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 <linux/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         fl6->flowi6_uid = sk->sk_uid;
  58
  59         if (!fl6->flowi6_oif)
  60                 fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
  61
  62         if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr))
  63                 fl6->flowi6_oif = np->mcast_oif;
  64
  65         security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
  66 }
  67
  68 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
  69 {
  70         struct ip6_flowlabel *flowlabel = NULL;
  71         struct in6_addr *final_p, final;
  72         struct ipv6_txoptions *opt;
  73         struct dst_entry *dst;
  74         struct inet_sock *inet = inet_sk(sk);
  75         struct ipv6_pinfo *np = inet6_sk(sk);
  76         struct flowi6 fl6;
  77         int err = 0;
  78
  79         if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
  80                 flowlabel = fl6_sock_lookup(sk, np->flow_label);
  81                 if (!flowlabel)
  82                         return -EINVAL;
  83         }
  84         ip6_datagram_flow_key_init(&fl6, sk);
  85
  86         rcu_read_lock();
  87         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
  88         final_p = fl6_update_dst(&fl6, opt, &final);
  89         rcu_read_unlock();
  90
  91         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
  92         if (IS_ERR(dst)) {
  93                 err = PTR_ERR(dst);
  94                 goto out;
  95         }
  96
  97         if (fix_sk_saddr) {
  98                 if (ipv6_addr_any(&np->saddr))
  99                         np->saddr = fl6.saddr;
 100
 101                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 102                         sk->sk_v6_rcv_saddr = fl6.saddr;
 103                         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 104                         if (sk->sk_prot->rehash)
 105                                 sk->sk_prot->rehash(sk);
 106                 }
 107         }
 108
 109         ip6_dst_store(sk, dst,
 110                       ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
 111                       &sk->sk_v6_daddr : NULL,
 112 #ifdef CONFIG_IPV6_SUBTREES
 113                       ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
 114                       &np->saddr :
 115 #endif
 116                       NULL);
 117
 118 out:
 119         fl6_sock_release(flowlabel);
 120         return err;
 121 }
 122
 123 void ip6_datagram_release_cb(struct sock *sk)
 124 {
 125         struct dst_entry *dst;
 126
 127         if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 128                 return;
 129
 130         rcu_read_lock();
 131         dst = __sk_dst_get(sk);
 132         if (!dst || !dst->obsolete ||
 133             dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
 134                 rcu_read_unlock();
 135                 return;
 136         }
 137         rcu_read_unlock();
 138
 139         ip6_datagram_dst_update(sk, false);
 140 }
 141 EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
 142
 143 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
 144                            int addr_len)
 145 {
 146         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
 147         struct inet_sock        *inet = inet_sk(sk);
 148         struct ipv6_pinfo       *np = inet6_sk(sk);
 149         struct in6_addr         *daddr;
 150         int                     addr_type;
 151         int                     err;
 152         __be32                  fl6_flowlabel = 0;
 153
 154         if (usin->sin6_family == AF_INET) {
 155                 if (__ipv6_only_sock(sk))
 156                         return -EAFNOSUPPORT;
 157                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
 158                 goto ipv4_connected;
 159         }
 160
 161         if (addr_len < SIN6_LEN_RFC2133)
 162                 return -EINVAL;
 163
 164         if (usin->sin6_family != AF_INET6)
 165                 return -EAFNOSUPPORT;
 166
 167         if (np->sndflow)
 168                 fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 169
 170         if (ipv6_addr_any(&usin->sin6_addr)) {
 171                 /*
 172                  *      connect to self
 173                  */
 174                 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
 175                         ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
 176                                                &usin->sin6_addr);
 177                 else
 178                         usin->sin6_addr = in6addr_loopback;
 179         }
 180
 181         addr_type = ipv6_addr_type(&usin->sin6_addr);
 182
 183         daddr = &usin->sin6_addr;
 184
 185         if (addr_type & IPV6_ADDR_MAPPED) {
 186                 struct sockaddr_in sin;
 187
 188                 if (__ipv6_only_sock(sk)) {
 189                         err = -ENETUNREACH;
 190                         goto out;
 191                 }
 192                 sin.sin_family = AF_INET;
 193                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
 194                 sin.sin_port = usin->sin6_port;
 195
 196                 err = __ip4_datagram_connect(sk,
 197                                              (struct sockaddr *) &sin,
 198                                              sizeof(sin));
