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tty: serial: lpuart: avoid leaking struct tty_struct
[linux/fpc-iii.git] / net / ipv4 / udp.c
blobf4e35b2ff8b8dc3956da415cb6a29bb147e25f04
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * The User Datagram Protocol (UDP).
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
11 * Alan Cox, <alan@lxorguk.ukuu.org.uk>
12 * Hirokazu Takahashi, <taka@valinux.co.jp>
13 *
14 * Fixes:
15 * Alan Cox : verify_area() calls
16 * Alan Cox : stopped close while in use off icmp
17 * messages. Not a fix but a botch that
18 * for udp at least is 'valid'.
19 * Alan Cox : Fixed icmp handling properly
20 * Alan Cox : Correct error for oversized datagrams
21 * Alan Cox : Tidied select() semantics.
22 * Alan Cox : udp_err() fixed properly, also now
23 * select and read wake correctly on errors
24 * Alan Cox : udp_send verify_area moved to avoid mem leak
25 * Alan Cox : UDP can count its memory
26 * Alan Cox : send to an unknown connection causes
27 * an ECONNREFUSED off the icmp, but
28 * does NOT close.
29 * Alan Cox : Switched to new sk_buff handlers. No more backlog!
30 * Alan Cox : Using generic datagram code. Even smaller and the PEEK
31 * bug no longer crashes it.
32 * Fred Van Kempen : Net2e support for sk->broadcast.
33 * Alan Cox : Uses skb_free_datagram
34 * Alan Cox : Added get/set sockopt support.
35 * Alan Cox : Broadcasting without option set returns EACCES.
36 * Alan Cox : No wakeup calls. Instead we now use the callbacks.
37 * Alan Cox : Use ip_tos and ip_ttl
38 * Alan Cox : SNMP Mibs
39 * Alan Cox : MSG_DONTROUTE, and 0.0.0.0 support.
40 * Matt Dillon : UDP length checks.
41 * Alan Cox : Smarter af_inet used properly.
42 * Alan Cox : Use new kernel side addressing.
43 * Alan Cox : Incorrect return on truncated datagram receive.
44 * Arnt Gulbrandsen : New udp_send and stuff
45 * Alan Cox : Cache last socket
46 * Alan Cox : Route cache
47 * Jon Peatfield : Minor efficiency fix to sendto().
48 * Mike Shaver : RFC1122 checks.
49 * Alan Cox : Nonblocking error fix.
50 * Willy Konynenberg : Transparent proxying support.
51 * Mike McLagan : Routing by source
52 * David S. Miller : New socket lookup architecture.
53 * Last socket cache retained as it
54 * does have a high hit rate.
55 * Olaf Kirch : Don't linearise iovec on sendmsg.
56 * Andi Kleen : Some cleanups, cache destination entry
57 * for connect.
58 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
59 * Melvin Smith : Check msg_name not msg_namelen in sendto(),
60 * return ENOTCONN for unconnected sockets (POSIX)
61 * Janos Farkas : don't deliver multi/broadcasts to a different
62 * bound-to-device socket
63 * Hirokazu Takahashi : HW checksumming for outgoing UDP
64 * datagrams.
65 * Hirokazu Takahashi : sendfile() on UDP works now.
66 * Arnaldo C. Melo : convert /proc/net/udp to seq_file
67 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
68 * Alexey Kuznetsov: allow both IPv4 and IPv6 sockets to bind
69 * a single port at the same time.
70 * Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
71 * James Chapman : Add L2TP encapsulation type.
72 *
73 *
74 * This program is free software; you can redistribute it and/or
75 * modify it under the terms of the GNU General Public License
76 * as published by the Free Software Foundation; either version
77 * 2 of the License, or (at your option) any later version.
78 */
79
80 #define pr_fmt(fmt) "UDP: " fmt
81
82 #include <linux/uaccess.h>
83 #include <asm/ioctls.h>
84 #include <linux/bootmem.h>
85 #include <linux/highmem.h>
86 #include <linux/swap.h>
87 #include <linux/types.h>
88 #include <linux/fcntl.h>
89 #include <linux/module.h>
90 #include <linux/socket.h>
91 #include <linux/sockios.h>
92 #include <linux/igmp.h>
93 #include <linux/inetdevice.h>
94 #include <linux/in.h>
95 #include <linux/errno.h>
96 #include <linux/timer.h>
97 #include <linux/mm.h>
98 #include <linux/inet.h>
99 #include <linux/netdevice.h>
100 #include <linux/slab.h>
101 #include <net/tcp_states.h>
102 #include <linux/skbuff.h>
103 #include <linux/proc_fs.h>
104 #include <linux/seq_file.h>
105 #include <net/net_namespace.h>
106 #include <net/icmp.h>
107 #include <net/inet_hashtables.h>
108 #include <net/route.h>
109 #include <net/checksum.h>
110 #include <net/xfrm.h>
111 #include <trace/events/udp.h>
112 #include <linux/static_key.h>
113 #include <trace/events/skb.h>
114 #include <net/busy_poll.h>
115 #include "udp_impl.h"
116 #include <net/sock_reuseport.h>
117 #include <net/addrconf.h>
118
119 struct udp_table udp_table __read_mostly;
120 EXPORT_SYMBOL(udp_table);
121
122 long sysctl_udp_mem[3] __read_mostly;
123 EXPORT_SYMBOL(sysctl_udp_mem);
124
125 atomic_long_t udp_memory_allocated;
126 EXPORT_SYMBOL(udp_memory_allocated);
127
128 #define MAX_UDP_PORTS 65536
129 #define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
130
131 /* IPCB reference means this can not be used from early demux */
132 static bool udp_lib_exact_dif_match(struct net *net, struct sk_buff *skb)
133 {
134 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
135 if (!net->ipv4.sysctl_udp_l3mdev_accept &&
136 skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
137 return true;
138 #endif
139 return false;
140 }
141
142 static int udp_lib_lport_inuse(struct net *net, __u16 num,
143 const struct udp_hslot *hslot,
144 unsigned long *bitmap,
145 struct sock *sk, unsigned int log)
146 {
147 struct sock *sk2;
148 kuid_t uid = sock_i_uid(sk);
149
150 sk_for_each(sk2, &hslot->head) {
151 if (net_eq(sock_net(sk2), net) &&
152 sk2 != sk &&
153 (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
154 (!sk2->sk_reuse || !sk->sk_reuse) &&
155 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
156 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
157 inet_rcv_saddr_equal(sk, sk2, true)) {
158 if (sk2->sk_reuseport && sk->sk_reuseport &&
159 !rcu_access_pointer(sk->sk_reuseport_cb) &&
160 uid_eq(uid, sock_i_uid(sk2))) {
161 if (!bitmap)
162 return 0;
163 } else {
164 if (!bitmap)
165 return 1;
166 __set_bit(udp_sk(sk2)->udp_port_hash >> log,
167 bitmap);
168 }
169 }
170 }
171 return 0;
172 }
173
174 /*
175 * Note: we still hold spinlock of primary hash chain, so no other writer
176 * can insert/delete a socket with local_port == num
177 */
178 static int udp_lib_lport_inuse2(struct net *net, __u16 num,
179 struct udp_hslot *hslot2,
180 struct sock *sk)
181 {
182 struct sock *sk2;
183 kuid_t uid = sock_i_uid(sk);
184 int res = 0;
185
186 spin_lock(&hslot2->lock);
187 udp_portaddr_for_each_entry(sk2, &hslot2->head) {
188 if (net_eq(sock_net(sk2), net) &&
189 sk2 != sk &&
190 (udp_sk(sk2)->udp_port_hash == num) &&
191 (!sk2->sk_reuse || !sk->sk_reuse) &&
192 (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if ||
193 sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
194 inet_rcv_saddr_equal(sk, sk2, true)) {
195 if (sk2->sk_reuseport && sk->sk_reuseport &&
196 !rcu_access_pointer(sk->sk_reuseport_cb) &&
197 uid_eq(uid, sock_i_uid(sk2))) {
198 res = 0;
199 } else {
200 res = 1;
201 }
202 break;
203 }
204 }
205 spin_unlock(&hslot2->lock);
206 return res;
207 }
208
209 static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot)
210 {
211 struct net *net = sock_net(sk);
212 kuid_t uid = sock_i_uid(sk);
213 struct sock *sk2;
214
215 sk_for_each(sk2, &hslot->head) {
216 if (net_eq(sock_net(sk2), net) &&
217 sk2 != sk &&
218 sk2->sk_family == sk->sk_family &&
219 ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
220 (udp_sk(sk2)->udp_port_hash == udp_sk(sk)->udp_port_hash) &&
221 (sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
222 sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
223 inet_rcv_saddr_equal(sk, sk2, false)) {
224 return reuseport_add_sock(sk, sk2,
225 inet_rcv_saddr_any(sk));
226 }
227 }
228
229 return reuseport_alloc(sk, inet_rcv_saddr_any(sk));
230 }
231
232 /**
233 * udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
234 *
235 * @sk: socket struct in question
236 * @snum: port number to look up
237 * @hash2_nulladdr: AF-dependent hash value in secondary hash chains,
238 * with NULL address
239 */
240 int udp_lib_get_port(struct sock *sk, unsigned short snum,
241 unsigned int hash2_nulladdr)
242 {
243 struct udp_hslot *hslot, *hslot2;
244 struct udp_table *udptable = sk->sk_prot->h.udp_table;
245 int error = 1;
246 struct net *net = sock_net(sk);
247
248 if (!snum) {
249 int low, high, remaining;
250 unsigned int rand;
251 unsigned short first, last;
252 DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
253
254 inet_get_local_port_range(net, &low, &high);
255 remaining = (high - low) + 1;
256
257 rand = prandom_u32();
258 first = reciprocal_scale(rand, remaining) + low;
259 /*
260 * force rand to be an odd multiple of UDP_HTABLE_SIZE
261 */
262 rand = (rand | 1) * (udptable->mask + 1);
263 last = first + udptable->mask + 1;
264 do {
265 hslot = udp_hashslot(udptable, net, first);
266 bitmap_zero(bitmap, PORTS_PER_CHAIN);
267 spin_lock_bh(&hslot->lock);
268 udp_lib_lport_inuse(net, snum, hslot, bitmap, sk,
269 udptable->log);
270
271 snum = first;
272 /*
273 * Iterate on all possible values of snum for this hash.
274 * Using steps of an odd multiple of UDP_HTABLE_SIZE
275 * give us randomization and full range coverage.
