliver_rcu(dev_net(skb->dev), skb, ret);
2231 }
2232 return 0;
2233}
2234
2235/* For TCP sockets, sk_rx_dst is protected by socket lock
2236 * For UDP, we use xchg() to guard against concurrent changes.
2237 */
2238bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
2239{
2240 struct dst_entry *old;
2241
2242 if (dst_hold_safe(dst)) {
2243 old = xchg(&sk->sk_rx_dst, dst);
2244 dst_release(old);
2245 return old != dst;
2246 }
2247 return false;
2248}
2249EXPORT_SYMBOL(udp_sk_rx_dst_set);
2250
2251/*
2252 * Multicasts and broadcasts go to each listener.
2253 *
2254 * Note: called only from the BH handler context.
2255 */
2256static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
2257 struct udphdr *uh,
2258 __be32 saddr, __be32 daddr,
2259 struct udp_table *udptable,
2260 int proto)
2261{
2262 struct sock *sk, *first = NULL;
2263 unsigned short hnum = ntohs(uh->dest);
2264 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
2265 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
2266 unsigned int offset = offsetof(typeof(*sk), sk_node);
2267 int dif = skb->dev->ifindex;
2268 int sdif = inet_sdif(skb);
2269 struct hlist_node *node;
2270 struct sk_buff *nskb;
2271
2272 if (use_hash2) {
2273 hash2_any = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum) &
2274 udptable->mask;
2275 hash2 = ipv4_portaddr_hash(net, daddr, hnum) & udptable->mask;
2276start_lookup:
2277 hslot = &udptable->hash2[hash2];
2278 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
2279 }
2280
2281 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
2282 if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr,
2283 uh->source, saddr, dif, sdif, hnum))
2284 continue;
2285
2286 if (!first) {
2287 first = sk;
2288 continue;
2289 }
2290 nskb = skb_clone(skb, GFP_ATOMIC);
2291
2292 if (unlikely(!nskb)) {
2293 atomic_inc(&sk->sk_drops);
2294 __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
2295 IS_UDPLITE(sk));
2296 __UDP_INC_STATS(net, UDP_MIB_INERRORS,
2297 IS_UDPLITE(sk));
2298 continue;
2299 }
2300 if (udp_queue_rcv_skb(sk, nskb) > 0)
2301 consume_skb(nskb);
2302 }
2303
2304 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
2305 if (use_hash2 && hash2 != hash2_any) {
2306 hash2 = hash2_any;
2307 goto start_lookup;
2308 }
2309
2310 if (first) {
2311 if (udp_queue_rcv_skb(first, skb) > 0)
2312 consume_skb(skb);
2313 } else {
2314 kfree_skb(skb);
2315 __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
2316 proto == IPPROTO_UDPLITE);
2317 }
2318 return 0;
2319}
2320
2321/* Initialize UDP checksum. If exited with zero value (success),
2322 * CHECKSUM_UNNECESSARY means, that no more checks are required.
2323 * Otherwise, csum completion requires checksumming packet body,
2324 * including udp header and folding it to skb->csum.
2325 */
2326static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
2327 int proto)
2328{
2329 int err;
2330
2331 UDP_SKB_CB(skb)->partial_cov = 0;
2332 UDP_SKB_CB(skb)->cscov = skb->len;
2333
2334 if (proto == IPPROTO_UDPLITE) {
2335 err = udplite_checksum_init(skb, uh);
2336 if (err)
2337 return err;
2338
2339 if (UDP_SKB_CB(skb)->partial_cov) {
2340 skb->csum = inet_compute_pseudo(skb, proto);
2341 return 0;
2342 }
2343 }
2344
2345 /* Note, we are only interested in != 0 or == 0, thus the
2346 * force to int.
2347 */
2348 err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
2349 inet_compute_pseudo);
2350 if (err)
2351 return err;
2352
2353 if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) {
2354 /* If SW calculated the value, we know it's bad */
2355 if (skb->csum_complete_sw)
2356 return 1;
2357
2358 /* HW says the value is bad. Let's validate that.
2359 * skb->csum is no longer the full packet checksum,
2360 * so don't treat it as such.
2361 */
2362 skb_checksum_complete_unset(skb);
2363 }
2364
2365 return 0;
2366}
2367
2368/* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
2369 * return code conversion for ip layer consumption
2370 */
2371static int udp_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
2372 struct udphdr *uh)
2373{
2374 int ret;
2375
2376 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
2377 skb_checksum_try_convert(skb, IPPROTO_UDP, inet_compute_pseudo);
2378
2379 ret = udp_queue_rcv_skb(sk, skb);
2380
2381 /* a return value > 0 means to resubmit the input, but
2382 * it wants the return to be -protocol, or 0
2383 */
2384 if (ret > 0)
2385 return -ret;
2386 return 0;
2387}
2388
2389/*
2390 * All we need to do is get the socket, and then do a checksum.
2391 */
2392
2393int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
2394 int proto)
2395{
2396 struct sock *sk;
2397 struct udphdr *uh;
2398 unsigned short ulen;
2399 struct rtable *rt = skb_rtable(skb);
2400 __be32 saddr, daddr;
2401 struct net *net = dev_net(skb->dev);
2402 bool refcounted;
2403
2404 /*
2405 * Validate the packet.
2406 */
2407 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
2408 goto drop; /* No space for header. */
2409
2410 uh = udp_hdr(skb);
2411 ulen = ntohs(uh->len);
2412 saddr = ip_hdr(skb)->saddr;
2413 daddr = ip_hdr(skb)->daddr;
2414
2415 if (ulen > skb->len)
2416 goto short_packet;
2417
2418 if (proto == IPPROTO_UDP) {
2419 /* UDP validates ulen. */
2420 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
2421 goto short_packet;
2422 uh = udp_hdr(skb);
2423 }
2424
2425 if (udp4_csum_init(skb, uh, proto))
2426 goto csum_error;
2427
2428 sk = skb_steal_sock(skb, &refcounted);
2429 if (sk) {
2430 struct dst_entry *dst = skb_dst(skb);
2431 int ret;
2432
2433 if (unlikely(sk->sk_rx_dst != dst))
2434 udp_sk_rx_dst_set(sk, dst);
2435
2436 ret = udp_unicast_rcv_skb(sk, skb, uh);
2437 if (refcounted)
2438 sock_put(sk);
2439 return ret;
2440 }
2441
2442 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
2443 return __udp4_lib_mcast_deliver(net, skb, uh,
2444 saddr, daddr, udptable, proto);
2445
2446 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
2447 if (sk)
2448 return udp_unicast_rcv_skb(sk, skb, uh);
2449
2450 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
2451 goto drop;
2452 nf_reset_ct(skb);
2453
2454 /* No socket. Drop packet silently, if checksum is wrong */
2455 if (udp_lib_checksum_complete(skb))
2456 goto csum_error;
2457
2458 __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
2459 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
2460
2461 /*
2462 * Hmm. We got an UDP packet to a port to which we
2463 * don't wanna listen. Ignore it.
2464 */
2465 kfree_skb(skb);
2466 return 0;
2467
2468short_packet:
2469 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
2470 proto == IPPROTO_UDPLITE ? "Lite" : "",
2471 &saddr, ntohs(uh->source),
2472 ulen, skb->len,
2473 &daddr, ntohs(uh->dest));
2474 goto drop;
2475
2476csum_error:
2477 /*
2478 * RFC1122: OK. Discards the bad packet silently (as far as
2479 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
2480 */
2481 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
2482 proto == IPPROTO_UDPLITE ? "Lite" : "",
2483 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
2484 ulen);
2485 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
2486drop:
2487 __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
2488 kfree_skb(skb);
2489 return 0;
2490}
2491
2492/* We can only early demux multicast if there is a single matching socket.
2493 * If more than one socket found returns NULL
2494 */
2495static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
2496 __be16 loc_port, __be32 loc_addr,
2497 __be16 rmt_port, __be32 rmt_addr,
2498 int dif, int sdif)
2499{
2500 struct sock *sk, *result;
2501 unsigned short hnum = ntohs(loc_port);
2502 unsigned int slot = udp_hashfn(net, hnum, udp_table.mask);
2503 struct udp_hslot *hslot = &udp_table.hash[slot];
2504
2505 /* Do not bother scanning a too big list */
2506 if (hslot->count > 10)
2507 return NULL;
2508
2509 result = NULL;
2510 sk_for_each_rcu(sk, &hslot->head) {
2511 if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr,
2512 rmt_port, rmt_addr, dif, sdif, hnum)) {
2513 if (result)
2514 return NULL;
2515 result = sk;
2516 }
2517 }
2518
2519 return result;
2520}
2521
2522/* For unicast we should only early demux connected sockets or we can
2523 * break forwarding setups. The chains here can be long so only check
2524 * if the first socket is an exact match and if not move on.
2525 */
2526static struct sock *__udp4_lib_demux_lookup(struct net *net,
2527 __be16 loc_port, __be32 loc_addr,
2528 __be16 rmt_port, __be32 rmt_addr,
2529 int dif, int sdif)
2530{
2531 unsigned short hnum = ntohs(loc_port);
2532 unsigned int hash2 = ipv4_portaddr_hash(net, loc_addr, hnum);
2533 unsigned int slot2 = hash2 & udp_table.mask;
2534 struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
2535 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
2536 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
2537 struct sock *sk;
2538
2539 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
2540 if (INET_MATCH(sk, net, acookie, rmt_addr,
2541 loc_addr, ports, dif, sdif))
2542 return sk;
2543 /* Only check first socket in chain */
2544 break;
2545 }
2546 return NULL;
2547}
2548
2549int udp_v4_early_demux(struct sk_buff *skb)
2550{
2551 struct net *net = dev_net(skb->dev);
2552 struct in_device *in_dev = NULL;
2553 const struct iphdr *iph;
2554 const struct udphdr *uh;
2555 struct sock *sk = NULL;
2556 struct dst_entry *dst;
2557 int dif = skb->dev->ifindex;
2558 int sdif = inet_sdif(skb);
2559 int ours;
2560
2561 /* validate the packet */
2562 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
2563 return 0;
2564
2565 iph = ip_hdr(skb);
2566 uh = udp_hdr(skb);
2567
2568 if (skb->pkt_type == PACKET_MULTICAST) {
2569 in_dev = __in_dev_get_rcu(skb->dev);
2570
2571 if (!in_dev)
2572 return 0;
2573
2574 ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
2575 iph->protocol);
2576 if (!ours)
2577 return 0;
2578
2579 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
2580 uh->source, iph->saddr,
2581 dif, sdif);
2582 } else if (skb->pkt_type == PACKET_HOST) {
2583 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
2584 uh->source, iph->saddr, dif, sdif);
2585 }
2586
2587 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
2588 return 0;
2589
2590 skb->sk = sk;
2591 skb->destructor = sock_efree;
2592 dst = READ_ONCE(sk->sk_rx_dst);
2593
2594 if (dst)
2595 dst = dst_check(dst, 0);
2596 if (dst) {
2597 u32 itag = 0;
2598
2599 /* set noref for now.
2600 * any place which wants to hold dst has to call
2601 * dst_hold_safe()
2602 */
2603 skb_dst_set_noref(skb, dst);
2604
2605 /* for unconnected multicast sockets we need to validate
2606 * the source on each packet
2607 */
2608 if (!inet_sk(sk)->inet_daddr && in_dev)
2609 return ip_mc_validate_source(skb, iph->daddr,
2610 iph->saddr,
2611 iph->tos & IPTOS_RT_MASK,
2612 skb->dev, in_dev, &itag);
2613 }
2614 return 0;
2615}
2616
2617int udp_rcv(struct sk_buff *skb)
2618{
2619 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
2620}
2621
2622void udp_destroy_sock(struct sock *sk)
2623{
2624 struct udp_sock *up = udp_sk(sk);
2625 bool slow = lock_sock_fast(sk);
2626
2627 /* protects from races with udp_abort() */
2628 sock_set_flag(sk, SOCK_DEAD);
2629 udp_flush_pending_frames(sk);
2630 unlock_sock_fast(sk, slow);
2631 if (static_branch_unlikely(&udp_encap_needed_key)) {
2632 if (up->encap_type) {
2633 void (*encap_destroy)(struct sock *sk);
2634 encap_destroy = READ_ONCE(up->encap_destroy);
2635 if (encap_destroy)
2636 encap_destroy(sk);
2637 }
2638 if (up->encap_enabled)
2639 static_branch_dec(&udp_encap_needed_key);
2640 }
2641}
2642
2643/*
2644 * Socket option code for UDP
2645 */
2646int udp_lib_setsockopt(struct sock *sk, int level, int optname,
2647 sockptr_t optval, unsigned int optlen,
2648 int (*push_pending_frames)(struct sock *))
2649{
2650 struct udp_sock *up = udp_sk(sk);
2651 int val, valbool;
2652 int err = 0;
2653 int is_udplite = IS_UDPLITE(sk);
2654
2655 if (optlen < sizeof(int))
2656 return -EINVAL;
2657
2658 if (copy_from_sockptr(&val, optval, sizeof(val)))
2659 return -EFAULT;
2660
2661 valbool = val ? 1 : 0;
2662
2663 switch (optname) {
2664 case UDP_CORK:
2665 if (val != 0) {
2666 WRITE_ONCE(up->corkflag, 1);
2667 } else {
2668 WRITE_ONCE(up->corkflag, 0);
2669 lock_sock(sk);
2670 push_pending_frames(sk);
2671 release_sock(sk);
2672 }
2673 break;
2674
2675 case UDP_ENCAP:
2676 switch (val) {
2677 case 0:
2678#ifdef CONFIG_XFRM
2679 case UDP_ENCAP_ESPINUDP:
2680 case UDP_ENCAP_ESPINUDP_NON_IKE:
2681#if IS_ENABLED(CONFIG_IPV6)
2682 if (sk->sk_family == AF_INET6)
2683 up->encap_rcv = ipv6_stub->xfrm6_udp_encap_rcv;
2684 else
2685#endif
2686 up->encap_rcv = xfrm4_udp_encap_rcv;
2687#endif
2688 fallthrough;
2689 case UDP_ENCAP_L2TPINUDP:
2690 up->encap_type = val;
2691 lock_sock(sk);
2692 udp_tunnel_encap_enable(sk->sk_socket);
2693 release_sock(sk);
2694 break;
2695 default:
2696 err = -ENOPROTOOPT;
2697 break;
2698 }
2699 break;
2700
2701 case UDP_NO_CHECK6_TX:
2702 up->no_check6_tx = valbool;
2703 break;
2704
2705 case UDP_NO_CHECK6_RX:
2706 up->no_check6_rx = valbool;
2707 break;
2708
2709 case UDP_SEGMENT:
2710 if (val < 0 || val > USHRT_MAX)
2711 return -EINVAL;
2712 WRITE_ONCE(up->gso_size, val);
2713 break;
2714
2715 case UDP_GRO:
2716 lock_sock(sk);
2717
2718 /* when enabling GRO, accept the related GSO packet type */
2719 if (valbool)
2720 udp_tunnel_encap_enable(sk->sk_socket);
2721 up->gro_enabled = valbool;
2722 up->accept_udp_l4 = valbool;
2723 release_sock(sk);
2724 break;
2725
2726 /*
2727 * UDP-Lite's partial checksum coverage (RFC 3828).
2728 */
2729 /* The sender sets actual checksum coverage length via this option.
2730 * The case coverage > packet length is handled by send module. */
2731 case UDPLITE_SEND_CSCOV:
2732 if (!is_udplite) /* Disable the option on UDP sockets */
2733 return -ENOPROTOOPT;
2734 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
2735 val = 8;
2736 else if (val > USHRT_MAX)
2737 val = USHRT_MAX;
2738 up->pcslen = val;
2739 up->pcflag |= UDPLITE_SEND_CC;
2740 break;
2741
2742 /* The receiver specifies a minimum checksum coverage value. To make
2743 * sense, this should be set to at least 8 (as done below). If zero is
2744 * used, this again means full checksum coverage. */
2745 case UDPLITE_RECV_CSCOV:
2746 if (!is_udplite) /* Disable the option on UDP sockets */
2747 return -ENOPROTOOPT;
2748 if (val != 0 && val < 8) /* Avoid silly minimal values. */
2749 val = 8;
2750 else if (val > USHRT_MAX)
2751 val = USHRT_MAX;
2752 up->pcrlen = val;
2753 up->pcflag |= UDPLITE_RECV_CC;
2754 break;
2755
2756 default:
2757 err = -ENOPROTOOPT;
2758 break;
2759 }
2760
2761 return err;
2762}
2763EXPORT_SYMBOL(udp_lib_setsockopt);
2764
2765int udp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
2766 unsigned int optlen)
2767{
2768 if (level == SOL_UDP || level == SOL_UDPLITE)
2769 return udp_lib_setsockopt(sk, level, optname,
2770 optval, optlen,
2771 udp_push_pending_frames);
2772 return ip_setsockopt(sk, level, optname, optval, optlen);
2773}
2774
2775int udp_lib_getsockopt(struct sock *sk, int level, int optname,
2776 char __user *optval, int __user *optlen)
2777{
2778 struct udp_sock *up = udp_sk(sk);
2779 int val, len;
2780
2781 if (get_user(len, optlen))
2782 return -EFAULT;
2783
2784 len = min_t(unsigned int, len, sizeof(int));
2785
2786 if (len < 0)
2787 return -EINVAL;
2788
2789 switch (optname) {
2790 case UDP_CORK:
2791 val = READ_ONCE(up->corkflag);
2792 break;
2793
2794 case UDP_ENCAP:
2795 val = up->encap_type;
2796 break;
2797
2798 case UDP_NO_CHECK6_TX:
2799 val = up->no_check6_tx;
2800 break;
2801
2802 case UDP_NO_CHECK6_RX:
2803 val = up->no_check6_rx;
2804 break;
2805
2806 case UDP_SEGMENT:
2807 val = READ_ONCE(up->gso_size);
2808 break;
2809
2810 case UDP_GRO:
2811 val = up->gro_enabled;
2812 break;
2813
2814 /* The following two cannot be changed on UDP sockets, the return is
2815 * always 0 (which corresponds to the full checksum coverage of UDP). */
2816 case UDPLITE_SEND_CSCOV:
2817 val = up->pcslen;
2818 break;
2819
2820 case UDPLITE_RECV_CSCOV:
2821 val = up->pcrlen;
2822 break;
2823
2824 default:
2825 return -ENOPROTOOPT;
2826 }
2827
2828 if (put_user(len, optlen))
2829 return -EFAULT;
2830 if (copy_to_user(optval, &val, len))
2831 return -EFAULT;
2832 return 0;
2833}
2834EXPORT_SYMBOL(udp_lib_getsockopt);
2835
2836int udp_getsockopt(struct sock *sk, int level, int optname,
2837 char __user *optval, int __user *optlen)
2838{
2839 if (level == SOL_UDP || level == SOL_UDPLITE)
2840 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2841 return ip_getsockopt(sk, level, optname, optval, optlen);
2842}
2843
2844/**
2845 * udp_poll - wait for a UDP event.
2846 * @file: - file struct
2847 * @sock: - socket
2848 * @wait: - poll table
2849 *
2850 * This is same as datagram poll, except for the special case of
2851 * blocking sockets. If application is using a blocking fd
2852 * and a packet with checksum error is in the queue;
2853 * then it could get return from select indicating data available
2854 * but then block when reading it. Add special case code
2855 * to work around these arguably broken applications.
