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Merge tag 'locks-v3.16-2' of git://git.samba.org/jlayton/linux
[linux/fpc-iii.git] / net / ipv4 / udp.c
blobd92f94b7e4025dd4779e75e6a75f2de560713778
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/inet_hashtables.h>
107 #include <net/route.h>
108 #include <net/checksum.h>
109 #include <net/xfrm.h>
110 #include <trace/events/udp.h>
111 #include <linux/static_key.h>
112 #include <trace/events/skb.h>
113 #include <net/busy_poll.h>
114 #include "udp_impl.h"
115
116 struct udp_table udp_table __read_mostly;
117 EXPORT_SYMBOL(udp_table);
118
119 long sysctl_udp_mem[3] __read_mostly;
120 EXPORT_SYMBOL(sysctl_udp_mem);
121
122 int sysctl_udp_rmem_min __read_mostly;
123 EXPORT_SYMBOL(sysctl_udp_rmem_min);
124
125 int sysctl_udp_wmem_min __read_mostly;
126 EXPORT_SYMBOL(sysctl_udp_wmem_min);
127
128 atomic_long_t udp_memory_allocated;
129 EXPORT_SYMBOL(udp_memory_allocated);
130
131 #define MAX_UDP_PORTS 65536
132 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
133
134 static int udp_lib_lport_inuse(struct net *net, __u16 num,
135 const struct udp_hslot *hslot,
136 unsigned long *bitmap,
137 struct sock *sk,
138 int (*saddr_comp)(const struct sock *sk1,
139 const struct sock *sk2),
140 unsigned int log)
141 {
142 struct sock *sk2;
143 struct hlist_nulls_node *node;
144 kuid_t uid = sock_i_uid(sk);
145
146 sk_nulls_for_each(sk2, node, &hslot->head)
147 if (net_eq(sock_net(sk2), net) &&
148 sk2 != sk &&
149 (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
150 (!sk2->sk_reuse || !sk->sk_reuse) &&
151 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
152 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
153 (!sk2->sk_reuseport || !sk->sk_reuseport ||
154 !uid_eq(uid, sock_i_uid(sk2))) &&
155 (*saddr_comp)(sk, sk2)) {
156 if (bitmap)
157 __set_bit(udp_sk(sk2)->udp_port_hash >> log,
158 bitmap);
159 else
160 return 1;
161 }
162 return 0;
163 }
164
165 /*
166 * Note: we still hold spinlock of primary hash chain, so no other writer
167 * can insert/delete a socket with local_port == num
168 */
169 static int udp_lib_lport_inuse2(struct net *net, __u16 num,
170 struct udp_hslot *hslot2,
171 struct sock *sk,
172 int (*saddr_comp)(const struct sock *sk1,
173 const struct sock *sk2))
174 {
175 struct sock *sk2;
176 struct hlist_nulls_node *node;
177 kuid_t uid = sock_i_uid(sk);
178 int res = 0;
179
180 spin_lock(&hslot2->lock);
181 udp_portaddr_for_each_entry(sk2, node, &hslot2->head)
182 if (net_eq(sock_net(sk2), net) &&
183 sk2 != sk &&
184 (udp_sk(sk2)->udp_port_hash == num) &&
185 (!sk2->sk_reuse || !sk->sk_reuse) &&
186 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
187 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
188 (!sk2->sk_reuseport || !sk->sk_reuseport ||
189 !uid_eq(uid, sock_i_uid(sk2))) &&
190 (*saddr_comp)(sk, sk2)) {
191 res = 1;
192 break;
193 }
194 spin_unlock(&hslot2->lock);
195 return res;
196 }
197
198 /**
199 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
200 *
201 * @sk: socket struct in question
202 * @snum: port number to look up
203 * @saddr_comp: AF-dependent comparison of bound local IP addresses
204 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
205 * with NULL address
206 */
207 int udp_lib_get_port(struct sock *sk, unsigned short snum,
208 int (*saddr_comp)(const struct sock *sk1,
209 const struct sock *sk2),
210 unsigned int hash2_nulladdr)
211 {
212 struct udp_hslot *hslot, *hslot2;
213 struct udp_table *udptable = sk->sk_prot->h.udp_table;
214 int error = 1;
215 struct net *net = sock_net(sk);
216
217 if (!snum) {
218 int low, high, remaining;
219 unsigned int rand;
220 unsigned short first, last;
221 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
222
223 inet_get_local_port_range(net, &low, &high);
224 remaining = (high - low) + 1;
225
226 rand = prandom_u32();
227 first = (((u64)rand * remaining) >> 32) + low;
228 /*
229 * force rand to be an odd multiple of UDP_HTABLE_SIZE
230 */
231 rand = (rand | 1) * (udptable->mask + 1);
232 last = first + udptable->mask + 1;
233 do {
234 hslot = udp_hashslot(udptable, net, first);
235 bitmap_zero(bitmap, PORTS_PER_CHAIN);
236 spin_lock_bh(&hslot->lock);
237 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
238 saddr_comp, udptable->log);
239
240 snum = first;
241 /*
242 * Iterate on all possible values of snum for this hash.
243 * Using steps of an odd multiple of UDP_HTABLE_SIZE
244 * give us randomization and full range coverage.
245 */
246 do {
247 if (low <= snum && snum <= high &&
248 !test_bit(snum >> udptable->log, bitmap) &&
249 !inet_is_local_reserved_port(net, snum))
250 goto found;
251 snum += rand;
252 } while (snum != first);
253 spin_unlock_bh(&hslot->lock);
254 } while (++first != last);
255 goto fail;
256 } else {
257 hslot = udp_hashslot(udptable, net, snum);
258 spin_lock_bh(&hslot->lock);
259 if (hslot->count > 10) {
260 int exist;
261 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum;
262
263 slot2 &= udptable->mask;
264 hash2_nulladdr &= udptable->mask;
265
266 hslot2 = udp_hashslot2(udptable, slot2);
267 if (hslot->count < hslot2->count)
268 goto scan_primary_hash;
269
270 exist = udp_lib_lport_inuse2(net, snum, hslot2,
271 sk, saddr_comp);
272 if (!exist && (hash2_nulladdr != slot2)) {
273 hslot2 = udp_hashslot2(udptable, hash2_nulladdr);
274 exist = udp_lib_lport_inuse2(net, snum, hslot2,
275 sk, saddr_comp);
276 }
277 if (exist)
278 goto fail_unlock;
279 else
280 goto found;
281 }
282 scan_primary_hash:
283 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk,
284 saddr_comp, 0))
285 goto fail_unlock;
286 }
287 found:
288 inet_sk(sk)->inet_num = snum;
289 udp_sk(sk)->udp_port_hash = snum;
290 udp_sk(sk)->udp_portaddr_hash ^= snum;
291 if (sk_unhashed(sk)) {
292 sk_nulls_add_node_rcu(sk, &hslot->head);
293 hslot->count++;
294 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
295
296 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
297 spin_lock(&hslot2->lock);
298 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
299 &hslot2->head);
300 hslot2->count++;
301 spin_unlock(&hslot2->lock);
302 }
303 error = 0;
304 fail_unlock:
305 spin_unlock_bh(&hslot->lock);
306 fail:
307 return error;
308 }
309 EXPORT_SYMBOL(udp_lib_get_port);
310
311 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
312 {
313 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
314
315 return (!ipv6_only_sock(sk2) &&
316 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr ||
317 inet1->inet_rcv_saddr == inet2->inet_rcv_saddr));
318 }
319
320 static unsigned int udp4_portaddr_hash(struct net *net, __be32 saddr,
321 unsigned int port)
322 {
323 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
324 }
325
326 int udp_v4_get_port(struct sock *sk, unsigned short snum)
327 {
328 unsigned int hash2_nulladdr =
329 udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
330 unsigned int hash2_partial =
331 udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);
332
333 /* precompute partial secondary hash */
334 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
335 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr);
336 }
337
338 static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr,
339 unsigned short hnum,
340 __be16 sport, __be32 daddr, __be16 dport, int dif)
341 {
342 int score = -1;
343
344 if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
345 !ipv6_only_sock(sk)) {
346 struct inet_sock *inet = inet_sk(sk);
347
348 score = (sk->sk_family == PF_INET ? 2 : 1);
349 if (inet->inet_rcv_saddr) {
350 if (inet->inet_rcv_saddr != daddr)
351 return -1;
352 score += 4;
353 }
354 if (inet->inet_daddr) {
355 if (inet->inet_daddr != saddr)
356 return -1;
357 score += 4;
358 }
359 if (inet->inet_dport) {
360 if (inet->inet_dport != sport)
361 return -1;
362 score += 4;
363 }
364 if (sk->sk_bound_dev_if) {
365 if (sk->sk_bound_dev_if != dif)
366 return -1;
367 score += 4;
368 }
369 }
370 return score;
371 }
372
373 /*
374 * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num)
375 */
376 static inline int compute_score2(struct sock *sk, struct net *net,
377 __be32 saddr, __be16 sport,
378 __be32 daddr, unsigned int hnum, int dif)
379 {
380 int score = -1;
381
382 if (net_eq(sock_net(sk), net) && !ipv6_only_sock(sk)) {
383 struct inet_sock *inet = inet_sk(sk);
384
385 if (inet->inet_rcv_saddr != daddr)
386 return -1;
387 if (inet->inet_num != hnum)
388 return -1;
389
390 score = (sk->sk_family == PF_INET ? 2 : 1);
391 if (inet->inet_daddr) {
392 if (inet->inet_daddr != saddr)
393 return -1;
394 score += 4;
395 }
396 if (inet->inet_dport) {
397 if (inet->inet_dport != sport)
398 return -1;
399 score += 4;
400 }
401 if (sk->sk_bound_dev_if) {
402 if (sk->sk_bound_dev_if != dif)
403 return -1;
404 score += 4;
405 }
406 }
407 return score;
408 }
409
410 static unsigned int udp_ehashfn(struct net *net, const __be32 laddr,
411 const __u16 lport, const __be32 faddr,
412 const __be16 fport)
413 {
414 static u32 udp_ehash_secret __read_mostly;
415
416 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret));
417
418 return __inet_ehashfn(laddr, lport, faddr, fport,
419 udp_ehash_secret + net_hash_mix(net));
420 }
421
422
423 /* called with read_rcu_lock() */
424 static struct sock *udp4_lib_lookup2(struct net *net,
425 __be32 saddr, __be16 sport,
426 __be32 daddr, unsigned int hnum, int dif,
427 struct udp_hslot *hslot2, unsigned int slot2)
428 {
429 struct sock *sk, *result;
430 struct hlist_nulls_node *node;
431 int score, badness, matches = 0, reuseport = 0;
432 u32 hash = 0;
433
434 begin:
435 result = NULL;
436 badness = 0;
437 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
438 score = compute_score2(sk, net, saddr, sport,
439 daddr, hnum, dif);
440 if (score > badness) {
441 result = sk;
442 badness = score;
443 reuseport = sk->sk_reuseport;
444 if (reuseport) {
445 hash = udp_ehashfn(net, daddr, hnum,
446 saddr, sport);
447 matches = 1;
448 }
449 } else if (score == badness && reuseport) {
450 matches++;
451 if (((u64)hash * matches) >> 32 == 0)
452 result = sk;
453 hash = next_pseudo_random32(hash);
454 }
455 }
456 /*
457 * if the nulls value we got at the end of this lookup is
458 * not the expected one, we must restart lookup.
