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 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 == NULL)
  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         opt = flowlabel ? flowlabel->opt : np->opt;
 171         final_p = fl6_update_dst(&fl6, opt, &final);
 172
 173         dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
 174         err = 0;
 175         if (IS_ERR(dst)) {
 176                 err = PTR_ERR(dst);
 177                 goto out;
 178         }
 179
 180         /* source address lookup done in ip6_dst_lookup */
 181
 182         if (ipv6_addr_any(&np->saddr))
 183                 np->saddr = fl6.saddr;
 184
 185         if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 186                 sk->sk_v6_rcv_saddr = fl6.saddr;
 187                 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 188                 if (sk->sk_prot->rehash)
 189                         sk->sk_prot->rehash(sk);
 190         }
 191
 192         ip6_dst_store(sk, dst,
 193                       ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
 194                       &sk->sk_v6_daddr : NULL,
 195 #ifdef CONFIG_IPV6_SUBTREES
 196                       ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
 197                       &np->saddr :
 198 #endif
 199                       NULL);
 200
 201         sk->sk_state = TCP_ESTABLISHED;
 202 out:
 203         fl6_sock_release(flowlabel);
 204         return err;
 205 }
 206 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 207
 208 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 209                      __be16 port, u32 info, u8 *payload)
 210 {
 211         struct ipv6_pinfo *np  = inet6_sk(sk);
 212         struct icmp6hdr *icmph = icmp6_hdr(skb);
 213         struct sock_exterr_skb *serr;
 214
 215         if (!np->recverr)
 216                 return;
 217
 218         skb = skb_clone(skb, GFP_ATOMIC);
 219         if (!skb)
 220                 return;
 221
 222         skb->protocol = htons(ETH_P_IPV6);
 223
 224         serr = SKB_EXT_ERR(skb);
 225         serr->ee.ee_errno = err;
 226         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 227         serr->ee.ee_type = icmph->icmp6_type;
 228         serr->ee.ee_code = icmph->icmp6_code;
 229         serr->ee.ee_pad = 0;
 230         serr->ee.ee_info = info;
 231         serr->ee.ee_data = 0;
 232         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 233                                   skb_network_header(skb);
 234         serr->port = port;
 235
 236         __skb_pull(skb, payload - skb->data);
 237         skb_reset_transport_header(skb);
 238
 239         if (sock_queue_err_skb(sk, skb))
 240                 kfree_skb(skb);
 241 }
 242
 243 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 244 {
 245         struct ipv6_pinfo *np = inet6_sk(sk);
 246         struct sock_exterr_skb *serr;
 247         struct ipv6hdr *iph;
 248         struct sk_buff *skb;
 249
 250         if (!np->recverr)
 251                 return;
 252
 253         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 254         if (!skb)
 255                 return;
 256
 257         skb->protocol = htons(ETH_P_IPV6);
 258
 259         skb_put(skb, sizeof(struct ipv6hdr));
 260         skb_reset_network_header(skb);
 261         iph = ipv6_hdr(skb);
 262         iph->daddr = fl6->daddr;
 263
 264         serr = SKB_EXT_ERR(skb);
 265         serr->ee.ee_errno = err;
 266         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 267         serr->ee.ee_type = 0;
 268         serr->ee.ee_code = 0;
 269         serr->ee.ee_pad = 0;
 270         serr->ee.ee_info = info;
 271         serr->ee.ee_data = 0;
 272         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 273         serr->port = fl6->fl6_dport;
 274
 275         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 276         skb_reset_transport_header(skb);
 277
 278         if (sock_queue_err_skb(sk, skb))
 279                 kfree_skb(skb);
 280 }
 281
 282 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 283 {
 284         struct ipv6_pinfo *np = inet6_sk(sk);
 285         struct ipv6hdr *iph;
 286         struct sk_buff *skb;
 287         struct ip6_mtuinfo *mtu_info;
 288
 289         if (!np->rxopt.bits.rxpmtu)
 290                 return;
 291
 292         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 293         if (!skb)
 294                 return;
 295
 296         skb_put(skb, sizeof(struct ipv6hdr));
 297         skb_reset_network_header(skb);
 298         iph = ipv6_hdr(skb);
 299         iph->daddr = fl6->daddr;
 300
 301         mtu_info = IP6CBMTU(skb);
 302
 303         mtu_info->ip6m_mtu = mtu;
 304         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 305         mtu_info->ip6m_addr.sin6_port = 0;
 306         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 307         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 308         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 309
 310         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 311         skb_reset_transport_header(skb);
 312
 313         skb = xchg(&np->rxpmtu, skb);
 314         kfree_skb(skb);
 315 }
 316
 317 /*
 318  *      Handle MSG_ERRQUEUE
 319  */
 320 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 321 {
 322         struct ipv6_pinfo *np = inet6_sk(sk);
 323         struct sock_exterr_skb *serr;
 324         struct sk_buff *skb, *skb2;
 325         struct sockaddr_in6 *sin;
 326         struct {
