kernel/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 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         ip6_set_txhash(sk);
 203 out:
 204         fl6_sock_release(flowlabel);
 205         return err;
 206 }
 207 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 208
 209 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 210                                  int addr_len)
 211 {
 212         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 213         if (sin6->sin6_family != AF_INET6)
 214                 return -EAFNOSUPPORT;
 215         return ip6_datagram_connect(sk, uaddr, addr_len);
 216 }
 217 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 218
 219 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 220                      __be16 port, u32 info, u8 *payload)
 221 {
 222         struct ipv6_pinfo *np  = inet6_sk(sk);
 223         struct icmp6hdr *icmph = icmp6_hdr(skb);
 224         struct sock_exterr_skb *serr;
 225
 226         if (!np->recverr)
 227                 return;
 228
 229         skb = skb_clone(skb, GFP_ATOMIC);
 230         if (!skb)
 231                 return;
 232
 233         skb->protocol = htons(ETH_P_IPV6);
 234
 235         serr = SKB_EXT_ERR(skb);
 236         serr->ee.ee_errno = err;
 237         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 238         serr->ee.ee_type = icmph->icmp6_type;
 239         serr->ee.ee_code = icmph->icmp6_code;
 240         serr->ee.ee_pad = 0;
 241         serr->ee.ee_info = info;
 242         serr->ee.ee_data = 0;
 243         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 244                                   skb_network_header(skb);
 245         serr->port = port;
 246
 247         __skb_pull(skb, payload - skb->data);
 248         skb_reset_transport_header(skb);
 249
 250         if (sock_queue_err_skb(sk, skb))
 251                 kfree_skb(skb);
 252 }
 253
 254 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 255 {
 256         struct ipv6_pinfo *np = inet6_sk(sk);
 257         struct sock_exterr_skb *serr;
 258         struct ipv6hdr *iph;
 259         struct sk_buff *skb;
 260
 261         if (!np->recverr)
 262                 return;
 263
 264         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 265         if (!skb)
 266                 return;
 267
 268         skb->protocol = htons(ETH_P_IPV6);
 269
 270         skb_put(skb, sizeof(struct ipv6hdr));
 271         skb_reset_network_header(skb);
 272         iph = ipv6_hdr(skb);
 273         iph->daddr = fl6->daddr;
 274
 275         serr = SKB_EXT_ERR(skb);
 276         serr->ee.ee_errno = err;
 277         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 278         serr->ee.ee_type = 0;
 279         serr->ee.ee_code = 0;
 280         serr->ee.ee_pad = 0;
 281         serr->ee.ee_info = info;
 282         serr->ee.ee_data = 0;
 283         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 284         serr->port = fl6->fl6_dport;
 285
 286         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 287         skb_reset_transport_header(skb);
 288
 289         if (sock_queue_err_skb(sk, skb))
 290                 kfree_skb(skb);
 291 }
 292
 293 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 294 {
 295         struct ipv6_pinfo *np = inet6_sk(sk);
 296         struct ipv6hdr *iph;
 297         struct sk_buff *skb;
 298         struct ip6_mtuinfo *mtu_info;
 299
 300         if (!np->rxopt.bits.rxpmtu)
 301                 return;
 302
 303         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 304         if (!skb)
 305                 return;
 306
 307         skb_put(skb, sizeof(struct ipv6hdr));
 308         skb_reset_network_header(skb);
 309         iph = ipv6_hdr(skb);
 310         iph->daddr = fl6->daddr;
 311
 312         mtu_info = IP6CBMTU(skb);
 313
 314         mtu_info->ip6m_mtu = mtu;
 315         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 316         mtu_info->ip6m_addr.sin6_port = 0;
 317         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 318         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 319         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 320
 321         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 322         skb_reset_transport_header(skb);
 323
 324         skb = xchg(&np->rxpmtu, skb);
 325         kfree_skb(skb);
 326 }
 327
 328 /* For some errors we have valid addr_offset even with zero payload and
 329  * zero port. Also, addr_offset should be supported if port is set.
 330  */
 331 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 332 {
 333         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 334                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 335                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 336 }
 337
 338 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 339  *
 340  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 341  * errors. This is no longer true, but the test remained, so the v6 stack,
 342  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 343  *
 344  * Timestamp code paths do not initialize the fields expected by cmsg:
 345  * the PKTINFO fields in skb->cb[]. Fill those in here.
