net/ipv6/datagram.c

   1 /*
   2  *      common UDP/RAW code
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 #include <linux/capability.h>
  15 #include <linux/errno.h>
  16 #include <linux/types.h>
  17 #include <linux/kernel.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/socket.h>
  20 #include <linux/sockios.h>
  21 #include <linux/in6.h>
  22 #include <linux/ipv6.h>
  23 #include <linux/route.h>
  24 #include <linux/slab.h>
  25 #include <linux/export.h>
  26
  27 #include <net/ipv6.h>
  28 #include <net/ndisc.h>
  29 #include <net/addrconf.h>
  30 #include <net/transp_v6.h>
  31 #include <net/ip6_route.h>
  32 #include <net/tcp_states.h>
  33 #include <net/dsfield.h>
  34
  35 #include <linux/errqueue.h>
  36 #include <linux/uaccess.h>
  37
  38 static bool ipv6_mapped_addr_any(const struct in6_addr *a)
  39 {
  40         return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
  41 }
  42
  43 static void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
  44 {
  45         struct inet_sock *inet = inet_sk(sk);
  46         struct ipv6_pinfo *np = inet6_sk(sk);
  47
  48         memset(fl6, 0, sizeof(*fl6));
  49         fl6->flowi6_proto = sk->sk_protocol;
  50         fl6->daddr = sk->sk_v6_daddr;
  51         fl6->saddr = np->saddr;
  52         fl6->flowi6_oif = sk->sk_bound_dev_if;
  53         fl6->flowi6_mark = sk->sk_mark;
  54         fl6->fl6_dport = inet->inet_dport;
  55         fl6->fl6_sport = inet->inet_sport;
  56         fl6->flowlabel = np->flow_label;
  57         fl6->flowi6_uid = sk->sk_uid;
  58
  59         if (!fl6->flowi6_oif)
  60                 fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
  61
  62         if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr))
  63                 fl6->flowi6_oif = np->mcast_oif;
  64
  65         security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
  66 }
  67
  68 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
  69 {
  70         struct ip6_flowlabel *flowlabel = NULL;
  71         struct in6_addr *final_p, final;
  72         struct ipv6_txoptions *opt;
  73         struct dst_entry *dst;
  74         struct inet_sock *inet = inet_sk(sk);
  75         struct ipv6_pinfo *np = inet6_sk(sk);
  76         struct flowi6 fl6;
  77         int err = 0;
  78
  79         if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
  80                 flowlabel = fl6_sock_lookup(sk, np->flow_label);
  81                 if (!flowlabel)
  82                         return -EINVAL;
  83         }
  84         ip6_datagram_flow_key_init(&fl6, sk);
  85
  86         rcu_read_lock();
  87         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
  88         final_p = fl6_update_dst(&fl6, opt, &final);
  89         rcu_read_unlock();
  90
  91         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
  92         if (IS_ERR(dst)) {
  93                 err = PTR_ERR(dst);
  94                 goto out;
  95         }
  96
  97         if (fix_sk_saddr) {
  98                 if (ipv6_addr_any(&np->saddr))
  99                         np->saddr = fl6.saddr;
 100
 101                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 102                         sk->sk_v6_rcv_saddr = fl6.saddr;
 103                         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 104                         if (sk->sk_prot->rehash)
 105                                 sk->sk_prot->rehash(sk);
 106                 }
 107         }
 108
 109         ip6_dst_store(sk, dst,
 110                       ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
 111                       &sk->sk_v6_daddr : NULL,
 112 #ifdef CONFIG_IPV6_SUBTREES
 113                       ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
 114                       &np->saddr :
 115 #endif
 116                       NULL);
 117
 118 out:
 119         fl6_sock_release(flowlabel);
 120         return err;
 121 }
 122
 123 void ip6_datagram_release_cb(struct sock *sk)
 124 {
 125         struct dst_entry *dst;
 126
 127         if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 128                 return;
 129
 130         rcu_read_lock();
 131         dst = __sk_dst_get(sk);
 132         if (!dst || !dst->obsolete ||
 133             dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
