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Linux/net/ipv6/datagram.c

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  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 <asm/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 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 44 {
 45         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
 46         struct inet_sock        *inet = inet_sk(sk);
 47         struct ipv6_pinfo       *np = inet6_sk(sk);
 48         struct in6_addr *daddr, *final_p, final;
 49         struct dst_entry        *dst;
 50         struct flowi6           fl6;
 51         struct ip6_flowlabel    *flowlabel = NULL;
 52         struct ipv6_txoptions   *opt;
 53         int                     addr_type;
 54         int                     err;
 55 
 56         if (usin->sin6_family == AF_INET) {
 57                 if (__ipv6_only_sock(sk))
 58                         return -EAFNOSUPPORT;
 59                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
 60                 goto ipv4_connected;
 61         }
 62 
 63         if (addr_len < SIN6_LEN_RFC2133)
 64                 return -EINVAL;
 65 
 66         if (usin->sin6_family != AF_INET6)
 67                 return -EAFNOSUPPORT;
 68 
 69         memset(&fl6, 0, sizeof(fl6));
 70         if (np->sndflow) {
 71                 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 72                 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 73                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
 74                         if (!flowlabel)
 75                                 return -EINVAL;
 76                 }
 77         }
 78 
 79         addr_type = ipv6_addr_type(&usin->sin6_addr);
 80 
 81         if (addr_type == IPV6_ADDR_ANY) {
 82                 /*
 83                  *      connect to self
 84                  */
 85                 usin->sin6_addr.s6_addr[15] = 0x01;
 86         }
 87 
 88         daddr = &usin->sin6_addr;
 89 
 90         if (addr_type == IPV6_ADDR_MAPPED) {
 91                 struct sockaddr_in sin;
 92 
 93                 if (__ipv6_only_sock(sk)) {
 94                         err = -ENETUNREACH;
 95                         goto out;
 96                 }
 97                 sin.sin_family = AF_INET;
 98                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
 99                 sin.sin_port = usin->sin6_port;
100 
101                 err = __ip4_datagram_connect(sk,
102                                              (struct sockaddr *) &sin,
103                                              sizeof(sin));
104 
105 ipv4_connected:
106                 if (err)
107                         goto out;
108 
109                 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
110 
111                 if (ipv6_addr_any(&np->saddr) ||
112                     ipv6_mapped_addr_any(&np->saddr))
113                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
114 
115                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
116                     ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
117                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
118                                                &sk->sk_v6_rcv_saddr);
119                         if (sk->sk_prot->rehash)
120                                 sk->sk_prot->rehash(sk);
121                 }
122 
123                 goto out;
124         }
125 
126         if (__ipv6_addr_needs_scope_id(addr_type)) {
127                 if (addr_len >= sizeof(struct sockaddr_in6) &&
128                     usin->sin6_scope_id) {
129                         if (sk->sk_bound_dev_if &&
130                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
131                                 err = -EINVAL;
132                                 goto out;
133                         }
134                         sk->sk_bound_dev_if = usin->sin6_scope_id;
135                 }
136 
137                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
138                         sk->sk_bound_dev_if = np->mcast_oif;
139 
140                 /* Connect to link-local address requires an interface */
141                 if (!sk->sk_bound_dev_if) {
142                         err = -EINVAL;
143                         goto out;
144                 }
145         }
146 
147         sk->sk_v6_daddr = *daddr;
148         np->flow_label = fl6.flowlabel;
149 
150         inet->inet_dport = usin->sin6_port;
151 
152         /*
153          *      Check for a route to destination an obtain the
154          *      destination cache for it.
