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,
  44                            int addr_len)
  45 {
  46         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
  47         struct inet_sock        *inet = inet_sk(sk);
  48         struct ipv6_pinfo       *np = inet6_sk(sk);
  49         struct in6_addr *daddr, *final_p, final;
  50         struct dst_entry        *dst;
  51         struct flowi6           fl6;
  52         struct ip6_flowlabel    *flowlabel = NULL;
  53         struct ipv6_txoptions   *opt;
  54         int                     addr_type;
  55         int                     err;
  56
  57         if (usin->sin6_family == AF_INET) {
  58                 if (__ipv6_only_sock(sk))
  59                         return -EAFNOSUPPORT;
  60                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
  61                 goto ipv4_connected;
  62         }
  63
  64         if (addr_len < SIN6_LEN_RFC2133)
  65                 return -EINVAL;
  66
  67         if (usin->sin6_family != AF_INET6)
  68                 return -EAFNOSUPPORT;
  69
  70         memset(&fl6, 0, sizeof(fl6));
  71         if (np->sndflow) {
  72                 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
  73                 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
  74                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
  75                         if (!flowlabel)
  76                                 return -EINVAL;
  77                 }
  78         }
  79
  80         if (ipv6_addr_any(&usin->sin6_addr)) {
  81                 /*
  82                  *      connect to self
  83                  */
  84                 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
  85                         ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
  86                                                &usin->sin6_addr);
  87                 else
  88                         usin->sin6_addr = in6addr_loopback;
  89         }
  90
  91         addr_type = ipv6_addr_type(&usin->sin6_addr);
  92
  93         daddr = &usin->sin6_addr;
  94
  95         if (addr_type & IPV6_ADDR_MAPPED) {
  96                 struct sockaddr_in sin;
  97
  98                 if (__ipv6_only_sock(sk)) {
  99                         err = -ENETUNREACH;
 100                         goto out;
 101                 }
 102                 sin.sin_family = AF_INET;
 103                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
 104                 sin.sin_port = usin->sin6_port;
 105
 106                 err = __ip4_datagram_connect(sk,
 107                                              (struct sockaddr *) &sin,
 108                                              sizeof(sin));
 109
 110 ipv4_connected:
 111                 if (err)
 112                         goto out;
 113
 114                 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 115
 116                 if (ipv6_addr_any(&np->saddr) ||
 117                     ipv6_mapped_addr_any(&np->saddr))
 118                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 119
 120                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 121                     ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 122                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 123                                                &sk->sk_v6_rcv_saddr);
 124                         if (sk->sk_prot->rehash)
 125                                 sk->sk_prot->rehash(sk);
 126                 }
 127
 128                 goto out;
 129         }
 130
 131         if (__ipv6_addr_needs_scope_id(addr_type)) {
 132                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 133                     usin->sin6_scope_id) {
 134                         if (sk->sk_bound_dev_if &&
 135                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 136                                 err = -EINVAL;
 137                                 goto out;
 138                         }
 139                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 140                 }
 141
 142                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 143                         sk->sk_bound_dev_if = np->mcast_oif;
 144
 145                 /* Connect to link-local address requires an interface */
 146                 if (!sk->sk_bound_dev_if) {
 147                         err = -EINVAL;
 148                         goto out;
 149                 }
 150         }
 151
 152         sk->sk_v6_daddr = *daddr;
 153         np->flow_label = fl6.flowlabel;
 154
 155         inet->inet_dport = usin->sin6_port;
 156
 157         /*
 158          *      Check for a route to destination an obtain the
 159          *      destination cache for it.