 134                 rcu_read_unlock();
 135                 return;
 136         }
 137         rcu_read_unlock();
 138
 139         ip6_datagram_dst_update(sk, false);
 140 }
 141 EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
 142
 143 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
 144                            int addr_len)
 145 {
 146         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
 147         struct inet_sock        *inet = inet_sk(sk);
 148         struct ipv6_pinfo       *np = inet6_sk(sk);
 149         struct in6_addr         *daddr;
 150         int                     addr_type;
 151         int                     err;
 152         __be32                  fl6_flowlabel = 0;
 153
 154         if (usin->sin6_family == AF_INET) {
 155                 if (__ipv6_only_sock(sk))
 156                         return -EAFNOSUPPORT;
 157                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
 158                 goto ipv4_connected;
 159         }
 160
 161         if (addr_len < SIN6_LEN_RFC2133)
 162                 return -EINVAL;
 163
 164         if (usin->sin6_family != AF_INET6)
 165                 return -EAFNOSUPPORT;
 166
 167         if (np->sndflow)
 168                 fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 169
 170         addr_type = ipv6_addr_type(&usin->sin6_addr);
 171
 172         if (addr_type == IPV6_ADDR_ANY) {
 173                 /*
 174                  *      connect to self
 175                  */
 176                 usin->sin6_addr.s6_addr[15] = 0x01;
 177         }
 178
 179         daddr = &usin->sin6_addr;
 180
 181         if (addr_type == IPV6_ADDR_MAPPED) {
 182                 struct sockaddr_in sin;
 183
 184                 if (__ipv6_only_sock(sk)) {
 185                         err = -ENETUNREACH;
 186                         goto out;
 187                 }
 188                 sin.sin_family = AF_INET;
 189                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
 190                 sin.sin_port = usin->sin6_port;
 191
 192                 err = __ip4_datagram_connect(sk,
 193                                              (struct sockaddr *) &sin,
 194                                              sizeof(sin));
 195
 196 ipv4_connected:
 197                 if (err)
 198                         goto out;
 199
 200                 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 201
 202                 if (ipv6_addr_any(&np->saddr) ||
 203                     ipv6_mapped_addr_any(&np->saddr))
 204                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 205
 206                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 207                     ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 208                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 209                                                &sk->sk_v6_rcv_saddr);
 210                         if (sk->sk_prot->rehash)
 211                                 sk->sk_prot->rehash(sk);
 212                 }
 213
 214                 goto out;
 215         }
 216
 217         if (__ipv6_addr_needs_scope_id(addr_type)) {
 218                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 219                     usin->sin6_scope_id) {
 220                         if (sk->sk_bound_dev_if &&
 221                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 222                                 err = -EINVAL;
 223                                 goto out;
 224                         }
 225                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 226                 }
 227
 228                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 229                         sk->sk_bound_dev_if = np->mcast_oif;
 230
 231                 /* Connect to link-local address requires an interface */
 232                 if (!sk->sk_bound_dev_if) {
 233                         err = -EINVAL;
 234                         goto out;
 235                 }
 236         }
 237
 238         sk->sk_v6_daddr = *daddr;
 239         np->flow_label = fl6_flowlabel;
 240
 241         inet->inet_dport = usin->sin6_port;
 242
 243         /*
 244          *      Check for a route to destination an obtain the
 245          *      destination cache for it.
