udp: fix rx queue len reported by diag and proc interface
[muen/linux.git] / net / ipv6 / datagram.c
1 /*
2  *      common UDP/RAW code
3  *      Linux INET6 implementation
4  *
5  *      Authors:
6  *      Pedro Roque             <roque@di.fc.ul.pt>
7  *
8  *      This program is free software; you can redistribute it and/or
9  *      modify it under the terms of the GNU General Public License
10  *      as published by the Free Software Foundation; either version
11  *      2 of the License, or (at your option) any later version.
12  */
13
14 #include <linux/capability.h>
15 #include <linux/errno.h>
16 #include <linux/types.h>
17 #include <linux/kernel.h>
18 #include <linux/interrupt.h>
19 #include <linux/socket.h>
20 #include <linux/sockios.h>
21 #include <linux/in6.h>
22 #include <linux/ipv6.h>
23 #include <linux/route.h>
24 #include <linux/slab.h>
25 #include <linux/export.h>
26
27 #include <net/ipv6.h>
28 #include <net/ndisc.h>
29 #include <net/addrconf.h>
30 #include <net/transp_v6.h>
31 #include <net/ip6_route.h>
32 #include <net/tcp_states.h>
33 #include <net/dsfield.h>
34
35 #include <linux/errqueue.h>
36 #include <linux/uaccess.h>
37
38 static bool ipv6_mapped_addr_any(const struct in6_addr *a)
39 {
40         return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
41 }
42
43 static void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
44 {
45         struct inet_sock *inet = inet_sk(sk);
46         struct ipv6_pinfo *np = inet6_sk(sk);
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_oif = sk->sk_bound_dev_if;
53         fl6->flowi6_mark = sk->sk_mark;
54         fl6->fl6_dport = inet->inet_dport;
55         fl6->fl6_sport = inet->inet_sport;
56         fl6->flowlabel = np->flow_label;
57         fl6->flowi6_uid = sk->sk_uid;
58
59         if (!fl6->flowi6_oif)
60                 fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
61
62         if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr))
63                 fl6->flowi6_oif = np->mcast_oif;
64
65         security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
66 }
67
68 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
69 {
70         struct ip6_flowlabel *flowlabel = NULL;
71         struct in6_addr *final_p, final;
72         struct ipv6_txoptions *opt;
73         struct dst_entry *dst;
74         struct inet_sock *inet = inet_sk(sk);
75         struct ipv6_pinfo *np = inet6_sk(sk);
76         struct flowi6 fl6;
77         int err = 0;
78
79         if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
80                 flowlabel = fl6_sock_lookup(sk, np->flow_label);
81                 if (!flowlabel)
82                         return -EINVAL;
83         }
84         ip6_datagram_flow_key_init(&fl6, sk);
85
86         rcu_read_lock();
87         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
88         final_p = fl6_update_dst(&fl6, opt, &final);
89         rcu_read_unlock();
90
91         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
92         if (IS_ERR(dst)) {
93                 err = PTR_ERR(dst);
94                 goto out;
95         }
96
97         if (fix_sk_saddr) {
98                 if (ipv6_addr_any(&np->saddr))
99                         np->saddr = fl6.saddr;
100
101                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
102                         sk->sk_v6_rcv_saddr = fl6.saddr;
103                         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
104                         if (sk->sk_prot->rehash)
105                                 sk->sk_prot->rehash(sk);
106                 }
107         }
108
109         ip6_sk_dst_store_flow(sk, dst, &fl6);
110
111 out:
112         fl6_sock_release(flowlabel);
113         return err;
114 }
115
116 void ip6_datagram_release_cb(struct sock *sk)
117 {
118         struct dst_entry *dst;
119
120         if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
121                 return;
122
123         rcu_read_lock();
124         dst = __sk_dst_get(sk);
125         if (!dst || !dst->obsolete ||
126             dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
127                 rcu_read_unlock();
128                 return;
129         }
130         rcu_read_unlock();
131
132         ip6_datagram_dst_update(sk, false);
133 }
134 EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
135
136 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
137                            int addr_len)
