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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
59static 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
69static 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
92int udp_v6_get_port(struct sock *sk, unsigned short snum)
93{
94 unsigned int hash2_nulladdr =
95 ipv6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
96 unsigned int hash2_partial =
97 ipv6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
98
99 /* precompute partial secondary hash */
100 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
101 return udp_lib_get_port(sk, snum, hash2_nulladdr);
102}
103
104static void udp_v6_rehash(struct sock *sk)
105{
106 u16 new_hash = ipv6_portaddr_hash(sock_net(sk),
107 &sk->sk_v6_rcv_saddr,
108 inet_sk(sk)->inet_num);
109
110 udp_lib_rehash(sk, new_hash);
111}
112
113static int compute_score(struct sock *sk, struct net *net,
114 const struct in6_addr *saddr, __be16 sport,
115 const struct in6_addr *daddr, unsigned short hnum,
116 int dif, int sdif, bool exact_dif)
117{
118 int score;
119 struct inet_sock *inet;
120
121 if (!net_eq(sock_net(sk), net) ||
122 udp_sk(sk)->udp_port_hash != hnum ||
123 sk->sk_family != PF_INET6)
124 return -1;
125
126 score = 0;
127 inet = inet_sk(sk);
128
129 if (inet->inet_dport) {
130 if (inet->inet_dport != sport)
131 return -1;
132 score++;
133 }
134
135 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
136 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
137 return -1;
138 score++;
139 }
140
141 if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
142 if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
143 return -1;
144 score++;
145 }
146
147 if (sk->sk_bound_dev_if || exact_dif) {
148 bool dev_match = (sk->sk_bound_dev_if == dif ||
149 sk->sk_bound_dev_if == sdif);
150
151 if (!dev_match)
152 return -1;
153 if (sk->sk_bound_dev_if)
154 score++;
155 }
156
157 if (sk->sk_incoming_cpu == raw_smp_processor_id())
158 score++;
159
160 return score;
161}
162
163/* called with rcu_read_lock() */
164static struct sock *udp6_lib_lookup2(struct net *net,
165 const struct in6_addr *saddr, __be16 sport,
166 const struct in6_addr *daddr, unsigned int hnum,
167 int dif, int sdif, bool exact_dif,
168 struct udp_hslot *hslot2, struct sk_buff *skb)
169{
170 struct sock *sk, *result;
171 int score, badness;
172 u32 hash = 0;
173
174 result = NULL;
175 badness = -1;
176 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
177 score = compute_score(sk, net, saddr, sport,
178 daddr, hnum, dif, sdif, exact_dif);
179 if (score > badness) {
180 if (sk->sk_reuseport) {
181 hash = udp6_ehashfn(net, daddr, hnum,
182 saddr, sport);
183
184 result = reuseport_select_sock(sk, hash, skb,
185 sizeof(struct udphdr));
186 if (result)
187 return result;
188 }
189 result = sk;
190 badness = score;
191 }
192 }
193 return result;
194}
195
196/* rcu_read_lock() must be held */
197struct sock *__udp6_lib_lookup(struct net *net,
198 const struct in6_addr *saddr, __be16 sport,
199 const struct in6_addr *daddr, __be16 dport,
200 int dif, int sdif, struct udp_table *udptable,
201 struct sk_buff *skb)
202{
203 struct sock *sk, *result;
204 unsigned short hnum = ntohs(dport);
205 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
206 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
207 bool exact_dif = udp6_lib_exact_dif_match(net, skb);
208 int score, badness;
209 u32 hash = 0;
210
211 if (hslot->count > 10) {
212 hash2 = ipv6_portaddr_hash(net, daddr, hnum);
213 slot2 = hash2 & udptable->mask;
214 hslot2 = &udptable->hash2[slot2];
215 if (hslot->count < hslot2->count)
216 goto begin;
217
218 result = udp6_lib_lookup2(net, saddr, sport,
219 daddr, hnum, dif, sdif, exact_dif,
220 hslot2, skb);
221 if (!result) {
222 unsigned int old_slot2 = slot2;
223 hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
224 slot2 = hash2 & udptable->mask;
225 /* avoid searching the same slot again. */
226 if (unlikely(slot2 == old_slot2))
227 return result;
228
229 hslot2 = &udptable->hash2[slot2];
230 if (hslot->count < hslot2->count)
231 goto begin;
232
233 result = udp6_lib_lookup2(net, saddr, sport,
234 daddr, hnum, dif, sdif,
235 exact_dif, hslot2,
236 skb);
237 }
238 return result;
239 }
240begin:
241 result = NULL;
242 badness = -1;
243 sk_for_each_rcu(sk, &hslot->head) {
244 score = compute_score(sk, net, saddr, sport, daddr, hnum, dif,
245 sdif, exact_dif);
246 if (score > badness) {
247 if (sk->sk_reuseport) {
248 hash = udp6_ehashfn(net, daddr, hnum,
249 saddr, sport);
250 result = reuseport_select_sock(sk, hash, skb,
251 sizeof(struct udphdr));
252 if (result)
253 return result;
254 }
255 result = sk;
256 badness = score;
257 }
258 }
259 return result;
260}
261EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
262
263static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
264 __be16 sport, __be16 dport,
265 struct udp_table *udptable)
266{
267 const struct ipv6hdr *iph = ipv6_hdr(skb);
268
269 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
270 &iph->daddr, dport, inet6_iif(skb),
271 inet6_sdif(skb), udptable, skb);
272}
273
274struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
275 __be16 sport, __be16 dport)
276{
277 const struct ipv6hdr *iph = ipv6_hdr(skb);
278
279 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
280 &iph->daddr, dport, inet6_iif(skb),
281 inet6_sdif(skb), &udp_table, skb);
282}
283EXPORT_SYMBOL_GPL(udp6_lib_lookup_skb);
284
285/* Must be called under rcu_read_lock().
286 * Does increment socket refcount.
287 */
288#if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \
289 IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY) || \
290 IS_ENABLED(CONFIG_NF_SOCKET_IPV6)
291struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
292 const struct in6_addr *daddr, __be16 dport, int dif)
293{
294 struct sock *sk;
295
296 sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport,
297 dif, 0, &udp_table, NULL);
298 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
299 sk = NULL;
300 return sk;
301}
302EXPORT_SYMBOL_GPL(udp6_lib_lookup);
303#endif
304
305/* do not use the scratch area len for jumbogram: their length execeeds the
306 * scratch area space; note that the IP6CB flags is still in the first
307 * cacheline, so checking for jumbograms is cheap
308 */
309static int udp6_skb_len(struct sk_buff *skb)
310{
311 return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb);
312}
313
314/*
315 * This should be easy, if there is something there we
316 * return it, otherwise we block.
317 */
318
319int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
320 int noblock, int flags, int *addr_len)
321{
322 struct ipv6_pinfo *np = inet6_sk(sk);
323 struct inet_sock *inet = inet_sk(sk);
324 struct sk_buff *skb;
325 unsigned int ulen, copied;
326 int peeked, peeking, off;
327 int err;
328 int is_udplite = IS_UDPLITE(sk);
329 bool checksum_valid = false;
330 int is_udp4;
331
332 if (flags & MSG_ERRQUEUE)
333 return ipv6_recv_error(sk, msg, len, addr_len);
334
335 if (np->rxpmtu && np->rxopt.bits.rxpmtu)
336 return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
337
338try_again:
339 peeking = flags & MSG_PEEK;
340 off = sk_peek_offset(sk, flags);
341 skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err);
342 if (!skb)
343 return err;
344
345 ulen = udp6_skb_len(skb);
346 copied = len;
347 if (copied > ulen - off)
348 copied = ulen - off;
349 else if (copied < ulen)
350 msg->msg_flags |= MSG_TRUNC;
351
352 is_udp4 = (skb->protocol == htons(ETH_P_IP));
353
354 /*
355 * If checksum is needed at all, try to do it while copying the
356 * data. If the data is truncated, or if we only want a partial
357 * coverage checksum (UDP-Lite), do it before the copy.
358 */
359
360 if (copied < ulen || peeking ||
361 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
362 checksum_valid = udp_skb_csum_unnecessary(skb) ||
363 !__udp_lib_checksum_complete(skb);
364 if (!checksum_valid)
365 goto csum_copy_err;
366 }
367
368 if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
369 if (udp_skb_is_linear(skb))
370 err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
371 else
372 err = skb_copy_datagram_msg(skb, off, msg, copied);
373 } else {
374 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
375 if (err == -EINVAL)
376 goto csum_copy_err;
377 }
378 if (unlikely(err)) {
379 if (!peeked) {
380 atomic_inc(&sk->sk_drops);
381 if (is_udp4)
382 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
383 is_udplite);
384 else
385 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
386 is_udplite);
387 }
388 kfree_skb(skb);
389 return err;
390 }
391 if (!peeked) {
392 if (is_udp4)
393 UDP_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS,
394 is_udplite);
395 else
396 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS,
397 is_udplite);
398 }
399
400 sock_recv_ts_and_drops(msg, sk, skb);
401
402 /* Copy the address. */
403 if (msg->msg_name) {
404 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
405 sin6->sin6_family = AF_INET6;
406 sin6->sin6_port = udp_hdr(skb)->source;
407 sin6->sin6_flowinfo = 0;
408
409 if (is_udp4) {
410 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
411 &sin6->sin6_addr);
412 sin6->sin6_scope_id = 0;
413 } else {
414 sin6->sin6_addr = ipv6_hdr(skb)->saddr;
415 sin6->sin6_scope_id =
416 ipv6_iface_scope_id(&sin6->sin6_addr,
417 inet6_iif(skb));
418 }
419 *addr_len = sizeof(*sin6);
420 }
421
422 if (np->rxopt.all)
423 ip6_datagram_recv_common_ctl(sk, msg, skb);
424
425 if (is_udp4) {
426 if (inet->cmsg_flags)
427 ip_cmsg_recv_offset(msg, sk, skb,
428 sizeof(struct udphdr), off);
429 } else {
430 if (np->rxopt.all)
431 ip6_datagram_recv_specific_ctl(sk, msg, skb);
432 }
433
434 err = copied;
435 if (flags & MSG_TRUNC)
436 err = ulen;
437
438 skb_consume_udp(sk, skb, peeking ? -err : err);
439 return err;
440
441csum_copy_err:
442 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
443 udp_skb_destructor)) {
444 if (is_udp4) {
445 UDP_INC_STATS(sock_net(sk),
446 UDP_MIB_CSUMERRORS, is_udplite);
447 UDP_INC_STATS(sock_net(sk),
448 UDP_MIB_INERRORS, is_udplite);
449 } else {
450 UDP6_INC_STATS(sock_net(sk),
451 UDP_MIB_CSUMERRORS, is_udplite);
452 UDP6_INC_STATS(sock_net(sk),
453 UDP_MIB_INERRORS, is_udplite);
454 }
455 }
456 kfree_skb(skb);
457
458 /* starting over for a new packet, but check if we need to yield */
459 cond_resched();
460 msg->msg_flags &= ~MSG_TRUNC;
461 goto try_again;
462}
463
464void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
465 u8 type, u8 code, int offset, __be32 info,
466 struct udp_table *udptable)
467{
468 struct ipv6_pinfo *np;
469 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
470 const struct in6_addr *saddr = &hdr->saddr;
471 const struct in6_addr *daddr = &hdr->daddr;
472 struct udphdr *uh = (struct udphdr *)(skb->data+offset);
473 struct sock *sk;
474 int harderr;
475 int err;
476 struct net *net = dev_net(skb->dev);
477
478 sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
479 inet6_iif(skb), 0, udptable, skb);
480 if (!sk) {
481 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
482 ICMP6_MIB_INERRORS);
483 return;
484 }
485
486 harderr = icmpv6_err_convert(type, code, &err);
487 np = inet6_sk(sk);
488
489 if (type == ICMPV6_PKT_TOOBIG) {
490 if (!ip6_sk_accept_pmtu(sk))
491 goto out;
492 ip6_sk_update_pmtu(skb, sk, info);
493 if (np->pmtudisc != IPV6_PMTUDISC_DONT)
494 harderr = 1;
495 }
496 if (type == NDISC_REDIRECT) {
497 ip6_sk_redirect(skb, sk);
498 goto out;
499 }
500
501 if (!np->recverr) {
502 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
503 goto out;
504 } else {
505 ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
506 }
507
508 sk->sk_err = err;
509 sk->sk_error_report(sk);
510out:
511 return;
512}
513
514static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
515{
516 int rc;
517
518 if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
519 sock_rps_save_rxhash(sk, skb);
520 sk_mark_napi_id(sk, skb);
521 sk_incoming_cpu_update(sk);
522 } else {
523 sk_mark_napi_id_once(sk, skb);
524 }
525
526 rc = __udp_enqueue_schedule_skb(sk, skb);
527 if (rc < 0) {
528 int is_udplite = IS_UDPLITE(sk);
529
530 /* Note that an ENOMEM error is charged twice */
531 if (rc == -ENOMEM)
532 UDP6_INC_STATS(sock_net(sk),
533 UDP_MIB_RCVBUFERRORS, is_udplite);
534 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
535 kfree_skb(skb);
536 return -1;
537 }
538
539 return 0;
540}
541
542static __inline__ void udpv6_err(struct sk_buff *skb,
543 struct inet6_skb_parm *opt, u8 type,
544 u8 code, int offset, __be32 info)
545{
546 __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
547}
548
549static struct static_key udpv6_encap_needed __read_mostly;
550void udpv6_encap_enable(void)
551{
552 static_key_enable(&udpv6_encap_needed);
553}
554EXPORT_SYMBOL(udpv6_encap_enable);
555
556static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
557{
558 struct udp_sock *up = udp_sk(sk);
559 int is_udplite = IS_UDPLITE(sk);
560
561 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
562 goto drop;
563
564 if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
565 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
566
567 /*
568 * This is an encapsulation socket so pass the skb to
569 * the socket's udp_encap_rcv() hook. Otherwise, just
570 * fall through and pass this up the UDP socket.
