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 <asm/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 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
  44 {
  45         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
  46         struct inet_sock        *inet = inet_sk(sk);
  47         struct ipv6_pinfo       *np = inet6_sk(sk);
  48         struct in6_addr *daddr, *final_p, final;
  49         struct dst_entry        *dst;
  50         struct flowi6           fl6;
  51         struct ip6_flowlabel    *flowlabel = NULL;
  52         struct ipv6_txoptions   *opt;
  53         int                     addr_type;
  54         int                     err;
  55
  56         if (usin->sin6_family == AF_INET) {
  57                 if (__ipv6_only_sock(sk))
  58                         return -EAFNOSUPPORT;
  59                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
  60                 goto ipv4_connected;
  61         }
  62
  63         if (addr_len < SIN6_LEN_RFC2133)
  64                 return -EINVAL;
  65
  66         if (usin->sin6_family != AF_INET6)
  67                 return -EAFNOSUPPORT;
  68
  69         memset(&fl6, 0, sizeof(fl6));
  70         if (np->sndflow) {
  71                 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
  72                 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
  73                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
  74                         if (!flowlabel)
  75                                 return -EINVAL;
  76                 }
  77         }
  78
  79         addr_type = ipv6_addr_type(&usin->sin6_addr);
  80
  81         if (addr_type == IPV6_ADDR_ANY) {
  82                 /*
  83                  *      connect to self
  84                  */
  85                 usin->sin6_addr.s6_addr[15] = 0x01;
  86         }
  87
  88         daddr = &usin->sin6_addr;
  89
  90         if (addr_type == IPV6_ADDR_MAPPED) {
  91                 struct sockaddr_in sin;
  92
  93                 if (__ipv6_only_sock(sk)) {
  94                         err = -ENETUNREACH;
  95                         goto out;
  96                 }
  97                 sin.sin_family = AF_INET;
  98                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
  99                 sin.sin_port = usin->sin6_port;
 100
 101                 err = __ip4_datagram_connect(sk,
 102                                              (struct sockaddr *) &sin,
 103                                              sizeof(sin));
 104
 105 ipv4_connected:
 106                 if (err)
 107                         goto out;
 108
 109                 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 110
 111                 if (ipv6_addr_any(&np->saddr) ||
 112                     ipv6_mapped_addr_any(&np->saddr))
 113                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 114
 115                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 116                     ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 117                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 118                                                &sk->sk_v6_rcv_saddr);
 119                         if (sk->sk_prot->rehash)
 120                                 sk->sk_prot->rehash(sk);
 121                 }
 122
 123                 goto out;
 124         }
 125
 126         if (__ipv6_addr_needs_scope_id(addr_type)) {
 127                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 128                     usin->sin6_scope_id) {
 129                         if (sk->sk_bound_dev_if &&
 130                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 131                                 err = -EINVAL;
 132                                 goto out;
 133                         }
 134                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 135                 }
 136
 137                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 138                         sk->sk_bound_dev_if = np->mcast_oif;
 139
 140                 /* Connect to link-local address requires an interface */
 141                 if (!sk->sk_bound_dev_if) {
 142                         err = -EINVAL;
 143                         goto out;
 144                 }
 145         }
 146
 147         sk->sk_v6_daddr = *daddr;
 148         np->flow_label = fl6.flowlabel;
 149
 150         inet->inet_dport = usin->sin6_port;
 151
 152         /*
 153          *      Check for a route to destination an obtain the
 154          *      destination cache for it.
