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_sk_dst_store_flow(sk, dst, &fl6);
 110
 111 out:
 112         fl6_sock_release(flowlabel);
 113         return err;
 114 }
 115
 116 void ip6_datagram_release_cb(struct sock *sk)
 117 {
 118         struct dst_entry *dst;
 119
 120         if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 121                 return;
 122
 123         rcu_read_lock();
 124         dst = __sk_dst_get(sk);
 125         if (!dst || !dst->obsolete ||
 126             dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
 127                 rcu_read_unlock();
 128                 return;
 129         }
 130         rcu_read_unlock();
 131
 132         ip6_datagram_dst_update(sk, false);
 133 }
 134 EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
 135
 136 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
 137                            int addr_len)
 138 {
 139         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
 140         struct inet_sock        *inet = inet_sk(sk);
 141         struct ipv6_pinfo       *np = inet6_sk(sk);
 142         struct in6_addr         *daddr, old_daddr;
 143         __be32                  fl6_flowlabel = 0;
 144         __be32                  old_fl6_flowlabel;
 145         __be16                  old_dport;
 146         int                     addr_type;
 147         int                     err;
 148
 149         if (usin->sin6_family == AF_INET) {
 150                 if (__ipv6_only_sock(sk))
 151                         return -EAFNOSUPPORT;
 152                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
 153                 goto ipv4_connected;
 154         }
 155
 156         if (addr_len < SIN6_LEN_RFC2133)
 157                 return -EINVAL;
 158
 159         if (usin->sin6_family != AF_INET6)
 160                 return -EAFNOSUPPORT;
 161
 162         if (np->sndflow)
 163                 fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 164
 165         if (ipv6_addr_any(&usin->sin6_addr)) {
 166                 /*
 167                  *      connect to self
 168                  */
 169                 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
 170                         ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
 171                                                &usin->sin6_addr);
 172                 else
 173                         usin->sin6_addr = in6addr_loopback;
 174         }
 175
 176         addr_type = ipv6_addr_type(&usin->sin6_addr);
 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_dev_equal_l3scope(sk, usin->sin6_scope_id)) {
 220                                 err = -EINVAL;
 221                                 goto out;
 222                         }
 223                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 224                 }
 225
 226                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 227                         sk->sk_bound_dev_if = np->mcast_oif;
 228
 229                 /* Connect to link-local address requires an interface */
 230                 if (!sk->sk_bound_dev_if) {
 231                         err = -EINVAL;
 232                         goto out;
 233                 }
 234         }
 235
 236         /* save the current peer information before updating it */
 237         old_daddr = sk->sk_v6_daddr;
 238         old_fl6_flowlabel = np->flow_label;
 239         old_dport = inet->inet_dport;
 240
 241         sk->sk_v6_daddr = *daddr;
 242         np->flow_label = fl6_flowlabel;
 243         inet->inet_dport = usin->sin6_port;
 244
 245         /*
 246          *      Check for a route to destination an obtain the
 247          *      destination cache for it.
 248          */
 249
 250         err = ip6_datagram_dst_update(sk, true);
 251         if (err) {
 252                 /* Restore the socket peer info, to keep it consistent with
 253                  * the old socket state
 254                  */
 255                 sk->sk_v6_daddr = old_daddr;
 256                 np->flow_label = old_fl6_flowlabel;
 257                 inet->inet_dport = old_dport;
 258                 goto out;
 259         }
 260
 261         sk->sk_state = TCP_ESTABLISHED;
 262         sk_set_txhash(sk);
 263 out:
 264         return err;
 265 }
 266 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 267
 268 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 269 {
 270         int res;
 271
 272         lock_sock(sk);