 160          */
 161
 162         fl6.flowi6_proto = sk->sk_protocol;
 163         fl6.daddr = sk->sk_v6_daddr;
 164         fl6.saddr = np->saddr;
 165         fl6.flowi6_oif = sk->sk_bound_dev_if;
 166         fl6.flowi6_mark = sk->sk_mark;
 167         fl6.fl6_dport = inet->inet_dport;
 168         fl6.fl6_sport = inet->inet_sport;
 169
 170         if (!fl6.flowi6_oif)
 171                 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
 172
 173         if (!fl6.flowi6_oif && (addr_type&IPV6_ADDR_MULTICAST))
 174                 fl6.flowi6_oif = np->mcast_oif;
 175
 176         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 177
 178         rcu_read_lock();
 179         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
 180         final_p = fl6_update_dst(&fl6, opt, &final);
 181         rcu_read_unlock();
 182
 183         dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
 184         err = 0;
 185         if (IS_ERR(dst)) {
 186                 err = PTR_ERR(dst);
 187                 goto out;
 188         }
 189
 190         /* source address lookup done in ip6_dst_lookup */
 191
 192         if (ipv6_addr_any(&np->saddr))
 193                 np->saddr = fl6.saddr;
 194
 195         if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 196                 sk->sk_v6_rcv_saddr = fl6.saddr;
 197                 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 198                 if (sk->sk_prot->rehash)
 199                         sk->sk_prot->rehash(sk);
 200         }
 201
 202         ip6_dst_store(sk, dst,
 203                       ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
 204                       &sk->sk_v6_daddr : NULL,
 205 #ifdef CONFIG_IPV6_SUBTREES
 206                       ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
 207                       &np->saddr :
 208 #endif
 209                       NULL);
 210
 211         sk->sk_state = TCP_ESTABLISHED;
 212         sk_set_txhash(sk);
 213 out:
 214         fl6_sock_release(flowlabel);
 215         return err;
 216 }
 217 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 218
 219 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 220 {
 221         int res;
 222
 223         lock_sock(sk);
 224         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 225         release_sock(sk);
 226         return res;
 227 }
 228 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 229
 230 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 231                                  int addr_len)
 232 {
 233         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 234         if (sin6->sin6_family != AF_INET6)
 235                 return -EAFNOSUPPORT;
 236         return ip6_datagram_connect(sk, uaddr, addr_len);
 237 }
 238 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 239
 240 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 241                      __be16 port, u32 info, u8 *payload)
 242 {
 243         struct ipv6_pinfo *np  = inet6_sk(sk);
 244         struct icmp6hdr *icmph = icmp6_hdr(skb);
 245         struct sock_exterr_skb *serr;
 246
 247         if (!np->recverr)
 248                 return;
 249
 250         skb = skb_clone(skb, GFP_ATOMIC);
 251         if (!skb)
 252                 return;
 253
 254         skb->protocol = htons(ETH_P_IPV6);
 255
 256         serr = SKB_EXT_ERR(skb);
 257         serr->ee.ee_errno = err;
 258         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 259         serr->ee.ee_type = icmph->icmp6_type;
 260         serr->ee.ee_code = icmph->icmp6_code;
 261         serr->ee.ee_pad = 0;
 262         serr->ee.ee_info = info;
 263         serr->ee.ee_data = 0;
 264         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 265                                   skb_network_header(skb);
 266         serr->port = port;
 267
 268         __skb_pull(skb, payload - skb->data);
 269         skb_reset_transport_header(skb);
 270
 271         if (sock_queue_err_skb(sk, skb))
 272                 kfree_skb(skb);
 273 }
 274
 275 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 276 {
 277         const struct ipv6_pinfo *np = inet6_sk(sk);
 278         struct sock_exterr_skb *serr;
 279         struct ipv6hdr *iph;
 280         struct sk_buff *skb;
 281
 282         if (!np->recverr)
 283                 return;
 284
 285         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 286         if (!skb)
 287                 return;
 288
 289         skb->protocol = htons(ETH_P_IPV6);
 290
 291         skb_put(skb, sizeof(struct ipv6hdr));
 292         skb_reset_network_header(skb);
 293         iph = ipv6_hdr(skb);
 294         iph->daddr = fl6->daddr;
 295         ip6_flow_hdr(iph, 0, 0);
 296
 297         serr = SKB_EXT_ERR(skb);
 298         serr->ee.ee_errno = err;
 299         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 300         serr->ee.ee_type = 0;
 301         serr->ee.ee_code = 0;
 302         serr->ee.ee_pad = 0;
 303         serr->ee.ee_info = info;
 304         serr->ee.ee_data = 0;
 305         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 306         serr->port = fl6->fl6_dport;
 307
 308         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 309         skb_reset_transport_header(skb);
 310
 311         if (sock_queue_err_skb(sk, skb))
 312                 kfree_skb(skb);
 313 }
 314
 315 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 316 {
 317         struct ipv6_pinfo *np = inet6_sk(sk);
 318         struct ipv6hdr *iph;
 319         struct sk_buff *skb;
 320         struct ip6_mtuinfo *mtu_info;
 321
 322         if (!np->rxopt.bits.rxpmtu)
 323                 return;
 324
 325         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 326         if (!skb)
 327                 return;
 328
 329         skb_put(skb, sizeof(struct ipv6hdr));
 330         skb_reset_network_header(skb);
 331         iph = ipv6_hdr(skb);
 332         iph->daddr = fl6->daddr;
 333
 334         mtu_info = IP6CBMTU(skb);
 335
 336         mtu_info->ip6m_mtu = mtu;
 337         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 338         mtu_info->ip6m_addr.sin6_port = 0;
 339         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 340         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 341         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 342
 343         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 344         skb_reset_transport_header(skb);
 345
 346         skb = xchg(&np->rxpmtu, skb);
 347         kfree_skb(skb);
 348 }
 349
 350 /* For some errors we have valid addr_offset even with zero payload and
 351  * zero port. Also, addr_offset should be supported if port is set.
