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(sock_net(sk), 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 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
 143                            int addr_len)
 144 {
 145         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
 146         struct inet_sock        *inet = inet_sk(sk);
 147         struct ipv6_pinfo       *np = inet6_sk(sk);
 148         struct in6_addr         *daddr, old_daddr;
 149         __be32                  fl6_flowlabel = 0;
 150         __be32                  old_fl6_flowlabel;
 151         __be32                  old_dport;
 152         int                     addr_type;
 153         int                     err;
 154
 155         if (usin->sin6_family == AF_INET) {
 156                 if (__ipv6_only_sock(sk))
 157                         return -EAFNOSUPPORT;
 158                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
 159                 goto ipv4_connected;
 160         }
 161
 162         if (addr_len < SIN6_LEN_RFC2133)
 163                 return -EINVAL;
 164
 165         if (usin->sin6_family != AF_INET6)
 166                 return -EAFNOSUPPORT;
 167
 168         if (np->sndflow)
 169                 fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 170
 171         if (ipv6_addr_any(&usin->sin6_addr)) {
 172                 /*
 173                  *      connect to self
 174                  */
 175                 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
 176                         ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
 177                                                &usin->sin6_addr);
 178                 else
 179                         usin->sin6_addr = in6addr_loopback;
 180         }
 181
 182         addr_type = ipv6_addr_type(&usin->sin6_addr);
 183
 184         daddr = &usin->sin6_addr;
 185
 186         if (addr_type & IPV6_ADDR_MAPPED) {
 187                 struct sockaddr_in sin;
 188
 189                 if (__ipv6_only_sock(sk)) {
 190                         err = -ENETUNREACH;
 191                         goto out;
 192                 }
 193                 sin.sin_family = AF_INET;
 194                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
 195                 sin.sin_port = usin->sin6_port;
 196
 197                 err = __ip4_datagram_connect(sk,
 198                                              (struct sockaddr *) &sin,
 199                                              sizeof(sin));
 200
 201 ipv4_connected:
 202                 if (err)
 203                         goto out;
 204
 205                 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 206
 207                 if (ipv6_addr_any(&np->saddr) ||
 208                     ipv6_mapped_addr_any(&np->saddr))
 209                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 210
 211                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 212                     ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 213                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 214                                                &sk->sk_v6_rcv_saddr);
 215                         if (sk->sk_prot->rehash)
 216                                 sk->sk_prot->rehash(sk);
 217                 }
 218
 219                 goto out;
 220         }
 221
 222         if (__ipv6_addr_needs_scope_id(addr_type)) {
 223                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 224                     usin->sin6_scope_id) {
 225                         if (sk->sk_bound_dev_if &&
 226                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 227                                 err = -EINVAL;
 228                                 goto out;
 229                         }
 230                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 231                 }
 232
 233                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 234                         sk->sk_bound_dev_if = np->mcast_oif;
 235
 236                 /* Connect to link-local address requires an interface */
 237                 if (!sk->sk_bound_dev_if) {
 238                         err = -EINVAL;
 239                         goto out;
 240                 }
 241         }
 242
 243         /* save the current peer information before updating it */
 244         old_daddr = sk->sk_v6_daddr;
 245         old_fl6_flowlabel = np->flow_label;
 246         old_dport = inet->inet_dport;
 247
 248         sk->sk_v6_daddr = *daddr;
 249         np->flow_label = fl6_flowlabel;
 250         inet->inet_dport = usin->sin6_port;
 251
 252         /*
 253          *      Check for a route to destination an obtain the
 254          *      destination cache for it.