 246          */
 247
 248         err = ip6_datagram_dst_update(sk, true);
 249         if (err)
 250                 goto out;
 251
 252         sk->sk_state = TCP_ESTABLISHED;
 253         sk_set_txhash(sk);
 254 out:
 255         return err;
 256 }
 257 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 258
 259 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 260 {
 261         int res;
 262
 263         lock_sock(sk);
 264         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 265         release_sock(sk);
 266         return res;
 267 }
 268 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 269
 270 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 271                                  int addr_len)
 272 {
 273         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 274         if (sin6->sin6_family != AF_INET6)
 275                 return -EAFNOSUPPORT;
 276         return ip6_datagram_connect(sk, uaddr, addr_len);
 277 }
 278 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 279
 280 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 281                      __be16 port, u32 info, u8 *payload)
 282 {
 283         struct ipv6_pinfo *np  = inet6_sk(sk);
 284         struct icmp6hdr *icmph = icmp6_hdr(skb);
 285         struct sock_exterr_skb *serr;
 286
 287         if (!np->recverr)
 288                 return;
 289
 290         skb = skb_clone(skb, GFP_ATOMIC);
 291         if (!skb)
 292                 return;
 293
 294         skb->protocol = htons(ETH_P_IPV6);
 295
 296         serr = SKB_EXT_ERR(skb);
 297         serr->ee.ee_errno = err;
 298         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 299         serr->ee.ee_type = icmph->icmp6_type;
 300         serr->ee.ee_code = icmph->icmp6_code;
 301         serr->ee.ee_pad = 0;
 302         serr->ee.ee_info = info;
 303         serr->ee.ee_data = 0;
 304         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 305                                   skb_network_header(skb);
 306         serr->port = port;
 307
 308         __skb_pull(skb, payload - skb->data);
 309         skb_reset_transport_header(skb);
 310
 311         if (sock_queue_err_skb(sk, skb))
 312                 kfree_skb(skb);
 313 }
 314
 315 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 316 {
 317         const struct ipv6_pinfo *np = inet6_sk(sk);
 318         struct sock_exterr_skb *serr;
 319         struct ipv6hdr *iph;
 320         struct sk_buff *skb;
 321
 322         if (!np->recverr)
 323                 return;
 324
 325         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 326         if (!skb)
 327                 return;
 328
 329         skb->protocol = htons(ETH_P_IPV6);
 330
 331         skb_put(skb, sizeof(struct ipv6hdr));
 332         skb_reset_network_header(skb);
 333         iph = ipv6_hdr(skb);
 334         iph->daddr = fl6->daddr;
 335
 336         serr = SKB_EXT_ERR(skb);
 337         serr->ee.ee_errno = err;
 338         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 339         serr->ee.ee_type = 0;
 340         serr->ee.ee_code = 0;
 341         serr->ee.ee_pad = 0;
 342         serr->ee.ee_info = info;
 343         serr->ee.ee_data = 0;
 344         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 345         serr->port = fl6->fl6_dport;
 346
 347         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 348         skb_reset_transport_header(skb);
 349
 350         if (sock_queue_err_skb(sk, skb))
 351                 kfree_skb(skb);
 352 }
 353
 354 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 355 {
 356         struct ipv6_pinfo *np = inet6_sk(sk);
 357         struct ipv6hdr *iph;
 358         struct sk_buff *skb;
 359         struct ip6_mtuinfo *mtu_info;
 360
 361         if (!np->rxopt.bits.rxpmtu)
 362                 return;
 363
 364         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 365         if (!skb)
 366                 return;
 367
 368         skb_put(skb, sizeof(struct ipv6hdr));
 369         skb_reset_network_header(skb);
 370         iph = ipv6_hdr(skb);
 371         iph->daddr = fl6->daddr;
 372
 373         mtu_info = IP6CBMTU(skb);
 374
 375         mtu_info->ip6m_mtu = mtu;
 376         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 377         mtu_info->ip6m_addr.sin6_port = 0;
 378         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 379         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 380         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 381
 382         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 383         skb_reset_transport_header(skb);
 384
 385         skb = xchg(&np->rxpmtu, skb);
 386         kfree_skb(skb);
 387 }
 388
 389 /* For some errors we have valid addr_offset even with zero payload and
 390  * zero port. Also, addr_offset should be supported if port is set.
 391  */
 392 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 393 {
 394         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 395                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 396                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 397 }
 398
 399 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 400  *
 401  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 402  * errors. This is no longer true, but the test remained, so the v6 stack,
 403  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 404  *
 405  * Timestamp code paths do not initialize the fields expected by cmsg:
 406  * the PKTINFO fields in skb->cb[]. Fill those in here.
