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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 <asm/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/in.h>
94#include <linux/errno.h>
95#include <linux/timer.h>
96#include <linux/mm.h>
97#include <linux/inet.h>
98#include <linux/netdevice.h>
99#include <linux/slab.h>
100#include <net/tcp_states.h>
101#include <linux/skbuff.h>
102#include <linux/proc_fs.h>
103#include <linux/seq_file.h>
104#include <net/net_namespace.h>
105#include <net/icmp.h>
106#include <net/route.h>
107#include <net/checksum.h>
108#include <net/xfrm.h>
109#include <trace/events/udp.h>
110#include <linux/static_key.h>
111#include "udp_impl.h"
112
113struct udp_table udp_table __read_mostly;
114EXPORT_SYMBOL(udp_table);
115
116long sysctl_udp_mem[3] __read_mostly;
117EXPORT_SYMBOL(sysctl_udp_mem);
118
119int sysctl_udp_rmem_min __read_mostly;
120EXPORT_SYMBOL(sysctl_udp_rmem_min);
121
122int sysctl_udp_wmem_min __read_mostly;
123EXPORT_SYMBOL(sysctl_udp_wmem_min);
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
131static int udp_lib_lport_inuse(struct net *net, __u16 num,
132 const struct udp_hslot *hslot,
133 unsigned long *bitmap,
134 struct sock *sk,
135 int (*saddr_comp)(const struct sock *sk1,
136 const struct sock *sk2),
137 unsigned int log)
138{
139 struct sock *sk2;
140 struct hlist_nulls_node *node;
141
142 sk_nulls_for_each(sk2, node, &hslot->head)
143 if (net_eq(sock_net(sk2), net) &&
144 sk2 != sk &&
145 (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
146 (!sk2->sk_reuse || !sk->sk_reuse) &&
147 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
148 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
149 (*saddr_comp)(sk, sk2)) {
150 if (bitmap)
151 __set_bit(udp_sk(sk2)->udp_port_hash >> log,
152 bitmap);
153 else
154 return 1;
155 }
156 return 0;
157}
158
159/*
160 * Note: we still hold spinlock of primary hash chain, so no other writer
161 * can insert/delete a socket with local_port == num
162 */
163static int udp_lib_lport_inuse2(struct net *net, __u16 num,
164 struct udp_hslot *hslot2,
165 struct sock *sk,
166 int (*saddr_comp)(const struct sock *sk1,
167 const struct sock *sk2))
168{
169 struct sock *sk2;
170 struct hlist_nulls_node *node;
171 int res = 0;
172
173 spin_lock(&hslot2->lock);
174 udp_portaddr_for_each_entry(sk2, node, &hslot2->head)
175 if (net_eq(sock_net(sk2), net) &&
176 sk2 != sk &&
177 (udp_sk(sk2)->udp_port_hash == num) &&
178 (!sk2->sk_reuse || !sk->sk_reuse) &&
179 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
180 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
181 (*saddr_comp)(sk, sk2)) {
182 res = 1;
183 break;
184 }
185 spin_unlock(&hslot2->lock);
186 return res;
187}
188
189/**
190 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
191 *
192 * @sk: socket struct in question
193 * @snum: port number to look up
194 * @saddr_comp: AF-dependent comparison of bound local IP addresses
195 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
196 * with NULL address
197 */
198int udp_lib_get_port(struct sock *sk, unsigned short snum,
199 int (*saddr_comp)(const struct sock *sk1,
200 const struct sock *sk2),
201 unsigned int hash2_nulladdr)
202{
203 struct udp_hslot *hslot, *hslot2;
204 struct udp_table *udptable = sk->sk_prot->h.udp_table;
205 int error = 1;
206 struct net *net = sock_net(sk);
207
208 if (!snum) {
209 int low, high, remaining;
210 unsigned int rand;
211 unsigned short first, last;
212 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
213
214 inet_get_local_port_range(&low, &high);
215 remaining = (high - low) + 1;
216
217 rand = net_random();
218 first = (((u64)rand * remaining) >> 32) + low;
219 /*
220 * force rand to be an odd multiple of UDP_HTABLE_SIZE
221 */
222 rand = (rand | 1) * (udptable->mask + 1);
223 last = first + udptable->mask + 1;
224 do {
225 hslot = udp_hashslot(udptable, net, first);
226 bitmap_zero(bitmap, PORTS_PER_CHAIN);
227 spin_lock_bh(&hslot->lock);
228 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
229 saddr_comp, udptable->log);
230
231 snum = first;
232 /*
233 * Iterate on all possible values of snum for this hash.
234 * Using steps of an odd multiple of UDP_HTABLE_SIZE
235 * give us randomization and full range coverage.
236 */
237 do {
238 if (low <= snum && snum <= high &&
239 !test_bit(snum >> udptable->log, bitmap) &&
240 !inet_is_reserved_local_port(snum))
241 goto found;
242 snum += rand;
243 } while (snum != first);
244 spin_unlock_bh(&hslot->lock);
245 } while (++first != last);
246 goto fail;
247 } else {
248 hslot = udp_hashslot(udptable, net, snum);
249 spin_lock_bh(&hslot->lock);
250 if (hslot->count > 10) {
251 int exist;
252 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum;
253
254 slot2 &= udptable->mask;
255 hash2_nulladdr &= udptable->mask;
256
257 hslot2 = udp_hashslot2(udptable, slot2);
258 if (hslot->count < hslot2->count)
259 goto scan_primary_hash;
260
261 exist = udp_lib_lport_inuse2(net, snum, hslot2,
262 sk, saddr_comp);
263 if (!exist && (hash2_nulladdr != slot2)) {
264 hslot2 = udp_hashslot2(udptable, hash2_nulladdr);
265 exist = udp_lib_lport_inuse2(net, snum, hslot2,
266 sk, saddr_comp);
267 }
268 if (exist)
269 goto fail_unlock;
270 else
271 goto found;
272 }
273scan_primary_hash:
274 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk,
275 saddr_comp, 0))
276 goto fail_unlock;
277 }
278found:
279 inet_sk(sk)->inet_num = snum;
280 udp_sk(sk)->udp_port_hash = snum;
281 udp_sk(sk)->udp_portaddr_hash ^= snum;
282 if (sk_unhashed(sk)) {
283 sk_nulls_add_node_rcu(sk, &hslot->head);
284 hslot->count++;
285 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
286
287 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
288 spin_lock(&hslot2->lock);
289 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
290 &hslot2->head);
291 hslot2->count++;
292 spin_unlock(&hslot2->lock);
293 }
294 error = 0;
295fail_unlock:
296 spin_unlock_bh(&hslot->lock);
297fail:
298 return error;
299}
300EXPORT_SYMBOL(udp_lib_get_port);
301
302static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
303{
304 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
305
306 return (!ipv6_only_sock(sk2) &&
307 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr ||
308 inet1->inet_rcv_saddr == inet2->inet_rcv_saddr));
309}
310
311static unsigned int udp4_portaddr_hash(struct net *net, __be32 saddr,
312 unsigned int port)
313{
314 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
315}
316
317int udp_v4_get_port(struct sock *sk, unsigned short snum)
318{
319 unsigned int hash2_nulladdr =
320 udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
321 unsigned int hash2_partial =
322 udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);
323
324 /* precompute partial secondary hash */
325 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
326 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr);
327}
328
329static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr,
330 unsigned short hnum,
331 __be16 sport, __be32 daddr, __be16 dport, int dif)
332{
333 int score = -1;
334
335 if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
336 !ipv6_only_sock(sk)) {
337 struct inet_sock *inet = inet_sk(sk);
338
339 score = (sk->sk_family == PF_INET ? 1 : 0);
340 if (inet->inet_rcv_saddr) {
341 if (inet->inet_rcv_saddr != daddr)
342 return -1;
343 score += 2;
344 }
345 if (inet->inet_daddr) {
346 if (inet->inet_daddr != saddr)
347 return -1;
348 score += 2;
349 }
350 if (inet->inet_dport) {
351 if (inet->inet_dport != sport)
352 return -1;
353 score += 2;
354 }
355 if (sk->sk_bound_dev_if) {
356 if (sk->sk_bound_dev_if != dif)
357 return -1;
358 score += 2;
359 }
360 }
361 return score;
362}
363
364/*
365 * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num)
366 */
367#define SCORE2_MAX (1 + 2 + 2 + 2)
368static inline int compute_score2(struct sock *sk, struct net *net,
369 __be32 saddr, __be16 sport,
370 __be32 daddr, unsigned int hnum, int dif)
371{
372 int score = -1;
373
374 if (net_eq(sock_net(sk), net) && !ipv6_only_sock(sk)) {
375 struct inet_sock *inet = inet_sk(sk);
376
377 if (inet->inet_rcv_saddr != daddr)
378 return -1;
379 if (inet->inet_num != hnum)
380 return -1;
381
382 score = (sk->sk_family == PF_INET ? 1 : 0);
383 if (inet->inet_daddr) {
384 if (inet->inet_daddr != saddr)
385 return -1;
386 score += 2;
387 }
388 if (inet->inet_dport) {
389 if (inet->inet_dport != sport)
390 return -1;
391 score += 2;
392 }
393 if (sk->sk_bound_dev_if) {
394 if (sk->sk_bound_dev_if != dif)
395 return -1;
396 score += 2;
397 }
398 }
399 return score;
400}
401
402
403/* called with read_rcu_lock() */
404static struct sock *udp4_lib_lookup2(struct net *net,
405 __be32 saddr, __be16 sport,
406 __be32 daddr, unsigned int hnum, int dif,
407 struct udp_hslot *hslot2, unsigned int slot2)
408{
409 struct sock *sk, *result;
410 struct hlist_nulls_node *node;
411 int score, badness;
412
413begin:
414 result = NULL;
415 badness = -1;
416 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
417 score = compute_score2(sk, net, saddr, sport,
418 daddr, hnum, dif);
419 if (score > badness) {
420 result = sk;
421 badness = score;
422 if (score == SCORE2_MAX)
423 goto exact_match;
424 }
425 }
426 /*
427 * if the nulls value we got at the end of this lookup is
428 * not the expected one, we must restart lookup.