 346  */
 347 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 348                                       struct sock_exterr_skb *serr)
 349 {
 350         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 351             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 352                 return true;
 353
 354         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 355                 return false;
 356
 357         if (!skb->dev)
 358                 return false;
 359
 360         if (skb->protocol == htons(ETH_P_IPV6))
 361                 IP6CB(skb)->iif = skb->dev->ifindex;
 362         else
 363                 PKTINFO_SKB_CB(skb)->ipi_ifindex = skb->dev->ifindex;
 364
 365         return true;
 366 }
 367
 368 /*
 369  *      Handle MSG_ERRQUEUE
 370  */
 371 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 372 {
 373         struct ipv6_pinfo *np = inet6_sk(sk);
 374         struct sock_exterr_skb *serr;
 375         struct sk_buff *skb;
 376         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 377         struct {
 378                 struct sock_extended_err ee;
 379                 struct sockaddr_in6      offender;
 380         } errhdr;
 381         int err;
 382         int copied;
 383
 384         err = -EAGAIN;
 385         skb = sock_dequeue_err_skb(sk);
 386         if (!skb)
 387                 goto out;
 388
 389         copied = skb->len;
 390         if (copied > len) {
 391                 msg->msg_flags |= MSG_TRUNC;
 392                 copied = len;
 393         }
 394         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 395         if (err)
 396                 goto out_free_skb;
 397
 398         sock_recv_timestamp(msg, sk, skb);
 399
 400         serr = SKB_EXT_ERR(skb);
 401
 402         if (sin && ipv6_datagram_support_addr(serr)) {
 403                 const unsigned char *nh = skb_network_header(skb);
 404                 sin->sin6_family = AF_INET6;
 405                 sin->sin6_flowinfo = 0;
 406                 sin->sin6_port = serr->port;
 407                 if (skb->protocol == htons(ETH_P_IPV6)) {
 408                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 409                                                                   struct ipv6hdr, daddr);
 410                         sin->sin6_addr = ip6h->daddr;
 411                         if (np->sndflow)
 412                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 413                         sin->sin6_scope_id =
 414                                 ipv6_iface_scope_id(&sin->sin6_addr,
 415                                                     IP6CB(skb)->iif);
 416                 } else {
 417                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 418                                                &sin->sin6_addr);
 419                         sin->sin6_scope_id = 0;
 420                 }
 421                 *addr_len = sizeof(*sin);
 422         }
 423
 424         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 425         sin = &errhdr.offender;
 426         memset(sin, 0, sizeof(*sin));
 427
 428         if (ip6_datagram_support_cmsg(skb, serr)) {
 429                 sin->sin6_family = AF_INET6;
 430                 if (np->rxopt.all)
 431                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 432                 if (skb->protocol == htons(ETH_P_IPV6)) {
 433                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 434                         if (np->rxopt.all)
 435                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 436                         sin->sin6_scope_id =
 437                                 ipv6_iface_scope_id(&sin->sin6_addr,
 438                                                     IP6CB(skb)->iif);
 439                 } else {
 440                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 441                                                &sin->sin6_addr);
 442                         if (inet_sk(sk)->cmsg_flags)
 443                                 ip_cmsg_recv(msg, skb);
 444                 }
 445         }
 446
 447         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 448
 449         /* Now we could try to dump offended packet options */
 450
 451         msg->msg_flags |= MSG_ERRQUEUE;
 452         err = copied;
 453
 454 out_free_skb:
 455         kfree_skb(skb);
 456 out:
 457         return err;
 458 }
 459 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 460
 461 /*
 462  *      Handle IPV6_RECVPATHMTU
 463  */
 464 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 465                      int *addr_len)
 466 {
 467         struct ipv6_pinfo *np = inet6_sk(sk);
 468         struct sk_buff *skb;
 469         struct ip6_mtuinfo mtu_info;
 470         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 471         int err;
 472         int copied;
 473
 474         err = -EAGAIN;
 475         skb = xchg(&np->rxpmtu, NULL);
 476         if (!skb)
 477                 goto out;
 478
 479         copied = skb->len;
 480         if (copied > len) {
 481                 msg->msg_flags |= MSG_TRUNC;
 482                 copied = len;
 483         }
 484         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 485         if (err)
 486                 goto out_free_skb;
 487
 488         sock_recv_timestamp(msg, sk, skb);
 489
 490         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 491
 492         if (sin) {
 493                 sin->sin6_family = AF_INET6;
 494                 sin->sin6_flowinfo = 0;
 495                 sin->sin6_port = 0;
 496                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 497                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 498                 *addr_len = sizeof(*sin);
 499         }
 500
 501         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 502
 503         err = copied;
 504
 505 out_free_skb:
 506         kfree_skb(skb);
 507 out:
 508         return err;
 509 }
 510
 511
 512 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 513                                  struct sk_buff *skb)
