1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * common UDP/RAW code
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 */
9
10 #include <linux/capability.h>
11 #include <linux/errno.h>
12 #include <linux/types.h>
13 #include <linux/kernel.h>
14 #include <linux/interrupt.h>
15 #include <linux/socket.h>
16 #include <linux/sockios.h>
17 #include <linux/in6.h>
18 #include <linux/ipv6.h>
19 #include <linux/route.h>
20 #include <linux/slab.h>
21 #include <linux/export.h>
22 #include <linux/icmp.h>
23
24 #include <net/ipv6.h>
25 #include <net/ndisc.h>
26 #include <net/addrconf.h>
27 #include <net/transp_v6.h>
28 #include <net/ip6_route.h>
29 #include <net/tcp_states.h>
30 #include <net/dsfield.h>
31 #include <net/sock_reuseport.h>
32
33 #include <linux/errqueue.h>
34 #include <linux/uaccess.h>
35
ipv6_mapped_addr_any(const struct in6_addr * a)36 static bool ipv6_mapped_addr_any(const struct in6_addr *a)
37 {
38 return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
39 }
40
ip6_datagram_flow_key_init(struct flowi6 * fl6,const struct sock * sk)41 static void ip6_datagram_flow_key_init(struct flowi6 *fl6,
42 const struct sock *sk)
43 {
44 const struct inet_sock *inet = inet_sk(sk);
45 const struct ipv6_pinfo *np = inet6_sk(sk);
46 int oif = sk->sk_bound_dev_if;
47
48 memset(fl6, 0, sizeof(*fl6));
49 fl6->flowi6_proto = sk->sk_protocol;
50 fl6->daddr = sk->sk_v6_daddr;
51 fl6->saddr = np->saddr;
52 fl6->flowi6_mark = sk->sk_mark;
53 fl6->fl6_dport = inet->inet_dport;
54 fl6->fl6_sport = inet->inet_sport;
55 fl6->flowlabel = ip6_make_flowinfo(np->tclass, np->flow_label);
56 fl6->flowi6_uid = sk->sk_uid;
57
58 if (!oif)
59 oif = np->sticky_pktinfo.ipi6_ifindex;
60
61 if (!oif) {
62 if (ipv6_addr_is_multicast(&fl6->daddr))
63 oif = np->mcast_oif;
64 else
65 oif = np->ucast_oif;
66 }
67
68 fl6->flowi6_oif = oif;
69 security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
70 }
71
ip6_datagram_dst_update(struct sock * sk,bool fix_sk_saddr)72 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
73 {
74 struct ip6_flowlabel *flowlabel = NULL;
75 struct in6_addr *final_p, final;
76 struct ipv6_txoptions *opt;
77 struct dst_entry *dst;
78 struct inet_sock *inet = inet_sk(sk);
79 struct ipv6_pinfo *np = inet6_sk(sk);
80 struct flowi6 fl6;
81 int err = 0;
82
83 if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
84 flowlabel = fl6_sock_lookup(sk, np->flow_label);
85 if (IS_ERR(flowlabel))
86 return -EINVAL;
87 }
88 ip6_datagram_flow_key_init(&fl6, sk);
89
90 rcu_read_lock();
91 opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
92 final_p = fl6_update_dst(&fl6, opt, &final);
93 rcu_read_unlock();
94
95 dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
96 if (IS_ERR(dst)) {
97 err = PTR_ERR(dst);
98 goto out;
99 }
100
101 if (fix_sk_saddr) {
102 if (ipv6_addr_any(&np->saddr))
103 np->saddr = fl6.saddr;
104
105 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
106 sk->sk_v6_rcv_saddr = fl6.saddr;
107 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
108 if (sk->sk_prot->rehash)
109 sk->sk_prot->rehash(sk);
110 }
111 }
112
113 ip6_sk_dst_store_flow(sk, dst, &fl6);
114
115 out:
116 fl6_sock_release(flowlabel);
117 return err;
118 }
119
ip6_datagram_release_cb(struct sock * sk)120 void ip6_datagram_release_cb(struct sock *sk)
121 {
122 struct dst_entry *dst;
123
124 if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