571 * up->encap_rcv() returns the following value:
572 * =0 if skb was successfully passed to the encap
573 * handler or was discarded by it.
574 * >0 if skb should be passed on to UDP.
575 * <0 if skb should be resubmitted as proto -N
576 */
577
578 /* if we're overly short, let UDP handle it */
579 encap_rcv = READ_ONCE(up->encap_rcv);
580 if (encap_rcv) {
581 int ret;
582
583 /* Verify checksum before giving to encap */
584 if (udp_lib_checksum_complete(skb))
585 goto csum_error;
586
587 ret = encap_rcv(sk, skb);
588 if (ret <= 0) {
589 __UDP_INC_STATS(sock_net(sk),
590 UDP_MIB_INDATAGRAMS,
591 is_udplite);
592 return -ret;
593 }
594 }
595
596 /* FALLTHROUGH -- it's a UDP Packet */
597 }
598
599 /*
600 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
601 */
602 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
603
604 if (up->pcrlen == 0) { /* full coverage was set */
605 net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n",
606 UDP_SKB_CB(skb)->cscov, skb->len);
607 goto drop;
608 }
609 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
610 net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
611 UDP_SKB_CB(skb)->cscov, up->pcrlen);
612 goto drop;
613 }
614 }
615
616 prefetch(&sk->sk_rmem_alloc);
617 if (rcu_access_pointer(sk->sk_filter) &&
618 udp_lib_checksum_complete(skb))
619 goto csum_error;
620
621 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
622 goto drop;
623
624 udp_csum_pull_header(skb);
625
626 skb_dst_drop(skb);
627
628 return __udpv6_queue_rcv_skb(sk, skb);
629
630csum_error:
631 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
632drop:
633 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
634 atomic_inc(&sk->sk_drops);
635 kfree_skb(skb);
636 return -1;
637}
638
639static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
640 __be16 loc_port, const struct in6_addr *loc_addr,
641 __be16 rmt_port, const struct in6_addr *rmt_addr,
642 int dif, unsigned short hnum)
643{
644 struct inet_sock *inet = inet_sk(sk);
645
646 if (!net_eq(sock_net(sk), net))
647 return false;
648
649 if (udp_sk(sk)->udp_port_hash != hnum ||
650 sk->sk_family != PF_INET6 ||
651 (inet->inet_dport && inet->inet_dport != rmt_port) ||
652 (!ipv6_addr_any(&sk->sk_v6_daddr) &&
653 !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
654 (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif) ||
655 (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
656 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
657 return false;
658 if (!inet6_mc_check(sk, loc_addr, rmt_addr))
659 return false;
660 return true;
661}
662
663static void udp6_csum_zero_error(struct sk_buff *skb)
664{
665 /* RFC 2460 section 8.1 says that we SHOULD log
666 * this error. Well, it is reasonable.
667 */
668 net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
669 &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
670 &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
671}
672
673/*
674 * Note: called only from the BH handler context,
675 * so we don't need to lock the hashes.
676 */
677static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
678 const struct in6_addr *saddr, const struct in6_addr *daddr,
679 struct udp_table *udptable, int proto)
680{
681 struct sock *sk, *first = NULL;
682 const struct udphdr *uh = udp_hdr(skb);
683 unsigned short hnum = ntohs(uh->dest);
684 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
685 unsigned int offset = offsetof(typeof(*sk), sk_node);
686 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
687 int dif = inet6_iif(skb);
688 struct hlist_node *node;
689 struct sk_buff *nskb;
690
691 if (use_hash2) {
692 hash2_any = ipv6_portaddr_hash(net, &in6addr_any, hnum) &
693 udptable->mask;
694 hash2 = ipv6_portaddr_hash(net, daddr, hnum) & udptable->mask;
695start_lookup:
696 hslot = &udptable->hash2[hash2];
697 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
698 }
699
700 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
701 if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
702 uh->source, saddr, dif, hnum))
703 continue;
704 /* If zero checksum and no_check is not on for
705 * the socket then skip it.
706 */
707 if (!uh->check && !udp_sk(sk)->no_check6_rx)
708 continue;
709 if (!first) {
710 first = sk;
711 continue;
712 }
713 nskb = skb_clone(skb, GFP_ATOMIC);
714 if (unlikely(!nskb)) {
715 atomic_inc(&sk->sk_drops);
716 __UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
717 IS_UDPLITE(sk));
718 __UDP6_INC_STATS(net, UDP_MIB_INERRORS,
719 IS_UDPLITE(sk));
720 continue;
721 }
722
723 if (udpv6_queue_rcv_skb(sk, nskb) > 0)
724 consume_skb(nskb);
725 }
726
727 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
728 if (use_hash2 && hash2 != hash2_any) {
729 hash2 = hash2_any;
730 goto start_lookup;
731 }
732
733 if (first) {
734 if (udpv6_queue_rcv_skb(first, skb) > 0)
735 consume_skb(skb);
736 } else {
737 kfree_skb(skb);
738 __UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
739 proto == IPPROTO_UDPLITE);
740 }
741 return 0;
742}
743
744static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
745{
746 if (udp_sk_rx_dst_set(sk, dst)) {
747 const struct rt6_info *rt = (const struct rt6_info *)dst;
748
749 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
750 }
751}
752
753int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
754 int proto)
755{
756 const struct in6_addr *saddr, *daddr;
757 struct net *net = dev_net(skb->dev);
758 struct udphdr *uh;
759 struct sock *sk;
760 u32 ulen = 0;
761
762 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
763 goto discard;
764
765 saddr = &ipv6_hdr(skb)->saddr;
766 daddr = &ipv6_hdr(skb)->daddr;
767 uh = udp_hdr(skb);
768
769 ulen = ntohs(uh->len);
770 if (ulen > skb->len)
771 goto short_packet;
772
773 if (proto == IPPROTO_UDP) {
774 /* UDP validates ulen. */
775
776 /* Check for jumbo payload */
777 if (ulen == 0)
778 ulen = skb->len;
779
780 if (ulen < sizeof(*uh))
781 goto short_packet;
782
783 if (ulen < skb->len) {
784 if (pskb_trim_rcsum(skb, ulen))
785 goto short_packet;
786 saddr = &ipv6_hdr(skb)->saddr;
787 daddr = &ipv6_hdr(skb)->daddr;
788 uh = udp_hdr(skb);
789 }
790 }
791
792 if (udp6_csum_init(skb, uh, proto))
793 goto csum_error;
794
795 /* Check if the socket is already available, e.g. due to early demux */
796 sk = skb_steal_sock(skb);
797 if (sk) {
798 struct dst_entry *dst = skb_dst(skb);
799 int ret;
800
801 if (unlikely(sk->sk_rx_dst != dst))
802 udp6_sk_rx_dst_set(sk, dst);
803
804 ret = udpv6_queue_rcv_skb(sk, skb);
805 sock_put(sk);
806
807 /* a return value > 0 means to resubmit the input */
808 if (ret > 0)
809 return ret;
810 return 0;
811 }
812
813 /*
814 * Multicast receive code
815 */
816 if (ipv6_addr_is_multicast(daddr))
817 return __udp6_lib_mcast_deliver(net, skb,
818 saddr, daddr, udptable, proto);
819
820 /* Unicast */
821 sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
822 if (sk) {
823 int ret;
824
825 if (!uh->check && !udp_sk(sk)->no_check6_rx) {
826 udp6_csum_zero_error(skb);
827 goto csum_error;
828 }
829
830 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
831 skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
832 ip6_compute_pseudo);
833
834 ret = udpv6_queue_rcv_skb(sk, skb);
835
836 /* a return value > 0 means to resubmit the input */
837 if (ret > 0)
838 return ret;
839
840 return 0;
841 }
842
843 if (!uh->check) {
844 udp6_csum_zero_error(skb);
845 goto csum_error;
846 }
847
848 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
849 goto discard;
850
851 if (udp_lib_checksum_complete(skb))
852 goto csum_error;
853
854 __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
855 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
856
857 kfree_skb(skb);
858 return 0;
859
860short_packet:
861 net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
862 proto == IPPROTO_UDPLITE ? "-Lite" : "",
863 saddr, ntohs(uh->source),
864 ulen, skb->len,
865 daddr, ntohs(uh->dest));
866 goto discard;
867csum_error:
868 __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
869discard:
870 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
871 kfree_skb(skb);
872 return 0;
873}
874
875
876static struct sock *__udp6_lib_demux_lookup(struct net *net,
877 __be16 loc_port, const struct in6_addr *loc_addr,
878 __be16 rmt_port, const struct in6_addr *rmt_addr,
879 int dif, int sdif)
880{
881 unsigned short hnum = ntohs(loc_port);
882 unsigned int hash2 = ipv6_portaddr_hash(net, loc_addr, hnum);
883 unsigned int slot2 = hash2 & udp_table.mask;
884 struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
885 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
886 struct sock *sk;
887
888 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
889 if (sk->sk_state == TCP_ESTABLISHED &&
890 INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif, sdif))
891 return sk;
892 /* Only check first socket in chain */
893 break;
894 }
895 return NULL;
896}
897
898static void udp_v6_early_demux(struct sk_buff *skb)
899{
900 struct net *net = dev_net(skb->dev);
901 const struct udphdr *uh;
902 struct sock *sk;
903 struct dst_entry *dst;
904 int dif = skb->dev->ifindex;
905 int sdif = inet6_sdif(skb);
906
907 if (!pskb_may_pull(skb, skb_transport_offset(skb) +
908 sizeof(struct udphdr)))
909 return;
910
911 uh = udp_hdr(skb);
912
913 if (skb->pkt_type == PACKET_HOST)
914 sk = __udp6_lib_demux_lookup(net, uh->dest,
915 &ipv6_hdr(skb)->daddr,
916 uh->source, &ipv6_hdr(skb)->saddr,
917 dif, sdif);
918 else
919 return;
920
921 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
922 return;
923
924 skb->sk = sk;
925 skb->destructor = sock_efree;
926 dst = READ_ONCE(sk->sk_rx_dst);
927
928 if (dst)
929 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
930 if (dst) {
931 /* set noref for now.
932 * any place which wants to hold dst has to call
933 * dst_hold_safe()
934 */
935 skb_dst_set_noref(skb, dst);
936 }
937}
938
939static __inline__ int udpv6_rcv(struct sk_buff *skb)
940{
941 return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
942}
943
944/*
945 * Throw away all pending data and cancel the corking. Socket is locked.
946 */
947static void udp_v6_flush_pending_frames(struct sock *sk)
948{
949 struct udp_sock *up = udp_sk(sk);
950
951 if (up->pending == AF_INET)
952 udp_flush_pending_frames(sk);
953 else if (up->pending) {
954 up->len = 0;
955 up->pending = 0;
956 ip6_flush_pending_frames(sk);
957 }
958}
959
960static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
961 int addr_len)
962{
963 /* The following checks are replicated from __ip6_datagram_connect()
964 * and intended to prevent BPF program called below from accessing
965 * bytes that are out of the bound specified by user in addr_len.
966 */
967 if (uaddr->sa_family == AF_INET) {
968 if (__ipv6_only_sock(sk))
969 return -EAFNOSUPPORT;
970 return udp_pre_connect(sk, uaddr, addr_len);
971 }
972
973 if (addr_len < SIN6_LEN_RFC2133)
974 return -EINVAL;
975
976 return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr);
977}
978
979/**
980 * udp6_hwcsum_outgoing - handle outgoing HW checksumming
981 * @sk: socket we are sending on
982 * @skb: sk_buff containing the filled-in UDP header
983 * (checksum field must be zeroed out)
984 */
985static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
986 const struct in6_addr *saddr,
987 const struct in6_addr *daddr, int len)
988{
989 unsigned int offset;
990 struct udphdr *uh = udp_hdr(skb);
991 struct sk_buff *frags = skb_shinfo(skb)->frag_list;
992 __wsum csum = 0;
993
994 if (!frags) {
995 /* Only one fragment on the socket. */
996 skb->csum_start = skb_transport_header(skb) - skb->head;
997 skb->csum_offset = offsetof(struct udphdr, check);
998 uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
999 } else {
1000 /*
1001 * HW-checksum won't work as there are two or more
1002 * fragments on the socket so that all csums of sk_buffs
1003 * should be together
1004 */
1005 offset = skb_transport_offset(skb);
1006 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
1007 csum = skb->csum;
1008
1009 skb->ip_summed = CHECKSUM_NONE;
1010
1011 do {
1012 csum = csum_add(csum, frags->csum);
1013 } while ((frags = frags->next));
1014
1015 uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
1016 csum);
1017 if (uh->check == 0)
1018 uh->check = CSUM_MANGLED_0;
1019 }
1020}
1021
1022/*
1023 * Sending
1024 */
1025
1026static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6)
1027{
1028 struct sock *sk = skb->sk;
1029 struct udphdr *uh;
1030 int err = 0;
1031 int is_udplite = IS_UDPLITE(sk);
1032 __wsum csum = 0;
1033 int offset = skb_transport_offset(skb);
1034 int len = skb->len - offset;
1035
1036 /*
1037 * Create a UDP header
1038 */
1039 uh = udp_hdr(skb);
1040 uh->source = fl6->fl6_sport;
1041 uh->dest = fl6->fl6_dport;
1042 uh->len = htons(len);
1043 uh->check = 0;
1044
1045 if (is_udplite)
1046 csum = udplite_csum(skb);
1047 else if (udp_sk(sk)->no_check6_tx) { /* UDP csum disabled */
1048 skb->ip_summed = CHECKSUM_NONE;
1049 goto send;
1050 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1051 udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len);
1052 goto send;
1053 } else
1054 csum = udp_csum(skb);
1055
1056 /* add protocol-dependent pseudo-header */
1057 uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
1058 len, fl6->flowi6_proto, csum);
1059 if (uh->check == 0)
1060 uh->check = CSUM_MANGLED_0;
1061
1062send:
1063 err = ip6_send_skb(skb);
1064 if (err) {
1065 if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
1066 UDP6_INC_STATS(sock_net(sk),
1067 UDP_MIB_SNDBUFERRORS, is_udplite);
1068 err = 0;
1069 }
1070 } else {
1071 UDP6_INC_STATS(sock_net(sk),
1072 UDP_MIB_OUTDATAGRAMS, is_udplite);
1073 }
1074 return err;
1075}
1076
1077static int udp_v6_push_pending_frames(struct sock *sk)
1078{
1079 struct sk_buff *skb;
1080 struct udp_sock *up = udp_sk(sk);
1081 struct flowi6 fl6;
1082 int err = 0;
1083
1084 if (up->pending == AF_INET)
1085 return udp_push_pending_frames(sk);
1086
1087 /* ip6_finish_skb will release the cork, so make a copy of
1088 * fl6 here.