138 {
139         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
140         struct inet_sock        *inet = inet_sk(sk);
141         struct ipv6_pinfo       *np = inet6_sk(sk);
142         struct in6_addr         *daddr, old_daddr;
143         __be32                  fl6_flowlabel = 0;
144         __be32                  old_fl6_flowlabel;
145         __be16                  old_dport;
146         int                     addr_type;
147         int                     err;
148
149         if (usin->sin6_family == AF_INET) {
150                 if (__ipv6_only_sock(sk))
151                         return -EAFNOSUPPORT;
152                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
153                 goto ipv4_connected;
154         }
155
156         if (addr_len < SIN6_LEN_RFC2133)
157                 return -EINVAL;
158
159         if (usin->sin6_family != AF_INET6)
160                 return -EAFNOSUPPORT;
161
162         if (np->sndflow)
163                 fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
164
165         if (ipv6_addr_any(&usin->sin6_addr)) {
166                 /*
167                  *      connect to self
168                  */
169                 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
170                         ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
171                                                &usin->sin6_addr);
172                 else
173                         usin->sin6_addr = in6addr_loopback;
174         }
175
176         addr_type = ipv6_addr_type(&usin->sin6_addr);
177
178         daddr = &usin->sin6_addr;
179
180         if (addr_type & IPV6_ADDR_MAPPED) {
181                 struct sockaddr_in sin;
182
183                 if (__ipv6_only_sock(sk)) {
184                         err = -ENETUNREACH;
185                         goto out;
186                 }
187                 sin.sin_family = AF_INET;
188                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
189                 sin.sin_port = usin->sin6_port;
190
191                 err = __ip4_datagram_connect(sk,
192                                              (struct sockaddr *) &sin,
193                                              sizeof(sin));
194
195 ipv4_connected:
196                 if (err)
197                         goto out;
198
199                 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
200
201                 if (ipv6_addr_any(&np->saddr) ||
202                     ipv6_mapped_addr_any(&np->saddr))
203                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
204
205                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
206                     ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
207                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
208                                                &sk->sk_v6_rcv_saddr);
209                         if (sk->sk_prot->rehash)
210                                 sk->sk_prot->rehash(sk);
211                 }
212
213                 goto out;
214         }
215
216         if (__ipv6_addr_needs_scope_id(addr_type)) {
217                 if (addr_len >= sizeof(struct sockaddr_in6) &&
218                     usin->sin6_scope_id) {
219                         if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id)) {
220                                 err = -EINVAL;
221                                 goto out;
222                         }
223                         sk->sk_bound_dev_if = usin->sin6_scope_id;
224                 }
225
226                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
227                         sk->sk_bound_dev_if = np->mcast_oif;
228
229                 /* Connect to link-local address requires an interface */
230                 if (!sk->sk_bound_dev_if) {
231                         err = -EINVAL;
232                         goto out;
233                 }
234         }
235
236         /* save the current peer information before updating it */
237         old_daddr = sk->sk_v6_daddr;
238         old_fl6_flowlabel = np->flow_label;
239         old_dport = inet->inet_dport;
240
241         sk->sk_v6_daddr = *daddr;
242         np->flow_label = fl6_flowlabel;
243         inet->inet_dport = usin->sin6_port;
244
245         /*
246          *      Check for a route to destination an obtain the
247          *      destination cache for it.