429 * We probably met an item that was moved to another chain.
430 */
431 if (get_nulls_value(node) != slot2)
432 goto begin;
433
434 if (result) {
435exact_match:
436 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
437 result = NULL;
438 else if (unlikely(compute_score2(result, net, saddr, sport,
439 daddr, hnum, dif) < badness)) {
440 sock_put(result);
441 goto begin;
442 }
443 }
444 return result;
445}
446
447/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
448 * harder than this. -DaveM
449 */
450struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
451 __be16 sport, __be32 daddr, __be16 dport,
452 int dif, struct udp_table *udptable)
453{
454 struct sock *sk, *result;
455 struct hlist_nulls_node *node;
456 unsigned short hnum = ntohs(dport);
457 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
458 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
459 int score, badness;
460
461 rcu_read_lock();
462 if (hslot->count > 10) {
463 hash2 = udp4_portaddr_hash(net, daddr, hnum);
464 slot2 = hash2 & udptable->mask;
465 hslot2 = &udptable->hash2[slot2];
466 if (hslot->count < hslot2->count)
467 goto begin;
468
469 result = udp4_lib_lookup2(net, saddr, sport,
470 daddr, hnum, dif,
471 hslot2, slot2);
472 if (!result) {
473 hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
474 slot2 = hash2 & udptable->mask;
475 hslot2 = &udptable->hash2[slot2];
476 if (hslot->count < hslot2->count)
477 goto begin;
478
479 result = udp4_lib_lookup2(net, saddr, sport,
480 htonl(INADDR_ANY), hnum, dif,
481 hslot2, slot2);
482 }
483 rcu_read_unlock();
484 return result;
485 }
486begin:
487 result = NULL;
488 badness = -1;
489 sk_nulls_for_each_rcu(sk, node, &hslot->head) {
490 score = compute_score(sk, net, saddr, hnum, sport,
491 daddr, dport, dif);
492 if (score > badness) {
493 result = sk;
494 badness = score;
495 }
496 }
497 /*
498 * if the nulls value we got at the end of this lookup is
499 * not the expected one, we must restart lookup.
500 * We probably met an item that was moved to another chain.
501 */
502 if (get_nulls_value(node) != slot)
503 goto begin;
504
505 if (result) {
506 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
507 result = NULL;
508 else if (unlikely(compute_score(result, net, saddr, hnum, sport,
509 daddr, dport, dif) < badness)) {
510 sock_put(result);
511 goto begin;
512 }
513 }
514 rcu_read_unlock();
515 return result;
516}
517EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
518
519static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
520 __be16 sport, __be16 dport,
521 struct udp_table *udptable)
522{
523 struct sock *sk;
524 const struct iphdr *iph = ip_hdr(skb);
525
526 if (unlikely(sk = skb_steal_sock(skb)))
527 return sk;
528 else
529 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
530 iph->daddr, dport, inet_iif(skb),
531 udptable);
532}
533
534struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
535 __be32 daddr, __be16 dport, int dif)
536{
537 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
538}
539EXPORT_SYMBOL_GPL(udp4_lib_lookup);
540
541static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
542 __be16 loc_port, __be32 loc_addr,
543 __be16 rmt_port, __be32 rmt_addr,
544 int dif)
545{
546 struct hlist_nulls_node *node;
547 struct sock *s = sk;
548 unsigned short hnum = ntohs(loc_port);
549
550 sk_nulls_for_each_from(s, node) {
551 struct inet_sock *inet = inet_sk(s);
552
553 if (!net_eq(sock_net(s), net) ||
554 udp_sk(s)->udp_port_hash != hnum ||
555 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
556 (inet->inet_dport != rmt_port && inet->inet_dport) ||
557 (inet->inet_rcv_saddr &&
558 inet->inet_rcv_saddr != loc_addr) ||
559 ipv6_only_sock(s) ||
560 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
561 continue;
562 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
563 continue;
564 goto found;
565 }
566 s = NULL;
567found:
568 return s;
569}
570
571/*
572 * This routine is called by the ICMP module when it gets some
573 * sort of error condition. If err < 0 then the socket should
574 * be closed and the error returned to the user. If err > 0
575 * it's just the icmp type << 8 | icmp code.
576 * Header points to the ip header of the error packet. We move
577 * on past this. Then (as it used to claim before adjustment)
578 * header points to the first 8 bytes of the udp header. We need
579 * to find the appropriate port.
580 */
581
582void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
583{
584 struct inet_sock *inet;
585 const struct iphdr *iph = (const struct iphdr *)skb->data;
586 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
587 const int type = icmp_hdr(skb)->type;
588 const int code = icmp_hdr(skb)->code;
589 struct sock *sk;
590 int harderr;
591 int err;
592 struct net *net = dev_net(skb->dev);
593
594 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
595 iph->saddr, uh->source, skb->dev->ifindex, udptable);
596 if (sk == NULL) {
597 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
598 return; /* No socket for error */
599 }
600
601 err = 0;
602 harderr = 0;
603 inet = inet_sk(sk);
604
605 switch (type) {
606 default:
607 case ICMP_TIME_EXCEEDED:
608 err = EHOSTUNREACH;
609 break;
610 case ICMP_SOURCE_QUENCH:
611 goto out;
612 case ICMP_PARAMETERPROB:
613 err = EPROTO;
614 harderr = 1;
615 break;
616 case ICMP_DEST_UNREACH:
617 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
618 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
619 err = EMSGSIZE;
620 harderr = 1;
621 break;
622 }
623 goto out;
624 }
625 err = EHOSTUNREACH;
626 if (code <= NR_ICMP_UNREACH) {
627 harderr = icmp_err_convert[code].fatal;
628 err = icmp_err_convert[code].errno;
629 }
630 break;
631 }
632
633 /*
634 * RFC1122: OK. Passes ICMP errors back to application, as per
635 * 4.1.3.3.
636 */
637 if (!inet->recverr) {
638 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
639 goto out;
640 } else
641 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
642
643 sk->sk_err = err;
644 sk->sk_error_report(sk);
645out:
646 sock_put(sk);
647}
648
649void udp_err(struct sk_buff *skb, u32 info)
650{
651 __udp4_lib_err(skb, info, &udp_table);
652}
653
654/*
655 * Throw away all pending data and cancel the corking. Socket is locked.
