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 void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
  44 {
  45         struct inet_sock *inet = inet_sk(sk);
  46         struct ipv6_pinfo *np = inet6_sk(sk);
  47
  48         memset(fl6, 0, sizeof(*fl6));
  49         fl6->flowi6_proto = sk->sk_protocol;
  50         fl6->daddr = sk->sk_v6_daddr;
  51         fl6->saddr = np->saddr;
  52         fl6->flowi6_oif = sk->sk_bound_dev_if;
  53         fl6->flowi6_mark = sk->sk_mark;
  54         fl6->fl6_dport = inet->inet_dport;
  55         fl6->fl6_sport = inet->inet_sport;
  56         fl6->flowlabel = np->flow_label;
  57
  58         if (!fl6->flowi6_oif)
  59                 fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
  60
  61         if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr))
  62                 fl6->flowi6_oif = np->mcast_oif;
  63
  64         security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
  65 }
  66
  67 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
  68 {
  69         struct ip6_flowlabel *flowlabel = NULL;
  70         struct in6_addr *final_p, final;
  71         struct ipv6_txoptions *opt;
  72         struct dst_entry *dst;
  73         struct inet_sock *inet = inet_sk(sk);
  74         struct ipv6_pinfo *np = inet6_sk(sk);
  75         struct flowi6 fl6;
  76         int err = 0;
  77
  78         if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
  79                 flowlabel = fl6_sock_lookup(sk, np->flow_label);
  80                 if (!flowlabel)
  81                         return -EINVAL;
  82         }
  83         ip6_datagram_flow_key_init(&fl6, sk);
  84
  85         rcu_read_lock();
  86         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
  87         final_p = fl6_update_dst(&fl6, opt, &final);
  88         rcu_read_unlock();
  89
  90         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
  91         if (IS_ERR(dst)) {
  92                 err = PTR_ERR(dst);
  93                 goto out;
  94         }
  95
  96         if (fix_sk_saddr) {
  97                 if (ipv6_addr_any(&np->saddr))
  98                         np->saddr = fl6.saddr;
  99
 100                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 101                         sk->sk_v6_rcv_saddr = fl6.saddr;
 102                         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 103                         if (sk->sk_prot->rehash)
 104                                 sk->sk_prot->rehash(sk);
 105                 }
 106         }
 107
 108         ip6_dst_store(sk, dst,
 109                       ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
 110                       &sk->sk_v6_daddr : NULL,
 111 #ifdef CONFIG_IPV6_SUBTREES
 112                       ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
 113                       &np->saddr :
 114 #endif
 115                       NULL);
 116
 117 out:
 118         fl6_sock_release(flowlabel);
 119         return err;
 120 }
 121
 122 void ip6_datagram_release_cb(struct sock *sk)
 123 {
 124         struct dst_entry *dst;
 125
 126         if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 127                 return;
 128
 129         rcu_read_lock();
 130         dst = __sk_dst_get(sk);
 131         if (!dst || !dst->obsolete ||
 132             dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
 133                 rcu_read_unlock();
 134                 return;
 135         }
 136         rcu_read_unlock();
 137
 138         ip6_datagram_dst_update(sk, false);
 139 }
 140 EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
 141
 142 static int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 143 {
 144         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
 145         struct inet_sock        *inet = inet_sk(sk);
 146         struct ipv6_pinfo       *np = inet6_sk(sk);
 147         struct in6_addr         *daddr;
 148         int                     addr_type;
 149         int                     err;
 150         __be32                  fl6_flowlabel = 0;
 151
 152         if (usin->sin6_family == AF_INET) {
 153                 if (__ipv6_only_sock(sk))
 154                         return -EAFNOSUPPORT;
 155                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
 156                 goto ipv4_connected;
 157         }
 158
 159         if (addr_len < SIN6_LEN_RFC2133)
 160                 return -EINVAL;
 161
 162         if (usin->sin6_family != AF_INET6)
 163                 return -EAFNOSUPPORT;
 164
 165         if (np->sndflow)
 166                 fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 167
 168         addr_type = ipv6_addr_type(&usin->sin6_addr);
 169
 170         if (addr_type == IPV6_ADDR_ANY) {
 171                 /*
 172                  *      connect to self
 173                  */
 174                 usin->sin6_addr.s6_addr[15] = 0x01;
 175         }
 176
 177         daddr = &usin->sin6_addr;
 178
 179         if (addr_type == IPV6_ADDR_MAPPED) {
 180                 struct sockaddr_in sin;
 181
 182                 if (__ipv6_only_sock(sk)) {
 183                         err = -ENETUNREACH;
 184                         goto out;
 185                 }
 186                 sin.sin_family = AF_INET;
 187                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
 188                 sin.sin_port = usin->sin6_port;
 189
 190                 err = __ip4_datagram_connect(sk,
