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Merge tag 'sched_urgent_for_v5.15_rc4' of git://git.kernel.org/pub/scm/linux/kernel...
[mirror_ubuntu-jammy-kernel.git] / net / ipv6 / udp.c
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/errno.h>
21 #include <linux/types.h>
22 #include <linux/socket.h>
23 #include <linux/sockios.h>
24 #include <linux/net.h>
25 #include <linux/in6.h>
26 #include <linux/netdevice.h>
27 #include <linux/if_arp.h>
28 #include <linux/ipv6.h>
29 #include <linux/icmpv6.h>
30 #include <linux/init.h>
31 #include <linux/module.h>
32 #include <linux/skbuff.h>
33 #include <linux/slab.h>
34 #include <linux/uaccess.h>
35 #include <linux/indirect_call_wrapper.h>
36
37 #include <net/addrconf.h>
38 #include <net/ndisc.h>
39 #include <net/protocol.h>
40 #include <net/transp_v6.h>
41 #include <net/ip6_route.h>
42 #include <net/raw.h>
43 #include <net/tcp_states.h>
44 #include <net/ip6_checksum.h>
45 #include <net/ip6_tunnel.h>
46 #include <net/xfrm.h>
47 #include <net/inet_hashtables.h>
48 #include <net/inet6_hashtables.h>
49 #include <net/busy_poll.h>
50 #include <net/sock_reuseport.h>
51
52 #include <linux/proc_fs.h>
53 #include <linux/seq_file.h>
54 #include <trace/events/skb.h>
55 #include "udp_impl.h"
56
57 static u32 udp6_ehashfn(const struct net *net,
58 const struct in6_addr *laddr,
59 const u16 lport,
60 const struct in6_addr *faddr,
61 const __be16 fport)
62 {
63 static u32 udp6_ehash_secret __read_mostly;
64 static u32 udp_ipv6_hash_secret __read_mostly;
65
66 u32 lhash, fhash;
67
68 net_get_random_once(&udp6_ehash_secret,
69 sizeof(udp6_ehash_secret));
70 net_get_random_once(&udp_ipv6_hash_secret,
71 sizeof(udp_ipv6_hash_secret));
72
73 lhash = (__force u32)laddr->s6_addr32[3];
74 fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret);
75
76 return __inet6_ehashfn(lhash, lport, fhash, fport,
77 udp_ipv6_hash_secret + net_hash_mix(net));
78 }
79
80 int udp_v6_get_port(struct sock *sk, unsigned short snum)
81 {
82 unsigned int hash2_nulladdr =
83 ipv6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
84 unsigned int hash2_partial =
85 ipv6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
86
87 /* precompute partial secondary hash */
88 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
89 return udp_lib_get_port(sk, snum, hash2_nulladdr);
90 }
91
92 void udp_v6_rehash(struct sock *sk)
93 {
94 u16 new_hash = ipv6_portaddr_hash(sock_net(sk),
95 &sk->sk_v6_rcv_saddr,
96 inet_sk(sk)->inet_num);
97
98 udp_lib_rehash(sk, new_hash);
99 }
100
101 static int compute_score(struct sock *sk, struct net *net,
102 const struct in6_addr *saddr, __be16 sport,
103 const struct in6_addr *daddr, unsigned short hnum,
104 int dif, int sdif)
105 {
106 int score;
107 struct inet_sock *inet;
108 bool dev_match;
109
110 if (!net_eq(sock_net(sk), net) ||
111 udp_sk(sk)->udp_port_hash != hnum ||
112 sk->sk_family != PF_INET6)
113 return -1;
114
115 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
116 return -1;
117
118 score = 0;
119 inet = inet_sk(sk);
120
121 if (inet->inet_dport) {
122 if (inet->inet_dport != sport)
123 return -1;
124 score++;
125 }
126
127 if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
128 if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
129 return -1;
130 score++;
131 }
132
133 dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif);
134 if (!dev_match)
135 return -1;
136 score++;
137
138 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
139 score++;
140
141 return score;
142 }
143
144 static struct sock *lookup_reuseport(struct net *net, struct sock *sk,
145 struct sk_buff *skb,
146 const struct in6_addr *saddr,
147 __be16 sport,
148 const struct in6_addr *daddr,
149 unsigned int hnum)
150 {
151 struct sock *reuse_sk = NULL;
152 u32 hash;
153
154 if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) {
155 hash = udp6_ehashfn(net, daddr, hnum, saddr, sport);
156 reuse_sk = reuseport_select_sock(sk, hash, skb,
157 sizeof(struct udphdr));
158 }
159 return reuse_sk;
160 }
161
162 /* called with rcu_read_lock() */
163 static struct sock *udp6_lib_lookup2(struct net *net,
164 const struct in6_addr *saddr, __be16 sport,
165 const struct in6_addr *daddr, unsigned int hnum,
166 int dif, int sdif, struct udp_hslot *hslot2,
167 struct sk_buff *skb)
168 {
169 struct sock *sk, *result;
170 int score, badness;
171
172 result = NULL;
173 badness = -1;
174 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
175 score = compute_score(sk, net, saddr, sport,
176 daddr, hnum, dif, sdif);
177 if (score > badness) {
178 result = lookup_reuseport(net, sk, skb,
179 saddr, sport, daddr, hnum);
180 /* Fall back to scoring if group has connections */
181 if (result && !reuseport_has_conns(sk, false))
182 return result;
183
184 result = result ? : sk;
185 badness = score;
186 }
187 }
188 return result;
189 }
190
191 static inline struct sock *udp6_lookup_run_bpf(struct net *net,
192 struct udp_table *udptable,
193 struct sk_buff *skb,
194 const struct in6_addr *saddr,
195 __be16 sport,
196 const struct in6_addr *daddr,
197 u16 hnum)
198 {
199 struct sock *sk, *reuse_sk;
200 bool no_reuseport;
201
202 if (udptable != &udp_table)
203 return NULL; /* only UDP is supported */
204
205 no_reuseport = bpf_sk_lookup_run_v6(net, IPPROTO_UDP,
206 saddr, sport, daddr, hnum, &sk);
207 if (no_reuseport || IS_ERR_OR_NULL(sk))
208 return sk;
209
210 reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum);
211 if (reuse_sk)
212 sk = reuse_sk;
213 return sk;
214 }
215
216 /* rcu_read_lock() must be held */
217 struct sock *__udp6_lib_lookup(struct net *net,
218 const struct in6_addr *saddr, __be16 sport,
219 const struct in6_addr *daddr, __be16 dport,
220 int dif, int sdif, struct udp_table *udptable,
221 struct sk_buff *skb)
222 {
223 unsigned short hnum = ntohs(dport);
224 unsigned int hash2, slot2;
225 struct udp_hslot *hslot2;
226 struct sock *result, *sk;
227
228 hash2 = ipv6_portaddr_hash(net, daddr, hnum);
229 slot2 = hash2 & udptable->mask;
230 hslot2 = &udptable->hash2[slot2];
231
232 /* Lookup connected or non-wildcard sockets */
233 result = udp6_lib_lookup2(net, saddr, sport,
234 daddr, hnum, dif, sdif,
235 hslot2, skb);
236 if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED)
237 goto done;
238
239 /* Lookup redirect from BPF */
240 if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
241 sk = udp6_lookup_run_bpf(net, udptable, skb,
242 saddr, sport, daddr, hnum);
243 if (sk) {
244 result = sk;
245 goto done;
246 }
247 }
248
249 /* Got non-wildcard socket or error on first lookup */
250 if (result)
251 goto done;
252
253 /* Lookup wildcard sockets */
254 hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
255 slot2 = hash2 & udptable->mask;
256 hslot2 = &udptable->hash2[slot2];
257
258 result = udp6_lib_lookup2(net, saddr, sport,
259 &in6addr_any, hnum, dif, sdif,
260 hslot2, skb);
261 done:
262 if (IS_ERR(result))
263 return NULL;
264 return result;
265 }
266 EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
267
268 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
269 __be16 sport, __be16 dport,
270 struct udp_table *udptable)
271 {
272 const struct ipv6hdr *iph = ipv6_hdr(skb);
273
274 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
275 &iph->daddr, dport, inet6_iif(skb),
276 inet6_sdif(skb), udptable, skb);
277 }
278
279 struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb,
280 __be16 sport, __be16 dport)
281 {
282 const struct ipv6hdr *iph = ipv6_hdr(skb);
283
284 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
285 &iph->daddr, dport, inet6_iif(skb),
286 inet6_sdif(skb), &udp_table, NULL);
287 }
288
289 /* Must be called under rcu_read_lock().