2856 */
2857__poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait)
2858{
2859 __poll_t mask = datagram_poll(file, sock, wait);
2860 struct sock *sk = sock->sk;
2861
2862 if (!skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
2863 mask |= EPOLLIN | EPOLLRDNORM;
2864
2865 /* Check for false positives due to checksum errors */
2866 if ((mask & EPOLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
2867 !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1)
2868 mask &= ~(EPOLLIN | EPOLLRDNORM);
2869
2870 return mask;
2871
2872}
2873EXPORT_SYMBOL(udp_poll);
2874
2875int udp_abort(struct sock *sk, int err)
2876{
2877 lock_sock(sk);
2878
2879 /* udp{v6}_destroy_sock() sets it under the sk lock, avoid racing
2880 * with close()
2881 */
2882 if (sock_flag(sk, SOCK_DEAD))
2883 goto out;
2884
2885 sk->sk_err = err;
2886 sk_error_report(sk);
2887 __udp_disconnect(sk, 0);
2888
2889out:
2890 release_sock(sk);
2891
2892 return 0;
2893}
2894EXPORT_SYMBOL_GPL(udp_abort);
2895
2896struct proto udp_prot = {
2897 .name = "UDP",
2898 .owner = THIS_MODULE,
2899 .close = udp_lib_close,
2900 .pre_connect = udp_pre_connect,
2901 .connect = ip4_datagram_connect,
2902 .disconnect = udp_disconnect,
2903 .ioctl = udp_ioctl,
2904 .init = udp_init_sock,
2905 .destroy = udp_destroy_sock,
2906 .setsockopt = udp_setsockopt,
2907 .getsockopt = udp_getsockopt,
2908 .sendmsg = udp_sendmsg,
2909 .recvmsg = udp_recvmsg,
2910 .sendpage = udp_sendpage,
2911 .release_cb = ip4_datagram_release_cb,
2912 .hash = udp_lib_hash,
2913 .unhash = udp_lib_unhash,
2914 .rehash = udp_v4_rehash,
2915 .get_port = udp_v4_get_port,
2916#ifdef CONFIG_BPF_SYSCALL
2917 .psock_update_sk_prot = udp_bpf_update_proto,
2918#endif
2919 .memory_allocated = &udp_memory_allocated,
2920 .sysctl_mem = sysctl_udp_mem,
2921 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
2922 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
2923 .obj_size = sizeof(struct udp_sock),
2924 .h.udp_table = &udp_table,
2925 .diag_destroy = udp_abort,
2926};
2927EXPORT_SYMBOL(udp_prot);
2928
2929/* ------------------------------------------------------------------------ */
2930#ifdef CONFIG_PROC_FS
2931
2932static struct sock *udp_get_first(struct seq_file *seq, int start)
2933{
2934 struct sock *sk;
2935 struct udp_seq_afinfo *afinfo;
2936 struct udp_iter_state *state = seq->private;
2937 struct net *net = seq_file_net(seq);
2938
2939 if (state->bpf_seq_afinfo)
2940 afinfo = state->bpf_seq_afinfo;
2941 else
2942 afinfo = PDE_DATA(file_inode(seq->file));
2943
2944 for (state->bucket = start; state->bucket <= afinfo->udp_table->mask;
2945 ++state->bucket) {
2946 struct udp_hslot *hslot = &afinfo->udp_table->hash[state->bucket];
2947
2948 if (hlist_empty(&hslot->head))
2949 continue;
2950
2951 spin_lock_bh(&hslot->lock);
2952 sk_for_each(sk, &hslot->head) {
2953 if (!net_eq(sock_net(sk), net))
2954 continue;
2955 if (afinfo->family == AF_UNSPEC ||
2956 sk->sk_family == afinfo->family)
2957 goto found;
2958 }
2959 spin_unlock_bh(&hslot->lock);
2960 }
2961 sk = NULL;
2962found:
2963 return sk;
2964}
2965
2966static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
2967{
2968 struct udp_seq_afinfo *afinfo;
2969 struct udp_iter_state *state = seq->private;
2970 struct net *net = seq_file_net(seq);
2971
2972 if (state->bpf_seq_afinfo)
2973 afinfo = state->bpf_seq_afinfo;
2974 else
2975 afinfo = PDE_DATA(file_inode(seq->file));
2976
2977 do {
2978 sk = sk_next(sk);
2979 } while (sk && (!net_eq(sock_net(sk), net) ||
2980 (afinfo->family != AF_UNSPEC &&
2981 sk->sk_family != afinfo->family)));
2982
2983 if (!sk) {
2984 if (state->bucket <= afinfo->udp_table->mask)
2985 spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock);
2986 return udp_get_first(seq, state->bucket + 1);
2987 }
2988 return sk;
2989}
2990
2991static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
2992{
2993 struct sock *sk = udp_get_first(seq, 0);
2994
2995 if (sk)
2996 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
2997 --pos;
2998 return pos ? NULL : sk;
2999}
3000
3001void *udp_seq_start(struct seq_file *seq, loff_t *pos)
3002{
3003 struct udp_iter_state *state = seq->private;
3004 state->bucket = MAX_UDP_PORTS;
3005
3006 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
3007}
3008EXPORT_SYMBOL(udp_seq_start);
3009
3010void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3011{
3012 struct sock *sk;
3013
3014 if (v == SEQ_START_TOKEN)
3015 sk = udp_get_idx(seq, 0);
3016 else
3017 sk = udp_get_next(seq, v);
3018
3019 ++*pos;
3020 return sk;
3021}
3022EXPORT_SYMBOL(udp_seq_next);
3023
3024void udp_seq_stop(struct seq_file *seq, void *v)
3025{
3026 struct udp_seq_afinfo *afinfo;
3027 struct udp_iter_state *state = seq->private;
3028
3029 if (state->bpf_seq_afinfo)
3030 afinfo = state->bpf_seq_afinfo;
3031 else
3032 afinfo = PDE_DATA(file_inode(seq->file));
3033
3034 if (state->bucket <= afinfo->udp_table->mask)
3035 spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock);
3036}
3037EXPORT_SYMBOL(udp_seq_stop);
3038
3039/* ------------------------------------------------------------------------ */
3040static void udp4_format_sock(struct sock *sp, struct seq_file *f,
3041 int bucket)
3042{
3043 struct inet_sock *inet = inet_sk(sp);
3044 __be32 dest = inet->inet_daddr;
3045 __be32 src = inet->inet_rcv_saddr;
3046 __u16 destp = ntohs(inet->inet_dport);
3047 __u16 srcp = ntohs(inet->inet_sport);
3048
3049 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
3050 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u",
3051 bucket, src, srcp, dest, destp, sp->sk_state,
3052 sk_wmem_alloc_get(sp),
3053 udp_rqueue_get(sp),
3054 0, 0L, 0,
3055 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
3056 0, sock_i_ino(sp),
3057 refcount_read(&sp->sk_refcnt), sp,
3058 atomic_read(&sp->sk_drops));
3059}
3060
3061int udp4_seq_show(struct seq_file *seq, void *v)
3062{
3063 seq_setwidth(seq, 127);
3064 if (v == SEQ_START_TOKEN)
3065 seq_puts(seq, " sl local_address rem_address st tx_queue "
3066 "rx_queue tr tm->when retrnsmt uid timeout "
3067 "inode ref pointer drops");
3068 else {
3069 struct udp_iter_state *state = seq->private;
3070
3071 udp4_format_sock(v, seq, state->bucket);
3072 }
3073 seq_pad(seq, '\n');
3074 return 0;
3075}
3076
3077#ifdef CONFIG_BPF_SYSCALL
3078struct bpf_iter__udp {
3079 __bpf_md_ptr(struct bpf_iter_meta *, meta);
3080 __bpf_md_ptr(struct udp_sock *, udp_sk);
3081 uid_t uid __aligned(8);
3082 int bucket __aligned(8);
3083};
3084
3085static int udp_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta,
3086 struct udp_sock *udp_sk, uid_t uid, int bucket)
3087{
3088 struct bpf_iter__udp ctx;
3089
3090 meta->seq_num--; /* skip SEQ_START_TOKEN */
3091 ctx.meta = meta;
3092 ctx.udp_sk = udp_sk;
3093 ctx.uid = uid;
3094 ctx.bucket = bucket;
3095 return bpf_iter_run_prog(prog, &ctx);
3096}
3097
3098static int bpf_iter_udp_seq_show(struct seq_file *seq, void *v)
3099{
3100 struct udp_iter_state *state = seq->private;
3101 struct bpf_iter_meta meta;
3102 struct bpf_prog *prog;
3103 struct sock *sk = v;
3104 uid_t uid;
3105
3106 if (v == SEQ_START_TOKEN)
3107 return 0;
3108
3109 uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk));
3110 meta.seq = seq;
3111 prog = bpf_iter_get_info(&meta, false);
3112 return udp_prog_seq_show(prog, &meta, v, uid, state->bucket);
3113}
3114
3115static void bpf_iter_udp_seq_stop(struct seq_file *seq, void *v)
3116{
3117 struct bpf_iter_meta meta;
3118 struct bpf_prog *prog;
3119
3120 if (!v) {
3121 meta.seq = seq;
3122 prog = bpf_iter_get_info(&meta, true);
3123 if (prog)
3124 (void)udp_prog_seq_show(prog, &meta, v, 0, 0);
3125 }
3126
3127 udp_seq_stop(seq, v);
3128}
3129
3130static const struct seq_operations bpf_iter_udp_seq_ops = {
3131 .start = udp_seq_start,
3132 .next = udp_seq_next,
3133 .stop = bpf_iter_udp_seq_stop,
3134 .show = bpf_iter_udp_seq_show,
3135};
3136#endif
3137
3138const struct seq_operations udp_seq_ops = {
3139 .start = udp_seq_start,
3140 .next = udp_seq_next,
3141 .stop = udp_seq_stop,
3142 .show = udp4_seq_show,
3143};
3144EXPORT_SYMBOL(udp_seq_ops);
3145
3146static struct udp_seq_afinfo udp4_seq_afinfo = {
3147 .family = AF_INET,
3148 .udp_table = &udp_table,
3149};
3150
3151static int __net_init udp4_proc_init_net(struct net *net)
3152{
3153 if (!proc_create_net_data("udp", 0444, net->proc_net, &udp_seq_ops,
3154 sizeof(struct udp_iter_state), &udp4_seq_afinfo))
3155 return -ENOMEM;
3156 return 0;
3157}
3158
3159static void __net_exit udp4_proc_exit_net(struct net *net)
3160{
3161 remove_proc_entry("udp", net->proc_net);
3162}
3163
3164static struct pernet_operations udp4_net_ops = {
3165 .init = udp4_proc_init_net,
3166 .exit = udp4_proc_exit_net,
3167};
3168
3169int __init udp4_proc_init(void)
3170{
3171 return register_pernet_subsys(&udp4_net_ops);
3172}
3173
3174void udp4_proc_exit(void)
3175{
3176 unregister_pernet_subsys(&udp4_net_ops);
3177}
3178#endif /* CONFIG_PROC_FS */
3179
3180static __initdata unsigned long uhash_entries;
3181static int __init set_uhash_entries(char *str)
3182{
3183 ssize_t ret;
3184
3185 if (!str)
3186 return 0;
3187
3188 ret = kstrtoul(str, 0, &uhash_entries);
3189 if (ret)
3190 return 0;
3191
3192 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
3193 uhash_entries = UDP_HTABLE_SIZE_MIN;
3194 return 1;
3195}
3196__setup("uhash_entries=", set_uhash_entries);
3197
3198void __init udp_table_init(struct udp_table *table, const char *name)
3199{
3200 unsigned int i;
3201
3202 table->hash = alloc_large_system_hash(name,
3203 2 * sizeof(struct udp_hslot),
3204 uhash_entries,
3205 21, /* one slot per 2 MB */
3206 0,
3207 &table->log,
3208 &table->mask,
3209 UDP_HTABLE_SIZE_MIN,
3210 64 * 1024);
3211
3212 table->hash2 = table->hash + (table->mask + 1);
3213 for (i = 0; i <= table->mask; i++) {
3214 INIT_HLIST_HEAD(&table->hash[i].head);
3215 table->hash[i].count = 0;
3216 spin_lock_init(&table->hash[i].lock);
3217 }
3218 for (i = 0; i <= table->mask; i++) {
3219 INIT_HLIST_HEAD(&table->hash2[i].head);
3220 table->hash2[i].count = 0;
3221 spin_lock_init(&table->hash2[i].lock);
3222 }
3223}
3224
3225u32 udp_flow_hashrnd(void)
3226{
3227 static u32 hashrnd __read_mostly;
3228
3229 net_get_random_once(&hashrnd, sizeof(hashrnd));
3230
3231 return hashrnd;
3232}
3233EXPORT_SYMBOL(udp_flow_hashrnd);
3234
3235static void __udp_sysctl_init(struct net *net)
3236{
3237 net->ipv4.sysctl_udp_rmem_min = SK_MEM_QUANTUM;
3238 net->ipv4.sysctl_udp_wmem_min = SK_MEM_QUANTUM;
3239
3240#ifdef CONFIG_NET_L3_MASTER_DEV
3241 net->ipv4.sysctl_udp_l3mdev_accept = 0;
3242#endif
3243}
3244
3245static int __net_init udp_sysctl_init(struct net *net)
3246{
3247 __udp_sysctl_init(net);
3248 return 0;
3249}
3250
3251static struct pernet_operations __net_initdata udp_sysctl_ops = {
3252 .init = udp_sysctl_init,
3253};
3254
3255#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
3256DEFINE_BPF_ITER_FUNC(udp, struct bpf_iter_meta *meta,
3257 struct udp_sock *udp_sk, uid_t uid, int bucket)
3258
3259static int bpf_iter_init_udp(void *priv_data, struct bpf_iter_aux_info *aux)
3260{
3261 struct udp_iter_state *st = priv_data;
3262 struct udp_seq_afinfo *afinfo;
3263 int ret;
3264
3265 afinfo = kmalloc(sizeof(*afinfo), GFP_USER | __GFP_NOWARN);
3266 if (!afinfo)
3267 return -ENOMEM;
3268
3269 afinfo->family = AF_UNSPEC;
3270 afinfo->udp_table = &udp_table;
3271 st->bpf_seq_afinfo = afinfo;
3272 ret = bpf_iter_init_seq_net(priv_data, aux);
3273 if (ret)
3274 kfree(afinfo);
3275 return ret;
3276}
3277
3278static void bpf_iter_fini_udp(void *priv_data)
3279{
3280 struct udp_iter_state *st = priv_data;
3281
3282 kfree(st->bpf_seq_afinfo);
3283 bpf_iter_fini_seq_net(priv_data);
3284}
3285
3286static const struct bpf_iter_seq_info udp_seq_info = {
3287 .seq_ops = &bpf_iter_udp_seq_ops,
3288 .init_seq_private = bpf_iter_init_udp,
3289 .fini_seq_private = bpf_iter_fini_udp,
3290 .seq_priv_size = sizeof(struct udp_iter_state),
3291};
3292
3293static struct bpf_iter_reg udp_reg_info = {
3294 .target = "udp",
3295 .ctx_arg_info_size = 1,
3296 .ctx_arg_info = {
3297 { offsetof(struct bpf_iter__udp, udp_sk),
3298 PTR_TO_BTF_ID_OR_NULL },
3299 },
3300 .seq_info = &udp_seq_info,
3301};
3302
3303static void __init bpf_iter_register(void)
3304{
3305 udp_reg_info.ctx_arg_info[0].btf_id = btf_sock_ids[BTF_SOCK_TYPE_UDP];
3306 if (bpf_iter_reg_target(&udp_reg_info))
3307 pr_warn("Warning: could not register bpf iterator udp\n");
3308}
3309#endif
3310
3311void __init udp_init(void)
3312{
3313 unsigned long limit;
3314 unsigned int i;
3315
3316 udp_table_init(&udp_table, "UDP");
3317 limit = nr_free_buffer_pages() / 8;
3318 limit = max(limit, 128UL);
3319 sysctl_udp_mem[0] = limit / 4 * 3;
3320 sysctl_udp_mem[1] = limit;
3321 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
3322
3323 __udp_sysctl_init(&init_net);
3324
3325 /* 16 spinlocks per cpu */
3326 udp_busylocks_log = ilog2(nr_cpu_ids) + 4;
3327 udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log,
3328 GFP_KERNEL);
3329 if (!udp_busylocks)
3330 panic("UDP: failed to alloc udp_busylocks\n");
3331 for (i = 0; i < (1U << udp_busylocks_log); i++)
3332 spin_lock_init(udp_busylocks + i);
3333
3334 if (register_pernet_subsys(&udp_sysctl_ops))
3335 panic("UDP: failed to init sysctl parameters.\n");
3336
3337#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
3338 bpf_iter_register();
3339#endif
3340}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * The User Datagram Protocol (UDP).
8 *
9 * Authors: Ross Biro
10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
12 * Alan Cox, <alan@lxorguk.ukuu.org.uk>
13 * Hirokazu Takahashi, <taka@valinux.co.jp>
14 *
15 * Fixes:
16 * Alan Cox : verify_area() calls
17 * Alan Cox : stopped close while in use off icmp
18 * messages. Not a fix but a botch that
19 * for udp at least is 'valid'.
20 * Alan Cox : Fixed icmp handling properly
21 * Alan Cox : Correct error for oversized datagrams
22 * Alan Cox : Tidied select() semantics.
23 * Alan Cox : udp_err() fixed properly, also now
24 * select and read wake correctly on errors
25 * Alan Cox : udp_send verify_area moved to avoid mem leak
26 * Alan Cox : UDP can count its memory
27 * Alan Cox : send to an unknown connection causes
28 * an ECONNREFUSED off the icmp, but
29 * does NOT close.
30 * Alan Cox : Switched to new sk_buff handlers. No more backlog!
31 * Alan Cox : Using generic datagram code. Even smaller and the PEEK
32 * bug no longer crashes it.
33 * Fred Van Kempen : Net2e support for sk->broadcast.
34 * Alan Cox : Uses skb_free_datagram
35 * Alan Cox : Added get/set sockopt support.
36 * Alan Cox : Broadcasting without option set returns EACCES.
37 * Alan Cox : No wakeup calls. Instead we now use the callbacks.
38 * Alan Cox : Use ip_tos and ip_ttl
39 * Alan Cox : SNMP Mibs
40 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support.
41 * Matt Dillon : UDP length checks.
42 * Alan Cox : Smarter af_inet used properly.
43 * Alan Cox : Use new kernel side addressing.
44 * Alan Cox : Incorrect return on truncated datagram receive.
45 * Arnt Gulbrandsen : New udp_send and stuff
46 * Alan Cox : Cache last socket
47 * Alan Cox : Route cache
48 * Jon Peatfield : Minor efficiency fix to sendto().
49 * Mike Shaver : RFC1122 checks.
50 * Alan Cox : Nonblocking error fix.
51 * Willy Konynenberg : Transparent proxying support.
52 * Mike McLagan : Routing by source
53 * David S. Miller : New socket lookup architecture.
54 * Last socket cache retained as it
55 * does have a high hit rate.
56 * Olaf Kirch : Don't linearise iovec on sendmsg.
57 * Andi Kleen : Some cleanups, cache destination entry
58 * for connect.
59 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
60 * Melvin Smith : Check msg_name not msg_namelen in sendto(),
61 * return ENOTCONN for unconnected sockets (POSIX)
62 * Janos Farkas : don't deliver multi/broadcasts to a different
63 * bound-to-device socket
64 * Hirokazu Takahashi : HW checksumming for outgoing UDP
65 * datagrams.
66 * Hirokazu Takahashi : sendfile() on UDP works now.
67 * Arnaldo C. Melo : convert /proc/net/udp to seq_file
68 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
69 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind
70 * a single port at the same time.
71 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
72 * James Chapman : Add L2TP encapsulation type.
