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TOMOYO Linux Cross Reference
Linux/net/ipv6/datagram.c

Version: ~ [ linux-5.12-rc7 ] ~ [ linux-5.11.13 ] ~ [ linux-5.10.29 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.111 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.186 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.230 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.266 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.266 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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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 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 
 58         if (!fl6->flowi6_oif)
 59                 fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
 60 
 61         if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr))
 62                 fl6->flowi6_oif = np->mcast_oif;
 63 
 64         security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
 65 }
 66 
 67 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
 68 {
 69         struct ip6_flowlabel *flowlabel = NULL;
 70         struct in6_addr *final_p, final;
 71         struct ipv6_txoptions *opt;
 72         struct dst_entry *dst;
 73         struct inet_sock *inet = inet_sk(sk);
 74         struct ipv6_pinfo *np = inet6_sk(sk);
 75         struct flowi6 fl6;
 76         int err = 0;
 77 
 78         if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
 79                 flowlabel = fl6_sock_lookup(sk, np->flow_label);
 80                 if (!flowlabel)
 81                         return -EINVAL;
 82         }
 83         ip6_datagram_flow_key_init(&fl6, sk);
 84 
 85         rcu_read_lock();
 86         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
 87         final_p = fl6_update_dst(&fl6, opt, &final);
 88         rcu_read_unlock();
 89 
 90         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
 91         if (IS_ERR(dst)) {
 92                 err = PTR_ERR(dst);
 93                 goto out;
 94         }
 95 
 96         if (fix_sk_saddr) {
 97                 if (ipv6_addr_any(&np->saddr))
 98                         np->saddr = fl6.saddr;
 99 
100                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
101                         sk->sk_v6_rcv_saddr = fl6.saddr;
102                         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
103                         if (sk->sk_prot->rehash)
104                                 sk->sk_prot->rehash(sk);
105                 }
106         }
107 
108         ip6_dst_store(sk, dst,
109                       ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
110                       &sk->sk_v6_daddr : NULL,
111 #ifdef CONFIG_IPV6_SUBTREES
112                       ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
113                       &np->saddr :
114 #endif
115                       NULL);
116 
117 out:
118         fl6_sock_release(flowlabel);
119         return err;
120 }
121 
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 || !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 
142 static int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
143 {
144         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
145         struct inet_sock        *inet = inet_sk(sk);
146         struct ipv6_pinfo       *np = inet6_sk(sk);
147         struct in6_addr         *daddr;
148         int                     addr_type;
149         int                     err;
150         __be32                  fl6_flowlabel = 0;
151 
152         if (usin->sin6_family == AF_INET) {
153                 if (__ipv6_only_sock(sk))
154                         return -EAFNOSUPPORT;
155                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
156                 goto ipv4_connected;
157         }
158 
159         if (addr_len < SIN6_LEN_RFC2133)
160                 return -EINVAL;
161 
162         if (usin->sin6_family != AF_INET6)
163                 return -EAFNOSUPPORT;
164 
165         if (np->sndflow)
166                 fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
167 
168         addr_type = ipv6_addr_type(&usin->sin6_addr);
169 
170         if (addr_type == IPV6_ADDR_ANY) {
171                 /*
172                  *      connect to self
173                  */
174                 usin->sin6_addr.s6_addr[15] = 0x01;
175         }
176 
177         daddr = &usin->sin6_addr;
178 
179         if (addr_type == IPV6_ADDR_MAPPED) {
180                 struct sockaddr_in sin;
181 
182                 if (__ipv6_only_sock(sk)) {
183                         err = -ENETUNREACH;
184                         goto out;
185                 }
186                 sin.sin_family = AF_INET;
187                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
188                 sin.sin_port = usin->sin6_port;
189 
190                 err = __ip4_datagram_connect(sk,
191                                              (struct sockaddr *) &sin,
192                                              sizeof(sin));
193 
194 ipv4_connected:
195                 if (err)
196                         goto out;
197 
198                 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
199 
200                 if (ipv6_addr_any(&np->saddr) ||
201                     ipv6_mapped_addr_any(&np->saddr))
202                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
203 
204                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
205                     ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
206                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
207                                                &sk->sk_v6_rcv_saddr);
208                         if (sk->sk_prot->rehash)
209                                 sk->sk_prot->rehash(sk);
210                 }
211 
212                 goto out;
213         }
214 
215         if (__ipv6_addr_needs_scope_id(addr_type)) {
216                 if (addr_len >= sizeof(struct sockaddr_in6) &&
217                     usin->sin6_scope_id) {
218                         if (sk->sk_bound_dev_if &&
219                             sk->sk_bound_dev_if != 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         sk->sk_v6_daddr = *daddr;
237         np->flow_label = fl6_flowlabel;
238 
239         inet->inet_dport = usin->sin6_port;
240 
241         /*
242          *      Check for a route to destination an obtain the
243          *      destination cache for it.
