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Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab...
[linux-2.6.git] / net / ipv4 / udp.c
blob0bf5d399a03c1c0eaedeedd4a6a9db4ee2af68e6
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 <trace/events/skb.h>
112 #include "udp_impl.h"
113
114 struct udp_table udp_table __read_mostly;
115 EXPORT_SYMBOL(udp_table);
116
117 long sysctl_udp_mem[3] __read_mostly;
118 EXPORT_SYMBOL(sysctl_udp_mem);
119
120 int sysctl_udp_rmem_min __read_mostly;
121 EXPORT_SYMBOL(sysctl_udp_rmem_min);
122
123 int sysctl_udp_wmem_min __read_mostly;
124 EXPORT_SYMBOL(sysctl_udp_wmem_min);
125
126 atomic_long_t udp_memory_allocated;
127 EXPORT_SYMBOL(udp_memory_allocated);
128
129 #define MAX_UDP_PORTS 65536
130 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
131
132 static int udp_lib_lport_inuse(struct net *net, __u16 num,
133 const struct udp_hslot *hslot,
134 unsigned long *bitmap,
135 struct sock *sk,
136 int (*saddr_comp)(const struct sock *sk1,
137 const struct sock *sk2),
138 unsigned int log)
139 {
140 struct sock *sk2;
141 struct hlist_nulls_node *node;
142 kuid_t uid = sock_i_uid(sk);
143
144 sk_nulls_for_each(sk2, node, &hslot->head)
145 if (net_eq(sock_net(sk2), net) &&
146 sk2 != sk &&
147 (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
148 (!sk2->sk_reuse || !sk->sk_reuse) &&
149 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
150 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
151 (!sk2->sk_reuseport || !sk->sk_reuseport ||
152 !uid_eq(uid, sock_i_uid(sk2))) &&
153 (*saddr_comp)(sk, sk2)) {
154 if (bitmap)
155 __set_bit(udp_sk(sk2)->udp_port_hash >> log,
156 bitmap);
157 else
158 return 1;
159 }
160 return 0;
161 }
162
163 /*
164 * Note: we still hold spinlock of primary hash chain, so no other writer
165 * can insert/delete a socket with local_port == num
166 */
167 static int udp_lib_lport_inuse2(struct net *net, __u16 num,
168 struct udp_hslot *hslot2,
169 struct sock *sk,
170 int (*saddr_comp)(const struct sock *sk1,
171 const struct sock *sk2))
172 {
173 struct sock *sk2;
174 struct hlist_nulls_node *node;
175 kuid_t uid = sock_i_uid(sk);
176 int res = 0;
177
178 spin_lock(&hslot2->lock);
179 udp_portaddr_for_each_entry(sk2, node, &hslot2->head)
180 if (net_eq(sock_net(sk2), net) &&
181 sk2 != sk &&
182 (udp_sk(sk2)->udp_port_hash == num) &&
183 (!sk2->sk_reuse || !sk->sk_reuse) &&
184 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
185 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
186 (!sk2->sk_reuseport || !sk->sk_reuseport ||
187 !uid_eq(uid, sock_i_uid(sk2))) &&
188 (*saddr_comp)(sk, sk2)) {
189 res = 1;
190 break;
191 }
192 spin_unlock(&hslot2->lock);
193 return res;
194 }
195
196 /**
197 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
198 *
199 * @sk: socket struct in question
200 * @snum: port number to look up
201 * @saddr_comp: AF-dependent comparison of bound local IP addresses
202 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
203 * with NULL address
204 */
205 int udp_lib_get_port(struct sock *sk, unsigned short snum,
206 int (*saddr_comp)(const struct sock *sk1,
207 const struct sock *sk2),
208 unsigned int hash2_nulladdr)
209 {
210 struct udp_hslot *hslot, *hslot2;
211 struct udp_table *udptable = sk->sk_prot->h.udp_table;
212 int error = 1;
213 struct net *net = sock_net(sk);
214
215 if (!snum) {
216 int low, high, remaining;
217 unsigned int rand;
218 unsigned short first, last;
219 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
220
221 inet_get_local_port_range(&low, &high);
222 remaining = (high - low) + 1;
223
224 rand = net_random();
225 first = (((u64)rand * remaining) >> 32) + low;
226 /*
227 * force rand to be an odd multiple of UDP_HTABLE_SIZE
228 */
229 rand = (rand | 1) * (udptable->mask + 1);
230 last = first + udptable->mask + 1;
231 do {
232 hslot = udp_hashslot(udptable, net, first);
233 bitmap_zero(bitmap, PORTS_PER_CHAIN);
234 spin_lock_bh(&hslot->lock);
235 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
236 saddr_comp, udptable->log);
237
238 snum = first;
239 /*
240 * Iterate on all possible values of snum for this hash.
241 * Using steps of an odd multiple of UDP_HTABLE_SIZE
242 * give us randomization and full range coverage.
243 */
244 do {
245 if (low <= snum && snum <= high &&
246 !test_bit(snum >> udptable->log, bitmap) &&
247 !inet_is_reserved_local_port(snum))
248 goto found;
249 snum += rand;
250 } while (snum != first);
251 spin_unlock_bh(&hslot->lock);
252 } while (++first != last);
253 goto fail;
254 } else {
255 hslot = udp_hashslot(udptable, net, snum);
256 spin_lock_bh(&hslot->lock);
257 if (hslot->count > 10) {
258 int exist;
259 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum;
260
261 slot2 &= udptable->mask;
262 hash2_nulladdr &= udptable->mask;
263
264 hslot2 = udp_hashslot2(udptable, slot2);
265 if (hslot->count < hslot2->count)
266 goto scan_primary_hash;
267
268 exist = udp_lib_lport_inuse2(net, snum, hslot2,
269 sk, saddr_comp);
270 if (!exist && (hash2_nulladdr != slot2)) {
271 hslot2 = udp_hashslot2(udptable, hash2_nulladdr);
272 exist = udp_lib_lport_inuse2(net, snum, hslot2,
273 sk, saddr_comp);
274 }
275 if (exist)
276 goto fail_unlock;
277 else
278 goto found;
279 }
280 scan_primary_hash:
281 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk,
282 saddr_comp, 0))
283 goto fail_unlock;
284 }
285 found:
286 inet_sk(sk)->inet_num = snum;
287 udp_sk(sk)->udp_port_hash = snum;
288 udp_sk(sk)->udp_portaddr_hash ^= snum;
289 if (sk_unhashed(sk)) {
290 sk_nulls_add_node_rcu(sk, &hslot->head);
291 hslot->count++;
292 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
293
294 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
295 spin_lock(&hslot2->lock);
296 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
297 &hslot2->head);
298 hslot2->count++;
299 spin_unlock(&hslot2->lock);
300 }
301 error = 0;
302 fail_unlock:
303 spin_unlock_bh(&hslot->lock);
304 fail:
305 return error;
306 }
307 EXPORT_SYMBOL(udp_lib_get_port);
308
309 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
310 {
311 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
312
313 return (!ipv6_only_sock(sk2) &&
314 (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr ||
315 inet1->inet_rcv_saddr == inet2->inet_rcv_saddr));
316 }
317
318 static unsigned int udp4_portaddr_hash(struct net *net, __be32 saddr,
319 unsigned int port)
320 {
321 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
322 }
323
324 int udp_v4_get_port(struct sock *sk, unsigned short snum)
325 {
326 unsigned int hash2_nulladdr =
327 udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
328 unsigned int hash2_partial =
329 udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);
330
331 /* precompute partial secondary hash */
332 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
333 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr);
334 }
335
336 static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr,
337 unsigned short hnum,
338 __be16 sport, __be32 daddr, __be16 dport, int dif)
339 {
340 int score = -1;
341
342 if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
343 !ipv6_only_sock(sk)) {
344 struct inet_sock *inet = inet_sk(sk);
345
346 score = (sk->sk_family == PF_INET ? 2 : 1);
347 if (inet->inet_rcv_saddr) {
348 if (inet->inet_rcv_saddr != daddr)
349 return -1;
350 score += 4;
351 }
352 if (inet->inet_daddr) {
353 if (inet->inet_daddr != saddr)
354 return -1;
355 score += 4;
356 }
357 if (inet->inet_dport) {
358 if (inet->inet_dport != sport)
359 return -1;
360 score += 4;
361 }
362 if (sk->sk_bound_dev_if) {
363 if (sk->sk_bound_dev_if != dif)
364 return -1;
365 score += 4;
366 }
367 }
368 return score;
369 }
370
371 /*
372 * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num)
373 */
374 static inline int compute_score2(struct sock *sk, struct net *net,
375 __be32 saddr, __be16 sport,
376 __be32 daddr, unsigned int hnum, int dif)
377 {
378 int score = -1;
379
380 if (net_eq(sock_net(sk), net) && !ipv6_only_sock(sk)) {
381 struct inet_sock *inet = inet_sk(sk);
382
383 if (inet->inet_rcv_saddr != daddr)
384 return -1;
385 if (inet->inet_num != hnum)
386 return -1;
387
388 score = (sk->sk_family == PF_INET ? 2 : 1);
389 if (inet->inet_daddr) {
390 if (inet->inet_daddr != saddr)
391 return -1;
392 score += 4;
393 }
394 if (inet->inet_dport) {
395 if (inet->inet_dport != sport)
396 return -1;
397 score += 4;
398 }
399 if (sk->sk_bound_dev_if) {
400 if (sk->sk_bound_dev_if != dif)
401 return -1;
402 score += 4;
403 }
404 }
405 return score;
406 }
407
408
409 /* called with read_rcu_lock() */
410 static struct sock *udp4_lib_lookup2(struct net *net,
411 __be32 saddr, __be16 sport,
412 __be32 daddr, unsigned int hnum, int dif,
413 struct udp_hslot *hslot2, unsigned int slot2)
414 {
415 struct sock *sk, *result;
416 struct hlist_nulls_node *node;
417 int score, badness, matches = 0, reuseport = 0;
418 u32 hash = 0;
419
420 begin:
421 result = NULL;
422 badness = 0;
423 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
424 score = compute_score2(sk, net, saddr, sport,
425 daddr, hnum, dif);
426 if (score > badness) {
427 result = sk;
428 badness = score;
429 reuseport = sk->sk_reuseport;
430 if (reuseport) {
431 hash = inet_ehashfn(net, daddr, hnum,
432 saddr, htons(sport));
433 matches = 1;
434 }
435 } else if (score == badness && reuseport) {
436 matches++;
437 if (((u64)hash * matches) >> 32 == 0)
438 result = sk;
439 hash = next_pseudo_random32(hash);
440 }
441 }
442 /*
443 * if the nulls value we got at the end of this lookup is
444 * not the expected one, we must restart lookup.