155          */
156 
157         fl6.flowi6_proto = sk->sk_protocol;
158         fl6.daddr = sk->sk_v6_daddr;
159         fl6.saddr = np->saddr;
160         fl6.flowi6_oif = sk->sk_bound_dev_if;
161         fl6.flowi6_mark = sk->sk_mark;
162         fl6.fl6_dport = inet->inet_dport;
163         fl6.fl6_sport = inet->inet_sport;
164 
165         if (!fl6.flowi6_oif && (addr_type&IPV6_ADDR_MULTICAST))
166                 fl6.flowi6_oif = np->mcast_oif;
167 
168         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
169 
170         rcu_read_lock();
171         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
172         final_p = fl6_update_dst(&fl6, opt, &final);
173         rcu_read_unlock();
174 
175         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
176         err = 0;
177         if (IS_ERR(dst)) {
178                 err = PTR_ERR(dst);
179                 goto out;
180         }
181 
182         /* source address lookup done in ip6_dst_lookup */
183 
184         if (ipv6_addr_any(&np->saddr))
185                 np->saddr = fl6.saddr;
186 
187         if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
188                 sk->sk_v6_rcv_saddr = fl6.saddr;
189                 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
190                 if (sk->sk_prot->rehash)
191                         sk->sk_prot->rehash(sk);
192         }
193 
194         ip6_dst_store(sk, dst,
195                       ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
196                       &sk->sk_v6_daddr : NULL,
197 #ifdef CONFIG_IPV6_SUBTREES
198                       ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
199                       &np->saddr :
200 #endif
201                       NULL);
202 
203         sk->sk_state = TCP_ESTABLISHED;
204         ip6_set_txhash(sk);
205 out:
206         fl6_sock_release(flowlabel);
207         return err;
208 }
209 
210 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
211 {
212         int res;
213 
214         lock_sock(sk);
215         res = __ip6_datagram_connect(sk, uaddr, addr_len);
216         release_sock(sk);
217         return res;
218 }
219 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
220 
221 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
222                                  int addr_len)
223 {
224         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
225         if (sin6->sin6_family != AF_INET6)
226                 return -EAFNOSUPPORT;
227         return ip6_datagram_connect(sk, uaddr, addr_len);
228 }
229 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
230 
231 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
232                      __be16 port, u32 info, u8 *payload)
233 {
234         struct ipv6_pinfo *np  = inet6_sk(sk);
235         struct icmp6hdr *icmph = icmp6_hdr(skb);
236         struct sock_exterr_skb *serr;
237 
238         if (!np->recverr)
239                 return;
240 
241         skb = skb_clone(skb, GFP_ATOMIC);
242         if (!skb)
243                 return;
244 
245         skb->protocol = htons(ETH_P_IPV6);
246 
247         serr = SKB_EXT_ERR(skb);
248         serr->ee.ee_errno = err;
249         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
250         serr->ee.ee_type = icmph->icmp6_type;
251         serr->ee.ee_code = icmph->icmp6_code;
252         serr->ee.ee_pad = 0;
253         serr->ee.ee_info = info;
254         serr->ee.ee_data = 0;
255         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
256                                   skb_network_header(skb);
257         serr->port = port;
258 
259         __skb_pull(skb, payload - skb->data);
260         skb_reset_transport_header(skb);
261 
262         if (sock_queue_err_skb(sk, skb))
263                 kfree_skb(skb);
264 }
265 
266 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
267 {
268         struct ipv6_pinfo *np = inet6_sk(sk);
269         struct sock_exterr_skb *serr;
270         struct ipv6hdr *iph;
271         struct sk_buff *skb;
272 
273         if (!np->recverr)
274                 return;
275 
276         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
277         if (!skb)
278                 return;
279 
280         skb->protocol = htons(ETH_P_IPV6);
281 
282         skb_put(skb, sizeof(struct ipv6hdr));
283         skb_reset_network_header(skb);
284         iph = ipv6_hdr(skb);
285         iph->daddr = fl6->daddr;
286 
287         serr = SKB_EXT_ERR(skb);
288         serr->ee.ee_errno = err;
289         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
290         serr->ee.ee_type = 0;
291         serr->ee.ee_code = 0;
292         serr->ee.ee_pad = 0;
293         serr->ee.ee_info = info;
294         serr->ee.ee_data = 0;
295         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
296         serr->port = fl6->fl6_dport;
297 
298         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
299         skb_reset_transport_header(skb);
300 
301         if (sock_queue_err_skb(sk, skb))
302                 kfree_skb(skb);
303 }
304 
305 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
306 {
307         struct ipv6_pinfo *np = inet6_sk(sk);