 155          */
 156
 157         fl6.flowi6_proto = sk->sk_protocol;
 158         fl6.daddr = sk->sk_v6_daddr;
 159         fl6.saddr = np->saddr;
 160         fl6.flowi6_oif = sk->sk_bound_dev_if;
 161         fl6.flowi6_mark = sk->sk_mark;
 162         fl6.fl6_dport = inet->inet_dport;
 163         fl6.fl6_sport = inet->inet_sport;
 164         fl6.flowi6_uid = sock_i_uid(sk);
 165
 166         if (!fl6.flowi6_oif)
 167                 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
 168
 169         if (!fl6.flowi6_oif && (addr_type&IPV6_ADDR_MULTICAST))
 170                 fl6.flowi6_oif = np->mcast_oif;
 171
 172         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 173
 174         rcu_read_lock();
 175         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
 176         final_p = fl6_update_dst(&fl6, opt, &final);
 177         rcu_read_unlock();
 178
 179         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
 180         err = 0;
 181         if (IS_ERR(dst)) {
 182                 err = PTR_ERR(dst);
 183                 goto out;
 184         }
 185
 186         /* source address lookup done in ip6_dst_lookup */
 187
 188         if (ipv6_addr_any(&np->saddr))
 189                 np->saddr = fl6.saddr;
 190
 191         if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 192                 sk->sk_v6_rcv_saddr = fl6.saddr;
 193                 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 194                 if (sk->sk_prot->rehash)
 195                         sk->sk_prot->rehash(sk);
 196         }
 197
 198         ip6_dst_store(sk, dst,
 199                       ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
 200                       &sk->sk_v6_daddr : NULL,
 201 #ifdef CONFIG_IPV6_SUBTREES
 202                       ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
 203                       &np->saddr :
 204 #endif
 205                       NULL);
 206
 207         sk->sk_state = TCP_ESTABLISHED;
 208         sk_set_txhash(sk);
 209 out:
 210         fl6_sock_release(flowlabel);
 211         return err;
 212 }
 213
 214 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 215 {
 216         int res;
 217
 218         lock_sock(sk);
 219         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 220         release_sock(sk);
 221         return res;
 222 }
 223 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 224
 225 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 226                                  int addr_len)
 227 {
 228         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 229         if (sin6->sin6_family != AF_INET6)
 230                 return -EAFNOSUPPORT;
 231         return ip6_datagram_connect(sk, uaddr, addr_len);
 232 }
 233 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 234
 235 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 236                      __be16 port, u32 info, u8 *payload)
 237 {
 238         struct ipv6_pinfo *np  = inet6_sk(sk);
 239         struct icmp6hdr *icmph = icmp6_hdr(skb);
 240         struct sock_exterr_skb *serr;
 241
 242         if (!np->recverr)
 243                 return;
 244
 245         skb = skb_clone(skb, GFP_ATOMIC);
 246         if (!skb)
 247                 return;
 248
 249         skb->protocol = htons(ETH_P_IPV6);
 250
 251         serr = SKB_EXT_ERR(skb);
 252         serr->ee.ee_errno = err;
 253         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 254         serr->ee.ee_type = icmph->icmp6_type;
 255         serr->ee.ee_code = icmph->icmp6_code;
 256         serr->ee.ee_pad = 0;
 257         serr->ee.ee_info = info;
 258         serr->ee.ee_data = 0;
 259         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 260                                   skb_network_header(skb);
 261         serr->port = port;
 262
 263         __skb_pull(skb, payload - skb->data);
 264         skb_reset_transport_header(skb);
 265
 266         if (sock_queue_err_skb(sk, skb))
 267                 kfree_skb(skb);
 268 }
 269
 270 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 271 {
 272         const struct ipv6_pinfo *np = inet6_sk(sk);
 273         struct sock_exterr_skb *serr;
 274         struct ipv6hdr *iph;
 275         struct sk_buff *skb;
 276
 277         if (!np->recverr)
 278                 return;
 279
 280         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 281         if (!skb)
 282                 return;
 283
 284         skb->protocol = htons(ETH_P_IPV6);
 285
 286         skb_put(skb, sizeof(struct ipv6hdr));
 287         skb_reset_network_header(skb);
 288         iph = ipv6_hdr(skb);
 289         iph->daddr = fl6->daddr;
 290
 291         serr = SKB_EXT_ERR(skb);
 292         serr->ee.ee_errno = err;
 293         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 294         serr->ee.ee_type = 0;
 295         serr->ee.ee_code = 0;
 296         serr->ee.ee_pad = 0;
 297         serr->ee.ee_info = info;
 298         serr->ee.ee_data = 0;
 299         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 300         serr->port = fl6->fl6_dport;
 301
 302         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 303         skb_reset_transport_header(skb);
 304
 305         if (sock_queue_err_skb(sk, skb))
 306                 kfree_skb(skb);
 307 }
 308
