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Merge branch 'component' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
[linux/fpc-iii.git] / net / ipv4 / udp.c
blobbe0b21852b138ebc5eed9caf37740cbe1cb1abe0
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/inetdevice.h>
94 #include <linux/in.h>
95 #include <linux/errno.h>
96 #include <linux/timer.h>
97 #include <linux/mm.h>
98 #include <linux/inet.h>
99 #include <linux/netdevice.h>
100 #include <linux/slab.h>
101 #include <net/tcp_states.h>
102 #include <linux/skbuff.h>
103 #include <linux/proc_fs.h>
104 #include <linux/seq_file.h>
105 #include <net/net_namespace.h>
106 #include <net/icmp.h>
107 #include <net/inet_hashtables.h>
108 #include <net/route.h>
109 #include <net/checksum.h>
110 #include <net/xfrm.h>
111 #include <trace/events/udp.h>
112 #include <linux/static_key.h>
113 #include <trace/events/skb.h>
114 #include <net/busy_poll.h>
115 #include "udp_impl.h"
116 #include <net/sock_reuseport.h>
117
118 struct udp_table udp_table __read_mostly;
119 EXPORT_SYMBOL(udp_table);
120
121 long sysctl_udp_mem[3] __read_mostly;
122 EXPORT_SYMBOL(sysctl_udp_mem);
123
124 int sysctl_udp_rmem_min __read_mostly;
125 EXPORT_SYMBOL(sysctl_udp_rmem_min);
126
127 int sysctl_udp_wmem_min __read_mostly;
128 EXPORT_SYMBOL(sysctl_udp_wmem_min);
129
130 atomic_long_t udp_memory_allocated;
131 EXPORT_SYMBOL(udp_memory_allocated);
132
133 #define MAX_UDP_PORTS 65536
134 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
135
136 static int udp_lib_lport_inuse(struct net *net, __u16 num,
137 const struct udp_hslot *hslot,
138 unsigned long *bitmap,
139 struct sock *sk,
140 int (*saddr_comp)(const struct sock *sk1,
141 const struct sock *sk2,
142 bool match_wildcard),
143 unsigned int log)
144 {
145 struct sock *sk2;
146 struct hlist_nulls_node *node;
147 kuid_t uid = sock_i_uid(sk);
148
149 sk_nulls_for_each(sk2, node, &hslot->head) {
150 if (net_eq(sock_net(sk2), net) &&
151 sk2 != sk &&
152 (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
153 (!sk2->sk_reuse || !sk->sk_reuse) &&
154 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
155 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
156 (!sk2->sk_reuseport || !sk->sk_reuseport ||
157 rcu_access_pointer(sk->sk_reuseport_cb) ||
158 !uid_eq(uid, sock_i_uid(sk2))) &&
159 saddr_comp(sk, sk2, true)) {
160 if (!bitmap)
161 return 1;
162 __set_bit(udp_sk(sk2)->udp_port_hash >> log, bitmap);
163 }
164 }
165 return 0;
166 }
167
168 /*
169 * Note: we still hold spinlock of primary hash chain, so no other writer
170 * can insert/delete a socket with local_port == num
171 */
172 static int udp_lib_lport_inuse2(struct net *net, __u16 num,
173 struct udp_hslot *hslot2,
174 struct sock *sk,
175 int (*saddr_comp)(const struct sock *sk1,
176 const struct sock *sk2,
177 bool match_wildcard))
178 {
179 struct sock *sk2;
180 struct hlist_nulls_node *node;
181 kuid_t uid = sock_i_uid(sk);
182 int res = 0;
183
184 spin_lock(&hslot2->lock);
185 udp_portaddr_for_each_entry(sk2, node, &hslot2->head) {
186 if (net_eq(sock_net(sk2), net) &&
187 sk2 != sk &&
188 (udp_sk(sk2)->udp_port_hash == num) &&
189 (!sk2->sk_reuse || !sk->sk_reuse) &&
190 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
191 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
192 (!sk2->sk_reuseport || !sk->sk_reuseport ||
193 rcu_access_pointer(sk->sk_reuseport_cb) ||
194 !uid_eq(uid, sock_i_uid(sk2))) &&
195 saddr_comp(sk, sk2, true)) {
196 res = 1;
197 break;
198 }
199 }
200 spin_unlock(&hslot2->lock);
201 return res;
202 }
203
204 static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot,
205 int (*saddr_same)(const struct sock *sk1,
206 const struct sock *sk2,
207 bool match_wildcard))
208 {
209 struct net *net = sock_net(sk);
210 struct hlist_nulls_node *node;
211 kuid_t uid = sock_i_uid(sk);
212 struct sock *sk2;
213
214 sk_nulls_for_each(sk2, node, &hslot->head) {
215 if (net_eq(sock_net(sk2), net) &&
216 sk2 != sk &&
217 sk2->sk_family == sk->sk_family &&
218 ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
219 (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) &&
220 (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
221 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
222 (*saddr_same)(sk, sk2, false)) {
223 return reuseport_add_sock(sk, sk2);
224 }
225 }
226
227 /* Initial allocation may have already happened via setsockopt */
228 if (!rcu_access_pointer(sk->sk_reuseport_cb))
229 return reuseport_alloc(sk);
230 return 0;
231 }
232
233 /**
234 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
235 *
236 * @sk: socket struct in question
237 * @snum: port number to look up
238 * @saddr_comp: AF-dependent comparison of bound local IP addresses
239 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
240 * with NULL address
241 */
242 int udp_lib_get_port(struct sock *sk, unsigned short snum,
243 int (*saddr_comp)(const struct sock *sk1,
244 const struct sock *sk2,
245 bool match_wildcard),
246 unsigned int hash2_nulladdr)
247 {
248 struct udp_hslot *hslot, *hslot2;
249 struct udp_table *udptable = sk->sk_prot->h.udp_table;
250 int error = 1;
251 struct net *net = sock_net(sk);
252
253 if (!snum) {
254 int low, high, remaining;
255 unsigned int rand;
256 unsigned short first, last;
257 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
258
259 inet_get_local_port_range(net, &low, &high);
260 remaining = (high - low) + 1;
261
262 rand = prandom_u32();
263 first = reciprocal_scale(rand, remaining) + low;
264 /*
265 * force rand to be an odd multiple of UDP_HTABLE_SIZE
266 */
267 rand = (rand | 1) * (udptable->mask + 1);
268 last = first + udptable->mask + 1;
269 do {
270 hslot = udp_hashslot(udptable, net, first);
271 bitmap_zero(bitmap, PORTS_PER_CHAIN);
272 spin_lock_bh(&hslot->lock);
273 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
274 saddr_comp, udptable->log);
275
276 snum = first;
277 /*
278 * Iterate on all possible values of snum for this hash.
279 * Using steps of an odd multiple of UDP_HTABLE_SIZE
280 * give us randomization and full range coverage.
281 */
282 do {
283 if (low <= snum && snum <= high &&
284 !test_bit(snum >> udptable->log, bitmap) &&
285 !inet_is_local_reserved_port(net, snum))
286 goto found;
287 snum += rand;
288 } while (snum != first);
289 spin_unlock_bh(&hslot->lock);
290 } while (++first != last);
291 goto fail;
292 } else {
293 hslot = udp_hashslot(udptable, net, snum);
294 spin_lock_bh(&hslot->lock);
295 if (hslot->count > 10) {
296 int exist;
297 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum;
298
299 slot2 &= udptable->mask;
300 hash2_nulladdr &= udptable->mask;
301
302 hslot2 = udp_hashslot2(udptable, slot2);
303 if (hslot->count < hslot2->count)
304 goto scan_primary_hash;
305
306 exist = udp_lib_lport_inuse2(net, snum, hslot2,
307 sk, saddr_comp);
308 if (!exist && (hash2_nulladdr != slot2)) {
309 hslot2 = udp_hashslot2(udptable, hash2_nulladdr);
310 exist = udp_lib_lport_inuse2(net, snum, hslot2,
311 sk, saddr_comp);
312 }
313 if (exist)
314 goto fail_unlock;
315 else
316 goto found;
317 }
318 scan_primary_hash:
319 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk,
320 saddr_comp, 0))
321 goto fail_unlock;
322 }
323 found:
324 inet_sk(sk)->inet_num = snum;
325 udp_sk(sk)->udp_port_hash = snum;
326 udp_sk(sk)->udp_portaddr_hash ^= snum;
327 if (sk_unhashed(sk)) {
328 if (sk->sk_reuseport &&
329 udp_reuseport_add_sock(sk, hslot, saddr_comp)) {
330 inet_sk(sk)->inet_num = 0;
331 udp_sk(sk)->udp_port_hash = 0;
332 udp_sk(sk)->udp_portaddr_hash ^= snum;
333 goto fail_unlock;
334 }
335
336 sk_nulls_add_node_rcu(sk, &hslot->head);
337 hslot->count++;
338 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
339
340 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
341 spin_lock(&hslot2->lock);
342 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
343 &hslot2->head);
344 hslot2->count++;
345 spin_unlock(&hslot2->lock);
346 }
347 error = 0;
348 fail_unlock:
349 spin_unlock_bh(&hslot->lock);
350 fail:
351 return error;
352 }
353 EXPORT_SYMBOL(udp_lib_get_port);
354
355 /* match_wildcard == true: 0.0.0.0 equals to any IPv4 addresses
356 * match_wildcard == false: addresses must be exactly the same, i.e.
