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

Version: ~ [ linux-5.4-rc3 ] ~ [ linux-5.3.6 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.79 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.149 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.196 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.196 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.75 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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_dst_store(sk, dst,
110                       ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
111                       &sk->sk_v6_daddr : NULL,
112 #ifdef CONFIG_IPV6_SUBTREES
113                       ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
114                       &np->saddr :
115 #endif
116                       NULL);
117 
118 out:
119         fl6_sock_release(flowlabel);
120         return err;
121 }
122 
123 void ip6_datagram_release_cb(struct sock *sk)
124 {
125         struct dst_entry *dst;
126 
127         if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
128                 return;
129 
130         rcu_read_lock();
131         dst = __sk_dst_get(sk);
132         if (!dst || !dst->obsolete ||
133             dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
134                 rcu_read_unlock();
135                 return;
136         }
137         rcu_read_unlock();
138 
139         ip6_datagram_dst_update(sk, false);
140 }
141 EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
142 
143 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
144                            int addr_len)
145 {
146         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
147         struct inet_sock        *inet = inet_sk(sk);
148         struct ipv6_pinfo       *np = inet6_sk(sk);
149         struct in6_addr         *daddr;
150         int                     addr_type;
151         int                     err;
152         __be32                  fl6_flowlabel = 0;
153 
154         if (usin->sin6_family == AF_INET) {
155                 if (__ipv6_only_sock(sk))
156                         return -EAFNOSUPPORT;
157                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
158                 goto ipv4_connected;
159         }
160 
161         if (addr_len < SIN6_LEN_RFC2133)
162                 return -EINVAL;
163 
164         if (usin->sin6_family != AF_INET6)
165                 return -EAFNOSUPPORT;
166 
167         if (np->sndflow)
168                 fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
169 
170         if (ipv6_addr_any(&usin->sin6_addr)) {
171                 /*
172                  *      connect to self
173                  */
174                 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
175                         ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
176                                                &usin->sin6_addr);
177                 else
178                         usin->sin6_addr = in6addr_loopback;
179         }
180 
181         addr_type = ipv6_addr_type(&usin->sin6_addr);
182 
183         daddr = &usin->sin6_addr;
184 
185         if (addr_type & IPV6_ADDR_MAPPED) {
186                 struct sockaddr_in sin;
187 
188                 if (__ipv6_only_sock(sk)) {
189                         err = -ENETUNREACH;
190                         goto out;
191                 }
192                 sin.sin_family = AF_INET;
193                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
194                 sin.sin_port = usin->sin6_port;
195 
196                 err = __ip4_datagram_connect(sk,
197                                              (struct sockaddr *) &sin,
198                                              sizeof(sin));
199 
200 ipv4_connected:
201                 if (err)
202                         goto out;
203 
204                 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
205 
206                 if (ipv6_addr_any(&np->saddr) ||
207                     ipv6_mapped_addr_any(&np->saddr))
208                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
209 
210                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
211                     ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
212                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
213                                                &sk->sk_v6_rcv_saddr);
214                         if (sk->sk_prot->rehash)
215                                 sk->sk_prot->rehash(sk);
216                 }
217 
218                 goto out;
219         }
220 
221         if (__ipv6_addr_needs_scope_id(addr_type)) {
222                 if (addr_len >= sizeof(struct sockaddr_in6) &&
223                     usin->sin6_scope_id) {
224                         if (sk->sk_bound_dev_if &&
225                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
226                                 err = -EINVAL;
227                                 goto out;
228                         }
229                         sk->sk_bound_dev_if = usin->sin6_scope_id;
230                 }
231 
232                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
233                         sk->sk_bound_dev_if = np->mcast_oif;
234 
235                 /* Connect to link-local address requires an interface */
236                 if (!sk->sk_bound_dev_if) {
237                         err = -EINVAL;
238                         goto out;
239                 }
240         }
241 
242         sk->sk_v6_daddr = *daddr;
243         np->flow_label = fl6_flowlabel;
244 
245         inet->inet_dport = usin->sin6_port;
246 
247         /*
248          *      Check for a route to destination an obtain the
249          *      destination cache for it.