73 */
74
75#define pr_fmt(fmt) "UDP: " fmt
76
77#include <linux/bpf-cgroup.h>
78#include <linux/uaccess.h>
79#include <asm/ioctls.h>
80#include <linux/memblock.h>
81#include <linux/highmem.h>
82#include <linux/types.h>
83#include <linux/fcntl.h>
84#include <linux/module.h>
85#include <linux/socket.h>
86#include <linux/sockios.h>
87#include <linux/igmp.h>
88#include <linux/inetdevice.h>
89#include <linux/in.h>
90#include <linux/errno.h>
91#include <linux/timer.h>
92#include <linux/mm.h>
93#include <linux/inet.h>
94#include <linux/netdevice.h>
95#include <linux/slab.h>
96#include <net/tcp_states.h>
97#include <linux/skbuff.h>
98#include <linux/proc_fs.h>
99#include <linux/seq_file.h>
100#include <net/net_namespace.h>
101#include <net/icmp.h>
102#include <net/inet_hashtables.h>
103#include <net/ip_tunnels.h>
104#include <net/route.h>
105#include <net/checksum.h>
106#include <net/gso.h>
107#include <net/xfrm.h>
108#include <trace/events/udp.h>
109#include <linux/static_key.h>
110#include <linux/btf_ids.h>
111#include <trace/events/skb.h>
112#include <net/busy_poll.h>
113#include "udp_impl.h"
114#include <net/sock_reuseport.h>
115#include <net/addrconf.h>
116#include <net/udp_tunnel.h>
117#include <net/gro.h>
118#if IS_ENABLED(CONFIG_IPV6)
119#include <net/ipv6_stubs.h>
120#endif
121
122struct udp_table udp_table __read_mostly;
123EXPORT_SYMBOL(udp_table);
124
125long sysctl_udp_mem[3] __read_mostly;
126EXPORT_SYMBOL(sysctl_udp_mem);
127
128atomic_long_t udp_memory_allocated ____cacheline_aligned_in_smp;
129EXPORT_SYMBOL(udp_memory_allocated);
130DEFINE_PER_CPU(int, udp_memory_per_cpu_fw_alloc);
131EXPORT_PER_CPU_SYMBOL_GPL(udp_memory_per_cpu_fw_alloc);
132
133#define MAX_UDP_PORTS 65536
134#define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN_PERNET)
135
136static struct udp_table *udp_get_table_prot(struct sock *sk)
137{
138 return sk->sk_prot->h.udp_table ? : sock_net(sk)->ipv4.udp_table;
139}
140
141static int udp_lib_lport_inuse(struct net *net, __u16 num,
142 const struct udp_hslot *hslot,
143 unsigned long *bitmap,
144 struct sock *sk, unsigned int log)
145{
146 struct sock *sk2;
147 kuid_t uid = sock_i_uid(sk);
148
149 sk_for_each(sk2, &hslot->head) {
150 if (net_eq(sock_net(sk2), net) &&
151 sk2 != sk &&
152 (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
153 (!sk2->sk_reuse || !sk->sk_reuse) &&
154 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
155 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
156 inet_rcv_saddr_equal(sk, sk2, true)) {
157 if (sk2->sk_reuseport && sk->sk_reuseport &&
158 !rcu_access_pointer(sk->sk_reuseport_cb) &&
159 uid_eq(uid, sock_i_uid(sk2))) {
160 if (!bitmap)
161 return 0;
162 } else {
163 if (!bitmap)
164 return 1;
165 __set_bit(udp_sk(sk2)->udp_port_hash >> log,
166 bitmap);
167 }
168 }
169 }
170 return 0;
171}
172
173/*
174 * Note: we still hold spinlock of primary hash chain, so no other writer
175 * can insert/delete a socket with local_port == num
176 */
177static int udp_lib_lport_inuse2(struct net *net, __u16 num,
178 struct udp_hslot *hslot2,
179 struct sock *sk)
180{
181 struct sock *sk2;
182 kuid_t uid = sock_i_uid(sk);
183 int res = 0;
184
185 spin_lock(&hslot2->lock);
186 udp_portaddr_for_each_entry(sk2, &hslot2->head) {
187 if (net_eq(sock_net(sk2), net) &&
188 sk2 != sk &&
189 (udp_sk(sk2)->udp_port_hash == num) &&
190 (!sk2->sk_reuse || !sk->sk_reuse) &&
191 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
192 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
193 inet_rcv_saddr_equal(sk, sk2, true)) {
194 if (sk2->sk_reuseport && sk->sk_reuseport &&
195 !rcu_access_pointer(sk->sk_reuseport_cb) &&
196 uid_eq(uid, sock_i_uid(sk2))) {
197 res = 0;
198 } else {
199 res = 1;
200 }
201 break;
202 }
203 }
204 spin_unlock(&hslot2->lock);
205 return res;
206}
207
208static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot)
209{
210 struct net *net = sock_net(sk);
211 kuid_t uid = sock_i_uid(sk);
212 struct sock *sk2;
213
214 sk_for_each(sk2, &hslot->head) {
215 if (net_eq(sock_net(sk2), net) &&
216 sk2 != sk &&
217 sk2->sk_family == sk->sk_family &&
218 ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
219 (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) &&
220 (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
221 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
222 inet_rcv_saddr_equal(sk, sk2, false)) {
223 return reuseport_add_sock(sk, sk2,
224 inet_rcv_saddr_any(sk));
225 }
226 }
227
228 return reuseport_alloc(sk, inet_rcv_saddr_any(sk));
229}
230
231/**
232 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
233 *
234 * @sk: socket struct in question
235 * @snum: port number to look up
236 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
237 * with NULL address
238 */
239int udp_lib_get_port(struct sock *sk, unsigned short snum,
240 unsigned int hash2_nulladdr)
241{
242 struct udp_table *udptable = udp_get_table_prot(sk);
243 struct udp_hslot *hslot, *hslot2;
244 struct net *net = sock_net(sk);
245 int error = -EADDRINUSE;
246
247 if (!snum) {
248 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
249 unsigned short first, last;
250 int low, high, remaining;
251 unsigned int rand;
252
253 inet_sk_get_local_port_range(sk, &low, &high);
254 remaining = (high - low) + 1;
255
256 rand = get_random_u32();
257 first = reciprocal_scale(rand, remaining) + low;
258 /*
259 * force rand to be an odd multiple of UDP_HTABLE_SIZE
260 */
261 rand = (rand | 1) * (udptable->mask + 1);
262 last = first + udptable->mask + 1;
263 do {
264 hslot = udp_hashslot(udptable, net, first);
265 bitmap_zero(bitmap, PORTS_PER_CHAIN);
266 spin_lock_bh(&hslot->lock);
267 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
268 udptable->log);
269
270 snum = first;
271 /*
272 * Iterate on all possible values of snum for this hash.
273 * Using steps of an odd multiple of UDP_HTABLE_SIZE
274 * give us randomization and full range coverage.
275 */
276 do {
277 if (low <= snum && snum <= high &&
278 !test_bit(snum >> udptable->log, bitmap) &&
279 !inet_is_local_reserved_port(net, snum))
280 goto found;
281 snum += rand;
282 } while (snum != first);
283 spin_unlock_bh(&hslot->lock);
284 cond_resched();
285 } while (++first != last);
286 goto fail;
287 } else {
288 hslot = udp_hashslot(udptable, net, snum);
289 spin_lock_bh(&hslot->lock);
290 if (hslot->count > 10) {
291 int exist;
292 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum;
293
294 slot2 &= udptable->mask;
295 hash2_nulladdr &= udptable->mask;
296
297 hslot2 = udp_hashslot2(udptable, slot2);
298 if (hslot->count < hslot2->count)
299 goto scan_primary_hash;
300
301 exist = udp_lib_lport_inuse2(net, snum, hslot2, sk);
302 if (!exist && (hash2_nulladdr != slot2)) {
303 hslot2 = udp_hashslot2(udptable, hash2_nulladdr);
304 exist = udp_lib_lport_inuse2(net, snum, hslot2,
305 sk);
306 }
307 if (exist)
308 goto fail_unlock;
309 else
310 goto found;
311 }
312scan_primary_hash:
313 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 0))
314 goto fail_unlock;
315 }
316found:
317 inet_sk(sk)->inet_num = snum;
318 udp_sk(sk)->udp_port_hash = snum;
319 udp_sk(sk)->udp_portaddr_hash ^= snum;
320 if (sk_unhashed(sk)) {
321 if (sk->sk_reuseport &&
322 udp_reuseport_add_sock(sk, hslot)) {
323 inet_sk(sk)->inet_num = 0;
324 udp_sk(sk)->udp_port_hash = 0;
325 udp_sk(sk)->udp_portaddr_hash ^= snum;
326 goto fail_unlock;
327 }
328
329 sk_add_node_rcu(sk, &hslot->head);
330 hslot->count++;
331 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
332
333 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
334 spin_lock(&hslot2->lock);
335 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
336 sk->sk_family == AF_INET6)
337 hlist_add_tail_rcu(&udp_sk(sk)->udp_portaddr_node,
338 &hslot2->head);
339 else
340 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
341 &hslot2->head);
342 hslot2->count++;
343 spin_unlock(&hslot2->lock);
344 }
345 sock_set_flag(sk, SOCK_RCU_FREE);
346 error = 0;
347fail_unlock:
348 spin_unlock_bh(&hslot->lock);
349fail:
350 return error;
351}
352EXPORT_SYMBOL(udp_lib_get_port);
353
354int udp_v4_get_port(struct sock *sk, unsigned short snum)
355{
356 unsigned int hash2_nulladdr =
357 ipv4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
358 unsigned int hash2_partial =
359 ipv4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);
360
361 /* precompute partial secondary hash */
362 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
363 return udp_lib_get_port(sk, snum, hash2_nulladdr);
364}
365
366static int compute_score(struct sock *sk, struct net *net,
367 __be32 saddr, __be16 sport,
368 __be32 daddr, unsigned short hnum,
369 int dif, int sdif)
370{
371 int score;
372 struct inet_sock *inet;
373 bool dev_match;
374
375 if (!net_eq(sock_net(sk), net) ||
376 udp_sk(sk)->udp_port_hash != hnum ||
377 ipv6_only_sock(sk))
378 return -1;
379
380 if (sk->sk_rcv_saddr != daddr)
381 return -1;
382
383 score = (sk->sk_family == PF_INET) ? 2 : 1;
384
385 inet = inet_sk(sk);
386 if (inet->inet_daddr) {
387 if (inet->inet_daddr != saddr)
388 return -1;
389 score += 4;
390 }
391
392 if (inet->inet_dport) {
393 if (inet->inet_dport != sport)
394 return -1;
395 score += 4;
396 }
397
398 dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if,
399 dif, sdif);
400 if (!dev_match)
401 return -1;
402 if (sk->sk_bound_dev_if)
403 score += 4;
404
405 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
406 score++;
407 return score;
408}
409
410INDIRECT_CALLABLE_SCOPE
411u32 udp_ehashfn(const struct net *net, const __be32 laddr, const __u16 lport,
412 const __be32 faddr, const __be16 fport)
413{
414 static u32 udp_ehash_secret __read_mostly;
415
416 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret));
417
418 return __inet_ehashfn(laddr, lport, faddr, fport,
419 udp_ehash_secret + net_hash_mix(net));
420}
421
422/* called with rcu_read_lock() */
423static struct sock *udp4_lib_lookup2(struct net *net,
424 __be32 saddr, __be16 sport,
425 __be32 daddr, unsigned int hnum,
426 int dif, int sdif,
427 struct udp_hslot *hslot2,
428 struct sk_buff *skb)
429{
430 struct sock *sk, *result;
431 int score, badness;
432
433 result = NULL;
434 badness = 0;
435 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
436 score = compute_score(sk, net, saddr, sport,
437 daddr, hnum, dif, sdif);
438 if (score > badness) {
439 badness = score;
440
441 if (sk->sk_state == TCP_ESTABLISHED) {
442 result = sk;
443 continue;
444 }
445
446 result = inet_lookup_reuseport(net, sk, skb, sizeof(struct udphdr),
447 saddr, sport, daddr, hnum, udp_ehashfn);
448 if (!result) {
449 result = sk;
450 continue;
451 }
452
453 /* Fall back to scoring if group has connections */
454 if (!reuseport_has_conns(sk))
455 return result;
456
457 /* Reuseport logic returned an error, keep original score. */
458 if (IS_ERR(result))
459 continue;
460
461 badness = compute_score(result, net, saddr, sport,
462 daddr, hnum, dif, sdif);
463
464 }
465 }
466 return result;
467}
468
469/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
470 * harder than this. -DaveM
471 */
472struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
473 __be16 sport, __be32 daddr, __be16 dport, int dif,
474 int sdif, struct udp_table *udptable, struct sk_buff *skb)
475{
476 unsigned short hnum = ntohs(dport);
477 unsigned int hash2, slot2;
478 struct udp_hslot *hslot2;
479 struct sock *result, *sk;
480
481 hash2 = ipv4_portaddr_hash(net, daddr, hnum);
482 slot2 = hash2 & udptable->mask;
483 hslot2 = &udptable->hash2[slot2];
484
485 /* Lookup connected or non-wildcard socket */
486 result = udp4_lib_lookup2(net, saddr, sport,
487 daddr, hnum, dif, sdif,
488 hslot2, skb);
489 if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED)
490 goto done;
491
492 /* Lookup redirect from BPF */
493 if (static_branch_unlikely(&bpf_sk_lookup_enabled) &&
494 udptable == net->ipv4.udp_table) {
495 sk = inet_lookup_run_sk_lookup(net, IPPROTO_UDP, skb, sizeof(struct udphdr),
496 saddr, sport, daddr, hnum, dif,
497 udp_ehashfn);
498 if (sk) {
499 result = sk;
500 goto done;
501 }
502 }
503
504 /* Got non-wildcard socket or error on first lookup */
505 if (result)
506 goto done;
507
508 /* Lookup wildcard sockets */
509 hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
510 slot2 = hash2 & udptable->mask;
511 hslot2 = &udptable->hash2[slot2];
512
513 result = udp4_lib_lookup2(net, saddr, sport,
514 htonl(INADDR_ANY), hnum, dif, sdif,
515 hslot2, skb);
516done:
517 if (IS_ERR(result))
518 return NULL;
519 return result;
520}
521EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
522
523static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
524 __be16 sport, __be16 dport,
525 struct udp_table *udptable)
526{
527 const struct iphdr *iph = ip_hdr(skb);
528
529 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
530 iph->daddr, dport, inet_iif(skb),
531 inet_sdif(skb), udptable, skb);
532}
533
534struct sock *udp4_lib_lookup_skb(const struct sk_buff *skb,
535 __be16 sport, __be16 dport)
536{
537 const struct iphdr *iph = ip_hdr(skb);
538 struct net *net = dev_net(skb->dev);
539 int iif, sdif;
540
541 inet_get_iif_sdif(skb, &iif, &sdif);
542
543 return __udp4_lib_lookup(net, iph->saddr, sport,
544 iph->daddr, dport, iif,
545 sdif, net->ipv4.udp_table, NULL);
546}
547
548/* Must be called under rcu_read_lock().
549 * Does increment socket refcount.
550 */
551#if IS_ENABLED(CONFIG_NF_TPROXY_IPV4) || IS_ENABLED(CONFIG_NF_SOCKET_IPV4)
552struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
553 __be32 daddr, __be16 dport, int dif)
554{
555 struct sock *sk;
556
557 sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport,
558 dif, 0, net->ipv4.udp_table, NULL);
559 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
560 sk = NULL;
561 return sk;
562}
563EXPORT_SYMBOL_GPL(udp4_lib_lookup);
564#endif
565
566static inline bool __udp_is_mcast_sock(struct net *net, const struct sock *sk,
567 __be16 loc_port, __be32 loc_addr,
568 __be16 rmt_port, __be32 rmt_addr,
569 int dif, int sdif, unsigned short hnum)
570{
571 const struct inet_sock *inet = inet_sk(sk);
572
573 if (!net_eq(sock_net(sk), net) ||
574 udp_sk(sk)->udp_port_hash != hnum ||
575 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
576 (inet->inet_dport != rmt_port && inet->inet_dport) ||
577 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) ||
578 ipv6_only_sock(sk) ||
579 !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
580 return false;
581 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif, sdif))
582 return false;
583 return true;
584}
585
586DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key);
587void udp_encap_enable(void)
588{
589 static_branch_inc(&udp_encap_needed_key);
590}
591EXPORT_SYMBOL(udp_encap_enable);
592
593void udp_encap_disable(void)
594{
595 static_branch_dec(&udp_encap_needed_key);
596}
597EXPORT_SYMBOL(udp_encap_disable);
598
599/* Handler for tunnels with arbitrary destination ports: no socket lookup, go
600 * through error handlers in encapsulations looking for a match.
601 */
602static int __udp4_lib_err_encap_no_sk(struct sk_buff *skb, u32 info)
603{
604 int i;
605
606 for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
607 int (*handler)(struct sk_buff *skb, u32 info);
608 const struct ip_tunnel_encap_ops *encap;
609
610 encap = rcu_dereference(iptun_encaps[i]);
611 if (!encap)
612 continue;
613 handler = encap->err_handler;
614 if (handler && !handler(skb, info))
615 return 0;
616 }
617
618 return -ENOENT;
619}
620
621/* Try to match ICMP errors to UDP tunnels by looking up a socket without
622 * reversing source and destination port: this will match tunnels that force the
623 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
624 * lwtunnels might actually break this assumption by being configured with
625 * different destination ports on endpoints, in this case we won't be able to
626 * trace ICMP messages back to them.
627 *
628 * If this doesn't match any socket, probe tunnels with arbitrary destination
629 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
630 * we've sent packets to won't necessarily match the local destination port.
631 *
632 * Then ask the tunnel implementation to match the error against a valid
633 * association.
634 *
635 * Return an error if we can't find a match, the socket if we need further
636 * processing, zero otherwise.
637 */
638static struct sock *__udp4_lib_err_encap(struct net *net,
639 const struct iphdr *iph,
640 struct udphdr *uh,
641 struct udp_table *udptable,
642 struct sock *sk,
643 struct sk_buff *skb, u32 info)
644{
645 int (*lookup)(struct sock *sk, struct sk_buff *skb);
646 int network_offset, transport_offset;
647 struct udp_sock *up;
648
649 network_offset = skb_network_offset(skb);
650 transport_offset = skb_transport_offset(skb);
651
652 /* Network header needs to point to the outer IPv4 header inside ICMP */
653 skb_reset_network_header(skb);
654
655 /* Transport header needs to point to the UDP header */
656 skb_set_transport_header(skb, iph->ihl << 2);
657
658 if (sk) {
659 up = udp_sk(sk);
660
661 lookup = READ_ONCE(up->encap_err_lookup);
662 if (lookup && lookup(sk, skb))
663 sk = NULL;
664
665 goto out;
666 }
667
668 sk = __udp4_lib_lookup(net, iph->daddr, uh->source,
669 iph->saddr, uh->dest, skb->dev->ifindex, 0,
670 udptable, NULL);
671 if (sk) {
672 up = udp_sk(sk);
673
674 lookup = READ_ONCE(up->encap_err_lookup);
675 if (!lookup || lookup(sk, skb))
676 sk = NULL;
677 }
678
679out:
680 if (!sk)
681 sk = ERR_PTR(__udp4_lib_err_encap_no_sk(skb, info));
682
683 skb_set_transport_header(skb, transport_offset);
684 skb_set_network_header(skb, network_offset);
685
686 return sk;
687}
688
689/*
690 * This routine is called by the ICMP module when it gets some
691 * sort of error condition. If err < 0 then the socket should
692 * be closed and the error returned to the user. If err > 0
693 * it's just the icmp type << 8 | icmp code.