125 return;
126
127 rcu_read_lock();
128 dst = __sk_dst_get(sk);
129 if (!dst || !dst->obsolete ||
130 dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
131 rcu_read_unlock();
132 return;
133 }
134 rcu_read_unlock();
135
136 ip6_datagram_dst_update(sk, false);
137 }
138 EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
139
__ip6_datagram_connect(struct sock * sk,struct sockaddr * uaddr,int addr_len)140 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
141 int addr_len)
142 {
143 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
144 struct inet_sock *inet = inet_sk(sk);
145 struct ipv6_pinfo *np = inet6_sk(sk);
146 struct in6_addr *daddr, old_daddr;
147 __be32 fl6_flowlabel = 0;
148 __be32 old_fl6_flowlabel;
149 __be16 old_dport;
150 int addr_type;
151 int err;
152
153 if (usin->sin6_family == AF_INET) {
154 if (ipv6_only_sock(sk))
155 return -EAFNOSUPPORT;
156 err = __ip4_datagram_connect(sk, uaddr, addr_len);
157 goto ipv4_connected;
158 }
159
160 if (addr_len < SIN6_LEN_RFC2133)
161 return -EINVAL;
162
163 if (usin->sin6_family != AF_INET6)
164 return -EAFNOSUPPORT;
165
166 if (np->sndflow)
167 fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
168
169 if (ipv6_addr_any(&usin->sin6_addr)) {
170 /*
171 * connect to self
172 */
173 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
174 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
175 &usin->sin6_addr);
176 else
177 usin->sin6_addr = in6addr_loopback;
178 }
179
180 addr_type = ipv6_addr_type(&usin->sin6_addr);
181
182 daddr = &usin->sin6_addr;
183
184 if (addr_type & IPV6_ADDR_MAPPED) {
185 struct sockaddr_in sin;
186
187 if (ipv6_only_sock(sk)) {
188 err = -ENETUNREACH;
189 goto out;
190 }
191 sin.sin_family = AF_INET;
192 sin.sin_addr.s_addr = daddr->s6_addr32[3];
193 sin.sin_port = usin->sin6_port;
194
195 err = __ip4_datagram_connect(sk,
196 (struct sockaddr *) &sin,
197 sizeof(sin));
198
199 ipv4_connected:
200 if (err)
201 goto out;
202
203 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
204
205 if (ipv6_addr_any(&np->saddr) ||
206 ipv6_mapped_addr_any(&np->saddr))
207 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
208
209 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
210 ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
211 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
212 &sk->sk_v6_rcv_saddr);
213 if (sk->sk_prot->rehash)
214 sk->sk_prot->rehash(sk);
215 }
216
217 goto out;
218 }
219
220 if (__ipv6_addr_needs_scope_id(addr_type)) {
221 if (addr_len >= sizeof(struct sockaddr_in6) &&
222 usin->sin6_scope_id) {
223 if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id)) {
224 err = -EINVAL;
225 goto out;
226 }
227 WRITE_ONCE(sk->sk_bound_dev_if, usin->sin6_scope_id);
228 }
229
230 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
231 WRITE_ONCE(sk->sk_bound_dev_if, np->mcast_oif);
232
233 /* Connect to link-local address requires an interface */
234 if (!sk->sk_bound_dev_if) {
235 err = -EINVAL;
236 goto out;
237 }
238 }
239
240 /* save the current peer information before updating it */
241 old_daddr = sk->sk_v6_daddr;
242 old_fl6_flowlabel = np->flow_label;
243 old_dport = inet->inet_dport;
244
245 sk->sk_v6_daddr = *daddr;
246 np->flow_label = fl6_flowlabel;
247 inet->inet_dport = usin->sin6_port;
248
249 /*
250 * Check for a route to destination an obtain the
251 * destination cache for it.
