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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/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 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret));
415
416 return __inet_ehashfn(laddr, lport, faddr, fport,
417 udp_ehash_secret + net_hash_mix(net));
418}
419
420/* called with rcu_read_lock() */
421static struct sock *udp4_lib_lookup2(struct net *net,
422 __be32 saddr, __be16 sport,
423 __be32 daddr, unsigned int hnum,
424 int dif, int sdif,
425 struct udp_hslot *hslot2,
426 struct sk_buff *skb)
427{
428 struct sock *sk, *result;
429 int score, badness;
430 bool need_rescore;
431
432 result = NULL;
433 badness = 0;
434 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
435 need_rescore = false;
436rescore:
437 score = compute_score(need_rescore ? result : sk, net, saddr,
438 sport, daddr, hnum, dif, sdif);
439 if (score > badness) {
440 badness = score;
441
442 if (need_rescore)
443 continue;
444
445 if (sk->sk_state == TCP_ESTABLISHED) {
446 result = sk;
447 continue;
448 }
449
450 result = inet_lookup_reuseport(net, sk, skb, sizeof(struct udphdr),
451 saddr, sport, daddr, hnum, udp_ehashfn);
452 if (!result) {
453 result = sk;
454 continue;
455 }
456
457 /* Fall back to scoring if group has connections */
458 if (!reuseport_has_conns(sk))
459 return result;
460
461 /* Reuseport logic returned an error, keep original score. */
462 if (IS_ERR(result))
463 continue;
464
465 /* compute_score is too long of a function to be
466 * inlined, and calling it again here yields
467 * measureable overhead for some
468 * workloads. Work around it by jumping
469 * backwards to rescore 'result'.
470 */
471 need_rescore = true;
472 goto rescore;
473 }
474 }
475 return result;
476}
477
478/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
479 * harder than this. -DaveM
480 */
481struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
482 __be16 sport, __be32 daddr, __be16 dport, int dif,
483 int sdif, struct udp_table *udptable, struct sk_buff *skb)
484{
485 unsigned short hnum = ntohs(dport);
486 unsigned int hash2, slot2;
487 struct udp_hslot *hslot2;
488 struct sock *result, *sk;
489
490 hash2 = ipv4_portaddr_hash(net, daddr, hnum);
491 slot2 = hash2 & udptable->mask;
492 hslot2 = &udptable->hash2[slot2];
493
494 /* Lookup connected or non-wildcard socket */
495 result = udp4_lib_lookup2(net, saddr, sport,
496 daddr, hnum, dif, sdif,
497 hslot2, skb);
498 if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED)
499 goto done;
500
501 /* Lookup redirect from BPF */
502 if (static_branch_unlikely(&bpf_sk_lookup_enabled) &&
503 udptable == net->ipv4.udp_table) {
504 sk = inet_lookup_run_sk_lookup(net, IPPROTO_UDP, skb, sizeof(struct udphdr),
505 saddr, sport, daddr, hnum, dif,
506 udp_ehashfn);
507 if (sk) {
508 result = sk;
509 goto done;
510 }
511 }
512
513 /* Got non-wildcard socket or error on first lookup */
514 if (result)
515 goto done;
516
517 /* Lookup wildcard sockets */
518 hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
519 slot2 = hash2 & udptable->mask;
520 hslot2 = &udptable->hash2[slot2];
521
522 result = udp4_lib_lookup2(net, saddr, sport,
523 htonl(INADDR_ANY), hnum, dif, sdif,
524 hslot2, skb);
525done:
526 if (IS_ERR(result))
527 return NULL;
528 return result;
529}
530EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
531
532static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
533 __be16 sport, __be16 dport,
534 struct udp_table *udptable)
535{
536 const struct iphdr *iph = ip_hdr(skb);
537
538 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
539 iph->daddr, dport, inet_iif(skb),
540 inet_sdif(skb), udptable, skb);
541}
542
543struct sock *udp4_lib_lookup_skb(const struct sk_buff *skb,
544 __be16 sport, __be16 dport)
545{
546 const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation];
547 const struct iphdr *iph = (struct iphdr *)(skb->data + offset);
548 struct net *net = dev_net(skb->dev);
549 int iif, sdif;
550
551 inet_get_iif_sdif(skb, &iif, &sdif);
552
553 return __udp4_lib_lookup(net, iph->saddr, sport,
554 iph->daddr, dport, iif,
555 sdif, net->ipv4.udp_table, NULL);
556}
557
558/* Must be called under rcu_read_lock().
559 * Does increment socket refcount.
560 */
561#if IS_ENABLED(CONFIG_NF_TPROXY_IPV4) || IS_ENABLED(CONFIG_NF_SOCKET_IPV4)
562struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
563 __be32 daddr, __be16 dport, int dif)
564{
565 struct sock *sk;
566
567 sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport,
568 dif, 0, net->ipv4.udp_table, NULL);
569 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
570 sk = NULL;
571 return sk;
572}
573EXPORT_SYMBOL_GPL(udp4_lib_lookup);
574#endif
575
576static inline bool __udp_is_mcast_sock(struct net *net, const struct sock *sk,
577 __be16 loc_port, __be32 loc_addr,
578 __be16 rmt_port, __be32 rmt_addr,
579 int dif, int sdif, unsigned short hnum)
580{
581 const struct inet_sock *inet = inet_sk(sk);
582
583 if (!net_eq(sock_net(sk), net) ||
584 udp_sk(sk)->udp_port_hash != hnum ||
585 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
586 (inet->inet_dport != rmt_port && inet->inet_dport) ||
587 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) ||
588 ipv6_only_sock(sk) ||
589 !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
590 return false;
591 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif, sdif))
592 return false;
593 return true;
594}
595
596DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key);
597EXPORT_SYMBOL(udp_encap_needed_key);
598
599#if IS_ENABLED(CONFIG_IPV6)
600DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
601EXPORT_SYMBOL(udpv6_encap_needed_key);
602#endif
603
604void udp_encap_enable(void)
605{
606 static_branch_inc(&udp_encap_needed_key);
607}
608EXPORT_SYMBOL(udp_encap_enable);
609
610void udp_encap_disable(void)
611{
612 static_branch_dec(&udp_encap_needed_key);
613}
614EXPORT_SYMBOL(udp_encap_disable);
615
616/* Handler for tunnels with arbitrary destination ports: no socket lookup, go
617 * through error handlers in encapsulations looking for a match.
618 */
619static int __udp4_lib_err_encap_no_sk(struct sk_buff *skb, u32 info)
620{
621 int i;
622
623 for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
624 int (*handler)(struct sk_buff *skb, u32 info);
625 const struct ip_tunnel_encap_ops *encap;
626
627 encap = rcu_dereference(iptun_encaps[i]);
628 if (!encap)
629 continue;
630 handler = encap->err_handler;
631 if (handler && !handler(skb, info))
632 return 0;
633 }
634
635 return -ENOENT;
636}
637
638/* Try to match ICMP errors to UDP tunnels by looking up a socket without
639 * reversing source and destination port: this will match tunnels that force the
640 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
641 * lwtunnels might actually break this assumption by being configured with
642 * different destination ports on endpoints, in this case we won't be able to
643 * trace ICMP messages back to them.
644 *
645 * If this doesn't match any socket, probe tunnels with arbitrary destination
646 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
647 * we've sent packets to won't necessarily match the local destination port.
648 *
649 * Then ask the tunnel implementation to match the error against a valid
650 * association.
651 *
652 * Return an error if we can't find a match, the socket if we need further
653 * processing, zero otherwise.
654 */
655static struct sock *__udp4_lib_err_encap(struct net *net,
656 const struct iphdr *iph,
657 struct udphdr *uh,
658 struct udp_table *udptable,
659 struct sock *sk,
660 struct sk_buff *skb, u32 info)
661{
662 int (*lookup)(struct sock *sk, struct sk_buff *skb);
663 int network_offset, transport_offset;
664 struct udp_sock *up;
665
666 network_offset = skb_network_offset(skb);
667 transport_offset = skb_transport_offset(skb);
668
669 /* Network header needs to point to the outer IPv4 header inside ICMP */
670 skb_reset_network_header(skb);
671
672 /* Transport header needs to point to the UDP header */
673 skb_set_transport_header(skb, iph->ihl << 2);
674
675 if (sk) {
676 up = udp_sk(sk);
677
678 lookup = READ_ONCE(up->encap_err_lookup);
679 if (lookup && lookup(sk, skb))
680 sk = NULL;
681
682 goto out;
683 }
684
685 sk = __udp4_lib_lookup(net, iph->daddr, uh->source,
686 iph->saddr, uh->dest, skb->dev->ifindex, 0,
687 udptable, NULL);
688 if (sk) {
689 up = udp_sk(sk);
690
691 lookup = READ_ONCE(up->encap_err_lookup);
692 if (!lookup || lookup(sk, skb))
693 sk = NULL;
694 }
695
696out:
697 if (!sk)
698 sk = ERR_PTR(__udp4_lib_err_encap_no_sk(skb, info));
699
700 skb_set_transport_header(skb, transport_offset);
701 skb_set_network_header(skb, network_offset);
702
703 return sk;
704}
705
706/*
707 * This routine is called by the ICMP module when it gets some
708 * sort of error condition. If err < 0 then the socket should
709 * be closed and the error returned to the user. If err > 0
710 * it's just the icmp type << 8 | icmp code.
711 * Header points to the ip header of the error packet. We move
712 * on past this. Then (as it used to claim before adjustment)
713 * header points to the first 8 bytes of the udp header. We need
714 * to find the appropriate port.
715 */
716
717int __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
718{
719 struct inet_sock *inet;
720 const struct iphdr *iph = (const struct iphdr *)skb->data;
721 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
722 const int type = icmp_hdr(skb)->type;
723 const int code = icmp_hdr(skb)->code;
724 bool tunnel = false;
725 struct sock *sk;
726 int harderr;
727 int err;
728 struct net *net = dev_net(skb->dev);
729
730 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
731 iph->saddr, uh->source, skb->dev->ifindex,
732 inet_sdif(skb), udptable, NULL);
733
734 if (!sk || READ_ONCE(udp_sk(sk)->encap_type)) {
735 /* No socket for error: try tunnels before discarding */
736 if (static_branch_unlikely(&udp_encap_needed_key)) {
737 sk = __udp4_lib_err_encap(net, iph, uh, udptable, sk, skb,
738 info);
739 if (!sk)
740 return 0;
741 } else
742 sk = ERR_PTR(-ENOENT);
743
744 if (IS_ERR(sk)) {
745 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
746 return PTR_ERR(sk);
747 }
748
749 tunnel = true;
750 }
751
752 err = 0;
753 harderr = 0;
754 inet = inet_sk(sk);
755
756 switch (type) {
757 default:
758 case ICMP_TIME_EXCEEDED:
759 err = EHOSTUNREACH;
760 break;
761 case ICMP_SOURCE_QUENCH:
762 goto out;
763 case ICMP_PARAMETERPROB:
764 err = EPROTO;
765 harderr = 1;
766 break;
767 case ICMP_DEST_UNREACH:
768 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
769 ipv4_sk_update_pmtu(skb, sk, info);
770 if (READ_ONCE(inet->pmtudisc) != IP_PMTUDISC_DONT) {
771 err = EMSGSIZE;
772 harderr = 1;
773 break;
774 }
775 goto out;
776 }
777 err = EHOSTUNREACH;
778 if (code <= NR_ICMP_UNREACH) {
779 harderr = icmp_err_convert[code].fatal;
780 err = icmp_err_convert[code].errno;
781 }
782 break;
783 case ICMP_REDIRECT:
784 ipv4_sk_redirect(skb, sk);
785 goto out;
786 }
787
788 /*
789 * RFC1122: OK. Passes ICMP errors back to application, as per
790 * 4.1.3.3.
791 */
792 if (tunnel) {
793 /* ...not for tunnels though: we don't have a sending socket */
794 if (udp_sk(sk)->encap_err_rcv)
795 udp_sk(sk)->encap_err_rcv(sk, skb, err, uh->dest, info,
796 (u8 *)(uh+1));
797 goto out;
798 }
799 if (!inet_test_bit(RECVERR, sk)) {
800 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
801 goto out;
802 } else
803 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
804
805 sk->sk_err = err;
806 sk_error_report(sk);
807out:
808 return 0;
809}
810
811int udp_err(struct sk_buff *skb, u32 info)
812{
813 return __udp4_lib_err(skb, info, dev_net(skb->dev)->ipv4.udp_table);
814}
815
816/*
817 * Throw away all pending data and cancel the corking. Socket is locked.
818 */
819void udp_flush_pending_frames(struct sock *sk)
820{
821 struct udp_sock *up = udp_sk(sk);
822
823 if (up->pending) {
824 up->len = 0;
825 WRITE_ONCE(up->pending, 0);
826 ip_flush_pending_frames(sk);
827 }
828}
829EXPORT_SYMBOL(udp_flush_pending_frames);
830
831/**
832 * udp4_hwcsum - handle outgoing HW checksumming
833 * @skb: sk_buff containing the filled-in UDP header
834 * (checksum field must be zeroed out)
835 * @src: source IP address
836 * @dst: destination IP address
837 */
838void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
839{
840 struct udphdr *uh = udp_hdr(skb);
841 int offset = skb_transport_offset(skb);
842 int len = skb->len - offset;
843 int hlen = len;
844 __wsum csum = 0;
845
846 if (!skb_has_frag_list(skb)) {
847 /*
848 * Only one fragment on the socket.
849 */
850 skb->csum_start = skb_transport_header(skb) - skb->head;
851 skb->csum_offset = offsetof(struct udphdr, check);
852 uh->check = ~csum_tcpudp_magic(src, dst, len,
853 IPPROTO_UDP, 0);
854 } else {
855 struct sk_buff *frags;
856
857 /*
858 * HW-checksum won't work as there are two or more
859 * fragments on the socket so that all csums of sk_buffs
860 * should be together
861 */
862 skb_walk_frags(skb, frags) {
863 csum = csum_add(csum, frags->csum);
864 hlen -= frags->len;
865 }
866
867 csum = skb_checksum(skb, offset, hlen, csum);
868 skb->ip_summed = CHECKSUM_NONE;
869
870 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
871 if (uh->check == 0)
872 uh->check = CSUM_MANGLED_0;
873 }
874}
875EXPORT_SYMBOL_GPL(udp4_hwcsum);
876
877/* Function to set UDP checksum for an IPv4 UDP packet. This is intended
878 * for the simple case like when setting the checksum for a UDP tunnel.
879 */
880void udp_set_csum(bool nocheck, struct sk_buff *skb,
881 __be32 saddr, __be32 daddr, int len)
882{
883 struct udphdr *uh = udp_hdr(skb);
884
885 if (nocheck) {
886 uh->check = 0;
887 } else if (skb_is_gso(skb)) {
888 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
889 } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
890 uh->check = 0;
891 uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb));
892 if (uh->check == 0)
893 uh->check = CSUM_MANGLED_0;
894 } else {
895 skb->ip_summed = CHECKSUM_PARTIAL;
896 skb->csum_start = skb_transport_header(skb) - skb->head;
897 skb->csum_offset = offsetof(struct udphdr, check);
898 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
899 }
900}
901EXPORT_SYMBOL(udp_set_csum);
902
903static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4,
904 struct inet_cork *cork)
905{
906 struct sock *sk = skb->sk;
907 struct inet_sock *inet = inet_sk(sk);
908 struct udphdr *uh;
909 int err;
910 int is_udplite = IS_UDPLITE(sk);
911 int offset = skb_transport_offset(skb);
912 int len = skb->len - offset;
913 int datalen = len - sizeof(*uh);
914 __wsum csum = 0;
915
916 /*
917 * Create a UDP header
918 */
919 uh = udp_hdr(skb);
920 uh->source = inet->inet_sport;
921 uh->dest = fl4->fl4_dport;
922 uh->len = htons(len);
923 uh->check = 0;
924
925 if (cork->gso_size) {
926 const int hlen = skb_network_header_len(skb) +
927 sizeof(struct udphdr);
928
929 if (hlen + cork->gso_size > cork->fragsize) {
930 kfree_skb(skb);
931 return -EINVAL;
932 }
933 if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) {
934 kfree_skb(skb);
935 return -EINVAL;
936 }
937 if (sk->sk_no_check_tx) {
938 kfree_skb(skb);
939 return -EINVAL;
940 }
941 if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
942 dst_xfrm(skb_dst(skb))) {
943 kfree_skb(skb);
944 return -EIO;
945 }
946
947 if (datalen > cork->gso_size) {
948 skb_shinfo(skb)->gso_size = cork->gso_size;
949 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
950 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
951 cork->gso_size);
952 }
953 goto csum_partial;
954 }
955
956 if (is_udplite) /* UDP-Lite */
957 csum = udplite_csum(skb);
958
959 else if (sk->sk_no_check_tx) { /* UDP csum off */
960
961 skb->ip_summed = CHECKSUM_NONE;
962 goto send;
963
964 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
965csum_partial:
966
967 udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
968 goto send;
969
970 } else
971 csum = udp_csum(skb);
972
973 /* add protocol-dependent pseudo-header */
974 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
975 sk->sk_protocol, csum);
976 if (uh->check == 0)
977 uh->check = CSUM_MANGLED_0;
978
979send:
980 err = ip_send_skb(sock_net(sk), skb);
981 if (err) {
982 if (err == -ENOBUFS &&
983 !inet_test_bit(RECVERR, sk)) {
984 UDP_INC_STATS(sock_net(sk),
985 UDP_MIB_SNDBUFERRORS, is_udplite);
986 err = 0;
987 }
988 } else
989 UDP_INC_STATS(sock_net(sk),
990 UDP_MIB_OUTDATAGRAMS, is_udplite);
991 return err;
992}
993
994/*
995 * Push out all pending data as one UDP datagram. Socket is locked.
996 */
997int udp_push_pending_frames(struct sock *sk)
998{
999 struct udp_sock *up = udp_sk(sk);
1000 struct inet_sock *inet = inet_sk(sk);
1001 struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
1002 struct sk_buff *skb;
1003 int err = 0;
1004
1005 skb = ip_finish_skb(sk, fl4);
1006 if (!skb)
1007 goto out;
1008
1009 err = udp_send_skb(skb, fl4, &inet->cork.base);
1010
1011out:
1012 up->len = 0;
1013 WRITE_ONCE(up->pending, 0);
1014 return err;
1015}
1016EXPORT_SYMBOL(udp_push_pending_frames);
1017
1018static int __udp_cmsg_send(struct cmsghdr *cmsg, u16 *gso_size)
1019{
1020 switch (cmsg->cmsg_type) {
1021 case UDP_SEGMENT:
1022 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u16)))
1023 return -EINVAL;
1024 *gso_size = *(__u16 *)CMSG_DATA(cmsg);
1025 return 0;
1026 default:
1027 return -EINVAL;
1028 }
1029}
1030
1031int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size)
1032{
1033 struct cmsghdr *cmsg;
1034 bool need_ip = false;
1035 int err;
1036
1037 for_each_cmsghdr(cmsg, msg) {
1038 if (!CMSG_OK(msg, cmsg))
1039 return -EINVAL;
1040
1041 if (cmsg->cmsg_level != SOL_UDP) {
1042 need_ip = true;
1043 continue;
1044 }
1045
1046 err = __udp_cmsg_send(cmsg, gso_size);
1047 if (err)
1048 return err;
1049 }
1050
1051 return need_ip;
1052}
1053EXPORT_SYMBOL_GPL(udp_cmsg_send);
1054
1055int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1056{
1057 struct inet_sock *inet = inet_sk(sk);
1058 struct udp_sock *up = udp_sk(sk);
1059 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
1060 struct flowi4 fl4_stack;
1061 struct flowi4 *fl4;
1062 int ulen = len;
1063 struct ipcm_cookie ipc;
1064 struct rtable *rt = NULL;
1065 int free = 0;
1066 int connected = 0;
1067 __be32 daddr, faddr, saddr;
1068 u8 tos, scope;
1069 __be16 dport;
1070 int err, is_udplite = IS_UDPLITE(sk);
1071 int corkreq = udp_test_bit(CORK, sk) || msg->msg_flags & MSG_MORE;
1072 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1073 struct sk_buff *skb;
1074 struct ip_options_data opt_copy;
1075 int uc_index;
1076
1077 if (len > 0xFFFF)
1078 return -EMSGSIZE;
1079
1080 /*
1081 * Check the flags.
1082 */
1083
1084 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
1085 return -EOPNOTSUPP;
1086
1087 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
1088
1089 fl4 = &inet->cork.fl.u.ip4;
1090 if (READ_ONCE(up->pending)) {
1091 /*
1092 * There are pending frames.
1093 * The socket lock must be held while it's corked.
1094 */
1095 lock_sock(sk);
1096 if (likely(up->pending)) {
1097 if (unlikely(up->pending != AF_INET)) {
1098 release_sock(sk);
1099 return -EINVAL;
1100 }
1101 goto do_append_data;
1102 }
1103 release_sock(sk);
1104 }
1105 ulen += sizeof(struct udphdr);
1106
1107 /*
1108 * Get and verify the address.
1109 */
1110 if (usin) {
1111 if (msg->msg_namelen < sizeof(*usin))
1112 return -EINVAL;
1113 if (usin->sin_family != AF_INET) {
1114 if (usin->sin_family != AF_UNSPEC)
1115 return -EAFNOSUPPORT;
1116 }
1117
1118 daddr = usin->sin_addr.s_addr;
1119 dport = usin->sin_port;
1120 if (dport == 0)
1121 return -EINVAL;
1122 } else {
1123 if (sk->sk_state != TCP_ESTABLISHED)
1124 return -EDESTADDRREQ;
1125 daddr = inet->inet_daddr;
1126 dport = inet->inet_dport;
1127 /* Open fast path for connected socket.
1128 Route will not be used, if at least one option is set.
1129 */
1130 connected = 1;
1131 }
1132
1133 ipcm_init_sk(&ipc, inet);
1134 ipc.gso_size = READ_ONCE(up->gso_size);
1135
1136 if (msg->msg_controllen) {
1137 err = udp_cmsg_send(sk, msg, &ipc.gso_size);
1138 if (err > 0) {
1139 err = ip_cmsg_send(sk, msg, &ipc,
1140 sk->sk_family == AF_INET6);
1141 connected = 0;
1142 }
1143 if (unlikely(err < 0)) {
1144 kfree(ipc.opt);
1145 return err;
1146 }
1147 if (ipc.opt)
1148 free = 1;
1149 }
1150 if (!ipc.opt) {
1151 struct ip_options_rcu *inet_opt;
1152
1153 rcu_read_lock();
1154 inet_opt = rcu_dereference(inet->inet_opt);
1155 if (inet_opt) {
1156 memcpy(&opt_copy, inet_opt,
1157 sizeof(*inet_opt) + inet_opt->opt.optlen);
1158 ipc.opt = &opt_copy.opt;
1159 }
1160 rcu_read_unlock();
1161 }
1162
1163 if (cgroup_bpf_enabled(CGROUP_UDP4_SENDMSG) && !connected) {
1164 err = BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk,
1165 (struct sockaddr *)usin,
1166 &msg->msg_namelen,
1167 &ipc.addr);
1168 if (err)
1169 goto out_free;
1170 if (usin) {
1171 if (usin->sin_port == 0) {
1172 /* BPF program set invalid port. Reject it. */
1173 err = -EINVAL;
1174 goto out_free;
1175 }
1176 daddr = usin->sin_addr.s_addr;
1177 dport = usin->sin_port;
1178 }
1179 }
1180
1181 saddr = ipc.addr;
1182 ipc.addr = faddr = daddr;
1183
1184 if (ipc.opt && ipc.opt->opt.srr) {
1185 if (!daddr) {
1186 err = -EINVAL;
1187 goto out_free;
1188 }
1189 faddr = ipc.opt->opt.faddr;
1190 connected = 0;
1191 }
1192 tos = get_rttos(&ipc, inet);
1193 scope = ip_sendmsg_scope(inet, &ipc, msg);
1194 if (scope == RT_SCOPE_LINK)
1195 connected = 0;
1196
1197 uc_index = READ_ONCE(inet->uc_index);
1198 if (ipv4_is_multicast(daddr)) {
1199 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
1200 ipc.oif = READ_ONCE(inet->mc_index);
1201 if (!saddr)
1202 saddr = READ_ONCE(inet->mc_addr);
1203 connected = 0;
1204 } else if (!ipc.oif) {
1205 ipc.oif = uc_index;
1206 } else if (ipv4_is_lbcast(daddr) && uc_index) {
1207 /* oif is set, packet is to local broadcast and
1208 * uc_index is set. oif is most likely set
1209 * by sk_bound_dev_if. If uc_index != oif check if the
1210 * oif is an L3 master and uc_index is an L3 slave.