 309 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 310 {
 311         struct ipv6_pinfo *np = inet6_sk(sk);
 312         struct ipv6hdr *iph;
 313         struct sk_buff *skb;
 314         struct ip6_mtuinfo *mtu_info;
 315
 316         if (!np->rxopt.bits.rxpmtu)
 317                 return;
 318
 319         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 320         if (!skb)
 321                 return;
 322
 323         skb_put(skb, sizeof(struct ipv6hdr));
 324         skb_reset_network_header(skb);
 325         iph = ipv6_hdr(skb);
 326         iph->daddr = fl6->daddr;
 327
 328         mtu_info = IP6CBMTU(skb);
 329
 330         mtu_info->ip6m_mtu = mtu;
 331         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 332         mtu_info->ip6m_addr.sin6_port = 0;
 333         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 334         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 335         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 336
 337         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 338         skb_reset_transport_header(skb);
 339
 340         skb = xchg(&np->rxpmtu, skb);
 341         kfree_skb(skb);
 342 }
 343
 344 /* For some errors we have valid addr_offset even with zero payload and
 345  * zero port. Also, addr_offset should be supported if port is set.
 346  */
 347 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 348 {
 349         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 350                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 351                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 352 }
 353
 354 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 355  *
 356  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 357  * errors. This is no longer true, but the test remained, so the v6 stack,
 358  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 359  *
 360  * Timestamp code paths do not initialize the fields expected by cmsg:
 361  * the PKTINFO fields in skb->cb[]. Fill those in here.
 362  */
 363 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 364                                       struct sock_exterr_skb *serr)
 365 {
 366         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 367             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 368                 return true;
 369
 370         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 371                 return false;
 372
 373         if (!skb->dev)
 374                 return false;
 375
 376         if (skb->protocol == htons(ETH_P_IPV6))
 377                 IP6CB(skb)->iif = skb->dev->ifindex;
 378         else
 379                 PKTINFO_SKB_CB(skb)->ipi_ifindex = skb->dev->ifindex;
 380
 381         return true;
 382 }
 383
 384 /*
 385  *      Handle MSG_ERRQUEUE
 386  */
 387 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 388 {
 389         struct ipv6_pinfo *np = inet6_sk(sk);
 390         struct sock_exterr_skb *serr;
 391         struct sk_buff *skb;
 392         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 393         struct {
 394                 struct sock_extended_err ee;
 395                 struct sockaddr_in6      offender;
 396         } errhdr;
 397         int err;
 398         int copied;
 399
 400         err = -EAGAIN;
 401         skb = sock_dequeue_err_skb(sk);
 402         if (!skb)
 403                 goto out;
 404
 405         copied = skb->len;
 406         if (copied > len) {
 407                 msg->msg_flags |= MSG_TRUNC;
 408                 copied = len;
 409         }
 410         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 411         if (err)
 412                 goto out_free_skb;
 413
 414         sock_recv_timestamp(msg, sk, skb);
 415
 416         serr = SKB_EXT_ERR(skb);
 417
 418         if (sin && ipv6_datagram_support_addr(serr)) {
 419                 const unsigned char *nh = skb_network_header(skb);
 420                 sin->sin6_family = AF_INET6;
 421                 sin->sin6_flowinfo = 0;
 422                 sin->sin6_port = serr->port;
 423                 if (skb->protocol == htons(ETH_P_IPV6)) {
 424                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 425                                                                   struct ipv6hdr, daddr);
 426                         sin->sin6_addr = ip6h->daddr;
 427                         if (np->sndflow)
 428                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 429                         sin->sin6_scope_id =
 430                                 ipv6_iface_scope_id(&sin->sin6_addr,
 431                                                     IP6CB(skb)->iif);
 432                 } else {
 433                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 434                                                &sin->sin6_addr);
 435                         sin->sin6_scope_id = 0;
 436                 }
 437                 *addr_len = sizeof(*sin);
 438         }
 439
 440         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 441         sin = &errhdr.offender;
 442         memset(sin, 0, sizeof(*sin));
 443
 444         if (ip6_datagram_support_cmsg(skb, serr)) {
 445                 sin->sin6_family = AF_INET6;
 446                 if (np->rxopt.all)