 273         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 274         release_sock(sk);
 275         return res;
 276 }
 277 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 278
 279 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 280                                  int addr_len)
 281 {
 282         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 283         if (sin6->sin6_family != AF_INET6)
 284                 return -EAFNOSUPPORT;
 285         return ip6_datagram_connect(sk, uaddr, addr_len);
 286 }
 287 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 288
 289 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 290                      __be16 port, u32 info, u8 *payload)
 291 {
 292         struct ipv6_pinfo *np  = inet6_sk(sk);
 293         struct icmp6hdr *icmph = icmp6_hdr(skb);
 294         struct sock_exterr_skb *serr;
 295
 296         if (!np->recverr)
 297                 return;
 298
 299         skb = skb_clone(skb, GFP_ATOMIC);
 300         if (!skb)
 301                 return;
 302
 303         skb->protocol = htons(ETH_P_IPV6);
 304
 305         serr = SKB_EXT_ERR(skb);
 306         serr->ee.ee_errno = err;
 307         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 308         serr->ee.ee_type = icmph->icmp6_type;
 309         serr->ee.ee_code = icmph->icmp6_code;
 310         serr->ee.ee_pad = 0;
 311         serr->ee.ee_info = info;
 312         serr->ee.ee_data = 0;
 313         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 314                                   skb_network_header(skb);
 315         serr->port = port;
 316
 317         __skb_pull(skb, payload - skb->data);
 318         skb_reset_transport_header(skb);
 319
 320         if (sock_queue_err_skb(sk, skb))
 321                 kfree_skb(skb);
 322 }
 323
 324 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 325 {
 326         const struct ipv6_pinfo *np = inet6_sk(sk);
 327         struct sock_exterr_skb *serr;
 328         struct ipv6hdr *iph;
 329         struct sk_buff *skb;
 330
 331         if (!np->recverr)
 332                 return;
 333
 334         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 335         if (!skb)
 336                 return;
 337
 338         skb->protocol = htons(ETH_P_IPV6);
 339
 340         skb_put(skb, sizeof(struct ipv6hdr));
 341         skb_reset_network_header(skb);
 342         iph = ipv6_hdr(skb);
 343         iph->daddr = fl6->daddr;
 344         ip6_flow_hdr(iph, 0, 0);
 345
 346         serr = SKB_EXT_ERR(skb);
 347         serr->ee.ee_errno = err;
 348         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 349         serr->ee.ee_type = 0;
 350         serr->ee.ee_code = 0;
 351         serr->ee.ee_pad = 0;
 352         serr->ee.ee_info = info;
 353         serr->ee.ee_data = 0;
 354         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 355         serr->port = fl6->fl6_dport;
 356
 357         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 358         skb_reset_transport_header(skb);
 359
 360         if (sock_queue_err_skb(sk, skb))
 361                 kfree_skb(skb);
 362 }
 363
 364 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 365 {
 366         struct ipv6_pinfo *np = inet6_sk(sk);
 367         struct ipv6hdr *iph;
 368         struct sk_buff *skb;
 369         struct ip6_mtuinfo *mtu_info;
 370
 371         if (!np->rxopt.bits.rxpmtu)
 372                 return;
 373
 374         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 375         if (!skb)
 376                 return;
 377
 378         skb_put(skb, sizeof(struct ipv6hdr));
 379         skb_reset_network_header(skb);
 380         iph = ipv6_hdr(skb);
 381         iph->daddr = fl6->daddr;
 382
 383         mtu_info = IP6CBMTU(skb);
 384
 385         mtu_info->ip6m_mtu = mtu;
 386         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 387         mtu_info->ip6m_addr.sin6_port = 0;
 388         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 389         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 390         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 391
 392         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 393         skb_reset_transport_header(skb);
 394
 395         skb = xchg(&np->rxpmtu, skb);
 396         kfree_skb(skb);
 397 }
 398
 399 /* For some errors we have valid addr_offset even with zero payload and
 400  * zero port. Also, addr_offset should be supported if port is set.
