net/ipv6/datagram.c

   1 /*
   2  *      common UDP/RAW code
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 #include <linux/capability.h>
  15 #include <linux/errno.h>
  16 #include <linux/types.h>
  17 #include <linux/kernel.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/socket.h>
  20 #include <linux/sockios.h>
  21 #include <linux/in6.h>
  22 #include <linux/ipv6.h>
  23 #include <linux/route.h>
  24 #include <linux/slab.h>
  25 #include <linux/export.h>
  26
  27 #include <net/ipv6.h>
  28 #include <net/ndisc.h>
  29 #include <net/addrconf.h>
  30 #include <net/transp_v6.h>
  31 #include <net/ip6_route.h>
  32 #include <net/tcp_states.h>
  33 #include <net/dsfield.h>
  34
  35 #include <linux/errqueue.h>
  36 #include <asm/uaccess.h>
  37
  38 static bool ipv6_mapped_addr_any(const struct in6_addr *a)
  39 {
  40         return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
  41 }
  42
  43 static void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
  44 {
  45         struct inet_sock *inet = inet_sk(sk);
  46         struct ipv6_pinfo *np = inet6_sk(sk);
  47
  48         memset(fl6, 0, sizeof(*fl6));
  49         fl6->flowi6_proto = sk->sk_protocol;
  50         fl6->daddr = sk->sk_v6_daddr;
  51         fl6->saddr = np->saddr;
  52         fl6->flowi6_oif = sk->sk_bound_dev_if;
  53         fl6->flowi6_mark = sk->sk_mark;
  54         fl6->fl6_dport = inet->inet_dport;
  55         fl6->fl6_sport = inet->inet_sport;
  56         fl6->flowlabel = np->flow_label;
  57
  58         if (!fl6->flowi6_oif)
  59                 fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
  60
  61         if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr))
  62                 fl6->flowi6_oif = np->mcast_oif;
  63
  64         security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
  65 }
  66
  67 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
  68 {
  69         struct ip6_flowlabel *flowlabel = NULL;
  70         struct in6_addr *final_p, final;
  71         struct ipv6_txoptions *opt;
  72         struct dst_entry *dst;
  73         struct inet_sock *inet = inet_sk(sk);
  74         struct ipv6_pinfo *np = inet6_sk(sk);
  75         struct flowi6 fl6;
  76         int err = 0;
  77
  78         if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
  79                 flowlabel = fl6_sock_lookup(sk, np->flow_label);
  80                 if (!flowlabel)
  81                         return -EINVAL;
  82         }
  83         ip6_datagram_flow_key_init(&fl6, sk);
  84
  85         rcu_read_lock();
  86         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
  87         final_p = fl6_update_dst(&fl6, opt, &final);
  88         rcu_read_unlock();
  89
  90         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
  91         if (IS_ERR(dst)) {
  92                 err = PTR_ERR(dst);
  93                 goto out;
  94         }
  95
  96         if (fix_sk_saddr) {
  97                 if (ipv6_addr_any(&np->saddr))
  98                         np->saddr = fl6.saddr;
  99
 100                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 101                         sk->sk_v6_rcv_saddr = fl6.saddr;
 102                         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 103                         if (sk->sk_prot->rehash)
 104                                 sk->sk_prot->rehash(sk);
 105                 }
 106         }
 107
 108         ip6_dst_store(sk, dst,
 109                       ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
 110                       &sk->sk_v6_daddr : NULL,
 111 #ifdef CONFIG_IPV6_SUBTREES
 112                       ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
 113                       &np->saddr :
 114 #endif
 115                       NULL);
 116
 117 out:
 118         fl6_sock_release(flowlabel);
 119         return err;
 120 }
 121
 122 void ip6_datagram_release_cb(struct sock *sk)
 123 {
 124         struct dst_entry *dst;
 125
 126         if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 127                 return;
 128
 129         rcu_read_lock();
 130         dst = __sk_dst_get(sk);
 131         if (!dst || !dst->obsolete ||
 132             dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
 133                 rcu_read_unlock();
 134                 return;
 135         }
 136         rcu_read_unlock();
 137
 138         ip6_datagram_dst_update(sk, false);
 139 }
 140 EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
 141
 142 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;
 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 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 257
 258 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 259 {
 260         int res;
 261
 262         lock_sock(sk);
 263         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 264         release_sock(sk);
 265         return res;
 266 }
 267 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 268
