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         if (ipv6_addr_any(&usin->sin6_addr)) {
 171                 /*
 172                  *      connect to self
 173                  */
 174                 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
 175                         ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
 176                                                &usin->sin6_addr);
 177                 else
 178                         usin->sin6_addr = in6addr_loopback;
 179         }
 180
 181         addr_type = ipv6_addr_type(&usin->sin6_addr);
 182
 183         daddr = &usin->sin6_addr;
 184
 185         if (addr_type & IPV6_ADDR_MAPPED) {
 186                 struct sockaddr_in sin;
 187
 188                 if (__ipv6_only_sock(sk)) {
 189                         err = -ENETUNREACH;
 190                         goto out;
 191                 }
 192                 sin.sin_family = AF_INET;
 193                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
 194                 sin.sin_port = usin->sin6_port;
 195
 196                 err = __ip4_datagram_connect(sk,
 197                                              (struct sockaddr *) &sin,
 198                                              sizeof(sin));
 199
 200 ipv4_connected:
 201                 if (err)
 202                         goto out;
 203
 204                 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 205
 206                 if (ipv6_addr_any(&np->saddr) ||
 207                     ipv6_mapped_addr_any(&np->saddr))
 208                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 209
 210                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 211                     ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 212                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 213                                                &sk->sk_v6_rcv_saddr);
 214                         if (sk->sk_prot->rehash)
 215                                 sk->sk_prot->rehash(sk);
 216                 }
 217
 218                 goto out;
 219         }
 220
 221         if (__ipv6_addr_needs_scope_id(addr_type)) {
 222                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 223                     usin->sin6_scope_id) {
 224                         if (sk->sk_bound_dev_if &&
 225                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 226                                 err = -EINVAL;
 227                                 goto out;
 228                         }
 229                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 230                 }
 231
 232                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 233                         sk->sk_bound_dev_if = np->mcast_oif;
 234
 235                 /* Connect to link-local address requires an interface */
 236                 if (!sk->sk_bound_dev_if) {
 237                         err = -EINVAL;
 238                         goto out;
 239                 }
 240         }
 241
 242         sk->sk_v6_daddr = *daddr;
 243         np->flow_label = fl6_flowlabel;
 244
 245         inet->inet_dport = usin->sin6_port;
 246
 247         /*
 248          *      Check for a route to destination an obtain the
 249          *      destination cache for it.
 250          */
 251
 252         err = ip6_datagram_dst_update(sk, true);
 253         if (err)
 254                 goto out;
 255
 256         sk->sk_state = TCP_ESTABLISHED;
 257         sk_set_txhash(sk);
 258 out:
 259         return err;
 260 }
 261 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 262
 263 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 264 {
 265         int res;
 266
 267         lock_sock(sk);
 268         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 269         release_sock(sk);
 270         return res;
 271 }
 272 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 273
 274 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 275                                  int addr_len)
 276 {
 277         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 278         if (sin6->sin6_family != AF_INET6)
 279                 return -EAFNOSUPPORT;
 280         return ip6_datagram_connect(sk, uaddr, addr_len);
 281 }
 282 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 283
 284 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 285                      __be16 port, u32 info, u8 *payload)
 286 {
 287         struct ipv6_pinfo *np  = inet6_sk(sk);
 288         struct icmp6hdr *icmph = icmp6_hdr(skb);
 289         struct sock_exterr_skb *serr;
 290
 291         if (!np->recverr)
 292                 return;
 293
 294         skb = skb_clone(skb, GFP_ATOMIC);
 295         if (!skb)
 296                 return;
 297
 298         skb->protocol = htons(ETH_P_IPV6);
 299
 300         serr = SKB_EXT_ERR(skb);
 301         serr->ee.ee_errno = err;
 302         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 303         serr->ee.ee_type = icmph->icmp6_type;
 304         serr->ee.ee_code = icmph->icmp6_code;
 305         serr->ee.ee_pad = 0;
 306         serr->ee.ee_info = info;
 307         serr->ee.ee_data = 0;
 308         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 309                                   skb_network_header(skb);
 310         serr->port = port;
 311
 312         __skb_pull(skb, payload - skb->data);
 313         skb_reset_transport_header(skb);
 314
 315         if (sock_queue_err_skb(sk, skb))
 316                 kfree_skb(skb);
 317 }
 318
 319 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 320 {
 321         const struct ipv6_pinfo *np = inet6_sk(sk);
 322         struct sock_exterr_skb *serr;