1089 */
1090 fl6 = inet_sk(sk)->cork.fl.u.ip6;
1091
1092 skb = ip6_finish_skb(sk);
1093 if (!skb)
1094 goto out;
1095
1096 err = udp_v6_send_skb(skb, &fl6);
1097
1098out:
1099 up->len = 0;
1100 up->pending = 0;
1101 return err;
1102}
1103
1104int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1105{
1106 struct ipv6_txoptions opt_space;
1107 struct udp_sock *up = udp_sk(sk);
1108 struct inet_sock *inet = inet_sk(sk);
1109 struct ipv6_pinfo *np = inet6_sk(sk);
1110 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1111 struct in6_addr *daddr, *final_p, final;
1112 struct ipv6_txoptions *opt = NULL;
1113 struct ipv6_txoptions *opt_to_free = NULL;
1114 struct ip6_flowlabel *flowlabel = NULL;
1115 struct flowi6 fl6;
1116 struct dst_entry *dst;
1117 struct ipcm6_cookie ipc6;
1118 int addr_len = msg->msg_namelen;
1119 bool connected = false;
1120 int ulen = len;
1121 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
1122 int err;
1123 int is_udplite = IS_UDPLITE(sk);
1124 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1125 struct sockcm_cookie sockc;
1126
1127 ipc6.hlimit = -1;
1128 ipc6.tclass = -1;
1129 ipc6.dontfrag = -1;
1130 sockc.tsflags = sk->sk_tsflags;
1131
1132 /* destination address check */
1133 if (sin6) {
1134 if (addr_len < offsetof(struct sockaddr, sa_data))
1135 return -EINVAL;
1136
1137 switch (sin6->sin6_family) {
1138 case AF_INET6:
1139 if (addr_len < SIN6_LEN_RFC2133)
1140 return -EINVAL;
1141 daddr = &sin6->sin6_addr;
1142 if (ipv6_addr_any(daddr) &&
1143 ipv6_addr_v4mapped(&np->saddr))
1144 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
1145 daddr);
1146 break;
1147 case AF_INET:
1148 goto do_udp_sendmsg;
1149 case AF_UNSPEC:
1150 msg->msg_name = sin6 = NULL;
1151 msg->msg_namelen = addr_len = 0;
1152 daddr = NULL;
1153 break;
1154 default:
1155 return -EINVAL;
1156 }
1157 } else if (!up->pending) {
1158 if (sk->sk_state != TCP_ESTABLISHED)
1159 return -EDESTADDRREQ;
1160 daddr = &sk->sk_v6_daddr;
1161 } else
1162 daddr = NULL;
1163
1164 if (daddr) {
1165 if (ipv6_addr_v4mapped(daddr)) {
1166 struct sockaddr_in sin;
1167 sin.sin_family = AF_INET;
1168 sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1169 sin.sin_addr.s_addr = daddr->s6_addr32[3];
1170 msg->msg_name = &sin;
1171 msg->msg_namelen = sizeof(sin);
1172do_udp_sendmsg:
1173 if (__ipv6_only_sock(sk))
1174 return -ENETUNREACH;
1175 return udp_sendmsg(sk, msg, len);
1176 }
1177 }
1178
1179 if (up->pending == AF_INET)
1180 return udp_sendmsg(sk, msg, len);
1181
1182 /* Rough check on arithmetic overflow,
1183 better check is made in ip6_append_data().
1184 */
1185 if (len > INT_MAX - sizeof(struct udphdr))
1186 return -EMSGSIZE;
1187
1188 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
1189 if (up->pending) {
1190 /*
1191 * There are pending frames.
1192 * The socket lock must be held while it's corked.
1193 */
1194 lock_sock(sk);
1195 if (likely(up->pending)) {
1196 if (unlikely(up->pending != AF_INET6)) {
1197 release_sock(sk);
1198 return -EAFNOSUPPORT;
1199 }
1200 dst = NULL;
1201 goto do_append_data;
1202 }
1203 release_sock(sk);
1204 }
1205 ulen += sizeof(struct udphdr);
1206
1207 memset(&fl6, 0, sizeof(fl6));
1208
1209 if (sin6) {
1210 if (sin6->sin6_port == 0)
1211 return -EINVAL;
1212
1213 fl6.fl6_dport = sin6->sin6_port;
1214 daddr = &sin6->sin6_addr;
1215
1216 if (np->sndflow) {
1217 fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1218 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
1219 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1220 if (!flowlabel)
1221 return -EINVAL;
1222 }
1223 }
1224
1225 /*
1226 * Otherwise it will be difficult to maintain
1227 * sk->sk_dst_cache.
1228 */
1229 if (sk->sk_state == TCP_ESTABLISHED &&
1230 ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
1231 daddr = &sk->sk_v6_daddr;
1232
1233 if (addr_len >= sizeof(struct sockaddr_in6) &&
1234 sin6->sin6_scope_id &&
1235 __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1236 fl6.flowi6_oif = sin6->sin6_scope_id;
1237 } else {
1238 if (sk->sk_state != TCP_ESTABLISHED)
1239 return -EDESTADDRREQ;
1240
1241 fl6.fl6_dport = inet->inet_dport;
1242 daddr = &sk->sk_v6_daddr;
1243 fl6.flowlabel = np->flow_label;
1244 connected = true;
1245 }
1246
1247 if (!fl6.flowi6_oif)
1248 fl6.flowi6_oif = sk->sk_bound_dev_if;
1249
1250 if (!fl6.flowi6_oif)
1251 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1252
1253 fl6.flowi6_mark = sk->sk_mark;
1254 fl6.flowi6_uid = sk->sk_uid;
1255
1256 if (msg->msg_controllen) {
1257 opt = &opt_space;
1258 memset(opt, 0, sizeof(struct ipv6_txoptions));
1259 opt->tot_len = sizeof(*opt);
1260 ipc6.opt = opt;
1261
1262 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, &sockc);
1263 if (err < 0) {
1264 fl6_sock_release(flowlabel);
1265 return err;
1266 }
1267 if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1268 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1269 if (!flowlabel)
1270 return -EINVAL;
1271 }
1272 if (!(opt->opt_nflen|opt->opt_flen))
1273 opt = NULL;
1274 connected = false;
1275 }
1276 if (!opt) {
1277 opt = txopt_get(np);
1278 opt_to_free = opt;
1279 }
1280 if (flowlabel)
1281 opt = fl6_merge_options(&opt_space, flowlabel, opt);
1282 opt = ipv6_fixup_options(&opt_space, opt);
1283 ipc6.opt = opt;
1284
1285 fl6.flowi6_proto = sk->sk_protocol;
1286 if (!ipv6_addr_any(daddr))
1287 fl6.daddr = *daddr;
1288 else
1289 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1290 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
1291 fl6.saddr = np->saddr;
1292 fl6.fl6_sport = inet->inet_sport;
1293
1294 final_p = fl6_update_dst(&fl6, opt, &final);
1295 if (final_p)
1296 connected = false;
1297
1298 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
1299 fl6.flowi6_oif = np->mcast_oif;
1300 connected = false;
1301 } else if (!fl6.flowi6_oif)
1302 fl6.flowi6_oif = np->ucast_oif;
1303
1304 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
1305
1306 if (ipc6.tclass < 0)
1307 ipc6.tclass = np->tclass;
1308
1309 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
1310
1311 dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, connected);
1312 if (IS_ERR(dst)) {
1313 err = PTR_ERR(dst);
1314 dst = NULL;
1315 goto out;
1316 }
1317
1318 if (ipc6.hlimit < 0)
1319 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
1320
1321 if (msg->msg_flags&MSG_CONFIRM)
1322 goto do_confirm;
1323back_from_confirm:
1324
1325 /* Lockless fast path for the non-corking case */
1326 if (!corkreq) {
1327 struct sk_buff *skb;
1328
1329 skb = ip6_make_skb(sk, getfrag, msg, ulen,
1330 sizeof(struct udphdr), &ipc6,
1331 &fl6, (struct rt6_info *)dst,
1332 msg->msg_flags, &sockc);
1333 err = PTR_ERR(skb);
1334 if (!IS_ERR_OR_NULL(skb))
1335 err = udp_v6_send_skb(skb, &fl6);
1336 goto out;
1337 }
1338
1339 lock_sock(sk);
1340 if (unlikely(up->pending)) {
1341 /* The socket is already corked while preparing it. */
1342 /* ... which is an evident application bug. --ANK */
1343 release_sock(sk);
1344
1345 net_dbg_ratelimited("udp cork app bug 2\n");
1346 err = -EINVAL;
1347 goto out;
1348 }
1349
1350 up->pending = AF_INET6;
1351
1352do_append_data:
1353 if (ipc6.dontfrag < 0)
1354 ipc6.dontfrag = np->dontfrag;
1355 up->len += ulen;
1356 err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr),
1357 &ipc6, &fl6, (struct rt6_info *)dst,
1358 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags, &sockc);
1359 if (err)
1360 udp_v6_flush_pending_frames(sk);
1361 else if (!corkreq)
1362 err = udp_v6_push_pending_frames(sk);
1363 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1364 up->pending = 0;
1365
1366 if (err > 0)
1367 err = np->recverr ? net_xmit_errno(err) : 0;
1368 release_sock(sk);
1369
1370out:
1371 dst_release(dst);
1372 fl6_sock_release(flowlabel);
1373 txopt_put(opt_to_free);
1374 if (!err)
1375 return len;
1376 /*
1377 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1378 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1379 * we don't have a good statistic (IpOutDiscards but it can be too many
1380 * things). We could add another new stat but at least for now that
1381 * seems like overkill.
1382 */
1383 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1384 UDP6_INC_STATS(sock_net(sk),
1385 UDP_MIB_SNDBUFERRORS, is_udplite);
1386 }
1387 return err;
1388
1389do_confirm:
1390 if (msg->msg_flags & MSG_PROBE)
1391 dst_confirm_neigh(dst, &fl6.daddr);
1392 if (!(msg->msg_flags&MSG_PROBE) || len)
1393 goto back_from_confirm;
1394 err = 0;
1395 goto out;
1396}
1397
1398void udpv6_destroy_sock(struct sock *sk)
1399{
1400 struct udp_sock *up = udp_sk(sk);
1401 lock_sock(sk);
1402 udp_v6_flush_pending_frames(sk);
1403 release_sock(sk);
1404
1405 if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
1406 void (*encap_destroy)(struct sock *sk);
1407 encap_destroy = READ_ONCE(up->encap_destroy);
1408 if (encap_destroy)
1409 encap_destroy(sk);
1410 }
1411
1412 inet6_destroy_sock(sk);
1413}
1414
1415/*
1416 * Socket option code for UDP
1417 */
1418int udpv6_setsockopt(struct sock *sk, int level, int optname,
1419 char __user *optval, unsigned int optlen)
1420{
1421 if (level == SOL_UDP || level == SOL_UDPLITE)
1422 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1423 udp_v6_push_pending_frames);
1424 return ipv6_setsockopt(sk, level, optname, optval, optlen);
1425}
1426
1427#ifdef CONFIG_COMPAT
1428int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
1429 char __user *optval, unsigned int optlen)
1430{
1431 if (level == SOL_UDP || level == SOL_UDPLITE)
1432 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1433 udp_v6_push_pending_frames);
1434 return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
1435}
1436#endif
1437
1438int udpv6_getsockopt(struct sock *sk, int level, int optname,
1439 char __user *optval, int __user *optlen)
1440{
1441 if (level == SOL_UDP || level == SOL_UDPLITE)
1442 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1443 return ipv6_getsockopt(sk, level, optname, optval, optlen);
1444}
1445
1446#ifdef CONFIG_COMPAT
1447int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
1448 char __user *optval, int __user *optlen)
1449{
1450 if (level == SOL_UDP || level == SOL_UDPLITE)
1451 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1452 return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
1453}
1454#endif
1455
1456/* thinking of making this const? Don't.
1457 * early_demux can change based on sysctl.