 269 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 270                                  int addr_len)
 271 {
 272         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 273         if (sin6->sin6_family != AF_INET6)
 274                 return -EAFNOSUPPORT;
 275         return ip6_datagram_connect(sk, uaddr, addr_len);
 276 }
 277 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 278
 279 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 280                      __be16 port, u32 info, u8 *payload)
 281 {
 282         struct ipv6_pinfo *np  = inet6_sk(sk);
 283         struct icmp6hdr *icmph = icmp6_hdr(skb);
 284         struct sock_exterr_skb *serr;
 285
 286         if (!np->recverr)
 287                 return;
 288
 289         skb = skb_clone(skb, GFP_ATOMIC);
 290         if (!skb)
 291                 return;
 292
 293         skb->protocol = htons(ETH_P_IPV6);
 294
 295         serr = SKB_EXT_ERR(skb);
 296         serr->ee.ee_errno = err;
 297         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 298         serr->ee.ee_type = icmph->icmp6_type;
 299         serr->ee.ee_code = icmph->icmp6_code;
 300         serr->ee.ee_pad = 0;
 301         serr->ee.ee_info = info;
 302         serr->ee.ee_data = 0;
 303         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 304                                   skb_network_header(skb);
 305         serr->port = port;
 306
 307         __skb_pull(skb, payload - skb->data);
 308         skb_reset_transport_header(skb);
 309
 310         if (sock_queue_err_skb(sk, skb))
 311                 kfree_skb(skb);
 312 }
 313
 314 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 315 {
 316         const struct ipv6_pinfo *np = inet6_sk(sk);
 317         struct sock_exterr_skb *serr;
 318         struct ipv6hdr *iph;
 319         struct sk_buff *skb;
 320
 321         if (!np->recverr)
 322                 return;
 323
 324         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 325         if (!skb)
 326                 return;
 327
 328         skb->protocol = htons(ETH_P_IPV6);
 329
 330         skb_put(skb, sizeof(struct ipv6hdr));
 331         skb_reset_network_header(skb);
 332         iph = ipv6_hdr(skb);
 333         iph->daddr = fl6->daddr;
 334
 335         serr = SKB_EXT_ERR(skb);
 336         serr->ee.ee_errno = err;
 337         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 338         serr->ee.ee_type = 0;
 339         serr->ee.ee_code = 0;
 340         serr->ee.ee_pad = 0;
 341         serr->ee.ee_info = info;
 342         serr->ee.ee_data = 0;
 343         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 344         serr->port = fl6->fl6_dport;
 345
 346         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 347         skb_reset_transport_header(skb);
 348
 349         if (sock_queue_err_skb(sk, skb))
 350                 kfree_skb(skb);
 351 }
 352
 353 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 354 {
 355         struct ipv6_pinfo *np = inet6_sk(sk);
 356         struct ipv6hdr *iph;
 357         struct sk_buff *skb;
 358         struct ip6_mtuinfo *mtu_info;
 359
 360         if (!np->rxopt.bits.rxpmtu)
 361                 return;
 362
 363         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 364         if (!skb)
 365                 return;
 366
 367         skb_put(skb, sizeof(struct ipv6hdr));
 368         skb_reset_network_header(skb);
 369         iph = ipv6_hdr(skb);
 370         iph->daddr = fl6->daddr;
 371
 372         mtu_info = IP6CBMTU(skb);
 373
 374         mtu_info->ip6m_mtu = mtu;
 375         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 376         mtu_info->ip6m_addr.sin6_port = 0;
 377         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 378         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 379         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 380
 381         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 382         skb_reset_transport_header(skb);
 383
 384         skb = xchg(&np->rxpmtu, skb);
 385         kfree_skb(skb);
 386 }
 387
 388 /* For some errors we have valid addr_offset even with zero payload and
 389  * zero port. Also, addr_offset should be supported if port is set.
 390  */
 391 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 392 {
 393         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 394                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 395                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 396 }
 397
 398 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 399  *
 400  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 401  * errors. This is no longer true, but the test remained, so the v6 stack,
 402  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 403  *
 404  * Timestamp code paths do not initialize the fields expected by cmsg:
 405  * the PKTINFO fields in skb->cb[]. Fill those in here.