656 */
657void udp_flush_pending_frames(struct sock *sk)
658{
659 struct udp_sock *up = udp_sk(sk);
660
661 if (up->pending) {
662 up->len = 0;
663 up->pending = 0;
664 ip_flush_pending_frames(sk);
665 }
666}
667EXPORT_SYMBOL(udp_flush_pending_frames);
668
669/**
670 * udp4_hwcsum - handle outgoing HW checksumming
671 * @skb: sk_buff containing the filled-in UDP header
672 * (checksum field must be zeroed out)
673 * @src: source IP address
674 * @dst: destination IP address
675 */
676static void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
677{
678 struct udphdr *uh = udp_hdr(skb);
679 struct sk_buff *frags = skb_shinfo(skb)->frag_list;
680 int offset = skb_transport_offset(skb);
681 int len = skb->len - offset;
682 int hlen = len;
683 __wsum csum = 0;
684
685 if (!frags) {
686 /*
687 * Only one fragment on the socket.
688 */
689 skb->csum_start = skb_transport_header(skb) - skb->head;
690 skb->csum_offset = offsetof(struct udphdr, check);
691 uh->check = ~csum_tcpudp_magic(src, dst, len,
692 IPPROTO_UDP, 0);
693 } else {
694 /*
695 * HW-checksum won't work as there are two or more
696 * fragments on the socket so that all csums of sk_buffs
697 * should be together
698 */
699 do {
700 csum = csum_add(csum, frags->csum);
701 hlen -= frags->len;
702 } while ((frags = frags->next));
703
704 csum = skb_checksum(skb, offset, hlen, csum);
705 skb->ip_summed = CHECKSUM_NONE;
706
707 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
708 if (uh->check == 0)
709 uh->check = CSUM_MANGLED_0;
710 }
711}
712
713static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4)
714{
715 struct sock *sk = skb->sk;
716 struct inet_sock *inet = inet_sk(sk);
717 struct udphdr *uh;
718 int err = 0;
719 int is_udplite = IS_UDPLITE(sk);
720 int offset = skb_transport_offset(skb);
721 int len = skb->len - offset;
722 __wsum csum = 0;
723
724 /*
725 * Create a UDP header
726 */
727 uh = udp_hdr(skb);
728 uh->source = inet->inet_sport;
729 uh->dest = fl4->fl4_dport;
730 uh->len = htons(len);
731 uh->check = 0;
732
733 if (is_udplite) /* UDP-Lite */
734 csum = udplite_csum(skb);
735
736 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */
737
738 skb->ip_summed = CHECKSUM_NONE;
739 goto send;
740
741 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
742
743 udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
744 goto send;
745
746 } else
747 csum = udp_csum(skb);
748
749 /* add protocol-dependent pseudo-header */
750 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
751 sk->sk_protocol, csum);
752 if (uh->check == 0)
753 uh->check = CSUM_MANGLED_0;
754
755send:
756 err = ip_send_skb(skb);
757 if (err) {
758 if (err == -ENOBUFS && !inet->recverr) {
759 UDP_INC_STATS_USER(sock_net(sk),
760 UDP_MIB_SNDBUFERRORS, is_udplite);
761 err = 0;
762 }
763 } else
764 UDP_INC_STATS_USER(sock_net(sk),
765 UDP_MIB_OUTDATAGRAMS, is_udplite);
766 return err;
767}
768
769/*
770 * Push out all pending data as one UDP datagram. Socket is locked.
771 */
772static int udp_push_pending_frames(struct sock *sk)
773{
774 struct udp_sock *up = udp_sk(sk);
775 struct inet_sock *inet = inet_sk(sk);
776 struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
777 struct sk_buff *skb;
778 int err = 0;
779
780 skb = ip_finish_skb(sk, fl4);
781 if (!skb)
782 goto out;
783
784 err = udp_send_skb(skb, fl4);
785
786out:
787 up->len = 0;
788 up->pending = 0;
789 return err;
790}
791
792int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
793 size_t len)
794{
795 struct inet_sock *inet = inet_sk(sk);
796 struct udp_sock *up = udp_sk(sk);
797 struct flowi4 fl4_stack;
798 struct flowi4 *fl4;
799 int ulen = len;
800 struct ipcm_cookie ipc;
801 struct rtable *rt = NULL;
802 int free = 0;
803 int connected = 0;
804 __be32 daddr, faddr, saddr;
805 __be16 dport;
806 u8 tos;
807 int err, is_udplite = IS_UDPLITE(sk);
808 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
809 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
810 struct sk_buff *skb;
811 struct ip_options_data opt_copy;
812
813 if (len > 0xFFFF)
814 return -EMSGSIZE;
815
816 /*
817 * Check the flags.
818 */
819
820 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
821 return -EOPNOTSUPP;
822
823 ipc.opt = NULL;
824 ipc.tx_flags = 0;
825
826 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
827
828 fl4 = &inet->cork.fl.u.ip4;
829 if (up->pending) {
830 /*
831 * There are pending frames.
832 * The socket lock must be held while it's corked.
833 */
834 lock_sock(sk);
835 if (likely(up->pending)) {
836 if (unlikely(up->pending != AF_INET)) {
837 release_sock(sk);
838 return -EINVAL;
839 }
840 goto do_append_data;
841 }
842 release_sock(sk);
843 }
844 ulen += sizeof(struct udphdr);
845
846 /*
847 * Get and verify the address.
848 */
849 if (msg->msg_name) {
850 struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
851 if (msg->msg_namelen < sizeof(*usin))
852 return -EINVAL;
853 if (usin->sin_family != AF_INET) {
854 if (usin->sin_family != AF_UNSPEC)
855 return -EAFNOSUPPORT;
856 }
857
858 daddr = usin->sin_addr.s_addr;
859 dport = usin->sin_port;
860 if (dport == 0)
861 return -EINVAL;
862 } else {
863 if (sk->sk_state != TCP_ESTABLISHED)
864 return -EDESTADDRREQ;
865 daddr = inet->inet_daddr;
866 dport = inet->inet_dport;
867 /* Open fast path for connected socket.
868 Route will not be used, if at least one option is set.
869 */
870 connected = 1;
871 }
872 ipc.addr = inet->inet_saddr;
873
874 ipc.oif = sk->sk_bound_dev_if;
875 err = sock_tx_timestamp(sk, &ipc.tx_flags);
876 if (err)
877 return err;
878 if (msg->msg_controllen) {
879 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
880 if (err)
881 return err;
882 if (ipc.opt)
883 free = 1;
884 connected = 0;
885 }
886 if (!ipc.opt) {
887 struct ip_options_rcu *inet_opt;
888
889 rcu_read_lock();
890 inet_opt = rcu_dereference(inet->inet_opt);
891 if (inet_opt) {
892 memcpy(&opt_copy, inet_opt,
893 sizeof(*inet_opt) + inet_opt->opt.optlen);
894 ipc.opt = &opt_copy.opt;
895 }
896 rcu_read_unlock();
897 }
898
899 saddr = ipc.addr;
900 ipc.addr = faddr = daddr;
901
902 if (ipc.opt && ipc.opt->opt.srr) {
903 if (!daddr)
904 return -EINVAL;
905 faddr = ipc.opt->opt.faddr;
906 connected = 0;
907 }
908 tos = RT_TOS(inet->tos);
909 if (sock_flag(sk, SOCK_LOCALROUTE) ||
910 (msg->msg_flags & MSG_DONTROUTE) ||
911 (ipc.opt && ipc.opt->opt.is_strictroute)) {
912 tos |= RTO_ONLINK;
913 connected = 0;
914 }
915
916 if (ipv4_is_multicast(daddr)) {
917 if (!ipc.oif)
918 ipc.oif = inet->mc_index;
919 if (!saddr)
920 saddr = inet->mc_addr;
921 connected = 0;
922 } else if (!ipc.oif)
923 ipc.oif = inet->uc_index;
924
925 if (connected)
926 rt = (struct rtable *)sk_dst_check(sk, 0);
927
928 if (rt == NULL) {
929 struct net *net = sock_net(sk);
930
931 fl4 = &fl4_stack;
932 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
933 RT_SCOPE_UNIVERSE, sk->sk_protocol,
934 inet_sk_flowi_flags(sk)|FLOWI_FLAG_CAN_SLEEP,
935 faddr, saddr, dport, inet->inet_sport);
936
937 security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
938 rt = ip_route_output_flow(net, fl4, sk);
939 if (IS_ERR(rt)) {
940 err = PTR_ERR(rt);
941 rt = NULL;
942 if (err == -ENETUNREACH)
943 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
944 goto out;
945 }
946
947 err = -EACCES;
948 if ((rt->rt_flags & RTCF_BROADCAST) &&
949 !sock_flag(sk, SOCK_BROADCAST))
950 goto out;
951 if (connected)
952 sk_dst_set(sk, dst_clone(&rt->dst));
953 }
954
955 if (msg->msg_flags&MSG_CONFIRM)
956 goto do_confirm;
957back_from_confirm:
958
959 saddr = fl4->saddr;
960 if (!ipc.addr)
961 daddr = ipc.addr = fl4->daddr;
962
963 /* Lockless fast path for the non-corking case. */
964 if (!corkreq) {
965 skb = ip_make_skb(sk, fl4, getfrag, msg->msg_iov, ulen,
966 sizeof(struct udphdr), &ipc, &rt,
967 msg->msg_flags);
968 err = PTR_ERR(skb);
969 if (skb && !IS_ERR(skb))
970 err = udp_send_skb(skb, fl4);
971 goto out;
972 }
973
974 lock_sock(sk);
975 if (unlikely(up->pending)) {
976 /* The socket is already corked while preparing it. */
977 /* ... which is an evident application bug. --ANK */
978 release_sock(sk);
979
980 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("cork app bug 2\n"));
981 err = -EINVAL;
982 goto out;
983 }
984 /*
985 * Now cork the socket to pend data.
