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[mirror_ubuntu-focal-kernel.git] / net / ipv6 / udp.c
1 /*
2 * UDP over IPv6
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * Based on linux/ipv4/udp.c
9 *
10 * Fixes:
11 * Hideaki YOSHIFUJI : sin6_scope_id support
12 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
13 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
14 * a single port at the same time.
15 * Kazunori MIYAZAWA @USAGI: change process style to use ip6_append_data
16 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/udp6 to seq_file.
17 *
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
22 */
23
24 #include <linux/errno.h>
25 #include <linux/types.h>
26 #include <linux/socket.h>
27 #include <linux/sockios.h>
28 #include <linux/net.h>
29 #include <linux/in6.h>
30 #include <linux/netdevice.h>
31 #include <linux/if_arp.h>
32 #include <linux/ipv6.h>
33 #include <linux/icmpv6.h>
34 #include <linux/init.h>
35 #include <linux/module.h>
36 #include <linux/skbuff.h>
37 #include <linux/slab.h>
38 #include <linux/uaccess.h>
39 #include <linux/indirect_call_wrapper.h>
40
41 #include <net/addrconf.h>
42 #include <net/ndisc.h>
43 #include <net/protocol.h>
44 #include <net/transp_v6.h>
45 #include <net/ip6_route.h>
46 #include <net/raw.h>
47 #include <net/tcp_states.h>
48 #include <net/ip6_checksum.h>
49 #include <net/ip6_tunnel.h>
50 #include <net/xfrm.h>
51 #include <net/inet_hashtables.h>
52 #include <net/inet6_hashtables.h>
53 #include <net/busy_poll.h>
54 #include <net/sock_reuseport.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
61 static bool udp6_lib_exact_dif_match(struct net *net, struct sk_buff *skb)
62 {
63 #if defined(CONFIG_NET_L3_MASTER_DEV)
64 if (!net->ipv4.sysctl_udp_l3mdev_accept &&
65 skb && ipv6_l3mdev_skb(IP6CB(skb)->flags))
66 return true;
67 #endif
68 return false;
69 }
70
71 static u32 udp6_ehashfn(const struct net *net,
72 const struct in6_addr *laddr,
73 const u16 lport,
74 const struct in6_addr *faddr,
75 const __be16 fport)
76 {
77 static u32 udp6_ehash_secret __read_mostly;
78 static u32 udp_ipv6_hash_secret __read_mostly;
79
80 u32 lhash, fhash;
81
82 net_get_random_once(&udp6_ehash_secret,
83 sizeof(udp6_ehash_secret));
84 net_get_random_once(&udp_ipv6_hash_secret,
85 sizeof(udp_ipv6_hash_secret));
86
87 lhash = (__force u32)laddr->s6_addr32[3];
88 fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret);
89
90 return __inet6_ehashfn(lhash, lport, fhash, fport,
91 udp_ipv6_hash_secret + net_hash_mix(net));
92 }
93
94 int udp_v6_get_port(struct sock *sk, unsigned short snum)
95 {
96 unsigned int hash2_nulladdr =
97 ipv6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
98 unsigned int hash2_partial =
99 ipv6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
100
101 /* precompute partial secondary hash */
102 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
103 return udp_lib_get_port(sk, snum, hash2_nulladdr);
104 }
105
106 void udp_v6_rehash(struct sock *sk)
107 {
108 u16 new_hash = ipv6_portaddr_hash(sock_net(sk),
109 &sk->sk_v6_rcv_saddr,
110 inet_sk(sk)->inet_num);
111
112 udp_lib_rehash(sk, new_hash);
113 }
114
115 static int compute_score(struct sock *sk, struct net *net,
116 const struct in6_addr *saddr, __be16 sport,
117 const struct in6_addr *daddr, unsigned short hnum,
118 int dif, int sdif, bool exact_dif)
119 {
120 int score;
121 struct inet_sock *inet;
122 bool dev_match;
123
124 if (!net_eq(sock_net(sk), net) ||
125 udp_sk(sk)->udp_port_hash != hnum ||
126 sk->sk_family != PF_INET6)
127 return -1;
128
129 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
130 return -1;
131
132 score = 0;
133 inet = inet_sk(sk);
134
135 if (inet->inet_dport) {
136 if (inet->inet_dport != sport)
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 dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif);
148 if (!dev_match)
149 return -1;
150 score++;
151
152 if (sk->sk_incoming_cpu == raw_smp_processor_id())
153 score++;
154
155 return score;
156 }
157
158 /* called with rcu_read_lock() */
159 static struct sock *udp6_lib_lookup2(struct net *net,
160 const struct in6_addr *saddr, __be16 sport,
161 const struct in6_addr *daddr, unsigned int hnum,
162 int dif, int sdif, bool exact_dif,
163 struct udp_hslot *hslot2, struct sk_buff *skb)
164 {
165 struct sock *sk, *result;
166 int score, badness;
167 u32 hash = 0;
168
169 result = NULL;
170 badness = -1;
171 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
172 score = compute_score(sk, net, saddr, sport,
173 daddr, hnum, dif, sdif, exact_dif);
174 if (score > badness) {
175 if (sk->sk_reuseport) {
176 hash = udp6_ehashfn(net, daddr, hnum,
177 saddr, sport);
178
179 result = reuseport_select_sock(sk, hash, skb,
180 sizeof(struct udphdr));
181 if (result)
182 return result;
183 }
184 result = sk;
185 badness = score;
186 }
187 }
188 return result;
189 }
190
191 /* rcu_read_lock() must be held */
192 struct sock *__udp6_lib_lookup(struct net *net,
193 const struct in6_addr *saddr, __be16 sport,
194 const struct in6_addr *daddr, __be16 dport,
195 int dif, int sdif, struct udp_table *udptable,
196 struct sk_buff *skb)
197 {
198 unsigned short hnum = ntohs(dport);
199 unsigned int hash2, slot2;
200 struct udp_hslot *hslot2;
201 struct sock *result;
202 bool exact_dif = udp6_lib_exact_dif_match(net, skb);
203
204 hash2 = ipv6_portaddr_hash(net, daddr, hnum);
205 slot2 = hash2 & udptable->mask;
206 hslot2 = &udptable->hash2[slot2];
207
208 result = udp6_lib_lookup2(net, saddr, sport,
209 daddr, hnum, dif, sdif, exact_dif,
210 hslot2, skb);
211 if (!result) {
212 hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
213 slot2 = hash2 & udptable->mask;
214
215 hslot2 = &udptable->hash2[slot2];
216
217 result = udp6_lib_lookup2(net, saddr, sport,
218 &in6addr_any, hnum, dif, sdif,
219 exact_dif, hslot2,
220 skb);
221 }
222 if (unlikely(IS_ERR(result)))
223 return NULL;
224 return result;
225 }
226 EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
227
228 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
229 __be16 sport, __be16 dport,
230 struct udp_table *udptable)
231 {
232 const struct ipv6hdr *iph = ipv6_hdr(skb);
233
234 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
235 &iph->daddr, dport, inet6_iif(skb),
236 inet6_sdif(skb), udptable, skb);
237 }
238
239 struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
240 __be16 sport, __be16 dport)
241 {
242 const struct ipv6hdr *iph = ipv6_hdr(skb);
243
244 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
245 &iph->daddr, dport, inet6_iif(skb),
246 inet6_sdif(skb), &udp_table, skb);
247 }
248 EXPORT_SYMBOL_GPL(udp6_lib_lookup_skb);
249
250 /* Must be called under rcu_read_lock().
