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udp6: set rx_dst_cookie on rx_dst updates
[mirror_ubuntu-artful-kernel.git] / net / ipv6 / udp.c
1 /*
2 * UDP over IPv6
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * Based on linux/ipv4/udp.c
9 *
10 * Fixes:
11 * Hideaki YOSHIFUJI : sin6_scope_id support
12 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
13 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
14 * a single port at the same time.
15 * Kazunori MIYAZAWA @USAGI: change process style to use ip6_append_data
16 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/udp6 to seq_file.
17 *
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
22 */
23
24 #include <linux/errno.h>
25 #include <linux/types.h>
26 #include <linux/socket.h>
27 #include <linux/sockios.h>
28 #include <linux/net.h>
29 #include <linux/in6.h>
30 #include <linux/netdevice.h>
31 #include <linux/if_arp.h>
32 #include <linux/ipv6.h>
33 #include <linux/icmpv6.h>
34 #include <linux/init.h>
35 #include <linux/module.h>
36 #include <linux/skbuff.h>
37 #include <linux/slab.h>
38 #include <linux/uaccess.h>
39
40 #include <net/addrconf.h>
41 #include <net/ndisc.h>
42 #include <net/protocol.h>
43 #include <net/transp_v6.h>
44 #include <net/ip6_route.h>
45 #include <net/raw.h>
46 #include <net/tcp_states.h>
47 #include <net/ip6_checksum.h>
48 #include <net/xfrm.h>
49 #include <net/inet_hashtables.h>
50 #include <net/inet6_hashtables.h>
51 #include <net/busy_poll.h>
52 #include <net/sock_reuseport.h>
53
54 #include <linux/proc_fs.h>
55 #include <linux/seq_file.h>
56 #include <trace/events/skb.h>
57 #include "udp_impl.h"
58
59 static bool udp6_lib_exact_dif_match(struct net *net, struct sk_buff *skb)
60 {
61 #if defined(CONFIG_NET_L3_MASTER_DEV)
62 if (!net->ipv4.sysctl_udp_l3mdev_accept &&
63 skb && ipv6_l3mdev_skb(IP6CB(skb)->flags))
64 return true;
65 #endif
66 return false;
67 }
68
69 static u32 udp6_ehashfn(const struct net *net,
70 const struct in6_addr *laddr,
71 const u16 lport,
72 const struct in6_addr *faddr,
73 const __be16 fport)
74 {
75 static u32 udp6_ehash_secret __read_mostly;
76 static u32 udp_ipv6_hash_secret __read_mostly;
77
78 u32 lhash, fhash;
79
80 net_get_random_once(&udp6_ehash_secret,
81 sizeof(udp6_ehash_secret));
82 net_get_random_once(&udp_ipv6_hash_secret,
83 sizeof(udp_ipv6_hash_secret));
84
85 lhash = (__force u32)laddr->s6_addr32[3];
86 fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret);
87
88 return __inet6_ehashfn(lhash, lport, fhash, fport,
89 udp_ipv6_hash_secret + net_hash_mix(net));
90 }
91
92 static u32 udp6_portaddr_hash(const struct net *net,
93 const struct in6_addr *addr6,
94 unsigned int port)
95 {
96 unsigned int hash, mix = net_hash_mix(net);
97
98 if (ipv6_addr_any(addr6))
99 hash = jhash_1word(0, mix);
100 else if (ipv6_addr_v4mapped(addr6))
101 hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix);
102 else
103 hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix);
104
105 return hash ^ port;
106 }
107
108 int udp_v6_get_port(struct sock *sk, unsigned short snum)
109 {
110 unsigned int hash2_nulladdr =
111 udp6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
112 unsigned int hash2_partial =
113 udp6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
114
115 /* precompute partial secondary hash */
116 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
117 return udp_lib_get_port(sk, snum, hash2_nulladdr);
118 }
119
120 static void udp_v6_rehash(struct sock *sk)
121 {
122 u16 new_hash = udp6_portaddr_hash(sock_net(sk),
123 &sk->sk_v6_rcv_saddr,
124 inet_sk(sk)->inet_num);
125
126 udp_lib_rehash(sk, new_hash);
127 }
128
129 static int compute_score(struct sock *sk, struct net *net,
130 const struct in6_addr *saddr, __be16 sport,
131 const struct in6_addr *daddr, unsigned short hnum,
132 int dif, bool exact_dif)
133 {
134 int score;
135 struct inet_sock *inet;
136
137 if (!net_eq(sock_net(sk), net) ||
138 udp_sk(sk)->udp_port_hash != hnum ||
139 sk->sk_family != PF_INET6)
140 return -1;
141
142 score = 0;
143 inet = inet_sk(sk);
144
145 if (inet->inet_dport) {
146 if (inet->inet_dport != sport)
147 return -1;
148 score++;
149 }
150
151 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
152 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
153 return -1;
154 score++;
155 }
156
157 if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
158 if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
159 return -1;
160 score++;
161 }
162
163 if (sk->sk_bound_dev_if || exact_dif) {
164 if (sk->sk_bound_dev_if != dif)
165 return -1;
166 score++;
167 }
168
169 if (sk->sk_incoming_cpu == raw_smp_processor_id())
170 score++;
171
172 return score;
173 }
174
175 /* called with rcu_read_lock() */
176 static struct sock *udp6_lib_lookup2(struct net *net,
177 const struct in6_addr *saddr, __be16 sport,
178 const struct in6_addr *daddr, unsigned int hnum, int dif,
179 bool exact_dif, struct udp_hslot *hslot2,
180 struct sk_buff *skb)
181 {
182 struct sock *sk, *result;
183 int score, badness, matches = 0, reuseport = 0;
184 u32 hash = 0;
185
186 result = NULL;
187 badness = -1;
188 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
189 score = compute_score(sk, net, saddr, sport,
190 daddr, hnum, dif, exact_dif);
191 if (score > badness) {
192 reuseport = sk->sk_reuseport;
193 if (reuseport) {
194 hash = udp6_ehashfn(net, daddr, hnum,
195 saddr, sport);
196