 407  */
 408 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 409                                       struct sock_exterr_skb *serr)
 410 {
 411         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 412             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 413                 return true;
 414
 415         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 416                 return false;
 417
 418         if (!skb->dev)
 419                 return false;
 420
 421         if (skb->protocol == htons(ETH_P_IPV6))
 422                 IP6CB(skb)->iif = skb->dev->ifindex;
 423         else
 424                 PKTINFO_SKB_CB(skb)->ipi_ifindex = skb->dev->ifindex;
 425
 426         return true;
 427 }
 428
 429 /*
 430  *      Handle MSG_ERRQUEUE
 431  */
 432 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 433 {
 434         struct ipv6_pinfo *np = inet6_sk(sk);
 435         struct sock_exterr_skb *serr;
 436         struct sk_buff *skb;
 437         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 438         struct {
 439                 struct sock_extended_err ee;
 440                 struct sockaddr_in6      offender;
 441         } errhdr;
 442         int err;
 443         int copied;
 444
 445         err = -EAGAIN;
 446         skb = sock_dequeue_err_skb(sk);
 447         if (!skb)
 448                 goto out;
 449
 450         copied = skb->len;
 451         if (copied > len) {
 452                 msg->msg_flags |= MSG_TRUNC;
 453                 copied = len;
 454         }
 455         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 456         if (unlikely(err)) {
 457                 kfree_skb(skb);
 458                 return err;
 459         }
 460         sock_recv_timestamp(msg, sk, skb);
 461
 462         serr = SKB_EXT_ERR(skb);
 463
 464         if (sin && ipv6_datagram_support_addr(serr)) {
 465                 const unsigned char *nh = skb_network_header(skb);
 466                 sin->sin6_family = AF_INET6;
 467                 sin->sin6_flowinfo = 0;
 468                 sin->sin6_port = serr->port;
 469                 if (skb->protocol == htons(ETH_P_IPV6)) {
 470                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 471                                                                   struct ipv6hdr, daddr);
 472                         sin->sin6_addr = ip6h->daddr;
 473                         if (np->sndflow)
 474                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 475                         sin->sin6_scope_id =
 476                                 ipv6_iface_scope_id(&sin->sin6_addr,
 477                                                     IP6CB(skb)->iif);
 478                 } else {
 479                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 480                                                &sin->sin6_addr);
 481                         sin->sin6_scope_id = 0;
 482                 }
 483                 *addr_len = sizeof(*sin);
 484         }
 485
 486         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 487         sin = &errhdr.offender;
 488         memset(sin, 0, sizeof(*sin));
 489
 490         if (ip6_datagram_support_cmsg(skb, serr)) {
 491                 sin->sin6_family = AF_INET6;
 492                 if (np->rxopt.all)
 493                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 494                 if (skb->protocol == htons(ETH_P_IPV6)) {
 495                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 496                         if (np->rxopt.all)
 497                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 498                         sin->sin6_scope_id =
 499                                 ipv6_iface_scope_id(&sin->sin6_addr,
 500                                                     IP6CB(skb)->iif);
 501                 } else {
 502                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 503                                                &sin->sin6_addr);
 504                         if (inet_sk(sk)->cmsg_flags)
 505                                 ip_cmsg_recv(msg, skb);
 506                 }
 507         }
 508
 509         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 510
 511         /* Now we could try to dump offended packet options */
 512
 513         msg->msg_flags |= MSG_ERRQUEUE;
 514         err = copied;
 515
 516         consume_skb(skb);
 517 out:
 518         return err;
 519 }
 520 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 521
 522 /*
 523  *      Handle IPV6_RECVPATHMTU
 524  */
 525 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 526                      int *addr_len)
 527 {
 528         struct ipv6_pinfo *np = inet6_sk(sk);
 529         struct sk_buff *skb;
 530         struct ip6_mtuinfo mtu_info;
 531         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 532         int err;
 533         int copied;
 534
 535         err = -EAGAIN;
 536         skb = xchg(&np->rxpmtu, NULL);
 537         if (!skb)
 538                 goto out;
 539
 540         copied = skb->len;
 541         if (copied > len) {
 542                 msg->msg_flags |= MSG_TRUNC;
 543                 copied = len;
 544         }
 545         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 546         if (err)
 547                 goto out_free_skb;
 548
 549         sock_recv_timestamp(msg, sk, skb);
 550
 551         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 552
 553         if (sin) {
 554                 sin->sin6_family = AF_INET6;
 555                 sin->sin6_flowinfo = 0;
 556                 sin->sin6_port = 0;
 557                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 558                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 559                 *addr_len = sizeof(*sin);
 560         }
 561
 562         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 563
 564         err = copied;
 565
 566 out_free_skb:
 567         kfree_skb(skb);
 568 out:
 569         return err;
 570 }
 571
 572
 573 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 574                                  struct sk_buff *skb)
 575 {
 576         struct ipv6_pinfo *np = inet6_sk(sk);
 577         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 578
 579         if (np->rxopt.bits.rxinfo) {
 580                 struct in6_pktinfo src_info;
 581
 582                 if (is_ipv6) {
 583                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 584                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 585                 } else {
 586                         src_info.ipi6_ifindex =
 587                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 588                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 589                                                &src_info.ipi6_addr);
 590                 }
 591
 592                 if (src_info.ipi6_ifindex >= 0)
 593                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 594                                  sizeof(src_info), &src_info);
 595         }
 596 }
 597
 598 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 599                                     struct sk_buff *skb)
 600 {
 601         struct ipv6_pinfo *np = inet6_sk(sk);
 602         struct inet6_skb_parm *opt = IP6CB(skb);
 603         unsigned char *nh = skb_network_header(skb);
 604
 605         if (np->rxopt.bits.rxhlim) {
 606                 int hlim = ipv6_hdr(skb)->hop_limit;
 607                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 608         }
 609
 610         if (np->rxopt.bits.rxtclass) {
 611                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 612                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 613         }
 614
 615         if (np->rxopt.bits.rxflow) {
 616                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 617                 if (flowinfo)
 618                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 619         }
 620
 621         /* HbH is allowed only once */
 622         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 623                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 624                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 625         }
 626
 627         if (opt->lastopt &&
 628             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 629                 /*
 630                  * Silly enough, but we need to reparse in order to
 631                  * report extension headers (except for HbH)
 632                  * in order.