 327                 struct sock_extended_err ee;
 328                 struct sockaddr_in6      offender;
 329         } errhdr;
 330         int err;
 331         int copied;
 332
 333         err = -EAGAIN;
 334         skb = skb_dequeue(&sk->sk_error_queue);
 335         if (skb == NULL)
 336                 goto out;
 337
 338         copied = skb->len;
 339         if (copied > len) {
 340                 msg->msg_flags |= MSG_TRUNC;
 341                 copied = len;
 342         }
 343         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 344         if (err)
 345                 goto out_free_skb;
 346
 347         sock_recv_timestamp(msg, sk, skb);
 348
 349         serr = SKB_EXT_ERR(skb);
 350
 351         sin = (struct sockaddr_in6 *)msg->msg_name;
 352         if (sin) {
 353                 const unsigned char *nh = skb_network_header(skb);
 354                 sin->sin6_family = AF_INET6;
 355                 sin->sin6_flowinfo = 0;
 356                 sin->sin6_port = serr->port;
 357                 if (skb->protocol == htons(ETH_P_IPV6)) {
 358                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 359                                                                   struct ipv6hdr, daddr);
 360                         sin->sin6_addr = ip6h->daddr;
 361                         if (np->sndflow)
 362                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 363                         sin->sin6_scope_id =
 364                                 ipv6_iface_scope_id(&sin->sin6_addr,
 365                                                     IP6CB(skb)->iif);
 366                 } else {
 367                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 368                                                &sin->sin6_addr);
 369                         sin->sin6_scope_id = 0;
 370                 }
 371                 *addr_len = sizeof(*sin);
 372         }
 373
 374         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 375         sin = &errhdr.offender;
 376         sin->sin6_family = AF_UNSPEC;
 377         if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
 378                 sin->sin6_family = AF_INET6;
 379                 sin->sin6_flowinfo = 0;
 380                 sin->sin6_port = 0;
 381                 if (skb->protocol == htons(ETH_P_IPV6)) {
 382                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 383                         if (np->rxopt.all)
 384                                 ip6_datagram_recv_ctl(sk, msg, skb);
 385                         sin->sin6_scope_id =
 386                                 ipv6_iface_scope_id(&sin->sin6_addr,
 387                                                     IP6CB(skb)->iif);
 388                 } else {
 389                         struct inet_sock *inet = inet_sk(sk);
 390
 391                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 392                                                &sin->sin6_addr);
 393                         sin->sin6_scope_id = 0;
 394                         if (inet->cmsg_flags)
 395                                 ip_cmsg_recv(msg, skb);
 396                 }
 397         }
 398
 399         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 400
 401         /* Now we could try to dump offended packet options */
 402
 403         msg->msg_flags |= MSG_ERRQUEUE;
 404         err = copied;
 405
 406         /* Reset and regenerate socket error */
 407         spin_lock_bh(&sk->sk_error_queue.lock);
 408         sk->sk_err = 0;
 409         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
 410                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
 411                 spin_unlock_bh(&sk->sk_error_queue.lock);
 412                 sk->sk_error_report(sk);
 413         } else {
 414                 spin_unlock_bh(&sk->sk_error_queue.lock);
 415         }
 416
 417 out_free_skb:
 418         kfree_skb(skb);
 419 out:
 420         return err;
 421 }
 422 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 423
 424 /*
 425  *      Handle IPV6_RECVPATHMTU
 426  */
 427 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 428                      int *addr_len)
 429 {
 430         struct ipv6_pinfo *np = inet6_sk(sk);
 431         struct sk_buff *skb;
 432         struct sockaddr_in6 *sin;
 433         struct ip6_mtuinfo mtu_info;
 434         int err;
 435         int copied;
 436
 437         err = -EAGAIN;
 438         skb = xchg(&np->rxpmtu, NULL);
 439         if (skb == NULL)
 440                 goto out;
 441
 442         copied = skb->len;
 443         if (copied > len) {
 444                 msg->msg_flags |= MSG_TRUNC;
 445                 copied = len;
 446         }
 447         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 448         if (err)
 449                 goto out_free_skb;
 450
 451         sock_recv_timestamp(msg, sk, skb);
 452
 453         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 454
 455         sin = (struct sockaddr_in6 *)msg->msg_name;
 456         if (sin) {
 457                 sin->sin6_family = AF_INET6;
 458                 sin->sin6_flowinfo = 0;
 459                 sin->sin6_port = 0;
 460                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 461                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 462                 *addr_len = sizeof(*sin);
 463         }
 464
 465         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 466
 467         err = copied;
 468