459 * We probably met an item that was moved to another chain.
460 */
461 if (get_nulls_value(node) != slot2)
462 goto begin;
463 if (result) {
464 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
465 result = NULL;
466 else if (unlikely(compute_score2(result, net, saddr, sport,
467 daddr, hnum, dif) < badness)) {
468 sock_put(result);
469 goto begin;
470 }
471 }
472 return result;
473 }
474
475 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
476 * harder than this. -DaveM
477 */
478 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
479 __be16 sport, __be32 daddr, __be16 dport,
480 int dif, struct udp_table *udptable)
481 {
482 struct sock *sk, *result;
483 struct hlist_nulls_node *node;
484 unsigned short hnum = ntohs(dport);
485 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
486 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
487 int score, badness, matches = 0, reuseport = 0;
488 u32 hash = 0;
489
490 rcu_read_lock();
491 if (hslot->count > 10) {
492 hash2 = udp4_portaddr_hash(net, daddr, hnum);
493 slot2 = hash2 & udptable->mask;
494 hslot2 = &udptable->hash2[slot2];
495 if (hslot->count < hslot2->count)
496 goto begin;
497
498 result = udp4_lib_lookup2(net, saddr, sport,
499 daddr, hnum, dif,
500 hslot2, slot2);
501 if (!result) {
502 hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
503 slot2 = hash2 & udptable->mask;
504 hslot2 = &udptable->hash2[slot2];
505 if (hslot->count < hslot2->count)
506 goto begin;
507
508 result = udp4_lib_lookup2(net, saddr, sport,
509 htonl(INADDR_ANY), hnum, dif,
510 hslot2, slot2);
511 }
512 rcu_read_unlock();
513 return result;
514 }
515 begin:
516 result = NULL;
517 badness = 0;
518 sk_nulls_for_each_rcu(sk, node, &hslot->head) {
519 score = compute_score(sk, net, saddr, hnum, sport,
520 daddr, dport, dif);
521 if (score > badness) {
522 result = sk;
523 badness = score;
524 reuseport = sk->sk_reuseport;
525 if (reuseport) {
526 hash = udp_ehashfn(net, daddr, hnum,
527 saddr, sport);
528 matches = 1;
529 }
530 } else if (score == badness && reuseport) {
531 matches++;
532 if (((u64)hash * matches) >> 32 == 0)
533 result = sk;
534 hash = next_pseudo_random32(hash);
535 }
536 }
537 /*
538 * if the nulls value we got at the end of this lookup is
539 * not the expected one, we must restart lookup.
540 * We probably met an item that was moved to another chain.
541 */
542 if (get_nulls_value(node) != slot)
543 goto begin;
544
545 if (result) {
546 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
547 result = NULL;
548 else if (unlikely(compute_score(result, net, saddr, hnum, sport,
549 daddr, dport, dif) < badness)) {
550 sock_put(result);
551 goto begin;
552 }
553 }
554 rcu_read_unlock();
555 return result;
556 }
557 EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
558
559 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
560 __be16 sport, __be16 dport,
561 struct udp_table *udptable)
562 {
563 const struct iphdr *iph = ip_hdr(skb);
564
565 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
566 iph->daddr, dport, inet_iif(skb),
567 udptable);
568 }
569
570 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
571 __be32 daddr, __be16 dport, int dif)
572 {
573 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
574 }
575 EXPORT_SYMBOL_GPL(udp4_lib_lookup);
576
577 static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk,
578 __be16 loc_port, __be32 loc_addr,
579 __be16 rmt_port, __be32 rmt_addr,
580 int dif, unsigned short hnum)
581 {
582 struct inet_sock *inet = inet_sk(sk);
583
584 if (!net_eq(sock_net(sk), net) ||
585 udp_sk(sk)->udp_port_hash != hnum ||
586 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
587 (inet->inet_dport != rmt_port && inet->inet_dport) ||
588 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) ||
589 ipv6_only_sock(sk) ||
590 (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
591 return false;
592 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif))
593 return false;
594 return true;
595 }
596
597 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
598 __be16 loc_port, __be32 loc_addr,
599 __be16 rmt_port, __be32 rmt_addr,
600 int dif)
601 {
602 struct hlist_nulls_node *node;
603 struct sock *s = sk;
604 unsigned short hnum = ntohs(loc_port);
605
606 sk_nulls_for_each_from(s, node) {
607 if (__udp_is_mcast_sock(net, s,
608 loc_port, loc_addr,
609 rmt_port, rmt_addr,
610 dif, hnum))
611 goto found;
612 }
613 s = NULL;
614 found:
615 return s;
616 }
617
618 /*
619 * This routine is called by the ICMP module when it gets some
620 * sort of error condition. If err < 0 then the socket should
621 * be closed and the error returned to the user. If err > 0
622 * it's just the icmp type << 8 | icmp code.
623 * Header points to the ip header of the error packet. We move
624 * on past this. Then (as it used to claim before adjustment)
625 * header points to the first 8 bytes of the udp header. We need
626 * to find the appropriate port.
627 */
628
629 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
630 {
631 struct inet_sock *inet;
632 const struct iphdr *iph = (const struct iphdr *)skb->data;
633 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
634 const int type = icmp_hdr(skb)->type;
635 const int code = icmp_hdr(skb)->code;
636 struct sock *sk;
637 int harderr;
638 int err;
639 struct net *net = dev_net(skb->dev);
640
641 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
642 iph->saddr, uh->source, skb->dev->ifindex, udptable);
643 if (sk == NULL) {
644 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
645 return; /* No socket for error */
646 }
647
648 err = 0;
649 harderr = 0;
650 inet = inet_sk(sk);
651
652 switch (type) {
653 default:
654 case ICMP_TIME_EXCEEDED:
655 err = EHOSTUNREACH;
656 break;
657 case ICMP_SOURCE_QUENCH:
658 goto out;
659 case ICMP_PARAMETERPROB:
660 err = EPROTO;
661 harderr = 1;
662 break;
663 case ICMP_DEST_UNREACH:
664 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
665 ipv4_sk_update_pmtu(skb, sk, info);
666 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
667 err = EMSGSIZE;
668 harderr = 1;
669 break;
670 }
671 goto out;
672 }
673 err = EHOSTUNREACH;
674 if (code <= NR_ICMP_UNREACH) {
675 harderr = icmp_err_convert[code].fatal;
676 err = icmp_err_convert[code].errno;
677 }
678 break;
679 case ICMP_REDIRECT:
680 ipv4_sk_redirect(skb, sk);
681 goto out;
682 }
683
684 /*
685 * RFC1122: OK. Passes ICMP errors back to application, as per
686 * 4.1.3.3.
687 */
688 if (!inet->recverr) {
689 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
690 goto out;
691 } else
692 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
693
694 sk->sk_err = err;
695 sk->sk_error_report(sk);
696 out:
697 sock_put(sk);
698 }
699
700 void udp_err(struct sk_buff *skb, u32 info)
701 {
702 __udp4_lib_err(skb, info, &udp_table);
703 }
704
705 /*
706 * Throw away all pending data and cancel the corking. Socket is locked.
707 */
708 void udp_flush_pending_frames(struct sock *sk)
709 {
710 struct udp_sock *up = udp_sk(sk);
711
712 if (up->pending) {
713 up->len = 0;
714 up->pending = 0;
715 ip_flush_pending_frames(sk);
716 }
717 }
718 EXPORT_SYMBOL(udp_flush_pending_frames);
719
720 /**
721 * udp4_hwcsum - handle outgoing HW checksumming
722 * @skb: sk_buff containing the filled-in UDP header
723 * (checksum field must be zeroed out)
724 * @src: source IP address
725 * @dst: destination IP address
726 */
727 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
728 {
729 struct udphdr *uh = udp_hdr(skb);
730 int offset = skb_transport_offset(skb);
731 int len = skb->len - offset;
732 int hlen = len;
733 __wsum csum = 0;
734
735 if (!skb_has_frag_list(skb)) {
736 /*
737 * Only one fragment on the socket.