 191                                              (struct sockaddr *) &sin,
 192                                              sizeof(sin));
 193
 194 ipv4_connected:
 195                 if (err)
 196                         goto out;
 197
 198                 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 199
 200                 if (ipv6_addr_any(&np->saddr) ||
 201                     ipv6_mapped_addr_any(&np->saddr))
 202                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 203
 204                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 205                     ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 206                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 207                                                &sk->sk_v6_rcv_saddr);
 208                         if (sk->sk_prot->rehash)
 209                                 sk->sk_prot->rehash(sk);
 210                 }
 211
 212                 goto out;
 213         }
 214
 215         if (__ipv6_addr_needs_scope_id(addr_type)) {
 216                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 217                     usin->sin6_scope_id) {
 218                         if (sk->sk_bound_dev_if &&
 219                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 220                                 err = -EINVAL;
 221                                 goto out;
 222                         }
 223                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 224                 }
 225
 226                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 227                         sk->sk_bound_dev_if = np->mcast_oif;
 228
 229                 /* Connect to link-local address requires an interface */
 230                 if (!sk->sk_bound_dev_if) {
 231                         err = -EINVAL;
 232                         goto out;
 233                 }
 234         }
 235
 236         sk->sk_v6_daddr = *daddr;
 237         np->flow_label = fl6_flowlabel;
 238
 239         inet->inet_dport = usin->sin6_port;
 240
 241         /*
 242          *      Check for a route to destination an obtain the
 243          *      destination cache for it.
 244          */
 245
 246         err = ip6_datagram_dst_update(sk, true);
 247         if (err)
 248                 goto out;
 249
 250         sk->sk_state = TCP_ESTABLISHED;
 251         sk_set_txhash(sk);
 252 out:
 253         return err;
 254 }
 255
 256 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 257 {
 258         int res;
 259
 260         lock_sock(sk);
 261         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 262         release_sock(sk);
 263         return res;
 264 }
 265 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 266
 267 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 268                                  int addr_len)
 269 {
 270         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 271         if (sin6->sin6_family != AF_INET6)
 272                 return -EAFNOSUPPORT;
 273         return ip6_datagram_connect(sk, uaddr, addr_len);
 274 }
 275 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 276
 277 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 278                      __be16 port, u32 info, u8 *payload)
 279 {
 280         struct ipv6_pinfo *np  = inet6_sk(sk);
 281         struct icmp6hdr *icmph = icmp6_hdr(skb);
 282         struct sock_exterr_skb *serr;
 283
 284         if (!np->recverr)
 285                 return;
 286
 287         skb = skb_clone(skb, GFP_ATOMIC);
 288         if (!skb)
 289                 return;
 290
 291         skb->protocol = htons(ETH_P_IPV6);
 292
 293         serr = SKB_EXT_ERR(skb);
 294         serr->ee.ee_errno = err;
 295         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 296         serr->ee.ee_type = icmph->icmp6_type;
 297         serr->ee.ee_code = icmph->icmp6_code;
 298         serr->ee.ee_pad = 0;
 299         serr->ee.ee_info = info;
 300         serr->ee.ee_data = 0;
 301         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 302                                   skb_network_header(skb);
 303         serr->port = port;
 304
 305         __skb_pull(skb, payload - skb->data);
 306         skb_reset_transport_header(skb);
 307
 308         if (sock_queue_err_skb(sk, skb))
 309                 kfree_skb(skb);
 310 }
 311
 312 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 313 {
 314         const struct ipv6_pinfo *np = inet6_sk(sk);
 315         struct sock_exterr_skb *serr;
 316         struct ipv6hdr *iph;
 317         struct sk_buff *skb;
 318
 319         if (!np->recverr)
 320                 return;
 321
 322         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 323         if (!skb)
 324                 return;
 325
 326         skb->protocol = htons(ETH_P_IPV6);
 327
 328         skb_put(skb, sizeof(struct ipv6hdr));
 329         skb_reset_network_header(skb);
 330         iph = ipv6_hdr(skb);
 331         iph->daddr = fl6->daddr;
 332
 333         serr = SKB_EXT_ERR(skb);
 334         serr->ee.ee_errno = err;
 335         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 336         serr->ee.ee_type = 0;
 337         serr->ee.ee_code = 0;
 338         serr->ee.ee_pad = 0;
 339         serr->ee.ee_info = info;
 340         serr->ee.ee_data = 0;
 341         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 342         serr->port = fl6->fl6_dport;