251 * Does increment socket refcount.
252 */
253 #if IS_ENABLED(CONFIG_NF_TPROXY_IPV6) || IS_ENABLED(CONFIG_NF_SOCKET_IPV6)
254 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
255 const struct in6_addr *daddr, __be16 dport, int dif)
256 {
257 struct sock *sk;
258
259 sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport,
260 dif, 0, &udp_table, NULL);
261 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
262 sk = NULL;
263 return sk;
264 }
265 EXPORT_SYMBOL_GPL(udp6_lib_lookup);
266 #endif
267
268 /* do not use the scratch area len for jumbogram: their length execeeds the
269 * scratch area space; note that the IP6CB flags is still in the first
270 * cacheline, so checking for jumbograms is cheap
271 */
272 static int udp6_skb_len(struct sk_buff *skb)
273 {
274 return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb);
275 }
276
277 /*
278 * This should be easy, if there is something there we
279 * return it, otherwise we block.
280 */
281
282 int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
283 int noblock, int flags, int *addr_len)
284 {
285 struct ipv6_pinfo *np = inet6_sk(sk);
286 struct inet_sock *inet = inet_sk(sk);
287 struct sk_buff *skb;
288 unsigned int ulen, copied;
289 int off, err, peeking = flags & MSG_PEEK;
290 int is_udplite = IS_UDPLITE(sk);
291 struct udp_mib __percpu *mib;
292 bool checksum_valid = false;
293 int is_udp4;
294
295 if (flags & MSG_ERRQUEUE)
296 return ipv6_recv_error(sk, msg, len, addr_len);
297
298 if (np->rxpmtu && np->rxopt.bits.rxpmtu)
299 return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
300
301 try_again:
302 off = sk_peek_offset(sk, flags);
303 skb = __skb_recv_udp(sk, flags, noblock, &off, &err);
304 if (!skb)
305 return err;
306
307 ulen = udp6_skb_len(skb);
308 copied = len;
309 if (copied > ulen - off)
310 copied = ulen - off;
311 else if (copied < ulen)
312 msg->msg_flags |= MSG_TRUNC;
313
314 is_udp4 = (skb->protocol == htons(ETH_P_IP));
315 mib = __UDPX_MIB(sk, is_udp4);
316
317 /*
318 * If checksum is needed at all, try to do it while copying the
319 * data. If the data is truncated, or if we only want a partial
320 * coverage checksum (UDP-Lite), do it before the copy.
321 */
322
323 if (copied < ulen || peeking ||
324 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
325 checksum_valid = udp_skb_csum_unnecessary(skb) ||
326 !__udp_lib_checksum_complete(skb);
327 if (!checksum_valid)
328 goto csum_copy_err;
329 }
330
331 if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
332 if (udp_skb_is_linear(skb))
333 err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
334 else
335 err = skb_copy_datagram_msg(skb, off, msg, copied);
336 } else {
337 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
338 if (err == -EINVAL)
339 goto csum_copy_err;
340 }
341 if (unlikely(err)) {
342 if (!peeking) {
343 atomic_inc(&sk->sk_drops);
344 SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
345 }
346 kfree_skb(skb);
347 return err;
348 }
349 if (!peeking)
350 SNMP_INC_STATS(mib, UDP_MIB_INDATAGRAMS);
351
352 sock_recv_ts_and_drops(msg, sk, skb);
353
354 /* Copy the address. */
355 if (msg->msg_name) {
356 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
357 sin6->sin6_family = AF_INET6;
358 sin6->sin6_port = udp_hdr(skb)->source;
359 sin6->sin6_flowinfo = 0;
360
361 if (is_udp4) {
362 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
363 &sin6->sin6_addr);
364 sin6->sin6_scope_id = 0;
365 } else {
366 sin6->sin6_addr = ipv6_hdr(skb)->saddr;
367 sin6->sin6_scope_id =
368 ipv6_iface_scope_id(&sin6->sin6_addr,
369 inet6_iif(skb));
370 }
371 *addr_len = sizeof(*sin6);
372 }
373
374 if (udp_sk(sk)->gro_enabled)
375 udp_cmsg_recv(msg, sk, skb);
376
377 if (np->rxopt.all)
378 ip6_datagram_recv_common_ctl(sk, msg, skb);
379
380 if (is_udp4) {
381 if (inet->cmsg_flags)
382 ip_cmsg_recv_offset(msg, sk, skb,
383 sizeof(struct udphdr), off);
384 } else {
385 if (np->rxopt.all)
386 ip6_datagram_recv_specific_ctl(sk, msg, skb);
387 }
388
389 err = copied;
390 if (flags & MSG_TRUNC)
391 err = ulen;
392
393 skb_consume_udp(sk, skb, peeking ? -err : err);
394 return err;
395
396 csum_copy_err:
397 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
398 udp_skb_destructor)) {
399 SNMP_INC_STATS(mib, UDP_MIB_CSUMERRORS);
400 SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
401 }
402 kfree_skb(skb);
403
404 /* starting over for a new packet, but check if we need to yield */
405 cond_resched();
406 msg->msg_flags &= ~MSG_TRUNC;
407 goto try_again;
408 }
409
410 DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
411 void udpv6_encap_enable(void)
412 {
413 static_branch_inc(&udpv6_encap_needed_key);
414 }
415 EXPORT_SYMBOL(udpv6_encap_enable);
416
417 /* Handler for tunnels with arbitrary destination ports: no socket lookup, go
418 * through error handlers in encapsulations looking for a match.
419 */
420 static int __udp6_lib_err_encap_no_sk(struct sk_buff *skb,
421 struct inet6_skb_parm *opt,
422 u8 type, u8 code, int offset, __be32 info)
423 {
424 int i;
425
426 for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
427 int (*handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
428 u8 type, u8 code, int offset, __be32 info);
429 const struct ip6_tnl_encap_ops *encap;
430
431 encap = rcu_dereference(ip6tun_encaps[i]);
432 if (!encap)
433 continue;
434 handler = encap->err_handler;
435 if (handler && !handler(skb, opt, type, code, offset, info))
436 return 0;
437 }
438
439 return -ENOENT;
440 }
441
442 /* Try to match ICMP errors to UDP tunnels by looking up a socket without
443 * reversing source and destination port: this will match tunnels that force the
444 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
445 * lwtunnels might actually break this assumption by being configured with
446 * different destination ports on endpoints, in this case we won't be able to
447 * trace ICMP messages back to them.