244          */
245 
246         err = ip6_datagram_dst_update(sk, true);
247         if (err)
248                 goto out;
249 
250         sk->sk_state = TCP_ESTABLISHED;
251         sk_set_txhash(sk);
252 out:
253         return err;
254 }
255 
256 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
257 {
258         int res;
259 
260         lock_sock(sk);
261         res = __ip6_datagram_connect(sk, uaddr, addr_len);
262         release_sock(sk);
263         return res;
264 }
265 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
266 
267 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
268                                  int addr_len)
269 {
270         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
271         if (sin6->sin6_family != AF_INET6)
272                 return -EAFNOSUPPORT;
273         return ip6_datagram_connect(sk, uaddr, addr_len);
274 }
275 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
276 
277 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
278                      __be16 port, u32 info, u8 *payload)
279 {
280         struct ipv6_pinfo *np  = inet6_sk(sk);
281         struct icmp6hdr *icmph = icmp6_hdr(skb);
282         struct sock_exterr_skb *serr;
283 
284         if (!np->recverr)
285                 return;
286 
287         skb = skb_clone(skb, GFP_ATOMIC);
288         if (!skb)
289                 return;
290 
291         skb->protocol = htons(ETH_P_IPV6);
292 
293         serr = SKB_EXT_ERR(skb);
294         serr->ee.ee_errno = err;
295         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
296         serr->ee.ee_type = icmph->icmp6_type;
297         serr->ee.ee_code = icmph->icmp6_code;
298         serr->ee.ee_pad = 0;
299         serr->ee.ee_info = info;
300         serr->ee.ee_data = 0;
301         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
302                                   skb_network_header(skb);
303         serr->port = port;
304 
305         __skb_pull(skb, payload - skb->data);
306         skb_reset_transport_header(skb);
307 
308         if (sock_queue_err_skb(sk, skb))
309                 kfree_skb(skb);
310 }
311 
312 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
313 {
314         const struct ipv6_pinfo *np = inet6_sk(sk);
315         struct sock_exterr_skb *serr;
316         struct ipv6hdr *iph;
317         struct sk_buff *skb;
318 
319         if (!np->recverr)
320                 return;
321 
322         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
323         if (!skb)
324                 return;
325 
326         skb->protocol = htons(ETH_P_IPV6);
327 
328         skb_put(skb, sizeof(struct ipv6hdr));
329         skb_reset_network_header(skb);
330         iph = ipv6_hdr(skb);
331         iph->daddr = fl6->daddr;
332 
333         serr = SKB_EXT_ERR(skb);
334         serr->ee.ee_errno = err;
335         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
336         serr->ee.ee_type = 0;
337         serr->ee.ee_code = 0;
338         serr->ee.ee_pad = 0;
339         serr->ee.ee_info = info;
340         serr->ee.ee_data = 0;
341         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
342         serr->port = fl6->fl6_dport;
343 
344         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
345         skb_reset_transport_header(skb);
346 
347         if (sock_queue_err_skb(sk, skb))
348                 kfree_skb(skb);
349 }
350 
351 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
352 {
353         struct ipv6_pinfo *np = inet6_sk(sk);
354         struct ipv6hdr *iph;
355         struct sk_buff *skb;
356         struct ip6_mtuinfo *mtu_info;
357 
358         if (!np->rxopt.bits.rxpmtu)
359                 return;
360 
361         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
362         if (!skb)
363                 return;
364 
365         skb_put(skb, sizeof(struct ipv6hdr));
366         skb_reset_network_header(skb);
367         iph = ipv6_hdr(skb);
368         iph->daddr = fl6->daddr;
369 
370         mtu_info = IP6CBMTU(skb);
371 
372         mtu_info->ip6m_mtu = mtu;
373         mtu_info->ip6m_addr.sin6_family = AF_INET6;
374         mtu_info->ip6m_addr.sin6_port = 0;
375         mtu_info->ip6m_addr.sin6_flowinfo = 0;
376         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
377         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
378 
379         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
380         skb_reset_transport_header(skb);
381 
382         skb = xchg(&np->rxpmtu, skb);
383         kfree_skb(skb);
384 }
385 
386 /* For some errors we have valid addr_offset even with zero payload and
387  * zero port. Also, addr_offset should be supported if port is set.