252 */
253
254 err = ip6_datagram_dst_update(sk, true);
255 if (err) {
256 /* Restore the socket peer info, to keep it consistent with
257 * the old socket state
258 */
259 sk->sk_v6_daddr = old_daddr;
260 np->flow_label = old_fl6_flowlabel;
261 inet->inet_dport = old_dport;
262 goto out;
263 }
264
265 reuseport_has_conns_set(sk);
266 sk->sk_state = TCP_ESTABLISHED;
267 sk_set_txhash(sk);
268 out:
269 return err;
270 }
271 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
272
ip6_datagram_connect(struct sock * sk,struct sockaddr * uaddr,int addr_len)273 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
274 {
275 int res;
276
277 lock_sock(sk);
278 res = __ip6_datagram_connect(sk, uaddr, addr_len);
279 release_sock(sk);
280 return res;
281 }
282 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
283
ip6_datagram_connect_v6_only(struct sock * sk,struct sockaddr * uaddr,int addr_len)284 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
285 int addr_len)
286 {
287 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
288 if (sin6->sin6_family != AF_INET6)
289 return -EAFNOSUPPORT;
290 return ip6_datagram_connect(sk, uaddr, addr_len);
291 }
292 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
293
ipv6_icmp_error_rfc4884(const struct sk_buff * skb,struct sock_ee_data_rfc4884 * out)294 static void ipv6_icmp_error_rfc4884(const struct sk_buff *skb,
295 struct sock_ee_data_rfc4884 *out)
296 {
297 switch (icmp6_hdr(skb)->icmp6_type) {
298 case ICMPV6_TIME_EXCEED:
299 case ICMPV6_DEST_UNREACH:
300 ip_icmp_error_rfc4884(skb, out, sizeof(struct icmp6hdr),
301 icmp6_hdr(skb)->icmp6_datagram_len * 8);
302 }
303 }
304
ipv6_icmp_error(struct sock * sk,struct sk_buff * skb,int err,__be16 port,u32 info,u8 * payload)305 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
306 __be16 port, u32 info, u8 *payload)
307 {
308 struct ipv6_pinfo *np = inet6_sk(sk);
309 struct icmp6hdr *icmph = icmp6_hdr(skb);
310 struct sock_exterr_skb *serr;
311
312 if (!np->recverr)
313 return;
314
315 skb = skb_clone(skb, GFP_ATOMIC);
316 if (!skb)
317 return;
318
319 skb->protocol = htons(ETH_P_IPV6);
320
321 serr = SKB_EXT_ERR(skb);
322 serr->ee.ee_errno = err;
323 serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
324 serr->ee.ee_type = icmph->icmp6_type;
325 serr->ee.ee_code = icmph->icmp6_code;
326 serr->ee.ee_pad = 0;
327 serr->ee.ee_info = info;
328 serr->ee.ee_data = 0;
329 serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
330 skb_network_header(skb);
331 serr->port = port;
332
333 __skb_pull(skb, payload - skb->data);
334
335 if (inet6_sk(sk)->recverr_rfc4884)
336 ipv6_icmp_error_rfc4884(skb, &serr->ee.ee_rfc4884);
337
338 skb_reset_transport_header(skb);
339
340 if (sock_queue_err_skb(sk, skb))
341 kfree_skb(skb);
342 }
343 EXPORT_SYMBOL_GPL(ipv6_icmp_error);
344
ipv6_local_error(struct sock * sk,int err,struct flowi6 * fl6,u32 info)345 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
346 {
347 const struct ipv6_pinfo *np = inet6_sk(sk);
348 struct sock_exterr_skb *serr;
349 struct ipv6hdr *iph;
350 struct sk_buff *skb;
351
352 if (!np->recverr)
353 return;
354
355 skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
356 if (!skb)
357 return;
358
359 skb->protocol = htons(ETH_P_IPV6);
360
361 skb_put(skb, sizeof(struct ipv6hdr));
362 skb_reset_network_header(skb);
363 iph = ipv6_hdr(skb);
364 iph->daddr = fl6->daddr;
365 ip6_flow_hdr(iph, 0, 0);
366
367 serr = SKB_EXT_ERR(skb);
368 serr->ee.ee_errno = err;
369 serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
370 serr->ee.ee_type = 0;
371 serr->ee.ee_code = 0;
372 serr->ee.ee_pad = 0;
373 serr->ee.ee_info = info;
374 serr->ee.ee_data = 0;
375 serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
376 serr->port = fl6->fl6_dport;
377
378 __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
379 skb_reset_transport_header(skb);
380
381 if (sock_queue_err_skb(sk, skb))
382 kfree_skb(skb);
383 }
384