276 */
277 do {
278 if (low <= snum && snum <= high &&
279 !test_bit(snum >> udptable->log, bitmap) &&
280 !inet_is_local_reserved_port(net, snum))
281 goto found;
282 snum += rand;
283 } while (snum != first);
284 spin_unlock_bh(&hslot->lock);
285 cond_resched();
286 } while (++first != last);
287 goto fail;
288 } else {
289 hslot = udp_hashslot(udptable, net, snum);
290 spin_lock_bh(&hslot->lock);
291 if (hslot->count > 10) {
292 int exist;
293 unsigned int slot2 = udp_sk(sk)->udp_portaddr_hash ^ snum;
294
295 slot2 &= udptable->mask;
296 hash2_nulladdr &= udptable->mask;
297
298 hslot2 = udp_hashslot2(udptable, slot2);
299 if (hslot->count < hslot2->count)
300 goto scan_primary_hash;
301
302 exist = udp_lib_lport_inuse2(net, snum, hslot2, sk);
303 if (!exist && (hash2_nulladdr != slot2)) {
304 hslot2 = udp_hashslot2(udptable, hash2_nulladdr);
305 exist = udp_lib_lport_inuse2(net, snum, hslot2,
306 sk);
307 }
308 if (exist)
309 goto fail_unlock;
310 else
311 goto found;
312 }
313 scan_primary_hash:
314 if (udp_lib_lport_inuse(net, snum, hslot, NULL, sk, 0))
315 goto fail_unlock;
316 }
317 found:
318 inet_sk(sk)->inet_num = snum;
319 udp_sk(sk)->udp_port_hash = snum;
320 udp_sk(sk)->udp_portaddr_hash ^= snum;
321 if (sk_unhashed(sk)) {
322 if (sk->sk_reuseport &&
323 udp_reuseport_add_sock(sk, hslot)) {
324 inet_sk(sk)->inet_num = 0;
325 udp_sk(sk)->udp_port_hash = 0;
326 udp_sk(sk)->udp_portaddr_hash ^= snum;
327 goto fail_unlock;
328 }
329
330 sk_add_node_rcu(sk, &hslot->head);
331 hslot->count++;
332 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
333
334 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
335 spin_lock(&hslot2->lock);
336 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
337 sk->sk_family == AF_INET6)
338 hlist_add_tail_rcu(&udp_sk(sk)->udp_portaddr_node,
339 &hslot2->head);
340 else
341 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
342 &hslot2->head);
343 hslot2->count++;
344 spin_unlock(&hslot2->lock);
345 }
346 sock_set_flag(sk, SOCK_RCU_FREE);
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 int udp_v4_get_port(struct sock *sk, unsigned short snum)
356 {
357 unsigned int hash2_nulladdr =
358 ipv4_portaddr_hash(sock_net(sk), htonl(INADDR_ANY), snum);
359 unsigned int hash2_partial =
360 ipv4_portaddr_hash(sock_net(sk), inet_sk(sk)->inet_rcv_saddr, 0);
361
362 /* precompute partial secondary hash */
363 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
364 return udp_lib_get_port(sk, snum, hash2_nulladdr);
365 }
366
367 static int compute_score(struct sock *sk, struct net *net,
368 __be32 saddr, __be16 sport,
369 __be32 daddr, unsigned short hnum,
370 int dif, int sdif, bool exact_dif)
371 {
372 int score;
373 struct inet_sock *inet;
374
375 if (!net_eq(sock_net(sk), net) ||
376 udp_sk(sk)->udp_port_hash != hnum ||
377 ipv6_only_sock(sk))
378 return -1;
379
380 score = (sk->sk_family == PF_INET) ? 2 : 1;
381 inet = inet_sk(sk);
382
383 if (inet->inet_rcv_saddr) {
384 if (inet->inet_rcv_saddr != daddr)
385 return -1;
386 score += 4;
387 }
388
389 if (inet->inet_daddr) {
390 if (inet->inet_daddr != saddr)
391 return -1;
392 score += 4;
393 }
394
395 if (inet->inet_dport) {
396 if (inet->inet_dport != sport)
397 return -1;
398 score += 4;
399 }
400
401 if (sk->sk_bound_dev_if || exact_dif) {
402 bool dev_match = (sk->sk_bound_dev_if == dif ||
403 sk->sk_bound_dev_if == sdif);
404
405 if (!dev_match)
406 return -1;
407 if (sk->sk_bound_dev_if)
408 score += 4;
409 }
410
411 if (sk->sk_incoming_cpu == raw_smp_processor_id())
412 score++;
413 return score;
414 }
415
416 static u32 udp_ehashfn(const struct net *net, const __be32 laddr,
417 const __u16 lport, const __be32 faddr,
418 const __be16 fport)
419 {
420 static u32 udp_ehash_secret __read_mostly;
421
422 net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret));
423
424 return __inet_ehashfn(laddr, lport, faddr, fport,
425 udp_ehash_secret + net_hash_mix(net));
426 }
427
428 /* called with rcu_read_lock() */
429 static struct sock *udp4_lib_lookup2(struct net *net,
430 __be32 saddr, __be16 sport,
431 __be32 daddr, unsigned int hnum,
432 int dif, int sdif, bool exact_dif,
433 struct udp_hslot *hslot2,
434 struct sk_buff *skb)
435 {
436 struct sock *sk, *result;
437 int score, badness;
438 u32 hash = 0;
439
440 result = NULL;
441 badness = 0;
442 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
443 score = compute_score(sk, net, saddr, sport,
444 daddr, hnum, dif, sdif, exact_dif);
445 if (score > badness) {
446 if (sk->sk_reuseport) {
447 hash = udp_ehashfn(net, daddr, hnum,
448 saddr, sport);
449 result = reuseport_select_sock(sk, hash, skb,
450 sizeof(struct udphdr));
451 if (result)
452 return result;
453 }
454 badness = score;
455 result = sk;
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, int dif,
466 int sdif, struct udp_table *udptable, struct sk_buff *skb)
467 {
468 struct sock *sk, *result;
469 unsigned short hnum = ntohs(dport);
470 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
471 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
472 bool exact_dif = udp_lib_exact_dif_match(net, skb);
473 int score, badness;
474 u32 hash = 0;
475
476 if (hslot->count > 10) {
477 hash2 = ipv4_portaddr_hash(net, daddr, hnum);
478 slot2 = hash2 & udptable->mask;
479 hslot2 = &udptable->hash2[slot2];
480 if (hslot->count < hslot2->count)
481 goto begin;
482
483 result = udp4_lib_lookup2(net, saddr, sport,
484 daddr, hnum, dif, sdif,
485 exact_dif, hslot2, skb);
486 if (!result) {
487 unsigned int old_slot2 = slot2;
488 hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum);
489 slot2 = hash2 & udptable->mask;
490 /* avoid searching the same slot again. */
491 if (unlikely(slot2 == old_slot2))
492 return result;
493
494 hslot2 = &udptable->hash2[slot2];
495 if (hslot->count < hslot2->count)
496 goto begin;
497
498 result = udp4_lib_lookup2(net, saddr, sport,
499 daddr, hnum, dif, sdif,
500 exact_dif, hslot2, skb);
501 }
502 if (unlikely(IS_ERR(result)))
503 return NULL;
504 return result;
505 }
506 begin:
507 result = NULL;
508 badness = 0;
509 sk_for_each_rcu(sk, &hslot->head) {
510 score = compute_score(sk, net, saddr, sport,
511 daddr, hnum, dif, sdif, exact_dif);
512 if (score > badness) {
513 if (sk->sk_reuseport) {
514 hash = udp_ehashfn(net, daddr, hnum,
515 saddr, sport);
516 result = reuseport_select_sock(sk, hash, skb,
517 sizeof(struct udphdr));
518 if (unlikely(IS_ERR(result)))
519 return NULL;
520 if (result)
521 return result;
522 }
523 result = sk;
524 badness = score;
525 }
526 }
527 return result;
528 }
529 EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
530
531 static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
532 __be16 sport, __be16 dport,
533 struct udp_table *udptable)
534 {
535 const struct iphdr *iph = ip_hdr(skb);
536
537 return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
538 iph->daddr, dport, inet_iif(skb),
539 inet_sdif(skb), udptable, skb);
540 }
541
542 struct sock *udp4_lib_lookup_skb(struct sk_buff *skb,
543 __be16 sport, __be16 dport)
544 {
545 return __udp4_lib_lookup_skb(skb, sport, dport, &udp_table);
546 }
547 EXPORT_SYMBOL_GPL(udp4_lib_lookup_skb);
548
549 /* Must be called under rcu_read_lock().
550 * Does increment socket refcount.
551 */
552 #if IS_ENABLED(CONFIG_NF_TPROXY_IPV4) || IS_ENABLED(CONFIG_NF_SOCKET_IPV4)
553 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
554 __be32 daddr, __be16 dport, int dif)
555 {
556 struct sock *sk;
557
558 sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport,
559 dif, 0, &udp_table, NULL);
560 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
561 sk = NULL;
562 return sk;
563 }
564 EXPORT_SYMBOL_GPL(udp4_lib_lookup);
565 #endif
566
567 static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk,
568 __be16 loc_port, __be32 loc_addr,
569 __be16 rmt_port, __be32 rmt_addr,
570 int dif, int sdif, unsigned short hnum)
571 {
572 struct inet_sock *inet = inet_sk(sk);
573
574 if (!net_eq(sock_net(sk), net) ||
575 udp_sk(sk)->udp_port_hash != hnum ||
576 (inet->inet_daddr && inet->inet_daddr != rmt_addr) ||
577 (inet->inet_dport != rmt_port && inet->inet_dport) ||
578 (inet->inet_rcv_saddr && inet->inet_rcv_saddr != loc_addr) ||
579 ipv6_only_sock(sk) ||
580 (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif &&
581 sk->sk_bound_dev_if != sdif))
582 return false;
583 if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif, sdif))
584 return false;
585 return true;
586 }
587
588 /*
589 * This routine is called by the ICMP module when it gets some
590 * sort of error condition. If err < 0 then the socket should
591 * be closed and the error returned to the user. If err > 0
592 * it's just the icmp type << 8 | icmp code.
593 * Header points to the ip header of the error packet. We move
594 * on past this. Then (as it used to claim before adjustment)
595 * header points to the first 8 bytes of the udp header. We need
596 * to find the appropriate port.
597 */
598
599 void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
600 {
601 struct inet_sock *inet;
602 const struct iphdr *iph = (const struct iphdr *)skb->data;
603 struct udphdr *uh = (struct udphdr *)(skb->data+(iph->ihl<<2));
604 const int type = icmp_hdr(skb)->type;
605 const int code = icmp_hdr(skb)->code;
606 struct sock *sk;
607 int harderr;
608 int err;
609 struct net *net = dev_net(skb->dev);
610
611 sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
612 iph->saddr, uh->source, skb->dev->ifindex, 0,
613 udptable, NULL);
614 if (!sk) {
615 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
616 return; /* No socket for error */
617 }
618
619 err = 0;
620 harderr = 0;
621 inet = inet_sk(sk);
622
623 switch (type) {
624 default:
625 case ICMP_TIME_EXCEEDED:
626 err = EHOSTUNREACH;
627 break;
628 case ICMP_SOURCE_QUENCH:
629 goto out;
630 case ICMP_PARAMETERPROB:
631 err = EPROTO;
632 harderr = 1;
633 break;
634 case ICMP_DEST_UNREACH:
635 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
636 ipv4_sk_update_pmtu(skb, sk, info);
637 if (inet->pmtudisc != IP_PMTUDISC_DONT) {
638 err = EMSGSIZE;
639 harderr = 1;
640 break;
641 }
642 goto out;
643 }
644 err = EHOSTUNREACH;
645 if (code <= NR_ICMP_UNREACH) {
646 harderr = icmp_err_convert[code].fatal;
647 err = icmp_err_convert[code].errno;
648 }
649 break;
650 case ICMP_REDIRECT:
651 ipv4_sk_redirect(skb, sk);
652 goto out;
653 }
654
655 /*
656 * RFC1122: OK. Passes ICMP errors back to application, as per
657 * 4.1.3.3.
658 */
659 if (!inet->recverr) {
660 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
661 goto out;
662 } else
663 ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1));
664
665 sk->sk_err = err;
666 sk->sk_error_report(sk);
667 out:
668 return;
669 }
670
671 void udp_err(struct sk_buff *skb, u32 info)
672 {
673 __udp4_lib_err(skb, info, &udp_table);
674 }
675
676 /*
677 * Throw away all pending data and cancel the corking. Socket is locked.
678 */
679 void udp_flush_pending_frames(struct sock *sk)
680 {
681 struct udp_sock *up = udp_sk(sk);
682
683 if (up->pending) {
684 up->len = 0;
685 up->pending = 0;
686 ip_flush_pending_frames(sk);
687 }
688 }
689 EXPORT_SYMBOL(udp_flush_pending_frames);
690
691 /**
692 * udp4_hwcsum - handle outgoing HW checksumming
693 * @skb: sk_buff containing the filled-in UDP header
694 * (checksum field must be zeroed out)
695 * @src: source IP address
696 * @dst: destination IP address
697 */
698 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst)
699 {
700 struct udphdr *uh = udp_hdr(skb);
701 int offset = skb_transport_offset(skb);
702 int len = skb->len - offset;
703 int hlen = len;
704 __wsum csum = 0;
705
706 if (!skb_has_frag_list(skb)) {
707 /*
708 * Only one fragment on the socket.
709 */
710 skb->csum_start = skb_transport_header(skb) - skb->head;
711 skb->csum_offset = offsetof(struct udphdr, check);
712 uh->check = ~csum_tcpudp_magic(src, dst, len,
713 IPPROTO_UDP, 0);
714 } else {
715 struct sk_buff *frags;
716
717 /*
718 * HW-checksum won't work as there are two or more
719 * fragments on the socket so that all csums of sk_buffs
720 * should be together
721 */
722 skb_walk_frags(skb, frags) {
723 csum = csum_add(csum, frags->csum);
724 hlen -= frags->len;
725 }
726
727 csum = skb_checksum(skb, offset, hlen, csum);
728 skb->ip_summed = CHECKSUM_NONE;
729
730 uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
731 if (uh->check == 0)
732 uh->check = CSUM_MANGLED_0;
733 }
734 }
735 EXPORT_SYMBOL_GPL(udp4_hwcsum);
736
737 /* Function to set UDP checksum for an IPv4 UDP packet. This is intended
738 * for the simple case like when setting the checksum for a UDP tunnel.
