kernel/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)
 166                 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
 167
 168         if (!fl6.flowi6_oif && (addr_type&IPV6_ADDR_MULTICAST))
 169                 fl6.flowi6_oif = np->mcast_oif;
 170
 171         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 172
 173         rcu_read_lock();
 174         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
 175         final_p = fl6_update_dst(&fl6, opt, &final);
 176         rcu_read_unlock();
 177
 178         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
 179         err = 0;
 180         if (IS_ERR(dst)) {
 181                 err = PTR_ERR(dst);
 182                 goto out;
 183         }
 184
 185         /* source address lookup done in ip6_dst_lookup */
 186
 187         if (ipv6_addr_any(&np->saddr))
 188                 np->saddr = fl6.saddr;
 189
 190         if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 191                 sk->sk_v6_rcv_saddr = fl6.saddr;
 192                 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 193                 if (sk->sk_prot->rehash)
 194                         sk->sk_prot->rehash(sk);
 195         }
 196
 197         ip6_dst_store(sk, dst,
 198                       ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
 199                       &sk->sk_v6_daddr : NULL,
 200 #ifdef CONFIG_IPV6_SUBTREES
 201                       ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
 202                       &np->saddr :
 203 #endif
 204                       NULL);
 205
 206         sk->sk_state = TCP_ESTABLISHED;
 207         sk_set_txhash(sk);
 208 out:
 209         fl6_sock_release(flowlabel);
 210         return err;
 211 }
 212
 213 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 214 {
 215         int res;
 216
 217         lock_sock(sk);
 218         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 219         release_sock(sk);
 220         return res;
 221 }
 222 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 223
 224 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 225                                  int addr_len)
 226 {
 227         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 228         if (sin6->sin6_family != AF_INET6)
 229                 return -EAFNOSUPPORT;
 230         return ip6_datagram_connect(sk, uaddr, addr_len);
 231 }
 232 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 233
 234 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 235                      __be16 port, u32 info, u8 *payload)
 236 {
 237         struct ipv6_pinfo *np  = inet6_sk(sk);
 238         struct icmp6hdr *icmph = icmp6_hdr(skb);
 239         struct sock_exterr_skb *serr;
 240
 241         if (!np->recverr)
 242                 return;
 243
 244         skb = skb_clone(skb, GFP_ATOMIC);
 245         if (!skb)
 246                 return;
 247
 248         skb->protocol = htons(ETH_P_IPV6);
 249
 250         serr = SKB_EXT_ERR(skb);
 251         serr->ee.ee_errno = err;
 252         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 253         serr->ee.ee_type = icmph->icmp6_type;
 254         serr->ee.ee_code = icmph->icmp6_code;
 255         serr->ee.ee_pad = 0;
 256         serr->ee.ee_info = info;
 257         serr->ee.ee_data = 0;
 258         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 259                                   skb_network_header(skb);
 260         serr->port = port;
 261
 262         __skb_pull(skb, payload - skb->data);
 263         skb_reset_transport_header(skb);
 264
 265         if (sock_queue_err_skb(sk, skb))
 266                 kfree_skb(skb);
 267 }
 268
 269 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 270 {
 271         const struct ipv6_pinfo *np = inet6_sk(sk);
 272         struct sock_exterr_skb *serr;
 273         struct ipv6hdr *iph;
 274         struct sk_buff *skb;
 275
 276         if (!np->recverr)
 277                 return;
 278
 279         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 280         if (!skb)
 281                 return;
 282
 283         skb->protocol = htons(ETH_P_IPV6);
 284
 285         skb_put(skb, sizeof(struct ipv6hdr));
 286         skb_reset_network_header(skb);
 287         iph = ipv6_hdr(skb);
 288         iph->daddr = fl6->daddr;
 289
 290         serr = SKB_EXT_ERR(skb);
 291         serr->ee.ee_errno = err;
 292         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 293         serr->ee.ee_type = 0;
 294         serr->ee.ee_code = 0;
 295         serr->ee.ee_pad = 0;
 296         serr->ee.ee_info = info;
 297         serr->ee.ee_data = 0;
 298         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 299         serr->port = fl6->fl6_dport;
 300
 301         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 302         skb_reset_transport_header(skb);
 303
 304         if (sock_queue_err_skb(sk, skb))
 305                 kfree_skb(skb);
 306 }
 307
 308 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 309 {
 310         struct ipv6_pinfo *np = inet6_sk(sk);
 311         struct ipv6hdr *iph;
 312         struct sk_buff *skb;
 313         struct ip6_mtuinfo *mtu_info;
 314