 343
 344         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 345         skb_reset_transport_header(skb);
 346
 347         if (sock_queue_err_skb(sk, skb))
 348                 kfree_skb(skb);
 349 }
 350
 351 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 352 {
 353         struct ipv6_pinfo *np = inet6_sk(sk);
 354         struct ipv6hdr *iph;
 355         struct sk_buff *skb;
 356         struct ip6_mtuinfo *mtu_info;
 357
 358         if (!np->rxopt.bits.rxpmtu)
 359                 return;
 360
 361         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 362         if (!skb)
 363                 return;
 364
 365         skb_put(skb, sizeof(struct ipv6hdr));
 366         skb_reset_network_header(skb);
 367         iph = ipv6_hdr(skb);
 368         iph->daddr = fl6->daddr;
 369
 370         mtu_info = IP6CBMTU(skb);
 371
 372         mtu_info->ip6m_mtu = mtu;
 373         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 374         mtu_info->ip6m_addr.sin6_port = 0;
 375         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 376         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 377         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 378
 379         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 380         skb_reset_transport_header(skb);
 381
 382         skb = xchg(&np->rxpmtu, skb);
 383         kfree_skb(skb);
 384 }
 385
 386 /* For some errors we have valid addr_offset even with zero payload and
 387  * zero port. Also, addr_offset should be supported if port is set.
 388  */
 389 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 390 {
 391         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 392                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 393                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 394 }
 395
 396 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 397  *
 398  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 399  * errors. This is no longer true, but the test remained, so the v6 stack,
 400  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 401  *
 402  * Timestamp code paths do not initialize the fields expected by cmsg:
 403  * the PKTINFO fields in skb->cb[]. Fill those in here.
 404  */
 405 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 406                                       struct sock_exterr_skb *serr)
 407 {
 408         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 409             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 410                 return true;
 411
 412         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 413                 return false;
 414
 415         if (!skb->dev)
 416                 return false;
 417
 418         if (skb->protocol == htons(ETH_P_IPV6))
 419                 IP6CB(skb)->iif = skb->dev->ifindex;
 420         else
 421                 PKTINFO_SKB_CB(skb)->ipi_ifindex = skb->dev->ifindex;
 422
 423         return true;
 424 }
 425
 426 /*
 427  *      Handle MSG_ERRQUEUE
 428  */
 429 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 430 {
 431         struct ipv6_pinfo *np = inet6_sk(sk);
 432         struct sock_exterr_skb *serr;
 433         struct sk_buff *skb;
 434         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 435         struct {
 436                 struct sock_extended_err ee;
 437                 struct sockaddr_in6      offender;
 438         } errhdr;
 439         int err;
 440         int copied;
 441
 442         err = -EAGAIN;
 443         skb = sock_dequeue_err_skb(sk);
 444         if (!skb)
 445                 goto out;
 446
 447         copied = skb->len;
 448         if (copied > len) {
 449                 msg->msg_flags |= MSG_TRUNC;
 450                 copied = len;
 451         }
 452         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 453         if (unlikely(err)) {
 454                 kfree_skb(skb);
 455                 return err;
 456         }
 457         sock_recv_timestamp(msg, sk, skb);
 458
 459         serr = SKB_EXT_ERR(skb);
 460
 461         if (sin && ipv6_datagram_support_addr(serr)) {
 462                 const unsigned char *nh = skb_network_header(skb);
 463                 sin->sin6_family = AF_INET6;
 464                 sin->sin6_flowinfo = 0;
 465                 sin->sin6_port = serr->port;
 466                 if (skb->protocol == htons(ETH_P_IPV6)) {
 467                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 468                                                                   struct ipv6hdr, daddr);
 469                         sin->sin6_addr = ip6h->daddr;
 470                         if (np->sndflow)
 471                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 472                         sin->sin6_scope_id =
 473                                 ipv6_iface_scope_id(&sin->sin6_addr,
 474                                                     IP6CB(skb)->iif);
 475                 } else {
 476                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 477                                                &sin->sin6_addr);
 478                         sin->sin6_scope_id = 0;
 479                 }
 480                 *addr_len = sizeof(*sin);
 481         }
 482
 483         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 484         sin = &errhdr.offender;
 485         memset(sin, 0, sizeof(*sin));
 486