197 result = reuseport_select_sock(sk, hash, skb,
198 sizeof(struct udphdr));
199 if (result)
200 return result;
201 matches = 1;
202 }
203 result = sk;
204 badness = score;
205 } else if (score == badness && reuseport) {
206 matches++;
207 if (reciprocal_scale(hash, matches) == 0)
208 result = sk;
209 hash = next_pseudo_random32(hash);
210 }
211 }
212 return result;
213 }
214
215 /* rcu_read_lock() must be held */
216 struct sock *__udp6_lib_lookup(struct net *net,
217 const struct in6_addr *saddr, __be16 sport,
218 const struct in6_addr *daddr, __be16 dport,
219 int dif, struct udp_table *udptable,
220 struct sk_buff *skb)
221 {
222 struct sock *sk, *result;
223 unsigned short hnum = ntohs(dport);
224 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
225 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
226 bool exact_dif = udp6_lib_exact_dif_match(net, skb);
227 int score, badness, matches = 0, reuseport = 0;
228 u32 hash = 0;
229
230 if (hslot->count > 10) {
231 hash2 = udp6_portaddr_hash(net, daddr, hnum);
232 slot2 = hash2 & udptable->mask;
233 hslot2 = &udptable->hash2[slot2];
234 if (hslot->count < hslot2->count)
235 goto begin;
236
237 result = udp6_lib_lookup2(net, saddr, sport,
238 daddr, hnum, dif, exact_dif,
239 hslot2, skb);
240 if (!result) {
241 unsigned int old_slot2 = slot2;
242 hash2 = udp6_portaddr_hash(net, &in6addr_any, hnum);
243 slot2 = hash2 & udptable->mask;
244 /* avoid searching the same slot again. */
245 if (unlikely(slot2 == old_slot2))
246 return result;
247
248 hslot2 = &udptable->hash2[slot2];
249 if (hslot->count < hslot2->count)
250 goto begin;
251
252 result = udp6_lib_lookup2(net, saddr, sport,
253 daddr, hnum, dif,
254 exact_dif, hslot2,
255 skb);
256 }
257 return result;
258 }
259 begin:
260 result = NULL;
261 badness = -1;
262 sk_for_each_rcu(sk, &hslot->head) {
263 score = compute_score(sk, net, saddr, sport, daddr, hnum, dif,
264 exact_dif);
265 if (score > badness) {
266 reuseport = sk->sk_reuseport;
267 if (reuseport) {
268 hash = udp6_ehashfn(net, daddr, hnum,
269 saddr, sport);
270 result = reuseport_select_sock(sk, hash, skb,
271 sizeof(struct udphdr));
272 if (result)
273 return result;
274 matches = 1;
275 }
276 result = sk;
277 badness = score;
278 } else if (score == badness && reuseport) {
279 matches++;
280 if (reciprocal_scale(hash, matches) == 0)
281 result = sk;
282 hash = next_pseudo_random32(hash);
283 }
284 }
285 return result;
286 }
287 EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
288
289 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
290 __be16 sport, __be16 dport,
291 struct udp_table *udptable)
292 {
293 const struct ipv6hdr *iph = ipv6_hdr(skb);
294
295 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
296 &iph->daddr, dport, inet6_iif(skb),
297 udptable, skb);
298 }
299
300 struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
301 __be16 sport, __be16 dport)
302 {
303 const struct ipv6hdr *iph = ipv6_hdr(skb);
304
305 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
306 &iph->daddr, dport, inet6_iif(skb),
307 &udp_table, skb);
308 }
309 EXPORT_SYMBOL_GPL(udp6_lib_lookup_skb);
310
311 /* Must be called under rcu_read_lock().
312 * Does increment socket refcount.
313 */
314 #if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \
315 IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY) || \
316 IS_ENABLED(CONFIG_NF_SOCKET_IPV6)
317 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
318 const struct in6_addr *daddr, __be16 dport, int dif)
319 {
320 struct sock *sk;
321
322 sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport,
323 dif, &udp_table, NULL);
324 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
325 sk = NULL;
326 return sk;
327 }
328 EXPORT_SYMBOL_GPL(udp6_lib_lookup);
329 #endif
330
331 /* do not use the scratch area len for jumbogram: their length execeeds the
332 * scratch area space; note that the IP6CB flags is still in the first
333 * cacheline, so checking for jumbograms is cheap
334 */
335 static int udp6_skb_len(struct sk_buff *skb)
336 {
337 return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb);
338 }
339
340 /*
341 * This should be easy, if there is something there we
342 * return it, otherwise we block.
343 */
344
345 int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
346 int noblock, int flags, int *addr_len)
347 {
348 struct ipv6_pinfo *np = inet6_sk(sk);
349 struct inet_sock *inet = inet_sk(sk);
350 struct sk_buff *skb;
351 unsigned int ulen, copied;
352 int peeked, peeking, off;
353 int err;
354 int is_udplite = IS_UDPLITE(sk);
355 bool checksum_valid = false;
356 int is_udp4;
357
358 if (flags & MSG_ERRQUEUE)
359 return ipv6_recv_error(sk, msg, len, addr_len);
360
361 if (np->rxpmtu && np->rxopt.bits.rxpmtu)
362 return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
363
364 try_again:
365 peeking = flags & MSG_PEEK;
366 off = sk_peek_offset(sk, flags);
367 skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err);
368 if (!skb)
369 return err;
370
371 ulen = udp6_skb_len(skb);
372 copied = len;
373 if (copied > ulen - off)
374 copied = ulen - off;
375 else if (copied < ulen)
376 msg->msg_flags |= MSG_TRUNC;
377
378 is_udp4 = (skb->protocol == htons(ETH_P_IP));
379
380 /*
381 * If checksum is needed at all, try to do it while copying the
382 * data. If the data is truncated, or if we only want a partial
383 * coverage checksum (UDP-Lite), do it before the copy.