ipv6_local_rxpmtu(struct sock * sk,struct flowi6 * fl6,u32 mtu)385 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
386 {
387 struct ipv6_pinfo *np = inet6_sk(sk);
388 struct ipv6hdr *iph;
389 struct sk_buff *skb;
390 struct ip6_mtuinfo *mtu_info;
391
392 if (!np->rxopt.bits.rxpmtu)
393 return;
394
395 skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
396 if (!skb)
397 return;
398
399 skb_put(skb, sizeof(struct ipv6hdr));
400 skb_reset_network_header(skb);
401 iph = ipv6_hdr(skb);
402 iph->daddr = fl6->daddr;
403
404 mtu_info = IP6CBMTU(skb);
405
406 mtu_info->ip6m_mtu = mtu;
407 mtu_info->ip6m_addr.sin6_family = AF_INET6;
408 mtu_info->ip6m_addr.sin6_port = 0;
409 mtu_info->ip6m_addr.sin6_flowinfo = 0;
410 mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
411 mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
412
413 __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
414 skb_reset_transport_header(skb);
415
416 skb = xchg(&np->rxpmtu, skb);
417 kfree_skb(skb);
418 }
419
420 /* For some errors we have valid addr_offset even with zero payload and
421 * zero port. Also, addr_offset should be supported if port is set.
422 */
ipv6_datagram_support_addr(struct sock_exterr_skb * serr)423 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
424 {
425 return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
426 serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
427 serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
428 }
429
430 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
431 *
432 * At one point, excluding local errors was a quick test to identify icmp/icmp6
433 * errors. This is no longer true, but the test remained, so the v6 stack,
434 * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
435 */
ip6_datagram_support_cmsg(struct sk_buff * skb,struct sock_exterr_skb * serr)436 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
437 struct sock_exterr_skb *serr)
438 {
439 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
440 serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
441 return true;
442
443 if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
444 return false;
445
446 if (!IP6CB(skb)->iif)
447 return false;
448
449 return true;
450 }
451
452 /*
453 * Handle MSG_ERRQUEUE
454 */
ipv6_recv_error(struct sock * sk,struct msghdr * msg,int len,int * addr_len)455 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
456 {
457 struct ipv6_pinfo *np = inet6_sk(sk);
458 struct sock_exterr_skb *serr;
459 struct sk_buff *skb;
460 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
461 struct {
462 struct sock_extended_err ee;
463 struct sockaddr_in6 offender;
464 } errhdr;
465 int err;
466 int copied;
467
468 err = -EAGAIN;
469 skb = sock_dequeue_err_skb(sk);
470 if (!skb)
471 goto out;
472
473 copied = skb->len;
474 if (copied > len) {
475 msg->msg_flags |= MSG_TRUNC;
476 copied = len;
477 }
478 err = skb_copy_datagram_msg(skb, 0, msg, copied);
479 if (unlikely(err)) {
480 kfree_skb(skb);
481 return err;
482 }
483 sock_recv_timestamp(msg, sk, skb);
484
485 serr = SKB_EXT_ERR(skb);
486
487 if (sin && ipv6_datagram_support_addr(serr)) {
488 const unsigned char *nh = skb_network_header(skb);
489 sin->sin6_family = AF_INET6;
490 sin->sin6_flowinfo = 0;
491 sin->sin6_port = serr->port;
492 if (skb->protocol == htons(ETH_P_IPV6)) {
493 const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
494 struct ipv6hdr, daddr);
495 sin->sin6_addr = ip6h->daddr;
496 if (np->sndflow)
497 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
498 sin->sin6_scope_id =
499 ipv6_iface_scope_id(&sin->sin6_addr,
500 IP6CB(skb)->iif);
501 } else {
502 ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
503 &sin->sin6_addr);
504 sin->sin6_scope_id = 0;
505 }
506 *addr_len = sizeof(*sin);
507 }
508
509 memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
510 sin = &errhdr.offender;
511 memset(sin, 0, sizeof(*sin));
512
513 if (ip6_datagram_support_cmsg(skb, serr)) {
514 sin->sin6_family = AF_INET6;