250          */
251 
252         err = ip6_datagram_dst_update(sk, true);
253         if (err) {
254                 /* Reset daddr and dport so that udp_v6_early_demux()
255                  * fails to find this socket
256                  */
257                 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
258                 inet->inet_dport = 0;
259                 goto out;
260         }
261 
262         sk->sk_state = TCP_ESTABLISHED;
263         sk_set_txhash(sk);
264 out:
265         return err;
266 }
267 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
268 
269 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
270 {
271         int res;
272 
273         lock_sock(sk);
274         res = __ip6_datagram_connect(sk, uaddr, addr_len);
275         release_sock(sk);
276         return res;
277 }
278 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
279 
280 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
281                                  int addr_len)
282 {
283         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
284         if (sin6->sin6_family != AF_INET6)
285                 return -EAFNOSUPPORT;
286         return ip6_datagram_connect(sk, uaddr, addr_len);
287 }
288 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
289 
290 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
291                      __be16 port, u32 info, u8 *payload)
292 {
293         struct ipv6_pinfo *np  = inet6_sk(sk);
294         struct icmp6hdr *icmph = icmp6_hdr(skb);
295         struct sock_exterr_skb *serr;
296 
297         if (!np->recverr)
298                 return;
299 
300         skb = skb_clone(skb, GFP_ATOMIC);
301         if (!skb)
302                 return;
303 
304         skb->protocol = htons(ETH_P_IPV6);
305 
306         serr = SKB_EXT_ERR(skb);
307         serr->ee.ee_errno = err;
308         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
309         serr->ee.ee_type = icmph->icmp6_type;
310         serr->ee.ee_code = icmph->icmp6_code;
311         serr->ee.ee_pad = 0;
312         serr->ee.ee_info = info;
313         serr->ee.ee_data = 0;
314         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
315                                   skb_network_header(skb);
316         serr->port = port;
317 
318         __skb_pull(skb, payload - skb->data);
319         skb_reset_transport_header(skb);
320 
321         if (sock_queue_err_skb(sk, skb))
322                 kfree_skb(skb);
323 }
324 
325 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
326 {
327         const struct ipv6_pinfo *np = inet6_sk(sk);
328         struct sock_exterr_skb *serr;
329         struct ipv6hdr *iph;
330         struct sk_buff *skb;
331 
332         if (!np->recverr)
333                 return;
334 
335         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
336         if (!skb)
337                 return;
338 
339         skb->protocol = htons(ETH_P_IPV6);
340 
341         skb_put(skb, sizeof(struct ipv6hdr));
342         skb_reset_network_header(skb);
343         iph = ipv6_hdr(skb);
344         iph->daddr = fl6->daddr;
345 
346         serr = SKB_EXT_ERR(skb);
347         serr->ee.ee_errno = err;
348         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
349         serr->ee.ee_type = 0;
350         serr->ee.ee_code = 0;
351         serr->ee.ee_pad = 0;
352         serr->ee.ee_info = info;
353         serr->ee.ee_data = 0;
354         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
355         serr->port = fl6->fl6_dport;
356 
357         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
358         skb_reset_transport_header(skb);
359 
360         if (sock_queue_err_skb(sk, skb))
361                 kfree_skb(skb);
362 }
363 
364 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
365 {
366         struct ipv6_pinfo *np = inet6_sk(sk);
367         struct ipv6hdr *iph;
368         struct sk_buff *skb;
369         struct ip6_mtuinfo *mtu_info;
370 
371         if (!np->rxopt.bits.rxpmtu)
372                 return;
373 
374         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
375         if (!skb)
376                 return;
377 
378         skb_put(skb, sizeof(struct ipv6hdr));
379         skb_reset_network_header(skb);
380         iph = ipv6_hdr(skb);
381         iph->daddr = fl6->daddr;
382 
383         mtu_info = IP6CBMTU(skb);
384 
385         mtu_info->ip6m_mtu = mtu;
386         mtu_info->ip6m_addr.sin6_family = AF_INET6;
387         mtu_info->ip6m_addr.sin6_port = 0;
388         mtu_info->ip6m_addr.sin6_flowinfo = 0;
389         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
390         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
391 
392         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
393         skb_reset_transport_header(skb);
394 
395         skb = xchg(&np->rxpmtu, skb);
396         kfree_skb(skb);
397 }
398 
399 /* For some errors we have valid addr_offset even with zero payload and
400  * zero port. Also, addr_offset should be supported if port is set.