 406  */
 407 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 408                                       struct sock_exterr_skb *serr)
 409 {
 410         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 411             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 412                 return true;
 413
 414         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 415                 return false;
 416
 417         if (!skb->dev)
 418                 return false;
 419
 420         if (skb->protocol == htons(ETH_P_IPV6))
 421                 IP6CB(skb)->iif = skb->dev->ifindex;
 422         else
 423                 PKTINFO_SKB_CB(skb)->ipi_ifindex = skb->dev->ifindex;
 424
 425         return true;
 426 }
 427
 428 /*
 429  *      Handle MSG_ERRQUEUE
 430  */
 431 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 432 {
 433         struct ipv6_pinfo *np = inet6_sk(sk);
 434         struct sock_exterr_skb *serr;
 435         struct sk_buff *skb;
 436         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 437         struct {
 438                 struct sock_extended_err ee;
 439                 struct sockaddr_in6      offender;
 440         } errhdr;
 441         int err;
 442         int copied;
 443
 444         err = -EAGAIN;
 445         skb = sock_dequeue_err_skb(sk);
 446         if (!skb)
 447                 goto out;
 448
 449         copied = skb->len;
 450         if (copied > len) {
 451                 msg->msg_flags |= MSG_TRUNC;
 452                 copied = len;
 453         }
 454         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 455         if (unlikely(err)) {
 456                 kfree_skb(skb);
 457                 return err;
 458         }
 459         sock_recv_timestamp(msg, sk, skb);
 460
 461         serr = SKB_EXT_ERR(skb);
 462
 463         if (sin && ipv6_datagram_support_addr(serr)) {
 464                 const unsigned char *nh = skb_network_header(skb);
 465                 sin->sin6_family = AF_INET6;
 466                 sin->sin6_flowinfo = 0;
 467                 sin->sin6_port = serr->port;
 468                 if (skb->protocol == htons(ETH_P_IPV6)) {
 469                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 470                                                                   struct ipv6hdr, daddr);
 471                         sin->sin6_addr = ip6h->daddr;
 472                         if (np->sndflow)
 473                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 474                         sin->sin6_scope_id =
 475                                 ipv6_iface_scope_id(&sin->sin6_addr,
 476                                                     IP6CB(skb)->iif);
 477                 } else {
 478                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 479                                                &sin->sin6_addr);
 480                         sin->sin6_scope_id = 0;
 481                 }
 482                 *addr_len = sizeof(*sin);
 483         }
 484
 485         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 486         sin = &errhdr.offender;
 487         memset(sin, 0, sizeof(*sin));
 488
 489         if (ip6_datagram_support_cmsg(skb, serr)) {
 490                 sin->sin6_family = AF_INET6;
 491                 if (np->rxopt.all)
 492                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 493                 if (skb->protocol == htons(ETH_P_IPV6)) {
 494                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 495                         if (np->rxopt.all)
 496                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 497                         sin->sin6_scope_id =
 498                                 ipv6_iface_scope_id(&sin->sin6_addr,
 499                                                     IP6CB(skb)->iif);
 500                 } else {
 501                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 502                                                &sin->sin6_addr);
 503                         if (inet_sk(sk)->cmsg_flags)
 504                                 ip_cmsg_recv(msg, skb);
 505                 }
 506         }
 507
 508         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 509
 510         /* Now we could try to dump offended packet options */
 511
 512         msg->msg_flags |= MSG_ERRQUEUE;
 513         err = copied;
 514
 515         consume_skb(skb);
 516 out:
 517         return err;
 518 }
 519 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 520
 521 /*
 522  *      Handle IPV6_RECVPATHMTU
 523  */
 524 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 525                      int *addr_len)
 526 {
 527         struct ipv6_pinfo *np = inet6_sk(sk);
 528         struct sk_buff *skb;
 529         struct ip6_mtuinfo mtu_info;
 530         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 531         int err;
 532         int copied;
 533
 534         err = -EAGAIN;
 535         skb = xchg(&np->rxpmtu, NULL);
 536         if (!skb)
 537                 goto out;
 538
 539         copied = skb->len;
 540         if (copied > len) {
 541                 msg->msg_flags |= MSG_TRUNC;
 542                 copied = len;
 543         }
 544         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 545         if (err)
 546                 goto out_free_skb;
 547
 548         sock_recv_timestamp(msg, sk, skb);
 549
 550         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 551
 552         if (sin) {
 553                 sin->sin6_family = AF_INET6;
 554                 sin->sin6_flowinfo = 0;
 555                 sin->sin6_port = 0;
 556                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 557                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 558                 *addr_len = sizeof(*sin);
 559         }
 560
 561         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 562
 563         err = copied;
 564
 565 out_free_skb:
 566         kfree_skb(skb);
 567 out:
 568         return err;
 569 }
 570
 571
 572 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 573                                  struct sk_buff *skb)