384 */
385
386 if (copied < ulen || peeking ||
387 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
388 checksum_valid = udp_skb_csum_unnecessary(skb) ||
389 !__udp_lib_checksum_complete(skb);
390 if (!checksum_valid)
391 goto csum_copy_err;
392 }
393
394 if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
395 if (udp_skb_is_linear(skb))
396 err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
397 else
398 err = skb_copy_datagram_msg(skb, off, msg, copied);
399 } else {
400 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
401 if (err == -EINVAL)
402 goto csum_copy_err;
403 }
404 if (unlikely(err)) {
405 if (!peeked) {
406 atomic_inc(&sk->sk_drops);
407 if (is_udp4)
408 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
409 is_udplite);
410 else
411 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
412 is_udplite);
413 }
414 kfree_skb(skb);
415 return err;
416 }
417 if (!peeked) {
418 if (is_udp4)
419 UDP_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS,
420 is_udplite);
421 else
422 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS,
423 is_udplite);
424 }
425
426 sock_recv_ts_and_drops(msg, sk, skb);
427
428 /* Copy the address. */
429 if (msg->msg_name) {
430 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
431 sin6->sin6_family = AF_INET6;
432 sin6->sin6_port = udp_hdr(skb)->source;
433 sin6->sin6_flowinfo = 0;
434
435 if (is_udp4) {
436 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
437 &sin6->sin6_addr);
438 sin6->sin6_scope_id = 0;
439 } else {
440 sin6->sin6_addr = ipv6_hdr(skb)->saddr;
441 sin6->sin6_scope_id =
442 ipv6_iface_scope_id(&sin6->sin6_addr,
443 inet6_iif(skb));
444 }
445 *addr_len = sizeof(*sin6);
446 }
447
448 if (np->rxopt.all)
449 ip6_datagram_recv_common_ctl(sk, msg, skb);
450
451 if (is_udp4) {
452 if (inet->cmsg_flags)
453 ip_cmsg_recv_offset(msg, sk, skb,
454 sizeof(struct udphdr), off);
455 } else {
456 if (np->rxopt.all)
457 ip6_datagram_recv_specific_ctl(sk, msg, skb);
458 }
459
460 err = copied;
461 if (flags & MSG_TRUNC)
462 err = ulen;
463
464 skb_consume_udp(sk, skb, peeking ? -err : err);
465 return err;
466
467 csum_copy_err:
468 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
469 udp_skb_destructor)) {
470 if (is_udp4) {
471 UDP_INC_STATS(sock_net(sk),
472 UDP_MIB_CSUMERRORS, is_udplite);
473 UDP_INC_STATS(sock_net(sk),
474 UDP_MIB_INERRORS, is_udplite);
475 } else {
476 UDP6_INC_STATS(sock_net(sk),
477 UDP_MIB_CSUMERRORS, is_udplite);
478 UDP6_INC_STATS(sock_net(sk),
479 UDP_MIB_INERRORS, is_udplite);
480 }
481 }
482 kfree_skb(skb);
483
484 /* starting over for a new packet, but check if we need to yield */
485 cond_resched();
486 msg->msg_flags &= ~MSG_TRUNC;
487 goto try_again;
488 }
489
490 void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
491 u8 type, u8 code, int offset, __be32 info,
492 struct udp_table *udptable)
493 {
494 struct ipv6_pinfo *np;
495 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
496 const struct in6_addr *saddr = &hdr->saddr;
497 const struct in6_addr *daddr = &hdr->daddr;
498 struct udphdr *uh = (struct udphdr *)(skb->data+offset);
499 struct sock *sk;
500 int harderr;
501 int err;
502 struct net *net = dev_net(skb->dev);
503
504 sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
505 inet6_iif(skb), udptable, skb);
506 if (!sk) {
507 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
508 ICMP6_MIB_INERRORS);
509 return;
510 }
511
512 harderr = icmpv6_err_convert(type, code, &err);
513 np = inet6_sk(sk);
514
515 if (type == ICMPV6_PKT_TOOBIG) {
516 if (!ip6_sk_accept_pmtu(sk))
517 goto out;
518 ip6_sk_update_pmtu(skb, sk, info);
519 if (np->pmtudisc != IPV6_PMTUDISC_DONT)
520 harderr = 1;
521 }
522 if (type == NDISC_REDIRECT) {
523 ip6_sk_redirect(skb, sk);
524 goto out;
525 }
526
527 if (!np->recverr) {
528 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
529 goto out;
530 } else {
531 ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
532 }
533
534 sk->sk_err = err;
535 sk->sk_error_report(sk);
536 out:
537 return;
538 }
539
540 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
541 {
542 int rc;
543
544 if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
545 sock_rps_save_rxhash(sk, skb);
546 sk_mark_napi_id(sk, skb);
547 sk_incoming_cpu_update(sk);
548 } else {
549 sk_mark_napi_id_once(sk, skb);
550 }
551
552 rc = __udp_enqueue_schedule_skb(sk, skb);
553 if (rc < 0) {
554 int is_udplite = IS_UDPLITE(sk);
555
556 /* Note that an ENOMEM error is charged twice */
557 if (rc == -ENOMEM)
558 UDP6_INC_STATS(sock_net(sk),
559 UDP_MIB_RCVBUFERRORS, is_udplite);
560 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
561 kfree_skb(skb);
562 return -1;
563 }
564
565 return 0;
566 }
567
568 static __inline__ void udpv6_err(struct sk_buff *skb,
569 struct inet6_skb_parm *opt, u8 type,
570 u8 code, int offset, __be32 info)
571 {
572 __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
573 }
574
575 static struct static_key udpv6_encap_needed __read_mostly;
576 void udpv6_encap_enable(void)
577 {
578 if (!static_key_enabled(&udpv6_encap_needed))
579 static_key_slow_inc(&udpv6_encap_needed);
580 }
581 EXPORT_SYMBOL(udpv6_encap_enable);
582
583 static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
584 {
585 struct udp_sock *up = udp_sk(sk);
586 int is_udplite = IS_UDPLITE(sk);
587
588 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
589 goto drop;
590
591 if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
592 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
593
594 /*
595 * This is an encapsulation socket so pass the skb to
596 * the socket's udp_encap_rcv() hook. Otherwise, just
597 * fall through and pass this up the UDP socket.
598 * up->encap_rcv() returns the following value:
599 * =0 if skb was successfully passed to the encap
600 * handler or was discarded by it.
601 * >0 if skb should be passed on to UDP.