738 */
739 skb->csum_start = skb_transport_header(skb) - skb->head;
740 skb->csum_offset = offsetof(struct udphdr, check);
741 uh->check = ~csum_tcpudp_magic(src, dst, len,
742 IPPROTO_UDP, 0);
743 } else {
744 struct sk_buff *frags;
745
746 /*
747 * HW-checksum won't work as there are two or more
748 * fragments on the socket so that all csums of sk_buffs
749 * should be together
750 */
751 skb_walk_frags(skb, frags) {
752 csum = csum_add(csum, frags->csum);
753 hlen -= frags->len;
754 }
755
756 csum = skb_checksum(skb, offset, hlen, csum);
757 skb->ip_summed = CHECKSUM_NONE;
758
759 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
760 if (uh->check == 0)
761 uh->check = CSUM_MANGLED_0;
762 }
763 }
764 EXPORT_SYMBOL_GPL(udp4_hwcsum);
765
766 /* Function to set UDP checksum for an IPv4 UDP packet. This is intended
767 * for the simple case like when setting the checksum for a UDP tunnel.
768 */
769 void udp_set_csum(bool nocheck, struct sk_buff *skb,
770 __be32 saddr, __be32 daddr, int len)
771 {
772 struct udphdr *uh = udp_hdr(skb);
773
774 if (nocheck)
775 uh->check = 0;
776 else if (skb_is_gso(skb))
777 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
778 else if (skb_dst(skb) && skb_dst(skb)->dev &&
779 (skb_dst(skb)->dev->features & NETIF_F_V4_CSUM)) {
780
781 BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL);
782
783 skb->ip_summed = CHECKSUM_PARTIAL;
784 skb->csum_start = skb_transport_header(skb) - skb->head;
785 skb->csum_offset = offsetof(struct udphdr, check);
786 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
787 } else {
788 __wsum csum;
789
790 BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL);
791
792 uh->check = 0;
793 csum = skb_checksum(skb, 0, len, 0);
794 uh->check = udp_v4_check(len, saddr, daddr, csum);
795 if (uh->check == 0)
796 uh->check = CSUM_MANGLED_0;
797
798 skb->ip_summed = CHECKSUM_UNNECESSARY;
799 }
800 }
801 EXPORT_SYMBOL(udp_set_csum);
802
803 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4)
804 {
805 struct sock *sk = skb->sk;
806 struct inet_sock *inet = inet_sk(sk);
807 struct udphdr *uh;
808 int err = 0;
809 int is_udplite = IS_UDPLITE(sk);
810 int offset = skb_transport_offset(skb);
811 int len = skb->len - offset;
812 __wsum csum = 0;
813
814 /*
815 * Create a UDP header
816 */
817 uh = udp_hdr(skb);
818 uh->source = inet->inet_sport;
819 uh->dest = fl4->fl4_dport;
820 uh->len = htons(len);
821 uh->check = 0;
822
823 if (is_udplite) /* UDP-Lite */
824 csum = udplite_csum(skb);
825
826 else if (sk->sk_no_check_tx) { /* UDP csum disabled */
827
828 skb->ip_summed = CHECKSUM_NONE;
829 goto send;
830
831 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
832
833 udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
834 goto send;
835
836 } else
837 csum = udp_csum(skb);
838
839 /* add protocol-dependent pseudo-header */
840 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
841 sk->sk_protocol, csum);
842 if (uh->check == 0)
843 uh->check = CSUM_MANGLED_0;
844
845 send:
846 err = ip_send_skb(sock_net(sk), skb);
847 if (err) {
848 if (err == -ENOBUFS && !inet->recverr) {
849 UDP_INC_STATS_USER(sock_net(sk),
850 UDP_MIB_SNDBUFERRORS, is_udplite);
851 err = 0;
852 }
853 } else
854 UDP_INC_STATS_USER(sock_net(sk),
855 UDP_MIB_OUTDATAGRAMS, is_udplite);
856 return err;
857 }
858
859 /*
860 * Push out all pending data as one UDP datagram. Socket is locked.
861 */
862 int udp_push_pending_frames(struct sock *sk)
863 {
864 struct udp_sock *up = udp_sk(sk);
865 struct inet_sock *inet = inet_sk(sk);
866 struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
867 struct sk_buff *skb;
868 int err = 0;
869
870 skb = ip_finish_skb(sk, fl4);
871 if (!skb)
872 goto out;
873
874 err = udp_send_skb(skb, fl4);
875
876 out:
877 up->len = 0;
878 up->pending = 0;
879 return err;
880 }
881 EXPORT_SYMBOL(udp_push_pending_frames);
882
883 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
884 size_t len)
885 {
886 struct inet_sock *inet = inet_sk(sk);
887 struct udp_sock *up = udp_sk(sk);
888 struct flowi4 fl4_stack;
889 struct flowi4 *fl4;
890 int ulen = len;
891 struct ipcm_cookie ipc;
892 struct rtable *rt = NULL;
893 int free = 0;
894 int connected = 0;
895 __be32 daddr, faddr, saddr;
896 __be16 dport;
897 u8 tos;
898 int err, is_udplite = IS_UDPLITE(sk);
899 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
900 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
901 struct sk_buff *skb;
902 struct ip_options_data opt_copy;
903
904 if (len > 0xFFFF)
905 return -EMSGSIZE;
906
907 /*
908 * Check the flags.
909 */
910
911 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
912 return -EOPNOTSUPP;
913
914 ipc.opt = NULL;
915 ipc.tx_flags = 0;
916 ipc.ttl = 0;
917 ipc.tos = -1;
918
919 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
920
921 fl4 = &inet->cork.fl.u.ip4;
922 if (up->pending) {
923 /*
924 * There are pending frames.
925 * The socket lock must be held while it's corked.
926 */
927 lock_sock(sk);
928 if (likely(up->pending)) {
929 if (unlikely(up->pending != AF_INET)) {
930 release_sock(sk);
931 return -EINVAL;
932 }
933 goto do_append_data;
934 }
935 release_sock(sk);
936 }
937 ulen += sizeof(struct udphdr);
938
939 /*
940 * Get and verify the address.
941 */
942 if (msg->msg_name) {
943 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
944 if (msg->msg_namelen < sizeof(*usin))
945 return -EINVAL;
946 if (usin->sin_family != AF_INET) {
947 if (usin->sin_family != AF_UNSPEC)
948 return -EAFNOSUPPORT;
949 }
950
951 daddr = usin->sin_addr.s_addr;
952 dport = usin->sin_port;
953 if (dport == 0)
954 return -EINVAL;
955 } else {
956 if (sk->sk_state != TCP_ESTABLISHED)
957 return -EDESTADDRREQ;
958 daddr = inet->inet_daddr;
959 dport = inet->inet_dport;
960 /* Open fast path for connected socket.
961 Route will not be used, if at least one option is set.
962 */
963 connected = 1;
964 }
965 ipc.addr = inet->inet_saddr;
966
967 ipc.oif = sk->sk_bound_dev_if;
968
969 sock_tx_timestamp(sk, &ipc.tx_flags);
970
971 if (msg->msg_controllen) {
972 err = ip_cmsg_send(sock_net(sk), msg, &ipc,
973 sk->sk_family == AF_INET6);
974 if (err)
975 return err;
976 if (ipc.opt)
977 free = 1;
978 connected = 0;
979 }
980 if (!ipc.opt) {
981 struct ip_options_rcu *inet_opt;
982
983 rcu_read_lock();
984 inet_opt = rcu_dereference(inet->inet_opt);
985 if (inet_opt) {
986 memcpy(&opt_copy, inet_opt,
987 sizeof(*inet_opt) + inet_opt->opt.optlen);
988 ipc.opt = &opt_copy.opt;
989 }
990 rcu_read_unlock();
991 }
992
993 saddr = ipc.addr;
994 ipc.addr = faddr = daddr;
995
996 if (ipc.opt && ipc.opt->opt.srr) {
997 if (!daddr)
998 return -EINVAL;
999 faddr = ipc.opt->opt.faddr;
1000 connected = 0;
1001 }
1002 tos = get_rttos(&ipc, inet);
1003 if (sock_flag(sk, SOCK_LOCALROUTE) ||
1004 (msg->msg_flags & MSG_DONTROUTE) ||
1005 (ipc.opt && ipc.opt->opt.is_strictroute)) {
1006 tos |= RTO_ONLINK;
1007 connected = 0;
1008 }
1009
1010 if (ipv4_is_multicast(daddr)) {
1011 if (!ipc.oif)
1012 ipc.oif = inet->mc_index;
1013 if (!saddr)
1014 saddr = inet->mc_addr;
1015 connected = 0;
1016 } else if (!ipc.oif)
1017 ipc.oif = inet->uc_index;
1018
1019 if (connected)
1020 rt = (struct rtable *)sk_dst_check(sk, 0);
1021
1022 if (rt == NULL) {
1023 struct net *net = sock_net(sk);
1024
1025 fl4 = &fl4_stack;
1026 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
1027 RT_SCOPE_UNIVERSE, sk->sk_protocol,
1028 inet_sk_flowi_flags(sk),
1029 faddr, saddr, dport, inet->inet_sport);
1030
1031 security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
1032 rt = ip_route_output_flow(net, fl4, sk);
1033 if (IS_ERR(rt)) {
1034 err = PTR_ERR(rt);
1035 rt = NULL;
1036 if (err == -ENETUNREACH)
1037 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
1038 goto out;
1039 }
1040
1041 err = -EACCES;
1042 if ((rt->rt_flags & RTCF_BROADCAST) &&
1043 !sock_flag(sk, SOCK_BROADCAST))
1044 goto out;
1045 if (connected)
1046 sk_dst_set(sk, dst_clone(&rt->dst));
1047 }
1048
1049 if (msg->msg_flags&MSG_CONFIRM)
1050 goto do_confirm;
1051 back_from_confirm:
1052
1053 saddr = fl4->saddr;
1054 if (!ipc.addr)
1055 daddr = ipc.addr = fl4->daddr;
1056
1057 /* Lockless fast path for the non-corking case. */
1058 if (!corkreq) {
1059 skb = ip_make_skb(sk, fl4, getfrag, msg->msg_iov, ulen,
1060 sizeof(struct udphdr), &ipc, &rt,
1061 msg->msg_flags);
1062 err = PTR_ERR(skb);
1063 if (!IS_ERR_OR_NULL(skb))
1064 err = udp_send_skb(skb, fl4);
1065 goto out;
1066 }
1067
1068 lock_sock(sk);
1069 if (unlikely(up->pending)) {
1070 /* The socket is already corked while preparing it. */
1071 /* ... which is an evident application bug. --ANK */
1072 release_sock(sk);
1073
1074 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("cork app bug 2\n"));
1075 err = -EINVAL;
1076 goto out;
1077 }
1078 /*
1079 * Now cork the socket to pend data.