 633                  *
 634                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 635                  * (and WILL NOT be) defined because
 636                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 637                  */
 638                 unsigned int off = sizeof(struct ipv6hdr);
 639                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 640
 641                 while (off <= opt->lastopt) {
 642                         unsigned int len;
 643                         u8 *ptr = nh + off;
 644
 645                         switch (nexthdr) {
 646                         case IPPROTO_DSTOPTS:
 647                                 nexthdr = ptr[0];
 648                                 len = (ptr[1] + 1) << 3;
 649                                 if (np->rxopt.bits.dstopts)
 650                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 651                                 break;
 652                         case IPPROTO_ROUTING:
 653                                 nexthdr = ptr[0];
 654                                 len = (ptr[1] + 1) << 3;
 655                                 if (np->rxopt.bits.srcrt)
 656                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 657                                 break;
 658                         case IPPROTO_AH:
 659                                 nexthdr = ptr[0];
 660                                 len = (ptr[1] + 2) << 2;
 661                                 break;
 662                         default:
 663                                 nexthdr = ptr[0];
 664                                 len = (ptr[1] + 1) << 3;
 665                                 break;
 666                         }
 667
 668                         off += len;
 669                 }
 670         }
 671
 672         /* socket options in old style */
 673         if (np->rxopt.bits.rxoinfo) {
 674                 struct in6_pktinfo src_info;
 675
 676                 src_info.ipi6_ifindex = opt->iif;
 677                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 678                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 679         }
 680         if (np->rxopt.bits.rxohlim) {
 681                 int hlim = ipv6_hdr(skb)->hop_limit;
 682                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 683         }
 684         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 685                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 686                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 687         }
 688         if (np->rxopt.bits.odstopts && opt->dst0) {
 689                 u8 *ptr = nh + opt->dst0;
 690                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 691         }
 692         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 693                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 694                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 695         }
 696         if (np->rxopt.bits.odstopts && opt->dst1) {
 697                 u8 *ptr = nh + opt->dst1;
 698                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 699         }
 700         if (np->rxopt.bits.rxorigdstaddr) {
 701                 struct sockaddr_in6 sin6;
 702                 __be16 *ports = (__be16 *) skb_transport_header(skb);
 703
 704                 if (skb_transport_offset(skb) + 4 <= (int)skb->len) {
 705                         /* All current transport protocols have the port numbers in the
 706                          * first four bytes of the transport header and this function is
 707                          * written with this assumption in mind.