602 * <0 if skb should be resubmitted as proto -N
603 */
604
605 /* if we're overly short, let UDP handle it */
606 encap_rcv = ACCESS_ONCE(up->encap_rcv);
607 if (encap_rcv) {
608 int ret;
609
610 /* Verify checksum before giving to encap */
611 if (udp_lib_checksum_complete(skb))
612 goto csum_error;
613
614 ret = encap_rcv(sk, skb);
615 if (ret <= 0) {
616 __UDP_INC_STATS(sock_net(sk),
617 UDP_MIB_INDATAGRAMS,
618 is_udplite);
619 return -ret;
620 }
621 }
622
623 /* FALLTHROUGH -- it's a UDP Packet */
624 }
625
626 /*
627 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
628 */
629 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
630
631 if (up->pcrlen == 0) { /* full coverage was set */
632 net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n",
633 UDP_SKB_CB(skb)->cscov, skb->len);
634 goto drop;
635 }
636 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
637 net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
638 UDP_SKB_CB(skb)->cscov, up->pcrlen);
639 goto drop;
640 }
641 }
642
643 prefetch(&sk->sk_rmem_alloc);
644 if (rcu_access_pointer(sk->sk_filter) &&
645 udp_lib_checksum_complete(skb))
646 goto csum_error;
647
648 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
649 goto drop;
650
651 udp_csum_pull_header(skb);
652
653 skb_dst_drop(skb);
654
655 return __udpv6_queue_rcv_skb(sk, skb);
656
657 csum_error:
658 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
659 drop:
660 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
661 atomic_inc(&sk->sk_drops);
662 kfree_skb(skb);
663 return -1;
664 }
665
666 static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
667 __be16 loc_port, const struct in6_addr *loc_addr,
668 __be16 rmt_port, const struct in6_addr *rmt_addr,
669 int dif, unsigned short hnum)
670 {
671 struct inet_sock *inet = inet_sk(sk);
672
673 if (!net_eq(sock_net(sk), net))
674 return false;
675
676 if (udp_sk(sk)->udp_port_hash != hnum ||
677 sk->sk_family != PF_INET6 ||
678 (inet->inet_dport && inet->inet_dport != rmt_port) ||
679 (!ipv6_addr_any(&sk->sk_v6_daddr) &&
680 !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
681 (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif) ||
682 (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
683 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
684 return false;
685 if (!inet6_mc_check(sk, loc_addr, rmt_addr))
686 return false;
687 return true;
688 }
689
690 static void udp6_csum_zero_error(struct sk_buff *skb)
691 {
692 /* RFC 2460 section 8.1 says that we SHOULD log
693 * this error. Well, it is reasonable.
694 */
695 net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
696 &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
697 &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
698 }
699
700 /*
701 * Note: called only from the BH handler context,
702 * so we don't need to lock the hashes.
703 */
704 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
705 const struct in6_addr *saddr, const struct in6_addr *daddr,
706 struct udp_table *udptable, int proto)
707 {
708 struct sock *sk, *first = NULL;
709 const struct udphdr *uh = udp_hdr(skb);
710 unsigned short hnum = ntohs(uh->dest);
711 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
712 unsigned int offset = offsetof(typeof(*sk), sk_node);
713 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
714 int dif = inet6_iif(skb);
715 struct hlist_node *node;
716 struct sk_buff *nskb;
717
718 if (use_hash2) {
719 hash2_any = udp6_portaddr_hash(net, &in6addr_any, hnum) &
720 udptable->mask;
721 hash2 = udp6_portaddr_hash(net, daddr, hnum) & udptable->mask;
722 start_lookup:
723 hslot = &udptable->hash2[hash2];
724 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
725 }
726
727 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
728 if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
729 uh->source, saddr, dif, hnum))
730 continue;
731 /* If zero checksum and no_check is not on for
732 * the socket then skip it.
733 */
734 if (!uh->check && !udp_sk(sk)->no_check6_rx)
735 continue;
736 if (!first) {
737 first = sk;
738 continue;
739 }
740 nskb = skb_clone(skb, GFP_ATOMIC);
741 if (unlikely(!nskb)) {
742 atomic_inc(&sk->sk_drops);
743 __UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
744 IS_UDPLITE(sk));
745 __UDP6_INC_STATS(net, UDP_MIB_INERRORS,
746 IS_UDPLITE(sk));
747 continue;
748 }
749
750 if (udpv6_queue_rcv_skb(sk, nskb) > 0)
751 consume_skb(nskb);
752 }
753
754 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
755 if (use_hash2 && hash2 != hash2_any) {
756 hash2 = hash2_any;
757 goto start_lookup;
758 }
759
760 if (first) {
761 if (udpv6_queue_rcv_skb(first, skb) > 0)
762 consume_skb(skb);
763 } else {
764 kfree_skb(skb);
765 __UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
766 proto == IPPROTO_UDPLITE);
767 }
768 return 0;
769 }
770
771 static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
772 {
773 if (udp_sk_rx_dst_set(sk, dst)) {
774 const struct rt6_info *rt = (const struct rt6_info *)dst;
775
776 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
777 }
778 }
779
780 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
781 int proto)
782 {
783 const struct in6_addr *saddr, *daddr;
784 struct net *net = dev_net(skb->dev);
785 struct udphdr *uh;
786 struct sock *sk;
787 u32 ulen = 0;
788
789 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
790 goto discard;
791
792 saddr = &ipv6_hdr(skb)->saddr;
793 daddr = &ipv6_hdr(skb)->daddr;
794 uh = udp_hdr(skb);
795
796 ulen = ntohs(uh->len);
797 if (ulen > skb->len)
798 goto short_packet;
799
800 if (proto == IPPROTO_UDP) {
801 /* UDP validates ulen. */
802
803 /* Check for jumbo payload */
804 if (ulen == 0)
805 ulen = skb->len;
806
807 if (ulen < sizeof(*uh))
808 goto short_packet;
809
810 if (ulen < skb->len) {
811 if (pskb_trim_rcsum(skb, ulen))
812 goto short_packet;
813 saddr = &ipv6_hdr(skb)->saddr;
814 daddr = &ipv6_hdr(skb)->daddr;
815 uh = udp_hdr(skb);
816 }
817 }
818
819 if (udp6_csum_init(skb, uh, proto))
820 goto csum_error;
821
822 /* Check if the socket is already available, e.g. due to early demux */
823 sk = skb_steal_sock(skb);
824 if (sk) {
825 struct dst_entry *dst = skb_dst(skb);
826 int ret;
827
828 if (unlikely(sk->sk_rx_dst != dst))
829 udp6_sk_rx_dst_set(sk, dst);
830
831 ret = udpv6_queue_rcv_skb(sk, skb);
832 sock_put(sk);
833
834 /* a return value > 0 means to resubmit the input */
835 if (ret > 0)
836 return ret;
837 return 0;
838 }
839
840 /*
841 * Multicast receive code
842 */
843 if (ipv6_addr_is_multicast(daddr))
844 return __udp6_lib_mcast_deliver(net, skb,
845 saddr, daddr, udptable, proto);