357 * 0.0.0.0 only equals to 0.0.0.0
358 */
359 static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2,
360 bool match_wildcard)
361 {
362 struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
363
364 if (!ipv6_only_sock(sk2)) {
365 if (inet1->inet_rcv_saddr == inet2->inet_rcv_saddr)
366 return 1;
367 if (!inet1->inet_rcv_saddr || !inet2->inet_rcv_saddr)
368 return match_wildcard;
369 }
370 return 0;
371 }
372
373 static u32 udp4_portaddr_hash(const struct net *net, __be32 saddr,
374 unsigned int port)
375 {
376 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
377 }
378
379 int udp_v4_get_port(struct sock *sk, unsigned short snum)
380 {
381 unsigned int hash2_nulladdr =
382 udp4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
383 unsigned int hash2_partial =
384 udp4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);
385
386 /* precompute partial secondary hash */
387 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
388 return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal, hash2_nulladdr);
389 }
390
391 static inline int compute_score(struct sock *sk, struct net *net,
392 __be32 saddr, unsigned short hnum, __be16 sport,
393 __be32 daddr, __be16 dport, int dif)
394 {
395 int score;
396 struct inet_sock *inet;
397
398 if (!net_eq(sock_net(sk), net) ||
399 udp_sk(sk)->udp_port_hash != hnum ||
400 ipv6_only_sock(sk))
401 return -1;
402
403 score = (sk->sk_family == PF_INET) ? 2 : 1;
404 inet = inet_sk(sk);
405
406 if (inet->inet_rcv_saddr) {
407 if (inet->inet_rcv_saddr != daddr)
408 return -1;
409 score += 4;
410 }
411
412 if (inet->inet_daddr) {
413 if (inet->inet_daddr != saddr)
414 return -1;
415 score += 4;
416 }
417
418 if (inet->inet_dport) {
419 if (inet->inet_dport != sport)
420 return -1;
421 score += 4;
422 }
423
424 if (sk->sk_bound_dev_if) {
425 if (sk->sk_bound_dev_if != dif)
426 return -1;
427 score += 4;
428 }
429 if (sk->sk_incoming_cpu == raw_smp_processor_id())
430 score++;
431 return score;
432 }
433
434 /*
435 * In this second variant, we check (daddr, dport) matches (inet_rcv_sadd, inet_num)
436 */
437 static inline int compute_score2(struct sock *sk, struct net *net,
438 __be32 saddr, __be16 sport,
439 __be32 daddr, unsigned int hnum, int dif)
440 {
441 int score;
442 struct inet_sock *inet;
443
444 if (!net_eq(sock_net(sk), net) ||
445 ipv6_only_sock(sk))
446 return -1;
447
448 inet = inet_sk(sk);
449
450 if (inet->inet_rcv_saddr != daddr ||
451 inet->inet_num != hnum)
452 return -1;
453
454 score = (sk->sk_family == PF_INET) ? 2 : 1;
455
456 if (inet->inet_daddr) {
457 if (inet->inet_daddr != saddr)
458 return -1;
459 score += 4;
460 }
461
462 if (inet->inet_dport) {
463 if (inet->inet_dport != sport)
464 return -1;
465 score += 4;
466 }
467
468 if (sk->sk_bound_dev_if) {
469 if (sk->sk_bound_dev_if != dif)
470 return -1;
471 score += 4;
472 }
473
474 if (sk->sk_incoming_cpu == raw_smp_processor_id())
475 score++;
476
477 return score;
478 }
479
480 static u32 udp_ehashfn(const struct net *net, const __be32 laddr,
481 const __u16 lport, const __be32 faddr,
482 const __be16 fport)
483 {
484 static u32 udp_ehash_secret __read_mostly;
485
486 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret));
487
488 return __inet_ehashfn(laddr, lport, faddr, fport,
489 udp_ehash_secret + net_hash_mix(net));
490 }
491
492 /* called with read_rcu_lock() */
493 static struct sock *udp4_lib_lookup2(struct net *net,
494 __be32 saddr, __be16 sport,
495 __be32 daddr, unsigned int hnum, int dif,
496 struct udp_hslot *hslot2, unsigned int slot2,
497 struct sk_buff *skb)
498 {
499 struct sock *sk, *result;
500 struct hlist_nulls_node *node;
501 int score, badness, matches = 0, reuseport = 0;
502 bool select_ok = true;
503 u32 hash = 0;
504
505 begin:
506 result = NULL;
507 badness = 0;
508 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
509 score = compute_score2(sk, net, saddr, sport,
510 daddr, hnum, dif);
511 if (score > badness) {
512 result = sk;
513 badness = score;
514 reuseport = sk->sk_reuseport;
515 if (reuseport) {
516 hash = udp_ehashfn(net, daddr, hnum,
517 saddr, sport);
518 if (select_ok) {
519 struct sock *sk2;
520
521 sk2 = reuseport_select_sock(sk, hash, skb,
522 sizeof(struct udphdr));
523 if (sk2) {
524 result = sk2;
525 select_ok = false;
526 goto found;
527 }
528 }
529 matches = 1;
530 }
531 } else if (score == badness && reuseport) {
532 matches++;
533 if (reciprocal_scale(hash, matches) == 0)
534 result = sk;
535 hash = next_pseudo_random32(hash);
536 }
537 }
538 /*
539 * if the nulls value we got at the end of this lookup is
540 * not the expected one, we must restart lookup.
541 * We probably met an item that was moved to another chain.
542 */
543 if (get_nulls_value(node) != slot2)
544 goto begin;
545 if (result) {
546 found:
547 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
548 result = NULL;
549 else if (unlikely(compute_score2(result, net, saddr, sport,
550 daddr, hnum, dif) < badness)) {
551 sock_put(result);
552 goto begin;
553 }
554 }
555 return result;
556 }
557
558 /* UDP is nearly always wildcards out the wazoo, it makes no sense to try
559 * harder than this. -DaveM
560 */
561 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
562 __be16 sport, __be32 daddr, __be16 dport,
563 int dif, struct udp_table *udptable, struct sk_buff *skb)
564 {
565 struct sock *sk, *result;
566 struct hlist_nulls_node *node;
567 unsigned short hnum = ntohs(dport);
568 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
569 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
570 int score, badness, matches = 0, reuseport = 0;
571 bool select_ok = true;
572 u32 hash = 0;
573
574 rcu_read_lock();
575 if (hslot->count > 10) {
576 hash2 = udp4_portaddr_hash(net, daddr, hnum);
577 slot2 = hash2 & udptable->mask;
578 hslot2 = &udptable->hash2[slot2];
579 if (hslot->count < hslot2->count)
580 goto begin;
581
582 result = udp4_lib_lookup2(net, saddr, sport,
583 daddr, hnum, dif,
584 hslot2, slot2, skb);
585 if (!result) {
586 hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
587 slot2 = hash2 & udptable->mask;
588 hslot2 = &udptable->hash2[slot2];
589 if (hslot->count < hslot2->count)
590 goto begin;
591
592 result = udp4_lib_lookup2(net, saddr, sport,
593 htonl(INADDR_ANY), hnum, dif,
594 hslot2, slot2, skb);
595 }
596 rcu_read_unlock();
597 return result;
598 }
599 begin:
600 result = NULL;
601 badness = 0;
602 sk_nulls_for_each_rcu(sk, node, &hslot->head) {
603 score = compute_score(sk, net, saddr, hnum, sport,
604 daddr, dport, dif);
605 if (score > badness) {
606 result = sk;
607 badness = score;
608 reuseport = sk->sk_reuseport;
609 if (reuseport) {
610 hash = udp_ehashfn(net, daddr, hnum,
611 saddr, sport);
612 if (select_ok) {
613 struct sock *sk2;
614
615 sk2 = reuseport_select_sock(sk, hash, skb,
616 sizeof(struct udphdr));
617 if (sk2) {
618 result = sk2;
619 select_ok = false;
620 goto found;
621 }
622 }
623 matches = 1;
624 }
625 } else if (score == badness && reuseport) {
626 matches++;
627 if (reciprocal_scale(hash, matches) == 0)
628 result = sk;
629 hash = next_pseudo_random32(hash);
630 }
631 }
632 /*
633 * if the nulls value we got at the end of this lookup is
634 * not the expected one, we must restart lookup.
635 * We probably met an item that was moved to another chain.
636 */
637 if (get_nulls_value(node) != slot)
638 goto begin;
639
640 if (result) {
641 found:
642 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
643 result = NULL;
644 else if (unlikely(compute_score(result, net, saddr, hnum, sport,
645 daddr, dport, dif) < badness)) {
646 sock_put(result);
647 goto begin;
648 }
649 }
650 rcu_read_unlock();
651 return result;
652 }
653 EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
654
655 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
656 __be16 sport, __be16 dport,
657 struct udp_table *udptable)
658 {
659 const struct iphdr *iph = ip_hdr(skb);
660
661 return __udp4_lib_lookup(dev_net(skb_dst(skb)->dev), iph->saddr, sport,
662 iph->daddr, dport, inet_iif(skb),
663 udptable, skb);
664 }
665
666 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
667 __be32 daddr, __be16 dport, int dif)
668 {
669 return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif,
670 &udp_table, NULL);
671 }
672 EXPORT_SYMBOL_GPL(udp4_lib_lookup);
673
674 static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk,
675 __be16 loc_port, __be32 loc_addr,
676 __be16 rmt_port, __be32 rmt_addr,
677 int dif, unsigned short hnum)
678 {
679 struct inet_sock *inet = inet_sk(sk);
680
681 if (!net_eq(sock_net(sk), net) ||
682 udp_sk(sk)->udp_port_hash != hnum ||
683 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
684 (inet->inet_dport != rmt_port && inet->inet_dport) ||
685 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) ||
686 ipv6_only_sock(sk) ||
687 (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
688 return false;
689 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif))
690 return false;
691 return true;
692 }
693
694 /*
695 * This routine is called by the ICMP module when it gets some
696 * sort of error condition. If err < 0 then the socket should
697 * be closed and the error returned to the user. If err > 0
698 * it's just the icmp type << 8 | icmp code.
699 * Header points to the ip header of the error packet. We move
700 * on past this. Then (as it used to claim before adjustment)
701 * header points to the first 8 bytes of the udp header. We need
702 * to find the appropriate port.