 487         if (ip6_datagram_support_cmsg(skb, serr)) {
 488                 sin->sin6_family = AF_INET6;
 489                 if (np->rxopt.all)
 490                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 491                 if (skb->protocol == htons(ETH_P_IPV6)) {
 492                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 493                         if (np->rxopt.all)
 494                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 495                         sin->sin6_scope_id =
 496                                 ipv6_iface_scope_id(&sin->sin6_addr,
 497                                                     IP6CB(skb)->iif);
 498                 } else {
 499                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 500                                                &sin->sin6_addr);
 501                         if (inet_sk(sk)->cmsg_flags)
 502                                 ip_cmsg_recv(msg, skb);
 503                 }
 504         }
 505
 506         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 507
 508         /* Now we could try to dump offended packet options */
 509
 510         msg->msg_flags |= MSG_ERRQUEUE;
 511         err = copied;
 512
 513         consume_skb(skb);
 514 out:
 515         return err;
 516 }
 517 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 518
 519 /*
 520  *      Handle IPV6_RECVPATHMTU
 521  */
 522 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 523                      int *addr_len)
 524 {
 525         struct ipv6_pinfo *np = inet6_sk(sk);
 526         struct sk_buff *skb;
 527         struct ip6_mtuinfo mtu_info;
 528         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 529         int err;
 530         int copied;
 531
 532         err = -EAGAIN;
 533         skb = xchg(&np->rxpmtu, NULL);
 534         if (!skb)
 535                 goto out;
 536
 537         copied = skb->len;
 538         if (copied > len) {
 539                 msg->msg_flags |= MSG_TRUNC;
 540                 copied = len;
 541         }
 542         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 543         if (err)
 544                 goto out_free_skb;
 545
 546         sock_recv_timestamp(msg, sk, skb);
 547
 548         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 549
 550         if (sin) {
 551                 sin->sin6_family = AF_INET6;
 552                 sin->sin6_flowinfo = 0;
 553                 sin->sin6_port = 0;
 554                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 555                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 556                 *addr_len = sizeof(*sin);
 557         }
 558
 559         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 560
 561         err = copied;
 562
 563 out_free_skb:
 564         kfree_skb(skb);
 565 out:
 566         return err;
 567 }
 568
 569
 570 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 571                                  struct sk_buff *skb)
 572 {
 573         struct ipv6_pinfo *np = inet6_sk(sk);
 574         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 575
 576         if (np->rxopt.bits.rxinfo) {
 577                 struct in6_pktinfo src_info;
 578
 579                 if (is_ipv6) {
 580                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 581                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 582                 } else {
 583                         src_info.ipi6_ifindex =
 584                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 585                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 586                                                &src_info.ipi6_addr);
 587                 }
 588
 589                 if (src_info.ipi6_ifindex >= 0)
 590                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 591                                  sizeof(src_info), &src_info);
 592         }
 593 }
 594
 595 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 596                                     struct sk_buff *skb)
 597 {
 598         struct ipv6_pinfo *np = inet6_sk(sk);
 599         struct inet6_skb_parm *opt = IP6CB(skb);
 600         unsigned char *nh = skb_network_header(skb);
 601
 602         if (np->rxopt.bits.rxhlim) {
 603                 int hlim = ipv6_hdr(skb)->hop_limit;
 604                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 605         }
 606
 607         if (np->rxopt.bits.rxtclass) {
 608                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 609                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 610         }
 611
 612         if (np->rxopt.bits.rxflow) {
 613                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 614                 if (flowinfo)
 615                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 616         }
 617
 618         /* HbH is allowed only once */
 619         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 620                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 621                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 622         }
 623
 624         if (opt->lastopt &&
 625             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 626                 /*
 627                  * Silly enough, but we need to reparse in order to
 628                  * report extension headers (except for HbH)
 629                  * in order.