 514 {
 515         struct ipv6_pinfo *np = inet6_sk(sk);
 516         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 517
 518         if (np->rxopt.bits.rxinfo) {
 519                 struct in6_pktinfo src_info;
 520
 521                 if (is_ipv6) {
 522                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 523                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 524                 } else {
 525                         src_info.ipi6_ifindex =
 526                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 527                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 528                                                &src_info.ipi6_addr);
 529                 }
 530
 531                 if (src_info.ipi6_ifindex >= 0)
 532                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 533                                  sizeof(src_info), &src_info);
 534         }
 535 }
 536
 537 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 538                                     struct sk_buff *skb)
 539 {
 540         struct ipv6_pinfo *np = inet6_sk(sk);
 541         struct inet6_skb_parm *opt = IP6CB(skb);
 542         unsigned char *nh = skb_network_header(skb);
 543
 544         if (np->rxopt.bits.rxhlim) {
 545                 int hlim = ipv6_hdr(skb)->hop_limit;
 546                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 547         }
 548
 549         if (np->rxopt.bits.rxtclass) {
 550                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 551                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 552         }
 553
 554         if (np->rxopt.bits.rxflow) {
 555                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 556                 if (flowinfo)
 557                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 558         }
 559
 560         /* HbH is allowed only once */
 561         if (np->rxopt.bits.hopopts && opt->hop) {
 562                 u8 *ptr = nh + opt->hop;
 563                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 564         }
 565
 566         if (opt->lastopt &&
 567             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 568                 /*
 569                  * Silly enough, but we need to reparse in order to
 570                  * report extension headers (except for HbH)
 571                  * in order.
 572                  *
 573                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 574                  * (and WILL NOT be) defined because
 575                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 576                  */
 577                 unsigned int off = sizeof(struct ipv6hdr);
 578                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 579
 580                 while (off <= opt->lastopt) {
 581                         unsigned int len;
 582                         u8 *ptr = nh + off;
 583
 584                         switch (nexthdr) {
 585                         case IPPROTO_DSTOPTS:
 586                                 nexthdr = ptr[0];
 587                                 len = (ptr[1] + 1) << 3;
 588                                 if (np->rxopt.bits.dstopts)
 589                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 590                                 break;
 591                         case IPPROTO_ROUTING:
 592                                 nexthdr = ptr[0];
 593                                 len = (ptr[1] + 1) << 3;
 594                                 if (np->rxopt.bits.srcrt)
 595                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 596                                 break;
 597                         case IPPROTO_AH:
 598                                 nexthdr = ptr[0];
 599                                 len = (ptr[1] + 2) << 2;
 600                                 break;
 601                         default:
 602                                 nexthdr = ptr[0];
 603                                 len = (ptr[1] + 1) << 3;
 604                                 break;
 605                         }
 606
 607                         off += len;
 608                 }
 609         }
 610
 611         /* socket options in old style */
 612         if (np->rxopt.bits.rxoinfo) {
 613                 struct in6_pktinfo src_info;
 614
 615                 src_info.ipi6_ifindex = opt->iif;
 616                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 617                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 618         }
 619         if (np->rxopt.bits.rxohlim) {
 620                 int hlim = ipv6_hdr(skb)->hop_limit;
 621                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 622         }
 623         if (np->rxopt.bits.ohopopts && opt->hop) {
 624                 u8 *ptr = nh + opt->hop;
 625                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 626         }
 627         if (np->rxopt.bits.odstopts && opt->dst0) {
 628                 u8 *ptr = nh + opt->dst0;
 629                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 630         }
 631         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 632                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 633                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 634         }
 635         if (np->rxopt.bits.odstopts && opt->dst1) {
 636                 u8 *ptr = nh + opt->dst1;
 637                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 638         }
 639         if (np->rxopt.bits.rxorigdstaddr) {
 640                 struct sockaddr_in6 sin6;
 641                 __be16 *ports = (__be16 *) skb_transport_header(skb);
 642
 643                 if (skb_transport_offset(skb) + 4 <= skb->len) {
 644                         /* All current transport protocols have the port numbers in the
 645                          * first four bytes of the transport header and this function is
 646                          * written with this assumption in mind.