248          */
249
250         err = ip6_datagram_dst_update(sk, true);
251         if (err) {
252                 /* Restore the socket peer info, to keep it consistent with
253                  * the old socket state
254                  */
255                 sk->sk_v6_daddr = old_daddr;
256                 np->flow_label = old_fl6_flowlabel;
257                 inet->inet_dport = old_dport;
258                 goto out;
259         }
260
261         sk->sk_state = TCP_ESTABLISHED;
262         sk_set_txhash(sk);
263 out:
264         return err;
265 }
266 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
267
268 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
269 {
270         int res;
271
272         lock_sock(sk);
273         res = __ip6_datagram_connect(sk, uaddr, addr_len);
274         release_sock(sk);
275         return res;
276 }
277 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
278
279 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
280                                  int addr_len)
281 {
282         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
283         if (sin6->sin6_family != AF_INET6)
284                 return -EAFNOSUPPORT;
285         return ip6_datagram_connect(sk, uaddr, addr_len);
286 }
287 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
288
289 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
290                      __be16 port, u32 info, u8 *payload)
291 {
292         struct ipv6_pinfo *np  = inet6_sk(sk);
293         struct icmp6hdr *icmph = icmp6_hdr(skb);
294         struct sock_exterr_skb *serr;
295
296         if (!np->recverr)
297                 return;
298
299         skb = skb_clone(skb, GFP_ATOMIC);
300         if (!skb)
301                 return;
302
303         skb->protocol = htons(ETH_P_IPV6);
304
305         serr = SKB_EXT_ERR(skb);
306         serr->ee.ee_errno = err;
307         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
308         serr->ee.ee_type = icmph->icmp6_type;
309         serr->ee.ee_code = icmph->icmp6_code;
310         serr->ee.ee_pad = 0;
311         serr->ee.ee_info = info;
312         serr->ee.ee_data = 0;
313         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
314                                   skb_network_header(skb);
315         serr->port = port;
316
317         __skb_pull(skb, payload - skb->data);
318         skb_reset_transport_header(skb);
319
320         if (sock_queue_err_skb(sk, skb))
321                 kfree_skb(skb);
322 }
323
324 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
325 {
326         const struct ipv6_pinfo *np = inet6_sk(sk);
327         struct sock_exterr_skb *serr;
328         struct ipv6hdr *iph;
329         struct sk_buff *skb;
330
331         if (!np->recverr)
332                 return;
333
334         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
335         if (!skb)
336                 return;
337
338         skb->protocol = htons(ETH_P_IPV6);
339
340         skb_put(skb, sizeof(struct ipv6hdr));
341         skb_reset_network_header(skb);
342         iph = ipv6_hdr(skb);
343         iph->daddr = fl6->daddr;
344
345         serr = SKB_EXT_ERR(skb);
346         serr->ee.ee_errno = err;
347         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
348         serr->ee.ee_type = 0;
349         serr->ee.ee_code = 0;
350         serr->ee.ee_pad = 0;
351         serr->ee.ee_info = info;
352         serr->ee.ee_data = 0;
353         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
354         serr->port = fl6->fl6_dport;
355
356         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
357         skb_reset_transport_header(skb);
358
359         if (sock_queue_err_skb(sk, skb))
360                 kfree_skb(skb);
361 }
362
363 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
364 {
365         struct ipv6_pinfo *np = inet6_sk(sk);
366         struct ipv6hdr *iph;
367         struct sk_buff *skb;
368         struct ip6_mtuinfo *mtu_info;
369
370         if (!np->rxopt.bits.rxpmtu)
371                 return;
372
373         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
374         if (!skb)
375                 return;
376
377         skb_put(skb, sizeof(struct ipv6hdr));
378         skb_reset_network_header(skb);
379         iph = ipv6_hdr(skb);
380         iph->daddr = fl6->daddr;
381
382         mtu_info = IP6CBMTU(skb);
383
384         mtu_info->ip6m_mtu = mtu;
385         mtu_info->ip6m_addr.sin6_family = AF_INET6;
386         mtu_info->ip6m_addr.sin6_port = 0;
387         mtu_info->ip6m_addr.sin6_flowinfo = 0;
388         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
389         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
390
391         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
392         skb_reset_transport_header(skb);
393
394         skb = xchg(&np->rxpmtu, skb);
395         kfree_skb(skb);
396 }
397
398 /* For some errors we have valid addr_offset even with zero payload and
399  * zero port. Also, addr_offset should be supported if port is set.