 199
 200 ipv4_connected:
 201                 if (err)
 202                         goto out;
 203
 204                 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 205
 206                 if (ipv6_addr_any(&np->saddr) ||
 207                     ipv6_mapped_addr_any(&np->saddr))
 208                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 209
 210                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 211                     ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 212                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 213                                                &sk->sk_v6_rcv_saddr);
 214                         if (sk->sk_prot->rehash)
 215                                 sk->sk_prot->rehash(sk);
 216                 }
 217
 218                 goto out;
 219         }
 220
 221         if (__ipv6_addr_needs_scope_id(addr_type)) {
 222                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 223                     usin->sin6_scope_id) {
 224                         if (sk->sk_bound_dev_if &&
 225                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 226                                 err = -EINVAL;
 227                                 goto out;
 228                         }
 229                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 230                 }
 231
 232                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 233                         sk->sk_bound_dev_if = np->mcast_oif;
 234
 235                 /* Connect to link-local address requires an interface */
 236                 if (!sk->sk_bound_dev_if) {
 237                         err = -EINVAL;
 238                         goto out;
 239                 }
 240         }
 241
 242         sk->sk_v6_daddr = *daddr;
 243         np->flow_label = fl6_flowlabel;
 244
 245         inet->inet_dport = usin->sin6_port;
 246
 247         /*
 248          *      Check for a route to destination an obtain the
 249          *      destination cache for it.
 250          */
 251
 252         err = ip6_datagram_dst_update(sk, true);
 253         if (err)
 254                 goto out;
 255
 256         sk->sk_state = TCP_ESTABLISHED;
 257         sk_set_txhash(sk);
 258 out:
 259         return err;
 260 }
 261 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 262
 263 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 264 {
 265         int res;
 266
 267         lock_sock(sk);
 268         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 269         release_sock(sk);
 270         return res;
 271 }
 272 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 273
 274 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 275                                  int addr_len)
 276 {
 277         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 278         if (sin6->sin6_family != AF_INET6)
 279                 return -EAFNOSUPPORT;
 280         return ip6_datagram_connect(sk, uaddr, addr_len);
 281 }
 282 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 283
 284 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 285                      __be16 port, u32 info, u8 *payload)
 286 {
 287         struct ipv6_pinfo *np  = inet6_sk(sk);
 288         struct icmp6hdr *icmph = icmp6_hdr(skb);
 289         struct sock_exterr_skb *serr;
 290
 291         if (!np->recverr)
 292                 return;
 293
 294         skb = skb_clone(skb, GFP_ATOMIC);
 295         if (!skb)
 296                 return;
 297
 298         skb->protocol = htons(ETH_P_IPV6);
 299
 300         serr = SKB_EXT_ERR(skb);
 301         serr->ee.ee_errno = err;
 302         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 303         serr->ee.ee_type = icmph->icmp6_type;
 304         serr->ee.ee_code = icmph->icmp6_code;
 305         serr->ee.ee_pad = 0;
 306         serr->ee.ee_info = info;
 307         serr->ee.ee_data = 0;
 308         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 309                                   skb_network_header(skb);
 310         serr->port = port;
 311
 312         __skb_pull(skb, payload - skb->data);
 313         skb_reset_transport_header(skb);
 314
 315         if (sock_queue_err_skb(sk, skb))
 316                 kfree_skb(skb);
 317 }
 318
 319 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 320 {
 321         const struct ipv6_pinfo *np = inet6_sk(sk);
 322         struct sock_exterr_skb *serr;
 323         struct ipv6hdr *iph;
 324         struct sk_buff *skb;
 325
 326         if (!np->recverr)
 327                 return;
 328
 329         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 330         if (!skb)
 331                 return;
 332
 333         skb->protocol = htons(ETH_P_IPV6);
 334
 335         skb_put(skb, sizeof(struct ipv6hdr));
 336         skb_reset_network_header(skb);
 337         iph = ipv6_hdr(skb);
 338         iph->daddr = fl6->daddr;
 339
 340         serr = SKB_EXT_ERR(skb);
 341         serr->ee.ee_errno = err;
 342         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 343         serr->ee.ee_type = 0;
 344         serr->ee.ee_code = 0;
 345         serr->ee.ee_pad = 0;
 346         serr->ee.ee_info = info;
 347         serr->ee.ee_data = 0;
 348         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 349         serr->port = fl6->fl6_dport;
 350