 647                          */
 648
 649                         sin6.sin6_family = AF_INET6;
 650                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 651                         sin6.sin6_port = ports[1];
 652                         sin6.sin6_flowinfo = 0;
 653                         sin6.sin6_scope_id =
 654                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 655                                                     opt->iif);
 656
 657                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 658                 }
 659         }
 660 }
 661
 662 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 663                           struct sk_buff *skb)
 664 {
 665         ip6_datagram_recv_common_ctl(sk, msg, skb);
 666         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 667 }
 668 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 669
 670 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 671                           struct msghdr *msg, struct flowi6 *fl6,
 672                           struct ipv6_txoptions *opt,
 673                           int *hlimit, int *tclass, int *dontfrag)
 674 {
 675         struct in6_pktinfo *src_info;
 676         struct cmsghdr *cmsg;
 677         struct ipv6_rt_hdr *rthdr;
 678         struct ipv6_opt_hdr *hdr;
 679         int len;
 680         int err = 0;
 681
 682         for_each_cmsghdr(cmsg, msg) {
 683                 int addr_type;
 684
 685                 if (!CMSG_OK(msg, cmsg)) {
 686                         err = -EINVAL;
 687                         goto exit_f;
 688                 }
 689
 690                 if (cmsg->cmsg_level != SOL_IPV6)
 691                         continue;
 692
 693                 switch (cmsg->cmsg_type) {
 694                 case IPV6_PKTINFO:
 695                 case IPV6_2292PKTINFO:
 696                     {
 697                         struct net_device *dev = NULL;
 698
 699                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 700                                 err = -EINVAL;
 701                                 goto exit_f;
 702                         }
 703
 704                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 705
 706                         if (src_info->ipi6_ifindex) {
 707                                 if (fl6->flowi6_oif &&
 708                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 709                                         return -EINVAL;
 710                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 711                         }
 712
 713                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 714
 715                         rcu_read_lock();
 716                         if (fl6->flowi6_oif) {
 717                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 718                                 if (!dev) {
 719                                         rcu_read_unlock();
 720                                         return -ENODEV;
 721                                 }
 722                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 723                                 rcu_read_unlock();
 724                                 return -EINVAL;
 725                         }
 726
 727                         if (addr_type != IPV6_ADDR_ANY) {
 728                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 729                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 730                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 731                                                    strict ? dev : NULL, 0) &&
 732                                     !ipv6_chk_acast_addr_src(net, dev,
 733                                                              &src_info->ipi6_addr))
 734                                         err = -EINVAL;
 735                                 else
 736                                         fl6->saddr = src_info->ipi6_addr;
 737                         }
 738
 739                         rcu_read_unlock();
 740
 741                         if (err)
 742                                 goto exit_f;
 743
 744                         break;
 745                     }
 746
 747                 case IPV6_FLOWINFO:
 748                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 749                                 err = -EINVAL;
 750                                 goto exit_f;
 751                         }
 752
 753                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 754                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 755                                         err = -EINVAL;
 756                                         goto exit_f;
 757                                 }
 758                         }
 759                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 760                         break;
 761
 762                 case IPV6_2292HOPOPTS:
 763                 case IPV6_HOPOPTS:
 764                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 765                                 err = -EINVAL;
 766                                 goto exit_f;
 767                         }
 768
 769                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 770                         len = ((hdr->hdrlen + 1) << 3);
 771                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 772                                 err = -EINVAL;
 773                                 goto exit_f;
 774                         }
 775                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 776                                 err = -EPERM;
 777                                 goto exit_f;
 778                         }
 779                         opt->opt_nflen += len;
 780                         opt->hopopt = hdr;
 781                         break;
 782
 783                 case IPV6_2292DSTOPTS:
 784                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 785                                 err = -EINVAL;
 786                                 goto exit_f;
 787                         }
 788
 789                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 790                         len = ((hdr->hdrlen + 1) << 3);
 791                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 792                                 err = -EINVAL;
 793                                 goto exit_f;
 794                         }
 795                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 796                                 err = -EPERM;
 797                                 goto exit_f;
 798                         }
 799                         if (opt->dst1opt) {
 800                                 err = -EINVAL;
 801                                 goto exit_f;
 802                         }
 803                         opt->opt_flen += len;