448 *
449 * If this doesn't match any socket, probe tunnels with arbitrary destination
450 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
451 * we've sent packets to won't necessarily match the local destination port.
452 *
453 * Then ask the tunnel implementation to match the error against a valid
454 * association.
455 *
456 * Return an error if we can't find a match, the socket if we need further
457 * processing, zero otherwise.
458 */
459 static struct sock *__udp6_lib_err_encap(struct net *net,
460 const struct ipv6hdr *hdr, int offset,
461 struct udphdr *uh,
462 struct udp_table *udptable,
463 struct sk_buff *skb,
464 struct inet6_skb_parm *opt,
465 u8 type, u8 code, __be32 info)
466 {
467 int network_offset, transport_offset;
468 struct sock *sk;
469
470 network_offset = skb_network_offset(skb);
471 transport_offset = skb_transport_offset(skb);
472
473 /* Network header needs to point to the outer IPv6 header inside ICMP */
474 skb_reset_network_header(skb);
475
476 /* Transport header needs to point to the UDP header */
477 skb_set_transport_header(skb, offset);
478
479 sk = __udp6_lib_lookup(net, &hdr->daddr, uh->source,
480 &hdr->saddr, uh->dest,
481 inet6_iif(skb), 0, udptable, skb);
482 if (sk) {
483 int (*lookup)(struct sock *sk, struct sk_buff *skb);
484 struct udp_sock *up = udp_sk(sk);
485
486 lookup = READ_ONCE(up->encap_err_lookup);
487 if (!lookup || lookup(sk, skb))
488 sk = NULL;
489 }
490
491 if (!sk) {
492 sk = ERR_PTR(__udp6_lib_err_encap_no_sk(skb, opt, type, code,
493 offset, info));
494 }
495
496 skb_set_transport_header(skb, transport_offset);
497 skb_set_network_header(skb, network_offset);
498
499 return sk;
500 }
501
502 int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
503 u8 type, u8 code, int offset, __be32 info,
504 struct udp_table *udptable)
505 {
506 struct ipv6_pinfo *np;
507 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
508 const struct in6_addr *saddr = &hdr->saddr;
509 const struct in6_addr *daddr = &hdr->daddr;
510 struct udphdr *uh = (struct udphdr *)(skb->data+offset);
511 bool tunnel = false;
512 struct sock *sk;
513 int harderr;
514 int err;
515 struct net *net = dev_net(skb->dev);
516
517 sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
518 inet6_iif(skb), inet6_sdif(skb), udptable, skb);
519 if (!sk) {
520 /* No socket for error: try tunnels before discarding */
521 sk = ERR_PTR(-ENOENT);
522 if (static_branch_unlikely(&udpv6_encap_needed_key)) {
523 sk = __udp6_lib_err_encap(net, hdr, offset, uh,
524 udptable, skb,
525 opt, type, code, info);
526 if (!sk)
527 return 0;
528 }
529
530 if (IS_ERR(sk)) {
531 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
532 ICMP6_MIB_INERRORS);
533 return PTR_ERR(sk);
534 }
535
536 tunnel = true;
537 }
538
539 harderr = icmpv6_err_convert(type, code, &err);
540 np = inet6_sk(sk);
541
542 if (type == ICMPV6_PKT_TOOBIG) {
543 if (!ip6_sk_accept_pmtu(sk))
544 goto out;
545 ip6_sk_update_pmtu(skb, sk, info);
546 if (np->pmtudisc != IPV6_PMTUDISC_DONT)
547 harderr = 1;
548 }
549 if (type == NDISC_REDIRECT) {
550 if (tunnel) {
551 ip6_redirect(skb, sock_net(sk), inet6_iif(skb),
552 sk->sk_mark, sk->sk_uid);
553 } else {
554 ip6_sk_redirect(skb, sk);
555 }
556 goto out;
557 }
558
559 /* Tunnels don't have an application socket: don't pass errors back */
560 if (tunnel)
561 goto out;
562
563 if (!np->recverr) {
564 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
565 goto out;
566 } else {
567 ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
568 }
569
570 sk->sk_err = err;
571 sk->sk_error_report(sk);
572 out:
573 return 0;
574 }
575
576 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
577 {
578 int rc;
579
580 if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
581 sock_rps_save_rxhash(sk, skb);
582 sk_mark_napi_id(sk, skb);
583 sk_incoming_cpu_update(sk);
584 } else {
585 sk_mark_napi_id_once(sk, skb);
586 }
587
588 rc = __udp_enqueue_schedule_skb(sk, skb);
589 if (rc < 0) {
590 int is_udplite = IS_UDPLITE(sk);
591
592 /* Note that an ENOMEM error is charged twice */
593 if (rc == -ENOMEM)
594 UDP6_INC_STATS(sock_net(sk),
595 UDP_MIB_RCVBUFERRORS, is_udplite);
596 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
597 kfree_skb(skb);
598 return -1;
599 }
600
601 return 0;
602 }
603
604 static __inline__ int udpv6_err(struct sk_buff *skb,
605 struct inet6_skb_parm *opt, u8 type,
606 u8 code, int offset, __be32 info)
607 {
608 return __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
609 }
610
611 static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
612 {
613 struct udp_sock *up = udp_sk(sk);
614 int is_udplite = IS_UDPLITE(sk);
615
616 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
617 goto drop;
618
619 if (static_branch_unlikely(&udpv6_encap_needed_key) && up->encap_type) {
620 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
621
622 /*
623 * This is an encapsulation socket so pass the skb to
624 * the socket's udp_encap_rcv() hook. Otherwise, just
625 * fall through and pass this up the UDP socket.
626 * up->encap_rcv() returns the following value:
627 * =0 if skb was successfully passed to the encap
628 * handler or was discarded by it.
629 * >0 if skb should be passed on to UDP.
