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_uid(sk);
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 = READ_ONCE(np->mcast_oif);
64 else
65 oif = READ_ONCE(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 inet_sock *inet = inet_sk(sk);
76 struct ipv6_pinfo *np = inet6_sk(sk);
77 struct ipv6_txoptions *opt;
78 struct in6_addr *final_p;
79 struct dst_entry *dst;
80 struct flowi6 *fl6;
81 int err = 0;
82
83 if (inet6_test_bit(SNDFLOW, sk) &&
84 (np->flow_label & IPV6_FLOWLABEL_MASK)) {
85 flowlabel = fl6_sock_lookup(sk, np->flow_label);
86 if (IS_ERR(flowlabel))
87 return -EINVAL;
88 }
89 fl6 = &inet_sk(sk)->cork.fl.u.ip6;
90 ip6_datagram_flow_key_init(fl6, sk);
91
92 rcu_read_lock();
93 opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
94 final_p = fl6_update_dst(fl6, opt, &np->final);
95 rcu_read_unlock();
96
97 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
98 if (IS_ERR(dst)) {
99 err = PTR_ERR(dst);
100 goto out;
101 }
102
103 if (fix_sk_saddr) {
104 if (ipv6_addr_any(&np->saddr))
105 np->saddr = fl6->saddr;
106
107 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
108 sk->sk_v6_rcv_saddr = fl6->saddr;
109 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
110 if (sk->sk_prot->rehash)
111 sk->sk_prot->rehash(sk);
112 }
113 }
114
115 ip6_sk_dst_store_flow(sk, dst, fl6);
116
117 out:
118 fl6_sock_release(flowlabel);
119 return err;
120 }
121
ip6_datagram_release_cb(struct sock * sk)122 void ip6_datagram_release_cb(struct sock *sk)
123 {
124 struct dst_entry *dst;
125
126 if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
127 return;
128
129 rcu_read_lock();
130 dst = __sk_dst_get(sk);
131 if (!dst || !READ_ONCE(dst->obsolete) ||
132 dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
133 rcu_read_unlock();
134 return;
135 }
136 rcu_read_unlock();
137
138 ip6_datagram_dst_update(sk, false);
139 }
140 EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
141
__ip6_datagram_connect(struct sock * sk,struct sockaddr_unsized * uaddr,int addr_len)142 int __ip6_datagram_connect(struct sock *sk, struct sockaddr_unsized *uaddr,
143 int addr_len)
144 {
145 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
146 struct inet_sock *inet = inet_sk(sk);
147 struct ipv6_pinfo *np = inet6_sk(sk);
148 struct in6_addr *daddr, old_daddr;
149 __be32 fl6_flowlabel = 0;
150 __be32 old_fl6_flowlabel;
151 __be16 old_dport;
152 int addr_type;
153 int err;
154
155 if (usin->sin6_family == AF_INET) {
156 if (ipv6_only_sock(sk))
157 return -EAFNOSUPPORT;
158 err = __ip4_datagram_connect(sk, uaddr, addr_len);
159 goto ipv4_connected;
160 }
161
162 if (addr_len < SIN6_LEN_RFC2133)
163 return -EINVAL;
164
165 if (usin->sin6_family != AF_INET6)
166 return -EAFNOSUPPORT;
167
168 if (inet6_test_bit(SNDFLOW, sk))
169 fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
170
171 if (ipv6_addr_any(&usin->sin6_addr)) {
172 /*
173 * connect to self
174 */
175 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
176 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
177 &usin->sin6_addr);
178 else
179 usin->sin6_addr = in6addr_loopback;
180 }
181
182 addr_type = ipv6_addr_type(&usin->sin6_addr);
183
184 daddr = &usin->sin6_addr;
185
186 if (addr_type & IPV6_ADDR_MAPPED) {
187 struct sockaddr_in sin;
188
189 if (ipv6_only_sock(sk)) {
190 err = -ENETUNREACH;
191 goto out;
192 }
193 sin.sin_family = AF_INET;
194 sin.sin_addr.s_addr = daddr->s6_addr32[3];
195 sin.sin_port = usin->sin6_port;
196
197 err = __ip4_datagram_connect(sk,
198 (struct sockaddr_unsized *)&sin,
199 sizeof(sin));
200
201 ipv4_connected:
202 if (err)
203 goto out;
204
205 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
206
207 if (ipv6_addr_any(&np->saddr) ||
208 ipv6_mapped_addr_any(&np->saddr))
209 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
210
211 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
212 ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
213 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
214 &sk->sk_v6_rcv_saddr);
215 if (sk->sk_prot->rehash)
216 sk->sk_prot->rehash(sk);
217 }
218
219 goto out;
220 }
221
222 if (__ipv6_addr_needs_scope_id(addr_type)) {
223 if (addr_len >= sizeof(struct sockaddr_in6) &&
224 usin->sin6_scope_id) {
225 if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id)) {
226 err = -EINVAL;
227 goto out;
228 }
229 WRITE_ONCE(sk->sk_bound_dev_if, usin->sin6_scope_id);
230 }
231
232 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
233 WRITE_ONCE(sk->sk_bound_dev_if, READ_ONCE(np->mcast_oif));
234
235 /* Connect to link-local address requires an interface */
236 if (!sk->sk_bound_dev_if) {
237 err = -EINVAL;
238 goto out;
239 }
240 }
241
242 /* save the current peer information before updating it */
243 old_daddr = sk->sk_v6_daddr;
244 old_fl6_flowlabel = np->flow_label;
245 old_dport = inet->inet_dport;
246
247 sk->sk_v6_daddr = *daddr;
248 np->flow_label = fl6_flowlabel;
249 inet->inet_dport = usin->sin6_port;
250
251 /*
252 * Check for a route to destination an obtain the
253 * destination cache for it.