703 */
704
705 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
706 {
707 struct inet_sock *inet;
708 const struct iphdr *iph = (const struct iphdr *)skb->data;
709 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
710 const int type = icmp_hdr(skb)->type;
711 const int code = icmp_hdr(skb)->code;
712 struct sock *sk;
713 int harderr;
714 int err;
715 struct net *net = dev_net(skb->dev);
716
717 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
718 iph->saddr, uh->source, skb->dev->ifindex, udptable,
719 NULL);
720 if (!sk) {
721 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
722 return; /* No socket for error */
723 }
724
725 err = 0;
726 harderr = 0;
727 inet = inet_sk(sk);
728
729 switch (type) {
730 default:
731 case ICMP_TIME_EXCEEDED:
732 err = EHOSTUNREACH;
733 break;
734 case ICMP_SOURCE_QUENCH:
735 goto out;
736 case ICMP_PARAMETERPROB:
737 err = EPROTO;
738 harderr = 1;
739 break;
740 case ICMP_DEST_UNREACH:
741 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
742 ipv4_sk_update_pmtu(skb, sk, info);
743 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
744 err = EMSGSIZE;
745 harderr = 1;
746 break;
747 }
748 goto out;
749 }
750 err = EHOSTUNREACH;
751 if (code <= NR_ICMP_UNREACH) {
752 harderr = icmp_err_convert[code].fatal;
753 err = icmp_err_convert[code].errno;
754 }
755 break;
756 case ICMP_REDIRECT:
757 ipv4_sk_redirect(skb, sk);
758 goto out;
759 }
760
761 /*
762 * RFC1122: OK. Passes ICMP errors back to application, as per
763 * 4.1.3.3.
764 */
765 if (!inet->recverr) {
766 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
767 goto out;
768 } else
769 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
770
771 sk->sk_err = err;
772 sk->sk_error_report(sk);
773 out:
774 sock_put(sk);
775 }
776
777 void udp_err(struct sk_buff *skb, u32 info)
778 {
779 __udp4_lib_err(skb, info, &udp_table);
780 }
781
782 /*
783 * Throw away all pending data and cancel the corking. Socket is locked.
784 */
785 void udp_flush_pending_frames(struct sock *sk)
786 {
787 struct udp_sock *up = udp_sk(sk);
788
789 if (up->pending) {
790 up->len = 0;
791 up->pending = 0;
792 ip_flush_pending_frames(sk);
793 }
794 }
795 EXPORT_SYMBOL(udp_flush_pending_frames);
796
797 /**
798 * udp4_hwcsum - handle outgoing HW checksumming
799 * @skb: sk_buff containing the filled-in UDP header
800 * (checksum field must be zeroed out)
801 * @src: source IP address
802 * @dst: destination IP address
803 */
804 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
805 {
806 struct udphdr *uh = udp_hdr(skb);
807 int offset = skb_transport_offset(skb);
808 int len = skb->len - offset;
809 int hlen = len;
810 __wsum csum = 0;
811
812 if (!skb_has_frag_list(skb)) {
813 /*
814 * Only one fragment on the socket.
815 */
816 skb->csum_start = skb_transport_header(skb) - skb->head;
817 skb->csum_offset = offsetof(struct udphdr, check);
818 uh->check = ~csum_tcpudp_magic(src, dst, len,
819 IPPROTO_UDP, 0);
820 } else {
821 struct sk_buff *frags;
822
823 /*
824 * HW-checksum won't work as there are two or more
825 * fragments on the socket so that all csums of sk_buffs
826 * should be together
827 */
828 skb_walk_frags(skb, frags) {
829 csum = csum_add(csum, frags->csum);
830 hlen -= frags->len;
831 }
832
833 csum = skb_checksum(skb, offset, hlen, csum);
834 skb->ip_summed = CHECKSUM_NONE;
835
836 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
837 if (uh->check == 0)
838 uh->check = CSUM_MANGLED_0;
839 }
840 }
841 EXPORT_SYMBOL_GPL(udp4_hwcsum);
842
843 /* Function to set UDP checksum for an IPv4 UDP packet. This is intended
844 * for the simple case like when setting the checksum for a UDP tunnel.
845 */
846 void udp_set_csum(bool nocheck, struct sk_buff *skb,
847 __be32 saddr, __be32 daddr, int len)
848 {
849 struct udphdr *uh = udp_hdr(skb);
850
851 if (nocheck)
852 uh->check = 0;
853 else if (skb_is_gso(skb))
854 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
855 else if (skb_dst(skb) && skb_dst(skb)->dev &&
856 (skb_dst(skb)->dev->features &
857 (NETIF_F_IP_CSUM | NETIF_F_HW_CSUM))) {
858
859 BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL);
860
861 skb->ip_summed = CHECKSUM_PARTIAL;
862 skb->csum_start = skb_transport_header(skb) - skb->head;
863 skb->csum_offset = offsetof(struct udphdr, check);
864 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
865 } else {
866 __wsum csum;
867
868 BUG_ON(skb->ip_summed == CHECKSUM_PARTIAL);
869
870 uh->check = 0;
871 csum = skb_checksum(skb, 0, len, 0);
872 uh->check = udp_v4_check(len, saddr, daddr, csum);
873 if (uh->check == 0)
874 uh->check = CSUM_MANGLED_0;
875
876 skb->ip_summed = CHECKSUM_UNNECESSARY;
877 }
878 }
879 EXPORT_SYMBOL(udp_set_csum);
880
881 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4)
882 {
883 struct sock *sk = skb->sk;
884 struct inet_sock *inet = inet_sk(sk);
885 struct udphdr *uh;
886 int err = 0;
887 int is_udplite = IS_UDPLITE(sk);
888 int offset = skb_transport_offset(skb);
889 int len = skb->len - offset;
890 __wsum csum = 0;
891
892 /*
893 * Create a UDP header
894 */
895 uh = udp_hdr(skb);
896 uh->source = inet->inet_sport;
897 uh->dest = fl4->fl4_dport;
898 uh->len = htons(len);
899 uh->check = 0;
900
901 if (is_udplite) /* UDP-Lite */
902 csum = udplite_csum(skb);
903
904 else if (sk->sk_no_check_tx) { /* UDP csum disabled */
905
906 skb->ip_summed = CHECKSUM_NONE;
907 goto send;
908
909 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
910
911 udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
912 goto send;
913
914 } else
915 csum = udp_csum(skb);
916
917 /* add protocol-dependent pseudo-header */
918 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
919 sk->sk_protocol, csum);
920 if (uh->check == 0)
921 uh->check = CSUM_MANGLED_0;
922
923 send:
924 err = ip_send_skb(sock_net(sk), skb);
925 if (err) {
926 if (err == -ENOBUFS && !inet->recverr) {
927 UDP_INC_STATS_USER(sock_net(sk),
928 UDP_MIB_SNDBUFERRORS, is_udplite);
929 err = 0;
930 }
931 } else
932 UDP_INC_STATS_USER(sock_net(sk),
933 UDP_MIB_OUTDATAGRAMS, is_udplite);
934 return err;
935 }
936
937 /*
938 * Push out all pending data as one UDP datagram. Socket is locked.
939 */
940 int udp_push_pending_frames(struct sock *sk)
941 {
942 struct udp_sock *up = udp_sk(sk);
943 struct inet_sock *inet = inet_sk(sk);
944 struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
945 struct sk_buff *skb;
946 int err = 0;
947
948 skb = ip_finish_skb(sk, fl4);
949 if (!skb)
950 goto out;
951
952 err = udp_send_skb(skb, fl4);
953
954 out:
955 up->len = 0;
956 up->pending = 0;
957 return err;
958 }
959 EXPORT_SYMBOL(udp_push_pending_frames);
960
961 int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
962 {
963 struct inet_sock *inet = inet_sk(sk);
964 struct udp_sock *up = udp_sk(sk);
965 struct flowi4 fl4_stack;
966 struct flowi4 *fl4;
967 int ulen = len;
968 struct ipcm_cookie ipc;
969 struct rtable *rt = NULL;
970 int free = 0;
971 int connected = 0;
972 __be32 daddr, faddr, saddr;
973 __be16 dport;
974 u8 tos;
975 int err, is_udplite = IS_UDPLITE(sk);
976 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
977 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
978 struct sk_buff *skb;
979 struct ip_options_data opt_copy;
980
981 if (len > 0xFFFF)
982 return -EMSGSIZE;
983
984 /*
985 * Check the flags.
986 */
987
988 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
989 return -EOPNOTSUPP;
990
991 ipc.opt = NULL;
992 ipc.tx_flags = 0;
993 ipc.ttl = 0;
994 ipc.tos = -1;
995
996 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
997
998 fl4 = &inet->cork.fl.u.ip4;
999 if (up->pending) {
1000 /*
1001 * There are pending frames.
1002 * The socket lock must be held while it's corked.
1003 */
1004 lock_sock(sk);
1005 if (likely(up->pending)) {
1006 if (unlikely(up->pending != AF_INET)) {
1007 release_sock(sk);
1008 return -EINVAL;
1009 }
1010 goto do_append_data;
1011 }
1012 release_sock(sk);
1013 }
1014 ulen += sizeof(struct udphdr);
1015
1016 /*
1017 * Get and verify the address.
1018 */
1019 if (msg->msg_name) {
1020 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
1021 if (msg->msg_namelen < sizeof(*usin))
1022 return -EINVAL;
1023 if (usin->sin_family != AF_INET) {
1024 if (usin->sin_family != AF_UNSPEC)
1025 return -EAFNOSUPPORT;
1026 }
1027
1028 daddr = usin->sin_addr.s_addr;
1029 dport = usin->sin_port;
1030 if (dport == 0)
1031 return -EINVAL;
1032 } else {
1033 if (sk->sk_state != TCP_ESTABLISHED)
1034 return -EDESTADDRREQ;
1035 daddr = inet->inet_daddr;
1036 dport = inet->inet_dport;
1037 /* Open fast path for connected socket.