694 * Header points to the ip header of the error packet. We move
695 * on past this. Then (as it used to claim before adjustment)
696 * header points to the first 8 bytes of the udp header. We need
697 * to find the appropriate port.
698 */
699
700int __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
701{
702 struct inet_sock *inet;
703 const struct iphdr *iph = (const struct iphdr *)skb->data;
704 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
705 const int type = icmp_hdr(skb)->type;
706 const int code = icmp_hdr(skb)->code;
707 bool tunnel = false;
708 struct sock *sk;
709 int harderr;
710 int err;
711 struct net *net = dev_net(skb->dev);
712
713 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
714 iph->saddr, uh->source, skb->dev->ifindex,
715 inet_sdif(skb), udptable, NULL);
716
717 if (!sk || READ_ONCE(udp_sk(sk)->encap_type)) {
718 /* No socket for error: try tunnels before discarding */
719 if (static_branch_unlikely(&udp_encap_needed_key)) {
720 sk = __udp4_lib_err_encap(net, iph, uh, udptable, sk, skb,
721 info);
722 if (!sk)
723 return 0;
724 } else
725 sk = ERR_PTR(-ENOENT);
726
727 if (IS_ERR(sk)) {
728 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
729 return PTR_ERR(sk);
730 }
731
732 tunnel = true;
733 }
734
735 err = 0;
736 harderr = 0;
737 inet = inet_sk(sk);
738
739 switch (type) {
740 default:
741 case ICMP_TIME_EXCEEDED:
742 err = EHOSTUNREACH;
743 break;
744 case ICMP_SOURCE_QUENCH:
745 goto out;
746 case ICMP_PARAMETERPROB:
747 err = EPROTO;
748 harderr = 1;
749 break;
750 case ICMP_DEST_UNREACH:
751 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
752 ipv4_sk_update_pmtu(skb, sk, info);
753 if (READ_ONCE(inet->pmtudisc) != IP_PMTUDISC_DONT) {
754 err = EMSGSIZE;
755 harderr = 1;
756 break;
757 }
758 goto out;
759 }
760 err = EHOSTUNREACH;
761 if (code <= NR_ICMP_UNREACH) {
762 harderr = icmp_err_convert[code].fatal;
763 err = icmp_err_convert[code].errno;
764 }
765 break;
766 case ICMP_REDIRECT:
767 ipv4_sk_redirect(skb, sk);
768 goto out;
769 }
770
771 /*
772 * RFC1122: OK. Passes ICMP errors back to application, as per
773 * 4.1.3.3.
774 */
775 if (tunnel) {
776 /* ...not for tunnels though: we don't have a sending socket */
777 if (udp_sk(sk)->encap_err_rcv)
778 udp_sk(sk)->encap_err_rcv(sk, skb, err, uh->dest, info,
779 (u8 *)(uh+1));
780 goto out;
781 }
782 if (!inet_test_bit(RECVERR, sk)) {
783 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
784 goto out;
785 } else
786 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
787
788 sk->sk_err = err;
789 sk_error_report(sk);
790out:
791 return 0;
792}
793
794int udp_err(struct sk_buff *skb, u32 info)
795{
796 return __udp4_lib_err(skb, info, dev_net(skb->dev)->ipv4.udp_table);
797}
798
799/*
800 * Throw away all pending data and cancel the corking. Socket is locked.
801 */
802void udp_flush_pending_frames(struct sock *sk)
803{
804 struct udp_sock *up = udp_sk(sk);
805
806 if (up->pending) {
807 up->len = 0;
808 WRITE_ONCE(up->pending, 0);
809 ip_flush_pending_frames(sk);
810 }
811}
812EXPORT_SYMBOL(udp_flush_pending_frames);
813
814/**
815 * udp4_hwcsum - handle outgoing HW checksumming
816 * @skb: sk_buff containing the filled-in UDP header
817 * (checksum field must be zeroed out)
818 * @src: source IP address
819 * @dst: destination IP address
820 */
821void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
822{
823 struct udphdr *uh = udp_hdr(skb);
824 int offset = skb_transport_offset(skb);
825 int len = skb->len - offset;
826 int hlen = len;
827 __wsum csum = 0;
828
829 if (!skb_has_frag_list(skb)) {
830 /*
831 * Only one fragment on the socket.
832 */
833 skb->csum_start = skb_transport_header(skb) - skb->head;
834 skb->csum_offset = offsetof(struct udphdr, check);
835 uh->check = ~csum_tcpudp_magic(src, dst, len,
836 IPPROTO_UDP, 0);
837 } else {
838 struct sk_buff *frags;
839
840 /*
841 * HW-checksum won't work as there are two or more
842 * fragments on the socket so that all csums of sk_buffs
843 * should be together
844 */
845 skb_walk_frags(skb, frags) {
846 csum = csum_add(csum, frags->csum);
847 hlen -= frags->len;
848 }
849
850 csum = skb_checksum(skb, offset, hlen, csum);
851 skb->ip_summed = CHECKSUM_NONE;
852
853 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
854 if (uh->check == 0)
855 uh->check = CSUM_MANGLED_0;
856 }
857}
858EXPORT_SYMBOL_GPL(udp4_hwcsum);
859
860/* Function to set UDP checksum for an IPv4 UDP packet. This is intended
861 * for the simple case like when setting the checksum for a UDP tunnel.
862 */
863void udp_set_csum(bool nocheck, struct sk_buff *skb,
864 __be32 saddr, __be32 daddr, int len)
865{
866 struct udphdr *uh = udp_hdr(skb);
867
868 if (nocheck) {
869 uh->check = 0;
870 } else if (skb_is_gso(skb)) {
871 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
872 } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
873 uh->check = 0;
874 uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb));
875 if (uh->check == 0)
876 uh->check = CSUM_MANGLED_0;
877 } else {
878 skb->ip_summed = CHECKSUM_PARTIAL;
879 skb->csum_start = skb_transport_header(skb) - skb->head;
880 skb->csum_offset = offsetof(struct udphdr, check);
881 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
882 }
883}
884EXPORT_SYMBOL(udp_set_csum);
885
886static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4,
887 struct inet_cork *cork)
888{
889 struct sock *sk = skb->sk;
890 struct inet_sock *inet = inet_sk(sk);
891 struct udphdr *uh;
892 int err;
893 int is_udplite = IS_UDPLITE(sk);
894 int offset = skb_transport_offset(skb);
895 int len = skb->len - offset;
896 int datalen = len - sizeof(*uh);
897 __wsum csum = 0;
898
899 /*
900 * Create a UDP header
901 */
902 uh = udp_hdr(skb);
903 uh->source = inet->inet_sport;
904 uh->dest = fl4->fl4_dport;
905 uh->len = htons(len);
906 uh->check = 0;
907
908 if (cork->gso_size) {
909 const int hlen = skb_network_header_len(skb) +
910 sizeof(struct udphdr);
911
912 if (hlen + cork->gso_size > cork->fragsize) {
913 kfree_skb(skb);
914 return -EINVAL;
915 }
916 if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) {
917 kfree_skb(skb);
918 return -EINVAL;
919 }
920 if (sk->sk_no_check_tx) {
921 kfree_skb(skb);
922 return -EINVAL;
923 }
924 if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
925 dst_xfrm(skb_dst(skb))) {
926 kfree_skb(skb);
927 return -EIO;
928 }
929
930 if (datalen > cork->gso_size) {
931 skb_shinfo(skb)->gso_size = cork->gso_size;
932 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
933 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
934 cork->gso_size);
935 }
936 goto csum_partial;
937 }
938
939 if (is_udplite) /* UDP-Lite */
940 csum = udplite_csum(skb);
941
942 else if (sk->sk_no_check_tx) { /* UDP csum off */
943
944 skb->ip_summed = CHECKSUM_NONE;
945 goto send;
946
947 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
948csum_partial:
949
950 udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
951 goto send;
952
953 } else
954 csum = udp_csum(skb);
955
956 /* add protocol-dependent pseudo-header */
957 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
958 sk->sk_protocol, csum);
959 if (uh->check == 0)
960 uh->check = CSUM_MANGLED_0;
961
962send:
963 err = ip_send_skb(sock_net(sk), skb);
964 if (err) {
965 if (err == -ENOBUFS &&
966 !inet_test_bit(RECVERR, sk)) {
967 UDP_INC_STATS(sock_net(sk),
968 UDP_MIB_SNDBUFERRORS, is_udplite);
969 err = 0;
970 }
971 } else
972 UDP_INC_STATS(sock_net(sk),
973 UDP_MIB_OUTDATAGRAMS, is_udplite);
974 return err;
975}
976
977/*
978 * Push out all pending data as one UDP datagram. Socket is locked.
979 */
980int udp_push_pending_frames(struct sock *sk)
981{
982 struct udp_sock *up = udp_sk(sk);
983 struct inet_sock *inet = inet_sk(sk);
984 struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
985 struct sk_buff *skb;
986 int err = 0;
987
988 skb = ip_finish_skb(sk, fl4);
989 if (!skb)
990 goto out;
991
992 err = udp_send_skb(skb, fl4, &inet->cork.base);
993
994out:
995 up->len = 0;
996 WRITE_ONCE(up->pending, 0);
997 return err;
998}
999EXPORT_SYMBOL(udp_push_pending_frames);
1000
1001static int __udp_cmsg_send(struct cmsghdr *cmsg, u16 *gso_size)
1002{
1003 switch (cmsg->cmsg_type) {
1004 case UDP_SEGMENT:
1005 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u16)))
1006 return -EINVAL;
1007 *gso_size = *(__u16 *)CMSG_DATA(cmsg);
1008 return 0;
1009 default:
1010 return -EINVAL;
1011 }
1012}
1013
1014int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size)
1015{
1016 struct cmsghdr *cmsg;
1017 bool need_ip = false;
1018 int err;
1019
1020 for_each_cmsghdr(cmsg, msg) {
1021 if (!CMSG_OK(msg, cmsg))
1022 return -EINVAL;
1023
1024 if (cmsg->cmsg_level != SOL_UDP) {
1025 need_ip = true;
1026 continue;
1027 }
1028
1029 err = __udp_cmsg_send(cmsg, gso_size);
1030 if (err)
1031 return err;
1032 }
1033
1034 return need_ip;
1035}
1036EXPORT_SYMBOL_GPL(udp_cmsg_send);
1037
1038int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1039{
1040 struct inet_sock *inet = inet_sk(sk);
1041 struct udp_sock *up = udp_sk(sk);
1042 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
1043 struct flowi4 fl4_stack;
1044 struct flowi4 *fl4;
1045 int ulen = len;
1046 struct ipcm_cookie ipc;
1047 struct rtable *rt = NULL;
1048 int free = 0;
1049 int connected = 0;
1050 __be32 daddr, faddr, saddr;
1051 u8 tos, scope;
1052 __be16 dport;
1053 int err, is_udplite = IS_UDPLITE(sk);
1054 int corkreq = udp_test_bit(CORK, sk) || msg->msg_flags & MSG_MORE;
1055 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1056 struct sk_buff *skb;
1057 struct ip_options_data opt_copy;
1058 int uc_index;
1059
1060 if (len > 0xFFFF)
1061 return -EMSGSIZE;
1062
1063 /*
1064 * Check the flags.
1065 */
1066
1067 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
1068 return -EOPNOTSUPP;
1069
1070 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
1071
1072 fl4 = &inet->cork.fl.u.ip4;
1073 if (READ_ONCE(up->pending)) {
1074 /*
1075 * There are pending frames.
1076 * The socket lock must be held while it's corked.
1077 */
1078 lock_sock(sk);
1079 if (likely(up->pending)) {
1080 if (unlikely(up->pending != AF_INET)) {
1081 release_sock(sk);
1082 return -EINVAL;
1083 }
1084 goto do_append_data;
1085 }
1086 release_sock(sk);
1087 }
1088 ulen += sizeof(struct udphdr);
1089
1090 /*
1091 * Get and verify the address.
1092 */
1093 if (usin) {
1094 if (msg->msg_namelen < sizeof(*usin))
1095 return -EINVAL;
1096 if (usin->sin_family != AF_INET) {
1097 if (usin->sin_family != AF_UNSPEC)
1098 return -EAFNOSUPPORT;
1099 }
1100
1101 daddr = usin->sin_addr.s_addr;
1102 dport = usin->sin_port;
1103 if (dport == 0)
1104 return -EINVAL;
1105 } else {
1106 if (sk->sk_state != TCP_ESTABLISHED)
1107 return -EDESTADDRREQ;
1108 daddr = inet->inet_daddr;
1109 dport = inet->inet_dport;
1110 /* Open fast path for connected socket.
1111 Route will not be used, if at least one option is set.
1112 */
1113 connected = 1;
1114 }
1115
1116 ipcm_init_sk(&ipc, inet);
1117 ipc.gso_size = READ_ONCE(up->gso_size);
1118
1119 if (msg->msg_controllen) {
1120 err = udp_cmsg_send(sk, msg, &ipc.gso_size);
1121 if (err > 0)
1122 err = ip_cmsg_send(sk, msg, &ipc,
1123 sk->sk_family == AF_INET6);
1124 if (unlikely(err < 0)) {
1125 kfree(ipc.opt);
1126 return err;
1127 }
1128 if (ipc.opt)
1129 free = 1;
1130 connected = 0;
1131 }
1132 if (!ipc.opt) {
1133 struct ip_options_rcu *inet_opt;
1134
1135 rcu_read_lock();
1136 inet_opt = rcu_dereference(inet->inet_opt);
1137 if (inet_opt) {
1138 memcpy(&opt_copy, inet_opt,
1139 sizeof(*inet_opt) + inet_opt->opt.optlen);
1140 ipc.opt = &opt_copy.opt;
1141 }
1142 rcu_read_unlock();
1143 }
1144
1145 if (cgroup_bpf_enabled(CGROUP_UDP4_SENDMSG) && !connected) {
1146 err = BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk,
1147 (struct sockaddr *)usin,
1148 &msg->msg_namelen,
1149 &ipc.addr);
1150 if (err)
1151 goto out_free;
1152 if (usin) {
1153 if (usin->sin_port == 0) {
1154 /* BPF program set invalid port. Reject it. */
1155 err = -EINVAL;
1156 goto out_free;
1157 }
1158 daddr = usin->sin_addr.s_addr;
1159 dport = usin->sin_port;
1160 }
1161 }
1162
1163 saddr = ipc.addr;
1164 ipc.addr = faddr = daddr;
1165
1166 if (ipc.opt && ipc.opt->opt.srr) {
1167 if (!daddr) {
1168 err = -EINVAL;
1169 goto out_free;
1170 }
1171 faddr = ipc.opt->opt.faddr;
1172 connected = 0;
1173 }
1174 tos = get_rttos(&ipc, inet);
1175 scope = ip_sendmsg_scope(inet, &ipc, msg);
1176 if (scope == RT_SCOPE_LINK)
1177 connected = 0;
1178
1179 uc_index = READ_ONCE(inet->uc_index);
1180 if (ipv4_is_multicast(daddr)) {
1181 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
1182 ipc.oif = READ_ONCE(inet->mc_index);
1183 if (!saddr)
1184 saddr = READ_ONCE(inet->mc_addr);
1185 connected = 0;
1186 } else if (!ipc.oif) {
1187 ipc.oif = uc_index;
1188 } else if (ipv4_is_lbcast(daddr) && uc_index) {
1189 /* oif is set, packet is to local broadcast and
1190 * uc_index is set. oif is most likely set
1191 * by sk_bound_dev_if. If uc_index != oif check if the
1192 * oif is an L3 master and uc_index is an L3 slave.
1193 * If so, we want to allow the send using the uc_index.
1194 */
1195 if (ipc.oif != uc_index &&
1196 ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk),
1197 uc_index)) {
1198 ipc.oif = uc_index;
1199 }
1200 }
1201
1202 if (connected)
1203 rt = (struct rtable *)sk_dst_check(sk, 0);
1204
1205 if (!rt) {
1206 struct net *net = sock_net(sk);
1207 __u8 flow_flags = inet_sk_flowi_flags(sk);
1208
1209 fl4 = &fl4_stack;
1210
1211 flowi4_init_output(fl4, ipc.oif, ipc.sockc.mark, tos, scope,
1212 sk->sk_protocol, flow_flags, faddr, saddr,
1213 dport, inet->inet_sport, sk->sk_uid);
1214
1215 security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));
1216 rt = ip_route_output_flow(net, fl4, sk);
1217 if (IS_ERR(rt)) {
1218 err = PTR_ERR(rt);
1219 rt = NULL;
1220 if (err == -ENETUNREACH)
1221 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
1222 goto out;
1223 }
1224
1225 err = -EACCES;
1226 if ((rt->rt_flags & RTCF_BROADCAST) &&
1227 !sock_flag(sk, SOCK_BROADCAST))
1228 goto out;
1229 if (connected)
1230 sk_dst_set(sk, dst_clone(&rt->dst));
1231 }
1232
1233 if (msg->msg_flags&MSG_CONFIRM)
1234 goto do_confirm;
1235back_from_confirm:
1236
1237 saddr = fl4->saddr;
1238 if (!ipc.addr)
1239 daddr = ipc.addr = fl4->daddr;
1240
1241 /* Lockless fast path for the non-corking case. */
1242 if (!corkreq) {
1243 struct inet_cork cork;
1244
1245 skb = ip_make_skb(sk, fl4, getfrag, msg, ulen,
1246 sizeof(struct udphdr), &ipc, &rt,
1247 &cork, msg->msg_flags);
1248 err = PTR_ERR(skb);
1249 if (!IS_ERR_OR_NULL(skb))
1250 err = udp_send_skb(skb, fl4, &cork);
1251 goto out;
1252 }
1253
1254 lock_sock(sk);
1255 if (unlikely(up->pending)) {
1256 /* The socket is already corked while preparing it. */
1257 /* ... which is an evident application bug. --ANK */
1258 release_sock(sk);
1259
1260 net_dbg_ratelimited("socket already corked\n");
1261 err = -EINVAL;
1262 goto out;
1263 }
1264 /*
1265 * Now cork the socket to pend data.
1266 */
1267 fl4 = &inet->cork.fl.u.ip4;
1268 fl4->daddr = daddr;
1269 fl4->saddr = saddr;
1270 fl4->fl4_dport = dport;
1271 fl4->fl4_sport = inet->inet_sport;
1272 WRITE_ONCE(up->pending, AF_INET);
1273
1274do_append_data:
1275 up->len += ulen;
1276 err = ip_append_data(sk, fl4, getfrag, msg, ulen,
1277 sizeof(struct udphdr), &ipc, &rt,
1278 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1279 if (err)
1280 udp_flush_pending_frames(sk);
1281 else if (!corkreq)
1282 err = udp_push_pending_frames(sk);
1283 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1284 WRITE_ONCE(up->pending, 0);
1285 release_sock(sk);
1286
1287out:
1288 ip_rt_put(rt);
1289out_free:
1290 if (free)
1291 kfree(ipc.opt);
1292 if (!err)
1293 return len;
1294 /*
1295 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1296 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1297 * we don't have a good statistic (IpOutDiscards but it can be too many
1298 * things). We could add another new stat but at least for now that
1299 * seems like overkill.
