net/ipv6/datagram.c

   1 /*
   2  *      common UDP/RAW code
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <[email protected]>
   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         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 static int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, 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;
 149         int                     addr_type;
 150         int                     err;
 151         __be32                  fl6_flowlabel = 0;
 152
 153         if (usin->sin6_family == AF_INET) {
 154                 if (__ipv6_only_sock(sk))
 155                         return -EAFNOSUPPORT;
 156                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
 157                 goto ipv4_connected;
 158         }
 159
 160         if (addr_len < SIN6_LEN_RFC2133)
 161                 return -EINVAL;
 162
 163         if (usin->sin6_family != AF_INET6)
 164                 return -EAFNOSUPPORT;
 165
 166         if (np->sndflow)
 167                 fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 168
 169         addr_type = ipv6_addr_type(&usin->sin6_addr);
 170
 171         if (addr_type == IPV6_ADDR_ANY) {
 172                 /*
 173                  *      connect to self
 174                  */
 175                 usin->sin6_addr.s6_addr[15] = 0x01;
 176         }
 177
 178         daddr = &usin->sin6_addr;
 179
 180         if (addr_type == IPV6_ADDR_MAPPED) {
 181                 struct sockaddr_in sin;
 182
 183                 if (__ipv6_only_sock(sk)) {
 184                         err = -ENETUNREACH;
 185                         goto out;
 186                 }
 187                 sin.sin_family = AF_INET;
 188                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
 189                 sin.sin_port = usin->sin6_port;
 190
 191                 err = __ip4_datagram_connect(sk,
 192                                              (struct sockaddr *) &sin,
 193                                              sizeof(sin));
 194
 195 ipv4_connected:
 196                 if (err)
 197                         goto out;
 198
 199                 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 200
 201                 if (ipv6_addr_any(&np->saddr) ||
 202                     ipv6_mapped_addr_any(&np->saddr))
 203                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 204
 205                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 206                     ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 207                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 208                                                &sk->sk_v6_rcv_saddr);
 209                         if (sk->sk_prot->rehash)
 210                                 sk->sk_prot->rehash(sk);
 211                 }
 212
 213                 goto out;
 214         }
 215
 216         if (__ipv6_addr_needs_scope_id(addr_type)) {
 217                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 218                     usin->sin6_scope_id) {
 219                         if (sk->sk_bound_dev_if &&
 220                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 221                                 err = -EINVAL;
 222                                 goto out;
 223                         }
 224                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 225                 }
 226
 227                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 228                         sk->sk_bound_dev_if = np->mcast_oif;
 229
 230                 /* Connect to link-local address requires an interface */
 231                 if (!sk->sk_bound_dev_if) {
 232                         err = -EINVAL;
 233                         goto out;
 234                 }
 235         }
 236
 237         sk->sk_v6_daddr = *daddr;
 238         np->flow_label = fl6_flowlabel;
 239
 240         inet->inet_dport = usin->sin6_port;
 241
 242         /*
 243          *      Check for a route to destination an obtain the
 244          *      destination cache for it.
