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(sock_net(sk), 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, old_daddr;
 150         __be32                  fl6_flowlabel = 0;
 151         __be32                  old_fl6_flowlabel;
 152         __be16                  old_dport;
 153         int                     addr_type;
 154         int                     err;
 155
 156         if (usin->sin6_family == AF_INET) {
 157                 if (__ipv6_only_sock(sk))
 158                         return -EAFNOSUPPORT;
 159                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
 160                 goto ipv4_connected;
 161         }
 162
 163         if (addr_len < SIN6_LEN_RFC2133)
 164                 return -EINVAL;
 165
 166         if (usin->sin6_family != AF_INET6)
 167                 return -EAFNOSUPPORT;
 168
 169         if (np->sndflow)
 170                 fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 171
 172         if (ipv6_addr_any(&usin->sin6_addr)) {
 173                 /*
 174                  *      connect to self
 175                  */
 176                 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
 177                         ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
 178                                                &usin->sin6_addr);
 179                 else
 180                         usin->sin6_addr = in6addr_loopback;
 181         }
 182
 183         addr_type = ipv6_addr_type(&usin->sin6_addr);
 184
 185         daddr = &usin->sin6_addr;
 186
 187         if (addr_type & IPV6_ADDR_MAPPED) {
 188                 struct sockaddr_in sin;
 189
 190                 if (__ipv6_only_sock(sk)) {
 191                         err = -ENETUNREACH;
 192                         goto out;
 193                 }
 194                 sin.sin_family = AF_INET;
 195                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
 196                 sin.sin_port = usin->sin6_port;
 197
 198                 err = __ip4_datagram_connect(sk,
 199                                              (struct sockaddr *) &sin,
 200                                              sizeof(sin));
 201
 202 ipv4_connected:
 203                 if (err)
 204                         goto out;
 205
 206                 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 207
 208                 if (ipv6_addr_any(&np->saddr) ||
 209                     ipv6_mapped_addr_any(&np->saddr))
 210                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 211
 212                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 213                     ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 214                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 215                                                &sk->sk_v6_rcv_saddr);
 216                         if (sk->sk_prot->rehash)
 217                                 sk->sk_prot->rehash(sk);
 218                 }
 219
 220                 goto out;
 221         }
 222
 223         if (__ipv6_addr_needs_scope_id(addr_type)) {
 224                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 225                     usin->sin6_scope_id) {
 226                         if (sk->sk_bound_dev_if &&
 227                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 228                                 err = -EINVAL;
 229                                 goto out;
 230                         }
 231                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 232                 }
 233
 234                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 235                         sk->sk_bound_dev_if = np->mcast_oif;
 236
 237                 /* Connect to link-local address requires an interface */
 238                 if (!sk->sk_bound_dev_if) {
 239                         err = -EINVAL;
 240                         goto out;
 241                 }
 242         }
 243
 244         /* save the current peer information before updating it */
 245         old_daddr = sk->sk_v6_daddr;
 246         old_fl6_flowlabel = np->flow_label;
 247         old_dport = inet->inet_dport;
 248
 249         sk->sk_v6_daddr = *daddr;
 250         np->flow_label = fl6_flowlabel;
 251         inet->inet_dport = usin->sin6_port;
 252
 253         /*
 254          *      Check for a route to destination an obtain the
 255          *      destination cache for it.