445 * We probably met an item that was moved to another chain.
446 */
447 if (get_nulls_value(node) != slot2)
448 goto begin;
449 if (result) {
450 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
451 result = NULL;
452 else if (unlikely(compute_score2(result, net, saddr, sport,
453 daddr, hnum, dif) < badness)) {
454 sock_put(result);
455 goto begin;
456 }
457 }
458 return result;
459 }
460
461 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
462 * harder than this. -DaveM
463 */
464 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
465 __be16 sport, __be32 daddr, __be16 dport,
466 int dif, struct udp_table *udptable)
467 {
468 struct sock *sk, *result;
469 struct hlist_nulls_node *node;
470 unsigned short hnum = ntohs(dport);
471 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
472 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
473 int score, badness, matches = 0, reuseport = 0;
474 u32 hash = 0;
475
476 rcu_read_lock();
477 if (hslot->count > 10) {
478 hash2 = udp4_portaddr_hash(net, daddr, hnum);
479 slot2 = hash2 & udptable->mask;
480 hslot2 = &udptable->hash2[slot2];
481 if (hslot->count < hslot2->count)
482 goto begin;
483
484 result = udp4_lib_lookup2(net, saddr, sport,
485 daddr, hnum, dif,
486 hslot2, slot2);
487 if (!result) {
488 hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
489 slot2 = hash2 & udptable->mask;
490 hslot2 = &udptable->hash2[slot2];
491 if (hslot->count < hslot2->count)
492 goto begin;
493
494 result = udp4_lib_lookup2(net, saddr, sport,
495 htonl(INADDR_ANY), hnum, dif,
496 hslot2, slot2);
497 }
498 rcu_read_unlock();
499 return result;
500 }
501 begin:
502 result = NULL;
503 badness = 0;
504 sk_nulls_for_each_rcu(sk, node, &hslot->head) {
505 score = compute_score(sk, net, saddr, hnum, sport,
506 daddr, dport, dif);
507 if (score > badness) {
508 result = sk;
509 badness = score;
510 reuseport = sk->sk_reuseport;
511 if (reuseport) {
512 hash = inet_ehashfn(net, daddr, hnum,
513 saddr, htons(sport));
514 matches = 1;
515 }
516 } else if (score == badness && reuseport) {
517 matches++;
518 if (((u64)hash * matches) >> 32 == 0)
519 result = sk;
520 hash = next_pseudo_random32(hash);
521 }
522 }
523 /*
524 * if the nulls value we got at the end of this lookup is
525 * not the expected one, we must restart lookup.
526 * We probably met an item that was moved to another chain.
527 */
528 if (get_nulls_value(node) != slot)
529 goto begin;
530
531 if (result) {
532 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
533 result = NULL;
534 else if (unlikely(compute_score(result, net, saddr, hnum, sport,
535 daddr, dport, dif) < badness)) {
536 sock_put(result);
537 goto begin;
538 }
539 }
540 rcu_read_unlock();
541 return result;
542 }
543 EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
544
545 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
546 __be16 sport, __be16 dport,
547 struct udp_table *udptable)
548 {
549 struct sock *sk;
550 const struct iphdr *iph = ip_hdr(skb);
551
552 if (unlikely(sk = skb_steal_sock(skb)))
553 return sk;
554 else
555 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
556 iph->daddr, dport, inet_iif(skb),
557 udptable);
558 }
559
560 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
561 __be32 daddr, __be16 dport, int dif)
562 {
563 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
564 }
565 EXPORT_SYMBOL_GPL(udp4_lib_lookup);
566
567 static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
568 __be16 loc_port, __be32 loc_addr,
569 __be16 rmt_port, __be32 rmt_addr,
570 int dif)
571 {
572 struct hlist_nulls_node *node;
573 struct sock *s = sk;
574 unsigned short hnum = ntohs(loc_port);
575
576 sk_nulls_for_each_from(s, node) {
577 struct inet_sock *inet = inet_sk(s);
578
579 if (!net_eq(sock_net(s), net) ||
580 udp_sk(s)->udp_port_hash != hnum ||
581 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
582 (inet->inet_dport != rmt_port && inet->inet_dport) ||
583 (inet->inet_rcv_saddr &&
584 inet->inet_rcv_saddr != loc_addr) ||
585 ipv6_only_sock(s) ||
586 (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
587 continue;
588 if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
589 continue;
590 goto found;
591 }
592 s = NULL;
593 found:
594 return s;
595 }
596
597 /*
598 * This routine is called by the ICMP module when it gets some
599 * sort of error condition. If err < 0 then the socket should
600 * be closed and the error returned to the user. If err > 0
601 * it's just the icmp type << 8 | icmp code.
602 * Header points to the ip header of the error packet. We move
603 * on past this. Then (as it used to claim before adjustment)
604 * header points to the first 8 bytes of the udp header. We need
605 * to find the appropriate port.
606 */
607
608 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
609 {
610 struct inet_sock *inet;
611 const struct iphdr *iph = (const struct iphdr *)skb->data;
612 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
613 const int type = icmp_hdr(skb)->type;
614 const int code = icmp_hdr(skb)->code;
615 struct sock *sk;
616 int harderr;
617 int err;
618 struct net *net = dev_net(skb->dev);
619
620 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
621 iph->saddr, uh->source, skb->dev->ifindex, udptable);
622 if (sk == NULL) {
623 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
624 return; /* No socket for error */
625 }
626
627 err = 0;
628 harderr = 0;
629 inet = inet_sk(sk);
630
631 switch (type) {
632 default:
633 case ICMP_TIME_EXCEEDED:
634 err = EHOSTUNREACH;
635 break;
636 case ICMP_SOURCE_QUENCH:
637 goto out;
638 case ICMP_PARAMETERPROB:
639 err = EPROTO;
640 harderr = 1;
641 break;
642 case ICMP_DEST_UNREACH:
643 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
644 ipv4_sk_update_pmtu(skb, sk, info);
645 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
646 err = EMSGSIZE;
647 harderr = 1;
648 break;
649 }
650 goto out;
651 }
652 err = EHOSTUNREACH;
653 if (code <= NR_ICMP_UNREACH) {
654 harderr = icmp_err_convert[code].fatal;
655 err = icmp_err_convert[code].errno;
656 }
657 break;
658 case ICMP_REDIRECT:
659 ipv4_sk_redirect(skb, sk);
660 break;
661 }
662
663 /*
664 * RFC1122: OK. Passes ICMP errors back to application, as per
665 * 4.1.3.3.
666 */
667 if (!inet->recverr) {
668 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
669 goto out;
670 } else
671 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
672
673 sk->sk_err = err;
674 sk->sk_error_report(sk);
675 out:
676 sock_put(sk);
677 }
678
679 void udp_err(struct sk_buff *skb, u32 info)
680 {
681 __udp4_lib_err(skb, info, &udp_table);
682 }
683
684 /*
685 * Throw away all pending data and cancel the corking. Socket is locked.