254 */
255
256 err = ip6_datagram_dst_update(sk, true);
257 if (err) {
258 /* Restore the socket peer info, to keep it consistent with
259 * the old socket state
260 */
261 sk->sk_v6_daddr = old_daddr;
262 np->flow_label = old_fl6_flowlabel;
263 inet->inet_dport = old_dport;
264 goto out;
265 }
266
267 reuseport_has_conns_set(sk);
268 sk->sk_state = TCP_ESTABLISHED;
269 sk_set_txhash(sk);
270 out:
271 return err;
272 }
273 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
274
ip6_datagram_connect(struct sock * sk,struct sockaddr_unsized * uaddr,int addr_len)275 int ip6_datagram_connect(struct sock *sk, struct sockaddr_unsized *uaddr, int addr_len)
276 {
277 int res;
278
279 lock_sock(sk);
280 res = __ip6_datagram_connect(sk, uaddr, addr_len);
281 release_sock(sk);
282 return res;
283 }
284 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
285
ip6_datagram_connect_v6_only(struct sock * sk,struct sockaddr_unsized * uaddr,int addr_len)286 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr_unsized *uaddr,
287 int addr_len)
288 {
289 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
290 if (sin6->sin6_family != AF_INET6)
291 return -EAFNOSUPPORT;
292 return ip6_datagram_connect(sk, uaddr, addr_len);
293 }
294 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
295
ipv6_icmp_error_rfc4884(const struct sk_buff * skb,struct sock_ee_data_rfc4884 * out)296 static void ipv6_icmp_error_rfc4884(const struct sk_buff *skb,
297 struct sock_ee_data_rfc4884 *out)
298 {
299 switch (icmp6_hdr(skb)->icmp6_type) {
300 case ICMPV6_TIME_EXCEED:
301 case ICMPV6_DEST_UNREACH:
302 ip_icmp_error_rfc4884(skb, out, sizeof(struct icmp6hdr),
303 icmp6_hdr(skb)->icmp6_datagram_len * 8);
304 }
305 }
306
ipv6_icmp_error(struct sock * sk,struct sk_buff * skb,int err,__be16 port,u32 info,u8 * payload)307 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
308 __be16 port, u32 info, u8 *payload)
309 {
310 struct icmp6hdr *icmph = icmp6_hdr(skb);
311 struct sock_exterr_skb *serr;
312
313 if (!inet6_test_bit(RECVERR6, sk))
314 return;
315
316 skb = skb_clone(skb, GFP_ATOMIC);
317 if (!skb)
318 return;
319
320 skb->protocol = htons(ETH_P_IPV6);
321
322 serr = SKB_EXT_ERR(skb);
323 serr->ee.ee_errno = err;
324 serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
325 serr->ee.ee_type = icmph->icmp6_type;
326 serr->ee.ee_code = icmph->icmp6_code;
327 serr->ee.ee_pad = 0;
328 serr->ee.ee_info = info;
329 serr->ee.ee_data = 0;
330 serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
331 skb_network_header(skb);
332 serr->port = port;
333
334 __skb_pull(skb, payload - skb->data);
335
336 if (inet6_test_bit(RECVERR6_RFC4884, sk))
337 ipv6_icmp_error_rfc4884(skb, &serr->ee.ee_rfc4884);
338
339 skb_reset_transport_header(skb);
340
341 if (sock_queue_err_skb(sk, skb))
342 kfree_skb(skb);
343 }
344 EXPORT_SYMBOL_GPL(ipv6_icmp_error);
345
ipv6_local_error(struct sock * sk,int err,struct flowi6 * fl6,u32 info)346 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
347 {
348 struct sock_exterr_skb *serr;
349 struct ipv6hdr *iph;
350 struct sk_buff *skb;
351
352 if (!inet6_test_bit(RECVERR6, sk))
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 (inet6_test_bit(SNDFLOW, sk))
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 *orthdr;
767 struct ipv6_rt_hdr *rthdr;
768 struct ipv6_opt_hdr *hdr;
769 struct ipv6_txoptions *opt = ipc6->opt;
770 int len;
771 int err = 0;
772
773 for_each_cmsghdr(cmsg, msg) {
774 int addr_type;
775
776 if (!CMSG_OK(msg, cmsg)) {
777 err = -EINVAL;
778 goto exit_f;
779 }
780