986 */
987 fl4 = &inet->cork.fl.u.ip4;
988 fl4->daddr = daddr;
989 fl4->saddr = saddr;
990 fl4->fl4_dport = dport;
991 fl4->fl4_sport = inet->inet_sport;
992 up->pending = AF_INET;
993
994do_append_data:
995 up->len += ulen;
996 err = ip_append_data(sk, fl4, getfrag, msg->msg_iov, ulen,
997 sizeof(struct udphdr), &ipc, &rt,
998 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
999 if (err)
1000 udp_flush_pending_frames(sk);
1001 else if (!corkreq)
1002 err = udp_push_pending_frames(sk);
1003 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1004 up->pending = 0;
1005 release_sock(sk);
1006
1007out:
1008 ip_rt_put(rt);
1009 if (free)
1010 kfree(ipc.opt);
1011 if (!err)
1012 return len;
1013 /*
1014 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1015 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1016 * we don't have a good statistic (IpOutDiscards but it can be too many
1017 * things). We could add another new stat but at least for now that
1018 * seems like overkill.
1019 */
1020 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1021 UDP_INC_STATS_USER(sock_net(sk),
1022 UDP_MIB_SNDBUFERRORS, is_udplite);
1023 }
1024 return err;
1025
1026do_confirm:
1027 dst_confirm(&rt->dst);
1028 if (!(msg->msg_flags&MSG_PROBE) || len)
1029 goto back_from_confirm;
1030 err = 0;
1031 goto out;
1032}
1033EXPORT_SYMBOL(udp_sendmsg);
1034
1035int udp_sendpage(struct sock *sk, struct page *page, int offset,
1036 size_t size, int flags)
1037{
1038 struct inet_sock *inet = inet_sk(sk);
1039 struct udp_sock *up = udp_sk(sk);
1040 int ret;
1041
1042 if (!up->pending) {
1043 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
1044
1045 /* Call udp_sendmsg to specify destination address which
1046 * sendpage interface can't pass.
1047 * This will succeed only when the socket is connected.
1048 */
1049 ret = udp_sendmsg(NULL, sk, &msg, 0);
1050 if (ret < 0)
1051 return ret;
1052 }
1053
1054 lock_sock(sk);
1055
1056 if (unlikely(!up->pending)) {
1057 release_sock(sk);
1058
1059 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("udp cork app bug 3\n"));
1060 return -EINVAL;
1061 }
1062
1063 ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
1064 page, offset, size, flags);
1065 if (ret == -EOPNOTSUPP) {
1066 release_sock(sk);
1067 return sock_no_sendpage(sk->sk_socket, page, offset,
1068 size, flags);
1069 }
1070 if (ret < 0) {
1071 udp_flush_pending_frames(sk);
1072 goto out;
1073 }
1074
1075 up->len += size;
1076 if (!(up->corkflag || (flags&MSG_MORE)))
1077 ret = udp_push_pending_frames(sk);
1078 if (!ret)
1079 ret = size;
1080out:
1081 release_sock(sk);
1082 return ret;
1083}
1084
1085
1086/**
1087 * first_packet_length - return length of first packet in receive queue
1088 * @sk: socket
1089 *
1090 * Drops all bad checksum frames, until a valid one is found.
1091 * Returns the length of found skb, or 0 if none is found.
1092 */
1093static unsigned int first_packet_length(struct sock *sk)
1094{
1095 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue;
1096 struct sk_buff *skb;
1097 unsigned int res;
1098
1099 __skb_queue_head_init(&list_kill);
1100
1101 spin_lock_bh(&rcvq->lock);
1102 while ((skb = skb_peek(rcvq)) != NULL &&
1103 udp_lib_checksum_complete(skb)) {
1104 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
1105 IS_UDPLITE(sk));
1106 atomic_inc(&sk->sk_drops);
1107 __skb_unlink(skb, rcvq);
1108 __skb_queue_tail(&list_kill, skb);
1109 }
1110 res = skb ? skb->len : 0;
1111 spin_unlock_bh(&rcvq->lock);
1112
1113 if (!skb_queue_empty(&list_kill)) {
1114 bool slow = lock_sock_fast(sk);
1115
1116 __skb_queue_purge(&list_kill);
1117 sk_mem_reclaim_partial(sk);
1118 unlock_sock_fast(sk, slow);
1119 }
1120 return res;
1121}
1122
1123/*
1124 * IOCTL requests applicable to the UDP protocol
1125 */
1126
1127int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
1128{
1129 switch (cmd) {
1130 case SIOCOUTQ:
1131 {
1132 int amount = sk_wmem_alloc_get(sk);
1133
1134 return put_user(amount, (int __user *)arg);
1135 }
1136
1137 case SIOCINQ:
1138 {
1139 unsigned int amount = first_packet_length(sk);
1140
1141 if (amount)
1142 /*
1143 * We will only return the amount
1144 * of this packet since that is all
1145 * that will be read.
1146 */
1147 amount -= sizeof(struct udphdr);
1148
1149 return put_user(amount, (int __user *)arg);
1150 }
1151
1152 default:
1153 return -ENOIOCTLCMD;
1154 }
1155
1156 return 0;
1157}
1158EXPORT_SYMBOL(udp_ioctl);
1159
1160/*
1161 * This should be easy, if there is something there we
1162 * return it, otherwise we block.
1163 */
1164
1165int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1166 size_t len, int noblock, int flags, int *addr_len)
1167{
1168 struct inet_sock *inet = inet_sk(sk);
1169 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
1170 struct sk_buff *skb;
1171 unsigned int ulen, copied;
1172 int peeked, off = 0;
1173 int err;
1174 int is_udplite = IS_UDPLITE(sk);
1175 bool slow;
1176
1177 /*
1178 * Check any passed addresses
1179 */
1180 if (addr_len)
1181 *addr_len = sizeof(*sin);
1182
1183 if (flags & MSG_ERRQUEUE)
1184 return ip_recv_error(sk, msg, len);
1185
1186try_again:
1187 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
1188 &peeked, &off, &err);
1189 if (!skb)
1190 goto out;
1191
1192 ulen = skb->len - sizeof(struct udphdr);
1193 copied = len;
1194 if (copied > ulen)
1195 copied = ulen;
1196 else if (copied < ulen)
1197 msg->msg_flags |= MSG_TRUNC;
1198
1199 /*
1200 * If checksum is needed at all, try to do it while copying the
1201 * data. If the data is truncated, or if we only want a partial
1202 * coverage checksum (UDP-Lite), do it before the copy.
