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 #include <net/sock_reuseport.h>
  35
  36 #include <linux/errqueue.h>
  37 #include <linux/uaccess.h>
  38
  39 static bool ipv6_mapped_addr_any(const struct in6_addr *a)
  40 {
  41         return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
  42 }
  43
  44 static void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
  45 {
  46         struct inet_sock *inet = inet_sk(sk);
  47         struct ipv6_pinfo *np = inet6_sk(sk);
  48
  49         memset(fl6, 0, sizeof(*fl6));
  50         fl6->flowi6_proto = sk->sk_protocol;
  51         fl6->daddr = sk->sk_v6_daddr;
  52         fl6->saddr = np->saddr;
  53         fl6->flowi6_oif = sk->sk_bound_dev_if;
  54         fl6->flowi6_mark = sk->sk_mark;
  55         fl6->fl6_dport = inet->inet_dport;
  56         fl6->fl6_sport = inet->inet_sport;
  57         fl6->flowlabel = np->flow_label;
  58         fl6->flowi6_uid = sk->sk_uid;
  59
  60         if (!fl6->flowi6_oif)
  61                 fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
  62
  63         if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr))
  64                 fl6->flowi6_oif = np->mcast_oif;
  65
  66         security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
  67 }
  68
  69 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
  70 {
  71         struct ip6_flowlabel *flowlabel = NULL;
  72         struct in6_addr *final_p, final;
  73         struct ipv6_txoptions *opt;
  74         struct dst_entry *dst;
  75         struct inet_sock *inet = inet_sk(sk);
  76         struct ipv6_pinfo *np = inet6_sk(sk);
  77         struct flowi6 fl6;
  78         int err = 0;
  79
  80         if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
  81                 flowlabel = fl6_sock_lookup(sk, np->flow_label);
  82                 if (!flowlabel)
  83                         return -EINVAL;
  84         }
  85         ip6_datagram_flow_key_init(&fl6, sk);
  86
  87         rcu_read_lock();
  88         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
  89         final_p = fl6_update_dst(&fl6, opt, &final);
  90         rcu_read_unlock();
  91
  92         dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
  93         if (IS_ERR(dst)) {
  94                 err = PTR_ERR(dst);
  95                 goto out;
  96         }
  97
  98         if (fix_sk_saddr) {
  99                 if (ipv6_addr_any(&np->saddr))
 100                         np->saddr = fl6.saddr;
 101
 102                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 103                         sk->sk_v6_rcv_saddr = fl6.saddr;
 104                         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 105                         if (sk->sk_prot->rehash)
 106                                 sk->sk_prot->rehash(sk);
 107                 }
 108         }
 109
 110         ip6_sk_dst_store_flow(sk, dst, &fl6);
 111
 112 out:
 113         fl6_sock_release(flowlabel);
 114         return err;
 115 }
 116
 117 void ip6_datagram_release_cb(struct sock *sk)
 118 {
 119         struct dst_entry *dst;
 120
 121         if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 122                 return;
 123
 124         rcu_read_lock();
 125         dst = __sk_dst_get(sk);
 126         if (!dst || !dst->obsolete ||
 127             dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
 128                 rcu_read_unlock();
 129                 return;
 130         }
 131         rcu_read_unlock();
 132
 133         ip6_datagram_dst_update(sk, false);
 134 }
 135 EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
 136
 137 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
 138                            int addr_len)
 139 {
 140         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
 141         struct inet_sock        *inet = inet_sk(sk);
 142         struct ipv6_pinfo       *np = inet6_sk(sk);
 143         struct in6_addr         *daddr, old_daddr;
 144         __be32                  fl6_flowlabel = 0;
 145         __be32                  old_fl6_flowlabel;
 146         __be16                  old_dport;
 147         int                     addr_type;
 148         int                     err;
 149
 150         if (usin->sin6_family == AF_INET) {
 151                 if (__ipv6_only_sock(sk))
 152                         return -EAFNOSUPPORT;
 153                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
 154                 goto ipv4_connected;
 155         }
 156
 157         if (addr_len < SIN6_LEN_RFC2133)
 158                 return -EINVAL;
 159
 160         if (usin->sin6_family != AF_INET6)
 161                 return -EAFNOSUPPORT;
 162
 163         if (np->sndflow)
 164                 fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 165
 166         if (ipv6_addr_any(&usin->sin6_addr)) {
 167                 /*
 168                  *      connect to self
 169                  */
 170                 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
 171                         ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
 172                                                &usin->sin6_addr);
 173                 else
 174                         usin->sin6_addr = in6addr_loopback;
 175         }
 176
 177         addr_type = ipv6_addr_type(&usin->sin6_addr);
 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_dev_equal_l3scope(sk, 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         /* save the current peer information before updating it */
 238         old_daddr = sk->sk_v6_daddr;
 239         old_fl6_flowlabel = np->flow_label;
 240         old_dport = inet->inet_dport;
 241
 242         sk->sk_v6_daddr = *daddr;
 243         np->flow_label = fl6_flowlabel;
 244         inet->inet_dport = usin->sin6_port;
 245
 246         /*
 247          *      Check for a route to destination an obtain the
 248          *      destination cache for it.