 630                  *
 631                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 632                  * (and WILL NOT be) defined because
 633                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 634                  */
 635                 unsigned int off = sizeof(struct ipv6hdr);
 636                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 637
 638                 while (off <= opt->lastopt) {
 639                         unsigned int len;
 640                         u8 *ptr = nh + off;
 641
 642                         switch (nexthdr) {
 643                         case IPPROTO_DSTOPTS:
 644                                 nexthdr = ptr[0];
 645                                 len = (ptr[1] + 1) << 3;
 646                                 if (np->rxopt.bits.dstopts)
 647                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 648                                 break;
 649                         case IPPROTO_ROUTING:
 650                                 nexthdr = ptr[0];
 651                                 len = (ptr[1] + 1) << 3;
 652                                 if (np->rxopt.bits.srcrt)
 653                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 654                                 break;
 655                         case IPPROTO_AH:
 656                                 nexthdr = ptr[0];
 657                                 len = (ptr[1] + 2) << 2;
 658                                 break;
 659                         default:
 660                                 nexthdr = ptr[0];
 661                                 len = (ptr[1] + 1) << 3;
 662                                 break;
 663                         }
 664
 665                         off += len;
 666                 }
 667         }
 668
 669         /* socket options in old style */
 670         if (np->rxopt.bits.rxoinfo) {
 671                 struct in6_pktinfo src_info;
 672
 673                 src_info.ipi6_ifindex = opt->iif;
 674                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 675                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 676         }
 677         if (np->rxopt.bits.rxohlim) {
 678                 int hlim = ipv6_hdr(skb)->hop_limit;
 679                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 680         }
 681         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 682                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 683                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 684         }
 685         if (np->rxopt.bits.odstopts && opt->dst0) {
 686                 u8 *ptr = nh + opt->dst0;
 687                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 688         }
 689         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 690                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 691                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 692         }
 693         if (np->rxopt.bits.odstopts && opt->dst1) {
 694                 u8 *ptr = nh + opt->dst1;
 695                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 696         }
 697         if (np->rxopt.bits.rxorigdstaddr) {
 698                 struct sockaddr_in6 sin6;
 699                 __be16 *ports = (__be16 *) skb_transport_header(skb);
 700
 701                 if (skb_transport_offset(skb) + 4 <= skb->len) {
 702                         /* All current transport protocols have the port numbers in the
 703                          * first four bytes of the transport header and this function is
 704                          * written with this assumption in mind.