 574 {
 575         struct ipv6_pinfo *np = inet6_sk(sk);
 576         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 577
 578         if (np->rxopt.bits.rxinfo) {
 579                 struct in6_pktinfo src_info;
 580
 581                 if (is_ipv6) {
 582                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 583                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 584                 } else {
 585                         src_info.ipi6_ifindex =
 586                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 587                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 588                                                &src_info.ipi6_addr);
 589                 }
 590
 591                 if (src_info.ipi6_ifindex >= 0)
 592                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 593                                  sizeof(src_info), &src_info);
 594         }
 595 }
 596
 597 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 598                                     struct sk_buff *skb)
 599 {
 600         struct ipv6_pinfo *np = inet6_sk(sk);
 601         struct inet6_skb_parm *opt = IP6CB(skb);
 602         unsigned char *nh = skb_network_header(skb);
 603
 604         if (np->rxopt.bits.rxhlim) {
 605                 int hlim = ipv6_hdr(skb)->hop_limit;
 606                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 607         }
 608
 609         if (np->rxopt.bits.rxtclass) {
 610                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 611                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 612         }
 613
 614         if (np->rxopt.bits.rxflow) {
 615                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 616                 if (flowinfo)
 617                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 618         }
 619
 620         /* HbH is allowed only once */
 621         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 622                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 623                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 624         }
 625
 626         if (opt->lastopt &&
 627             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 628                 /*
 629                  * Silly enough, but we need to reparse in order to
 630                  * report extension headers (except for HbH)
 631                  * in order.
 632                  *
 633                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 634                  * (and WILL NOT be) defined because
 635                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 636                  */
 637                 unsigned int off = sizeof(struct ipv6hdr);
 638                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 639
 640                 while (off <= opt->lastopt) {
 641                         unsigned int len;
 642                         u8 *ptr = nh + off;
 643
 644                         switch (nexthdr) {
 645                         case IPPROTO_DSTOPTS:
 646                                 nexthdr = ptr[0];
 647                                 len = (ptr[1] + 1) << 3;
 648                                 if (np->rxopt.bits.dstopts)
 649                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 650                                 break;
 651                         case IPPROTO_ROUTING:
 652                                 nexthdr = ptr[0];
 653                                 len = (ptr[1] + 1) << 3;
 654                                 if (np->rxopt.bits.srcrt)
 655                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 656                                 break;
 657                         case IPPROTO_AH:
 658                                 nexthdr = ptr[0];
 659                                 len = (ptr[1] + 2) << 2;
 660                                 break;
 661                         default:
 662                                 nexthdr = ptr[0];
 663                                 len = (ptr[1] + 1) << 3;
 664                                 break;
 665                         }
 666
 667                         off += len;
 668                 }
 669         }
 670
 671         /* socket options in old style */
 672         if (np->rxopt.bits.rxoinfo) {
 673                 struct in6_pktinfo src_info;
 674
 675                 src_info.ipi6_ifindex = opt->iif;
 676                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 677                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 678         }
 679         if (np->rxopt.bits.rxohlim) {
 680                 int hlim = ipv6_hdr(skb)->hop_limit;
 681                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 682         }
 683         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 684                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 685                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 686         }
 687         if (np->rxopt.bits.odstopts && opt->dst0) {
 688                 u8 *ptr = nh + opt->dst0;
 689                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 690         }
 691         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 692                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 693                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 694         }
 695         if (np->rxopt.bits.odstopts && opt->dst1) {
 696                 u8 *ptr = nh + opt->dst1;
 697                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 698         }
 699         if (np->rxopt.bits.rxorigdstaddr) {
 700                 struct sockaddr_in6 sin6;
 701                 __be16 *ports = (__be16 *) skb_transport_header(skb);
 702
 703                 if (skb_transport_offset(skb) + 4 <= skb->len) {
 704                         /* All current transport protocols have the port numbers in the
 705                          * first four bytes of the transport header and this function is
 706                          * written with this assumption in mind.