308         struct ipv6hdr *iph;
309         struct sk_buff *skb;
310         struct ip6_mtuinfo *mtu_info;
311 
312         if (!np->rxopt.bits.rxpmtu)
313                 return;
314 
315         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
316         if (!skb)
317                 return;
318 
319         skb_put(skb, sizeof(struct ipv6hdr));
320         skb_reset_network_header(skb);
321         iph = ipv6_hdr(skb);
322         iph->daddr = fl6->daddr;
323 
324         mtu_info = IP6CBMTU(skb);
325 
326         mtu_info->ip6m_mtu = mtu;
327         mtu_info->ip6m_addr.sin6_family = AF_INET6;
328         mtu_info->ip6m_addr.sin6_port = 0;
329         mtu_info->ip6m_addr.sin6_flowinfo = 0;
330         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
331         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
332 
333         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
334         skb_reset_transport_header(skb);
335 
336         skb = xchg(&np->rxpmtu, skb);
337         kfree_skb(skb);
338 }
339 
340 /* For some errors we have valid addr_offset even with zero payload and
341  * zero port. Also, addr_offset should be supported if port is set.
342  */
343 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
344 {
345         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
346                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
347                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
348 }
349 
350 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
351  *
352  * At one point, excluding local errors was a quick test to identify icmp/icmp6
353  * errors. This is no longer true, but the test remained, so the v6 stack,
354  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
355  *
356  * Timestamp code paths do not initialize the fields expected by cmsg:
357  * the PKTINFO fields in skb->cb[]. Fill those in here.
358  */
359 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
360                                       struct sock_exterr_skb *serr)
361 {
362         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
363             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
364                 return true;
365 
366         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
367                 return false;
368 
369         if (!skb->dev)
370                 return false;
371 
372         if (skb->protocol == htons(ETH_P_IPV6))
373                 IP6CB(skb)->iif = skb->dev->ifindex;
374         else
375                 PKTINFO_SKB_CB(skb)->ipi_ifindex = skb->dev->ifindex;
376 
377         return true;
378 }
379 
380 /*
381  *      Handle MSG_ERRQUEUE
382  */
383 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
384 {
385         struct ipv6_pinfo *np = inet6_sk(sk);
386         struct sock_exterr_skb *serr;
387         struct sk_buff *skb;
388         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
389         struct {
390                 struct sock_extended_err ee;
391                 struct sockaddr_in6      offender;
392         } errhdr;
393         int err;
394         int copied;
395 
396         err = -EAGAIN;
397         skb = sock_dequeue_err_skb(sk);
398         if (!skb)
399                 goto out;
400 
401         copied = skb->len;
402         if (copied > len) {
403                 msg->msg_flags |= MSG_TRUNC;
404                 copied = len;
405         }
406         err = skb_copy_datagram_msg(skb, 0, msg, copied);
407         if (err)
408                 goto out_free_skb;
409 
410         sock_recv_timestamp(msg, sk, skb);
411 
412         serr = SKB_EXT_ERR(skb);
413 
414         if (sin && ipv6_datagram_support_addr(serr)) {
415                 const unsigned char *nh = skb_network_header(skb);
416                 sin->sin6_family = AF_INET6;
417                 sin->sin6_flowinfo = 0;
418                 sin->sin6_port = serr->port;
419                 if (skb->protocol == htons(ETH_P_IPV6)) {
420                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
421                                                                   struct ipv6hdr, daddr);
422                         sin->sin6_addr = ip6h->daddr;
423                         if (np->sndflow)
424                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
425                         sin->sin6_scope_id =
426                                 ipv6_iface_scope_id(&sin->sin6_addr,
427                                                     IP6CB(skb)->iif);
428                 } else {
429                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
430                                                &sin->sin6_addr);
431                         sin->sin6_scope_id = 0;
432                 }
433                 *addr_len = sizeof(*sin);
434         }
435 
436         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
437         sin = &errhdr.offender;
438         memset(sin, 0, sizeof(*sin));
439 
440         if (ip6_datagram_support_cmsg(skb, serr)) {
441                 sin->sin6_family = AF_INET6;
442                 if (np->rxopt.all)