1300 */
1301 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1302 UDP_INC_STATS(sock_net(sk),
1303 UDP_MIB_SNDBUFERRORS, is_udplite);
1304 }
1305 return err;
1306
1307do_confirm:
1308 if (msg->msg_flags & MSG_PROBE)
1309 dst_confirm_neigh(&rt->dst, &fl4->daddr);
1310 if (!(msg->msg_flags&MSG_PROBE) || len)
1311 goto back_from_confirm;
1312 err = 0;
1313 goto out;
1314}
1315EXPORT_SYMBOL(udp_sendmsg);
1316
1317void udp_splice_eof(struct socket *sock)
1318{
1319 struct sock *sk = sock->sk;
1320 struct udp_sock *up = udp_sk(sk);
1321
1322 if (!READ_ONCE(up->pending) || udp_test_bit(CORK, sk))
1323 return;
1324
1325 lock_sock(sk);
1326 if (up->pending && !udp_test_bit(CORK, sk))
1327 udp_push_pending_frames(sk);
1328 release_sock(sk);
1329}
1330EXPORT_SYMBOL_GPL(udp_splice_eof);
1331
1332#define UDP_SKB_IS_STATELESS 0x80000000
1333
1334/* all head states (dst, sk, nf conntrack) except skb extensions are
1335 * cleared by udp_rcv().
1336 *
1337 * We need to preserve secpath, if present, to eventually process
1338 * IP_CMSG_PASSSEC at recvmsg() time.
1339 *
1340 * Other extensions can be cleared.
1341 */
1342static bool udp_try_make_stateless(struct sk_buff *skb)
1343{
1344 if (!skb_has_extensions(skb))
1345 return true;
1346
1347 if (!secpath_exists(skb)) {
1348 skb_ext_reset(skb);
1349 return true;
1350 }
1351
1352 return false;
1353}
1354
1355static void udp_set_dev_scratch(struct sk_buff *skb)
1356{
1357 struct udp_dev_scratch *scratch = udp_skb_scratch(skb);
1358
1359 BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long));
1360 scratch->_tsize_state = skb->truesize;
1361#if BITS_PER_LONG == 64
1362 scratch->len = skb->len;
1363 scratch->csum_unnecessary = !!skb_csum_unnecessary(skb);
1364 scratch->is_linear = !skb_is_nonlinear(skb);
1365#endif
1366 if (udp_try_make_stateless(skb))
1367 scratch->_tsize_state |= UDP_SKB_IS_STATELESS;
1368}
1369
1370static void udp_skb_csum_unnecessary_set(struct sk_buff *skb)
1371{
1372 /* We come here after udp_lib_checksum_complete() returned 0.
1373 * This means that __skb_checksum_complete() might have
1374 * set skb->csum_valid to 1.
1375 * On 64bit platforms, we can set csum_unnecessary
1376 * to true, but only if the skb is not shared.
1377 */
1378#if BITS_PER_LONG == 64
1379 if (!skb_shared(skb))
1380 udp_skb_scratch(skb)->csum_unnecessary = true;
1381#endif
1382}
1383
1384static int udp_skb_truesize(struct sk_buff *skb)
1385{
1386 return udp_skb_scratch(skb)->_tsize_state & ~UDP_SKB_IS_STATELESS;
1387}
1388
1389static bool udp_skb_has_head_state(struct sk_buff *skb)
1390{
1391 return !(udp_skb_scratch(skb)->_tsize_state & UDP_SKB_IS_STATELESS);
1392}
1393
1394/* fully reclaim rmem/fwd memory allocated for skb */
1395static void udp_rmem_release(struct sock *sk, int size, int partial,
1396 bool rx_queue_lock_held)
1397{
1398 struct udp_sock *up = udp_sk(sk);
1399 struct sk_buff_head *sk_queue;
1400 int amt;
1401
1402 if (likely(partial)) {
1403 up->forward_deficit += size;
1404 size = up->forward_deficit;
1405 if (size < READ_ONCE(up->forward_threshold) &&
1406 !skb_queue_empty(&up->reader_queue))
1407 return;
1408 } else {
1409 size += up->forward_deficit;
1410 }
1411 up->forward_deficit = 0;
1412
1413 /* acquire the sk_receive_queue for fwd allocated memory scheduling,
1414 * if the called don't held it already
1415 */
1416 sk_queue = &sk->sk_receive_queue;
1417 if (!rx_queue_lock_held)
1418 spin_lock(&sk_queue->lock);
1419
1420
1421 sk_forward_alloc_add(sk, size);
1422 amt = (sk->sk_forward_alloc - partial) & ~(PAGE_SIZE - 1);
1423 sk_forward_alloc_add(sk, -amt);
1424
1425 if (amt)
1426 __sk_mem_reduce_allocated(sk, amt >> PAGE_SHIFT);
1427
1428 atomic_sub(size, &sk->sk_rmem_alloc);
1429
1430 /* this can save us from acquiring the rx queue lock on next receive */
1431 skb_queue_splice_tail_init(sk_queue, &up->reader_queue);
1432
1433 if (!rx_queue_lock_held)
1434 spin_unlock(&sk_queue->lock);
1435}
1436
1437/* Note: called with reader_queue.lock held.
1438 * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch
1439 * This avoids a cache line miss while receive_queue lock is held.
1440 * Look at __udp_enqueue_schedule_skb() to find where this copy is done.
1441 */
1442void udp_skb_destructor(struct sock *sk, struct sk_buff *skb)
1443{
1444 prefetch(&skb->data);
1445 udp_rmem_release(sk, udp_skb_truesize(skb), 1, false);
1446}
1447EXPORT_SYMBOL(udp_skb_destructor);
1448
1449/* as above, but the caller held the rx queue lock, too */
1450static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb)
1451{
1452 prefetch(&skb->data);
1453 udp_rmem_release(sk, udp_skb_truesize(skb), 1, true);
1454}
1455
1456/* Idea of busylocks is to let producers grab an extra spinlock
1457 * to relieve pressure on the receive_queue spinlock shared by consumer.
1458 * Under flood, this means that only one producer can be in line
1459 * trying to acquire the receive_queue spinlock.
1460 * These busylock can be allocated on a per cpu manner, instead of a
1461 * per socket one (that would consume a cache line per socket)
1462 */
1463static int udp_busylocks_log __read_mostly;
1464static spinlock_t *udp_busylocks __read_mostly;
1465
1466static spinlock_t *busylock_acquire(void *ptr)
1467{
1468 spinlock_t *busy;
1469
1470 busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log);
1471 spin_lock(busy);
1472 return busy;
1473}
1474
1475static void busylock_release(spinlock_t *busy)
1476{
1477 if (busy)
1478 spin_unlock(busy);
1479}
1480
1481static int udp_rmem_schedule(struct sock *sk, int size)
1482{
1483 int delta;
1484
1485 delta = size - sk->sk_forward_alloc;
1486 if (delta > 0 && !__sk_mem_schedule(sk, delta, SK_MEM_RECV))
1487 return -ENOBUFS;
1488
1489 return 0;
1490}
1491
1492int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
1493{
1494 struct sk_buff_head *list = &sk->sk_receive_queue;
1495 int rmem, err = -ENOMEM;
1496 spinlock_t *busy = NULL;
1497 int size;
1498
1499 /* try to avoid the costly atomic add/sub pair when the receive
1500 * queue is full; always allow at least a packet
1501 */
1502 rmem = atomic_read(&sk->sk_rmem_alloc);
1503 if (rmem > sk->sk_rcvbuf)
1504 goto drop;
1505
1506 /* Under mem pressure, it might be helpful to help udp_recvmsg()
1507 * having linear skbs :
1508 * - Reduce memory overhead and thus increase receive queue capacity
1509 * - Less cache line misses at copyout() time
1510 * - Less work at consume_skb() (less alien page frag freeing)
1511 */
1512 if (rmem > (sk->sk_rcvbuf >> 1)) {
1513 skb_condense(skb);
1514
1515 busy = busylock_acquire(sk);
1516 }
1517 size = skb->truesize;
1518 udp_set_dev_scratch(skb);
1519
1520 /* we drop only if the receive buf is full and the receive
1521 * queue contains some other skb
1522 */
1523 rmem = atomic_add_return(size, &sk->sk_rmem_alloc);
1524 if (rmem > (size + (unsigned int)sk->sk_rcvbuf))
1525 goto uncharge_drop;
1526
1527 spin_lock(&list->lock);
1528 err = udp_rmem_schedule(sk, size);
1529 if (err) {
1530 spin_unlock(&list->lock);
1531 goto uncharge_drop;
1532 }
1533
1534 sk_forward_alloc_add(sk, -size);
1535
1536 /* no need to setup a destructor, we will explicitly release the
1537 * forward allocated memory on dequeue
1538 */
1539 sock_skb_set_dropcount(sk, skb);
1540
1541 __skb_queue_tail(list, skb);
1542 spin_unlock(&list->lock);
1543
1544 if (!sock_flag(sk, SOCK_DEAD))
1545 INDIRECT_CALL_1(sk->sk_data_ready, sock_def_readable, sk);
1546
1547 busylock_release(busy);
1548 return 0;
1549
1550uncharge_drop:
1551 atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1552
1553drop:
1554 atomic_inc(&sk->sk_drops);
1555 busylock_release(busy);
1556 return err;
1557}
1558EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb);
1559
1560void udp_destruct_common(struct sock *sk)
1561{
1562 /* reclaim completely the forward allocated memory */
1563 struct udp_sock *up = udp_sk(sk);
1564 unsigned int total = 0;
1565 struct sk_buff *skb;
1566
1567 skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue);
1568 while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) {
1569 total += skb->truesize;
1570 kfree_skb(skb);
1571 }
1572 udp_rmem_release(sk, total, 0, true);
1573}
1574EXPORT_SYMBOL_GPL(udp_destruct_common);
1575
1576static void udp_destruct_sock(struct sock *sk)
1577{
1578 udp_destruct_common(sk);
1579 inet_sock_destruct(sk);
1580}
1581
1582int udp_init_sock(struct sock *sk)
1583{
1584 udp_lib_init_sock(sk);
1585 sk->sk_destruct = udp_destruct_sock;
1586 set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
1587 return 0;
1588}
1589
1590void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len)
1591{
1592 sk_peek_offset_bwd(sk, len);
1593
1594 if (!skb_unref(skb))
1595 return;
1596
1597 /* In the more common cases we cleared the head states previously,
1598 * see __udp_queue_rcv_skb().
1599 */
1600 if (unlikely(udp_skb_has_head_state(skb)))
1601 skb_release_head_state(skb);
1602 __consume_stateless_skb(skb);
1603}
1604EXPORT_SYMBOL_GPL(skb_consume_udp);
1605
1606static struct sk_buff *__first_packet_length(struct sock *sk,
1607 struct sk_buff_head *rcvq,
1608 int *total)
1609{
1610 struct sk_buff *skb;
1611
1612 while ((skb = skb_peek(rcvq)) != NULL) {
1613 if (udp_lib_checksum_complete(skb)) {
1614 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS,
1615 IS_UDPLITE(sk));
1616 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
1617 IS_UDPLITE(sk));
1618 atomic_inc(&sk->sk_drops);
1619 __skb_unlink(skb, rcvq);
1620 *total += skb->truesize;
1621 kfree_skb(skb);
1622 } else {
1623 udp_skb_csum_unnecessary_set(skb);
1624 break;
1625 }
1626 }
1627 return skb;
1628}
1629
1630/**
1631 * first_packet_length - return length of first packet in receive queue
1632 * @sk: socket
1633 *
1634 * Drops all bad checksum frames, until a valid one is found.
1635 * Returns the length of found skb, or -1 if none is found.
1636 */
1637static int first_packet_length(struct sock *sk)
1638{
1639 struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue;
1640 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1641 struct sk_buff *skb;
1642 int total = 0;
1643 int res;
1644
1645 spin_lock_bh(&rcvq->lock);
1646 skb = __first_packet_length(sk, rcvq, &total);
1647 if (!skb && !skb_queue_empty_lockless(sk_queue)) {
1648 spin_lock(&sk_queue->lock);
1649 skb_queue_splice_tail_init(sk_queue, rcvq);
1650 spin_unlock(&sk_queue->lock);
1651
1652 skb = __first_packet_length(sk, rcvq, &total);
1653 }
1654 res = skb ? skb->len : -1;
1655 if (total)
1656 udp_rmem_release(sk, total, 1, false);
1657 spin_unlock_bh(&rcvq->lock);
1658 return res;
1659}
1660
1661/*
1662 * IOCTL requests applicable to the UDP protocol
1663 */
1664
1665int udp_ioctl(struct sock *sk, int cmd, int *karg)
1666{
1667 switch (cmd) {
1668 case SIOCOUTQ:
1669 {
1670 *karg = sk_wmem_alloc_get(sk);
1671 return 0;
1672 }
1673
1674 case SIOCINQ:
1675 {
1676 *karg = max_t(int, 0, first_packet_length(sk));
1677 return 0;
1678 }
1679
1680 default:
1681 return -ENOIOCTLCMD;
1682 }
1683
1684 return 0;
1685}
1686EXPORT_SYMBOL(udp_ioctl);
1687
1688struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
1689 int *off, int *err)
1690{
1691 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1692 struct sk_buff_head *queue;
1693 struct sk_buff *last;
1694 long timeo;
1695 int error;
1696
1697 queue = &udp_sk(sk)->reader_queue;
1698 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1699 do {
1700 struct sk_buff *skb;
1701
1702 error = sock_error(sk);
1703 if (error)
1704 break;
1705
1706 error = -EAGAIN;
1707 do {
1708 spin_lock_bh(&queue->lock);
1709 skb = __skb_try_recv_from_queue(sk, queue, flags, off,
1710 err, &last);
1711 if (skb) {
1712 if (!(flags & MSG_PEEK))
1713 udp_skb_destructor(sk, skb);
1714 spin_unlock_bh(&queue->lock);
1715 return skb;
1716 }
1717
1718 if (skb_queue_empty_lockless(sk_queue)) {
1719 spin_unlock_bh(&queue->lock);
1720 goto busy_check;
1721 }
1722
1723 /* refill the reader queue and walk it again
1724 * keep both queues locked to avoid re-acquiring
1725 * the sk_receive_queue lock if fwd memory scheduling
1726 * is needed.
1727 */
1728 spin_lock(&sk_queue->lock);
1729 skb_queue_splice_tail_init(sk_queue, queue);
1730
1731 skb = __skb_try_recv_from_queue(sk, queue, flags, off,
1732 err, &last);
1733 if (skb && !(flags & MSG_PEEK))
1734 udp_skb_dtor_locked(sk, skb);
1735 spin_unlock(&sk_queue->lock);
1736 spin_unlock_bh(&queue->lock);
1737 if (skb)
1738 return skb;
1739
1740busy_check:
1741 if (!sk_can_busy_loop(sk))
1742 break;
1743
1744 sk_busy_loop(sk, flags & MSG_DONTWAIT);
1745 } while (!skb_queue_empty_lockless(sk_queue));
1746
1747 /* sk_queue is empty, reader_queue may contain peeked packets */
1748 } while (timeo &&
1749 !__skb_wait_for_more_packets(sk, &sk->sk_receive_queue,
1750 &error, &timeo,
1751 (struct sk_buff *)sk_queue));
1752
1753 *err = error;
1754 return NULL;
1755}
1756EXPORT_SYMBOL(__skb_recv_udp);
1757
1758int udp_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
1759{
1760 struct sk_buff *skb;
1761 int err;
1762
1763try_again:
1764 skb = skb_recv_udp(sk, MSG_DONTWAIT, &err);
1765 if (!skb)
1766 return err;
1767
1768 if (udp_lib_checksum_complete(skb)) {
1769 int is_udplite = IS_UDPLITE(sk);
1770 struct net *net = sock_net(sk);
1771
1772 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, is_udplite);
1773 __UDP_INC_STATS(net, UDP_MIB_INERRORS, is_udplite);
1774 atomic_inc(&sk->sk_drops);
1775 kfree_skb(skb);
1776 goto try_again;
1777 }
1778
1779 WARN_ON_ONCE(!skb_set_owner_sk_safe(skb, sk));
1780 return recv_actor(sk, skb);
1781}
1782EXPORT_SYMBOL(udp_read_skb);
1783
1784/*
1785 * This should be easy, if there is something there we
1786 * return it, otherwise we block.
1787 */
1788
1789int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
1790 int *addr_len)
1791{
1792 struct inet_sock *inet = inet_sk(sk);
1793 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
1794 struct sk_buff *skb;
1795 unsigned int ulen, copied;
1796 int off, err, peeking = flags & MSG_PEEK;
1797 int is_udplite = IS_UDPLITE(sk);
1798 bool checksum_valid = false;
1799
1800 if (flags & MSG_ERRQUEUE)
1801 return ip_recv_error(sk, msg, len, addr_len);
1802
1803try_again:
1804 off = sk_peek_offset(sk, flags);
1805 skb = __skb_recv_udp(sk, flags, &off, &err);
1806 if (!skb)
1807 return err;
1808
1809 ulen = udp_skb_len(skb);
1810 copied = len;
1811 if (copied > ulen - off)
1812 copied = ulen - off;
1813 else if (copied < ulen)
1814 msg->msg_flags |= MSG_TRUNC;
1815
1816 /*
1817 * If checksum is needed at all, try to do it while copying the
1818 * data. If the data is truncated, or if we only want a partial
1819 * coverage checksum (UDP-Lite), do it before the copy.
1820 */
1821
1822 if (copied < ulen || peeking ||
1823 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
1824 checksum_valid = udp_skb_csum_unnecessary(skb) ||
1825 !__udp_lib_checksum_complete(skb);
1826 if (!checksum_valid)
1827 goto csum_copy_err;
1828 }
1829
1830 if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
1831 if (udp_skb_is_linear(skb))
1832 err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
1833 else
1834 err = skb_copy_datagram_msg(skb, off, msg, copied);
1835 } else {
1836 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
1837
1838 if (err == -EINVAL)
1839 goto csum_copy_err;
1840 }
1841
1842 if (unlikely(err)) {
1843 if (!peeking) {
1844 atomic_inc(&sk->sk_drops);
1845 UDP_INC_STATS(sock_net(sk),
1846 UDP_MIB_INERRORS, is_udplite);
1847 }
1848 kfree_skb(skb);
1849 return err;
1850 }
1851
1852 if (!peeking)
1853 UDP_INC_STATS(sock_net(sk),
1854 UDP_MIB_INDATAGRAMS, is_udplite);
1855
1856 sock_recv_cmsgs(msg, sk, skb);
1857
1858 /* Copy the address. */
1859 if (sin) {
1860 sin->sin_family = AF_INET;
1861 sin->sin_port = udp_hdr(skb)->source;
1862 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1863 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1864 *addr_len = sizeof(*sin);
1865
1866 BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk,
1867 (struct sockaddr *)sin,
1868 addr_len);
1869 }
1870
1871 if (udp_test_bit(GRO_ENABLED, sk))
1872 udp_cmsg_recv(msg, sk, skb);
1873
1874 if (inet_cmsg_flags(inet))
1875 ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off);
1876
1877 err = copied;
1878 if (flags & MSG_TRUNC)
1879 err = ulen;
1880
1881 skb_consume_udp(sk, skb, peeking ? -err : err);
1882 return err;
1883
1884csum_copy_err:
1885 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
1886 udp_skb_destructor)) {
1887 UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1888 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1889 }
1890 kfree_skb(skb);
1891
1892 /* starting over for a new packet, but check if we need to yield */
1893 cond_resched();
1894 msg->msg_flags &= ~MSG_TRUNC;
1895 goto try_again;
1896}
1897
1898int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
1899{
1900 /* This check is replicated from __ip4_datagram_connect() and
1901 * intended to prevent BPF program called below from accessing bytes
1902 * that are out of the bound specified by user in addr_len.
1903 */
1904 if (addr_len < sizeof(struct sockaddr_in))
1905 return -EINVAL;
1906
1907 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr, &addr_len);
1908}
1909EXPORT_SYMBOL(udp_pre_connect);
1910
1911int __udp_disconnect(struct sock *sk, int flags)
1912{
1913 struct inet_sock *inet = inet_sk(sk);
1914 /*
1915 * 1003.1g - break association.