781 if (cmsg->cmsg_level == SOL_SOCKET) {
782 err = __sock_cmsg_send(sk, cmsg, &ipc6->sockc);
783 if (err)
784 return err;
785 continue;
786 }
787
788 if (cmsg->cmsg_level != SOL_IPV6)
789 continue;
790
791 switch (cmsg->cmsg_type) {
792 case IPV6_PKTINFO:
793 case IPV6_2292PKTINFO:
794 {
795 struct net_device *dev = NULL;
796 int src_idx;
797
798 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
799 err = -EINVAL;
800 goto exit_f;
801 }
802
803 src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
804 src_idx = src_info->ipi6_ifindex;
805
806 if (src_idx) {
807 if (fl6->flowi6_oif &&
808 src_idx != fl6->flowi6_oif &&
809 (READ_ONCE(sk->sk_bound_dev_if) != fl6->flowi6_oif ||
810 !sk_dev_equal_l3scope(sk, src_idx)))
811 return -EINVAL;
812 fl6->flowi6_oif = src_idx;
813 }
814
815 addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
816
817 rcu_read_lock();
818 if (fl6->flowi6_oif) {
819 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
820 if (!dev) {
821 rcu_read_unlock();
822 return -ENODEV;
823 }
824 } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
825 rcu_read_unlock();
826 return -EINVAL;
827 }
828
829 if (addr_type != IPV6_ADDR_ANY) {
830 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
831 if (!ipv6_can_nonlocal_bind(net, inet_sk(sk)) &&
832 !ipv6_chk_addr_and_flags(net, &src_info->ipi6_addr,
833 dev, !strict, 0,
834 IFA_F_TENTATIVE) &&
835 !ipv6_chk_acast_addr_src(net, dev,
836 &src_info->ipi6_addr))
837 err = -EINVAL;
838 else
839 fl6->saddr = src_info->ipi6_addr;
840 }
841
842 rcu_read_unlock();
843
844 if (err)
845 goto exit_f;
846
847 break;
848 }
849
850 case IPV6_FLOWINFO:
851 if (cmsg->cmsg_len < CMSG_LEN(4)) {
852 err = -EINVAL;
853 goto exit_f;
854 }
855
856 if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
857 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
858 err = -EINVAL;
859 goto exit_f;
860 }
861 }
862 fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
863 break;
864
865 case IPV6_2292HOPOPTS:
866 case IPV6_HOPOPTS:
867 if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
868 err = -EINVAL;
869 goto exit_f;
870 }
871
872 hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
873 len = ((hdr->hdrlen + 1) << 3);
874 if (cmsg->cmsg_len < CMSG_LEN(len)) {
875 err = -EINVAL;
876 goto exit_f;
877 }
878 if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
879 err = -EPERM;
880 goto exit_f;
881 }
882 opt->opt_nflen += len;
883 opt->hopopt = hdr;
884 break;
885
886 case IPV6_2292DSTOPTS:
887 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
888 err = -EINVAL;
889 goto exit_f;
890 }
891
892 hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
893 len = ((hdr->hdrlen + 1) << 3);
894 if (cmsg->cmsg_len < CMSG_LEN(len)) {
895 err = -EINVAL;
896 goto exit_f;
897 }
898 if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
899 err = -EPERM;
900 goto exit_f;
901 }
902 if (opt->dst1opt) {
903 err = -EINVAL;
904 goto exit_f;
905 }
906 opt->opt_flen += len;
907 opt->dst1opt = hdr;
908 break;
909
910 case IPV6_DSTOPTS:
911 case IPV6_RTHDRDSTOPTS:
912 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
913 err = -EINVAL;
914 goto exit_f;
915 }
916
917 hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
918 len = ((hdr->hdrlen + 1) << 3);
919 if (cmsg->cmsg_len < CMSG_LEN(len)) {
920 err = -EINVAL;
921 goto exit_f;
922 }
923 if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
924 err = -EPERM;
925 goto exit_f;
926 }
927 if (cmsg->cmsg_type == IPV6_DSTOPTS) {
928 if (opt->dst1opt)
929 opt->opt_flen -= ipv6_optlen(opt->dst1opt);
930 opt->opt_flen += len;