1211 * If so, we want to allow the send using the uc_index.
1212 */
1213 if (ipc.oif != uc_index &&
1214 ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk),
1215 uc_index)) {
1216 ipc.oif = uc_index;
1217 }
1218 }
1219
1220 if (connected)
1221 rt = dst_rtable(sk_dst_check(sk, 0));
1222
1223 if (!rt) {
1224 struct net *net = sock_net(sk);
1225 __u8 flow_flags = inet_sk_flowi_flags(sk);
1226
1227 fl4 = &fl4_stack;
1228
1229 flowi4_init_output(fl4, ipc.oif, ipc.sockc.mark, tos, scope,
1230 sk->sk_protocol, flow_flags, faddr, saddr,
1231 dport, inet->inet_sport, sk->sk_uid);
1232
1233 security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));
1234 rt = ip_route_output_flow(net, fl4, sk);
1235 if (IS_ERR(rt)) {
1236 err = PTR_ERR(rt);
1237 rt = NULL;
1238 if (err == -ENETUNREACH)
1239 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
1240 goto out;
1241 }
1242
1243 err = -EACCES;
1244 if ((rt->rt_flags & RTCF_BROADCAST) &&
1245 !sock_flag(sk, SOCK_BROADCAST))
1246 goto out;
1247 if (connected)
1248 sk_dst_set(sk, dst_clone(&rt->dst));
1249 }
1250
1251 if (msg->msg_flags&MSG_CONFIRM)
1252 goto do_confirm;
1253back_from_confirm:
1254
1255 saddr = fl4->saddr;
1256 if (!ipc.addr)
1257 daddr = ipc.addr = fl4->daddr;
1258
1259 /* Lockless fast path for the non-corking case. */
1260 if (!corkreq) {
1261 struct inet_cork cork;
1262
1263 skb = ip_make_skb(sk, fl4, getfrag, msg, ulen,
1264 sizeof(struct udphdr), &ipc, &rt,
1265 &cork, msg->msg_flags);
1266 err = PTR_ERR(skb);
1267 if (!IS_ERR_OR_NULL(skb))
1268 err = udp_send_skb(skb, fl4, &cork);
1269 goto out;
1270 }
1271
1272 lock_sock(sk);
1273 if (unlikely(up->pending)) {
1274 /* The socket is already corked while preparing it. */
1275 /* ... which is an evident application bug. --ANK */
1276 release_sock(sk);
1277
1278 net_dbg_ratelimited("socket already corked\n");
1279 err = -EINVAL;
1280 goto out;
1281 }
1282 /*
1283 * Now cork the socket to pend data.
1284 */
1285 fl4 = &inet->cork.fl.u.ip4;
1286 fl4->daddr = daddr;
1287 fl4->saddr = saddr;
1288 fl4->fl4_dport = dport;
1289 fl4->fl4_sport = inet->inet_sport;
1290 WRITE_ONCE(up->pending, AF_INET);
1291
1292do_append_data:
1293 up->len += ulen;
1294 err = ip_append_data(sk, fl4, getfrag, msg, ulen,
1295 sizeof(struct udphdr), &ipc, &rt,
1296 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1297 if (err)
1298 udp_flush_pending_frames(sk);
1299 else if (!corkreq)
1300 err = udp_push_pending_frames(sk);
1301 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1302 WRITE_ONCE(up->pending, 0);
1303 release_sock(sk);
1304
1305out:
1306 ip_rt_put(rt);
1307out_free:
1308 if (free)
1309 kfree(ipc.opt);
1310 if (!err)
1311 return len;
1312 /*
1313 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1314 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1315 * we don't have a good statistic (IpOutDiscards but it can be too many
1316 * things). We could add another new stat but at least for now that
1317 * seems like overkill.
1318 */
1319 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1320 UDP_INC_STATS(sock_net(sk),
1321 UDP_MIB_SNDBUFERRORS, is_udplite);
1322 }
1323 return err;
1324
1325do_confirm:
1326 if (msg->msg_flags & MSG_PROBE)
1327 dst_confirm_neigh(&rt->dst, &fl4->daddr);
1328 if (!(msg->msg_flags&MSG_PROBE) || len)
1329 goto back_from_confirm;
1330 err = 0;
1331 goto out;
1332}
1333EXPORT_SYMBOL(udp_sendmsg);
1334
1335void udp_splice_eof(struct socket *sock)
1336{
1337 struct sock *sk = sock->sk;
1338 struct udp_sock *up = udp_sk(sk);
1339
1340 if (!READ_ONCE(up->pending) || udp_test_bit(CORK, sk))
1341 return;
1342
1343 lock_sock(sk);
1344 if (up->pending && !udp_test_bit(CORK, sk))
1345 udp_push_pending_frames(sk);
1346 release_sock(sk);
1347}
1348EXPORT_SYMBOL_GPL(udp_splice_eof);
1349
1350#define UDP_SKB_IS_STATELESS 0x80000000
1351
1352/* all head states (dst, sk, nf conntrack) except skb extensions are
1353 * cleared by udp_rcv().
1354 *
1355 * We need to preserve secpath, if present, to eventually process
1356 * IP_CMSG_PASSSEC at recvmsg() time.
1357 *
1358 * Other extensions can be cleared.
1359 */
1360static bool udp_try_make_stateless(struct sk_buff *skb)
1361{
1362 if (!skb_has_extensions(skb))
1363 return true;
1364
1365 if (!secpath_exists(skb)) {
1366 skb_ext_reset(skb);
1367 return true;
1368 }
1369
1370 return false;
1371}
1372
1373static void udp_set_dev_scratch(struct sk_buff *skb)
1374{
1375 struct udp_dev_scratch *scratch = udp_skb_scratch(skb);
1376
1377 BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long));
1378 scratch->_tsize_state = skb->truesize;
1379#if BITS_PER_LONG == 64
1380 scratch->len = skb->len;
1381 scratch->csum_unnecessary = !!skb_csum_unnecessary(skb);
1382 scratch->is_linear = !skb_is_nonlinear(skb);
1383#endif
1384 if (udp_try_make_stateless(skb))
1385 scratch->_tsize_state |= UDP_SKB_IS_STATELESS;
1386}
1387
1388static void udp_skb_csum_unnecessary_set(struct sk_buff *skb)
1389{
1390 /* We come here after udp_lib_checksum_complete() returned 0.
1391 * This means that __skb_checksum_complete() might have
1392 * set skb->csum_valid to 1.
1393 * On 64bit platforms, we can set csum_unnecessary
1394 * to true, but only if the skb is not shared.
1395 */
1396#if BITS_PER_LONG == 64
1397 if (!skb_shared(skb))
1398 udp_skb_scratch(skb)->csum_unnecessary = true;
1399#endif
1400}
1401
1402static int udp_skb_truesize(struct sk_buff *skb)
1403{
1404 return udp_skb_scratch(skb)->_tsize_state & ~UDP_SKB_IS_STATELESS;
1405}
1406
1407static bool udp_skb_has_head_state(struct sk_buff *skb)
1408{
1409 return !(udp_skb_scratch(skb)->_tsize_state & UDP_SKB_IS_STATELESS);
1410}
1411
1412/* fully reclaim rmem/fwd memory allocated for skb */
1413static void udp_rmem_release(struct sock *sk, int size, int partial,
1414 bool rx_queue_lock_held)
1415{
1416 struct udp_sock *up = udp_sk(sk);
1417 struct sk_buff_head *sk_queue;
1418 int amt;
1419
1420 if (likely(partial)) {
1421 up->forward_deficit += size;
1422 size = up->forward_deficit;
1423 if (size < READ_ONCE(up->forward_threshold) &&
1424 !skb_queue_empty(&up->reader_queue))
1425 return;
1426 } else {
1427 size += up->forward_deficit;
1428 }
1429 up->forward_deficit = 0;
1430
1431 /* acquire the sk_receive_queue for fwd allocated memory scheduling,
1432 * if the called don't held it already
1433 */
1434 sk_queue = &sk->sk_receive_queue;
1435 if (!rx_queue_lock_held)
1436 spin_lock(&sk_queue->lock);
1437
1438
1439 sk_forward_alloc_add(sk, size);
1440 amt = (sk->sk_forward_alloc - partial) & ~(PAGE_SIZE - 1);
1441 sk_forward_alloc_add(sk, -amt);
1442
1443 if (amt)
1444 __sk_mem_reduce_allocated(sk, amt >> PAGE_SHIFT);
1445
1446 atomic_sub(size, &sk->sk_rmem_alloc);
1447
1448 /* this can save us from acquiring the rx queue lock on next receive */
1449 skb_queue_splice_tail_init(sk_queue, &up->reader_queue);
1450
1451 if (!rx_queue_lock_held)
1452 spin_unlock(&sk_queue->lock);
1453}
1454
1455/* Note: called with reader_queue.lock held.
1456 * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch
1457 * This avoids a cache line miss while receive_queue lock is held.
1458 * Look at __udp_enqueue_schedule_skb() to find where this copy is done.
1459 */
1460void udp_skb_destructor(struct sock *sk, struct sk_buff *skb)
1461{
1462 prefetch(&skb->data);
1463 udp_rmem_release(sk, udp_skb_truesize(skb), 1, false);
1464}
1465EXPORT_SYMBOL(udp_skb_destructor);
1466
1467/* as above, but the caller held the rx queue lock, too */
1468static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb)
1469{
1470 prefetch(&skb->data);
1471 udp_rmem_release(sk, udp_skb_truesize(skb), 1, true);
1472}
1473
1474/* Idea of busylocks is to let producers grab an extra spinlock
1475 * to relieve pressure on the receive_queue spinlock shared by consumer.
1476 * Under flood, this means that only one producer can be in line
1477 * trying to acquire the receive_queue spinlock.
1478 * These busylock can be allocated on a per cpu manner, instead of a
1479 * per socket one (that would consume a cache line per socket)
1480 */
1481static int udp_busylocks_log __read_mostly;
1482static spinlock_t *udp_busylocks __read_mostly;
1483
1484static spinlock_t *busylock_acquire(void *ptr)
1485{
1486 spinlock_t *busy;
1487
1488 busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log);
1489 spin_lock(busy);
1490 return busy;
1491}
1492
1493static void busylock_release(spinlock_t *busy)
1494{
1495 if (busy)
1496 spin_unlock(busy);
1497}
1498
1499static int udp_rmem_schedule(struct sock *sk, int size)
1500{
1501 int delta;
1502
1503 delta = size - sk->sk_forward_alloc;
1504 if (delta > 0 && !__sk_mem_schedule(sk, delta, SK_MEM_RECV))
1505 return -ENOBUFS;
1506
1507 return 0;
1508}
1509
1510int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
1511{
1512 struct sk_buff_head *list = &sk->sk_receive_queue;
1513 int rmem, err = -ENOMEM;
1514 spinlock_t *busy = NULL;
1515 int size;
1516
1517 /* try to avoid the costly atomic add/sub pair when the receive
1518 * queue is full; always allow at least a packet
1519 */
1520 rmem = atomic_read(&sk->sk_rmem_alloc);
1521 if (rmem > sk->sk_rcvbuf)
1522 goto drop;
1523
1524 /* Under mem pressure, it might be helpful to help udp_recvmsg()
1525 * having linear skbs :
1526 * - Reduce memory overhead and thus increase receive queue capacity
1527 * - Less cache line misses at copyout() time
1528 * - Less work at consume_skb() (less alien page frag freeing)
1529 */
1530 if (rmem > (sk->sk_rcvbuf >> 1)) {
1531 skb_condense(skb);
1532
1533 busy = busylock_acquire(sk);
1534 }
1535 size = skb->truesize;
1536 udp_set_dev_scratch(skb);
1537
1538 /* we drop only if the receive buf is full and the receive
1539 * queue contains some other skb
1540 */
1541 rmem = atomic_add_return(size, &sk->sk_rmem_alloc);
1542 if (rmem > (size + (unsigned int)sk->sk_rcvbuf))
1543 goto uncharge_drop;
1544
1545 spin_lock(&list->lock);
1546 err = udp_rmem_schedule(sk, size);
1547 if (err) {
1548 spin_unlock(&list->lock);
1549 goto uncharge_drop;
1550 }
1551
1552 sk_forward_alloc_add(sk, -size);
1553
1554 /* no need to setup a destructor, we will explicitly release the
1555 * forward allocated memory on dequeue
1556 */
1557 sock_skb_set_dropcount(sk, skb);
1558
1559 __skb_queue_tail(list, skb);
1560 spin_unlock(&list->lock);
1561
1562 if (!sock_flag(sk, SOCK_DEAD))
1563 INDIRECT_CALL_1(sk->sk_data_ready, sock_def_readable, sk);
1564
1565 busylock_release(busy);
1566 return 0;
1567
1568uncharge_drop:
1569 atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1570
1571drop:
1572 atomic_inc(&sk->sk_drops);
1573 busylock_release(busy);
1574 return err;
1575}
1576EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb);
1577
1578void udp_destruct_common(struct sock *sk)
1579{
1580 /* reclaim completely the forward allocated memory */
1581 struct udp_sock *up = udp_sk(sk);
1582 unsigned int total = 0;
1583 struct sk_buff *skb;
1584
1585 skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue);
1586 while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) {
1587 total += skb->truesize;
1588 kfree_skb(skb);
1589 }
1590 udp_rmem_release(sk, total, 0, true);
1591}
1592EXPORT_SYMBOL_GPL(udp_destruct_common);
1593
1594static void udp_destruct_sock(struct sock *sk)
1595{
1596 udp_destruct_common(sk);
1597 inet_sock_destruct(sk);
1598}
1599
1600int udp_init_sock(struct sock *sk)
1601{
1602 udp_lib_init_sock(sk);
1603 sk->sk_destruct = udp_destruct_sock;
1604 set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
1605 return 0;
1606}
1607
1608void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len)
1609{
1610 if (unlikely(READ_ONCE(udp_sk(sk)->peeking_with_offset)))
1611 sk_peek_offset_bwd(sk, len);
1612
1613 if (!skb_unref(skb))
1614 return;
1615
1616 /* In the more common cases we cleared the head states previously,
1617 * see __udp_queue_rcv_skb().
1618 */
1619 if (unlikely(udp_skb_has_head_state(skb)))
1620 skb_release_head_state(skb);
1621 __consume_stateless_skb(skb);
1622}
1623EXPORT_SYMBOL_GPL(skb_consume_udp);
1624
1625static struct sk_buff *__first_packet_length(struct sock *sk,
1626 struct sk_buff_head *rcvq,
1627 int *total)
1628{
1629 struct sk_buff *skb;
1630
1631 while ((skb = skb_peek(rcvq)) != NULL) {
1632 if (udp_lib_checksum_complete(skb)) {
1633 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS,
1634 IS_UDPLITE(sk));
1635 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
1636 IS_UDPLITE(sk));
1637 atomic_inc(&sk->sk_drops);
1638 __skb_unlink(skb, rcvq);
1639 *total += skb->truesize;
1640 kfree_skb(skb);
1641 } else {
1642 udp_skb_csum_unnecessary_set(skb);
1643 break;
1644 }
1645 }
1646 return skb;
1647}
1648
1649/**
1650 * first_packet_length - return length of first packet in receive queue
1651 * @sk: socket
1652 *
1653 * Drops all bad checksum frames, until a valid one is found.
1654 * Returns the length of found skb, or -1 if none is found.
1655 */
1656static int first_packet_length(struct sock *sk)
1657{
1658 struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue;
1659 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1660 struct sk_buff *skb;
1661 int total = 0;
1662 int res;
1663
1664 spin_lock_bh(&rcvq->lock);
1665 skb = __first_packet_length(sk, rcvq, &total);
1666 if (!skb && !skb_queue_empty_lockless(sk_queue)) {
1667 spin_lock(&sk_queue->lock);
1668 skb_queue_splice_tail_init(sk_queue, rcvq);
1669 spin_unlock(&sk_queue->lock);
1670
1671 skb = __first_packet_length(sk, rcvq, &total);
1672 }
1673 res = skb ? skb->len : -1;
1674 if (total)
1675 udp_rmem_release(sk, total, 1, false);
1676 spin_unlock_bh(&rcvq->lock);
1677 return res;
1678}
1679
1680/*
1681 * IOCTL requests applicable to the UDP protocol
1682 */
1683
1684int udp_ioctl(struct sock *sk, int cmd, int *karg)
1685{
1686 switch (cmd) {
1687 case SIOCOUTQ:
1688 {
1689 *karg = sk_wmem_alloc_get(sk);
1690 return 0;
1691 }
1692
1693 case SIOCINQ:
1694 {
1695 *karg = max_t(int, 0, first_packet_length(sk));
1696 return 0;
1697 }
1698
1699 default:
1700 return -ENOIOCTLCMD;
1701 }
1702
1703 return 0;
1704}
1705EXPORT_SYMBOL(udp_ioctl);
1706
1707struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
1708 int *off, int *err)
1709{
1710 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1711 struct sk_buff_head *queue;
1712 struct sk_buff *last;
1713 long timeo;
1714 int error;
1715
1716 queue = &udp_sk(sk)->reader_queue;
1717 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1718 do {
1719 struct sk_buff *skb;
1720
1721 error = sock_error(sk);
1722 if (error)
1723 break;
1724
1725 error = -EAGAIN;
1726 do {
1727 spin_lock_bh(&queue->lock);
1728 skb = __skb_try_recv_from_queue(sk, queue, flags, off,
1729 err, &last);
1730 if (skb) {
1731 if (!(flags & MSG_PEEK))
1732 udp_skb_destructor(sk, skb);
1733 spin_unlock_bh(&queue->lock);
1734 return skb;
1735 }
1736
1737 if (skb_queue_empty_lockless(sk_queue)) {
1738 spin_unlock_bh(&queue->lock);
1739 goto busy_check;
1740 }
1741
1742 /* refill the reader queue and walk it again
1743 * keep both queues locked to avoid re-acquiring
1744 * the sk_receive_queue lock if fwd memory scheduling
1745 * is needed.
1746 */
1747 spin_lock(&sk_queue->lock);
1748 skb_queue_splice_tail_init(sk_queue, queue);
1749
1750 skb = __skb_try_recv_from_queue(sk, queue, flags, off,
1751 err, &last);
1752 if (skb && !(flags & MSG_PEEK))
1753 udp_skb_dtor_locked(sk, skb);
1754 spin_unlock(&sk_queue->lock);
1755 spin_unlock_bh(&queue->lock);
1756 if (skb)
1757 return skb;
1758
1759busy_check:
1760 if (!sk_can_busy_loop(sk))
1761 break;
1762
1763 sk_busy_loop(sk, flags & MSG_DONTWAIT);
1764 } while (!skb_queue_empty_lockless(sk_queue));
1765
1766 /* sk_queue is empty, reader_queue may contain peeked packets */
1767 } while (timeo &&
1768 !__skb_wait_for_more_packets(sk, &sk->sk_receive_queue,
1769 &error, &timeo,
1770 (struct sk_buff *)sk_queue));
1771
1772 *err = error;
1773 return NULL;
1774}
1775EXPORT_SYMBOL(__skb_recv_udp);
1776
1777int udp_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
1778{
1779 struct sk_buff *skb;
1780 int err;
1781
1782try_again:
1783 skb = skb_recv_udp(sk, MSG_DONTWAIT, &err);
1784 if (!skb)
1785 return err;
1786
1787 if (udp_lib_checksum_complete(skb)) {
1788 int is_udplite = IS_UDPLITE(sk);
1789 struct net *net = sock_net(sk);
1790
1791 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, is_udplite);
1792 __UDP_INC_STATS(net, UDP_MIB_INERRORS, is_udplite);
1793 atomic_inc(&sk->sk_drops);
1794 kfree_skb(skb);
1795 goto try_again;
1796 }
1797
1798 WARN_ON_ONCE(!skb_set_owner_sk_safe(skb, sk));
1799 return recv_actor(sk, skb);
1800}
1801EXPORT_SYMBOL(udp_read_skb);
1802
1803/*
1804 * This should be easy, if there is something there we
1805 * return it, otherwise we block.
1806 */
1807
1808int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
1809 int *addr_len)
1810{
1811 struct inet_sock *inet = inet_sk(sk);
1812 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
1813 struct sk_buff *skb;
1814 unsigned int ulen, copied;
1815 int off, err, peeking = flags & MSG_PEEK;
1816 int is_udplite = IS_UDPLITE(sk);
1817 bool checksum_valid = false;
1818
1819 if (flags & MSG_ERRQUEUE)
1820 return ip_recv_error(sk, msg, len, addr_len);
1821
1822try_again:
1823 off = sk_peek_offset(sk, flags);
1824 skb = __skb_recv_udp(sk, flags, &off, &err);
1825 if (!skb)
1826 return err;
1827
1828 ulen = udp_skb_len(skb);
1829 copied = len;
1830 if (copied > ulen - off)
1831 copied = ulen - off;
1832 else if (copied < ulen)
1833 msg->msg_flags |= MSG_TRUNC;
1834
1835 /*
1836 * If checksum is needed at all, try to do it while copying the
1837 * data. If the data is truncated, or if we only want a partial
1838 * coverage checksum (UDP-Lite), do it before the copy.
1839 */
1840
1841 if (copied < ulen || peeking ||
1842 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
1843 checksum_valid = udp_skb_csum_unnecessary(skb) ||
1844 !__udp_lib_checksum_complete(skb);
1845 if (!checksum_valid)
1846 goto csum_copy_err;
1847 }
1848
1849 if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
1850 if (udp_skb_is_linear(skb))
1851 err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
1852 else
1853 err = skb_copy_datagram_msg(skb, off, msg, copied);
1854 } else {
1855 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
1856
1857 if (err == -EINVAL)
1858 goto csum_copy_err;
1859 }
1860
1861 if (unlikely(err)) {
1862 if (!peeking) {
1863 atomic_inc(&sk->sk_drops);
1864 UDP_INC_STATS(sock_net(sk),
1865 UDP_MIB_INERRORS, is_udplite);
1866 }
1867 kfree_skb(skb);
1868 return err;
1869 }
1870
1871 if (!peeking)
1872 UDP_INC_STATS(sock_net(sk),
1873 UDP_MIB_INDATAGRAMS, is_udplite);
1874
1875 sock_recv_cmsgs(msg, sk, skb);
1876
1877 /* Copy the address. */
1878 if (sin) {
1879 sin->sin_family = AF_INET;
1880 sin->sin_port = udp_hdr(skb)->source;
1881 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1882 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1883 *addr_len = sizeof(*sin);
1884
1885 BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk,
1886 (struct sockaddr *)sin,
1887 addr_len);
1888 }
1889
1890 if (udp_test_bit(GRO_ENABLED, sk))
1891 udp_cmsg_recv(msg, sk, skb);
1892
1893 if (inet_cmsg_flags(inet))
1894 ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off);
1895
1896 err = copied;
1897 if (flags & MSG_TRUNC)
1898 err = ulen;
1899
1900 skb_consume_udp(sk, skb, peeking ? -err : err);
1901 return err;
1902
1903csum_copy_err:
1904 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
1905 udp_skb_destructor)) {
1906 UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1907 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1908 }
1909 kfree_skb(skb);
1910
1911 /* starting over for a new packet, but check if we need to yield */
1912 cond_resched();
1913 msg->msg_flags &= ~MSG_TRUNC;
1914 goto try_again;
1915}
1916
1917int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
1918{
1919 /* This check is replicated from __ip4_datagram_connect() and
1920 * intended to prevent BPF program called below from accessing bytes
1921 * that are out of the bound specified by user in addr_len.
1922 */
1923 if (addr_len < sizeof(struct sockaddr_in))
1924 return -EINVAL;
1925
1926 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr, &addr_len);
1927}
1928EXPORT_SYMBOL(udp_pre_connect);
1929
1930int __udp_disconnect(struct sock *sk, int flags)
1931{
1932 struct inet_sock *inet = inet_sk(sk);
1933 /*
1934 * 1003.1g - break association.