 707                          */
 708
 709                         sin6.sin6_family = AF_INET6;
 710                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 711                         sin6.sin6_port = ports[1];
 712                         sin6.sin6_flowinfo = 0;
 713                         sin6.sin6_scope_id =
 714                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 715                                                     opt->iif);
 716
 717                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 718                 }
 719         }
 720 }
 721
 722 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 723                           struct sk_buff *skb)
 724 {
 725         ip6_datagram_recv_common_ctl(sk, msg, skb);
 726         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 727 }
 728 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 729
 730 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 731                           struct msghdr *msg, struct flowi6 *fl6,
 732                           struct ipcm6_cookie *ipc6, struct sockcm_cookie *sockc)
 733 {
 734         struct in6_pktinfo *src_info;
 735         struct cmsghdr *cmsg;
 736         struct ipv6_rt_hdr *rthdr;
 737         struct ipv6_opt_hdr *hdr;
 738         struct ipv6_txoptions *opt = ipc6->opt;
 739         int len;
 740         int err = 0;
 741
 742         for_each_cmsghdr(cmsg, msg) {
 743                 int addr_type;
 744
 745                 if (!CMSG_OK(msg, cmsg)) {
 746                         err = -EINVAL;
 747                         goto exit_f;
 748                 }
 749
 750                 if (cmsg->cmsg_level == SOL_SOCKET) {
 751                         err = __sock_cmsg_send(sk, msg, cmsg, sockc);
 752                         if (err)
 753                                 return err;
 754                         continue;
 755                 }
 756
 757                 if (cmsg->cmsg_level != SOL_IPV6)
 758                         continue;
 759
 760                 switch (cmsg->cmsg_type) {
 761                 case IPV6_PKTINFO:
 762                 case IPV6_2292PKTINFO:
 763                     {
 764                         struct net_device *dev = NULL;
 765
 766                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 767                                 err = -EINVAL;
 768                                 goto exit_f;
 769                         }
 770
 771                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 772
 773                         if (src_info->ipi6_ifindex) {
 774                                 if (fl6->flowi6_oif &&
 775                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 776                                         return -EINVAL;
 777                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 778                         }
 779
 780                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 781
 782                         rcu_read_lock();
 783                         if (fl6->flowi6_oif) {
 784                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 785                                 if (!dev) {
 786                                         rcu_read_unlock();
 787                                         return -ENODEV;
 788                                 }
 789                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 790                                 rcu_read_unlock();
 791                                 return -EINVAL;
 792                         }
 793
 794                         if (addr_type != IPV6_ADDR_ANY) {
 795                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 796                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 797                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 798                                                    strict ? dev : NULL, 0) &&
 799                                     !ipv6_chk_acast_addr_src(net, dev,
 800                                                              &src_info->ipi6_addr))
 801                                         err = -EINVAL;
 802                                 else
 803                                         fl6->saddr = src_info->ipi6_addr;
 804                         }
 805
 806                         rcu_read_unlock();
 807
 808                         if (err)
 809                                 goto exit_f;
 810
 811                         break;
 812                     }
 813
 814                 case IPV6_FLOWINFO:
 815                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 816                                 err = -EINVAL;
 817                                 goto exit_f;
 818                         }
 819
 820                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 821                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 822                                         err = -EINVAL;
 823                                         goto exit_f;
 824                                 }
 825                         }
 826                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 827                         break;
 828
 829                 case IPV6_2292HOPOPTS:
 830                 case IPV6_HOPOPTS:
 831                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 832                                 err = -EINVAL;
 833                                 goto exit_f;
 834                         }
 835
 836                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 837                         len = ((hdr->hdrlen + 1) << 3);
 838                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 839                                 err = -EINVAL;
 840                                 goto exit_f;
 841                         }
 842                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 843                                 err = -EPERM;
 844                                 goto exit_f;
 845                         }
 846                         opt->opt_nflen += len;
 847                         opt->hopopt = hdr;
 848                         break;
 849
 850                 case IPV6_2292DSTOPTS:
 851                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 852                                 err = -EINVAL;
 853                                 goto exit_f;
 854                         }
 855
 856                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 857                         len = ((hdr->hdrlen + 1) << 3);
 858                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 859                                 err = -EINVAL;
 860                                 goto exit_f;
 861                         }
 862                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 863                                 err = -EPERM;
 864                                 goto exit_f;
 865                         }
 866                         if (opt->dst1opt) {
 867                                 err = -EINVAL;