 323         struct ipv6hdr *iph;
 324         struct sk_buff *skb;
 325
 326         if (!np->recverr)
 327                 return;
 328
 329         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 330         if (!skb)
 331                 return;
 332
 333         skb->protocol = htons(ETH_P_IPV6);
 334
 335         skb_put(skb, sizeof(struct ipv6hdr));
 336         skb_reset_network_header(skb);
 337         iph = ipv6_hdr(skb);
 338         iph->daddr = fl6->daddr;
 339
 340         serr = SKB_EXT_ERR(skb);
 341         serr->ee.ee_errno = err;
 342         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 343         serr->ee.ee_type = 0;
 344         serr->ee.ee_code = 0;
 345         serr->ee.ee_pad = 0;
 346         serr->ee.ee_info = info;
 347         serr->ee.ee_data = 0;
 348         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 349         serr->port = fl6->fl6_dport;
 350
 351         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 352         skb_reset_transport_header(skb);
 353
 354         if (sock_queue_err_skb(sk, skb))
 355                 kfree_skb(skb);
 356 }
 357
 358 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 359 {
 360         struct ipv6_pinfo *np = inet6_sk(sk);
 361         struct ipv6hdr *iph;
 362         struct sk_buff *skb;
 363         struct ip6_mtuinfo *mtu_info;
 364
 365         if (!np->rxopt.bits.rxpmtu)
 366                 return;
 367
 368         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 369         if (!skb)
 370                 return;
 371
 372         skb_put(skb, sizeof(struct ipv6hdr));
 373         skb_reset_network_header(skb);
 374         iph = ipv6_hdr(skb);
 375         iph->daddr = fl6->daddr;
 376
 377         mtu_info = IP6CBMTU(skb);
 378
 379         mtu_info->ip6m_mtu = mtu;
 380         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 381         mtu_info->ip6m_addr.sin6_port = 0;
 382         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 383         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 384         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 385
 386         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 387         skb_reset_transport_header(skb);
 388
 389         skb = xchg(&np->rxpmtu, skb);
 390         kfree_skb(skb);
 391 }
 392
 393 /* For some errors we have valid addr_offset even with zero payload and
 394  * zero port. Also, addr_offset should be supported if port is set.
 395  */
 396 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 397 {
 398         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 399                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 400                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 401 }
 402
 403 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 404  *
 405  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 406  * errors. This is no longer true, but the test remained, so the v6 stack,
 407  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 408  */
 409 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 410                                       struct sock_exterr_skb *serr)
 411 {
 412         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 413             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 414                 return true;
 415
 416         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 417                 return false;
 418
 419         if (!IP6CB(skb)->iif)
 420                 return false;
 421
 422         return true;
 423 }
 424
 425 /*
 426  *      Handle MSG_ERRQUEUE
 427  */
 428 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 429 {
 430         struct ipv6_pinfo *np = inet6_sk(sk);
 431         struct sock_exterr_skb *serr;
 432         struct sk_buff *skb;
 433         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 434         struct {
 435                 struct sock_extended_err ee;
 436                 struct sockaddr_in6      offender;
 437         } errhdr;
 438         int err;
 439         int copied;
 440
 441         err = -EAGAIN;
 442         skb = sock_dequeue_err_skb(sk);
 443         if (!skb)
 444                 goto out;
 445
 446         copied = skb->len;
 447         if (copied > len) {
 448                 msg->msg_flags |= MSG_TRUNC;
 449                 copied = len;
 450         }
 451         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 452         if (unlikely(err)) {
 453                 kfree_skb(skb);
 454                 return err;
 455         }
 456         sock_recv_timestamp(msg, sk, skb);
 457
 458         serr = SKB_EXT_ERR(skb);
 459
 460         if (sin && ipv6_datagram_support_addr(serr)) {
 461                 const unsigned char *nh = skb_network_header(skb);
 462                 sin->sin6_family = AF_INET6;
 463                 sin->sin6_flowinfo = 0;
 464                 sin->sin6_port = serr->port;
 465                 if (skb->protocol == htons(ETH_P_IPV6)) {
 466                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 467                                                                   struct ipv6hdr, daddr);
 468                         sin->sin6_addr = ip6h->daddr;
 469                         if (np->sndflow)
 470                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 471                         sin->sin6_scope_id =
 472                                 ipv6_iface_scope_id(&sin->sin6_addr,
 473                                                     IP6CB(skb)->iif);
 474                 } else {
 475                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 476                                                &sin->sin6_addr);