1458 */
1459static struct inet6_protocol udpv6_protocol = {
1460 .early_demux = udp_v6_early_demux,
1461 .early_demux_handler = udp_v6_early_demux,
1462 .handler = udpv6_rcv,
1463 .err_handler = udpv6_err,
1464 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1465};
1466
1467/* ------------------------------------------------------------------------ */
1468#ifdef CONFIG_PROC_FS
1469int udp6_seq_show(struct seq_file *seq, void *v)
1470{
1471 if (v == SEQ_START_TOKEN) {
1472 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1473 } else {
1474 int bucket = ((struct udp_iter_state *)seq->private)->bucket;
1475 struct inet_sock *inet = inet_sk(v);
1476 __u16 srcp = ntohs(inet->inet_sport);
1477 __u16 destp = ntohs(inet->inet_dport);
1478 ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket);
1479 }
1480 return 0;
1481}
1482
1483static const struct file_operations udp6_afinfo_seq_fops = {
1484 .open = udp_seq_open,
1485 .read = seq_read,
1486 .llseek = seq_lseek,
1487 .release = seq_release_net
1488};
1489
1490static struct udp_seq_afinfo udp6_seq_afinfo = {
1491 .name = "udp6",
1492 .family = AF_INET6,
1493 .udp_table = &udp_table,
1494 .seq_fops = &udp6_afinfo_seq_fops,
1495 .seq_ops = {
1496 .show = udp6_seq_show,
1497 },
1498};
1499
1500int __net_init udp6_proc_init(struct net *net)
1501{
1502 return udp_proc_register(net, &udp6_seq_afinfo);
1503}
1504
1505void udp6_proc_exit(struct net *net)
1506{
1507 udp_proc_unregister(net, &udp6_seq_afinfo);
1508}
1509#endif /* CONFIG_PROC_FS */
1510
1511/* ------------------------------------------------------------------------ */
1512
1513struct proto udpv6_prot = {
1514 .name = "UDPv6",
1515 .owner = THIS_MODULE,
1516 .close = udp_lib_close,
1517 .pre_connect = udpv6_pre_connect,
1518 .connect = ip6_datagram_connect,
1519 .disconnect = udp_disconnect,
1520 .ioctl = udp_ioctl,
1521 .init = udp_init_sock,
1522 .destroy = udpv6_destroy_sock,
1523 .setsockopt = udpv6_setsockopt,
1524 .getsockopt = udpv6_getsockopt,
1525 .sendmsg = udpv6_sendmsg,
1526 .recvmsg = udpv6_recvmsg,
1527 .release_cb = ip6_datagram_release_cb,
1528 .hash = udp_lib_hash,
1529 .unhash = udp_lib_unhash,
1530 .rehash = udp_v6_rehash,
1531 .get_port = udp_v6_get_port,
1532 .memory_allocated = &udp_memory_allocated,
1533 .sysctl_mem = sysctl_udp_mem,
1534 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
1535 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
1536 .obj_size = sizeof(struct udp6_sock),
1537 .h.udp_table = &udp_table,
1538#ifdef CONFIG_COMPAT
1539 .compat_setsockopt = compat_udpv6_setsockopt,
1540 .compat_getsockopt = compat_udpv6_getsockopt,
1541#endif
1542 .diag_destroy = udp_abort,
1543};
1544
1545static struct inet_protosw udpv6_protosw = {
1546 .type = SOCK_DGRAM,
1547 .protocol = IPPROTO_UDP,
1548 .prot = &udpv6_prot,
1549 .ops = &inet6_dgram_ops,
1550 .flags = INET_PROTOSW_PERMANENT,
1551};
1552
1553int __init udpv6_init(void)
1554{
1555 int ret;
1556
1557 ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1558 if (ret)
1559 goto out;
1560
1561 ret = inet6_register_protosw(&udpv6_protosw);
1562 if (ret)
1563 goto out_udpv6_protocol;
1564out:
1565 return ret;
1566
1567out_udpv6_protocol:
1568 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1569 goto out;
1570}
1571
1572void udpv6_exit(void)
1573{
1574 inet6_unregister_protosw(&udpv6_protosw);
1575 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1576}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * UDP over IPv6
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 *
9 * Based on linux/ipv4/udp.c
10 *
11 * Fixes:
12 * Hideaki YOSHIFUJI : sin6_scope_id support
13 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
14 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
15 * a single port at the same time.
16 * Kazunori MIYAZAWA @USAGI: change process style to use ip6_append_data
17 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/udp6 to seq_file.
18 */
19
20#include <linux/bpf-cgroup.h>
21#include <linux/errno.h>
22#include <linux/types.h>
23#include <linux/socket.h>
24#include <linux/sockios.h>
25#include <linux/net.h>
26#include <linux/in6.h>
27#include <linux/netdevice.h>
28#include <linux/if_arp.h>
29#include <linux/ipv6.h>
30#include <linux/icmpv6.h>
31#include <linux/init.h>
32#include <linux/module.h>
33#include <linux/skbuff.h>
34#include <linux/slab.h>
35#include <linux/uaccess.h>
36#include <linux/indirect_call_wrapper.h>
37#include <trace/events/udp.h>
38
39#include <net/addrconf.h>
40#include <net/ndisc.h>
41#include <net/protocol.h>
42#include <net/transp_v6.h>
43#include <net/ip6_route.h>
44#include <net/raw.h>
45#include <net/seg6.h>
46#include <net/tcp_states.h>
47#include <net/ip6_checksum.h>
48#include <net/ip6_tunnel.h>
49#include <net/xfrm.h>
50#include <net/inet_hashtables.h>
51#include <net/inet6_hashtables.h>
52#include <net/busy_poll.h>
53#include <net/sock_reuseport.h>
54#include <net/gro.h>
55
56#include <linux/proc_fs.h>
57#include <linux/seq_file.h>
58#include <trace/events/skb.h>
59#include "udp_impl.h"
60
61static void udpv6_destruct_sock(struct sock *sk)
62{
63 udp_destruct_common(sk);
64 inet6_sock_destruct(sk);
65}
66
67int udpv6_init_sock(struct sock *sk)
68{
69 udp_lib_init_sock(sk);
70 sk->sk_destruct = udpv6_destruct_sock;
71 set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
72 return 0;
73}
74
75INDIRECT_CALLABLE_SCOPE
76u32 udp6_ehashfn(const struct net *net,
77 const struct in6_addr *laddr,
78 const u16 lport,
79 const struct in6_addr *faddr,
80 const __be16 fport)
81{
82 u32 lhash, fhash;
83
84 net_get_random_once(&udp6_ehash_secret,
85 sizeof(udp6_ehash_secret));
86 net_get_random_once(&udp_ipv6_hash_secret,
87 sizeof(udp_ipv6_hash_secret));
88
89 lhash = (__force u32)laddr->s6_addr32[3];
90 fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret);
91
92 return __inet6_ehashfn(lhash, lport, fhash, fport,
93 udp6_ehash_secret + net_hash_mix(net));
94}
95
96int udp_v6_get_port(struct sock *sk, unsigned short snum)
97{
98 unsigned int hash2_nulladdr =
99 ipv6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
100 unsigned int hash2_partial =
101 ipv6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
102
103 /* precompute partial secondary hash */
104 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
105 return udp_lib_get_port(sk, snum, hash2_nulladdr);
106}
107
108void udp_v6_rehash(struct sock *sk)
109{
110 u16 new_hash = ipv6_portaddr_hash(sock_net(sk),
111 &sk->sk_v6_rcv_saddr,
112 inet_sk(sk)->inet_num);
113 u16 new_hash4;
114
115 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr)) {
116 new_hash4 = udp_ehashfn(sock_net(sk),
117 sk->sk_rcv_saddr, sk->sk_num,
118 sk->sk_daddr, sk->sk_dport);
119 } else {
120 new_hash4 = udp6_ehashfn(sock_net(sk),
121 &sk->sk_v6_rcv_saddr, sk->sk_num,
122 &sk->sk_v6_daddr, sk->sk_dport);
123 }
124
125 udp_lib_rehash(sk, new_hash, new_hash4);
126}
127
128static int compute_score(struct sock *sk, const struct net *net,
129 const struct in6_addr *saddr, __be16 sport,
130 const struct in6_addr *daddr, unsigned short hnum,
131 int dif, int sdif)
132{
133 int bound_dev_if, score;
134 struct inet_sock *inet;
135 bool dev_match;
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 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
143 return -1;
144
145 score = 0;
146 inet = inet_sk(sk);
147
148 if (inet->inet_dport) {
149 if (inet->inet_dport != sport)
150 return -1;
151 score++;
152 }
153
154 if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
155 if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
156 return -1;
157 score++;
158 }
159
160 bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
161 dev_match = udp_sk_bound_dev_eq(net, bound_dev_if, dif, sdif);
162 if (!dev_match)
163 return -1;
164 if (bound_dev_if)
165 score++;
166
167 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
168 score++;
169
170 return score;
171}
172
173/**
174 * udp6_lib_lookup1() - Simplified lookup using primary hash (destination port)
175 * @net: Network namespace
176 * @saddr: Source address, network order
177 * @sport: Source port, network order
178 * @daddr: Destination address, network order
179 * @hnum: Destination port, host order
180 * @dif: Destination interface index
181 * @sdif: Destination bridge port index, if relevant
182 * @udptable: Set of UDP hash tables
183 *
184 * Simplified lookup to be used as fallback if no sockets are found due to a
185 * potential race between (receive) address change, and lookup happening before
186 * the rehash operation. This function ignores SO_REUSEPORT groups while scoring
187 * result sockets, because if we have one, we don't need the fallback at all.
188 *
189 * Called under rcu_read_lock().
190 *
191 * Return: socket with highest matching score if any, NULL if none
192 */
193static struct sock *udp6_lib_lookup1(const struct net *net,
194 const struct in6_addr *saddr, __be16 sport,
195 const struct in6_addr *daddr,
196 unsigned int hnum, int dif, int sdif,
197 const struct udp_table *udptable)
198{
199 unsigned int slot = udp_hashfn(net, hnum, udptable->mask);
200 struct udp_hslot *hslot = &udptable->hash[slot];
201 struct sock *sk, *result = NULL;
202 int score, badness = 0;
203
204 sk_for_each_rcu(sk, &hslot->head) {
205 score = compute_score(sk, net,
206 saddr, sport, daddr, hnum, dif, sdif);
207 if (score > badness) {
208 result = sk;
209 badness = score;
210 }
211 }
212
213 return result;
214}
215
216/* called with rcu_read_lock() */
217static struct sock *udp6_lib_lookup2(const struct net *net,
218 const struct in6_addr *saddr, __be16 sport,
219 const struct in6_addr *daddr, unsigned int hnum,
220 int dif, int sdif, struct udp_hslot *hslot2,
221 struct sk_buff *skb)
222{
223 struct sock *sk, *result;
224 int score, badness;
225 bool need_rescore;
226
227 result = NULL;
228 badness = -1;
229 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
230 need_rescore = false;
231rescore:
232 score = compute_score(need_rescore ? result : sk, net, saddr,
233 sport, daddr, hnum, dif, sdif);
234 if (score > badness) {
235 badness = score;
236
237 if (need_rescore)
238 continue;
239
240 if (sk->sk_state == TCP_ESTABLISHED) {
241 result = sk;
242 continue;
243 }
244
245 result = inet6_lookup_reuseport(net, sk, skb, sizeof(struct udphdr),
246 saddr, sport, daddr, hnum, udp6_ehashfn);
247 if (!result) {
248 result = sk;
249 continue;
250 }
251
252 /* Fall back to scoring if group has connections */
253 if (!reuseport_has_conns(sk))
254 return result;
255
256 /* Reuseport logic returned an error, keep original score. */
257 if (IS_ERR(result))
258 continue;
259
260 /* compute_score is too long of a function to be
261 * inlined, and calling it again here yields
262 * measureable overhead for some
263 * workloads. Work around it by jumping
264 * backwards to rescore 'result'.
265 */
266 need_rescore = true;
267 goto rescore;
268 }
269 }
270 return result;
271}
272
273#if IS_ENABLED(CONFIG_BASE_SMALL)
274static struct sock *udp6_lib_lookup4(const struct net *net,
275 const struct in6_addr *saddr, __be16 sport,
276 const struct in6_addr *daddr,
277 unsigned int hnum, int dif, int sdif,
278 struct udp_table *udptable)
279{
280 return NULL;
281}
282
283static void udp6_hash4(struct sock *sk)
284{
285}
286#else /* !CONFIG_BASE_SMALL */
287static struct sock *udp6_lib_lookup4(const struct net *net,
288 const struct in6_addr *saddr, __be16 sport,
289 const struct in6_addr *daddr,
290 unsigned int hnum, int dif, int sdif,
291 struct udp_table *udptable)
292{
293 const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
294 const struct hlist_nulls_node *node;
295 struct udp_hslot *hslot4;
296 unsigned int hash4, slot;
297 struct udp_sock *up;
298 struct sock *sk;
299
300 hash4 = udp6_ehashfn(net, daddr, hnum, saddr, sport);
301 slot = hash4 & udptable->mask;
302 hslot4 = &udptable->hash4[slot];
303
304begin:
305 udp_lrpa_for_each_entry_rcu(up, node, &hslot4->nulls_head) {
306 sk = (struct sock *)up;
307 if (inet6_match(net, sk, saddr, daddr, ports, dif, sdif))
308 return sk;
309 }
310
311 /* if the nulls value we got at the end of this lookup is not the
312 * expected one, we must restart lookup. We probably met an item that
313 * was moved to another chain due to rehash.