 245          */
 246
 247         err = ip6_datagram_dst_update(sk, true);
 248         if (err)
 249                 goto out;
 250
 251         sk->sk_state = TCP_ESTABLISHED;
 252         sk_set_txhash(sk);
 253 out:
 254         return err;
 255 }
 256
 257 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 258 {
 259         int res;
 260
 261         lock_sock(sk);
 262         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 263         release_sock(sk);
 264         return res;
 265 }
 266 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 267
 268 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 269                                  int addr_len)
 270 {
 271         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 272         if (sin6->sin6_family != AF_INET6)
 273                 return -EAFNOSUPPORT;
 274         return ip6_datagram_connect(sk, uaddr, addr_len);
 275 }
 276 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 277
 278 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 279                      __be16 port, u32 info, u8 *payload)
 280 {
 281         struct ipv6_pinfo *np  = inet6_sk(sk);
 282         struct icmp6hdr *icmph = icmp6_hdr(skb);
 283         struct sock_exterr_skb *serr;
 284
 285         if (!np->recverr)
 286                 return;
 287
 288         skb = skb_clone(skb, GFP_ATOMIC);
 289         if (!skb)
 290                 return;
 291
 292         skb->protocol = htons(ETH_P_IPV6);
 293
 294         serr = SKB_EXT_ERR(skb);
 295         serr->ee.ee_errno = err;
 296         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 297         serr->ee.ee_type = icmph->icmp6_type;
 298         serr->ee.ee_code = icmph->icmp6_code;
 299         serr->ee.ee_pad = 0;
 300         serr->ee.ee_info = info;
 301         serr->ee.ee_data = 0;
 302         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 303                                   skb_network_header(skb);
 304         serr->port = port;
 305
 306         __skb_pull(skb, payload - skb->data);
 307         skb_reset_transport_header(skb);
 308
 309         if (sock_queue_err_skb(sk, skb))
 310                 kfree_skb(skb);
 311 }
 312
 313 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 314 {
 315         const struct ipv6_pinfo *np = inet6_sk(sk);
 316         struct sock_exterr_skb *serr;
 317         struct ipv6hdr *iph;
 318         struct sk_buff *skb;
 319
 320         if (!np->recverr)
 321                 return;
 322
 323         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 324         if (!skb)
 325                 return;
 326
 327         skb->protocol = htons(ETH_P_IPV6);
 328
 329         skb_put(skb, sizeof(struct ipv6hdr));
 330         skb_reset_network_header(skb);
 331         iph = ipv6_hdr(skb);
 332         iph->daddr = fl6->daddr;
 333
 334         serr = SKB_EXT_ERR(skb);
 335         serr->ee.ee_errno = err;
 336         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 337         serr->ee.ee_type = 0;
 338         serr->ee.ee_code = 0;
 339         serr->ee.ee_pad = 0;
 340         serr->ee.ee_info = info;
 341         serr->ee.ee_data = 0;
 342         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 343         serr->port = fl6->fl6_dport;
 344
 345         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 346         skb_reset_transport_header(skb);
 347
 348         if (sock_queue_err_skb(sk, skb))
 349                 kfree_skb(skb);
 350 }
 351
 352 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 353 {
 354         struct ipv6_pinfo *np = inet6_sk(sk);
 355         struct ipv6hdr *iph;
 356         struct sk_buff *skb;
 357         struct ip6_mtuinfo *mtu_info;
 358
 359         if (!np->rxopt.bits.rxpmtu)
 360                 return;
 361
 362         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 363         if (!skb)
 364                 return;
 365
 366         skb_put(skb, sizeof(struct ipv6hdr));
 367         skb_reset_network_header(skb);
 368         iph = ipv6_hdr(skb);
 369         iph->daddr = fl6->daddr;
 370
 371         mtu_info = IP6CBMTU(skb);
 372
 373         mtu_info->ip6m_mtu = mtu;
 374         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 375         mtu_info->ip6m_addr.sin6_port = 0;
 376         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 377         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 378         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 379
 380         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 381         skb_reset_transport_header(skb);
 382
 383         skb = xchg(&np->rxpmtu, skb);
 384         kfree_skb(skb);
 385 }
 386
 387 /* For some errors we have valid addr_offset even with zero payload and
 388  * zero port. Also, addr_offset should be supported if port is set.
 389  */
 390 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 391 {
 392         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 393                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 394                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 395 }
 396
 397 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 398  *
 399  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 400  * errors. This is no longer true, but the test remained, so the v6 stack,
 401  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 402  *
 403  * Timestamp code paths do not initialize the fields expected by cmsg:
 404  * the PKTINFO fields in skb->cb[]. Fill those in here.