 256          */
 257
 258         err = ip6_datagram_dst_update(sk, true);
 259         if (err) {
 260                 /* Restore the socket peer info, to keep it consistent with
 261                  * the old socket state
 262                  */
 263                 sk->sk_v6_daddr = old_daddr;
 264                 np->flow_label = old_fl6_flowlabel;
 265                 inet->inet_dport = old_dport;
 266                 goto out;
 267         }
 268
 269         sk->sk_state = TCP_ESTABLISHED;
 270         sk_set_txhash(sk);
 271 out:
 272         return err;
 273 }
 274 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 275
 276 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 277 {
 278         int res;
 279
 280         lock_sock(sk);
 281         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 282         release_sock(sk);
 283         return res;
 284 }
 285 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 286
 287 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 288                                  int addr_len)
 289 {
 290         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 291         if (sin6->sin6_family != AF_INET6)
 292                 return -EAFNOSUPPORT;
 293         return ip6_datagram_connect(sk, uaddr, addr_len);
 294 }
 295 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 296
 297 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 298                      __be16 port, u32 info, u8 *payload)
 299 {
 300         struct ipv6_pinfo *np  = inet6_sk(sk);
 301         struct icmp6hdr *icmph = icmp6_hdr(skb);
 302         struct sock_exterr_skb *serr;
 303
 304         if (!np->recverr)
 305                 return;
 306
 307         skb = skb_clone(skb, GFP_ATOMIC);
 308         if (!skb)
 309                 return;
 310
 311         skb->protocol = htons(ETH_P_IPV6);
 312
 313         serr = SKB_EXT_ERR(skb);
 314         serr->ee.ee_errno = err;
 315         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 316         serr->ee.ee_type = icmph->icmp6_type;
 317         serr->ee.ee_code = icmph->icmp6_code;
 318         serr->ee.ee_pad = 0;
 319         serr->ee.ee_info = info;
 320         serr->ee.ee_data = 0;
 321         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 322                                   skb_network_header(skb);
 323         serr->port = port;
 324
 325         __skb_pull(skb, payload - skb->data);
 326         skb_reset_transport_header(skb);
 327
 328         if (sock_queue_err_skb(sk, skb))
 329                 kfree_skb(skb);
 330 }
 331
 332 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 333 {
 334         const struct ipv6_pinfo *np = inet6_sk(sk);
 335         struct sock_exterr_skb *serr;
 336         struct ipv6hdr *iph;
 337         struct sk_buff *skb;
 338
 339         if (!np->recverr)
 340                 return;
 341
 342         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 343         if (!skb)
 344                 return;
 345
 346         skb->protocol = htons(ETH_P_IPV6);
 347
 348         skb_put(skb, sizeof(struct ipv6hdr));
 349         skb_reset_network_header(skb);
 350         iph = ipv6_hdr(skb);
 351         iph->daddr = fl6->daddr;
 352         ip6_flow_hdr(iph, 0, 0);
 353
 354         serr = SKB_EXT_ERR(skb);
 355         serr->ee.ee_errno = err;
 356         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 357         serr->ee.ee_type = 0;
 358         serr->ee.ee_code = 0;
 359         serr->ee.ee_pad = 0;
 360         serr->ee.ee_info = info;
 361         serr->ee.ee_data = 0;
 362         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 363         serr->port = fl6->fl6_dport;
 364
 365         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 366         skb_reset_transport_header(skb);
 367
 368         if (sock_queue_err_skb(sk, skb))
 369                 kfree_skb(skb);
 370 }
 371
 372 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 373 {
 374         struct ipv6_pinfo *np = inet6_sk(sk);
 375         struct ipv6hdr *iph;
 376         struct sk_buff *skb;
 377         struct ip6_mtuinfo *mtu_info;
 378
 379         if (!np->rxopt.bits.rxpmtu)
 380                 return;
 381
 382         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 383         if (!skb)
 384                 return;
 385
 386         skb_put(skb, sizeof(struct ipv6hdr));
 387         skb_reset_network_header(skb);
 388         iph = ipv6_hdr(skb);
 389         iph->daddr = fl6->daddr;
 390
 391         mtu_info = IP6CBMTU(skb);
 392
 393         mtu_info->ip6m_mtu = mtu;
 394         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 395         mtu_info->ip6m_addr.sin6_port = 0;
 396         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 397         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 398         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 399
 400         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 401         skb_reset_transport_header(skb);
 402
 403         skb = xchg(&np->rxpmtu, skb);
 404         kfree_skb(skb);
 405 }
 406
 407 /* For some errors we have valid addr_offset even with zero payload and
 408  * zero port. Also, addr_offset should be supported if port is set.