1935 */
1936
1937 sk->sk_state = TCP_CLOSE;
1938 inet->inet_daddr = 0;
1939 inet->inet_dport = 0;
1940 sock_rps_reset_rxhash(sk);
1941 sk->sk_bound_dev_if = 0;
1942 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) {
1943 inet_reset_saddr(sk);
1944 if (sk->sk_prot->rehash &&
1945 (sk->sk_userlocks & SOCK_BINDPORT_LOCK))
1946 sk->sk_prot->rehash(sk);
1947 }
1948
1949 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1950 sk->sk_prot->unhash(sk);
1951 inet->inet_sport = 0;
1952 }
1953 sk_dst_reset(sk);
1954 return 0;
1955}
1956EXPORT_SYMBOL(__udp_disconnect);
1957
1958int udp_disconnect(struct sock *sk, int flags)
1959{
1960 lock_sock(sk);
1961 __udp_disconnect(sk, flags);
1962 release_sock(sk);
1963 return 0;
1964}
1965EXPORT_SYMBOL(udp_disconnect);
1966
1967void udp_lib_unhash(struct sock *sk)
1968{
1969 if (sk_hashed(sk)) {
1970 struct udp_table *udptable = udp_get_table_prot(sk);
1971 struct udp_hslot *hslot, *hslot2;
1972
1973 hslot = udp_hashslot(udptable, sock_net(sk),
1974 udp_sk(sk)->udp_port_hash);
1975 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1976
1977 spin_lock_bh(&hslot->lock);
1978 if (rcu_access_pointer(sk->sk_reuseport_cb))
1979 reuseport_detach_sock(sk);
1980 if (sk_del_node_init_rcu(sk)) {
1981 hslot->count--;
1982 inet_sk(sk)->inet_num = 0;
1983 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1984
1985 spin_lock(&hslot2->lock);
1986 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1987 hslot2->count--;
1988 spin_unlock(&hslot2->lock);
1989 }
1990 spin_unlock_bh(&hslot->lock);
1991 }
1992}
1993EXPORT_SYMBOL(udp_lib_unhash);
1994
1995/*
1996 * inet_rcv_saddr was changed, we must rehash secondary hash
1997 */
1998void udp_lib_rehash(struct sock *sk, u16 newhash)
1999{
2000 if (sk_hashed(sk)) {
2001 struct udp_table *udptable = udp_get_table_prot(sk);
2002 struct udp_hslot *hslot, *hslot2, *nhslot2;
2003
2004 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
2005 nhslot2 = udp_hashslot2(udptable, newhash);
2006 udp_sk(sk)->udp_portaddr_hash = newhash;
2007
2008 if (hslot2 != nhslot2 ||
2009 rcu_access_pointer(sk->sk_reuseport_cb)) {
2010 hslot = udp_hashslot(udptable, sock_net(sk),
2011 udp_sk(sk)->udp_port_hash);
2012 /* we must lock primary chain too */
2013 spin_lock_bh(&hslot->lock);
2014 if (rcu_access_pointer(sk->sk_reuseport_cb))
2015 reuseport_detach_sock(sk);
2016
2017 if (hslot2 != nhslot2) {
2018 spin_lock(&hslot2->lock);
2019 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
2020 hslot2->count--;
2021 spin_unlock(&hslot2->lock);
2022
2023 spin_lock(&nhslot2->lock);
2024 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
2025 &nhslot2->head);
2026 nhslot2->count++;
2027 spin_unlock(&nhslot2->lock);
2028 }
2029
2030 spin_unlock_bh(&hslot->lock);
2031 }
2032 }
2033}
2034EXPORT_SYMBOL(udp_lib_rehash);
2035
2036void udp_v4_rehash(struct sock *sk)
2037{
2038 u16 new_hash = ipv4_portaddr_hash(sock_net(sk),
2039 inet_sk(sk)->inet_rcv_saddr,
2040 inet_sk(sk)->inet_num);
2041 udp_lib_rehash(sk, new_hash);
2042}
2043
2044static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2045{
2046 int rc;
2047
2048 if (inet_sk(sk)->inet_daddr) {
2049 sock_rps_save_rxhash(sk, skb);
2050 sk_mark_napi_id(sk, skb);
2051 sk_incoming_cpu_update(sk);
2052 } else {
2053 sk_mark_napi_id_once(sk, skb);
2054 }
2055
2056 rc = __udp_enqueue_schedule_skb(sk, skb);
2057 if (rc < 0) {
2058 int is_udplite = IS_UDPLITE(sk);
2059 int drop_reason;
2060
2061 /* Note that an ENOMEM error is charged twice */
2062 if (rc == -ENOMEM) {
2063 UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS,
2064 is_udplite);
2065 drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
2066 } else {
2067 UDP_INC_STATS(sock_net(sk), UDP_MIB_MEMERRORS,
2068 is_udplite);
2069 drop_reason = SKB_DROP_REASON_PROTO_MEM;
2070 }
2071 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
2072 kfree_skb_reason(skb, drop_reason);
2073 trace_udp_fail_queue_rcv_skb(rc, sk);
2074 return -1;
2075 }
2076
2077 return 0;
2078}
2079
2080/* returns:
2081 * -1: error
2082 * 0: success
2083 * >0: "udp encap" protocol resubmission
2084 *
2085 * Note that in the success and error cases, the skb is assumed to
2086 * have either been requeued or freed.
2087 */
2088static int udp_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
2089{
2090 int drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
2091 struct udp_sock *up = udp_sk(sk);
2092 int is_udplite = IS_UDPLITE(sk);
2093
2094 /*
2095 * Charge it to the socket, dropping if the queue is full.
2096 */
2097 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {
2098 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
2099 goto drop;
2100 }
2101 nf_reset_ct(skb);
2102
2103 if (static_branch_unlikely(&udp_encap_needed_key) &&
2104 READ_ONCE(up->encap_type)) {
2105 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
2106
2107 /*
2108 * This is an encapsulation socket so pass the skb to
2109 * the socket's udp_encap_rcv() hook. Otherwise, just
2110 * fall through and pass this up the UDP socket.
2111 * up->encap_rcv() returns the following value:
2112 * =0 if skb was successfully passed to the encap
2113 * handler or was discarded by it.
2114 * >0 if skb should be passed on to UDP.
2115 * <0 if skb should be resubmitted as proto -N
2116 */
2117
2118 /* if we're overly short, let UDP handle it */
2119 encap_rcv = READ_ONCE(up->encap_rcv);
2120 if (encap_rcv) {
2121 int ret;
2122
2123 /* Verify checksum before giving to encap */
2124 if (udp_lib_checksum_complete(skb))
2125 goto csum_error;
2126
2127 ret = encap_rcv(sk, skb);
2128 if (ret <= 0) {
2129 __UDP_INC_STATS(sock_net(sk),
2130 UDP_MIB_INDATAGRAMS,
2131 is_udplite);
2132 return -ret;
2133 }
2134 }
2135
2136 /* FALLTHROUGH -- it's a UDP Packet */
2137 }
2138
2139 /*
2140 * UDP-Lite specific tests, ignored on UDP sockets
2141 */
2142 if (udp_test_bit(UDPLITE_RECV_CC, sk) && UDP_SKB_CB(skb)->partial_cov) {
2143 u16 pcrlen = READ_ONCE(up->pcrlen);
2144
2145 /*
2146 * MIB statistics other than incrementing the error count are
2147 * disabled for the following two types of errors: these depend
2148 * on the application settings, not on the functioning of the
2149 * protocol stack as such.
2150 *
2151 * RFC 3828 here recommends (sec 3.3): "There should also be a
2152 * way ... to ... at least let the receiving application block
2153 * delivery of packets with coverage values less than a value
2154 * provided by the application."
2155 */
2156 if (pcrlen == 0) { /* full coverage was set */
2157 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n",
2158 UDP_SKB_CB(skb)->cscov, skb->len);
2159 goto drop;
2160 }
2161 /* The next case involves violating the min. coverage requested
2162 * by the receiver. This is subtle: if receiver wants x and x is
2163 * greater than the buffersize/MTU then receiver will complain
2164 * that it wants x while sender emits packets of smaller size y.
2165 * Therefore the above ...()->partial_cov statement is essential.
2166 */
2167 if (UDP_SKB_CB(skb)->cscov < pcrlen) {
2168 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n",
2169 UDP_SKB_CB(skb)->cscov, pcrlen);
2170 goto drop;
2171 }
2172 }
2173
2174 prefetch(&sk->sk_rmem_alloc);
2175 if (rcu_access_pointer(sk->sk_filter) &&
2176 udp_lib_checksum_complete(skb))
2177 goto csum_error;
2178
2179 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) {
2180 drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
2181 goto drop;
2182 }
2183
2184 udp_csum_pull_header(skb);
2185
2186 ipv4_pktinfo_prepare(sk, skb, true);
2187 return __udp_queue_rcv_skb(sk, skb);
2188
2189csum_error:
2190 drop_reason = SKB_DROP_REASON_UDP_CSUM;
2191 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
2192drop:
2193 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
2194 atomic_inc(&sk->sk_drops);
2195 kfree_skb_reason(skb, drop_reason);
2196 return -1;
2197}
2198
2199static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2200{
2201 struct sk_buff *next, *segs;
2202 int ret;
2203
2204 if (likely(!udp_unexpected_gso(sk, skb)))
2205 return udp_queue_rcv_one_skb(sk, skb);
2206
2207 BUILD_BUG_ON(sizeof(struct udp_skb_cb) > SKB_GSO_CB_OFFSET);
2208 __skb_push(skb, -skb_mac_offset(skb));
2209 segs = udp_rcv_segment(sk, skb, true);
2210 skb_list_walk_safe(segs, skb, next) {
2211 __skb_pull(skb, skb_transport_offset(skb));
2212
2213 udp_post_segment_fix_csum(skb);
2214 ret = udp_queue_rcv_one_skb(sk, skb);
2215 if (ret > 0)
2216 ip_protocol_deliver_rcu(dev_net(skb->dev), skb, ret);
2217 }
2218 return 0;
2219}
2220
2221/* For TCP sockets, sk_rx_dst is protected by socket lock
2222 * For UDP, we use xchg() to guard against concurrent changes.
2223 */
2224bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
2225{
2226 struct dst_entry *old;
2227
2228 if (dst_hold_safe(dst)) {
2229 old = xchg((__force struct dst_entry **)&sk->sk_rx_dst, dst);
2230 dst_release(old);
2231 return old != dst;
2232 }
2233 return false;
2234}
2235EXPORT_SYMBOL(udp_sk_rx_dst_set);
2236
2237/*
2238 * Multicasts and broadcasts go to each listener.
2239 *
2240 * Note: called only from the BH handler context.
2241 */
2242static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
2243 struct udphdr *uh,
2244 __be32 saddr, __be32 daddr,
2245 struct udp_table *udptable,
2246 int proto)
2247{
2248 struct sock *sk, *first = NULL;
2249 unsigned short hnum = ntohs(uh->dest);
2250 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
2251 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
2252 unsigned int offset = offsetof(typeof(*sk), sk_node);
2253 int dif = skb->dev->ifindex;
2254 int sdif = inet_sdif(skb);
2255 struct hlist_node *node;
2256 struct sk_buff *nskb;
2257
2258 if (use_hash2) {
2259 hash2_any = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum) &
2260 udptable->mask;
2261 hash2 = ipv4_portaddr_hash(net, daddr, hnum) & udptable->mask;
2262start_lookup:
2263 hslot = &udptable->hash2[hash2];
2264 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
2265 }
2266
2267 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
2268 if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr,
2269 uh->source, saddr, dif, sdif, hnum))
2270 continue;
2271
2272 if (!first) {
2273 first = sk;
2274 continue;
2275 }
2276 nskb = skb_clone(skb, GFP_ATOMIC);
2277
2278 if (unlikely(!nskb)) {
2279 atomic_inc(&sk->sk_drops);
2280 __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
2281 IS_UDPLITE(sk));
2282 __UDP_INC_STATS(net, UDP_MIB_INERRORS,
2283 IS_UDPLITE(sk));
2284 continue;
2285 }
2286 if (udp_queue_rcv_skb(sk, nskb) > 0)
2287 consume_skb(nskb);
2288 }
2289
2290 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
2291 if (use_hash2 && hash2 != hash2_any) {
2292 hash2 = hash2_any;
2293 goto start_lookup;
2294 }
2295
2296 if (first) {
2297 if (udp_queue_rcv_skb(first, skb) > 0)
2298 consume_skb(skb);
2299 } else {
2300 kfree_skb(skb);
2301 __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
2302 proto == IPPROTO_UDPLITE);
2303 }
2304 return 0;
2305}
2306
2307/* Initialize UDP checksum. If exited with zero value (success),
2308 * CHECKSUM_UNNECESSARY means, that no more checks are required.
2309 * Otherwise, csum completion requires checksumming packet body,
2310 * including udp header and folding it to skb->csum.
2311 */
2312static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
2313 int proto)
2314{
2315 int err;
2316
2317 UDP_SKB_CB(skb)->partial_cov = 0;
2318 UDP_SKB_CB(skb)->cscov = skb->len;
2319
2320 if (proto == IPPROTO_UDPLITE) {
2321 err = udplite_checksum_init(skb, uh);
2322 if (err)
2323 return err;
2324
2325 if (UDP_SKB_CB(skb)->partial_cov) {
2326 skb->csum = inet_compute_pseudo(skb, proto);
2327 return 0;
2328 }
2329 }
2330
2331 /* Note, we are only interested in != 0 or == 0, thus the
2332 * force to int.
2333 */
2334 err = (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
2335 inet_compute_pseudo);
2336 if (err)
2337 return err;
2338
2339 if (skb->ip_summed == CHECKSUM_COMPLETE && !skb->csum_valid) {
2340 /* If SW calculated the value, we know it's bad */
2341 if (skb->csum_complete_sw)
2342 return 1;
2343
2344 /* HW says the value is bad. Let's validate that.
2345 * skb->csum is no longer the full packet checksum,
2346 * so don't treat it as such.
2347 */
2348 skb_checksum_complete_unset(skb);
2349 }
2350
2351 return 0;
2352}
2353
2354/* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
2355 * return code conversion for ip layer consumption
2356 */
2357static int udp_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
2358 struct udphdr *uh)
2359{
2360 int ret;
2361
2362 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
2363 skb_checksum_try_convert(skb, IPPROTO_UDP, inet_compute_pseudo);
2364
2365 ret = udp_queue_rcv_skb(sk, skb);
2366
2367 /* a return value > 0 means to resubmit the input, but
2368 * it wants the return to be -protocol, or 0
2369 */
2370 if (ret > 0)
2371 return -ret;
2372 return 0;
2373}
2374
2375/*
2376 * All we need to do is get the socket, and then do a checksum.
2377 */
2378
2379int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
2380 int proto)
2381{
2382 struct sock *sk;
2383 struct udphdr *uh;
2384 unsigned short ulen;
2385 struct rtable *rt = skb_rtable(skb);
2386 __be32 saddr, daddr;
2387 struct net *net = dev_net(skb->dev);
2388 bool refcounted;
2389 int drop_reason;
2390
2391 drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
2392
2393 /*
2394 * Validate the packet.
2395 */
2396 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
2397 goto drop; /* No space for header. */
2398
2399 uh = udp_hdr(skb);
2400 ulen = ntohs(uh->len);
2401 saddr = ip_hdr(skb)->saddr;
2402 daddr = ip_hdr(skb)->daddr;
2403
2404 if (ulen > skb->len)
2405 goto short_packet;
2406
2407 if (proto == IPPROTO_UDP) {
2408 /* UDP validates ulen. */
2409 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
2410 goto short_packet;
2411 uh = udp_hdr(skb);
2412 }
2413
2414 if (udp4_csum_init(skb, uh, proto))
2415 goto csum_error;
2416
2417 sk = inet_steal_sock(net, skb, sizeof(struct udphdr), saddr, uh->source, daddr, uh->dest,
2418 &refcounted, udp_ehashfn);
2419 if (IS_ERR(sk))
2420 goto no_sk;
2421
2422 if (sk) {
2423 struct dst_entry *dst = skb_dst(skb);
2424 int ret;
2425
2426 if (unlikely(rcu_dereference(sk->sk_rx_dst) != dst))
2427 udp_sk_rx_dst_set(sk, dst);
2428
2429 ret = udp_unicast_rcv_skb(sk, skb, uh);
2430 if (refcounted)
2431 sock_put(sk);
2432 return ret;
2433 }
2434
2435 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
2436 return __udp4_lib_mcast_deliver(net, skb, uh,
2437 saddr, daddr, udptable, proto);
2438
2439 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
2440 if (sk)
2441 return udp_unicast_rcv_skb(sk, skb, uh);
2442no_sk:
2443 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
2444 goto drop;
2445 nf_reset_ct(skb);
2446
2447 /* No socket. Drop packet silently, if checksum is wrong */
2448 if (udp_lib_checksum_complete(skb))
2449 goto csum_error;
2450
2451 drop_reason = SKB_DROP_REASON_NO_SOCKET;
2452 __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
2453 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
2454
2455 /*
2456 * Hmm. We got an UDP packet to a port to which we
2457 * don't wanna listen. Ignore it.
2458 */
2459 kfree_skb_reason(skb, drop_reason);
2460 return 0;
2461
2462short_packet:
2463 drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL;
2464 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
2465 proto == IPPROTO_UDPLITE ? "Lite" : "",
2466 &saddr, ntohs(uh->source),
2467 ulen, skb->len,
2468 &daddr, ntohs(uh->dest));
2469 goto drop;
2470
2471csum_error:
2472 /*
2473 * RFC1122: OK. Discards the bad packet silently (as far as
2474 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
2475 */
2476 drop_reason = SKB_DROP_REASON_UDP_CSUM;
2477 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
2478 proto == IPPROTO_UDPLITE ? "Lite" : "",
2479 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
2480 ulen);
2481 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
2482drop:
2483 __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
2484 kfree_skb_reason(skb, drop_reason);
2485 return 0;
2486}
2487
2488/* We can only early demux multicast if there is a single matching socket.
2489 * If more than one socket found returns NULL
2490 */
2491static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
2492 __be16 loc_port, __be32 loc_addr,
2493 __be16 rmt_port, __be32 rmt_addr,
2494 int dif, int sdif)
2495{
2496 struct udp_table *udptable = net->ipv4.udp_table;
2497 unsigned short hnum = ntohs(loc_port);
2498 struct sock *sk, *result;
2499 struct udp_hslot *hslot;
2500 unsigned int slot;
2501
2502 slot = udp_hashfn(net, hnum, udptable->mask);
2503 hslot = &udptable->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 struct udp_table *udptable = net->ipv4.udp_table;
2532 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
2533 unsigned short hnum = ntohs(loc_port);
2534 unsigned int hash2, slot2;
2535 struct udp_hslot *hslot2;
2536 __portpair ports;
2537 struct sock *sk;
2538
2539 hash2 = ipv4_portaddr_hash(net, loc_addr, hnum);
2540 slot2 = hash2 & udptable->mask;
2541 hslot2 = &udptable->hash2[slot2];
2542 ports = INET_COMBINED_PORTS(rmt_port, hnum);
2543
2544 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
2545 if (inet_match(net, sk, acookie, ports, dif, sdif))
2546 return sk;
2547 /* Only check first socket in chain */
2548 break;
2549 }
2550 return NULL;
2551}
2552
2553int udp_v4_early_demux(struct sk_buff *skb)
2554{
2555 struct net *net = dev_net(skb->dev);
2556 struct in_device *in_dev = NULL;
2557 const struct iphdr *iph;
2558 const struct udphdr *uh;
2559 struct sock *sk = NULL;
2560 struct dst_entry *dst;
2561 int dif = skb->dev->ifindex;
2562 int sdif = inet_sdif(skb);
2563 int ours;
2564
2565 /* validate the packet */
2566 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
2567 return 0;
2568
2569 iph = ip_hdr(skb);
2570 uh = udp_hdr(skb);
2571
2572 if (skb->pkt_type == PACKET_MULTICAST) {
2573 in_dev = __in_dev_get_rcu(skb->dev);
2574
2575 if (!in_dev)
2576 return 0;
2577
2578 ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
2579 iph->protocol);
2580 if (!ours)
2581 return 0;
2582
2583 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
2584 uh->source, iph->saddr,
2585 dif, sdif);
2586 } else if (skb->pkt_type == PACKET_HOST) {
2587 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
2588 uh->source, iph->saddr, dif, sdif);
2589 }
2590
2591 if (!sk)
2592 return 0;
2593
2594 skb->sk = sk;
2595 DEBUG_NET_WARN_ON_ONCE(sk_is_refcounted(sk));
2596 skb->destructor = sock_pfree;
2597 dst = rcu_dereference(sk->sk_rx_dst);
2598
2599 if (dst)
2600 dst = dst_check(dst, 0);
2601 if (dst) {
2602 u32 itag = 0;
2603
2604 /* set noref for now.
2605 * any place which wants to hold dst has to call
2606 * dst_hold_safe()
2607 */
2608 skb_dst_set_noref(skb, dst);
2609
2610 /* for unconnected multicast sockets we need to validate
2611 * the source on each packet
2612 */
2613 if (!inet_sk(sk)->inet_daddr && in_dev)
2614 return ip_mc_validate_source(skb, iph->daddr,
2615 iph->saddr,
2616 iph->tos & IPTOS_RT_MASK,
2617 skb->dev, in_dev, &itag);
2618 }
2619 return 0;
2620}
2621
2622int udp_rcv(struct sk_buff *skb)
2623{
2624 return __udp4_lib_rcv(skb, dev_net(skb->dev)->ipv4.udp_table, IPPROTO_UDP);
2625}
2626
2627void udp_destroy_sock(struct sock *sk)
2628{
2629 struct udp_sock *up = udp_sk(sk);
2630 bool slow = lock_sock_fast(sk);
2631
2632 /* protects from races with udp_abort() */
2633 sock_set_flag(sk, SOCK_DEAD);
2634 udp_flush_pending_frames(sk);
2635 unlock_sock_fast(sk, slow);
2636 if (static_branch_unlikely(&udp_encap_needed_key)) {
2637 if (up->encap_type) {
2638 void (*encap_destroy)(struct sock *sk);
2639 encap_destroy = READ_ONCE(up->encap_destroy);
2640 if (encap_destroy)
2641 encap_destroy(sk);
2642 }
2643 if (udp_test_bit(ENCAP_ENABLED, sk))
2644 static_branch_dec(&udp_encap_needed_key);
2645 }
2646}
2647
2648static void set_xfrm_gro_udp_encap_rcv(__u16 encap_type, unsigned short family,
2649 struct sock *sk)
2650{
2651#ifdef CONFIG_XFRM
2652 if (udp_test_bit(GRO_ENABLED, sk) && encap_type == UDP_ENCAP_ESPINUDP) {
2653 if (family == AF_INET)
2654 WRITE_ONCE(udp_sk(sk)->gro_receive, xfrm4_gro_udp_encap_rcv);
2655 else if (IS_ENABLED(CONFIG_IPV6) && family == AF_INET6)
2656 WRITE_ONCE(udp_sk(sk)->gro_receive, ipv6_stub->xfrm6_gro_udp_encap_rcv);
2657 }
2658#endif
2659}
2660
2661/*
2662 * Socket option code for UDP
2663 */
2664int udp_lib_setsockopt(struct sock *sk, int level, int optname,
2665 sockptr_t optval, unsigned int optlen,
2666 int (*push_pending_frames)(struct sock *))
2667{
2668 struct udp_sock *up = udp_sk(sk);
2669 int val, valbool;
2670 int err = 0;
2671 int is_udplite = IS_UDPLITE(sk);
2672
2673 if (level == SOL_SOCKET) {
2674 err = sk_setsockopt(sk, level, optname, optval, optlen);
2675
2676 if (optname == SO_RCVBUF || optname == SO_RCVBUFFORCE) {
2677 sockopt_lock_sock(sk);
2678 /* paired with READ_ONCE in udp_rmem_release() */
2679 WRITE_ONCE(up->forward_threshold, sk->sk_rcvbuf >> 2);
2680 sockopt_release_sock(sk);
2681 }
2682 return err;
2683 }
2684
2685 if (optlen < sizeof(int))
2686 return -EINVAL;
2687
2688 if (copy_from_sockptr(&val, optval, sizeof(val)))
2689 return -EFAULT;
2690
2691 valbool = val ? 1 : 0;
2692
2693 switch (optname) {
2694 case UDP_CORK:
2695 if (val != 0) {
2696 udp_set_bit(CORK, sk);
2697 } else {
2698 udp_clear_bit(CORK, sk);
2699 lock_sock(sk);
2700 push_pending_frames(sk);
2701 release_sock(sk);
2702 }
2703 break;
2704
2705 case UDP_ENCAP:
2706 switch (val) {
2707 case 0:
2708#ifdef CONFIG_XFRM
2709 case UDP_ENCAP_ESPINUDP:
2710 set_xfrm_gro_udp_encap_rcv(val, sk->sk_family, sk);
2711 fallthrough;
2712 case UDP_ENCAP_ESPINUDP_NON_IKE:
2713#if IS_ENABLED(CONFIG_IPV6)
2714 if (sk->sk_family == AF_INET6)
2715 WRITE_ONCE(up->encap_rcv,
2716 ipv6_stub->xfrm6_udp_encap_rcv);
2717 else
2718#endif
2719 WRITE_ONCE(up->encap_rcv,
2720 xfrm4_udp_encap_rcv);
2721#endif
2722 fallthrough;
2723 case UDP_ENCAP_L2TPINUDP:
2724 WRITE_ONCE(up->encap_type, val);
2725 udp_tunnel_encap_enable(sk);
2726 break;
2727 default:
2728 err = -ENOPROTOOPT;
2729 break;
2730 }
2731 break;
2732
2733 case UDP_NO_CHECK6_TX:
2734 udp_set_no_check6_tx(sk, valbool);
2735 break;
2736
2737 case UDP_NO_CHECK6_RX:
2738 udp_set_no_check6_rx(sk, valbool);
2739 break;
2740
2741 case UDP_SEGMENT:
2742 if (val < 0 || val > USHRT_MAX)
2743 return -EINVAL;
2744 WRITE_ONCE(up->gso_size, val);
2745 break;
2746
2747 case UDP_GRO:
2748
2749 /* when enabling GRO, accept the related GSO packet type */
2750 if (valbool)
2751 udp_tunnel_encap_enable(sk);
2752 udp_assign_bit(GRO_ENABLED, sk, valbool);
2753 udp_assign_bit(ACCEPT_L4, sk, valbool);
2754 set_xfrm_gro_udp_encap_rcv(up->encap_type, sk->sk_family, sk);
2755 break;
2756
2757 /*
2758 * UDP-Lite's partial checksum coverage (RFC 3828).