515 if (np->rxopt.all)
516 ip6_datagram_recv_common_ctl(sk, msg, skb);
517 if (skb->protocol == htons(ETH_P_IPV6)) {
518 sin->sin6_addr = ipv6_hdr(skb)->saddr;
519 if (np->rxopt.all)
520 ip6_datagram_recv_specific_ctl(sk, msg, skb);
521 sin->sin6_scope_id =
522 ipv6_iface_scope_id(&sin->sin6_addr,
523 IP6CB(skb)->iif);
524 } else {
525 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
526 &sin->sin6_addr);
527 if (inet_cmsg_flags(inet_sk(sk)))
528 ip_cmsg_recv(msg, skb);
529 }
530 }
531
532 put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
533
534 /* Now we could try to dump offended packet options */
535
536 msg->msg_flags |= MSG_ERRQUEUE;
537 err = copied;
538
539 consume_skb(skb);
540 out:
541 return err;
542 }
543 EXPORT_SYMBOL_GPL(ipv6_recv_error);
544
545 /*
546 * Handle IPV6_RECVPATHMTU
547 */
ipv6_recv_rxpmtu(struct sock * sk,struct msghdr * msg,int len,int * addr_len)548 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
549 int *addr_len)
550 {
551 struct ipv6_pinfo *np = inet6_sk(sk);
552 struct sk_buff *skb;
553 struct ip6_mtuinfo mtu_info;
554 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
555 int err;
556 int copied;
557
558 err = -EAGAIN;
559 skb = xchg(&np->rxpmtu, NULL);
560 if (!skb)
561 goto out;
562
563 copied = skb->len;
564 if (copied > len) {
565 msg->msg_flags |= MSG_TRUNC;
566 copied = len;
567 }
568 err = skb_copy_datagram_msg(skb, 0, msg, copied);
569 if (err)
570 goto out_free_skb;
571
572 sock_recv_timestamp(msg, sk, skb);
573
574 memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
575
576 if (sin) {
577 sin->sin6_family = AF_INET6;
578 sin->sin6_flowinfo = 0;
579 sin->sin6_port = 0;
580 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
581 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
582 *addr_len = sizeof(*sin);
583 }
584
585 put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
586
587 err = copied;
588
589 out_free_skb:
590 kfree_skb(skb);
591 out:
592 return err;
593 }
594
595
ip6_datagram_recv_common_ctl(struct sock * sk,struct msghdr * msg,struct sk_buff * skb)596 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
597 struct sk_buff *skb)
598 {
599 struct ipv6_pinfo *np = inet6_sk(sk);
600 bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
601
602 if (np->rxopt.bits.rxinfo) {
603 struct in6_pktinfo src_info;
604
605 if (is_ipv6) {
606 src_info.ipi6_ifindex = IP6CB(skb)->iif;
607 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
608 } else {
609 src_info.ipi6_ifindex =
610 PKTINFO_SKB_CB(skb)->ipi_ifindex;
611 ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
612 &src_info.ipi6_addr);
613 }
614
615 if (src_info.ipi6_ifindex >= 0)
616 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
617 sizeof(src_info), &src_info);
618 }
619 }
620
ip6_datagram_recv_specific_ctl(struct sock * sk,struct msghdr * msg,struct sk_buff * skb)621 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
622 struct sk_buff *skb)
623 {
624 struct ipv6_pinfo *np = inet6_sk(sk);
625 struct inet6_skb_parm *opt = IP6CB(skb);
626 unsigned char *nh = skb_network_header(skb);
627
628 if (np->rxopt.bits.rxhlim) {
629 int hlim = ipv6_hdr(skb)->hop_limit;
630 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
631 }
632
633 if (np->rxopt.bits.rxtclass) {
634 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
635 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
636 }
637
638 if (np->rxopt.bits.rxflow) {
639 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
640 if (flowinfo)
641 put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
642 }
643
644 /* HbH is allowed only once */
645 if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
646 u8 *ptr = nh + sizeof(struct ipv6hdr);
647 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
648 }
649
650 if (opt->lastopt &&
651 (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
652 /*
653 * Silly enough, but we need to reparse in order to
654 * report extension headers (except for HbH)
655 * in order.