 315         if (!np->rxopt.bits.rxpmtu)
 316                 return;
 317
 318         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 319         if (!skb)
 320                 return;
 321
 322         skb_put(skb, sizeof(struct ipv6hdr));
 323         skb_reset_network_header(skb);
 324         iph = ipv6_hdr(skb);
 325         iph->daddr = fl6->daddr;
 326
 327         mtu_info = IP6CBMTU(skb);
 328
 329         mtu_info->ip6m_mtu = mtu;
 330         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 331         mtu_info->ip6m_addr.sin6_port = 0;
 332         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 333         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 334         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 335
 336         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 337         skb_reset_transport_header(skb);
 338
 339         skb = xchg(&np->rxpmtu, skb);
 340         kfree_skb(skb);
 341 }
 342
 343 /* For some errors we have valid addr_offset even with zero payload and
 344  * zero port. Also, addr_offset should be supported if port is set.
 345  */
 346 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 347 {
 348         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 349                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 350                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 351 }
 352
 353 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 354  *
 355  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 356  * errors. This is no longer true, but the test remained, so the v6 stack,
 357  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 358  *
 359  * Timestamp code paths do not initialize the fields expected by cmsg:
 360  * the PKTINFO fields in skb->cb[]. Fill those in here.
 361  */
 362 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 363                                       struct sock_exterr_skb *serr)
 364 {
 365         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 366             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 367                 return true;
 368
 369         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 370                 return false;
 371
 372         if (!skb->dev)
 373                 return false;
 374
 375         if (skb->protocol == htons(ETH_P_IPV6))
 376                 IP6CB(skb)->iif = skb->dev->ifindex;
 377         else
 378                 PKTINFO_SKB_CB(skb)->ipi_ifindex = skb->dev->ifindex;
 379
 380         return true;
 381 }
 382
 383 /*
 384  *      Handle MSG_ERRQUEUE
 385  */
 386 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 387 {
 388         struct ipv6_pinfo *np = inet6_sk(sk);
 389         struct sock_exterr_skb *serr;
 390         struct sk_buff *skb;
 391         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 392         struct {
 393                 struct sock_extended_err ee;
 394                 struct sockaddr_in6      offender;
 395         } errhdr;
 396         int err;
 397         int copied;
 398
 399         err = -EAGAIN;
 400         skb = sock_dequeue_err_skb(sk);
 401         if (!skb)
 402                 goto out;
 403
 404         copied = skb->len;
 405         if (copied > len) {
 406                 msg->msg_flags |= MSG_TRUNC;
 407                 copied = len;
 408         }
 409         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 410         if (err)
 411                 goto out_free_skb;
 412
 413         sock_recv_timestamp(msg, sk, skb);
 414
 415         serr = SKB_EXT_ERR(skb);
 416
 417         if (sin && ipv6_datagram_support_addr(serr)) {
 418                 const unsigned char *nh = skb_network_header(skb);
 419                 sin->sin6_family = AF_INET6;
 420                 sin->sin6_flowinfo = 0;
 421                 sin->sin6_port = serr->port;
 422                 if (skb->protocol == htons(ETH_P_IPV6)) {
 423                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 424                                                                   struct ipv6hdr, daddr);
 425                         sin->sin6_addr = ip6h->daddr;
 426                         if (np->sndflow)
 427                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 428                         sin->sin6_scope_id =
 429                                 ipv6_iface_scope_id(&sin->sin6_addr,
 430                                                     IP6CB(skb)->iif);
 431                 } else {
 432                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 433                                                &sin->sin6_addr);
 434                         sin->sin6_scope_id = 0;
 435                 }
 436                 *addr_len = sizeof(*sin);
 437         }
 438
 439         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 440         sin = &errhdr.offender;
 441         memset(sin, 0, sizeof(*sin));
 442
 443         if (ip6_datagram_support_cmsg(skb, serr)) {
 444                 sin->sin6_family = AF_INET6;
 445                 if (np->rxopt.all)
 446                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 447                 if (skb->protocol == htons(ETH_P_IPV6)) {