2759 */
2760 /* The sender sets actual checksum coverage length via this option.
2761 * The case coverage > packet length is handled by send module. */
2762 case UDPLITE_SEND_CSCOV:
2763 if (!is_udplite) /* Disable the option on UDP sockets */
2764 return -ENOPROTOOPT;
2765 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
2766 val = 8;
2767 else if (val > USHRT_MAX)
2768 val = USHRT_MAX;
2769 WRITE_ONCE(up->pcslen, val);
2770 udp_set_bit(UDPLITE_SEND_CC, sk);
2771 break;
2772
2773 /* The receiver specifies a minimum checksum coverage value. To make
2774 * sense, this should be set to at least 8 (as done below). If zero is
2775 * used, this again means full checksum coverage. */
2776 case UDPLITE_RECV_CSCOV:
2777 if (!is_udplite) /* Disable the option on UDP sockets */
2778 return -ENOPROTOOPT;
2779 if (val != 0 && val < 8) /* Avoid silly minimal values. */
2780 val = 8;
2781 else if (val > USHRT_MAX)
2782 val = USHRT_MAX;
2783 WRITE_ONCE(up->pcrlen, val);
2784 udp_set_bit(UDPLITE_RECV_CC, sk);
2785 break;
2786
2787 default:
2788 err = -ENOPROTOOPT;
2789 break;
2790 }
2791
2792 return err;
2793}
2794EXPORT_SYMBOL(udp_lib_setsockopt);
2795
2796int udp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
2797 unsigned int optlen)
2798{
2799 if (level == SOL_UDP || level == SOL_UDPLITE || level == SOL_SOCKET)
2800 return udp_lib_setsockopt(sk, level, optname,
2801 optval, optlen,
2802 udp_push_pending_frames);
2803 return ip_setsockopt(sk, level, optname, optval, optlen);
2804}
2805
2806int udp_lib_getsockopt(struct sock *sk, int level, int optname,
2807 char __user *optval, int __user *optlen)
2808{
2809 struct udp_sock *up = udp_sk(sk);
2810 int val, len;
2811
2812 if (get_user(len, optlen))
2813 return -EFAULT;
2814
2815 if (len < 0)
2816 return -EINVAL;
2817
2818 len = min_t(unsigned int, len, sizeof(int));
2819
2820 switch (optname) {
2821 case UDP_CORK:
2822 val = udp_test_bit(CORK, sk);
2823 break;
2824
2825 case UDP_ENCAP:
2826 val = READ_ONCE(up->encap_type);
2827 break;
2828
2829 case UDP_NO_CHECK6_TX:
2830 val = udp_get_no_check6_tx(sk);
2831 break;
2832
2833 case UDP_NO_CHECK6_RX:
2834 val = udp_get_no_check6_rx(sk);
2835 break;
2836
2837 case UDP_SEGMENT:
2838 val = READ_ONCE(up->gso_size);
2839 break;
2840
2841 case UDP_GRO:
2842 val = udp_test_bit(GRO_ENABLED, sk);
2843 break;
2844
2845 /* The following two cannot be changed on UDP sockets, the return is
2846 * always 0 (which corresponds to the full checksum coverage of UDP). */
2847 case UDPLITE_SEND_CSCOV:
2848 val = READ_ONCE(up->pcslen);
2849 break;
2850
2851 case UDPLITE_RECV_CSCOV:
2852 val = READ_ONCE(up->pcrlen);
2853 break;
2854
2855 default:
2856 return -ENOPROTOOPT;
2857 }
2858
2859 if (put_user(len, optlen))
2860 return -EFAULT;
2861 if (copy_to_user(optval, &val, len))
2862 return -EFAULT;
2863 return 0;
2864}
2865EXPORT_SYMBOL(udp_lib_getsockopt);
2866
2867int udp_getsockopt(struct sock *sk, int level, int optname,
2868 char __user *optval, int __user *optlen)
2869{
2870 if (level == SOL_UDP || level == SOL_UDPLITE)
2871 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2872 return ip_getsockopt(sk, level, optname, optval, optlen);
2873}
2874
2875/**
2876 * udp_poll - wait for a UDP event.
2877 * @file: - file struct
2878 * @sock: - socket
2879 * @wait: - poll table
2880 *
2881 * This is same as datagram poll, except for the special case of
2882 * blocking sockets. If application is using a blocking fd
2883 * and a packet with checksum error is in the queue;
2884 * then it could get return from select indicating data available
2885 * but then block when reading it. Add special case code
2886 * to work around these arguably broken applications.
2887 */
2888__poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait)
2889{
2890 __poll_t mask = datagram_poll(file, sock, wait);
2891 struct sock *sk = sock->sk;
2892
2893 if (!skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
2894 mask |= EPOLLIN | EPOLLRDNORM;
2895
2896 /* Check for false positives due to checksum errors */
2897 if ((mask & EPOLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
2898 !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1)
2899 mask &= ~(EPOLLIN | EPOLLRDNORM);
2900
2901 /* psock ingress_msg queue should not contain any bad checksum frames */
2902 if (sk_is_readable(sk))
2903 mask |= EPOLLIN | EPOLLRDNORM;
2904 return mask;
2905
2906}
2907EXPORT_SYMBOL(udp_poll);
2908
2909int udp_abort(struct sock *sk, int err)
2910{
2911 if (!has_current_bpf_ctx())
2912 lock_sock(sk);
2913
2914 /* udp{v6}_destroy_sock() sets it under the sk lock, avoid racing
2915 * with close()
2916 */
2917 if (sock_flag(sk, SOCK_DEAD))
2918 goto out;
2919
2920 sk->sk_err = err;
2921 sk_error_report(sk);
2922 __udp_disconnect(sk, 0);
2923
2924out:
2925 if (!has_current_bpf_ctx())
2926 release_sock(sk);
2927
2928 return 0;
2929}
2930EXPORT_SYMBOL_GPL(udp_abort);
2931
2932struct proto udp_prot = {
2933 .name = "UDP",
2934 .owner = THIS_MODULE,
2935 .close = udp_lib_close,
2936 .pre_connect = udp_pre_connect,
2937 .connect = ip4_datagram_connect,
2938 .disconnect = udp_disconnect,
2939 .ioctl = udp_ioctl,
2940 .init = udp_init_sock,
2941 .destroy = udp_destroy_sock,
2942 .setsockopt = udp_setsockopt,
2943 .getsockopt = udp_getsockopt,
2944 .sendmsg = udp_sendmsg,
2945 .recvmsg = udp_recvmsg,
2946 .splice_eof = udp_splice_eof,
2947 .release_cb = ip4_datagram_release_cb,
2948 .hash = udp_lib_hash,
2949 .unhash = udp_lib_unhash,
2950 .rehash = udp_v4_rehash,
2951 .get_port = udp_v4_get_port,
2952 .put_port = udp_lib_unhash,
2953#ifdef CONFIG_BPF_SYSCALL
2954 .psock_update_sk_prot = udp_bpf_update_proto,
2955#endif
2956 .memory_allocated = &udp_memory_allocated,
2957 .per_cpu_fw_alloc = &udp_memory_per_cpu_fw_alloc,
2958
2959 .sysctl_mem = sysctl_udp_mem,
2960 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
2961 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
2962 .obj_size = sizeof(struct udp_sock),
2963 .h.udp_table = NULL,
2964 .diag_destroy = udp_abort,
2965};
2966EXPORT_SYMBOL(udp_prot);
2967
2968/* ------------------------------------------------------------------------ */
2969#ifdef CONFIG_PROC_FS
2970
2971static unsigned short seq_file_family(const struct seq_file *seq);
2972static bool seq_sk_match(struct seq_file *seq, const struct sock *sk)
2973{
2974 unsigned short family = seq_file_family(seq);
2975
2976 /* AF_UNSPEC is used as a match all */
2977 return ((family == AF_UNSPEC || family == sk->sk_family) &&
2978 net_eq(sock_net(sk), seq_file_net(seq)));
2979}
2980
2981#ifdef CONFIG_BPF_SYSCALL
2982static const struct seq_operations bpf_iter_udp_seq_ops;
2983#endif
2984static struct udp_table *udp_get_table_seq(struct seq_file *seq,
2985 struct net *net)
2986{
2987 const struct udp_seq_afinfo *afinfo;
2988
2989#ifdef CONFIG_BPF_SYSCALL
2990 if (seq->op == &bpf_iter_udp_seq_ops)
2991 return net->ipv4.udp_table;
2992#endif
2993
2994 afinfo = pde_data(file_inode(seq->file));
2995 return afinfo->udp_table ? : net->ipv4.udp_table;
2996}
2997
2998static struct sock *udp_get_first(struct seq_file *seq, int start)
2999{
3000 struct udp_iter_state *state = seq->private;
3001 struct net *net = seq_file_net(seq);
3002 struct udp_table *udptable;
3003 struct sock *sk;
3004
3005 udptable = udp_get_table_seq(seq, net);
3006
3007 for (state->bucket = start; state->bucket <= udptable->mask;
3008 ++state->bucket) {
3009 struct udp_hslot *hslot = &udptable->hash[state->bucket];
3010
3011 if (hlist_empty(&hslot->head))
3012 continue;
3013
3014 spin_lock_bh(&hslot->lock);
3015 sk_for_each(sk, &hslot->head) {
3016 if (seq_sk_match(seq, sk))
3017 goto found;
3018 }
3019 spin_unlock_bh(&hslot->lock);
3020 }
3021 sk = NULL;
3022found:
3023 return sk;
3024}
3025
3026static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
3027{
3028 struct udp_iter_state *state = seq->private;
3029 struct net *net = seq_file_net(seq);
3030 struct udp_table *udptable;
3031
3032 do {
3033 sk = sk_next(sk);
3034 } while (sk && !seq_sk_match(seq, sk));
3035
3036 if (!sk) {
3037 udptable = udp_get_table_seq(seq, net);
3038
3039 if (state->bucket <= udptable->mask)
3040 spin_unlock_bh(&udptable->hash[state->bucket].lock);
3041
3042 return udp_get_first(seq, state->bucket + 1);
3043 }
3044 return sk;
3045}
3046
3047static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
3048{
3049 struct sock *sk = udp_get_first(seq, 0);
3050
3051 if (sk)
3052 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
3053 --pos;
3054 return pos ? NULL : sk;
3055}
3056
3057void *udp_seq_start(struct seq_file *seq, loff_t *pos)
3058{
3059 struct udp_iter_state *state = seq->private;
3060 state->bucket = MAX_UDP_PORTS;
3061
3062 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
3063}
3064EXPORT_SYMBOL(udp_seq_start);
3065
3066void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3067{
3068 struct sock *sk;
3069
3070 if (v == SEQ_START_TOKEN)
3071 sk = udp_get_idx(seq, 0);
3072 else
3073 sk = udp_get_next(seq, v);
3074
3075 ++*pos;
3076 return sk;
3077}
3078EXPORT_SYMBOL(udp_seq_next);
3079
3080void udp_seq_stop(struct seq_file *seq, void *v)
3081{
3082 struct udp_iter_state *state = seq->private;
3083 struct udp_table *udptable;
3084
3085 udptable = udp_get_table_seq(seq, seq_file_net(seq));
3086
3087 if (state->bucket <= udptable->mask)
3088 spin_unlock_bh(&udptable->hash[state->bucket].lock);
3089}
3090EXPORT_SYMBOL(udp_seq_stop);
3091
3092/* ------------------------------------------------------------------------ */
3093static void udp4_format_sock(struct sock *sp, struct seq_file *f,
3094 int bucket)
3095{
3096 struct inet_sock *inet = inet_sk(sp);
3097 __be32 dest = inet->inet_daddr;
3098 __be32 src = inet->inet_rcv_saddr;
3099 __u16 destp = ntohs(inet->inet_dport);
3100 __u16 srcp = ntohs(inet->inet_sport);
3101
3102 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
3103 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u",
3104 bucket, src, srcp, dest, destp, sp->sk_state,
3105 sk_wmem_alloc_get(sp),
3106 udp_rqueue_get(sp),
3107 0, 0L, 0,
3108 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
3109 0, sock_i_ino(sp),
3110 refcount_read(&sp->sk_refcnt), sp,
3111 atomic_read(&sp->sk_drops));
3112}
3113
3114int udp4_seq_show(struct seq_file *seq, void *v)
3115{
3116 seq_setwidth(seq, 127);
3117 if (v == SEQ_START_TOKEN)
3118 seq_puts(seq, " sl local_address rem_address st tx_queue "
3119 "rx_queue tr tm->when retrnsmt uid timeout "
3120 "inode ref pointer drops");
3121 else {
3122 struct udp_iter_state *state = seq->private;
3123
3124 udp4_format_sock(v, seq, state->bucket);
3125 }
3126 seq_pad(seq, '\n');
3127 return 0;
3128}
3129
3130#ifdef CONFIG_BPF_SYSCALL
3131struct bpf_iter__udp {
3132 __bpf_md_ptr(struct bpf_iter_meta *, meta);
3133 __bpf_md_ptr(struct udp_sock *, udp_sk);
3134 uid_t uid __aligned(8);
3135 int bucket __aligned(8);
3136};
3137
3138struct bpf_udp_iter_state {
3139 struct udp_iter_state state;
3140 unsigned int cur_sk;
3141 unsigned int end_sk;
3142 unsigned int max_sk;
3143 int offset;
3144 struct sock **batch;
3145 bool st_bucket_done;
3146};
3147
3148static int bpf_iter_udp_realloc_batch(struct bpf_udp_iter_state *iter,
3149 unsigned int new_batch_sz);
3150static struct sock *bpf_iter_udp_batch(struct seq_file *seq)
3151{
3152 struct bpf_udp_iter_state *iter = seq->private;
3153 struct udp_iter_state *state = &iter->state;
3154 struct net *net = seq_file_net(seq);
3155 int resume_bucket, resume_offset;
3156 struct udp_table *udptable;
3157 unsigned int batch_sks = 0;
3158 bool resized = false;
3159 struct sock *sk;
3160
3161 resume_bucket = state->bucket;
3162 resume_offset = iter->offset;
3163
3164 /* The current batch is done, so advance the bucket. */
3165 if (iter->st_bucket_done)
3166 state->bucket++;
3167
3168 udptable = udp_get_table_seq(seq, net);
3169
3170again:
3171 /* New batch for the next bucket.
3172 * Iterate over the hash table to find a bucket with sockets matching
3173 * the iterator attributes, and return the first matching socket from
3174 * the bucket. The remaining matched sockets from the bucket are batched
3175 * before releasing the bucket lock. This allows BPF programs that are
3176 * called in seq_show to acquire the bucket lock if needed.
3177 */
3178 iter->cur_sk = 0;
3179 iter->end_sk = 0;
3180 iter->st_bucket_done = false;
3181 batch_sks = 0;
3182
3183 for (; state->bucket <= udptable->mask; state->bucket++) {
3184 struct udp_hslot *hslot2 = &udptable->hash2[state->bucket];
3185
3186 if (hlist_empty(&hslot2->head))
3187 continue;
3188
3189 iter->offset = 0;
3190 spin_lock_bh(&hslot2->lock);
3191 udp_portaddr_for_each_entry(sk, &hslot2->head) {
3192 if (seq_sk_match(seq, sk)) {
3193 /* Resume from the last iterated socket at the
3194 * offset in the bucket before iterator was stopped.
3195 */
3196 if (state->bucket == resume_bucket &&
3197 iter->offset < resume_offset) {
3198 ++iter->offset;
3199 continue;
3200 }
3201 if (iter->end_sk < iter->max_sk) {
3202 sock_hold(sk);
3203 iter->batch[iter->end_sk++] = sk;
3204 }
3205 batch_sks++;
3206 }
3207 }
3208 spin_unlock_bh(&hslot2->lock);
3209
3210 if (iter->end_sk)
3211 break;
3212 }
3213
3214 /* All done: no batch made. */
3215 if (!iter->end_sk)
3216 return NULL;
3217
3218 if (iter->end_sk == batch_sks) {
3219 /* Batching is done for the current bucket; return the first
3220 * socket to be iterated from the batch.
3221 */
3222 iter->st_bucket_done = true;
3223 goto done;
3224 }
3225 if (!resized && !bpf_iter_udp_realloc_batch(iter, batch_sks * 3 / 2)) {
3226 resized = true;
3227 /* After allocating a larger batch, retry one more time to grab
3228 * the whole bucket.
3229 */
3230 goto again;
3231 }
3232done:
3233 return iter->batch[0];
3234}
3235
3236static void *bpf_iter_udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3237{
3238 struct bpf_udp_iter_state *iter = seq->private;
3239 struct sock *sk;
3240
3241 /* Whenever seq_next() is called, the iter->cur_sk is
3242 * done with seq_show(), so unref the iter->cur_sk.
3243 */
3244 if (iter->cur_sk < iter->end_sk) {
3245 sock_put(iter->batch[iter->cur_sk++]);
3246 ++iter->offset;
3247 }
3248
3249 /* After updating iter->cur_sk, check if there are more sockets
3250 * available in the current bucket batch.
3251 */
3252 if (iter->cur_sk < iter->end_sk)
3253 sk = iter->batch[iter->cur_sk];
3254 else
3255 /* Prepare a new batch. */
3256 sk = bpf_iter_udp_batch(seq);
3257
3258 ++*pos;
3259 return sk;
3260}
3261
3262static void *bpf_iter_udp_seq_start(struct seq_file *seq, loff_t *pos)
3263{
3264 /* bpf iter does not support lseek, so it always
3265 * continue from where it was stop()-ped.