 409  */
 410 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 411 {
 412         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 413                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 414                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 415 }
 416
 417 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 418  *
 419  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 420  * errors. This is no longer true, but the test remained, so the v6 stack,
 421  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 422  */
 423 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 424                                       struct sock_exterr_skb *serr)
 425 {
 426         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 427             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 428                 return true;
 429
 430         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 431                 return false;
 432
 433         if (!IP6CB(skb)->iif)
 434                 return false;
 435
 436         return true;
 437 }
 438
 439 /*
 440  *      Handle MSG_ERRQUEUE
 441  */
 442 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 443 {
 444         struct ipv6_pinfo *np = inet6_sk(sk);
 445         struct sock_exterr_skb *serr;
 446         struct sk_buff *skb;
 447         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 448         struct {
 449                 struct sock_extended_err ee;
 450                 struct sockaddr_in6      offender;
 451         } errhdr;
 452         int err;
 453         int copied;
 454
 455         err = -EAGAIN;
 456         skb = sock_dequeue_err_skb(sk);
 457         if (!skb)
 458                 goto out;
 459
 460         copied = skb->len;
 461         if (copied > len) {
 462                 msg->msg_flags |= MSG_TRUNC;
 463                 copied = len;
 464         }
 465         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 466         if (unlikely(err)) {
 467                 kfree_skb(skb);
 468                 return err;
 469         }
 470         sock_recv_timestamp(msg, sk, skb);
 471
 472         serr = SKB_EXT_ERR(skb);
 473
 474         if (sin && ipv6_datagram_support_addr(serr)) {
 475                 const unsigned char *nh = skb_network_header(skb);
 476                 sin->sin6_family = AF_INET6;
 477                 sin->sin6_flowinfo = 0;
 478                 sin->sin6_port = serr->port;
 479                 if (skb->protocol == htons(ETH_P_IPV6)) {
 480                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 481                                                                   struct ipv6hdr, daddr);
 482                         sin->sin6_addr = ip6h->daddr;
 483                         if (np->sndflow)
 484                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 485                         sin->sin6_scope_id =
 486                                 ipv6_iface_scope_id(&sin->sin6_addr,
 487                                                     IP6CB(skb)->iif);
 488                 } else {
 489                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 490                                                &sin->sin6_addr);
 491                         sin->sin6_scope_id = 0;
 492                 }
 493                 *addr_len = sizeof(*sin);
 494         }
 495
 496         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 497         sin = &errhdr.offender;
 498         memset(sin, 0, sizeof(*sin));
 499
 500         if (ip6_datagram_support_cmsg(skb, serr)) {
 501                 sin->sin6_family = AF_INET6;
 502                 if (np->rxopt.all)
 503                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 504                 if (skb->protocol == htons(ETH_P_IPV6)) {
 505                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 506                         if (np->rxopt.all)
 507                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 508                         sin->sin6_scope_id =
 509                                 ipv6_iface_scope_id(&sin->sin6_addr,
 510                                                     IP6CB(skb)->iif);
 511                 } else {
 512                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 513                                                &sin->sin6_addr);
 514                         if (inet_sk(sk)->cmsg_flags)
 515                                 ip_cmsg_recv(msg, skb);
 516                 }
 517         }
 518
 519         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 520
 521         /* Now we could try to dump offended packet options */
 522
 523         msg->msg_flags |= MSG_ERRQUEUE;
 524         err = copied;
 525
 526         consume_skb(skb);
 527 out:
 528         return err;
 529 }
 530 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 531
 532 /*
 533  *      Handle IPV6_RECVPATHMTU
 534  */
 535 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 536                      int *addr_len)
 537 {
 538         struct ipv6_pinfo *np = inet6_sk(sk);
 539         struct sk_buff *skb;
 540         struct ip6_mtuinfo mtu_info;
 541         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 542         int err;
 543         int copied;
 544
 545         err = -EAGAIN;
 546         skb = xchg(&np->rxpmtu, NULL);
 547         if (!skb)
 548                 goto out;
 549
 550         copied = skb->len;
 551         if (copied > len) {
 552                 msg->msg_flags |= MSG_TRUNC;
 553                 copied = len;
 554         }
 555         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 556         if (err)
 557                 goto out_free_skb;
 558
 559         sock_recv_timestamp(msg, sk, skb);
 560
 561         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 562
 563         if (sin) {
 564                 sin->sin6_family = AF_INET6;
 565                 sin->sin6_flowinfo = 0;
 566                 sin->sin6_port = 0;
 567                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 568                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 569                 *addr_len = sizeof(*sin);
 570         }
 571
 572         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 573
 574         err = copied;
 575
 576 out_free_skb:
 577         kfree_skb(skb);
 578 out:
 579         return err;
 580 }
 581
 582
 583 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 584                                  struct sk_buff *skb)
 585 {
 586         struct ipv6_pinfo *np = inet6_sk(sk);
 587         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 588
 589         if (np->rxopt.bits.rxinfo) {
 590                 struct in6_pktinfo src_info;
 591
 592                 if (is_ipv6) {
 593                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 594                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 595                 } else {
 596                         src_info.ipi6_ifindex =
 597                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 598                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 599                                                &src_info.ipi6_addr);
 600                 }
 601
 602                 if (src_info.ipi6_ifindex >= 0)
 603                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 604                                  sizeof(src_info), &src_info);
 605         }
 606 }
 607
 608 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 609                                     struct sk_buff *skb)
 610 {
 611         struct ipv6_pinfo *np = inet6_sk(sk);
 612         struct inet6_skb_parm *opt = IP6CB(skb);
 613         unsigned char *nh = skb_network_header(skb);
 614
 615         if (np->rxopt.bits.rxhlim) {
 616                 int hlim = ipv6_hdr(skb)->hop_limit;
 617                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 618         }
 619
 620         if (np->rxopt.bits.rxtclass) {
 621                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 622                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 623         }
 624
 625         if (np->rxopt.bits.rxflow) {
 626                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 627                 if (flowinfo)
 628                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 629         }
 630
 631         /* HbH is allowed only once */
 632         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 633                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 634                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 635         }
 636
 637         if (opt->lastopt &&
 638             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 639                 /*
 640                  * Silly enough, but we need to reparse in order to
 641                  * report extension headers (except for HbH)
 642                  * in order.