1080 */
1081 fl4 = &inet->cork.fl.u.ip4;
1082 fl4->daddr = daddr;
1083 fl4->saddr = saddr;
1084 fl4->fl4_dport = dport;
1085 fl4->fl4_sport = inet->inet_sport;
1086 up->pending = AF_INET;
1087
1088 do_append_data:
1089 up->len += ulen;
1090 err = ip_append_data(sk, fl4, getfrag, msg->msg_iov, ulen,
1091 sizeof(struct udphdr), &ipc, &rt,
1092 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1093 if (err)
1094 udp_flush_pending_frames(sk);
1095 else if (!corkreq)
1096 err = udp_push_pending_frames(sk);
1097 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1098 up->pending = 0;
1099 release_sock(sk);
1100
1101 out:
1102 ip_rt_put(rt);
1103 if (free)
1104 kfree(ipc.opt);
1105 if (!err)
1106 return len;
1107 /*
1108 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1109 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1110 * we don't have a good statistic (IpOutDiscards but it can be too many
1111 * things). We could add another new stat but at least for now that
1112 * seems like overkill.
1113 */
1114 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1115 UDP_INC_STATS_USER(sock_net(sk),
1116 UDP_MIB_SNDBUFERRORS, is_udplite);
1117 }
1118 return err;
1119
1120 do_confirm:
1121 dst_confirm(&rt->dst);
1122 if (!(msg->msg_flags&MSG_PROBE) || len)
1123 goto back_from_confirm;
1124 err = 0;
1125 goto out;
1126 }
1127 EXPORT_SYMBOL(udp_sendmsg);
1128
1129 int udp_sendpage(struct sock *sk, struct page *page, int offset,
1130 size_t size, int flags)
1131 {
1132 struct inet_sock *inet = inet_sk(sk);
1133 struct udp_sock *up = udp_sk(sk);
1134 int ret;
1135
1136 if (flags & MSG_SENDPAGE_NOTLAST)
1137 flags |= MSG_MORE;
1138
1139 if (!up->pending) {
1140 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
1141
1142 /* Call udp_sendmsg to specify destination address which
1143 * sendpage interface can't pass.
1144 * This will succeed only when the socket is connected.
1145 */
1146 ret = udp_sendmsg(NULL, sk, &msg, 0);
1147 if (ret < 0)
1148 return ret;
1149 }
1150
1151 lock_sock(sk);
1152
1153 if (unlikely(!up->pending)) {
1154 release_sock(sk);
1155
1156 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("udp cork app bug 3\n"));
1157 return -EINVAL;
1158 }
1159
1160 ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
1161 page, offset, size, flags);
1162 if (ret == -EOPNOTSUPP) {
1163 release_sock(sk);
1164 return sock_no_sendpage(sk->sk_socket, page, offset,
1165 size, flags);
1166 }
1167 if (ret < 0) {
1168 udp_flush_pending_frames(sk);
1169 goto out;
1170 }
1171
1172 up->len += size;
1173 if (!(up->corkflag || (flags&MSG_MORE)))
1174 ret = udp_push_pending_frames(sk);
1175 if (!ret)
1176 ret = size;
1177 out:
1178 release_sock(sk);
1179 return ret;
1180 }
1181
1182
1183 /**
1184 * first_packet_length - return length of first packet in receive queue
1185 * @sk: socket
1186 *
1187 * Drops all bad checksum frames, until a valid one is found.
1188 * Returns the length of found skb, or 0 if none is found.
1189 */
1190 static unsigned int first_packet_length(struct sock *sk)
1191 {
1192 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue;
1193 struct sk_buff *skb;
1194 unsigned int res;
1195
1196 __skb_queue_head_init(&list_kill);
1197
1198 spin_lock_bh(&rcvq->lock);
1199 while ((skb = skb_peek(rcvq)) != NULL &&
1200 udp_lib_checksum_complete(skb)) {
1201 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS,
1202 IS_UDPLITE(sk));
1203 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
1204 IS_UDPLITE(sk));
1205 atomic_inc(&sk->sk_drops);
1206 __skb_unlink(skb, rcvq);
1207 __skb_queue_tail(&list_kill, skb);
1208 }
1209 res = skb ? skb->len : 0;
1210 spin_unlock_bh(&rcvq->lock);
1211
1212 if (!skb_queue_empty(&list_kill)) {
1213 bool slow = lock_sock_fast(sk);
1214
1215 __skb_queue_purge(&list_kill);
1216 sk_mem_reclaim_partial(sk);
1217 unlock_sock_fast(sk, slow);
1218 }
1219 return res;
1220 }
1221
1222 /*
1223 * IOCTL requests applicable to the UDP protocol
1224 */
1225
1226 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
1227 {
1228 switch (cmd) {
1229 case SIOCOUTQ:
1230 {
1231 int amount = sk_wmem_alloc_get(sk);
1232
1233 return put_user(amount, (int __user *)arg);
1234 }
1235
1236 case SIOCINQ:
1237 {
1238 unsigned int amount = first_packet_length(sk);
1239
1240 if (amount)
1241 /*
1242 * We will only return the amount
1243 * of this packet since that is all
1244 * that will be read.
1245 */
1246 amount -= sizeof(struct udphdr);
1247
1248 return put_user(amount, (int __user *)arg);
1249 }
1250
1251 default:
1252 return -ENOIOCTLCMD;
1253 }
1254
1255 return 0;
1256 }
1257 EXPORT_SYMBOL(udp_ioctl);
1258
1259 /*
1260 * This should be easy, if there is something there we
1261 * return it, otherwise we block.
1262 */
1263
1264 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1265 size_t len, int noblock, int flags, int *addr_len)
1266 {
1267 struct inet_sock *inet = inet_sk(sk);
1268 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
1269 struct sk_buff *skb;
1270 unsigned int ulen, copied;
1271 int peeked, off = 0;
1272 int err;
1273 int is_udplite = IS_UDPLITE(sk);
1274 bool slow;
1275
1276 if (flags & MSG_ERRQUEUE)
1277 return ip_recv_error(sk, msg, len, addr_len);
1278
1279 try_again:
1280 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
1281 &peeked, &off, &err);
1282 if (!skb)
1283 goto out;
1284
1285 ulen = skb->len - sizeof(struct udphdr);
1286 copied = len;
1287 if (copied > ulen)
1288 copied = ulen;
1289 else if (copied < ulen)
1290 msg->msg_flags |= MSG_TRUNC;
1291
1292 /*
1293 * If checksum is needed at all, try to do it while copying the
1294 * data. If the data is truncated, or if we only want a partial
1295 * coverage checksum (UDP-Lite), do it before the copy.
1296 */
1297
1298 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
1299 if (udp_lib_checksum_complete(skb))
1300 goto csum_copy_err;
1301 }
1302
1303 if (skb_csum_unnecessary(skb))
1304 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
1305 msg->msg_iov, copied);
1306 else {
1307 err = skb_copy_and_csum_datagram_iovec(skb,
1308 sizeof(struct udphdr),
1309 msg->msg_iov);
1310
1311 if (err == -EINVAL)
1312 goto csum_copy_err;
1313 }
1314
1315 if (unlikely(err)) {
1316 trace_kfree_skb(skb, udp_recvmsg);
1317 if (!peeked) {
1318 atomic_inc(&sk->sk_drops);
1319 UDP_INC_STATS_USER(sock_net(sk),
1320 UDP_MIB_INERRORS, is_udplite);
1321 }
1322 goto out_free;
1323 }
1324
1325 if (!peeked)
1326 UDP_INC_STATS_USER(sock_net(sk),
1327 UDP_MIB_INDATAGRAMS, is_udplite);
1328
1329 sock_recv_ts_and_drops(msg, sk, skb);
1330
1331 /* Copy the address. */
1332 if (sin) {
1333 sin->sin_family = AF_INET;
1334 sin->sin_port = udp_hdr(skb)->source;
1335 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1336 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1337 *addr_len = sizeof(*sin);
1338 }
1339 if (inet->cmsg_flags)
1340 ip_cmsg_recv(msg, skb);
1341
1342 err = copied;
1343 if (flags & MSG_TRUNC)
1344 err = ulen;
1345
1346 out_free:
1347 skb_free_datagram_locked(sk, skb);
1348 out:
1349 return err;
1350
1351 csum_copy_err:
1352 slow = lock_sock_fast(sk);
1353 if (!skb_kill_datagram(sk, skb, flags)) {
1354 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1355 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1356 }
1357 unlock_sock_fast(sk, slow);
1358
1359 if (noblock)
1360 return -EAGAIN;
1361
1362 /* starting over for a new packet */
1363 msg->msg_flags &= ~MSG_TRUNC;
1364 goto try_again;
1365 }
1366
1367
1368 int udp_disconnect(struct sock *sk, int flags)
1369 {
1370 struct inet_sock *inet = inet_sk(sk);
1371 /*
1372 * 1003.1g - break association.