388  */
389 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
390 {
391         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
392                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
393                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
394 }
395 
396 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
397  *
398  * At one point, excluding local errors was a quick test to identify icmp/icmp6
399  * errors. This is no longer true, but the test remained, so the v6 stack,
400  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
401  *
402  * Timestamp code paths do not initialize the fields expected by cmsg:
403  * the PKTINFO fields in skb->cb[]. Fill those in here.
404  */
405 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
406                                       struct sock_exterr_skb *serr)
407 {
408         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
409             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
410                 return true;
411 
412         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
413                 return false;
414 
415         if (!skb->dev)
416                 return false;
417 
418         if (skb->protocol == htons(ETH_P_IPV6))
419                 IP6CB(skb)->iif = skb->dev->ifindex;
420         else
421                 PKTINFO_SKB_CB(skb)->ipi_ifindex = skb->dev->ifindex;
422 
423         return true;
424 }
425 
426 /*
427  *      Handle MSG_ERRQUEUE
428  */
429 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
430 {
431         struct ipv6_pinfo *np = inet6_sk(sk);
432         struct sock_exterr_skb *serr;
433         struct sk_buff *skb;
434         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
435         struct {
436                 struct sock_extended_err ee;
437                 struct sockaddr_in6      offender;
438         } errhdr;
439         int err;
440         int copied;
441 
442         err = -EAGAIN;
443         skb = sock_dequeue_err_skb(sk);
444         if (!skb)
445                 goto out;
446 
447         copied = skb->len;
448         if (copied > len) {
449                 msg->msg_flags |= MSG_TRUNC;
450                 copied = len;
451         }
452         err = skb_copy_datagram_msg(skb, 0, msg, copied);
453         if (err)
454                 goto out_free_skb;
455 
456         sock_recv_timestamp(msg, sk, skb);
457 
458         serr = SKB_EXT_ERR(skb);
459 
460         if (sin && ipv6_datagram_support_addr(serr)) {
461                 const unsigned char *nh = skb_network_header(skb);
462                 sin->sin6_family = AF_INET6;
463                 sin->sin6_flowinfo = 0;
464                 sin->sin6_port = serr->port;
465                 if (skb->protocol == htons(ETH_P_IPV6)) {
466                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
467                                                                   struct ipv6hdr, daddr);
468                         sin->sin6_addr = ip6h->daddr;
469                         if (np->sndflow)
470                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
471                         sin->sin6_scope_id =
472                                 ipv6_iface_scope_id(&sin->sin6_addr,
473                                                     IP6CB(skb)->iif);
474                 } else {
475                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
476                                                &sin->sin6_addr);
477                         sin->sin6_scope_id = 0;
478                 }
479                 *addr_len = sizeof(*sin);
480         }
481 
482         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
483         sin = &errhdr.offender;
484         memset(sin, 0, sizeof(*sin));
485 
486         if (ip6_datagram_support_cmsg(skb, serr)) {
487                 sin->sin6_family = AF_INET6;
488                 if (np->rxopt.all)
489                         ip6_datagram_recv_common_ctl(sk, msg, skb);
490                 if (skb->protocol == htons(ETH_P_IPV6)) {
491                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
492                         if (np->rxopt.all)
493                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
494                         sin->sin6_scope_id =
495                                 ipv6_iface_scope_id(&sin->sin6_addr,
496                                                     IP6CB(skb)->iif);
497                 } else {
498                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
499                                                &sin->sin6_addr);
500                         if (inet_sk(sk)->cmsg_flags)
501                                 ip_cmsg_recv(msg, skb);
502                 }
503         }
504 
505         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
506 
507         /* Now we could try to dump offended packet options */
508 
509         msg->msg_flags |= MSG_ERRQUEUE;
510         err = copied;
511 
512 out_free_skb:
513         kfree_skb(skb);
514 out:
515         return err;
516 }
517 EXPORT_SYMBOL_GPL(ipv6_recv_error);
518 
519 /*
520  *      Handle IPV6_RECVPATHMTU
521  */
522 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
523                      int *addr_len)
524 {
525         struct ipv6_pinfo *np = inet6_sk(sk);
526         struct sk_buff *skb;
527         struct ip6_mtuinfo mtu_info;
528         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
529         int err;
530         int copied;
531 
532         err = -EAGAIN;
533         skb = xchg(&np->rxpmtu, NULL);
534         if (!skb)
535                 goto out;
536 
537         copied = skb->len;
538         if (copied > len) {
539                 msg->msg_flags |= MSG_TRUNC;
540                 copied = len;
541         }
542         err = skb_copy_datagram_msg(skb, 0, msg, copied);
543         if (err)
544                 goto out_free_skb;
545 
546         sock_recv_timestamp(msg, sk, skb);
547 
548         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
549 
550         if (sin) {
551                 sin->sin6_family = AF_INET6;
552                 sin->sin6_flowinfo = 0;
553                 sin->sin6_port = 0;
554                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
555                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
556                 *addr_len = sizeof(*sin);