314 */
315 if (get_nulls_value(node) != slot)
316 goto begin;
317
318 return NULL;
319}
320
321static void udp6_hash4(struct sock *sk)
322{
323 struct net *net = sock_net(sk);
324 unsigned int hash;
325
326 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr)) {
327 udp4_hash4(sk);
328 return;
329 }
330
331 if (sk_unhashed(sk) || ipv6_addr_any(&sk->sk_v6_rcv_saddr))
332 return;
333
334 hash = udp6_ehashfn(net, &sk->sk_v6_rcv_saddr, sk->sk_num,
335 &sk->sk_v6_daddr, sk->sk_dport);
336
337 udp_lib_hash4(sk, hash);
338}
339#endif /* CONFIG_BASE_SMALL */
340
341/* rcu_read_lock() must be held */
342struct sock *__udp6_lib_lookup(const struct net *net,
343 const struct in6_addr *saddr, __be16 sport,
344 const struct in6_addr *daddr, __be16 dport,
345 int dif, int sdif, struct udp_table *udptable,
346 struct sk_buff *skb)
347{
348 unsigned short hnum = ntohs(dport);
349 struct udp_hslot *hslot2;
350 struct sock *result, *sk;
351 unsigned int hash2;
352
353 hash2 = ipv6_portaddr_hash(net, daddr, hnum);
354 hslot2 = udp_hashslot2(udptable, hash2);
355
356 if (udp_has_hash4(hslot2)) {
357 result = udp6_lib_lookup4(net, saddr, sport, daddr, hnum,
358 dif, sdif, udptable);
359 if (result) /* udp6_lib_lookup4 return sk or NULL */
360 return result;
361 }
362
363 /* Lookup connected or non-wildcard sockets */
364 result = udp6_lib_lookup2(net, saddr, sport,
365 daddr, hnum, dif, sdif,
366 hslot2, skb);
367 if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED)
368 goto done;
369
370 /* Lookup redirect from BPF */
371 if (static_branch_unlikely(&bpf_sk_lookup_enabled) &&
372 udptable == net->ipv4.udp_table) {
373 sk = inet6_lookup_run_sk_lookup(net, IPPROTO_UDP, skb, sizeof(struct udphdr),
374 saddr, sport, daddr, hnum, dif,
375 udp6_ehashfn);
376 if (sk) {
377 result = sk;
378 goto done;
379 }
380 }
381
382 /* Got non-wildcard socket or error on first lookup */
383 if (result)
384 goto done;
385
386 /* Lookup wildcard sockets */
387 hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
388 hslot2 = udp_hashslot2(udptable, hash2);
389
390 result = udp6_lib_lookup2(net, saddr, sport,
391 &in6addr_any, hnum, dif, sdif,
392 hslot2, skb);
393 if (!IS_ERR_OR_NULL(result))
394 goto done;
395
396 /* Cover address change/lookup/rehash race: see __udp4_lib_lookup() */
397 result = udp6_lib_lookup1(net, saddr, sport, daddr, hnum, dif, sdif,
398 udptable);
399
400done:
401 if (IS_ERR(result))
402 return NULL;
403 return result;
404}
405EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
406
407static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
408 __be16 sport, __be16 dport,
409 struct udp_table *udptable)
410{
411 const struct ipv6hdr *iph = ipv6_hdr(skb);
412
413 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
414 &iph->daddr, dport, inet6_iif(skb),
415 inet6_sdif(skb), udptable, skb);
416}
417
418struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb,
419 __be16 sport, __be16 dport)
420{
421 const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation];
422 const struct ipv6hdr *iph = (struct ipv6hdr *)(skb->data + offset);
423 struct net *net = dev_net(skb->dev);
424 int iif, sdif;
425
426 inet6_get_iif_sdif(skb, &iif, &sdif);
427
428 return __udp6_lib_lookup(net, &iph->saddr, sport,
429 &iph->daddr, dport, iif,
430 sdif, net->ipv4.udp_table, NULL);
431}
432
433/* Must be called under rcu_read_lock().
434 * Does increment socket refcount.
435 */
436#if IS_ENABLED(CONFIG_NF_TPROXY_IPV6) || IS_ENABLED(CONFIG_NF_SOCKET_IPV6)
437struct sock *udp6_lib_lookup(const struct net *net, const struct in6_addr *saddr, __be16 sport,
438 const struct in6_addr *daddr, __be16 dport, int dif)
439{
440 struct sock *sk;
441
442 sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport,
443 dif, 0, net->ipv4.udp_table, NULL);
444 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
445 sk = NULL;
446 return sk;
447}
448EXPORT_SYMBOL_GPL(udp6_lib_lookup);
449#endif
450
451/* do not use the scratch area len for jumbogram: their length execeeds the
452 * scratch area space; note that the IP6CB flags is still in the first
453 * cacheline, so checking for jumbograms is cheap
454 */
455static int udp6_skb_len(struct sk_buff *skb)
456{
457 return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb);
458}
459
460/*
461 * This should be easy, if there is something there we
462 * return it, otherwise we block.
463 */
464
465int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
466 int flags, int *addr_len)
467{
468 struct ipv6_pinfo *np = inet6_sk(sk);
469 struct inet_sock *inet = inet_sk(sk);
470 struct sk_buff *skb;
471 unsigned int ulen, copied;
472 int off, err, peeking = flags & MSG_PEEK;
473 int is_udplite = IS_UDPLITE(sk);
474 struct udp_mib __percpu *mib;
475 bool checksum_valid = false;
476 int is_udp4;
477
478 if (flags & MSG_ERRQUEUE)
479 return ipv6_recv_error(sk, msg, len, addr_len);
480
481 if (np->rxpmtu && np->rxopt.bits.rxpmtu)
482 return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
483
484try_again:
485 off = sk_peek_offset(sk, flags);
486 skb = __skb_recv_udp(sk, flags, &off, &err);
487 if (!skb)
488 return err;
489
490 ulen = udp6_skb_len(skb);
491 copied = len;
492 if (copied > ulen - off)
493 copied = ulen - off;
494 else if (copied < ulen)
495 msg->msg_flags |= MSG_TRUNC;
496
497 is_udp4 = (skb->protocol == htons(ETH_P_IP));
498 mib = __UDPX_MIB(sk, is_udp4);
499
500 /*
501 * If checksum is needed at all, try to do it while copying the
502 * data. If the data is truncated, or if we only want a partial
503 * coverage checksum (UDP-Lite), do it before the copy.
504 */
505
506 if (copied < ulen || peeking ||
507 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
508 checksum_valid = udp_skb_csum_unnecessary(skb) ||
509 !__udp_lib_checksum_complete(skb);
510 if (!checksum_valid)
511 goto csum_copy_err;
512 }
513
514 if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
515 if (udp_skb_is_linear(skb))
516 err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
517 else
518 err = skb_copy_datagram_msg(skb, off, msg, copied);
519 } else {
520 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
521 if (err == -EINVAL)
522 goto csum_copy_err;
523 }
524 if (unlikely(err)) {
525 if (!peeking) {
526 atomic_inc(&sk->sk_drops);
527 SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
528 }
529 kfree_skb(skb);
530 return err;
531 }
532 if (!peeking)
533 SNMP_INC_STATS(mib, UDP_MIB_INDATAGRAMS);
534
535 sock_recv_cmsgs(msg, sk, skb);
536
537 /* Copy the address. */
538 if (msg->msg_name) {
539 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
540 sin6->sin6_family = AF_INET6;
541 sin6->sin6_port = udp_hdr(skb)->source;
542 sin6->sin6_flowinfo = 0;
543
544 if (is_udp4) {
545 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
546 &sin6->sin6_addr);
547 sin6->sin6_scope_id = 0;
548 } else {
549 sin6->sin6_addr = ipv6_hdr(skb)->saddr;
550 sin6->sin6_scope_id =
551 ipv6_iface_scope_id(&sin6->sin6_addr,
552 inet6_iif(skb));
553 }
554 *addr_len = sizeof(*sin6);
555
556 BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk,
557 (struct sockaddr *)sin6,
558 addr_len);
559 }
560
561 if (udp_test_bit(GRO_ENABLED, sk))
562 udp_cmsg_recv(msg, sk, skb);
563
564 if (np->rxopt.all)
565 ip6_datagram_recv_common_ctl(sk, msg, skb);
566
567 if (is_udp4) {
568 if (inet_cmsg_flags(inet))
569 ip_cmsg_recv_offset(msg, sk, skb,
570 sizeof(struct udphdr), off);
571 } else {
572 if (np->rxopt.all)
573 ip6_datagram_recv_specific_ctl(sk, msg, skb);
574 }
575
576 err = copied;
577 if (flags & MSG_TRUNC)
578 err = ulen;
579
580 skb_consume_udp(sk, skb, peeking ? -err : err);
581 return err;
582
583csum_copy_err:
584 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
585 udp_skb_destructor)) {
586 SNMP_INC_STATS(mib, UDP_MIB_CSUMERRORS);
587 SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
588 }
589 kfree_skb(skb);
590
591 /* starting over for a new packet, but check if we need to yield */
592 cond_resched();
593 msg->msg_flags &= ~MSG_TRUNC;
594 goto try_again;
595}
596
597DECLARE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
598void udpv6_encap_enable(void)
599{
600 static_branch_inc(&udpv6_encap_needed_key);
601}
602EXPORT_SYMBOL(udpv6_encap_enable);
603
604/* Handler for tunnels with arbitrary destination ports: no socket lookup, go
605 * through error handlers in encapsulations looking for a match.
606 */
607static int __udp6_lib_err_encap_no_sk(struct sk_buff *skb,
608 struct inet6_skb_parm *opt,
609 u8 type, u8 code, int offset, __be32 info)
610{
611 int i;
612
613 for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
614 int (*handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
615 u8 type, u8 code, int offset, __be32 info);
616 const struct ip6_tnl_encap_ops *encap;
617
618 encap = rcu_dereference(ip6tun_encaps[i]);
619 if (!encap)
620 continue;
621 handler = encap->err_handler;
622 if (handler && !handler(skb, opt, type, code, offset, info))
623 return 0;
624 }
625
626 return -ENOENT;
627}
628
629/* Try to match ICMP errors to UDP tunnels by looking up a socket without
630 * reversing source and destination port: this will match tunnels that force the
631 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
632 * lwtunnels might actually break this assumption by being configured with
633 * different destination ports on endpoints, in this case we won't be able to
634 * trace ICMP messages back to them.
635 *
636 * If this doesn't match any socket, probe tunnels with arbitrary destination
637 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
638 * we've sent packets to won't necessarily match the local destination port.
639 *
640 * Then ask the tunnel implementation to match the error against a valid
641 * association.
642 *
643 * Return an error if we can't find a match, the socket if we need further
644 * processing, zero otherwise.
645 */
646static struct sock *__udp6_lib_err_encap(struct net *net,
647 const struct ipv6hdr *hdr, int offset,
648 struct udphdr *uh,
649 struct udp_table *udptable,
650 struct sock *sk,
651 struct sk_buff *skb,
652 struct inet6_skb_parm *opt,
653 u8 type, u8 code, __be32 info)
654{
655 int (*lookup)(struct sock *sk, struct sk_buff *skb);
656 int network_offset, transport_offset;
657 struct udp_sock *up;
658
659 network_offset = skb_network_offset(skb);
660 transport_offset = skb_transport_offset(skb);
661
662 /* Network header needs to point to the outer IPv6 header inside ICMP */
663 skb_reset_network_header(skb);
664
665 /* Transport header needs to point to the UDP header */
666 skb_set_transport_header(skb, offset);
667
668 if (sk) {
669 up = udp_sk(sk);
670
671 lookup = READ_ONCE(up->encap_err_lookup);
672 if (lookup && lookup(sk, skb))
673 sk = NULL;
674
675 goto out;
676 }
677
678 sk = __udp6_lib_lookup(net, &hdr->daddr, uh->source,
679 &hdr->saddr, uh->dest,
680 inet6_iif(skb), 0, udptable, skb);
681 if (sk) {
682 up = udp_sk(sk);
683
684 lookup = READ_ONCE(up->encap_err_lookup);
685 if (!lookup || lookup(sk, skb))
686 sk = NULL;
687 }
688
689out:
690 if (!sk) {
691 sk = ERR_PTR(__udp6_lib_err_encap_no_sk(skb, opt, type, code,
692 offset, info));
693 }
694
695 skb_set_transport_header(skb, transport_offset);
696 skb_set_network_header(skb, network_offset);
697
698 return sk;
699}
700
701int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
702 u8 type, u8 code, int offset, __be32 info,
703 struct udp_table *udptable)
704{
705 struct ipv6_pinfo *np;
706 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
707 const struct in6_addr *saddr = &hdr->saddr;
708 const struct in6_addr *daddr = seg6_get_daddr(skb, opt) ? : &hdr->daddr;
709 struct udphdr *uh = (struct udphdr *)(skb->data+offset);
710 bool tunnel = false;
711 struct sock *sk;
712 int harderr;
713 int err;
714 struct net *net = dev_net(skb->dev);
715
716 sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
717 inet6_iif(skb), inet6_sdif(skb), udptable, NULL);
718
719 if (!sk || READ_ONCE(udp_sk(sk)->encap_type)) {
720 /* No socket for error: try tunnels before discarding */
721 if (static_branch_unlikely(&udpv6_encap_needed_key)) {
722 sk = __udp6_lib_err_encap(net, hdr, offset, uh,
723 udptable, sk, skb,
724 opt, type, code, info);
725 if (!sk)
726 return 0;
727 } else
728 sk = ERR_PTR(-ENOENT);
729
730 if (IS_ERR(sk)) {
731 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
732 ICMP6_MIB_INERRORS);
733 return PTR_ERR(sk);
734 }
735
736 tunnel = true;
737 }
738
739 harderr = icmpv6_err_convert(type, code, &err);
740 np = inet6_sk(sk);
741
742 if (type == ICMPV6_PKT_TOOBIG) {
743 if (!ip6_sk_accept_pmtu(sk))
744 goto out;
745 ip6_sk_update_pmtu(skb, sk, info);
746 if (READ_ONCE(np->pmtudisc) != IPV6_PMTUDISC_DONT)
747 harderr = 1;
748 }
749 if (type == NDISC_REDIRECT) {
750 if (tunnel) {
751 ip6_redirect(skb, sock_net(sk), inet6_iif(skb),
752 READ_ONCE(sk->sk_mark), sk->sk_uid);
753 } else {
754 ip6_sk_redirect(skb, sk);
755 }
756 goto out;
757 }
758
759 /* Tunnels don't have an application socket: don't pass errors back */
760 if (tunnel) {
761 if (udp_sk(sk)->encap_err_rcv)
762 udp_sk(sk)->encap_err_rcv(sk, skb, err, uh->dest,
763 ntohl(info), (u8 *)(uh+1));
764 goto out;
765 }
766
767 if (!inet6_test_bit(RECVERR6, sk)) {
768 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
769 goto out;
770 } else {
771 ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
772 }
773
774 sk->sk_err = err;
775 sk_error_report(sk);
776out:
777 return 0;
778}
779
780static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
781{
782 int rc;
783
784 if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
785 sock_rps_save_rxhash(sk, skb);
786 sk_mark_napi_id(sk, skb);
787 sk_incoming_cpu_update(sk);
788 } else {
789 sk_mark_napi_id_once(sk, skb);
790 }
791
792 rc = __udp_enqueue_schedule_skb(sk, skb);
793 if (rc < 0) {
794 int is_udplite = IS_UDPLITE(sk);
795 enum skb_drop_reason drop_reason;
796
797 /* Note that an ENOMEM error is charged twice */
798 if (rc == -ENOMEM) {
799 UDP6_INC_STATS(sock_net(sk),
800 UDP_MIB_RCVBUFERRORS, is_udplite);
801 drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
802 } else {
803 UDP6_INC_STATS(sock_net(sk),
804 UDP_MIB_MEMERRORS, is_udplite);
805 drop_reason = SKB_DROP_REASON_PROTO_MEM;
806 }
807 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
808 trace_udp_fail_queue_rcv_skb(rc, sk, skb);
809 sk_skb_reason_drop(sk, skb, drop_reason);
810 return -1;
811 }
812
813 return 0;
814}
815
816static __inline__ int udpv6_err(struct sk_buff *skb,
817 struct inet6_skb_parm *opt, u8 type,
818 u8 code, int offset, __be32 info)
819{
820 return __udp6_lib_err(skb, opt, type, code, offset, info,
821 dev_net(skb->dev)->ipv4.udp_table);
822}
823
824static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
825{
826 enum skb_drop_reason drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
827 struct udp_sock *up = udp_sk(sk);
828 int is_udplite = IS_UDPLITE(sk);
829
830 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
831 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
832 goto drop;
833 }
834 nf_reset_ct(skb);
835
836 if (static_branch_unlikely(&udpv6_encap_needed_key) &&
837 READ_ONCE(up->encap_type)) {
838 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
839
840 /*
841 * This is an encapsulation socket so pass the skb to
842 * the socket's udp_encap_rcv() hook. Otherwise, just
843 * fall through and pass this up the UDP socket.