 705                          */
 706
 707                         sin6.sin6_family = AF_INET6;
 708                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 709                         sin6.sin6_port = ports[1];
 710                         sin6.sin6_flowinfo = 0;
 711                         sin6.sin6_scope_id =
 712                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 713                                                     opt->iif);
 714
 715                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 716                 }
 717         }
 718 }
 719
 720 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 721                           struct sk_buff *skb)
 722 {
 723         ip6_datagram_recv_common_ctl(sk, msg, skb);
 724         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 725 }
 726 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 727
 728 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 729                           struct msghdr *msg, struct flowi6 *fl6,
 730                           struct ipcm6_cookie *ipc6, struct sockcm_cookie *sockc)
 731 {
 732         struct in6_pktinfo *src_info;
 733         struct cmsghdr *cmsg;
 734         struct ipv6_rt_hdr *rthdr;
 735         struct ipv6_opt_hdr *hdr;
 736         struct ipv6_txoptions *opt = ipc6->opt;
 737         int len;
 738         int err = 0;
 739
 740         for_each_cmsghdr(cmsg, msg) {
 741                 int addr_type;
 742
 743                 if (!CMSG_OK(msg, cmsg)) {
 744                         err = -EINVAL;
 745                         goto exit_f;
 746                 }
 747
 748                 if (cmsg->cmsg_level == SOL_SOCKET) {
 749                         err = __sock_cmsg_send(sk, msg, cmsg, sockc);
 750                         if (err)
 751                                 return err;
 752                         continue;
 753                 }
 754
 755                 if (cmsg->cmsg_level != SOL_IPV6)
 756                         continue;
 757
 758                 switch (cmsg->cmsg_type) {
 759                 case IPV6_PKTINFO:
 760                 case IPV6_2292PKTINFO:
 761                     {
 762                         struct net_device *dev = NULL;
 763
 764                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 765                                 err = -EINVAL;
 766                                 goto exit_f;
 767                         }
 768
 769                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 770
 771                         if (src_info->ipi6_ifindex) {
 772                                 if (fl6->flowi6_oif &&
 773                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 774                                         return -EINVAL;
 775                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 776                         }
 777
 778                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 779
 780                         rcu_read_lock();
 781                         if (fl6->flowi6_oif) {
 782                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 783                                 if (!dev) {
 784                                         rcu_read_unlock();
 785                                         return -ENODEV;
 786                                 }
 787                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 788                                 rcu_read_unlock();
 789                                 return -EINVAL;
 790                         }
 791
 792                         if (addr_type != IPV6_ADDR_ANY) {
 793                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 794                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 795                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 796                                                    strict ? dev : NULL, 0) &&
 797                                     !ipv6_chk_acast_addr_src(net, dev,
 798                                                              &src_info->ipi6_addr))
 799                                         err = -EINVAL;
 800                                 else
 801                                         fl6->saddr = src_info->ipi6_addr;
 802                         }
 803
 804                         rcu_read_unlock();
 805
 806                         if (err)
 807                                 goto exit_f;
 808
 809                         break;
 810                     }
 811
 812                 case IPV6_FLOWINFO:
 813                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 814                                 err = -EINVAL;
 815                                 goto exit_f;
 816                         }
 817
 818                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 819                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 820                                         err = -EINVAL;
 821                                         goto exit_f;
 822                                 }
 823                         }
 824                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 825                         break;
 826
 827                 case IPV6_2292HOPOPTS:
 828                 case IPV6_HOPOPTS:
 829                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 830                                 err = -EINVAL;
 831                                 goto exit_f;
 832                         }
 833
 834                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 835                         len = ((hdr->hdrlen + 1) << 3);
 836                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 837                                 err = -EINVAL;
 838                                 goto exit_f;
 839                         }
 840                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 841                                 err = -EPERM;
 842                                 goto exit_f;
 843                         }
 844                         opt->opt_nflen += len;
 845                         opt->hopopt = hdr;
 846                         break;
 847
 848                 case IPV6_2292DSTOPTS:
 849                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 850                                 err = -EINVAL;
 851                                 goto exit_f;
 852                         }
 853
 854                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 855                         len = ((hdr->hdrlen + 1) << 3);
 856                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 857                                 err = -EINVAL;
 858                                 goto exit_f;
 859                         }
 860                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 861                                 err = -EPERM;
 862                                 goto exit_f;
 863                         }
 864                         if (opt->dst1opt) {
 865                                 err = -EINVAL;