290 * Does increment socket refcount.
291 */
292 #if IS_ENABLED(CONFIG_NF_TPROXY_IPV6) || IS_ENABLED(CONFIG_NF_SOCKET_IPV6)
293 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
294 const struct in6_addr *daddr, __be16 dport, int dif)
295 {
296 struct sock *sk;
297
298 sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport,
299 dif, 0, &udp_table, NULL);
300 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
301 sk = NULL;
302 return sk;
303 }
304 EXPORT_SYMBOL_GPL(udp6_lib_lookup);
305 #endif
306
307 /* do not use the scratch area len for jumbogram: their length execeeds the
308 * scratch area space; note that the IP6CB flags is still in the first
309 * cacheline, so checking for jumbograms is cheap
310 */
311 static int udp6_skb_len(struct sk_buff *skb)
312 {
313 return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb);
314 }
315
316 /*
317 * This should be easy, if there is something there we
318 * return it, otherwise we block.
319 */
320
321 int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
322 int noblock, int flags, int *addr_len)
323 {
324 struct ipv6_pinfo *np = inet6_sk(sk);
325 struct inet_sock *inet = inet_sk(sk);
326 struct sk_buff *skb;
327 unsigned int ulen, copied;
328 int off, err, peeking = flags & MSG_PEEK;
329 int is_udplite = IS_UDPLITE(sk);
330 struct udp_mib __percpu *mib;
331 bool checksum_valid = false;
332 int is_udp4;
333
334 if (flags & MSG_ERRQUEUE)
335 return ipv6_recv_error(sk, msg, len, addr_len);
336
337 if (np->rxpmtu && np->rxopt.bits.rxpmtu)
338 return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
339
340 try_again:
341 off = sk_peek_offset(sk, flags);
342 skb = __skb_recv_udp(sk, flags, noblock, &off, &err);
343 if (!skb)
344 return err;
345
346 ulen = udp6_skb_len(skb);
347 copied = len;
348 if (copied > ulen - off)
349 copied = ulen - off;
350 else if (copied < ulen)
351 msg->msg_flags |= MSG_TRUNC;
352
353 is_udp4 = (skb->protocol == htons(ETH_P_IP));
354 mib = __UDPX_MIB(sk, is_udp4);
355
356 /*
357 * If checksum is needed at all, try to do it while copying the
358 * data. If the data is truncated, or if we only want a partial
359 * coverage checksum (UDP-Lite), do it before the copy.
360 */
361
362 if (copied < ulen || peeking ||
363 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
364 checksum_valid = udp_skb_csum_unnecessary(skb) ||
365 !__udp_lib_checksum_complete(skb);
366 if (!checksum_valid)
367 goto csum_copy_err;
368 }
369
370 if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
371 if (udp_skb_is_linear(skb))
372 err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
373 else
374 err = skb_copy_datagram_msg(skb, off, msg, copied);
375 } else {
376 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
377 if (err == -EINVAL)
378 goto csum_copy_err;
379 }
380 if (unlikely(err)) {
381 if (!peeking) {
382 atomic_inc(&sk->sk_drops);
383 SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
384 }
385 kfree_skb(skb);
386 return err;
387 }
388 if (!peeking)
389 SNMP_INC_STATS(mib, UDP_MIB_INDATAGRAMS);
390
391 sock_recv_ts_and_drops(msg, sk, skb);
392
393 /* Copy the address. */
394 if (msg->msg_name) {
395 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
396 sin6->sin6_family = AF_INET6;
397 sin6->sin6_port = udp_hdr(skb)->source;
398 sin6->sin6_flowinfo = 0;
399
400 if (is_udp4) {
401 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
402 &sin6->sin6_addr);
403 sin6->sin6_scope_id = 0;
404 } else {
405 sin6->sin6_addr = ipv6_hdr(skb)->saddr;
406 sin6->sin6_scope_id =
407 ipv6_iface_scope_id(&sin6->sin6_addr,
408 inet6_iif(skb));
409 }
410 *addr_len = sizeof(*sin6);
411
412 BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk,
413 (struct sockaddr *)sin6);
414 }
415
416 if (udp_sk(sk)->gro_enabled)
417 udp_cmsg_recv(msg, sk, skb);
418
419 if (np->rxopt.all)
420 ip6_datagram_recv_common_ctl(sk, msg, skb);
421
422 if (is_udp4) {
423 if (inet->cmsg_flags)
424 ip_cmsg_recv_offset(msg, sk, skb,
425 sizeof(struct udphdr), off);
426 } else {
427 if (np->rxopt.all)
428 ip6_datagram_recv_specific_ctl(sk, msg, skb);
429 }
430
431 err = copied;
432 if (flags & MSG_TRUNC)
433 err = ulen;
434
435 skb_consume_udp(sk, skb, peeking ? -err : err);
436 return err;
437
438 csum_copy_err:
439 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
440 udp_skb_destructor)) {
441 SNMP_INC_STATS(mib, UDP_MIB_CSUMERRORS);
442 SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
443 }
444 kfree_skb(skb);
445
446 /* starting over for a new packet, but check if we need to yield */
447 cond_resched();
448 msg->msg_flags &= ~MSG_TRUNC;
449 goto try_again;
450 }
451
452 DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
453 void udpv6_encap_enable(void)
454 {
455 static_branch_inc(&udpv6_encap_needed_key);
456 }
457 EXPORT_SYMBOL(udpv6_encap_enable);
458
459 /* Handler for tunnels with arbitrary destination ports: no socket lookup, go
460 * through error handlers in encapsulations looking for a match.