739 */
740 void udp_set_csum(bool nocheck, struct sk_buff *skb,
741 __be32 saddr, __be32 daddr, int len)
742 {
743 struct udphdr *uh = udp_hdr(skb);
744
745 if (nocheck) {
746 uh->check = 0;
747 } else if (skb_is_gso(skb)) {
748 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
749 } else if (skb->ip_summed == CHECKSUM_PARTIAL) {
750 uh->check = 0;
751 uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb));
752 if (uh->check == 0)
753 uh->check = CSUM_MANGLED_0;
754 } else {
755 skb->ip_summed = CHECKSUM_PARTIAL;
756 skb->csum_start = skb_transport_header(skb) - skb->head;
757 skb->csum_offset = offsetof(struct udphdr, check);
758 uh->check = ~udp_v4_check(len, saddr, daddr, 0);
759 }
760 }
761 EXPORT_SYMBOL(udp_set_csum);
762
763 static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4,
764 struct inet_cork *cork)
765 {
766 struct sock *sk = skb->sk;
767 struct inet_sock *inet = inet_sk(sk);
768 struct udphdr *uh;
769 int err = 0;
770 int is_udplite = IS_UDPLITE(sk);
771 int offset = skb_transport_offset(skb);
772 int len = skb->len - offset;
773 __wsum csum = 0;
774
775 /*
776 * Create a UDP header
777 */
778 uh = udp_hdr(skb);
779 uh->source = inet->inet_sport;
780 uh->dest = fl4->fl4_dport;
781 uh->len = htons(len);
782 uh->check = 0;
783
784 if (cork->gso_size) {
785 const int hlen = skb_network_header_len(skb) +
786 sizeof(struct udphdr);
787
788 if (hlen + cork->gso_size > cork->fragsize)
789 return -EINVAL;
790 if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS)
791 return -EINVAL;
792 if (sk->sk_no_check_tx)
793 return -EINVAL;
794 if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
795 dst_xfrm(skb_dst(skb)))
796 return -EIO;
797
798 skb_shinfo(skb)->gso_size = cork->gso_size;
799 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
800 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(len - sizeof(uh),
801 cork->gso_size);
802 goto csum_partial;
803 }
804
805 if (is_udplite) /* UDP-Lite */
806 csum = udplite_csum(skb);
807
808 else if (sk->sk_no_check_tx) { /* UDP csum off */
809
810 skb->ip_summed = CHECKSUM_NONE;
811 goto send;
812
813 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
814 csum_partial:
815
816 udp4_hwcsum(skb, fl4->saddr, fl4->daddr);
817 goto send;
818
819 } else
820 csum = udp_csum(skb);
821
822 /* add protocol-dependent pseudo-header */
823 uh->check = csum_tcpudp_magic(fl4->saddr, fl4->daddr, len,
824 sk->sk_protocol, csum);
825 if (uh->check == 0)
826 uh->check = CSUM_MANGLED_0;
827
828 send:
829 err = ip_send_skb(sock_net(sk), skb);
830 if (err) {
831 if (err == -ENOBUFS && !inet->recverr) {
832 UDP_INC_STATS(sock_net(sk),
833 UDP_MIB_SNDBUFERRORS, is_udplite);
834 err = 0;
835 }
836 } else
837 UDP_INC_STATS(sock_net(sk),
838 UDP_MIB_OUTDATAGRAMS, is_udplite);
839 return err;
840 }
841
842 /*
843 * Push out all pending data as one UDP datagram. Socket is locked.
844 */
845 int udp_push_pending_frames(struct sock *sk)
846 {
847 struct udp_sock *up = udp_sk(sk);
848 struct inet_sock *inet = inet_sk(sk);
849 struct flowi4 *fl4 = &inet->cork.fl.u.ip4;
850 struct sk_buff *skb;
851 int err = 0;
852
853 skb = ip_finish_skb(sk, fl4);
854 if (!skb)
855 goto out;
856
857 err = udp_send_skb(skb, fl4, &inet->cork.base);
858
859 out:
860 up->len = 0;
861 up->pending = 0;
862 return err;
863 }
864 EXPORT_SYMBOL(udp_push_pending_frames);
865
866 static int __udp_cmsg_send(struct cmsghdr *cmsg, u16 *gso_size)
867 {
868 switch (cmsg->cmsg_type) {
869 case UDP_SEGMENT:
870 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u16)))
871 return -EINVAL;
872 *gso_size = *(__u16 *)CMSG_DATA(cmsg);
873 return 0;
874 default:
875 return -EINVAL;
876 }
877 }
878
879 int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size)
880 {
881 struct cmsghdr *cmsg;
882 bool need_ip = false;
883 int err;
884
885 for_each_cmsghdr(cmsg, msg) {
886 if (!CMSG_OK(msg, cmsg))
887 return -EINVAL;
888
889 if (cmsg->cmsg_level != SOL_UDP) {
890 need_ip = true;
891 continue;
892 }
893
894 err = __udp_cmsg_send(cmsg, gso_size);
895 if (err)
896 return err;
897 }
898
899 return need_ip;
900 }
901 EXPORT_SYMBOL_GPL(udp_cmsg_send);
902
903 int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
904 {
905 struct inet_sock *inet = inet_sk(sk);
906 struct udp_sock *up = udp_sk(sk);
907 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
908 struct flowi4 fl4_stack;
909 struct flowi4 *fl4;
910 int ulen = len;
911 struct ipcm_cookie ipc;
912 struct rtable *rt = NULL;
913 int free = 0;
914 int connected = 0;
915 __be32 daddr, faddr, saddr;
916 __be16 dport;
917 u8 tos;
918 int err, is_udplite = IS_UDPLITE(sk);
919 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
920 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
921 struct sk_buff *skb;
922 struct ip_options_data opt_copy;
923
924 if (len > 0xFFFF)
925 return -EMSGSIZE;
926
927 /*
928 * Check the flags.
929 */
930
931 if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */
932 return -EOPNOTSUPP;
933
934 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
935
936 fl4 = &inet->cork.fl.u.ip4;
937 if (up->pending) {
938 /*
939 * There are pending frames.
940 * The socket lock must be held while it's corked.
941 */
942 lock_sock(sk);
943 if (likely(up->pending)) {
944 if (unlikely(up->pending != AF_INET)) {
945 release_sock(sk);
946 return -EINVAL;
947 }
948 goto do_append_data;
949 }
950 release_sock(sk);
951 }
952 ulen += sizeof(struct udphdr);
953
954 /*
955 * Get and verify the address.
956 */
957 if (usin) {
958 if (msg->msg_namelen < sizeof(*usin))
959 return -EINVAL;
960 if (usin->sin_family != AF_INET) {
961 if (usin->sin_family != AF_UNSPEC)
962 return -EAFNOSUPPORT;
963 }
964
965 daddr = usin->sin_addr.s_addr;
966 dport = usin->sin_port;
967 if (dport == 0)
968 return -EINVAL;
969 } else {
970 if (sk->sk_state != TCP_ESTABLISHED)
971 return -EDESTADDRREQ;
972 daddr = inet->inet_daddr;
973 dport = inet->inet_dport;
974 /* Open fast path for connected socket.
975 Route will not be used, if at least one option is set.
976 */
977 connected = 1;
978 }
979
980 ipcm_init_sk(&ipc, inet);
981 ipc.gso_size = up->gso_size;
982
983 if (msg->msg_controllen) {
984 err = udp_cmsg_send(sk, msg, &ipc.gso_size);
985 if (err > 0)
986 err = ip_cmsg_send(sk, msg, &ipc,
987 sk->sk_family == AF_INET6);
988 if (unlikely(err < 0)) {
989 kfree(ipc.opt);
990 return err;
991 }
992 if (ipc.opt)
993 free = 1;
994 connected = 0;
995 }
996 if (!ipc.opt) {
997 struct ip_options_rcu *inet_opt;
998
999 rcu_read_lock();
1000 inet_opt = rcu_dereference(inet->inet_opt);
1001 if (inet_opt) {
1002 memcpy(&opt_copy, inet_opt,
1003 sizeof(*inet_opt) + inet_opt->opt.optlen);
1004 ipc.opt = &opt_copy.opt;
1005 }
1006 rcu_read_unlock();
1007 }
1008
1009 if (cgroup_bpf_enabled && !connected) {
1010 err = BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk,
1011 (struct sockaddr *)usin, &ipc.addr);
1012 if (err)
1013 goto out_free;
1014 if (usin) {
1015 if (usin->sin_port == 0) {
1016 /* BPF program set invalid port. Reject it. */
1017 err = -EINVAL;
1018 goto out_free;
1019 }
1020 daddr = usin->sin_addr.s_addr;
1021 dport = usin->sin_port;
1022 }
1023 }
1024
1025 saddr = ipc.addr;
1026 ipc.addr = faddr = daddr;
1027
1028 if (ipc.opt && ipc.opt->opt.srr) {
1029 if (!daddr) {
1030 err = -EINVAL;
1031 goto out_free;
1032 }
1033 faddr = ipc.opt->opt.faddr;
1034 connected = 0;
1035 }
1036 tos = get_rttos(&ipc, inet);
1037 if (sock_flag(sk, SOCK_LOCALROUTE) ||
1038 (msg->msg_flags & MSG_DONTROUTE) ||
1039 (ipc.opt && ipc.opt->opt.is_strictroute)) {
1040 tos |= RTO_ONLINK;
1041 connected = 0;
1042 }
1043
1044 if (ipv4_is_multicast(daddr)) {
1045 if (!ipc.oif)
1046 ipc.oif = inet->mc_index;
1047 if (!saddr)
1048 saddr = inet->mc_addr;
1049 connected = 0;
1050 } else if (!ipc.oif) {
1051 ipc.oif = inet->uc_index;
1052 } else if (ipv4_is_lbcast(daddr) && inet->uc_index) {
1053 /* oif is set, packet is to local broadcast and
1054 * and uc_index is set. oif is most likely set
1055 * by sk_bound_dev_if. If uc_index != oif check if the
1056 * oif is an L3 master and uc_index is an L3 slave.
1057 * If so, we want to allow the send using the uc_index.
1058 */
1059 if (ipc.oif != inet->uc_index &&
1060 ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk),
1061 inet->uc_index)) {
1062 ipc.oif = inet->uc_index;
1063 }
1064 }
1065
1066 if (connected)
1067 rt = (struct rtable *)sk_dst_check(sk, 0);
1068
1069 if (!rt) {
1070 struct net *net = sock_net(sk);
1071 __u8 flow_flags = inet_sk_flowi_flags(sk);
1072
1073 fl4 = &fl4_stack;
1074
1075 flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
1076 RT_SCOPE_UNIVERSE, sk->sk_protocol,
1077 flow_flags,
1078 faddr, saddr, dport, inet->inet_sport,
1079 sk->sk_uid);
1080
1081 security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
1082 rt = ip_route_output_flow(net, fl4, sk);
1083 if (IS_ERR(rt)) {
1084 err = PTR_ERR(rt);
1085 rt = NULL;
1086 if (err == -ENETUNREACH)
1087 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
1088 goto out;
1089 }
1090
1091 err = -EACCES;
1092 if ((rt->rt_flags & RTCF_BROADCAST) &&
1093 !sock_flag(sk, SOCK_BROADCAST))
1094 goto out;
1095 if (connected)
1096 sk_dst_set(sk, dst_clone(&rt->dst));
1097 }
1098
1099 if (msg->msg_flags&MSG_CONFIRM)
1100 goto do_confirm;
1101 back_from_confirm:
1102
1103 saddr = fl4->saddr;
1104 if (!ipc.addr)
1105 daddr = ipc.addr = fl4->daddr;
1106
1107 /* Lockless fast path for the non-corking case. */
1108 if (!corkreq) {
1109 struct inet_cork cork;
1110
1111 skb = ip_make_skb(sk, fl4, getfrag, msg, ulen,
1112 sizeof(struct udphdr), &ipc, &rt,
1113 &cork, msg->msg_flags);
1114 err = PTR_ERR(skb);
1115 if (!IS_ERR_OR_NULL(skb))
1116 err = udp_send_skb(skb, fl4, &cork);
1117 goto out;
1118 }
1119
1120 lock_sock(sk);
1121 if (unlikely(up->pending)) {
1122 /* The socket is already corked while preparing it. */
1123 /* ... which is an evident application bug. --ANK */
1124 release_sock(sk);
1125
1126 net_dbg_ratelimited("socket already corked\n");
1127 err = -EINVAL;
1128 goto out;
1129 }
1130 /*
1131 * Now cork the socket to pend data.