 249          */
 250
 251         err = ip6_datagram_dst_update(sk, true);
 252         if (err) {
 253                 /* Restore the socket peer info, to keep it consistent with
 254                  * the old socket state
 255                  */
 256                 sk->sk_v6_daddr = old_daddr;
 257                 np->flow_label = old_fl6_flowlabel;
 258                 inet->inet_dport = old_dport;
 259                 goto out;
 260         }
 261
 262         reuseport_has_conns(sk, true);
 263         sk->sk_state = TCP_ESTABLISHED;
 264         sk_set_txhash(sk);
 265 out:
 266         return err;
 267 }
 268 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 269
 270 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 271 {
 272         int res;
 273
 274         lock_sock(sk);
 275         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 276         release_sock(sk);
 277         return res;
 278 }
 279 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 280
 281 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 282                                  int addr_len)
 283 {
 284         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 285         if (sin6->sin6_family != AF_INET6)
 286                 return -EAFNOSUPPORT;
 287         return ip6_datagram_connect(sk, uaddr, addr_len);
 288 }
 289 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 290
 291 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 292                      __be16 port, u32 info, u8 *payload)
 293 {
 294         struct ipv6_pinfo *np  = inet6_sk(sk);
 295         struct icmp6hdr *icmph = icmp6_hdr(skb);
 296         struct sock_exterr_skb *serr;
 297
 298         if (!np->recverr)
 299                 return;
 300
 301         skb = skb_clone(skb, GFP_ATOMIC);
 302         if (!skb)
 303                 return;
 304
 305         skb->protocol = htons(ETH_P_IPV6);
 306
 307         serr = SKB_EXT_ERR(skb);
 308         serr->ee.ee_errno = err;
 309         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 310         serr->ee.ee_type = icmph->icmp6_type;
 311         serr->ee.ee_code = icmph->icmp6_code;
 312         serr->ee.ee_pad = 0;
 313         serr->ee.ee_info = info;
 314         serr->ee.ee_data = 0;
 315         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 316                                   skb_network_header(skb);
 317         serr->port = port;
 318
 319         __skb_pull(skb, payload - skb->data);
 320         skb_reset_transport_header(skb);
 321
 322         if (sock_queue_err_skb(sk, skb))
 323                 kfree_skb(skb);
 324 }
 325
 326 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 327 {
 328         const struct ipv6_pinfo *np = inet6_sk(sk);
 329         struct sock_exterr_skb *serr;
 330         struct ipv6hdr *iph;
 331         struct sk_buff *skb;
 332
 333         if (!np->recverr)
 334                 return;
 335
 336         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 337         if (!skb)
 338                 return;
 339
 340         skb->protocol = htons(ETH_P_IPV6);
 341
 342         skb_put(skb, sizeof(struct ipv6hdr));
 343         skb_reset_network_header(skb);
 344         iph = ipv6_hdr(skb);
 345         iph->daddr = fl6->daddr;
 346         ip6_flow_hdr(iph, 0, 0);
 347
 348         serr = SKB_EXT_ERR(skb);
 349         serr->ee.ee_errno = err;
 350         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 351         serr->ee.ee_type = 0;
 352         serr->ee.ee_code = 0;
 353         serr->ee.ee_pad = 0;
 354         serr->ee.ee_info = info;
 355         serr->ee.ee_data = 0;
 356         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 357         serr->port = fl6->fl6_dport;
 358
 359         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 360         skb_reset_transport_header(skb);
 361
 362         if (sock_queue_err_skb(sk, skb))
 363                 kfree_skb(skb);
 364 }
 365
 366 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 367 {
 368         struct ipv6_pinfo *np = inet6_sk(sk);
 369         struct ipv6hdr *iph;
 370         struct sk_buff *skb;
 371         struct ip6_mtuinfo *mtu_info;
 372
 373         if (!np->rxopt.bits.rxpmtu)
 374                 return;
 375
 376         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 377         if (!skb)
 378                 return;
 379
 380         skb_put(skb, sizeof(struct ipv6hdr));
 381         skb_reset_network_header(skb);
 382         iph = ipv6_hdr(skb);
 383         iph->daddr = fl6->daddr;
 384
 385         mtu_info = IP6CBMTU(skb);
 386
 387         mtu_info->ip6m_mtu = mtu;
 388         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 389         mtu_info->ip6m_addr.sin6_port = 0;