 448                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 449                         if (np->rxopt.all)
 450                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 451                         sin->sin6_scope_id =
 452                                 ipv6_iface_scope_id(&sin->sin6_addr,
 453                                                     IP6CB(skb)->iif);
 454                 } else {
 455                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 456                                                &sin->sin6_addr);
 457                         if (inet_sk(sk)->cmsg_flags)
 458                                 ip_cmsg_recv(msg, skb);
 459                 }
 460         }
 461
 462         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 463
 464         /* Now we could try to dump offended packet options */
 465
 466         msg->msg_flags |= MSG_ERRQUEUE;
 467         err = copied;
 468
 469 out_free_skb:
 470         kfree_skb(skb);
 471 out:
 472         return err;
 473 }
 474 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 475
 476 /*
 477  *      Handle IPV6_RECVPATHMTU
 478  */
 479 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 480                      int *addr_len)
 481 {
 482         struct ipv6_pinfo *np = inet6_sk(sk);
 483         struct sk_buff *skb;
 484         struct ip6_mtuinfo mtu_info;
 485         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 486         int err;
 487         int copied;
 488
 489         err = -EAGAIN;
 490         skb = xchg(&np->rxpmtu, NULL);
 491         if (!skb)
 492                 goto out;
 493
 494         copied = skb->len;
 495         if (copied > len) {
 496                 msg->msg_flags |= MSG_TRUNC;
 497                 copied = len;
 498         }
 499         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 500         if (err)
 501                 goto out_free_skb;
 502
 503         sock_recv_timestamp(msg, sk, skb);
 504
 505         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 506
 507         if (sin) {
 508                 sin->sin6_family = AF_INET6;
 509                 sin->sin6_flowinfo = 0;
 510                 sin->sin6_port = 0;
 511                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 512                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 513                 *addr_len = sizeof(*sin);
 514         }
 515
 516         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 517
 518         err = copied;
 519
 520 out_free_skb:
 521         kfree_skb(skb);
 522 out:
 523         return err;
 524 }
 525
 526
 527 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 528                                  struct sk_buff *skb)
 529 {
 530         struct ipv6_pinfo *np = inet6_sk(sk);
 531         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 532
 533         if (np->rxopt.bits.rxinfo) {
 534                 struct in6_pktinfo src_info;
 535
 536                 if (is_ipv6) {
 537                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 538                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 539                 } else {
 540                         src_info.ipi6_ifindex =
 541                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 542                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 543                                                &src_info.ipi6_addr);
 544                 }
 545
 546                 if (src_info.ipi6_ifindex >= 0)
 547                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 548                                  sizeof(src_info), &src_info);
 549         }
 550 }
 551
 552 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 553                                     struct sk_buff *skb)
 554 {
 555         struct ipv6_pinfo *np = inet6_sk(sk);
 556         struct inet6_skb_parm *opt = IP6CB(skb);
 557         unsigned char *nh = skb_network_header(skb);
 558
 559         if (np->rxopt.bits.rxhlim) {
 560                 int hlim = ipv6_hdr(skb)->hop_limit;
 561                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 562         }
 563
 564         if (np->rxopt.bits.rxtclass) {
 565                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 566                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 567         }
 568
 569         if (np->rxopt.bits.rxflow) {
 570                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 571                 if (flowinfo)
 572                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 573         }
 574
 575         /* HbH is allowed only once */
 576         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 577                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 578                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 579         }
 580
 581         if (opt->lastopt &&
 582             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 583                 /*
 584                  * Silly enough, but we need to reparse in order to
 585                  * report extension headers (except for HbH)
 586                  * in order.