844 * up->encap_rcv() returns the following value:
845 * =0 if skb was successfully passed to the encap
846 * handler or was discarded by it.
847 * >0 if skb should be passed on to UDP.
848 * <0 if skb should be resubmitted as proto -N
849 */
850
851 /* if we're overly short, let UDP handle it */
852 encap_rcv = READ_ONCE(up->encap_rcv);
853 if (encap_rcv) {
854 int ret;
855
856 /* Verify checksum before giving to encap */
857 if (udp_lib_checksum_complete(skb))
858 goto csum_error;
859
860 ret = encap_rcv(sk, skb);
861 if (ret <= 0) {
862 __UDP6_INC_STATS(sock_net(sk),
863 UDP_MIB_INDATAGRAMS,
864 is_udplite);
865 return -ret;
866 }
867 }
868
869 /* FALLTHROUGH -- it's a UDP Packet */
870 }
871
872 /*
873 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
874 */
875 if (udp_test_bit(UDPLITE_RECV_CC, sk) && UDP_SKB_CB(skb)->partial_cov) {
876 u16 pcrlen = READ_ONCE(up->pcrlen);
877
878 if (pcrlen == 0) { /* full coverage was set */
879 net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n",
880 UDP_SKB_CB(skb)->cscov, skb->len);
881 goto drop;
882 }
883 if (UDP_SKB_CB(skb)->cscov < pcrlen) {
884 net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
885 UDP_SKB_CB(skb)->cscov, pcrlen);
886 goto drop;
887 }
888 }
889
890 prefetch(&sk->sk_rmem_alloc);
891 if (rcu_access_pointer(sk->sk_filter) &&
892 udp_lib_checksum_complete(skb))
893 goto csum_error;
894
895 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) {
896 drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
897 goto drop;
898 }
899
900 udp_csum_pull_header(skb);
901
902 skb_dst_drop(skb);
903
904 return __udpv6_queue_rcv_skb(sk, skb);
905
906csum_error:
907 drop_reason = SKB_DROP_REASON_UDP_CSUM;
908 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
909drop:
910 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
911 atomic_inc(&sk->sk_drops);
912 sk_skb_reason_drop(sk, skb, drop_reason);
913 return -1;
914}
915
916static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
917{
918 struct sk_buff *next, *segs;
919 int ret;
920
921 if (likely(!udp_unexpected_gso(sk, skb)))
922 return udpv6_queue_rcv_one_skb(sk, skb);
923
924 __skb_push(skb, -skb_mac_offset(skb));
925 segs = udp_rcv_segment(sk, skb, false);
926 skb_list_walk_safe(segs, skb, next) {
927 __skb_pull(skb, skb_transport_offset(skb));
928
929 udp_post_segment_fix_csum(skb);
930 ret = udpv6_queue_rcv_one_skb(sk, skb);
931 if (ret > 0)
932 ip6_protocol_deliver_rcu(dev_net(skb->dev), skb, ret,
933 true);
934 }
935 return 0;
936}
937
938static bool __udp_v6_is_mcast_sock(struct net *net, const struct sock *sk,
939 __be16 loc_port, const struct in6_addr *loc_addr,
940 __be16 rmt_port, const struct in6_addr *rmt_addr,
941 int dif, int sdif, unsigned short hnum)
942{
943 const struct inet_sock *inet = inet_sk(sk);
944
945 if (!net_eq(sock_net(sk), net))
946 return false;
947
948 if (udp_sk(sk)->udp_port_hash != hnum ||
949 sk->sk_family != PF_INET6 ||
950 (inet->inet_dport && inet->inet_dport != rmt_port) ||
951 (!ipv6_addr_any(&sk->sk_v6_daddr) &&
952 !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
953 !udp_sk_bound_dev_eq(net, READ_ONCE(sk->sk_bound_dev_if), dif, sdif) ||
954 (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
955 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
956 return false;
957 if (!inet6_mc_check(sk, loc_addr, rmt_addr))
958 return false;
959 return true;
960}
961
962static void udp6_csum_zero_error(struct sk_buff *skb)
963{
964 /* RFC 2460 section 8.1 says that we SHOULD log
965 * this error. Well, it is reasonable.
966 */
967 net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
968 &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
969 &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
970}
971
972/*
973 * Note: called only from the BH handler context,
974 * so we don't need to lock the hashes.
975 */
976static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
977 const struct in6_addr *saddr, const struct in6_addr *daddr,
978 struct udp_table *udptable, int proto)
979{
980 struct sock *sk, *first = NULL;
981 const struct udphdr *uh = udp_hdr(skb);
982 unsigned short hnum = ntohs(uh->dest);
983 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
984 unsigned int offset = offsetof(typeof(*sk), sk_node);
985 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
986 int dif = inet6_iif(skb);
987 int sdif = inet6_sdif(skb);
988 struct hlist_node *node;
989 struct sk_buff *nskb;
990
991 if (use_hash2) {
992 hash2_any = ipv6_portaddr_hash(net, &in6addr_any, hnum) &
993 udptable->mask;
994 hash2 = ipv6_portaddr_hash(net, daddr, hnum) & udptable->mask;
995start_lookup:
996 hslot = &udptable->hash2[hash2].hslot;
997 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
998 }
999
1000 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
1001 if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
1002 uh->source, saddr, dif, sdif,
1003 hnum))
1004 continue;
1005 /* If zero checksum and no_check is not on for
1006 * the socket then skip it.
1007 */
1008 if (!uh->check && !udp_get_no_check6_rx(sk))
1009 continue;
1010 if (!first) {
1011 first = sk;
1012 continue;
1013 }
1014 nskb = skb_clone(skb, GFP_ATOMIC);
1015 if (unlikely(!nskb)) {
1016 atomic_inc(&sk->sk_drops);
1017 __UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
1018 IS_UDPLITE(sk));
1019 __UDP6_INC_STATS(net, UDP_MIB_INERRORS,
1020 IS_UDPLITE(sk));
1021 continue;
1022 }
1023
1024 if (udpv6_queue_rcv_skb(sk, nskb) > 0)
1025 consume_skb(nskb);
1026 }
1027
1028 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
1029 if (use_hash2 && hash2 != hash2_any) {
1030 hash2 = hash2_any;
1031 goto start_lookup;
1032 }
1033
1034 if (first) {
1035 if (udpv6_queue_rcv_skb(first, skb) > 0)
1036 consume_skb(skb);
1037 } else {
1038 kfree_skb(skb);
1039 __UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
1040 proto == IPPROTO_UDPLITE);
1041 }
1042 return 0;
1043}
1044
1045static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
1046{
1047 if (udp_sk_rx_dst_set(sk, dst))
1048 sk->sk_rx_dst_cookie = rt6_get_cookie(dst_rt6_info(dst));
1049}
1050
1051/* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
1052 * return code conversion for ip layer consumption
1053 */
1054static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
1055 struct udphdr *uh)
1056{
1057 int ret;
1058
1059 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
1060 skb_checksum_try_convert(skb, IPPROTO_UDP, ip6_compute_pseudo);
1061
1062 ret = udpv6_queue_rcv_skb(sk, skb);
1063
1064 /* a return value > 0 means to resubmit the input */
1065 if (ret > 0)
1066 return ret;
1067 return 0;
1068}
1069
1070int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
1071 int proto)
1072{
1073 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
1074 const struct in6_addr *saddr, *daddr;
1075 struct net *net = dev_net(skb->dev);
1076 struct sock *sk = NULL;
1077 struct udphdr *uh;
1078 bool refcounted;
1079 u32 ulen = 0;
1080
1081 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1082 goto discard;
1083
1084 saddr = &ipv6_hdr(skb)->saddr;
1085 daddr = &ipv6_hdr(skb)->daddr;
1086 uh = udp_hdr(skb);
1087
1088 ulen = ntohs(uh->len);
1089 if (ulen > skb->len)
1090 goto short_packet;
1091
1092 if (proto == IPPROTO_UDP) {
1093 /* UDP validates ulen. */
1094
1095 /* Check for jumbo payload */
1096 if (ulen == 0)
1097 ulen = skb->len;
1098
1099 if (ulen < sizeof(*uh))
1100 goto short_packet;
1101
1102 if (ulen < skb->len) {
1103 if (pskb_trim_rcsum(skb, ulen))
1104 goto short_packet;
1105 saddr = &ipv6_hdr(skb)->saddr;
1106 daddr = &ipv6_hdr(skb)->daddr;
1107 uh = udp_hdr(skb);
1108 }
1109 }
1110
1111 if (udp6_csum_init(skb, uh, proto))
1112 goto csum_error;
1113
1114 /* Check if the socket is already available, e.g. due to early demux */
1115 sk = inet6_steal_sock(net, skb, sizeof(struct udphdr), saddr, uh->source, daddr, uh->dest,
1116 &refcounted, udp6_ehashfn);
1117 if (IS_ERR(sk))
1118 goto no_sk;
1119
1120 if (sk) {
1121 struct dst_entry *dst = skb_dst(skb);
1122 int ret;
1123
1124 if (unlikely(rcu_dereference(sk->sk_rx_dst) != dst))
1125 udp6_sk_rx_dst_set(sk, dst);
1126
1127 if (!uh->check && !udp_get_no_check6_rx(sk)) {
1128 if (refcounted)
1129 sock_put(sk);
1130 goto report_csum_error;
1131 }
1132
1133 ret = udp6_unicast_rcv_skb(sk, skb, uh);
1134 if (refcounted)
1135 sock_put(sk);
1136 return ret;
1137 }
1138
1139 /*
1140 * Multicast receive code
1141 */
1142 if (ipv6_addr_is_multicast(daddr))
1143 return __udp6_lib_mcast_deliver(net, skb,
1144 saddr, daddr, udptable, proto);
1145
1146 /* Unicast */
1147 sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1148 if (sk) {
1149 if (!uh->check && !udp_get_no_check6_rx(sk))
1150 goto report_csum_error;
1151 return udp6_unicast_rcv_skb(sk, skb, uh);
1152 }
1153no_sk:
1154 reason = SKB_DROP_REASON_NO_SOCKET;
1155
1156 if (!uh->check)
1157 goto report_csum_error;
1158
1159 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1160 goto discard;
1161 nf_reset_ct(skb);
1162
1163 if (udp_lib_checksum_complete(skb))
1164 goto csum_error;
1165
1166 __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1167 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
1168
1169 sk_skb_reason_drop(sk, skb, reason);
1170 return 0;
1171
1172short_packet:
1173 if (reason == SKB_DROP_REASON_NOT_SPECIFIED)
1174 reason = SKB_DROP_REASON_PKT_TOO_SMALL;
1175 net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
1176 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1177 saddr, ntohs(uh->source),
1178 ulen, skb->len,
1179 daddr, ntohs(uh->dest));
1180 goto discard;
1181
1182report_csum_error:
1183 udp6_csum_zero_error(skb);
1184csum_error:
1185 if (reason == SKB_DROP_REASON_NOT_SPECIFIED)
1186 reason = SKB_DROP_REASON_UDP_CSUM;
1187 __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
1188discard:
1189 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1190 sk_skb_reason_drop(sk, skb, reason);
1191 return 0;
1192}
1193
1194
1195static struct sock *__udp6_lib_demux_lookup(struct net *net,
1196 __be16 loc_port, const struct in6_addr *loc_addr,
1197 __be16 rmt_port, const struct in6_addr *rmt_addr,
1198 int dif, int sdif)
1199{
1200 struct udp_table *udptable = net->ipv4.udp_table;
1201 unsigned short hnum = ntohs(loc_port);
1202 struct udp_hslot *hslot2;
1203 unsigned int hash2;
1204 __portpair ports;
1205 struct sock *sk;
1206
1207 hash2 = ipv6_portaddr_hash(net, loc_addr, hnum);
1208 hslot2 = udp_hashslot2(udptable, hash2);
1209 ports = INET_COMBINED_PORTS(rmt_port, hnum);
1210
1211 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
1212 if (sk->sk_state == TCP_ESTABLISHED &&
1213 inet6_match(net, sk, rmt_addr, loc_addr, ports, dif, sdif))
1214 return sk;
1215 /* Only check first socket in chain */
1216 break;
1217 }
1218 return NULL;
1219}
1220
1221void udp_v6_early_demux(struct sk_buff *skb)
1222{
1223 struct net *net = dev_net(skb->dev);
1224 const struct udphdr *uh;
1225 struct sock *sk;
1226 struct dst_entry *dst;
1227 int dif = skb->dev->ifindex;
1228 int sdif = inet6_sdif(skb);
1229
1230 if (!pskb_may_pull(skb, skb_transport_offset(skb) +
1231 sizeof(struct udphdr)))
1232 return;
1233
1234 uh = udp_hdr(skb);
1235
1236 if (skb->pkt_type == PACKET_HOST)
1237 sk = __udp6_lib_demux_lookup(net, uh->dest,
1238 &ipv6_hdr(skb)->daddr,
1239 uh->source, &ipv6_hdr(skb)->saddr,
1240 dif, sdif);
1241 else
1242 return;
1243
1244 if (!sk)
1245 return;
1246
1247 skb->sk = sk;
1248 DEBUG_NET_WARN_ON_ONCE(sk_is_refcounted(sk));
1249 skb->destructor = sock_pfree;
1250 dst = rcu_dereference(sk->sk_rx_dst);
1251
1252 if (dst)
1253 dst = dst_check(dst, sk->sk_rx_dst_cookie);
1254 if (dst) {
1255 /* set noref for now.