400  */
401 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
402 {
403         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
404                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
405                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
406 }
407
408 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
409  *
410  * At one point, excluding local errors was a quick test to identify icmp/icmp6
411  * errors. This is no longer true, but the test remained, so the v6 stack,
412  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
413  */
414 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
415                                       struct sock_exterr_skb *serr)
416 {
417         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
418             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
419                 return true;
420
421         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
422                 return false;
423
424         if (!IP6CB(skb)->iif)
425                 return false;
426
427         return true;
428 }
429
430 /*
431  *      Handle MSG_ERRQUEUE
432  */
433 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
434 {
435         struct ipv6_pinfo *np = inet6_sk(sk);
436         struct sock_exterr_skb *serr;
437         struct sk_buff *skb;
438         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
439         struct {
440                 struct sock_extended_err ee;
441                 struct sockaddr_in6      offender;
442         } errhdr;
443         int err;
444         int copied;
445
446         err = -EAGAIN;
447         skb = sock_dequeue_err_skb(sk);
448         if (!skb)
449                 goto out;
450
451         copied = skb->len;
452         if (copied > len) {
453                 msg->msg_flags |= MSG_TRUNC;
454                 copied = len;
455         }
456         err = skb_copy_datagram_msg(skb, 0, msg, copied);
457         if (unlikely(err)) {
458                 kfree_skb(skb);
459                 return err;
460         }
461         sock_recv_timestamp(msg, sk, skb);
462
463         serr = SKB_EXT_ERR(skb);
464
465         if (sin && ipv6_datagram_support_addr(serr)) {
466                 const unsigned char *nh = skb_network_header(skb);
467                 sin->sin6_family = AF_INET6;
468                 sin->sin6_flowinfo = 0;
469                 sin->sin6_port = serr->port;
470                 if (skb->protocol == htons(ETH_P_IPV6)) {
471                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
472                                                                   struct ipv6hdr, daddr);
473                         sin->sin6_addr = ip6h->daddr;
474                         if (np->sndflow)
475                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
476                         sin->sin6_scope_id =
477                                 ipv6_iface_scope_id(&sin->sin6_addr,
478                                                     IP6CB(skb)->iif);
479                 } else {
480                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
481                                                &sin->sin6_addr);
482                         sin->sin6_scope_id = 0;
483                 }
484                 *addr_len = sizeof(*sin);
485         }
486
487         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
488         sin = &errhdr.offender;
489         memset(sin, 0, sizeof(*sin));
490
491         if (ip6_datagram_support_cmsg(skb, serr)) {
492                 sin->sin6_family = AF_INET6;
493                 if (np->rxopt.all)
494                         ip6_datagram_recv_common_ctl(sk, msg, skb);
495                 if (skb->protocol == htons(ETH_P_IPV6)) {
496                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
497                         if (np->rxopt.all)
498                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
499                         sin->sin6_scope_id =
500                                 ipv6_iface_scope_id(&sin->sin6_addr,
501                                                     IP6CB(skb)->iif);
502                 } else {
503                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
504                                                &sin->sin6_addr);
505                         if (inet_sk(sk)->cmsg_flags)
506                                 ip_cmsg_recv(msg, skb);
507                 }
508         }
509
510         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
511
512         /* Now we could try to dump offended packet options */
513
514         msg->msg_flags |= MSG_ERRQUEUE;
515         err = copied;
516
517         consume_skb(skb);
518 out:
519         return err;
520 }
521 EXPORT_SYMBOL_GPL(ipv6_recv_error);
522
523 /*
524  *      Handle IPV6_RECVPATHMTU
525  */
526 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
527                      int *addr_len)
528 {
529         struct ipv6_pinfo *np = inet6_sk(sk);
530         struct sk_buff *skb;
531         struct ip6_mtuinfo mtu_info;
532         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
533         int err;
534         int copied;
535
536         err = -EAGAIN;
537         skb = xchg(&np->rxpmtu, NULL);
538         if (!skb)
539                 goto out;
540
541         copied = skb->len;
542         if (copied > len) {
543                 msg->msg_flags |= MSG_TRUNC;
544                 copied = len;
545         }
546         err = skb_copy_datagram_msg(skb, 0, msg, copied);
547         if (err)
548                 goto out_free_skb;
549
550         sock_recv_timestamp(msg, sk, skb);
551
552         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
553
554         if (sin) {
555                 sin->sin6_family = AF_INET6;
556                 sin->sin6_flowinfo = 0;
557                 sin->sin6_port = 0;
558                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
559                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
560                 *addr_len = sizeof(*sin);
561         }
562
563         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
564
565         err = copied;
566
567 out_free_skb:
568         kfree_skb(skb);
569 out:
570         return err;
571 }
572
573
574 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
575                                  struct sk_buff *skb)
576 {
577         struct ipv6_pinfo *np = inet6_sk(sk);
578         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
579
580         if (np->rxopt.bits.rxinfo) {
581                 struct in6_pktinfo src_info;
582
583                 if (is_ipv6) {
584                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
585                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
586                 } else {
587                         src_info.ipi6_ifindex =
588                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
589                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
590                                                &src_info.ipi6_addr);
591                 }
592
593                 if (src_info.ipi6_ifindex >= 0)
594                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
595                                  sizeof(src_info), &src_info);
596         }
597 }
598
599 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
600                                     struct sk_buff *skb)
601 {
602         struct ipv6_pinfo *np = inet6_sk(sk);
603         struct inet6_skb_parm *opt = IP6CB(skb);
604         unsigned char *nh = skb_network_header(skb);
605
606         if (np->rxopt.bits.rxhlim) {
607                 int hlim = ipv6_hdr(skb)->hop_limit;
608                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
609         }
610
611         if (np->rxopt.bits.rxtclass) {
612                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
613                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
614         }
615
616         if (np->rxopt.bits.rxflow) {
617                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
618                 if (flowinfo)
619                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
620         }
621
622         /* HbH is allowed only once */
623         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
624                 u8 *ptr = nh + sizeof(struct ipv6hdr);
625                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
626         }
627
628         if (opt->lastopt &&
629             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
630                 /*
631                  * Silly enough, but we need to reparse in order to
632                  * report extension headers (except for HbH)
633                  * in order.
634                  *
635                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
636                  * (and WILL NOT be) defined because
637                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
638                  */
639                 unsigned int off = sizeof(struct ipv6hdr);
640                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
641
642                 while (off <= opt->lastopt) {
643                         unsigned int len;
644                         u8 *ptr = nh + off;
645
646                         switch (nexthdr) {
647                         case IPPROTO_DSTOPTS:
648                                 nexthdr = ptr[0];
649                                 len = (ptr[1] + 1) << 3;
650                                 if (np->rxopt.bits.dstopts)
651                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
652                                 break;
653                         case IPPROTO_ROUTING:
654                                 nexthdr = ptr[0];
655                                 len = (ptr[1] + 1) << 3;
656                                 if (np->rxopt.bits.srcrt)
657                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
658                                 break;
659                         case IPPROTO_AH:
660                                 nexthdr = ptr[0];
661                                 len = (ptr[1] + 2) << 2;
662                                 break;
663                         default:
664                                 nexthdr = ptr[0];
665                                 len = (ptr[1] + 1) << 3;
666                                 break;
667                         }
668
669                         off += len;
670                 }
671         }
672
673         /* socket options in old style */
674         if (np->rxopt.bits.rxoinfo) {
675                 struct in6_pktinfo src_info;
676
677                 src_info.ipi6_ifindex = opt->iif;
678                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
679                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
680         }
681         if (np->rxopt.bits.rxohlim) {
682                 int hlim = ipv6_hdr(skb)->hop_limit;
683                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
684         }
685         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
686                 u8 *ptr = nh + sizeof(struct ipv6hdr);
687                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
688         }
689         if (np->rxopt.bits.odstopts && opt->dst0) {
690                 u8 *ptr = nh + opt->dst0;
691                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
692         }
693         if (np->rxopt.bits.osrcrt && opt->srcrt) {
694                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
695                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
696         }
697         if (np->rxopt.bits.odstopts && opt->dst1) {
698                 u8 *ptr = nh + opt->dst1;
699                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
700         }
701         if (np->rxopt.bits.rxorigdstaddr) {
702                 struct sockaddr_in6 sin6;
703                 __be16 *ports = (__be16 *) skb_transport_header(skb);
704
705                 if (skb_transport_offset(skb) + 4 <= (int)skb->len) {
706                         /* All current transport protocols have the port numbers in the
707                          * first four bytes of the transport header and this function is
708                          * written with this assumption in mind.