 447                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 448                 if (skb->protocol == htons(ETH_P_IPV6)) {
 449                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 450                         if (np->rxopt.all)
 451                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 452                         sin->sin6_scope_id =
 453                                 ipv6_iface_scope_id(&sin->sin6_addr,
 454                                                     IP6CB(skb)->iif);
 455                 } else {
 456                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 457                                                &sin->sin6_addr);
 458                         if (inet_sk(sk)->cmsg_flags)
 459                                 ip_cmsg_recv(msg, skb);
 460                 }
 461         }
 462
 463         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 464
 465         /* Now we could try to dump offended packet options */
 466
 467         msg->msg_flags |= MSG_ERRQUEUE;
 468         err = copied;
 469
 470 out_free_skb:
 471         kfree_skb(skb);
 472 out:
 473         return err;
 474 }
 475 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 476
 477 /*
 478  *      Handle IPV6_RECVPATHMTU
 479  */
 480 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 481                      int *addr_len)
 482 {
 483         struct ipv6_pinfo *np = inet6_sk(sk);
 484         struct sk_buff *skb;
 485         struct ip6_mtuinfo mtu_info;
 486         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 487         int err;
 488         int copied;
 489
 490         err = -EAGAIN;
 491         skb = xchg(&np->rxpmtu, NULL);
 492         if (!skb)
 493                 goto out;
 494
 495         copied = skb->len;
 496         if (copied > len) {
 497                 msg->msg_flags |= MSG_TRUNC;
 498                 copied = len;
 499         }
 500         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 501         if (err)
 502                 goto out_free_skb;
 503
 504         sock_recv_timestamp(msg, sk, skb);
 505
 506         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 507
 508         if (sin) {
 509                 sin->sin6_family = AF_INET6;
 510                 sin->sin6_flowinfo = 0;
 511                 sin->sin6_port = 0;
 512                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 513                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 514                 *addr_len = sizeof(*sin);
 515         }
 516
 517         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 518
 519         err = copied;
 520
 521 out_free_skb:
 522         kfree_skb(skb);
 523 out:
 524         return err;
 525 }
 526
 527
 528 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 529                                  struct sk_buff *skb)
 530 {
 531         struct ipv6_pinfo *np = inet6_sk(sk);
 532         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 533
 534         if (np->rxopt.bits.rxinfo) {
 535                 struct in6_pktinfo src_info;
 536
 537                 if (is_ipv6) {
 538                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 539                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 540                 } else {
 541                         src_info.ipi6_ifindex =
 542                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 543                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 544                                                &src_info.ipi6_addr);
 545                 }
 546
 547                 if (src_info.ipi6_ifindex >= 0)
 548                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 549                                  sizeof(src_info), &src_info);
 550         }
 551 }
 552
 553 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 554                                     struct sk_buff *skb)
 555 {
 556         struct ipv6_pinfo *np = inet6_sk(sk);
 557         struct inet6_skb_parm *opt = IP6CB(skb);
 558         unsigned char *nh = skb_network_header(skb);
 559
 560         if (np->rxopt.bits.rxhlim) {
 561                 int hlim = ipv6_hdr(skb)->hop_limit;
 562                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 563         }
 564
 565         if (np->rxopt.bits.rxtclass) {
 566                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 567                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 568         }
 569
 570         if (np->rxopt.bits.rxflow) {
 571                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 572                 if (flowinfo)
 573                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 574         }
 575
 576         /* HbH is allowed only once */
 577         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 578                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 579                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 580         }
 581
 582         if (opt->lastopt &&
 583             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 584                 /*
 585                  * Silly enough, but we need to reparse in order to
 586                  * report extension headers (except for HbH)
 587                  * in order.