443                         ip6_datagram_recv_common_ctl(sk, msg, skb);
444                 if (skb->protocol == htons(ETH_P_IPV6)) {
445                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
446                         if (np->rxopt.all)
447                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
448                         sin->sin6_scope_id =
449                                 ipv6_iface_scope_id(&sin->sin6_addr,
450                                                     IP6CB(skb)->iif);
451                 } else {
452                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
453                                                &sin->sin6_addr);
454                         if (inet_sk(sk)->cmsg_flags)
455                                 ip_cmsg_recv(msg, skb);
456                 }
457         }
458 
459         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
460 
461         /* Now we could try to dump offended packet options */
462 
463         msg->msg_flags |= MSG_ERRQUEUE;
464         err = copied;
465 
466 out_free_skb:
467         kfree_skb(skb);
468 out:
469         return err;
470 }
471 EXPORT_SYMBOL_GPL(ipv6_recv_error);
472 
473 /*
474  *      Handle IPV6_RECVPATHMTU
475  */
476 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
477                      int *addr_len)
478 {
479         struct ipv6_pinfo *np = inet6_sk(sk);
480         struct sk_buff *skb;
481         struct ip6_mtuinfo mtu_info;
482         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
483         int err;
484         int copied;
485 
486         err = -EAGAIN;
487         skb = xchg(&np->rxpmtu, NULL);
488         if (!skb)
489                 goto out;
490 
491         copied = skb->len;
492         if (copied > len) {
493                 msg->msg_flags |= MSG_TRUNC;
494                 copied = len;
495         }
496         err = skb_copy_datagram_msg(skb, 0, msg, copied);
497         if (err)
498                 goto out_free_skb;
499 
500         sock_recv_timestamp(msg, sk, skb);
501 
502         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
503 
504         if (sin) {
505                 sin->sin6_family = AF_INET6;
506                 sin->sin6_flowinfo = 0;
507                 sin->sin6_port = 0;
508                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
509                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
510                 *addr_len = sizeof(*sin);
511         }
512 
513         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
514 
515         err = copied;
516 
517 out_free_skb:
518         kfree_skb(skb);
519 out:
520         return err;
521 }
522 
523 
524 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
525                                  struct sk_buff *skb)
526 {
527         struct ipv6_pinfo *np = inet6_sk(sk);
528         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
529 
530         if (np->rxopt.bits.rxinfo) {
531                 struct in6_pktinfo src_info;
532 
533                 if (is_ipv6) {
534                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
535                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
536                 } else {
537                         src_info.ipi6_ifindex =
538                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
539                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
540                                                &src_info.ipi6_addr);
541                 }
542 
543                 if (src_info.ipi6_ifindex >= 0)
544                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
545                                  sizeof(src_info), &src_info);
546         }
547 }
548 
549 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
550                                     struct sk_buff *skb)
551 {
552         struct ipv6_pinfo *np = inet6_sk(sk);
553         struct inet6_skb_parm *opt = IP6CB(skb);
554         unsigned char *nh = skb_network_header(skb);
555 
556         if (np->rxopt.bits.rxhlim) {
557                 int hlim = ipv6_hdr(skb)->hop_limit;
558                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
559         }
560 
561         if (np->rxopt.bits.rxtclass) {
562                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
563                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
564         }
565 
566         if (np->rxopt.bits.rxflow) {
567                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
568                 if (flowinfo)
569                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
570         }
571 
572         /* HbH is allowed only once */
573         if (np->rxopt.bits.hopopts && opt->hop) {
574                 u8 *ptr = nh + opt->hop;
575                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
576         }
577 
578         if (opt->lastopt &&
579             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
580                 /*
581                  * Silly enough, but we need to reparse in order to
582                  * report extension headers (except for HbH)
583                  * in order.