461 */
462 static int __udp6_lib_err_encap_no_sk(struct sk_buff *skb,
463 struct inet6_skb_parm *opt,
464 u8 type, u8 code, int offset, __be32 info)
465 {
466 int i;
467
468 for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
469 int (*handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
470 u8 type, u8 code, int offset, __be32 info);
471 const struct ip6_tnl_encap_ops *encap;
472
473 encap = rcu_dereference(ip6tun_encaps[i]);
474 if (!encap)
475 continue;
476 handler = encap->err_handler;
477 if (handler && !handler(skb, opt, type, code, offset, info))
478 return 0;
479 }
480
481 return -ENOENT;
482 }
483
484 /* Try to match ICMP errors to UDP tunnels by looking up a socket without
485 * reversing source and destination port: this will match tunnels that force the
486 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
487 * lwtunnels might actually break this assumption by being configured with
488 * different destination ports on endpoints, in this case we won't be able to
489 * trace ICMP messages back to them.
490 *
491 * If this doesn't match any socket, probe tunnels with arbitrary destination
492 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
493 * we've sent packets to won't necessarily match the local destination port.
494 *
495 * Then ask the tunnel implementation to match the error against a valid
496 * association.
497 *
498 * Return an error if we can't find a match, the socket if we need further
499 * processing, zero otherwise.
500 */
501 static struct sock *__udp6_lib_err_encap(struct net *net,
502 const struct ipv6hdr *hdr, int offset,
503 struct udphdr *uh,
504 struct udp_table *udptable,
505 struct sock *sk,
506 struct sk_buff *skb,
507 struct inet6_skb_parm *opt,
508 u8 type, u8 code, __be32 info)
509 {
510 int (*lookup)(struct sock *sk, struct sk_buff *skb);
511 int network_offset, transport_offset;
512 struct udp_sock *up;
513
514 network_offset = skb_network_offset(skb);
515 transport_offset = skb_transport_offset(skb);
516
517 /* Network header needs to point to the outer IPv6 header inside ICMP */
518 skb_reset_network_header(skb);
519
520 /* Transport header needs to point to the UDP header */
521 skb_set_transport_header(skb, offset);
522
523 if (sk) {
524 up = udp_sk(sk);
525
526 lookup = READ_ONCE(up->encap_err_lookup);
527 if (lookup && lookup(sk, skb))
528 sk = NULL;
529
530 goto out;
531 }
532
533 sk = __udp6_lib_lookup(net, &hdr->daddr, uh->source,
534 &hdr->saddr, uh->dest,
535 inet6_iif(skb), 0, udptable, skb);
536 if (sk) {
537 up = udp_sk(sk);
538
539 lookup = READ_ONCE(up->encap_err_lookup);
540 if (!lookup || lookup(sk, skb))
541 sk = NULL;
542 }
543
544 out:
545 if (!sk) {
546 sk = ERR_PTR(__udp6_lib_err_encap_no_sk(skb, opt, type, code,
547 offset, info));
548 }
549
550 skb_set_transport_header(skb, transport_offset);
551 skb_set_network_header(skb, network_offset);
552
553 return sk;
554 }
555
556 int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
557 u8 type, u8 code, int offset, __be32 info,
558 struct udp_table *udptable)
559 {
560 struct ipv6_pinfo *np;
561 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
562 const struct in6_addr *saddr = &hdr->saddr;
563 const struct in6_addr *daddr = &hdr->daddr;
564 struct udphdr *uh = (struct udphdr *)(skb->data+offset);
565 bool tunnel = false;
566 struct sock *sk;
567 int harderr;
568 int err;
569 struct net *net = dev_net(skb->dev);
570
571 sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
572 inet6_iif(skb), inet6_sdif(skb), udptable, NULL);
573
574 if (!sk || udp_sk(sk)->encap_type) {
575 /* No socket for error: try tunnels before discarding */
576 if (static_branch_unlikely(&udpv6_encap_needed_key)) {
577 sk = __udp6_lib_err_encap(net, hdr, offset, uh,
578 udptable, sk, skb,
579 opt, type, code, info);
580 if (!sk)
581 return 0;
582 } else
583 sk = ERR_PTR(-ENOENT);
584
585 if (IS_ERR(sk)) {
586 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
587 ICMP6_MIB_INERRORS);
588 return PTR_ERR(sk);
589 }
590
591 tunnel = true;
592 }
593
594 harderr = icmpv6_err_convert(type, code, &err);
595 np = inet6_sk(sk);
596
597 if (type == ICMPV6_PKT_TOOBIG) {
598 if (!ip6_sk_accept_pmtu(sk))
599 goto out;
600 ip6_sk_update_pmtu(skb, sk, info);
601 if (np->pmtudisc != IPV6_PMTUDISC_DONT)
602 harderr = 1;
603 }
604 if (type == NDISC_REDIRECT) {
605 if (tunnel) {
606 ip6_redirect(skb, sock_net(sk), inet6_iif(skb),
607 sk->sk_mark, sk->sk_uid);
608 } else {
609 ip6_sk_redirect(skb, sk);
610 }
611 goto out;
612 }
613
614 /* Tunnels don't have an application socket: don't pass errors back */
615 if (tunnel)
616 goto out;
617
618 if (!np->recverr) {
619 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
620 goto out;
621 } else {
622 ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
623 }
624
625 sk->sk_err = err;
626 sk_error_report(sk);
627 out:
628 return 0;
629 }
630
631 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
632 {
633 int rc;
634
635 if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
636 sock_rps_save_rxhash(sk, skb);
637 sk_mark_napi_id(sk, skb);
638 sk_incoming_cpu_update(sk);
639 } else {
640 sk_mark_napi_id_once(sk, skb);
641 }
642
643 rc = __udp_enqueue_schedule_skb(sk, skb);
644 if (rc < 0) {
645 int is_udplite = IS_UDPLITE(sk);
646
647 /* Note that an ENOMEM error is charged twice */
648 if (rc == -ENOMEM)
649 UDP6_INC_STATS(sock_net(sk),
650 UDP_MIB_RCVBUFERRORS, is_udplite);
651 else
652 UDP6_INC_STATS(sock_net(sk),
653 UDP_MIB_MEMERRORS, is_udplite);
654 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
655 kfree_skb(skb);
656 return -1;
657 }
658
659 return 0;
660 }
661
662 static __inline__ int udpv6_err(struct sk_buff *skb,
663 struct inet6_skb_parm *opt, u8 type,
664 u8 code, int offset, __be32 info)
665 {
666 return __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
667 }
668
669 static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
670 {
671 struct udp_sock *up = udp_sk(sk);
672 int is_udplite = IS_UDPLITE(sk);
673
674 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
675 goto drop;
676
677 if (static_branch_unlikely(&udpv6_encap_needed_key) && up->encap_type) {
678 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
679
680 /*
681 * This is an encapsulation socket so pass the skb to
682 * the socket's udp_encap_rcv() hook. Otherwise, just
683 * fall through and pass this up the UDP socket.