846
847 /* Unicast */
848 sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
849 if (sk) {
850 int ret;
851
852 if (!uh->check && !udp_sk(sk)->no_check6_rx) {
853 udp6_csum_zero_error(skb);
854 goto csum_error;
855 }
856
857 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
858 skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
859 ip6_compute_pseudo);
860
861 ret = udpv6_queue_rcv_skb(sk, skb);
862
863 /* a return value > 0 means to resubmit the input */
864 if (ret > 0)
865 return ret;
866
867 return 0;
868 }
869
870 if (!uh->check) {
871 udp6_csum_zero_error(skb);
872 goto csum_error;
873 }
874
875 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
876 goto discard;
877
878 if (udp_lib_checksum_complete(skb))
879 goto csum_error;
880
881 __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
882 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
883
884 kfree_skb(skb);
885 return 0;
886
887 short_packet:
888 net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
889 proto == IPPROTO_UDPLITE ? "-Lite" : "",
890 saddr, ntohs(uh->source),
891 ulen, skb->len,
892 daddr, ntohs(uh->dest));
893 goto discard;
894 csum_error:
895 __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
896 discard:
897 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
898 kfree_skb(skb);
899 return 0;
900 }
901
902
903 static struct sock *__udp6_lib_demux_lookup(struct net *net,
904 __be16 loc_port, const struct in6_addr *loc_addr,
905 __be16 rmt_port, const struct in6_addr *rmt_addr,
906 int dif)
907 {
908 unsigned short hnum = ntohs(loc_port);
909 unsigned int hash2 = udp6_portaddr_hash(net, loc_addr, hnum);
910 unsigned int slot2 = hash2 & udp_table.mask;
911 struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
912 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
913 struct sock *sk;
914
915 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
916 if (sk->sk_state == TCP_ESTABLISHED &&
917 INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif))
918 return sk;
919 /* Only check first socket in chain */
920 break;
921 }
922 return NULL;
923 }
924
925 static void udp_v6_early_demux(struct sk_buff *skb)
926 {
927 struct net *net = dev_net(skb->dev);
928 const struct udphdr *uh;
929 struct sock *sk;
930 struct dst_entry *dst;
931 int dif = skb->dev->ifindex;
932
933 if (!pskb_may_pull(skb, skb_transport_offset(skb) +
934 sizeof(struct udphdr)))
935 return;
936
937 uh = udp_hdr(skb);
938
939 if (skb->pkt_type == PACKET_HOST)
940 sk = __udp6_lib_demux_lookup(net, uh->dest,
941 &ipv6_hdr(skb)->daddr,
942 uh->source, &ipv6_hdr(skb)->saddr,
943 dif);
944 else
945 return;
946
947 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
948 return;
949
950 skb->sk = sk;
951 skb->destructor = sock_efree;
952 dst = READ_ONCE(sk->sk_rx_dst);
953
954 if (dst)
955 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
956 if (dst) {
957 /* set noref for now.
958 * any place which wants to hold dst has to call
959 * dst_hold_safe()
960 */
961 skb_dst_set_noref(skb, dst);
962 }
963 }
964
965 static __inline__ int udpv6_rcv(struct sk_buff *skb)
966 {
967 return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
968 }
969
970 /*
971 * Throw away all pending data and cancel the corking. Socket is locked.
972 */
973 static void udp_v6_flush_pending_frames(struct sock *sk)
974 {
975 struct udp_sock *up = udp_sk(sk);
976
977 if (up->pending == AF_INET)
978 udp_flush_pending_frames(sk);
979 else if (up->pending) {
980 up->len = 0;
981 up->pending = 0;
982 ip6_flush_pending_frames(sk);
983 }
984 }
985
986 /**
987 * udp6_hwcsum_outgoing - handle outgoing HW checksumming
988 * @sk: socket we are sending on
989 * @skb: sk_buff containing the filled-in UDP header
990 * (checksum field must be zeroed out)
991 */
992 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
993 const struct in6_addr *saddr,
994 const struct in6_addr *daddr, int len)
995 {
996 unsigned int offset;
997 struct udphdr *uh = udp_hdr(skb);
998 struct sk_buff *frags = skb_shinfo(skb)->frag_list;
999 __wsum csum = 0;
1000
1001 if (!frags) {
1002 /* Only one fragment on the socket. */
1003 skb->csum_start = skb_transport_header(skb) - skb->head;
1004 skb->csum_offset = offsetof(struct udphdr, check);
1005 uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
1006 } else {
1007 /*
1008 * HW-checksum won't work as there are two or more
1009 * fragments on the socket so that all csums of sk_buffs
1010 * should be together
1011 */
1012 offset = skb_transport_offset(skb);
1013 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
1014
1015 skb->ip_summed = CHECKSUM_NONE;
1016
1017 do {
1018 csum = csum_add(csum, frags->csum);
1019 } while ((frags = frags->next));
1020
1021 uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
1022 csum);
1023 if (uh->check == 0)
1024 uh->check = CSUM_MANGLED_0;
1025 }
1026 }
1027
1028 /*
1029 * Sending
1030 */
1031
1032 static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6)
1033 {
1034 struct sock *sk = skb->sk;
1035 struct udphdr *uh;
1036 int err = 0;
1037 int is_udplite = IS_UDPLITE(sk);
1038 __wsum csum = 0;
1039 int offset = skb_transport_offset(skb);
1040 int len = skb->len - offset;
1041
1042 /*
1043 * Create a UDP header
1044 */
1045 uh = udp_hdr(skb);
1046 uh->source = fl6->fl6_sport;
1047 uh->dest = fl6->fl6_dport;
1048 uh->len = htons(len);
1049 uh->check = 0;
1050
1051 if (is_udplite)
1052 csum = udplite_csum(skb);
1053 else if (udp_sk(sk)->no_check6_tx) { /* UDP csum disabled */
1054 skb->ip_summed = CHECKSUM_NONE;
1055 goto send;
1056 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1057 udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len);
1058 goto send;
1059 } else
1060 csum = udp_csum(skb);
1061
1062 /* add protocol-dependent pseudo-header */
1063 uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
1064 len, fl6->flowi6_proto, csum);
1065 if (uh->check == 0)
1066 uh->check = CSUM_MANGLED_0;
1067
1068 send:
1069 err = ip6_send_skb(skb);
1070 if (err) {
1071 if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
1072 UDP6_INC_STATS(sock_net(sk),
1073 UDP_MIB_SNDBUFERRORS, is_udplite);
1074 err = 0;
1075 }
1076 } else {
1077 UDP6_INC_STATS(sock_net(sk),
1078 UDP_MIB_OUTDATAGRAMS, is_udplite);
1079 }
1080 return err;
1081 }
1082
1083 static int udp_v6_push_pending_frames(struct sock *sk)
1084 {
1085 struct sk_buff *skb;
1086 struct udp_sock *up = udp_sk(sk);
1087 struct flowi6 fl6;
1088 int err = 0;
1089
1090 if (up->pending == AF_INET)
1091 return udp_push_pending_frames(sk);
1092
1093 /* ip6_finish_skb will release the cork, so make a copy of
1094 * fl6 here.