709                          */
710
711                         sin6.sin6_family = AF_INET6;
712                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
713                         sin6.sin6_port = ports[1];
714                         sin6.sin6_flowinfo = 0;
715                         sin6.sin6_scope_id =
716                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
717                                                     opt->iif);
718
719                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
720                 }
721         }
722         if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
723                 int val = opt->frag_max_size;
724
725                 put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
726         }
727 }
728
729 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
730                           struct sk_buff *skb)
731 {
732         ip6_datagram_recv_common_ctl(sk, msg, skb);
733         ip6_datagram_recv_specific_ctl(sk, msg, skb);
734 }
735 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
736
737 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
738                           struct msghdr *msg, struct flowi6 *fl6,
739                           struct ipcm6_cookie *ipc6, struct sockcm_cookie *sockc)
740 {
741         struct in6_pktinfo *src_info;
742         struct cmsghdr *cmsg;
743         struct ipv6_rt_hdr *rthdr;
744         struct ipv6_opt_hdr *hdr;
745         struct ipv6_txoptions *opt = ipc6->opt;
746         int len;
747         int err = 0;
748
749         for_each_cmsghdr(cmsg, msg) {
750                 int addr_type;
751
752                 if (!CMSG_OK(msg, cmsg)) {
753                         err = -EINVAL;
754                         goto exit_f;
755                 }
756
757                 if (cmsg->cmsg_level == SOL_SOCKET) {
758                         err = __sock_cmsg_send(sk, msg, cmsg, sockc);
759                         if (err)
760                                 return err;
761                         continue;
762                 }
763
764                 if (cmsg->cmsg_level != SOL_IPV6)
765                         continue;
766
767                 switch (cmsg->cmsg_type) {
768                 case IPV6_PKTINFO:
769                 case IPV6_2292PKTINFO:
770                     {
771                         struct net_device *dev = NULL;
772
773                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
774                                 err = -EINVAL;
775                                 goto exit_f;
776                         }
777
778                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
779
780                         if (src_info->ipi6_ifindex) {
781                                 if (fl6->flowi6_oif &&
782                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
783                                         return -EINVAL;
784                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
785                         }
786
787                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
788
789                         rcu_read_lock();
790                         if (fl6->flowi6_oif) {
791                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
792                                 if (!dev) {
793                                         rcu_read_unlock();
794                                         return -ENODEV;
795                                 }
796                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
797                                 rcu_read_unlock();
798                                 return -EINVAL;
799                         }
800
801                         if (addr_type != IPV6_ADDR_ANY) {
802                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
803                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
804                                     !ipv6_chk_addr_and_flags(net, &src_info->ipi6_addr,
805                                                              dev, !strict, 0,
806                                                              IFA_F_TENTATIVE) &&
807                                     !ipv6_chk_acast_addr_src(net, dev,
808                                                              &src_info->ipi6_addr))
809                                         err = -EINVAL;
810                                 else
811                                         fl6->saddr = src_info->ipi6_addr;
812                         }
813
814                         rcu_read_unlock();
815
816                         if (err)
817                                 goto exit_f;
818
819                         break;
820                     }
821
822                 case IPV6_FLOWINFO:
823                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
824                                 err = -EINVAL;
825                                 goto exit_f;
826                         }
827
828                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
829                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
830                                         err = -EINVAL;
831                                         goto exit_f;
832                                 }
833                         }
834                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
835                         break;
836
837                 case IPV6_2292HOPOPTS:
838                 case IPV6_HOPOPTS:
839                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
840                                 err = -EINVAL;
841                                 goto exit_f;
842                         }
843
844                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
845                         len = ((hdr->hdrlen + 1) << 3);
846                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
847                                 err = -EINVAL;
848                                 goto exit_f;
849                         }
850                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
851                                 err = -EPERM;
852                                 goto exit_f;
853                         }
854                         opt->opt_nflen += len;
855                         opt->hopopt = hdr;
856                         break;
857
858                 case IPV6_2292DSTOPTS:
859                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
860                                 err = -EINVAL;
861                                 goto exit_f;
862                         }
863
864                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
865                         len = ((hdr->hdrlen + 1) << 3);
866                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
867                                 err = -EINVAL;
868                                 goto exit_f;
869                         }
870                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
871                                 err = -EPERM;