 477                         sin->sin6_scope_id = 0;
 478                 }
 479                 *addr_len = sizeof(*sin);
 480         }
 481
 482         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 483         sin = &errhdr.offender;
 484         memset(sin, 0, sizeof(*sin));
 485
 486         if (ip6_datagram_support_cmsg(skb, serr)) {
 487                 sin->sin6_family = AF_INET6;
 488                 if (np->rxopt.all)
 489                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 490                 if (skb->protocol == htons(ETH_P_IPV6)) {
 491                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 492                         if (np->rxopt.all)
 493                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 494                         sin->sin6_scope_id =
 495                                 ipv6_iface_scope_id(&sin->sin6_addr,
 496                                                     IP6CB(skb)->iif);
 497                 } else {
 498                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 499                                                &sin->sin6_addr);
 500                         if (inet_sk(sk)->cmsg_flags)
 501                                 ip_cmsg_recv(msg, skb);
 502                 }
 503         }
 504
 505         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 506
 507         /* Now we could try to dump offended packet options */
 508
 509         msg->msg_flags |= MSG_ERRQUEUE;
 510         err = copied;
 511
 512         consume_skb(skb);
 513 out:
 514         return err;
 515 }
 516 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 517
 518 /*
 519  *      Handle IPV6_RECVPATHMTU
 520  */
 521 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 522                      int *addr_len)
 523 {
 524         struct ipv6_pinfo *np = inet6_sk(sk);
 525         struct sk_buff *skb;
 526         struct ip6_mtuinfo mtu_info;
 527         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 528         int err;
 529         int copied;
 530
 531         err = -EAGAIN;
 532         skb = xchg(&np->rxpmtu, NULL);
 533         if (!skb)
 534                 goto out;
 535
 536         copied = skb->len;
 537         if (copied > len) {
 538                 msg->msg_flags |= MSG_TRUNC;
 539                 copied = len;
 540         }
 541         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 542         if (err)
 543                 goto out_free_skb;
 544
 545         sock_recv_timestamp(msg, sk, skb);
 546
 547         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 548
 549         if (sin) {
 550                 sin->sin6_family = AF_INET6;
 551                 sin->sin6_flowinfo = 0;
 552                 sin->sin6_port = 0;
 553                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 554                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 555                 *addr_len = sizeof(*sin);
 556         }
 557
 558         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 559
 560         err = copied;
 561
 562 out_free_skb:
 563         kfree_skb(skb);
 564 out:
 565         return err;
 566 }
 567
 568
 569 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 570                                  struct sk_buff *skb)
 571 {
 572         struct ipv6_pinfo *np = inet6_sk(sk);
 573         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 574
 575         if (np->rxopt.bits.rxinfo) {
 576                 struct in6_pktinfo src_info;
 577
 578                 if (is_ipv6) {
 579                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 580                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 581                 } else {
 582                         src_info.ipi6_ifindex =
 583                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 584                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 585                                                &src_info.ipi6_addr);
 586                 }
 587
 588                 if (src_info.ipi6_ifindex >= 0)
 589                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 590                                  sizeof(src_info), &src_info);
 591         }
 592 }
 593
 594 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 595                                     struct sk_buff *skb)
 596 {
 597         struct ipv6_pinfo *np = inet6_sk(sk);
 598         struct inet6_skb_parm *opt = IP6CB(skb);
 599         unsigned char *nh = skb_network_header(skb);
 600
 601         if (np->rxopt.bits.rxhlim) {
 602                 int hlim = ipv6_hdr(skb)->hop_limit;
 603                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 604         }
 605
 606         if (np->rxopt.bits.rxtclass) {
 607                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 608                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 609         }
 610
 611         if (np->rxopt.bits.rxflow) {
 612                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 613                 if (flowinfo)
 614                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 615         }
 616
 617         /* HbH is allowed only once */
 618         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 619                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 620                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 621         }
 622
 623         if (opt->lastopt &&
 624             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 625                 /*
 626                  * Silly enough, but we need to reparse in order to
 627                  * report extension headers (except for HbH)
 628                  * in order.