 469 out_free_skb:
 470         kfree_skb(skb);
 471 out:
 472         return err;
 473 }
 474
 475
 476 int ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 477                           struct sk_buff *skb)
 478 {
 479         struct ipv6_pinfo *np = inet6_sk(sk);
 480         struct inet6_skb_parm *opt = IP6CB(skb);
 481         unsigned char *nh = skb_network_header(skb);
 482
 483         if (np->rxopt.bits.rxinfo) {
 484                 struct in6_pktinfo src_info;
 485
 486                 src_info.ipi6_ifindex = opt->iif;
 487                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 488                 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
 489         }
 490
 491         if (np->rxopt.bits.rxhlim) {
 492                 int hlim = ipv6_hdr(skb)->hop_limit;
 493                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 494         }
 495
 496         if (np->rxopt.bits.rxtclass) {
 497                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 498                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 499         }
 500
 501         if (np->rxopt.bits.rxflow) {
 502                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 503                 if (flowinfo)
 504                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 505         }
 506
 507         /* HbH is allowed only once */
 508         if (np->rxopt.bits.hopopts && opt->hop) {
 509                 u8 *ptr = nh + opt->hop;
 510                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 511         }
 512
 513         if (opt->lastopt &&
 514             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 515                 /*
 516                  * Silly enough, but we need to reparse in order to
 517                  * report extension headers (except for HbH)
 518                  * in order.
 519                  *
 520                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 521                  * (and WILL NOT be) defined because
 522                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 523                  */
 524                 unsigned int off = sizeof(struct ipv6hdr);
 525                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 526
 527                 while (off <= opt->lastopt) {
 528                         unsigned int len;
 529                         u8 *ptr = nh + off;
 530
 531                         switch (nexthdr) {
 532                         case IPPROTO_DSTOPTS:
 533                                 nexthdr = ptr[0];
 534                                 len = (ptr[1] + 1) << 3;
 535                                 if (np->rxopt.bits.dstopts)
 536                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 537                                 break;
 538                         case IPPROTO_ROUTING:
 539                                 nexthdr = ptr[0];
 540                                 len = (ptr[1] + 1) << 3;
 541                                 if (np->rxopt.bits.srcrt)
 542                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 543                                 break;
 544                         case IPPROTO_AH:
 545                                 nexthdr = ptr[0];
 546                                 len = (ptr[1] + 2) << 2;
 547                                 break;
 548                         default:
 549                                 nexthdr = ptr[0];
 550                                 len = (ptr[1] + 1) << 3;
 551                                 break;
 552                         }
 553
 554                         off += len;
 555                 }
 556         }
 557
 558         /* socket options in old style */
 559         if (np->rxopt.bits.rxoinfo) {
 560                 struct in6_pktinfo src_info;
 561
 562                 src_info.ipi6_ifindex = opt->iif;
 563                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 564                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 565         }
 566         if (np->rxopt.bits.rxohlim) {
 567                 int hlim = ipv6_hdr(skb)->hop_limit;
 568                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 569         }
 570         if (np->rxopt.bits.ohopopts && opt->hop) {
 571                 u8 *ptr = nh + opt->hop;
 572                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 573         }
 574         if (np->rxopt.bits.odstopts && opt->dst0) {
 575                 u8 *ptr = nh + opt->dst0;
 576                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 577         }
 578         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 579                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 580                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 581         }
 582         if (np->rxopt.bits.odstopts && opt->dst1) {
 583                 u8 *ptr = nh + opt->dst1;
 584                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 585         }
 586         if (np->rxopt.bits.rxorigdstaddr) {
 587                 struct sockaddr_in6 sin6;
 588                 __be16 *ports = (__be16 *) skb_transport_header(skb);
 589
 590                 if (skb_transport_offset(skb) + 4 <= skb->len) {
 591                         /* All current transport protocols have the port numbers in the
 592                          * first four bytes of the transport header and this function is
 593                          * written with this assumption in mind.