 587                  *
 588                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 589                  * (and WILL NOT be) defined because
 590                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 591                  */
 592                 unsigned int off = sizeof(struct ipv6hdr);
 593                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 594
 595                 while (off <= opt->lastopt) {
 596                         unsigned int len;
 597                         u8 *ptr = nh + off;
 598
 599                         switch (nexthdr) {
 600                         case IPPROTO_DSTOPTS:
 601                                 nexthdr = ptr[0];
 602                                 len = (ptr[1] + 1) << 3;
 603                                 if (np->rxopt.bits.dstopts)
 604                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 605                                 break;
 606                         case IPPROTO_ROUTING:
 607                                 nexthdr = ptr[0];
 608                                 len = (ptr[1] + 1) << 3;
 609                                 if (np->rxopt.bits.srcrt)
 610                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 611                                 break;
 612                         case IPPROTO_AH:
 613                                 nexthdr = ptr[0];
 614                                 len = (ptr[1] + 2) << 2;
 615                                 break;
 616                         default:
 617                                 nexthdr = ptr[0];
 618                                 len = (ptr[1] + 1) << 3;
 619                                 break;
 620                         }
 621
 622                         off += len;
 623                 }
 624         }
 625
 626         /* socket options in old style */
 627         if (np->rxopt.bits.rxoinfo) {
 628                 struct in6_pktinfo src_info;
 629
 630                 src_info.ipi6_ifindex = opt->iif;
 631                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 632                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 633         }
 634         if (np->rxopt.bits.rxohlim) {
 635                 int hlim = ipv6_hdr(skb)->hop_limit;
 636                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 637         }
 638         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 639                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 640                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 641         }
 642         if (np->rxopt.bits.odstopts && opt->dst0) {
 643                 u8 *ptr = nh + opt->dst0;
 644                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 645         }
 646         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 647                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 648                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 649         }
 650         if (np->rxopt.bits.odstopts && opt->dst1) {
 651                 u8 *ptr = nh + opt->dst1;
 652                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 653         }
 654         if (np->rxopt.bits.rxorigdstaddr) {
 655                 struct sockaddr_in6 sin6;
 656                 __be16 *ports = (__be16 *) skb_transport_header(skb);
 657
 658                 if (skb_transport_offset(skb) + 4 <= skb->len) {
 659                         /* All current transport protocols have the port numbers in the
 660                          * first four bytes of the transport header and this function is
 661                          * written with this assumption in mind.