557         }
558 
559         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
560 
561         err = copied;
562 
563 out_free_skb:
564         kfree_skb(skb);
565 out:
566         return err;
567 }
568 
569 
570 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
571                                  struct sk_buff *skb)
572 {
573         struct ipv6_pinfo *np = inet6_sk(sk);
574         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
575 
576         if (np->rxopt.bits.rxinfo) {
577                 struct in6_pktinfo src_info;
578 
579                 if (is_ipv6) {
580                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
581                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
582                 } else {
583                         src_info.ipi6_ifindex =
584                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
585                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
586                                                &src_info.ipi6_addr);
587                 }
588 
589                 if (src_info.ipi6_ifindex >= 0)
590                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
591                                  sizeof(src_info), &src_info);
592         }
593 }
594 
595 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
596                                     struct sk_buff *skb)
597 {
598         struct ipv6_pinfo *np = inet6_sk(sk);
599         struct inet6_skb_parm *opt = IP6CB(skb);
600         unsigned char *nh = skb_network_header(skb);
601 
602         if (np->rxopt.bits.rxhlim) {
603                 int hlim = ipv6_hdr(skb)->hop_limit;
604                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
605         }
606 
607         if (np->rxopt.bits.rxtclass) {
608                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
609                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
610         }
611 
612         if (np->rxopt.bits.rxflow) {
613                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
614                 if (flowinfo)
615                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
616         }
617 
618         /* HbH is allowed only once */
619         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
620                 u8 *ptr = nh + sizeof(struct ipv6hdr);
621                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
622         }
623 
624         if (opt->lastopt &&
625             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
626                 /*
627                  * Silly enough, but we need to reparse in order to
628                  * report extension headers (except for HbH)
629                  * in order.
630                  *
631                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
632                  * (and WILL NOT be) defined because
633                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
634                  */
635                 unsigned int off = sizeof(struct ipv6hdr);
636                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
637 
638                 while (off <= opt->lastopt) {
639                         unsigned int len;
640                         u8 *ptr = nh + off;
641 
642                         switch (nexthdr) {
643                         case IPPROTO_DSTOPTS:
644                                 nexthdr = ptr[0];
645                                 len = (ptr[1] + 1) << 3;
646                                 if (np->rxopt.bits.dstopts)
647                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
648                                 break;
649                         case IPPROTO_ROUTING:
650                                 nexthdr = ptr[0];
651                                 len = (ptr[1] + 1) << 3;
652                                 if (np->rxopt.bits.srcrt)
653                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
654                                 break;
655                         case IPPROTO_AH:
656                                 nexthdr = ptr[0];
657                                 len = (ptr[1] + 2) << 2;
658                                 break;
659                         default:
660                                 nexthdr = ptr[0];
661                                 len = (ptr[1] + 1) << 3;
662                                 break;
663                         }
664 
665                         off += len;
666                 }
667         }
668 
669         /* socket options in old style */
670         if (np->rxopt.bits.rxoinfo) {
671                 struct in6_pktinfo src_info;
672 
673                 src_info.ipi6_ifindex = opt->iif;
674                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
675                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
676         }
677         if (np->rxopt.bits.rxohlim) {
678                 int hlim = ipv6_hdr(skb)->hop_limit;
679                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
680         }
681         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
682                 u8 *ptr = nh + sizeof(struct ipv6hdr);
683                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
684         }
685         if (np->rxopt.bits.odstopts && opt->dst0) {
686                 u8 *ptr = nh + opt->dst0;
687                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
688         }
689         if (np->rxopt.bits.osrcrt && opt->srcrt) {
690                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
691                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
692         }
693         if (np->rxopt.bits.odstopts && opt->dst1) {
694                 u8 *ptr = nh + opt->dst1;
695                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
696         }
697         if (np->rxopt.bits.rxorigdstaddr) {
698                 struct sockaddr_in6 sin6;
699                 __be16 *ports = (__be16 *) skb_transport_header(skb);
700 
701                 if (skb_transport_offset(skb) + 4 <= skb->len) {
702                         /* All current transport protocols have the port numbers in the
703                          * first four bytes of the transport header and this function is
704                          * written with this assumption in mind.