630 * <0 if skb should be resubmitted as proto -N
631 */
632
633 /* if we're overly short, let UDP handle it */
634 encap_rcv = READ_ONCE(up->encap_rcv);
635 if (encap_rcv) {
636 int ret;
637
638 /* Verify checksum before giving to encap */
639 if (udp_lib_checksum_complete(skb))
640 goto csum_error;
641
642 ret = encap_rcv(sk, skb);
643 if (ret <= 0) {
644 __UDP_INC_STATS(sock_net(sk),
645 UDP_MIB_INDATAGRAMS,
646 is_udplite);
647 return -ret;
648 }
649 }
650
651 /* FALLTHROUGH -- it's a UDP Packet */
652 }
653
654 /*
655 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
656 */
657 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
658
659 if (up->pcrlen == 0) { /* full coverage was set */
660 net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n",
661 UDP_SKB_CB(skb)->cscov, skb->len);
662 goto drop;
663 }
664 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
665 net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
666 UDP_SKB_CB(skb)->cscov, up->pcrlen);
667 goto drop;
668 }
669 }
670
671 prefetch(&sk->sk_rmem_alloc);
672 if (rcu_access_pointer(sk->sk_filter) &&
673 udp_lib_checksum_complete(skb))
674 goto csum_error;
675
676 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
677 goto drop;
678
679 udp_csum_pull_header(skb);
680
681 skb_dst_drop(skb);
682
683 return __udpv6_queue_rcv_skb(sk, skb);
684
685 csum_error:
686 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
687 drop:
688 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
689 atomic_inc(&sk->sk_drops);
690 kfree_skb(skb);
691 return -1;
692 }
693
694 static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
695 {
696 struct sk_buff *next, *segs;
697 int ret;
698
699 if (likely(!udp_unexpected_gso(sk, skb)))
700 return udpv6_queue_rcv_one_skb(sk, skb);
701
702 __skb_push(skb, -skb_mac_offset(skb));
703 segs = udp_rcv_segment(sk, skb, false);
704 for (skb = segs; skb; skb = next) {
705 next = skb->next;
706 __skb_pull(skb, skb_transport_offset(skb));
707
708 ret = udpv6_queue_rcv_one_skb(sk, skb);
709 if (ret > 0)
710 ip6_protocol_deliver_rcu(dev_net(skb->dev), skb, ret,
711 true);
712 }
713 return 0;
714 }
715
716 static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
717 __be16 loc_port, const struct in6_addr *loc_addr,
718 __be16 rmt_port, const struct in6_addr *rmt_addr,
719 int dif, int sdif, unsigned short hnum)
720 {
721 struct inet_sock *inet = inet_sk(sk);
722
723 if (!net_eq(sock_net(sk), net))
724 return false;
725
726 if (udp_sk(sk)->udp_port_hash != hnum ||
727 sk->sk_family != PF_INET6 ||
728 (inet->inet_dport && inet->inet_dport != rmt_port) ||
729 (!ipv6_addr_any(&sk->sk_v6_daddr) &&
730 !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
731 !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif) ||
732 (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
733 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
734 return false;
735 if (!inet6_mc_check(sk, loc_addr, rmt_addr))
736 return false;
737 return true;
738 }
739
740 static void udp6_csum_zero_error(struct sk_buff *skb)
741 {
742 /* RFC 2460 section 8.1 says that we SHOULD log
743 * this error. Well, it is reasonable.
744 */
745 net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
746 &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
747 &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
748 }
749
750 /*
751 * Note: called only from the BH handler context,
752 * so we don't need to lock the hashes.
753 */
754 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
755 const struct in6_addr *saddr, const struct in6_addr *daddr,
756 struct udp_table *udptable, int proto)
757 {
758 struct sock *sk, *first = NULL;
759 const struct udphdr *uh = udp_hdr(skb);
760 unsigned short hnum = ntohs(uh->dest);
761 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
762 unsigned int offset = offsetof(typeof(*sk), sk_node);
763 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
764 int dif = inet6_iif(skb);
765 int sdif = inet6_sdif(skb);
766 struct hlist_node *node;
767 struct sk_buff *nskb;
768
769 if (use_hash2) {
770 hash2_any = ipv6_portaddr_hash(net, &in6addr_any, hnum) &
771 udptable->mask;
772 hash2 = ipv6_portaddr_hash(net, daddr, hnum) & udptable->mask;
773 start_lookup:
774 hslot = &udptable->hash2[hash2];
775 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
776 }
777
778 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
779 if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
780 uh->source, saddr, dif, sdif,
781 hnum))
782 continue;
783 /* If zero checksum and no_check is not on for
784 * the socket then skip it.
785 */
786 if (!uh->check && !udp_sk(sk)->no_check6_rx)
787 continue;
788 if (!first) {
789 first = sk;
790 continue;
791 }
792 nskb = skb_clone(skb, GFP_ATOMIC);
793 if (unlikely(!nskb)) {
794 atomic_inc(&sk->sk_drops);
795 __UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
796 IS_UDPLITE(sk));
797 __UDP6_INC_STATS(net, UDP_MIB_INERRORS,
798 IS_UDPLITE(sk));
799 continue;
800 }
801
802 if (udpv6_queue_rcv_skb(sk, nskb) > 0)
803 consume_skb(nskb);
804 }
805
806 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
807 if (use_hash2 && hash2 != hash2_any) {
808 hash2 = hash2_any;
809 goto start_lookup;
810 }
811
812 if (first) {
813 if (udpv6_queue_rcv_skb(first, skb) > 0)
814 consume_skb(skb);
815 } else {
816 kfree_skb(skb);
817 __UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
818 proto == IPPROTO_UDPLITE);
819 }
820 return 0;
821 }
822
823 static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
824 {
825 if (udp_sk_rx_dst_set(sk, dst)) {
826 const struct rt6_info *rt = (const struct rt6_info *)dst;
827
828 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
829 }
830 }
831
832 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