 351         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 352         skb_reset_transport_header(skb);
 353
 354         if (sock_queue_err_skb(sk, skb))
 355                 kfree_skb(skb);
 356 }
 357
 358 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 359 {
 360         struct ipv6_pinfo *np = inet6_sk(sk);
 361         struct ipv6hdr *iph;
 362         struct sk_buff *skb;
 363         struct ip6_mtuinfo *mtu_info;
 364
 365         if (!np->rxopt.bits.rxpmtu)
 366                 return;
 367
 368         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 369         if (!skb)
 370                 return;
 371
 372         skb_put(skb, sizeof(struct ipv6hdr));
 373         skb_reset_network_header(skb);
 374         iph = ipv6_hdr(skb);
 375         iph->daddr = fl6->daddr;
 376
 377         mtu_info = IP6CBMTU(skb);
 378
 379         mtu_info->ip6m_mtu = mtu;
 380         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 381         mtu_info->ip6m_addr.sin6_port = 0;
 382         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 383         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 384         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 385
 386         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 387         skb_reset_transport_header(skb);
 388
 389         skb = xchg(&np->rxpmtu, skb);
 390         kfree_skb(skb);
 391 }
 392
 393 /* For some errors we have valid addr_offset even with zero payload and
 394  * zero port. Also, addr_offset should be supported if port is set.
 395  */
 396 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 397 {
 398         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 399                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 400                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 401 }
 402
 403 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 404  *
 405  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 406  * errors. This is no longer true, but the test remained, so the v6 stack,
 407  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 408  *
 409  * Timestamp code paths do not initialize the fields expected by cmsg:
 410  * the PKTINFO fields in skb->cb[]. Fill those in here.
 411  */
 412 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 413                                       struct sock_exterr_skb *serr)
 414 {
 415         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 416             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 417                 return true;
 418
 419         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 420                 return false;
 421
 422         if (!skb->dev)
 423                 return false;
 424
 425         if (skb->protocol == htons(ETH_P_IPV6))
 426                 IP6CB(skb)->iif = skb->dev->ifindex;
 427         else
 428                 PKTINFO_SKB_CB(skb)->ipi_ifindex = skb->dev->ifindex;
 429
 430         return true;
 431 }
 432
 433 /*
 434  *      Handle MSG_ERRQUEUE
 435  */
 436 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 437 {
 438         struct ipv6_pinfo *np = inet6_sk(sk);
 439         struct sock_exterr_skb *serr;
 440         struct sk_buff *skb;
 441         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 442         struct {
 443                 struct sock_extended_err ee;
 444                 struct sockaddr_in6      offender;
 445         } errhdr;
 446         int err;
 447         int copied;
 448
 449         err = -EAGAIN;
 450         skb = sock_dequeue_err_skb(sk);
 451         if (!skb)
 452                 goto out;
 453
 454         copied = skb->len;
 455         if (copied > len) {
 456                 msg->msg_flags |= MSG_TRUNC;
 457                 copied = len;
 458         }
 459         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 460         if (unlikely(err)) {
 461                 kfree_skb(skb);
 462                 return err;
 463         }
 464         sock_recv_timestamp(msg, sk, skb);
 465
 466         serr = SKB_EXT_ERR(skb);
 467
 468         if (sin && ipv6_datagram_support_addr(serr)) {
 469                 const unsigned char *nh = skb_network_header(skb);
 470                 sin->sin6_family = AF_INET6;
 471                 sin->sin6_flowinfo = 0;
 472                 sin->sin6_port = serr->port;
 473                 if (skb->protocol == htons(ETH_P_IPV6)) {
 474                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 475                                                                   struct ipv6hdr, daddr);
 476                         sin->sin6_addr = ip6h->daddr;
 477                         if (np->sndflow)
 478                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 479                         sin->sin6_scope_id =
 480                                 ipv6_iface_scope_id(&sin->sin6_addr,
 481                                                     IP6CB(skb)->iif);
 482                 } else {
 483                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 484                                                &sin->sin6_addr);
 485                         sin->sin6_scope_id = 0;
 486                 }
 487                 *addr_len = sizeof(*sin);
 488         }
 489
 490         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 491         sin = &errhdr.offender;
 492         memset(sin, 0, sizeof(*sin));
 493
 494         if (ip6_datagram_support_cmsg(skb, serr)) {