684 * up->encap_rcv() returns the following value:
685 * =0 if skb was successfully passed to the encap
686 * handler or was discarded by it.
687 * >0 if skb should be passed on to UDP.
688 * <0 if skb should be resubmitted as proto -N
689 */
690
691 /* if we're overly short, let UDP handle it */
692 encap_rcv = READ_ONCE(up->encap_rcv);
693 if (encap_rcv) {
694 int ret;
695
696 /* Verify checksum before giving to encap */
697 if (udp_lib_checksum_complete(skb))
698 goto csum_error;
699
700 ret = encap_rcv(sk, skb);
701 if (ret <= 0) {
702 __UDP_INC_STATS(sock_net(sk),
703 UDP_MIB_INDATAGRAMS,
704 is_udplite);
705 return -ret;
706 }
707 }
708
709 /* FALLTHROUGH -- it's a UDP Packet */
710 }
711
712 /*
713 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
714 */
715 if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
716
717 if (up->pcrlen == 0) { /* full coverage was set */
718 net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n",
719 UDP_SKB_CB(skb)->cscov, skb->len);
720 goto drop;
721 }
722 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
723 net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
724 UDP_SKB_CB(skb)->cscov, up->pcrlen);
725 goto drop;
726 }
727 }
728
729 prefetch(&sk->sk_rmem_alloc);
730 if (rcu_access_pointer(sk->sk_filter) &&
731 udp_lib_checksum_complete(skb))
732 goto csum_error;
733
734 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
735 goto drop;
736
737 udp_csum_pull_header(skb);
738
739 skb_dst_drop(skb);
740
741 return __udpv6_queue_rcv_skb(sk, skb);
742
743 csum_error:
744 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
745 drop:
746 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
747 atomic_inc(&sk->sk_drops);
748 kfree_skb(skb);
749 return -1;
750 }
751
752 static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
753 {
754 struct sk_buff *next, *segs;
755 int ret;
756
757 if (likely(!udp_unexpected_gso(sk, skb)))
758 return udpv6_queue_rcv_one_skb(sk, skb);
759
760 __skb_push(skb, -skb_mac_offset(skb));
761 segs = udp_rcv_segment(sk, skb, false);
762 skb_list_walk_safe(segs, skb, next) {
763 __skb_pull(skb, skb_transport_offset(skb));
764
765 udp_post_segment_fix_csum(skb);
766 ret = udpv6_queue_rcv_one_skb(sk, skb);
767 if (ret > 0)
768 ip6_protocol_deliver_rcu(dev_net(skb->dev), skb, ret,
769 true);
770 }
771 return 0;
772 }
773
774 static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
775 __be16 loc_port, const struct in6_addr *loc_addr,
776 __be16 rmt_port, const struct in6_addr *rmt_addr,
777 int dif, int sdif, unsigned short hnum)
778 {
779 struct inet_sock *inet = inet_sk(sk);
780
781 if (!net_eq(sock_net(sk), net))
782 return false;
783
784 if (udp_sk(sk)->udp_port_hash != hnum ||
785 sk->sk_family != PF_INET6 ||
786 (inet->inet_dport && inet->inet_dport != rmt_port) ||
787 (!ipv6_addr_any(&sk->sk_v6_daddr) &&
788 !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
789 !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif) ||
790 (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
791 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
792 return false;
793 if (!inet6_mc_check(sk, loc_addr, rmt_addr))
794 return false;
795 return true;
796 }
797
798 static void udp6_csum_zero_error(struct sk_buff *skb)
799 {
800 /* RFC 2460 section 8.1 says that we SHOULD log
801 * this error. Well, it is reasonable.
802 */
803 net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
804 &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
805 &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
806 }
807
808 /*
809 * Note: called only from the BH handler context,
810 * so we don't need to lock the hashes.
811 */
812 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
813 const struct in6_addr *saddr, const struct in6_addr *daddr,
814 struct udp_table *udptable, int proto)
815 {
816 struct sock *sk, *first = NULL;
817 const struct udphdr *uh = udp_hdr(skb);
818 unsigned short hnum = ntohs(uh->dest);
819 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
820 unsigned int offset = offsetof(typeof(*sk), sk_node);
821 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
822 int dif = inet6_iif(skb);
823 int sdif = inet6_sdif(skb);
824 struct hlist_node *node;
825 struct sk_buff *nskb;
826
827 if (use_hash2) {
828 hash2_any = ipv6_portaddr_hash(net, &in6addr_any, hnum) &
829 udptable->mask;
830 hash2 = ipv6_portaddr_hash(net, daddr, hnum) & udptable->mask;
831 start_lookup:
832 hslot = &udptable->hash2[hash2];
833 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
834 }
835
836 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
837 if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
838 uh->source, saddr, dif, sdif,
839 hnum))
840 continue;
841 /* If zero checksum and no_check is not on for
842 * the socket then skip it.
843 */
844 if (!uh->check && !udp_sk(sk)->no_check6_rx)
845 continue;
846 if (!first) {
847 first = sk;
848 continue;
849 }
850 nskb = skb_clone(skb, GFP_ATOMIC);
851 if (unlikely(!nskb)) {
852 atomic_inc(&sk->sk_drops);
853 __UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
854 IS_UDPLITE(sk));
855 __UDP6_INC_STATS(net, UDP_MIB_INERRORS,
856 IS_UDPLITE(sk));
857 continue;
858 }
859
860 if (udpv6_queue_rcv_skb(sk, nskb) > 0)
861 consume_skb(nskb);
862 }
863
864 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
865 if (use_hash2 && hash2 != hash2_any) {
866 hash2 = hash2_any;
867 goto start_lookup;
868 }
869
870 if (first) {
871 if (udpv6_queue_rcv_skb(first, skb) > 0)
872 consume_skb(skb);
873 } else {
874 kfree_skb(skb);
875 __UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
876 proto == IPPROTO_UDPLITE);
877 }
878 return 0;
879 }
880
881 static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
882 {
883 if (udp_sk_rx_dst_set(sk, dst)) {
884 const struct rt6_info *rt = (const struct rt6_info *)dst;
885
886 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
887 }
888 }
889
890 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