 390         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 391         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 392         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 393
 394         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 395         skb_reset_transport_header(skb);
 396
 397         skb = xchg(&np->rxpmtu, skb);
 398         kfree_skb(skb);
 399 }
 400
 401 /* For some errors we have valid addr_offset even with zero payload and
 402  * zero port. Also, addr_offset should be supported if port is set.
 403  */
 404 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 405 {
 406         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 407                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 408                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 409 }
 410
 411 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 412  *
 413  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 414  * errors. This is no longer true, but the test remained, so the v6 stack,
 415  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 416  */
 417 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 418                                       struct sock_exterr_skb *serr)
 419 {
 420         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 421             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 422                 return true;
 423
 424         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 425                 return false;
 426
 427         if (!IP6CB(skb)->iif)
 428                 return false;
 429
 430         return true;
 431 }
 432
 433 /*
 434  *      Handle MSG_ERRQUEUE
 435  */
 436 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 437 {
 438         struct ipv6_pinfo *np = inet6_sk(sk);
 439         struct sock_exterr_skb *serr;
 440         struct sk_buff *skb;
 441         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 442         struct {
 443                 struct sock_extended_err ee;
 444                 struct sockaddr_in6      offender;
 445         } errhdr;
 446         int err;
 447         int copied;
 448
 449         err = -EAGAIN;
 450         skb = sock_dequeue_err_skb(sk);
 451         if (!skb)
 452                 goto out;
 453
 454         copied = skb->len;
 455         if (copied > len) {
 456                 msg->msg_flags |= MSG_TRUNC;
 457                 copied = len;
 458         }
 459         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 460         if (unlikely(err)) {
 461                 kfree_skb(skb);
 462                 return err;
 463         }
 464         sock_recv_timestamp(msg, sk, skb);
 465
 466         serr = SKB_EXT_ERR(skb);
 467
 468         if (sin && ipv6_datagram_support_addr(serr)) {
 469                 const unsigned char *nh = skb_network_header(skb);
 470                 sin->sin6_family = AF_INET6;
 471                 sin->sin6_flowinfo = 0;
 472                 sin->sin6_port = serr->port;
 473                 if (skb->protocol == htons(ETH_P_IPV6)) {
 474                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 475                                                                   struct ipv6hdr, daddr);
 476                         sin->sin6_addr = ip6h->daddr;
 477                         if (np->sndflow)
 478                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 479                         sin->sin6_scope_id =
 480                                 ipv6_iface_scope_id(&sin->sin6_addr,
 481                                                     IP6CB(skb)->iif);
 482                 } else {
 483                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 484                                                &sin->sin6_addr);
 485                         sin->sin6_scope_id = 0;
 486                 }
 487                 *addr_len = sizeof(*sin);
 488         }
 489
 490         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 491         sin = &errhdr.offender;
 492         memset(sin, 0, sizeof(*sin));
 493
 494         if (ip6_datagram_support_cmsg(skb, serr)) {
 495                 sin->sin6_family = AF_INET6;
 496                 if (np->rxopt.all)
 497                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 498                 if (skb->protocol == htons(ETH_P_IPV6)) {
 499                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 500                         if (np->rxopt.all)
 501                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 502                         sin->sin6_scope_id =
 503                                 ipv6_iface_scope_id(&sin->sin6_addr,
 504                                                     IP6CB(skb)->iif);
 505                 } else {