584                  *
585                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
586                  * (and WILL NOT be) defined because
587                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
588                  */
589                 unsigned int off = sizeof(struct ipv6hdr);
590                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
591 
592                 while (off <= opt->lastopt) {
593                         unsigned int len;
594                         u8 *ptr = nh + off;
595 
596                         switch (nexthdr) {
597                         case IPPROTO_DSTOPTS:
598                                 nexthdr = ptr[0];
599                                 len = (ptr[1] + 1) << 3;
600                                 if (np->rxopt.bits.dstopts)
601                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
602                                 break;
603                         case IPPROTO_ROUTING:
604                                 nexthdr = ptr[0];
605                                 len = (ptr[1] + 1) << 3;
606                                 if (np->rxopt.bits.srcrt)
607                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
608                                 break;
609                         case IPPROTO_AH:
610                                 nexthdr = ptr[0];
611                                 len = (ptr[1] + 2) << 2;
612                                 break;
613                         default:
614                                 nexthdr = ptr[0];
615                                 len = (ptr[1] + 1) << 3;
616                                 break;
617                         }
618 
619                         off += len;
620                 }
621         }
622 
623         /* socket options in old style */
624         if (np->rxopt.bits.rxoinfo) {
625                 struct in6_pktinfo src_info;
626 
627                 src_info.ipi6_ifindex = opt->iif;
628                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
629                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
630         }
631         if (np->rxopt.bits.rxohlim) {
632                 int hlim = ipv6_hdr(skb)->hop_limit;
633                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
634         }
635         if (np->rxopt.bits.ohopopts && opt->hop) {
636                 u8 *ptr = nh + opt->hop;
637                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
638         }
639         if (np->rxopt.bits.odstopts && opt->dst0) {
640                 u8 *ptr = nh + opt->dst0;
641                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
642         }
643         if (np->rxopt.bits.osrcrt && opt->srcrt) {
644                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
645                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
646         }
647         if (np->rxopt.bits.odstopts && opt->dst1) {
648                 u8 *ptr = nh + opt->dst1;
649                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
650         }
651         if (np->rxopt.bits.rxorigdstaddr) {
652                 struct sockaddr_in6 sin6;
653                 __be16 *ports = (__be16 *) skb_transport_header(skb);
654 
655                 if (skb_transport_offset(skb) + 4 <= skb->len) {
656                         /* All current transport protocols have the port numbers in the
657                          * first four bytes of the transport header and this function is
658                          * written with this assumption in mind.