891 * return code conversion for ip layer consumption
892 */
893 static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
894 struct udphdr *uh)
895 {
896 int ret;
897
898 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
899 skb_checksum_try_convert(skb, IPPROTO_UDP, ip6_compute_pseudo);
900
901 ret = udpv6_queue_rcv_skb(sk, skb);
902
903 /* a return value > 0 means to resubmit the input */
904 if (ret > 0)
905 return ret;
906 return 0;
907 }
908
909 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
910 int proto)
911 {
912 const struct in6_addr *saddr, *daddr;
913 struct net *net = dev_net(skb->dev);
914 struct udphdr *uh;
915 struct sock *sk;
916 bool refcounted;
917 u32 ulen = 0;
918
919 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
920 goto discard;
921
922 saddr = &ipv6_hdr(skb)->saddr;
923 daddr = &ipv6_hdr(skb)->daddr;
924 uh = udp_hdr(skb);
925
926 ulen = ntohs(uh->len);
927 if (ulen > skb->len)
928 goto short_packet;
929
930 if (proto == IPPROTO_UDP) {
931 /* UDP validates ulen. */
932
933 /* Check for jumbo payload */
934 if (ulen == 0)
935 ulen = skb->len;
936
937 if (ulen < sizeof(*uh))
938 goto short_packet;
939
940 if (ulen < skb->len) {
941 if (pskb_trim_rcsum(skb, ulen))
942 goto short_packet;
943 saddr = &ipv6_hdr(skb)->saddr;
944 daddr = &ipv6_hdr(skb)->daddr;
945 uh = udp_hdr(skb);
946 }
947 }
948
949 if (udp6_csum_init(skb, uh, proto))
950 goto csum_error;
951
952 /* Check if the socket is already available, e.g. due to early demux */
953 sk = skb_steal_sock(skb, &refcounted);
954 if (sk) {
955 struct dst_entry *dst = skb_dst(skb);
956 int ret;
957
958 if (unlikely(sk->sk_rx_dst != dst))
959 udp6_sk_rx_dst_set(sk, dst);
960
961 if (!uh->check && !udp_sk(sk)->no_check6_rx) {
962 if (refcounted)
963 sock_put(sk);
964 goto report_csum_error;
965 }
966
967 ret = udp6_unicast_rcv_skb(sk, skb, uh);
968 if (refcounted)
969 sock_put(sk);
970 return ret;
971 }
972
973 /*
974 * Multicast receive code
975 */
976 if (ipv6_addr_is_multicast(daddr))
977 return __udp6_lib_mcast_deliver(net, skb,
978 saddr, daddr, udptable, proto);
979
980 /* Unicast */
981 sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
982 if (sk) {
983 if (!uh->check && !udp_sk(sk)->no_check6_rx)
984 goto report_csum_error;
985 return udp6_unicast_rcv_skb(sk, skb, uh);
986 }
987
988 if (!uh->check)
989 goto report_csum_error;
990
991 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
992 goto discard;
993
994 if (udp_lib_checksum_complete(skb))
995 goto csum_error;
996
997 __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
998 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
999
1000 kfree_skb(skb);
1001 return 0;
1002
1003 short_packet:
1004 net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
1005 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1006 saddr, ntohs(uh->source),
1007 ulen, skb->len,
1008 daddr, ntohs(uh->dest));
1009 goto discard;
1010
1011 report_csum_error:
1012 udp6_csum_zero_error(skb);
1013 csum_error:
1014 __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
1015 discard:
1016 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1017 kfree_skb(skb);
1018 return 0;
1019 }
1020
1021
1022 static struct sock *__udp6_lib_demux_lookup(struct net *net,
1023 __be16 loc_port, const struct in6_addr *loc_addr,
1024 __be16 rmt_port, const struct in6_addr *rmt_addr,
1025 int dif, int sdif)
1026 {
1027 unsigned short hnum = ntohs(loc_port);
1028 unsigned int hash2 = ipv6_portaddr_hash(net, loc_addr, hnum);
1029 unsigned int slot2 = hash2 & udp_table.mask;
1030 struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
1031 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
1032 struct sock *sk;
1033
1034 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
1035 if (sk->sk_state == TCP_ESTABLISHED &&
1036 INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif, sdif))
1037 return sk;
1038 /* Only check first socket in chain */
1039 break;
1040 }
1041 return NULL;
1042 }
1043
1044 INDIRECT_CALLABLE_SCOPE void udp_v6_early_demux(struct sk_buff *skb)
1045 {
1046 struct net *net = dev_net(skb->dev);
1047 const struct udphdr *uh;
1048 struct sock *sk;
1049 struct dst_entry *dst;
1050 int dif = skb->dev->ifindex;
1051 int sdif = inet6_sdif(skb);
1052
1053 if (!pskb_may_pull(skb, skb_transport_offset(skb) +
1054 sizeof(struct udphdr)))
1055 return;
1056
1057 uh = udp_hdr(skb);
1058
1059 if (skb->pkt_type == PACKET_HOST)
1060 sk = __udp6_lib_demux_lookup(net, uh->dest,
1061 &ipv6_hdr(skb)->daddr,
1062 uh->source, &ipv6_hdr(skb)->saddr,
1063 dif, sdif);
1064 else
1065 return;
1066
1067 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
1068 return;
1069
1070 skb->sk = sk;
1071 skb->destructor = sock_efree;
1072 dst = READ_ONCE(sk->sk_rx_dst);
1073
1074 if (dst)
1075 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1076 if (dst) {
1077 /* set noref for now.
1078 * any place which wants to hold dst has to call
1079 * dst_hold_safe()
1080 */
1081 skb_dst_set_noref(skb, dst);
1082 }
1083 }
1084
1085 INDIRECT_CALLABLE_SCOPE int udpv6_rcv(struct sk_buff *skb)
1086 {
1087 return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1088 }
1089
1090 /*
1091 * Throw away all pending data and cancel the corking. Socket is locked.
1092 */
1093 static void udp_v6_flush_pending_frames(struct sock *sk)
1094 {
1095 struct udp_sock *up = udp_sk(sk);
1096
1097 if (up->pending == AF_INET)
1098 udp_flush_pending_frames(sk);
1099 else if (up->pending) {
1100 up->len = 0;
1101 up->pending = 0;
1102 ip6_flush_pending_frames(sk);
1103 }
1104 }
1105
1106 static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
1107 int addr_len)
1108 {
1109 if (addr_len < offsetofend(struct sockaddr, sa_family))
1110 return -EINVAL;
1111 /* The following checks are replicated from __ip6_datagram_connect()
1112 * and intended to prevent BPF program called below from accessing
1113 * bytes that are out of the bound specified by user in addr_len.