 629                  *
 630                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 631                  * (and WILL NOT be) defined because
 632                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 633                  */
 634                 unsigned int off = sizeof(struct ipv6hdr);
 635                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 636
 637                 while (off <= opt->lastopt) {
 638                         unsigned int len;
 639                         u8 *ptr = nh + off;
 640
 641                         switch (nexthdr) {
 642                         case IPPROTO_DSTOPTS:
 643                                 nexthdr = ptr[0];
 644                                 len = (ptr[1] + 1) << 3;
 645                                 if (np->rxopt.bits.dstopts)
 646                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 647                                 break;
 648                         case IPPROTO_ROUTING:
 649                                 nexthdr = ptr[0];
 650                                 len = (ptr[1] + 1) << 3;
 651                                 if (np->rxopt.bits.srcrt)
 652                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 653                                 break;
 654                         case IPPROTO_AH:
 655                                 nexthdr = ptr[0];
 656                                 len = (ptr[1] + 2) << 2;
 657                                 break;
 658                         default:
 659                                 nexthdr = ptr[0];
 660                                 len = (ptr[1] + 1) << 3;
 661                                 break;
 662                         }
 663
 664                         off += len;
 665                 }
 666         }
 667
 668         /* socket options in old style */
 669         if (np->rxopt.bits.rxoinfo) {
 670                 struct in6_pktinfo src_info;
 671
 672                 src_info.ipi6_ifindex = opt->iif;
 673                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 674                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 675         }
 676         if (np->rxopt.bits.rxohlim) {
 677                 int hlim = ipv6_hdr(skb)->hop_limit;
 678                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 679         }
 680         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 681                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 682                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 683         }
 684         if (np->rxopt.bits.odstopts && opt->dst0) {
 685                 u8 *ptr = nh + opt->dst0;
 686                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 687         }
 688         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 689                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 690                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 691         }
 692         if (np->rxopt.bits.odstopts && opt->dst1) {
 693                 u8 *ptr = nh + opt->dst1;
 694                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 695         }
 696         if (np->rxopt.bits.rxorigdstaddr) {
 697                 struct sockaddr_in6 sin6;
 698                 __be16 *ports = (__be16 *) skb_transport_header(skb);
 699
 700                 if (skb_transport_offset(skb) + 4 <= (int)skb->len) {
 701                         /* All current transport protocols have the port numbers in the
 702                          * first four bytes of the transport header and this function is
 703                          * written with this assumption in mind.