1038 Route will not be used, if at least one option is set.
1039 */
1040 connected = 1;
1041 }
1042 ipc.addr = inet->inet_saddr;
1043
1044 ipc.oif = sk->sk_bound_dev_if;
1045
1046 sock_tx_timestamp(sk, &ipc.tx_flags);
1047
1048 if (msg->msg_controllen) {
1049 err = ip_cmsg_send(sock_net(sk), msg, &ipc,
1050 sk->sk_family == AF_INET6);
1051 if (err)
1052 return err;
1053 if (ipc.opt)
1054 free = 1;
1055 connected = 0;
1056 }
1057 if (!ipc.opt) {
1058 struct ip_options_rcu *inet_opt;
1059
1060 rcu_read_lock();
1061 inet_opt = rcu_dereference(inet->inet_opt);
1062 if (inet_opt) {
1063 memcpy(&opt_copy, inet_opt,
1064 sizeof(*inet_opt) + inet_opt->opt.optlen);
1065 ipc.opt = &opt_copy.opt;
1066 }
1067 rcu_read_unlock();
1068 }
1069
1070 saddr = ipc.addr;
1071 ipc.addr = faddr = daddr;
1072
1073 if (ipc.opt && ipc.opt->opt.srr) {
1074 if (!daddr)
1075 return -EINVAL;
1076 faddr = ipc.opt->opt.faddr;
1077 connected = 0;
1078 }
1079 tos = get_rttos(&ipc, inet);
1080 if (sock_flag(sk, SOCK_LOCALROUTE) ||
1081 (msg->msg_flags & MSG_DONTROUTE) ||
1082 (ipc.opt && ipc.opt->opt.is_strictroute)) {
1083 tos |= RTO_ONLINK;
1084 connected = 0;
1085 }
1086
1087 if (ipv4_is_multicast(daddr)) {
1088 if (!ipc.oif)
1089 ipc.oif = inet->mc_index;
1090 if (!saddr)
1091 saddr = inet->mc_addr;
1092 connected = 0;
1093 } else if (!ipc.oif)
1094 ipc.oif = inet->uc_index;
1095
1096 if (connected)
1097 rt = (struct rtable *)sk_dst_check(sk, 0);
1098
1099 if (!rt) {
1100 struct net *net = sock_net(sk);
1101 __u8 flow_flags = inet_sk_flowi_flags(sk);
1102
1103 fl4 = &fl4_stack;
1104
1105 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
1106 RT_SCOPE_UNIVERSE, sk->sk_protocol,
1107 flow_flags,
1108 faddr, saddr, dport, inet->inet_sport);
1109
1110 if (!saddr && ipc.oif) {
1111 err = l3mdev_get_saddr(net, ipc.oif, fl4);
1112 if (err < 0)
1113 goto out;
1114 }
1115
1116 security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
1117 rt = ip_route_output_flow(net, fl4, sk);
1118 if (IS_ERR(rt)) {
1119 err = PTR_ERR(rt);
1120 rt = NULL;
1121 if (err == -ENETUNREACH)
1122 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
1123 goto out;
1124 }
1125
1126 err = -EACCES;
1127 if ((rt->rt_flags & RTCF_BROADCAST) &&
1128 !sock_flag(sk, SOCK_BROADCAST))
1129 goto out;
1130 if (connected)
1131 sk_dst_set(sk, dst_clone(&rt->dst));
1132 }
1133
1134 if (msg->msg_flags&MSG_CONFIRM)
1135 goto do_confirm;
1136 back_from_confirm:
1137
1138 saddr = fl4->saddr;
1139 if (!ipc.addr)
1140 daddr = ipc.addr = fl4->daddr;
1141
1142 /* Lockless fast path for the non-corking case. */
1143 if (!corkreq) {
1144 skb = ip_make_skb(sk, fl4, getfrag, msg, ulen,
1145 sizeof(struct udphdr), &ipc, &rt,
1146 msg->msg_flags);
1147 err = PTR_ERR(skb);
1148 if (!IS_ERR_OR_NULL(skb))
1149 err = udp_send_skb(skb, fl4);
1150 goto out;
1151 }
1152
1153 lock_sock(sk);
1154 if (unlikely(up->pending)) {
1155 /* The socket is already corked while preparing it. */
1156 /* ... which is an evident application bug. --ANK */
1157 release_sock(sk);
1158
1159 net_dbg_ratelimited("cork app bug 2\n");
1160 err = -EINVAL;
1161 goto out;
1162 }
1163 /*
1164 * Now cork the socket to pend data.
1165 */
1166 fl4 = &inet->cork.fl.u.ip4;
1167 fl4->daddr = daddr;
1168 fl4->saddr = saddr;
1169 fl4->fl4_dport = dport;
1170 fl4->fl4_sport = inet->inet_sport;
1171 up->pending = AF_INET;
1172
1173 do_append_data:
1174 up->len += ulen;
1175 err = ip_append_data(sk, fl4, getfrag, msg, ulen,
1176 sizeof(struct udphdr), &ipc, &rt,
1177 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1178 if (err)
1179 udp_flush_pending_frames(sk);
1180 else if (!corkreq)
1181 err = udp_push_pending_frames(sk);
1182 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1183 up->pending = 0;
1184 release_sock(sk);
1185
1186 out:
1187 ip_rt_put(rt);
1188 if (free)
1189 kfree(ipc.opt);
1190 if (!err)
1191 return len;
1192 /*
1193 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1194 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1195 * we don't have a good statistic (IpOutDiscards but it can be too many
1196 * things). We could add another new stat but at least for now that
1197 * seems like overkill.
1198 */
1199 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1200 UDP_INC_STATS_USER(sock_net(sk),
1201 UDP_MIB_SNDBUFERRORS, is_udplite);
1202 }
1203 return err;
1204
1205 do_confirm:
1206 dst_confirm(&rt->dst);
1207 if (!(msg->msg_flags&MSG_PROBE) || len)
1208 goto back_from_confirm;
1209 err = 0;
1210 goto out;
1211 }
1212 EXPORT_SYMBOL(udp_sendmsg);
1213
1214 int udp_sendpage(struct sock *sk, struct page *page, int offset,
1215 size_t size, int flags)
1216 {
1217 struct inet_sock *inet = inet_sk(sk);
1218 struct udp_sock *up = udp_sk(sk);
1219 int ret;
1220
1221 if (flags & MSG_SENDPAGE_NOTLAST)
1222 flags |= MSG_MORE;
1223
1224 if (!up->pending) {
1225 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
1226
1227 /* Call udp_sendmsg to specify destination address which
1228 * sendpage interface can't pass.
1229 * This will succeed only when the socket is connected.
1230 */
1231 ret = udp_sendmsg(sk, &msg, 0);
1232 if (ret < 0)
1233 return ret;
1234 }
1235
1236 lock_sock(sk);
1237
1238 if (unlikely(!up->pending)) {
1239 release_sock(sk);
1240
1241 net_dbg_ratelimited("udp cork app bug 3\n");
1242 return -EINVAL;
1243 }
1244
1245 ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
1246 page, offset, size, flags);
1247 if (ret == -EOPNOTSUPP) {
1248 release_sock(sk);
1249 return sock_no_sendpage(sk->sk_socket, page, offset,
1250 size, flags);
1251 }
1252 if (ret < 0) {
1253 udp_flush_pending_frames(sk);
1254 goto out;
1255 }
1256
1257 up->len += size;
1258 if (!(up->corkflag || (flags&MSG_MORE)))
1259 ret = udp_push_pending_frames(sk);
1260 if (!ret)
1261 ret = size;
1262 out:
1263 release_sock(sk);
1264 return ret;
1265 }
1266
1267 /**
1268 * first_packet_length - return length of first packet in receive queue
1269 * @sk: socket
1270 *
1271 * Drops all bad checksum frames, until a valid one is found.
1272 * Returns the length of found skb, or 0 if none is found.
1273 */
1274 static unsigned int first_packet_length(struct sock *sk)
1275 {
1276 struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue;
1277 struct sk_buff *skb;
1278 unsigned int res;
1279
1280 __skb_queue_head_init(&list_kill);
1281
1282 spin_lock_bh(&rcvq->lock);
1283 while ((skb = skb_peek(rcvq)) != NULL &&
1284 udp_lib_checksum_complete(skb)) {
1285 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS,
1286 IS_UDPLITE(sk));
1287 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
1288 IS_UDPLITE(sk));
1289 atomic_inc(&sk->sk_drops);
1290 __skb_unlink(skb, rcvq);
1291 __skb_queue_tail(&list_kill, skb);
1292 }
1293 res = skb ? skb->len : 0;
1294 spin_unlock_bh(&rcvq->lock);
1295
1296 if (!skb_queue_empty(&list_kill)) {
1297 bool slow = lock_sock_fast(sk);
1298
1299 __skb_queue_purge(&list_kill);
1300 sk_mem_reclaim_partial(sk);
1301 unlock_sock_fast(sk, slow);
1302 }
1303 return res;
1304 }
1305
1306 /*
1307 * IOCTL requests applicable to the UDP protocol
1308 */
1309
1310 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
1311 {
1312 switch (cmd) {
1313 case SIOCOUTQ:
1314 {
1315 int amount = sk_wmem_alloc_get(sk);
1316
1317 return put_user(amount, (int __user *)arg);
1318 }
1319
1320 case SIOCINQ:
1321 {
1322 unsigned int amount = first_packet_length(sk);
1323
1324 if (amount)
1325 /*
1326 * We will only return the amount
1327 * of this packet since that is all
1328 * that will be read.
1329 */
1330 amount -= sizeof(struct udphdr);
1331
1332 return put_user(amount, (int __user *)arg);
1333 }
1334
1335 default:
1336 return -ENOIOCTLCMD;
1337 }
1338
1339 return 0;
1340 }
1341 EXPORT_SYMBOL(udp_ioctl);
1342
1343 /*
1344 * This should be easy, if there is something there we
1345 * return it, otherwise we block.
1346 */
1347
1348 int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
1349 int flags, int *addr_len)
1350 {
1351 struct inet_sock *inet = inet_sk(sk);
1352 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
1353 struct sk_buff *skb;
1354 unsigned int ulen, copied;
1355 int peeked, off = 0;
1356 int err;
1357 int is_udplite = IS_UDPLITE(sk);
1358 bool checksum_valid = false;
1359 bool slow;
1360
1361 if (flags & MSG_ERRQUEUE)
1362 return ip_recv_error(sk, msg, len, addr_len);
1363
1364 try_again:
1365 skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
1366 &peeked, &off, &err);
1367 if (!skb)
1368 goto out;
1369
1370 ulen = skb->len - sizeof(struct udphdr);
1371 copied = len;
1372 if (copied > ulen)
1373 copied = ulen;
1374 else if (copied < ulen)
1375 msg->msg_flags |= MSG_TRUNC;
1376
1377 /*
1378 * If checksum is needed at all, try to do it while copying the
1379 * data. If the data is truncated, or if we only want a partial
1380 * coverage checksum (UDP-Lite), do it before the copy.