659                          */
660 
661                         sin6.sin6_family = AF_INET6;
662                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
663                         sin6.sin6_port = ports[1];
664                         sin6.sin6_flowinfo = 0;
665                         sin6.sin6_scope_id =
666                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
667                                                     opt->iif);
668 
669                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
670                 }
671         }
672 }
673 
674 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
675                           struct sk_buff *skb)
676 {
677         ip6_datagram_recv_common_ctl(sk, msg, skb);
678         ip6_datagram_recv_specific_ctl(sk, msg, skb);
679 }
680 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
681 
682 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
683                           struct msghdr *msg, struct flowi6 *fl6,
684                           struct ipv6_txoptions *opt,
685                           int *hlimit, int *tclass, int *dontfrag)
686 {
687         struct in6_pktinfo *src_info;
688         struct cmsghdr *cmsg;
689         struct ipv6_rt_hdr *rthdr;
690         struct ipv6_opt_hdr *hdr;
691         int len;
692         int err = 0;
693 
694         for_each_cmsghdr(cmsg, msg) {
695                 int addr_type;
696 
697                 if (!CMSG_OK(msg, cmsg)) {
698                         err = -EINVAL;
699                         goto exit_f;
700                 }
701 
702                 if (cmsg->cmsg_level != SOL_IPV6)
703                         continue;
704 
705                 switch (cmsg->cmsg_type) {
706                 case IPV6_PKTINFO:
707                 case IPV6_2292PKTINFO:
708                     {
709                         struct net_device *dev = NULL;
710 
711                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
712                                 err = -EINVAL;
713                                 goto exit_f;
714                         }
715 
716                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
717 
718                         if (src_info->ipi6_ifindex) {
719                                 if (fl6->flowi6_oif &&
720                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
721                                         return -EINVAL;
722                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
723                         }
724 
725                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
726 
727                         rcu_read_lock();
728                         if (fl6->flowi6_oif) {
729                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
730                                 if (!dev) {
731                                         rcu_read_unlock();
732                                         return -ENODEV;
733                                 }
734                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
735                                 rcu_read_unlock();
736                                 return -EINVAL;
737                         }
738 
739                         if (addr_type != IPV6_ADDR_ANY) {
740                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
741                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
742                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
743                                                    strict ? dev : NULL, 0) &&
744                                     !ipv6_chk_acast_addr_src(net, dev,
745                                                              &src_info->ipi6_addr))
746                                         err = -EINVAL;
747                                 else
748                                         fl6->saddr = src_info->ipi6_addr;
749                         }
750 
751                         rcu_read_unlock();
752 
753                         if (err)
754                                 goto exit_f;
755 
756                         break;
757                     }
758 
759                 case IPV6_FLOWINFO:
760                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
761                                 err = -EINVAL;
762                                 goto exit_f;
763                         }
764 
765                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
766                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
767                                         err = -EINVAL;
768                                         goto exit_f;
769                                 }
770                         }
771                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
772                         break;
773 
774                 case IPV6_2292HOPOPTS:
775                 case IPV6_HOPOPTS:
776                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
777                                 err = -EINVAL;
778                                 goto exit_f;
779                         }
780 
781                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
782                         len = ((hdr->hdrlen + 1) << 3);
783                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
784                                 err = -EINVAL;
785                                 goto exit_f;
786                         }
787                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
788                                 err = -EPERM;
789                                 goto exit_f;
790                         }
791                         opt->opt_nflen += len;
792                         opt->hopopt = hdr;
793                         break;
794 
795                 case IPV6_2292DSTOPTS:
796                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
797                                 err = -EINVAL;
798                                 goto exit_f;
799                         }
800 
801                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
802                         len = ((hdr->hdrlen + 1) << 3);
803                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
804                                 err = -EINVAL;
805                                 goto exit_f;
806                         }
807                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
808                                 err = -EPERM;
809                                 goto exit_f;
810                         }
811                         if (opt->dst1opt) {
812                                 err = -EINVAL;
813                                 goto exit_f;
814                         }
815                         opt->opt_flen += len;