 704                          */
 705
 706                         sin6.sin6_family = AF_INET6;
 707                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 708                         sin6.sin6_port = ports[1];
 709                         sin6.sin6_flowinfo = 0;
 710                         sin6.sin6_scope_id =
 711                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 712                                                     opt->iif);
 713
 714                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 715                 }
 716         }
 717         if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
 718                 int val = opt->frag_max_size;
 719
 720                 put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
 721         }
 722 }
 723
 724 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 725                           struct sk_buff *skb)
 726 {
 727         ip6_datagram_recv_common_ctl(sk, msg, skb);
 728         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 729 }
 730 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 731
 732 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 733                           struct msghdr *msg, struct flowi6 *fl6,
 734                           struct ipcm6_cookie *ipc6, struct sockcm_cookie *sockc)
 735 {
 736         struct in6_pktinfo *src_info;
 737         struct cmsghdr *cmsg;
 738         struct ipv6_rt_hdr *rthdr;
 739         struct ipv6_opt_hdr *hdr;
 740         struct ipv6_txoptions *opt = ipc6->opt;
 741         int len;
 742         int err = 0;
 743
 744         for_each_cmsghdr(cmsg, msg) {
 745                 int addr_type;
 746
 747                 if (!CMSG_OK(msg, cmsg)) {
 748                         err = -EINVAL;
 749                         goto exit_f;
 750                 }
 751
 752                 if (cmsg->cmsg_level == SOL_SOCKET) {
 753                         err = __sock_cmsg_send(sk, msg, cmsg, sockc);
 754                         if (err)
 755                                 return err;
 756                         continue;
 757                 }
 758
 759                 if (cmsg->cmsg_level != SOL_IPV6)
 760                         continue;
 761
 762                 switch (cmsg->cmsg_type) {
 763                 case IPV6_PKTINFO:
 764                 case IPV6_2292PKTINFO:
 765                     {
 766                         struct net_device *dev = NULL;
 767
 768                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 769                                 err = -EINVAL;
 770                                 goto exit_f;
 771                         }
 772
 773                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 774
 775                         if (src_info->ipi6_ifindex) {
 776                                 if (fl6->flowi6_oif &&
 777                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 778                                         return -EINVAL;
 779                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 780                         }
 781
 782                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 783
 784                         rcu_read_lock();
 785                         if (fl6->flowi6_oif) {
 786                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 787                                 if (!dev) {
 788                                         rcu_read_unlock();
 789                                         return -ENODEV;
 790                                 }
 791                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 792                                 rcu_read_unlock();
 793                                 return -EINVAL;
 794                         }
 795
 796                         if (addr_type != IPV6_ADDR_ANY) {
 797                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 798                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 799                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 800                                                    strict ? dev : NULL, 0) &&
 801                                     !ipv6_chk_acast_addr_src(net, dev,
 802                                                              &src_info->ipi6_addr))
 803                                         err = -EINVAL;
 804                                 else
 805                                         fl6->saddr = src_info->ipi6_addr;
 806                         }
 807
 808                         rcu_read_unlock();
 809
 810                         if (err)
 811                                 goto exit_f;
 812
 813                         break;
 814                     }
 815
 816                 case IPV6_FLOWINFO:
 817                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 818                                 err = -EINVAL;
 819                                 goto exit_f;
 820                         }
 821
 822                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 823                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 824                                         err = -EINVAL;
 825                                         goto exit_f;
 826                                 }
 827                         }
 828                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 829                         break;
 830
 831                 case IPV6_2292HOPOPTS:
 832                 case IPV6_HOPOPTS:
 833                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 834                                 err = -EINVAL;
 835                                 goto exit_f;
 836                         }
 837
 838                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 839                         len = ((hdr->hdrlen + 1) << 3);
 840                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 841                                 err = -EINVAL;
 842                                 goto exit_f;
 843                         }
 844                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 845                                 err = -EPERM;
 846                                 goto exit_f;
 847                         }
 848                         opt->opt_nflen += len;
 849                         opt->hopopt = hdr;
 850                         break;
 851
 852                 case IPV6_2292DSTOPTS:
 853                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 854                                 err = -EINVAL;
 855                                 goto exit_f;
 856                         }
 857
 858                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 859                         len = ((hdr->hdrlen + 1) << 3);
 860                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 861                                 err = -EINVAL;
 862                                 goto exit_f;
 863                         }
 864                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 865                                 err = -EPERM;
 866                                 goto exit_f;
 867                         }