 495                 sin->sin6_family = AF_INET6;
 496                 if (np->rxopt.all)
 497                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 498                 if (skb->protocol == htons(ETH_P_IPV6)) {
 499                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 500                         if (np->rxopt.all)
 501                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 502                         sin->sin6_scope_id =
 503                                 ipv6_iface_scope_id(&sin->sin6_addr,
 504                                                     IP6CB(skb)->iif);
 505                 } else {
 506                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 507                                                &sin->sin6_addr);
 508                         if (inet_sk(sk)->cmsg_flags)
 509                                 ip_cmsg_recv(msg, skb);
 510                 }
 511         }
 512
 513         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 514
 515         /* Now we could try to dump offended packet options */
 516
 517         msg->msg_flags |= MSG_ERRQUEUE;
 518         err = copied;
 519
 520         consume_skb(skb);
 521 out:
 522         return err;
 523 }
 524 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 525
 526 /*
 527  *      Handle IPV6_RECVPATHMTU
 528  */
 529 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 530                      int *addr_len)
 531 {
 532         struct ipv6_pinfo *np = inet6_sk(sk);
 533         struct sk_buff *skb;
 534         struct ip6_mtuinfo mtu_info;
 535         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 536         int err;
 537         int copied;
 538
 539         err = -EAGAIN;
 540         skb = xchg(&np->rxpmtu, NULL);
 541         if (!skb)
 542                 goto out;
 543
 544         copied = skb->len;
 545         if (copied > len) {
 546                 msg->msg_flags |= MSG_TRUNC;
 547                 copied = len;
 548         }
 549         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 550         if (err)
 551                 goto out_free_skb;
 552
 553         sock_recv_timestamp(msg, sk, skb);
 554
 555         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 556
 557         if (sin) {
 558                 sin->sin6_family = AF_INET6;
 559                 sin->sin6_flowinfo = 0;
 560                 sin->sin6_port = 0;
 561                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 562                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 563                 *addr_len = sizeof(*sin);
 564         }
 565
 566         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 567
 568         err = copied;
 569
 570 out_free_skb:
 571         kfree_skb(skb);
 572 out:
 573         return err;
 574 }
 575
 576
 577 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 578                                  struct sk_buff *skb)
 579 {
 580         struct ipv6_pinfo *np = inet6_sk(sk);
 581         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 582
 583         if (np->rxopt.bits.rxinfo) {
 584                 struct in6_pktinfo src_info;
 585
 586                 if (is_ipv6) {
 587                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 588                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 589                 } else {
 590                         src_info.ipi6_ifindex =
 591                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 592                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 593                                                &src_info.ipi6_addr);
 594                 }
 595
 596                 if (src_info.ipi6_ifindex >= 0)
 597                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 598                                  sizeof(src_info), &src_info);
 599         }
 600 }
 601
 602 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 603                                     struct sk_buff *skb)
 604 {
 605         struct ipv6_pinfo *np = inet6_sk(sk);
 606         struct inet6_skb_parm *opt = IP6CB(skb);
 607         unsigned char *nh = skb_network_header(skb);
 608
 609         if (np->rxopt.bits.rxhlim) {
 610                 int hlim = ipv6_hdr(skb)->hop_limit;
 611                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 612         }
 613
 614         if (np->rxopt.bits.rxtclass) {
 615                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 616                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 617         }
 618
 619         if (np->rxopt.bits.rxflow) {
 620                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 621                 if (flowinfo)
 622                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 623         }
 624
 625         /* HbH is allowed only once */
 626         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 627                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 628                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 629         }
 630
 631         if (opt->lastopt &&
 632             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 633                 /*
 634                  * Silly enough, but we need to reparse in order to
 635                  * report extension headers (except for HbH)
 636                  * in order.