 352  */
 353 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 354 {
 355         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 356                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 357                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 358 }
 359
 360 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 361  *
 362  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 363  * errors. This is no longer true, but the test remained, so the v6 stack,
 364  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 365  *
 366  * Timestamp code paths do not initialize the fields expected by cmsg:
 367  * the PKTINFO fields in skb->cb[]. Fill those in here.
 368  */
 369 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 370                                       struct sock_exterr_skb *serr)
 371 {
 372         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 373             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 374                 return true;
 375
 376         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 377                 return false;
 378
 379         if (!skb->dev)
 380                 return false;
 381
 382         if (skb->protocol == htons(ETH_P_IPV6))
 383                 IP6CB(skb)->iif = skb->dev->ifindex;
 384         else
 385                 PKTINFO_SKB_CB(skb)->ipi_ifindex = skb->dev->ifindex;
 386
 387         return true;
 388 }
 389
 390 /*
 391  *      Handle MSG_ERRQUEUE
 392  */
 393 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 394 {
 395         struct ipv6_pinfo *np = inet6_sk(sk);
 396         struct sock_exterr_skb *serr;
 397         struct sk_buff *skb;
 398         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 399         struct {
 400                 struct sock_extended_err ee;
 401                 struct sockaddr_in6      offender;
 402         } errhdr;
 403         int err;
 404         int copied;
 405
 406         err = -EAGAIN;
 407         skb = sock_dequeue_err_skb(sk);
 408         if (!skb)
 409                 goto out;
 410
 411         copied = skb->len;
 412         if (copied > len) {
 413                 msg->msg_flags |= MSG_TRUNC;
 414                 copied = len;
 415         }
 416         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 417         if (err)
 418                 goto out_free_skb;
 419
 420         sock_recv_timestamp(msg, sk, skb);
 421
 422         serr = SKB_EXT_ERR(skb);
 423
 424         if (sin && ipv6_datagram_support_addr(serr)) {
 425                 const unsigned char *nh = skb_network_header(skb);
 426                 sin->sin6_family = AF_INET6;
 427                 sin->sin6_flowinfo = 0;
 428                 sin->sin6_port = serr->port;
 429                 if (skb->protocol == htons(ETH_P_IPV6)) {
 430                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 431                                                                   struct ipv6hdr, daddr);
 432                         sin->sin6_addr = ip6h->daddr;
 433                         if (np->sndflow)
 434                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 435                         sin->sin6_scope_id =
 436                                 ipv6_iface_scope_id(&sin->sin6_addr,
 437                                                     IP6CB(skb)->iif);
 438                 } else {
 439                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 440                                                &sin->sin6_addr);
 441                         sin->sin6_scope_id = 0;
 442                 }
 443                 *addr_len = sizeof(*sin);
 444         }
 445
 446         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 447         sin = &errhdr.offender;
 448         memset(sin, 0, sizeof(*sin));
 449
 450         if (ip6_datagram_support_cmsg(skb, serr)) {
 451                 sin->sin6_family = AF_INET6;
 452                 if (np->rxopt.all)
 453                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 454                 if (skb->protocol == htons(ETH_P_IPV6)) {
 455                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 456                         if (np->rxopt.all)
 457                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 458                         sin->sin6_scope_id =
 459                                 ipv6_iface_scope_id(&sin->sin6_addr,
 460                                                     IP6CB(skb)->iif);
 461                 } else {
 462                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 463                                                &sin->sin6_addr);
 464                         if (inet_sk(sk)->cmsg_flags)
 465                                 ip_cmsg_recv(msg, skb);
 466                 }
 467         }
 468
 469         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 470
 471         /* Now we could try to dump offended packet options */
 472
 473         msg->msg_flags |= MSG_ERRQUEUE;
 474         err = copied;
 475
 476 out_free_skb:
 477         kfree_skb(skb);
 478 out:
 479         return err;
 480 }
 481 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 482
 483 /*
 484  *      Handle IPV6_RECVPATHMTU
 485  */
 486 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 487                      int *addr_len)
 488 {
 489         struct ipv6_pinfo *np = inet6_sk(sk);
 490         struct sk_buff *skb;
 491         struct ip6_mtuinfo mtu_info;
 492         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 493         int err;
 494         int copied;
 495
 496         err = -EAGAIN;
 497         skb = xchg(&np->rxpmtu, NULL);
 498         if (!skb)
 499                 goto out;
 500
 501         copied = skb->len;
 502         if (copied > len) {
 503                 msg->msg_flags |= MSG_TRUNC;
 504                 copied = len;
 505         }
 506         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 507         if (err)
 508                 goto out_free_skb;
 509
 510         sock_recv_timestamp(msg, sk, skb);
 511
 512         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 513
 514         if (sin) {
 515                 sin->sin6_family = AF_INET6;
 516                 sin->sin6_flowinfo = 0;
 517                 sin->sin6_port = 0;
 518                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 519                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 520                 *addr_len = sizeof(*sin);
 521         }
 522