3266 */
3267 if (*pos)
3268 return bpf_iter_udp_batch(seq);
3269
3270 return SEQ_START_TOKEN;
3271}
3272
3273static int udp_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta,
3274 struct udp_sock *udp_sk, uid_t uid, int bucket)
3275{
3276 struct bpf_iter__udp ctx;
3277
3278 meta->seq_num--; /* skip SEQ_START_TOKEN */
3279 ctx.meta = meta;
3280 ctx.udp_sk = udp_sk;
3281 ctx.uid = uid;
3282 ctx.bucket = bucket;
3283 return bpf_iter_run_prog(prog, &ctx);
3284}
3285
3286static int bpf_iter_udp_seq_show(struct seq_file *seq, void *v)
3287{
3288 struct udp_iter_state *state = seq->private;
3289 struct bpf_iter_meta meta;
3290 struct bpf_prog *prog;
3291 struct sock *sk = v;
3292 uid_t uid;
3293 int ret;
3294
3295 if (v == SEQ_START_TOKEN)
3296 return 0;
3297
3298 lock_sock(sk);
3299
3300 if (unlikely(sk_unhashed(sk))) {
3301 ret = SEQ_SKIP;
3302 goto unlock;
3303 }
3304
3305 uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk));
3306 meta.seq = seq;
3307 prog = bpf_iter_get_info(&meta, false);
3308 ret = udp_prog_seq_show(prog, &meta, v, uid, state->bucket);
3309
3310unlock:
3311 release_sock(sk);
3312 return ret;
3313}
3314
3315static void bpf_iter_udp_put_batch(struct bpf_udp_iter_state *iter)
3316{
3317 while (iter->cur_sk < iter->end_sk)
3318 sock_put(iter->batch[iter->cur_sk++]);
3319}
3320
3321static void bpf_iter_udp_seq_stop(struct seq_file *seq, void *v)
3322{
3323 struct bpf_udp_iter_state *iter = seq->private;
3324 struct bpf_iter_meta meta;
3325 struct bpf_prog *prog;
3326
3327 if (!v) {
3328 meta.seq = seq;
3329 prog = bpf_iter_get_info(&meta, true);
3330 if (prog)
3331 (void)udp_prog_seq_show(prog, &meta, v, 0, 0);
3332 }
3333
3334 if (iter->cur_sk < iter->end_sk) {
3335 bpf_iter_udp_put_batch(iter);
3336 iter->st_bucket_done = false;
3337 }
3338}
3339
3340static const struct seq_operations bpf_iter_udp_seq_ops = {
3341 .start = bpf_iter_udp_seq_start,
3342 .next = bpf_iter_udp_seq_next,
3343 .stop = bpf_iter_udp_seq_stop,
3344 .show = bpf_iter_udp_seq_show,
3345};
3346#endif
3347
3348static unsigned short seq_file_family(const struct seq_file *seq)
3349{
3350 const struct udp_seq_afinfo *afinfo;
3351
3352#ifdef CONFIG_BPF_SYSCALL
3353 /* BPF iterator: bpf programs to filter sockets. */
3354 if (seq->op == &bpf_iter_udp_seq_ops)
3355 return AF_UNSPEC;
3356#endif
3357
3358 /* Proc fs iterator */
3359 afinfo = pde_data(file_inode(seq->file));
3360 return afinfo->family;
3361}
3362
3363const struct seq_operations udp_seq_ops = {
3364 .start = udp_seq_start,
3365 .next = udp_seq_next,
3366 .stop = udp_seq_stop,
3367 .show = udp4_seq_show,
3368};
3369EXPORT_SYMBOL(udp_seq_ops);
3370
3371static struct udp_seq_afinfo udp4_seq_afinfo = {
3372 .family = AF_INET,
3373 .udp_table = NULL,
3374};
3375
3376static int __net_init udp4_proc_init_net(struct net *net)
3377{
3378 if (!proc_create_net_data("udp", 0444, net->proc_net, &udp_seq_ops,
3379 sizeof(struct udp_iter_state), &udp4_seq_afinfo))
3380 return -ENOMEM;
3381 return 0;
3382}
3383
3384static void __net_exit udp4_proc_exit_net(struct net *net)
3385{
3386 remove_proc_entry("udp", net->proc_net);
3387}
3388
3389static struct pernet_operations udp4_net_ops = {
3390 .init = udp4_proc_init_net,
3391 .exit = udp4_proc_exit_net,
3392};
3393
3394int __init udp4_proc_init(void)
3395{
3396 return register_pernet_subsys(&udp4_net_ops);
3397}
3398
3399void udp4_proc_exit(void)
3400{
3401 unregister_pernet_subsys(&udp4_net_ops);
3402}
3403#endif /* CONFIG_PROC_FS */
3404
3405static __initdata unsigned long uhash_entries;
3406static int __init set_uhash_entries(char *str)
3407{
3408 ssize_t ret;
3409
3410 if (!str)
3411 return 0;
3412
3413 ret = kstrtoul(str, 0, &uhash_entries);
3414 if (ret)
3415 return 0;
3416
3417 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
3418 uhash_entries = UDP_HTABLE_SIZE_MIN;
3419 return 1;
3420}
3421__setup("uhash_entries=", set_uhash_entries);
3422
3423void __init udp_table_init(struct udp_table *table, const char *name)
3424{
3425 unsigned int i;
3426
3427 table->hash = alloc_large_system_hash(name,
3428 2 * sizeof(struct udp_hslot),
3429 uhash_entries,
3430 21, /* one slot per 2 MB */
3431 0,
3432 &table->log,
3433 &table->mask,
3434 UDP_HTABLE_SIZE_MIN,
3435 UDP_HTABLE_SIZE_MAX);
3436
3437 table->hash2 = table->hash + (table->mask + 1);
3438 for (i = 0; i <= table->mask; i++) {
3439 INIT_HLIST_HEAD(&table->hash[i].head);
3440 table->hash[i].count = 0;
3441 spin_lock_init(&table->hash[i].lock);
3442 }
3443 for (i = 0; i <= table->mask; i++) {
3444 INIT_HLIST_HEAD(&table->hash2[i].head);
3445 table->hash2[i].count = 0;
3446 spin_lock_init(&table->hash2[i].lock);
3447 }
3448}
3449
3450u32 udp_flow_hashrnd(void)
3451{
3452 static u32 hashrnd __read_mostly;
3453
3454 net_get_random_once(&hashrnd, sizeof(hashrnd));
3455
3456 return hashrnd;
3457}
3458EXPORT_SYMBOL(udp_flow_hashrnd);
3459
3460static void __net_init udp_sysctl_init(struct net *net)
3461{
3462 net->ipv4.sysctl_udp_rmem_min = PAGE_SIZE;
3463 net->ipv4.sysctl_udp_wmem_min = PAGE_SIZE;
3464
3465#ifdef CONFIG_NET_L3_MASTER_DEV
3466 net->ipv4.sysctl_udp_l3mdev_accept = 0;
3467#endif
3468}
3469
3470static struct udp_table __net_init *udp_pernet_table_alloc(unsigned int hash_entries)
3471{
3472 struct udp_table *udptable;
3473 int i;
3474
3475 udptable = kmalloc(sizeof(*udptable), GFP_KERNEL);
3476 if (!udptable)
3477 goto out;
3478
3479 udptable->hash = vmalloc_huge(hash_entries * 2 * sizeof(struct udp_hslot),
3480 GFP_KERNEL_ACCOUNT);
3481 if (!udptable->hash)
3482 goto free_table;
3483
3484 udptable->hash2 = udptable->hash + hash_entries;
3485 udptable->mask = hash_entries - 1;
3486 udptable->log = ilog2(hash_entries);
3487
3488 for (i = 0; i < hash_entries; i++) {
3489 INIT_HLIST_HEAD(&udptable->hash[i].head);
3490 udptable->hash[i].count = 0;
3491 spin_lock_init(&udptable->hash[i].lock);
3492
3493 INIT_HLIST_HEAD(&udptable->hash2[i].head);
3494 udptable->hash2[i].count = 0;
3495 spin_lock_init(&udptable->hash2[i].lock);
3496 }
3497
3498 return udptable;
3499
3500free_table:
3501 kfree(udptable);
3502out:
3503 return NULL;
3504}
3505
3506static void __net_exit udp_pernet_table_free(struct net *net)
3507{
3508 struct udp_table *udptable = net->ipv4.udp_table;
3509
3510 if (udptable == &udp_table)
3511 return;
3512
3513 kvfree(udptable->hash);
3514 kfree(udptable);
3515}
3516
3517static void __net_init udp_set_table(struct net *net)
3518{
3519 struct udp_table *udptable;
3520 unsigned int hash_entries;
3521 struct net *old_net;
3522
3523 if (net_eq(net, &init_net))
3524 goto fallback;
3525
3526 old_net = current->nsproxy->net_ns;
3527 hash_entries = READ_ONCE(old_net->ipv4.sysctl_udp_child_hash_entries);
3528 if (!hash_entries)
3529 goto fallback;
3530
3531 /* Set min to keep the bitmap on stack in udp_lib_get_port() */
3532 if (hash_entries < UDP_HTABLE_SIZE_MIN_PERNET)
3533 hash_entries = UDP_HTABLE_SIZE_MIN_PERNET;
3534 else
3535 hash_entries = roundup_pow_of_two(hash_entries);
3536
3537 udptable = udp_pernet_table_alloc(hash_entries);
3538 if (udptable) {
3539 net->ipv4.udp_table = udptable;
3540 } else {
3541 pr_warn("Failed to allocate UDP hash table (entries: %u) "
3542 "for a netns, fallback to the global one\n",
3543 hash_entries);
3544fallback:
3545 net->ipv4.udp_table = &udp_table;
3546 }
3547}
3548
3549static int __net_init udp_pernet_init(struct net *net)
3550{
3551 udp_sysctl_init(net);
3552 udp_set_table(net);
3553
3554 return 0;
3555}
3556
3557static void __net_exit udp_pernet_exit(struct net *net)
3558{
3559 udp_pernet_table_free(net);
3560}
3561
3562static struct pernet_operations __net_initdata udp_sysctl_ops = {
3563 .init = udp_pernet_init,
3564 .exit = udp_pernet_exit,
3565};
3566
3567#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
3568DEFINE_BPF_ITER_FUNC(udp, struct bpf_iter_meta *meta,
3569 struct udp_sock *udp_sk, uid_t uid, int bucket)
3570
3571static int bpf_iter_udp_realloc_batch(struct bpf_udp_iter_state *iter,
3572 unsigned int new_batch_sz)
3573{
3574 struct sock **new_batch;
3575
3576 new_batch = kvmalloc_array(new_batch_sz, sizeof(*new_batch),
3577 GFP_USER | __GFP_NOWARN);
3578 if (!new_batch)
3579 return -ENOMEM;
3580
3581 bpf_iter_udp_put_batch(iter);
3582 kvfree(iter->batch);
3583 iter->batch = new_batch;
3584 iter->max_sk = new_batch_sz;
3585
3586 return 0;
3587}
3588
3589#define INIT_BATCH_SZ 16
3590
3591static int bpf_iter_init_udp(void *priv_data, struct bpf_iter_aux_info *aux)
3592{
3593 struct bpf_udp_iter_state *iter = priv_data;
3594 int ret;
3595
3596 ret = bpf_iter_init_seq_net(priv_data, aux);
3597 if (ret)
3598 return ret;
3599
3600 ret = bpf_iter_udp_realloc_batch(iter, INIT_BATCH_SZ);
3601 if (ret)
3602 bpf_iter_fini_seq_net(priv_data);
3603
3604 return ret;
3605}
3606
3607static void bpf_iter_fini_udp(void *priv_data)
3608{
3609 struct bpf_udp_iter_state *iter = priv_data;
3610
3611 bpf_iter_fini_seq_net(priv_data);
3612 kvfree(iter->batch);
3613}
3614
3615static const struct bpf_iter_seq_info udp_seq_info = {
3616 .seq_ops = &bpf_iter_udp_seq_ops,
3617 .init_seq_private = bpf_iter_init_udp,
3618 .fini_seq_private = bpf_iter_fini_udp,
3619 .seq_priv_size = sizeof(struct bpf_udp_iter_state),
3620};
3621
3622static struct bpf_iter_reg udp_reg_info = {
3623 .target = "udp",
3624 .ctx_arg_info_size = 1,
3625 .ctx_arg_info = {
3626 { offsetof(struct bpf_iter__udp, udp_sk),
3627 PTR_TO_BTF_ID_OR_NULL | PTR_TRUSTED },
3628 },
3629 .seq_info = &udp_seq_info,
3630};
3631
3632static void __init bpf_iter_register(void)
3633{
3634 udp_reg_info.ctx_arg_info[0].btf_id = btf_sock_ids[BTF_SOCK_TYPE_UDP];
3635 if (bpf_iter_reg_target(&udp_reg_info))
3636 pr_warn("Warning: could not register bpf iterator udp\n");
3637}
3638#endif
3639
3640void __init udp_init(void)
3641{
3642 unsigned long limit;
3643 unsigned int i;
3644
3645 udp_table_init(&udp_table, "UDP");
3646 limit = nr_free_buffer_pages() / 8;
3647 limit = max(limit, 128UL);
3648 sysctl_udp_mem[0] = limit / 4 * 3;
3649 sysctl_udp_mem[1] = limit;
3650 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
3651
3652 /* 16 spinlocks per cpu */
3653 udp_busylocks_log = ilog2(nr_cpu_ids) + 4;
3654 udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log,
3655 GFP_KERNEL);
3656 if (!udp_busylocks)
3657 panic("UDP: failed to alloc udp_busylocks\n");
3658 for (i = 0; i < (1U << udp_busylocks_log); i++)
3659 spin_lock_init(udp_busylocks + i);
3660
3661 if (register_pernet_subsys(&udp_sysctl_ops))
3662 panic("UDP: failed to init sysctl parameters.\n");
3663
3664#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
3665 bpf_iter_register();
3666#endif
3667}
1/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * The User Datagram Protocol (UDP).
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
11 * Alan Cox, <alan@lxorguk.ukuu.org.uk>
12 * Hirokazu Takahashi, <taka@valinux.co.jp>
13 *
14 * Fixes:
15 * Alan Cox : verify_area() calls
16 * Alan Cox : stopped close while in use off icmp
17 * messages. Not a fix but a botch that
18 * for udp at least is 'valid'.
19 * Alan Cox : Fixed icmp handling properly
20 * Alan Cox : Correct error for oversized datagrams
21 * Alan Cox : Tidied select() semantics.
22 * Alan Cox : udp_err() fixed properly, also now
23 * select and read wake correctly on errors
24 * Alan Cox : udp_send verify_area moved to avoid mem leak
25 * Alan Cox : UDP can count its memory
26 * Alan Cox : send to an unknown connection causes
27 * an ECONNREFUSED off the icmp, but
28 * does NOT close.
29 * Alan Cox : Switched to new sk_buff handlers. No more backlog!
30 * Alan Cox : Using generic datagram code. Even smaller and the PEEK
31 * bug no longer crashes it.
32 * Fred Van Kempen : Net2e support for sk->broadcast.
33 * Alan Cox : Uses skb_free_datagram
34 * Alan Cox : Added get/set sockopt support.
35 * Alan Cox : Broadcasting without option set returns EACCES.
36 * Alan Cox : No wakeup calls. Instead we now use the callbacks.
37 * Alan Cox : Use ip_tos and ip_ttl
38 * Alan Cox : SNMP Mibs
39 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support.
40 * Matt Dillon : UDP length checks.
41 * Alan Cox : Smarter af_inet used properly.
42 * Alan Cox : Use new kernel side addressing.
43 * Alan Cox : Incorrect return on truncated datagram receive.
44 * Arnt Gulbrandsen : New udp_send and stuff
45 * Alan Cox : Cache last socket
46 * Alan Cox : Route cache
47 * Jon Peatfield : Minor efficiency fix to sendto().
48 * Mike Shaver : RFC1122 checks.
49 * Alan Cox : Nonblocking error fix.
50 * Willy Konynenberg : Transparent proxying support.
51 * Mike McLagan : Routing by source
52 * David S. Miller : New socket lookup architecture.
53 * Last socket cache retained as it
54 * does have a high hit rate.
55 * Olaf Kirch : Don't linearise iovec on sendmsg.
56 * Andi Kleen : Some cleanups, cache destination entry
57 * for connect.
58 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
59 * Melvin Smith : Check msg_name not msg_namelen in sendto(),
60 * return ENOTCONN for unconnected sockets (POSIX)
61 * Janos Farkas : don't deliver multi/broadcasts to a different
62 * bound-to-device socket
63 * Hirokazu Takahashi : HW checksumming for outgoing UDP
64 * datagrams.
65 * Hirokazu Takahashi : sendfile() on UDP works now.
66 * Arnaldo C. Melo : convert /proc/net/udp to seq_file
67 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
68 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind
69 * a single port at the same time.
70 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
71 * James Chapman : Add L2TP encapsulation type.
72 *
73 *
74 * This program is free software; you can redistribute it and/or
75 * modify it under the terms of the GNU General Public License
76 * as published by the Free Software Foundation; either version
77 * 2 of the License, or (at your option) any later version.
78 */
79
80#define pr_fmt(fmt) "UDP: " fmt
81
82#include <linux/uaccess.h>
83#include <asm/ioctls.h>
84#include <linux/bootmem.h>
85#include <linux/highmem.h>
86#include <linux/swap.h>
87#include <linux/types.h>
88#include <linux/fcntl.h>
89#include <linux/module.h>
90#include <linux/socket.h>
91#include <linux/sockios.h>
92#include <linux/igmp.h>
93#include <linux/inetdevice.h>
94#include <linux/in.h>
95#include <linux/errno.h>
96#include <linux/timer.h>
97#include <linux/mm.h>
98#include <linux/inet.h>
99#include <linux/netdevice.h>
100#include <linux/slab.h>
101#include <net/tcp_states.h>
102#include <linux/skbuff.h>
103#include <linux/proc_fs.h>
104#include <linux/seq_file.h>
105#include <net/net_namespace.h>
106#include <net/icmp.h>
107#include <net/inet_hashtables.h>
108#include <net/route.h>
109#include <net/checksum.h>
110#include <net/xfrm.h>
111#include <trace/events/udp.h>
112#include <linux/static_key.h>
113#include <trace/events/skb.h>
114#include <net/busy_poll.h>
115#include "udp_impl.h"
116#include <net/sock_reuseport.h>
117#include <net/addrconf.h>
118
119struct udp_table udp_table __read_mostly;
120EXPORT_SYMBOL(udp_table);
121
122long sysctl_udp_mem[3] __read_mostly;
123EXPORT_SYMBOL(sysctl_udp_mem);
124
125atomic_long_t udp_memory_allocated;
126EXPORT_SYMBOL(udp_memory_allocated);
127
128#define MAX_UDP_PORTS 65536
129#define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
130
131/* IPCB reference means this can not be used from early demux */
132static bool udp_lib_exact_dif_match(struct net *net, struct sk_buff *skb)
133{
134#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
135 if (!net->ipv4.sysctl_udp_l3mdev_accept &&
136 skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
137 return true;
138#endif
139 return false;
140}
141
142static int udp_lib_lport_inuse(struct net *net, __u16 num,
143 const struct udp_hslot *hslot,
144 unsigned long *bitmap,
145 struct sock *sk, unsigned int log)
146{
147 struct sock *sk2;
148 kuid_t uid = sock_i_uid(sk);
149
150 sk_for_each(sk2, &hslot->head) {
151 if (net_eq(sock_net(sk2), net) &&
152 sk2 != sk &&
153 (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
154 (!sk2->sk_reuse || !sk->sk_reuse) &&
155 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
156 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
157 inet_rcv_saddr_equal(sk, sk2, true)) {
158 if (sk2->sk_reuseport && sk->sk_reuseport &&
159 !rcu_access_pointer(sk->sk_reuseport_cb) &&
160 uid_eq(uid, sock_i_uid(sk2))) {
161 if (!bitmap)
162 return 0;
163 } else {
164 if (!bitmap)
165 return 1;
166 __set_bit(udp_sk(sk2)->udp_port_hash >> log,
167 bitmap);
168 }
169 }
170 }
171 return 0;
172}
173
174/*
175 * Note: we still hold spinlock of primary hash chain, so no other writer
176 * can insert/delete a socket with local_port == num
177 */
178static int udp_lib_lport_inuse2(struct net *net, __u16 num,
179 struct udp_hslot *hslot2,
180 struct sock *sk)
181{
182 struct sock *sk2;
183 kuid_t uid = sock_i_uid(sk);
184 int res = 0;
185
186 spin_lock(&hslot2->lock);
187 udp_portaddr_for_each_entry(sk2, &hslot2->head) {
188 if (net_eq(sock_net(sk2), net) &&
189 sk2 != sk &&
190 (udp_sk(sk2)->udp_port_hash == num) &&
191 (!sk2->sk_reuse || !sk->sk_reuse) &&
192 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
193 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
194 inet_rcv_saddr_equal(sk, sk2, true)) {
195 if (sk2->sk_reuseport && sk->sk_reuseport &&
196 !rcu_access_pointer(sk->sk_reuseport_cb) &&
197 uid_eq(uid, sock_i_uid(sk2))) {
198 res = 0;
199 } else {
200 res = 1;
201 }
202 break;
203 }
204 }
205 spin_unlock(&hslot2->lock);
206 return res;
207}
208
209static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot)
210{
211 struct net *net = sock_net(sk);
212 kuid_t uid = sock_i_uid(sk);
213 struct sock *sk2;
214
215 sk_for_each(sk2, &hslot->head) {
216 if (net_eq(sock_net(sk2), net) &&
217 sk2 != sk &&
218 sk2->sk_family == sk->sk_family &&
219 ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
220 (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) &&
221 (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
222 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
223 inet_rcv_saddr_equal(sk, sk2, false)) {
224 return reuseport_add_sock(sk, sk2);
225 }
226 }
227
228 return reuseport_alloc(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_hslot *hslot, *hslot2;
243 struct udp_table *udptable = sk->sk_prot->h.udp_table;
244 int error = 1;
245 struct net *net = sock_net(sk);
246
247 if (!snum) {
248 int low, high, remaining;
249 unsigned int rand;
250 unsigned short first, last;
251 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
252
253 inet_get_local_port_range(net, &low, &high);
254 remaining = (high - low) + 1;
255
256 rand = prandom_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, bool exact_dif)
370{
371 int score;
372 struct inet_sock *inet;
373
374 if (!net_eq(sock_net(sk), net) ||
375 udp_sk(sk)->udp_port_hash != hnum ||
376 ipv6_only_sock(sk))
377 return -1;
378
379 score = (sk->sk_family == PF_INET) ? 2 : 1;
380 inet = inet_sk(sk);
381
382 if (inet->inet_rcv_saddr) {
383 if (inet->inet_rcv_saddr != daddr)
384 return -1;
385 score += 4;
386 }
387
388 if (inet->inet_daddr) {
389 if (inet->inet_daddr != saddr)
390 return -1;
391 score += 4;
392 }
393
394 if (inet->inet_dport) {
395 if (inet->inet_dport != sport)
396 return -1;
397 score += 4;
398 }
399
400 if (sk->sk_bound_dev_if || exact_dif) {
401 bool dev_match = (sk->sk_bound_dev_if == dif ||
402 sk->sk_bound_dev_if == sdif);
403
404 if (!dev_match)
405 return -1;
406 if (sk->sk_bound_dev_if)
407 score += 4;
408 }
409
410 if (sk->sk_incoming_cpu == raw_smp_processor_id())
411 score++;
412 return score;
413}
414
415static u32 udp_ehashfn(const struct net *net, const __be32 laddr,
416 const __u16 lport, const __be32 faddr,
417 const __be16 fport)
418{
419 static u32 udp_ehash_secret __read_mostly;
420
421 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret));
422
423 return __inet_ehashfn(laddr, lport, faddr, fport,
424 udp_ehash_secret + net_hash_mix(net));
425}
426
427/* called with rcu_read_lock() */
428static struct sock *udp4_lib_lookup2(struct net *net,
429 __be32 saddr, __be16 sport,
430 __be32 daddr, unsigned int hnum,
431 int dif, int sdif, bool exact_dif,
432 struct udp_hslot *hslot2,
433 struct sk_buff *skb)
434{
435 struct sock *sk, *result;
436 int score, badness;
437 u32 hash = 0;
438
439 result = NULL;
440 badness = 0;
441 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
442 score = compute_score(sk, net, saddr, sport,
443 daddr, hnum, dif, sdif, exact_dif);
444 if (score > badness) {
445 if (sk->sk_reuseport) {
446 hash = udp_ehashfn(net, daddr, hnum,
447 saddr, sport);
448 result = reuseport_select_sock(sk, hash, skb,
449 sizeof(struct udphdr));
450 if (result)
451 return result;
452 }
453 badness = score;
454 result = sk;
455 }
456 }
457 return result;
458}
459
460/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
461 * harder than this. -DaveM
462 */
463struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
464 __be16 sport, __be32 daddr, __be16 dport, int dif,
465 int sdif, struct udp_table *udptable, struct sk_buff *skb)
466{
467 struct sock *sk, *result;
468 unsigned short hnum = ntohs(dport);
469 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
470 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
471 bool exact_dif = udp_lib_exact_dif_match(net, skb);
472 int score, badness;
473 u32 hash = 0;
474
475 if (hslot->count > 10) {
476 hash2 = ipv4_portaddr_hash(net, daddr, hnum);
477 slot2 = hash2 & udptable->mask;
478 hslot2 = &udptable->hash2[slot2];
479 if (hslot->count < hslot2->count)
480 goto begin;
481
482 result = udp4_lib_lookup2(net, saddr, sport,
483 daddr, hnum, dif, sdif,
484 exact_dif, hslot2, skb);
485 if (!result) {
486 unsigned int old_slot2 = slot2;
487 hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
488 slot2 = hash2 & udptable->mask;
489 /* avoid searching the same slot again. */
490 if (unlikely(slot2 == old_slot2))
491 return result;
492
493 hslot2 = &udptable->hash2[slot2];
494 if (hslot->count < hslot2->count)
495 goto begin;
496
497 result = udp4_lib_lookup2(net, saddr, sport,
498 daddr, hnum, dif, sdif,
499 exact_dif, hslot2, skb);
500 }
501 return result;
502 }
503begin:
504 result = NULL;
505 badness = 0;
506 sk_for_each_rcu(sk, &hslot->head) {
507 score = compute_score(sk, net, saddr, sport,
508 daddr, hnum, dif, sdif, exact_dif);
509 if (score > badness) {
510 if (sk->sk_reuseport) {
511 hash = udp_ehashfn(net, daddr, hnum,
512 saddr, sport);
513 result = reuseport_select_sock(sk, hash, skb,
514 sizeof(struct udphdr));
515 if (result)
516 return result;
517 }
518 result = sk;
519 badness = score;
520 }
521 }
522 return result;
523}
524EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
525
526static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
527 __be16 sport, __be16 dport,
528 struct udp_table *udptable)
529{
530 const struct iphdr *iph = ip_hdr(skb);
531
532 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
533 iph->daddr, dport, inet_iif(skb),
534 inet_sdif(skb), udptable, skb);
535}
536
537struct sock *udp4_lib_lookup_skb(struct sk_buff *skb,
538 __be16 sport, __be16 dport)
539{
540 return __udp4_lib_lookup_skb(skb, sport, dport, &udp_table);
541}
542EXPORT_SYMBOL_GPL(udp4_lib_lookup_skb);
543
544/* Must be called under rcu_read_lock().
545 * Does increment socket refcount.
546 */
547#if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \
548 IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY) || \
549 IS_ENABLED(CONFIG_NF_SOCKET_IPV4)
550struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
551 __be32 daddr, __be16 dport, int dif)
552{
553 struct sock *sk;
554
555 sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport,
556 dif, 0, &udp_table, NULL);
557 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
558 sk = NULL;
559 return sk;
560}
561EXPORT_SYMBOL_GPL(udp4_lib_lookup);
562#endif
563
564static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk,
565 __be16 loc_port, __be32 loc_addr,
566 __be16 rmt_port, __be32 rmt_addr,
567 int dif, int sdif, unsigned short hnum)
568{
569 struct inet_sock *inet = inet_sk(sk);
570
571 if (!net_eq(sock_net(sk), net) ||
572 udp_sk(sk)->udp_port_hash != hnum ||
573 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
574 (inet->inet_dport != rmt_port && inet->inet_dport) ||
575 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) ||
576 ipv6_only_sock(sk) ||
577 (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif &&
578 sk->sk_bound_dev_if != sdif))
579 return false;
580 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif, sdif))
581 return false;
582 return true;
583}
584
585/*
586 * This routine is called by the ICMP module when it gets some
587 * sort of error condition. If err < 0 then the socket should
588 * be closed and the error returned to the user. If err > 0
589 * it's just the icmp type << 8 | icmp code.