833 * return code conversion for ip layer consumption
834 */
835 static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
836 struct udphdr *uh)
837 {
838 int ret;
839
840 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
841 skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
842 ip6_compute_pseudo);
843
844 ret = udpv6_queue_rcv_skb(sk, skb);
845
846 /* a return value > 0 means to resubmit the input */
847 if (ret > 0)
848 return ret;
849 return 0;
850 }
851
852 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
853 int proto)
854 {
855 const struct in6_addr *saddr, *daddr;
856 struct net *net = dev_net(skb->dev);
857 struct udphdr *uh;
858 struct sock *sk;
859 u32 ulen = 0;
860
861 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
862 goto discard;
863
864 saddr = &ipv6_hdr(skb)->saddr;
865 daddr = &ipv6_hdr(skb)->daddr;
866 uh = udp_hdr(skb);
867
868 ulen = ntohs(uh->len);
869 if (ulen > skb->len)
870 goto short_packet;
871
872 if (proto == IPPROTO_UDP) {
873 /* UDP validates ulen. */
874
875 /* Check for jumbo payload */
876 if (ulen == 0)
877 ulen = skb->len;
878
879 if (ulen < sizeof(*uh))
880 goto short_packet;
881
882 if (ulen < skb->len) {
883 if (pskb_trim_rcsum(skb, ulen))
884 goto short_packet;
885 saddr = &ipv6_hdr(skb)->saddr;
886 daddr = &ipv6_hdr(skb)->daddr;
887 uh = udp_hdr(skb);
888 }
889 }
890
891 if (udp6_csum_init(skb, uh, proto))
892 goto csum_error;
893
894 /* Check if the socket is already available, e.g. due to early demux */
895 sk = skb_steal_sock(skb);
896 if (sk) {
897 struct dst_entry *dst = skb_dst(skb);
898 int ret;
899
900 if (unlikely(sk->sk_rx_dst != dst))
901 udp6_sk_rx_dst_set(sk, dst);
902
903 if (!uh->check && !udp_sk(sk)->no_check6_rx) {
904 sock_put(sk);
905 goto report_csum_error;
906 }
907
908 ret = udp6_unicast_rcv_skb(sk, skb, uh);
909 sock_put(sk);
910 return ret;
911 }
912
913 /*
914 * Multicast receive code
915 */
916 if (ipv6_addr_is_multicast(daddr))
917 return __udp6_lib_mcast_deliver(net, skb,
918 saddr, daddr, udptable, proto);
919
920 /* Unicast */
921 sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
922 if (sk) {
923 if (!uh->check && !udp_sk(sk)->no_check6_rx)
924 goto report_csum_error;
925 return udp6_unicast_rcv_skb(sk, skb, uh);
926 }
927
928 if (!uh->check)
929 goto report_csum_error;
930
931 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
932 goto discard;
933
934 if (udp_lib_checksum_complete(skb))
935 goto csum_error;
936
937 __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
938 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
939
940 kfree_skb(skb);
941 return 0;
942
943 short_packet:
944 net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
945 proto == IPPROTO_UDPLITE ? "-Lite" : "",
946 saddr, ntohs(uh->source),
947 ulen, skb->len,
948 daddr, ntohs(uh->dest));
949 goto discard;
950
951 report_csum_error:
952 udp6_csum_zero_error(skb);
953 csum_error:
954 __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
955 discard:
956 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
957 kfree_skb(skb);
958 return 0;
959 }
960
961
962 static struct sock *__udp6_lib_demux_lookup(struct net *net,
963 __be16 loc_port, const struct in6_addr *loc_addr,
964 __be16 rmt_port, const struct in6_addr *rmt_addr,
965 int dif, int sdif)
966 {
967 unsigned short hnum = ntohs(loc_port);
968 unsigned int hash2 = ipv6_portaddr_hash(net, loc_addr, hnum);
969 unsigned int slot2 = hash2 & udp_table.mask;
970 struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
971 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
972 struct sock *sk;
973
974 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
975 if (sk->sk_state == TCP_ESTABLISHED &&
976 INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif, sdif))
977 return sk;
978 /* Only check first socket in chain */
979 break;
980 }
981 return NULL;
982 }
983
984 INDIRECT_CALLABLE_SCOPE void udp_v6_early_demux(struct sk_buff *skb)
985 {
986 struct net *net = dev_net(skb->dev);
987 const struct udphdr *uh;
988 struct sock *sk;
989 struct dst_entry *dst;
990 int dif = skb->dev->ifindex;
991 int sdif = inet6_sdif(skb);
992
993 if (!pskb_may_pull(skb, skb_transport_offset(skb) +
994 sizeof(struct udphdr)))
995 return;
996
997 uh = udp_hdr(skb);
998
999 if (skb->pkt_type == PACKET_HOST)
1000 sk = __udp6_lib_demux_lookup(net, uh->dest,
1001 &ipv6_hdr(skb)->daddr,
1002 uh->source, &ipv6_hdr(skb)->saddr,
1003 dif, sdif);
1004 else
1005 return;
1006
1007 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
1008 return;
1009
1010 skb->sk = sk;
1011 skb->destructor = sock_efree;
1012 dst = READ_ONCE(sk->sk_rx_dst);
1013
1014 if (dst)
1015 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1016 if (dst) {
1017 /* set noref for now.
1018 * any place which wants to hold dst has to call
1019 * dst_hold_safe()
1020 */
1021 skb_dst_set_noref(skb, dst);
1022 }
1023 }
1024
1025 INDIRECT_CALLABLE_SCOPE int udpv6_rcv(struct sk_buff *skb)
1026 {
1027 return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1028 }
1029
1030 /*
1031 * Throw away all pending data and cancel the corking. Socket is locked.
1032 */
1033 static void udp_v6_flush_pending_frames(struct sock *sk)
1034 {
1035 struct udp_sock *up = udp_sk(sk);
1036
1037 if (up->pending == AF_INET)
1038 udp_flush_pending_frames(sk);
1039 else if (up->pending) {
1040 up->len = 0;
1041 up->pending = 0;
1042 ip6_flush_pending_frames(sk);
1043 }
1044 }
1045
1046 static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
1047 int addr_len)
1048 {
1049 if (addr_len < offsetofend(struct sockaddr, sa_family))
1050 return -EINVAL;
1051 /* The following checks are replicated from __ip6_datagram_connect()
1052 * and intended to prevent BPF program called below from accessing
1053 * bytes that are out of the bound specified by user in addr_len.