705                          */
706 
707                         sin6.sin6_family = AF_INET6;
708                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
709                         sin6.sin6_port = ports[1];
710                         sin6.sin6_flowinfo = 0;
711                         sin6.sin6_scope_id =
712                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
713                                                     opt->iif);
714 
715                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
716                 }
717         }
718 }
719 
720 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
721                           struct sk_buff *skb)
722 {
723         ip6_datagram_recv_common_ctl(sk, msg, skb);
724         ip6_datagram_recv_specific_ctl(sk, msg, skb);
725 }
726 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
727 
728 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
729                           struct msghdr *msg, struct flowi6 *fl6,
730                           struct ipv6_txoptions *opt,
731                           int *hlimit, int *tclass, int *dontfrag)
732 {
733         struct in6_pktinfo *src_info;
734         struct cmsghdr *cmsg;
735         struct ipv6_rt_hdr *rthdr;
736         struct ipv6_opt_hdr *hdr;
737         int len;
738         int err = 0;
739 
740         for_each_cmsghdr(cmsg, msg) {
741                 int addr_type;
742 
743                 if (!CMSG_OK(msg, cmsg)) {
744                         err = -EINVAL;
745                         goto exit_f;
746                 }
747 
748                 if (cmsg->cmsg_level != SOL_IPV6)
749                         continue;
750 
751                 switch (cmsg->cmsg_type) {
752                 case IPV6_PKTINFO:
753                 case IPV6_2292PKTINFO:
754                     {
755                         struct net_device *dev = NULL;
756 
757                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
758                                 err = -EINVAL;
759                                 goto exit_f;
760                         }
761 
762                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
763 
764                         if (src_info->ipi6_ifindex) {
765                                 if (fl6->flowi6_oif &&
766                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
767                                         return -EINVAL;
768                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
769                         }
770 
771                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
772 
773                         rcu_read_lock();
774                         if (fl6->flowi6_oif) {
775                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
776                                 if (!dev) {
777                                         rcu_read_unlock();
778                                         return -ENODEV;
779                                 }
780                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
781                                 rcu_read_unlock();
782                                 return -EINVAL;
783                         }
784 
785                         if (addr_type != IPV6_ADDR_ANY) {
786                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
787                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
788                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
789                                                    strict ? dev : NULL, 0) &&
790                                     !ipv6_chk_acast_addr_src(net, dev,
791                                                              &src_info->ipi6_addr))
792                                         err = -EINVAL;
793                                 else
794                                         fl6->saddr = src_info->ipi6_addr;
795                         }
796 
797                         rcu_read_unlock();
798 
799                         if (err)
800                                 goto exit_f;
801 
802                         break;
803                     }
804 
805                 case IPV6_FLOWINFO:
806                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
807                                 err = -EINVAL;
808                                 goto exit_f;
809                         }
810 
811                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
812                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
813                                         err = -EINVAL;
814                                         goto exit_f;
815                                 }
816                         }
817                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
818                         break;
819 
820                 case IPV6_2292HOPOPTS:
821                 case IPV6_HOPOPTS:
822                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
823                                 err = -EINVAL;
824                                 goto exit_f;
825                         }
826 
827                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
828                         len = ((hdr->hdrlen + 1) << 3);
829                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
830                                 err = -EINVAL;
831                                 goto exit_f;
832                         }
833                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
834                                 err = -EPERM;
835                                 goto exit_f;
836                         }
837                         opt->opt_nflen += len;
838                         opt->hopopt = hdr;
839                         break;
840 
841                 case IPV6_2292DSTOPTS:
842                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
843                                 err = -EINVAL;
844                                 goto exit_f;
845                         }
846 
847                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
848                         len = ((hdr->hdrlen + 1) << 3);
849                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
850                                 err = -EINVAL;
851                                 goto exit_f;
852                         }
853                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
854                                 err = -EPERM;