 643                  *
 644                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 645                  * (and WILL NOT be) defined because
 646                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 647                  */
 648                 unsigned int off = sizeof(struct ipv6hdr);
 649                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 650
 651                 while (off <= opt->lastopt) {
 652                         unsigned int len;
 653                         u8 *ptr = nh + off;
 654
 655                         switch (nexthdr) {
 656                         case IPPROTO_DSTOPTS:
 657                                 nexthdr = ptr[0];
 658                                 len = (ptr[1] + 1) << 3;
 659                                 if (np->rxopt.bits.dstopts)
 660                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 661                                 break;
 662                         case IPPROTO_ROUTING:
 663                                 nexthdr = ptr[0];
 664                                 len = (ptr[1] + 1) << 3;
 665                                 if (np->rxopt.bits.srcrt)
 666                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 667                                 break;
 668                         case IPPROTO_AH:
 669                                 nexthdr = ptr[0];
 670                                 len = (ptr[1] + 2) << 2;
 671                                 break;
 672                         default:
 673                                 nexthdr = ptr[0];
 674                                 len = (ptr[1] + 1) << 3;
 675                                 break;
 676                         }
 677
 678                         off += len;
 679                 }
 680         }
 681
 682         /* socket options in old style */
 683         if (np->rxopt.bits.rxoinfo) {
 684                 struct in6_pktinfo src_info;
 685
 686                 src_info.ipi6_ifindex = opt->iif;
 687                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 688                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 689         }
 690         if (np->rxopt.bits.rxohlim) {
 691                 int hlim = ipv6_hdr(skb)->hop_limit;
 692                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 693         }
 694         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 695                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 696                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 697         }
 698         if (np->rxopt.bits.odstopts && opt->dst0) {
 699                 u8 *ptr = nh + opt->dst0;
 700                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 701         }
 702         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 703                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 704                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 705         }
 706         if (np->rxopt.bits.odstopts && opt->dst1) {
 707                 u8 *ptr = nh + opt->dst1;
 708                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 709         }
 710         if (np->rxopt.bits.rxorigdstaddr) {
 711                 struct sockaddr_in6 sin6;
 712                 __be16 _ports[2], *ports;
 713
 714                 ports = skb_header_pointer(skb, skb_transport_offset(skb),
 715                                            sizeof(_ports), &_ports);
 716                 if (ports) {
 717                         /* All current transport protocols have the port numbers in the
 718                          * first four bytes of the transport header and this function is
 719                          * written with this assumption in mind.