1054 */
1055 if (uaddr->sa_family == AF_INET) {
1056 if (__ipv6_only_sock(sk))
1057 return -EAFNOSUPPORT;
1058 return udp_pre_connect(sk, uaddr, addr_len);
1059 }
1060
1061 if (addr_len < SIN6_LEN_RFC2133)
1062 return -EINVAL;
1063
1064 return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr);
1065 }
1066
1067 /**
1068 * udp6_hwcsum_outgoing - handle outgoing HW checksumming
1069 * @sk: socket we are sending on
1070 * @skb: sk_buff containing the filled-in UDP header
1071 * (checksum field must be zeroed out)
1072 */
1073 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
1074 const struct in6_addr *saddr,
1075 const struct in6_addr *daddr, int len)
1076 {
1077 unsigned int offset;
1078 struct udphdr *uh = udp_hdr(skb);
1079 struct sk_buff *frags = skb_shinfo(skb)->frag_list;
1080 __wsum csum = 0;
1081
1082 if (!frags) {
1083 /* Only one fragment on the socket. */
1084 skb->csum_start = skb_transport_header(skb) - skb->head;
1085 skb->csum_offset = offsetof(struct udphdr, check);
1086 uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
1087 } else {
1088 /*
1089 * HW-checksum won't work as there are two or more
1090 * fragments on the socket so that all csums of sk_buffs
1091 * should be together
1092 */
1093 offset = skb_transport_offset(skb);
1094 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
1095 csum = skb->csum;
1096
1097 skb->ip_summed = CHECKSUM_NONE;
1098
1099 do {
1100 csum = csum_add(csum, frags->csum);
1101 } while ((frags = frags->next));
1102
1103 uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
1104 csum);
1105 if (uh->check == 0)
1106 uh->check = CSUM_MANGLED_0;
1107 }
1108 }
1109
1110 /*
1111 * Sending
1112 */
1113
1114 static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6,
1115 struct inet_cork *cork)
1116 {
1117 struct sock *sk = skb->sk;
1118 struct udphdr *uh;
1119 int err = 0;
1120 int is_udplite = IS_UDPLITE(sk);
1121 __wsum csum = 0;
1122 int offset = skb_transport_offset(skb);
1123 int len = skb->len - offset;
1124
1125 /*
1126 * Create a UDP header
1127 */
1128 uh = udp_hdr(skb);
1129 uh->source = fl6->fl6_sport;
1130 uh->dest = fl6->fl6_dport;
1131 uh->len = htons(len);
1132 uh->check = 0;
1133
1134 if (cork->gso_size) {
1135 const int hlen = skb_network_header_len(skb) +
1136 sizeof(struct udphdr);
1137
1138 if (hlen + cork->gso_size > cork->fragsize) {
1139 kfree_skb(skb);
1140 return -EINVAL;
1141 }
1142 if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) {
1143 kfree_skb(skb);
1144 return -EINVAL;
1145 }
1146 if (udp_sk(sk)->no_check6_tx) {
1147 kfree_skb(skb);
1148 return -EINVAL;
1149 }
1150 if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
1151 dst_xfrm(skb_dst(skb))) {
1152 kfree_skb(skb);
1153 return -EIO;
1154 }
1155
1156 skb_shinfo(skb)->gso_size = cork->gso_size;
1157 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
1158 goto csum_partial;
1159 }
1160
1161 if (is_udplite)
1162 csum = udplite_csum(skb);
1163 else if (udp_sk(sk)->no_check6_tx) { /* UDP csum disabled */
1164 skb->ip_summed = CHECKSUM_NONE;
1165 goto send;
1166 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1167 csum_partial:
1168 udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len);
1169 goto send;
1170 } else
1171 csum = udp_csum(skb);
1172
1173 /* add protocol-dependent pseudo-header */
1174 uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
1175 len, fl6->flowi6_proto, csum);
1176 if (uh->check == 0)
1177 uh->check = CSUM_MANGLED_0;
1178
1179 send:
1180 err = ip6_send_skb(skb);
1181 if (err) {
1182 if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
1183 UDP6_INC_STATS(sock_net(sk),
1184 UDP_MIB_SNDBUFERRORS, is_udplite);
1185 err = 0;
1186 }
1187 } else {
1188 UDP6_INC_STATS(sock_net(sk),
1189 UDP_MIB_OUTDATAGRAMS, is_udplite);
1190 }
1191 return err;
1192 }
1193
1194 static int udp_v6_push_pending_frames(struct sock *sk)
1195 {
1196 struct sk_buff *skb;
1197 struct udp_sock *up = udp_sk(sk);
1198 struct flowi6 fl6;
1199 int err = 0;
1200
1201 if (up->pending == AF_INET)
1202 return udp_push_pending_frames(sk);
1203
1204 /* ip6_finish_skb will release the cork, so make a copy of
1205 * fl6 here.
1206 */
1207 fl6 = inet_sk(sk)->cork.fl.u.ip6;
1208
1209 skb = ip6_finish_skb(sk);
1210 if (!skb)
1211 goto out;
1212
1213 err = udp_v6_send_skb(skb, &fl6, &inet_sk(sk)->cork.base);
1214
1215 out:
1216 up->len = 0;
1217 up->pending = 0;
1218 return err;
1219 }
1220
1221 int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1222 {
1223 struct ipv6_txoptions opt_space;
1224 struct udp_sock *up = udp_sk(sk);
1225 struct inet_sock *inet = inet_sk(sk);
1226 struct ipv6_pinfo *np = inet6_sk(sk);
1227 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1228 struct in6_addr *daddr, *final_p, final;
1229 struct ipv6_txoptions *opt = NULL;
1230 struct ipv6_txoptions *opt_to_free = NULL;
1231 struct ip6_flowlabel *flowlabel = NULL;
1232 struct flowi6 fl6;
1233 struct dst_entry *dst;
1234 struct ipcm6_cookie ipc6;
1235 int addr_len = msg->msg_namelen;
1236 bool connected = false;
1237 int ulen = len;
1238 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
1239 int err;
1240 int is_udplite = IS_UDPLITE(sk);
1241 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1242
1243 ipcm6_init(&ipc6);
1244 ipc6.gso_size = up->gso_size;
1245 ipc6.sockc.tsflags = sk->sk_tsflags;
1246
1247 /* destination address check */
1248 if (sin6) {
1249 if (addr_len < offsetof(struct sockaddr, sa_data))
1250 return -EINVAL;
1251
1252 switch (sin6->sin6_family) {
1253 case AF_INET6:
1254 if (addr_len < SIN6_LEN_RFC2133)
1255 return -EINVAL;
1256 daddr = &sin6->sin6_addr;
1257 if (ipv6_addr_any(daddr) &&
1258 ipv6_addr_v4mapped(&np->saddr))
1259 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
1260 daddr);
1261 break;
1262 case AF_INET:
1263 goto do_udp_sendmsg;
1264 case AF_UNSPEC:
1265 msg->msg_name = sin6 = NULL;
1266 msg->msg_namelen = addr_len = 0;
1267 daddr = NULL;
1268 break;
1269 default:
1270 return -EINVAL;
1271 }
1272 } else if (!up->pending) {
1273 if (sk->sk_state != TCP_ESTABLISHED)
1274 return -EDESTADDRREQ;
1275 daddr = &sk->sk_v6_daddr;
1276 } else
1277 daddr = NULL;
1278
1279 if (daddr) {
1280 if (ipv6_addr_v4mapped(daddr)) {
1281 struct sockaddr_in sin;
1282 sin.sin_family = AF_INET;
1283 sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1284 sin.sin_addr.s_addr = daddr->s6_addr32[3];
1285 msg->msg_name = &sin;
1286 msg->msg_namelen = sizeof(sin);
1287 do_udp_sendmsg:
1288 if (__ipv6_only_sock(sk))
1289 return -ENETUNREACH;
1290 return udp_sendmsg(sk, msg, len);
1291 }
1292 }
1293
1294 if (up->pending == AF_INET)
1295 return udp_sendmsg(sk, msg, len);
1296
1297 /* Rough check on arithmetic overflow,
1298 better check is made in ip6_append_data().
1299 */
1300 if (len > INT_MAX - sizeof(struct udphdr))
1301 return -EMSGSIZE;
1302
1303 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
1304 if (up->pending) {
1305 /*
1306 * There are pending frames.
1307 * The socket lock must be held while it's corked.