 506                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 507                                                &sin->sin6_addr);
 508                         if (inet_sk(sk)->cmsg_flags)
 509                                 ip_cmsg_recv(msg, skb);
 510                 }
 511         }
 512
 513         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 514
 515         /* Now we could try to dump offended packet options */
 516
 517         msg->msg_flags |= MSG_ERRQUEUE;
 518         err = copied;
 519
 520         consume_skb(skb);
 521 out:
 522         return err;
 523 }
 524 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 525
 526 /*
 527  *      Handle IPV6_RECVPATHMTU
 528  */
 529 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 530                      int *addr_len)
 531 {
 532         struct ipv6_pinfo *np = inet6_sk(sk);
 533         struct sk_buff *skb;
 534         struct ip6_mtuinfo mtu_info;
 535         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 536         int err;
 537         int copied;
 538
 539         err = -EAGAIN;
 540         skb = xchg(&np->rxpmtu, NULL);
 541         if (!skb)
 542                 goto out;
 543
 544         copied = skb->len;
 545         if (copied > len) {
 546                 msg->msg_flags |= MSG_TRUNC;
 547                 copied = len;
 548         }
 549         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 550         if (err)
 551                 goto out_free_skb;
 552
 553         sock_recv_timestamp(msg, sk, skb);
 554
 555         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 556
 557         if (sin) {
 558                 sin->sin6_family = AF_INET6;
 559                 sin->sin6_flowinfo = 0;
 560                 sin->sin6_port = 0;
 561                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 562                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 563                 *addr_len = sizeof(*sin);
 564         }
 565
 566         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 567
 568         err = copied;
 569
 570 out_free_skb:
 571         kfree_skb(skb);
 572 out:
 573         return err;
 574 }
 575
 576
 577 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 578                                  struct sk_buff *skb)
 579 {
 580         struct ipv6_pinfo *np = inet6_sk(sk);
 581         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 582
 583         if (np->rxopt.bits.rxinfo) {
 584                 struct in6_pktinfo src_info;
 585
 586                 if (is_ipv6) {
 587                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 588                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 589                 } else {
 590                         src_info.ipi6_ifindex =
 591                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 592                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 593                                                &src_info.ipi6_addr);
 594                 }
 595
 596                 if (src_info.ipi6_ifindex >= 0)
 597                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 598                                  sizeof(src_info), &src_info);
 599         }
 600 }
 601
 602 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 603                                     struct sk_buff *skb)
 604 {
 605         struct ipv6_pinfo *np = inet6_sk(sk);
 606         struct inet6_skb_parm *opt = IP6CB(skb);
 607         unsigned char *nh = skb_network_header(skb);
 608
 609         if (np->rxopt.bits.rxhlim) {
 610                 int hlim = ipv6_hdr(skb)->hop_limit;
 611                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 612         }
 613
 614         if (np->rxopt.bits.rxtclass) {
 615                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 616                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 617         }
 618
 619         if (np->rxopt.bits.rxflow) {
 620                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 621                 if (flowinfo)
 622                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 623         }
 624
 625         /* HbH is allowed only once */
 626         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 627                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 628                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 629         }
 630
 631         if (opt->lastopt &&
 632             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 633                 /*
 634                  * Silly enough, but we need to reparse in order to
 635                  * report extension headers (except for HbH)
 636                  * in order.