 588                  *
 589                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 590                  * (and WILL NOT be) defined because
 591                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 592                  */
 593                 unsigned int off = sizeof(struct ipv6hdr);
 594                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 595
 596                 while (off <= opt->lastopt) {
 597                         unsigned int len;
 598                         u8 *ptr = nh + off;
 599
 600                         switch (nexthdr) {
 601                         case IPPROTO_DSTOPTS:
 602                                 nexthdr = ptr[0];
 603                                 len = (ptr[1] + 1) << 3;
 604                                 if (np->rxopt.bits.dstopts)
 605                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 606                                 break;
 607                         case IPPROTO_ROUTING:
 608                                 nexthdr = ptr[0];
 609                                 len = (ptr[1] + 1) << 3;
 610                                 if (np->rxopt.bits.srcrt)
 611                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 612                                 break;
 613                         case IPPROTO_AH:
 614                                 nexthdr = ptr[0];
 615                                 len = (ptr[1] + 2) << 2;
 616                                 break;
 617                         default:
 618                                 nexthdr = ptr[0];
 619                                 len = (ptr[1] + 1) << 3;
 620                                 break;
 621                         }
 622
 623                         off += len;
 624                 }
 625         }
 626
 627         /* socket options in old style */
 628         if (np->rxopt.bits.rxoinfo) {
 629                 struct in6_pktinfo src_info;
 630
 631                 src_info.ipi6_ifindex = opt->iif;
 632                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 633                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 634         }
 635         if (np->rxopt.bits.rxohlim) {
 636                 int hlim = ipv6_hdr(skb)->hop_limit;
 637                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 638         }
 639         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 640                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 641                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 642         }
 643         if (np->rxopt.bits.odstopts && opt->dst0) {
 644                 u8 *ptr = nh + opt->dst0;
 645                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 646         }
 647         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 648                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 649                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 650         }
 651         if (np->rxopt.bits.odstopts && opt->dst1) {
 652                 u8 *ptr = nh + opt->dst1;
 653                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 654         }
 655         if (np->rxopt.bits.rxorigdstaddr) {
 656                 struct sockaddr_in6 sin6;
 657                 __be16 *ports = (__be16 *) skb_transport_header(skb);
 658
 659                 if (skb_transport_offset(skb) + 4 <= skb->len) {
 660                         /* All current transport protocols have the port numbers in the
 661                          * first four bytes of the transport header and this function is
 662                          * written with this assumption in mind.