 401  */
 402 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 403 {
 404         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 405                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 406                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 407 }
 408
 409 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 410  *
 411  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 412  * errors. This is no longer true, but the test remained, so the v6 stack,
 413  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 414  */
 415 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 416                                       struct sock_exterr_skb *serr)
 417 {
 418         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 419             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 420                 return true;
 421
 422         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 423                 return false;
 424
 425         if (!IP6CB(skb)->iif)
 426                 return false;
 427
 428         return true;
 429 }
 430
 431 /*
 432  *      Handle MSG_ERRQUEUE
 433  */
 434 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 435 {
 436         struct ipv6_pinfo *np = inet6_sk(sk);
 437         struct sock_exterr_skb *serr;
 438         struct sk_buff *skb;
 439         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 440         struct {
 441                 struct sock_extended_err ee;
 442                 struct sockaddr_in6      offender;
 443         } errhdr;
 444         int err;
 445         int copied;
 446
 447         err = -EAGAIN;
 448         skb = sock_dequeue_err_skb(sk);
 449         if (!skb)
 450                 goto out;
 451
 452         copied = skb->len;
 453         if (copied > len) {
 454                 msg->msg_flags |= MSG_TRUNC;
 455                 copied = len;
 456         }
 457         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 458         if (unlikely(err)) {
 459                 kfree_skb(skb);
 460                 return err;
 461         }
 462         sock_recv_timestamp(msg, sk, skb);
 463
 464         serr = SKB_EXT_ERR(skb);
 465
 466         if (sin && ipv6_datagram_support_addr(serr)) {
 467                 const unsigned char *nh = skb_network_header(skb);
 468                 sin->sin6_family = AF_INET6;
 469                 sin->sin6_flowinfo = 0;
 470                 sin->sin6_port = serr->port;
 471                 if (skb->protocol == htons(ETH_P_IPV6)) {
 472                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 473                                                                   struct ipv6hdr, daddr);
 474                         sin->sin6_addr = ip6h->daddr;
 475                         if (np->sndflow)
 476                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 477                         sin->sin6_scope_id =
 478                                 ipv6_iface_scope_id(&sin->sin6_addr,
 479                                                     IP6CB(skb)->iif);
 480                 } else {
 481                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 482                                                &sin->sin6_addr);
 483                         sin->sin6_scope_id = 0;
 484                 }
 485                 *addr_len = sizeof(*sin);
 486         }
 487
 488         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 489         sin = &errhdr.offender;
 490         memset(sin, 0, sizeof(*sin));
 491
 492         if (ip6_datagram_support_cmsg(skb, serr)) {
 493                 sin->sin6_family = AF_INET6;
 494                 if (np->rxopt.all)
 495                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 496                 if (skb->protocol == htons(ETH_P_IPV6)) {
 497                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 498                         if (np->rxopt.all)
 499                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 500                         sin->sin6_scope_id =
 501                                 ipv6_iface_scope_id(&sin->sin6_addr,
 502                                                     IP6CB(skb)->iif);
 503                 } else {
 504                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 505                                                &sin->sin6_addr);
 506                         if (inet_sk(sk)->cmsg_flags)
 507                                 ip_cmsg_recv(msg, skb);
 508                 }
 509         }
 510
 511         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 512
 513         /* Now we could try to dump offended packet options */
 514
 515         msg->msg_flags |= MSG_ERRQUEUE;
 516         err = copied;
 517
 518         consume_skb(skb);
 519 out:
 520         return err;
 521 }
 522 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 523
 524 /*
 525  *      Handle IPV6_RECVPATHMTU
 526  */
 527 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 528                      int *addr_len)
 529 {
 530         struct ipv6_pinfo *np = inet6_sk(sk);
 531         struct sk_buff *skb;
 532         struct ip6_mtuinfo mtu_info;
 533         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 534         int err;
 535         int copied;
 536
 537         err = -EAGAIN;
 538         skb = xchg(&np->rxpmtu, NULL);
 539         if (!skb)
 540                 goto out;
 541
 542         copied = skb->len;
 543         if (copied > len) {
 544                 msg->msg_flags |= MSG_TRUNC;
 545                 copied = len;
 546         }
 547         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 548         if (err)
 549                 goto out_free_skb;
 550
 551         sock_recv_timestamp(msg, sk, skb);
 552
 553         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 554
 555         if (sin) {
 556                 sin->sin6_family = AF_INET6;
 557                 sin->sin6_flowinfo = 0;
 558                 sin->sin6_port = 0;
 559                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 560                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 561                 *addr_len = sizeof(*sin);
 562         }
 563
 564         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 565
 566         err = copied;
 567
 568 out_free_skb:
 569         kfree_skb(skb);
 570 out:
 571         return err;
 572 }
 573
 574
 575 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 576                                  struct sk_buff *skb)
 577 {
 578         struct ipv6_pinfo *np = inet6_sk(sk);
 579         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 580
 581         if (np->rxopt.bits.rxinfo) {
 582                 struct in6_pktinfo src_info;
 583
 584                 if (is_ipv6) {
 585                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 586                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 587                 } else {
 588                         src_info.ipi6_ifindex =
 589                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 590                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 591                                                &src_info.ipi6_addr);
 592                 }
 593
 594                 if (src_info.ipi6_ifindex >= 0)
 595                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 596                                  sizeof(src_info), &src_info);
 597         }
 598 }
 599
 600 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 601                                     struct sk_buff *skb)
 602 {
 603         struct ipv6_pinfo *np = inet6_sk(sk);
 604         struct inet6_skb_parm *opt = IP6CB(skb);
 605         unsigned char *nh = skb_network_header(skb);
 606
 607         if (np->rxopt.bits.rxhlim) {
 608                 int hlim = ipv6_hdr(skb)->hop_limit;
 609                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 610         }
 611
 612         if (np->rxopt.bits.rxtclass) {
 613                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 614                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 615         }
 616
 617         if (np->rxopt.bits.rxflow) {
 618                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 619                 if (flowinfo)
 620                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 621         }
 622
 623         /* HbH is allowed only once */
 624         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 625                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 626                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 627         }
 628
 629         if (opt->lastopt &&
 630             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 631                 /*
 632                  * Silly enough, but we need to reparse in order to
 633                  * report extension headers (except for HbH)
 634                  * in order.