 594                          */
 595
 596                         sin6.sin6_family = AF_INET6;
 597                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 598                         sin6.sin6_port = ports[1];
 599                         sin6.sin6_flowinfo = 0;
 600                         sin6.sin6_scope_id =
 601                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 602                                                     opt->iif);
 603
 604                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 605                 }
 606         }
 607         return 0;
 608 }
 609 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 610
 611 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 612                           struct msghdr *msg, struct flowi6 *fl6,
 613                           struct ipv6_txoptions *opt,
 614                           int *hlimit, int *tclass, int *dontfrag)
 615 {
 616         struct in6_pktinfo *src_info;
 617         struct cmsghdr *cmsg;
 618         struct ipv6_rt_hdr *rthdr;
 619         struct ipv6_opt_hdr *hdr;
 620         int len;
 621         int err = 0;
 622
 623         for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 624                 int addr_type;
 625
 626                 if (!CMSG_OK(msg, cmsg)) {
 627                         err = -EINVAL;
 628                         goto exit_f;
 629                 }
 630
 631                 if (cmsg->cmsg_level != SOL_IPV6)
 632                         continue;
 633
 634                 switch (cmsg->cmsg_type) {
 635                 case IPV6_PKTINFO:
 636                 case IPV6_2292PKTINFO:
 637                     {
 638                         struct net_device *dev = NULL;
 639
 640                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 641                                 err = -EINVAL;
 642                                 goto exit_f;
 643                         }
 644
 645                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 646
 647                         if (src_info->ipi6_ifindex) {
 648                                 if (fl6->flowi6_oif &&
 649                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 650                                         return -EINVAL;
 651                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 652                         }
 653
 654                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 655
 656                         rcu_read_lock();
 657                         if (fl6->flowi6_oif) {
 658                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 659                                 if (!dev) {
 660                                         rcu_read_unlock();
 661                                         return -ENODEV;
 662                                 }
 663                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 664                                 rcu_read_unlock();
 665                                 return -EINVAL;
 666                         }
 667
 668                         if (addr_type != IPV6_ADDR_ANY) {
 669                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 670                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 671                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 672                                                    strict ? dev : NULL, 0))
 673                                         err = -EINVAL;
 674                                 else
 675                                         fl6->saddr = src_info->ipi6_addr;
 676                         }
 677
 678                         rcu_read_unlock();
 679
 680                         if (err)
 681                                 goto exit_f;
 682
 683                         break;
 684                     }
 685
 686                 case IPV6_FLOWINFO:
 687                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 688                                 err = -EINVAL;
 689                                 goto exit_f;
 690                         }
 691
 692                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 693                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 694                                         err = -EINVAL;
 695                                         goto exit_f;
 696                                 }
 697                         }
 698                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 699                         break;
 700
 701                 case IPV6_2292HOPOPTS:
 702                 case IPV6_HOPOPTS:
 703                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 704                                 err = -EINVAL;
 705                                 goto exit_f;
 706                         }
 707
 708                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 709                         len = ((hdr->hdrlen + 1) << 3);
 710                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 711                                 err = -EINVAL;
 712                                 goto exit_f;
 713                         }
 714                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 715                                 err = -EPERM;
 716                                 goto exit_f;
 717                         }
 718                         opt->opt_nflen += len;
 719                         opt->hopopt = hdr;
 720                         break;
 721
 722                 case IPV6_2292DSTOPTS:
 723                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 724                                 err = -EINVAL;
 725                                 goto exit_f;
 726                         }
 727
 728                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 729                         len = ((hdr->hdrlen + 1) << 3);
 730                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 731                                 err = -EINVAL;
 732                                 goto exit_f;
 733                         }
 734                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 735                                 err = -EPERM;
 736                                 goto exit_f;
 737                         }
 738                         if (opt->dst1opt) {
 739                                 err = -EINVAL;
 740                                 goto exit_f;
 741                         }
 742                         opt->opt_flen += len;
 743                         opt->dst1opt = hdr;
 744                         break;
 745
 746                 case IPV6_DSTOPTS:
 747                 case IPV6_RTHDRDSTOPTS:
 748                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 749                                 err = -EINVAL;
 750                                 goto exit_f;
 751                         }
 752
 753                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 754                         len = ((hdr->hdrlen + 1) << 3);
 755                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 756                                 err = -EINVAL;
 757                                 goto exit_f;
 758                         }
 759                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 760                                 err = -EPERM;
 761                                 goto exit_f;
 762                         }
 763                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 764                                 opt->opt_flen += len;
 765                                 opt->dst1opt = hdr;
 766                         } else {
 767                                 opt->opt_nflen += len;
 768                                 opt->dst0opt = hdr;
 769                         }
 770                         break;
 771
 772                 case IPV6_2292RTHDR:
 773                 case IPV6_RTHDR:
 774                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 775                                 err = -EINVAL;
 776                                 goto exit_f;
 777                         }
 778
 779                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 780
 781                         switch (rthdr->type) {
 782 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 783                         case IPV6_SRCRT_TYPE_2:
 784                                 if (rthdr->hdrlen != 2 ||
 785                                     rthdr->segments_left != 1) {
 786                                         err = -EINVAL;
 787                                         goto exit_f;
 788                                 }
 789                                 break;
 790 #endif
 791                         default:
 792                                 err = -EINVAL;
 793                                 goto exit_f;
 794                         }
 795
 796                         len = ((rthdr->hdrlen + 1) << 3);
 797
 798                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 799                                 err = -EINVAL;
 800                                 goto exit_f;
 801                         }
 802
 803                         /* segments left must also match */
 804                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 805                                 err = -EINVAL;
 806                                 goto exit_f;
 807                         }
 808
 809                         opt->opt_nflen += len;
 810                         opt->srcrt = rthdr;
 811
 812                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 813                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 814
 815                                 opt->opt_nflen += dsthdrlen;
 816                                 opt->dst0opt = opt->dst1opt;
 817                                 opt->dst1opt = NULL;
 818                                 opt->opt_flen -= dsthdrlen;
 819                         }
 820
 821                         break;
 822
 823                 case IPV6_2292HOPLIMIT:
 824                 case IPV6_HOPLIMIT:
 825                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 826                                 err = -EINVAL;
 827                                 goto exit_f;
 828                         }
 829
 830                         *hlimit = *(int *)CMSG_DATA(cmsg);
 831                         if (*hlimit < -1 || *hlimit > 0xff) {
 832                                 err = -EINVAL;
 833                                 goto exit_f;
 834                         }
 835
 836                         break;
 837
 838                 case IPV6_TCLASS:
 839                     {
 840                         int tc;
 841
 842                         err = -EINVAL;
 843                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 844                                 goto exit_f;
 845
 846                         tc = *(int *)CMSG_DATA(cmsg);
 847                         if (tc < -1 || tc > 0xff)
 848                                 goto exit_f;
 849
 850                         err = 0;
 851                         *tclass = tc;
 852
 853                         break;
 854                     }
 855
 856                 case IPV6_DONTFRAG:
 857                     {
 858                         int df;
 859
 860                         err = -EINVAL;
 861                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 862                                 goto exit_f;
 863
 864                         df = *(int *)CMSG_DATA(cmsg);
 865                         if (df < 0 || df > 1)
 866                                 goto exit_f;
 867
 868                         err = 0;
 869                         *dontfrag = df;
 870
 871                         break;
 872                     }
 873                 default:
 874                         LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
 875                                        cmsg->cmsg_type);
 876                         err = -EINVAL;
 877                         goto exit_f;
 878                 }
 879         }
 880
 881 exit_f:
 882         return err;
 883 }
 884 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
 885
 886 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
 887                              __u16 srcp, __u16 destp, int bucket)
 888 {
 889         const struct in6_addr *dest, *src;
 890
 891         dest  = &sp->sk_v6_daddr;
 892         src   = &sp->sk_v6_rcv_saddr;
 893         seq_printf(seq,
 894                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
 895                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
 896                    bucket,
 897                    src->s6_addr32[0], src->s6_addr32[1],
 898                    src->s6_addr32[2], src->s6_addr32[3], srcp,
 899                    dest->s6_addr32[0], dest->s6_addr32[1],
 900                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
 901                    sp->sk_state,
 902                    sk_wmem_alloc_get(sp),
 903                    sk_rmem_alloc_get(sp),
 904                    0, 0L, 0,
 905                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
 906                    0,
 907                    sock_i_ino(sp),
 908                    atomic_read(&sp->sk_refcnt), sp,
 909                    atomic_read(&sp->sk_drops));
 910 }