686 */
687 void udp_flush_pending_frames(struct sock *sk)
688 {
689 struct udp_sock *up = udp_sk(sk);
690
691 if (up->pending) {
692 up->len = 0;
693 up->pending = 0;
694 ip_flush_pending_frames(sk);
695 }
696 }
697 EXPORT_SYMBOL(udp_flush_pending_frames);
698
699 /**
700 * udp4_hwcsum - handle outgoing HW checksumming
701 * @skb: sk_buff containing the filled-in UDP header
702 * (checksum field must be zeroed out)
703 * @src: source IP address
704 * @dst: destination IP address
705 */
706 static void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
707 {
708 struct udphdr *uh = udp_hdr(skb);
709 struct sk_buff *frags = skb_shinfo(skb)->frag_list;
710 int offset = skb_transport_offset(skb);
711 int len = skb->len - offset;
712 int hlen = len;
713 __wsum csum = 0;
714
715 if (!frags) {
716 /*
717 * Only one fragment on the socket.
718 */
719 skb->csum_start = skb_transport_header(skb) - skb->head;
720 skb->csum_offset = offsetof(struct udphdr, check);
721 uh->check = ~csum_tcpudp_magic(src, dst, len,
722 IPPROTO_UDP, 0);
723 } else {
724 /*
725 * HW-checksum won't work as there are two or more
726 * fragments on the socket so that all csums of sk_buffs
727 * should be together
728 */
729 do {
730 csum = csum_add(csum, frags->csum);
731 hlen -= frags->len;
732 } while ((frags = frags->next));
733
734 csum = skb_checksum(skb, offset, hlen, csum);
735 skb->ip_summed = CHECKSUM_NONE;
736
737 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
738 if (uh->check == 0)
739 uh->check = CSUM_MANGLED_0;
740 }
741 }
742
743 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4)
744 {
745 struct sock *sk = skb->sk;
746 struct inet_sock *inet = inet_sk(sk);
747 struct udphdr *uh;
748 int err = 0;
749 int is_udplite = IS_UDPLITE(sk);
750 int offset = skb_transport_offset(skb);
751 int len = skb->len - offset;
752 __wsum csum = 0;
753
754 /*
755 * Create a UDP header
756 */
757 uh = udp_hdr(skb);
758 uh->source = inet->inet_sport;
759 uh->dest = fl4->fl4_dport;
760 uh->len = htons(len);
761 uh->check = 0;
762
763 if (is_udplite) /* UDP-Lite */
764 csum = udplite_csum(skb);
765
766 else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */
767
768 skb->ip_summed = CHECKSUM_NONE;
769 goto send;
770
771 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
772
773 udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
774 goto send;
775
776 } else
777 csum = udp_csum(skb);
778
779 /* add protocol-dependent pseudo-header */
780 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
781 sk->sk_protocol, csum);
782 if (uh->check == 0)
783 uh->check = CSUM_MANGLED_0;
784
785 send:
786 err = ip_send_skb(sock_net(sk), skb);
787 if (err) {
788 if (err == -ENOBUFS && !inet->recverr) {
789 UDP_INC_STATS_USER(sock_net(sk),
790 UDP_MIB_SNDBUFERRORS, is_udplite);
791 err = 0;
792 }
793 } else
794 UDP_INC_STATS_USER(sock_net(sk),
795 UDP_MIB_OUTDATAGRAMS, is_udplite);
796 return err;
797 }
798
799 /*
800 * Push out all pending data as one UDP datagram. Socket is locked.
801 */
802 static int udp_push_pending_frames(struct sock *sk)
803 {
804 struct udp_sock *up = udp_sk(sk);
805 struct inet_sock *inet = inet_sk(sk);
806 struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
807 struct sk_buff *skb;
808 int err = 0;
809
810 skb = ip_finish_skb(sk, fl4);
811 if (!skb)
812 goto out;
813
814 err = udp_send_skb(skb, fl4);
815
816 out:
817 up->len = 0;
818 up->pending = 0;
819 return err;
820 }
821
822 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
823 size_t len)
824 {
825 struct inet_sock *inet = inet_sk(sk);
826 struct udp_sock *up = udp_sk(sk);
827 struct flowi4 fl4_stack;
828 struct flowi4 *fl4;
829 int ulen = len;
830 struct ipcm_cookie ipc;
831 struct rtable *rt = NULL;
832 int free = 0;
833 int connected = 0;
834 __be32 daddr, faddr, saddr;
835 __be16 dport;
836 u8 tos;
837 int err, is_udplite = IS_UDPLITE(sk);
838 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
839 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
840 struct sk_buff *skb;
841 struct ip_options_data opt_copy;
842
843 if (len > 0xFFFF)
844 return -EMSGSIZE;
845
846 /*
847 * Check the flags.
848 */
849
850 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
851 return -EOPNOTSUPP;
852
853 ipc.opt = NULL;
854 ipc.tx_flags = 0;
855
856 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
857
858 fl4 = &inet->cork.fl.u.ip4;
859 if (up->pending) {
860 /*
861 * There are pending frames.
862 * The socket lock must be held while it's corked.
863 */
864 lock_sock(sk);
865 if (likely(up->pending)) {
866 if (unlikely(up->pending != AF_INET)) {
867 release_sock(sk);
868 return -EINVAL;
869 }
870 goto do_append_data;
871 }
872 release_sock(sk);
873 }
874 ulen += sizeof(struct udphdr);
875
876 /*
877 * Get and verify the address.
878 */
879 if (msg->msg_name) {
880 struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
881 if (msg->msg_namelen < sizeof(*usin))
882 return -EINVAL;
883 if (usin->sin_family != AF_INET) {
884 if (usin->sin_family != AF_UNSPEC)
885 return -EAFNOSUPPORT;
886 }
887
888 daddr = usin->sin_addr.s_addr;
889 dport = usin->sin_port;
890 if (dport == 0)
891 return -EINVAL;
892 } else {
893 if (sk->sk_state != TCP_ESTABLISHED)
894 return -EDESTADDRREQ;
895 daddr = inet->inet_daddr;
896 dport = inet->inet_dport;
897 /* Open fast path for connected socket.
898 Route will not be used, if at least one option is set.
899 */
900 connected = 1;
901 }
902 ipc.addr = inet->inet_saddr;
903
904 ipc.oif = sk->sk_bound_dev_if;
905
906 sock_tx_timestamp(sk, &ipc.tx_flags);
907
908 if (msg->msg_controllen) {
909 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
910 if (err)
911 return err;
912 if (ipc.opt)
913 free = 1;
914 connected = 0;
915 }
916 if (!ipc.opt) {
917 struct ip_options_rcu *inet_opt;
918
919 rcu_read_lock();
920 inet_opt = rcu_dereference(inet->inet_opt);
921 if (inet_opt) {
922 memcpy(&opt_copy, inet_opt,
923 sizeof(*inet_opt) + inet_opt->opt.optlen);
924 ipc.opt = &opt_copy.opt;
925 }
926 rcu_read_unlock();
927 }
928
929 saddr = ipc.addr;
930 ipc.addr = faddr = daddr;
931
932 if (ipc.opt && ipc.opt->opt.srr) {
933 if (!daddr)
934 return -EINVAL;
935 faddr = ipc.opt->opt.faddr;
936 connected = 0;
937 }
938 tos = RT_TOS(inet->tos);
939 if (sock_flag(sk, SOCK_LOCALROUTE) ||
940 (msg->msg_flags & MSG_DONTROUTE) ||
941 (ipc.opt && ipc.opt->opt.is_strictroute)) {
942 tos |= RTO_ONLINK;
943 connected = 0;
944 }
945
946 if (ipv4_is_multicast(daddr)) {
947 if (!ipc.oif)
948 ipc.oif = inet->mc_index;
949 if (!saddr)
950 saddr = inet->mc_addr;
951 connected = 0;
952 } else if (!ipc.oif)
953 ipc.oif = inet->uc_index;
954
955 if (connected)
956 rt = (struct rtable *)sk_dst_check(sk, 0);
957
958 if (rt == NULL) {
959 struct net *net = sock_net(sk);
960
961 fl4 = &fl4_stack;
962 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
963 RT_SCOPE_UNIVERSE, sk->sk_protocol,
964 inet_sk_flowi_flags(sk)|FLOWI_FLAG_CAN_SLEEP,
965 faddr, saddr, dport, inet->inet_sport);
966
967 security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
968 rt = ip_route_output_flow(net, fl4, sk);
969 if (IS_ERR(rt)) {
970 err = PTR_ERR(rt);
971 rt = NULL;
972 if (err == -ENETUNREACH)
973 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
974 goto out;
975 }
976
977 err = -EACCES;
978 if ((rt->rt_flags & RTCF_BROADCAST) &&
979 !sock_flag(sk, SOCK_BROADCAST))
980 goto out;
981 if (connected)
982 sk_dst_set(sk, dst_clone(&rt->dst));
983 }
984
985 if (msg->msg_flags&MSG_CONFIRM)
986 goto do_confirm;
987 back_from_confirm:
988
989 saddr = fl4->saddr;
990 if (!ipc.addr)
991 daddr = ipc.addr = fl4->daddr;
992
993 /* Lockless fast path for the non-corking case. */
994 if (!corkreq) {
995 skb = ip_make_skb(sk, fl4, getfrag, msg->msg_iov, ulen,
996 sizeof(struct udphdr), &ipc, &rt,
997 msg->msg_flags);
998 err = PTR_ERR(skb);
999 if (!IS_ERR_OR_NULL(skb))
1000 err = udp_send_skb(skb, fl4);
1001 goto out;
1002 }
1003
1004 lock_sock(sk);
1005 if (unlikely(up->pending)) {
1006 /* The socket is already corked while preparing it. */
1007 /* ... which is an evident application bug. --ANK */
1008 release_sock(sk);
1009
1010 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("cork app bug 2\n"));
1011 err = -EINVAL;
1012 goto out;
1013 }
1014 /*
1015 * Now cork the socket to pend data.