 708                          */
 709
 710                         sin6.sin6_family = AF_INET6;
 711                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 712                         sin6.sin6_port = ports[1];
 713                         sin6.sin6_flowinfo = 0;
 714                         sin6.sin6_scope_id =
 715                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 716                                                     opt->iif);
 717
 718                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 719                 }
 720         }
 721         if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
 722                 int val = opt->frag_max_size;
 723
 724                 put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
 725         }
 726 }
 727
 728 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 729                           struct sk_buff *skb)
 730 {
 731         ip6_datagram_recv_common_ctl(sk, msg, skb);
 732         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 733 }
 734 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 735
 736 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 737                           struct msghdr *msg, struct flowi6 *fl6,
 738                           struct ipcm6_cookie *ipc6, struct sockcm_cookie *sockc)
 739 {
 740         struct in6_pktinfo *src_info;
 741         struct cmsghdr *cmsg;
 742         struct ipv6_rt_hdr *rthdr;
 743         struct ipv6_opt_hdr *hdr;
 744         struct ipv6_txoptions *opt = ipc6->opt;
 745         int len;
 746         int err = 0;
 747
 748         for_each_cmsghdr(cmsg, msg) {
 749                 int addr_type;
 750
 751                 if (!CMSG_OK(msg, cmsg)) {
 752                         err = -EINVAL;
 753                         goto exit_f;
 754                 }
 755
 756                 if (cmsg->cmsg_level == SOL_SOCKET) {
 757                         err = __sock_cmsg_send(sk, msg, cmsg, sockc);
 758                         if (err)
 759                                 return err;
 760                         continue;
 761                 }
 762
 763                 if (cmsg->cmsg_level != SOL_IPV6)
 764                         continue;
 765
 766                 switch (cmsg->cmsg_type) {
 767                 case IPV6_PKTINFO:
 768                 case IPV6_2292PKTINFO:
 769                     {
 770                         struct net_device *dev = NULL;
 771
 772                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 773                                 err = -EINVAL;
 774                                 goto exit_f;
 775                         }
 776
 777                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 778
 779                         if (src_info->ipi6_ifindex) {
 780                                 if (fl6->flowi6_oif &&
 781                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 782                                         return -EINVAL;
 783                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 784                         }
 785
 786                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 787
 788                         rcu_read_lock();
 789                         if (fl6->flowi6_oif) {
 790                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 791                                 if (!dev) {
 792                                         rcu_read_unlock();
 793                                         return -ENODEV;
 794                                 }
 795                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 796                                 rcu_read_unlock();
 797                                 return -EINVAL;
 798                         }
 799
 800                         if (addr_type != IPV6_ADDR_ANY) {
 801                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 802                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 803                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 804                                                    strict ? dev : NULL, 0) &&
 805                                     !ipv6_chk_acast_addr_src(net, dev,
 806                                                              &src_info->ipi6_addr))
 807                                         err = -EINVAL;
 808                                 else
 809                                         fl6->saddr = src_info->ipi6_addr;
 810                         }
 811
 812                         rcu_read_unlock();
 813
 814                         if (err)
 815                                 goto exit_f;
 816
 817                         break;
 818                     }
 819
 820                 case IPV6_FLOWINFO:
 821                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 822                                 err = -EINVAL;
 823                                 goto exit_f;
 824                         }
 825
 826                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 827                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 828                                         err = -EINVAL;
 829                                         goto exit_f;
 830                                 }
 831                         }
 832                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 833                         break;
 834
 835                 case IPV6_2292HOPOPTS:
 836                 case IPV6_HOPOPTS:
 837                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 838                                 err = -EINVAL;
 839                                 goto exit_f;
 840                         }
 841
 842                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 843                         len = ((hdr->hdrlen + 1) << 3);
 844                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 845                                 err = -EINVAL;
 846                                 goto exit_f;
 847                         }
 848                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 849                                 err = -EPERM;
 850                                 goto exit_f;
 851                         }
 852                         opt->opt_nflen += len;
 853                         opt->hopopt = hdr;
 854                         break;
 855
 856                 case IPV6_2292DSTOPTS:
 857                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 858                                 err = -EINVAL;
 859                                 goto exit_f;
 860                         }
 861
 862                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 863                         len = ((hdr->hdrlen + 1) << 3);
 864                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 865                                 err = -EINVAL;
 866                                 goto exit_f;
 867                         }
 868                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 869                                 err = -EPERM;
 870                                 goto exit_f;
 871                         }