855                                 goto exit_f;
856                         }
857                         if (opt->dst1opt) {
858                                 err = -EINVAL;
859                                 goto exit_f;
860                         }
861                         opt->opt_flen += len;
862                         opt->dst1opt = hdr;
863                         break;
864 
865                 case IPV6_DSTOPTS:
866                 case IPV6_RTHDRDSTOPTS:
867                         if (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                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
883                                 opt->opt_flen += len;
884                                 opt->dst1opt = hdr;
885                         } else {
886                                 opt->opt_nflen += len;
887                                 opt->dst0opt = hdr;
888                         }
889                         break;
890 
891                 case IPV6_2292RTHDR:
892                 case IPV6_RTHDR:
893                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
894                                 err = -EINVAL;
895                                 goto exit_f;
896                         }
897 
898                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
899 
900                         switch (rthdr->type) {
901 #if IS_ENABLED(CONFIG_IPV6_MIP6)
902                         case IPV6_SRCRT_TYPE_2:
903                                 if (rthdr->hdrlen != 2 ||
904                                     rthdr->segments_left != 1) {
905                                         err = -EINVAL;
906                                         goto exit_f;
907                                 }
908                                 break;
909 #endif
910                         default:
911                                 err = -EINVAL;
912                                 goto exit_f;
913                         }
914 
915                         len = ((rthdr->hdrlen + 1) << 3);
916 
917                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
918                                 err = -EINVAL;
919                                 goto exit_f;
920                         }
921 
922                         /* segments left must also match */
923                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
924                                 err = -EINVAL;
925                                 goto exit_f;
926                         }
927 
928                         opt->opt_nflen += len;
929                         opt->srcrt = rthdr;
930 
931                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
932                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
933 
934                                 opt->opt_nflen += dsthdrlen;
935                                 opt->dst0opt = opt->dst1opt;
936                                 opt->dst1opt = NULL;
937                                 opt->opt_flen -= dsthdrlen;
938                         }
939 
940                         break;
941 
942                 case IPV6_2292HOPLIMIT:
943                 case IPV6_HOPLIMIT:
944                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
945                                 err = -EINVAL;
946                                 goto exit_f;
947                         }
948 
949                         *hlimit = *(int *)CMSG_DATA(cmsg);
950                         if (*hlimit < -1 || *hlimit > 0xff) {
951                                 err = -EINVAL;
952                                 goto exit_f;
953                         }
954 
955                         break;
956 
957                 case IPV6_TCLASS:
958                     {
959                         int tc;
960 
961                         err = -EINVAL;
962                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
963                                 goto exit_f;
964 
965                         tc = *(int *)CMSG_DATA(cmsg);
966                         if (tc < -1 || tc > 0xff)
967                                 goto exit_f;
968 
969                         err = 0;
970                         *tclass = tc;
971 
972                         break;
973                     }
974 
975                 case IPV6_DONTFRAG:
976                     {
977                         int df;
978 
979                         err = -EINVAL;
980                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
981                                 goto exit_f;
982 
983                         df = *(int *)CMSG_DATA(cmsg);
984                         if (df < 0 || df > 1)
985                                 goto exit_f;
986 
987                         err = 0;
988                         *dontfrag = df;
989 
990                         break;
991                     }
992                 default:
993                         net_dbg_ratelimited("invalid cmsg type: %d\n",
994                                             cmsg->cmsg_type);
995                         err = -EINVAL;
996                         goto exit_f;
997                 }
998         }
999 
1000 exit_f:
1001         return err;
1002 }
1003 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1004 
1005 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1006                              __u16 srcp, __u16 destp, int bucket)
1007 {
1008         const struct in6_addr *dest, *src;
1009 
1010         dest  = &sp->sk_v6_daddr;
1011         src   = &sp->sk_v6_rcv_saddr;
1012         seq_printf(seq,
1013                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1014                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
1015                    bucket,
1016                    src->s6_addr32[0], src->s6_addr32[1],
1017                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1018                    dest->s6_addr32[0], dest->s6_addr32[1],
1019                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1020                    sp->sk_state,
1021                    sk_wmem_alloc_get(sp),
1022                    sk_rmem_alloc_get(sp),
1023                    0, 0L, 0,
1024                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1025                    0,
1026                    sock_i_ino(sp),
1027                    atomic_read(&sp->sk_refcnt), sp,
1028                    atomic_read(&sp->sk_drops));
1029 }
1030 

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