1256 * any place which wants to hold dst has to call
1257 * dst_hold_safe()
1258 */
1259 skb_dst_set_noref(skb, dst);
1260 }
1261}
1262
1263INDIRECT_CALLABLE_SCOPE int udpv6_rcv(struct sk_buff *skb)
1264{
1265 return __udp6_lib_rcv(skb, dev_net(skb->dev)->ipv4.udp_table, IPPROTO_UDP);
1266}
1267
1268/*
1269 * Throw away all pending data and cancel the corking. Socket is locked.
1270 */
1271static void udp_v6_flush_pending_frames(struct sock *sk)
1272{
1273 struct udp_sock *up = udp_sk(sk);
1274
1275 if (up->pending == AF_INET)
1276 udp_flush_pending_frames(sk);
1277 else if (up->pending) {
1278 up->len = 0;
1279 WRITE_ONCE(up->pending, 0);
1280 ip6_flush_pending_frames(sk);
1281 }
1282}
1283
1284static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
1285 int addr_len)
1286{
1287 if (addr_len < offsetofend(struct sockaddr, sa_family))
1288 return -EINVAL;
1289 /* The following checks are replicated from __ip6_datagram_connect()
1290 * and intended to prevent BPF program called below from accessing
1291 * bytes that are out of the bound specified by user in addr_len.
1292 */
1293 if (uaddr->sa_family == AF_INET) {
1294 if (ipv6_only_sock(sk))
1295 return -EAFNOSUPPORT;
1296 return udp_pre_connect(sk, uaddr, addr_len);
1297 }
1298
1299 if (addr_len < SIN6_LEN_RFC2133)
1300 return -EINVAL;
1301
1302 return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr, &addr_len);
1303}
1304
1305static int udpv6_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
1306{
1307 int res;
1308
1309 lock_sock(sk);
1310 res = __ip6_datagram_connect(sk, uaddr, addr_len);
1311 if (!res)
1312 udp6_hash4(sk);
1313 release_sock(sk);
1314 return res;
1315}
1316
1317/**
1318 * udp6_hwcsum_outgoing - handle outgoing HW checksumming
1319 * @sk: socket we are sending on
1320 * @skb: sk_buff containing the filled-in UDP header
1321 * (checksum field must be zeroed out)
1322 * @saddr: source address
1323 * @daddr: destination address
1324 * @len: length of packet
1325 */
1326static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
1327 const struct in6_addr *saddr,
1328 const struct in6_addr *daddr, int len)
1329{
1330 unsigned int offset;
1331 struct udphdr *uh = udp_hdr(skb);
1332 struct sk_buff *frags = skb_shinfo(skb)->frag_list;
1333 __wsum csum = 0;
1334
1335 if (!frags) {
1336 /* Only one fragment on the socket. */
1337 skb->csum_start = skb_transport_header(skb) - skb->head;
1338 skb->csum_offset = offsetof(struct udphdr, check);
1339 uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
1340 } else {
1341 /*
1342 * HW-checksum won't work as there are two or more
1343 * fragments on the socket so that all csums of sk_buffs
1344 * should be together
1345 */
1346 offset = skb_transport_offset(skb);
1347 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
1348 csum = skb->csum;
1349
1350 skb->ip_summed = CHECKSUM_NONE;
1351
1352 do {
1353 csum = csum_add(csum, frags->csum);
1354 } while ((frags = frags->next));
1355
1356 uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
1357 csum);
1358 if (uh->check == 0)
1359 uh->check = CSUM_MANGLED_0;
1360 }
1361}
1362
1363/*
1364 * Sending
1365 */
1366
1367static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6,
1368 struct inet_cork *cork)
1369{
1370 struct sock *sk = skb->sk;
1371 struct udphdr *uh;
1372 int err = 0;
1373 int is_udplite = IS_UDPLITE(sk);
1374 __wsum csum = 0;
1375 int offset = skb_transport_offset(skb);
1376 int len = skb->len - offset;
1377 int datalen = len - sizeof(*uh);
1378
1379 /*
1380 * Create a UDP header
1381 */
1382 uh = udp_hdr(skb);
1383 uh->source = fl6->fl6_sport;
1384 uh->dest = fl6->fl6_dport;
1385 uh->len = htons(len);
1386 uh->check = 0;
1387
1388 if (cork->gso_size) {
1389 const int hlen = skb_network_header_len(skb) +
1390 sizeof(struct udphdr);
1391
1392 if (hlen + min(datalen, cork->gso_size) > cork->fragsize) {
1393 kfree_skb(skb);
1394 return -EMSGSIZE;
1395 }
1396 if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) {
1397 kfree_skb(skb);
1398 return -EINVAL;
1399 }
1400 if (udp_get_no_check6_tx(sk)) {
1401 kfree_skb(skb);
1402 return -EINVAL;
1403 }
1404 if (is_udplite || dst_xfrm(skb_dst(skb))) {
1405 kfree_skb(skb);
1406 return -EIO;
1407 }
1408
1409 if (datalen > cork->gso_size) {
1410 skb_shinfo(skb)->gso_size = cork->gso_size;
1411 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
1412 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
1413 cork->gso_size);
1414
1415 /* Don't checksum the payload, skb will get segmented */
1416 goto csum_partial;
1417 }
1418 }
1419
1420 if (is_udplite)
1421 csum = udplite_csum(skb);
1422 else if (udp_get_no_check6_tx(sk)) { /* UDP csum disabled */
1423 skb->ip_summed = CHECKSUM_NONE;
1424 goto send;
1425 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1426csum_partial:
1427 udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len);
1428 goto send;
1429 } else
1430 csum = udp_csum(skb);
1431
1432 /* add protocol-dependent pseudo-header */
1433 uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
1434 len, fl6->flowi6_proto, csum);
1435 if (uh->check == 0)
1436 uh->check = CSUM_MANGLED_0;
1437
1438send:
1439 err = ip6_send_skb(skb);
1440 if (err) {
1441 if (err == -ENOBUFS && !inet6_test_bit(RECVERR6, sk)) {
1442 UDP6_INC_STATS(sock_net(sk),
1443 UDP_MIB_SNDBUFERRORS, is_udplite);
1444 err = 0;
1445 }
1446 } else {
1447 UDP6_INC_STATS(sock_net(sk),
1448 UDP_MIB_OUTDATAGRAMS, is_udplite);
1449 }
1450 return err;
1451}
1452
1453static int udp_v6_push_pending_frames(struct sock *sk)
1454{
1455 struct sk_buff *skb;
1456 struct udp_sock *up = udp_sk(sk);
1457 int err = 0;
1458
1459 if (up->pending == AF_INET)
1460 return udp_push_pending_frames(sk);
1461
1462 skb = ip6_finish_skb(sk);
1463 if (!skb)
1464 goto out;
1465
1466 err = udp_v6_send_skb(skb, &inet_sk(sk)->cork.fl.u.ip6,
1467 &inet_sk(sk)->cork.base);
1468out:
1469 up->len = 0;
1470 WRITE_ONCE(up->pending, 0);
1471 return err;
1472}
1473
1474int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1475{
1476 struct ipv6_txoptions opt_space;
1477 struct udp_sock *up = udp_sk(sk);
1478 struct inet_sock *inet = inet_sk(sk);
1479 struct ipv6_pinfo *np = inet6_sk(sk);
1480 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1481 struct in6_addr *daddr, *final_p, final;
1482 struct ipv6_txoptions *opt = NULL;
1483 struct ipv6_txoptions *opt_to_free = NULL;
1484 struct ip6_flowlabel *flowlabel = NULL;
1485 struct inet_cork_full cork;
1486 struct flowi6 *fl6 = &cork.fl.u.ip6;
1487 struct dst_entry *dst;
1488 struct ipcm6_cookie ipc6;
1489 int addr_len = msg->msg_namelen;
1490 bool connected = false;
1491 int ulen = len;
1492 int corkreq = udp_test_bit(CORK, sk) || msg->msg_flags & MSG_MORE;
1493 int err;
1494 int is_udplite = IS_UDPLITE(sk);
1495 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1496
1497 ipcm6_init(&ipc6);
1498 ipc6.gso_size = READ_ONCE(up->gso_size);
1499 ipc6.sockc.tsflags = READ_ONCE(sk->sk_tsflags);
1500 ipc6.sockc.mark = READ_ONCE(sk->sk_mark);
1501
1502 /* destination address check */
1503 if (sin6) {
1504 if (addr_len < offsetof(struct sockaddr, sa_data))
1505 return -EINVAL;
1506
1507 switch (sin6->sin6_family) {
1508 case AF_INET6:
1509 if (addr_len < SIN6_LEN_RFC2133)
1510 return -EINVAL;
1511 daddr = &sin6->sin6_addr;
1512 if (ipv6_addr_any(daddr) &&
1513 ipv6_addr_v4mapped(&np->saddr))
1514 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
1515 daddr);
1516 break;
1517 case AF_INET:
1518 goto do_udp_sendmsg;
1519 case AF_UNSPEC:
1520 msg->msg_name = sin6 = NULL;
1521 msg->msg_namelen = addr_len = 0;
1522 daddr = NULL;
1523 break;
1524 default:
1525 return -EINVAL;
1526 }
1527 } else if (!READ_ONCE(up->pending)) {
1528 if (sk->sk_state != TCP_ESTABLISHED)
1529 return -EDESTADDRREQ;
1530 daddr = &sk->sk_v6_daddr;
1531 } else
1532 daddr = NULL;
1533
1534 if (daddr) {
1535 if (ipv6_addr_v4mapped(daddr)) {
1536 struct sockaddr_in sin;
1537 sin.sin_family = AF_INET;
1538 sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1539 sin.sin_addr.s_addr = daddr->s6_addr32[3];
1540 msg->msg_name = &sin;
1541 msg->msg_namelen = sizeof(sin);
1542do_udp_sendmsg:
1543 err = ipv6_only_sock(sk) ?
1544 -ENETUNREACH : udp_sendmsg(sk, msg, len);
1545 msg->msg_name = sin6;
1546 msg->msg_namelen = addr_len;
1547 return err;
1548 }
1549 }
1550
1551 /* Rough check on arithmetic overflow,
1552 better check is made in ip6_append_data().
1553 */
1554 if (len > INT_MAX - sizeof(struct udphdr))
1555 return -EMSGSIZE;
1556
1557 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
1558 if (READ_ONCE(up->pending)) {
1559 if (READ_ONCE(up->pending) == AF_INET)
1560 return udp_sendmsg(sk, msg, len);
1561 /*
1562 * There are pending frames.
1563 * The socket lock must be held while it's corked.
1564 */
1565 lock_sock(sk);
1566 if (likely(up->pending)) {
1567 if (unlikely(up->pending != AF_INET6)) {
1568 release_sock(sk);
1569 return -EAFNOSUPPORT;
1570 }
1571 dst = NULL;
1572 goto do_append_data;
1573 }
1574 release_sock(sk);
1575 }
1576 ulen += sizeof(struct udphdr);
1577
1578 memset(fl6, 0, sizeof(*fl6));
1579
1580 if (sin6) {
1581 if (sin6->sin6_port == 0)
1582 return -EINVAL;
1583
1584 fl6->fl6_dport = sin6->sin6_port;
1585 daddr = &sin6->sin6_addr;
1586
1587 if (inet6_test_bit(SNDFLOW, sk)) {
1588 fl6->flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1589 if (fl6->flowlabel & IPV6_FLOWLABEL_MASK) {
1590 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
1591 if (IS_ERR(flowlabel))
1592 return -EINVAL;
1593 }
1594 }
1595
1596 /*
1597 * Otherwise it will be difficult to maintain
1598 * sk->sk_dst_cache.