 255          */
 256
 257         err = ip6_datagram_dst_update(sk, true);
 258         if (err) {
 259                 /* Restore the socket peer info, to keep it consistent with
 260                  * the old socket state
 261                  */
 262                 sk->sk_v6_daddr = old_daddr;
 263                 np->flow_label = old_fl6_flowlabel;
 264                 inet->inet_dport = old_dport;
 265                 goto out;
 266         }
 267
 268         sk->sk_state = TCP_ESTABLISHED;
 269         sk_set_txhash(sk);
 270 out:
 271         return err;
 272 }
 273 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 274
 275 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 276 {
 277         int res;
 278
 279         lock_sock(sk);
 280         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 281         release_sock(sk);
 282         return res;
 283 }
 284 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 285
 286 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 287                                  int addr_len)
 288 {
 289         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 290         if (sin6->sin6_family != AF_INET6)
 291                 return -EAFNOSUPPORT;
 292         return ip6_datagram_connect(sk, uaddr, addr_len);
 293 }
 294 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 295
 296 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 297                      __be16 port, u32 info, u8 *payload)
 298 {
 299         struct ipv6_pinfo *np  = inet6_sk(sk);
 300         struct icmp6hdr *icmph = icmp6_hdr(skb);
 301         struct sock_exterr_skb *serr;
 302
 303         if (!np->recverr)
 304                 return;
 305
 306         skb = skb_clone(skb, GFP_ATOMIC);
 307         if (!skb)
 308                 return;
 309
 310         skb->protocol = htons(ETH_P_IPV6);
 311
 312         serr = SKB_EXT_ERR(skb);
 313         serr->ee.ee_errno = err;
 314         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 315         serr->ee.ee_type = icmph->icmp6_type;
 316         serr->ee.ee_code = icmph->icmp6_code;
 317         serr->ee.ee_pad = 0;
 318         serr->ee.ee_info = info;
 319         serr->ee.ee_data = 0;
 320         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 321                                   skb_network_header(skb);
 322         serr->port = port;
 323
 324         __skb_pull(skb, payload - skb->data);
 325         skb_reset_transport_header(skb);
 326
 327         if (sock_queue_err_skb(sk, skb))
 328                 kfree_skb(skb);
 329 }
 330
 331 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 332 {
 333         const struct ipv6_pinfo *np = inet6_sk(sk);
 334         struct sock_exterr_skb *serr;
 335         struct ipv6hdr *iph;
 336         struct sk_buff *skb;
 337
 338         if (!np->recverr)
 339                 return;
 340
 341         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 342         if (!skb)
 343                 return;
 344
 345         skb->protocol = htons(ETH_P_IPV6);
 346
 347         skb_put(skb, sizeof(struct ipv6hdr));
 348         skb_reset_network_header(skb);
 349         iph = ipv6_hdr(skb);
 350         iph->daddr = fl6->daddr;
 351         ip6_flow_hdr(iph, 0, 0);
 352
 353         serr = SKB_EXT_ERR(skb);
 354         serr->ee.ee_errno = err;
 355         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 356         serr->ee.ee_type = 0;
 357         serr->ee.ee_code = 0;
 358         serr->ee.ee_pad = 0;
 359         serr->ee.ee_info = info;
 360         serr->ee.ee_data = 0;
 361         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 362         serr->port = fl6->fl6_dport;
 363
 364         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 365         skb_reset_transport_header(skb);
 366
 367         if (sock_queue_err_skb(sk, skb))
 368                 kfree_skb(skb);
 369 }
 370
 371 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 372 {
 373         struct ipv6_pinfo *np = inet6_sk(sk);
 374         struct ipv6hdr *iph;
 375         struct sk_buff *skb;
 376         struct ip6_mtuinfo *mtu_info;
 377
 378         if (!np->rxopt.bits.rxpmtu)
 379                 return;
 380
 381         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 382         if (!skb)
 383                 return;
 384
 385         skb_put(skb, sizeof(struct ipv6hdr));
 386         skb_reset_network_header(skb);
 387         iph = ipv6_hdr(skb);
 388         iph->daddr = fl6->daddr;
 389
 390         mtu_info = IP6CBMTU(skb);
 391
 392         mtu_info->ip6m_mtu = mtu;
 393         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 394         mtu_info->ip6m_addr.sin6_port = 0;
 395         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 396         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 397         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 398
 399         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 400         skb_reset_transport_header(skb);
 401
 402         skb = xchg(&np->rxpmtu, skb);
 403         kfree_skb(skb);
 404 }
 405
 406 /* For some errors we have valid addr_offset even with zero payload and
 407  * zero port. Also, addr_offset should be supported if port is set.