1916 */
1917
1918 sk->sk_state = TCP_CLOSE;
1919 inet->inet_daddr = 0;
1920 inet->inet_dport = 0;
1921 sock_rps_reset_rxhash(sk);
1922 sk->sk_bound_dev_if = 0;
1923 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) {
1924 inet_reset_saddr(sk);
1925 if (sk->sk_prot->rehash &&
1926 (sk->sk_userlocks & SOCK_BINDPORT_LOCK))
1927 sk->sk_prot->rehash(sk);
1928 }
1929
1930 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1931 sk->sk_prot->unhash(sk);
1932 inet->inet_sport = 0;
1933 }
1934 sk_dst_reset(sk);
1935 return 0;
1936}
1937EXPORT_SYMBOL(__udp_disconnect);
1938
1939int udp_disconnect(struct sock *sk, int flags)
1940{
1941 lock_sock(sk);
1942 __udp_disconnect(sk, flags);
1943 release_sock(sk);
1944 return 0;
1945}
1946EXPORT_SYMBOL(udp_disconnect);
1947
1948void udp_lib_unhash(struct sock *sk)
1949{
1950 if (sk_hashed(sk)) {
1951 struct udp_table *udptable = udp_get_table_prot(sk);
1952 struct udp_hslot *hslot, *hslot2;
1953
1954 hslot = udp_hashslot(udptable, sock_net(sk),
1955 udp_sk(sk)->udp_port_hash);
1956 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1957
1958 spin_lock_bh(&hslot->lock);
1959 if (rcu_access_pointer(sk->sk_reuseport_cb))
1960 reuseport_detach_sock(sk);
1961 if (sk_del_node_init_rcu(sk)) {
1962 hslot->count--;
1963 inet_sk(sk)->inet_num = 0;
1964 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1965
1966 spin_lock(&hslot2->lock);
1967 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1968 hslot2->count--;
1969 spin_unlock(&hslot2->lock);
1970 }
1971 spin_unlock_bh(&hslot->lock);
1972 }
1973}
1974EXPORT_SYMBOL(udp_lib_unhash);
1975
1976/*
1977 * inet_rcv_saddr was changed, we must rehash secondary hash
1978 */
1979void udp_lib_rehash(struct sock *sk, u16 newhash)
1980{
1981 if (sk_hashed(sk)) {
1982 struct udp_table *udptable = udp_get_table_prot(sk);
1983 struct udp_hslot *hslot, *hslot2, *nhslot2;
1984
1985 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1986 nhslot2 = udp_hashslot2(udptable, newhash);
1987 udp_sk(sk)->udp_portaddr_hash = newhash;
1988
1989 if (hslot2 != nhslot2 ||
1990 rcu_access_pointer(sk->sk_reuseport_cb)) {
1991 hslot = udp_hashslot(udptable, sock_net(sk),
1992 udp_sk(sk)->udp_port_hash);
1993 /* we must lock primary chain too */
1994 spin_lock_bh(&hslot->lock);
1995 if (rcu_access_pointer(sk->sk_reuseport_cb))
1996 reuseport_detach_sock(sk);
1997
1998 if (hslot2 != nhslot2) {
1999 spin_lock(&hslot2->lock);
2000 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
2001 hslot2->count--;
2002 spin_unlock(&hslot2->lock);
2003
2004 spin_lock(&nhslot2->lock);
2005 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
2006 &nhslot2->head);
2007 nhslot2->count++;
2008 spin_unlock(&nhslot2->lock);
2009 }
2010
2011 spin_unlock_bh(&hslot->lock);
2012 }
2013 }
2014}
2015EXPORT_SYMBOL(udp_lib_rehash);
2016
2017void udp_v4_rehash(struct sock *sk)
2018{
2019 u16 new_hash = ipv4_portaddr_hash(sock_net(sk),
2020 inet_sk(sk)->inet_rcv_saddr,
2021 inet_sk(sk)->inet_num);
2022 udp_lib_rehash(sk, new_hash);
2023}
2024
2025static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2026{
2027 int rc;
2028
2029 if (inet_sk(sk)->inet_daddr) {
2030 sock_rps_save_rxhash(sk, skb);
2031 sk_mark_napi_id(sk, skb);
2032 sk_incoming_cpu_update(sk);
2033 } else {
2034 sk_mark_napi_id_once(sk, skb);
2035 }
2036
2037 rc = __udp_enqueue_schedule_skb(sk, skb);
2038 if (rc < 0) {
2039 int is_udplite = IS_UDPLITE(sk);
2040 int drop_reason;
2041
2042 /* Note that an ENOMEM error is charged twice */
2043 if (rc == -ENOMEM) {
2044 UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS,
2045 is_udplite);
2046 drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
2047 } else {
2048 UDP_INC_STATS(sock_net(sk), UDP_MIB_MEMERRORS,
2049 is_udplite);
2050 drop_reason = SKB_DROP_REASON_PROTO_MEM;
2051 }
2052 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
2053 kfree_skb_reason(skb, drop_reason);
2054 trace_udp_fail_queue_rcv_skb(rc, sk);
2055 return -1;
2056 }
2057
2058 return 0;
2059}
2060
2061/* returns:
2062 * -1: error
2063 * 0: success
2064 * >0: "udp encap" protocol resubmission
2065 *
2066 * Note that in the success and error cases, the skb is assumed to
2067 * have either been requeued or freed.
2068 */
2069static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
2070{
2071 int drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
2072 struct udp_sock *up = udp_sk(sk);
2073 int is_udplite = IS_UDPLITE(sk);
2074
2075 /*
2076 * Charge it to the socket, dropping if the queue is full.
2077 */
2078 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {
2079 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
2080 goto drop;
2081 }
2082 nf_reset_ct(skb);
2083
2084 if (static_branch_unlikely(&udp_encap_needed_key) &&
2085 READ_ONCE(up->encap_type)) {
2086 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
2087
2088 /*
2089 * This is an encapsulation socket so pass the skb to
2090 * the socket's udp_encap_rcv() hook. Otherwise, just
2091 * fall through and pass this up the UDP socket.
2092 * up->encap_rcv() returns the following value:
2093 * =0 if skb was successfully passed to the encap
2094 * handler or was discarded by it.
2095 * >0 if skb should be passed on to UDP.
2096 * <0 if skb should be resubmitted as proto -N
2097 */
2098
2099 /* if we're overly short, let UDP handle it */
2100 encap_rcv = READ_ONCE(up->encap_rcv);
2101 if (encap_rcv) {
2102 int ret;
2103
2104 /* Verify checksum before giving to encap */
2105 if (udp_lib_checksum_complete(skb))
2106 goto csum_error;
2107
2108 ret = encap_rcv(sk, skb);
2109 if (ret <= 0) {
2110 __UDP_INC_STATS(sock_net(sk),
2111 UDP_MIB_INDATAGRAMS,
2112 is_udplite);
2113 return -ret;
2114 }
2115 }
2116
2117 /* FALLTHROUGH -- it's a UDP Packet */
2118 }
2119
2120 /*
2121 * UDP-Lite specific tests, ignored on UDP sockets
2122 */
2123 if (udp_test_bit(UDPLITE_RECV_CC, sk) && UDP_SKB_CB(skb)->partial_cov) {
2124 u16 pcrlen = READ_ONCE(up->pcrlen);
2125
2126 /*
2127 * MIB statistics other than incrementing the error count are
2128 * disabled for the following two types of errors: these depend
2129 * on the application settings, not on the functioning of the
2130 * protocol stack as such.
2131 *
2132 * RFC 3828 here recommends (sec 3.3): "There should also be a
2133 * way ... to ... at least let the receiving application block
2134 * delivery of packets with coverage values less than a value
2135 * provided by the application."
2136 */
2137 if (pcrlen == 0) { /* full coverage was set */
2138 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n",
2139 UDP_SKB_CB(skb)->cscov, skb->len);
2140 goto drop;
2141 }
2142 /* The next case involves violating the min. coverage requested
2143 * by the receiver. This is subtle: if receiver wants x and x is
2144 * greater than the buffersize/MTU then receiver will complain
2145 * that it wants x while sender emits packets of smaller size y.
2146 * Therefore the above ...()->partial_cov statement is essential.
2147 */
2148 if (UDP_SKB_CB(skb)->cscov < pcrlen) {
2149 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n",
2150 UDP_SKB_CB(skb)->cscov, pcrlen);
2151 goto drop;
2152 }
2153 }
2154
2155 prefetch(&sk->sk_rmem_alloc);
2156 if (rcu_access_pointer(sk->sk_filter) &&
2157 udp_lib_checksum_complete(skb))
2158 goto csum_error;
2159
2160 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) {
2161 drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
2162 goto drop;
2163 }
2164
2165 udp_csum_pull_header(skb);
2166
2167 ipv4_pktinfo_prepare(sk, skb, true);
2168 return __udp_queue_rcv_skb(sk, skb);
2169
2170csum_error:
2171 drop_reason = SKB_DROP_REASON_UDP_CSUM;
2172 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
2173drop:
2174 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
2175 atomic_inc(&sk->sk_drops);
2176 kfree_skb_reason(skb, drop_reason);
2177 return -1;
2178}
2179
2180static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2181{
2182 struct sk_buff *next, *segs;
2183 int ret;
2184
2185 if (likely(!udp_unexpected_gso(sk, skb)))
2186 return udp_queue_rcv_one_skb(sk, skb);
2187
2188 BUILD_BUG_ON(sizeof(struct udp_skb_cb) > SKB_GSO_CB_OFFSET);
2189 __skb_push(skb, -skb_mac_offset(skb));
2190 segs = udp_rcv_segment(sk, skb, true);
2191 skb_list_walk_safe(segs, skb, next) {
2192 __skb_pull(skb, skb_transport_offset(skb));
2193
2194 udp_post_segment_fix_csum(skb);
2195 ret = udp_queue_rcv_one_skb(sk, skb);
2196 if (ret > 0)
2197 ip_protocol_deliver_rcu(dev_net(skb->dev), skb, ret);
2198 }
2199 return 0;
2200}
2201
2202/* For TCP sockets, sk_rx_dst is protected by socket lock
2203 * For UDP, we use xchg() to guard against concurrent changes.
2204 */
2205bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
2206{
2207 struct dst_entry *old;
2208
2209 if (dst_hold_safe(dst)) {
2210 old = xchg((__force struct dst_entry **)&sk->sk_rx_dst, dst);
2211 dst_release(old);
2212 return old != dst;
2213 }
2214 return false;
2215}
2216EXPORT_SYMBOL(udp_sk_rx_dst_set);
2217
2218/*
2219 * Multicasts and broadcasts go to each listener.
2220 *
2221 * Note: called only from the BH handler context.
2222 */
2223static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
2224 struct udphdr *uh,
2225 __be32 saddr, __be32 daddr,
2226 struct udp_table *udptable,
2227 int proto)
2228{
2229 struct sock *sk, *first = NULL;
2230 unsigned short hnum = ntohs(uh->dest);
2231 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
2232 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
2233 unsigned int offset = offsetof(typeof(*sk), sk_node);
2234 int dif = skb->dev->ifindex;
2235 int sdif = inet_sdif(skb);
2236 struct hlist_node *node;
2237 struct sk_buff *nskb;
2238
2239 if (use_hash2) {
2240 hash2_any = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum) &
2241 udptable->mask;
2242 hash2 = ipv4_portaddr_hash(net, daddr, hnum) & udptable->mask;
2243start_lookup:
2244 hslot = &udptable->hash2[hash2];
2245 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
2246 }
2247
2248 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
2249 if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr,
2250 uh->source, saddr, dif, sdif, hnum))
2251 continue;
2252
2253 if (!first) {
2254 first = sk;
2255 continue;
2256 }
2257 nskb = skb_clone(skb, GFP_ATOMIC);
2258
2259 if (unlikely(!nskb)) {
2260 atomic_inc(&sk->sk_drops);
2261 __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
2262 IS_UDPLITE(sk));
2263 __UDP_INC_STATS(net, UDP_MIB_INERRORS,
2264 IS_UDPLITE(sk));
2265 continue;
2266 }
2267 if (udp_queue_rcv_skb(sk, nskb) > 0)
2268 consume_skb(nskb);
2269 }
2270
2271 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
2272 if (use_hash2 && hash2 != hash2_any) {
2273 hash2 = hash2_any;
2274 goto start_lookup;
2275 }
2276
2277 if (first) {
2278 if (udp_queue_rcv_skb(first, skb) > 0)
2279 consume_skb(skb);
2280 } else {
2281 kfree_skb(skb);
2282 __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
2283 proto == IPPROTO_UDPLITE);
2284 }
2285 return 0;
2286}
2287
2288/* Initialize UDP checksum. If exited with zero value (success),
2289 * CHECKSUM_UNNECESSARY means, that no more checks are required.
2290 * Otherwise, csum completion requires checksumming packet body,
2291 * including udp header and folding it to skb->csum.
2292 */
2293static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
2294 int proto)
2295{
2296 int err;
2297
2298 UDP_SKB_CB(skb)->partial_cov = 0;
2299 UDP_SKB_CB(skb)->cscov = skb->len;
2300
2301 if (proto == IPPROTO_UDPLITE) {
2302 err = udplite_checksum_init(skb, uh);
2303 if (err)
2304 return err;
2305
2306 if (UDP_SKB_CB(skb)->partial_cov) {
2307 skb->csum = inet_compute_pseudo(skb, proto);
2308 return 0;
2309 }
2310 }
2311
2312 /* Note, we are only interested in != 0 or == 0, thus the
2313 * force to int.
2314 */
2315 err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
2316 inet_compute_pseudo);
2317 if (err)
2318 return err;
2319
2320 if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) {
2321 /* If SW calculated the value, we know it's bad */
2322 if (skb->csum_complete_sw)
2323 return 1;
2324
2325 /* HW says the value is bad. Let's validate that.
2326 * skb->csum is no longer the full packet checksum,
2327 * so don't treat it as such.
2328 */
2329 skb_checksum_complete_unset(skb);
2330 }
2331
2332 return 0;
2333}
2334
2335/* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
2336 * return code conversion for ip layer consumption
2337 */
2338static int udp_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
2339 struct udphdr *uh)
2340{
2341 int ret;
2342
2343 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
2344 skb_checksum_try_convert(skb, IPPROTO_UDP, inet_compute_pseudo);
2345
2346 ret = udp_queue_rcv_skb(sk, skb);
2347
2348 /* a return value > 0 means to resubmit the input, but
2349 * it wants the return to be -protocol, or 0
2350 */
2351 if (ret > 0)
2352 return -ret;
2353 return 0;
2354}
2355
2356/*
2357 * All we need to do is get the socket, and then do a checksum.
2358 */
2359
2360int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
2361 int proto)
2362{
2363 struct sock *sk;
2364 struct udphdr *uh;
2365 unsigned short ulen;
2366 struct rtable *rt = skb_rtable(skb);
2367 __be32 saddr, daddr;
2368 struct net *net = dev_net(skb->dev);
2369 bool refcounted;
2370 int drop_reason;
2371
2372 drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
2373
2374 /*
2375 * Validate the packet.
2376 */
2377 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
2378 goto drop; /* No space for header. */
2379
2380 uh = udp_hdr(skb);
2381 ulen = ntohs(uh->len);
2382 saddr = ip_hdr(skb)->saddr;
2383 daddr = ip_hdr(skb)->daddr;
2384
2385 if (ulen > skb->len)
2386 goto short_packet;
2387
2388 if (proto == IPPROTO_UDP) {
2389 /* UDP validates ulen. */
2390 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
2391 goto short_packet;
2392 uh = udp_hdr(skb);
2393 }
2394
2395 if (udp4_csum_init(skb, uh, proto))
2396 goto csum_error;
2397
2398 sk = inet_steal_sock(net, skb, sizeof(struct udphdr), saddr, uh->source, daddr, uh->dest,
2399 &refcounted, udp_ehashfn);
2400 if (IS_ERR(sk))
2401 goto no_sk;
2402
2403 if (sk) {
2404 struct dst_entry *dst = skb_dst(skb);
2405 int ret;
2406
2407 if (unlikely(rcu_dereference(sk->sk_rx_dst) != dst))
2408 udp_sk_rx_dst_set(sk, dst);
2409
2410 ret = udp_unicast_rcv_skb(sk, skb, uh);
2411 if (refcounted)
2412 sock_put(sk);
2413 return ret;
2414 }
2415
2416 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
2417 return __udp4_lib_mcast_deliver(net, skb, uh,
2418 saddr, daddr, udptable, proto);
2419
2420 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
2421 if (sk)
2422 return udp_unicast_rcv_skb(sk, skb, uh);
2423no_sk:
2424 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
2425 goto drop;
2426 nf_reset_ct(skb);
2427
2428 /* No socket. Drop packet silently, if checksum is wrong */
2429 if (udp_lib_checksum_complete(skb))
2430 goto csum_error;
2431
2432 drop_reason = SKB_DROP_REASON_NO_SOCKET;
2433 __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
2434 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
2435
2436 /*
2437 * Hmm. We got an UDP packet to a port to which we
2438 * don't wanna listen. Ignore it.
2439 */
2440 kfree_skb_reason(skb, drop_reason);
2441 return 0;
2442
2443short_packet:
2444 drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL;
2445 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
2446 proto == IPPROTO_UDPLITE ? "Lite" : "",
2447 &saddr, ntohs(uh->source),
2448 ulen, skb->len,
2449 &daddr, ntohs(uh->dest));
2450 goto drop;
2451
2452csum_error:
2453 /*
2454 * RFC1122: OK. Discards the bad packet silently (as far as
2455 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
2456 */
2457 drop_reason = SKB_DROP_REASON_UDP_CSUM;
2458 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
2459 proto == IPPROTO_UDPLITE ? "Lite" : "",
2460 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
2461 ulen);
2462 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
2463drop:
2464 __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
2465 kfree_skb_reason(skb, drop_reason);
2466 return 0;
2467}
2468
2469/* We can only early demux multicast if there is a single matching socket.
2470 * If more than one socket found returns NULL
2471 */
2472static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
2473 __be16 loc_port, __be32 loc_addr,
2474 __be16 rmt_port, __be32 rmt_addr,
2475 int dif, int sdif)
2476{
2477 struct udp_table *udptable = net->ipv4.udp_table;
2478 unsigned short hnum = ntohs(loc_port);
2479 struct sock *sk, *result;
2480 struct udp_hslot *hslot;
2481 unsigned int slot;
2482
2483 slot = udp_hashfn(net, hnum, udptable->mask);
2484 hslot = &udptable->hash[slot];
2485
2486 /* Do not bother scanning a too big list */
2487 if (hslot->count > 10)
2488 return NULL;
2489
2490 result = NULL;
2491 sk_for_each_rcu(sk, &hslot->head) {
2492 if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr,
2493 rmt_port, rmt_addr, dif, sdif, hnum)) {
2494 if (result)
2495 return NULL;
2496 result = sk;
2497 }
2498 }
2499
2500 return result;
2501}
2502
2503/* For unicast we should only early demux connected sockets or we can
2504 * break forwarding setups. The chains here can be long so only check
2505 * if the first socket is an exact match and if not move on.