1381 */
1382
1383 if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
1384 checksum_valid = !udp_lib_checksum_complete(skb);
1385 if (!checksum_valid)
1386 goto csum_copy_err;
1387 }
1388
1389 if (checksum_valid || skb_csum_unnecessary(skb))
1390 err = skb_copy_datagram_msg(skb, sizeof(struct udphdr),
1391 msg, copied);
1392 else {
1393 err = skb_copy_and_csum_datagram_msg(skb, sizeof(struct udphdr),
1394 msg);
1395
1396 if (err == -EINVAL)
1397 goto csum_copy_err;
1398 }
1399
1400 if (unlikely(err)) {
1401 trace_kfree_skb(skb, udp_recvmsg);
1402 if (!peeked) {
1403 atomic_inc(&sk->sk_drops);
1404 UDP_INC_STATS_USER(sock_net(sk),
1405 UDP_MIB_INERRORS, is_udplite);
1406 }
1407 goto out_free;
1408 }
1409
1410 if (!peeked)
1411 UDP_INC_STATS_USER(sock_net(sk),
1412 UDP_MIB_INDATAGRAMS, is_udplite);
1413
1414 sock_recv_ts_and_drops(msg, sk, skb);
1415
1416 /* Copy the address. */
1417 if (sin) {
1418 sin->sin_family = AF_INET;
1419 sin->sin_port = udp_hdr(skb)->source;
1420 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1421 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1422 *addr_len = sizeof(*sin);
1423 }
1424 if (inet->cmsg_flags)
1425 ip_cmsg_recv_offset(msg, skb, sizeof(struct udphdr));
1426
1427 err = copied;
1428 if (flags & MSG_TRUNC)
1429 err = ulen;
1430
1431 out_free:
1432 skb_free_datagram_locked(sk, skb);
1433 out:
1434 return err;
1435
1436 csum_copy_err:
1437 slow = lock_sock_fast(sk);
1438 if (!skb_kill_datagram(sk, skb, flags)) {
1439 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1440 UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1441 }
1442 unlock_sock_fast(sk, slow);
1443
1444 /* starting over for a new packet, but check if we need to yield */
1445 cond_resched();
1446 msg->msg_flags &= ~MSG_TRUNC;
1447 goto try_again;
1448 }
1449
1450 int udp_disconnect(struct sock *sk, int flags)
1451 {
1452 struct inet_sock *inet = inet_sk(sk);
1453 /*
1454 * 1003.1g - break association.
1455 */
1456
1457 sk->sk_state = TCP_CLOSE;
1458 inet->inet_daddr = 0;
1459 inet->inet_dport = 0;
1460 sock_rps_reset_rxhash(sk);
1461 sk->sk_bound_dev_if = 0;
1462 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1463 inet_reset_saddr(sk);
1464
1465 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1466 sk->sk_prot->unhash(sk);
1467 inet->inet_sport = 0;
1468 }
1469 sk_dst_reset(sk);
1470 return 0;
1471 }
1472 EXPORT_SYMBOL(udp_disconnect);
1473
1474 void udp_lib_unhash(struct sock *sk)
1475 {
1476 if (sk_hashed(sk)) {
1477 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1478 struct udp_hslot *hslot, *hslot2;
1479
1480 hslot = udp_hashslot(udptable, sock_net(sk),
1481 udp_sk(sk)->udp_port_hash);
1482 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1483
1484 spin_lock_bh(&hslot->lock);
1485 if (rcu_access_pointer(sk->sk_reuseport_cb))
1486 reuseport_detach_sock(sk);
1487 if (sk_nulls_del_node_init_rcu(sk)) {
1488 hslot->count--;
1489 inet_sk(sk)->inet_num = 0;
1490 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1491
1492 spin_lock(&hslot2->lock);
1493 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1494 hslot2->count--;
1495 spin_unlock(&hslot2->lock);
1496 }
1497 spin_unlock_bh(&hslot->lock);
1498 }
1499 }
1500 EXPORT_SYMBOL(udp_lib_unhash);
1501
1502 /*
1503 * inet_rcv_saddr was changed, we must rehash secondary hash
1504 */
1505 void udp_lib_rehash(struct sock *sk, u16 newhash)
1506 {
1507 if (sk_hashed(sk)) {
1508 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1509 struct udp_hslot *hslot, *hslot2, *nhslot2;
1510
1511 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1512 nhslot2 = udp_hashslot2(udptable, newhash);
1513 udp_sk(sk)->udp_portaddr_hash = newhash;
1514
1515 if (hslot2 != nhslot2 ||
1516 rcu_access_pointer(sk->sk_reuseport_cb)) {
1517 hslot = udp_hashslot(udptable, sock_net(sk),
1518 udp_sk(sk)->udp_port_hash);
1519 /* we must lock primary chain too */
1520 spin_lock_bh(&hslot->lock);
1521 if (rcu_access_pointer(sk->sk_reuseport_cb))
1522 reuseport_detach_sock(sk);
1523
1524 if (hslot2 != nhslot2) {
1525 spin_lock(&hslot2->lock);
1526 hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1527 hslot2->count--;
1528 spin_unlock(&hslot2->lock);
1529
1530 spin_lock(&nhslot2->lock);
1531 hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
1532 &nhslot2->head);
1533 nhslot2->count++;
1534 spin_unlock(&nhslot2->lock);
1535 }
1536
1537 spin_unlock_bh(&hslot->lock);
1538 }
1539 }
1540 }
1541 EXPORT_SYMBOL(udp_lib_rehash);
1542
1543 static void udp_v4_rehash(struct sock *sk)
1544 {
1545 u16 new_hash = udp4_portaddr_hash(sock_net(sk),
1546 inet_sk(sk)->inet_rcv_saddr,
1547 inet_sk(sk)->inet_num);
1548 udp_lib_rehash(sk, new_hash);
1549 }
1550
1551 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1552 {
1553 int rc;
1554
1555 if (inet_sk(sk)->inet_daddr) {
1556 sock_rps_save_rxhash(sk, skb);
1557 sk_mark_napi_id(sk, skb);
1558 sk_incoming_cpu_update(sk);
1559 }
1560
1561 rc = sock_queue_rcv_skb(sk, skb);
1562 if (rc < 0) {
1563 int is_udplite = IS_UDPLITE(sk);
1564
1565 /* Note that an ENOMEM error is charged twice */
1566 if (rc == -ENOMEM)
1567 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1568 is_udplite);
1569 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1570 kfree_skb(skb);
1571 trace_udp_fail_queue_rcv_skb(rc, sk);
1572 return -1;
1573 }
1574
1575 return 0;
1576
1577 }
1578
1579 static struct static_key udp_encap_needed __read_mostly;
1580 void udp_encap_enable(void)
1581 {
1582 if (!static_key_enabled(&udp_encap_needed))
1583 static_key_slow_inc(&udp_encap_needed);
1584 }
1585 EXPORT_SYMBOL(udp_encap_enable);
1586
1587 /* returns:
1588 * -1: error
1589 * 0: success
1590 * >0: "udp encap" protocol resubmission
1591 *
1592 * Note that in the success and error cases, the skb is assumed to
1593 * have either been requeued or freed.
1594 */
1595 int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1596 {
1597 struct udp_sock *up = udp_sk(sk);
1598 int rc;
1599 int is_udplite = IS_UDPLITE(sk);
1600
1601 /*
1602 * Charge it to the socket, dropping if the queue is full.
1603 */
1604 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1605 goto drop;
1606 nf_reset(skb);
1607
1608 if (static_key_false(&udp_encap_needed) && up->encap_type) {
1609 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
1610
1611 /*
1612 * This is an encapsulation socket so pass the skb to
1613 * the socket's udp_encap_rcv() hook. Otherwise, just
1614 * fall through and pass this up the UDP socket.
1615 * up->encap_rcv() returns the following value:
1616 * =0 if skb was successfully passed to the encap
1617 * handler or was discarded by it.
1618 * >0 if skb should be passed on to UDP.
1619 * <0 if skb should be resubmitted as proto -N
1620 */
1621
1622 /* if we're overly short, let UDP handle it */
1623 encap_rcv = ACCESS_ONCE(up->encap_rcv);
1624 if (skb->len > sizeof(struct udphdr) && encap_rcv) {
1625 int ret;
1626
1627 /* Verify checksum before giving to encap */
1628 if (udp_lib_checksum_complete(skb))
1629 goto csum_error;
1630
1631 ret = encap_rcv(sk, skb);
1632 if (ret <= 0) {
1633 UDP_INC_STATS_BH(sock_net(sk),
1634 UDP_MIB_INDATAGRAMS,
1635 is_udplite);
1636 return -ret;
1637 }
1638 }
1639
1640 /* FALLTHROUGH -- it's a UDP Packet */
1641 }
1642
1643 /*
1644 * UDP-Lite specific tests, ignored on UDP sockets
1645 */
1646 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1647
1648 /*
1649 * MIB statistics other than incrementing the error count are
1650 * disabled for the following two types of errors: these depend
1651 * on the application settings, not on the functioning of the
1652 * protocol stack as such.
1653 *
1654 * RFC 3828 here recommends (sec 3.3): "There should also be a
1655 * way ... to ... at least let the receiving application block
1656 * delivery of packets with coverage values less than a value
1657 * provided by the application."
1658 */
1659 if (up->pcrlen == 0) { /* full coverage was set */
1660 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n",
1661 UDP_SKB_CB(skb)->cscov, skb->len);
1662 goto drop;
1663 }
1664 /* The next case involves violating the min. coverage requested
1665 * by the receiver. This is subtle: if receiver wants x and x is
1666 * greater than the buffersize/MTU then receiver will complain
1667 * that it wants x while sender emits packets of smaller size y.
1668 * Therefore the above ...()->partial_cov statement is essential.