1203 */
1204
1205 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
1206 if (udp_lib_checksum_complete(skb))
1207 goto csum_copy_err;
1208 }
1209
1210 if (skb_csum_unnecessary(skb))
1211 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
1212 msg->msg_iov, copied);
1213 else {
1214 err = skb_copy_and_csum_datagram_iovec(skb,
1215 sizeof(struct udphdr),
1216 msg->msg_iov);
1217
1218 if (err == -EINVAL)
1219 goto csum_copy_err;
1220 }
1221
1222 if (err)
1223 goto out_free;
1224
1225 if (!peeked)
1226 UDP_INC_STATS_USER(sock_net(sk),
1227 UDP_MIB_INDATAGRAMS, is_udplite);
1228
1229 sock_recv_ts_and_drops(msg, sk, skb);
1230
1231 /* Copy the address. */
1232 if (sin) {
1233 sin->sin_family = AF_INET;
1234 sin->sin_port = udp_hdr(skb)->source;
1235 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1236 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1237 }
1238 if (inet->cmsg_flags)
1239 ip_cmsg_recv(msg, skb);
1240
1241 err = copied;
1242 if (flags & MSG_TRUNC)
1243 err = ulen;
1244
1245out_free:
1246 skb_free_datagram_locked(sk, skb);
1247out:
1248 return err;
1249
1250csum_copy_err:
1251 slow = lock_sock_fast(sk);
1252 if (!skb_kill_datagram(sk, skb, flags))
1253 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1254 unlock_sock_fast(sk, slow);
1255
1256 if (noblock)
1257 return -EAGAIN;
1258
1259 /* starting over for a new packet */
1260 msg->msg_flags &= ~MSG_TRUNC;
1261 goto try_again;
1262}
1263
1264
1265int udp_disconnect(struct sock *sk, int flags)
1266{
1267 struct inet_sock *inet = inet_sk(sk);
1268 /*
1269 * 1003.1g - break association.
1270 */
1271
1272 sk->sk_state = TCP_CLOSE;
1273 inet->inet_daddr = 0;
1274 inet->inet_dport = 0;
1275 sock_rps_reset_rxhash(sk);
1276 sk->sk_bound_dev_if = 0;
1277 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1278 inet_reset_saddr(sk);
1279
1280 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1281 sk->sk_prot->unhash(sk);
1282 inet->inet_sport = 0;
1283 }
1284 sk_dst_reset(sk);
1285 return 0;
1286}
1287EXPORT_SYMBOL(udp_disconnect);
1288
1289void udp_lib_unhash(struct sock *sk)
1290{
1291 if (sk_hashed(sk)) {
1292 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1293 struct udp_hslot *hslot, *hslot2;
1294
1295 hslot = udp_hashslot(udptable, sock_net(sk),
1296 udp_sk(sk)->udp_port_hash);
1297 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1298
1299 spin_lock_bh(&hslot->lock);
1300 if (sk_nulls_del_node_init_rcu(sk)) {
1301 hslot->count--;
1302 inet_sk(sk)->inet_num = 0;
1303 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1304
1305 spin_lock(&hslot2->lock);
1306 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1307 hslot2->count--;
1308 spin_unlock(&hslot2->lock);
1309 }
1310 spin_unlock_bh(&hslot->lock);
1311 }
1312}
1313EXPORT_SYMBOL(udp_lib_unhash);
1314
1315/*
1316 * inet_rcv_saddr was changed, we must rehash secondary hash
1317 */
1318void udp_lib_rehash(struct sock *sk, u16 newhash)
1319{
1320 if (sk_hashed(sk)) {
1321 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1322 struct udp_hslot *hslot, *hslot2, *nhslot2;
1323
1324 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1325 nhslot2 = udp_hashslot2(udptable, newhash);
1326 udp_sk(sk)->udp_portaddr_hash = newhash;
1327 if (hslot2 != nhslot2) {
1328 hslot = udp_hashslot(udptable, sock_net(sk),
1329 udp_sk(sk)->udp_port_hash);
1330 /* we must lock primary chain too */
1331 spin_lock_bh(&hslot->lock);
1332
1333 spin_lock(&hslot2->lock);
1334 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1335 hslot2->count--;
1336 spin_unlock(&hslot2->lock);
1337
1338 spin_lock(&nhslot2->lock);
1339 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
1340 &nhslot2->head);
1341 nhslot2->count++;
1342 spin_unlock(&nhslot2->lock);
1343
1344 spin_unlock_bh(&hslot->lock);
1345 }
1346 }
1347}
1348EXPORT_SYMBOL(udp_lib_rehash);
1349
1350static void udp_v4_rehash(struct sock *sk)
1351{
1352 u16 new_hash = udp4_portaddr_hash(sock_net(sk),
1353 inet_sk(sk)->inet_rcv_saddr,
1354 inet_sk(sk)->inet_num);
1355 udp_lib_rehash(sk, new_hash);
1356}
1357
1358static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1359{
1360 int rc;
1361
1362 if (inet_sk(sk)->inet_daddr)
1363 sock_rps_save_rxhash(sk, skb);
1364
1365 rc = sock_queue_rcv_skb(sk, skb);
1366 if (rc < 0) {
1367 int is_udplite = IS_UDPLITE(sk);
1368
1369 /* Note that an ENOMEM error is charged twice */
1370 if (rc == -ENOMEM)
1371 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1372 is_udplite);
1373 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1374 kfree_skb(skb);
1375 trace_udp_fail_queue_rcv_skb(rc, sk);
1376 return -1;
1377 }
1378
1379 return 0;
1380
1381}
1382
1383static struct static_key udp_encap_needed __read_mostly;
1384void udp_encap_enable(void)
1385{
1386 if (!static_key_enabled(&udp_encap_needed))
1387 static_key_slow_inc(&udp_encap_needed);
1388}
1389EXPORT_SYMBOL(udp_encap_enable);
1390
1391/* returns:
1392 * -1: error
1393 * 0: success
1394 * >0: "udp encap" protocol resubmission
1395 *
1396 * Note that in the success and error cases, the skb is assumed to
1397 * have either been requeued or freed.
1398 */
1399int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1400{
1401 struct udp_sock *up = udp_sk(sk);
1402 int rc;
1403 int is_udplite = IS_UDPLITE(sk);
1404
1405 /*
1406 * Charge it to the socket, dropping if the queue is full.
1407 */
1408 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1409 goto drop;
1410 nf_reset(skb);
1411
1412 if (static_key_false(&udp_encap_needed) && up->encap_type) {
1413 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
1414
1415 /*
1416 * This is an encapsulation socket so pass the skb to
1417 * the socket's udp_encap_rcv() hook. Otherwise, just
1418 * fall through and pass this up the UDP socket.
1419 * up->encap_rcv() returns the following value:
1420 * =0 if skb was successfully passed to the encap
1421 * handler or was discarded by it.
1422 * >0 if skb should be passed on to UDP.
1423 * <0 if skb should be resubmitted as proto -N
1424 */
1425
1426 /* if we're overly short, let UDP handle it */
1427 encap_rcv = ACCESS_ONCE(up->encap_rcv);
1428 if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
1429 int ret;
1430
1431 ret = encap_rcv(sk, skb);
1432 if (ret <= 0) {
1433 UDP_INC_STATS_BH(sock_net(sk),
1434 UDP_MIB_INDATAGRAMS,
1435 is_udplite);
1436 return -ret;
1437 }
1438 }
1439
1440 /* FALLTHROUGH -- it's a UDP Packet */
1441 }
1442
1443 /*
1444 * UDP-Lite specific tests, ignored on UDP sockets
1445 */
1446 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1447
1448 /*
1449 * MIB statistics other than incrementing the error count are
1450 * disabled for the following two types of errors: these depend
1451 * on the application settings, not on the functioning of the
1452 * protocol stack as such.
1453 *
1454 * RFC 3828 here recommends (sec 3.3): "There should also be a
1455 * way ... to ... at least let the receiving application block
1456 * delivery of packets with coverage values less than a value
1457 * provided by the application."
1458 */
1459 if (up->pcrlen == 0) { /* full coverage was set */
1460 LIMIT_NETDEBUG(KERN_WARNING "UDPLite: partial coverage %d while full coverage %d requested\n",
1461 UDP_SKB_CB(skb)->cscov, skb->len);
1462 goto drop;
1463 }
1464 /* The next case involves violating the min. coverage requested
1465 * by the receiver. This is subtle: if receiver wants x and x is
1466 * greater than the buffersize/MTU then receiver will complain
1467 * that it wants x while sender emits packets of smaller size y.
1468 * Therefore the above ...()->partial_cov statement is essential.