931 opt->dst1opt = hdr;
932 } else {
933 if (opt->dst0opt)
934 opt->opt_nflen -= ipv6_optlen(opt->dst0opt);
935 opt->opt_nflen += len;
936 opt->dst0opt = hdr;
937 }
938 break;
939
940 case IPV6_2292RTHDR:
941 case IPV6_RTHDR:
942 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
943 err = -EINVAL;
944 goto exit_f;
945 }
946
947 rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
948
949 switch (rthdr->type) {
950 #if IS_ENABLED(CONFIG_IPV6_MIP6)
951 case IPV6_SRCRT_TYPE_2:
952 if (rthdr->hdrlen != 2 ||
953 rthdr->segments_left != 1) {
954 err = -EINVAL;
955 goto exit_f;
956 }
957 break;
958 #endif
959 default:
960 err = -EINVAL;
961 goto exit_f;
962 }
963
964 len = ((rthdr->hdrlen + 1) << 3);
965
966 if (cmsg->cmsg_len < CMSG_LEN(len)) {
967 err = -EINVAL;
968 goto exit_f;
969 }
970
971 /* segments left must also match */
972 if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
973 err = -EINVAL;
974 goto exit_f;
975 }
976
977 orthdr = opt->srcrt;
978 if (orthdr)
979 opt->opt_nflen -= ((orthdr->hdrlen + 1) << 3);
980 opt->opt_nflen += len;
981 opt->srcrt = rthdr;
982
983 if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
984 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
985
986 if (opt->dst0opt)
987 opt->opt_nflen -= ipv6_optlen(opt->dst0opt);
988 opt->opt_nflen += dsthdrlen;
989 opt->dst0opt = opt->dst1opt;
990 opt->dst1opt = NULL;
991 opt->opt_flen -= dsthdrlen;
992 }
993
994 break;
995
996 case IPV6_2292HOPLIMIT:
997 case IPV6_HOPLIMIT:
998 if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
999 err = -EINVAL;
1000 goto exit_f;
1001 }
1002
1003 ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
1004 if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
1005 err = -EINVAL;
1006 goto exit_f;
1007 }
1008
1009 break;
1010
1011 case IPV6_TCLASS:
1012 {
1013 int tc;
1014
1015 err = -EINVAL;
1016 if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1017 goto exit_f;
1018
1019 tc = *(int *)CMSG_DATA(cmsg);
1020 if (tc < -1 || tc > 0xff)
1021 goto exit_f;
1022
1023 err = 0;
1024 ipc6->tclass = tc;
1025
1026 break;
1027 }
1028
1029 case IPV6_DONTFRAG:
1030 {
1031 int df;
1032
1033 err = -EINVAL;
1034 if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1035 goto exit_f;
1036
1037 df = *(int *)CMSG_DATA(cmsg);
1038 if (df < 0 || df > 1)
1039 goto exit_f;
1040
1041 err = 0;
1042 ipc6->dontfrag = df;
1043
1044 break;
1045 }
1046 default:
1047 net_dbg_ratelimited("invalid cmsg type: %d\n",
1048 cmsg->cmsg_type);
1049 err = -EINVAL;
1050 goto exit_f;
1051 }
1052 }
1053
1054 exit_f:
1055 return err;
1056 }
1057 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1058
__ip6_dgram_sock_seq_show(struct seq_file * seq,struct sock * sp,__u16 srcp,__u16 destp,int rqueue,int bucket)1059 void __ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1060 __u16 srcp, __u16 destp, int rqueue, int bucket)
1061 {
1062 const struct in6_addr *dest, *src;
1063
1064 dest = &sp->sk_v6_daddr;
1065 src = &sp->sk_v6_rcv_saddr;
1066 seq_printf(seq,
1067 "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1068 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u\n",
1069 bucket,
1070 src->s6_addr32[0], src->s6_addr32[1],
1071 src->s6_addr32[2], src->s6_addr32[3], srcp,
1072 dest->s6_addr32[0], dest->s6_addr32[1],
1073 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1074 sp->sk_state,
1075 sk_wmem_alloc_get(sp),
1076 rqueue,
1077 0, 0L, 0,
1078 from_kuid_munged(seq_user_ns(seq), sk_uid(sp)),
1079 0,
1080 sock_i_ino(sp),
1081 refcount_read(&sp->sk_refcnt), sp,
1082 sk_drops_read(sp));
1083 }
1084