656 *
657 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
658 * (and WILL NOT be) defined because
659 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
660 */
661 unsigned int off = sizeof(struct ipv6hdr);
662 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
663
664 while (off <= opt->lastopt) {
665 unsigned int len;
666 u8 *ptr = nh + off;
667
668 switch (nexthdr) {
669 case IPPROTO_DSTOPTS:
670 nexthdr = ptr[0];
671 len = (ptr[1] + 1) << 3;
672 if (np->rxopt.bits.dstopts)
673 put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
674 break;
675 case IPPROTO_ROUTING:
676 nexthdr = ptr[0];
677 len = (ptr[1] + 1) << 3;
678 if (np->rxopt.bits.srcrt)
679 put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
680 break;
681 case IPPROTO_AH:
682 nexthdr = ptr[0];
683 len = (ptr[1] + 2) << 2;
684 break;
685 default:
686 nexthdr = ptr[0];
687 len = (ptr[1] + 1) << 3;
688 break;
689 }
690
691 off += len;
692 }
693 }
694
695 /* socket options in old style */
696 if (np->rxopt.bits.rxoinfo) {
697 struct in6_pktinfo src_info;
698
699 src_info.ipi6_ifindex = opt->iif;
700 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
701 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
702 }
703 if (np->rxopt.bits.rxohlim) {
704 int hlim = ipv6_hdr(skb)->hop_limit;
705 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
706 }
707 if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
708 u8 *ptr = nh + sizeof(struct ipv6hdr);
709 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
710 }
711 if (np->rxopt.bits.odstopts && opt->dst0) {
712 u8 *ptr = nh + opt->dst0;
713 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
714 }
715 if (np->rxopt.bits.osrcrt && opt->srcrt) {
716 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
717 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
718 }
719 if (np->rxopt.bits.odstopts && opt->dst1) {
720 u8 *ptr = nh + opt->dst1;
721 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
722 }
723 if (np->rxopt.bits.rxorigdstaddr) {
724 struct sockaddr_in6 sin6;
725 __be16 _ports[2], *ports;
726
727 ports = skb_header_pointer(skb, skb_transport_offset(skb),
728 sizeof(_ports), &_ports);
729 if (ports) {
730 /* All current transport protocols have the port numbers in the
731 * first four bytes of the transport header and this function is
732 * written with this assumption in mind.
733 */
734 sin6.sin6_family = AF_INET6;
735 sin6.sin6_addr = ipv6_hdr(skb)->daddr;
736 sin6.sin6_port = ports[1];
737 sin6.sin6_flowinfo = 0;
738 sin6.sin6_scope_id =
739 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
740 opt->iif);
741
742 put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
743 }
744 }
745 if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
746 int val = opt->frag_max_size;
747
748 put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
749 }
750 }
751
ip6_datagram_recv_ctl(struct sock * sk,struct msghdr * msg,struct sk_buff * skb)752 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
753 struct sk_buff *skb)
754 {
755 ip6_datagram_recv_common_ctl(sk, msg, skb);
756 ip6_datagram_recv_specific_ctl(sk, msg, skb);
757 }
758 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
759
ip6_datagram_send_ctl(struct net * net,struct sock * sk,struct msghdr * msg,struct flowi6 * fl6,struct ipcm6_cookie * ipc6)760 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
761 struct msghdr *msg, struct flowi6 *fl6,
762 struct ipcm6_cookie *ipc6)
763 {
764 struct in6_pktinfo *src_info;
765 struct cmsghdr *cmsg;
766 struct ipv6_rt_hdr *rthdr;