 804                         opt->dst1opt = hdr;
 805                         break;
 806
 807                 case IPV6_DSTOPTS:
 808                 case IPV6_RTHDRDSTOPTS:
 809                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 810                                 err = -EINVAL;
 811                                 goto exit_f;
 812                         }
 813
 814                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 815                         len = ((hdr->hdrlen + 1) << 3);
 816                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 817                                 err = -EINVAL;
 818                                 goto exit_f;
 819                         }
 820                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 821                                 err = -EPERM;
 822                                 goto exit_f;
 823                         }
 824                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 825                                 opt->opt_flen += len;
 826                                 opt->dst1opt = hdr;
 827                         } else {
 828                                 opt->opt_nflen += len;
 829                                 opt->dst0opt = hdr;
 830                         }
 831                         break;
 832
 833                 case IPV6_2292RTHDR:
 834                 case IPV6_RTHDR:
 835                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 836                                 err = -EINVAL;
 837                                 goto exit_f;
 838                         }
 839
 840                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 841
 842                         switch (rthdr->type) {
 843 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 844                         case IPV6_SRCRT_TYPE_2:
 845                                 if (rthdr->hdrlen != 2 ||
 846                                     rthdr->segments_left != 1) {
 847                                         err = -EINVAL;
 848                                         goto exit_f;
 849                                 }
 850                                 break;
 851 #endif
 852                         default:
 853                                 err = -EINVAL;
 854                                 goto exit_f;
 855                         }
 856
 857                         len = ((rthdr->hdrlen + 1) << 3);
 858
 859                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 860                                 err = -EINVAL;
 861                                 goto exit_f;
 862                         }
 863
 864                         /* segments left must also match */
 865                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 866                                 err = -EINVAL;
 867                                 goto exit_f;
 868                         }
 869
 870                         opt->opt_nflen += len;
 871                         opt->srcrt = rthdr;
 872
 873                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 874                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 875
 876                                 opt->opt_nflen += dsthdrlen;
 877                                 opt->dst0opt = opt->dst1opt;
 878                                 opt->dst1opt = NULL;
 879                                 opt->opt_flen -= dsthdrlen;
 880                         }
 881
 882                         break;
 883
 884                 case IPV6_2292HOPLIMIT:
 885                 case IPV6_HOPLIMIT:
 886                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 887                                 err = -EINVAL;
 888                                 goto exit_f;
 889                         }
 890
 891                         *hlimit = *(int *)CMSG_DATA(cmsg);
 892                         if (*hlimit < -1 || *hlimit > 0xff) {
 893                                 err = -EINVAL;
 894                                 goto exit_f;
 895                         }
 896
 897                         break;
 898
 899                 case IPV6_TCLASS:
 900                     {
 901                         int tc;
 902
 903                         err = -EINVAL;
 904                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 905                                 goto exit_f;
 906
 907                         tc = *(int *)CMSG_DATA(cmsg);
 908                         if (tc < -1 || tc > 0xff)
 909                                 goto exit_f;
 910
 911                         err = 0;
 912                         *tclass = tc;
 913
 914                         break;
 915                     }
 916
 917                 case IPV6_DONTFRAG:
 918                     {
 919                         int df;
 920
 921                         err = -EINVAL;
 922                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 923                                 goto exit_f;
 924
 925                         df = *(int *)CMSG_DATA(cmsg);
 926                         if (df < 0 || df > 1)
 927                                 goto exit_f;
 928
 929                         err = 0;
 930                         *dontfrag = df;
 931
 932                         break;
 933                     }
 934                 default:
 935                         net_dbg_ratelimited("invalid cmsg type: %d\n",
 936                                             cmsg->cmsg_type);
 937                         err = -EINVAL;
 938                         goto exit_f;
 939                 }
 940         }
 941
 942 exit_f:
 943         return err;
 944 }
 945 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
 946
 947 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
 948                              __u16 srcp, __u16 destp, int bucket)
 949 {
 950         const struct in6_addr *dest, *src;
 951
 952         dest  = &sp->sk_v6_daddr;
 953         src   = &sp->sk_v6_rcv_saddr;
 954         seq_printf(seq,
 955                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
 956                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
 957                    bucket,
 958                    src->s6_addr32[0], src->s6_addr32[1],
 959                    src->s6_addr32[2], src->s6_addr32[3], srcp,
 960                    dest->s6_addr32[0], dest->s6_addr32[1],
 961                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
 962                    sp->sk_state,
 963                    sk_wmem_alloc_get(sp),
 964                    sk_rmem_alloc_get(sp),
 965                    0, 0L, 0,
 966                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
 967                    0,
 968                    sock_i_ino(sp),
 969                    atomic_read(&sp->sk_refcnt), sp,
 970                    atomic_read(&sp->sk_drops));
 971 }