 635                  *
 636                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 637                  * (and WILL NOT be) defined because
 638                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 639                  */
 640                 unsigned int off = sizeof(struct ipv6hdr);
 641                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 642
 643                 while (off <= opt->lastopt) {
 644                         unsigned int len;
 645                         u8 *ptr = nh + off;
 646
 647                         switch (nexthdr) {
 648                         case IPPROTO_DSTOPTS:
 649                                 nexthdr = ptr[0];
 650                                 len = (ptr[1] + 1) << 3;
 651                                 if (np->rxopt.bits.dstopts)
 652                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 653                                 break;
 654                         case IPPROTO_ROUTING:
 655                                 nexthdr = ptr[0];
 656                                 len = (ptr[1] + 1) << 3;
 657                                 if (np->rxopt.bits.srcrt)
 658                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 659                                 break;
 660                         case IPPROTO_AH:
 661                                 nexthdr = ptr[0];
 662                                 len = (ptr[1] + 2) << 2;
 663                                 break;
 664                         default:
 665                                 nexthdr = ptr[0];
 666                                 len = (ptr[1] + 1) << 3;
 667                                 break;
 668                         }
 669
 670                         off += len;
 671                 }
 672         }
 673
 674         /* socket options in old style */
 675         if (np->rxopt.bits.rxoinfo) {
 676                 struct in6_pktinfo src_info;
 677
 678                 src_info.ipi6_ifindex = opt->iif;
 679                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 680                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 681         }
 682         if (np->rxopt.bits.rxohlim) {
 683                 int hlim = ipv6_hdr(skb)->hop_limit;
 684                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 685         }
 686         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 687                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 688                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 689         }
 690         if (np->rxopt.bits.odstopts && opt->dst0) {
 691                 u8 *ptr = nh + opt->dst0;
 692                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 693         }
 694         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 695                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 696                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 697         }
 698         if (np->rxopt.bits.odstopts && opt->dst1) {
 699                 u8 *ptr = nh + opt->dst1;
 700                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 701         }
 702         if (np->rxopt.bits.rxorigdstaddr) {
 703                 struct sockaddr_in6 sin6;
 704                 __be16 _ports[2], *ports;
 705
 706                 ports = skb_header_pointer(skb, skb_transport_offset(skb),
 707                                            sizeof(_ports), &_ports);
 708                 if (ports) {
 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                         sin6.sin6_family = AF_INET6;
 714                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 715                         sin6.sin6_port = ports[1];
 716                         sin6.sin6_flowinfo = 0;
 717                         sin6.sin6_scope_id =
 718                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 719                                                     opt->iif);
 720
 721                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 722                 }
 723         }
 724         if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
 725                 int val = opt->frag_max_size;
 726
 727                 put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
 728         }
 729 }
 730
 731 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 732                           struct sk_buff *skb)
 733 {
 734         ip6_datagram_recv_common_ctl(sk, msg, skb);
 735         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 736 }
 737 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 738
 739 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 740                           struct msghdr *msg, struct flowi6 *fl6,
 741                           struct ipcm6_cookie *ipc6)
 742 {
 743         struct in6_pktinfo *src_info;
 744         struct cmsghdr *cmsg;
 745         struct ipv6_rt_hdr *rthdr;
 746         struct ipv6_opt_hdr *hdr;
 747         struct ipv6_txoptions *opt = ipc6->opt;
 748         int len;
 749         int err = 0;
 750
 751         for_each_cmsghdr(cmsg, msg) {
 752                 int addr_type;
 753
 754                 if (!CMSG_OK(msg, cmsg)) {
 755                         err = -EINVAL;
 756                         goto exit_f;
 757                 }
 758
 759                 if (cmsg->cmsg_level == SOL_SOCKET) {
 760                         err = __sock_cmsg_send(sk, msg, cmsg, &ipc6->sockc);
 761                         if (err)
 762                                 return err;
 763                         continue;
 764                 }
 765
 766                 if (cmsg->cmsg_level != SOL_IPV6)
 767                         continue;
 768
 769                 switch (cmsg->cmsg_type) {
 770                 case IPV6_PKTINFO:
 771                 case IPV6_2292PKTINFO:
 772                     {
 773                         struct net_device *dev = NULL;
 774                         int src_idx;