1373 */
1374
1375 sk->sk_state = TCP_CLOSE;
1376 inet->inet_daddr = 0;
1377 inet->inet_dport = 0;
1378 sock_rps_reset_rxhash(sk);
1379 sk->sk_bound_dev_if = 0;
1380 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1381 inet_reset_saddr(sk);
1382
1383 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1384 sk->sk_prot->unhash(sk);
1385 inet->inet_sport = 0;
1386 }
1387 sk_dst_reset(sk);
1388 return 0;
1389 }
1390 EXPORT_SYMBOL(udp_disconnect);
1391
1392 void udp_lib_unhash(struct sock *sk)
1393 {
1394 if (sk_hashed(sk)) {
1395 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1396 struct udp_hslot *hslot, *hslot2;
1397
1398 hslot = udp_hashslot(udptable, sock_net(sk),
1399 udp_sk(sk)->udp_port_hash);
1400 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1401
1402 spin_lock_bh(&hslot->lock);
1403 if (sk_nulls_del_node_init_rcu(sk)) {
1404 hslot->count--;
1405 inet_sk(sk)->inet_num = 0;
1406 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1407
1408 spin_lock(&hslot2->lock);
1409 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1410 hslot2->count--;
1411 spin_unlock(&hslot2->lock);
1412 }
1413 spin_unlock_bh(&hslot->lock);
1414 }
1415 }
1416 EXPORT_SYMBOL(udp_lib_unhash);
1417
1418 /*
1419 * inet_rcv_saddr was changed, we must rehash secondary hash
1420 */
1421 void udp_lib_rehash(struct sock *sk, u16 newhash)
1422 {
1423 if (sk_hashed(sk)) {
1424 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1425 struct udp_hslot *hslot, *hslot2, *nhslot2;
1426
1427 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1428 nhslot2 = udp_hashslot2(udptable, newhash);
1429 udp_sk(sk)->udp_portaddr_hash = newhash;
1430 if (hslot2 != nhslot2) {
1431 hslot = udp_hashslot(udptable, sock_net(sk),
1432 udp_sk(sk)->udp_port_hash);
1433 /* we must lock primary chain too */
1434 spin_lock_bh(&hslot->lock);
1435
1436 spin_lock(&hslot2->lock);
1437 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1438 hslot2->count--;
1439 spin_unlock(&hslot2->lock);
1440
1441 spin_lock(&nhslot2->lock);
1442 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
1443 &nhslot2->head);
1444 nhslot2->count++;
1445 spin_unlock(&nhslot2->lock);
1446
1447 spin_unlock_bh(&hslot->lock);
1448 }
1449 }
1450 }
1451 EXPORT_SYMBOL(udp_lib_rehash);
1452
1453 static void udp_v4_rehash(struct sock *sk)
1454 {
1455 u16 new_hash = udp4_portaddr_hash(sock_net(sk),
1456 inet_sk(sk)->inet_rcv_saddr,
1457 inet_sk(sk)->inet_num);
1458 udp_lib_rehash(sk, new_hash);
1459 }
1460
1461 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1462 {
1463 int rc;
1464
1465 if (inet_sk(sk)->inet_daddr) {
1466 sock_rps_save_rxhash(sk, skb);
1467 sk_mark_napi_id(sk, skb);
1468 }
1469
1470 rc = sock_queue_rcv_skb(sk, skb);
1471 if (rc < 0) {
1472 int is_udplite = IS_UDPLITE(sk);
1473
1474 /* Note that an ENOMEM error is charged twice */
1475 if (rc == -ENOMEM)
1476 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1477 is_udplite);
1478 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1479 kfree_skb(skb);
1480 trace_udp_fail_queue_rcv_skb(rc, sk);
1481 return -1;
1482 }
1483
1484 return 0;
1485
1486 }
1487
1488 static struct static_key udp_encap_needed __read_mostly;
1489 void udp_encap_enable(void)
1490 {
1491 if (!static_key_enabled(&udp_encap_needed))
1492 static_key_slow_inc(&udp_encap_needed);
1493 }
1494 EXPORT_SYMBOL(udp_encap_enable);
1495
1496 /* returns:
1497 * -1: error
1498 * 0: success
1499 * >0: "udp encap" protocol resubmission
1500 *
1501 * Note that in the success and error cases, the skb is assumed to
1502 * have either been requeued or freed.
1503 */
1504 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1505 {
1506 struct udp_sock *up = udp_sk(sk);
1507 int rc;
1508 int is_udplite = IS_UDPLITE(sk);
1509
1510 /*
1511 * Charge it to the socket, dropping if the queue is full.
1512 */
1513 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1514 goto drop;
1515 nf_reset(skb);
1516
1517 if (static_key_false(&udp_encap_needed) && up->encap_type) {
1518 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
1519
1520 /*
1521 * This is an encapsulation socket so pass the skb to
1522 * the socket's udp_encap_rcv() hook. Otherwise, just
1523 * fall through and pass this up the UDP socket.
1524 * up->encap_rcv() returns the following value:
1525 * =0 if skb was successfully passed to the encap
1526 * handler or was discarded by it.
1527 * >0 if skb should be passed on to UDP.
1528 * <0 if skb should be resubmitted as proto -N
1529 */
1530
1531 /* if we're overly short, let UDP handle it */
1532 encap_rcv = ACCESS_ONCE(up->encap_rcv);
1533 if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
1534 int ret;
1535
1536 /* Verify checksum before giving to encap */
1537 if (udp_lib_checksum_complete(skb))
1538 goto csum_error;
1539
1540 ret = encap_rcv(sk, skb);
1541 if (ret <= 0) {
1542 UDP_INC_STATS_BH(sock_net(sk),
1543 UDP_MIB_INDATAGRAMS,
1544 is_udplite);
1545 return -ret;
1546 }
1547 }
1548
1549 /* FALLTHROUGH -- it's a UDP Packet */
1550 }
1551
1552 /*
1553 * UDP-Lite specific tests, ignored on UDP sockets
1554 */
1555 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1556
1557 /*
1558 * MIB statistics other than incrementing the error count are
1559 * disabled for the following two types of errors: these depend
1560 * on the application settings, not on the functioning of the
1561 * protocol stack as such.
1562 *
1563 * RFC 3828 here recommends (sec 3.3): "There should also be a
1564 * way ... to ... at least let the receiving application block
1565 * delivery of packets with coverage values less than a value
1566 * provided by the application."
1567 */
1568 if (up->pcrlen == 0) { /* full coverage was set */
1569 LIMIT_NETDEBUG(KERN_WARNING "UDPLite: partial coverage %d while full coverage %d requested\n",
1570 UDP_SKB_CB(skb)->cscov, skb->len);
1571 goto drop;
1572 }
1573 /* The next case involves violating the min. coverage requested
1574 * by the receiver. This is subtle: if receiver wants x and x is
1575 * greater than the buffersize/MTU then receiver will complain
1576 * that it wants x while sender emits packets of smaller size y.
1577 * Therefore the above ...()->partial_cov statement is essential.
1578 */
1579 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1580 LIMIT_NETDEBUG(KERN_WARNING "UDPLite: coverage %d too small, need min %d\n",
1581 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1582 goto drop;
1583 }
1584 }
1585
1586 if (rcu_access_pointer(sk->sk_filter) &&
1587 udp_lib_checksum_complete(skb))
1588 goto csum_error;
1589
1590
1591 if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf))
1592 goto drop;
1593
1594 rc = 0;
1595
1596 ipv4_pktinfo_prepare(sk, skb);
1597 bh_lock_sock(sk);
1598 if (!sock_owned_by_user(sk))
1599 rc = __udp_queue_rcv_skb(sk, skb);
1600 else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
1601 bh_unlock_sock(sk);
1602 goto drop;
1603 }
1604 bh_unlock_sock(sk);
1605
1606 return rc;
1607
1608 csum_error:
1609 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1610 drop:
1611 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1612 atomic_inc(&sk->sk_drops);
1613 kfree_skb(skb);
1614 return -1;
1615 }
1616
1617
1618 static void flush_stack(struct sock **stack, unsigned int count,
1619 struct sk_buff *skb, unsigned int final)
1620 {
1621 unsigned int i;
1622 struct sk_buff *skb1 = NULL;
1623 struct sock *sk;
1624
1625 for (i = 0; i < count; i++) {
1626 sk = stack[i];
1627 if (likely(skb1 == NULL))
1628 skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
1629
1630 if (!skb1) {
1631 atomic_inc(&sk->sk_drops);
1632 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1633 IS_UDPLITE(sk));
1634 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
1635 IS_UDPLITE(sk));
1636 }
1637
1638 if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0)
1639 skb1 = NULL;
1640 }
1641 if (unlikely(skb1))
1642 kfree_skb(skb1);
1643 }
1644
1645 /* For TCP sockets, sk_rx_dst is protected by socket lock
1646 * For UDP, we use xchg() to guard against concurrent changes.
1647 */
1648 static void udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
1649 {
1650 struct dst_entry *old;
1651
1652 dst_hold(dst);
1653 old = xchg(&sk->sk_rx_dst, dst);
1654 dst_release(old);
1655 }
1656
1657 /*
1658 * Multicasts and broadcasts go to each listener.
1659 *
1660 * Note: called only from the BH handler context.