2506 */
2507static struct sock *__udp4_lib_demux_lookup(struct net *net,
2508 __be16 loc_port, __be32 loc_addr,
2509 __be16 rmt_port, __be32 rmt_addr,
2510 int dif, int sdif)
2511{
2512 struct udp_table *udptable = net->ipv4.udp_table;
2513 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
2514 unsigned short hnum = ntohs(loc_port);
2515 unsigned int hash2, slot2;
2516 struct udp_hslot *hslot2;
2517 __portpair ports;
2518 struct sock *sk;
2519
2520 hash2 = ipv4_portaddr_hash(net, loc_addr, hnum);
2521 slot2 = hash2 & udptable->mask;
2522 hslot2 = &udptable->hash2[slot2];
2523 ports = INET_COMBINED_PORTS(rmt_port, hnum);
2524
2525 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
2526 if (inet_match(net, sk, acookie, ports, dif, sdif))
2527 return sk;
2528 /* Only check first socket in chain */
2529 break;
2530 }
2531 return NULL;
2532}
2533
2534int udp_v4_early_demux(struct sk_buff *skb)
2535{
2536 struct net *net = dev_net(skb->dev);
2537 struct in_device *in_dev = NULL;
2538 const struct iphdr *iph;
2539 const struct udphdr *uh;
2540 struct sock *sk = NULL;
2541 struct dst_entry *dst;
2542 int dif = skb->dev->ifindex;
2543 int sdif = inet_sdif(skb);
2544 int ours;
2545
2546 /* validate the packet */
2547 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
2548 return 0;
2549
2550 iph = ip_hdr(skb);
2551 uh = udp_hdr(skb);
2552
2553 if (skb->pkt_type == PACKET_MULTICAST) {
2554 in_dev = __in_dev_get_rcu(skb->dev);
2555
2556 if (!in_dev)
2557 return 0;
2558
2559 ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
2560 iph->protocol);
2561 if (!ours)
2562 return 0;
2563
2564 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
2565 uh->source, iph->saddr,
2566 dif, sdif);
2567 } else if (skb->pkt_type == PACKET_HOST) {
2568 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
2569 uh->source, iph->saddr, dif, sdif);
2570 }
2571
2572 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
2573 return 0;
2574
2575 skb->sk = sk;
2576 skb->destructor = sock_efree;
2577 dst = rcu_dereference(sk->sk_rx_dst);
2578
2579 if (dst)
2580 dst = dst_check(dst, 0);
2581 if (dst) {
2582 u32 itag = 0;
2583
2584 /* set noref for now.
2585 * any place which wants to hold dst has to call
2586 * dst_hold_safe()
2587 */
2588 skb_dst_set_noref(skb, dst);
2589
2590 /* for unconnected multicast sockets we need to validate
2591 * the source on each packet
2592 */
2593 if (!inet_sk(sk)->inet_daddr && in_dev)
2594 return ip_mc_validate_source(skb, iph->daddr,
2595 iph->saddr,
2596 iph->tos & IPTOS_RT_MASK,
2597 skb->dev, in_dev, &itag);
2598 }
2599 return 0;
2600}
2601
2602int udp_rcv(struct sk_buff *skb)
2603{
2604 return __udp4_lib_rcv(skb, dev_net(skb->dev)->ipv4.udp_table, IPPROTO_UDP);
2605}
2606
2607void udp_destroy_sock(struct sock *sk)
2608{
2609 struct udp_sock *up = udp_sk(sk);
2610 bool slow = lock_sock_fast(sk);
2611
2612 /* protects from races with udp_abort() */
2613 sock_set_flag(sk, SOCK_DEAD);
2614 udp_flush_pending_frames(sk);
2615 unlock_sock_fast(sk, slow);
2616 if (static_branch_unlikely(&udp_encap_needed_key)) {
2617 if (up->encap_type) {
2618 void (*encap_destroy)(struct sock *sk);
2619 encap_destroy = READ_ONCE(up->encap_destroy);
2620 if (encap_destroy)
2621 encap_destroy(sk);
2622 }
2623 if (udp_test_bit(ENCAP_ENABLED, sk))
2624 static_branch_dec(&udp_encap_needed_key);
2625 }
2626}
2627
2628static void set_xfrm_gro_udp_encap_rcv(__u16 encap_type, unsigned short family,
2629 struct sock *sk)
2630{
2631#ifdef CONFIG_XFRM
2632 if (udp_test_bit(GRO_ENABLED, sk) && encap_type == UDP_ENCAP_ESPINUDP) {
2633 if (family == AF_INET)
2634 WRITE_ONCE(udp_sk(sk)->gro_receive, xfrm4_gro_udp_encap_rcv);
2635 else if (IS_ENABLED(CONFIG_IPV6) && family == AF_INET6)
2636 WRITE_ONCE(udp_sk(sk)->gro_receive, ipv6_stub->xfrm6_gro_udp_encap_rcv);
2637 }
2638#endif
2639}
2640
2641/*
2642 * Socket option code for UDP
2643 */
2644int udp_lib_setsockopt(struct sock *sk, int level, int optname,
2645 sockptr_t optval, unsigned int optlen,
2646 int (*push_pending_frames)(struct sock *))
2647{
2648 struct udp_sock *up = udp_sk(sk);
2649 int val, valbool;
2650 int err = 0;
2651 int is_udplite = IS_UDPLITE(sk);
2652
2653 if (level == SOL_SOCKET) {
2654 err = sk_setsockopt(sk, level, optname, optval, optlen);
2655
2656 if (optname == SO_RCVBUF || optname == SO_RCVBUFFORCE) {
2657 sockopt_lock_sock(sk);
2658 /* paired with READ_ONCE in udp_rmem_release() */
2659 WRITE_ONCE(up->forward_threshold, sk->sk_rcvbuf >> 2);
2660 sockopt_release_sock(sk);
2661 }
2662 return err;
2663 }
2664
2665 if (optlen < sizeof(int))
2666 return -EINVAL;
2667
2668 if (copy_from_sockptr(&val, optval, sizeof(val)))
2669 return -EFAULT;
2670
2671 valbool = val ? 1 : 0;
2672
2673 switch (optname) {
2674 case UDP_CORK:
2675 if (val != 0) {
2676 udp_set_bit(CORK, sk);
2677 } else {
2678 udp_clear_bit(CORK, sk);
2679 lock_sock(sk);
2680 push_pending_frames(sk);
2681 release_sock(sk);
2682 }
2683 break;
2684
2685 case UDP_ENCAP:
2686 switch (val) {
2687 case 0:
2688#ifdef CONFIG_XFRM
2689 case UDP_ENCAP_ESPINUDP:
2690 set_xfrm_gro_udp_encap_rcv(val, sk->sk_family, sk);
2691 fallthrough;
2692 case UDP_ENCAP_ESPINUDP_NON_IKE:
2693#if IS_ENABLED(CONFIG_IPV6)
2694 if (sk->sk_family == AF_INET6)
2695 WRITE_ONCE(up->encap_rcv,
2696 ipv6_stub->xfrm6_udp_encap_rcv);
2697 else
2698#endif
2699 WRITE_ONCE(up->encap_rcv,
2700 xfrm4_udp_encap_rcv);
2701#endif
2702 fallthrough;
2703 case UDP_ENCAP_L2TPINUDP:
2704 WRITE_ONCE(up->encap_type, val);
2705 udp_tunnel_encap_enable(sk);
2706 break;
2707 default:
2708 err = -ENOPROTOOPT;
2709 break;
2710 }
2711 break;
2712
2713 case UDP_NO_CHECK6_TX:
2714 udp_set_no_check6_tx(sk, valbool);
2715 break;
2716
2717 case UDP_NO_CHECK6_RX:
2718 udp_set_no_check6_rx(sk, valbool);
2719 break;
2720
2721 case UDP_SEGMENT:
2722 if (val < 0 || val > USHRT_MAX)
2723 return -EINVAL;
2724 WRITE_ONCE(up->gso_size, val);
2725 break;
2726
2727 case UDP_GRO:
2728
2729 /* when enabling GRO, accept the related GSO packet type */
2730 if (valbool)
2731 udp_tunnel_encap_enable(sk);
2732 udp_assign_bit(GRO_ENABLED, sk, valbool);
2733 udp_assign_bit(ACCEPT_L4, sk, valbool);
2734 set_xfrm_gro_udp_encap_rcv(up->encap_type, sk->sk_family, sk);
2735 break;
2736
2737 /*
2738 * UDP-Lite's partial checksum coverage (RFC 3828).
2739 */
2740 /* The sender sets actual checksum coverage length via this option.
2741 * The case coverage > packet length is handled by send module. */
2742 case UDPLITE_SEND_CSCOV:
2743 if (!is_udplite) /* Disable the option on UDP sockets */
2744 return -ENOPROTOOPT;
2745 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
2746 val = 8;
2747 else if (val > USHRT_MAX)
2748 val = USHRT_MAX;
2749 WRITE_ONCE(up->pcslen, val);
2750 udp_set_bit(UDPLITE_SEND_CC, sk);
2751 break;
2752
2753 /* The receiver specifies a minimum checksum coverage value. To make
2754 * sense, this should be set to at least 8 (as done below). If zero is
2755 * used, this again means full checksum coverage. */
2756 case UDPLITE_RECV_CSCOV:
2757 if (!is_udplite) /* Disable the option on UDP sockets */
2758 return -ENOPROTOOPT;
2759 if (val != 0 && val < 8) /* Avoid silly minimal values. */
2760 val = 8;
2761 else if (val > USHRT_MAX)
2762 val = USHRT_MAX;
2763 WRITE_ONCE(up->pcrlen, val);
2764 udp_set_bit(UDPLITE_RECV_CC, sk);
2765 break;
2766
2767 default:
2768 err = -ENOPROTOOPT;
2769 break;
2770 }
2771
2772 return err;
2773}
2774EXPORT_SYMBOL(udp_lib_setsockopt);
2775
2776int udp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
2777 unsigned int optlen)
2778{
2779 if (level == SOL_UDP || level == SOL_UDPLITE || level == SOL_SOCKET)
2780 return udp_lib_setsockopt(sk, level, optname,
2781 optval, optlen,
2782 udp_push_pending_frames);
2783 return ip_setsockopt(sk, level, optname, optval, optlen);
2784}
2785
2786int udp_lib_getsockopt(struct sock *sk, int level, int optname,
2787 char __user *optval, int __user *optlen)
2788{
2789 struct udp_sock *up = udp_sk(sk);
2790 int val, len;
2791
2792 if (get_user(len, optlen))
2793 return -EFAULT;
2794
2795 len = min_t(unsigned int, len, sizeof(int));
2796
2797 if (len < 0)
2798 return -EINVAL;
2799
2800 switch (optname) {
2801 case UDP_CORK:
2802 val = udp_test_bit(CORK, sk);
2803 break;
2804
2805 case UDP_ENCAP:
2806 val = READ_ONCE(up->encap_type);
2807 break;
2808
2809 case UDP_NO_CHECK6_TX:
2810 val = udp_get_no_check6_tx(sk);
2811 break;
2812
2813 case UDP_NO_CHECK6_RX:
2814 val = udp_get_no_check6_rx(sk);
2815 break;
2816
2817 case UDP_SEGMENT:
2818 val = READ_ONCE(up->gso_size);
2819 break;
2820
2821 case UDP_GRO:
2822 val = udp_test_bit(GRO_ENABLED, sk);
2823 break;
2824
2825 /* The following two cannot be changed on UDP sockets, the return is
2826 * always 0 (which corresponds to the full checksum coverage of UDP). */
2827 case UDPLITE_SEND_CSCOV:
2828 val = READ_ONCE(up->pcslen);
2829 break;
2830
2831 case UDPLITE_RECV_CSCOV:
2832 val = READ_ONCE(up->pcrlen);
2833 break;
2834
2835 default:
2836 return -ENOPROTOOPT;
2837 }
2838
2839 if (put_user(len, optlen))
2840 return -EFAULT;
2841 if (copy_to_user(optval, &val, len))
2842 return -EFAULT;
2843 return 0;
2844}
2845EXPORT_SYMBOL(udp_lib_getsockopt);
2846
2847int udp_getsockopt(struct sock *sk, int level, int optname,
2848 char __user *optval, int __user *optlen)
2849{
2850 if (level == SOL_UDP || level == SOL_UDPLITE)
2851 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2852 return ip_getsockopt(sk, level, optname, optval, optlen);
2853}
2854
2855/**
2856 * udp_poll - wait for a UDP event.
2857 * @file: - file struct
2858 * @sock: - socket
2859 * @wait: - poll table
2860 *
2861 * This is same as datagram poll, except for the special case of
2862 * blocking sockets. If application is using a blocking fd
2863 * and a packet with checksum error is in the queue;
2864 * then it could get return from select indicating data available
2865 * but then block when reading it. Add special case code
2866 * to work around these arguably broken applications.
2867 */
2868__poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait)
2869{
2870 __poll_t mask = datagram_poll(file, sock, wait);
2871 struct sock *sk = sock->sk;
2872
2873 if (!skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
2874 mask |= EPOLLIN | EPOLLRDNORM;
2875
2876 /* Check for false positives due to checksum errors */
2877 if ((mask & EPOLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
2878 !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1)
2879 mask &= ~(EPOLLIN | EPOLLRDNORM);
2880
2881 /* psock ingress_msg queue should not contain any bad checksum frames */
2882 if (sk_is_readable(sk))
2883 mask |= EPOLLIN | EPOLLRDNORM;
2884 return mask;
2885
2886}
2887EXPORT_SYMBOL(udp_poll);
2888
2889int udp_abort(struct sock *sk, int err)
2890{
2891 if (!has_current_bpf_ctx())
2892 lock_sock(sk);
2893
2894 /* udp{v6}_destroy_sock() sets it under the sk lock, avoid racing
2895 * with close()
2896 */
2897 if (sock_flag(sk, SOCK_DEAD))
2898 goto out;
2899
2900 sk->sk_err = err;
2901 sk_error_report(sk);
2902 __udp_disconnect(sk, 0);
2903
2904out:
2905 if (!has_current_bpf_ctx())
2906 release_sock(sk);
2907
2908 return 0;
2909}
2910EXPORT_SYMBOL_GPL(udp_abort);
2911
2912struct proto udp_prot = {
2913 .name = "UDP",
2914 .owner = THIS_MODULE,
2915 .close = udp_lib_close,
2916 .pre_connect = udp_pre_connect,
2917 .connect = ip4_datagram_connect,
2918 .disconnect = udp_disconnect,
2919 .ioctl = udp_ioctl,
2920 .init = udp_init_sock,
2921 .destroy = udp_destroy_sock,
2922 .setsockopt = udp_setsockopt,
2923 .getsockopt = udp_getsockopt,
2924 .sendmsg = udp_sendmsg,
2925 .recvmsg = udp_recvmsg,
2926 .splice_eof = udp_splice_eof,
2927 .release_cb = ip4_datagram_release_cb,
2928 .hash = udp_lib_hash,
2929 .unhash = udp_lib_unhash,
2930 .rehash = udp_v4_rehash,
2931 .get_port = udp_v4_get_port,
2932 .put_port = udp_lib_unhash,
2933#ifdef CONFIG_BPF_SYSCALL
2934 .psock_update_sk_prot = udp_bpf_update_proto,
2935#endif
2936 .memory_allocated = &udp_memory_allocated,
2937 .per_cpu_fw_alloc = &udp_memory_per_cpu_fw_alloc,
2938
2939 .sysctl_mem = sysctl_udp_mem,
2940 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
2941 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
2942 .obj_size = sizeof(struct udp_sock),
2943 .h.udp_table = NULL,
2944 .diag_destroy = udp_abort,
2945};
2946EXPORT_SYMBOL(udp_prot);
2947
2948/* ------------------------------------------------------------------------ */
2949#ifdef CONFIG_PROC_FS
2950
2951static unsigned short seq_file_family(const struct seq_file *seq);
2952static bool seq_sk_match(struct seq_file *seq, const struct sock *sk)
2953{
2954 unsigned short family = seq_file_family(seq);
2955
2956 /* AF_UNSPEC is used as a match all */
2957 return ((family == AF_UNSPEC || family == sk->sk_family) &&
2958 net_eq(sock_net(sk), seq_file_net(seq)));
2959}
2960
2961#ifdef CONFIG_BPF_SYSCALL
2962static const struct seq_operations bpf_iter_udp_seq_ops;
2963#endif
2964static struct udp_table *udp_get_table_seq(struct seq_file *seq,
2965 struct net *net)
2966{
2967 const struct udp_seq_afinfo *afinfo;
2968
2969#ifdef CONFIG_BPF_SYSCALL
2970 if (seq->op == &bpf_iter_udp_seq_ops)
2971 return net->ipv4.udp_table;
2972#endif
2973
2974 afinfo = pde_data(file_inode(seq->file));
2975 return afinfo->udp_table ? : net->ipv4.udp_table;
2976}
2977
2978static struct sock *udp_get_first(struct seq_file *seq, int start)
2979{
2980 struct udp_iter_state *state = seq->private;
2981 struct net *net = seq_file_net(seq);
2982 struct udp_table *udptable;
2983 struct sock *sk;
2984
2985 udptable = udp_get_table_seq(seq, net);
2986
2987 for (state->bucket = start; state->bucket <= udptable->mask;
2988 ++state->bucket) {
2989 struct udp_hslot *hslot = &udptable->hash[state->bucket];
2990
2991 if (hlist_empty(&hslot->head))
2992 continue;
2993
2994 spin_lock_bh(&hslot->lock);
2995 sk_for_each(sk, &hslot->head) {
2996 if (seq_sk_match(seq, sk))
2997 goto found;
2998 }
2999 spin_unlock_bh(&hslot->lock);
3000 }
3001 sk = NULL;
3002found:
3003 return sk;
3004}
3005
3006static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
3007{
3008 struct udp_iter_state *state = seq->private;
3009 struct net *net = seq_file_net(seq);
3010 struct udp_table *udptable;
3011
3012 do {
3013 sk = sk_next(sk);
3014 } while (sk && !seq_sk_match(seq, sk));
3015
3016 if (!sk) {
3017 udptable = udp_get_table_seq(seq, net);
3018
3019 if (state->bucket <= udptable->mask)
3020 spin_unlock_bh(&udptable->hash[state->bucket].lock);
3021
3022 return udp_get_first(seq, state->bucket + 1);
3023 }
3024 return sk;
3025}
3026
3027static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
3028{
3029 struct sock *sk = udp_get_first(seq, 0);
3030
3031 if (sk)
3032 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
3033 --pos;
3034 return pos ? NULL : sk;
3035}
3036
3037void *udp_seq_start(struct seq_file *seq, loff_t *pos)
3038{
3039 struct udp_iter_state *state = seq->private;
3040 state->bucket = MAX_UDP_PORTS;
3041
3042 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
3043}
3044EXPORT_SYMBOL(udp_seq_start);
3045
3046void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3047{
3048 struct sock *sk;
3049
3050 if (v == SEQ_START_TOKEN)
3051 sk = udp_get_idx(seq, 0);
3052 else
3053 sk = udp_get_next(seq, v);
3054
3055 ++*pos;
3056 return sk;
3057}
3058EXPORT_SYMBOL(udp_seq_next);
3059
3060void udp_seq_stop(struct seq_file *seq, void *v)
3061{
3062 struct udp_iter_state *state = seq->private;
3063 struct udp_table *udptable;
3064
3065 udptable = udp_get_table_seq(seq, seq_file_net(seq));
3066
3067 if (state->bucket <= udptable->mask)
3068 spin_unlock_bh(&udptable->hash[state->bucket].lock);
3069}
3070EXPORT_SYMBOL(udp_seq_stop);
3071
3072/* ------------------------------------------------------------------------ */
3073static void udp4_format_sock(struct sock *sp, struct seq_file *f,
3074 int bucket)
3075{
3076 struct inet_sock *inet = inet_sk(sp);
3077 __be32 dest = inet->inet_daddr;
3078 __be32 src = inet->inet_rcv_saddr;
3079 __u16 destp = ntohs(inet->inet_dport);
3080 __u16 srcp = ntohs(inet->inet_sport);
3081
3082 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
3083 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u",
3084 bucket, src, srcp, dest, destp, sp->sk_state,
3085 sk_wmem_alloc_get(sp),
3086 udp_rqueue_get(sp),
3087 0, 0L, 0,
3088 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
3089 0, sock_i_ino(sp),
3090 refcount_read(&sp->sk_refcnt), sp,
3091 atomic_read(&sp->sk_drops));
3092}
3093
3094int udp4_seq_show(struct seq_file *seq, void *v)
3095{
3096 seq_setwidth(seq, 127);
3097 if (v == SEQ_START_TOKEN)
3098 seq_puts(seq, " sl local_address rem_address st tx_queue "
3099 "rx_queue tr tm->when retrnsmt uid timeout "
3100 "inode ref pointer drops");
3101 else {
3102 struct udp_iter_state *state = seq->private;
3103
3104 udp4_format_sock(v, seq, state->bucket);
3105 }
3106 seq_pad(seq, '\n');
3107 return 0;
3108}
3109
3110#ifdef CONFIG_BPF_SYSCALL
3111struct bpf_iter__udp {
3112 __bpf_md_ptr(struct bpf_iter_meta *, meta);
3113 __bpf_md_ptr(struct udp_sock *, udp_sk);
3114 uid_t uid __aligned(8);
3115 int bucket __aligned(8);
3116};
3117
3118struct bpf_udp_iter_state {
3119 struct udp_iter_state state;
3120 unsigned int cur_sk;
3121 unsigned int end_sk;
3122 unsigned int max_sk;
3123 int offset;
3124 struct sock **batch;
3125 bool st_bucket_done;
3126};
3127
3128static int bpf_iter_udp_realloc_batch(struct bpf_udp_iter_state *iter,
3129 unsigned int new_batch_sz);
3130static struct sock *bpf_iter_udp_batch(struct seq_file *seq)
3131{
3132 struct bpf_udp_iter_state *iter = seq->private;
3133 struct udp_iter_state *state = &iter->state;
3134 struct net *net = seq_file_net(seq);
3135 int resume_bucket, resume_offset;
3136 struct udp_table *udptable;
3137 unsigned int batch_sks = 0;
3138 bool resized = false;
3139 struct sock *sk;
3140
3141 resume_bucket = state->bucket;
3142 resume_offset = iter->offset;
3143
3144 /* The current batch is done, so advance the bucket. */
3145 if (iter->st_bucket_done)
3146 state->bucket++;
3147
3148 udptable = udp_get_table_seq(seq, net);
3149
3150again:
3151 /* New batch for the next bucket.