1469 */
1470 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1471 LIMIT_NETDEBUG(KERN_WARNING "UDPLite: coverage %d too small, need min %d\n",
1472 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1473 goto drop;
1474 }
1475 }
1476
1477 if (rcu_access_pointer(sk->sk_filter) &&
1478 udp_lib_checksum_complete(skb))
1479 goto drop;
1480
1481
1482 if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf))
1483 goto drop;
1484
1485 rc = 0;
1486
1487 ipv4_pktinfo_prepare(skb);
1488 bh_lock_sock(sk);
1489 if (!sock_owned_by_user(sk))
1490 rc = __udp_queue_rcv_skb(sk, skb);
1491 else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
1492 bh_unlock_sock(sk);
1493 goto drop;
1494 }
1495 bh_unlock_sock(sk);
1496
1497 return rc;
1498
1499drop:
1500 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1501 atomic_inc(&sk->sk_drops);
1502 kfree_skb(skb);
1503 return -1;
1504}
1505
1506
1507static void flush_stack(struct sock **stack, unsigned int count,
1508 struct sk_buff *skb, unsigned int final)
1509{
1510 unsigned int i;
1511 struct sk_buff *skb1 = NULL;
1512 struct sock *sk;
1513
1514 for (i = 0; i < count; i++) {
1515 sk = stack[i];
1516 if (likely(skb1 == NULL))
1517 skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
1518
1519 if (!skb1) {
1520 atomic_inc(&sk->sk_drops);
1521 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1522 IS_UDPLITE(sk));
1523 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
1524 IS_UDPLITE(sk));
1525 }
1526
1527 if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0)
1528 skb1 = NULL;
1529 }
1530 if (unlikely(skb1))
1531 kfree_skb(skb1);
1532}
1533
1534/*
1535 * Multicasts and broadcasts go to each listener.
1536 *
1537 * Note: called only from the BH handler context.
1538 */
1539static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1540 struct udphdr *uh,
1541 __be32 saddr, __be32 daddr,
1542 struct udp_table *udptable)
1543{
1544 struct sock *sk, *stack[256 / sizeof(struct sock *)];
1545 struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
1546 int dif;
1547 unsigned int i, count = 0;
1548
1549 spin_lock(&hslot->lock);
1550 sk = sk_nulls_head(&hslot->head);
1551 dif = skb->dev->ifindex;
1552 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1553 while (sk) {
1554 stack[count++] = sk;
1555 sk = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest,
1556 daddr, uh->source, saddr, dif);
1557 if (unlikely(count == ARRAY_SIZE(stack))) {
1558 if (!sk)
1559 break;
1560 flush_stack(stack, count, skb, ~0);
1561 count = 0;
1562 }
1563 }
1564 /*
1565 * before releasing chain lock, we must take a reference on sockets
1566 */
1567 for (i = 0; i < count; i++)
1568 sock_hold(stack[i]);
1569
1570 spin_unlock(&hslot->lock);
1571
1572 /*
1573 * do the slow work with no lock held
1574 */
1575 if (count) {
1576 flush_stack(stack, count, skb, count - 1);
1577
1578 for (i = 0; i < count; i++)
1579 sock_put(stack[i]);
1580 } else {
1581 kfree_skb(skb);
1582 }
1583 return 0;
1584}
1585
1586/* Initialize UDP checksum. If exited with zero value (success),
1587 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1588 * Otherwise, csum completion requires chacksumming packet body,
1589 * including udp header and folding it to skb->csum.
1590 */
1591static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1592 int proto)
1593{
1594 const struct iphdr *iph;
1595 int err;
1596
1597 UDP_SKB_CB(skb)->partial_cov = 0;
1598 UDP_SKB_CB(skb)->cscov = skb->len;
1599
1600 if (proto == IPPROTO_UDPLITE) {
1601 err = udplite_checksum_init(skb, uh);
1602 if (err)
1603 return err;
1604 }
1605
1606 iph = ip_hdr(skb);
1607 if (uh->check == 0) {
1608 skb->ip_summed = CHECKSUM_UNNECESSARY;
1609 } else if (skb->ip_summed == CHECKSUM_COMPLETE) {
1610 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1611 proto, skb->csum))
1612 skb->ip_summed = CHECKSUM_UNNECESSARY;
1613 }
1614 if (!skb_csum_unnecessary(skb))
1615 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1616 skb->len, proto, 0);
1617 /* Probably, we should checksum udp header (it should be in cache
1618 * in any case) and data in tiny packets (< rx copybreak).
1619 */
1620
1621 return 0;
1622}
1623
1624/*
1625 * All we need to do is get the socket, and then do a checksum.
1626 */
1627
1628int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1629 int proto)
1630{
1631 struct sock *sk;
1632 struct udphdr *uh;
1633 unsigned short ulen;
1634 struct rtable *rt = skb_rtable(skb);
1635 __be32 saddr, daddr;
1636 struct net *net = dev_net(skb->dev);
1637
1638 /*
1639 * Validate the packet.
1640 */
1641 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1642 goto drop; /* No space for header. */
1643
1644 uh = udp_hdr(skb);
1645 ulen = ntohs(uh->len);
1646 saddr = ip_hdr(skb)->saddr;
1647 daddr = ip_hdr(skb)->daddr;
1648
1649 if (ulen > skb->len)
1650 goto short_packet;
1651
1652 if (proto == IPPROTO_UDP) {
1653 /* UDP validates ulen. */
1654 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
1655 goto short_packet;
1656 uh = udp_hdr(skb);
1657 }
1658
1659 if (udp4_csum_init(skb, uh, proto))
1660 goto csum_error;
1661
1662 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1663 return __udp4_lib_mcast_deliver(net, skb, uh,
1664 saddr, daddr, udptable);
1665
1666 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1667
1668 if (sk != NULL) {
1669 int ret = udp_queue_rcv_skb(sk, skb);
1670 sock_put(sk);
1671
1672 /* a return value > 0 means to resubmit the input, but
1673 * it wants the return to be -protocol, or 0
1674 */
1675 if (ret > 0)
1676 return -ret;
1677 return 0;
1678 }
1679
1680 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1681 goto drop;
1682 nf_reset(skb);
1683
1684 /* No socket. Drop packet silently, if checksum is wrong */
1685 if (udp_lib_checksum_complete(skb))
1686 goto csum_error;
1687
1688 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1689 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1690
1691 /*
1692 * Hmm. We got an UDP packet to a port to which we
1693 * don't wanna listen. Ignore it.
1694 */
1695 kfree_skb(skb);
1696 return 0;
1697
1698short_packet:
1699 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1700 proto == IPPROTO_UDPLITE ? "Lite" : "",
1701 &saddr, ntohs(uh->source),
1702 ulen, skb->len,
1703 &daddr, ntohs(uh->dest));
1704 goto drop;
1705
1706csum_error:
1707 /*
1708 * RFC1122: OK. Discards the bad packet silently (as far as
1709 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1710 */
1711 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1712 proto == IPPROTO_UDPLITE ? "Lite" : "",
1713 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
1714 ulen);
1715drop:
1716 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1717 kfree_skb(skb);
1718 return 0;
1719}
1720
1721int udp_rcv(struct sk_buff *skb)
1722{
1723 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1724}
1725
1726void udp_destroy_sock(struct sock *sk)
1727{
1728 bool slow = lock_sock_fast(sk);
1729 udp_flush_pending_frames(sk);
1730 unlock_sock_fast(sk, slow);
1731}
1732
1733/*
1734 * Socket option code for UDP
1735 */
1736int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1737 char __user *optval, unsigned int optlen,
1738 int (*push_pending_frames)(struct sock *))
1739{
1740 struct udp_sock *up = udp_sk(sk);
1741 int val;
1742 int err = 0;
1743 int is_udplite = IS_UDPLITE(sk);
1744
1745 if (optlen < sizeof(int))
1746 return -EINVAL;
1747
1748 if (get_user(val, (int __user *)optval))
1749 return -EFAULT;
1750
1751 switch (optname) {
1752 case UDP_CORK:
1753 if (val != 0) {
1754 up->corkflag = 1;
1755 } else {
1756 up->corkflag = 0;
1757 lock_sock(sk);
1758 (*push_pending_frames)(sk);
1759 release_sock(sk);
1760 }
1761 break;
1762
1763 case UDP_ENCAP:
1764 switch (val) {
1765 case 0:
1766 case UDP_ENCAP_ESPINUDP:
1767 case UDP_ENCAP_ESPINUDP_NON_IKE:
1768 up->encap_rcv = xfrm4_udp_encap_rcv;
1769 /* FALLTHROUGH */
1770 case UDP_ENCAP_L2TPINUDP:
1771 up->encap_type = val;
1772 udp_encap_enable();
1773 break;
1774 default:
1775 err = -ENOPROTOOPT;
1776 break;
1777 }
1778 break;
1779
1780 /*
1781 * UDP-Lite's partial checksum coverage (RFC 3828).
1782 */
1783 /* The sender sets actual checksum coverage length via this option.