1661 */
1662 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1663 struct udphdr *uh,
1664 __be32 saddr, __be32 daddr,
1665 struct udp_table *udptable)
1666 {
1667 struct sock *sk, *stack[256 / sizeof(struct sock *)];
1668 struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
1669 int dif;
1670 unsigned int i, count = 0;
1671
1672 spin_lock(&hslot->lock);
1673 sk = sk_nulls_head(&hslot->head);
1674 dif = skb->dev->ifindex;
1675 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1676 while (sk) {
1677 stack[count++] = sk;
1678 sk = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest,
1679 daddr, uh->source, saddr, dif);
1680 if (unlikely(count == ARRAY_SIZE(stack))) {
1681 if (!sk)
1682 break;
1683 flush_stack(stack, count, skb, ~0);
1684 count = 0;
1685 }
1686 }
1687 /*
1688 * before releasing chain lock, we must take a reference on sockets
1689 */
1690 for (i = 0; i < count; i++)
1691 sock_hold(stack[i]);
1692
1693 spin_unlock(&hslot->lock);
1694
1695 /*
1696 * do the slow work with no lock held
1697 */
1698 if (count) {
1699 flush_stack(stack, count, skb, count - 1);
1700
1701 for (i = 0; i < count; i++)
1702 sock_put(stack[i]);
1703 } else {
1704 kfree_skb(skb);
1705 }
1706 return 0;
1707 }
1708
1709 /* Initialize UDP checksum. If exited with zero value (success),
1710 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1711 * Otherwise, csum completion requires chacksumming packet body,
1712 * including udp header and folding it to skb->csum.
1713 */
1714 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1715 int proto)
1716 {
1717 int err;
1718
1719 UDP_SKB_CB(skb)->partial_cov = 0;
1720 UDP_SKB_CB(skb)->cscov = skb->len;
1721
1722 if (proto == IPPROTO_UDPLITE) {
1723 err = udplite_checksum_init(skb, uh);
1724 if (err)
1725 return err;
1726 }
1727
1728 return skb_checksum_init_zero_check(skb, proto, uh->check,
1729 inet_compute_pseudo);
1730 }
1731
1732 /*
1733 * All we need to do is get the socket, and then do a checksum.
1734 */
1735
1736 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1737 int proto)
1738 {
1739 struct sock *sk;
1740 struct udphdr *uh;
1741 unsigned short ulen;
1742 struct rtable *rt = skb_rtable(skb);
1743 __be32 saddr, daddr;
1744 struct net *net = dev_net(skb->dev);
1745
1746 /*
1747 * Validate the packet.
1748 */
1749 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1750 goto drop; /* No space for header. */
1751
1752 uh = udp_hdr(skb);
1753 ulen = ntohs(uh->len);
1754 saddr = ip_hdr(skb)->saddr;
1755 daddr = ip_hdr(skb)->daddr;
1756
1757 if (ulen > skb->len)
1758 goto short_packet;
1759
1760 if (proto == IPPROTO_UDP) {
1761 /* UDP validates ulen. */
1762 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
1763 goto short_packet;
1764 uh = udp_hdr(skb);
1765 }
1766
1767 if (udp4_csum_init(skb, uh, proto))
1768 goto csum_error;
1769
1770 sk = skb_steal_sock(skb);
1771 if (sk) {
1772 struct dst_entry *dst = skb_dst(skb);
1773 int ret;
1774
1775 if (unlikely(sk->sk_rx_dst != dst))
1776 udp_sk_rx_dst_set(sk, dst);
1777
1778 ret = udp_queue_rcv_skb(sk, skb);
1779 sock_put(sk);
1780 /* a return value > 0 means to resubmit the input, but
1781 * it wants the return to be -protocol, or 0
1782 */
1783 if (ret > 0)
1784 return -ret;
1785 return 0;
1786 } else {
1787 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1788 return __udp4_lib_mcast_deliver(net, skb, uh,
1789 saddr, daddr, udptable);
1790
1791 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1792 }
1793
1794 if (sk != NULL) {
1795 int ret;
1796
1797 ret = udp_queue_rcv_skb(sk, skb);
1798 sock_put(sk);
1799
1800 /* a return value > 0 means to resubmit the input, but
1801 * it wants the return to be -protocol, or 0
1802 */
1803 if (ret > 0)
1804 return -ret;
1805 return 0;
1806 }
1807
1808 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1809 goto drop;
1810 nf_reset(skb);
1811
1812 /* No socket. Drop packet silently, if checksum is wrong */
1813 if (udp_lib_checksum_complete(skb))
1814 goto csum_error;
1815
1816 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1817 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1818
1819 /*
1820 * Hmm. We got an UDP packet to a port to which we
1821 * don't wanna listen. Ignore it.
1822 */
1823 kfree_skb(skb);
1824 return 0;
1825
1826 short_packet:
1827 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1828 proto == IPPROTO_UDPLITE ? "Lite" : "",
1829 &saddr, ntohs(uh->source),
1830 ulen, skb->len,
1831 &daddr, ntohs(uh->dest));
1832 goto drop;
1833
1834 csum_error:
1835 /*
1836 * RFC1122: OK. Discards the bad packet silently (as far as
1837 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1838 */
1839 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1840 proto == IPPROTO_UDPLITE ? "Lite" : "",
1841 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
1842 ulen);
1843 UDP_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
1844 drop:
1845 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1846 kfree_skb(skb);
1847 return 0;
1848 }
1849
1850 /* We can only early demux multicast if there is a single matching socket.
1851 * If more than one socket found returns NULL
1852 */
1853 static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
1854 __be16 loc_port, __be32 loc_addr,
1855 __be16 rmt_port, __be32 rmt_addr,
1856 int dif)
1857 {
1858 struct sock *sk, *result;
1859 struct hlist_nulls_node *node;
1860 unsigned short hnum = ntohs(loc_port);
1861 unsigned int count, slot = udp_hashfn(net, hnum, udp_table.mask);
1862 struct udp_hslot *hslot = &udp_table.hash[slot];
1863
1864 /* Do not bother scanning a too big list */
1865 if (hslot->count > 10)
1866 return NULL;
1867
1868 rcu_read_lock();
1869 begin:
1870 count = 0;
1871 result = NULL;
1872 sk_nulls_for_each_rcu(sk, node, &hslot->head) {
1873 if (__udp_is_mcast_sock(net, sk,
1874 loc_port, loc_addr,
1875 rmt_port, rmt_addr,
1876 dif, hnum)) {
1877 result = sk;
1878 ++count;
1879 }
1880 }
1881 /*
1882 * if the nulls value we got at the end of this lookup is
1883 * not the expected one, we must restart lookup.
1884 * We probably met an item that was moved to another chain.
1885 */
1886 if (get_nulls_value(node) != slot)
1887 goto begin;
1888
1889 if (result) {
1890 if (count != 1 ||
1891 unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
1892 result = NULL;
1893 else if (unlikely(!__udp_is_mcast_sock(net, result,
1894 loc_port, loc_addr,
1895 rmt_port, rmt_addr,
1896 dif, hnum))) {
1897 sock_put(result);
1898 result = NULL;
1899 }
1900 }
1901 rcu_read_unlock();
1902 return result;
1903 }
1904
1905 /* For unicast we should only early demux connected sockets or we can
1906 * break forwarding setups. The chains here can be long so only check
1907 * if the first socket is an exact match and if not move on.
1908 */
1909 static struct sock *__udp4_lib_demux_lookup(struct net *net,
1910 __be16 loc_port, __be32 loc_addr,
1911 __be16 rmt_port, __be32 rmt_addr,
1912 int dif)
1913 {
1914 struct sock *sk, *result;
1915 struct hlist_nulls_node *node;
1916 unsigned short hnum = ntohs(loc_port);
1917 unsigned int hash2 = udp4_portaddr_hash(net, loc_addr, hnum);
1918 unsigned int slot2 = hash2 & udp_table.mask;
1919 struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
1920 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
1921 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
1922
1923 rcu_read_lock();
1924 result = NULL;
1925 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
1926 if (INET_MATCH(sk, net, acookie,
1927 rmt_addr, loc_addr, ports, dif))
1928 result = sk;
1929 /* Only check first socket in chain */
1930 break;
1931 }
1932
1933 if (result) {
1934 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
1935 result = NULL;
1936 else if (unlikely(!INET_MATCH(sk, net, acookie,
1937 rmt_addr, loc_addr,
1938 ports, dif))) {
1939 sock_put(result);
1940 result = NULL;
1941 }
1942 }
1943 rcu_read_unlock();
1944 return result;
1945 }
1946
1947 void udp_v4_early_demux(struct sk_buff *skb)
1948 {
1949 struct net *net = dev_net(skb->dev);
1950 const struct iphdr *iph;
1951 const struct udphdr *uh;
1952 struct sock *sk;
1953 struct dst_entry *dst;
1954 int dif = skb->dev->ifindex;
1955
1956 /* validate the packet */
1957 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
1958 return;
1959
1960 iph = ip_hdr(skb);
1961 uh = udp_hdr(skb);
1962
1963 if (skb->pkt_type == PACKET_BROADCAST ||
1964 skb->pkt_type == PACKET_MULTICAST)
1965 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
1966 uh->source, iph->saddr, dif);
1967 else if (skb->pkt_type == PACKET_HOST)
1968 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
1969 uh->source, iph->saddr, dif);
1970 else
1971 return;
1972
1973 if (!sk)
1974 return;
1975
1976 skb->sk = sk;
1977 skb->destructor = sock_edemux;
1978 dst = sk->sk_rx_dst;
1979
1980 if (dst)
1981 dst = dst_check(dst, 0);
1982 if (dst)
1983 skb_dst_set_noref(skb, dst);
1984 }
1985
1986 int udp_rcv(struct sk_buff *skb)
1987 {
1988 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1989 }
1990
1991 void udp_destroy_sock(struct sock *sk)
1992 {
1993 struct udp_sock *up = udp_sk(sk);
1994 bool slow = lock_sock_fast(sk);
1995 udp_flush_pending_frames(sk);
1996 unlock_sock_fast(sk, slow);
1997 if (static_key_false(&udp_encap_needed) && up->encap_type) {
1998 void (*encap_destroy)(struct sock *sk);
1999 encap_destroy = ACCESS_ONCE(up->encap_destroy);
2000 if (encap_destroy)
2001 encap_destroy(sk);
2002 }
2003 }
2004
2005 /*
2006 * Socket option code for UDP
2007 */
2008 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
2009 char __user *optval, unsigned int optlen,
2010 int (*push_pending_frames)(struct sock *))
2011 {
2012 struct udp_sock *up = udp_sk(sk);
2013 int val, valbool;
2014 int err = 0;
2015 int is_udplite = IS_UDPLITE(sk);
2016
2017 if (optlen < sizeof(int))
2018 return -EINVAL;
2019
2020 if (get_user(val, (int __user *)optval))
2021 return -EFAULT;
2022
2023 valbool = val ? 1 : 0;
2024
2025 switch (optname) {
2026 case UDP_CORK:
2027 if (val != 0) {
2028 up->corkflag = 1;
2029 } else {
2030 up->corkflag = 0;
2031 lock_sock(sk);
2032 (*push_pending_frames)(sk);
2033 release_sock(sk);
2034 }
2035 break;
2036
2037 case UDP_ENCAP:
2038 switch (val) {
2039 case 0:
2040 case UDP_ENCAP_ESPINUDP:
2041 case UDP_ENCAP_ESPINUDP_NON_IKE:
2042 up->encap_rcv = xfrm4_udp_encap_rcv;
2043 /* FALLTHROUGH */
2044 case UDP_ENCAP_L2TPINUDP:
2045 up->encap_type = val;
2046 udp_encap_enable();
2047 break;
2048 default:
2049 err = -ENOPROTOOPT;
2050 break;
2051 }
2052 break;
2053
2054 case UDP_NO_CHECK6_TX:
2055 up->no_check6_tx = valbool;
2056 break;
2057
2058 case UDP_NO_CHECK6_RX:
2059 up->no_check6_rx = valbool;
2060 break;
2061
2062 /*
2063 * UDP-Lite's partial checksum coverage (RFC 3828).