 523         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 524
 525         err = copied;
 526
 527 out_free_skb:
 528         kfree_skb(skb);
 529 out:
 530         return err;
 531 }
 532
 533
 534 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 535                                  struct sk_buff *skb)
 536 {
 537         struct ipv6_pinfo *np = inet6_sk(sk);
 538         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 539
 540         if (np->rxopt.bits.rxinfo) {
 541                 struct in6_pktinfo src_info;
 542
 543                 if (is_ipv6) {
 544                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 545                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 546                 } else {
 547                         src_info.ipi6_ifindex =
 548                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 549                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 550                                                &src_info.ipi6_addr);
 551                 }
 552
 553                 if (src_info.ipi6_ifindex >= 0)
 554                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 555                                  sizeof(src_info), &src_info);
 556         }
 557 }
 558
 559 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 560                                     struct sk_buff *skb)
 561 {
 562         struct ipv6_pinfo *np = inet6_sk(sk);
 563         struct inet6_skb_parm *opt = IP6CB(skb);
 564         unsigned char *nh = skb_network_header(skb);
 565
 566         if (np->rxopt.bits.rxhlim) {
 567                 int hlim = ipv6_hdr(skb)->hop_limit;
 568                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 569         }
 570
 571         if (np->rxopt.bits.rxtclass) {
 572                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 573                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 574         }
 575
 576         if (np->rxopt.bits.rxflow) {
 577                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 578                 if (flowinfo)
 579                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 580         }
 581
 582         /* HbH is allowed only once */
 583         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 584                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 585                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 586         }
 587
 588         if (opt->lastopt &&
 589             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 590                 /*
 591                  * Silly enough, but we need to reparse in order to
 592                  * report extension headers (except for HbH)
 593                  * in order.
 594                  *
 595                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 596                  * (and WILL NOT be) defined because
 597                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 598                  */
 599                 unsigned int off = sizeof(struct ipv6hdr);
 600                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 601
 602                 while (off <= opt->lastopt) {
 603                         unsigned int len;
 604                         u8 *ptr = nh + off;
 605
 606                         switch (nexthdr) {
 607                         case IPPROTO_DSTOPTS:
 608                                 nexthdr = ptr[0];
 609                                 len = (ptr[1] + 1) << 3;
 610                                 if (np->rxopt.bits.dstopts)
 611                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 612                                 break;
 613                         case IPPROTO_ROUTING:
 614                                 nexthdr = ptr[0];
 615                                 len = (ptr[1] + 1) << 3;
 616                                 if (np->rxopt.bits.srcrt)
 617                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 618                                 break;
 619                         case IPPROTO_AH:
 620                                 nexthdr = ptr[0];
 621                                 len = (ptr[1] + 2) << 2;
 622                                 break;
 623                         default:
 624                                 nexthdr = ptr[0];
 625                                 len = (ptr[1] + 1) << 3;
 626                                 break;
 627                         }
 628
 629                         off += len;
 630                 }
 631         }
 632
 633         /* socket options in old style */
 634         if (np->rxopt.bits.rxoinfo) {
 635                 struct in6_pktinfo src_info;
 636
 637                 src_info.ipi6_ifindex = opt->iif;
 638                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 639                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 640         }
 641         if (np->rxopt.bits.rxohlim) {
 642                 int hlim = ipv6_hdr(skb)->hop_limit;
 643                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 644         }
 645         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 646                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 647                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 648         }
 649         if (np->rxopt.bits.odstopts && opt->dst0) {
 650                 u8 *ptr = nh + opt->dst0;
 651                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 652         }
 653         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 654                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 655                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 656         }
 657         if (np->rxopt.bits.odstopts && opt->dst1) {
 658                 u8 *ptr = nh + opt->dst1;
 659                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 660         }
 661         if (np->rxopt.bits.rxorigdstaddr) {
 662                 struct sockaddr_in6 sin6;
 663                 __be16 _ports[2], *ports;
 664
 665                 ports = skb_header_pointer(skb, skb_transport_offset(skb),
 666                                            sizeof(_ports), &_ports);
 667                 if (ports) {
 668                         /* All current transport protocols have the port numbers in the
 669                          * first four bytes of the transport header and this function is
 670                          * written with this assumption in mind.