1114 */
1115 if (uaddr->sa_family == AF_INET) {
1116 if (__ipv6_only_sock(sk))
1117 return -EAFNOSUPPORT;
1118 return udp_pre_connect(sk, uaddr, addr_len);
1119 }
1120
1121 if (addr_len < SIN6_LEN_RFC2133)
1122 return -EINVAL;
1123
1124 return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr);
1125 }
1126
1127 /**
1128 * udp6_hwcsum_outgoing - handle outgoing HW checksumming
1129 * @sk: socket we are sending on
1130 * @skb: sk_buff containing the filled-in UDP header
1131 * (checksum field must be zeroed out)
1132 * @saddr: source address
1133 * @daddr: destination address
1134 * @len: length of packet
1135 */
1136 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
1137 const struct in6_addr *saddr,
1138 const struct in6_addr *daddr, int len)
1139 {
1140 unsigned int offset;
1141 struct udphdr *uh = udp_hdr(skb);
1142 struct sk_buff *frags = skb_shinfo(skb)->frag_list;
1143 __wsum csum = 0;
1144
1145 if (!frags) {
1146 /* Only one fragment on the socket. */
1147 skb->csum_start = skb_transport_header(skb) - skb->head;
1148 skb->csum_offset = offsetof(struct udphdr, check);
1149 uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
1150 } else {
1151 /*
1152 * HW-checksum won't work as there are two or more
1153 * fragments on the socket so that all csums of sk_buffs
1154 * should be together
1155 */
1156 offset = skb_transport_offset(skb);
1157 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
1158 csum = skb->csum;
1159
1160 skb->ip_summed = CHECKSUM_NONE;
1161
1162 do {
1163 csum = csum_add(csum, frags->csum);
1164 } while ((frags = frags->next));
1165
1166 uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
1167 csum);
1168 if (uh->check == 0)
1169 uh->check = CSUM_MANGLED_0;
1170 }
1171 }
1172
1173 /*
1174 * Sending
1175 */
1176
1177 static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6,
1178 struct inet_cork *cork)
1179 {
1180 struct sock *sk = skb->sk;
1181 struct udphdr *uh;
1182 int err = 0;
1183 int is_udplite = IS_UDPLITE(sk);
1184 __wsum csum = 0;
1185 int offset = skb_transport_offset(skb);
1186 int len = skb->len - offset;
1187 int datalen = len - sizeof(*uh);
1188
1189 /*
1190 * Create a UDP header
1191 */
1192 uh = udp_hdr(skb);
1193 uh->source = fl6->fl6_sport;
1194 uh->dest = fl6->fl6_dport;
1195 uh->len = htons(len);
1196 uh->check = 0;
1197
1198 if (cork->gso_size) {
1199 const int hlen = skb_network_header_len(skb) +
1200 sizeof(struct udphdr);
1201
1202 if (hlen + cork->gso_size > cork->fragsize) {
1203 kfree_skb(skb);
1204 return -EINVAL;
1205 }
1206 if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) {
1207 kfree_skb(skb);
1208 return -EINVAL;
1209 }
1210 if (udp_sk(sk)->no_check6_tx) {
1211 kfree_skb(skb);
1212 return -EINVAL;
1213 }
1214 if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
1215 dst_xfrm(skb_dst(skb))) {
1216 kfree_skb(skb);
1217 return -EIO;
1218 }
1219
1220 if (datalen > cork->gso_size) {
1221 skb_shinfo(skb)->gso_size = cork->gso_size;
1222 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
1223 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
1224 cork->gso_size);
1225 }
1226 goto csum_partial;
1227 }
1228
1229 if (is_udplite)
1230 csum = udplite_csum(skb);
1231 else if (udp_sk(sk)->no_check6_tx) { /* UDP csum disabled */
1232 skb->ip_summed = CHECKSUM_NONE;
1233 goto send;
1234 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1235 csum_partial:
1236 udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len);
1237 goto send;
1238 } else
1239 csum = udp_csum(skb);
1240
1241 /* add protocol-dependent pseudo-header */
1242 uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
1243 len, fl6->flowi6_proto, csum);
1244 if (uh->check == 0)
1245 uh->check = CSUM_MANGLED_0;
1246
1247 send:
1248 err = ip6_send_skb(skb);
1249 if (err) {
1250 if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
1251 UDP6_INC_STATS(sock_net(sk),
1252 UDP_MIB_SNDBUFERRORS, is_udplite);
1253 err = 0;
1254 }
1255 } else {
1256 UDP6_INC_STATS(sock_net(sk),
1257 UDP_MIB_OUTDATAGRAMS, is_udplite);
1258 }
1259 return err;
1260 }
1261
1262 static int udp_v6_push_pending_frames(struct sock *sk)
1263 {
1264 struct sk_buff *skb;
1265 struct udp_sock *up = udp_sk(sk);
1266 struct flowi6 fl6;
1267 int err = 0;
1268
1269 if (up->pending == AF_INET)
1270 return udp_push_pending_frames(sk);
1271
1272 /* ip6_finish_skb will release the cork, so make a copy of
1273 * fl6 here.
1274 */
1275 fl6 = inet_sk(sk)->cork.fl.u.ip6;
1276
1277 skb = ip6_finish_skb(sk);
1278 if (!skb)
1279 goto out;
1280
1281 err = udp_v6_send_skb(skb, &fl6, &inet_sk(sk)->cork.base);
1282
1283 out:
1284 up->len = 0;
1285 up->pending = 0;
1286 return err;
1287 }
1288
1289 int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1290 {
1291 struct ipv6_txoptions opt_space;
1292 struct udp_sock *up = udp_sk(sk);
1293 struct inet_sock *inet = inet_sk(sk);
1294 struct ipv6_pinfo *np = inet6_sk(sk);
1295 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1296 struct in6_addr *daddr, *final_p, final;
1297 struct ipv6_txoptions *opt = NULL;
1298 struct ipv6_txoptions *opt_to_free = NULL;
1299 struct ip6_flowlabel *flowlabel = NULL;
1300 struct flowi6 fl6;
1301 struct dst_entry *dst;
1302 struct ipcm6_cookie ipc6;
1303 int addr_len = msg->msg_namelen;
1304 bool connected = false;
1305 int ulen = len;
1306 int corkreq = READ_ONCE(up->corkflag) || msg->msg_flags&MSG_MORE;
1307 int err;
1308 int is_udplite = IS_UDPLITE(sk);
1309 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1310
1311 ipcm6_init(&ipc6);
1312 ipc6.gso_size = READ_ONCE(up->gso_size);
1313 ipc6.sockc.tsflags = sk->sk_tsflags;
1314 ipc6.sockc.mark = sk->sk_mark;
1315
1316 /* destination address check */
1317 if (sin6) {
1318 if (addr_len < offsetof(struct sockaddr, sa_data))
1319 return -EINVAL;
1320
1321 switch (sin6->sin6_family) {
1322 case AF_INET6:
1323 if (addr_len < SIN6_LEN_RFC2133)
1324 return -EINVAL;
1325 daddr = &sin6->sin6_addr;
1326 if (ipv6_addr_any(daddr) &&
1327 ipv6_addr_v4mapped(&np->saddr))
1328 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
1329 daddr);
1330 break;
1331 case AF_INET:
1332 goto do_udp_sendmsg;
1333 case AF_UNSPEC:
1334 msg->msg_name = sin6 = NULL;
1335 msg->msg_namelen = addr_len = 0;
1336 daddr = NULL;
1337 break;
1338 default:
1339 return -EINVAL;
1340 }
1341 } else if (!up->pending) {
1342 if (sk->sk_state != TCP_ESTABLISHED)
1343 return -EDESTADDRREQ;
1344 daddr = &sk->sk_v6_daddr;
1345 } else
1346 daddr = NULL;
1347
1348 if (daddr) {
1349 if (ipv6_addr_v4mapped(daddr)) {
1350 struct sockaddr_in sin;
1351 sin.sin_family = AF_INET;
1352 sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1353 sin.sin_addr.s_addr = daddr->s6_addr32[3];
1354 msg->msg_name = &sin;
1355 msg->msg_namelen = sizeof(sin);
1356 do_udp_sendmsg:
1357 if (__ipv6_only_sock(sk))
1358 return -ENETUNREACH;
1359 return udp_sendmsg(sk, msg, len);
1360 }
1361 }
1362
1363 if (up->pending == AF_INET)
1364 return udp_sendmsg(sk, msg, len);
1365
1366 /* Rough check on arithmetic overflow,
1367 better check is made in ip6_append_data().