590 * Header points to the ip header of the error packet. We move
591 * on past this. Then (as it used to claim before adjustment)
592 * header points to the first 8 bytes of the udp header. We need
593 * to find the appropriate port.
594 */
595
596void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
597{
598 struct inet_sock *inet;
599 const struct iphdr *iph = (const struct iphdr *)skb->data;
600 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
601 const int type = icmp_hdr(skb)->type;
602 const int code = icmp_hdr(skb)->code;
603 struct sock *sk;
604 int harderr;
605 int err;
606 struct net *net = dev_net(skb->dev);
607
608 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
609 iph->saddr, uh->source, skb->dev->ifindex, 0,
610 udptable, NULL);
611 if (!sk) {
612 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
613 return; /* No socket for error */
614 }
615
616 err = 0;
617 harderr = 0;
618 inet = inet_sk(sk);
619
620 switch (type) {
621 default:
622 case ICMP_TIME_EXCEEDED:
623 err = EHOSTUNREACH;
624 break;
625 case ICMP_SOURCE_QUENCH:
626 goto out;
627 case ICMP_PARAMETERPROB:
628 err = EPROTO;
629 harderr = 1;
630 break;
631 case ICMP_DEST_UNREACH:
632 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
633 ipv4_sk_update_pmtu(skb, sk, info);
634 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
635 err = EMSGSIZE;
636 harderr = 1;
637 break;
638 }
639 goto out;
640 }
641 err = EHOSTUNREACH;
642 if (code <= NR_ICMP_UNREACH) {
643 harderr = icmp_err_convert[code].fatal;
644 err = icmp_err_convert[code].errno;
645 }
646 break;
647 case ICMP_REDIRECT:
648 ipv4_sk_redirect(skb, sk);
649 goto out;
650 }
651
652 /*
653 * RFC1122: OK. Passes ICMP errors back to application, as per
654 * 4.1.3.3.
655 */
656 if (!inet->recverr) {
657 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
658 goto out;
659 } else
660 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
661
662 sk->sk_err = err;
663 sk->sk_error_report(sk);
664out:
665 return;
666}
667
668void udp_err(struct sk_buff *skb, u32 info)
669{
670 __udp4_lib_err(skb, info, &udp_table);
671}
672
673/*
674 * Throw away all pending data and cancel the corking. Socket is locked.
675 */
676void udp_flush_pending_frames(struct sock *sk)
677{
678 struct udp_sock *up = udp_sk(sk);
679
680 if (up->pending) {
681 up->len = 0;
682 up->pending = 0;
683 ip_flush_pending_frames(sk);
684 }
685}
686EXPORT_SYMBOL(udp_flush_pending_frames);
687
688/**
689 * udp4_hwcsum - handle outgoing HW checksumming
690 * @skb: sk_buff containing the filled-in UDP header
691 * (checksum field must be zeroed out)
692 * @src: source IP address
693 * @dst: destination IP address
694 */
695void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
696{
697 struct udphdr *uh = udp_hdr(skb);
698 int offset = skb_transport_offset(skb);
699 int len = skb->len - offset;
700 int hlen = len;
701 __wsum csum = 0;
702
703 if (!skb_has_frag_list(skb)) {
704 /*
705 * Only one fragment on the socket.
706 */
707 skb->csum_start = skb_transport_header(skb) - skb->head;
708 skb->csum_offset = offsetof(struct udphdr, check);
709 uh->check = ~csum_tcpudp_magic(src, dst, len,
710 IPPROTO_UDP, 0);
711 } else {
712 struct sk_buff *frags;
713
714 /*
715 * HW-checksum won't work as there are two or more
716 * fragments on the socket so that all csums of sk_buffs
717 * should be together
718 */
719 skb_walk_frags(skb, frags) {
720 csum = csum_add(csum, frags->csum);
721 hlen -= frags->len;
722 }
723
724 csum = skb_checksum(skb, offset, hlen, csum);
725 skb->ip_summed = CHECKSUM_NONE;
726
727 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
728 if (uh->check == 0)
729 uh->check = CSUM_MANGLED_0;
730 }
731}
732EXPORT_SYMBOL_GPL(udp4_hwcsum);
733
734/* Function to set UDP checksum for an IPv4 UDP packet. This is intended
735 * for the simple case like when setting the checksum for a UDP tunnel.
736 */
737void udp_set_csum(bool nocheck, struct sk_buff *skb,
738 __be32 saddr, __be32 daddr, int len)
739{
740 struct udphdr *uh = udp_hdr(skb);
741
742 if (nocheck) {
743 uh->check = 0;
744 } else if (skb_is_gso(skb)) {
745 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
746 } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
747 uh->check = 0;
748 uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb));
749 if (uh->check == 0)
750 uh->check = CSUM_MANGLED_0;
751 } else {
752 skb->ip_summed = CHECKSUM_PARTIAL;
753 skb->csum_start = skb_transport_header(skb) - skb->head;
754 skb->csum_offset = offsetof(struct udphdr, check);
755 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
756 }
757}
758EXPORT_SYMBOL(udp_set_csum);
759
760static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4)
761{
762 struct sock *sk = skb->sk;
763 struct inet_sock *inet = inet_sk(sk);
764 struct udphdr *uh;
765 int err = 0;
766 int is_udplite = IS_UDPLITE(sk);
767 int offset = skb_transport_offset(skb);
768 int len = skb->len - offset;
769 __wsum csum = 0;
770
771 /*
772 * Create a UDP header
773 */
774 uh = udp_hdr(skb);
775 uh->source = inet->inet_sport;
776 uh->dest = fl4->fl4_dport;
777 uh->len = htons(len);
778 uh->check = 0;
779
780 if (is_udplite) /* UDP-Lite */
781 csum = udplite_csum(skb);
782
783 else if (sk->sk_no_check_tx) { /* UDP csum off */
784
785 skb->ip_summed = CHECKSUM_NONE;
786 goto send;
787
788 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
789
790 udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
791 goto send;
792
793 } else
794 csum = udp_csum(skb);
795
796 /* add protocol-dependent pseudo-header */
797 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
798 sk->sk_protocol, csum);
799 if (uh->check == 0)
800 uh->check = CSUM_MANGLED_0;
801
802send:
803 err = ip_send_skb(sock_net(sk), skb);
804 if (err) {
805 if (err == -ENOBUFS && !inet->recverr) {
806 UDP_INC_STATS(sock_net(sk),
807 UDP_MIB_SNDBUFERRORS, is_udplite);
808 err = 0;
809 }
810 } else
811 UDP_INC_STATS(sock_net(sk),
812 UDP_MIB_OUTDATAGRAMS, is_udplite);
813 return err;
814}
815
816/*
817 * Push out all pending data as one UDP datagram. Socket is locked.
818 */
819int udp_push_pending_frames(struct sock *sk)
820{
821 struct udp_sock *up = udp_sk(sk);
822 struct inet_sock *inet = inet_sk(sk);
823 struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
824 struct sk_buff *skb;
825 int err = 0;
826
827 skb = ip_finish_skb(sk, fl4);
828 if (!skb)
829 goto out;
830
831 err = udp_send_skb(skb, fl4);
832
833out:
834 up->len = 0;
835 up->pending = 0;
836 return err;
837}
838EXPORT_SYMBOL(udp_push_pending_frames);
839
840int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
841{
842 struct inet_sock *inet = inet_sk(sk);
843 struct udp_sock *up = udp_sk(sk);
844 struct flowi4 fl4_stack;
845 struct flowi4 *fl4;
846 int ulen = len;
847 struct ipcm_cookie ipc;
848 struct rtable *rt = NULL;
849 int free = 0;
850 int connected = 0;
851 __be32 daddr, faddr, saddr;
852 __be16 dport;
853 u8 tos;
854 int err, is_udplite = IS_UDPLITE(sk);
855 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
856 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
857 struct sk_buff *skb;
858 struct ip_options_data opt_copy;
859
860 if (len > 0xFFFF)
861 return -EMSGSIZE;
862
863 /*
864 * Check the flags.
865 */
866
867 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
868 return -EOPNOTSUPP;
869
870 ipc.opt = NULL;
871 ipc.tx_flags = 0;
872 ipc.ttl = 0;
873 ipc.tos = -1;
874
875 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
876
877 fl4 = &inet->cork.fl.u.ip4;
878 if (up->pending) {
879 /*
880 * There are pending frames.
881 * The socket lock must be held while it's corked.
882 */
883 lock_sock(sk);
884 if (likely(up->pending)) {
885 if (unlikely(up->pending != AF_INET)) {
886 release_sock(sk);
887 return -EINVAL;
888 }
889 goto do_append_data;
890 }
891 release_sock(sk);
892 }
893 ulen += sizeof(struct udphdr);
894
895 /*
896 * Get and verify the address.
897 */
898 if (msg->msg_name) {
899 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
900 if (msg->msg_namelen < sizeof(*usin))
901 return -EINVAL;
902 if (usin->sin_family != AF_INET) {
903 if (usin->sin_family != AF_UNSPEC)
904 return -EAFNOSUPPORT;
905 }
906
907 daddr = usin->sin_addr.s_addr;
908 dport = usin->sin_port;
909 if (dport == 0)
910 return -EINVAL;
911 } else {
912 if (sk->sk_state != TCP_ESTABLISHED)
913 return -EDESTADDRREQ;
914 daddr = inet->inet_daddr;
915 dport = inet->inet_dport;
916 /* Open fast path for connected socket.
917 Route will not be used, if at least one option is set.
918 */
919 connected = 1;
920 }
921
922 ipc.sockc.tsflags = sk->sk_tsflags;
923 ipc.addr = inet->inet_saddr;
924 ipc.oif = sk->sk_bound_dev_if;
925
926 if (msg->msg_controllen) {
927 err = ip_cmsg_send(sk, msg, &ipc, sk->sk_family == AF_INET6);
928 if (unlikely(err)) {
929 kfree(ipc.opt);
930 return err;
931 }
932 if (ipc.opt)
933 free = 1;
934 connected = 0;
935 }
936 if (!ipc.opt) {
937 struct ip_options_rcu *inet_opt;
938
939 rcu_read_lock();
940 inet_opt = rcu_dereference(inet->inet_opt);
941 if (inet_opt) {
942 memcpy(&opt_copy, inet_opt,
943 sizeof(*inet_opt) + inet_opt->opt.optlen);
944 ipc.opt = &opt_copy.opt;
945 }
946 rcu_read_unlock();
947 }
948
949 saddr = ipc.addr;
950 ipc.addr = faddr = daddr;
951
952 sock_tx_timestamp(sk, ipc.sockc.tsflags, &ipc.tx_flags);
953
954 if (ipc.opt && ipc.opt->opt.srr) {
955 if (!daddr) {
956 err = -EINVAL;
957 goto out_free;
958 }
959 faddr = ipc.opt->opt.faddr;
960 connected = 0;
961 }
962 tos = get_rttos(&ipc, inet);
963 if (sock_flag(sk, SOCK_LOCALROUTE) ||
964 (msg->msg_flags & MSG_DONTROUTE) ||
965 (ipc.opt && ipc.opt->opt.is_strictroute)) {
966 tos |= RTO_ONLINK;
967 connected = 0;
968 }
969
970 if (ipv4_is_multicast(daddr)) {
971 if (!ipc.oif)
972 ipc.oif = inet->mc_index;
973 if (!saddr)
974 saddr = inet->mc_addr;
975 connected = 0;
976 } else if (!ipc.oif) {
977 ipc.oif = inet->uc_index;
978 } else if (ipv4_is_lbcast(daddr) && inet->uc_index) {
979 /* oif is set, packet is to local broadcast and
980 * and uc_index is set. oif is most likely set
981 * by sk_bound_dev_if. If uc_index != oif check if the
982 * oif is an L3 master and uc_index is an L3 slave.
983 * If so, we want to allow the send using the uc_index.
984 */
985 if (ipc.oif != inet->uc_index &&
986 ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk),
987 inet->uc_index)) {
988 ipc.oif = inet->uc_index;
989 }
990 }
991
992 if (connected)
993 rt = (struct rtable *)sk_dst_check(sk, 0);
994
995 if (!rt) {
996 struct net *net = sock_net(sk);
997 __u8 flow_flags = inet_sk_flowi_flags(sk);
998
999 fl4 = &fl4_stack;
1000
1001 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
1002 RT_SCOPE_UNIVERSE, sk->sk_protocol,
1003 flow_flags,
1004 faddr, saddr, dport, inet->inet_sport,
1005 sk->sk_uid);
1006
1007 security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
1008 rt = ip_route_output_flow(net, fl4, sk);
1009 if (IS_ERR(rt)) {
1010 err = PTR_ERR(rt);
1011 rt = NULL;
1012 if (err == -ENETUNREACH)
1013 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
1014 goto out;
1015 }
1016
1017 err = -EACCES;
1018 if ((rt->rt_flags & RTCF_BROADCAST) &&
1019 !sock_flag(sk, SOCK_BROADCAST))
1020 goto out;
1021 if (connected)
1022 sk_dst_set(sk, dst_clone(&rt->dst));
1023 }
1024
1025 if (msg->msg_flags&MSG_CONFIRM)
1026 goto do_confirm;
1027back_from_confirm:
1028
1029 saddr = fl4->saddr;
1030 if (!ipc.addr)
1031 daddr = ipc.addr = fl4->daddr;
1032
1033 /* Lockless fast path for the non-corking case. */
1034 if (!corkreq) {
1035 skb = ip_make_skb(sk, fl4, getfrag, msg, ulen,
1036 sizeof(struct udphdr), &ipc, &rt,
1037 msg->msg_flags);
1038 err = PTR_ERR(skb);
1039 if (!IS_ERR_OR_NULL(skb))
1040 err = udp_send_skb(skb, fl4);
1041 goto out;
1042 }
1043
1044 lock_sock(sk);
1045 if (unlikely(up->pending)) {
1046 /* The socket is already corked while preparing it. */
1047 /* ... which is an evident application bug. --ANK */
1048 release_sock(sk);
1049
1050 net_dbg_ratelimited("socket already corked\n");
1051 err = -EINVAL;
1052 goto out;
1053 }
1054 /*
1055 * Now cork the socket to pend data.
1056 */
1057 fl4 = &inet->cork.fl.u.ip4;
1058 fl4->daddr = daddr;
1059 fl4->saddr = saddr;
1060 fl4->fl4_dport = dport;
1061 fl4->fl4_sport = inet->inet_sport;
1062 up->pending = AF_INET;
1063
1064do_append_data:
1065 up->len += ulen;
1066 err = ip_append_data(sk, fl4, getfrag, msg, ulen,
1067 sizeof(struct udphdr), &ipc, &rt,
1068 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1069 if (err)
1070 udp_flush_pending_frames(sk);
1071 else if (!corkreq)
1072 err = udp_push_pending_frames(sk);
1073 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1074 up->pending = 0;
1075 release_sock(sk);
1076
1077out:
1078 ip_rt_put(rt);
1079out_free:
1080 if (free)
1081 kfree(ipc.opt);
1082 if (!err)
1083 return len;
1084 /*
1085 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1086 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1087 * we don't have a good statistic (IpOutDiscards but it can be too many
1088 * things). We could add another new stat but at least for now that
1089 * seems like overkill.
1090 */
1091 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1092 UDP_INC_STATS(sock_net(sk),
1093 UDP_MIB_SNDBUFERRORS, is_udplite);
1094 }
1095 return err;
1096
1097do_confirm:
1098 if (msg->msg_flags & MSG_PROBE)
1099 dst_confirm_neigh(&rt->dst, &fl4->daddr);
1100 if (!(msg->msg_flags&MSG_PROBE) || len)
1101 goto back_from_confirm;
1102 err = 0;
1103 goto out;
1104}
1105EXPORT_SYMBOL(udp_sendmsg);
1106
1107int udp_sendpage(struct sock *sk, struct page *page, int offset,
1108 size_t size, int flags)
1109{
1110 struct inet_sock *inet = inet_sk(sk);
1111 struct udp_sock *up = udp_sk(sk);
1112 int ret;
1113
1114 if (flags & MSG_SENDPAGE_NOTLAST)
1115 flags |= MSG_MORE;
1116
1117 if (!up->pending) {
1118 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
1119
1120 /* Call udp_sendmsg to specify destination address which
1121 * sendpage interface can't pass.
1122 * This will succeed only when the socket is connected.
1123 */
1124 ret = udp_sendmsg(sk, &msg, 0);
1125 if (ret < 0)
1126 return ret;
1127 }
1128
1129 lock_sock(sk);
1130
1131 if (unlikely(!up->pending)) {
1132 release_sock(sk);
1133
1134 net_dbg_ratelimited("cork failed\n");
1135 return -EINVAL;
1136 }
1137
1138 ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
1139 page, offset, size, flags);
1140 if (ret == -EOPNOTSUPP) {
1141 release_sock(sk);
1142 return sock_no_sendpage(sk->sk_socket, page, offset,
1143 size, flags);
1144 }
1145 if (ret < 0) {
1146 udp_flush_pending_frames(sk);
1147 goto out;
1148 }
1149
1150 up->len += size;
1151 if (!(up->corkflag || (flags&MSG_MORE)))
1152 ret = udp_push_pending_frames(sk);
1153 if (!ret)
1154 ret = size;
1155out:
1156 release_sock(sk);
1157 return ret;
1158}
1159
1160#define UDP_SKB_IS_STATELESS 0x80000000
1161
1162static void udp_set_dev_scratch(struct sk_buff *skb)
1163{
1164 struct udp_dev_scratch *scratch = udp_skb_scratch(skb);
1165
1166 BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long));
1167 scratch->_tsize_state = skb->truesize;
1168#if BITS_PER_LONG == 64
1169 scratch->len = skb->len;
1170 scratch->csum_unnecessary = !!skb_csum_unnecessary(skb);
1171 scratch->is_linear = !skb_is_nonlinear(skb);
1172#endif
1173 /* all head states execept sp (dst, sk, nf) are always cleared by
1174 * udp_rcv() and we need to preserve secpath, if present, to eventually
1175 * process IP_CMSG_PASSSEC at recvmsg() time
1176 */
1177 if (likely(!skb_sec_path(skb)))
1178 scratch->_tsize_state |= UDP_SKB_IS_STATELESS;
1179}
1180
1181static int udp_skb_truesize(struct sk_buff *skb)
1182{
1183 return udp_skb_scratch(skb)->_tsize_state & ~UDP_SKB_IS_STATELESS;
1184}
1185
1186static bool udp_skb_has_head_state(struct sk_buff *skb)
1187{
1188 return !(udp_skb_scratch(skb)->_tsize_state & UDP_SKB_IS_STATELESS);
1189}
1190
1191/* fully reclaim rmem/fwd memory allocated for skb */
1192static void udp_rmem_release(struct sock *sk, int size, int partial,
1193 bool rx_queue_lock_held)
1194{
1195 struct udp_sock *up = udp_sk(sk);
1196 struct sk_buff_head *sk_queue;
1197 int amt;
1198
1199 if (likely(partial)) {
1200 up->forward_deficit += size;
1201 size = up->forward_deficit;
1202 if (size < (sk->sk_rcvbuf >> 2))
1203 return;
1204 } else {
1205 size += up->forward_deficit;
1206 }
1207 up->forward_deficit = 0;
1208
1209 /* acquire the sk_receive_queue for fwd allocated memory scheduling,
1210 * if the called don't held it already
1211 */
1212 sk_queue = &sk->sk_receive_queue;
1213 if (!rx_queue_lock_held)
1214 spin_lock(&sk_queue->lock);
1215
1216
1217 sk->sk_forward_alloc += size;
1218 amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1);
1219 sk->sk_forward_alloc -= amt;
1220
1221 if (amt)
1222 __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT);
1223
1224 atomic_sub(size, &sk->sk_rmem_alloc);
1225
1226 /* this can save us from acquiring the rx queue lock on next receive */
1227 skb_queue_splice_tail_init(sk_queue, &up->reader_queue);
1228
1229 if (!rx_queue_lock_held)
1230 spin_unlock(&sk_queue->lock);
1231}
1232
1233/* Note: called with reader_queue.lock held.
1234 * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch
1235 * This avoids a cache line miss while receive_queue lock is held.
1236 * Look at __udp_enqueue_schedule_skb() to find where this copy is done.
1237 */
1238void udp_skb_destructor(struct sock *sk, struct sk_buff *skb)
1239{
1240 prefetch(&skb->data);
1241 udp_rmem_release(sk, udp_skb_truesize(skb), 1, false);
1242}
1243EXPORT_SYMBOL(udp_skb_destructor);
1244
1245/* as above, but the caller held the rx queue lock, too */
1246static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb)
1247{
1248 prefetch(&skb->data);
1249 udp_rmem_release(sk, udp_skb_truesize(skb), 1, true);
1250}
1251
1252/* Idea of busylocks is to let producers grab an extra spinlock
1253 * to relieve pressure on the receive_queue spinlock shared by consumer.
1254 * Under flood, this means that only one producer can be in line
1255 * trying to acquire the receive_queue spinlock.
1256 * These busylock can be allocated on a per cpu manner, instead of a
1257 * per socket one (that would consume a cache line per socket)
1258 */
1259static int udp_busylocks_log __read_mostly;
1260static spinlock_t *udp_busylocks __read_mostly;
1261
1262static spinlock_t *busylock_acquire(void *ptr)
1263{
1264 spinlock_t *busy;
1265
1266 busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log);
1267 spin_lock(busy);
1268 return busy;
1269}
1270
1271static void busylock_release(spinlock_t *busy)
1272{
1273 if (busy)
1274 spin_unlock(busy);
1275}
1276
1277int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
1278{
1279 struct sk_buff_head *list = &sk->sk_receive_queue;
1280 int rmem, delta, amt, err = -ENOMEM;
1281 spinlock_t *busy = NULL;
1282 int size;
1283
1284 /* try to avoid the costly atomic add/sub pair when the receive
1285 * queue is full; always allow at least a packet
1286 */
1287 rmem = atomic_read(&sk->sk_rmem_alloc);
1288 if (rmem > sk->sk_rcvbuf)
1289 goto drop;
1290
1291 /* Under mem pressure, it might be helpful to help udp_recvmsg()
1292 * having linear skbs :
1293 * - Reduce memory overhead and thus increase receive queue capacity
1294 * - Less cache line misses at copyout() time
1295 * - Less work at consume_skb() (less alien page frag freeing)
1296 */
1297 if (rmem > (sk->sk_rcvbuf >> 1)) {
1298 skb_condense(skb);
1299
1300 busy = busylock_acquire(sk);
1301 }
1302 size = skb->truesize;
1303 udp_set_dev_scratch(skb);
1304
1305 /* we drop only if the receive buf is full and the receive
1306 * queue contains some other skb
1307 */
1308 rmem = atomic_add_return(size, &sk->sk_rmem_alloc);
1309 if (rmem > (size + sk->sk_rcvbuf))
1310 goto uncharge_drop;
1311
1312 spin_lock(&list->lock);
1313 if (size >= sk->sk_forward_alloc) {
1314 amt = sk_mem_pages(size);
1315 delta = amt << SK_MEM_QUANTUM_SHIFT;
1316 if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) {
1317 err = -ENOBUFS;
1318 spin_unlock(&list->lock);
1319 goto uncharge_drop;
1320 }
1321
1322 sk->sk_forward_alloc += delta;
1323 }
1324
1325 sk->sk_forward_alloc -= size;
1326
1327 /* no need to setup a destructor, we will explicitly release the
1328 * forward allocated memory on dequeue
1329 */
1330 sock_skb_set_dropcount(sk, skb);
1331
1332 __skb_queue_tail(list, skb);
1333 spin_unlock(&list->lock);
1334
1335 if (!sock_flag(sk, SOCK_DEAD))
1336 sk->sk_data_ready(sk);
1337
1338 busylock_release(busy);
1339 return 0;
1340
1341uncharge_drop:
1342 atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1343
1344drop:
1345 atomic_inc(&sk->sk_drops);
1346 busylock_release(busy);
1347 return err;
1348}
1349EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb);
1350
1351void udp_destruct_sock(struct sock *sk)
1352{
1353 /* reclaim completely the forward allocated memory */
1354 struct udp_sock *up = udp_sk(sk);
1355 unsigned int total = 0;
1356 struct sk_buff *skb;
1357
1358 skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue);
1359 while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) {
1360 total += skb->truesize;
1361 kfree_skb(skb);
1362 }
1363 udp_rmem_release(sk, total, 0, true);
1364
1365 inet_sock_destruct(sk);
1366}
1367EXPORT_SYMBOL_GPL(udp_destruct_sock);
1368
1369int udp_init_sock(struct sock *sk)
1370{
1371 skb_queue_head_init(&udp_sk(sk)->reader_queue);
1372 sk->sk_destruct = udp_destruct_sock;
1373 return 0;
1374}
1375EXPORT_SYMBOL_GPL(udp_init_sock);
1376
1377void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len)
1378{
1379 if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) {
1380 bool slow = lock_sock_fast(sk);
1381
1382 sk_peek_offset_bwd(sk, len);
1383 unlock_sock_fast(sk, slow);
1384 }
1385
1386 if (!skb_unref(skb))
1387 return;
1388
1389 /* In the more common cases we cleared the head states previously,
1390 * see __udp_queue_rcv_skb().