 662                          */
 663
 664                         sin6.sin6_family = AF_INET6;
 665                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 666                         sin6.sin6_port = ports[1];
 667                         sin6.sin6_flowinfo = 0;
 668                         sin6.sin6_scope_id =
 669                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 670                                                     opt->iif);
 671
 672                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 673                 }
 674         }
 675 }
 676
 677 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 678                           struct sk_buff *skb)
 679 {
 680         ip6_datagram_recv_common_ctl(sk, msg, skb);
 681         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 682 }
 683 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 684
 685 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 686                           struct msghdr *msg, struct flowi6 *fl6,
 687                           struct ipv6_txoptions *opt,
 688                           int *hlimit, int *tclass, int *dontfrag)
 689 {
 690         struct in6_pktinfo *src_info;
 691         struct cmsghdr *cmsg;
 692         struct ipv6_rt_hdr *rthdr;
 693         struct ipv6_opt_hdr *hdr;
 694         int len;
 695         int err = 0;
 696
 697         for_each_cmsghdr(cmsg, msg) {
 698                 int addr_type;
 699
 700                 if (!CMSG_OK(msg, cmsg)) {
 701                         err = -EINVAL;
 702                         goto exit_f;
 703                 }
 704
 705                 if (cmsg->cmsg_level != SOL_IPV6)
 706                         continue;
 707
 708                 switch (cmsg->cmsg_type) {
 709                 case IPV6_PKTINFO:
 710                 case IPV6_2292PKTINFO:
 711                     {
 712                         struct net_device *dev = NULL;
 713
 714                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 715                                 err = -EINVAL;
 716                                 goto exit_f;
 717                         }
 718
 719                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 720
 721                         if (src_info->ipi6_ifindex) {
 722                                 if (fl6->flowi6_oif &&
 723                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 724                                         return -EINVAL;
 725                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 726                         }
 727
 728                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 729
 730                         rcu_read_lock();
 731                         if (fl6->flowi6_oif) {
 732                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 733                                 if (!dev) {
 734                                         rcu_read_unlock();
 735                                         return -ENODEV;
 736                                 }
 737                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 738                                 rcu_read_unlock();
 739                                 return -EINVAL;
 740                         }
 741
 742                         if (addr_type != IPV6_ADDR_ANY) {
 743                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 744                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 745                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 746                                                    strict ? dev : NULL, 0) &&
 747                                     !ipv6_chk_acast_addr_src(net, dev,
 748                                                              &src_info->ipi6_addr))
 749                                         err = -EINVAL;
 750                                 else
 751                                         fl6->saddr = src_info->ipi6_addr;
 752                         }
 753
 754                         rcu_read_unlock();
 755
 756                         if (err)
 757                                 goto exit_f;
 758
 759                         break;
 760                     }
 761
 762                 case IPV6_FLOWINFO:
 763                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 764                                 err = -EINVAL;
 765                                 goto exit_f;
 766                         }
 767
 768                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 769                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 770                                         err = -EINVAL;
 771                                         goto exit_f;
 772                                 }
 773                         }
 774                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 775                         break;
 776
 777                 case IPV6_2292HOPOPTS:
 778                 case IPV6_HOPOPTS:
 779                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 780                                 err = -EINVAL;
 781                                 goto exit_f;
 782                         }
 783
 784                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 785                         len = ((hdr->hdrlen + 1) << 3);
 786                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 787                                 err = -EINVAL;
 788                                 goto exit_f;
 789                         }
 790                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 791                                 err = -EPERM;
 792                                 goto exit_f;
 793                         }
 794                         opt->opt_nflen += len;
 795                         opt->hopopt = hdr;
 796                         break;
 797
 798                 case IPV6_2292DSTOPTS:
 799                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 800                                 err = -EINVAL;
 801                                 goto exit_f;
 802                         }
 803
 804                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 805                         len = ((hdr->hdrlen + 1) << 3);
 806                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 807                                 err = -EINVAL;
 808                                 goto exit_f;
 809                         }
 810                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 811                                 err = -EPERM;
 812                                 goto exit_f;
 813                         }
 814                         if (opt->dst1opt) {
 815                                 err = -EINVAL;
 816                                 goto exit_f;
 817                         }
 818                         opt->opt_flen += len;