1368 */
1369 if (len > INT_MAX - sizeof(struct udphdr))
1370 return -EMSGSIZE;
1371
1372 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
1373 if (up->pending) {
1374 /*
1375 * There are pending frames.
1376 * The socket lock must be held while it's corked.
1377 */
1378 lock_sock(sk);
1379 if (likely(up->pending)) {
1380 if (unlikely(up->pending != AF_INET6)) {
1381 release_sock(sk);
1382 return -EAFNOSUPPORT;
1383 }
1384 dst = NULL;
1385 goto do_append_data;
1386 }
1387 release_sock(sk);
1388 }
1389 ulen += sizeof(struct udphdr);
1390
1391 memset(&fl6, 0, sizeof(fl6));
1392
1393 if (sin6) {
1394 if (sin6->sin6_port == 0)
1395 return -EINVAL;
1396
1397 fl6.fl6_dport = sin6->sin6_port;
1398 daddr = &sin6->sin6_addr;
1399
1400 if (np->sndflow) {
1401 fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1402 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
1403 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1404 if (IS_ERR(flowlabel))
1405 return -EINVAL;
1406 }
1407 }
1408
1409 /*
1410 * Otherwise it will be difficult to maintain
1411 * sk->sk_dst_cache.
1412 */
1413 if (sk->sk_state == TCP_ESTABLISHED &&
1414 ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
1415 daddr = &sk->sk_v6_daddr;
1416
1417 if (addr_len >= sizeof(struct sockaddr_in6) &&
1418 sin6->sin6_scope_id &&
1419 __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1420 fl6.flowi6_oif = sin6->sin6_scope_id;
1421 } else {
1422 if (sk->sk_state != TCP_ESTABLISHED)
1423 return -EDESTADDRREQ;
1424
1425 fl6.fl6_dport = inet->inet_dport;
1426 daddr = &sk->sk_v6_daddr;
1427 fl6.flowlabel = np->flow_label;
1428 connected = true;
1429 }
1430
1431 if (!fl6.flowi6_oif)
1432 fl6.flowi6_oif = sk->sk_bound_dev_if;
1433
1434 if (!fl6.flowi6_oif)
1435 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1436
1437 fl6.flowi6_mark = ipc6.sockc.mark;
1438 fl6.flowi6_uid = sk->sk_uid;
1439
1440 if (msg->msg_controllen) {
1441 opt = &opt_space;
1442 memset(opt, 0, sizeof(struct ipv6_txoptions));
1443 opt->tot_len = sizeof(*opt);
1444 ipc6.opt = opt;
1445
1446 err = udp_cmsg_send(sk, msg, &ipc6.gso_size);
1447 if (err > 0)
1448 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6,
1449 &ipc6);
1450 if (err < 0) {
1451 fl6_sock_release(flowlabel);
1452 return err;
1453 }
1454 if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1455 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1456 if (IS_ERR(flowlabel))
1457 return -EINVAL;
1458 }
1459 if (!(opt->opt_nflen|opt->opt_flen))
1460 opt = NULL;
1461 connected = false;
1462 }
1463 if (!opt) {
1464 opt = txopt_get(np);
1465 opt_to_free = opt;
1466 }
1467 if (flowlabel)
1468 opt = fl6_merge_options(&opt_space, flowlabel, opt);
1469 opt = ipv6_fixup_options(&opt_space, opt);
1470 ipc6.opt = opt;
1471
1472 fl6.flowi6_proto = sk->sk_protocol;
1473 fl6.daddr = *daddr;
1474 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
1475 fl6.saddr = np->saddr;
1476 fl6.fl6_sport = inet->inet_sport;
1477
1478 if (cgroup_bpf_enabled(CGROUP_UDP6_SENDMSG) && !connected) {
1479 err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk,
1480 (struct sockaddr *)sin6, &fl6.saddr);
1481 if (err)
1482 goto out_no_dst;
1483 if (sin6) {
1484 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
1485 /* BPF program rewrote IPv6-only by IPv4-mapped
1486 * IPv6. It's currently unsupported.
1487 */
1488 err = -ENOTSUPP;
1489 goto out_no_dst;
1490 }
1491 if (sin6->sin6_port == 0) {
1492 /* BPF program set invalid port. Reject it. */
1493 err = -EINVAL;
1494 goto out_no_dst;
1495 }
1496 fl6.fl6_dport = sin6->sin6_port;
1497 fl6.daddr = sin6->sin6_addr;
1498 }
1499 }
1500
1501 if (ipv6_addr_any(&fl6.daddr))
1502 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1503
1504 final_p = fl6_update_dst(&fl6, opt, &final);
1505 if (final_p)
1506 connected = false;
1507
1508 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
1509 fl6.flowi6_oif = np->mcast_oif;
1510 connected = false;
1511 } else if (!fl6.flowi6_oif)
1512 fl6.flowi6_oif = np->ucast_oif;
1513
1514 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
1515
1516 if (ipc6.tclass < 0)
1517 ipc6.tclass = np->tclass;
1518
1519 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
1520
1521 dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, connected);
1522 if (IS_ERR(dst)) {
1523 err = PTR_ERR(dst);
1524 dst = NULL;
1525 goto out;
1526 }
1527
1528 if (ipc6.hlimit < 0)
1529 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
1530
1531 if (msg->msg_flags&MSG_CONFIRM)
1532 goto do_confirm;
1533 back_from_confirm:
1534
1535 /* Lockless fast path for the non-corking case */
1536 if (!corkreq) {
1537 struct inet_cork_full cork;
1538 struct sk_buff *skb;
1539
1540 skb = ip6_make_skb(sk, getfrag, msg, ulen,
1541 sizeof(struct udphdr), &ipc6,
1542 &fl6, (struct rt6_info *)dst,
1543 msg->msg_flags, &cork);
1544 err = PTR_ERR(skb);
1545 if (!IS_ERR_OR_NULL(skb))
1546 err = udp_v6_send_skb(skb, &fl6, &cork.base);
1547 goto out;
1548 }
1549
1550 lock_sock(sk);
1551 if (unlikely(up->pending)) {
1552 /* The socket is already corked while preparing it. */
1553 /* ... which is an evident application bug. --ANK */
1554 release_sock(sk);
1555
1556 net_dbg_ratelimited("udp cork app bug 2\n");
1557 err = -EINVAL;
1558 goto out;
1559 }
1560
1561 up->pending = AF_INET6;
1562
1563 do_append_data:
1564 if (ipc6.dontfrag < 0)
1565 ipc6.dontfrag = np->dontfrag;
1566 up->len += ulen;
1567 err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr),
1568 &ipc6, &fl6, (struct rt6_info *)dst,
1569 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1570 if (err)
1571 udp_v6_flush_pending_frames(sk);
1572 else if (!corkreq)
1573 err = udp_v6_push_pending_frames(sk);
1574 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1575 up->pending = 0;
1576
1577 if (err > 0)
1578 err = np->recverr ? net_xmit_errno(err) : 0;
1579 release_sock(sk);
1580
1581 out:
1582 dst_release(dst);
1583 out_no_dst:
1584 fl6_sock_release(flowlabel);
1585 txopt_put(opt_to_free);
1586 if (!err)
1587 return len;
1588 /*
1589 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1590 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1591 * we don't have a good statistic (IpOutDiscards but it can be too many
1592 * things). We could add another new stat but at least for now that
1593 * seems like overkill.