767 struct ipv6_opt_hdr *hdr;
768 struct ipv6_txoptions *opt = ipc6->opt;
769 int len;
770 int err = 0;
771
772 for_each_cmsghdr(cmsg, msg) {
773 int addr_type;
774
775 if (!CMSG_OK(msg, cmsg)) {
776 err = -EINVAL;
777 goto exit_f;
778 }
779
780 if (cmsg->cmsg_level == SOL_SOCKET) {
781 err = __sock_cmsg_send(sk, cmsg, &ipc6->sockc);
782 if (err)
783 return err;
784 continue;
785 }
786
787 if (cmsg->cmsg_level != SOL_IPV6)
788 continue;
789
790 switch (cmsg->cmsg_type) {
791 case IPV6_PKTINFO:
792 case IPV6_2292PKTINFO:
793 {
794 struct net_device *dev = NULL;
795 int src_idx;
796
797 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
798 err = -EINVAL;
799 goto exit_f;
800 }
801
802 src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
803 src_idx = src_info->ipi6_ifindex;
804
805 if (src_idx) {
806 if (fl6->flowi6_oif &&
807 src_idx != fl6->flowi6_oif &&
808 (READ_ONCE(sk->sk_bound_dev_if) != fl6->flowi6_oif ||
809 !sk_dev_equal_l3scope(sk, src_idx)))
810 return -EINVAL;
811 fl6->flowi6_oif = src_idx;
812 }
813
814 addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
815
816 rcu_read_lock();
817 if (fl6->flowi6_oif) {
818 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
819 if (!dev) {
820 rcu_read_unlock();
821 return -ENODEV;
822 }
823 } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
824 rcu_read_unlock();
825 return -EINVAL;
826 }
827
828 if (addr_type != IPV6_ADDR_ANY) {
829 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
830 if (!ipv6_can_nonlocal_bind(net, inet_sk(sk)) &&
831 !ipv6_chk_addr_and_flags(net, &src_info->ipi6_addr,
832 dev, !strict, 0,
833 IFA_F_TENTATIVE) &&
834 !ipv6_chk_acast_addr_src(net, dev,
835 &src_info->ipi6_addr))
836 err = -EINVAL;
837 else
838 fl6->saddr = src_info->ipi6_addr;
839 }
840
841 rcu_read_unlock();
842
843 if (err)
844 goto exit_f;
845
846 break;
847 }
848
849 case IPV6_FLOWINFO:
850 if (cmsg->cmsg_len < CMSG_LEN(4)) {
851 err = -EINVAL;
852 goto exit_f;
853 }
854
855 if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
856 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
857 err = -EINVAL;
858 goto exit_f;
859 }
860 }
861 fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
862 break;
863
864 case IPV6_2292HOPOPTS:
865 case IPV6_HOPOPTS:
866 if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
867 err = -EINVAL;
868 goto exit_f;
869 }
870
871 hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
872 len = ((hdr->hdrlen + 1) << 3);
873 if (cmsg->cmsg_len < CMSG_LEN(len)) {
874 err = -EINVAL;
875 goto exit_f;
876 }
877 if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
878 err = -EPERM;
879 goto exit_f;
880 }
881 opt->opt_nflen += len;
882 opt->hopopt = hdr;
883 break;
884
885 case IPV6_2292DSTOPTS:
886 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
887 err = -EINVAL;
888 goto exit_f;
889 }
890
891 hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
892 len = ((hdr->hdrlen + 1) << 3);
893 if (cmsg->cmsg_len < CMSG_LEN(len)) {
894 err = -EINVAL;
895 goto exit_f;
896 }
897 if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
898 err = -EPERM;
899 goto exit_f;
900 }
901 if (opt->dst1opt) {
902 err = -EINVAL;
903 goto exit_f;
904 }
905 opt->opt_flen += len;
906 opt->dst1opt = hdr;
907 break;
908
909 case IPV6_DSTOPTS:
910 case IPV6_RTHDRDSTOPTS:
911 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
912 err = -EINVAL;
913 goto exit_f;
914 }
915
916 hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
917 len = ((hdr->hdrlen + 1) << 3);
918 if (cmsg->cmsg_len < CMSG_LEN(len)) {