 671                          */
 672                         sin6.sin6_family = AF_INET6;
 673                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 674                         sin6.sin6_port = ports[1];
 675                         sin6.sin6_flowinfo = 0;
 676                         sin6.sin6_scope_id =
 677                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 678                                                     opt->iif);
 679
 680                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 681                 }
 682         }
 683 }
 684
 685 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 686                           struct sk_buff *skb)
 687 {
 688         ip6_datagram_recv_common_ctl(sk, msg, skb);
 689         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 690 }
 691 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 692
 693 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 694                           struct msghdr *msg, struct flowi6 *fl6,
 695                           struct ipv6_txoptions *opt,
 696                           int *hlimit, int *tclass, int *dontfrag)
 697 {
 698         struct in6_pktinfo *src_info;
 699         struct cmsghdr *cmsg;
 700         struct ipv6_rt_hdr *rthdr;
 701         struct ipv6_opt_hdr *hdr;
 702         int len;
 703         int err = 0;
 704
 705         for_each_cmsghdr(cmsg, msg) {
 706                 int addr_type;
 707
 708                 if (!CMSG_OK(msg, cmsg)) {
 709                         err = -EINVAL;
 710                         goto exit_f;
 711                 }
 712
 713                 if (cmsg->cmsg_level != SOL_IPV6)
 714                         continue;
 715
 716                 switch (cmsg->cmsg_type) {
 717                 case IPV6_PKTINFO:
 718                 case IPV6_2292PKTINFO:
 719                     {
 720                         struct net_device *dev = NULL;
 721
 722                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 723                                 err = -EINVAL;
 724                                 goto exit_f;
 725                         }
 726
 727                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 728
 729                         if (src_info->ipi6_ifindex) {
 730                                 if (fl6->flowi6_oif &&
 731                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 732                                         return -EINVAL;
 733                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 734                         }
 735
 736                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 737
 738                         rcu_read_lock();
 739                         if (fl6->flowi6_oif) {
 740                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 741                                 if (!dev) {
 742                                         rcu_read_unlock();
 743                                         return -ENODEV;
 744                                 }
 745                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 746                                 rcu_read_unlock();
 747                                 return -EINVAL;
 748                         }
 749
 750                         if (addr_type != IPV6_ADDR_ANY) {
 751                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 752                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 753                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 754                                                    strict ? dev : NULL, 0) &&
 755                                     !ipv6_chk_acast_addr_src(net, dev,
 756                                                              &src_info->ipi6_addr))
 757                                         err = -EINVAL;
 758                                 else
 759                                         fl6->saddr = src_info->ipi6_addr;
 760                         }
 761
 762                         rcu_read_unlock();
 763
 764                         if (err)
 765                                 goto exit_f;
 766
 767                         break;
 768                     }
 769
 770                 case IPV6_FLOWINFO:
 771                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 772                                 err = -EINVAL;
 773                                 goto exit_f;
 774                         }
 775
 776                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 777                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 778                                         err = -EINVAL;
 779                                         goto exit_f;
 780                                 }
 781                         }
 782                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 783                         break;
 784
 785                 case IPV6_2292HOPOPTS:
 786                 case IPV6_HOPOPTS:
 787                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 788                                 err = -EINVAL;
 789                                 goto exit_f;
 790                         }
 791
 792                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 793                         len = ((hdr->hdrlen + 1) << 3);
 794                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 795                                 err = -EINVAL;
 796                                 goto exit_f;
 797                         }
 798                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 799                                 err = -EPERM;
 800                                 goto exit_f;
 801                         }
 802                         opt->opt_nflen += len;
 803                         opt->hopopt = hdr;
 804                         break;
 805
 806                 case IPV6_2292DSTOPTS:
 807                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 808                                 err = -EINVAL;
 809                                 goto exit_f;
 810                         }
 811
 812                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 813                         len = ((hdr->hdrlen + 1) << 3);