 819                         opt->dst1opt = hdr;
 820                         break;
 821
 822                 case IPV6_DSTOPTS:
 823                 case IPV6_RTHDRDSTOPTS:
 824                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 825                                 err = -EINVAL;
 826                                 goto exit_f;
 827                         }
 828
 829                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 830                         len = ((hdr->hdrlen + 1) << 3);
 831                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 832                                 err = -EINVAL;
 833                                 goto exit_f;
 834                         }
 835                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 836                                 err = -EPERM;
 837                                 goto exit_f;
 838                         }
 839                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 840                                 opt->opt_flen += len;
 841                                 opt->dst1opt = hdr;
 842                         } else {
 843                                 opt->opt_nflen += len;
 844                                 opt->dst0opt = hdr;
 845                         }
 846                         break;
 847
 848                 case IPV6_2292RTHDR:
 849                 case IPV6_RTHDR:
 850                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 851                                 err = -EINVAL;
 852                                 goto exit_f;
 853                         }
 854
 855                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 856
 857                         switch (rthdr->type) {
 858 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 859                         case IPV6_SRCRT_TYPE_2:
 860                                 if (rthdr->hdrlen != 2 ||
 861                                     rthdr->segments_left != 1) {
 862                                         err = -EINVAL;
 863                                         goto exit_f;
 864                                 }
 865                                 break;
 866 #endif
 867                         default:
 868                                 err = -EINVAL;
 869                                 goto exit_f;
 870                         }
 871
 872                         len = ((rthdr->hdrlen + 1) << 3);
 873
 874                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 875                                 err = -EINVAL;
 876                                 goto exit_f;
 877                         }
 878
 879                         /* segments left must also match */
 880                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 881                                 err = -EINVAL;
 882                                 goto exit_f;
 883                         }
 884
 885                         opt->opt_nflen += len;
 886                         opt->srcrt = rthdr;
 887
 888                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 889                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 890
 891                                 opt->opt_nflen += dsthdrlen;
 892                                 opt->dst0opt = opt->dst1opt;
 893                                 opt->dst1opt = NULL;
 894                                 opt->opt_flen -= dsthdrlen;
 895                         }
 896
 897                         break;
 898
 899                 case IPV6_2292HOPLIMIT:
 900                 case IPV6_HOPLIMIT:
 901                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 902                                 err = -EINVAL;
 903                                 goto exit_f;
 904                         }
 905
 906                         *hlimit = *(int *)CMSG_DATA(cmsg);
 907                         if (*hlimit < -1 || *hlimit > 0xff) {
 908                                 err = -EINVAL;
 909                                 goto exit_f;
 910                         }
 911
 912                         break;
 913
 914                 case IPV6_TCLASS:
 915                     {
 916                         int tc;
 917
 918                         err = -EINVAL;
 919                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 920                                 goto exit_f;
 921
 922                         tc = *(int *)CMSG_DATA(cmsg);
 923                         if (tc < -1 || tc > 0xff)
 924                                 goto exit_f;
 925
 926                         err = 0;
 927                         *tclass = tc;
 928
 929                         break;
 930                     }
 931
 932                 case IPV6_DONTFRAG:
 933                     {
 934                         int df;
 935
 936                         err = -EINVAL;
 937                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 938                                 goto exit_f;
 939
 940                         df = *(int *)CMSG_DATA(cmsg);
 941                         if (df < 0 || df > 1)
 942                                 goto exit_f;
 943
 944                         err = 0;
 945                         *dontfrag = df;
 946
 947                         break;
 948                     }
 949                 default:
 950                         net_dbg_ratelimited("invalid cmsg type: %d\n",
 951                                             cmsg->cmsg_type);
 952                         err = -EINVAL;
 953                         goto exit_f;
 954                 }
 955         }
 956
 957 exit_f:
 958         return err;
 959 }
 960 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
 961
 962 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
 963                              __u16 srcp, __u16 destp, int bucket)
 964 {
 965         const struct in6_addr *dest, *src;
 966
 967         dest  = &sp->sk_v6_daddr;
 968         src   = &sp->sk_v6_rcv_saddr;
 969         seq_printf(seq,
 970                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
 971                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
 972                    bucket,
 973                    src->s6_addr32[0], src->s6_addr32[1],
 974                    src->s6_addr32[2], src->s6_addr32[3], srcp,
 975                    dest->s6_addr32[0], dest->s6_addr32[1],
 976                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
 977                    sp->sk_state,
 978                    sk_wmem_alloc_get(sp),
 979                    sk_rmem_alloc_get(sp),
 980                    0, 0L, 0,
 981                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
 982                    0,
 983                    sock_i_ino(sp),
 984                    atomic_read(&sp->sk_refcnt), sp,
 985                    atomic_read(&sp->sk_drops));
 986 }