401  */
402 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
403 {
404         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
405                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
406                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
407 }
408 
409 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
410  *
411  * At one point, excluding local errors was a quick test to identify icmp/icmp6
412  * errors. This is no longer true, but the test remained, so the v6 stack,
413  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
414  */
415 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
416                                       struct sock_exterr_skb *serr)
417 {
418         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
419             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
420                 return true;
421 
422         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
423                 return false;
424 
425         if (!IP6CB(skb)->iif)
426                 return false;
427 
428         return true;
429 }
430 
431 /*
432  *      Handle MSG_ERRQUEUE
433  */
434 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
435 {
436         struct ipv6_pinfo *np = inet6_sk(sk);
437         struct sock_exterr_skb *serr;
438         struct sk_buff *skb;
439         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
440         struct {
441                 struct sock_extended_err ee;
442                 struct sockaddr_in6      offender;
443         } errhdr;
444         int err;
445         int copied;
446 
447         err = -EAGAIN;
448         skb = sock_dequeue_err_skb(sk);
449         if (!skb)
450                 goto out;
451 
452         copied = skb->len;
453         if (copied > len) {
454                 msg->msg_flags |= MSG_TRUNC;
455                 copied = len;
456         }
457         err = skb_copy_datagram_msg(skb, 0, msg, copied);
458         if (unlikely(err)) {
459                 kfree_skb(skb);
460                 return err;
461         }
462         sock_recv_timestamp(msg, sk, skb);
463 
464         serr = SKB_EXT_ERR(skb);
465 
466         if (sin && ipv6_datagram_support_addr(serr)) {
467                 const unsigned char *nh = skb_network_header(skb);
468                 sin->sin6_family = AF_INET6;
469                 sin->sin6_flowinfo = 0;
470                 sin->sin6_port = serr->port;
471                 if (skb->protocol == htons(ETH_P_IPV6)) {
472                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
473                                                                   struct ipv6hdr, daddr);
474                         sin->sin6_addr = ip6h->daddr;
475                         if (np->sndflow)
476                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
477                         sin->sin6_scope_id =
478                                 ipv6_iface_scope_id(&sin->sin6_addr,
479                                                     IP6CB(skb)->iif);
480                 } else {
481                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
482                                                &sin->sin6_addr);
483                         sin->sin6_scope_id = 0;
484                 }
485                 *addr_len = sizeof(*sin);
486         }
487 
488         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
489         sin = &errhdr.offender;
490         memset(sin, 0, sizeof(*sin));
491 
492         if (ip6_datagram_support_cmsg(skb, serr)) {
493                 sin->sin6_family = AF_INET6;
494                 if (np->rxopt.all)
495                         ip6_datagram_recv_common_ctl(sk, msg, skb);
496                 if (skb->protocol == htons(ETH_P_IPV6)) {
497                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
498                         if (np->rxopt.all)
499                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
500                         sin->sin6_scope_id =
501                                 ipv6_iface_scope_id(&sin->sin6_addr,
502                                                     IP6CB(skb)->iif);
503                 } else {
504                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
505                                                &sin->sin6_addr);
506                         if (inet_sk(sk)->cmsg_flags)
507                                 ip_cmsg_recv(msg, skb);
508                 }
509         }
510 
511         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
512 
513         /* Now we could try to dump offended packet options */
514 
515         msg->msg_flags |= MSG_ERRQUEUE;
516         err = copied;
517 
518         consume_skb(skb);
519 out:
520         return err;
521 }
522 EXPORT_SYMBOL_GPL(ipv6_recv_error);
523 
524 /*
525  *      Handle IPV6_RECVPATHMTU
526  */
527 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
528                      int *addr_len)
529 {
530         struct ipv6_pinfo *np = inet6_sk(sk);
531         struct sk_buff *skb;
532         struct ip6_mtuinfo mtu_info;
533         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
534         int err;
535         int copied;
536 
537         err = -EAGAIN;
538         skb = xchg(&np->rxpmtu, NULL);
539         if (!skb)
540                 goto out;
541 
542         copied = skb->len;
543         if (copied > len) {
544                 msg->msg_flags |= MSG_TRUNC;
545                 copied = len;
546         }
547         err = skb_copy_datagram_msg(skb, 0, msg, copied);
548         if (err)
549                 goto out_free_skb;
550 
551         sock_recv_timestamp(msg, sk, skb);
552 
553         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
554 
555         if (sin) {
556                 sin->sin6_family = AF_INET6;
557                 sin->sin6_flowinfo = 0;
558                 sin->sin6_port = 0;
559                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
560                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
561                 *addr_len = sizeof(*sin);
562         }
563 
564         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
565 
566         err = copied;
567 
568 out_free_skb:
569         kfree_skb(skb);
570 out:
571         return err;
572 }
573 
574 
575 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
576                                  struct sk_buff *skb)
577 {
578         struct ipv6_pinfo *np = inet6_sk(sk);
579         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
580 
581         if (np->rxopt.bits.rxinfo) {
582                 struct in6_pktinfo src_info;
583 
584                 if (is_ipv6) {
585                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
586                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
587                 } else {
588                         src_info.ipi6_ifindex =
589                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
590                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
591                                                &src_info.ipi6_addr);
592                 }
593 
594                 if (src_info.ipi6_ifindex >= 0)
595                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
596                                  sizeof(src_info), &src_info);
597         }
598 }
599 
600 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
601                                     struct sk_buff *skb)
602 {
603         struct ipv6_pinfo *np = inet6_sk(sk);
604         struct inet6_skb_parm *opt = IP6CB(skb);
605         unsigned char *nh = skb_network_header(skb);
606 
607         if (np->rxopt.bits.rxhlim) {
608                 int hlim = ipv6_hdr(skb)->hop_limit;
609                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
610         }
611 
612         if (np->rxopt.bits.rxtclass) {
613                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
614                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
615         }
616 
617         if (np->rxopt.bits.rxflow) {
618                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
619                 if (flowinfo)
620                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
621         }
622 
623         /* HbH is allowed only once */
624         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
625                 u8 *ptr = nh + sizeof(struct ipv6hdr);
626                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
627         }
628 
629         if (opt->lastopt &&
630             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
631                 /*
632                  * Silly enough, but we need to reparse in order to
633                  * report extension headers (except for HbH)
634                  * in order.
635                  *
636                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
637                  * (and WILL NOT be) defined because
638                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
639                  */
640                 unsigned int off = sizeof(struct ipv6hdr);
641                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
642 
643                 while (off <= opt->lastopt) {
644                         unsigned int len;
645                         u8 *ptr = nh + off;
646 
647                         switch (nexthdr) {
648                         case IPPROTO_DSTOPTS:
649                                 nexthdr = ptr[0];
650                                 len = (ptr[1] + 1) << 3;
651                                 if (np->rxopt.bits.dstopts)
652                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
653                                 break;
654                         case IPPROTO_ROUTING:
655                                 nexthdr = ptr[0];
656                                 len = (ptr[1] + 1) << 3;
657                                 if (np->rxopt.bits.srcrt)
658                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
659                                 break;
660                         case IPPROTO_AH:
661                                 nexthdr = ptr[0];
662                                 len = (ptr[1] + 2) << 2;
663                                 break;
664                         default:
665                                 nexthdr = ptr[0];
666                                 len = (ptr[1] + 1) << 3;
667                                 break;
668                         }
669 
670                         off += len;
671                 }
672         }
673 
674         /* socket options in old style */
675         if (np->rxopt.bits.rxoinfo) {
676                 struct in6_pktinfo src_info;
677 
678                 src_info.ipi6_ifindex = opt->iif;
679                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
680                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
681         }
682         if (np->rxopt.bits.rxohlim) {
683                 int hlim = ipv6_hdr(skb)->hop_limit;
684                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
685         }
686         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
687                 u8 *ptr = nh + sizeof(struct ipv6hdr);
688                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
689         }
690         if (np->rxopt.bits.odstopts && opt->dst0) {
691                 u8 *ptr = nh + opt->dst0;
692                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
693         }
694         if (np->rxopt.bits.osrcrt && opt->srcrt) {
695                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
696                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
697         }
698         if (np->rxopt.bits.odstopts && opt->dst1) {
699                 u8 *ptr = nh + opt->dst1;
700                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
701         }
702         if (np->rxopt.bits.rxorigdstaddr) {
703                 struct sockaddr_in6 sin6;
704                 __be16 *ports = (__be16 *) skb_transport_header(skb);
705 
706                 if (skb_transport_offset(skb) + 4 <= (int)skb->len) {
707                         /* All current transport protocols have the port numbers in the
708                          * first four bytes of the transport header and this function is
709                          * written with this assumption in mind.