1308 */
1309 lock_sock(sk);
1310 if (likely(up->pending)) {
1311 if (unlikely(up->pending != AF_INET6)) {
1312 release_sock(sk);
1313 return -EAFNOSUPPORT;
1314 }
1315 dst = NULL;
1316 goto do_append_data;
1317 }
1318 release_sock(sk);
1319 }
1320 ulen += sizeof(struct udphdr);
1321
1322 memset(&fl6, 0, sizeof(fl6));
1323
1324 if (sin6) {
1325 if (sin6->sin6_port == 0)
1326 return -EINVAL;
1327
1328 fl6.fl6_dport = sin6->sin6_port;
1329 daddr = &sin6->sin6_addr;
1330
1331 if (np->sndflow) {
1332 fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1333 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
1334 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1335 if (!flowlabel)
1336 return -EINVAL;
1337 }
1338 }
1339
1340 /*
1341 * Otherwise it will be difficult to maintain
1342 * sk->sk_dst_cache.
1343 */
1344 if (sk->sk_state == TCP_ESTABLISHED &&
1345 ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
1346 daddr = &sk->sk_v6_daddr;
1347
1348 if (addr_len >= sizeof(struct sockaddr_in6) &&
1349 sin6->sin6_scope_id &&
1350 __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1351 fl6.flowi6_oif = sin6->sin6_scope_id;
1352 } else {
1353 if (sk->sk_state != TCP_ESTABLISHED)
1354 return -EDESTADDRREQ;
1355
1356 fl6.fl6_dport = inet->inet_dport;
1357 daddr = &sk->sk_v6_daddr;
1358 fl6.flowlabel = np->flow_label;
1359 connected = true;
1360 }
1361
1362 if (!fl6.flowi6_oif)
1363 fl6.flowi6_oif = sk->sk_bound_dev_if;
1364
1365 if (!fl6.flowi6_oif)
1366 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1367
1368 fl6.flowi6_mark = sk->sk_mark;
1369 fl6.flowi6_uid = sk->sk_uid;
1370
1371 if (msg->msg_controllen) {
1372 opt = &opt_space;
1373 memset(opt, 0, sizeof(struct ipv6_txoptions));
1374 opt->tot_len = sizeof(*opt);
1375 ipc6.opt = opt;
1376
1377 err = udp_cmsg_send(sk, msg, &ipc6.gso_size);
1378 if (err > 0)
1379 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6,
1380 &ipc6);
1381 if (err < 0) {
1382 fl6_sock_release(flowlabel);
1383 return err;
1384 }
1385 if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1386 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1387 if (!flowlabel)
1388 return -EINVAL;
1389 }
1390 if (!(opt->opt_nflen|opt->opt_flen))
1391 opt = NULL;
1392 connected = false;
1393 }
1394 if (!opt) {
1395 opt = txopt_get(np);
1396 opt_to_free = opt;
1397 }
1398 if (flowlabel)
1399 opt = fl6_merge_options(&opt_space, flowlabel, opt);
1400 opt = ipv6_fixup_options(&opt_space, opt);
1401 ipc6.opt = opt;
1402
1403 fl6.flowi6_proto = sk->sk_protocol;
1404 fl6.daddr = *daddr;
1405 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
1406 fl6.saddr = np->saddr;
1407 fl6.fl6_sport = inet->inet_sport;
1408
1409 if (cgroup_bpf_enabled && !connected) {
1410 err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk,
1411 (struct sockaddr *)sin6, &fl6.saddr);
1412 if (err)
1413 goto out_no_dst;
1414 if (sin6) {
1415 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
1416 /* BPF program rewrote IPv6-only by IPv4-mapped
1417 * IPv6. It's currently unsupported.
1418 */
1419 err = -ENOTSUPP;
1420 goto out_no_dst;
1421 }
1422 if (sin6->sin6_port == 0) {
1423 /* BPF program set invalid port. Reject it. */
1424 err = -EINVAL;
1425 goto out_no_dst;
1426 }
1427 fl6.fl6_dport = sin6->sin6_port;
1428 fl6.daddr = sin6->sin6_addr;
1429 }
1430 }
1431
1432 if (ipv6_addr_any(&fl6.daddr))
1433 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1434
1435 final_p = fl6_update_dst(&fl6, opt, &final);
1436 if (final_p)
1437 connected = false;
1438
1439 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
1440 fl6.flowi6_oif = np->mcast_oif;
1441 connected = false;
1442 } else if (!fl6.flowi6_oif)
1443 fl6.flowi6_oif = np->ucast_oif;
1444
1445 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
1446
1447 if (ipc6.tclass < 0)
1448 ipc6.tclass = np->tclass;
1449
1450 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
1451
1452 dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, connected);
1453 if (IS_ERR(dst)) {
1454 err = PTR_ERR(dst);
1455 dst = NULL;
1456 goto out;
1457 }
1458
1459 if (ipc6.hlimit < 0)
1460 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
1461
1462 if (msg->msg_flags&MSG_CONFIRM)
1463 goto do_confirm;
1464 back_from_confirm:
1465
1466 /* Lockless fast path for the non-corking case */
1467 if (!corkreq) {
1468 struct inet_cork_full cork;
1469 struct sk_buff *skb;
1470
1471 skb = ip6_make_skb(sk, getfrag, msg, ulen,
1472 sizeof(struct udphdr), &ipc6,
1473 &fl6, (struct rt6_info *)dst,
1474 msg->msg_flags, &cork);
1475 err = PTR_ERR(skb);
1476 if (!IS_ERR_OR_NULL(skb))
1477 err = udp_v6_send_skb(skb, &fl6, &cork.base);
1478 goto out;
1479 }
1480
1481 lock_sock(sk);
1482 if (unlikely(up->pending)) {
1483 /* The socket is already corked while preparing it. */
1484 /* ... which is an evident application bug. --ANK */
1485 release_sock(sk);
1486
1487 net_dbg_ratelimited("udp cork app bug 2\n");
1488 err = -EINVAL;
1489 goto out;
1490 }
1491
1492 up->pending = AF_INET6;
1493
1494 do_append_data:
1495 if (ipc6.dontfrag < 0)
1496 ipc6.dontfrag = np->dontfrag;
1497 up->len += ulen;
1498 err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr),
1499 &ipc6, &fl6, (struct rt6_info *)dst,
1500 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1501 if (err)
1502 udp_v6_flush_pending_frames(sk);
1503 else if (!corkreq)
1504 err = udp_v6_push_pending_frames(sk);
1505 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1506 up->pending = 0;
1507
1508 if (err > 0)
1509 err = np->recverr ? net_xmit_errno(err) : 0;
1510 release_sock(sk);
1511
1512 out:
1513 dst_release(dst);
1514 out_no_dst:
1515 fl6_sock_release(flowlabel);
1516 txopt_put(opt_to_free);
1517 if (!err)
1518 return len;
1519 /*
1520 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1521 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1522 * we don't have a good statistic (IpOutDiscards but it can be too many
1523 * things). We could add another new stat but at least for now that
1524 * seems like overkill.