1669 */
1670 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1671 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n",
1672 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1673 goto drop;
1674 }
1675 }
1676
1677 if (rcu_access_pointer(sk->sk_filter) &&
1678 udp_lib_checksum_complete(skb))
1679 goto csum_error;
1680
1681 if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
1682 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1683 is_udplite);
1684 goto drop;
1685 }
1686
1687 rc = 0;
1688
1689 ipv4_pktinfo_prepare(sk, skb);
1690 bh_lock_sock(sk);
1691 if (!sock_owned_by_user(sk))
1692 rc = __udp_queue_rcv_skb(sk, skb);
1693 else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
1694 bh_unlock_sock(sk);
1695 goto drop;
1696 }
1697 bh_unlock_sock(sk);
1698
1699 return rc;
1700
1701 csum_error:
1702 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1703 drop:
1704 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1705 atomic_inc(&sk->sk_drops);
1706 kfree_skb(skb);
1707 return -1;
1708 }
1709
1710 static void flush_stack(struct sock **stack, unsigned int count,
1711 struct sk_buff *skb, unsigned int final)
1712 {
1713 unsigned int i;
1714 struct sk_buff *skb1 = NULL;
1715 struct sock *sk;
1716
1717 for (i = 0; i < count; i++) {
1718 sk = stack[i];
1719 if (likely(!skb1))
1720 skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
1721
1722 if (!skb1) {
1723 atomic_inc(&sk->sk_drops);
1724 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1725 IS_UDPLITE(sk));
1726 UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
1727 IS_UDPLITE(sk));
1728 }
1729
1730 if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0)
1731 skb1 = NULL;
1732
1733 sock_put(sk);
1734 }
1735 if (unlikely(skb1))
1736 kfree_skb(skb1);
1737 }
1738
1739 /* For TCP sockets, sk_rx_dst is protected by socket lock
1740 * For UDP, we use xchg() to guard against concurrent changes.
1741 */
1742 static void udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
1743 {
1744 struct dst_entry *old;
1745
1746 dst_hold(dst);
1747 old = xchg(&sk->sk_rx_dst, dst);
1748 dst_release(old);
1749 }
1750
1751 /*
1752 * Multicasts and broadcasts go to each listener.
1753 *
1754 * Note: called only from the BH handler context.
1755 */
1756 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
1757 struct udphdr *uh,
1758 __be32 saddr, __be32 daddr,
1759 struct udp_table *udptable,
1760 int proto)
1761 {
1762 struct sock *sk, *stack[256 / sizeof(struct sock *)];
1763 struct hlist_nulls_node *node;
1764 unsigned short hnum = ntohs(uh->dest);
1765 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
1766 int dif = skb->dev->ifindex;
1767 unsigned int count = 0, offset = offsetof(typeof(*sk), sk_nulls_node);
1768 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
1769 bool inner_flushed = false;
1770
1771 if (use_hash2) {
1772 hash2_any = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum) &
1773 udp_table.mask;
1774 hash2 = udp4_portaddr_hash(net, daddr, hnum) & udp_table.mask;
1775 start_lookup:
1776 hslot = &udp_table.hash2[hash2];
1777 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
1778 }
1779
1780 spin_lock(&hslot->lock);
1781 sk_nulls_for_each_entry_offset(sk, node, &hslot->head, offset) {
1782 if (__udp_is_mcast_sock(net, sk,
1783 uh->dest, daddr,
1784 uh->source, saddr,
1785 dif, hnum)) {
1786 if (unlikely(count == ARRAY_SIZE(stack))) {
1787 flush_stack(stack, count, skb, ~0);
1788 inner_flushed = true;
1789 count = 0;
1790 }
1791 stack[count++] = sk;
1792 sock_hold(sk);
1793 }
1794 }
1795
1796 spin_unlock(&hslot->lock);
1797
1798 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
1799 if (use_hash2 && hash2 != hash2_any) {
1800 hash2 = hash2_any;
1801 goto start_lookup;
1802 }
1803
1804 /*
1805 * do the slow work with no lock held
1806 */
1807 if (count) {
1808 flush_stack(stack, count, skb, count - 1);
1809 } else {
1810 if (!inner_flushed)
1811 UDP_INC_STATS_BH(net, UDP_MIB_IGNOREDMULTI,
1812 proto == IPPROTO_UDPLITE);
1813 consume_skb(skb);
1814 }
1815 return 0;
1816 }
1817
1818 /* Initialize UDP checksum. If exited with zero value (success),
1819 * CHECKSUM_UNNECESSARY means, that no more checks are required.
1820 * Otherwise, csum completion requires chacksumming packet body,
1821 * including udp header and folding it to skb->csum.
1822 */
1823 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
1824 int proto)
1825 {
1826 int err;
1827
1828 UDP_SKB_CB(skb)->partial_cov = 0;
1829 UDP_SKB_CB(skb)->cscov = skb->len;
1830
1831 if (proto == IPPROTO_UDPLITE) {
1832 err = udplite_checksum_init(skb, uh);
1833 if (err)
1834 return err;
1835 }
1836
1837 return skb_checksum_init_zero_check(skb, proto, uh->check,
1838 inet_compute_pseudo);
1839 }
1840
1841 /*
1842 * All we need to do is get the socket, and then do a checksum.
1843 */
1844
1845 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1846 int proto)
1847 {
1848 struct sock *sk;
1849 struct udphdr *uh;
1850 unsigned short ulen;
1851 struct rtable *rt = skb_rtable(skb);
1852 __be32 saddr, daddr;
1853 struct net *net = dev_net(skb->dev);
1854
1855 /*
1856 * Validate the packet.
1857 */
1858 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1859 goto drop; /* No space for header. */
1860
1861 uh = udp_hdr(skb);
1862 ulen = ntohs(uh->len);
1863 saddr = ip_hdr(skb)->saddr;
1864 daddr = ip_hdr(skb)->daddr;
1865
1866 if (ulen > skb->len)
1867 goto short_packet;
1868
1869 if (proto == IPPROTO_UDP) {
1870 /* UDP validates ulen. */
1871 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
1872 goto short_packet;
1873 uh = udp_hdr(skb);
1874 }
1875
1876 if (udp4_csum_init(skb, uh, proto))
1877 goto csum_error;
1878
1879 sk = skb_steal_sock(skb);
1880 if (sk) {
1881 struct dst_entry *dst = skb_dst(skb);
1882 int ret;
1883
1884 if (unlikely(sk->sk_rx_dst != dst))
1885 udp_sk_rx_dst_set(sk, dst);
1886
1887 ret = udp_queue_rcv_skb(sk, skb);
1888 sock_put(sk);
1889 /* a return value > 0 means to resubmit the input, but
1890 * it wants the return to be -protocol, or 0
1891 */
1892 if (ret > 0)
1893 return -ret;
1894 return 0;
1895 }
1896
1897 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
1898 return __udp4_lib_mcast_deliver(net, skb, uh,
1899 saddr, daddr, udptable, proto);
1900
1901 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1902 if (sk) {
1903 int ret;
1904
1905 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
1906 skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
1907 inet_compute_pseudo);
1908
1909 ret = udp_queue_rcv_skb(sk, skb);
1910 sock_put(sk);
1911
1912 /* a return value > 0 means to resubmit the input, but
1913 * it wants the return to be -protocol, or 0
1914 */
1915 if (ret > 0)
1916 return -ret;
1917 return 0;
1918 }
1919
1920 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1921 goto drop;
1922 nf_reset(skb);
1923
1924 /* No socket. Drop packet silently, if checksum is wrong */
1925 if (udp_lib_checksum_complete(skb))
1926 goto csum_error;
1927
1928 UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1929 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
1930
1931 /*
1932 * Hmm. We got an UDP packet to a port to which we
1933 * don't wanna listen. Ignore it.
1934 */
1935 kfree_skb(skb);
1936 return 0;
1937
1938 short_packet:
1939 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
1940 proto == IPPROTO_UDPLITE ? "Lite" : "",
1941 &saddr, ntohs(uh->source),
1942 ulen, skb->len,
1943 &daddr, ntohs(uh->dest));
1944 goto drop;
1945
1946 csum_error:
1947 /*
1948 * RFC1122: OK. Discards the bad packet silently (as far as
1949 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
1950 */
1951 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
1952 proto == IPPROTO_UDPLITE ? "Lite" : "",
1953 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
1954 ulen);
1955 UDP_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
1956 drop:
1957 UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1958 kfree_skb(skb);
1959 return 0;
1960 }
1961
1962 /* We can only early demux multicast if there is a single matching socket.
1963 * If more than one socket found returns NULL
1964 */
1965 static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
1966 __be16 loc_port, __be32 loc_addr,
1967 __be16 rmt_port, __be32 rmt_addr,
1968 int dif)
1969 {
1970 struct sock *sk, *result;
1971 struct hlist_nulls_node *node;
1972 unsigned short hnum = ntohs(loc_port);
1973 unsigned int count, slot = udp_hashfn(net, hnum, udp_table.mask);
1974 struct udp_hslot *hslot = &udp_table.hash[slot];
1975
1976 /* Do not bother scanning a too big list */
1977 if (hslot->count > 10)
1978 return NULL;
1979
1980 rcu_read_lock();
1981 begin:
1982 count = 0;
1983 result = NULL;
1984 sk_nulls_for_each_rcu(sk, node, &hslot->head) {
1985 if (__udp_is_mcast_sock(net, sk,
1986 loc_port, loc_addr,
1987 rmt_port, rmt_addr,
1988 dif, hnum)) {
1989 result = sk;
1990 ++count;
1991 }
1992 }
1993 /*
1994 * if the nulls value we got at the end of this lookup is
1995 * not the expected one, we must restart lookup.
1996 * We probably met an item that was moved to another chain.
1997 */
1998 if (get_nulls_value(node) != slot)
1999 goto begin;
2000
2001 if (result) {
2002 if (count != 1 ||
2003 unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
2004 result = NULL;
2005 else if (unlikely(!__udp_is_mcast_sock(net, result,
2006 loc_port, loc_addr,
2007 rmt_port, rmt_addr,
2008 dif, hnum))) {
2009 sock_put(result);
2010 result = NULL;
2011 }
2012 }
2013 rcu_read_unlock();
2014 return result;
2015 }
2016
2017 /* For unicast we should only early demux connected sockets or we can
2018 * break forwarding setups. The chains here can be long so only check
2019 * if the first socket is an exact match and if not move on.