1132 */
1133 fl4 = &inet->cork.fl.u.ip4;
1134 fl4->daddr = daddr;
1135 fl4->saddr = saddr;
1136 fl4->fl4_dport = dport;
1137 fl4->fl4_sport = inet->inet_sport;
1138 up->pending = AF_INET;
1139
1140 do_append_data:
1141 up->len += ulen;
1142 err = ip_append_data(sk, fl4, getfrag, msg, ulen,
1143 sizeof(struct udphdr), &ipc, &rt,
1144 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1145 if (err)
1146 udp_flush_pending_frames(sk);
1147 else if (!corkreq)
1148 err = udp_push_pending_frames(sk);
1149 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1150 up->pending = 0;
1151 release_sock(sk);
1152
1153 out:
1154 ip_rt_put(rt);
1155 out_free:
1156 if (free)
1157 kfree(ipc.opt);
1158 if (!err)
1159 return len;
1160 /*
1161 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1162 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1163 * we don't have a good statistic (IpOutDiscards but it can be too many
1164 * things). We could add another new stat but at least for now that
1165 * seems like overkill.
1166 */
1167 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1168 UDP_INC_STATS(sock_net(sk),
1169 UDP_MIB_SNDBUFERRORS, is_udplite);
1170 }
1171 return err;
1172
1173 do_confirm:
1174 if (msg->msg_flags & MSG_PROBE)
1175 dst_confirm_neigh(&rt->dst, &fl4->daddr);
1176 if (!(msg->msg_flags&MSG_PROBE) || len)
1177 goto back_from_confirm;
1178 err = 0;
1179 goto out;
1180 }
1181 EXPORT_SYMBOL(udp_sendmsg);
1182
1183 int udp_sendpage(struct sock *sk, struct page *page, int offset,
1184 size_t size, int flags)
1185 {
1186 struct inet_sock *inet = inet_sk(sk);
1187 struct udp_sock *up = udp_sk(sk);
1188 int ret;
1189
1190 if (flags & MSG_SENDPAGE_NOTLAST)
1191 flags |= MSG_MORE;
1192
1193 if (!up->pending) {
1194 struct msghdr msg = { .msg_flags = flags|MSG_MORE };
1195
1196 /* Call udp_sendmsg to specify destination address which
1197 * sendpage interface can't pass.
1198 * This will succeed only when the socket is connected.
1199 */
1200 ret = udp_sendmsg(sk, &msg, 0);
1201 if (ret < 0)
1202 return ret;
1203 }
1204
1205 lock_sock(sk);
1206
1207 if (unlikely(!up->pending)) {
1208 release_sock(sk);
1209
1210 net_dbg_ratelimited("cork failed\n");
1211 return -EINVAL;
1212 }
1213
1214 ret = ip_append_page(sk, &inet->cork.fl.u.ip4,
1215 page, offset, size, flags);
1216 if (ret == -EOPNOTSUPP) {
1217 release_sock(sk);
1218 return sock_no_sendpage(sk->sk_socket, page, offset,
1219 size, flags);
1220 }
1221 if (ret < 0) {
1222 udp_flush_pending_frames(sk);
1223 goto out;
1224 }
1225
1226 up->len += size;
1227 if (!(up->corkflag || (flags&MSG_MORE)))
1228 ret = udp_push_pending_frames(sk);
1229 if (!ret)
1230 ret = size;
1231 out:
1232 release_sock(sk);
1233 return ret;
1234 }
1235
1236 #define UDP_SKB_IS_STATELESS 0x80000000
1237
1238 static void udp_set_dev_scratch(struct sk_buff *skb)
1239 {
1240 struct udp_dev_scratch *scratch = udp_skb_scratch(skb);
1241
1242 BUILD_BUG_ON(sizeof(struct udp_dev_scratch) > sizeof(long));
1243 scratch->_tsize_state = skb->truesize;
1244 #if BITS_PER_LONG == 64
1245 scratch->len = skb->len;
1246 scratch->csum_unnecessary = !!skb_csum_unnecessary(skb);
1247 scratch->is_linear = !skb_is_nonlinear(skb);
1248 #endif
1249 /* all head states execept sp (dst, sk, nf) are always cleared by
1250 * udp_rcv() and we need to preserve secpath, if present, to eventually
1251 * process IP_CMSG_PASSSEC at recvmsg() time
1252 */
1253 if (likely(!skb_sec_path(skb)))
1254 scratch->_tsize_state |= UDP_SKB_IS_STATELESS;
1255 }
1256
1257 static int udp_skb_truesize(struct sk_buff *skb)
1258 {
1259 return udp_skb_scratch(skb)->_tsize_state & ~UDP_SKB_IS_STATELESS;
1260 }
1261
1262 static bool udp_skb_has_head_state(struct sk_buff *skb)
1263 {
1264 return !(udp_skb_scratch(skb)->_tsize_state & UDP_SKB_IS_STATELESS);
1265 }
1266
1267 /* fully reclaim rmem/fwd memory allocated for skb */
1268 static void udp_rmem_release(struct sock *sk, int size, int partial,
1269 bool rx_queue_lock_held)
1270 {
1271 struct udp_sock *up = udp_sk(sk);
1272 struct sk_buff_head *sk_queue;
1273 int amt;
1274
1275 if (likely(partial)) {
1276 up->forward_deficit += size;
1277 size = up->forward_deficit;
1278 if (size < (sk->sk_rcvbuf >> 2))
1279 return;
1280 } else {
1281 size += up->forward_deficit;
1282 }
1283 up->forward_deficit = 0;
1284
1285 /* acquire the sk_receive_queue for fwd allocated memory scheduling,
1286 * if the called don't held it already
1287 */
1288 sk_queue = &sk->sk_receive_queue;
1289 if (!rx_queue_lock_held)
1290 spin_lock(&sk_queue->lock);
1291
1292
1293 sk->sk_forward_alloc += size;
1294 amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1);
1295 sk->sk_forward_alloc -= amt;
1296
1297 if (amt)
1298 __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT);
1299
1300 atomic_sub(size, &sk->sk_rmem_alloc);
1301
1302 /* this can save us from acquiring the rx queue lock on next receive */
1303 skb_queue_splice_tail_init(sk_queue, &up->reader_queue);
1304
1305 if (!rx_queue_lock_held)
1306 spin_unlock(&sk_queue->lock);
1307 }
1308
1309 /* Note: called with reader_queue.lock held.
1310 * Instead of using skb->truesize here, find a copy of it in skb->dev_scratch
1311 * This avoids a cache line miss while receive_queue lock is held.
1312 * Look at __udp_enqueue_schedule_skb() to find where this copy is done.
1313 */
1314 void udp_skb_destructor(struct sock *sk, struct sk_buff *skb)
1315 {
1316 prefetch(&skb->data);
1317 udp_rmem_release(sk, udp_skb_truesize(skb), 1, false);
1318 }
1319 EXPORT_SYMBOL(udp_skb_destructor);
1320
1321 /* as above, but the caller held the rx queue lock, too */
1322 static void udp_skb_dtor_locked(struct sock *sk, struct sk_buff *skb)
1323 {
1324 prefetch(&skb->data);
1325 udp_rmem_release(sk, udp_skb_truesize(skb), 1, true);
1326 }
1327
1328 /* Idea of busylocks is to let producers grab an extra spinlock
1329 * to relieve pressure on the receive_queue spinlock shared by consumer.
1330 * Under flood, this means that only one producer can be in line
1331 * trying to acquire the receive_queue spinlock.
1332 * These busylock can be allocated on a per cpu manner, instead of a
1333 * per socket one (that would consume a cache line per socket)
1334 */
1335 static int udp_busylocks_log __read_mostly;
1336 static spinlock_t *udp_busylocks __read_mostly;
1337
1338 static spinlock_t *busylock_acquire(void *ptr)
1339 {
1340 spinlock_t *busy;
1341
1342 busy = udp_busylocks + hash_ptr(ptr, udp_busylocks_log);
1343 spin_lock(busy);
1344 return busy;
1345 }
1346
1347 static void busylock_release(spinlock_t *busy)
1348 {
1349 if (busy)
1350 spin_unlock(busy);
1351 }
1352
1353 int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
1354 {
1355 struct sk_buff_head *list = &sk->sk_receive_queue;
1356 int rmem, delta, amt, err = -ENOMEM;
1357 spinlock_t *busy = NULL;
1358 int size;
1359
1360 /* try to avoid the costly atomic add/sub pair when the receive
1361 * queue is full; always allow at least a packet
1362 */
1363 rmem = atomic_read(&sk->sk_rmem_alloc);
1364 if (rmem > sk->sk_rcvbuf)
1365 goto drop;
1366
1367 /* Under mem pressure, it might be helpful to help udp_recvmsg()
1368 * having linear skbs :
1369 * - Reduce memory overhead and thus increase receive queue capacity
1370 * - Less cache line misses at copyout() time
1371 * - Less work at consume_skb() (less alien page frag freeing)
1372 */
1373 if (rmem > (sk->sk_rcvbuf >> 1)) {
1374 skb_condense(skb);
1375
1376 busy = busylock_acquire(sk);
1377 }
1378 size = skb->truesize;
1379 udp_set_dev_scratch(skb);
1380
1381 /* we drop only if the receive buf is full and the receive
1382 * queue contains some other skb
1383 */
1384 rmem = atomic_add_return(size, &sk->sk_rmem_alloc);
1385 if (rmem > (size + sk->sk_rcvbuf))
1386 goto uncharge_drop;
1387
1388 spin_lock(&list->lock);
1389 if (size >= sk->sk_forward_alloc) {
1390 amt = sk_mem_pages(size);
1391 delta = amt << SK_MEM_QUANTUM_SHIFT;
1392 if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) {
1393 err = -ENOBUFS;
1394 spin_unlock(&list->lock);
1395 goto uncharge_drop;
1396 }
1397
1398 sk->sk_forward_alloc += delta;
1399 }
1400
1401 sk->sk_forward_alloc -= size;
1402
1403 /* no need to setup a destructor, we will explicitly release the
1404 * forward allocated memory on dequeue
1405 */
1406 sock_skb_set_dropcount(sk, skb);
1407
1408 __skb_queue_tail(list, skb);
1409 spin_unlock(&list->lock);
1410
1411 if (!sock_flag(sk, SOCK_DEAD))
1412 sk->sk_data_ready(sk);
1413
1414 busylock_release(busy);
1415 return 0;
1416
1417 uncharge_drop:
1418 atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1419
1420 drop:
1421 atomic_inc(&sk->sk_drops);
1422 busylock_release(busy);
1423 return err;
1424 }
1425 EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb);
1426
1427 void udp_destruct_sock(struct sock *sk)
1428 {
1429 /* reclaim completely the forward allocated memory */
1430 struct udp_sock *up = udp_sk(sk);
1431 unsigned int total = 0;
1432 struct sk_buff *skb;
1433
1434 skb_queue_splice_tail_init(&sk->sk_receive_queue, &up->reader_queue);
1435 while ((skb = __skb_dequeue(&up->reader_queue)) != NULL) {
1436 total += skb->truesize;
1437 kfree_skb(skb);
1438 }
1439 udp_rmem_release(sk, total, 0, true);
1440
1441 inet_sock_destruct(sk);
1442 }
1443 EXPORT_SYMBOL_GPL(udp_destruct_sock);
1444
1445 int udp_init_sock(struct sock *sk)
1446 {
1447 skb_queue_head_init(&udp_sk(sk)->reader_queue);
1448 sk->sk_destruct = udp_destruct_sock;
1449 return 0;
1450 }
1451 EXPORT_SYMBOL_GPL(udp_init_sock);
1452
1453 void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len)
1454 {
1455 if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) {
1456 bool slow = lock_sock_fast(sk);
1457
1458 sk_peek_offset_bwd(sk, len);
1459 unlock_sock_fast(sk, slow);
1460 }
1461
1462 if (!skb_unref(skb))
1463 return;
1464
1465 /* In the more common cases we cleared the head states previously,
1466 * see __udp_queue_rcv_skb().