 637                  *
 638                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 639                  * (and WILL NOT be) defined because
 640                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 641                  */
 642                 unsigned int off = sizeof(struct ipv6hdr);
 643                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 644
 645                 while (off <= opt->lastopt) {
 646                         unsigned int len;
 647                         u8 *ptr = nh + off;
 648
 649                         switch (nexthdr) {
 650                         case IPPROTO_DSTOPTS:
 651                                 nexthdr = ptr[0];
 652                                 len = (ptr[1] + 1) << 3;
 653                                 if (np->rxopt.bits.dstopts)
 654                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 655                                 break;
 656                         case IPPROTO_ROUTING:
 657                                 nexthdr = ptr[0];
 658                                 len = (ptr[1] + 1) << 3;
 659                                 if (np->rxopt.bits.srcrt)
 660                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 661                                 break;
 662                         case IPPROTO_AH:
 663                                 nexthdr = ptr[0];
 664                                 len = (ptr[1] + 2) << 2;
 665                                 break;
 666                         default:
 667                                 nexthdr = ptr[0];
 668                                 len = (ptr[1] + 1) << 3;
 669                                 break;
 670                         }
 671
 672                         off += len;
 673                 }
 674         }
 675
 676         /* socket options in old style */
 677         if (np->rxopt.bits.rxoinfo) {
 678                 struct in6_pktinfo src_info;
 679
 680                 src_info.ipi6_ifindex = opt->iif;
 681                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 682                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 683         }
 684         if (np->rxopt.bits.rxohlim) {
 685                 int hlim = ipv6_hdr(skb)->hop_limit;
 686                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 687         }
 688         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 689                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 690                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 691         }
 692         if (np->rxopt.bits.odstopts && opt->dst0) {
 693                 u8 *ptr = nh + opt->dst0;
 694                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 695         }
 696         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 697                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 698                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 699         }
 700         if (np->rxopt.bits.odstopts && opt->dst1) {
 701                 u8 *ptr = nh + opt->dst1;
 702                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 703         }
 704         if (np->rxopt.bits.rxorigdstaddr) {
 705                 struct sockaddr_in6 sin6;
 706                 __be16 *ports = (__be16 *) skb_transport_header(skb);
 707
 708                 if (skb_transport_offset(skb) + 4 <= (int)skb->len) {
 709                         /* All current transport protocols have the port numbers in the
 710                          * first four bytes of the transport header and this function is
 711                          * written with this assumption in mind.