3152 * Iterate over the hash table to find a bucket with sockets matching
3153 * the iterator attributes, and return the first matching socket from
3154 * the bucket. The remaining matched sockets from the bucket are batched
3155 * before releasing the bucket lock. This allows BPF programs that are
3156 * called in seq_show to acquire the bucket lock if needed.
3157 */
3158 iter->cur_sk = 0;
3159 iter->end_sk = 0;
3160 iter->st_bucket_done = false;
3161 batch_sks = 0;
3162
3163 for (; state->bucket <= udptable->mask; state->bucket++) {
3164 struct udp_hslot *hslot2 = &udptable->hash2[state->bucket];
3165
3166 if (hlist_empty(&hslot2->head))
3167 continue;
3168
3169 iter->offset = 0;
3170 spin_lock_bh(&hslot2->lock);
3171 udp_portaddr_for_each_entry(sk, &hslot2->head) {
3172 if (seq_sk_match(seq, sk)) {
3173 /* Resume from the last iterated socket at the
3174 * offset in the bucket before iterator was stopped.
3175 */
3176 if (state->bucket == resume_bucket &&
3177 iter->offset < resume_offset) {
3178 ++iter->offset;
3179 continue;
3180 }
3181 if (iter->end_sk < iter->max_sk) {
3182 sock_hold(sk);
3183 iter->batch[iter->end_sk++] = sk;
3184 }
3185 batch_sks++;
3186 }
3187 }
3188 spin_unlock_bh(&hslot2->lock);
3189
3190 if (iter->end_sk)
3191 break;
3192 }
3193
3194 /* All done: no batch made. */
3195 if (!iter->end_sk)
3196 return NULL;
3197
3198 if (iter->end_sk == batch_sks) {
3199 /* Batching is done for the current bucket; return the first
3200 * socket to be iterated from the batch.
3201 */
3202 iter->st_bucket_done = true;
3203 goto done;
3204 }
3205 if (!resized && !bpf_iter_udp_realloc_batch(iter, batch_sks * 3 / 2)) {
3206 resized = true;
3207 /* After allocating a larger batch, retry one more time to grab
3208 * the whole bucket.
3209 */
3210 goto again;
3211 }
3212done:
3213 return iter->batch[0];
3214}
3215
3216static void *bpf_iter_udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3217{
3218 struct bpf_udp_iter_state *iter = seq->private;
3219 struct sock *sk;
3220
3221 /* Whenever seq_next() is called, the iter->cur_sk is
3222 * done with seq_show(), so unref the iter->cur_sk.
3223 */
3224 if (iter->cur_sk < iter->end_sk) {
3225 sock_put(iter->batch[iter->cur_sk++]);
3226 ++iter->offset;
3227 }
3228
3229 /* After updating iter->cur_sk, check if there are more sockets
3230 * available in the current bucket batch.
3231 */
3232 if (iter->cur_sk < iter->end_sk)
3233 sk = iter->batch[iter->cur_sk];
3234 else
3235 /* Prepare a new batch. */
3236 sk = bpf_iter_udp_batch(seq);
3237
3238 ++*pos;
3239 return sk;
3240}
3241
3242static void *bpf_iter_udp_seq_start(struct seq_file *seq, loff_t *pos)
3243{
3244 /* bpf iter does not support lseek, so it always
3245 * continue from where it was stop()-ped.
3246 */
3247 if (*pos)
3248 return bpf_iter_udp_batch(seq);
3249
3250 return SEQ_START_TOKEN;
3251}
3252
3253static int udp_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta,
3254 struct udp_sock *udp_sk, uid_t uid, int bucket)
3255{
3256 struct bpf_iter__udp ctx;
3257
3258 meta->seq_num--; /* skip SEQ_START_TOKEN */
3259 ctx.meta = meta;
3260 ctx.udp_sk = udp_sk;
3261 ctx.uid = uid;
3262 ctx.bucket = bucket;
3263 return bpf_iter_run_prog(prog, &ctx);
3264}
3265
3266static int bpf_iter_udp_seq_show(struct seq_file *seq, void *v)
3267{
3268 struct udp_iter_state *state = seq->private;
3269 struct bpf_iter_meta meta;
3270 struct bpf_prog *prog;
3271 struct sock *sk = v;
3272 uid_t uid;
3273 int ret;
3274
3275 if (v == SEQ_START_TOKEN)
3276 return 0;
3277
3278 lock_sock(sk);
3279
3280 if (unlikely(sk_unhashed(sk))) {
3281 ret = SEQ_SKIP;
3282 goto unlock;
3283 }
3284
3285 uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk));
3286 meta.seq = seq;
3287 prog = bpf_iter_get_info(&meta, false);
3288 ret = udp_prog_seq_show(prog, &meta, v, uid, state->bucket);
3289
3290unlock:
3291 release_sock(sk);
3292 return ret;
3293}
3294
3295static void bpf_iter_udp_put_batch(struct bpf_udp_iter_state *iter)
3296{
3297 while (iter->cur_sk < iter->end_sk)
3298 sock_put(iter->batch[iter->cur_sk++]);
3299}
3300
3301static void bpf_iter_udp_seq_stop(struct seq_file *seq, void *v)
3302{
3303 struct bpf_udp_iter_state *iter = seq->private;
3304 struct bpf_iter_meta meta;
3305 struct bpf_prog *prog;
3306
3307 if (!v) {
3308 meta.seq = seq;
3309 prog = bpf_iter_get_info(&meta, true);
3310 if (prog)
3311 (void)udp_prog_seq_show(prog, &meta, v, 0, 0);
3312 }
3313
3314 if (iter->cur_sk < iter->end_sk) {
3315 bpf_iter_udp_put_batch(iter);
3316 iter->st_bucket_done = false;
3317 }
3318}
3319
3320static const struct seq_operations bpf_iter_udp_seq_ops = {
3321 .start = bpf_iter_udp_seq_start,
3322 .next = bpf_iter_udp_seq_next,
3323 .stop = bpf_iter_udp_seq_stop,
3324 .show = bpf_iter_udp_seq_show,
3325};
3326#endif
3327
3328static unsigned short seq_file_family(const struct seq_file *seq)
3329{
3330 const struct udp_seq_afinfo *afinfo;
3331
3332#ifdef CONFIG_BPF_SYSCALL
3333 /* BPF iterator: bpf programs to filter sockets. */
3334 if (seq->op == &bpf_iter_udp_seq_ops)
3335 return AF_UNSPEC;
3336#endif
3337
3338 /* Proc fs iterator */
3339 afinfo = pde_data(file_inode(seq->file));
3340 return afinfo->family;
3341}
3342
3343const struct seq_operations udp_seq_ops = {
3344 .start = udp_seq_start,
3345 .next = udp_seq_next,
3346 .stop = udp_seq_stop,
3347 .show = udp4_seq_show,
3348};
3349EXPORT_SYMBOL(udp_seq_ops);
3350
3351static struct udp_seq_afinfo udp4_seq_afinfo = {
3352 .family = AF_INET,
3353 .udp_table = NULL,
3354};
3355
3356static int __net_init udp4_proc_init_net(struct net *net)
3357{
3358 if (!proc_create_net_data("udp", 0444, net->proc_net, &udp_seq_ops,
3359 sizeof(struct udp_iter_state), &udp4_seq_afinfo))
3360 return -ENOMEM;
3361 return 0;
3362}
3363
3364static void __net_exit udp4_proc_exit_net(struct net *net)
3365{
3366 remove_proc_entry("udp", net->proc_net);
3367}
3368
3369static struct pernet_operations udp4_net_ops = {
3370 .init = udp4_proc_init_net,
3371 .exit = udp4_proc_exit_net,
3372};
3373
3374int __init udp4_proc_init(void)
3375{
3376 return register_pernet_subsys(&udp4_net_ops);
3377}
3378
3379void udp4_proc_exit(void)
3380{
3381 unregister_pernet_subsys(&udp4_net_ops);
3382}
3383#endif /* CONFIG_PROC_FS */
3384
3385static __initdata unsigned long uhash_entries;
3386static int __init set_uhash_entries(char *str)
3387{
3388 ssize_t ret;
3389
3390 if (!str)
3391 return 0;
3392
3393 ret = kstrtoul(str, 0, &uhash_entries);
3394 if (ret)
3395 return 0;
3396
3397 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
3398 uhash_entries = UDP_HTABLE_SIZE_MIN;
3399 return 1;
3400}
3401__setup("uhash_entries=", set_uhash_entries);
3402
3403void __init udp_table_init(struct udp_table *table, const char *name)
3404{
3405 unsigned int i;
3406
3407 table->hash = alloc_large_system_hash(name,
3408 2 * sizeof(struct udp_hslot),
3409 uhash_entries,
3410 21, /* one slot per 2 MB */
3411 0,
3412 &table->log,
3413 &table->mask,
3414 UDP_HTABLE_SIZE_MIN,
3415 UDP_HTABLE_SIZE_MAX);
3416
3417 table->hash2 = table->hash + (table->mask + 1);
3418 for (i = 0; i <= table->mask; i++) {
3419 INIT_HLIST_HEAD(&table->hash[i].head);
3420 table->hash[i].count = 0;
3421 spin_lock_init(&table->hash[i].lock);
3422 }
3423 for (i = 0; i <= table->mask; i++) {
3424 INIT_HLIST_HEAD(&table->hash2[i].head);
3425 table->hash2[i].count = 0;
3426 spin_lock_init(&table->hash2[i].lock);
3427 }
3428}
3429
3430u32 udp_flow_hashrnd(void)
3431{
3432 static u32 hashrnd __read_mostly;
3433
3434 net_get_random_once(&hashrnd, sizeof(hashrnd));
3435
3436 return hashrnd;
3437}
3438EXPORT_SYMBOL(udp_flow_hashrnd);
3439
3440static void __net_init udp_sysctl_init(struct net *net)
3441{
3442 net->ipv4.sysctl_udp_rmem_min = PAGE_SIZE;
3443 net->ipv4.sysctl_udp_wmem_min = PAGE_SIZE;
3444
3445#ifdef CONFIG_NET_L3_MASTER_DEV
3446 net->ipv4.sysctl_udp_l3mdev_accept = 0;
3447#endif
3448}
3449
3450static struct udp_table __net_init *udp_pernet_table_alloc(unsigned int hash_entries)
3451{
3452 struct udp_table *udptable;
3453 int i;
3454
3455 udptable = kmalloc(sizeof(*udptable), GFP_KERNEL);
3456 if (!udptable)
3457 goto out;
3458
3459 udptable->hash = vmalloc_huge(hash_entries * 2 * sizeof(struct udp_hslot),
3460 GFP_KERNEL_ACCOUNT);
3461 if (!udptable->hash)
3462 goto free_table;
3463
3464 udptable->hash2 = udptable->hash + hash_entries;
3465 udptable->mask = hash_entries - 1;
3466 udptable->log = ilog2(hash_entries);
3467
3468 for (i = 0; i < hash_entries; i++) {
3469 INIT_HLIST_HEAD(&udptable->hash[i].head);
3470 udptable->hash[i].count = 0;
3471 spin_lock_init(&udptable->hash[i].lock);
3472
3473 INIT_HLIST_HEAD(&udptable->hash2[i].head);
3474 udptable->hash2[i].count = 0;
3475 spin_lock_init(&udptable->hash2[i].lock);
3476 }
3477
3478 return udptable;
3479
3480free_table:
3481 kfree(udptable);
3482out:
3483 return NULL;
3484}
3485
3486static void __net_exit udp_pernet_table_free(struct net *net)
3487{
3488 struct udp_table *udptable = net->ipv4.udp_table;
3489
3490 if (udptable == &udp_table)
3491 return;
3492
3493 kvfree(udptable->hash);
3494 kfree(udptable);
3495}
3496
3497static void __net_init udp_set_table(struct net *net)
3498{
3499 struct udp_table *udptable;
3500 unsigned int hash_entries;
3501 struct net *old_net;
3502
3503 if (net_eq(net, &init_net))
3504 goto fallback;
3505
3506 old_net = current->nsproxy->net_ns;
3507 hash_entries = READ_ONCE(old_net->ipv4.sysctl_udp_child_hash_entries);
3508 if (!hash_entries)
3509 goto fallback;
3510
3511 /* Set min to keep the bitmap on stack in udp_lib_get_port() */
3512 if (hash_entries < UDP_HTABLE_SIZE_MIN_PERNET)
3513 hash_entries = UDP_HTABLE_SIZE_MIN_PERNET;
3514 else
3515 hash_entries = roundup_pow_of_two(hash_entries);
3516
3517 udptable = udp_pernet_table_alloc(hash_entries);
3518 if (udptable) {
3519 net->ipv4.udp_table = udptable;
3520 } else {
3521 pr_warn("Failed to allocate UDP hash table (entries: %u) "
3522 "for a netns, fallback to the global one\n",
3523 hash_entries);
3524fallback:
3525 net->ipv4.udp_table = &udp_table;
3526 }
3527}
3528
3529static int __net_init udp_pernet_init(struct net *net)
3530{
3531 udp_sysctl_init(net);
3532 udp_set_table(net);
3533
3534 return 0;
3535}
3536
3537static void __net_exit udp_pernet_exit(struct net *net)
3538{
3539 udp_pernet_table_free(net);
3540}
3541
3542static struct pernet_operations __net_initdata udp_sysctl_ops = {
3543 .init = udp_pernet_init,
3544 .exit = udp_pernet_exit,
3545};
3546
3547#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
3548DEFINE_BPF_ITER_FUNC(udp, struct bpf_iter_meta *meta,
3549 struct udp_sock *udp_sk, uid_t uid, int bucket)
3550
3551static int bpf_iter_udp_realloc_batch(struct bpf_udp_iter_state *iter,
3552 unsigned int new_batch_sz)
3553{
3554 struct sock **new_batch;
3555
3556 new_batch = kvmalloc_array(new_batch_sz, sizeof(*new_batch),
3557 GFP_USER | __GFP_NOWARN);
3558 if (!new_batch)
3559 return -ENOMEM;
3560
3561 bpf_iter_udp_put_batch(iter);
3562 kvfree(iter->batch);
3563 iter->batch = new_batch;
3564 iter->max_sk = new_batch_sz;
3565
3566 return 0;
3567}
3568
3569#define INIT_BATCH_SZ 16
3570
3571static int bpf_iter_init_udp(void *priv_data, struct bpf_iter_aux_info *aux)
3572{
3573 struct bpf_udp_iter_state *iter = priv_data;
3574 int ret;
3575
3576 ret = bpf_iter_init_seq_net(priv_data, aux);
3577 if (ret)
3578 return ret;
3579
3580 ret = bpf_iter_udp_realloc_batch(iter, INIT_BATCH_SZ);
3581 if (ret)
3582 bpf_iter_fini_seq_net(priv_data);
3583
3584 return ret;
3585}
3586
3587static void bpf_iter_fini_udp(void *priv_data)
3588{
3589 struct bpf_udp_iter_state *iter = priv_data;
3590
3591 bpf_iter_fini_seq_net(priv_data);
3592 kvfree(iter->batch);
3593}
3594
3595static const struct bpf_iter_seq_info udp_seq_info = {
3596 .seq_ops = &bpf_iter_udp_seq_ops,
3597 .init_seq_private = bpf_iter_init_udp,
3598 .fini_seq_private = bpf_iter_fini_udp,
3599 .seq_priv_size = sizeof(struct bpf_udp_iter_state),
3600};
3601
3602static struct bpf_iter_reg udp_reg_info = {
3603 .target = "udp",
3604 .ctx_arg_info_size = 1,
3605 .ctx_arg_info = {
3606 { offsetof(struct bpf_iter__udp, udp_sk),
3607 PTR_TO_BTF_ID_OR_NULL | PTR_TRUSTED },
3608 },
3609 .seq_info = &udp_seq_info,
3610};
3611
3612static void __init bpf_iter_register(void)
3613{
3614 udp_reg_info.ctx_arg_info[0].btf_id = btf_sock_ids[BTF_SOCK_TYPE_UDP];
3615 if (bpf_iter_reg_target(&udp_reg_info))
3616 pr_warn("Warning: could not register bpf iterator udp\n");
3617}
3618#endif
3619
3620void __init udp_init(void)
3621{
3622 unsigned long limit;
3623 unsigned int i;
3624
3625 udp_table_init(&udp_table, "UDP");
3626 limit = nr_free_buffer_pages() / 8;
3627 limit = max(limit, 128UL);
3628 sysctl_udp_mem[0] = limit / 4 * 3;
3629 sysctl_udp_mem[1] = limit;
3630 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
3631
3632 /* 16 spinlocks per cpu */
3633 udp_busylocks_log = ilog2(nr_cpu_ids) + 4;
3634 udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log,
3635 GFP_KERNEL);
3636 if (!udp_busylocks)
3637 panic("UDP: failed to alloc udp_busylocks\n");
3638 for (i = 0; i < (1U << udp_busylocks_log); i++)
3639 spin_lock_init(udp_busylocks + i);
3640
3641 if (register_pernet_subsys(&udp_sysctl_ops))
3642 panic("UDP: failed to init sysctl parameters.\n");
3643
3644#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
3645 bpf_iter_register();
3646#endif
3647}