1599 */
1600 if (sk->sk_state == TCP_ESTABLISHED &&
1601 ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
1602 daddr = &sk->sk_v6_daddr;
1603
1604 if (addr_len >= sizeof(struct sockaddr_in6) &&
1605 sin6->sin6_scope_id &&
1606 __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1607 fl6->flowi6_oif = sin6->sin6_scope_id;
1608 } else {
1609 if (sk->sk_state != TCP_ESTABLISHED)
1610 return -EDESTADDRREQ;
1611
1612 fl6->fl6_dport = inet->inet_dport;
1613 daddr = &sk->sk_v6_daddr;
1614 fl6->flowlabel = np->flow_label;
1615 connected = true;
1616 }
1617
1618 if (!fl6->flowi6_oif)
1619 fl6->flowi6_oif = READ_ONCE(sk->sk_bound_dev_if);
1620
1621 if (!fl6->flowi6_oif)
1622 fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1623
1624 fl6->flowi6_uid = sk->sk_uid;
1625
1626 if (msg->msg_controllen) {
1627 opt = &opt_space;
1628 memset(opt, 0, sizeof(struct ipv6_txoptions));
1629 opt->tot_len = sizeof(*opt);
1630 ipc6.opt = opt;
1631
1632 err = udp_cmsg_send(sk, msg, &ipc6.gso_size);
1633 if (err > 0) {
1634 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, fl6,
1635 &ipc6);
1636 connected = false;
1637 }
1638 if (err < 0) {
1639 fl6_sock_release(flowlabel);
1640 return err;
1641 }
1642 if ((fl6->flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1643 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
1644 if (IS_ERR(flowlabel))
1645 return -EINVAL;
1646 }
1647 if (!(opt->opt_nflen|opt->opt_flen))
1648 opt = NULL;
1649 }
1650 if (!opt) {
1651 opt = txopt_get(np);
1652 opt_to_free = opt;
1653 }
1654 if (flowlabel)
1655 opt = fl6_merge_options(&opt_space, flowlabel, opt);
1656 opt = ipv6_fixup_options(&opt_space, opt);
1657 ipc6.opt = opt;
1658
1659 fl6->flowi6_proto = sk->sk_protocol;
1660 fl6->flowi6_mark = ipc6.sockc.mark;
1661 fl6->daddr = *daddr;
1662 if (ipv6_addr_any(&fl6->saddr) && !ipv6_addr_any(&np->saddr))
1663 fl6->saddr = np->saddr;
1664 fl6->fl6_sport = inet->inet_sport;
1665
1666 if (cgroup_bpf_enabled(CGROUP_UDP6_SENDMSG) && !connected) {
1667 err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk,
1668 (struct sockaddr *)sin6,
1669 &addr_len,
1670 &fl6->saddr);
1671 if (err)
1672 goto out_no_dst;
1673 if (sin6) {
1674 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
1675 /* BPF program rewrote IPv6-only by IPv4-mapped
1676 * IPv6. It's currently unsupported.
1677 */
1678 err = -ENOTSUPP;
1679 goto out_no_dst;
1680 }
1681 if (sin6->sin6_port == 0) {
1682 /* BPF program set invalid port. Reject it. */
1683 err = -EINVAL;
1684 goto out_no_dst;
1685 }
1686 fl6->fl6_dport = sin6->sin6_port;
1687 fl6->daddr = sin6->sin6_addr;
1688 }
1689 }
1690
1691 if (ipv6_addr_any(&fl6->daddr))
1692 fl6->daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1693
1694 final_p = fl6_update_dst(fl6, opt, &final);
1695 if (final_p)
1696 connected = false;
1697
1698 if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr)) {
1699 fl6->flowi6_oif = READ_ONCE(np->mcast_oif);
1700 connected = false;
1701 } else if (!fl6->flowi6_oif)
1702 fl6->flowi6_oif = READ_ONCE(np->ucast_oif);
1703
1704 security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
1705
1706 if (ipc6.tclass < 0)
1707 ipc6.tclass = np->tclass;
1708
1709 fl6->flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6->flowlabel);
1710
1711 dst = ip6_sk_dst_lookup_flow(sk, fl6, final_p, connected);
1712 if (IS_ERR(dst)) {
1713 err = PTR_ERR(dst);
1714 dst = NULL;
1715 goto out;
1716 }
1717
1718 if (ipc6.hlimit < 0)
1719 ipc6.hlimit = ip6_sk_dst_hoplimit(np, fl6, dst);
1720
1721 if (msg->msg_flags&MSG_CONFIRM)
1722 goto do_confirm;
1723back_from_confirm:
1724
1725 /* Lockless fast path for the non-corking case */
1726 if (!corkreq) {
1727 struct sk_buff *skb;
1728
1729 skb = ip6_make_skb(sk, getfrag, msg, ulen,
1730 sizeof(struct udphdr), &ipc6,
1731 dst_rt6_info(dst),
1732 msg->msg_flags, &cork);
1733 err = PTR_ERR(skb);
1734 if (!IS_ERR_OR_NULL(skb))
1735 err = udp_v6_send_skb(skb, fl6, &cork.base);
1736 /* ip6_make_skb steals dst reference */
1737 goto out_no_dst;
1738 }
1739
1740 lock_sock(sk);
1741 if (unlikely(up->pending)) {
1742 /* The socket is already corked while preparing it. */
1743 /* ... which is an evident application bug. --ANK */
1744 release_sock(sk);
1745
1746 net_dbg_ratelimited("udp cork app bug 2\n");
1747 err = -EINVAL;
1748 goto out;
1749 }
1750
1751 WRITE_ONCE(up->pending, AF_INET6);
1752
1753do_append_data:
1754 if (ipc6.dontfrag < 0)
1755 ipc6.dontfrag = inet6_test_bit(DONTFRAG, sk);
1756 up->len += ulen;
1757 err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr),
1758 &ipc6, fl6, dst_rt6_info(dst),
1759 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1760 if (err)
1761 udp_v6_flush_pending_frames(sk);
1762 else if (!corkreq)
1763 err = udp_v6_push_pending_frames(sk);
1764 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1765 WRITE_ONCE(up->pending, 0);
1766
1767 if (err > 0)
1768 err = inet6_test_bit(RECVERR6, sk) ? net_xmit_errno(err) : 0;
1769 release_sock(sk);
1770
1771out:
1772 dst_release(dst);
1773out_no_dst:
1774 fl6_sock_release(flowlabel);
1775 txopt_put(opt_to_free);
1776 if (!err)
1777 return len;
1778 /*
1779 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1780 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1781 * we don't have a good statistic (IpOutDiscards but it can be too many
1782 * things). We could add another new stat but at least for now that
1783 * seems like overkill.
1784 */
1785 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1786 UDP6_INC_STATS(sock_net(sk),
1787 UDP_MIB_SNDBUFERRORS, is_udplite);
1788 }
1789 return err;
1790
1791do_confirm:
1792 if (msg->msg_flags & MSG_PROBE)
1793 dst_confirm_neigh(dst, &fl6->daddr);
1794 if (!(msg->msg_flags&MSG_PROBE) || len)
1795 goto back_from_confirm;
1796 err = 0;
1797 goto out;
1798}
1799EXPORT_SYMBOL(udpv6_sendmsg);
1800
1801static void udpv6_splice_eof(struct socket *sock)
1802{
1803 struct sock *sk = sock->sk;
1804 struct udp_sock *up = udp_sk(sk);
1805
1806 if (!READ_ONCE(up->pending) || udp_test_bit(CORK, sk))
1807 return;
1808
1809 lock_sock(sk);
1810 if (up->pending && !udp_test_bit(CORK, sk))
1811 udp_v6_push_pending_frames(sk);
1812 release_sock(sk);
1813}
1814
1815void udpv6_destroy_sock(struct sock *sk)
1816{
1817 struct udp_sock *up = udp_sk(sk);
1818 lock_sock(sk);
1819
1820 /* protects from races with udp_abort() */
1821 sock_set_flag(sk, SOCK_DEAD);
1822 udp_v6_flush_pending_frames(sk);
1823 release_sock(sk);
1824
1825 if (static_branch_unlikely(&udpv6_encap_needed_key)) {
1826 if (up->encap_type) {
1827 void (*encap_destroy)(struct sock *sk);
1828 encap_destroy = READ_ONCE(up->encap_destroy);
1829 if (encap_destroy)
1830 encap_destroy(sk);
1831 }
1832 if (udp_test_bit(ENCAP_ENABLED, sk)) {
1833 static_branch_dec(&udpv6_encap_needed_key);
1834 udp_encap_disable();
1835 }
1836 }
1837}
1838
1839/*
1840 * Socket option code for UDP
1841 */
1842int udpv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1843 unsigned int optlen)
1844{
1845 if (level == SOL_UDP || level == SOL_UDPLITE || level == SOL_SOCKET)
1846 return udp_lib_setsockopt(sk, level, optname,
1847 optval, optlen,
1848 udp_v6_push_pending_frames);
1849 return ipv6_setsockopt(sk, level, optname, optval, optlen);
1850}
1851
1852int udpv6_getsockopt(struct sock *sk, int level, int optname,
1853 char __user *optval, int __user *optlen)
1854{
1855 if (level == SOL_UDP || level == SOL_UDPLITE)
1856 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1857 return ipv6_getsockopt(sk, level, optname, optval, optlen);
1858}
1859
1860
1861/* ------------------------------------------------------------------------ */
1862#ifdef CONFIG_PROC_FS
1863int udp6_seq_show(struct seq_file *seq, void *v)
1864{
1865 if (v == SEQ_START_TOKEN) {
1866 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1867 } else {
1868 int bucket = ((struct udp_iter_state *)seq->private)->bucket;
1869 const struct inet_sock *inet = inet_sk((const struct sock *)v);
1870 __u16 srcp = ntohs(inet->inet_sport);
1871 __u16 destp = ntohs(inet->inet_dport);
1872 __ip6_dgram_sock_seq_show(seq, v, srcp, destp,
1873 udp_rqueue_get(v), bucket);
1874 }
1875 return 0;
1876}
1877
1878const struct seq_operations udp6_seq_ops = {
1879 .start = udp_seq_start,
1880 .next = udp_seq_next,
1881 .stop = udp_seq_stop,
1882 .show = udp6_seq_show,
1883};
1884EXPORT_SYMBOL(udp6_seq_ops);
1885
1886static struct udp_seq_afinfo udp6_seq_afinfo = {
1887 .family = AF_INET6,
1888 .udp_table = NULL,
1889};
1890
1891int __net_init udp6_proc_init(struct net *net)
1892{
1893 if (!proc_create_net_data("udp6", 0444, net->proc_net, &udp6_seq_ops,
1894 sizeof(struct udp_iter_state), &udp6_seq_afinfo))
1895 return -ENOMEM;
1896 return 0;
1897}
1898
1899void udp6_proc_exit(struct net *net)
1900{
1901 remove_proc_entry("udp6", net->proc_net);
1902}
1903#endif /* CONFIG_PROC_FS */
1904
1905/* ------------------------------------------------------------------------ */
1906
1907struct proto udpv6_prot = {
1908 .name = "UDPv6",
1909 .owner = THIS_MODULE,
1910 .close = udp_lib_close,
1911 .pre_connect = udpv6_pre_connect,
1912 .connect = udpv6_connect,
1913 .disconnect = udp_disconnect,
1914 .ioctl = udp_ioctl,
1915 .init = udpv6_init_sock,
1916 .destroy = udpv6_destroy_sock,
1917 .setsockopt = udpv6_setsockopt,
1918 .getsockopt = udpv6_getsockopt,
1919 .sendmsg = udpv6_sendmsg,
1920 .recvmsg = udpv6_recvmsg,
1921 .splice_eof = udpv6_splice_eof,
1922 .release_cb = ip6_datagram_release_cb,
1923 .hash = udp_lib_hash,
1924 .unhash = udp_lib_unhash,
1925 .rehash = udp_v6_rehash,
1926 .get_port = udp_v6_get_port,
1927 .put_port = udp_lib_unhash,
1928#ifdef CONFIG_BPF_SYSCALL
1929 .psock_update_sk_prot = udp_bpf_update_proto,
1930#endif
1931
1932 .memory_allocated = &udp_memory_allocated,
1933 .per_cpu_fw_alloc = &udp_memory_per_cpu_fw_alloc,
1934
1935 .sysctl_mem = sysctl_udp_mem,
1936 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
1937 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
1938 .obj_size = sizeof(struct udp6_sock),
1939 .ipv6_pinfo_offset = offsetof(struct udp6_sock, inet6),
1940 .h.udp_table = NULL,
1941 .diag_destroy = udp_abort,
1942};
1943
1944static struct inet_protosw udpv6_protosw = {
1945 .type = SOCK_DGRAM,
1946 .protocol = IPPROTO_UDP,
1947 .prot = &udpv6_prot,
1948 .ops = &inet6_dgram_ops,
1949 .flags = INET_PROTOSW_PERMANENT,
1950};
1951
1952int __init udpv6_init(void)
1953{
1954 int ret;
1955
1956 net_hotdata.udpv6_protocol = (struct inet6_protocol) {
1957 .handler = udpv6_rcv,
1958 .err_handler = udpv6_err,
1959 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1960 };
1961 ret = inet6_add_protocol(&net_hotdata.udpv6_protocol, IPPROTO_UDP);
1962 if (ret)
1963 goto out;
1964
1965 ret = inet6_register_protosw(&udpv6_protosw);
1966 if (ret)
1967 goto out_udpv6_protocol;
1968out:
1969 return ret;
1970
1971out_udpv6_protocol:
1972 inet6_del_protocol(&net_hotdata.udpv6_protocol, IPPROTO_UDP);
1973 goto out;
1974}
1975
1976void udpv6_exit(void)
1977{
1978 inet6_unregister_protosw(&udpv6_protosw);
1979 inet6_del_protocol(&net_hotdata.udpv6_protocol, IPPROTO_UDP);
1980}