 720                          */
 721                         sin6.sin6_family = AF_INET6;
 722                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 723                         sin6.sin6_port = ports[1];
 724                         sin6.sin6_flowinfo = 0;
 725                         sin6.sin6_scope_id =
 726                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 727                                                     opt->iif);
 728
 729                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 730                 }
 731         }
 732         if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
 733                 int val = opt->frag_max_size;
 734
 735                 put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
 736         }
 737 }
 738
 739 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 740                           struct sk_buff *skb)
 741 {
 742         ip6_datagram_recv_common_ctl(sk, msg, skb);
 743         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 744 }
 745 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 746
 747 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 748                           struct msghdr *msg, struct flowi6 *fl6,
 749                           struct ipcm6_cookie *ipc6, struct sockcm_cookie *sockc)
 750 {
 751         struct in6_pktinfo *src_info;
 752         struct cmsghdr *cmsg;
 753         struct ipv6_rt_hdr *rthdr;
 754         struct ipv6_opt_hdr *hdr;
 755         struct ipv6_txoptions *opt = ipc6->opt;
 756         int len;
 757         int err = 0;
 758
 759         for_each_cmsghdr(cmsg, msg) {
 760                 int addr_type;
 761
 762                 if (!CMSG_OK(msg, cmsg)) {
 763                         err = -EINVAL;
 764                         goto exit_f;
 765                 }
 766
 767                 if (cmsg->cmsg_level == SOL_SOCKET) {
 768                         err = __sock_cmsg_send(sk, msg, cmsg, sockc);
 769                         if (err)
 770                                 return err;
 771                         continue;
 772                 }
 773
 774                 if (cmsg->cmsg_level != SOL_IPV6)
 775                         continue;
 776
 777                 switch (cmsg->cmsg_type) {
 778                 case IPV6_PKTINFO:
 779                 case IPV6_2292PKTINFO:
 780                     {
 781                         struct net_device *dev = NULL;
 782
 783                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 784                                 err = -EINVAL;
 785                                 goto exit_f;
 786                         }
 787
 788                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 789
 790                         if (src_info->ipi6_ifindex) {
 791                                 if (fl6->flowi6_oif &&
 792                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 793                                         return -EINVAL;
 794                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 795                         }
 796
 797                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 798
 799                         rcu_read_lock();
 800                         if (fl6->flowi6_oif) {
 801                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 802                                 if (!dev) {
 803                                         rcu_read_unlock();
 804                                         return -ENODEV;
 805                                 }
 806                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 807                                 rcu_read_unlock();
 808                                 return -EINVAL;
 809                         }
 810
 811                         if (addr_type != IPV6_ADDR_ANY) {
 812                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 813                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 814                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 815                                                    strict ? dev : NULL, 0) &&
 816                                     !ipv6_chk_acast_addr_src(net, dev,
 817                                                              &src_info->ipi6_addr))
 818                                         err = -EINVAL;
 819                                 else
 820                                         fl6->saddr = src_info->ipi6_addr;
 821                         }
 822
 823                         rcu_read_unlock();
 824
 825                         if (err)
 826                                 goto exit_f;
 827
 828                         break;
 829                     }
 830
 831                 case IPV6_FLOWINFO:
 832                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 833                                 err = -EINVAL;
 834                                 goto exit_f;
 835                         }
 836
 837                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 838                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 839                                         err = -EINVAL;
 840                                         goto exit_f;
 841                                 }
 842                         }
 843                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 844                         break;
 845
 846                 case IPV6_2292HOPOPTS:
 847                 case IPV6_HOPOPTS:
 848                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 849                                 err = -EINVAL;
 850                                 goto exit_f;
 851                         }
 852
 853                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 854                         len = ((hdr->hdrlen + 1) << 3);
 855                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 856                                 err = -EINVAL;
 857                                 goto exit_f;
 858                         }
 859                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 860                                 err = -EPERM;
 861                                 goto exit_f;
 862                         }
 863                         opt->opt_nflen += len;
 864                         opt->hopopt = hdr;
 865                         break;
 866
 867                 case IPV6_2292DSTOPTS:
 868                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 869                                 err = -EINVAL;
 870                                 goto exit_f;
 871                         }
 872
 873                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 874                         len = ((hdr->hdrlen + 1) << 3);
 875                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 876                                 err = -EINVAL;
 877                                 goto exit_f;
 878                         }
 879                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 880                                 err = -EPERM;
 881                                 goto exit_f;
 882                         }