1467 */
1468 if (unlikely(udp_skb_has_head_state(skb)))
1469 skb_release_head_state(skb);
1470 __consume_stateless_skb(skb);
1471 }
1472 EXPORT_SYMBOL_GPL(skb_consume_udp);
1473
1474 static struct sk_buff *__first_packet_length(struct sock *sk,
1475 struct sk_buff_head *rcvq,
1476 int *total)
1477 {
1478 struct sk_buff *skb;
1479
1480 while ((skb = skb_peek(rcvq)) != NULL) {
1481 if (udp_lib_checksum_complete(skb)) {
1482 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS,
1483 IS_UDPLITE(sk));
1484 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
1485 IS_UDPLITE(sk));
1486 atomic_inc(&sk->sk_drops);
1487 __skb_unlink(skb, rcvq);
1488 *total += skb->truesize;
1489 kfree_skb(skb);
1490 } else {
1491 /* the csum related bits could be changed, refresh
1492 * the scratch area
1493 */
1494 udp_set_dev_scratch(skb);
1495 break;
1496 }
1497 }
1498 return skb;
1499 }
1500
1501 /**
1502 * first_packet_length - return length of first packet in receive queue
1503 * @sk: socket
1504 *
1505 * Drops all bad checksum frames, until a valid one is found.
1506 * Returns the length of found skb, or -1 if none is found.
1507 */
1508 static int first_packet_length(struct sock *sk)
1509 {
1510 struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue;
1511 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1512 struct sk_buff *skb;
1513 int total = 0;
1514 int res;
1515
1516 spin_lock_bh(&rcvq->lock);
1517 skb = __first_packet_length(sk, rcvq, &total);
1518 if (!skb && !skb_queue_empty(sk_queue)) {
1519 spin_lock(&sk_queue->lock);
1520 skb_queue_splice_tail_init(sk_queue, rcvq);
1521 spin_unlock(&sk_queue->lock);
1522
1523 skb = __first_packet_length(sk, rcvq, &total);
1524 }
1525 res = skb ? skb->len : -1;
1526 if (total)
1527 udp_rmem_release(sk, total, 1, false);
1528 spin_unlock_bh(&rcvq->lock);
1529 return res;
1530 }
1531
1532 /*
1533 * IOCTL requests applicable to the UDP protocol
1534 */
1535
1536 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
1537 {
1538 switch (cmd) {
1539 case SIOCOUTQ:
1540 {
1541 int amount = sk_wmem_alloc_get(sk);
1542
1543 return put_user(amount, (int __user *)arg);
1544 }
1545
1546 case SIOCINQ:
1547 {
1548 int amount = max_t(int, 0, first_packet_length(sk));
1549
1550 return put_user(amount, (int __user *)arg);
1551 }
1552
1553 default:
1554 return -ENOIOCTLCMD;
1555 }
1556
1557 return 0;
1558 }
1559 EXPORT_SYMBOL(udp_ioctl);
1560
1561 struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
1562 int noblock, int *peeked, int *off, int *err)
1563 {
1564 struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
1565 struct sk_buff_head *queue;
1566 struct sk_buff *last;
1567 long timeo;
1568 int error;
1569
1570 queue = &udp_sk(sk)->reader_queue;
1571 flags |= noblock ? MSG_DONTWAIT : 0;
1572 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1573 do {
1574 struct sk_buff *skb;
1575
1576 error = sock_error(sk);
1577 if (error)
1578 break;
1579
1580 error = -EAGAIN;
1581 *peeked = 0;
1582 do {
1583 spin_lock_bh(&queue->lock);
1584 skb = __skb_try_recv_from_queue(sk, queue, flags,
1585 udp_skb_destructor,
1586 peeked, off, err,
1587 &last);
1588 if (skb) {
1589 spin_unlock_bh(&queue->lock);
1590 return skb;
1591 }
1592
1593 if (skb_queue_empty(sk_queue)) {
1594 spin_unlock_bh(&queue->lock);
1595 goto busy_check;
1596 }
1597
1598 /* refill the reader queue and walk it again
1599 * keep both queues locked to avoid re-acquiring
1600 * the sk_receive_queue lock if fwd memory scheduling
1601 * is needed.
1602 */
1603 spin_lock(&sk_queue->lock);
1604 skb_queue_splice_tail_init(sk_queue, queue);
1605
1606 skb = __skb_try_recv_from_queue(sk, queue, flags,
1607 udp_skb_dtor_locked,
1608 peeked, off, err,
1609 &last);
1610 spin_unlock(&sk_queue->lock);
1611 spin_unlock_bh(&queue->lock);
1612 if (skb)
1613 return skb;
1614
1615 busy_check:
1616 if (!sk_can_busy_loop(sk))
1617 break;
1618
1619 sk_busy_loop(sk, flags & MSG_DONTWAIT);
1620 } while (!skb_queue_empty(sk_queue));
1621
1622 /* sk_queue is empty, reader_queue may contain peeked packets */
1623 } while (timeo &&
1624 !__skb_wait_for_more_packets(sk, &error, &timeo,
1625 (struct sk_buff *)sk_queue));
1626
1627 *err = error;
1628 return NULL;
1629 }
1630 EXPORT_SYMBOL_GPL(__skb_recv_udp);
1631
1632 /*
1633 * This should be easy, if there is something there we
1634 * return it, otherwise we block.
1635 */
1636
1637 int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
1638 int flags, int *addr_len)
1639 {
1640 struct inet_sock *inet = inet_sk(sk);
1641 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
1642 struct sk_buff *skb;
1643 unsigned int ulen, copied;
1644 int peeked, peeking, off;
1645 int err;
1646 int is_udplite = IS_UDPLITE(sk);
1647 bool checksum_valid = false;
1648
1649 if (flags & MSG_ERRQUEUE)
1650 return ip_recv_error(sk, msg, len, addr_len);
1651
1652 try_again:
1653 peeking = flags & MSG_PEEK;
1654 off = sk_peek_offset(sk, flags);
1655 skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err);
1656 if (!skb)
1657 return err;
1658
1659 ulen = udp_skb_len(skb);
1660 copied = len;
1661 if (copied > ulen - off)
1662 copied = ulen - off;
1663 else if (copied < ulen)
1664 msg->msg_flags |= MSG_TRUNC;
1665
1666 /*
1667 * If checksum is needed at all, try to do it while copying the
1668 * data. If the data is truncated, or if we only want a partial
1669 * coverage checksum (UDP-Lite), do it before the copy.
1670 */
1671
1672 if (copied < ulen || peeking ||
1673 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
1674 checksum_valid = udp_skb_csum_unnecessary(skb) ||
1675 !__udp_lib_checksum_complete(skb);
1676 if (!checksum_valid)
1677 goto csum_copy_err;
1678 }
1679
1680 if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
1681 if (udp_skb_is_linear(skb))
1682 err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
1683 else
1684 err = skb_copy_datagram_msg(skb, off, msg, copied);
1685 } else {
1686 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
1687
1688 if (err == -EINVAL)
1689 goto csum_copy_err;
1690 }
1691
1692 if (unlikely(err)) {
1693 if (!peeked) {
1694 atomic_inc(&sk->sk_drops);
1695 UDP_INC_STATS(sock_net(sk),
1696 UDP_MIB_INERRORS, is_udplite);
1697 }
1698 kfree_skb(skb);
1699 return err;
1700 }
1701
1702 if (!peeked)
1703 UDP_INC_STATS(sock_net(sk),
1704 UDP_MIB_INDATAGRAMS, is_udplite);
1705
1706 sock_recv_ts_and_drops(msg, sk, skb);
1707
1708 /* Copy the address. */
1709 if (sin) {
1710 sin->sin_family = AF_INET;
1711 sin->sin_port = udp_hdr(skb)->source;
1712 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1713 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
1714 *addr_len = sizeof(*sin);
1715 }
1716 if (inet->cmsg_flags)
1717 ip_cmsg_recv_offset(msg, sk, skb, sizeof(struct udphdr), off);
1718
1719 err = copied;
1720 if (flags & MSG_TRUNC)
1721 err = ulen;
1722
1723 skb_consume_udp(sk, skb, peeking ? -err : err);
1724 return err;
1725
1726 csum_copy_err:
1727 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
1728 udp_skb_destructor)) {
1729 UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
1730 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1731 }
1732 kfree_skb(skb);
1733
1734 /* starting over for a new packet, but check if we need to yield */
1735 cond_resched();
1736 msg->msg_flags &= ~MSG_TRUNC;
1737 goto try_again;
1738 }
1739
1740 int udp_pre_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
1741 {
1742 /* This check is replicated from __ip4_datagram_connect() and
1743 * intended to prevent BPF program called below from accessing bytes
1744 * that are out of the bound specified by user in addr_len.
1745 */
1746 if (addr_len < sizeof(struct sockaddr_in))
1747 return -EINVAL;
1748
1749 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr);
1750 }
1751 EXPORT_SYMBOL(udp_pre_connect);
1752
1753 int __udp_disconnect(struct sock *sk, int flags)
1754 {
1755 struct inet_sock *inet = inet_sk(sk);
1756 /*
1757 * 1003.1g - break association.
1758 */
1759
1760 sk->sk_state = TCP_CLOSE;
1761 inet->inet_daddr = 0;
1762 inet->inet_dport = 0;
1763 sock_rps_reset_rxhash(sk);
1764 sk->sk_bound_dev_if = 0;
1765 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
1766 inet_reset_saddr(sk);
1767
1768 if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
1769 sk->sk_prot->unhash(sk);
1770 inet->inet_sport = 0;
1771 }
1772 sk_dst_reset(sk);
1773 return 0;
1774 }
1775 EXPORT_SYMBOL(__udp_disconnect);
1776
1777 int udp_disconnect(struct sock *sk, int flags)
1778 {
1779 lock_sock(sk);
1780 __udp_disconnect(sk, flags);
1781 release_sock(sk);
1782 return 0;
1783 }
1784 EXPORT_SYMBOL(udp_disconnect);
1785
1786 void udp_lib_unhash(struct sock *sk)
1787 {
1788 if (sk_hashed(sk)) {
1789 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1790 struct udp_hslot *hslot, *hslot2;
1791
1792 hslot = udp_hashslot(udptable, sock_net(sk),
1793 udp_sk(sk)->udp_port_hash);
1794 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1795
1796 spin_lock_bh(&hslot->lock);
1797 if (rcu_access_pointer(sk->sk_reuseport_cb))
1798 reuseport_detach_sock(sk);
1799 if (sk_del_node_init_rcu(sk)) {
1800 hslot->count--;
1801 inet_sk(sk)->inet_num = 0;
1802 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
1803
1804 spin_lock(&hslot2->lock);
1805 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1806 hslot2->count--;
1807 spin_unlock(&hslot2->lock);
1808 }
1809 spin_unlock_bh(&hslot->lock);
1810 }
1811 }
1812 EXPORT_SYMBOL(udp_lib_unhash);
1813
1814 /*
1815 * inet_rcv_saddr was changed, we must rehash secondary hash
1816 */
1817 void udp_lib_rehash(struct sock *sk, u16 newhash)
1818 {
1819 if (sk_hashed(sk)) {
1820 struct udp_table *udptable = sk->sk_prot->h.udp_table;
1821 struct udp_hslot *hslot, *hslot2, *nhslot2;
1822
1823 hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
1824 nhslot2 = udp_hashslot2(udptable, newhash);
1825 udp_sk(sk)->udp_portaddr_hash = newhash;
1826
1827 if (hslot2 != nhslot2 ||
1828 rcu_access_pointer(sk->sk_reuseport_cb)) {
1829 hslot = udp_hashslot(udptable, sock_net(sk),
1830 udp_sk(sk)->udp_port_hash);
1831 /* we must lock primary chain too */
1832 spin_lock_bh(&hslot->lock);
1833 if (rcu_access_pointer(sk->sk_reuseport_cb))
1834 reuseport_detach_sock(sk);
1835
1836 if (hslot2 != nhslot2) {
1837 spin_lock(&hslot2->lock);
1838 hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
1839 hslot2->count--;
1840 spin_unlock(&hslot2->lock);
1841
1842 spin_lock(&nhslot2->lock);
1843 hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
1844 &nhslot2->head);
1845 nhslot2->count++;
1846 spin_unlock(&nhslot2->lock);
1847 }
1848
1849 spin_unlock_bh(&hslot->lock);
1850 }
1851 }
1852 }
1853 EXPORT_SYMBOL(udp_lib_rehash);
1854
1855 static void udp_v4_rehash(struct sock *sk)
1856 {
1857 u16 new_hash = ipv4_portaddr_hash(sock_net(sk),
1858 inet_sk(sk)->inet_rcv_saddr,
1859 inet_sk(sk)->inet_num);
1860 udp_lib_rehash(sk, new_hash);
1861 }
1862
1863 static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1864 {
1865 int rc;
1866
1867 if (inet_sk(sk)->inet_daddr) {
1868 sock_rps_save_rxhash(sk, skb);
1869 sk_mark_napi_id(sk, skb);
1870 sk_incoming_cpu_update(sk);
1871 } else {
1872 sk_mark_napi_id_once(sk, skb);
1873 }
1874
1875 rc = __udp_enqueue_schedule_skb(sk, skb);
1876 if (rc < 0) {
1877 int is_udplite = IS_UDPLITE(sk);
1878
1879 /* Note that an ENOMEM error is charged twice */
1880 if (rc == -ENOMEM)
1881 UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS,
1882 is_udplite);
1883 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
1884 kfree_skb(skb);
1885 trace_udp_fail_queue_rcv_skb(rc, sk);
1886 return -1;
1887 }
1888
1889 return 0;
1890 }
1891
1892 static DEFINE_STATIC_KEY_FALSE(udp_encap_needed_key);
1893 void udp_encap_enable(void)
1894 {
1895 static_branch_enable(&udp_encap_needed_key);
1896 }
1897 EXPORT_SYMBOL(udp_encap_enable);
1898
1899 /* returns:
1900 * -1: error
1901 * 0: success
1902 * >0: "udp encap" protocol resubmission
1903 *
1904 * Note that in the success and error cases, the skb is assumed to
1905 * have either been requeued or freed.