 408  */
 409 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 410 {
 411         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 412                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 413                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 414 }
 415
 416 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 417  *
 418  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 419  * errors. This is no longer true, but the test remained, so the v6 stack,
 420  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 421  */
 422 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 423                                       struct sock_exterr_skb *serr)
 424 {
 425         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 426             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 427                 return true;
 428
 429         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 430                 return false;
 431
 432         if (!IP6CB(skb)->iif)
 433                 return false;
 434
 435         return true;
 436 }
 437
 438 /*
 439  *      Handle MSG_ERRQUEUE
 440  */
 441 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 442 {
 443         struct ipv6_pinfo *np = inet6_sk(sk);
 444         struct sock_exterr_skb *serr;
 445         struct sk_buff *skb;
 446         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 447         struct {
 448                 struct sock_extended_err ee;
 449                 struct sockaddr_in6      offender;
 450         } errhdr;
 451         int err;
 452         int copied;
 453
 454         err = -EAGAIN;
 455         skb = sock_dequeue_err_skb(sk);
 456         if (!skb)
 457                 goto out;
 458
 459         copied = skb->len;
 460         if (copied > len) {
 461                 msg->msg_flags |= MSG_TRUNC;
 462                 copied = len;
 463         }
 464         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 465         if (unlikely(err)) {
 466                 kfree_skb(skb);
 467                 return err;
 468         }
 469         sock_recv_timestamp(msg, sk, skb);
 470
 471         serr = SKB_EXT_ERR(skb);
 472
 473         if (sin && ipv6_datagram_support_addr(serr)) {
 474                 const unsigned char *nh = skb_network_header(skb);
 475                 sin->sin6_family = AF_INET6;
 476                 sin->sin6_flowinfo = 0;
 477                 sin->sin6_port = serr->port;
 478                 if (skb->protocol == htons(ETH_P_IPV6)) {
 479                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 480                                                                   struct ipv6hdr, daddr);
 481                         sin->sin6_addr = ip6h->daddr;
 482                         if (np->sndflow)
 483                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 484                         sin->sin6_scope_id =
 485                                 ipv6_iface_scope_id(&sin->sin6_addr,
 486                                                     IP6CB(skb)->iif);
 487                 } else {
 488                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 489                                                &sin->sin6_addr);
 490                         sin->sin6_scope_id = 0;
 491                 }
 492                 *addr_len = sizeof(*sin);
 493         }
 494
 495         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 496         sin = &errhdr.offender;
 497         memset(sin, 0, sizeof(*sin));
 498
 499         if (ip6_datagram_support_cmsg(skb, serr)) {
 500                 sin->sin6_family = AF_INET6;
 501                 if (np->rxopt.all)
 502                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 503                 if (skb->protocol == htons(ETH_P_IPV6)) {
 504                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 505                         if (np->rxopt.all)
 506                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 507                         sin->sin6_scope_id =
 508                                 ipv6_iface_scope_id(&sin->sin6_addr,
 509                                                     IP6CB(skb)->iif);
 510                 } else {
 511                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 512                                                &sin->sin6_addr);
 513                         if (inet_sk(sk)->cmsg_flags)
 514                                 ip_cmsg_recv(msg, skb);
 515                 }
 516         }
 517
 518         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 519
 520         /* Now we could try to dump offended packet options */
 521
 522         msg->msg_flags |= MSG_ERRQUEUE;
 523         err = copied;
 524
 525         consume_skb(skb);
 526 out:
 527         return err;
 528 }
 529 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 530
 531 /*
 532  *      Handle IPV6_RECVPATHMTU
 533  */
 534 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 535                      int *addr_len)
 536 {
 537         struct ipv6_pinfo *np = inet6_sk(sk);
 538         struct sk_buff *skb;
 539         struct ip6_mtuinfo mtu_info;
 540         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 541         int err;
 542         int copied;
 543
 544         err = -EAGAIN;
 545         skb = xchg(&np->rxpmtu, NULL);
 546         if (!skb)
 547                 goto out;
 548
 549         copied = skb->len;
 550         if (copied > len) {
 551                 msg->msg_flags |= MSG_TRUNC;
 552                 copied = len;
 553         }
 554         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 555         if (err)
 556                 goto out_free_skb;
 557
 558         sock_recv_timestamp(msg, sk, skb);
 559
 560         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 561
 562         if (sin) {
 563                 sin->sin6_family = AF_INET6;
 564                 sin->sin6_flowinfo = 0;
 565                 sin->sin6_port = 0;
 566                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 567                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 568                 *addr_len = sizeof(*sin);
 569         }
 570
 571         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 572
 573         err = copied;
 574
 575 out_free_skb:
 576         kfree_skb(skb);
 577 out:
 578         return err;