1016 */
1017 fl4 = &inet->cork.fl.u.ip4;
1018 fl4->daddr = daddr;
1019 fl4->saddr = saddr;
1020 fl4->fl4_dport = dport;
1021 fl4->fl4_sport = inet->inet_sport;
1022 up->pending = AF_INET;
1023
1024 do_append_data:
1025 up->len += ulen;
1026 err = ip_append_data(sk, fl4, getfrag, msg->msg_iov, ulen,
1027 sizeof(struct udphdr), &ipc, &rt,
1028 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1029 if (err)
1030 udp_flush_pending_frames(sk);
1031 else if (!corkreq)
1032 err = udp_push_pending_frames(sk);
1033 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1034 up->pending = 0;
1035 release_sock(sk);
1036
1037 out:
1038 ip_rt_put(rt);
1039 if (free)
1040 kfree(ipc.opt);
1041 if (!err)
1042 return len;
1043 /*
1044 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1045 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1046 * we don't have a good statistic (IpOutDiscards but it can be too many
1047 * things). We could add another new stat but at least for now that
1048 * seems like overkill.
1049 */
1050 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1051 UDP_INC_STATS_USER(sock_net(sk),
1052 UDP_MIB_SNDBUFERRORS, is_udplite);
1053 }
1054 return err;
1055
1056 do_confirm:
1057 dst_confirm(&rt->dst);
1058 if (!(msg->msg_flags&MSG_PROBE) || len)
1059 goto back_from_confirm;
1060 err = 0;
1061 goto out;
1062 }
1063 EXPORT_SYMBOL(udp_sendmsg);
1064
1065 int udp_sendpage(struct sock *sk, struct page *page, int offset,
1066 size_t size, int flags)
1067 {
1068 struct inet_sock *inet = inet_sk(sk);
1069 struct udp_sock *up = udp_sk(sk);
1070 int ret;
1071
1072 if (!up->pending) {
1073 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
1074
1075 /* Call udp_sendmsg to specify destination address which
1076 * sendpage interface can't pass.
1077 * This will succeed only when the socket is connected.
1078 */
1079 ret = udp_sendmsg(NULL, sk, &msg, 0);
1080 if (ret < 0)
1081 return ret;
1082 }
1083
1084 lock_sock(sk);
1085
1086 if (unlikely(!up->pending)) {
1087 release_sock(sk);
1088
1089 LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("udp cork app bug 3\n"));
1090 return -EINVAL;
1091 }
1092
1093 ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
1094 page, offset, size, flags);
1095 if (ret == -EOPNOTSUPP) {
1096 release_sock(sk);
1097 return sock_no_sendpage(sk->sk_socket, page, offset,
1098 size, flags);
1099 }
1100 if (ret < 0) {
1101 udp_flush_pending_frames(sk);
1102 goto out;
1103 }
1104
1105 up->len += size;
1106 if (!(up->corkflag || (flags&MSG_MORE)))
1107 ret = udp_push_pending_frames(sk);
1108 if (!ret)
1109 ret = size;
1110 out:
1111 release_sock(sk);
1112 return ret;
1113 }
1114
1115
1116 /**
1117 * first_packet_length - return length of first packet in receive queue
1118 * @sk: socket
1119 *
1120 * Drops all bad checksum frames, until a valid one is found.
1121 * Returns the length of found skb, or 0 if none is found.
1122 */
1123 static unsigned int first_packet_length(struct sock *sk)
1124 {
1125 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue;
1126 struct sk_buff *skb;
1127 unsigned int res;
1128
1129 __skb_queue_head_init(&list_kill);
1130
1131 spin_lock_bh(&rcvq->lock);
1132 while ((skb = skb_peek(rcvq)) != NULL &&
1133 udp_lib_checksum_complete(skb)) {
1134 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS,
1135 IS_UDPLITE(sk));
1136 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
1137 IS_UDPLITE(sk));
1138 atomic_inc(&sk->sk_drops);
1139 __skb_unlink(skb, rcvq);
1140 __skb_queue_tail(&list_kill, skb);
1141 }
1142 res = skb ? skb->len : 0;
1143 spin_unlock_bh(&rcvq->lock);
1144
1145 if (!skb_queue_empty(&list_kill)) {
1146 bool slow = lock_sock_fast(sk);
1147
1148 __skb_queue_purge(&list_kill);
1149 sk_mem_reclaim_partial(sk);
1150 unlock_sock_fast(sk, slow);
1151 }
1152 return res;
1153 }
1154
1155 /*
1156 * IOCTL requests applicable to the UDP protocol
1157 */
1158
1159 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
1160 {
1161 switch (cmd) {
1162 case SIOCOUTQ:
1163 {
1164 int amount = sk_wmem_alloc_get(sk);
1165
1166 return put_user(amount, (int __user *)arg);
1167 }
1168
1169 case SIOCINQ:
1170 {
1171 unsigned int amount = first_packet_length(sk);
1172
1173 if (amount)
1174 /*
1175 * We will only return the amount
1176 * of this packet since that is all
1177 * that will be read.
1178 */
1179 amount -= sizeof(struct udphdr);
1180
1181 return put_user(amount, (int __user *)arg);
1182 }
1183
1184 default:
1185 return -ENOIOCTLCMD;
1186 }
1187
1188 return 0;
1189 }
1190 EXPORT_SYMBOL(udp_ioctl);
1191
1192 /*
1193 * This should be easy, if there is something there we
1194 * return it, otherwise we block.
1195 */
1196
1197 int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
1198 size_t len, int noblock, int flags, int *addr_len)
1199 {
1200 struct inet_sock *inet = inet_sk(sk);
1201 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
1202 struct sk_buff *skb;
1203 unsigned int ulen, copied;
1204 int peeked, off = 0;
1205 int err;
1206 int is_udplite = IS_UDPLITE(sk);
1207 bool slow;
1208
1209 /*
1210 * Check any passed addresses
1211 */
1212 if (addr_len)
1213 *addr_len = sizeof(*sin);
1214
1215 if (flags & MSG_ERRQUEUE)
1216 return ip_recv_error(sk, msg, len);
1217
1218 try_again:
1219 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
1220 &peeked, &off, &err);
1221 if (!skb)
1222 goto out;
1223
1224 ulen = skb->len - sizeof(struct udphdr);
1225 copied = len;
1226 if (copied > ulen)
1227 copied = ulen;
1228 else if (copied < ulen)
1229 msg->msg_flags |= MSG_TRUNC;
1230
1231 /*
1232 * If checksum is needed at all, try to do it while copying the
1233 * data. If the data is truncated, or if we only want a partial
1234 * coverage checksum (UDP-Lite), do it before the copy.
1235 */
1236
1237 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
1238 if (udp_lib_checksum_complete(skb))
1239 goto csum_copy_err;
1240 }
1241
1242 if (skb_csum_unnecessary(skb))
1243 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
1244 msg->msg_iov, copied);
1245 else {
1246 err = skb_copy_and_csum_datagram_iovec(skb,
1247 sizeof(struct udphdr),
1248 msg->msg_iov);
1249
1250 if (err == -EINVAL)
1251 goto csum_copy_err;
1252 }
1253
1254 if (unlikely(err)) {
1255 trace_kfree_skb(skb, udp_recvmsg);
1256 if (!peeked) {
1257 atomic_inc(&sk->sk_drops);
1258 UDP_INC_STATS_USER(sock_net(sk),
1259 UDP_MIB_INERRORS, is_udplite);
1260 }
1261 goto out_free;
1262 }
1263
1264 if (!peeked)
1265 UDP_INC_STATS_USER(sock_net(sk),
1266 UDP_MIB_INDATAGRAMS, is_udplite);
1267
1268 sock_recv_ts_and_drops(msg, sk, skb);
1269
1270 /* Copy the address. */
1271 if (sin) {
1272 sin->sin_family = AF_INET;
1273 sin->sin_port = udp_hdr(skb)->source;
1274 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1275 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1276 }
1277 if (inet->cmsg_flags)
1278 ip_cmsg_recv(msg, skb);
1279
1280 err = copied;
1281 if (flags & MSG_TRUNC)
1282 err = ulen;
1283
1284 out_free:
1285 skb_free_datagram_locked(sk, skb);
1286 out:
1287 return err;
1288
1289 csum_copy_err:
1290 slow = lock_sock_fast(sk);
1291 if (!skb_kill_datagram(sk, skb, flags)) {
1292 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1293 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1294 }
1295 unlock_sock_fast(sk, slow);
1296
1297 if (noblock)
1298 return -EAGAIN;
1299
1300 /* starting over for a new packet */
1301 msg->msg_flags &= ~MSG_TRUNC;
1302 goto try_again;
1303 }
1304
1305
1306 int udp_disconnect(struct sock *sk, int flags)
1307 {
1308 struct inet_sock *inet = inet_sk(sk);
1309 /*
1310 * 1003.1g - break association.