 663                          */
 664
 665                         sin6.sin6_family = AF_INET6;
 666                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 667                         sin6.sin6_port = ports[1];
 668                         sin6.sin6_flowinfo = 0;
 669                         sin6.sin6_scope_id =
 670                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 671                                                     opt->iif);
 672
 673                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 674                 }
 675         }
 676 }
 677
 678 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 679                           struct sk_buff *skb)
 680 {
 681         ip6_datagram_recv_common_ctl(sk, msg, skb);
 682         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 683 }
 684 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 685
 686 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 687                           struct msghdr *msg, struct flowi6 *fl6,
 688                           struct ipv6_txoptions *opt,
 689                           int *hlimit, int *tclass, int *dontfrag)
 690 {
 691         struct in6_pktinfo *src_info;
 692         struct cmsghdr *cmsg;
 693         struct ipv6_rt_hdr *rthdr;
 694         struct ipv6_opt_hdr *hdr;
 695         int len;
 696         int err = 0;
 697
 698         for_each_cmsghdr(cmsg, msg) {
 699                 int addr_type;
 700
 701                 if (!CMSG_OK(msg, cmsg)) {
 702                         err = -EINVAL;
 703                         goto exit_f;
 704                 }
 705
 706                 if (cmsg->cmsg_level != SOL_IPV6)
 707                         continue;
 708
 709                 switch (cmsg->cmsg_type) {
 710                 case IPV6_PKTINFO:
 711                 case IPV6_2292PKTINFO:
 712                     {
 713                         struct net_device *dev = NULL;
 714
 715                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 716                                 err = -EINVAL;
 717                                 goto exit_f;
 718                         }
 719
 720                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 721
 722                         if (src_info->ipi6_ifindex) {
 723                                 if (fl6->flowi6_oif &&
 724                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 725                                         return -EINVAL;
 726                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 727                         }
 728
 729                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 730
 731                         rcu_read_lock();
 732                         if (fl6->flowi6_oif) {
 733                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 734                                 if (!dev) {
 735                                         rcu_read_unlock();
 736                                         return -ENODEV;
 737                                 }
 738                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 739                                 rcu_read_unlock();
 740                                 return -EINVAL;
 741                         }
 742
 743                         if (addr_type != IPV6_ADDR_ANY) {
 744                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 745                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 746                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 747                                                    strict ? dev : NULL, 0) &&
 748                                     !ipv6_chk_acast_addr_src(net, dev,
 749                                                              &src_info->ipi6_addr))
 750                                         err = -EINVAL;
 751                                 else
 752                                         fl6->saddr = src_info->ipi6_addr;
 753                         }
 754
 755                         rcu_read_unlock();
 756
 757                         if (err)
 758                                 goto exit_f;
 759
 760                         break;
 761                     }
 762
 763                 case IPV6_FLOWINFO:
 764                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 765                                 err = -EINVAL;
 766                                 goto exit_f;
 767                         }
 768
 769                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 770                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 771                                         err = -EINVAL;
 772                                         goto exit_f;
 773                                 }
 774                         }
 775                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 776                         break;
 777
 778                 case IPV6_2292HOPOPTS:
 779                 case IPV6_HOPOPTS:
 780                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 781                                 err = -EINVAL;
 782                                 goto exit_f;
 783                         }
 784
 785                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 786                         len = ((hdr->hdrlen + 1) << 3);
 787                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 788                                 err = -EINVAL;
 789                                 goto exit_f;
 790                         }
 791                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 792                                 err = -EPERM;
 793                                 goto exit_f;
 794                         }
 795                         opt->opt_nflen += len;
 796                         opt->hopopt = hdr;
 797                         break;
 798
 799                 case IPV6_2292DSTOPTS:
 800                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 801                                 err = -EINVAL;
 802                                 goto exit_f;
 803                         }
 804
 805                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 806                         len = ((hdr->hdrlen + 1) << 3);
 807                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 808                                 err = -EINVAL;
 809                                 goto exit_f;
 810                         }
 811                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 812                                 err = -EPERM;
 813                                 goto exit_f;
 814                         }
 815                         if (opt->dst1opt) {
 816                                 err = -EINVAL;
 817                                 goto exit_f;
 818                         }
 819                         opt->opt_flen += len;