 712                          */
 713
 714                         sin6.sin6_family = AF_INET6;
 715                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 716                         sin6.sin6_port = ports[1];
 717                         sin6.sin6_flowinfo = 0;
 718                         sin6.sin6_scope_id =
 719                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 720                                                     opt->iif);
 721
 722                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 723                 }
 724         }
 725         if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
 726                 int val = opt->frag_max_size;
 727
 728                 put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
 729         }
 730 }
 731
 732 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 733                           struct sk_buff *skb)
 734 {
 735         ip6_datagram_recv_common_ctl(sk, msg, skb);
 736         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 737 }
 738 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 739
 740 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 741                           struct msghdr *msg, struct flowi6 *fl6,
 742                           struct ipcm6_cookie *ipc6, struct sockcm_cookie *sockc)
 743 {
 744         struct in6_pktinfo *src_info;
 745         struct cmsghdr *cmsg;
 746         struct ipv6_rt_hdr *rthdr;
 747         struct ipv6_opt_hdr *hdr;
 748         struct ipv6_txoptions *opt = ipc6->opt;
 749         int len;
 750         int err = 0;
 751
 752         for_each_cmsghdr(cmsg, msg) {
 753                 int addr_type;
 754
 755                 if (!CMSG_OK(msg, cmsg)) {
 756                         err = -EINVAL;
 757                         goto exit_f;
 758                 }
 759
 760                 if (cmsg->cmsg_level == SOL_SOCKET) {
 761                         err = __sock_cmsg_send(sk, msg, cmsg, sockc);
 762                         if (err)
 763                                 return err;
 764                         continue;
 765                 }
 766
 767                 if (cmsg->cmsg_level != SOL_IPV6)
 768                         continue;
 769
 770                 switch (cmsg->cmsg_type) {
 771                 case IPV6_PKTINFO:
 772                 case IPV6_2292PKTINFO:
 773                     {
 774                         struct net_device *dev = NULL;
 775
 776                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 777                                 err = -EINVAL;
 778                                 goto exit_f;
 779                         }
 780
 781                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 782
 783                         if (src_info->ipi6_ifindex) {
 784                                 if (fl6->flowi6_oif &&
 785                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 786                                         return -EINVAL;
 787                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 788                         }
 789
 790                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 791
 792                         rcu_read_lock();
 793                         if (fl6->flowi6_oif) {
 794                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 795                                 if (!dev) {
 796                                         rcu_read_unlock();
 797                                         return -ENODEV;
 798                                 }
 799                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 800                                 rcu_read_unlock();
 801                                 return -EINVAL;
 802                         }
 803
 804                         if (addr_type != IPV6_ADDR_ANY) {
 805                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 806                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 807                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 808                                                    strict ? dev : NULL, 0) &&
 809                                     !ipv6_chk_acast_addr_src(net, dev,
 810                                                              &src_info->ipi6_addr))
 811                                         err = -EINVAL;
 812                                 else
 813                                         fl6->saddr = src_info->ipi6_addr;
 814                         }
 815
 816                         rcu_read_unlock();
 817
 818                         if (err)
 819                                 goto exit_f;
 820
 821                         break;
 822                     }
 823
 824                 case IPV6_FLOWINFO:
 825                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 826                                 err = -EINVAL;
 827                                 goto exit_f;
 828                         }
 829
 830                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 831                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 832                                         err = -EINVAL;
 833                                         goto exit_f;
 834                                 }
 835                         }
 836                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 837                         break;
 838
 839                 case IPV6_2292HOPOPTS:
 840                 case IPV6_HOPOPTS:
 841                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 842                                 err = -EINVAL;
 843                                 goto exit_f;
 844                         }
 845
 846                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 847                         len = ((hdr->hdrlen + 1) << 3);
 848                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 849                                 err = -EINVAL;
 850                                 goto exit_f;
 851                         }
 852                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 853                                 err = -EPERM;
 854                                 goto exit_f;
 855                         }
 856                         opt->opt_nflen += len;
 857                         opt->hopopt = hdr;
 858                         break;
 859
 860                 case IPV6_2292DSTOPTS:
 861                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 862                                 err = -EINVAL;
 863                                 goto exit_f;
 864                         }
 865
 866                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 867                         len = ((hdr->hdrlen + 1) << 3);
 868                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 869                                 err = -EINVAL;
 870                                 goto exit_f;
 871                         }
 872                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 873                                 err = -EPERM;
 874                                 goto exit_f;
 875                         }