1311 */
1312
1313 sk->sk_state = TCP_CLOSE;
1314 inet->inet_daddr = 0;
1315 inet->inet_dport = 0;
1316 sock_rps_reset_rxhash(sk);
1317 sk->sk_bound_dev_if = 0;
1318 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1319 inet_reset_saddr(sk);
1320
1321 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1322 sk->sk_prot->unhash(sk);
1323 inet->inet_sport = 0;
1324 }
1325 sk_dst_reset(sk);
1326 return 0;
1327 }
1328 EXPORT_SYMBOL(udp_disconnect);
1329
1330 void udp_lib_unhash(struct sock *sk)
1331 {
1332 if (sk_hashed(sk)) {
1333 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1334 struct udp_hslot *hslot, *hslot2;
1335
1336 hslot = udp_hashslot(udptable, sock_net(sk),
1337 udp_sk(sk)->udp_port_hash);
1338 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1339
1340 spin_lock_bh(&hslot->lock);
1341 if (sk_nulls_del_node_init_rcu(sk)) {
1342 hslot->count--;
1343 inet_sk(sk)->inet_num = 0;
1344 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1345
1346 spin_lock(&hslot2->lock);
1347 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1348 hslot2->count--;
1349 spin_unlock(&hslot2->lock);
1350 }
1351 spin_unlock_bh(&hslot->lock);
1352 }
1353 }
1354 EXPORT_SYMBOL(udp_lib_unhash);
1355
1356 /*
1357 * inet_rcv_saddr was changed, we must rehash secondary hash
1358 */
1359 void udp_lib_rehash(struct sock *sk, u16 newhash)
1360 {
1361 if (sk_hashed(sk)) {
1362 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1363 struct udp_hslot *hslot, *hslot2, *nhslot2;
1364
1365 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1366 nhslot2 = udp_hashslot2(udptable, newhash);
1367 udp_sk(sk)->udp_portaddr_hash = newhash;
1368 if (hslot2 != nhslot2) {
1369 hslot = udp_hashslot(udptable, sock_net(sk),
1370 udp_sk(sk)->udp_port_hash);
1371 /* we must lock primary chain too */
1372 spin_lock_bh(&hslot->lock);
1373
1374 spin_lock(&hslot2->lock);
1375 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1376 hslot2->count--;
1377 spin_unlock(&hslot2->lock);
1378
1379 spin_lock(&nhslot2->lock);
1380 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
1381 &nhslot2->head);
1382 nhslot2->count++;
1383 spin_unlock(&nhslot2->lock);
1384
1385 spin_unlock_bh(&hslot->lock);
1386 }
1387 }
1388 }
1389 EXPORT_SYMBOL(udp_lib_rehash);
1390
1391 static void udp_v4_rehash(struct sock *sk)
1392 {
1393 u16 new_hash = udp4_portaddr_hash(sock_net(sk),
1394 inet_sk(sk)->inet_rcv_saddr,
1395 inet_sk(sk)->inet_num);
1396 udp_lib_rehash(sk, new_hash);
1397 }
1398
1399 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1400 {
1401 int rc;
1402
1403 if (inet_sk(sk)->inet_daddr)
1404 sock_rps_save_rxhash(sk, skb);
1405
1406 rc = sock_queue_rcv_skb(sk, skb);
1407 if (rc < 0) {
1408 int is_udplite = IS_UDPLITE(sk);
1409
1410 /* Note that an ENOMEM error is charged twice */
1411 if (rc == -ENOMEM)
1412 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1413 is_udplite);
1414 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1415 kfree_skb(skb);
1416 trace_udp_fail_queue_rcv_skb(rc, sk);
1417 return -1;
1418 }
1419
1420 return 0;
1421
1422 }
1423
1424 static struct static_key udp_encap_needed __read_mostly;
1425 void udp_encap_enable(void)
1426 {
1427 if (!static_key_enabled(&udp_encap_needed))
1428 static_key_slow_inc(&udp_encap_needed);
1429 }
1430 EXPORT_SYMBOL(udp_encap_enable);
1431
1432 /* returns:
1433 * -1: error
1434 * 0: success
1435 * >0: "udp encap" protocol resubmission
1436 *
1437 * Note that in the success and error cases, the skb is assumed to
1438 * have either been requeued or freed.
1439 */
1440 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1441 {
1442 struct udp_sock *up = udp_sk(sk);
1443 int rc;
1444 int is_udplite = IS_UDPLITE(sk);
1445
1446 /*
1447 * Charge it to the socket, dropping if the queue is full.
1448 */
1449 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1450 goto drop;
1451 nf_reset(skb);
1452
1453 if (static_key_false(&udp_encap_needed) && up->encap_type) {
1454 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
1455
1456 /*
1457 * This is an encapsulation socket so pass the skb to
1458 * the socket's udp_encap_rcv() hook. Otherwise, just
1459 * fall through and pass this up the UDP socket.
1460 * up->encap_rcv() returns the following value:
1461 * =0 if skb was successfully passed to the encap
1462 * handler or was discarded by it.
1463 * >0 if skb should be passed on to UDP.
1464 * <0 if skb should be resubmitted as proto -N
1465 */
1466
1467 /* if we're overly short, let UDP handle it */
1468 encap_rcv = ACCESS_ONCE(up->encap_rcv);
1469 if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
1470 int ret;
1471
1472 ret = encap_rcv(sk, skb);
1473 if (ret <= 0) {
1474 UDP_INC_STATS_BH(sock_net(sk),
1475 UDP_MIB_INDATAGRAMS,
1476 is_udplite);
1477 return -ret;
1478 }
1479 }
1480
1481 /* FALLTHROUGH -- it's a UDP Packet */
1482 }
1483
1484 /*
1485 * UDP-Lite specific tests, ignored on UDP sockets
1486 */
1487 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1488
1489 /*
1490 * MIB statistics other than incrementing the error count are
1491 * disabled for the following two types of errors: these depend
1492 * on the application settings, not on the functioning of the
1493 * protocol stack as such.
1494 *
1495 * RFC 3828 here recommends (sec 3.3): "There should also be a
1496 * way ... to ... at least let the receiving application block
1497 * delivery of packets with coverage values less than a value
1498 * provided by the application."
1499 */
1500 if (up->pcrlen == 0) { /* full coverage was set */
1501 LIMIT_NETDEBUG(KERN_WARNING "UDPLite: partial coverage %d while full coverage %d requested\n",
1502 UDP_SKB_CB(skb)->cscov, skb->len);
1503 goto drop;
1504 }
1505 /* The next case involves violating the min. coverage requested
1506 * by the receiver. This is subtle: if receiver wants x and x is
1507 * greater than the buffersize/MTU then receiver will complain
1508 * that it wants x while sender emits packets of smaller size y.
1509 * Therefore the above ...()->partial_cov statement is essential.
1510 */
1511 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1512 LIMIT_NETDEBUG(KERN_WARNING "UDPLite: coverage %d too small, need min %d\n",
1513 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1514 goto drop;
1515 }
1516 }
1517
1518 if (rcu_access_pointer(sk->sk_filter) &&
1519 udp_lib_checksum_complete(skb))
1520 goto csum_error;
1521
1522
1523 if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf))
1524 goto drop;
1525
1526 rc = 0;
1527
1528 ipv4_pktinfo_prepare(skb);
1529 bh_lock_sock(sk);
1530 if (!sock_owned_by_user(sk))
1531 rc = __udp_queue_rcv_skb(sk, skb);
1532 else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
1533 bh_unlock_sock(sk);
1534 goto drop;
1535 }
1536 bh_unlock_sock(sk);
1537
1538 return rc;
1539
1540 csum_error:
1541 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1542 drop:
1543 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1544 atomic_inc(&sk->sk_drops);
1545 kfree_skb(skb);
1546 return -1;
1547 }
1548
1549
1550 static void flush_stack(struct sock **stack, unsigned int count,
1551 struct sk_buff *skb, unsigned int final)
1552 {
1553 unsigned int i;
1554 struct sk_buff *skb1 = NULL;
1555 struct sock *sk;
1556
1557 for (i = 0; i < count; i++) {
1558 sk = stack[i];
1559 if (likely(skb1 == NULL))
1560 skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
1561
1562 if (!skb1) {
1563 atomic_inc(&sk->sk_drops);
1564 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1565 IS_UDPLITE(sk));
1566 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
1567 IS_UDPLITE(sk));
1568 }
1569
1570 if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0)
1571 skb1 = NULL;
1572 }
1573 if (unlikely(skb1))
1574 kfree_skb(skb1);
1575 }
1576
1577 /*
1578 * Multicasts and broadcasts go to each listener.
1579 *
1580 * Note: called only from the BH handler context.