2064 */
2065 /* The sender sets actual checksum coverage length via this option.
2066 * The case coverage > packet length is handled by send module. */
2067 case UDPLITE_SEND_CSCOV:
2068 if (!is_udplite) /* Disable the option on UDP sockets */
2069 return -ENOPROTOOPT;
2070 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
2071 val = 8;
2072 else if (val > USHRT_MAX)
2073 val = USHRT_MAX;
2074 up->pcslen = val;
2075 up->pcflag |= UDPLITE_SEND_CC;
2076 break;
2077
2078 /* The receiver specifies a minimum checksum coverage value. To make
2079 * sense, this should be set to at least 8 (as done below). If zero is
2080 * used, this again means full checksum coverage. */
2081 case UDPLITE_RECV_CSCOV:
2082 if (!is_udplite) /* Disable the option on UDP sockets */
2083 return -ENOPROTOOPT;
2084 if (val != 0 && val < 8) /* Avoid silly minimal values. */
2085 val = 8;
2086 else if (val > USHRT_MAX)
2087 val = USHRT_MAX;
2088 up->pcrlen = val;
2089 up->pcflag |= UDPLITE_RECV_CC;
2090 break;
2091
2092 default:
2093 err = -ENOPROTOOPT;
2094 break;
2095 }
2096
2097 return err;
2098 }
2099 EXPORT_SYMBOL(udp_lib_setsockopt);
2100
2101 int udp_setsockopt(struct sock *sk, int level, int optname,
2102 char __user *optval, unsigned int optlen)
2103 {
2104 if (level == SOL_UDP || level == SOL_UDPLITE)
2105 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
2106 udp_push_pending_frames);
2107 return ip_setsockopt(sk, level, optname, optval, optlen);
2108 }
2109
2110 #ifdef CONFIG_COMPAT
2111 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
2112 char __user *optval, unsigned int optlen)
2113 {
2114 if (level == SOL_UDP || level == SOL_UDPLITE)
2115 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
2116 udp_push_pending_frames);
2117 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
2118 }
2119 #endif
2120
2121 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
2122 char __user *optval, int __user *optlen)
2123 {
2124 struct udp_sock *up = udp_sk(sk);
2125 int val, len;
2126
2127 if (get_user(len, optlen))
2128 return -EFAULT;
2129
2130 len = min_t(unsigned int, len, sizeof(int));
2131
2132 if (len < 0)
2133 return -EINVAL;
2134
2135 switch (optname) {
2136 case UDP_CORK:
2137 val = up->corkflag;
2138 break;
2139
2140 case UDP_ENCAP:
2141 val = up->encap_type;
2142 break;
2143
2144 case UDP_NO_CHECK6_TX:
2145 val = up->no_check6_tx;
2146 break;
2147
2148 case UDP_NO_CHECK6_RX:
2149 val = up->no_check6_rx;
2150 break;
2151
2152 /* The following two cannot be changed on UDP sockets, the return is
2153 * always 0 (which corresponds to the full checksum coverage of UDP). */
2154 case UDPLITE_SEND_CSCOV:
2155 val = up->pcslen;
2156 break;
2157
2158 case UDPLITE_RECV_CSCOV:
2159 val = up->pcrlen;
2160 break;
2161
2162 default:
2163 return -ENOPROTOOPT;
2164 }
2165
2166 if (put_user(len, optlen))
2167 return -EFAULT;
2168 if (copy_to_user(optval, &val, len))
2169 return -EFAULT;
2170 return 0;
2171 }
2172 EXPORT_SYMBOL(udp_lib_getsockopt);
2173
2174 int udp_getsockopt(struct sock *sk, int level, int optname,
2175 char __user *optval, int __user *optlen)
2176 {
2177 if (level == SOL_UDP || level == SOL_UDPLITE)
2178 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2179 return ip_getsockopt(sk, level, optname, optval, optlen);
2180 }
2181
2182 #ifdef CONFIG_COMPAT
2183 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
2184 char __user *optval, int __user *optlen)
2185 {
2186 if (level == SOL_UDP || level == SOL_UDPLITE)
2187 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2188 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
2189 }
2190 #endif
2191 /**
2192 * udp_poll - wait for a UDP event.
2193 * @file - file struct
2194 * @sock - socket
2195 * @wait - poll table
2196 *
2197 * This is same as datagram poll, except for the special case of
2198 * blocking sockets. If application is using a blocking fd
2199 * and a packet with checksum error is in the queue;
2200 * then it could get return from select indicating data available
2201 * but then block when reading it. Add special case code
2202 * to work around these arguably broken applications.
2203 */
2204 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
2205 {
2206 unsigned int mask = datagram_poll(file, sock, wait);
2207 struct sock *sk = sock->sk;
2208
2209 sock_rps_record_flow(sk);
2210
2211 /* Check for false positives due to checksum errors */
2212 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
2213 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk))
2214 mask &= ~(POLLIN | POLLRDNORM);
2215
2216 return mask;
2217
2218 }
2219 EXPORT_SYMBOL(udp_poll);
2220
2221 struct proto udp_prot = {
2222 .name = "UDP",
2223 .owner = THIS_MODULE,
2224 .close = udp_lib_close,
2225 .connect = ip4_datagram_connect,
2226 .disconnect = udp_disconnect,
2227 .ioctl = udp_ioctl,
2228 .destroy = udp_destroy_sock,
2229 .setsockopt = udp_setsockopt,
2230 .getsockopt = udp_getsockopt,
2231 .sendmsg = udp_sendmsg,
2232 .recvmsg = udp_recvmsg,
2233 .sendpage = udp_sendpage,
2234 .backlog_rcv = __udp_queue_rcv_skb,
2235 .release_cb = ip4_datagram_release_cb,
2236 .hash = udp_lib_hash,
2237 .unhash = udp_lib_unhash,
2238 .rehash = udp_v4_rehash,
2239 .get_port = udp_v4_get_port,
2240 .memory_allocated = &udp_memory_allocated,
2241 .sysctl_mem = sysctl_udp_mem,
2242 .sysctl_wmem = &sysctl_udp_wmem_min,
2243 .sysctl_rmem = &sysctl_udp_rmem_min,
2244 .obj_size = sizeof(struct udp_sock),
2245 .slab_flags = SLAB_DESTROY_BY_RCU,
2246 .h.udp_table = &udp_table,
2247 #ifdef CONFIG_COMPAT
2248 .compat_setsockopt = compat_udp_setsockopt,
2249 .compat_getsockopt = compat_udp_getsockopt,
2250 #endif
2251 .clear_sk = sk_prot_clear_portaddr_nulls,
2252 };
2253 EXPORT_SYMBOL(udp_prot);
2254
2255 /* ------------------------------------------------------------------------ */
2256 #ifdef CONFIG_PROC_FS
2257
2258 static struct sock *udp_get_first(struct seq_file *seq, int start)
2259 {
2260 struct sock *sk;
2261 struct udp_iter_state *state = seq->private;
2262 struct net *net = seq_file_net(seq);
2263
2264 for (state->bucket = start; state->bucket <= state->udp_table->mask;
2265 ++state->bucket) {
2266 struct hlist_nulls_node *node;
2267 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
2268
2269 if (hlist_nulls_empty(&hslot->head))
2270 continue;
2271
2272 spin_lock_bh(&hslot->lock);
2273 sk_nulls_for_each(sk, node, &hslot->head) {
2274 if (!net_eq(sock_net(sk), net))
2275 continue;
2276 if (sk->sk_family == state->family)
2277 goto found;
2278 }
2279 spin_unlock_bh(&hslot->lock);
2280 }
2281 sk = NULL;
2282 found:
2283 return sk;
2284 }
2285
2286 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
2287 {
2288 struct udp_iter_state *state = seq->private;
2289 struct net *net = seq_file_net(seq);
2290
2291 do {
2292 sk = sk_nulls_next(sk);
2293 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
2294
2295 if (!sk) {
2296 if (state->bucket <= state->udp_table->mask)
2297 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2298 return udp_get_first(seq, state->bucket + 1);
2299 }
2300 return sk;
2301 }
2302
2303 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
2304 {
2305 struct sock *sk = udp_get_first(seq, 0);
2306
2307 if (sk)
2308 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
2309 --pos;
2310 return pos ? NULL : sk;
2311 }
2312
2313 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
2314 {
2315 struct udp_iter_state *state = seq->private;
2316 state->bucket = MAX_UDP_PORTS;
2317
2318 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
2319 }
2320
2321 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2322 {
2323 struct sock *sk;
2324
2325 if (v == SEQ_START_TOKEN)
2326 sk = udp_get_idx(seq, 0);