919 err = -EINVAL;
920 goto exit_f;
921 }
922 if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
923 err = -EPERM;
924 goto exit_f;
925 }
926 if (cmsg->cmsg_type == IPV6_DSTOPTS) {
927 opt->opt_flen += len;
928 opt->dst1opt = hdr;
929 } else {
930 opt->opt_nflen += len;
931 opt->dst0opt = hdr;
932 }
933 break;
934
935 case IPV6_2292RTHDR:
936 case IPV6_RTHDR:
937 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
938 err = -EINVAL;
939 goto exit_f;
940 }
941
942 rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
943
944 switch (rthdr->type) {
945 #if IS_ENABLED(CONFIG_IPV6_MIP6)
946 case IPV6_SRCRT_TYPE_2:
947 if (rthdr->hdrlen != 2 ||
948 rthdr->segments_left != 1) {
949 err = -EINVAL;
950 goto exit_f;
951 }
952 break;
953 #endif
954 default:
955 err = -EINVAL;
956 goto exit_f;
957 }
958
959 len = ((rthdr->hdrlen + 1) << 3);
960
961 if (cmsg->cmsg_len < CMSG_LEN(len)) {
962 err = -EINVAL;
963 goto exit_f;
964 }
965
966 /* segments left must also match */
967 if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
968 err = -EINVAL;
969 goto exit_f;
970 }
971
972 opt->opt_nflen += len;
973 opt->srcrt = rthdr;
974
975 if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
976 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
977
978 opt->opt_nflen += dsthdrlen;
979 opt->dst0opt = opt->dst1opt;
980 opt->dst1opt = NULL;
981 opt->opt_flen -= dsthdrlen;
982 }
983
984 break;
985
986 case IPV6_2292HOPLIMIT:
987 case IPV6_HOPLIMIT:
988 if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
989 err = -EINVAL;
990 goto exit_f;
991 }
992
993 ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
994 if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
995 err = -EINVAL;
996 goto exit_f;
997 }
998
999 break;
1000
1001 case IPV6_TCLASS:
1002 {
1003 int tc;
1004
1005 err = -EINVAL;
1006 if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1007 goto exit_f;
1008
1009 tc = *(int *)CMSG_DATA(cmsg);
1010 if (tc < -1 || tc > 0xff)
1011 goto exit_f;
1012
1013 err = 0;
1014 ipc6->tclass = tc;
1015
1016 break;
1017 }
1018
1019 case IPV6_DONTFRAG:
1020 {
1021 int df;
1022
1023 err = -EINVAL;
1024 if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1025 goto exit_f;
1026
1027 df = *(int *)CMSG_DATA(cmsg);
1028 if (df < 0 || df > 1)
1029 goto exit_f;
1030
1031 err = 0;
1032 ipc6->dontfrag = df;
1033
1034 break;
1035 }
1036 default:
1037 net_dbg_ratelimited("invalid cmsg type: %d\n",
1038 cmsg->cmsg_type);
1039 err = -EINVAL;
1040 goto exit_f;
1041 }
1042 }
1043
1044 exit_f:
1045 return err;
1046 }
1047 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1048
__ip6_dgram_sock_seq_show(struct seq_file * seq,struct sock * sp,__u16 srcp,__u16 destp,int rqueue,int bucket)1049 void __ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1050 __u16 srcp, __u16 destp, int rqueue, int bucket)
1051 {
1052 const struct in6_addr *dest, *src;
1053
1054 dest = &sp->sk_v6_daddr;
1055 src = &sp->sk_v6_rcv_saddr;
1056 seq_printf(seq,
1057 "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1058 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u\n",
1059 bucket,
1060 src->s6_addr32[0], src->s6_addr32[1],
1061 src->s6_addr32[2], src->s6_addr32[3], srcp,
1062 dest->s6_addr32[0], dest->s6_addr32[1],
1063 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1064 sp->sk_state,
1065 sk_wmem_alloc_get(sp),
1066 rqueue,
1067 0, 0L, 0,
1068 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1069 0,
1070 sock_i_ino(sp),
1071 refcount_read(&sp->sk_refcnt), sp,
1072 atomic_read(&sp->sk_drops));
1073 }
1074