1581 */
1582 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1583 struct udphdr *uh,
1584 __be32 saddr, __be32 daddr,
1585 struct udp_table *udptable)
1586 {
1587 struct sock *sk, *stack[256 / sizeof(struct sock *)];
1588 struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
1589 int dif;
1590 unsigned int i, count = 0;
1591
1592 spin_lock(&hslot->lock);
1593 sk = sk_nulls_head(&hslot->head);
1594 dif = skb->dev->ifindex;
1595 sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
1596 while (sk) {
1597 stack[count++] = sk;
1598 sk = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest,
1599 daddr, uh->source, saddr, dif);
1600 if (unlikely(count == ARRAY_SIZE(stack))) {
1601 if (!sk)
1602 break;
1603 flush_stack(stack, count, skb, ~0);
1604 count = 0;
1605 }
1606 }
1607 /*
1608 * before releasing chain lock, we must take a reference on sockets
1609 */
1610 for (i = 0; i < count; i++)
1611 sock_hold(stack[i]);
1612
1613 spin_unlock(&hslot->lock);
1614
1615 /*
1616 * do the slow work with no lock held
1617 */
1618 if (count) {
1619 flush_stack(stack, count, skb, count - 1);
1620
1621 for (i = 0; i < count; i++)
1622 sock_put(stack[i]);
1623 } else {
1624 kfree_skb(skb);
1625 }
1626 return 0;
1627 }
1628
1629 /* Initialize UDP checksum. If exited with zero value (success),
1630 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1631 * Otherwise, csum completion requires chacksumming packet body,
1632 * including udp header and folding it to skb->csum.
1633 */
1634 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1635 int proto)
1636 {
1637 const struct iphdr *iph;
1638 int err;
1639
1640 UDP_SKB_CB(skb)->partial_cov = 0;
1641 UDP_SKB_CB(skb)->cscov = skb->len;
1642
1643 if (proto == IPPROTO_UDPLITE) {
1644 err = udplite_checksum_init(skb, uh);
1645 if (err)
1646 return err;
1647 }
1648
1649 iph = ip_hdr(skb);
1650 if (uh->check == 0) {
1651 skb->ip_summed = CHECKSUM_UNNECESSARY;
1652 } else if (skb->ip_summed == CHECKSUM_COMPLETE) {
1653 if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
1654 proto, skb->csum))
1655 skb->ip_summed = CHECKSUM_UNNECESSARY;
1656 }
1657 if (!skb_csum_unnecessary(skb))
1658 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1659 skb->len, proto, 0);
1660 /* Probably, we should checksum udp header (it should be in cache
1661 * in any case) and data in tiny packets (< rx copybreak).
1662 */
1663
1664 return 0;
1665 }
1666
1667 /*
1668 * All we need to do is get the socket, and then do a checksum.
1669 */
1670
1671 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1672 int proto)
1673 {
1674 struct sock *sk;
1675 struct udphdr *uh;
1676 unsigned short ulen;
1677 struct rtable *rt = skb_rtable(skb);
1678 __be32 saddr, daddr;
1679 struct net *net = dev_net(skb->dev);
1680
1681 /*
1682 * Validate the packet.
1683 */
1684 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1685 goto drop; /* No space for header. */
1686
1687 uh = udp_hdr(skb);
1688 ulen = ntohs(uh->len);
1689 saddr = ip_hdr(skb)->saddr;
1690 daddr = ip_hdr(skb)->daddr;
1691
1692 if (ulen > skb->len)
1693 goto short_packet;
1694
1695 if (proto == IPPROTO_UDP) {
1696 /* UDP validates ulen. */
1697 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
1698 goto short_packet;
1699 uh = udp_hdr(skb);
1700 }
1701
1702 if (udp4_csum_init(skb, uh, proto))
1703 goto csum_error;
1704
1705 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1706 return __udp4_lib_mcast_deliver(net, skb, uh,
1707 saddr, daddr, udptable);
1708
1709 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1710
1711 if (sk != NULL) {
1712 int ret = udp_queue_rcv_skb(sk, skb);
1713 sock_put(sk);
1714
1715 /* a return value > 0 means to resubmit the input, but
1716 * it wants the return to be -protocol, or 0
1717 */
1718 if (ret > 0)
1719 return -ret;
1720 return 0;
1721 }
1722
1723 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1724 goto drop;
1725 nf_reset(skb);
1726
1727 /* No socket. Drop packet silently, if checksum is wrong */
1728 if (udp_lib_checksum_complete(skb))
1729 goto csum_error;
1730
1731 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1732 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1733
1734 /*
1735 * Hmm. We got an UDP packet to a port to which we
1736 * don't wanna listen. Ignore it.
1737 */
1738 kfree_skb(skb);
1739 return 0;
1740
1741 short_packet:
1742 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1743 proto == IPPROTO_UDPLITE ? "Lite" : "",
1744 &saddr, ntohs(uh->source),
1745 ulen, skb->len,
1746 &daddr, ntohs(uh->dest));
1747 goto drop;
1748
1749 csum_error:
1750 /*
1751 * RFC1122: OK. Discards the bad packet silently (as far as
1752 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1753 */
1754 LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1755 proto == IPPROTO_UDPLITE ? "Lite" : "",
1756 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
1757 ulen);
1758 UDP_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
1759 drop:
1760 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1761 kfree_skb(skb);
1762 return 0;
1763 }
1764
1765 int udp_rcv(struct sk_buff *skb)
1766 {
1767 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1768 }
1769
1770 void udp_destroy_sock(struct sock *sk)
1771 {
1772 struct udp_sock *up = udp_sk(sk);
1773 bool slow = lock_sock_fast(sk);
1774 udp_flush_pending_frames(sk);
1775 unlock_sock_fast(sk, slow);
1776 if (static_key_false(&udp_encap_needed) && up->encap_type) {
1777 void (*encap_destroy)(struct sock *sk);
1778 encap_destroy = ACCESS_ONCE(up->encap_destroy);
1779 if (encap_destroy)
1780 encap_destroy(sk);
1781 }
1782 }
1783
1784 /*
1785 * Socket option code for UDP
1786 */
1787 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
1788 char __user *optval, unsigned int optlen,
1789 int (*push_pending_frames)(struct sock *))
1790 {
1791 struct udp_sock *up = udp_sk(sk);
1792 int val;
1793 int err = 0;
1794 int is_udplite = IS_UDPLITE(sk);
1795
1796 if (optlen < sizeof(int))
1797 return -EINVAL;
1798
1799 if (get_user(val, (int __user *)optval))
1800 return -EFAULT;
1801
1802 switch (optname) {
1803 case UDP_CORK:
1804 if (val != 0) {
1805 up->corkflag = 1;
1806 } else {
1807 up->corkflag = 0;
1808 lock_sock(sk);
1809 (*push_pending_frames)(sk);
1810 release_sock(sk);
1811 }
1812 break;
1813
1814 case UDP_ENCAP:
1815 switch (val) {
1816 case 0:
1817 case UDP_ENCAP_ESPINUDP:
1818 case UDP_ENCAP_ESPINUDP_NON_IKE:
1819 up->encap_rcv = xfrm4_udp_encap_rcv;
1820 /* FALLTHROUGH */
1821 case UDP_ENCAP_L2TPINUDP:
1822 up->encap_type = val;
1823 udp_encap_enable();
1824 break;
1825 default:
1826 err = -ENOPROTOOPT;
1827 break;
1828 }
1829 break;
1830
1831 /*
1832 * UDP-Lite's partial checksum coverage (RFC 3828).
1833 */
1834 /* The sender sets actual checksum coverage length via this option.