2327 else
2328 sk = udp_get_next(seq, v);
2329
2330 ++*pos;
2331 return sk;
2332 }
2333
2334 static void udp_seq_stop(struct seq_file *seq, void *v)
2335 {
2336 struct udp_iter_state *state = seq->private;
2337
2338 if (state->bucket <= state->udp_table->mask)
2339 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2340 }
2341
2342 int udp_seq_open(struct inode *inode, struct file *file)
2343 {
2344 struct udp_seq_afinfo *afinfo = PDE_DATA(inode);
2345 struct udp_iter_state *s;
2346 int err;
2347
2348 err = seq_open_net(inode, file, &afinfo->seq_ops,
2349 sizeof(struct udp_iter_state));
2350 if (err < 0)
2351 return err;
2352
2353 s = ((struct seq_file *)file->private_data)->private;
2354 s->family = afinfo->family;
2355 s->udp_table = afinfo->udp_table;
2356 return err;
2357 }
2358 EXPORT_SYMBOL(udp_seq_open);
2359
2360 /* ------------------------------------------------------------------------ */
2361 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
2362 {
2363 struct proc_dir_entry *p;
2364 int rc = 0;
2365
2366 afinfo->seq_ops.start = udp_seq_start;
2367 afinfo->seq_ops.next = udp_seq_next;
2368 afinfo->seq_ops.stop = udp_seq_stop;
2369
2370 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2371 afinfo->seq_fops, afinfo);
2372 if (!p)
2373 rc = -ENOMEM;
2374 return rc;
2375 }
2376 EXPORT_SYMBOL(udp_proc_register);
2377
2378 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
2379 {
2380 remove_proc_entry(afinfo->name, net->proc_net);
2381 }
2382 EXPORT_SYMBOL(udp_proc_unregister);
2383
2384 /* ------------------------------------------------------------------------ */
2385 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
2386 int bucket)
2387 {
2388 struct inet_sock *inet = inet_sk(sp);
2389 __be32 dest = inet->inet_daddr;
2390 __be32 src = inet->inet_rcv_saddr;
2391 __u16 destp = ntohs(inet->inet_dport);
2392 __u16 srcp = ntohs(inet->inet_sport);
2393
2394 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
2395 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
2396 bucket, src, srcp, dest, destp, sp->sk_state,
2397 sk_wmem_alloc_get(sp),
2398 sk_rmem_alloc_get(sp),
2399 0, 0L, 0,
2400 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
2401 0, sock_i_ino(sp),
2402 atomic_read(&sp->sk_refcnt), sp,
2403 atomic_read(&sp->sk_drops));
2404 }
2405
2406 int udp4_seq_show(struct seq_file *seq, void *v)
2407 {
2408 seq_setwidth(seq, 127);
2409 if (v == SEQ_START_TOKEN)
2410 seq_puts(seq, " sl local_address rem_address st tx_queue "
2411 "rx_queue tr tm->when retrnsmt uid timeout "
2412 "inode ref pointer drops");
2413 else {
2414 struct udp_iter_state *state = seq->private;
2415
2416 udp4_format_sock(v, seq, state->bucket);
2417 }
2418 seq_pad(seq, '\n');
2419 return 0;
2420 }
2421
2422 static const struct file_operations udp_afinfo_seq_fops = {
2423 .owner = THIS_MODULE,
2424 .open = udp_seq_open,
2425 .read = seq_read,
2426 .llseek = seq_lseek,
2427 .release = seq_release_net
2428 };
2429
2430 /* ------------------------------------------------------------------------ */
2431 static struct udp_seq_afinfo udp4_seq_afinfo = {
2432 .name = "udp",
2433 .family = AF_INET,
2434 .udp_table = &udp_table,
2435 .seq_fops = &udp_afinfo_seq_fops,
2436 .seq_ops = {
2437 .show = udp4_seq_show,
2438 },
2439 };
2440
2441 static int __net_init udp4_proc_init_net(struct net *net)
2442 {
2443 return udp_proc_register(net, &udp4_seq_afinfo);
2444 }
2445
2446 static void __net_exit udp4_proc_exit_net(struct net *net)
2447 {
2448 udp_proc_unregister(net, &udp4_seq_afinfo);
2449 }
2450
2451 static struct pernet_operations udp4_net_ops = {
2452 .init = udp4_proc_init_net,
2453 .exit = udp4_proc_exit_net,
2454 };
2455
2456 int __init udp4_proc_init(void)
2457 {
2458 return register_pernet_subsys(&udp4_net_ops);
2459 }
2460
2461 void udp4_proc_exit(void)
2462 {
2463 unregister_pernet_subsys(&udp4_net_ops);
2464 }
2465 #endif /* CONFIG_PROC_FS */
2466
2467 static __initdata unsigned long uhash_entries;
2468 static int __init set_uhash_entries(char *str)
2469 {
2470 ssize_t ret;
2471
2472 if (!str)
2473 return 0;
2474
2475 ret = kstrtoul(str, 0, &uhash_entries);
2476 if (ret)
2477 return 0;
2478
2479 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
2480 uhash_entries = UDP_HTABLE_SIZE_MIN;
2481 return 1;
2482 }
2483 __setup("uhash_entries=", set_uhash_entries);
2484
2485 void __init udp_table_init(struct udp_table *table, const char *name)
2486 {
2487 unsigned int i;
2488
2489 table->hash = alloc_large_system_hash(name,
2490 2 * sizeof(struct udp_hslot),
2491 uhash_entries,
2492 21, /* one slot per 2 MB */
2493 0,
2494 &table->log,
2495 &table->mask,
2496 UDP_HTABLE_SIZE_MIN,
2497 64 * 1024);
2498
2499 table->hash2 = table->hash + (table->mask + 1);
2500 for (i = 0; i <= table->mask; i++) {
2501 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
2502 table->hash[i].count = 0;
2503 spin_lock_init(&table->hash[i].lock);
2504 }
2505 for (i = 0; i <= table->mask; i++) {
2506 INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i);
2507 table->hash2[i].count = 0;
2508 spin_lock_init(&table->hash2[i].lock);
2509 }
2510 }
2511
2512 void __init udp_init(void)
2513 {
2514 unsigned long limit;
2515
2516 udp_table_init(&udp_table, "UDP");
2517 limit = nr_free_buffer_pages() / 8;
2518 limit = max(limit, 128UL);
2519 sysctl_udp_mem[0] = limit / 4 * 3;
2520 sysctl_udp_mem[1] = limit;
2521 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
2522
2523 sysctl_udp_rmem_min = SK_MEM_QUANTUM;
2524 sysctl_udp_wmem_min = SK_MEM_QUANTUM;
2525 }
2526
2527 struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
2528 netdev_features_t features)
2529 {
2530 struct sk_buff *segs = ERR_PTR(-EINVAL);
2531 u16 mac_offset = skb->mac_header;
2532 int mac_len = skb->mac_len;
2533 int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
2534 __be16 protocol = skb->protocol;
2535 netdev_features_t enc_features;
2536 int udp_offset, outer_hlen;
2537 unsigned int oldlen;
2538 bool need_csum;
2539
2540 oldlen = (u16)~skb->len;
2541
2542 if (unlikely(!pskb_may_pull(skb, tnl_hlen)))
2543 goto out;
2544
2545 skb->encapsulation = 0;
2546 __skb_pull(skb, tnl_hlen);
2547 skb_reset_mac_header(skb);
2548 skb_set_network_header(skb, skb_inner_network_offset(skb));
2549 skb->mac_len = skb_inner_network_offset(skb);
2550 skb->protocol = htons(ETH_P_TEB);
2551
2552 need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM);
2553 if (need_csum)
2554 skb->encap_hdr_csum = 1;
2555
2556 /* segment inner packet. */
2557 enc_features = skb->dev->hw_enc_features & netif_skb_features(skb);
2558 segs = skb_mac_gso_segment(skb, enc_features);
2559 if (!segs || IS_ERR(segs)) {
2560 skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset,
2561 mac_len);
2562 goto out;
2563 }
2564
2565 outer_hlen = skb_tnl_header_len(skb);
2566 udp_offset = outer_hlen - tnl_hlen;
2567 skb = segs;
2568 do {
2569 struct udphdr *uh;
2570 int len;
2571
2572 skb_reset_inner_headers(skb);
2573 skb->encapsulation = 1;
2574
2575 skb->mac_len = mac_len;
2576
2577 skb_push(skb, outer_hlen);
2578 skb_reset_mac_header(skb);
2579 skb_set_network_header(skb, mac_len);
2580 skb_set_transport_header(skb, udp_offset);
2581 len = skb->len - udp_offset;
2582 uh = udp_hdr(skb);
2583 uh->len = htons(len);
2584
2585 if (need_csum) {
2586 __be32 delta = htonl(oldlen + len);
2587
2588 uh->check = ~csum_fold((__force __wsum)
2589 ((__force u32)uh->check +
2590 (__force u32)delta));
2591 uh->check = gso_make_checksum(skb, ~uh->check);
2592
2593 if (uh->check == 0)
2594 uh->check = CSUM_MANGLED_0;
2595 }
2596
2597 skb->protocol = protocol;
2598 } while ((skb = skb->next));
2599 out:
2600 return segs;
2601 }
Linux with added FPC-III support