1525 */
1526 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1527 UDP6_INC_STATS(sock_net(sk),
1528 UDP_MIB_SNDBUFERRORS, is_udplite);
1529 }
1530 return err;
1531
1532 do_confirm:
1533 if (msg->msg_flags & MSG_PROBE)
1534 dst_confirm_neigh(dst, &fl6.daddr);
1535 if (!(msg->msg_flags&MSG_PROBE) || len)
1536 goto back_from_confirm;
1537 err = 0;
1538 goto out;
1539 }
1540
1541 void udpv6_destroy_sock(struct sock *sk)
1542 {
1543 struct udp_sock *up = udp_sk(sk);
1544 lock_sock(sk);
1545 udp_v6_flush_pending_frames(sk);
1546 release_sock(sk);
1547
1548 if (static_branch_unlikely(&udpv6_encap_needed_key)) {
1549 if (up->encap_type) {
1550 void (*encap_destroy)(struct sock *sk);
1551 encap_destroy = READ_ONCE(up->encap_destroy);
1552 if (encap_destroy)
1553 encap_destroy(sk);
1554 }
1555 if (up->encap_enabled)
1556 static_branch_dec(&udpv6_encap_needed_key);
1557 }
1558
1559 inet6_destroy_sock(sk);
1560 }
1561
1562 /*
1563 * Socket option code for UDP
1564 */
1565 int udpv6_setsockopt(struct sock *sk, int level, int optname,
1566 char __user *optval, unsigned int optlen)
1567 {
1568 if (level == SOL_UDP || level == SOL_UDPLITE)
1569 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1570 udp_v6_push_pending_frames);
1571 return ipv6_setsockopt(sk, level, optname, optval, optlen);
1572 }
1573
1574 #ifdef CONFIG_COMPAT
1575 int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
1576 char __user *optval, unsigned int optlen)
1577 {
1578 if (level == SOL_UDP || level == SOL_UDPLITE)
1579 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1580 udp_v6_push_pending_frames);
1581 return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
1582 }
1583 #endif
1584
1585 int udpv6_getsockopt(struct sock *sk, int level, int optname,
1586 char __user *optval, int __user *optlen)
1587 {
1588 if (level == SOL_UDP || level == SOL_UDPLITE)
1589 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1590 return ipv6_getsockopt(sk, level, optname, optval, optlen);
1591 }
1592
1593 #ifdef CONFIG_COMPAT
1594 int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
1595 char __user *optval, int __user *optlen)
1596 {
1597 if (level == SOL_UDP || level == SOL_UDPLITE)
1598 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1599 return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
1600 }
1601 #endif
1602
1603 /* thinking of making this const? Don't.
1604 * early_demux can change based on sysctl.
1605 */
1606 static struct inet6_protocol udpv6_protocol = {
1607 .early_demux = udp_v6_early_demux,
1608 .early_demux_handler = udp_v6_early_demux,
1609 .handler = udpv6_rcv,
1610 .err_handler = udpv6_err,
1611 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1612 };
1613
1614 /* ------------------------------------------------------------------------ */
1615 #ifdef CONFIG_PROC_FS
1616 int udp6_seq_show(struct seq_file *seq, void *v)
1617 {
1618 if (v == SEQ_START_TOKEN) {
1619 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1620 } else {
1621 int bucket = ((struct udp_iter_state *)seq->private)->bucket;
1622 struct inet_sock *inet = inet_sk(v);
1623 __u16 srcp = ntohs(inet->inet_sport);
1624 __u16 destp = ntohs(inet->inet_dport);
1625 __ip6_dgram_sock_seq_show(seq, v, srcp, destp,
1626 udp_rqueue_get(v), bucket);
1627 }
1628 return 0;
1629 }
1630
1631 const struct seq_operations udp6_seq_ops = {
1632 .start = udp_seq_start,
1633 .next = udp_seq_next,
1634 .stop = udp_seq_stop,
1635 .show = udp6_seq_show,
1636 };
1637 EXPORT_SYMBOL(udp6_seq_ops);
1638
1639 static struct udp_seq_afinfo udp6_seq_afinfo = {
1640 .family = AF_INET6,
1641 .udp_table = &udp_table,
1642 };
1643
1644 int __net_init udp6_proc_init(struct net *net)
1645 {
1646 if (!proc_create_net_data("udp6", 0444, net->proc_net, &udp6_seq_ops,
1647 sizeof(struct udp_iter_state), &udp6_seq_afinfo))
1648 return -ENOMEM;
1649 return 0;
1650 }
1651
1652 void udp6_proc_exit(struct net *net)
1653 {
1654 remove_proc_entry("udp6", net->proc_net);
1655 }
1656 #endif /* CONFIG_PROC_FS */
1657
1658 /* ------------------------------------------------------------------------ */
1659
1660 struct proto udpv6_prot = {
1661 .name = "UDPv6",
1662 .owner = THIS_MODULE,
1663 .close = udp_lib_close,
1664 .pre_connect = udpv6_pre_connect,
1665 .connect = ip6_datagram_connect,
1666 .disconnect = udp_disconnect,
1667 .ioctl = udp_ioctl,
1668 .init = udp_init_sock,
1669 .destroy = udpv6_destroy_sock,
1670 .setsockopt = udpv6_setsockopt,
1671 .getsockopt = udpv6_getsockopt,
1672 .sendmsg = udpv6_sendmsg,
1673 .recvmsg = udpv6_recvmsg,
1674 .release_cb = ip6_datagram_release_cb,
1675 .hash = udp_lib_hash,
1676 .unhash = udp_lib_unhash,
1677 .rehash = udp_v6_rehash,
1678 .get_port = udp_v6_get_port,
1679 .memory_allocated = &udp_memory_allocated,
1680 .sysctl_mem = sysctl_udp_mem,
1681 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
1682 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
1683 .obj_size = sizeof(struct udp6_sock),
1684 .h.udp_table = &udp_table,
1685 #ifdef CONFIG_COMPAT
1686 .compat_setsockopt = compat_udpv6_setsockopt,
1687 .compat_getsockopt = compat_udpv6_getsockopt,
1688 #endif
1689 .diag_destroy = udp_abort,
1690 };
1691
1692 static struct inet_protosw udpv6_protosw = {
1693 .type = SOCK_DGRAM,
1694 .protocol = IPPROTO_UDP,
1695 .prot = &udpv6_prot,
1696 .ops = &inet6_dgram_ops,
1697 .flags = INET_PROTOSW_PERMANENT,
1698 };
1699
1700 int __init udpv6_init(void)
1701 {
1702 int ret;
1703
1704 ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1705 if (ret)
1706 goto out;
1707
1708 ret = inet6_register_protosw(&udpv6_protosw);
1709 if (ret)
1710 goto out_udpv6_protocol;
1711 out:
1712 return ret;
1713
1714 out_udpv6_protocol:
1715 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1716 goto out;
1717 }
1718
1719 void udpv6_exit(void)
1720 {
1721 inet6_unregister_protosw(&udpv6_protosw);
1722 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1723 }
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