 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                         src_idx = src_info->ipi6_ifindex;
 783
 784                         if (src_idx) {
 785                                 if (fl6->flowi6_oif &&
 786                                     src_idx != fl6->flowi6_oif &&
 787                                     (sk->sk_bound_dev_if != fl6->flowi6_oif ||
 788                                      !sk_dev_equal_l3scope(sk, src_idx)))
 789                                         return -EINVAL;
 790                                 fl6->flowi6_oif = src_idx;
 791                         }
 792
 793                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 794
 795                         rcu_read_lock();
 796                         if (fl6->flowi6_oif) {
 797                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 798                                 if (!dev) {
 799                                         rcu_read_unlock();
 800                                         return -ENODEV;
 801                                 }
 802                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 803                                 rcu_read_unlock();
 804                                 return -EINVAL;
 805                         }
 806
 807                         if (addr_type != IPV6_ADDR_ANY) {
 808                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 809                                 if (!ipv6_can_nonlocal_bind(net, inet_sk(sk)) &&
 810                                     !ipv6_chk_addr_and_flags(net, &src_info->ipi6_addr,
 811                                                              dev, !strict, 0,
 812                                                              IFA_F_TENTATIVE) &&
 813                                     !ipv6_chk_acast_addr_src(net, dev,
 814                                                              &src_info->ipi6_addr))
 815                                         err = -EINVAL;
 816                                 else
 817                                         fl6->saddr = src_info->ipi6_addr;
 818                         }
 819
 820                         rcu_read_unlock();
 821
 822                         if (err)
 823                                 goto exit_f;
 824
 825                         break;
 826                     }
 827
 828                 case IPV6_FLOWINFO:
 829                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 830                                 err = -EINVAL;
 831                                 goto exit_f;
 832                         }
 833
 834                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 835                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 836                                         err = -EINVAL;
 837                                         goto exit_f;
 838                                 }
 839                         }
 840                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 841                         break;
 842
 843                 case IPV6_2292HOPOPTS:
 844                 case IPV6_HOPOPTS:
 845                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 846                                 err = -EINVAL;
 847                                 goto exit_f;
 848                         }
 849
 850                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 851                         len = ((hdr->hdrlen + 1) << 3);
 852                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 853                                 err = -EINVAL;
 854                                 goto exit_f;
 855                         }
 856                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 857                                 err = -EPERM;
 858                                 goto exit_f;
 859                         }
 860                         opt->opt_nflen += len;
 861                         opt->hopopt = hdr;
 862                         break;
 863
 864                 case IPV6_2292DSTOPTS:
 865                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 866                                 err = -EINVAL;
 867                                 goto exit_f;
 868                         }
 869
 870                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 871                         len = ((hdr->hdrlen + 1) << 3);
 872                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 873                                 err = -EINVAL;
 874                                 goto exit_f;
 875                         }
 876                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 877                                 err = -EPERM;
 878                                 goto exit_f;
 879                         }
 880                         if (opt->dst1opt) {
 881                                 err = -EINVAL;
 882                                 goto exit_f;
 883                         }
 884                         opt->opt_flen += len;
 885                         opt->dst1opt = hdr;
 886                         break;
 887
 888                 case IPV6_DSTOPTS:
 889                 case IPV6_RTHDRDSTOPTS:
 890                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 891                                 err = -EINVAL;
 892                                 goto exit_f;
 893                         }
 894
 895                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 896                         len = ((hdr->hdrlen + 1) << 3);
 897                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 898                                 err = -EINVAL;
 899                                 goto exit_f;
 900                         }
 901                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 902                                 err = -EPERM;
 903                                 goto exit_f;
 904                         }