1784 * The case coverage > packet length is handled by send module. */
1785 case UDPLITE_SEND_CSCOV:
1786 if (!is_udplite) /* Disable the option on UDP sockets */
1787 return -ENOPROTOOPT;
1788 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
1789 val = 8;
1790 else if (val > USHRT_MAX)
1791 val = USHRT_MAX;
1792 up->pcslen = val;
1793 up->pcflag |= UDPLITE_SEND_CC;
1794 break;
1795
1796 /* The receiver specifies a minimum checksum coverage value. To make
1797 * sense, this should be set to at least 8 (as done below). If zero is
1798 * used, this again means full checksum coverage. */
1799 case UDPLITE_RECV_CSCOV:
1800 if (!is_udplite) /* Disable the option on UDP sockets */
1801 return -ENOPROTOOPT;
1802 if (val != 0 && val < 8) /* Avoid silly minimal values. */
1803 val = 8;
1804 else if (val > USHRT_MAX)
1805 val = USHRT_MAX;
1806 up->pcrlen = val;
1807 up->pcflag |= UDPLITE_RECV_CC;
1808 break;
1809
1810 default:
1811 err = -ENOPROTOOPT;
1812 break;
1813 }
1814
1815 return err;
1816}
1817EXPORT_SYMBOL(udp_lib_setsockopt);
1818
1819int udp_setsockopt(struct sock *sk, int level, int optname,
1820 char __user *optval, unsigned int optlen)
1821{
1822 if (level == SOL_UDP || level == SOL_UDPLITE)
1823 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1824 udp_push_pending_frames);
1825 return ip_setsockopt(sk, level, optname, optval, optlen);
1826}
1827
1828#ifdef CONFIG_COMPAT
1829int compat_udp_setsockopt(struct sock *sk, int level, int optname,
1830 char __user *optval, unsigned int optlen)
1831{
1832 if (level == SOL_UDP || level == SOL_UDPLITE)
1833 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1834 udp_push_pending_frames);
1835 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
1836}
1837#endif
1838
1839int udp_lib_getsockopt(struct sock *sk, int level, int optname,
1840 char __user *optval, int __user *optlen)
1841{
1842 struct udp_sock *up = udp_sk(sk);
1843 int val, len;
1844
1845 if (get_user(len, optlen))
1846 return -EFAULT;
1847
1848 len = min_t(unsigned int, len, sizeof(int));
1849
1850 if (len < 0)
1851 return -EINVAL;
1852
1853 switch (optname) {
1854 case UDP_CORK:
1855 val = up->corkflag;
1856 break;
1857
1858 case UDP_ENCAP:
1859 val = up->encap_type;
1860 break;
1861
1862 /* The following two cannot be changed on UDP sockets, the return is
1863 * always 0 (which corresponds to the full checksum coverage of UDP). */
1864 case UDPLITE_SEND_CSCOV:
1865 val = up->pcslen;
1866 break;
1867
1868 case UDPLITE_RECV_CSCOV:
1869 val = up->pcrlen;
1870 break;
1871
1872 default:
1873 return -ENOPROTOOPT;
1874 }
1875
1876 if (put_user(len, optlen))
1877 return -EFAULT;
1878 if (copy_to_user(optval, &val, len))
1879 return -EFAULT;
1880 return 0;
1881}
1882EXPORT_SYMBOL(udp_lib_getsockopt);
1883
1884int udp_getsockopt(struct sock *sk, int level, int optname,
1885 char __user *optval, int __user *optlen)
1886{
1887 if (level == SOL_UDP || level == SOL_UDPLITE)
1888 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1889 return ip_getsockopt(sk, level, optname, optval, optlen);
1890}
1891
1892#ifdef CONFIG_COMPAT
1893int compat_udp_getsockopt(struct sock *sk, int level, int optname,
1894 char __user *optval, int __user *optlen)
1895{
1896 if (level == SOL_UDP || level == SOL_UDPLITE)
1897 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1898 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
1899}
1900#endif
1901/**
1902 * udp_poll - wait for a UDP event.
1903 * @file - file struct
1904 * @sock - socket
1905 * @wait - poll table
1906 *
1907 * This is same as datagram poll, except for the special case of
1908 * blocking sockets. If application is using a blocking fd
1909 * and a packet with checksum error is in the queue;
1910 * then it could get return from select indicating data available
1911 * but then block when reading it. Add special case code
1912 * to work around these arguably broken applications.
1913 */
1914unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
1915{
1916 unsigned int mask = datagram_poll(file, sock, wait);
1917 struct sock *sk = sock->sk;
1918
1919 /* Check for false positives due to checksum errors */
1920 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
1921 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk))
1922 mask &= ~(POLLIN | POLLRDNORM);
1923
1924 return mask;
1925
1926}
1927EXPORT_SYMBOL(udp_poll);
1928
1929struct proto udp_prot = {
1930 .name = "UDP",
1931 .owner = THIS_MODULE,
1932 .close = udp_lib_close,
1933 .connect = ip4_datagram_connect,
1934 .disconnect = udp_disconnect,
1935 .ioctl = udp_ioctl,
1936 .destroy = udp_destroy_sock,
1937 .setsockopt = udp_setsockopt,
1938 .getsockopt = udp_getsockopt,
1939 .sendmsg = udp_sendmsg,
1940 .recvmsg = udp_recvmsg,
1941 .sendpage = udp_sendpage,
1942 .backlog_rcv = __udp_queue_rcv_skb,
1943 .hash = udp_lib_hash,
1944 .unhash = udp_lib_unhash,
1945 .rehash = udp_v4_rehash,
1946 .get_port = udp_v4_get_port,
1947 .memory_allocated = &udp_memory_allocated,
1948 .sysctl_mem = sysctl_udp_mem,
1949 .sysctl_wmem = &sysctl_udp_wmem_min,
1950 .sysctl_rmem = &sysctl_udp_rmem_min,
1951 .obj_size = sizeof(struct udp_sock),
1952 .slab_flags = SLAB_DESTROY_BY_RCU,
1953 .h.udp_table = &udp_table,
1954#ifdef CONFIG_COMPAT
1955 .compat_setsockopt = compat_udp_setsockopt,
1956 .compat_getsockopt = compat_udp_getsockopt,
1957#endif
1958 .clear_sk = sk_prot_clear_portaddr_nulls,
1959};
1960EXPORT_SYMBOL(udp_prot);
1961
1962/* ------------------------------------------------------------------------ */
1963#ifdef CONFIG_PROC_FS
1964
1965static struct sock *udp_get_first(struct seq_file *seq, int start)
1966{
1967 struct sock *sk;
1968 struct udp_iter_state *state = seq->private;
1969 struct net *net = seq_file_net(seq);
1970
1971 for (state->bucket = start; state->bucket <= state->udp_table->mask;
1972 ++state->bucket) {
1973 struct hlist_nulls_node *node;
1974 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
1975
1976 if (hlist_nulls_empty(&hslot->head))
1977 continue;
1978
1979 spin_lock_bh(&hslot->lock);
1980 sk_nulls_for_each(sk, node, &hslot->head) {
1981 if (!net_eq(sock_net(sk), net))
1982 continue;
1983 if (sk->sk_family == state->family)
1984 goto found;
1985 }
1986 spin_unlock_bh(&hslot->lock);
1987 }
1988 sk = NULL;
1989found:
1990 return sk;
1991}
1992
1993static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
1994{
1995 struct udp_iter_state *state = seq->private;
1996 struct net *net = seq_file_net(seq);
1997
1998 do {
1999 sk = sk_nulls_next(sk);
2000 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
2001
2002 if (!sk) {
2003 if (state->bucket <= state->udp_table->mask)
2004 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2005 return udp_get_first(seq, state->bucket + 1);
2006 }
2007 return sk;
2008}
2009
2010static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
2011{
2012 struct sock *sk = udp_get_first(seq, 0);
2013
2014 if (sk)
2015 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
2016 --pos;
2017 return pos ? NULL : sk;
2018}
2019
2020static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
2021{
2022 struct udp_iter_state *state = seq->private;
2023 state->bucket = MAX_UDP_PORTS;
2024
2025 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
2026}
2027
2028static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2029{
2030 struct sock *sk;