1906 */
1907 static int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1908 {
1909 struct udp_sock *up = udp_sk(sk);
1910 int is_udplite = IS_UDPLITE(sk);
1911
1912 /*
1913 * Charge it to the socket, dropping if the queue is full.
1914 */
1915 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1916 goto drop;
1917 nf_reset(skb);
1918
1919 if (static_branch_unlikely(&udp_encap_needed_key) && up->encap_type) {
1920 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
1921
1922 /*
1923 * This is an encapsulation socket so pass the skb to
1924 * the socket's udp_encap_rcv() hook. Otherwise, just
1925 * fall through and pass this up the UDP socket.
1926 * up->encap_rcv() returns the following value:
1927 * =0 if skb was successfully passed to the encap
1928 * handler or was discarded by it.
1929 * >0 if skb should be passed on to UDP.
1930 * <0 if skb should be resubmitted as proto -N
1931 */
1932
1933 /* if we're overly short, let UDP handle it */
1934 encap_rcv = READ_ONCE(up->encap_rcv);
1935 if (encap_rcv) {
1936 int ret;
1937
1938 /* Verify checksum before giving to encap */
1939 if (udp_lib_checksum_complete(skb))
1940 goto csum_error;
1941
1942 ret = encap_rcv(sk, skb);
1943 if (ret <= 0) {
1944 __UDP_INC_STATS(sock_net(sk),
1945 UDP_MIB_INDATAGRAMS,
1946 is_udplite);
1947 return -ret;
1948 }
1949 }
1950
1951 /* FALLTHROUGH -- it's a UDP Packet */
1952 }
1953
1954 /*
1955 * UDP-Lite specific tests, ignored on UDP sockets
1956 */
1957 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
1958
1959 /*
1960 * MIB statistics other than incrementing the error count are
1961 * disabled for the following two types of errors: these depend
1962 * on the application settings, not on the functioning of the
1963 * protocol stack as such.
1964 *
1965 * RFC 3828 here recommends (sec 3.3): "There should also be a
1966 * way ... to ... at least let the receiving application block
1967 * delivery of packets with coverage values less than a value
1968 * provided by the application."
1969 */
1970 if (up->pcrlen == 0) { /* full coverage was set */
1971 net_dbg_ratelimited("UDPLite: partial coverage %d while full coverage %d requested\n",
1972 UDP_SKB_CB(skb)->cscov, skb->len);
1973 goto drop;
1974 }
1975 /* The next case involves violating the min. coverage requested
1976 * by the receiver. This is subtle: if receiver wants x and x is
1977 * greater than the buffersize/MTU then receiver will complain
1978 * that it wants x while sender emits packets of smaller size y.
1979 * Therefore the above ...()->partial_cov statement is essential.
1980 */
1981 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
1982 net_dbg_ratelimited("UDPLite: coverage %d too small, need min %d\n",
1983 UDP_SKB_CB(skb)->cscov, up->pcrlen);
1984 goto drop;
1985 }
1986 }
1987
1988 prefetch(&sk->sk_rmem_alloc);
1989 if (rcu_access_pointer(sk->sk_filter) &&
1990 udp_lib_checksum_complete(skb))
1991 goto csum_error;
1992
1993 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
1994 goto drop;
1995
1996 udp_csum_pull_header(skb);
1997
1998 ipv4_pktinfo_prepare(sk, skb);
1999 return __udp_queue_rcv_skb(sk, skb);
2000
2001 csum_error:
2002 __UDP_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
2003 drop:
2004 __UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
2005 atomic_inc(&sk->sk_drops);
2006 kfree_skb(skb);
2007 return -1;
2008 }
2009
2010 /* For TCP sockets, sk_rx_dst is protected by socket lock
2011 * For UDP, we use xchg() to guard against concurrent changes.
2012 */
2013 bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
2014 {
2015 struct dst_entry *old;
2016
2017 if (dst_hold_safe(dst)) {
2018 old = xchg(&sk->sk_rx_dst, dst);
2019 dst_release(old);
2020 return old != dst;
2021 }
2022 return false;
2023 }
2024 EXPORT_SYMBOL(udp_sk_rx_dst_set);
2025
2026 /*
2027 * Multicasts and broadcasts go to each listener.
2028 *
2029 * Note: called only from the BH handler context.
2030 */
2031 static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
2032 struct udphdr *uh,
2033 __be32 saddr, __be32 daddr,
2034 struct udp_table *udptable,
2035 int proto)
2036 {
2037 struct sock *sk, *first = NULL;
2038 unsigned short hnum = ntohs(uh->dest);
2039 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
2040 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
2041 unsigned int offset = offsetof(typeof(*sk), sk_node);
2042 int dif = skb->dev->ifindex;
2043 int sdif = inet_sdif(skb);
2044 struct hlist_node *node;
2045 struct sk_buff *nskb;
2046
2047 if (use_hash2) {
2048 hash2_any = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum) &
2049 udptable->mask;
2050 hash2 = ipv4_portaddr_hash(net, daddr, hnum) & udptable->mask;
2051 start_lookup:
2052 hslot = &udptable->hash2[hash2];
2053 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
2054 }
2055
2056 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
2057 if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr,
2058 uh->source, saddr, dif, sdif, hnum))
2059 continue;
2060
2061 if (!first) {
2062 first = sk;
2063 continue;
2064 }
2065 nskb = skb_clone(skb, GFP_ATOMIC);
2066
2067 if (unlikely(!nskb)) {
2068 atomic_inc(&sk->sk_drops);
2069 __UDP_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
2070 IS_UDPLITE(sk));
2071 __UDP_INC_STATS(net, UDP_MIB_INERRORS,
2072 IS_UDPLITE(sk));
2073 continue;
2074 }
2075 if (udp_queue_rcv_skb(sk, nskb) > 0)
2076 consume_skb(nskb);
2077 }
2078
2079 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
2080 if (use_hash2 && hash2 != hash2_any) {
2081 hash2 = hash2_any;
2082 goto start_lookup;
2083 }
2084
2085 if (first) {
2086 if (udp_queue_rcv_skb(first, skb) > 0)
2087 consume_skb(skb);
2088 } else {
2089 kfree_skb(skb);
2090 __UDP_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
2091 proto == IPPROTO_UDPLITE);
2092 }
2093 return 0;
2094 }
2095
2096 /* Initialize UDP checksum. If exited with zero value (success),
2097 * CHECKSUM_UNNECESSARY means, that no more checks are required.
2098 * Otherwise, csum completion requires chacksumming packet body,
2099 * including udp header and folding it to skb->csum.
2100 */
2101 static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
2102 int proto)
2103 {
2104 int err;
2105
2106 UDP_SKB_CB(skb)->partial_cov = 0;
2107 UDP_SKB_CB(skb)->cscov = skb->len;
2108
2109 if (proto == IPPROTO_UDPLITE) {
2110 err = udplite_checksum_init(skb, uh);
2111 if (err)
2112 return err;
2113
2114 if (UDP_SKB_CB(skb)->partial_cov) {
2115 skb->csum = inet_compute_pseudo(skb, proto);
2116 return 0;
2117 }
2118 }
2119
2120 /* Note, we are only interested in != 0 or == 0, thus the
2121 * force to int.
2122 */
2123 return (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
2124 inet_compute_pseudo);
2125 }
2126
2127 /*
2128 * All we need to do is get the socket, and then do a checksum.
2129 */
2130
2131 int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
2132 int proto)
2133 {
2134 struct sock *sk;
2135 struct udphdr *uh;
2136 unsigned short ulen;
2137 struct rtable *rt = skb_rtable(skb);
2138 __be32 saddr, daddr;
2139 struct net *net = dev_net(skb->dev);
2140
2141 /*
2142 * Validate the packet.
2143 */
2144 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
2145 goto drop; /* No space for header. */
2146
2147 uh = udp_hdr(skb);
2148 ulen = ntohs(uh->len);
2149 saddr = ip_hdr(skb)->saddr;
2150 daddr = ip_hdr(skb)->daddr;
2151
2152 if (ulen > skb->len)
2153 goto short_packet;
2154
2155 if (proto == IPPROTO_UDP) {
2156 /* UDP validates ulen. */
2157 if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
2158 goto short_packet;
2159 uh = udp_hdr(skb);
2160 }
2161
2162 if (udp4_csum_init(skb, uh, proto))
2163 goto csum_error;
2164
2165 sk = skb_steal_sock(skb);
2166 if (sk) {
2167 struct dst_entry *dst = skb_dst(skb);
2168 int ret;
2169
2170 if (unlikely(sk->sk_rx_dst != dst))
2171 udp_sk_rx_dst_set(sk, dst);
2172
2173 ret = udp_queue_rcv_skb(sk, skb);
2174 sock_put(sk);
2175 /* a return value > 0 means to resubmit the input, but
2176 * it wants the return to be -protocol, or 0
2177 */
2178 if (ret > 0)
2179 return -ret;
2180 return 0;
2181 }
2182
2183 if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
2184 return __udp4_lib_mcast_deliver(net, skb, uh,
2185 saddr, daddr, udptable, proto);
2186
2187 sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
2188 if (sk) {
2189 int ret;
2190
2191 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
2192 skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
2193 inet_compute_pseudo);
2194
2195 ret = udp_queue_rcv_skb(sk, skb);
2196
2197 /* a return value > 0 means to resubmit the input, but
2198 * it wants the return to be -protocol, or 0
2199 */
2200 if (ret > 0)
2201 return -ret;
2202 return 0;
2203 }
2204
2205 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
2206 goto drop;
2207 nf_reset(skb);
2208
2209 /* No socket. Drop packet silently, if checksum is wrong */
2210 if (udp_lib_checksum_complete(skb))
2211 goto csum_error;
2212
2213 __UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
2214 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
2215
2216 /*
2217 * Hmm. We got an UDP packet to a port to which we
2218 * don't wanna listen. Ignore it.