 868                         if (opt->dst1opt) {
 869                                 err = -EINVAL;
 870                                 goto exit_f;
 871                         }
 872                         opt->opt_flen += len;
 873                         opt->dst1opt = hdr;
 874                         break;
 875
 876                 case IPV6_DSTOPTS:
 877                 case IPV6_RTHDRDSTOPTS:
 878                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 879                                 err = -EINVAL;
 880                                 goto exit_f;
 881                         }
 882
 883                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 884                         len = ((hdr->hdrlen + 1) << 3);
 885                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 886                                 err = -EINVAL;
 887                                 goto exit_f;
 888                         }
 889                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 890                                 err = -EPERM;
 891                                 goto exit_f;
 892                         }
 893                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 894                                 opt->opt_flen += len;
 895                                 opt->dst1opt = hdr;
 896                         } else {
 897                                 opt->opt_nflen += len;
 898                                 opt->dst0opt = hdr;
 899                         }
 900                         break;
 901
 902                 case IPV6_2292RTHDR:
 903                 case IPV6_RTHDR:
 904                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 905                                 err = -EINVAL;
 906                                 goto exit_f;
 907                         }
 908
 909                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 910
 911                         switch (rthdr->type) {
 912 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 913                         case IPV6_SRCRT_TYPE_2:
 914                                 if (rthdr->hdrlen != 2 ||
 915                                     rthdr->segments_left != 1) {
 916                                         err = -EINVAL;
 917                                         goto exit_f;
 918                                 }
 919                                 break;
 920 #endif
 921                         default:
 922                                 err = -EINVAL;
 923                                 goto exit_f;
 924                         }
 925
 926                         len = ((rthdr->hdrlen + 1) << 3);
 927
 928                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 929                                 err = -EINVAL;
 930                                 goto exit_f;
 931                         }
 932
 933                         /* segments left must also match */
 934                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 935                                 err = -EINVAL;
 936                                 goto exit_f;
 937                         }
 938
 939                         opt->opt_nflen += len;
 940                         opt->srcrt = rthdr;
 941
 942                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 943                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 944
 945                                 opt->opt_nflen += dsthdrlen;
 946                                 opt->dst0opt = opt->dst1opt;
 947                                 opt->dst1opt = NULL;
 948                                 opt->opt_flen -= dsthdrlen;
 949                         }
 950
 951                         break;
 952
 953                 case IPV6_2292HOPLIMIT:
 954                 case IPV6_HOPLIMIT:
 955                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 956                                 err = -EINVAL;
 957                                 goto exit_f;
 958                         }
 959
 960                         ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 961                         if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 962                                 err = -EINVAL;
 963                                 goto exit_f;
 964                         }
 965
 966                         break;
 967
 968                 case IPV6_TCLASS:
 969                     {
 970                         int tc;
 971
 972                         err = -EINVAL;
 973                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 974                                 goto exit_f;
 975
 976                         tc = *(int *)CMSG_DATA(cmsg);
 977                         if (tc < -1 || tc > 0xff)
 978                                 goto exit_f;
 979
 980                         err = 0;
 981                         ipc6->tclass = tc;
 982
 983                         break;
 984                     }
 985
 986                 case IPV6_DONTFRAG:
 987                     {
 988                         int df;
 989
 990                         err = -EINVAL;
 991                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 992                                 goto exit_f;
 993
 994                         df = *(int *)CMSG_DATA(cmsg);
 995                         if (df < 0 || df > 1)
 996                                 goto exit_f;
 997
 998                         err = 0;
 999                         ipc6->dontfrag = df;
1000
1001                         break;
1002                     }
1003                 default:
1004                         net_dbg_ratelimited("invalid cmsg type: %d\n",
1005                                             cmsg->cmsg_type);
1006                         err = -EINVAL;
1007                         goto exit_f;
1008                 }
1009         }
1010
1011 exit_f:
1012         return err;
1013 }
1014 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1015
1016 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1017                              __u16 srcp, __u16 destp, int bucket)
1018 {
1019         const struct in6_addr *dest, *src;
1020
1021         dest  = &sp->sk_v6_daddr;
1022         src   = &sp->sk_v6_rcv_saddr;
1023         seq_printf(seq,
1024                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1025                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
1026                    bucket,
1027                    src->s6_addr32[0], src->s6_addr32[1],
1028                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1029                    dest->s6_addr32[0], dest->s6_addr32[1],
1030                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1031                    sp->sk_state,
1032                    sk_wmem_alloc_get(sp),
1033                    sk_rmem_alloc_get(sp),
1034                    0, 0L, 0,
1035                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1036                    0,
1037                    sock_i_ino(sp),
1038                    atomic_read(&sp->sk_refcnt), sp,
1039                    atomic_read(&sp->sk_drops));
1040 }