net/ipv6/datagram.c

   1 /*
   2  *      common UDP/RAW code
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 #include <linux/capability.h>
  15 #include <linux/errno.h>
  16 #include <linux/types.h>
  17 #include <linux/kernel.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/socket.h>
  20 #include <linux/sockios.h>
  21 #include <linux/in6.h>
  22 #include <linux/ipv6.h>
  23 #include <linux/route.h>
  24 #include <linux/slab.h>
  25 #include <linux/export.h>
  26
  27 #include <net/ipv6.h>
  28 #include <net/ndisc.h>
  29 #include <net/addrconf.h>
  30 #include <net/transp_v6.h>
  31 #include <net/ip6_route.h>
  32 #include <net/tcp_states.h>
  33 #include <net/dsfield.h>
  34
  35 #include <linux/errqueue.h>
  36 #include <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         sk_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         const 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->flags & IP6SKB_HOPBYHOP)) {
 574                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 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->flags & IP6SKB_HOPBYHOP)) {
 636                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 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 }