2020 */
2021 static struct sock *__udp4_lib_demux_lookup(struct net *net,
2022 __be16 loc_port, __be32 loc_addr,
2023 __be16 rmt_port, __be32 rmt_addr,
2024 int dif)
2025 {
2026 struct sock *sk, *result;
2027 struct hlist_nulls_node *node;
2028 unsigned short hnum = ntohs(loc_port);
2029 unsigned int hash2 = udp4_portaddr_hash(net, loc_addr, hnum);
2030 unsigned int slot2 = hash2 & udp_table.mask;
2031 struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
2032 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
2033 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
2034
2035 rcu_read_lock();
2036 result = NULL;
2037 udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
2038 if (INET_MATCH(sk, net, acookie,
2039 rmt_addr, loc_addr, ports, dif))
2040 result = sk;
2041 /* Only check first socket in chain */
2042 break;
2043 }
2044
2045 if (result) {
2046 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
2047 result = NULL;
2048 else if (unlikely(!INET_MATCH(sk, net, acookie,
2049 rmt_addr, loc_addr,
2050 ports, dif))) {
2051 sock_put(result);
2052 result = NULL;
2053 }
2054 }
2055 rcu_read_unlock();
2056 return result;
2057 }
2058
2059 void udp_v4_early_demux(struct sk_buff *skb)
2060 {
2061 struct net *net = dev_net(skb->dev);
2062 const struct iphdr *iph;
2063 const struct udphdr *uh;
2064 struct sock *sk;
2065 struct dst_entry *dst;
2066 int dif = skb->dev->ifindex;
2067 int ours;
2068
2069 /* validate the packet */
2070 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
2071 return;
2072
2073 iph = ip_hdr(skb);
2074 uh = udp_hdr(skb);
2075
2076 if (skb->pkt_type == PACKET_BROADCAST ||
2077 skb->pkt_type == PACKET_MULTICAST) {
2078 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
2079
2080 if (!in_dev)
2081 return;
2082
2083 ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
2084 iph->protocol);
2085 if (!ours)
2086 return;
2087 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
2088 uh->source, iph->saddr, dif);
2089 } else if (skb->pkt_type == PACKET_HOST) {
2090 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
2091 uh->source, iph->saddr, dif);
2092 } else {
2093 return;
2094 }
2095
2096 if (!sk)
2097 return;
2098
2099 skb->sk = sk;
2100 skb->destructor = sock_efree;
2101 dst = READ_ONCE(sk->sk_rx_dst);
2102
2103 if (dst)
2104 dst = dst_check(dst, 0);
2105 if (dst) {
2106 /* DST_NOCACHE can not be used without taking a reference */
2107 if (dst->flags & DST_NOCACHE) {
2108 if (likely(atomic_inc_not_zero(&dst->__refcnt)))
2109 skb_dst_set(skb, dst);
2110 } else {
2111 skb_dst_set_noref(skb, dst);
2112 }
2113 }
2114 }
2115
2116 int udp_rcv(struct sk_buff *skb)
2117 {
2118 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
2119 }
2120
2121 void udp_destroy_sock(struct sock *sk)
2122 {
2123 struct udp_sock *up = udp_sk(sk);
2124 bool slow = lock_sock_fast(sk);
2125 udp_flush_pending_frames(sk);
2126 unlock_sock_fast(sk, slow);
2127 if (static_key_false(&udp_encap_needed) && up->encap_type) {
2128 void (*encap_destroy)(struct sock *sk);
2129 encap_destroy = ACCESS_ONCE(up->encap_destroy);
2130 if (encap_destroy)
2131 encap_destroy(sk);
2132 }
2133 }
2134
2135 /*
2136 * Socket option code for UDP
2137 */
2138 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
2139 char __user *optval, unsigned int optlen,
2140 int (*push_pending_frames)(struct sock *))
2141 {
2142 struct udp_sock *up = udp_sk(sk);
2143 int val, valbool;
2144 int err = 0;
2145 int is_udplite = IS_UDPLITE(sk);
2146
2147 if (optlen < sizeof(int))
2148 return -EINVAL;
2149
2150 if (get_user(val, (int __user *)optval))
2151 return -EFAULT;
2152
2153 valbool = val ? 1 : 0;
2154
2155 switch (optname) {
2156 case UDP_CORK:
2157 if (val != 0) {
2158 up->corkflag = 1;
2159 } else {
2160 up->corkflag = 0;
2161 lock_sock(sk);
2162 push_pending_frames(sk);
2163 release_sock(sk);
2164 }
2165 break;
2166
2167 case UDP_ENCAP:
2168 switch (val) {
2169 case 0:
2170 case UDP_ENCAP_ESPINUDP:
2171 case UDP_ENCAP_ESPINUDP_NON_IKE:
2172 up->encap_rcv = xfrm4_udp_encap_rcv;
2173 /* FALLTHROUGH */
2174 case UDP_ENCAP_L2TPINUDP:
2175 up->encap_type = val;
2176 udp_encap_enable();
2177 break;
2178 default:
2179 err = -ENOPROTOOPT;
2180 break;
2181 }
2182 break;
2183
2184 case UDP_NO_CHECK6_TX:
2185 up->no_check6_tx = valbool;
2186 break;
2187
2188 case UDP_NO_CHECK6_RX:
2189 up->no_check6_rx = valbool;
2190 break;
2191
2192 /*
2193 * UDP-Lite's partial checksum coverage (RFC 3828).
2194 */
2195 /* The sender sets actual checksum coverage length via this option.
2196 * The case coverage > packet length is handled by send module. */
2197 case UDPLITE_SEND_CSCOV:
2198 if (!is_udplite) /* Disable the option on UDP sockets */
2199 return -ENOPROTOOPT;
2200 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
2201 val = 8;
2202 else if (val > USHRT_MAX)
2203 val = USHRT_MAX;
2204 up->pcslen = val;
2205 up->pcflag |= UDPLITE_SEND_CC;
2206 break;
2207
2208 /* The receiver specifies a minimum checksum coverage value. To make
2209 * sense, this should be set to at least 8 (as done below). If zero is
2210 * used, this again means full checksum coverage. */
2211 case UDPLITE_RECV_CSCOV:
2212 if (!is_udplite) /* Disable the option on UDP sockets */
2213 return -ENOPROTOOPT;
2214 if (val != 0 && val < 8) /* Avoid silly minimal values. */
2215 val = 8;
2216 else if (val > USHRT_MAX)
2217 val = USHRT_MAX;
2218 up->pcrlen = val;
2219 up->pcflag |= UDPLITE_RECV_CC;
2220 break;
2221
2222 default:
2223 err = -ENOPROTOOPT;
2224 break;
2225 }
2226
2227 return err;
2228 }
2229 EXPORT_SYMBOL(udp_lib_setsockopt);
2230
2231 int udp_setsockopt(struct sock *sk, int level, int optname,
2232 char __user *optval, unsigned int optlen)
2233 {
2234 if (level == SOL_UDP || level == SOL_UDPLITE)
2235 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
2236 udp_push_pending_frames);
2237 return ip_setsockopt(sk, level, optname, optval, optlen);
2238 }
2239
2240 #ifdef CONFIG_COMPAT
2241 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
2242 char __user *optval, unsigned int optlen)
2243 {
2244 if (level == SOL_UDP || level == SOL_UDPLITE)
2245 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
2246 udp_push_pending_frames);
2247 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
2248 }
2249 #endif
2250
2251 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
2252 char __user *optval, int __user *optlen)
2253 {
2254 struct udp_sock *up = udp_sk(sk);
2255 int val, len;
2256
2257 if (get_user(len, optlen))
2258 return -EFAULT;
2259
2260 len = min_t(unsigned int, len, sizeof(int));
2261
2262 if (len < 0)
2263 return -EINVAL;
2264
2265 switch (optname) {
2266 case UDP_CORK:
2267 val = up->corkflag;
2268 break;
2269
2270 case UDP_ENCAP:
2271 val = up->encap_type;
2272 break;
2273
2274 case UDP_NO_CHECK6_TX:
2275 val = up->no_check6_tx;
2276 break;
2277
2278 case UDP_NO_CHECK6_RX:
2279 val = up->no_check6_rx;
2280 break;
2281
2282 /* The following two cannot be changed on UDP sockets, the return is
2283 * always 0 (which corresponds to the full checksum coverage of UDP). */
2284 case UDPLITE_SEND_CSCOV:
2285 val = up->pcslen;
2286 break;
2287
2288 case UDPLITE_RECV_CSCOV:
2289 val = up->pcrlen;
2290 break;
2291
2292 default:
2293 return -ENOPROTOOPT;
2294 }
2295
2296 if (put_user(len, optlen))
2297 return -EFAULT;
2298 if (copy_to_user(optval, &val, len))
2299 return -EFAULT;
2300 return 0;
2301 }
2302 EXPORT_SYMBOL(udp_lib_getsockopt);
2303
2304 int udp_getsockopt(struct sock *sk, int level, int optname,
2305 char __user *optval, int __user *optlen)
2306 {
2307 if (level == SOL_UDP || level == SOL_UDPLITE)
2308 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2309 return ip_getsockopt(sk, level, optname, optval, optlen);
2310 }
2311
2312 #ifdef CONFIG_COMPAT
2313 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
2314 char __user *optval, int __user *optlen)
2315 {
2316 if (level == SOL_UDP || level == SOL_UDPLITE)
2317 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2318 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
2319 }
2320 #endif
2321 /**
2322 * udp_poll - wait for a UDP event.
2323 * @file - file struct
2324 * @sock - socket
2325 * @wait - poll table
2326 *
2327 * This is same as datagram poll, except for the special case of
2328 * blocking sockets. If application is using a blocking fd
2329 * and a packet with checksum error is in the queue;
2330 * then it could get return from select indicating data available
2331 * but then block when reading it. Add special case code
2332 * to work around these arguably broken applications.