2219 */
2220 kfree_skb(skb);
2221 return 0;
2222
2223 short_packet:
2224 net_dbg_ratelimited("UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
2225 proto == IPPROTO_UDPLITE ? "Lite" : "",
2226 &saddr, ntohs(uh->source),
2227 ulen, skb->len,
2228 &daddr, ntohs(uh->dest));
2229 goto drop;
2230
2231 csum_error:
2232 /*
2233 * RFC1122: OK. Discards the bad packet silently (as far as
2234 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
2235 */
2236 net_dbg_ratelimited("UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
2237 proto == IPPROTO_UDPLITE ? "Lite" : "",
2238 &saddr, ntohs(uh->source), &daddr, ntohs(uh->dest),
2239 ulen);
2240 __UDP_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
2241 drop:
2242 __UDP_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
2243 kfree_skb(skb);
2244 return 0;
2245 }
2246
2247 /* We can only early demux multicast if there is a single matching socket.
2248 * If more than one socket found returns NULL
2249 */
2250 static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
2251 __be16 loc_port, __be32 loc_addr,
2252 __be16 rmt_port, __be32 rmt_addr,
2253 int dif, int sdif)
2254 {
2255 struct sock *sk, *result;
2256 unsigned short hnum = ntohs(loc_port);
2257 unsigned int slot = udp_hashfn(net, hnum, udp_table.mask);
2258 struct udp_hslot *hslot = &udp_table.hash[slot];
2259
2260 /* Do not bother scanning a too big list */
2261 if (hslot->count > 10)
2262 return NULL;
2263
2264 result = NULL;
2265 sk_for_each_rcu(sk, &hslot->head) {
2266 if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr,
2267 rmt_port, rmt_addr, dif, sdif, hnum)) {
2268 if (result)
2269 return NULL;
2270 result = sk;
2271 }
2272 }
2273
2274 return result;
2275 }
2276
2277 /* For unicast we should only early demux connected sockets or we can
2278 * break forwarding setups. The chains here can be long so only check
2279 * if the first socket is an exact match and if not move on.
2280 */
2281 static struct sock *__udp4_lib_demux_lookup(struct net *net,
2282 __be16 loc_port, __be32 loc_addr,
2283 __be16 rmt_port, __be32 rmt_addr,
2284 int dif, int sdif)
2285 {
2286 unsigned short hnum = ntohs(loc_port);
2287 unsigned int hash2 = ipv4_portaddr_hash(net, loc_addr, hnum);
2288 unsigned int slot2 = hash2 & udp_table.mask;
2289 struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
2290 INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
2291 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
2292 struct sock *sk;
2293
2294 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
2295 if (INET_MATCH(sk, net, acookie, rmt_addr,
2296 loc_addr, ports, dif, sdif))
2297 return sk;
2298 /* Only check first socket in chain */
2299 break;
2300 }
2301 return NULL;
2302 }
2303
2304 int udp_v4_early_demux(struct sk_buff *skb)
2305 {
2306 struct net *net = dev_net(skb->dev);
2307 struct in_device *in_dev = NULL;
2308 const struct iphdr *iph;
2309 const struct udphdr *uh;
2310 struct sock *sk = NULL;
2311 struct dst_entry *dst;
2312 int dif = skb->dev->ifindex;
2313 int sdif = inet_sdif(skb);
2314 int ours;
2315
2316 /* validate the packet */
2317 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
2318 return 0;
2319
2320 iph = ip_hdr(skb);
2321 uh = udp_hdr(skb);
2322
2323 if (skb->pkt_type == PACKET_MULTICAST) {
2324 in_dev = __in_dev_get_rcu(skb->dev);
2325
2326 if (!in_dev)
2327 return 0;
2328
2329 ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
2330 iph->protocol);
2331 if (!ours)
2332 return 0;
2333
2334 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
2335 uh->source, iph->saddr,
2336 dif, sdif);
2337 } else if (skb->pkt_type == PACKET_HOST) {
2338 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
2339 uh->source, iph->saddr, dif, sdif);
2340 }
2341
2342 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
2343 return 0;
2344
2345 skb->sk = sk;
2346 skb->destructor = sock_efree;
2347 dst = READ_ONCE(sk->sk_rx_dst);
2348
2349 if (dst)
2350 dst = dst_check(dst, 0);
2351 if (dst) {
2352 u32 itag = 0;
2353
2354 /* set noref for now.
2355 * any place which wants to hold dst has to call
2356 * dst_hold_safe()
2357 */
2358 skb_dst_set_noref(skb, dst);
2359
2360 /* for unconnected multicast sockets we need to validate
2361 * the source on each packet
2362 */
2363 if (!inet_sk(sk)->inet_daddr && in_dev)
2364 return ip_mc_validate_source(skb, iph->daddr,
2365 iph->saddr, iph->tos,
2366 skb->dev, in_dev, &itag);
2367 }
2368 return 0;
2369 }
2370
2371 int udp_rcv(struct sk_buff *skb)
2372 {
2373 return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
2374 }
2375
2376 void udp_destroy_sock(struct sock *sk)
2377 {
2378 struct udp_sock *up = udp_sk(sk);
2379 bool slow = lock_sock_fast(sk);
2380 udp_flush_pending_frames(sk);
2381 unlock_sock_fast(sk, slow);
2382 if (static_branch_unlikely(&udp_encap_needed_key) && up->encap_type) {
2383 void (*encap_destroy)(struct sock *sk);
2384 encap_destroy = READ_ONCE(up->encap_destroy);
2385 if (encap_destroy)
2386 encap_destroy(sk);
2387 }
2388 }
2389
2390 /*
2391 * Socket option code for UDP
2392 */
2393 int udp_lib_setsockopt(struct sock *sk, int level, int optname,
2394 char __user *optval, unsigned int optlen,
2395 int (*push_pending_frames)(struct sock *))
2396 {
2397 struct udp_sock *up = udp_sk(sk);
2398 int val, valbool;
2399 int err = 0;
2400 int is_udplite = IS_UDPLITE(sk);
2401
2402 if (optlen < sizeof(int))
2403 return -EINVAL;
2404
2405 if (get_user(val, (int __user *)optval))
2406 return -EFAULT;
2407
2408 valbool = val ? 1 : 0;
2409
2410 switch (optname) {
2411 case UDP_CORK:
2412 if (val != 0) {
2413 up->corkflag = 1;
2414 } else {
2415 up->corkflag = 0;
2416 lock_sock(sk);
2417 push_pending_frames(sk);
2418 release_sock(sk);
2419 }
2420 break;
2421
2422 case UDP_ENCAP:
2423 switch (val) {
2424 case 0:
2425 case UDP_ENCAP_ESPINUDP:
2426 case UDP_ENCAP_ESPINUDP_NON_IKE:
2427 up->encap_rcv = xfrm4_udp_encap_rcv;
2428 /* FALLTHROUGH */
2429 case UDP_ENCAP_L2TPINUDP:
2430 up->encap_type = val;
2431 udp_encap_enable();
2432 break;
2433 default:
2434 err = -ENOPROTOOPT;
2435 break;
2436 }
2437 break;
2438
2439 case UDP_NO_CHECK6_TX:
2440 up->no_check6_tx = valbool;
2441 break;
2442
2443 case UDP_NO_CHECK6_RX:
2444 up->no_check6_rx = valbool;
2445 break;
2446
2447 case UDP_SEGMENT:
2448 if (val < 0 || val > USHRT_MAX)
2449 return -EINVAL;
2450 up->gso_size = val;
2451 break;
2452
2453 /*
2454 * UDP-Lite's partial checksum coverage (RFC 3828).
2455 */
2456 /* The sender sets actual checksum coverage length via this option.
2457 * The case coverage > packet length is handled by send module. */
2458 case UDPLITE_SEND_CSCOV:
2459 if (!is_udplite) /* Disable the option on UDP sockets */
2460 return -ENOPROTOOPT;
2461 if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
2462 val = 8;
2463 else if (val > USHRT_MAX)
2464 val = USHRT_MAX;
2465 up->pcslen = val;
2466 up->pcflag |= UDPLITE_SEND_CC;
2467 break;
2468
2469 /* The receiver specifies a minimum checksum coverage value. To make
2470 * sense, this should be set to at least 8 (as done below). If zero is
2471 * used, this again means full checksum coverage. */
2472 case UDPLITE_RECV_CSCOV:
2473 if (!is_udplite) /* Disable the option on UDP sockets */
2474 return -ENOPROTOOPT;
2475 if (val != 0 && val < 8) /* Avoid silly minimal values. */
2476 val = 8;
2477 else if (val > USHRT_MAX)
2478 val = USHRT_MAX;
2479 up->pcrlen = val;
2480 up->pcflag |= UDPLITE_RECV_CC;
2481 break;
2482
2483 default:
2484 err = -ENOPROTOOPT;
2485 break;
2486 }
2487
2488 return err;
2489 }
2490 EXPORT_SYMBOL(udp_lib_setsockopt);
2491
2492 int udp_setsockopt(struct sock *sk, int level, int optname,
2493 char __user *optval, unsigned int optlen)
2494 {
2495 if (level == SOL_UDP || level == SOL_UDPLITE)
2496 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
2497 udp_push_pending_frames);
2498 return ip_setsockopt(sk, level, optname, optval, optlen);
2499 }
2500
2501 #ifdef CONFIG_COMPAT
2502 int compat_udp_setsockopt(struct sock *sk, int level, int optname,
2503 char __user *optval, unsigned int optlen)
2504 {
2505 if (level == SOL_UDP || level == SOL_UDPLITE)
2506 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
2507 udp_push_pending_frames);
2508 return compat_ip_setsockopt(sk, level, optname, optval, optlen);
2509 }
2510 #endif
2511
2512 int udp_lib_getsockopt(struct sock *sk, int level, int optname,
2513 char __user *optval, int __user *optlen)
2514 {
2515 struct udp_sock *up = udp_sk(sk);
2516 int val, len;
2517
2518 if (get_user(len, optlen))
2519 return -EFAULT;
2520
2521 len = min_t(unsigned int, len, sizeof(int));
2522
2523 if (len < 0)
2524 return -EINVAL;
2525
2526 switch (optname) {
2527 case UDP_CORK:
2528 val = up->corkflag;
2529 break;
2530
2531 case UDP_ENCAP:
2532 val = up->encap_type;
2533 break;
2534
2535 case UDP_NO_CHECK6_TX:
2536 val = up->no_check6_tx;
2537 break;
2538
2539 case UDP_NO_CHECK6_RX:
2540 val = up->no_check6_rx;
2541 break;
2542
2543 case UDP_SEGMENT:
2544 val = up->gso_size;
2545 break;
2546
2547 /* The following two cannot be changed on UDP sockets, the return is
2548 * always 0 (which corresponds to the full checksum coverage of UDP). */
2549 case UDPLITE_SEND_CSCOV:
2550 val = up->pcslen;
2551 break;
2552
2553 case UDPLITE_RECV_CSCOV:
2554 val = up->pcrlen;
2555 break;
2556
2557 default:
2558 return -ENOPROTOOPT;
2559 }
2560
2561 if (put_user(len, optlen))
2562 return -EFAULT;
2563 if (copy_to_user(optval, &val, len))
2564 return -EFAULT;
2565 return 0;
2566 }
2567 EXPORT_SYMBOL(udp_lib_getsockopt);
2568
2569 int udp_getsockopt(struct sock *sk, int level, int optname,
2570 char __user *optval, int __user *optlen)
2571 {
2572 if (level == SOL_UDP || level == SOL_UDPLITE)
2573 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2574 return ip_getsockopt(sk, level, optname, optval, optlen);
2575 }
2576
2577 #ifdef CONFIG_COMPAT
2578 int compat_udp_getsockopt(struct sock *sk, int level, int optname,
2579 char __user *optval, int __user *optlen)
2580 {
2581 if (level == SOL_UDP || level == SOL_UDPLITE)
2582 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
2583 return compat_ip_getsockopt(sk, level, optname, optval, optlen);
2584 }
2585 #endif
2586 /**
2587 * udp_poll - wait for a UDP event.
2588 * @file - file struct
2589 * @sock - socket
2590 * @wait - poll table
2591 *
2592 * This is same as datagram poll, except for the special case of
2593 * blocking sockets. If application is using a blocking fd
2594 * and a packet with checksum error is in the queue;
2595 * then it could get return from select indicating data available
2596 * but then block when reading it. Add special case code
2597 * to work around these arguably broken applications.