 405  */
 406 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 407                                       struct sock_exterr_skb *serr)
 408 {
 409         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 410             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 411                 return true;
 412
 413         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 414                 return false;
 415
 416         if (!skb->dev)
 417                 return false;
 418
 419         if (skb->protocol == htons(ETH_P_IPV6))
 420                 IP6CB(skb)->iif = skb->dev->ifindex;
 421         else
 422                 PKTINFO_SKB_CB(skb)->ipi_ifindex = skb->dev->ifindex;
 423
 424         return true;
 425 }
 426
 427 /*
 428  *      Handle MSG_ERRQUEUE
 429  */
 430 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 431 {
 432         struct ipv6_pinfo *np = inet6_sk(sk);
 433         struct sock_exterr_skb *serr;
 434         struct sk_buff *skb;
 435         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 436         struct {
 437                 struct sock_extended_err ee;
 438                 struct sockaddr_in6      offender;
 439         } errhdr;
 440         int err;
 441         int copied;
 442
 443         err = -EAGAIN;
 444         skb = sock_dequeue_err_skb(sk);
 445         if (!skb)
 446                 goto out;
 447
 448         copied = skb->len;
 449         if (copied > len) {
 450                 msg->msg_flags |= MSG_TRUNC;
 451                 copied = len;
 452         }
 453         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 454         if (unlikely(err)) {
 455                 kfree_skb(skb);
 456                 return err;
 457         }
 458         sock_recv_timestamp(msg, sk, skb);
 459
 460         serr = SKB_EXT_ERR(skb);
 461
 462         if (sin && ipv6_datagram_support_addr(serr)) {
 463                 const unsigned char *nh = skb_network_header(skb);
 464                 sin->sin6_family = AF_INET6;
 465                 sin->sin6_flowinfo = 0;
 466                 sin->sin6_port = serr->port;
 467                 if (skb->protocol == htons(ETH_P_IPV6)) {
 468                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 469                                                                   struct ipv6hdr, daddr);
 470                         sin->sin6_addr = ip6h->daddr;
 471                         if (np->sndflow)
 472                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 473                         sin->sin6_scope_id =
 474                                 ipv6_iface_scope_id(&sin->sin6_addr,
 475                                                     IP6CB(skb)->iif);
 476                 } else {
 477                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 478                                                &sin->sin6_addr);
 479                         sin->sin6_scope_id = 0;
 480                 }
 481                 *addr_len = sizeof(*sin);
 482         }
 483
 484         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 485         sin = &errhdr.offender;
 486         memset(sin, 0, sizeof(*sin));
 487
 488         if (ip6_datagram_support_cmsg(skb, serr)) {
 489                 sin->sin6_family = AF_INET6;
 490                 if (np->rxopt.all)
 491                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 492                 if (skb->protocol == htons(ETH_P_IPV6)) {
 493                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 494                         if (np->rxopt.all)
 495                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 496                         sin->sin6_scope_id =
 497                                 ipv6_iface_scope_id(&sin->sin6_addr,
 498                                                     IP6CB(skb)->iif);
 499                 } else {
 500                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 501                                                &sin->sin6_addr);
 502                         if (inet_sk(sk)->cmsg_flags)
 503                                 ip_cmsg_recv(msg, skb);
 504                 }
 505         }
 506
 507         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 508
 509         /* Now we could try to dump offended packet options */
 510
 511         msg->msg_flags |= MSG_ERRQUEUE;
 512         err = copied;
 513
 514         consume_skb(skb);
 515 out:
 516         return err;
 517 }
 518 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 519
 520 /*
 521  *      Handle IPV6_RECVPATHMTU
 522  */
 523 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 524                      int *addr_len)
 525 {
 526         struct ipv6_pinfo *np = inet6_sk(sk);
 527         struct sk_buff *skb;
 528         struct ip6_mtuinfo mtu_info;
 529         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 530         int err;
 531         int copied;
 532
 533         err = -EAGAIN;
 534         skb = xchg(&np->rxpmtu, NULL);
 535         if (!skb)
 536                 goto out;
 537
 538         copied = skb->len;
 539         if (copied > len) {
 540                 msg->msg_flags |= MSG_TRUNC;
 541                 copied = len;
 542         }
 543         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 544         if (err)
 545                 goto out_free_skb;
 546
 547         sock_recv_timestamp(msg, sk, skb);
 548
 549         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 550
 551         if (sin) {
 552                 sin->sin6_family = AF_INET6;
 553                 sin->sin6_flowinfo = 0;
 554                 sin->sin6_port = 0;
 555                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 556                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 557                 *addr_len = sizeof(*sin);
 558         }
 559
 560         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 561
 562         err = copied;
 563
 564 out_free_skb:
 565         kfree_skb(skb);
 566 out:
 567         return err;
 568 }
 569
 570
 571 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 572                                  struct sk_buff *skb)
 573 {
 574         struct ipv6_pinfo *np = inet6_sk(sk);
 575         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 576
 577         if (np->rxopt.bits.rxinfo) {
 578                 struct in6_pktinfo src_info;
 579
 580                 if (is_ipv6) {
 581                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 582                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 583                 } else {
 584                         src_info.ipi6_ifindex =
 585                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 586                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 587                                                &src_info.ipi6_addr);
 588                 }
 589
 590                 if (src_info.ipi6_ifindex >= 0)
 591                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 592                                  sizeof(src_info), &src_info);
 593         }
 594 }
 595
 596 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 597                                     struct sk_buff *skb)
 598 {
 599         struct ipv6_pinfo *np = inet6_sk(sk);
 600         struct inet6_skb_parm *opt = IP6CB(skb);
 601         unsigned char *nh = skb_network_header(skb);
 602
 603         if (np->rxopt.bits.rxhlim) {
 604                 int hlim = ipv6_hdr(skb)->hop_limit;
 605                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 606         }
 607
 608         if (np->rxopt.bits.rxtclass) {
 609                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 610                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 611         }
 612
 613         if (np->rxopt.bits.rxflow) {
 614                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 615                 if (flowinfo)
 616                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 617         }
 618
 619         /* HbH is allowed only once */
 620         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 621                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 622                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 623         }
 624
 625         if (opt->lastopt &&
 626             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 627                 /*
 628                  * Silly enough, but we need to reparse in order to
 629                  * report extension headers (except for HbH)
 630                  * in order.