 872                         if (opt->dst1opt) {
 873                                 err = -EINVAL;
 874                                 goto exit_f;
 875                         }
 876                         opt->opt_flen += len;
 877                         opt->dst1opt = hdr;
 878                         break;
 879
 880                 case IPV6_DSTOPTS:
 881                 case IPV6_RTHDRDSTOPTS:
 882                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 883                                 err = -EINVAL;
 884                                 goto exit_f;
 885                         }
 886
 887                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 888                         len = ((hdr->hdrlen + 1) << 3);
 889                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 890                                 err = -EINVAL;
 891                                 goto exit_f;
 892                         }
 893                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 894                                 err = -EPERM;
 895                                 goto exit_f;
 896                         }
 897                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 898                                 opt->opt_flen += len;
 899                                 opt->dst1opt = hdr;
 900                         } else {
 901                                 opt->opt_nflen += len;
 902                                 opt->dst0opt = hdr;
 903                         }
 904                         break;
 905
 906                 case IPV6_2292RTHDR:
 907                 case IPV6_RTHDR:
 908                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 909                                 err = -EINVAL;
 910                                 goto exit_f;
 911                         }
 912
 913                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 914
 915                         switch (rthdr->type) {
 916 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 917                         case IPV6_SRCRT_TYPE_2:
 918                                 if (rthdr->hdrlen != 2 ||
 919                                     rthdr->segments_left != 1) {
 920                                         err = -EINVAL;
 921                                         goto exit_f;
 922                                 }
 923                                 break;
 924 #endif
 925                         default:
 926                                 err = -EINVAL;
 927                                 goto exit_f;
 928                         }
 929
 930                         len = ((rthdr->hdrlen + 1) << 3);
 931
 932                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 933                                 err = -EINVAL;
 934                                 goto exit_f;
 935                         }
 936
 937                         /* segments left must also match */
 938                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 939                                 err = -EINVAL;
 940                                 goto exit_f;
 941                         }
 942
 943                         opt->opt_nflen += len;
 944                         opt->srcrt = rthdr;
 945
 946                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 947                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 948
 949                                 opt->opt_nflen += dsthdrlen;
 950                                 opt->dst0opt = opt->dst1opt;
 951                                 opt->dst1opt = NULL;
 952                                 opt->opt_flen -= dsthdrlen;
 953                         }
 954
 955                         break;
 956
 957                 case IPV6_2292HOPLIMIT:
 958                 case IPV6_HOPLIMIT:
 959                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 960                                 err = -EINVAL;
 961                                 goto exit_f;
 962                         }
 963
 964                         ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 965                         if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 966                                 err = -EINVAL;
 967                                 goto exit_f;
 968                         }
 969
 970                         break;
 971
 972                 case IPV6_TCLASS:
 973                     {
 974                         int tc;
 975
 976                         err = -EINVAL;
 977                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 978                                 goto exit_f;
 979
 980                         tc = *(int *)CMSG_DATA(cmsg);
 981                         if (tc < -1 || tc > 0xff)
 982                                 goto exit_f;
 983
 984                         err = 0;
 985                         ipc6->tclass = tc;
 986
 987                         break;
 988                     }
 989
 990                 case IPV6_DONTFRAG:
 991                     {
 992                         int df;
 993
 994                         err = -EINVAL;
 995                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 996                                 goto exit_f;
 997
 998                         df = *(int *)CMSG_DATA(cmsg);
 999                         if (df < 0 || df > 1)
1000                                 goto exit_f;
1001
1002                         err = 0;
1003                         ipc6->dontfrag = df;
1004
1005                         break;
1006                     }
1007                 default:
1008                         net_dbg_ratelimited("invalid cmsg type: %d\n",
1009                                             cmsg->cmsg_type);
1010                         err = -EINVAL;
1011                         goto exit_f;
1012                 }
1013         }
1014
1015 exit_f:
1016         return err;
1017 }
1018 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1019
1020 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1021                              __u16 srcp, __u16 destp, int bucket)
1022 {
1023         const struct in6_addr *dest, *src;
1024
1025         dest  = &sp->sk_v6_daddr;
1026         src   = &sp->sk_v6_rcv_saddr;
1027         seq_printf(seq,
1028                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1029                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
1030                    bucket,
1031                    src->s6_addr32[0], src->s6_addr32[1],
1032                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1033                    dest->s6_addr32[0], dest->s6_addr32[1],
1034                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1035                    sp->sk_state,
1036                    sk_wmem_alloc_get(sp),
1037                    sk_rmem_alloc_get(sp),
1038                    0, 0L, 0,
1039                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1040                    0,
1041                    sock_i_ino(sp),
1042                    atomic_read(&sp->sk_refcnt), sp,
1043                    atomic_read(&sp->sk_drops));
1044 }