1095 */
1096 fl6 = inet_sk(sk)->cork.fl.u.ip6;
1097
1098 skb = ip6_finish_skb(sk);
1099 if (!skb)
1100 goto out;
1101
1102 err = udp_v6_send_skb(skb, &fl6);
1103
1104 out:
1105 up->len = 0;
1106 up->pending = 0;
1107 return err;
1108 }
1109
1110 int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1111 {
1112 struct ipv6_txoptions opt_space;
1113 struct udp_sock *up = udp_sk(sk);
1114 struct inet_sock *inet = inet_sk(sk);
1115 struct ipv6_pinfo *np = inet6_sk(sk);
1116 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1117 struct in6_addr *daddr, *final_p, final;
1118 struct ipv6_txoptions *opt = NULL;
1119 struct ipv6_txoptions *opt_to_free = NULL;
1120 struct ip6_flowlabel *flowlabel = NULL;
1121 struct flowi6 fl6;
1122 struct dst_entry *dst;
1123 struct ipcm6_cookie ipc6;
1124 int addr_len = msg->msg_namelen;
1125 int ulen = len;
1126 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
1127 int err;
1128 int connected = 0;
1129 int is_udplite = IS_UDPLITE(sk);
1130 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1131 struct sockcm_cookie sockc;
1132
1133 ipc6.hlimit = -1;
1134 ipc6.tclass = -1;
1135 ipc6.dontfrag = -1;
1136 sockc.tsflags = sk->sk_tsflags;
1137
1138 /* destination address check */
1139 if (sin6) {
1140 if (addr_len < offsetof(struct sockaddr, sa_data))
1141 return -EINVAL;
1142
1143 switch (sin6->sin6_family) {
1144 case AF_INET6:
1145 if (addr_len < SIN6_LEN_RFC2133)
1146 return -EINVAL;
1147 daddr = &sin6->sin6_addr;
1148 if (ipv6_addr_any(daddr) &&
1149 ipv6_addr_v4mapped(&np->saddr))
1150 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
1151 daddr);
1152 break;
1153 case AF_INET:
1154 goto do_udp_sendmsg;
1155 case AF_UNSPEC:
1156 msg->msg_name = sin6 = NULL;
1157 msg->msg_namelen = addr_len = 0;
1158 daddr = NULL;
1159 break;
1160 default:
1161 return -EINVAL;
1162 }
1163 } else if (!up->pending) {
1164 if (sk->sk_state != TCP_ESTABLISHED)
1165 return -EDESTADDRREQ;
1166 daddr = &sk->sk_v6_daddr;
1167 } else
1168 daddr = NULL;
1169
1170 if (daddr) {
1171 if (ipv6_addr_v4mapped(daddr)) {
1172 struct sockaddr_in sin;
1173 sin.sin_family = AF_INET;
1174 sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1175 sin.sin_addr.s_addr = daddr->s6_addr32[3];
1176 msg->msg_name = &sin;
1177 msg->msg_namelen = sizeof(sin);
1178 do_udp_sendmsg:
1179 if (__ipv6_only_sock(sk))
1180 return -ENETUNREACH;
1181 return udp_sendmsg(sk, msg, len);
1182 }
1183 }
1184
1185 if (up->pending == AF_INET)
1186 return udp_sendmsg(sk, msg, len);
1187
1188 /* Rough check on arithmetic overflow,
1189 better check is made in ip6_append_data().
1190 */
1191 if (len > INT_MAX - sizeof(struct udphdr))
1192 return -EMSGSIZE;
1193
1194 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
1195 if (up->pending) {
1196 /*
1197 * There are pending frames.
1198 * The socket lock must be held while it's corked.
1199 */
1200 lock_sock(sk);
1201 if (likely(up->pending)) {
1202 if (unlikely(up->pending != AF_INET6)) {
1203 release_sock(sk);
1204 return -EAFNOSUPPORT;
1205 }
1206 dst = NULL;
1207 goto do_append_data;
1208 }
1209 release_sock(sk);
1210 }
1211 ulen += sizeof(struct udphdr);
1212
1213 memset(&fl6, 0, sizeof(fl6));
1214
1215 if (sin6) {
1216 if (sin6->sin6_port == 0)
1217 return -EINVAL;
1218
1219 fl6.fl6_dport = sin6->sin6_port;
1220 daddr = &sin6->sin6_addr;
1221
1222 if (np->sndflow) {
1223 fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1224 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
1225 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1226 if (!flowlabel)
1227 return -EINVAL;
1228 }
1229 }
1230
1231 /*
1232 * Otherwise it will be difficult to maintain
1233 * sk->sk_dst_cache.