816                         opt->dst1opt = hdr;
817                         break;
818 
819                 case IPV6_DSTOPTS:
820                 case IPV6_RTHDRDSTOPTS:
821                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
822                                 err = -EINVAL;
823                                 goto exit_f;
824                         }
825 
826                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
827                         len = ((hdr->hdrlen + 1) << 3);
828                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
829                                 err = -EINVAL;
830                                 goto exit_f;
831                         }
832                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
833                                 err = -EPERM;
834                                 goto exit_f;
835                         }
836                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
837                                 opt->opt_flen += len;
838                                 opt->dst1opt = hdr;
839                         } else {
840                                 opt->opt_nflen += len;
841                                 opt->dst0opt = hdr;
842                         }
843                         break;
844 
845                 case IPV6_2292RTHDR:
846                 case IPV6_RTHDR:
847                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
848                                 err = -EINVAL;
849                                 goto exit_f;
850                         }
851 
852                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
853 
854                         switch (rthdr->type) {
855 #if IS_ENABLED(CONFIG_IPV6_MIP6)
856                         case IPV6_SRCRT_TYPE_2:
857                                 if (rthdr->hdrlen != 2 ||
858                                     rthdr->segments_left != 1) {
859                                         err = -EINVAL;
860                                         goto exit_f;
861                                 }
862                                 break;
863 #endif
864                         default:
865                                 err = -EINVAL;
866                                 goto exit_f;
867                         }
868 
869                         len = ((rthdr->hdrlen + 1) << 3);
870 
871                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
872                                 err = -EINVAL;
873                                 goto exit_f;
874                         }
875 
876                         /* segments left must also match */
877                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
878                                 err = -EINVAL;
879                                 goto exit_f;
880                         }
881 
882                         opt->opt_nflen += len;
883                         opt->srcrt = rthdr;
884 
885                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
886                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
887 
888                                 opt->opt_nflen += dsthdrlen;
889                                 opt->dst0opt = opt->dst1opt;
890                                 opt->dst1opt = NULL;
891                                 opt->opt_flen -= dsthdrlen;
892                         }
893 
894                         break;
895 
896                 case IPV6_2292HOPLIMIT:
897                 case IPV6_HOPLIMIT:
898                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
899                                 err = -EINVAL;
900                                 goto exit_f;
901                         }
902 
903                         *hlimit = *(int *)CMSG_DATA(cmsg);
904                         if (*hlimit < -1 || *hlimit > 0xff) {
905                                 err = -EINVAL;
906                                 goto exit_f;
907                         }
908 
909                         break;
910 
911                 case IPV6_TCLASS:
912                     {
913                         int tc;
914 
915                         err = -EINVAL;
916                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
917                                 goto exit_f;
918 
919                         tc = *(int *)CMSG_DATA(cmsg);
920                         if (tc < -1 || tc > 0xff)
921                                 goto exit_f;
922 
923                         err = 0;
924                         *tclass = tc;
925 
926                         break;
927                     }
928 
929                 case IPV6_DONTFRAG:
930                     {
931                         int df;
932 
933                         err = -EINVAL;
934                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
935                                 goto exit_f;
936 
937                         df = *(int *)CMSG_DATA(cmsg);
938                         if (df < 0 || df > 1)
939                                 goto exit_f;
940 
941                         err = 0;
942                         *dontfrag = df;
943 
944                         break;
945                     }
946                 default:
947                         net_dbg_ratelimited("invalid cmsg type: %d\n",
948                                             cmsg->cmsg_type);
949                         err = -EINVAL;
950                         goto exit_f;
951                 }
952         }
953 
954 exit_f:
955         return err;
956 }
957 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
958 
959 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
960                              __u16 srcp, __u16 destp, int bucket)
961 {
962         const struct in6_addr *dest, *src;
963 
964         dest  = &sp->sk_v6_daddr;
965         src   = &sp->sk_v6_rcv_saddr;
966         seq_printf(seq,
967                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
968                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
969                    bucket,
970                    src->s6_addr32[0], src->s6_addr32[1],
971                    src->s6_addr32[2], src->s6_addr32[3], srcp,
972                    dest->s6_addr32[0], dest->s6_addr32[1],
973                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
974                    sp->sk_state,
975                    sk_wmem_alloc_get(sp),
976                    sk_rmem_alloc_get(sp),
977                    0, 0L, 0,
978                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
979                    0,
980                    sock_i_ino(sp),
981                    atomic_read(&sp->sk_refcnt), sp,
982                    atomic_read(&sp->sk_drops));
983 }
984 

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