872                                 goto exit_f;
873                         }
874                         if (opt->dst1opt) {
875                                 err = -EINVAL;
876                                 goto exit_f;
877                         }
878                         opt->opt_flen += len;
879                         opt->dst1opt = hdr;
880                         break;
881
882                 case IPV6_DSTOPTS:
883                 case IPV6_RTHDRDSTOPTS:
884                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
885                                 err = -EINVAL;
886                                 goto exit_f;
887                         }
888
889                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
890                         len = ((hdr->hdrlen + 1) << 3);
891                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
892                                 err = -EINVAL;
893                                 goto exit_f;
894                         }
895                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
896                                 err = -EPERM;
897                                 goto exit_f;
898                         }
899                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
900                                 opt->opt_flen += len;
901                                 opt->dst1opt = hdr;
902                         } else {
903                                 opt->opt_nflen += len;
904                                 opt->dst0opt = hdr;
905                         }
906                         break;
907
908                 case IPV6_2292RTHDR:
909                 case IPV6_RTHDR:
910                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
911                                 err = -EINVAL;
912                                 goto exit_f;
913                         }
914
915                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
916
917                         switch (rthdr->type) {
918 #if IS_ENABLED(CONFIG_IPV6_MIP6)
919                         case IPV6_SRCRT_TYPE_2:
920                                 if (rthdr->hdrlen != 2 ||
921                                     rthdr->segments_left != 1) {
922                                         err = -EINVAL;
923                                         goto exit_f;
924                                 }
925                                 break;
926 #endif
927                         default:
928                                 err = -EINVAL;
929                                 goto exit_f;
930                         }
931
932                         len = ((rthdr->hdrlen + 1) << 3);
933
934                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
935                                 err = -EINVAL;
936                                 goto exit_f;
937                         }
938
939                         /* segments left must also match */
940                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
941                                 err = -EINVAL;
942                                 goto exit_f;
943                         }
944
945                         opt->opt_nflen += len;
946                         opt->srcrt = rthdr;
947
948                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
949                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
950
951                                 opt->opt_nflen += dsthdrlen;
952                                 opt->dst0opt = opt->dst1opt;
953                                 opt->dst1opt = NULL;
954                                 opt->opt_flen -= dsthdrlen;
955                         }
956
957                         break;
958
959                 case IPV6_2292HOPLIMIT:
960                 case IPV6_HOPLIMIT:
961                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
962                                 err = -EINVAL;
963                                 goto exit_f;
964                         }
965
966                         ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
967                         if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
968                                 err = -EINVAL;
969                                 goto exit_f;
970                         }
971
972                         break;
973
974                 case IPV6_TCLASS:
975                     {
976                         int tc;
977
978                         err = -EINVAL;
979                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
980                                 goto exit_f;
981
982                         tc = *(int *)CMSG_DATA(cmsg);
983                         if (tc < -1 || tc > 0xff)
984                                 goto exit_f;
985
986                         err = 0;
987                         ipc6->tclass = tc;
988
989                         break;
990                     }
991
992                 case IPV6_DONTFRAG:
993                     {
994                         int df;
995
996                         err = -EINVAL;
997                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
998                                 goto exit_f;
999
1000                         df = *(int *)CMSG_DATA(cmsg);
1001                         if (df < 0 || df > 1)
1002                                 goto exit_f;
1003
1004                         err = 0;
1005                         ipc6->dontfrag = df;
1006
1007                         break;
1008                     }
1009                 default:
1010                         net_dbg_ratelimited("invalid cmsg type: %d\n",
1011                                             cmsg->cmsg_type);
1012                         err = -EINVAL;
1013                         goto exit_f;
1014                 }
1015         }
1016
1017 exit_f:
1018         return err;
1019 }
1020 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1021
1022 void __ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1023                                __u16 srcp, __u16 destp, int rqueue, int bucket)
1024 {
1025         const struct in6_addr *dest, *src;
1026
1027         dest  = &sp->sk_v6_daddr;
1028         src   = &sp->sk_v6_rcv_saddr;
1029         seq_printf(seq,
1030                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1031                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
1032                    bucket,
1033                    src->s6_addr32[0], src->s6_addr32[1],
1034                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1035                    dest->s6_addr32[0], dest->s6_addr32[1],
1036                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1037                    sp->sk_state,
1038                    sk_wmem_alloc_get(sp),
1039                    rqueue,
1040                    0, 0L, 0,
1041                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1042                    0,
1043                    sock_i_ino(sp),
1044                    refcount_read(&sp->sk_refcnt), sp,
1045                    atomic_read(&sp->sk_drops));
1046 }