 579 }
 580
 581
 582 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 583                                  struct sk_buff *skb)
 584 {
 585         struct ipv6_pinfo *np = inet6_sk(sk);
 586         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 587
 588         if (np->rxopt.bits.rxinfo) {
 589                 struct in6_pktinfo src_info;
 590
 591                 if (is_ipv6) {
 592                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 593                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 594                 } else {
 595                         src_info.ipi6_ifindex =
 596                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 597                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 598                                                &src_info.ipi6_addr);
 599                 }
 600
 601                 if (src_info.ipi6_ifindex >= 0)
 602                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 603                                  sizeof(src_info), &src_info);
 604         }
 605 }
 606
 607 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 608                                     struct sk_buff *skb)
 609 {
 610         struct ipv6_pinfo *np = inet6_sk(sk);
 611         struct inet6_skb_parm *opt = IP6CB(skb);
 612         unsigned char *nh = skb_network_header(skb);
 613
 614         if (np->rxopt.bits.rxhlim) {
 615                 int hlim = ipv6_hdr(skb)->hop_limit;
 616                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 617         }
 618
 619         if (np->rxopt.bits.rxtclass) {
 620                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 621                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 622         }
 623
 624         if (np->rxopt.bits.rxflow) {
 625                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 626                 if (flowinfo)
 627                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 628         }
 629
 630         /* HbH is allowed only once */
 631         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 632                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 633                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 634         }
 635
 636         if (opt->lastopt &&
 637             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 638                 /*
 639                  * Silly enough, but we need to reparse in order to
 640                  * report extension headers (except for HbH)
 641                  * in order.
 642                  *
 643                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 644                  * (and WILL NOT be) defined because
 645                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 646                  */
 647                 unsigned int off = sizeof(struct ipv6hdr);
 648                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 649
 650                 while (off <= opt->lastopt) {
 651                         unsigned int len;
 652                         u8 *ptr = nh + off;
 653
 654                         switch (nexthdr) {
 655                         case IPPROTO_DSTOPTS:
 656                                 nexthdr = ptr[0];
 657                                 len = (ptr[1] + 1) << 3;
 658                                 if (np->rxopt.bits.dstopts)
 659                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 660                                 break;
 661                         case IPPROTO_ROUTING:
 662                                 nexthdr = ptr[0];
 663                                 len = (ptr[1] + 1) << 3;
 664                                 if (np->rxopt.bits.srcrt)
 665                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 666                                 break;
 667                         case IPPROTO_AH:
 668                                 nexthdr = ptr[0];
 669                                 len = (ptr[1] + 2) << 2;
 670                                 break;
 671                         default:
 672                                 nexthdr = ptr[0];
 673                                 len = (ptr[1] + 1) << 3;
 674                                 break;
 675                         }
 676
 677                         off += len;
 678                 }
 679         }
 680
 681         /* socket options in old style */
 682         if (np->rxopt.bits.rxoinfo) {
 683                 struct in6_pktinfo src_info;
 684
 685                 src_info.ipi6_ifindex = opt->iif;
 686                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 687                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 688         }
 689         if (np->rxopt.bits.rxohlim) {
 690                 int hlim = ipv6_hdr(skb)->hop_limit;
 691                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 692         }
 693         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 694                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 695                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 696         }
 697         if (np->rxopt.bits.odstopts && opt->dst0) {
 698                 u8 *ptr = nh + opt->dst0;
 699                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 700         }
 701         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 702                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 703                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 704         }
 705         if (np->rxopt.bits.odstopts && opt->dst1) {
 706                 u8 *ptr = nh + opt->dst1;
 707                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 708         }
 709         if (np->rxopt.bits.rxorigdstaddr) {
 710                 struct sockaddr_in6 sin6;
 711                 __be16 _ports[2], *ports;
 712
 713                 ports = skb_header_pointer(skb, skb_transport_offset(skb),
 714                                            sizeof(_ports), &_ports);
 715                 if (ports) {
 716                         /* All current transport protocols have the port numbers in the
 717                          * first four bytes of the transport header and this function is
 718                          * written with this assumption in mind.