 631                  *
 632                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 633                  * (and WILL NOT be) defined because
 634                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 635                  */
 636                 unsigned int off = sizeof(struct ipv6hdr);
 637                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 638
 639                 while (off <= opt->lastopt) {
 640                         unsigned int len;
 641                         u8 *ptr = nh + off;
 642
 643                         switch (nexthdr) {
 644                         case IPPROTO_DSTOPTS:
 645                                 nexthdr = ptr[0];
 646                                 len = (ptr[1] + 1) << 3;
 647                                 if (np->rxopt.bits.dstopts)
 648                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 649                                 break;
 650                         case IPPROTO_ROUTING:
 651                                 nexthdr = ptr[0];
 652                                 len = (ptr[1] + 1) << 3;
 653                                 if (np->rxopt.bits.srcrt)
 654                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 655                                 break;
 656                         case IPPROTO_AH:
 657                                 nexthdr = ptr[0];
 658                                 len = (ptr[1] + 2) << 2;
 659                                 break;
 660                         default:
 661                                 nexthdr = ptr[0];
 662                                 len = (ptr[1] + 1) << 3;
 663                                 break;
 664                         }
 665
 666                         off += len;
 667                 }
 668         }
 669
 670         /* socket options in old style */
 671         if (np->rxopt.bits.rxoinfo) {
 672                 struct in6_pktinfo src_info;
 673
 674                 src_info.ipi6_ifindex = opt->iif;
 675                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 676                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 677         }
 678         if (np->rxopt.bits.rxohlim) {
 679                 int hlim = ipv6_hdr(skb)->hop_limit;
 680                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 681         }
 682         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 683                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 684                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 685         }
 686         if (np->rxopt.bits.odstopts && opt->dst0) {
 687                 u8 *ptr = nh + opt->dst0;
 688                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 689         }
 690         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 691                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 692                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 693         }
 694         if (np->rxopt.bits.odstopts && opt->dst1) {
 695                 u8 *ptr = nh + opt->dst1;
 696                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 697         }
 698         if (np->rxopt.bits.rxorigdstaddr) {
 699                 struct sockaddr_in6 sin6;
 700                 __be16 *ports = (__be16 *) skb_transport_header(skb);
 701
 702                 if (skb_transport_offset(skb) + 4 <= skb->len) {
 703                         /* All current transport protocols have the port numbers in the
 704                          * first four bytes of the transport header and this function is
 705                          * written with this assumption in mind.
