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