2031
2032 if (v == SEQ_START_TOKEN)
2033 sk = udp_get_idx(seq, 0);
2034 else
2035 sk = udp_get_next(seq, v);
2036
2037 ++*pos;
2038 return sk;
2039}
2040
2041static void udp_seq_stop(struct seq_file *seq, void *v)
2042{
2043 struct udp_iter_state *state = seq->private;
2044
2045 if (state->bucket <= state->udp_table->mask)
2046 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2047}
2048
2049int udp_seq_open(struct inode *inode, struct file *file)
2050{
2051 struct udp_seq_afinfo *afinfo = PDE(inode)->data;
2052 struct udp_iter_state *s;
2053 int err;
2054
2055 err = seq_open_net(inode, file, &afinfo->seq_ops,
2056 sizeof(struct udp_iter_state));
2057 if (err < 0)
2058 return err;
2059
2060 s = ((struct seq_file *)file->private_data)->private;
2061 s->family = afinfo->family;
2062 s->udp_table = afinfo->udp_table;
2063 return err;
2064}
2065EXPORT_SYMBOL(udp_seq_open);
2066
2067/* ------------------------------------------------------------------------ */
2068int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
2069{
2070 struct proc_dir_entry *p;
2071 int rc = 0;
2072
2073 afinfo->seq_ops.start = udp_seq_start;
2074 afinfo->seq_ops.next = udp_seq_next;
2075 afinfo->seq_ops.stop = udp_seq_stop;
2076
2077 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2078 afinfo->seq_fops, afinfo);
2079 if (!p)
2080 rc = -ENOMEM;
2081 return rc;
2082}
2083EXPORT_SYMBOL(udp_proc_register);
2084
2085void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
2086{
2087 proc_net_remove(net, afinfo->name);
2088}
2089EXPORT_SYMBOL(udp_proc_unregister);
2090
2091/* ------------------------------------------------------------------------ */
2092static void udp4_format_sock(struct sock *sp, struct seq_file *f,
2093 int bucket, int *len)
2094{
2095 struct inet_sock *inet = inet_sk(sp);
2096 __be32 dest = inet->inet_daddr;
2097 __be32 src = inet->inet_rcv_saddr;
2098 __u16 destp = ntohs(inet->inet_dport);
2099 __u16 srcp = ntohs(inet->inet_sport);
2100
2101 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
2102 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d%n",
2103 bucket, src, srcp, dest, destp, sp->sk_state,
2104 sk_wmem_alloc_get(sp),
2105 sk_rmem_alloc_get(sp),
2106 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
2107 atomic_read(&sp->sk_refcnt), sp,
2108 atomic_read(&sp->sk_drops), len);
2109}
2110
2111int udp4_seq_show(struct seq_file *seq, void *v)
2112{
2113 if (v == SEQ_START_TOKEN)
2114 seq_printf(seq, "%-127s\n",
2115 " sl local_address rem_address st tx_queue "
2116 "rx_queue tr tm->when retrnsmt uid timeout "
2117 "inode ref pointer drops");
2118 else {
2119 struct udp_iter_state *state = seq->private;
2120 int len;
2121
2122 udp4_format_sock(v, seq, state->bucket, &len);
2123 seq_printf(seq, "%*s\n", 127 - len, "");
2124 }
2125 return 0;
2126}
2127
2128static const struct file_operations udp_afinfo_seq_fops = {
2129 .owner = THIS_MODULE,
2130 .open = udp_seq_open,
2131 .read = seq_read,
2132 .llseek = seq_lseek,
2133 .release = seq_release_net
2134};
2135
2136/* ------------------------------------------------------------------------ */
2137static struct udp_seq_afinfo udp4_seq_afinfo = {
2138 .name = "udp",
2139 .family = AF_INET,
2140 .udp_table = &udp_table,
2141 .seq_fops = &udp_afinfo_seq_fops,
2142 .seq_ops = {
2143 .show = udp4_seq_show,
2144 },
2145};
2146
2147static int __net_init udp4_proc_init_net(struct net *net)
2148{
2149 return udp_proc_register(net, &udp4_seq_afinfo);
2150}
2151
2152static void __net_exit udp4_proc_exit_net(struct net *net)
2153{
2154 udp_proc_unregister(net, &udp4_seq_afinfo);
2155}
2156
2157static struct pernet_operations udp4_net_ops = {
2158 .init = udp4_proc_init_net,
2159 .exit = udp4_proc_exit_net,
2160};
2161
2162int __init udp4_proc_init(void)
2163{
2164 return register_pernet_subsys(&udp4_net_ops);
2165}
2166
2167void udp4_proc_exit(void)
2168{
2169 unregister_pernet_subsys(&udp4_net_ops);
2170}
2171#endif /* CONFIG_PROC_FS */
2172
2173static __initdata unsigned long uhash_entries;
2174static int __init set_uhash_entries(char *str)
2175{
2176 ssize_t ret;
2177
2178 if (!str)
2179 return 0;
2180
2181 ret = kstrtoul(str, 0, &uhash_entries);
2182 if (ret)
2183 return 0;
2184
2185 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
2186 uhash_entries = UDP_HTABLE_SIZE_MIN;
2187 return 1;
2188}
2189__setup("uhash_entries=", set_uhash_entries);
2190
2191void __init udp_table_init(struct udp_table *table, const char *name)
2192{
2193 unsigned int i;
2194
2195 table->hash = alloc_large_system_hash(name,
2196 2 * sizeof(struct udp_hslot),
2197 uhash_entries,
2198 21, /* one slot per 2 MB */
2199 0,
2200 &table->log,
2201 &table->mask,
2202 UDP_HTABLE_SIZE_MIN,
2203 64 * 1024);
2204
2205 table->hash2 = table->hash + (table->mask + 1);
2206 for (i = 0; i <= table->mask; i++) {
2207 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
2208 table->hash[i].count = 0;
2209 spin_lock_init(&table->hash[i].lock);
2210 }
2211 for (i = 0; i <= table->mask; i++) {
2212 INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i);
2213 table->hash2[i].count = 0;
2214 spin_lock_init(&table->hash2[i].lock);
2215 }
2216}
2217
2218void __init udp_init(void)
2219{
2220 unsigned long limit;
2221
2222 udp_table_init(&udp_table, "UDP");
2223 limit = nr_free_buffer_pages() / 8;
2224 limit = max(limit, 128UL);
2225 sysctl_udp_mem[0] = limit / 4 * 3;
2226 sysctl_udp_mem[1] = limit;
2227 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
2228
2229 sysctl_udp_rmem_min = SK_MEM_QUANTUM;
2230 sysctl_udp_wmem_min = SK_MEM_QUANTUM;
2231}
2232
2233int udp4_ufo_send_check(struct sk_buff *skb)
2234{
2235 const struct iphdr *iph;
2236 struct udphdr *uh;
2237
2238 if (!pskb_may_pull(skb, sizeof(*uh)))
2239 return -EINVAL;
2240
2241 iph = ip_hdr(skb);
2242 uh = udp_hdr(skb);
2243
2244 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
2245 IPPROTO_UDP, 0);
2246 skb->csum_start = skb_transport_header(skb) - skb->head;
2247 skb->csum_offset = offsetof(struct udphdr, check);
2248 skb->ip_summed = CHECKSUM_PARTIAL;
2249 return 0;
2250}
2251
2252struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
2253 netdev_features_t features)
2254{
2255 struct sk_buff *segs = ERR_PTR(-EINVAL);
2256 unsigned int mss;
2257 int offset;
2258 __wsum csum;
2259
2260 mss = skb_shinfo(skb)->gso_size;
2261 if (unlikely(skb->len <= mss))
2262 goto out;
2263
2264 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
2265 /* Packet is from an untrusted source, reset gso_segs. */
2266 int type = skb_shinfo(skb)->gso_type;
2267
2268 if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) ||
2269 !(type & (SKB_GSO_UDP))))
2270 goto out;
2271
2272 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
2273
2274 segs = NULL;
2275 goto out;
2276 }
2277
2278 /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
2279 * do checksum of UDP packets sent as multiple IP fragments.
2280 */
2281 offset = skb_checksum_start_offset(skb);
2282 csum = skb_checksum(skb, offset, skb->len - offset, 0);
2283 offset += skb->csum_offset;
2284 *(__sum16 *)(skb->data + offset) = csum_fold(csum);
2285 skb->ip_summed = CHECKSUM_NONE;
2286
2287 /* Fragment the skb. IP headers of the fragments are updated in
2288 * inet_gso_segment()
2289 */
2290 segs = skb_segment(skb, features);
2291out:
2292 return segs;
2293}
2294