 706                          */
 707
 708                         sin6.sin6_family = AF_INET6;
 709                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 710                         sin6.sin6_port = ports[1];
 711                         sin6.sin6_flowinfo = 0;
 712                         sin6.sin6_scope_id =
 713                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 714                                                     opt->iif);
 715
 716                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 717                 }
 718         }
 719         if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
 720                 int val = opt->frag_max_size;
 721
 722                 put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
 723         }
 724 }
 725
 726 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 727                           struct sk_buff *skb)
 728 {
 729         ip6_datagram_recv_common_ctl(sk, msg, skb);
 730         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 731 }
 732 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 733
 734 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 735                           struct msghdr *msg, struct flowi6 *fl6,
 736                           struct ipcm6_cookie *ipc6, struct sockcm_cookie *sockc)
 737 {
 738         struct in6_pktinfo *src_info;
 739         struct cmsghdr *cmsg;
 740         struct ipv6_rt_hdr *rthdr;
 741         struct ipv6_opt_hdr *hdr;
 742         struct ipv6_txoptions *opt = ipc6->opt;
 743         int len;
 744         int err = 0;
 745
 746         for_each_cmsghdr(cmsg, msg) {
 747                 int addr_type;
 748
 749                 if (!CMSG_OK(msg, cmsg)) {
 750                         err = -EINVAL;
 751                         goto exit_f;
 752                 }
 753
 754                 if (cmsg->cmsg_level == SOL_SOCKET) {
 755                         err = __sock_cmsg_send(sk, msg, cmsg, sockc);
 756                         if (err)
 757                                 return err;
 758                         continue;
 759                 }
 760
 761                 if (cmsg->cmsg_level != SOL_IPV6)
 762                         continue;
 763
 764                 switch (cmsg->cmsg_type) {
 765                 case IPV6_PKTINFO:
 766                 case IPV6_2292PKTINFO:
 767                     {
 768                         struct net_device *dev = NULL;
 769
 770                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 771                                 err = -EINVAL;
 772                                 goto exit_f;
 773                         }
 774
 775                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 776
 777                         if (src_info->ipi6_ifindex) {
 778                                 if (fl6->flowi6_oif &&
 779                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 780                                         return -EINVAL;
 781                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 782                         }
 783
 784                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 785
 786                         rcu_read_lock();
 787                         if (fl6->flowi6_oif) {
 788                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 789                                 if (!dev) {
 790                                         rcu_read_unlock();
 791                                         return -ENODEV;
 792                                 }
 793                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 794                                 rcu_read_unlock();
 795                                 return -EINVAL;
 796                         }
 797
 798                         if (addr_type != IPV6_ADDR_ANY) {
 799                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 800                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 801                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 802                                                    strict ? dev : NULL, 0) &&
 803                                     !ipv6_chk_acast_addr_src(net, dev,
 804                                                              &src_info->ipi6_addr))
 805                                         err = -EINVAL;
 806                                 else
 807                                         fl6->saddr = src_info->ipi6_addr;
 808                         }
 809
 810                         rcu_read_unlock();
 811
 812                         if (err)
 813                                 goto exit_f;
 814
 815                         break;
 816                     }
 817
 818                 case IPV6_FLOWINFO:
 819                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 820                                 err = -EINVAL;
 821                                 goto exit_f;
 822                         }
 823
 824                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 825                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 826                                         err = -EINVAL;
 827                                         goto exit_f;
 828                                 }
 829                         }
 830                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 831                         break;
 832
 833                 case IPV6_2292HOPOPTS:
 834                 case IPV6_HOPOPTS:
 835                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 836                                 err = -EINVAL;
 837                                 goto exit_f;
 838                         }
 839
 840                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 841                         len = ((hdr->hdrlen + 1) << 3);
 842                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 843                                 err = -EINVAL;
 844                                 goto exit_f;
 845                         }
 846                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 847                                 err = -EPERM;
 848                                 goto exit_f;
 849                         }
 850                         opt->opt_nflen += len;
 851                         opt->hopopt = hdr;
 852                         break;
 853
 854                 case IPV6_2292DSTOPTS:
 855                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 856                                 err = -EINVAL;
 857                                 goto exit_f;
 858                         }
 859
 860                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 861                         len = ((hdr->hdrlen + 1) << 3);
 862                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 863                                 err = -EINVAL;
 864                                 goto exit_f;
 865                         }
 866                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 867                                 err = -EPERM;
 868                                 goto exit_f;
 869                         }