 866                                 goto exit_f;
 867                         }
 868                         opt->opt_flen += len;
 869                         opt->dst1opt = hdr;
 870                         break;
 871
 872                 case IPV6_DSTOPTS:
 873                 case IPV6_RTHDRDSTOPTS:
 874                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 875                                 err = -EINVAL;
 876                                 goto exit_f;
 877                         }
 878
 879                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 880                         len = ((hdr->hdrlen + 1) << 3);
 881                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 882                                 err = -EINVAL;
 883                                 goto exit_f;
 884                         }
 885                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 886                                 err = -EPERM;
 887                                 goto exit_f;
 888                         }
 889                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 890                                 opt->opt_flen += len;
 891                                 opt->dst1opt = hdr;
 892                         } else {
 893                                 opt->opt_nflen += len;
 894                                 opt->dst0opt = hdr;
 895                         }
 896                         break;
 897
 898                 case IPV6_2292RTHDR:
 899                 case IPV6_RTHDR:
 900                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 901                                 err = -EINVAL;
 902                                 goto exit_f;
 903                         }
 904
 905                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 906
 907                         switch (rthdr->type) {
 908 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 909                         case IPV6_SRCRT_TYPE_2:
 910                                 if (rthdr->hdrlen != 2 ||
 911                                     rthdr->segments_left != 1) {
 912                                         err = -EINVAL;
 913                                         goto exit_f;
 914                                 }
 915                                 break;
 916 #endif
 917                         default:
 918                                 err = -EINVAL;
 919                                 goto exit_f;
 920                         }
 921
 922                         len = ((rthdr->hdrlen + 1) << 3);
 923
 924                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 925                                 err = -EINVAL;
 926                                 goto exit_f;
 927                         }
 928
 929                         /* segments left must also match */
 930                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 931                                 err = -EINVAL;
 932                                 goto exit_f;
 933                         }
 934
 935                         opt->opt_nflen += len;
 936                         opt->srcrt = rthdr;
 937
 938                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 939                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 940
 941                                 opt->opt_nflen += dsthdrlen;
 942                                 opt->dst0opt = opt->dst1opt;
 943                                 opt->dst1opt = NULL;
 944                                 opt->opt_flen -= dsthdrlen;
 945                         }
 946
 947                         break;
 948
 949                 case IPV6_2292HOPLIMIT:
 950                 case IPV6_HOPLIMIT:
 951                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 952                                 err = -EINVAL;
 953                                 goto exit_f;
 954                         }
 955
 956                         ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 957                         if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 958                                 err = -EINVAL;
 959                                 goto exit_f;
 960                         }
 961
 962                         break;
 963
 964                 case IPV6_TCLASS:
 965                     {
 966                         int tc;
 967
 968                         err = -EINVAL;
 969                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 970                                 goto exit_f;
 971
 972                         tc = *(int *)CMSG_DATA(cmsg);
 973                         if (tc < -1 || tc > 0xff)
 974                                 goto exit_f;
 975
 976                         err = 0;
 977                         ipc6->tclass = tc;
 978
 979                         break;
 980                     }
 981
 982                 case IPV6_DONTFRAG:
 983                     {
 984                         int df;
 985
 986                         err = -EINVAL;
 987                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 988                                 goto exit_f;
 989
 990                         df = *(int *)CMSG_DATA(cmsg);
 991                         if (df < 0 || df > 1)
 992                                 goto exit_f;
 993
 994                         err = 0;
 995                         ipc6->dontfrag = df;
 996
 997                         break;
 998                     }
 999                 default:
1000                         net_dbg_ratelimited("invalid cmsg type: %d\n",
1001                                             cmsg->cmsg_type);
1002                         err = -EINVAL;
1003                         goto exit_f;
1004                 }
1005         }
1006
1007 exit_f:
1008         return err;
1009 }
1010 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1011
1012 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1013                              __u16 srcp, __u16 destp, int bucket)
1014 {
1015         const struct in6_addr *dest, *src;
1016
1017         dest  = &sp->sk_v6_daddr;
1018         src   = &sp->sk_v6_rcv_saddr;
1019         seq_printf(seq,
1020                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1021                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
1022                    bucket,
1023                    src->s6_addr32[0], src->s6_addr32[1],
1024                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1025                    dest->s6_addr32[0], dest->s6_addr32[1],
1026                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1027                    sp->sk_state,
1028                    sk_wmem_alloc_get(sp),
1029                    sk_rmem_alloc_get(sp),
1030                    0, 0L, 0,
1031                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1032                    0,
1033                    sock_i_ino(sp),
1034                    atomic_read(&sp->sk_refcnt), sp,
1035                    atomic_read(&sp->sk_drops));
1036 }