1391 */
1392 if (unlikely(udp_skb_has_head_state(skb)))
1393 skb_release_head_state(skb);
1394 __consume_stateless_skb(skb);
1395}
1396EXPORT_SYMBOL_GPL(skb_consume_udp);
1397
1398static struct sk_buff *__first_packet_length(struct sock *sk,
1399 struct sk_buff_head *rcvq,
1400 int *total)
1401{
1402 struct sk_buff *skb;
1403
1404 while ((skb = skb_peek(rcvq)) != NULL) {
1405 if (udp_lib_checksum_complete(skb)) {
1406 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS,
1407 IS_UDPLITE(sk));
1408 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
1409 IS_UDPLITE(sk));
1410 atomic_inc(&sk->sk_drops);
1411 __skb_unlink(skb, rcvq);
1412 *total += skb->truesize;
1413 kfree_skb(skb);
1414 } else {
1415 /* the csum related bits could be changed, refresh
1416 * the scratch area
1417 */
1418 udp_set_dev_scratch(skb);
1419 break;
1420 }
1421 }
1422 return skb;
1423}
1424
1425/**
1426 * first_packet_length - return length of first packet in receive queue
1427 * @sk: socket
1428 *
1429 * Drops all bad checksum frames, until a valid one is found.
1430 * Returns the length of found skb, or -1 if none is found.
1431 */
1432static int first_packet_length(struct sock *sk)
1433{
1434 struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue;
1435 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1436 struct sk_buff *skb;
1437 int total = 0;
1438 int res;
1439
1440 spin_lock_bh(&rcvq->lock);
1441 skb = __first_packet_length(sk, rcvq, &total);
1442 if (!skb && !skb_queue_empty(sk_queue)) {
1443 spin_lock(&sk_queue->lock);
1444 skb_queue_splice_tail_init(sk_queue, rcvq);
1445 spin_unlock(&sk_queue->lock);
1446
1447 skb = __first_packet_length(sk, rcvq, &total);
1448 }
1449 res = skb ? skb->len : -1;
1450 if (total)
1451 udp_rmem_release(sk, total, 1, false);
1452 spin_unlock_bh(&rcvq->lock);
1453 return res;
1454}
1455
1456/*
1457 * IOCTL requests applicable to the UDP protocol
1458 */
1459
1460int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
1461{
1462 switch (cmd) {
1463 case SIOCOUTQ:
1464 {
1465 int amount = sk_wmem_alloc_get(sk);
1466
1467 return put_user(amount, (int __user *)arg);
1468 }
1469
1470 case SIOCINQ:
1471 {
1472 int amount = max_t(int, 0, first_packet_length(sk));
1473
1474 return put_user(amount, (int __user *)arg);
1475 }
1476
1477 default:
1478 return -ENOIOCTLCMD;
1479 }
1480
1481 return 0;
1482}
1483EXPORT_SYMBOL(udp_ioctl);
1484
1485struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
1486 int noblock, int *peeked, int *off, int *err)
1487{
1488 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1489 struct sk_buff_head *queue;
1490 struct sk_buff *last;
1491 long timeo;
1492 int error;
1493
1494 queue = &udp_sk(sk)->reader_queue;
1495 flags |= noblock ? MSG_DONTWAIT : 0;
1496 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1497 do {
1498 struct sk_buff *skb;
1499
1500 error = sock_error(sk);
1501 if (error)
1502 break;
1503
1504 error = -EAGAIN;
1505 *peeked = 0;
1506 do {
1507 spin_lock_bh(&queue->lock);
1508 skb = __skb_try_recv_from_queue(sk, queue, flags,
1509 udp_skb_destructor,
1510 peeked, off, err,
1511 &last);
1512 if (skb) {
1513 spin_unlock_bh(&queue->lock);
1514 return skb;
1515 }
1516
1517 if (skb_queue_empty(sk_queue)) {
1518 spin_unlock_bh(&queue->lock);
1519 goto busy_check;
1520 }
1521
1522 /* refill the reader queue and walk it again
1523 * keep both queues locked to avoid re-acquiring
1524 * the sk_receive_queue lock if fwd memory scheduling
1525 * is needed.
1526 */
1527 spin_lock(&sk_queue->lock);
1528 skb_queue_splice_tail_init(sk_queue, queue);
1529
1530 skb = __skb_try_recv_from_queue(sk, queue, flags,
1531 udp_skb_dtor_locked,
1532 peeked, off, err,
1533 &last);
1534 spin_unlock(&sk_queue->lock);
1535 spin_unlock_bh(&queue->lock);
1536 if (skb)
1537 return skb;
1538
1539busy_check:
1540 if (!sk_can_busy_loop(sk))
1541 break;
1542
1543 sk_busy_loop(sk, flags & MSG_DONTWAIT);
1544 } while (!skb_queue_empty(sk_queue));
1545
1546 /* sk_queue is empty, reader_queue may contain peeked packets */
1547 } while (timeo &&
1548 !__skb_wait_for_more_packets(sk, &error, &timeo,
1549 (struct sk_buff *)sk_queue));
1550
1551 *err = error;
1552 return NULL;
1553}
1554EXPORT_SYMBOL_GPL(__skb_recv_udp);
1555
1556/*
1557 * This should be easy, if there is something there we
1558 * return it, otherwise we block.
1559 */
1560
1561int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
1562 int flags, int *addr_len)
1563{
1564 struct inet_sock *inet = inet_sk(sk);
1565 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
1566 struct sk_buff *skb;
1567 unsigned int ulen, copied;
1568 int peeked, peeking, off;
1569 int err;
1570 int is_udplite = IS_UDPLITE(sk);
1571 bool checksum_valid = false;
1572
1573 if (flags & MSG_ERRQUEUE)
1574 return ip_recv_error(sk, msg, len, addr_len);
1575
1576try_again:
1577 peeking = flags & MSG_PEEK;
1578 off = sk_peek_offset(sk, flags);
1579 skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err);
1580 if (!skb)
1581 return err;
1582
1583 ulen = udp_skb_len(skb);
1584 copied = len;
1585 if (copied > ulen - off)
1586 copied = ulen - off;
1587 else if (copied < ulen)
1588 msg->msg_flags |= MSG_TRUNC;
1589
1590 /*
1591 * If checksum is needed at all, try to do it while copying the
1592 * data. If the data is truncated, or if we only want a partial
1593 * coverage checksum (UDP-Lite), do it before the copy.
1594 */
1595
1596 if (copied < ulen || peeking ||
1597 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
1598 checksum_valid = udp_skb_csum_unnecessary(skb) ||
1599 !__udp_lib_checksum_complete(skb);
1600 if (!checksum_valid)
1601 goto csum_copy_err;
1602 }
1603
1604 if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
1605 if (udp_skb_is_linear(skb))
1606 err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
1607 else
1608 err = skb_copy_datagram_msg(skb, off, msg, copied);
1609 } else {
1610 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
1611
1612 if (err == -EINVAL)
1613 goto csum_copy_err;
1614 }
1615
1616 if (unlikely(err)) {
1617 if (!peeked) {
1618 atomic_inc(&sk->sk_drops);
1619 UDP_INC_STATS(sock_net(sk),
1620 UDP_MIB_INERRORS, is_udplite);
1621 }
1622 kfree_skb(skb);
1623 return err;
1624 }
1625
1626 if (!peeked)
1627 UDP_INC_STATS(sock_net(sk),
1628 UDP_MIB_INDATAGRAMS, is_udplite);
1629
1630 sock_recv_ts_and_drops(msg, sk, skb);
1631
1632 /* Copy the address. */
1633 if (sin) {
1634 sin->sin_family = AF_INET;
1635 sin->sin_port = udp_hdr(skb)->source;
1636 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1637 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1638 *addr_len = sizeof(*sin);
1639 }
1640 if (inet->cmsg_flags)
1641 ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off);
1642
1643 err = copied;
1644 if (flags & MSG_TRUNC)
1645 err = ulen;
1646
1647 skb_consume_udp(sk, skb, peeking ? -err : err);
1648 return err;
1649
1650csum_copy_err:
1651 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
1652 udp_skb_destructor)) {
1653 UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1654 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1655 }
1656 kfree_skb(skb);
1657
1658 /* starting over for a new packet, but check if we need to yield */
1659 cond_resched();
1660 msg->msg_flags &= ~MSG_TRUNC;
1661 goto try_again;
1662}
1663
1664int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
1665{
1666 /* This check is replicated from __ip4_datagram_connect() and
1667 * intended to prevent BPF program called below from accessing bytes
1668 * that are out of the bound specified by user in addr_len.
1669 */
1670 if (addr_len < sizeof(struct sockaddr_in))
1671 return -EINVAL;
1672
1673 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr);
1674}
1675EXPORT_SYMBOL(udp_pre_connect);
1676
1677int __udp_disconnect(struct sock *sk, int flags)
1678{
1679 struct inet_sock *inet = inet_sk(sk);
1680 /*
1681 * 1003.1g - break association.
1682 */
1683
1684 sk->sk_state = TCP_CLOSE;
1685 inet->inet_daddr = 0;
1686 inet->inet_dport = 0;
1687 sock_rps_reset_rxhash(sk);
1688 sk->sk_bound_dev_if = 0;
1689 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1690 inet_reset_saddr(sk);
1691
1692 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1693 sk->sk_prot->unhash(sk);
1694 inet->inet_sport = 0;
1695 }
1696 sk_dst_reset(sk);
1697 return 0;
1698}
1699EXPORT_SYMBOL(__udp_disconnect);
1700
1701int udp_disconnect(struct sock *sk, int flags)
1702{
1703 lock_sock(sk);
1704 __udp_disconnect(sk, flags);
1705 release_sock(sk);
1706 return 0;
1707}
1708EXPORT_SYMBOL(udp_disconnect);
1709
1710void udp_lib_unhash(struct sock *sk)
1711{
1712 if (sk_hashed(sk)) {
1713 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1714 struct udp_hslot *hslot, *hslot2;
1715
1716 hslot = udp_hashslot(udptable, sock_net(sk),
1717 udp_sk(sk)->udp_port_hash);
1718 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1719
1720 spin_lock_bh(&hslot->lock);
1721 if (rcu_access_pointer(sk->sk_reuseport_cb))
1722 reuseport_detach_sock(sk);
1723 if (sk_del_node_init_rcu(sk)) {
1724 hslot->count--;
1725 inet_sk(sk)->inet_num = 0;
1726 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1727
1728 spin_lock(&hslot2->lock);
1729 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1730 hslot2->count--;
1731 spin_unlock(&hslot2->lock);
1732 }
1733 spin_unlock_bh(&hslot->lock);
1734 }
1735}
1736EXPORT_SYMBOL(udp_lib_unhash);
1737
1738/*
1739 * inet_rcv_saddr was changed, we must rehash secondary hash
1740 */
1741void udp_lib_rehash(struct sock *sk, u16 newhash)
1742{
1743 if (sk_hashed(sk)) {
1744 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1745 struct udp_hslot *hslot, *hslot2, *nhslot2;
1746
1747 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1748 nhslot2 = udp_hashslot2(udptable, newhash);
1749 udp_sk(sk)->udp_portaddr_hash = newhash;
1750
1751 if (hslot2 != nhslot2 ||
1752 rcu_access_pointer(sk->sk_reuseport_cb)) {
1753 hslot = udp_hashslot(udptable, sock_net(sk),
1754 udp_sk(sk)->udp_port_hash);
1755 /* we must lock primary chain too */
1756 spin_lock_bh(&hslot->lock);
1757 if (rcu_access_pointer(sk->sk_reuseport_cb))
1758 reuseport_detach_sock(sk);
1759
1760 if (hslot2 != nhslot2) {
1761 spin_lock(&hslot2->lock);
1762 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1763 hslot2->count--;
1764 spin_unlock(&hslot2->lock);
1765
1766 spin_lock(&nhslot2->lock);
1767 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
1768 &nhslot2->head);
1769 nhslot2->count++;
1770 spin_unlock(&nhslot2->lock);
1771 }
1772
1773 spin_unlock_bh(&hslot->lock);
1774 }
1775 }
1776}
1777EXPORT_SYMBOL(udp_lib_rehash);
1778
1779static void udp_v4_rehash(struct sock *sk)
1780{
1781 u16 new_hash = ipv4_portaddr_hash(sock_net(sk),
1782 inet_sk(sk)->inet_rcv_saddr,
1783 inet_sk(sk)->inet_num);
1784 udp_lib_rehash(sk, new_hash);
1785}
1786
1787static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1788{
1789 int rc;
1790
1791 if (inet_sk(sk)->inet_daddr) {
1792 sock_rps_save_rxhash(sk, skb);
1793 sk_mark_napi_id(sk, skb);
1794 sk_incoming_cpu_update(sk);
1795 } else {
1796 sk_mark_napi_id_once(sk, skb);
1797 }
1798
1799 rc = __udp_enqueue_schedule_skb(sk, skb);
1800 if (rc < 0) {
1801 int is_udplite = IS_UDPLITE(sk);
1802
1803 /* Note that an ENOMEM error is charged twice */
1804 if (rc == -ENOMEM)
1805 UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1806 is_udplite);
1807 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1808 kfree_skb(skb);
1809 trace_udp_fail_queue_rcv_skb(rc, sk);
1810 return -1;
1811 }
1812
1813 return 0;
1814}
1815
1816static struct static_key udp_encap_needed __read_mostly;
1817void udp_encap_enable(void)
1818{
1819 static_key_enable(&udp_encap_needed);
1820}
1821EXPORT_SYMBOL(udp_encap_enable);
1822
1823/* returns:
1824 * -1: error
1825 * 0: success
1826 * >0: "udp encap" protocol resubmission
1827 *
1828 * Note that in the success and error cases, the skb is assumed to
1829 * have either been requeued or freed.
1830 */
1831static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1832{
1833 struct udp_sock *up = udp_sk(sk);
1834 int is_udplite = IS_UDPLITE(sk);
1835
1836 /*
1837 * Charge it to the socket, dropping if the queue is full.
1838 */
1839 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1840 goto drop;
1841 nf_reset(skb);
1842
1843 if (static_key_false(&udp_encap_needed) && up->encap_type) {
1844 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
1845
1846 /*
1847 * This is an encapsulation socket so pass the skb to
1848 * the socket's udp_encap_rcv() hook. Otherwise, just
1849 * fall through and pass this up the UDP socket.
1850 * up->encap_rcv() returns the following value:
1851 * =0 if skb was successfully passed to the encap
1852 * handler or was discarded by it.
1853 * >0 if skb should be passed on to UDP.
1854 * <0 if skb should be resubmitted as proto -N
1855 */
1856
1857 /* if we're overly short, let UDP handle it */
1858 encap_rcv = READ_ONCE(up->encap_rcv);
1859 if (encap_rcv) {
1860 int ret;
1861
1862 /* Verify checksum before giving to encap */
1863 if (udp_lib_checksum_complete(skb))
1864 goto csum_error;
1865
1866 ret = encap_rcv(sk, skb);
1867 if (ret <= 0) {
1868 __UDP_INC_STATS(sock_net(sk),
1869 UDP_MIB_INDATAGRAMS,
1870 is_udplite);
1871 return -ret;
1872 }
1873 }
1874
1875 /* FALLTHROUGH -- it's a UDP Packet */
1876 }
1877
1878 /*
1879 * UDP-Lite specific tests, ignored on UDP sockets
1880 */
1881 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1882
1883 /*
1884 * MIB statistics other than incrementing the error count are
1885 * disabled for the following two types of errors: these depend
1886 * on the application settings, not on the functioning of the
1887 * protocol stack as such.
1888 *
1889 * RFC 3828 here recommends (sec 3.3): "There should also be a
1890 * way ... to ... at least let the receiving application block
1891 * delivery of packets with coverage values less than a value
1892 * provided by the application."
1893 */
1894 if (up->pcrlen == 0) { /* full coverage was set */
1895 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n",
1896 UDP_SKB_CB(skb)->cscov, skb->len);
1897 goto drop;
1898 }
1899 /* The next case involves violating the min. coverage requested
1900 * by the receiver. This is subtle: if receiver wants x and x is
1901 * greater than the buffersize/MTU then receiver will complain
1902 * that it wants x while sender emits packets of smaller size y.
1903 * Therefore the above ...()->partial_cov statement is essential.
1904 */
1905 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1906 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n",
1907 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1908 goto drop;
1909 }
1910 }
1911
1912 prefetch(&sk->sk_rmem_alloc);
1913 if (rcu_access_pointer(sk->sk_filter) &&
1914 udp_lib_checksum_complete(skb))
1915 goto csum_error;
1916
1917 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
1918 goto drop;
1919
1920 udp_csum_pull_header(skb);
1921
1922 ipv4_pktinfo_prepare(sk, skb);
1923 return __udp_queue_rcv_skb(sk, skb);
1924
1925csum_error:
1926 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1927drop:
1928 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1929 atomic_inc(&sk->sk_drops);
1930 kfree_skb(skb);
1931 return -1;
1932}
1933
1934/* For TCP sockets, sk_rx_dst is protected by socket lock
1935 * For UDP, we use xchg() to guard against concurrent changes.
1936 */
1937bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
1938{
1939 struct dst_entry *old;
1940
1941 if (dst_hold_safe(dst)) {
1942 old = xchg(&sk->sk_rx_dst, dst);
1943 dst_release(old);
1944 return old != dst;
1945 }
1946 return false;
1947}
1948EXPORT_SYMBOL(udp_sk_rx_dst_set);
1949
1950/*
1951 * Multicasts and broadcasts go to each listener.
1952 *
1953 * Note: called only from the BH handler context.
1954 */
1955static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1956 struct udphdr *uh,
1957 __be32 saddr, __be32 daddr,
1958 struct udp_table *udptable,
1959 int proto)
1960{
1961 struct sock *sk, *first = NULL;
1962 unsigned short hnum = ntohs(uh->dest);
1963 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
1964 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
1965 unsigned int offset = offsetof(typeof(*sk), sk_node);
1966 int dif = skb->dev->ifindex;
1967 int sdif = inet_sdif(skb);
1968 struct hlist_node *node;
1969 struct sk_buff *nskb;
1970
1971 if (use_hash2) {
1972 hash2_any = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum) &
1973 udptable->mask;
1974 hash2 = ipv4_portaddr_hash(net, daddr, hnum) & udptable->mask;
1975start_lookup:
1976 hslot = &udptable->hash2[hash2];
1977 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
1978 }
1979
1980 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
1981 if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr,
1982 uh->source, saddr, dif, sdif, hnum))
1983 continue;
1984
1985 if (!first) {
1986 first = sk;
1987 continue;
1988 }
1989 nskb = skb_clone(skb, GFP_ATOMIC);
1990
1991 if (unlikely(!nskb)) {
1992 atomic_inc(&sk->sk_drops);
1993 __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
1994 IS_UDPLITE(sk));
1995 __UDP_INC_STATS(net, UDP_MIB_INERRORS,
1996 IS_UDPLITE(sk));
1997 continue;
1998 }
1999 if (udp_queue_rcv_skb(sk, nskb) > 0)
2000 consume_skb(nskb);
2001 }
2002
2003 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
2004 if (use_hash2 && hash2 != hash2_any) {
2005 hash2 = hash2_any;
2006 goto start_lookup;
2007 }
2008
2009 if (first) {
2010 if (udp_queue_rcv_skb(first, skb) > 0)
2011 consume_skb(skb);
2012 } else {
2013 kfree_skb(skb);
2014 __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
2015 proto == IPPROTO_UDPLITE);
2016 }
2017 return 0;
2018}
2019
2020/* Initialize UDP checksum. If exited with zero value (success),
2021 * CHECKSUM_UNNECESSARY means, that no more checks are required.
2022 * Otherwise, csum completion requires chacksumming packet body,
2023 * including udp header and folding it to skb->csum.
2024 */
2025static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
2026 int proto)
2027{
2028 int err;
2029
2030 UDP_SKB_CB(skb)->partial_cov = 0;
2031 UDP_SKB_CB(skb)->cscov = skb->len;
2032
2033 if (proto == IPPROTO_UDPLITE) {
2034 err = udplite_checksum_init(skb, uh);
2035 if (err)
2036 return err;
2037
2038 if (UDP_SKB_CB(skb)->partial_cov) {
2039 skb->csum = inet_compute_pseudo(skb, proto);
2040 return 0;
2041 }
2042 }
2043
2044 /* Note, we are only interested in != 0 or == 0, thus the
2045 * force to int.
2046 */
2047 return (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
2048 inet_compute_pseudo);
2049}
2050
2051/*
2052 * All we need to do is get the socket, and then do a checksum.
2053 */
2054
2055int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
2056 int proto)
2057{
2058 struct sock *sk;
2059 struct udphdr *uh;
2060 unsigned short ulen;
2061 struct rtable *rt = skb_rtable(skb);
2062 __be32 saddr, daddr;
2063 struct net *net = dev_net(skb->dev);
2064
2065 /*
2066 * Validate the packet.
2067 */
2068 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
2069 goto drop; /* No space for header. */
2070
2071 uh = udp_hdr(skb);
2072 ulen = ntohs(uh->len);
2073 saddr = ip_hdr(skb)->saddr;
2074 daddr = ip_hdr(skb)->daddr;
2075
2076 if (ulen > skb->len)
2077 goto short_packet;
2078
2079 if (proto == IPPROTO_UDP) {
2080 /* UDP validates ulen. */
2081 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
2082 goto short_packet;
2083 uh = udp_hdr(skb);
2084 }
2085
2086 if (udp4_csum_init(skb, uh, proto))
2087 goto csum_error;
2088
2089 sk = skb_steal_sock(skb);
2090 if (sk) {
2091 struct dst_entry *dst = skb_dst(skb);
2092 int ret;
2093
2094 if (unlikely(sk->sk_rx_dst != dst))
2095 udp_sk_rx_dst_set(sk, dst);
2096
2097 ret = udp_queue_rcv_skb(sk, skb);
2098 sock_put(sk);
2099 /* a return value > 0 means to resubmit the input, but
2100 * it wants the return to be -protocol, or 0
2101 */
2102 if (ret > 0)
2103 return -ret;
2104 return 0;
2105 }
2106
2107 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
2108 return __udp4_lib_mcast_deliver(net, skb, uh,
2109 saddr, daddr, udptable, proto);
2110
2111 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
2112 if (sk) {
2113 int ret;
2114
2115 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
2116 skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
2117 inet_compute_pseudo);
2118
2119 ret = udp_queue_rcv_skb(sk, skb);
2120
2121 /* a return value > 0 means to resubmit the input, but
2122 * it wants the return to be -protocol, or 0
2123 */
2124 if (ret > 0)
2125 return -ret;
2126 return 0;
2127 }
2128
2129 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
2130 goto drop;
2131 nf_reset(skb);
2132
2133 /* No socket. Drop packet silently, if checksum is wrong */
2134 if (udp_lib_checksum_complete(skb))
2135 goto csum_error;
2136
2137 __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
2138 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
2139
2140 /*
2141 * Hmm. We got an UDP packet to a port to which we
2142 * don't wanna listen. Ignore it.