 876                         if (opt->dst1opt) {
 877                                 err = -EINVAL;
 878                                 goto exit_f;
 879                         }
 880                         opt->opt_flen += len;
 881                         opt->dst1opt = hdr;
 882                         break;
 883
 884                 case IPV6_DSTOPTS:
 885                 case IPV6_RTHDRDSTOPTS:
 886                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 887                                 err = -EINVAL;
 888                                 goto exit_f;
 889                         }
 890
 891                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 892                         len = ((hdr->hdrlen + 1) << 3);
 893                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 894                                 err = -EINVAL;
 895                                 goto exit_f;
 896                         }
 897                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 898                                 err = -EPERM;
 899                                 goto exit_f;
 900                         }
 901                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 902                                 opt->opt_flen += len;
 903                                 opt->dst1opt = hdr;
 904                         } else {
 905                                 opt->opt_nflen += len;
 906                                 opt->dst0opt = hdr;
 907                         }
 908                         break;
 909
 910                 case IPV6_2292RTHDR:
 911                 case IPV6_RTHDR:
 912                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 913                                 err = -EINVAL;
 914                                 goto exit_f;
 915                         }
 916
 917                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 918
 919                         switch (rthdr->type) {
 920 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 921                         case IPV6_SRCRT_TYPE_2:
 922                                 if (rthdr->hdrlen != 2 ||
 923                                     rthdr->segments_left != 1) {
 924                                         err = -EINVAL;
 925                                         goto exit_f;
 926                                 }
 927                                 break;
 928 #endif
 929                         default:
 930                                 err = -EINVAL;
 931                                 goto exit_f;
 932                         }
 933
 934                         len = ((rthdr->hdrlen + 1) << 3);
 935
 936                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 937                                 err = -EINVAL;
 938                                 goto exit_f;
 939                         }
 940
 941                         /* segments left must also match */
 942                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 943                                 err = -EINVAL;
 944                                 goto exit_f;
 945                         }
 946
 947                         opt->opt_nflen += len;
 948                         opt->srcrt = rthdr;
 949
 950                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 951                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 952
 953                                 opt->opt_nflen += dsthdrlen;
 954                                 opt->dst0opt = opt->dst1opt;
 955                                 opt->dst1opt = NULL;
 956                                 opt->opt_flen -= dsthdrlen;
 957                         }
 958
 959                         break;
 960
 961                 case IPV6_2292HOPLIMIT:
 962                 case IPV6_HOPLIMIT:
 963                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 964                                 err = -EINVAL;
 965                                 goto exit_f;
 966                         }
 967
 968                         ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 969                         if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 970                                 err = -EINVAL;
 971                                 goto exit_f;
 972                         }
 973
 974                         break;
 975
 976                 case IPV6_TCLASS:
 977                     {
 978                         int tc;
 979
 980                         err = -EINVAL;
 981                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 982                                 goto exit_f;
 983
 984                         tc = *(int *)CMSG_DATA(cmsg);
 985                         if (tc < -1 || tc > 0xff)
 986                                 goto exit_f;
 987
 988                         err = 0;
 989                         ipc6->tclass = tc;
 990
 991                         break;
 992                     }
 993
 994                 case IPV6_DONTFRAG:
 995                     {
 996                         int df;
 997
 998                         err = -EINVAL;
 999                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1000                                 goto exit_f;
1001
1002                         df = *(int *)CMSG_DATA(cmsg);
1003                         if (df < 0 || df > 1)
1004                                 goto exit_f;
1005
1006                         err = 0;
1007                         ipc6->dontfrag = df;
1008
1009                         break;
1010                     }
1011                 default:
1012                         net_dbg_ratelimited("invalid cmsg type: %d\n",
1013                                             cmsg->cmsg_type);
1014                         err = -EINVAL;
1015                         goto exit_f;
1016                 }
1017         }
1018
1019 exit_f:
1020         return err;
1021 }
1022 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1023
1024 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1025                              __u16 srcp, __u16 destp, int bucket)
1026 {
1027         const struct in6_addr *dest, *src;
1028
1029         dest  = &sp->sk_v6_daddr;
1030         src   = &sp->sk_v6_rcv_saddr;
1031         seq_printf(seq,
1032                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1033                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
1034                    bucket,
1035                    src->s6_addr32[0], src->s6_addr32[1],
1036                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1037                    dest->s6_addr32[0], dest->s6_addr32[1],
1038                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1039                    sp->sk_state,
1040                    sk_wmem_alloc_get(sp),
1041                    sk_rmem_alloc_get(sp),
1042                    0, 0L, 0,
1043                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1044                    0,
1045                    sock_i_ino(sp),
1046                    atomic_read(&sp->sk_refcnt), sp,
1047                    atomic_read(&sp->sk_drops));
1048 }