 883                         if (opt->dst1opt) {
 884                                 err = -EINVAL;
 885                                 goto exit_f;
 886                         }
 887                         opt->opt_flen += len;
 888                         opt->dst1opt = hdr;
 889                         break;
 890
 891                 case IPV6_DSTOPTS:
 892                 case IPV6_RTHDRDSTOPTS:
 893                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 894                                 err = -EINVAL;
 895                                 goto exit_f;
 896                         }
 897
 898                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 899                         len = ((hdr->hdrlen + 1) << 3);
 900                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 901                                 err = -EINVAL;
 902                                 goto exit_f;
 903                         }
 904                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 905                                 err = -EPERM;
 906                                 goto exit_f;
 907                         }
 908                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 909                                 opt->opt_flen += len;
 910                                 opt->dst1opt = hdr;
 911                         } else {
 912                                 opt->opt_nflen += len;
 913                                 opt->dst0opt = hdr;
 914                         }
 915                         break;
 916
 917                 case IPV6_2292RTHDR:
 918                 case IPV6_RTHDR:
 919                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 920                                 err = -EINVAL;
 921                                 goto exit_f;
 922                         }
 923
 924                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 925
 926                         switch (rthdr->type) {
 927 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 928                         case IPV6_SRCRT_TYPE_2:
 929                                 if (rthdr->hdrlen != 2 ||
 930                                     rthdr->segments_left != 1) {
 931                                         err = -EINVAL;
 932                                         goto exit_f;
 933                                 }
 934                                 break;
 935 #endif
 936                         default:
 937                                 err = -EINVAL;
 938                                 goto exit_f;
 939                         }
 940
 941                         len = ((rthdr->hdrlen + 1) << 3);
 942
 943                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 944                                 err = -EINVAL;
 945                                 goto exit_f;
 946                         }
 947
 948                         /* segments left must also match */
 949                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 950                                 err = -EINVAL;
 951                                 goto exit_f;
 952                         }
 953
 954                         opt->opt_nflen += len;
 955                         opt->srcrt = rthdr;
 956
 957                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 958                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 959
 960                                 opt->opt_nflen += dsthdrlen;
 961                                 opt->dst0opt = opt->dst1opt;
 962                                 opt->dst1opt = NULL;
 963                                 opt->opt_flen -= dsthdrlen;
 964                         }
 965
 966                         break;
 967
 968                 case IPV6_2292HOPLIMIT:
 969                 case IPV6_HOPLIMIT:
 970                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 971                                 err = -EINVAL;
 972                                 goto exit_f;
 973                         }
 974
 975                         ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 976                         if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 977                                 err = -EINVAL;
 978                                 goto exit_f;
 979                         }
 980
 981                         break;
 982
 983                 case IPV6_TCLASS:
 984                     {
 985                         int tc;
 986
 987                         err = -EINVAL;
 988                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 989                                 goto exit_f;
 990
 991                         tc = *(int *)CMSG_DATA(cmsg);
 992                         if (tc < -1 || tc > 0xff)
 993                                 goto exit_f;
 994
 995                         err = 0;
 996                         ipc6->tclass = tc;
 997
 998                         break;
 999                     }
1000
1001                 case IPV6_DONTFRAG:
1002                     {
1003                         int df;
1004
1005                         err = -EINVAL;
1006                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1007                                 goto exit_f;
1008
1009                         df = *(int *)CMSG_DATA(cmsg);
1010                         if (df < 0 || df > 1)
1011                                 goto exit_f;
1012
1013                         err = 0;
1014                         ipc6->dontfrag = df;
1015
1016                         break;
1017                     }
1018                 default:
1019                         net_dbg_ratelimited("invalid cmsg type: %d\n",
1020                                             cmsg->cmsg_type);
1021                         err = -EINVAL;
1022                         goto exit_f;
1023                 }
1024         }
1025
1026 exit_f:
1027         return err;
1028 }
1029 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1030
1031 void __ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1032                                __u16 srcp, __u16 destp, int rqueue, int bucket)
1033 {
1034         const struct in6_addr *dest, *src;
1035
1036         dest  = &sp->sk_v6_daddr;
1037         src   = &sp->sk_v6_rcv_saddr;
1038         seq_printf(seq,
1039                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1040                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
1041                    bucket,
1042                    src->s6_addr32[0], src->s6_addr32[1],
1043                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1044                    dest->s6_addr32[0], dest->s6_addr32[1],
1045                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1046                    sp->sk_state,
1047                    sk_wmem_alloc_get(sp),
1048                    rqueue,
1049                    0, 0L, 0,
1050                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1051                    0,
1052                    sock_i_ino(sp),
1053                    refcount_read(&sp->sk_refcnt), sp,
1054                    atomic_read(&sp->sk_drops));
1055 }