2143 */
2144 kfree_skb(skb);
2145 return 0;
2146
2147short_packet:
2148 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
2149 proto == IPPROTO_UDPLITE ? "Lite" : "",
2150 &saddr, ntohs(uh->source),
2151 ulen, skb->len,
2152 &daddr, ntohs(uh->dest));
2153 goto drop;
2154
2155csum_error:
2156 /*
2157 * RFC1122: OK. Discards the bad packet silently (as far as
2158 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
2159 */
2160 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
2161 proto == IPPROTO_UDPLITE ? "Lite" : "",
2162 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
2163 ulen);
2164 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
2165drop:
2166 __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
2167 kfree_skb(skb);
2168 return 0;
2169}
2170
2171/* We can only early demux multicast if there is a single matching socket.
2172 * If more than one socket found returns NULL
2173 */
2174static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
2175 __be16 loc_port, __be32 loc_addr,
2176 __be16 rmt_port, __be32 rmt_addr,
2177 int dif, int sdif)
2178{
2179 struct sock *sk, *result;
2180 unsigned short hnum = ntohs(loc_port);
2181 unsigned int slot = udp_hashfn(net, hnum, udp_table.mask);
2182 struct udp_hslot *hslot = &udp_table.hash[slot];
2183
2184 /* Do not bother scanning a too big list */
2185 if (hslot->count > 10)
2186 return NULL;
2187
2188 result = NULL;
2189 sk_for_each_rcu(sk, &hslot->head) {
2190 if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr,
2191 rmt_port, rmt_addr, dif, sdif, hnum)) {
2192 if (result)
2193 return NULL;
2194 result = sk;
2195 }
2196 }
2197
2198 return result;
2199}
2200
2201/* For unicast we should only early demux connected sockets or we can
2202 * break forwarding setups. The chains here can be long so only check
2203 * if the first socket is an exact match and if not move on.
2204 */
2205static struct sock *__udp4_lib_demux_lookup(struct net *net,
2206 __be16 loc_port, __be32 loc_addr,
2207 __be16 rmt_port, __be32 rmt_addr,
2208 int dif, int sdif)
2209{
2210 unsigned short hnum = ntohs(loc_port);
2211 unsigned int hash2 = ipv4_portaddr_hash(net, loc_addr, hnum);
2212 unsigned int slot2 = hash2 & udp_table.mask;
2213 struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
2214 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
2215 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
2216 struct sock *sk;
2217
2218 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
2219 if (INET_MATCH(sk, net, acookie, rmt_addr,
2220 loc_addr, ports, dif, sdif))
2221 return sk;
2222 /* Only check first socket in chain */
2223 break;
2224 }
2225 return NULL;
2226}
2227
2228int udp_v4_early_demux(struct sk_buff *skb)
2229{
2230 struct net *net = dev_net(skb->dev);
2231 struct in_device *in_dev = NULL;
2232 const struct iphdr *iph;
2233 const struct udphdr *uh;
2234 struct sock *sk = NULL;
2235 struct dst_entry *dst;
2236 int dif = skb->dev->ifindex;
2237 int sdif = inet_sdif(skb);
2238 int ours;
2239
2240 /* validate the packet */
2241 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
2242 return 0;
2243
2244 iph = ip_hdr(skb);
2245 uh = udp_hdr(skb);
2246
2247 if (skb->pkt_type == PACKET_MULTICAST) {
2248 in_dev = __in_dev_get_rcu(skb->dev);
2249
2250 if (!in_dev)
2251 return 0;
2252
2253 ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
2254 iph->protocol);
2255 if (!ours)
2256 return 0;
2257
2258 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
2259 uh->source, iph->saddr,
2260 dif, sdif);
2261 } else if (skb->pkt_type == PACKET_HOST) {
2262 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
2263 uh->source, iph->saddr, dif, sdif);
2264 }
2265
2266 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
2267 return 0;
2268
2269 skb->sk = sk;
2270 skb->destructor = sock_efree;
2271 dst = READ_ONCE(sk->sk_rx_dst);
2272
2273 if (dst)
2274 dst = dst_check(dst, 0);
2275 if (dst) {
2276 u32 itag = 0;
2277
2278 /* set noref for now.
2279 * any place which wants to hold dst has to call
2280 * dst_hold_safe()
2281 */
2282 skb_dst_set_noref(skb, dst);
2283
2284 /* for unconnected multicast sockets we need to validate
2285 * the source on each packet
2286 */
2287 if (!inet_sk(sk)->inet_daddr && in_dev)
2288 return ip_mc_validate_source(skb, iph->daddr,
2289 iph->saddr, iph->tos,
2290 skb->dev, in_dev, &itag);
2291 }
2292 return 0;
2293}
2294
2295int udp_rcv(struct sk_buff *skb)
2296{
2297 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
2298}
2299
2300void udp_destroy_sock(struct sock *sk)
2301{
2302 struct udp_sock *up = udp_sk(sk);
2303 bool slow = lock_sock_fast(sk);
2304 udp_flush_pending_frames(sk);
2305 unlock_sock_fast(sk, slow);
2306 if (static_key_false(&udp_encap_needed) && up->encap_type) {
2307 void (*encap_destroy)(struct sock *sk);
2308 encap_destroy = READ_ONCE(up->encap_destroy);
2309 if (encap_destroy)
2310 encap_destroy(sk);
2311 }
2312}
2313
2314/*
2315 * Socket option code for UDP
2316 */
2317int udp_lib_setsockopt(struct sock *sk, int level, int optname,
2318 char __user *optval, unsigned int optlen,
2319 int (*push_pending_frames)(struct sock *))
2320{
2321 struct udp_sock *up = udp_sk(sk);
2322 int val, valbool;
2323 int err = 0;
2324 int is_udplite = IS_UDPLITE(sk);
2325
2326 if (optlen < sizeof(int))
2327 return -EINVAL;
2328
2329 if (get_user(val, (int __user *)optval))
2330 return -EFAULT;
2331
2332 valbool = val ? 1 : 0;
2333
2334 switch (optname) {
2335 case UDP_CORK:
2336 if (val != 0) {
2337 up->corkflag = 1;
2338 } else {
2339 up->corkflag = 0;
2340 lock_sock(sk);
2341 push_pending_frames(sk);
2342 release_sock(sk);
2343 }
2344 break;
2345
2346 case UDP_ENCAP:
2347 switch (val) {
2348 case 0:
2349 case UDP_ENCAP_ESPINUDP:
2350 case UDP_ENCAP_ESPINUDP_NON_IKE:
2351 up->encap_rcv = xfrm4_udp_encap_rcv;
2352 /* FALLTHROUGH */
2353 case UDP_ENCAP_L2TPINUDP:
2354 up->encap_type = val;
2355 udp_encap_enable();
2356 break;
2357 default:
2358 err = -ENOPROTOOPT;
2359 break;
2360 }
2361 break;
2362
2363 case UDP_NO_CHECK6_TX:
2364 up->no_check6_tx = valbool;
2365 break;
2366
2367 case UDP_NO_CHECK6_RX:
2368 up->no_check6_rx = valbool;
2369 break;
2370
2371 /*
2372 * UDP-Lite's partial checksum coverage (RFC 3828).
2373 */
2374 /* The sender sets actual checksum coverage length via this option.
2375 * The case coverage > packet length is handled by send module. */
2376 case UDPLITE_SEND_CSCOV:
2377 if (!is_udplite) /* Disable the option on UDP sockets */
2378 return -ENOPROTOOPT;
2379 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
2380 val = 8;
2381 else if (val > USHRT_MAX)
2382 val = USHRT_MAX;
2383 up->pcslen = val;
2384 up->pcflag |= UDPLITE_SEND_CC;
2385 break;
2386
2387 /* The receiver specifies a minimum checksum coverage value. To make
2388 * sense, this should be set to at least 8 (as done below). If zero is
2389 * used, this again means full checksum coverage. */
2390 case UDPLITE_RECV_CSCOV:
2391 if (!is_udplite) /* Disable the option on UDP sockets */
2392 return -ENOPROTOOPT;
2393 if (val != 0 && val < 8) /* Avoid silly minimal values. */
2394 val = 8;
2395 else if (val > USHRT_MAX)
2396 val = USHRT_MAX;
2397 up->pcrlen = val;
2398 up->pcflag |= UDPLITE_RECV_CC;
2399 break;
2400
2401 default:
2402 err = -ENOPROTOOPT;
2403 break;
2404 }
2405
2406 return err;
2407}
2408EXPORT_SYMBOL(udp_lib_setsockopt);
2409
2410int udp_setsockopt(struct sock *sk, int level, int optname,
2411 char __user *optval, unsigned int optlen)
2412{
2413 if (level == SOL_UDP || level == SOL_UDPLITE)
2414 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
2415 udp_push_pending_frames);
2416 return ip_setsockopt(sk, level, optname, optval, optlen);
2417}
2418
2419#ifdef CONFIG_COMPAT
2420int compat_udp_setsockopt(struct sock *sk, int level, int optname,
2421 char __user *optval, unsigned int optlen)
2422{
2423 if (level == SOL_UDP || level == SOL_UDPLITE)
2424 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
2425 udp_push_pending_frames);
2426 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
2427}
2428#endif
2429
2430int udp_lib_getsockopt(struct sock *sk, int level, int optname,
2431 char __user *optval, int __user *optlen)
2432{
2433 struct udp_sock *up = udp_sk(sk);
2434 int val, len;
2435
2436 if (get_user(len, optlen))
2437 return -EFAULT;
2438
2439 len = min_t(unsigned int, len, sizeof(int));
2440
2441 if (len < 0)
2442 return -EINVAL;
2443
2444 switch (optname) {
2445 case UDP_CORK:
2446 val = up->corkflag;
2447 break;
2448
2449 case UDP_ENCAP:
2450 val = up->encap_type;
2451 break;
2452
2453 case UDP_NO_CHECK6_TX:
2454 val = up->no_check6_tx;
2455 break;
2456
2457 case UDP_NO_CHECK6_RX:
2458 val = up->no_check6_rx;
2459 break;
2460
2461 /* The following two cannot be changed on UDP sockets, the return is
2462 * always 0 (which corresponds to the full checksum coverage of UDP). */
2463 case UDPLITE_SEND_CSCOV:
2464 val = up->pcslen;
2465 break;
2466
2467 case UDPLITE_RECV_CSCOV:
2468 val = up->pcrlen;
2469 break;
2470
2471 default:
2472 return -ENOPROTOOPT;
2473 }
2474
2475 if (put_user(len, optlen))
2476 return -EFAULT;
2477 if (copy_to_user(optval, &val, len))
2478 return -EFAULT;
2479 return 0;
2480}
2481EXPORT_SYMBOL(udp_lib_getsockopt);
2482
2483int udp_getsockopt(struct sock *sk, int level, int optname,
2484 char __user *optval, int __user *optlen)
2485{
2486 if (level == SOL_UDP || level == SOL_UDPLITE)
2487 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2488 return ip_getsockopt(sk, level, optname, optval, optlen);
2489}
2490
2491#ifdef CONFIG_COMPAT
2492int compat_udp_getsockopt(struct sock *sk, int level, int optname,
2493 char __user *optval, int __user *optlen)
2494{
2495 if (level == SOL_UDP || level == SOL_UDPLITE)
2496 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2497 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
2498}
2499#endif
2500/**
2501 * udp_poll - wait for a UDP event.
2502 * @file - file struct
2503 * @sock - socket
2504 * @wait - poll table
2505 *
2506 * This is same as datagram poll, except for the special case of
2507 * blocking sockets. If application is using a blocking fd
2508 * and a packet with checksum error is in the queue;
2509 * then it could get return from select indicating data available
2510 * but then block when reading it. Add special case code
2511 * to work around these arguably broken applications.
2512 */
2513__poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait)
2514{
2515 __poll_t mask = datagram_poll(file, sock, wait);
2516 struct sock *sk = sock->sk;
2517
2518 if (!skb_queue_empty(&udp_sk(sk)->reader_queue))
2519 mask |= EPOLLIN | EPOLLRDNORM;
2520
2521 /* Check for false positives due to checksum errors */
2522 if ((mask & EPOLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
2523 !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1)
2524 mask &= ~(EPOLLIN | EPOLLRDNORM);
2525
2526 return mask;
2527
2528}
2529EXPORT_SYMBOL(udp_poll);
2530
2531int udp_abort(struct sock *sk, int err)
2532{
2533 lock_sock(sk);
2534
2535 sk->sk_err = err;
2536 sk->sk_error_report(sk);
2537 __udp_disconnect(sk, 0);
2538
2539 release_sock(sk);
2540
2541 return 0;
2542}
2543EXPORT_SYMBOL_GPL(udp_abort);
2544
2545struct proto udp_prot = {
2546 .name = "UDP",
2547 .owner = THIS_MODULE,
2548 .close = udp_lib_close,
2549 .pre_connect = udp_pre_connect,
2550 .connect = ip4_datagram_connect,
2551 .disconnect = udp_disconnect,
2552 .ioctl = udp_ioctl,
2553 .init = udp_init_sock,
2554 .destroy = udp_destroy_sock,
2555 .setsockopt = udp_setsockopt,
2556 .getsockopt = udp_getsockopt,
2557 .sendmsg = udp_sendmsg,
2558 .recvmsg = udp_recvmsg,
2559 .sendpage = udp_sendpage,
2560 .release_cb = ip4_datagram_release_cb,
2561 .hash = udp_lib_hash,
2562 .unhash = udp_lib_unhash,
2563 .rehash = udp_v4_rehash,
2564 .get_port = udp_v4_get_port,
2565 .memory_allocated = &udp_memory_allocated,
2566 .sysctl_mem = sysctl_udp_mem,
2567 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
2568 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
2569 .obj_size = sizeof(struct udp_sock),
2570 .h.udp_table = &udp_table,
2571#ifdef CONFIG_COMPAT
2572 .compat_setsockopt = compat_udp_setsockopt,
2573 .compat_getsockopt = compat_udp_getsockopt,
2574#endif
2575 .diag_destroy = udp_abort,
2576};
2577EXPORT_SYMBOL(udp_prot);
2578
2579/* ------------------------------------------------------------------------ */
2580#ifdef CONFIG_PROC_FS
2581
2582static struct sock *udp_get_first(struct seq_file *seq, int start)
2583{
2584 struct sock *sk;
2585 struct udp_iter_state *state = seq->private;
2586 struct net *net = seq_file_net(seq);
2587
2588 for (state->bucket = start; state->bucket <= state->udp_table->mask;
2589 ++state->bucket) {
2590 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
2591
2592 if (hlist_empty(&hslot->head))
2593 continue;
2594
2595 spin_lock_bh(&hslot->lock);
2596 sk_for_each(sk, &hslot->head) {
2597 if (!net_eq(sock_net(sk), net))
2598 continue;
2599 if (sk->sk_family == state->family)
2600 goto found;
2601 }
2602 spin_unlock_bh(&hslot->lock);
2603 }
2604 sk = NULL;
2605found:
2606 return sk;
2607}
2608
2609static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
2610{
2611 struct udp_iter_state *state = seq->private;
2612 struct net *net = seq_file_net(seq);
2613
2614 do {
2615 sk = sk_next(sk);
2616 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
2617
2618 if (!sk) {
2619 if (state->bucket <= state->udp_table->mask)
2620 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2621 return udp_get_first(seq, state->bucket + 1);
2622 }
2623 return sk;
2624}
2625
2626static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
2627{
2628 struct sock *sk = udp_get_first(seq, 0);
2629
2630 if (sk)
2631 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
2632 --pos;
2633 return pos ? NULL : sk;
2634}
2635
2636static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
2637{
2638 struct udp_iter_state *state = seq->private;
2639 state->bucket = MAX_UDP_PORTS;
2640
2641 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
2642}
2643
2644static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2645{
2646 struct sock *sk;
2647
2648 if (v == SEQ_START_TOKEN)
2649 sk = udp_get_idx(seq, 0);
2650 else
2651 sk = udp_get_next(seq, v);
2652
2653 ++*pos;
2654 return sk;
2655}
2656
2657static void udp_seq_stop(struct seq_file *seq, void *v)
2658{
2659 struct udp_iter_state *state = seq->private;
2660
2661 if (state->bucket <= state->udp_table->mask)
2662 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2663}
2664
2665int udp_seq_open(struct inode *inode, struct file *file)
2666{
2667 struct udp_seq_afinfo *afinfo = PDE_DATA(inode);
2668 struct udp_iter_state *s;
2669 int err;
2670
2671 err = seq_open_net(inode, file, &afinfo->seq_ops,
2672 sizeof(struct udp_iter_state));
2673 if (err < 0)
2674 return err;
2675
2676 s = ((struct seq_file *)file->private_data)->private;
2677 s->family = afinfo->family;
2678 s->udp_table = afinfo->udp_table;
2679 return err;
2680}
2681EXPORT_SYMBOL(udp_seq_open);
2682
2683/* ------------------------------------------------------------------------ */
2684int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
2685{
2686 struct proc_dir_entry *p;
2687 int rc = 0;
2688
2689 afinfo->seq_ops.start = udp_seq_start;
2690 afinfo->seq_ops.next = udp_seq_next;
2691 afinfo->seq_ops.stop = udp_seq_stop;
2692
2693 p = proc_create_data(afinfo->name, 0444, net->proc_net,
2694 afinfo->seq_fops, afinfo);
2695 if (!p)
2696 rc = -ENOMEM;
2697 return rc;
2698}
2699EXPORT_SYMBOL(udp_proc_register);
2700
2701void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
2702{
2703 remove_proc_entry(afinfo->name, net->proc_net);
2704}
2705EXPORT_SYMBOL(udp_proc_unregister);
2706
2707/* ------------------------------------------------------------------------ */
2708static void udp4_format_sock(struct sock *sp, struct seq_file *f,
2709 int bucket)
2710{
2711 struct inet_sock *inet = inet_sk(sp);
2712 __be32 dest = inet->inet_daddr;
2713 __be32 src = inet->inet_rcv_saddr;
2714 __u16 destp = ntohs(inet->inet_dport);
2715 __u16 srcp = ntohs(inet->inet_sport);
2716
2717 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
2718 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
2719 bucket, src, srcp, dest, destp, sp->sk_state,
2720 sk_wmem_alloc_get(sp),
2721 sk_rmem_alloc_get(sp),
2722 0, 0L, 0,
2723 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
2724 0, sock_i_ino(sp),
2725 refcount_read(&sp->sk_refcnt), sp,
2726 atomic_read(&sp->sk_drops));
2727}
2728
2729int udp4_seq_show(struct seq_file *seq, void *v)
2730{
2731 seq_setwidth(seq, 127);
2732 if (v == SEQ_START_TOKEN)
2733 seq_puts(seq, " sl local_address rem_address st tx_queue "
2734 "rx_queue tr tm->when retrnsmt uid timeout "
2735 "inode ref pointer drops");
2736 else {
2737 struct udp_iter_state *state = seq->private;
2738
2739 udp4_format_sock(v, seq, state->bucket);
2740 }
2741 seq_pad(seq, '\n');
2742 return 0;
2743}
2744
2745static const struct file_operations udp_afinfo_seq_fops = {
2746 .open = udp_seq_open,
2747 .read = seq_read,
2748 .llseek = seq_lseek,
2749 .release = seq_release_net
2750};
2751
2752/* ------------------------------------------------------------------------ */
2753static struct udp_seq_afinfo udp4_seq_afinfo = {
2754 .name = "udp",
2755 .family = AF_INET,
2756 .udp_table = &udp_table,
2757 .seq_fops = &udp_afinfo_seq_fops,
2758 .seq_ops = {
2759 .show = udp4_seq_show,
2760 },
2761};
2762
2763static int __net_init udp4_proc_init_net(struct net *net)
2764{
2765 return udp_proc_register(net, &udp4_seq_afinfo);
2766}
2767
2768static void __net_exit udp4_proc_exit_net(struct net *net)
2769{
2770 udp_proc_unregister(net, &udp4_seq_afinfo);
2771}
2772
2773static struct pernet_operations udp4_net_ops = {
2774 .init = udp4_proc_init_net,
2775 .exit = udp4_proc_exit_net,
2776};
2777
2778int __init udp4_proc_init(void)
2779{
2780 return register_pernet_subsys(&udp4_net_ops);
2781}
2782
2783void udp4_proc_exit(void)
2784{
2785 unregister_pernet_subsys(&udp4_net_ops);
2786}
2787#endif /* CONFIG_PROC_FS */
2788
2789static __initdata unsigned long uhash_entries;
2790static int __init set_uhash_entries(char *str)
2791{
2792 ssize_t ret;
2793
2794 if (!str)
2795 return 0;
2796
2797 ret = kstrtoul(str, 0, &uhash_entries);
2798 if (ret)
2799 return 0;
2800
2801 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
2802 uhash_entries = UDP_HTABLE_SIZE_MIN;
2803 return 1;
2804}
2805__setup("uhash_entries=", set_uhash_entries);
2806
2807void __init udp_table_init(struct udp_table *table, const char *name)
2808{
2809 unsigned int i;
2810
2811 table->hash = alloc_large_system_hash(name,
2812 2 * sizeof(struct udp_hslot),
2813 uhash_entries,
2814 21, /* one slot per 2 MB */
2815 0,
2816 &table->log,
2817 &table->mask,
2818 UDP_HTABLE_SIZE_MIN,
2819 64 * 1024);
2820
2821 table->hash2 = table->hash + (table->mask + 1);
2822 for (i = 0; i <= table->mask; i++) {
2823 INIT_HLIST_HEAD(&table->hash[i].head);
2824 table->hash[i].count = 0;
2825 spin_lock_init(&table->hash[i].lock);
2826 }
2827 for (i = 0; i <= table->mask; i++) {
2828 INIT_HLIST_HEAD(&table->hash2[i].head);
2829 table->hash2[i].count = 0;
2830 spin_lock_init(&table->hash2[i].lock);
2831 }
2832}
2833
2834u32 udp_flow_hashrnd(void)
2835{
2836 static u32 hashrnd __read_mostly;
2837
2838 net_get_random_once(&hashrnd, sizeof(hashrnd));
2839
2840 return hashrnd;
2841}
2842EXPORT_SYMBOL(udp_flow_hashrnd);
2843
2844static void __udp_sysctl_init(struct net *net)
2845{
2846 net->ipv4.sysctl_udp_rmem_min = SK_MEM_QUANTUM;
2847 net->ipv4.sysctl_udp_wmem_min = SK_MEM_QUANTUM;
2848
2849#ifdef CONFIG_NET_L3_MASTER_DEV
2850 net->ipv4.sysctl_udp_l3mdev_accept = 0;
2851#endif
2852}
2853
2854static int __net_init udp_sysctl_init(struct net *net)
2855{
2856 __udp_sysctl_init(net);
2857 return 0;
2858}
2859
2860static struct pernet_operations __net_initdata udp_sysctl_ops = {
2861 .init = udp_sysctl_init,
2862};
2863
2864void __init udp_init(void)
2865{
2866 unsigned long limit;
2867 unsigned int i;
2868
2869 udp_table_init(&udp_table, "UDP");
2870 limit = nr_free_buffer_pages() / 8;
2871 limit = max(limit, 128UL);
2872 sysctl_udp_mem[0] = limit / 4 * 3;
2873 sysctl_udp_mem[1] = limit;
2874 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
2875
2876 __udp_sysctl_init(&init_net);
2877
2878 /* 16 spinlocks per cpu */
2879 udp_busylocks_log = ilog2(nr_cpu_ids) + 4;
2880 udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log,
2881 GFP_KERNEL);
2882 if (!udp_busylocks)
2883 panic("UDP: failed to alloc udp_busylocks\n");
2884 for (i = 0; i < (1U << udp_busylocks_log); i++)
2885 spin_lock_init(udp_busylocks + i);
2886
2887 if (register_pernet_subsys(&udp_sysctl_ops))
2888 panic("UDP: failed to init sysctl parameters.\n");
2889}