 719                          */
 720                         sin6.sin6_family = AF_INET6;
 721                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 722                         sin6.sin6_port = ports[1];
 723                         sin6.sin6_flowinfo = 0;
 724                         sin6.sin6_scope_id =
 725                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 726                                                     opt->iif);
 727
 728                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 729                 }
 730         }
 731 }
 732
 733 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 734                           struct sk_buff *skb)
 735 {
 736         ip6_datagram_recv_common_ctl(sk, msg, skb);
 737         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 738 }
 739 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 740
 741 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 742                           struct msghdr *msg, struct flowi6 *fl6,
 743                           struct ipcm6_cookie *ipc6, struct sockcm_cookie *sockc)
 744 {
 745         struct in6_pktinfo *src_info;
 746         struct cmsghdr *cmsg;
 747         struct ipv6_rt_hdr *rthdr;
 748         struct ipv6_opt_hdr *hdr;
 749         struct ipv6_txoptions *opt = ipc6->opt;
 750         int len;
 751         int err = 0;
 752
 753         for_each_cmsghdr(cmsg, msg) {
 754                 int addr_type;
 755
 756                 if (!CMSG_OK(msg, cmsg)) {
 757                         err = -EINVAL;
 758                         goto exit_f;
 759                 }
 760
 761                 if (cmsg->cmsg_level == SOL_SOCKET) {
 762                         err = __sock_cmsg_send(sk, msg, cmsg, sockc);
 763                         if (err)
 764                                 return err;
 765                         continue;
 766                 }
 767
 768                 if (cmsg->cmsg_level != SOL_IPV6)
 769                         continue;
 770
 771                 switch (cmsg->cmsg_type) {
 772                 case IPV6_PKTINFO:
 773                 case IPV6_2292PKTINFO:
 774                     {
 775                         struct net_device *dev = NULL;
 776
 777                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 778                                 err = -EINVAL;
 779                                 goto exit_f;
 780                         }
 781
 782                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 783
 784                         if (src_info->ipi6_ifindex) {
 785                                 if (fl6->flowi6_oif &&
 786                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 787                                         return -EINVAL;
 788                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 789                         }
 790
 791                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 792
 793                         rcu_read_lock();
 794                         if (fl6->flowi6_oif) {
 795                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 796                                 if (!dev) {
 797                                         rcu_read_unlock();
 798                                         return -ENODEV;
 799                                 }
 800                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 801                                 rcu_read_unlock();
 802                                 return -EINVAL;
 803                         }
 804
 805                         if (addr_type != IPV6_ADDR_ANY) {
 806                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 807                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 808                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 809                                                    strict ? dev : NULL, 0) &&
 810                                     !ipv6_chk_acast_addr_src(net, dev,
 811                                                              &src_info->ipi6_addr))
 812                                         err = -EINVAL;
 813                                 else
 814                                         fl6->saddr = src_info->ipi6_addr;
 815                         }
 816
 817                         rcu_read_unlock();
 818
 819                         if (err)
 820                                 goto exit_f;
 821
 822                         break;
 823                     }
 824
 825                 case IPV6_FLOWINFO:
 826                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 827                                 err = -EINVAL;
 828                                 goto exit_f;
 829                         }
 830
 831                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 832                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 833                                         err = -EINVAL;
 834                                         goto exit_f;
 835                                 }
 836                         }
 837                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 838                         break;
 839
 840                 case IPV6_2292HOPOPTS:
 841                 case IPV6_HOPOPTS:
 842                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 843                                 err = -EINVAL;
 844                                 goto exit_f;
 845                         }
 846
 847                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 848                         len = ((hdr->hdrlen + 1) << 3);
 849                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 850                                 err = -EINVAL;
 851                                 goto exit_f;
 852                         }
 853                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 854                                 err = -EPERM;
 855                                 goto exit_f;
 856                         }
 857                         opt->opt_nflen += len;
 858                         opt->hopopt = hdr;
 859                         break;
 860
 861                 case IPV6_2292DSTOPTS:
 862                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 863                                 err = -EINVAL;
 864                                 goto exit_f;
 865                         }
 866
 867                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 868                         len = ((hdr->hdrlen + 1) << 3);
 869                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 870                                 err = -EINVAL;
 871                                 goto exit_f;
 872                         }
 873                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 874                                 err = -EPERM;
 875                                 goto exit_f;
 876                         }
 877                         if (opt->dst1opt) {
 878                                 err = -EINVAL;