1594 */
1595 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1596 UDP6_INC_STATS(sock_net(sk),
1597 UDP_MIB_SNDBUFERRORS, is_udplite);
1598 }
1599 return err;
1600
1601 do_confirm:
1602 if (msg->msg_flags & MSG_PROBE)
1603 dst_confirm_neigh(dst, &fl6.daddr);
1604 if (!(msg->msg_flags&MSG_PROBE) || len)
1605 goto back_from_confirm;
1606 err = 0;
1607 goto out;
1608 }
1609
1610 void udpv6_destroy_sock(struct sock *sk)
1611 {
1612 struct udp_sock *up = udp_sk(sk);
1613 lock_sock(sk);
1614
1615 /* protects from races with udp_abort() */
1616 sock_set_flag(sk, SOCK_DEAD);
1617 udp_v6_flush_pending_frames(sk);
1618 release_sock(sk);
1619
1620 if (static_branch_unlikely(&udpv6_encap_needed_key)) {
1621 if (up->encap_type) {
1622 void (*encap_destroy)(struct sock *sk);
1623 encap_destroy = READ_ONCE(up->encap_destroy);
1624 if (encap_destroy)
1625 encap_destroy(sk);
1626 }
1627 if (up->encap_enabled) {
1628 static_branch_dec(&udpv6_encap_needed_key);
1629 udp_encap_disable();
1630 }
1631 }
1632
1633 inet6_destroy_sock(sk);
1634 }
1635
1636 /*
1637 * Socket option code for UDP
1638 */
1639 int udpv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1640 unsigned int optlen)
1641 {
1642 if (level == SOL_UDP || level == SOL_UDPLITE)
1643 return udp_lib_setsockopt(sk, level, optname,
1644 optval, optlen,
1645 udp_v6_push_pending_frames);
1646 return ipv6_setsockopt(sk, level, optname, optval, optlen);
1647 }
1648
1649 int udpv6_getsockopt(struct sock *sk, int level, int optname,
1650 char __user *optval, int __user *optlen)
1651 {
1652 if (level == SOL_UDP || level == SOL_UDPLITE)
1653 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1654 return ipv6_getsockopt(sk, level, optname, optval, optlen);
1655 }
1656
1657 /* thinking of making this const? Don't.
1658 * early_demux can change based on sysctl.
1659 */
1660 static struct inet6_protocol udpv6_protocol = {
1661 .early_demux = udp_v6_early_demux,
1662 .early_demux_handler = udp_v6_early_demux,
1663 .handler = udpv6_rcv,
1664 .err_handler = udpv6_err,
1665 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1666 };
1667
1668 /* ------------------------------------------------------------------------ */
1669 #ifdef CONFIG_PROC_FS
1670 int udp6_seq_show(struct seq_file *seq, void *v)
1671 {
1672 if (v == SEQ_START_TOKEN) {
1673 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1674 } else {
1675 int bucket = ((struct udp_iter_state *)seq->private)->bucket;
1676 struct inet_sock *inet = inet_sk(v);
1677 __u16 srcp = ntohs(inet->inet_sport);
1678 __u16 destp = ntohs(inet->inet_dport);
1679 __ip6_dgram_sock_seq_show(seq, v, srcp, destp,
1680 udp_rqueue_get(v), bucket);
1681 }
1682 return 0;
1683 }
1684
1685 const struct seq_operations udp6_seq_ops = {
1686 .start = udp_seq_start,
1687 .next = udp_seq_next,
1688 .stop = udp_seq_stop,
1689 .show = udp6_seq_show,
1690 };
1691 EXPORT_SYMBOL(udp6_seq_ops);
1692
1693 static struct udp_seq_afinfo udp6_seq_afinfo = {
1694 .family = AF_INET6,
1695 .udp_table = &udp_table,
1696 };
1697
1698 int __net_init udp6_proc_init(struct net *net)
1699 {
1700 if (!proc_create_net_data("udp6", 0444, net->proc_net, &udp6_seq_ops,
1701 sizeof(struct udp_iter_state), &udp6_seq_afinfo))
1702 return -ENOMEM;
1703 return 0;
1704 }
1705
1706 void udp6_proc_exit(struct net *net)
1707 {
1708 remove_proc_entry("udp6", net->proc_net);
1709 }
1710 #endif /* CONFIG_PROC_FS */
1711
1712 /* ------------------------------------------------------------------------ */
1713
1714 struct proto udpv6_prot = {
1715 .name = "UDPv6",
1716 .owner = THIS_MODULE,
1717 .close = udp_lib_close,
1718 .pre_connect = udpv6_pre_connect,
1719 .connect = ip6_datagram_connect,
1720 .disconnect = udp_disconnect,
1721 .ioctl = udp_ioctl,
1722 .init = udp_init_sock,
1723 .destroy = udpv6_destroy_sock,
1724 .setsockopt = udpv6_setsockopt,
1725 .getsockopt = udpv6_getsockopt,
1726 .sendmsg = udpv6_sendmsg,
1727 .recvmsg = udpv6_recvmsg,
1728 .release_cb = ip6_datagram_release_cb,
1729 .hash = udp_lib_hash,
1730 .unhash = udp_lib_unhash,
1731 .rehash = udp_v6_rehash,
1732 .get_port = udp_v6_get_port,
1733 #ifdef CONFIG_BPF_SYSCALL
1734 .psock_update_sk_prot = udp_bpf_update_proto,
1735 #endif
1736 .memory_allocated = &udp_memory_allocated,
1737 .sysctl_mem = sysctl_udp_mem,
1738 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
1739 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
1740 .obj_size = sizeof(struct udp6_sock),
1741 .h.udp_table = &udp_table,
1742 .diag_destroy = udp_abort,
1743 };
1744
1745 static struct inet_protosw udpv6_protosw = {
1746 .type = SOCK_DGRAM,
1747 .protocol = IPPROTO_UDP,
1748 .prot = &udpv6_prot,
1749 .ops = &inet6_dgram_ops,
1750 .flags = INET_PROTOSW_PERMANENT,
1751 };
1752
1753 int __init udpv6_init(void)
1754 {
1755 int ret;
1756
1757 ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1758 if (ret)
1759 goto out;
1760
1761 ret = inet6_register_protosw(&udpv6_protosw);
1762 if (ret)
1763 goto out_udpv6_protocol;
1764 out:
1765 return ret;
1766
1767 out_udpv6_protocol:
1768 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1769 goto out;
1770 }
1771
1772 void udpv6_exit(void)
1773 {
1774 inet6_unregister_protosw(&udpv6_protosw);
1775 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1776 }
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