710                          */
711 
712                         sin6.sin6_family = AF_INET6;
713                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
714                         sin6.sin6_port = ports[1];
715                         sin6.sin6_flowinfo = 0;
716                         sin6.sin6_scope_id =
717                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
718                                                     opt->iif);
719 
720                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
721                 }
722         }
723         if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
724                 int val = opt->frag_max_size;
725 
726                 put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
727         }
728 }
729 
730 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
731                           struct sk_buff *skb)
732 {
733         ip6_datagram_recv_common_ctl(sk, msg, skb);
734         ip6_datagram_recv_specific_ctl(sk, msg, skb);
735 }
736 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
737 
738 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
739                           struct msghdr *msg, struct flowi6 *fl6,
740                           struct ipcm6_cookie *ipc6, struct sockcm_cookie *sockc)
741 {
742         struct in6_pktinfo *src_info;
743         struct cmsghdr *cmsg;
744         struct ipv6_rt_hdr *rthdr;
745         struct ipv6_opt_hdr *hdr;
746         struct ipv6_txoptions *opt = ipc6->opt;
747         int len;
748         int err = 0;
749 
750         for_each_cmsghdr(cmsg, msg) {
751                 int addr_type;
752 
753                 if (!CMSG_OK(msg, cmsg)) {
754                         err = -EINVAL;
755                         goto exit_f;
756                 }
757 
758                 if (cmsg->cmsg_level == SOL_SOCKET) {
759                         err = __sock_cmsg_send(sk, msg, cmsg, sockc);
760                         if (err)
761                                 return err;
762                         continue;
763                 }
764 
765                 if (cmsg->cmsg_level != SOL_IPV6)
766                         continue;
767 
768                 switch (cmsg->cmsg_type) {
769                 case IPV6_PKTINFO:
770                 case IPV6_2292PKTINFO:
771                     {
772                         struct net_device *dev = NULL;
773 
774                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
775                                 err = -EINVAL;
776                                 goto exit_f;
777                         }
778 
779                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
780 
781                         if (src_info->ipi6_ifindex) {
782                                 if (fl6->flowi6_oif &&
783                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
784                                         return -EINVAL;
785                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
786                         }
787 
788                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
789 
790                         rcu_read_lock();
791                         if (fl6->flowi6_oif) {
792                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
793                                 if (!dev) {
794                                         rcu_read_unlock();
795                                         return -ENODEV;
796                                 }
797                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
798                                 rcu_read_unlock();
799                                 return -EINVAL;
800                         }
801 
802                         if (addr_type != IPV6_ADDR_ANY) {
803                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
804                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
805                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
806                                                    strict ? dev : NULL, 0) &&
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 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                    sk_rmem_alloc_get(sp),
1040                    0, 0L, 0,
1041                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1042                    0,
1043                    sock_i_ino(sp),
1044                    atomic_read(&sp->sk_refcnt), sp,
1045                    atomic_read(&sp->sk_drops));
1046 }
1047 

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