 879                                 goto exit_f;
 880                         }
 881                         opt->opt_flen += len;
 882                         opt->dst1opt = hdr;
 883                         break;
 884
 885                 case IPV6_DSTOPTS:
 886                 case IPV6_RTHDRDSTOPTS:
 887                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 888                                 err = -EINVAL;
 889                                 goto exit_f;
 890                         }
 891
 892                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 893                         len = ((hdr->hdrlen + 1) << 3);
 894                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 895                                 err = -EINVAL;
 896                                 goto exit_f;
 897                         }
 898                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 899                                 err = -EPERM;
 900                                 goto exit_f;
 901                         }
 902                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 903                                 opt->opt_flen += len;
 904                                 opt->dst1opt = hdr;
 905                         } else {
 906                                 opt->opt_nflen += len;
 907                                 opt->dst0opt = hdr;
 908                         }
 909                         break;
 910
 911                 case IPV6_2292RTHDR:
 912                 case IPV6_RTHDR:
 913                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 914                                 err = -EINVAL;
 915                                 goto exit_f;
 916                         }
 917
 918                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 919
 920                         switch (rthdr->type) {
 921 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 922                         case IPV6_SRCRT_TYPE_2:
 923                                 if (rthdr->hdrlen != 2 ||
 924                                     rthdr->segments_left != 1) {
 925                                         err = -EINVAL;
 926                                         goto exit_f;
 927                                 }
 928                                 break;
 929 #endif
 930                         default:
 931                                 err = -EINVAL;
 932                                 goto exit_f;
 933                         }
 934
 935                         len = ((rthdr->hdrlen + 1) << 3);
 936
 937                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 938                                 err = -EINVAL;
 939                                 goto exit_f;
 940                         }
 941
 942                         /* segments left must also match */
 943                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 944                                 err = -EINVAL;
 945                                 goto exit_f;
 946                         }
 947
 948                         opt->opt_nflen += len;
 949                         opt->srcrt = rthdr;
 950
 951                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 952                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 953
 954                                 opt->opt_nflen += dsthdrlen;
 955                                 opt->dst0opt = opt->dst1opt;
 956                                 opt->dst1opt = NULL;
 957                                 opt->opt_flen -= dsthdrlen;
 958                         }
 959
 960                         break;
 961
 962                 case IPV6_2292HOPLIMIT:
 963                 case IPV6_HOPLIMIT:
 964                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 965                                 err = -EINVAL;
 966                                 goto exit_f;
 967                         }
 968
 969                         ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 970                         if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 971                                 err = -EINVAL;
 972                                 goto exit_f;
 973                         }
 974
 975                         break;
 976
 977                 case IPV6_TCLASS:
 978                     {
 979                         int tc;
 980
 981                         err = -EINVAL;
 982                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 983                                 goto exit_f;
 984
 985                         tc = *(int *)CMSG_DATA(cmsg);
 986                         if (tc < -1 || tc > 0xff)
 987                                 goto exit_f;
 988
 989                         err = 0;
 990                         ipc6->tclass = tc;
 991
 992                         break;
 993                     }
 994
 995                 case IPV6_DONTFRAG:
 996                     {
 997                         int df;
 998
 999                         err = -EINVAL;
1000                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1001                                 goto exit_f;
1002
1003                         df = *(int *)CMSG_DATA(cmsg);
1004                         if (df < 0 || df > 1)
1005                                 goto exit_f;
1006
1007                         err = 0;
1008                         ipc6->dontfrag = df;
1009
1010                         break;
1011                     }
1012                 default:
1013                         net_dbg_ratelimited("invalid cmsg type: %d\n",
1014                                             cmsg->cmsg_type);
1015                         err = -EINVAL;
1016                         goto exit_f;
1017                 }
1018         }
1019
1020 exit_f:
1021         return err;
1022 }
1023 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1024
1025 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1026                              __u16 srcp, __u16 destp, int bucket)
1027 {
1028         const struct in6_addr *dest, *src;
1029
1030         dest  = &sp->sk_v6_daddr;
1031         src   = &sp->sk_v6_rcv_saddr;
1032         seq_printf(seq,
1033                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1034                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
1035                    bucket,
1036                    src->s6_addr32[0], src->s6_addr32[1],
1037                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1038                    dest->s6_addr32[0], dest->s6_addr32[1],
1039                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1040                    sp->sk_state,
1041                    sk_wmem_alloc_get(sp),
1042                    sk_rmem_alloc_get(sp),
1043                    0, 0L, 0,
1044                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1045                    0,
1046                    sock_i_ino(sp),
1047                    atomic_read(&sp->sk_refcnt), sp,
1048                    atomic_read(&sp->sk_drops));
1049 }