 820                         opt->dst1opt = hdr;
 821                         break;
 822
 823                 case IPV6_DSTOPTS:
 824                 case IPV6_RTHDRDSTOPTS:
 825                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 826                                 err = -EINVAL;
 827                                 goto exit_f;
 828                         }
 829
 830                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 831                         len = ((hdr->hdrlen + 1) << 3);
 832                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 833                                 err = -EINVAL;
 834                                 goto exit_f;
 835                         }
 836                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 837                                 err = -EPERM;
 838                                 goto exit_f;
 839                         }
 840                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 841                                 opt->opt_flen += len;
 842                                 opt->dst1opt = hdr;
 843                         } else {
 844                                 opt->opt_nflen += len;
 845                                 opt->dst0opt = hdr;
 846                         }
 847                         break;
 848
 849                 case IPV6_2292RTHDR:
 850                 case IPV6_RTHDR:
 851                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 852                                 err = -EINVAL;
 853                                 goto exit_f;
 854                         }
 855
 856                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 857
 858                         switch (rthdr->type) {
 859 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 860                         case IPV6_SRCRT_TYPE_2:
 861                                 if (rthdr->hdrlen != 2 ||
 862                                     rthdr->segments_left != 1) {
 863                                         err = -EINVAL;
 864                                         goto exit_f;
 865                                 }
 866                                 break;
 867 #endif
 868                         default:
 869                                 err = -EINVAL;
 870                                 goto exit_f;
 871                         }
 872
 873                         len = ((rthdr->hdrlen + 1) << 3);
 874
 875                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 876                                 err = -EINVAL;
 877                                 goto exit_f;
 878                         }
 879
 880                         /* segments left must also match */
 881                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 882                                 err = -EINVAL;
 883                                 goto exit_f;
 884                         }
 885
 886                         opt->opt_nflen += len;
 887                         opt->srcrt = rthdr;
 888
 889                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 890                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 891
 892                                 opt->opt_nflen += dsthdrlen;
 893                                 opt->dst0opt = opt->dst1opt;
 894                                 opt->dst1opt = NULL;
 895                                 opt->opt_flen -= dsthdrlen;
 896                         }
 897
 898                         break;
 899
 900                 case IPV6_2292HOPLIMIT:
 901                 case IPV6_HOPLIMIT:
 902                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 903                                 err = -EINVAL;
 904                                 goto exit_f;
 905                         }
 906
 907                         *hlimit = *(int *)CMSG_DATA(cmsg);
 908                         if (*hlimit < -1 || *hlimit > 0xff) {
 909                                 err = -EINVAL;
 910                                 goto exit_f;
 911                         }
 912
 913                         break;
 914
 915                 case IPV6_TCLASS:
 916                     {
 917                         int tc;
 918
 919                         err = -EINVAL;
 920                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 921                                 goto exit_f;
 922
 923                         tc = *(int *)CMSG_DATA(cmsg);
 924                         if (tc < -1 || tc > 0xff)
 925                                 goto exit_f;
 926
 927                         err = 0;
 928                         *tclass = tc;
 929
 930                         break;
 931                     }
 932
 933                 case IPV6_DONTFRAG:
 934                     {
 935                         int df;
 936
 937                         err = -EINVAL;
 938                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 939                                 goto exit_f;
 940
 941                         df = *(int *)CMSG_DATA(cmsg);
 942                         if (df < 0 || df > 1)
 943                                 goto exit_f;
 944
 945                         err = 0;
 946                         *dontfrag = df;
 947
 948                         break;
 949                     }
 950                 default:
 951                         net_dbg_ratelimited("invalid cmsg type: %d\n",
 952                                             cmsg->cmsg_type);
 953                         err = -EINVAL;
 954                         goto exit_f;
 955                 }
 956         }
 957
 958 exit_f:
 959         return err;
 960 }
 961 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
 962
 963 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
 964                              __u16 srcp, __u16 destp, int bucket)
 965 {
 966         const struct in6_addr *dest, *src;
 967
 968         dest  = &sp->sk_v6_daddr;
 969         src   = &sp->sk_v6_rcv_saddr;
 970         seq_printf(seq,
 971                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
 972                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
 973                    bucket,
 974                    src->s6_addr32[0], src->s6_addr32[1],
 975                    src->s6_addr32[2], src->s6_addr32[3], srcp,
 976                    dest->s6_addr32[0], dest->s6_addr32[1],
 977                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
 978                    sp->sk_state,
 979                    sk_wmem_alloc_get(sp),
 980                    sk_rmem_alloc_get(sp),
 981                    0, 0L, 0,
 982                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
 983                    0,
 984                    sock_i_ino(sp),
 985                    atomic_read(&sp->sk_refcnt), sp,
 986                    atomic_read(&sp->sk_drops));
 987 }