2598 */
2599 __poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait)
2600 {
2601 __poll_t mask = datagram_poll(file, sock, wait);
2602 struct sock *sk = sock->sk;
2603
2604 if (!skb_queue_empty(&udp_sk(sk)->reader_queue))
2605 mask |= EPOLLIN | EPOLLRDNORM;
2606
2607 /* Check for false positives due to checksum errors */
2608 if ((mask & EPOLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
2609 !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1)
2610 mask &= ~(EPOLLIN | EPOLLRDNORM);
2611
2612 return mask;
2613
2614 }
2615 EXPORT_SYMBOL(udp_poll);
2616
2617 int udp_abort(struct sock *sk, int err)
2618 {
2619 lock_sock(sk);
2620
2621 sk->sk_err = err;
2622 sk->sk_error_report(sk);
2623 __udp_disconnect(sk, 0);
2624
2625 release_sock(sk);
2626
2627 return 0;
2628 }
2629 EXPORT_SYMBOL_GPL(udp_abort);
2630
2631 struct proto udp_prot = {
2632 .name = "UDP",
2633 .owner = THIS_MODULE,
2634 .close = udp_lib_close,
2635 .pre_connect = udp_pre_connect,
2636 .connect = ip4_datagram_connect,
2637 .disconnect = udp_disconnect,
2638 .ioctl = udp_ioctl,
2639 .init = udp_init_sock,
2640 .destroy = udp_destroy_sock,
2641 .setsockopt = udp_setsockopt,
2642 .getsockopt = udp_getsockopt,
2643 .sendmsg = udp_sendmsg,
2644 .recvmsg = udp_recvmsg,
2645 .sendpage = udp_sendpage,
2646 .release_cb = ip4_datagram_release_cb,
2647 .hash = udp_lib_hash,
2648 .unhash = udp_lib_unhash,
2649 .rehash = udp_v4_rehash,
2650 .get_port = udp_v4_get_port,
2651 .memory_allocated = &udp_memory_allocated,
2652 .sysctl_mem = sysctl_udp_mem,
2653 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
2654 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
2655 .obj_size = sizeof(struct udp_sock),
2656 .h.udp_table = &udp_table,
2657 #ifdef CONFIG_COMPAT
2658 .compat_setsockopt = compat_udp_setsockopt,
2659 .compat_getsockopt = compat_udp_getsockopt,
2660 #endif
2661 .diag_destroy = udp_abort,
2662 };
2663 EXPORT_SYMBOL(udp_prot);
2664
2665 /* ------------------------------------------------------------------------ */
2666 #ifdef CONFIG_PROC_FS
2667
2668 static struct sock *udp_get_first(struct seq_file *seq, int start)
2669 {
2670 struct sock *sk;
2671 struct udp_seq_afinfo *afinfo = PDE_DATA(file_inode(seq->file));
2672 struct udp_iter_state *state = seq->private;
2673 struct net *net = seq_file_net(seq);
2674
2675 for (state->bucket = start; state->bucket <= afinfo->udp_table->mask;
2676 ++state->bucket) {
2677 struct udp_hslot *hslot = &afinfo->udp_table->hash[state->bucket];
2678
2679 if (hlist_empty(&hslot->head))
2680 continue;
2681
2682 spin_lock_bh(&hslot->lock);
2683 sk_for_each(sk, &hslot->head) {
2684 if (!net_eq(sock_net(sk), net))
2685 continue;
2686 if (sk->sk_family == afinfo->family)
2687 goto found;
2688 }
2689 spin_unlock_bh(&hslot->lock);
2690 }
2691 sk = NULL;
2692 found:
2693 return sk;
2694 }
2695
2696 static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
2697 {
2698 struct udp_seq_afinfo *afinfo = PDE_DATA(file_inode(seq->file));
2699 struct udp_iter_state *state = seq->private;
2700 struct net *net = seq_file_net(seq);
2701
2702 do {
2703 sk = sk_next(sk);
2704 } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != afinfo->family));
2705
2706 if (!sk) {
2707 if (state->bucket <= afinfo->udp_table->mask)
2708 spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock);
2709 return udp_get_first(seq, state->bucket + 1);
2710 }
2711 return sk;
2712 }
2713
2714 static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
2715 {
2716 struct sock *sk = udp_get_first(seq, 0);
2717
2718 if (sk)
2719 while (pos && (sk = udp_get_next(seq, sk)) != NULL)
2720 --pos;
2721 return pos ? NULL : sk;
2722 }
2723
2724 void *udp_seq_start(struct seq_file *seq, loff_t *pos)
2725 {
2726 struct udp_iter_state *state = seq->private;
2727 state->bucket = MAX_UDP_PORTS;
2728
2729 return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
2730 }
2731 EXPORT_SYMBOL(udp_seq_start);
2732
2733 void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2734 {
2735 struct sock *sk;
2736
2737 if (v == SEQ_START_TOKEN)
2738 sk = udp_get_idx(seq, 0);
2739 else
2740 sk = udp_get_next(seq, v);
2741
2742 ++*pos;
2743 return sk;
2744 }
2745 EXPORT_SYMBOL(udp_seq_next);
2746
2747 void udp_seq_stop(struct seq_file *seq, void *v)
2748 {
2749 struct udp_seq_afinfo *afinfo = PDE_DATA(file_inode(seq->file));
2750 struct udp_iter_state *state = seq->private;
2751
2752 if (state->bucket <= afinfo->udp_table->mask)
2753 spin_unlock_bh(&afinfo->udp_table->hash[state->bucket].lock);
2754 }
2755 EXPORT_SYMBOL(udp_seq_stop);
2756
2757 /* ------------------------------------------------------------------------ */
2758 static void udp4_format_sock(struct sock *sp, struct seq_file *f,
2759 int bucket)
2760 {
2761 struct inet_sock *inet = inet_sk(sp);
2762 __be32 dest = inet->inet_daddr;
2763 __be32 src = inet->inet_rcv_saddr;
2764 __u16 destp = ntohs(inet->inet_dport);
2765 __u16 srcp = ntohs(inet->inet_sport);
2766
2767 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
2768 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
2769 bucket, src, srcp, dest, destp, sp->sk_state,
2770 sk_wmem_alloc_get(sp),
2771 udp_rqueue_get(sp),
2772 0, 0L, 0,
2773 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
2774 0, sock_i_ino(sp),
2775 refcount_read(&sp->sk_refcnt), sp,
2776 atomic_read(&sp->sk_drops));
2777 }
2778
2779 int udp4_seq_show(struct seq_file *seq, void *v)
2780 {
2781 seq_setwidth(seq, 127);
2782 if (v == SEQ_START_TOKEN)
2783 seq_puts(seq, " sl local_address rem_address st tx_queue "
2784 "rx_queue tr tm->when retrnsmt uid timeout "
2785 "inode ref pointer drops");
2786 else {
2787 struct udp_iter_state *state = seq->private;
2788
2789 udp4_format_sock(v, seq, state->bucket);
2790 }
2791 seq_pad(seq, '\n');
2792 return 0;
2793 }
2794
2795 const struct seq_operations udp_seq_ops = {
2796 .start = udp_seq_start,
2797 .next = udp_seq_next,
2798 .stop = udp_seq_stop,
2799 .show = udp4_seq_show,
2800 };
2801 EXPORT_SYMBOL(udp_seq_ops);
2802
2803 static struct udp_seq_afinfo udp4_seq_afinfo = {
2804 .family = AF_INET,
2805 .udp_table = &udp_table,
2806 };
2807
2808 static int __net_init udp4_proc_init_net(struct net *net)
2809 {
2810 if (!proc_create_net_data("udp", 0444, net->proc_net, &udp_seq_ops,
2811 sizeof(struct udp_iter_state), &udp4_seq_afinfo))
2812 return -ENOMEM;
2813 return 0;
2814 }
2815
2816 static void __net_exit udp4_proc_exit_net(struct net *net)
2817 {
2818 remove_proc_entry("udp", net->proc_net);
2819 }
2820
2821 static struct pernet_operations udp4_net_ops = {
2822 .init = udp4_proc_init_net,
2823 .exit = udp4_proc_exit_net,
2824 };
2825
2826 int __init udp4_proc_init(void)
2827 {
2828 return register_pernet_subsys(&udp4_net_ops);
2829 }
2830
2831 void udp4_proc_exit(void)
2832 {
2833 unregister_pernet_subsys(&udp4_net_ops);
2834 }
2835 #endif /* CONFIG_PROC_FS */
2836
2837 static __initdata unsigned long uhash_entries;
2838 static int __init set_uhash_entries(char *str)
2839 {
2840 ssize_t ret;
2841
2842 if (!str)
2843 return 0;
2844
2845 ret = kstrtoul(str, 0, &uhash_entries);
2846 if (ret)
2847 return 0;
2848
2849 if (uhash_entries && uhash_entries < UDP_HTABLE_SIZE_MIN)
2850 uhash_entries = UDP_HTABLE_SIZE_MIN;
2851 return 1;
2852 }
2853 __setup("uhash_entries=", set_uhash_entries);
2854
2855 void __init udp_table_init(struct udp_table *table, const char *name)
2856 {
2857 unsigned int i;
2858
2859 table->hash = alloc_large_system_hash(name,
2860 2 * sizeof(struct udp_hslot),
2861 uhash_entries,
2862 21, /* one slot per 2 MB */
2863 0,
2864 &table->log,
2865 &table->mask,
2866 UDP_HTABLE_SIZE_MIN,
2867 64 * 1024);
2868
2869 table->hash2 = table->hash + (table->mask + 1);
2870 for (i = 0; i <= table->mask; i++) {
2871 INIT_HLIST_HEAD(&table->hash[i].head);
2872 table->hash[i].count = 0;
2873 spin_lock_init(&table->hash[i].lock);
2874 }
2875 for (i = 0; i <= table->mask; i++) {
2876 INIT_HLIST_HEAD(&table->hash2[i].head);
2877 table->hash2[i].count = 0;
2878 spin_lock_init(&table->hash2[i].lock);
2879 }
2880 }
2881
2882 u32 udp_flow_hashrnd(void)
2883 {
2884 static u32 hashrnd __read_mostly;
2885
2886 net_get_random_once(&hashrnd, sizeof(hashrnd));
2887
2888 return hashrnd;
2889 }
2890 EXPORT_SYMBOL(udp_flow_hashrnd);
2891
2892 static void __udp_sysctl_init(struct net *net)
2893 {
2894 net->ipv4.sysctl_udp_rmem_min = SK_MEM_QUANTUM;
2895 net->ipv4.sysctl_udp_wmem_min = SK_MEM_QUANTUM;
2896
2897 #ifdef CONFIG_NET_L3_MASTER_DEV
2898 net->ipv4.sysctl_udp_l3mdev_accept = 0;
2899 #endif
2900 }
2901
2902 static int __net_init udp_sysctl_init(struct net *net)
2903 {
2904 __udp_sysctl_init(net);
2905 return 0;
2906 }
2907
2908 static struct pernet_operations __net_initdata udp_sysctl_ops = {
2909 .init = udp_sysctl_init,
2910 };
2911
2912 void __init udp_init(void)
2913 {
2914 unsigned long limit;
2915 unsigned int i;
2916
2917 udp_table_init(&udp_table, "UDP");
2918 limit = nr_free_buffer_pages() / 8;
2919 limit = max(limit, 128UL);
2920 sysctl_udp_mem[0] = limit / 4 * 3;
2921 sysctl_udp_mem[1] = limit;
2922 sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
2923
2924 __udp_sysctl_init(&init_net);
2925
2926 /* 16 spinlocks per cpu */
2927 udp_busylocks_log = ilog2(nr_cpu_ids) + 4;
2928 udp_busylocks = kmalloc(sizeof(spinlock_t) << udp_busylocks_log,
2929 GFP_KERNEL);
2930 if (!udp_busylocks)
2931 panic("UDP: failed to alloc udp_busylocks\n");
2932 for (i = 0; i < (1U << udp_busylocks_log); i++)
2933 spin_lock_init(udp_busylocks + i);
2934
2935 if (register_pernet_subsys(&udp_sysctl_ops))
2936 panic("UDP: failed to init sysctl parameters.\n");
2937 }
Linux with added FPC-III support