2333 */
2334 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
2335 {
2336 unsigned int mask = datagram_poll(file, sock, wait);
2337 struct sock *sk = sock->sk;
2338
2339 sock_rps_record_flow(sk);
2340
2341 /* Check for false positives due to checksum errors */
2342 if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
2343 !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk))
2344 mask &= ~(POLLIN | POLLRDNORM);
2345
2346 return mask;
2347
2348 }
2349 EXPORT_SYMBOL(udp_poll);
2350
2351 struct proto udp_prot = {
2352 .name = "UDP",
2353 .owner = THIS_MODULE,
2354 .close = udp_lib_close,
2355 .connect = ip4_datagram_connect,
2356 .disconnect = udp_disconnect,
2357 .ioctl = udp_ioctl,
2358 .destroy = udp_destroy_sock,
2359 .setsockopt = udp_setsockopt,
2360 .getsockopt = udp_getsockopt,
2361 .sendmsg = udp_sendmsg,
2362 .recvmsg = udp_recvmsg,
2363 .sendpage = udp_sendpage,
2364 .backlog_rcv = __udp_queue_rcv_skb,
2365 .release_cb = ip4_datagram_release_cb,
2366 .hash = udp_lib_hash,
2367 .unhash = udp_lib_unhash,
2368 .rehash = udp_v4_rehash,
2369 .get_port = udp_v4_get_port,
2370 .memory_allocated = &udp_memory_allocated,
2371 .sysctl_mem = sysctl_udp_mem,
2372 .sysctl_wmem = &sysctl_udp_wmem_min,
2373 .sysctl_rmem = &sysctl_udp_rmem_min,
2374 .obj_size = sizeof(struct udp_sock),
2375 .slab_flags = SLAB_DESTROY_BY_RCU,
2376 .h.udp_table = &udp_table,
2377 #ifdef CONFIG_COMPAT
2378 .compat_setsockopt = compat_udp_setsockopt,
2379 .compat_getsockopt = compat_udp_getsockopt,
2380 #endif
2381 .clear_sk = sk_prot_clear_portaddr_nulls,
2382 };
2383 EXPORT_SYMBOL(udp_prot);
2384
2385 /* ------------------------------------------------------------------------ */
2386 #ifdef CONFIG_PROC_FS
2387
2388 static struct sock *udp_get_first(struct seq_file *seq, int start)
2389 {
2390 struct sock *sk;
2391 struct udp_iter_state *state = seq->private;
2392 struct net *net = seq_file_net(seq);
2393
2394 for (state->bucket = start; state->bucket <= state->udp_table->mask;
2395 ++state->bucket) {
2396 struct hlist_nulls_node *node;
2397 struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
2398
2399 if (hlist_nulls_empty(&hslot->head))
2400 continue;
2401
2402 spin_lock_bh(&hslot->lock);
2403 sk_nulls_for_each(sk, node, &hslot->head) {
2404 if (!net_eq(sock_net(sk), net))
2405 continue;
2406 if (sk->sk_family == state->family)
2407 goto found;
2408 }
2409 spin_unlock_bh(&hslot->lock);
2410 }
2411 sk = NULL;
2412 found:
2413 return sk;
2414 }
2415
2416 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
2417 {
2418 struct udp_iter_state *state = seq->private;
2419 struct net *net = seq_file_net(seq);
2420
2421 do {
2422 sk = sk_nulls_next(sk);
2423 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
2424
2425 if (!sk) {
2426 if (state->bucket <= state->udp_table->mask)
2427 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2428 return udp_get_first(seq, state->bucket + 1);
2429 }
2430 return sk;
2431 }
2432
2433 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
2434 {
2435 struct sock *sk = udp_get_first(seq, 0);
2436
2437 if (sk)
2438 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
2439 --pos;
2440 return pos ? NULL : sk;
2441 }
2442
2443 static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
2444 {
2445 struct udp_iter_state *state = seq->private;
2446 state->bucket = MAX_UDP_PORTS;
2447
2448 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
2449 }
2450
2451 static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2452 {
2453 struct sock *sk;
2454
2455 if (v == SEQ_START_TOKEN)
2456 sk = udp_get_idx(seq, 0);
2457 else
2458 sk = udp_get_next(seq, v);
2459
2460 ++*pos;
2461 return sk;
2462 }
2463
2464 static void udp_seq_stop(struct seq_file *seq, void *v)
2465 {
2466 struct udp_iter_state *state = seq->private;
2467
2468 if (state->bucket <= state->udp_table->mask)
2469 spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
2470 }
2471
2472 int udp_seq_open(struct inode *inode, struct file *file)
2473 {
2474 struct udp_seq_afinfo *afinfo = PDE_DATA(inode);
2475 struct udp_iter_state *s;
2476 int err;
2477
2478 err = seq_open_net(inode, file, &afinfo->seq_ops,
2479 sizeof(struct udp_iter_state));
2480 if (err < 0)
2481 return err;
2482
2483 s = ((struct seq_file *)file->private_data)->private;
2484 s->family = afinfo->family;
2485 s->udp_table = afinfo->udp_table;
2486 return err;
2487 }
2488 EXPORT_SYMBOL(udp_seq_open);
2489
2490 /* ------------------------------------------------------------------------ */
2491 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
2492 {
2493 struct proc_dir_entry *p;
2494 int rc = 0;
2495
2496 afinfo->seq_ops.start = udp_seq_start;
2497 afinfo->seq_ops.next = udp_seq_next;
2498 afinfo->seq_ops.stop = udp_seq_stop;
2499
2500 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2501 afinfo->seq_fops, afinfo);
2502 if (!p)
2503 rc = -ENOMEM;
2504 return rc;
2505 }
2506 EXPORT_SYMBOL(udp_proc_register);
2507
2508 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
2509 {
2510 remove_proc_entry(afinfo->name, net->proc_net);
2511 }
2512 EXPORT_SYMBOL(udp_proc_unregister);
2513
2514 /* ------------------------------------------------------------------------ */
2515 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
2516 int bucket)
2517 {
2518 struct inet_sock *inet = inet_sk(sp);
2519 __be32 dest = inet->inet_daddr;
2520 __be32 src = inet->inet_rcv_saddr;
2521 __u16 destp = ntohs(inet->inet_dport);
2522 __u16 srcp = ntohs(inet->inet_sport);
2523
2524 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
2525 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
2526 bucket, src, srcp, dest, destp, sp->sk_state,
2527 sk_wmem_alloc_get(sp),
2528 sk_rmem_alloc_get(sp),
2529 0, 0L, 0,
2530 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
2531 0, sock_i_ino(sp),
2532 atomic_read(&sp->sk_refcnt), sp,
2533 atomic_read(&sp->sk_drops));
2534 }
2535
2536 int udp4_seq_show(struct seq_file *seq, void *v)
2537 {
2538 seq_setwidth(seq, 127);
2539 if (v == SEQ_START_TOKEN)
2540 seq_puts(seq, " sl local_address rem_address st tx_queue "
2541 "rx_queue tr tm->when retrnsmt uid timeout "
2542 "inode ref pointer drops");
2543 else {
2544 struct udp_iter_state *state = seq->private;
2545
2546 udp4_format_sock(v, seq, state->bucket);
2547 }
2548 seq_pad(seq, '\n');
2549 return 0;
2550 }
2551
2552 static const struct file_operations udp_afinfo_seq_fops = {
2553 .owner = THIS_MODULE,
2554 .open = udp_seq_open,
2555 .read = seq_read,
2556 .llseek = seq_lseek,
2557 .release = seq_release_net
2558 };
2559
2560 /* ------------------------------------------------------------------------ */
2561 static struct udp_seq_afinfo udp4_seq_afinfo = {
2562 .name = "udp",
2563 .family = AF_INET,
2564 .udp_table = &udp_table,
2565 .seq_fops = &udp_afinfo_seq_fops,
2566 .seq_ops = {
2567 .show = udp4_seq_show,
2568 },
2569 };
2570
2571 static int __net_init udp4_proc_init_net(struct net *net)
2572 {
2573 return udp_proc_register(net, &udp4_seq_afinfo);
2574 }
2575
2576 static void __net_exit udp4_proc_exit_net(struct net *net)
2577 {
2578 udp_proc_unregister(net, &udp4_seq_afinfo);
2579 }
2580
2581 static struct pernet_operations udp4_net_ops = {
2582 .init = udp4_proc_init_net,
2583 .exit = udp4_proc_exit_net,
2584 };
2585
2586 int __init udp4_proc_init(void)
2587 {
2588 return register_pernet_subsys(&udp4_net_ops);
2589 }
2590
2591 void udp4_proc_exit(void)
2592 {
2593 unregister_pernet_subsys(&udp4_net_ops);
2594 }
2595 #endif /* CONFIG_PROC_FS */
2596
2597 static __initdata unsigned long uhash_entries;
2598 static int __init set_uhash_entries(char *str)
2599 {
2600 ssize_t ret;
2601
2602 if (!str)
2603 return 0;
2604
2605 ret = kstrtoul(str, 0, &uhash_entries);
2606 if (ret)
2607 return 0;
2608
2609 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
2610 uhash_entries = UDP_HTABLE_SIZE_MIN;
2611 return 1;
2612 }
2613 __setup("uhash_entries=", set_uhash_entries);
2614
2615 void __init udp_table_init(struct udp_table *table, const char *name)
2616 {
2617 unsigned int i;
2618
2619 table->hash = alloc_large_system_hash(name,
2620 2 * sizeof(struct udp_hslot),
2621 uhash_entries,
2622 21, /* one slot per 2 MB */
2623 0,
2624 &table->log,
2625 &table->mask,
2626 UDP_HTABLE_SIZE_MIN,
2627 64 * 1024);
2628
2629 table->hash2 = table->hash + (table->mask + 1);
2630 for (i = 0; i <= table->mask; i++) {
2631 INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
2632 table->hash[i].count = 0;
2633 spin_lock_init(&table->hash[i].lock);
2634 }
2635 for (i = 0; i <= table->mask; i++) {
2636 INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i);
2637 table->hash2[i].count = 0;
2638 spin_lock_init(&table->hash2[i].lock);
2639 }
2640 }
2641
2642 u32 udp_flow_hashrnd(void)
2643 {
2644 static u32 hashrnd __read_mostly;
2645
2646 net_get_random_once(&hashrnd, sizeof(hashrnd));
2647
2648 return hashrnd;
2649 }
2650 EXPORT_SYMBOL(udp_flow_hashrnd);
2651
2652 void __init udp_init(void)
2653 {
2654 unsigned long limit;
2655
2656 udp_table_init(&udp_table, "UDP");
2657 limit = nr_free_buffer_pages() / 8;
2658 limit = max(limit, 128UL);
2659 sysctl_udp_mem[0] = limit / 4 * 3;
2660 sysctl_udp_mem[1] = limit;
2661 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
2662
2663 sysctl_udp_rmem_min = SK_MEM_QUANTUM;
2664 sysctl_udp_wmem_min = SK_MEM_QUANTUM;
2665 }
Linux with added FPC-III support