1234 */
1235 if (sk->sk_state == TCP_ESTABLISHED &&
1236 ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
1237 daddr = &sk->sk_v6_daddr;
1238
1239 if (addr_len >= sizeof(struct sockaddr_in6) &&
1240 sin6->sin6_scope_id &&
1241 __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1242 fl6.flowi6_oif = sin6->sin6_scope_id;
1243 } else {
1244 if (sk->sk_state != TCP_ESTABLISHED)
1245 return -EDESTADDRREQ;
1246
1247 fl6.fl6_dport = inet->inet_dport;
1248 daddr = &sk->sk_v6_daddr;
1249 fl6.flowlabel = np->flow_label;
1250 connected = 1;
1251 }
1252
1253 if (!fl6.flowi6_oif)
1254 fl6.flowi6_oif = sk->sk_bound_dev_if;
1255
1256 if (!fl6.flowi6_oif)
1257 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1258
1259 fl6.flowi6_mark = sk->sk_mark;
1260 fl6.flowi6_uid = sk->sk_uid;
1261
1262 if (msg->msg_controllen) {
1263 opt = &opt_space;
1264 memset(opt, 0, sizeof(struct ipv6_txoptions));
1265 opt->tot_len = sizeof(*opt);
1266 ipc6.opt = opt;
1267
1268 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, &sockc);
1269 if (err < 0) {
1270 fl6_sock_release(flowlabel);
1271 return err;
1272 }
1273 if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1274 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1275 if (!flowlabel)
1276 return -EINVAL;
1277 }
1278 if (!(opt->opt_nflen|opt->opt_flen))
1279 opt = NULL;
1280 connected = 0;
1281 }
1282 if (!opt) {
1283 opt = txopt_get(np);
1284 opt_to_free = opt;
1285 }
1286 if (flowlabel)
1287 opt = fl6_merge_options(&opt_space, flowlabel, opt);
1288 opt = ipv6_fixup_options(&opt_space, opt);
1289 ipc6.opt = opt;
1290
1291 fl6.flowi6_proto = sk->sk_protocol;
1292 if (!ipv6_addr_any(daddr))
1293 fl6.daddr = *daddr;
1294 else
1295 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1296 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
1297 fl6.saddr = np->saddr;
1298 fl6.fl6_sport = inet->inet_sport;
1299
1300 final_p = fl6_update_dst(&fl6, opt, &final);
1301 if (final_p)
1302 connected = 0;
1303
1304 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
1305 fl6.flowi6_oif = np->mcast_oif;
1306 connected = 0;
1307 } else if (!fl6.flowi6_oif)
1308 fl6.flowi6_oif = np->ucast_oif;
1309
1310 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
1311
1312 if (ipc6.tclass < 0)
1313 ipc6.tclass = np->tclass;
1314
1315 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
1316
1317 dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p);
1318 if (IS_ERR(dst)) {
1319 err = PTR_ERR(dst);
1320 dst = NULL;
1321 goto out;
1322 }
1323
1324 if (ipc6.hlimit < 0)
1325 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
1326
1327 if (msg->msg_flags&MSG_CONFIRM)
1328 goto do_confirm;
1329 back_from_confirm:
1330
1331 /* Lockless fast path for the non-corking case */
1332 if (!corkreq) {
1333 struct sk_buff *skb;
1334
1335 skb = ip6_make_skb(sk, getfrag, msg, ulen,
1336 sizeof(struct udphdr), &ipc6,
1337 &fl6, (struct rt6_info *)dst,
1338 msg->msg_flags, &sockc);
1339 err = PTR_ERR(skb);
1340 if (!IS_ERR_OR_NULL(skb))
1341 err = udp_v6_send_skb(skb, &fl6);
1342 goto release_dst;
1343 }
1344
1345 lock_sock(sk);
1346 if (unlikely(up->pending)) {
1347 /* The socket is already corked while preparing it. */
1348 /* ... which is an evident application bug. --ANK */
1349 release_sock(sk);
1350
1351 net_dbg_ratelimited("udp cork app bug 2\n");
1352 err = -EINVAL;
1353 goto out;
1354 }
1355
1356 up->pending = AF_INET6;
1357
1358 do_append_data:
1359 if (ipc6.dontfrag < 0)
1360 ipc6.dontfrag = np->dontfrag;
1361 up->len += ulen;
1362 err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr),
1363 &ipc6, &fl6, (struct rt6_info *)dst,
1364 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags, &sockc);
1365 if (err)
1366 udp_v6_flush_pending_frames(sk);
1367 else if (!corkreq)
1368 err = udp_v6_push_pending_frames(sk);
1369 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1370 up->pending = 0;
1371
1372 if (err > 0)
1373 err = np->recverr ? net_xmit_errno(err) : 0;
1374 release_sock(sk);
1375
1376 release_dst:
1377 if (dst) {
1378 if (connected) {
1379 ip6_dst_store(sk, dst,
1380 ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
1381 &sk->sk_v6_daddr : NULL,
1382 #ifdef CONFIG_IPV6_SUBTREES
1383 ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
1384 &np->saddr :
1385 #endif
1386 NULL);
1387 } else {
1388 dst_release(dst);
1389 }
1390 dst = NULL;
1391 }
1392
1393 out:
1394 dst_release(dst);
1395 fl6_sock_release(flowlabel);
1396 txopt_put(opt_to_free);
1397 if (!err)
1398 return len;
1399 /*
1400 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1401 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1402 * we don't have a good statistic (IpOutDiscards but it can be too many
1403 * things). We could add another new stat but at least for now that
1404 * seems like overkill.