 905                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 906                                 opt->opt_flen += len;
 907                                 opt->dst1opt = hdr;
 908                         } else {
 909                                 opt->opt_nflen += len;
 910                                 opt->dst0opt = hdr;
 911                         }
 912                         break;
 913
 914                 case IPV6_2292RTHDR:
 915                 case IPV6_RTHDR:
 916                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 917                                 err = -EINVAL;
 918                                 goto exit_f;
 919                         }
 920
 921                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 922
 923                         switch (rthdr->type) {
 924 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 925                         case IPV6_SRCRT_TYPE_2:
 926                                 if (rthdr->hdrlen != 2 ||
 927                                     rthdr->segments_left != 1) {
 928                                         err = -EINVAL;
 929                                         goto exit_f;
 930                                 }
 931                                 break;
 932 #endif
 933                         default:
 934                                 err = -EINVAL;
 935                                 goto exit_f;
 936                         }
 937
 938                         len = ((rthdr->hdrlen + 1) << 3);
 939
 940                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 941                                 err = -EINVAL;
 942                                 goto exit_f;
 943                         }
 944
 945                         /* segments left must also match */
 946                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 947                                 err = -EINVAL;
 948                                 goto exit_f;
 949                         }
 950
 951                         opt->opt_nflen += len;
 952                         opt->srcrt = rthdr;
 953
 954                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 955                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 956
 957                                 opt->opt_nflen += dsthdrlen;
 958                                 opt->dst0opt = opt->dst1opt;
 959                                 opt->dst1opt = NULL;
 960                                 opt->opt_flen -= dsthdrlen;
 961                         }
 962
 963                         break;
 964
 965                 case IPV6_2292HOPLIMIT:
 966                 case IPV6_HOPLIMIT:
 967                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 968                                 err = -EINVAL;
 969                                 goto exit_f;
 970                         }
 971
 972                         ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 973                         if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 974                                 err = -EINVAL;
 975                                 goto exit_f;
 976                         }
 977
 978                         break;
 979
 980                 case IPV6_TCLASS:
 981                     {
 982                         int tc;
 983
 984                         err = -EINVAL;
 985                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 986                                 goto exit_f;
 987
 988                         tc = *(int *)CMSG_DATA(cmsg);
 989                         if (tc < -1 || tc > 0xff)
 990                                 goto exit_f;
 991
 992                         err = 0;
 993                         ipc6->tclass = tc;
 994
 995                         break;
 996                     }
 997
 998                 case IPV6_DONTFRAG:
 999                     {
1000                         int df;
1001
1002                         err = -EINVAL;
1003                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1004                                 goto exit_f;
1005
1006                         df = *(int *)CMSG_DATA(cmsg);
1007                         if (df < 0 || df > 1)
1008                                 goto exit_f;
1009
1010                         err = 0;
1011                         ipc6->dontfrag = df;
1012
1013                         break;
1014                     }
1015                 default:
1016                         net_dbg_ratelimited("invalid cmsg type: %d\n",
1017                                             cmsg->cmsg_type);
1018                         err = -EINVAL;
1019                         goto exit_f;
1020                 }
1021         }
1022
1023 exit_f:
1024         return err;
1025 }
1026 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1027
1028 void __ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1029                                __u16 srcp, __u16 destp, int rqueue, int bucket)
1030 {
1031         const struct in6_addr *dest, *src;
1032
1033         dest  = &sp->sk_v6_daddr;
1034         src   = &sp->sk_v6_rcv_saddr;
1035         seq_printf(seq,
1036                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1037                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
1038                    bucket,
1039                    src->s6_addr32[0], src->s6_addr32[1],
1040                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1041                    dest->s6_addr32[0], dest->s6_addr32[1],
1042                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1043                    sp->sk_state,
1044                    sk_wmem_alloc_get(sp),
1045                    rqueue,
1046                    0, 0L, 0,
1047                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1048                    0,
1049                    sock_i_ino(sp),
1050                    refcount_read(&sp->sk_refcnt), sp,
1051                    atomic_read(&sp->sk_drops));
1052 }