1835 * The case coverage > packet length is handled by send module. */
1836 case UDPLITE_SEND_CSCOV:
1837 if (!is_udplite) /* Disable the option on UDP sockets */
1838 return -ENOPROTOOPT;
1839 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
1840 val = 8;
1841 else if (val > USHRT_MAX)
1842 val = USHRT_MAX;
1843 up->pcslen = val;
1844 up->pcflag |= UDPLITE_SEND_CC;
1845 break;
1846
1847 /* The receiver specifies a minimum checksum coverage value. To make
1848 * sense, this should be set to at least 8 (as done below). If zero is
1849 * used, this again means full checksum coverage. */
1850 case UDPLITE_RECV_CSCOV:
1851 if (!is_udplite) /* Disable the option on UDP sockets */
1852 return -ENOPROTOOPT;
1853 if (val != 0 && val < 8) /* Avoid silly minimal values. */
1854 val = 8;
1855 else if (val > USHRT_MAX)
1856 val = USHRT_MAX;
1857 up->pcrlen = val;
1858 up->pcflag |= UDPLITE_RECV_CC;
1859 break;
1860
1861 default:
1862 err = -ENOPROTOOPT;
1863 break;
1864 }
1865
1866 return err;
1867 }
1868 EXPORT_SYMBOL(udp_lib_setsockopt);
1869
1870 int udp_setsockopt(struct sock *sk, int level, int optname,
1871 char __user *optval, unsigned int optlen)
1872 {
1873 if (level == SOL_UDP || level == SOL_UDPLITE)
1874 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1875 udp_push_pending_frames);
1876 return ip_setsockopt(sk, level, optname, optval, optlen);
1877 }
1878
1879 #ifdef CONFIG_COMPAT
1880 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
1881 char __user *optval, unsigned int optlen)
1882 {
1883 if (level == SOL_UDP || level == SOL_UDPLITE)
1884 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1885 udp_push_pending_frames);
1886 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
1887 }
1888 #endif
1889
1890 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
1891 char __user *optval, int __user *optlen)
1892 {
1893 struct udp_sock *up = udp_sk(sk);
1894 int val, len;
1895
1896 if (get_user(len, optlen))
1897 return -EFAULT;
1898
1899 len = min_t(unsigned int, len, sizeof(int));
1900
1901 if (len < 0)
1902 return -EINVAL;
1903
1904 switch (optname) {
1905 case UDP_CORK:
1906 val = up->corkflag;
1907 break;
1908
1909 case UDP_ENCAP:
1910 val = up->encap_type;
1911 break;
1912
1913 /* The following two cannot be changed on UDP sockets, the return is
1914 * always 0 (which corresponds to the full checksum coverage of UDP). */
1915 case UDPLITE_SEND_CSCOV:
1916 val = up->pcslen;
1917 break;
1918
1919 case UDPLITE_RECV_CSCOV:
1920 val = up->pcrlen;
1921 break;
1922
1923 default:
1924 return -ENOPROTOOPT;
1925 }
1926
1927 if (put_user(len, optlen))
1928 return -EFAULT;
1929 if (copy_to_user(optval, &val, len))
1930 return -EFAULT;
1931 return 0;
1932 }
1933 EXPORT_SYMBOL(udp_lib_getsockopt);
1934
1935 int udp_getsockopt(struct sock *sk, int level, int optname,
1936 char __user *optval, int __user *optlen)
1937 {
1938 if (level == SOL_UDP || level == SOL_UDPLITE)
1939 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1940 return ip_getsockopt(sk, level, optname, optval, optlen);
1941 }
1942
1943 #ifdef CONFIG_COMPAT
1944 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
1945 char __user *optval, int __user *optlen)
1946 {
1947 if (level == SOL_UDP || level == SOL_UDPLITE)
1948 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1949 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
1950 }
1951 #endif
1952 /**
1953 * udp_poll - wait for a UDP event.
1954 * @file - file struct
1955 * @sock - socket
1956 * @wait - poll table
1957 *
1958 * This is same as datagram poll, except for the special case of
1959 * blocking sockets. If application is using a blocking fd
1960 * and a packet with checksum error is in the queue;
1961 * then it could get return from select indicating data available
1962 * but then block when reading it. Add special case code
1963 * to work around these arguably broken applications.
1964 */
1965 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
1966 {
1967 unsigned int mask = datagram_poll(file, sock, wait);
1968 struct sock *sk = sock->sk;
1969
1970 /* Check for false positives due to checksum errors */
1971 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
1972 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk))
1973 mask &= ~(POLLIN | POLLRDNORM);
1974
1975 return mask;
1976
1977 }
1978 EXPORT_SYMBOL(udp_poll);
1979
1980 struct proto udp_prot = {
1981 .name = "UDP",
1982 .owner = THIS_MODULE,
1983 .close = udp_lib_close,
1984 .connect = ip4_datagram_connect,
1985 .disconnect = udp_disconnect,
1986 .ioctl = udp_ioctl,
1987 .destroy = udp_destroy_sock,
1988 .setsockopt = udp_setsockopt,
1989 .getsockopt = udp_getsockopt,
1990 .sendmsg = udp_sendmsg,
1991 .recvmsg = udp_recvmsg,
1992 .sendpage = udp_sendpage,
1993 .backlog_rcv = __udp_queue_rcv_skb,
1994 .release_cb = ip4_datagram_release_cb,
1995 .hash = udp_lib_hash,
1996 .unhash = udp_lib_unhash,
1997 .rehash = udp_v4_rehash,
1998 .get_port = udp_v4_get_port,
1999 .memory_allocated = &udp_memory_allocated,
2000 .sysctl_mem = sysctl_udp_mem,
2001 .sysctl_wmem = &sysctl_udp_wmem_min,
2002 .sysctl_rmem = &sysctl_udp_rmem_min,
2003 .obj_size = sizeof(struct udp_sock),
2004 .slab_flags = SLAB_DESTROY_BY_RCU,
2005 .h.udp_table = &udp_table,
2006 #ifdef CONFIG_COMPAT
2007 .compat_setsockopt = compat_udp_setsockopt,
2008 .compat_getsockopt = compat_udp_getsockopt,
2009 #endif
2010 .clear_sk = sk_prot_clear_portaddr_nulls,
2011 };
2012 EXPORT_SYMBOL(udp_prot);
2013
2014 /* ------------------------------------------------------------------------ */
2015 #ifdef CONFIG_PROC_FS
2016
2017 static struct sock *udp_get_first(struct seq_file *seq, int start)
2018 {
2019 struct sock *sk;
2020 struct udp_iter_state *state = seq->private;
2021 struct net *net = seq_file_net(seq);
2022
2023 for (state->bucket = start; state->bucket <= state->udp_table->mask;
2024 ++state->bucket) {
2025 struct hlist_nulls_node *node;
2026 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
2027
2028 if (hlist_nulls_empty(&hslot->head))
2029 continue;
2030
2031 spin_lock_bh(&hslot->lock);
2032 sk_nulls_for_each(sk, node, &hslot->head) {
2033 if (!net_eq(sock_net(sk), net))
2034 continue;
2035 if (sk->sk_family == state->family)
2036 goto found;
2037 }
2038 spin_unlock_bh(&hslot->lock);
2039 }
2040 sk = NULL;
2041 found:
2042 return sk;
2043 }
2044
2045 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
2046 {
2047 struct udp_iter_state *state = seq->private;
2048 struct net *net = seq_file_net(seq);
2049
2050 do {
2051 sk = sk_nulls_next(sk);
2052 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
2053
2054 if (!sk) {
2055 if (state->bucket <= state->udp_table->mask)
2056 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2057 return udp_get_first(seq, state->bucket + 1);
2058 }
2059 return sk;
2060 }
2061
2062 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
2063 {
2064 struct sock *sk = udp_get_first(seq, 0);
2065
2066 if (sk)
2067 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
2068 --pos;
2069 return pos ? NULL : sk;
2070 }
2071
2072 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
2073 {
2074 struct udp_iter_state *state = seq->private;
2075 state->bucket = MAX_UDP_PORTS;
2076
2077 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
2078 }
2079
2080 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2081 {
2082 struct sock *sk;
2083
2084 if (v == SEQ_START_TOKEN)
2085 sk = udp_get_idx(seq, 0);
2086 else
2087 sk = udp_get_next(seq, v);
2088
2089 ++*pos;
2090 return sk;
2091 }
2092
2093 static void udp_seq_stop(struct seq_file *seq, void *v)
2094 {
2095 struct udp_iter_state *state = seq->private;
2096
2097 if (state->bucket <= state->udp_table->mask)
2098 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2099 }
2100
2101 int udp_seq_open(struct inode *inode, struct file *file)
2102 {
2103 struct udp_seq_afinfo *afinfo = PDE_DATA(inode);
2104 struct udp_iter_state *s;
2105 int err;
2106
2107 err = seq_open_net(inode, file, &afinfo->seq_ops,
2108 sizeof(struct udp_iter_state));
2109 if (err < 0)
2110 return err;
2111
2112 s = ((struct seq_file *)file->private_data)->private;
2113 s->family = afinfo->family;
2114 s->udp_table = afinfo->udp_table;
2115 return err;
2116 }
2117 EXPORT_SYMBOL(udp_seq_open);
2118
2119 /* ------------------------------------------------------------------------ */
2120 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
2121 {
2122 struct proc_dir_entry *p;
2123 int rc = 0;