1405 */
1406 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1407 UDP6_INC_STATS(sock_net(sk),
1408 UDP_MIB_SNDBUFERRORS, is_udplite);
1409 }
1410 return err;
1411
1412 do_confirm:
1413 if (msg->msg_flags & MSG_PROBE)
1414 dst_confirm_neigh(dst, &fl6.daddr);
1415 if (!(msg->msg_flags&MSG_PROBE) || len)
1416 goto back_from_confirm;
1417 err = 0;
1418 goto out;
1419 }
1420
1421 void udpv6_destroy_sock(struct sock *sk)
1422 {
1423 struct udp_sock *up = udp_sk(sk);
1424 lock_sock(sk);
1425 udp_v6_flush_pending_frames(sk);
1426 release_sock(sk);
1427
1428 if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
1429 void (*encap_destroy)(struct sock *sk);
1430 encap_destroy = ACCESS_ONCE(up->encap_destroy);
1431 if (encap_destroy)
1432 encap_destroy(sk);
1433 }
1434
1435 inet6_destroy_sock(sk);
1436 }
1437
1438 /*
1439 * Socket option code for UDP
1440 */
1441 int udpv6_setsockopt(struct sock *sk, int level, int optname,
1442 char __user *optval, unsigned int optlen)
1443 {
1444 if (level == SOL_UDP || level == SOL_UDPLITE)
1445 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1446 udp_v6_push_pending_frames);
1447 return ipv6_setsockopt(sk, level, optname, optval, optlen);
1448 }
1449
1450 #ifdef CONFIG_COMPAT
1451 int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
1452 char __user *optval, unsigned int optlen)
1453 {
1454 if (level == SOL_UDP || level == SOL_UDPLITE)
1455 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1456 udp_v6_push_pending_frames);
1457 return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
1458 }
1459 #endif
1460
1461 int udpv6_getsockopt(struct sock *sk, int level, int optname,
1462 char __user *optval, int __user *optlen)
1463 {
1464 if (level == SOL_UDP || level == SOL_UDPLITE)
1465 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1466 return ipv6_getsockopt(sk, level, optname, optval, optlen);
1467 }
1468
1469 #ifdef CONFIG_COMPAT
1470 int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
1471 char __user *optval, int __user *optlen)
1472 {
1473 if (level == SOL_UDP || level == SOL_UDPLITE)
1474 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1475 return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
1476 }
1477 #endif
1478
1479 static struct inet6_protocol udpv6_protocol = {
1480 .early_demux = udp_v6_early_demux,
1481 .early_demux_handler = udp_v6_early_demux,
1482 .handler = udpv6_rcv,
1483 .err_handler = udpv6_err,
1484 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1485 };
1486
1487 /* ------------------------------------------------------------------------ */
1488 #ifdef CONFIG_PROC_FS
1489 int udp6_seq_show(struct seq_file *seq, void *v)
1490 {
1491 if (v == SEQ_START_TOKEN) {
1492 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1493 } else {
1494 int bucket = ((struct udp_iter_state *)seq->private)->bucket;
1495 struct inet_sock *inet = inet_sk(v);
1496 __u16 srcp = ntohs(inet->inet_sport);
1497 __u16 destp = ntohs(inet->inet_dport);
1498 ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket);
1499 }
1500 return 0;
1501 }
1502
1503 static const struct file_operations udp6_afinfo_seq_fops = {
1504 .owner = THIS_MODULE,
1505 .open = udp_seq_open,
1506 .read = seq_read,
1507 .llseek = seq_lseek,
1508 .release = seq_release_net
1509 };
1510
1511 static struct udp_seq_afinfo udp6_seq_afinfo = {
1512 .name = "udp6",
1513 .family = AF_INET6,
1514 .udp_table = &udp_table,
1515 .seq_fops = &udp6_afinfo_seq_fops,
1516 .seq_ops = {
1517 .show = udp6_seq_show,
1518 },
1519 };
1520
1521 int __net_init udp6_proc_init(struct net *net)
1522 {
1523 return udp_proc_register(net, &udp6_seq_afinfo);
1524 }
1525
1526 void udp6_proc_exit(struct net *net)
1527 {
1528 udp_proc_unregister(net, &udp6_seq_afinfo);
1529 }
1530 #endif /* CONFIG_PROC_FS */
1531
1532 /* ------------------------------------------------------------------------ */
1533
1534 struct proto udpv6_prot = {
1535 .name = "UDPv6",
1536 .owner = THIS_MODULE,
1537 .close = udp_lib_close,
1538 .connect = ip6_datagram_connect,
1539 .disconnect = udp_disconnect,
1540 .ioctl = udp_ioctl,
1541 .init = udp_init_sock,
1542 .destroy = udpv6_destroy_sock,
1543 .setsockopt = udpv6_setsockopt,
1544 .getsockopt = udpv6_getsockopt,
1545 .sendmsg = udpv6_sendmsg,
1546 .recvmsg = udpv6_recvmsg,
1547 .release_cb = ip6_datagram_release_cb,
1548 .hash = udp_lib_hash,
1549 .unhash = udp_lib_unhash,
1550 .rehash = udp_v6_rehash,
1551 .get_port = udp_v6_get_port,
1552 .memory_allocated = &udp_memory_allocated,
1553 .sysctl_mem = sysctl_udp_mem,
1554 .sysctl_wmem = &sysctl_udp_wmem_min,
1555 .sysctl_rmem = &sysctl_udp_rmem_min,
1556 .obj_size = sizeof(struct udp6_sock),
1557 .h.udp_table = &udp_table,
1558 #ifdef CONFIG_COMPAT
1559 .compat_setsockopt = compat_udpv6_setsockopt,
1560 .compat_getsockopt = compat_udpv6_getsockopt,
1561 #endif
1562 .diag_destroy = udp_abort,
1563 };
1564
1565 static struct inet_protosw udpv6_protosw = {
1566 .type = SOCK_DGRAM,
1567 .protocol = IPPROTO_UDP,
1568 .prot = &udpv6_prot,
1569 .ops = &inet6_dgram_ops,
1570 .flags = INET_PROTOSW_PERMANENT,
1571 };
1572
1573 int __init udpv6_init(void)
1574 {
1575 int ret;
1576
1577 ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1578 if (ret)
1579 goto out;
1580
1581 ret = inet6_register_protosw(&udpv6_protosw);
1582 if (ret)
1583 goto out_udpv6_protocol;
1584 out:
1585 return ret;
1586
1587 out_udpv6_protocol:
1588 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1589 goto out;
1590 }
1591
1592 void udpv6_exit(void)
1593 {
1594 inet6_unregister_protosw(&udpv6_protosw);
1595 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1596 }
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