 637                  *
 638                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 639                  * (and WILL NOT be) defined because
 640                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 641                  */
 642                 unsigned int off = sizeof(struct ipv6hdr);
 643                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 644
 645                 while (off <= opt->lastopt) {
 646                         unsigned int len;
 647                         u8 *ptr = nh + off;
 648
 649                         switch (nexthdr) {
 650                         case IPPROTO_DSTOPTS:
 651                                 nexthdr = ptr[0];
 652                                 len = (ptr[1] + 1) << 3;
 653                                 if (np->rxopt.bits.dstopts)
 654                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 655                                 break;
 656                         case IPPROTO_ROUTING:
 657                                 nexthdr = ptr[0];
 658                                 len = (ptr[1] + 1) << 3;
 659                                 if (np->rxopt.bits.srcrt)
 660                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 661                                 break;
 662                         case IPPROTO_AH:
 663                                 nexthdr = ptr[0];
 664                                 len = (ptr[1] + 2) << 2;
 665                                 break;
 666                         default:
 667                                 nexthdr = ptr[0];
 668                                 len = (ptr[1] + 1) << 3;
 669                                 break;
 670                         }
 671
 672                         off += len;
 673                 }
 674         }
 675
 676         /* socket options in old style */
 677         if (np->rxopt.bits.rxoinfo) {
 678                 struct in6_pktinfo src_info;
 679
 680                 src_info.ipi6_ifindex = opt->iif;
 681                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 682                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 683         }
 684         if (np->rxopt.bits.rxohlim) {
 685                 int hlim = ipv6_hdr(skb)->hop_limit;
 686                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 687         }
 688         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 689                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 690                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 691         }
 692         if (np->rxopt.bits.odstopts && opt->dst0) {
 693                 u8 *ptr = nh + opt->dst0;
 694                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 695         }
 696         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 697                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 698                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 699         }
 700         if (np->rxopt.bits.odstopts && opt->dst1) {
 701                 u8 *ptr = nh + opt->dst1;
 702                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 703         }
 704         if (np->rxopt.bits.rxorigdstaddr) {
 705                 struct sockaddr_in6 sin6;
 706                 __be16 _ports[2], *ports;
 707
 708                 ports = skb_header_pointer(skb, skb_transport_offset(skb),
 709                                            sizeof(_ports), &_ports);
 710                 if (ports) {
 711                         /* All current transport protocols have the port numbers in the
 712                          * first four bytes of the transport header and this function is
 713                          * written with this assumption in mind.
 714                          */
 715                         sin6.sin6_family = AF_INET6;
 716                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 717                         sin6.sin6_port = ports[1];
 718                         sin6.sin6_flowinfo = 0;
 719                         sin6.sin6_scope_id =
 720                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 721                                                     opt->iif);
 722
 723                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 724                 }
 725         }
 726         if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
 727                 int val = opt->frag_max_size;
 728
 729                 put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
 730         }
 731 }
 732
 733 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 734                           struct sk_buff *skb)
 735 {
 736         ip6_datagram_recv_common_ctl(sk, msg, skb);
 737         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 738 }
 739 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 740
 741 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 742                           struct msghdr *msg, struct flowi6 *fl6,
 743                           struct ipcm6_cookie *ipc6)
 744 {
 745         struct in6_pktinfo *src_info;
 746         struct cmsghdr *cmsg;
 747         struct ipv6_rt_hdr *rthdr;
 748         struct ipv6_opt_hdr *hdr;
 749         struct ipv6_txoptions *opt = ipc6->opt;
 750         int len;
 751         int err = 0;
 752
 753         for_each_cmsghdr(cmsg, msg) {
 754                 int addr_type;
 755
 756                 if (!CMSG_OK(msg, cmsg)) {
 757                         err = -EINVAL;
 758                         goto exit_f;
 759                 }
 760
 761                 if (cmsg->cmsg_level == SOL_SOCKET) {
 762                         err = __sock_cmsg_send(sk, msg, cmsg, &ipc6->sockc);
 763                         if (err)
 764                                 return err;
 765                         continue;
 766                 }
 767
 768                 if (cmsg->cmsg_level != SOL_IPV6)
 769                         continue;
 770
 771                 switch (cmsg->cmsg_type) {
 772                 case IPV6_PKTINFO:
 773                 case IPV6_2292PKTINFO:
 774                     {
 775                         struct net_device *dev = NULL;
 776
 777                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 778                                 err = -EINVAL;
 779                                 goto exit_f;
 780                         }
 781
 782                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 783
 784                         if (src_info->ipi6_ifindex) {
 785                                 if (fl6->flowi6_oif &&
 786                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 787                                         return -EINVAL;
 788                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 789                         }
 790
 791                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 792
 793                         rcu_read_lock();
 794                         if (fl6->flowi6_oif) {
 795                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 796                                 if (!dev) {
 797                                         rcu_read_unlock();
 798                                         return -ENODEV;
 799                                 }
 800                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 801                                 rcu_read_unlock();
 802                                 return -EINVAL;
 803                         }
 804
 805                         if (addr_type != IPV6_ADDR_ANY) {
 806                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 807                                 if (!ipv6_can_nonlocal_bind(net, inet_sk(sk)) &&
 808                                     !ipv6_chk_addr_and_flags(net, &src_info->ipi6_addr,
 809                                                              dev, !strict, 0,
 810                                                              IFA_F_TENTATIVE) &&
 811                                     !ipv6_chk_acast_addr_src(net, dev,
 812                                                              &src_info->ipi6_addr))
 813                                         err = -EINVAL;
 814                                 else
 815                                         fl6->saddr = src_info->ipi6_addr;
 816                         }
 817
 818                         rcu_read_unlock();
 819
 820                         if (err)
 821                                 goto exit_f;
 822
 823                         break;
 824                     }
 825
 826                 case IPV6_FLOWINFO:
 827                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 828                                 err = -EINVAL;
 829                                 goto exit_f;
 830                         }
 831
 832                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 833                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 834                                         err = -EINVAL;
 835                                         goto exit_f;
 836                                 }
 837                         }
 838                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 839                         break;
 840
 841                 case IPV6_2292HOPOPTS:
 842                 case IPV6_HOPOPTS:
 843                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 844                                 err = -EINVAL;
 845                                 goto exit_f;
 846                         }
 847
 848                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 849                         len = ((hdr->hdrlen + 1) << 3);
 850                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 851                                 err = -EINVAL;
 852                                 goto exit_f;
 853                         }
 854                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 855                                 err = -EPERM;
 856                                 goto exit_f;
 857                         }
 858                         opt->opt_nflen += len;
 859                         opt->hopopt = hdr;
 860                         break;
 861
 862                 case IPV6_2292DSTOPTS:
 863                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 864                                 err = -EINVAL;
 865                                 goto exit_f;
 866                         }
 867
 868                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 869                         len = ((hdr->hdrlen + 1) << 3);
 870                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 871                                 err = -EINVAL;
 872                                 goto exit_f;
 873                         }
 874                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 875                                 err = -EPERM;
 876                                 goto exit_f;
 877                         }
 878                         if (opt->dst1opt) {
 879                                 err = -EINVAL;
 880                                 goto exit_f;
 881                         }
 882                         opt->opt_flen += len;
 883                         opt->dst1opt = hdr;
 884                         break;
 885
 886                 case IPV6_DSTOPTS:
 887                 case IPV6_RTHDRDSTOPTS:
 888                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 889                                 err = -EINVAL;
 890                                 goto exit_f;
 891                         }
 892
 893                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 894                         len = ((hdr->hdrlen + 1) << 3);
 895                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 896                                 err = -EINVAL;
 897                                 goto exit_f;
 898                         }
 899                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 900                                 err = -EPERM;