 870                         if (opt->dst1opt) {
 871                                 err = -EINVAL;
 872                                 goto exit_f;
 873                         }
 874                         opt->opt_flen += len;
 875                         opt->dst1opt = hdr;
 876                         break;
 877
 878                 case IPV6_DSTOPTS:
 879                 case IPV6_RTHDRDSTOPTS:
 880                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 881                                 err = -EINVAL;
 882                                 goto exit_f;
 883                         }
 884
 885                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 886                         len = ((hdr->hdrlen + 1) << 3);
 887                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 888                                 err = -EINVAL;
 889                                 goto exit_f;
 890                         }
 891                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 892                                 err = -EPERM;
 893                                 goto exit_f;
 894                         }
 895                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 896                                 opt->opt_flen += len;
 897                                 opt->dst1opt = hdr;
 898                         } else {
 899                                 opt->opt_nflen += len;
 900                                 opt->dst0opt = hdr;
 901                         }
 902                         break;
 903
 904                 case IPV6_2292RTHDR:
 905                 case IPV6_RTHDR:
 906                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 907                                 err = -EINVAL;
 908                                 goto exit_f;
 909                         }
 910
 911                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 912
 913                         switch (rthdr->type) {
 914 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 915                         case IPV6_SRCRT_TYPE_2:
 916                                 if (rthdr->hdrlen != 2 ||
 917                                     rthdr->segments_left != 1) {
 918                                         err = -EINVAL;
 919                                         goto exit_f;
 920                                 }
 921                                 break;
 922 #endif
 923                         default:
 924                                 err = -EINVAL;
 925                                 goto exit_f;
 926                         }
 927
 928                         len = ((rthdr->hdrlen + 1) << 3);
 929
 930                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 931                                 err = -EINVAL;
 932                                 goto exit_f;
 933                         }
 934
 935                         /* segments left must also match */
 936                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 937                                 err = -EINVAL;
 938                                 goto exit_f;
 939                         }
 940
 941                         opt->opt_nflen += len;
 942                         opt->srcrt = rthdr;
 943
 944                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 945                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 946
 947                                 opt->opt_nflen += dsthdrlen;
 948                                 opt->dst0opt = opt->dst1opt;
 949                                 opt->dst1opt = NULL;
 950                                 opt->opt_flen -= dsthdrlen;
 951                         }
 952
 953                         break;
 954
 955                 case IPV6_2292HOPLIMIT:
 956                 case IPV6_HOPLIMIT:
 957                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 958                                 err = -EINVAL;
 959                                 goto exit_f;
 960                         }
 961
 962                         ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 963                         if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 964                                 err = -EINVAL;
 965                                 goto exit_f;
 966                         }
 967
 968                         break;
 969
 970                 case IPV6_TCLASS:
 971                     {
 972                         int tc;
 973
 974                         err = -EINVAL;
 975                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 976                                 goto exit_f;
 977
 978                         tc = *(int *)CMSG_DATA(cmsg);
 979                         if (tc < -1 || tc > 0xff)
 980                                 goto exit_f;
 981
 982                         err = 0;
 983                         ipc6->tclass = tc;
 984
 985                         break;
 986                     }
 987
 988                 case IPV6_DONTFRAG:
 989                     {
 990                         int df;
 991
 992                         err = -EINVAL;
 993                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 994                                 goto exit_f;
 995
 996                         df = *(int *)CMSG_DATA(cmsg);
 997                         if (df < 0 || df > 1)
 998                                 goto exit_f;
 999
1000                         err = 0;
1001                         ipc6->dontfrag = df;
1002
1003                         break;
1004                     }
1005                 default:
1006                         net_dbg_ratelimited("invalid cmsg type: %d\n",
1007                                             cmsg->cmsg_type);
1008                         err = -EINVAL;
1009                         goto exit_f;
1010                 }
1011         }
1012
1013 exit_f:
1014         return err;
1015 }
1016 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1017
1018 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1019                              __u16 srcp, __u16 destp, int bucket)
1020 {
1021         const struct in6_addr *dest, *src;
1022
1023         dest  = &sp->sk_v6_daddr;
1024         src   = &sp->sk_v6_rcv_saddr;
1025         seq_printf(seq,
1026                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1027                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
1028                    bucket,
1029                    src->s6_addr32[0], src->s6_addr32[1],
1030                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1031                    dest->s6_addr32[0], dest->s6_addr32[1],
1032                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1033                    sp->sk_state,
1034                    sk_wmem_alloc_get(sp),
1035                    sk_rmem_alloc_get(sp),
1036                    0, 0L, 0,
1037                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1038                    0,
1039                    sock_i_ino(sp),
1040                    atomic_read(&sp->sk_refcnt), sp,
1041                    atomic_read(&sp->sk_drops));
1042 }