2124
2125 afinfo->seq_ops.start = udp_seq_start;
2126 afinfo->seq_ops.next = udp_seq_next;
2127 afinfo->seq_ops.stop = udp_seq_stop;
2128
2129 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2130 afinfo->seq_fops, afinfo);
2131 if (!p)
2132 rc = -ENOMEM;
2133 return rc;
2134 }
2135 EXPORT_SYMBOL(udp_proc_register);
2136
2137 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
2138 {
2139 remove_proc_entry(afinfo->name, net->proc_net);
2140 }
2141 EXPORT_SYMBOL(udp_proc_unregister);
2142
2143 /* ------------------------------------------------------------------------ */
2144 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
2145 int bucket, int *len)
2146 {
2147 struct inet_sock *inet = inet_sk(sp);
2148 __be32 dest = inet->inet_daddr;
2149 __be32 src = inet->inet_rcv_saddr;
2150 __u16 destp = ntohs(inet->inet_dport);
2151 __u16 srcp = ntohs(inet->inet_sport);
2152
2153 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
2154 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d%n",
2155 bucket, src, srcp, dest, destp, sp->sk_state,
2156 sk_wmem_alloc_get(sp),
2157 sk_rmem_alloc_get(sp),
2158 0, 0L, 0,
2159 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
2160 0, sock_i_ino(sp),
2161 atomic_read(&sp->sk_refcnt), sp,
2162 atomic_read(&sp->sk_drops), len);
2163 }
2164
2165 int udp4_seq_show(struct seq_file *seq, void *v)
2166 {
2167 if (v == SEQ_START_TOKEN)
2168 seq_printf(seq, "%-127s\n",
2169 " sl local_address rem_address st tx_queue "
2170 "rx_queue tr tm->when retrnsmt uid timeout "
2171 "inode ref pointer drops");
2172 else {
2173 struct udp_iter_state *state = seq->private;
2174 int len;
2175
2176 udp4_format_sock(v, seq, state->bucket, &len);
2177 seq_printf(seq, "%*s\n", 127 - len, "");
2178 }
2179 return 0;
2180 }
2181
2182 static const struct file_operations udp_afinfo_seq_fops = {
2183 .owner = THIS_MODULE,
2184 .open = udp_seq_open,
2185 .read = seq_read,
2186 .llseek = seq_lseek,
2187 .release = seq_release_net
2188 };
2189
2190 /* ------------------------------------------------------------------------ */
2191 static struct udp_seq_afinfo udp4_seq_afinfo = {
2192 .name = "udp",
2193 .family = AF_INET,
2194 .udp_table = &udp_table,
2195 .seq_fops = &udp_afinfo_seq_fops,
2196 .seq_ops = {
2197 .show = udp4_seq_show,
2198 },
2199 };
2200
2201 static int __net_init udp4_proc_init_net(struct net *net)
2202 {
2203 return udp_proc_register(net, &udp4_seq_afinfo);
2204 }
2205
2206 static void __net_exit udp4_proc_exit_net(struct net *net)
2207 {
2208 udp_proc_unregister(net, &udp4_seq_afinfo);
2209 }
2210
2211 static struct pernet_operations udp4_net_ops = {
2212 .init = udp4_proc_init_net,
2213 .exit = udp4_proc_exit_net,
2214 };
2215
2216 int __init udp4_proc_init(void)
2217 {
2218 return register_pernet_subsys(&udp4_net_ops);
2219 }
2220
2221 void udp4_proc_exit(void)
2222 {
2223 unregister_pernet_subsys(&udp4_net_ops);
2224 }
2225 #endif /* CONFIG_PROC_FS */
2226
2227 static __initdata unsigned long uhash_entries;
2228 static int __init set_uhash_entries(char *str)
2229 {
2230 ssize_t ret;
2231
2232 if (!str)
2233 return 0;
2234
2235 ret = kstrtoul(str, 0, &uhash_entries);
2236 if (ret)
2237 return 0;
2238
2239 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
2240 uhash_entries = UDP_HTABLE_SIZE_MIN;
2241 return 1;
2242 }
2243 __setup("uhash_entries=", set_uhash_entries);
2244
2245 void __init udp_table_init(struct udp_table *table, const char *name)
2246 {
2247 unsigned int i;
2248
2249 table->hash = alloc_large_system_hash(name,
2250 2 * sizeof(struct udp_hslot),
2251 uhash_entries,
2252 21, /* one slot per 2 MB */
2253 0,
2254 &table->log,
2255 &table->mask,
2256 UDP_HTABLE_SIZE_MIN,
2257 64 * 1024);
2258
2259 table->hash2 = table->hash + (table->mask + 1);
2260 for (i = 0; i <= table->mask; i++) {
2261 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
2262 table->hash[i].count = 0;
2263 spin_lock_init(&table->hash[i].lock);
2264 }
2265 for (i = 0; i <= table->mask; i++) {
2266 INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i);
2267 table->hash2[i].count = 0;
2268 spin_lock_init(&table->hash2[i].lock);
2269 }
2270 }
2271
2272 void __init udp_init(void)
2273 {
2274 unsigned long limit;
2275
2276 udp_table_init(&udp_table, "UDP");
2277 limit = nr_free_buffer_pages() / 8;
2278 limit = max(limit, 128UL);
2279 sysctl_udp_mem[0] = limit / 4 * 3;
2280 sysctl_udp_mem[1] = limit;
2281 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
2282
2283 sysctl_udp_rmem_min = SK_MEM_QUANTUM;
2284 sysctl_udp_wmem_min = SK_MEM_QUANTUM;
2285 }
2286
2287 int udp4_ufo_send_check(struct sk_buff *skb)
2288 {
2289 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
2290 return -EINVAL;
2291
2292 if (likely(!skb->encapsulation)) {
2293 const struct iphdr *iph;
2294 struct udphdr *uh;
2295
2296 iph = ip_hdr(skb);
2297 uh = udp_hdr(skb);
2298
2299 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
2300 IPPROTO_UDP, 0);
2301 skb->csum_start = skb_transport_header(skb) - skb->head;
2302 skb->csum_offset = offsetof(struct udphdr, check);
2303 skb->ip_summed = CHECKSUM_PARTIAL;
2304 }
2305 return 0;
2306 }
2307
2308 static struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
2309 netdev_features_t features)
2310 {
2311 struct sk_buff *segs = ERR_PTR(-EINVAL);
2312 int mac_len = skb->mac_len;
2313 int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
2314 __be16 protocol = skb->protocol;
2315 netdev_features_t enc_features;
2316 int outer_hlen;
2317
2318 if (unlikely(!pskb_may_pull(skb, tnl_hlen)))
2319 goto out;
2320
2321 skb->encapsulation = 0;
2322 __skb_pull(skb, tnl_hlen);
2323 skb_reset_mac_header(skb);
2324 skb_set_network_header(skb, skb_inner_network_offset(skb));
2325 skb->mac_len = skb_inner_network_offset(skb);
2326 skb->protocol = htons(ETH_P_TEB);
2327
2328 /* segment inner packet. */
2329 enc_features = skb->dev->hw_enc_features & netif_skb_features(skb);
2330 segs = skb_mac_gso_segment(skb, enc_features);
2331 if (!segs || IS_ERR(segs))
2332 goto out;
2333
2334 outer_hlen = skb_tnl_header_len(skb);
2335 skb = segs;
2336 do {
2337 struct udphdr *uh;
2338 int udp_offset = outer_hlen - tnl_hlen;
2339
2340 skb->mac_len = mac_len;
2341
2342 skb_push(skb, outer_hlen);
2343 skb_reset_mac_header(skb);
2344 skb_set_network_header(skb, mac_len);
2345 skb_set_transport_header(skb, udp_offset);
2346 uh = udp_hdr(skb);
2347 uh->len = htons(skb->len - udp_offset);
2348
2349 /* csum segment if tunnel sets skb with csum. */
2350 if (unlikely(uh->check)) {
2351 struct iphdr *iph = ip_hdr(skb);
2352
2353 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
2354 skb->len - udp_offset,
2355 IPPROTO_UDP, 0);
2356 uh->check = csum_fold(skb_checksum(skb, udp_offset,
2357 skb->len - udp_offset, 0));
2358 if (uh->check == 0)
2359 uh->check = CSUM_MANGLED_0;
2360
2361 }
2362 skb->ip_summed = CHECKSUM_NONE;
2363 skb->protocol = protocol;
2364 } while ((skb = skb->next));
2365 out:
2366 return segs;
2367 }
2368
2369 struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
2370 netdev_features_t features)
2371 {
2372 struct sk_buff *segs = ERR_PTR(-EINVAL);
2373 unsigned int mss;
2374 mss = skb_shinfo(skb)->gso_size;
2375 if (unlikely(skb->len <= mss))
2376 goto out;
2377
2378 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
2379 /* Packet is from an untrusted source, reset gso_segs. */
2380 int type = skb_shinfo(skb)->gso_type;
2381
2382 if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY |
2383 SKB_GSO_UDP_TUNNEL |
2384 SKB_GSO_GRE) ||
2385 !(type & (SKB_GSO_UDP))))
2386 goto out;
2387
2388 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
2389
2390 segs = NULL;
2391 goto out;
2392 }
2393
2394 /* Fragment the skb. IP headers of the fragments are updated in
2395 * inet_gso_segment()
2396 */
2397 if (skb->encapsulation && skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL)
2398 segs = skb_udp_tunnel_segment(skb, features);
2399 else {
2400 int offset;
2401 __wsum csum;
2402
2403 /* Do software UFO. Complete and fill in the UDP checksum as
2404 * HW cannot do checksum of UDP packets sent as multiple
2405 * IP fragments.
2406 */
2407 offset = skb_checksum_start_offset(skb);
2408 csum = skb_checksum(skb, offset, skb->len - offset, 0);
2409 offset += skb->csum_offset;
2410 *(__sum16 *)(skb->data + offset) = csum_fold(csum);
2411 skb->ip_summed = CHECKSUM_NONE;
2412
2413 segs = skb_segment(skb, features);
2414 }
2415 out:
2416 return segs;
2417 }
Linus' kernel tree