 901                                 goto exit_f;
 902                         }
 903                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 904                                 opt->opt_flen += len;
 905                                 opt->dst1opt = hdr;
 906                         } else {
 907                                 opt->opt_nflen += len;
 908                                 opt->dst0opt = hdr;
 909                         }
 910                         break;
 911
 912                 case IPV6_2292RTHDR:
 913                 case IPV6_RTHDR:
 914                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 915                                 err = -EINVAL;
 916                                 goto exit_f;
 917                         }
 918
 919                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 920
 921                         switch (rthdr->type) {
 922 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 923                         case IPV6_SRCRT_TYPE_2:
 924                                 if (rthdr->hdrlen != 2 ||
 925                                     rthdr->segments_left != 1) {
 926                                         err = -EINVAL;
 927                                         goto exit_f;
 928                                 }
 929                                 break;
 930 #endif
 931                         default:
 932                                 err = -EINVAL;
 933                                 goto exit_f;
 934                         }
 935
 936                         len = ((rthdr->hdrlen + 1) << 3);
 937
 938                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 939                                 err = -EINVAL;
 940                                 goto exit_f;
 941                         }
 942
 943                         /* segments left must also match */
 944                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 945                                 err = -EINVAL;
 946                                 goto exit_f;
 947                         }
 948
 949                         opt->opt_nflen += len;
 950                         opt->srcrt = rthdr;
 951
 952                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 953                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 954
 955                                 opt->opt_nflen += dsthdrlen;
 956                                 opt->dst0opt = opt->dst1opt;
 957                                 opt->dst1opt = NULL;
 958                                 opt->opt_flen -= dsthdrlen;
 959                         }
 960
 961                         break;
 962
 963                 case IPV6_2292HOPLIMIT:
 964                 case IPV6_HOPLIMIT:
 965                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 966                                 err = -EINVAL;
 967                                 goto exit_f;
 968                         }
 969
 970                         ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 971                         if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 972                                 err = -EINVAL;
 973                                 goto exit_f;
 974                         }
 975
 976                         break;
 977
 978                 case IPV6_TCLASS:
 979                     {
 980                         int tc;
 981
 982                         err = -EINVAL;
 983                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 984                                 goto exit_f;
 985
 986                         tc = *(int *)CMSG_DATA(cmsg);
 987                         if (tc < -1 || tc > 0xff)
 988                                 goto exit_f;
 989
 990                         err = 0;
 991                         ipc6->tclass = tc;
 992
 993                         break;
 994                     }
 995
 996                 case IPV6_DONTFRAG:
 997                     {
 998                         int df;
 999
1000                         err = -EINVAL;
1001                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1002                                 goto exit_f;
1003
1004                         df = *(int *)CMSG_DATA(cmsg);
1005                         if (df < 0 || df > 1)
1006                                 goto exit_f;
1007
1008                         err = 0;
1009                         ipc6->dontfrag = df;
1010
1011                         break;
1012                     }
1013                 default:
1014                         net_dbg_ratelimited("invalid cmsg type: %d\n",
1015                                             cmsg->cmsg_type);
1016                         err = -EINVAL;
1017                         goto exit_f;
1018                 }
1019         }
1020
1021 exit_f:
1022         return err;
1023 }
1024 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1025
1026 void __ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1027                                __u16 srcp, __u16 destp, int rqueue, int bucket)
1028 {
1029         const struct in6_addr *dest, *src;
1030
1031         dest  = &sp->sk_v6_daddr;
1032         src   = &sp->sk_v6_rcv_saddr;
1033         seq_printf(seq,
1034                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1035                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
1036                    bucket,
1037                    src->s6_addr32[0], src->s6_addr32[1],
1038                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1039                    dest->s6_addr32[0], dest->s6_addr32[1],
1040                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1041                    sp->sk_state,
1042                    sk_wmem_alloc_get(sp),
1043                    rqueue,
1044                    0, 0L, 0,
1045                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1046                    0,
1047                    sock_i_ino(sp),
1048                    refcount_read(&sp->sk_refcnt), sp,
1049                    atomic_read(&sp->sk_drops));
1050 }