 868                                 goto exit_f;
 869                         }
 870                         opt->opt_flen += len;
 871                         opt->dst1opt = hdr;
 872                         break;
 873
 874                 case IPV6_DSTOPTS:
 875                 case IPV6_RTHDRDSTOPTS:
 876                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 877                                 err = -EINVAL;
 878                                 goto exit_f;
 879                         }
 880
 881                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 882                         len = ((hdr->hdrlen + 1) << 3);
 883                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 884                                 err = -EINVAL;
 885                                 goto exit_f;
 886                         }
 887                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 888                                 err = -EPERM;
 889                                 goto exit_f;
 890                         }
 891                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 892                                 opt->opt_flen += len;
 893                                 opt->dst1opt = hdr;
 894                         } else {
 895                                 opt->opt_nflen += len;
 896                                 opt->dst0opt = hdr;
 897                         }
 898                         break;
 899
 900                 case IPV6_2292RTHDR:
 901                 case IPV6_RTHDR:
 902                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 903                                 err = -EINVAL;
 904                                 goto exit_f;
 905                         }
 906
 907                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 908
 909                         switch (rthdr->type) {
 910 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 911                         case IPV6_SRCRT_TYPE_2:
 912                                 if (rthdr->hdrlen != 2 ||
 913                                     rthdr->segments_left != 1) {
 914                                         err = -EINVAL;
 915                                         goto exit_f;
 916                                 }
 917                                 break;
 918 #endif
 919                         default:
 920                                 err = -EINVAL;
 921                                 goto exit_f;
 922                         }
 923
 924                         len = ((rthdr->hdrlen + 1) << 3);
 925
 926                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 927                                 err = -EINVAL;
 928                                 goto exit_f;
 929                         }
 930
 931                         /* segments left must also match */
 932                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 933                                 err = -EINVAL;
 934                                 goto exit_f;
 935                         }
 936
 937                         opt->opt_nflen += len;
 938                         opt->srcrt = rthdr;
 939
 940                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 941                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 942
 943                                 opt->opt_nflen += dsthdrlen;
 944                                 opt->dst0opt = opt->dst1opt;
 945                                 opt->dst1opt = NULL;
 946                                 opt->opt_flen -= dsthdrlen;
 947                         }
 948
 949                         break;
 950
 951                 case IPV6_2292HOPLIMIT:
 952                 case IPV6_HOPLIMIT:
 953                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 954                                 err = -EINVAL;
 955                                 goto exit_f;
 956                         }
 957
 958                         ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 959                         if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 960                                 err = -EINVAL;
 961                                 goto exit_f;
 962                         }
 963
 964                         break;
 965
 966                 case IPV6_TCLASS:
 967                     {
 968                         int tc;
 969
 970                         err = -EINVAL;
 971                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 972                                 goto exit_f;
 973
 974                         tc = *(int *)CMSG_DATA(cmsg);
 975                         if (tc < -1 || tc > 0xff)
 976                                 goto exit_f;
 977
 978                         err = 0;
 979                         ipc6->tclass = tc;
 980
 981                         break;
 982                     }
 983
 984                 case IPV6_DONTFRAG:
 985                     {
 986                         int df;
 987
 988                         err = -EINVAL;
 989                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 990                                 goto exit_f;
 991
 992                         df = *(int *)CMSG_DATA(cmsg);
 993                         if (df < 0 || df > 1)
 994                                 goto exit_f;
 995
 996                         err = 0;
 997                         ipc6->dontfrag = df;
 998
 999                         break;
1000                     }
1001                 default:
1002                         net_dbg_ratelimited("invalid cmsg type: %d\n",
1003                                             cmsg->cmsg_type);
1004                         err = -EINVAL;
1005                         goto exit_f;
1006                 }
1007         }
1008
1009 exit_f:
1010         return err;
1011 }
1012 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1013
1014 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1015                              __u16 srcp, __u16 destp, int bucket)
1016 {
1017         const struct in6_addr *dest, *src;
1018
1019         dest  = &sp->sk_v6_daddr;
1020         src   = &sp->sk_v6_rcv_saddr;
1021         seq_printf(seq,
1022                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1023                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
1024                    bucket,
1025                    src->s6_addr32[0], src->s6_addr32[1],
1026                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1027                    dest->s6_addr32[0], dest->s6_addr32[1],
1028                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1029                    sp->sk_state,
1030                    sk_wmem_alloc_get(sp),
1031                    sk_rmem_alloc_get(sp),
1032                    0, 0L, 0,
1033                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1034                    0,
1035                    sock_i_ino(sp),
1036                    atomic_read(&sp->sk_refcnt), sp,
1037                    atomic_read(&sp->sk_drops));
1038 }