 814                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 815                                 err = -EINVAL;
 816                                 goto exit_f;
 817                         }
 818                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 819                                 err = -EPERM;
 820                                 goto exit_f;
 821                         }
 822                         if (opt->dst1opt) {
 823                                 err = -EINVAL;
 824                                 goto exit_f;
 825                         }
 826                         opt->opt_flen += len;
 827                         opt->dst1opt = hdr;
 828                         break;
 829
 830                 case IPV6_DSTOPTS:
 831                 case IPV6_RTHDRDSTOPTS:
 832                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 833                                 err = -EINVAL;
 834                                 goto exit_f;
 835                         }
 836
 837                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 838                         len = ((hdr->hdrlen + 1) << 3);
 839                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 840                                 err = -EINVAL;
 841                                 goto exit_f;
 842                         }
 843                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 844                                 err = -EPERM;
 845                                 goto exit_f;
 846                         }
 847                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 848                                 opt->opt_flen += len;
 849                                 opt->dst1opt = hdr;
 850                         } else {
 851                                 opt->opt_nflen += len;
 852                                 opt->dst0opt = hdr;
 853                         }
 854                         break;
 855
 856                 case IPV6_2292RTHDR:
 857                 case IPV6_RTHDR:
 858                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 859                                 err = -EINVAL;
 860                                 goto exit_f;
 861                         }
 862
 863                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 864
 865                         switch (rthdr->type) {
 866 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 867                         case IPV6_SRCRT_TYPE_2:
 868                                 if (rthdr->hdrlen != 2 ||
 869                                     rthdr->segments_left != 1) {
 870                                         err = -EINVAL;
 871                                         goto exit_f;
 872                                 }
 873                                 break;
 874 #endif
 875                         default:
 876                                 err = -EINVAL;
 877                                 goto exit_f;
 878                         }
 879
 880                         len = ((rthdr->hdrlen + 1) << 3);
 881
 882                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 883                                 err = -EINVAL;
 884                                 goto exit_f;
 885                         }
 886
 887                         /* segments left must also match */
 888                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 889                                 err = -EINVAL;
 890                                 goto exit_f;
 891                         }
 892
 893                         opt->opt_nflen += len;
 894                         opt->srcrt = rthdr;
 895
 896                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 897                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 898
 899                                 opt->opt_nflen += dsthdrlen;
 900                                 opt->dst0opt = opt->dst1opt;
 901                                 opt->dst1opt = NULL;
 902                                 opt->opt_flen -= dsthdrlen;
 903                         }
 904
 905                         break;
 906
 907                 case IPV6_2292HOPLIMIT:
 908                 case IPV6_HOPLIMIT:
 909                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 910                                 err = -EINVAL;
 911                                 goto exit_f;
 912                         }
 913
 914                         *hlimit = *(int *)CMSG_DATA(cmsg);
 915                         if (*hlimit < -1 || *hlimit > 0xff) {
 916                                 err = -EINVAL;
 917                                 goto exit_f;
 918                         }
 919
 920                         break;
 921
 922                 case IPV6_TCLASS:
 923                     {
 924                         int tc;
 925
 926                         err = -EINVAL;
 927                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 928                                 goto exit_f;
 929
 930                         tc = *(int *)CMSG_DATA(cmsg);
 931                         if (tc < -1 || tc > 0xff)
 932                                 goto exit_f;
 933
 934                         err = 0;
 935                         *tclass = tc;
 936
 937                         break;
 938                     }
 939
 940                 case IPV6_DONTFRAG:
 941                     {
 942                         int df;
 943
 944                         err = -EINVAL;
 945                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 946                                 goto exit_f;
 947
 948                         df = *(int *)CMSG_DATA(cmsg);
 949                         if (df < 0 || df > 1)
 950                                 goto exit_f;
 951
 952                         err = 0;
 953                         *dontfrag = df;
 954
 955                         break;
 956                     }
 957                 default:
 958                         net_dbg_ratelimited("invalid cmsg type: %d\n",
 959                                             cmsg->cmsg_type);
 960                         err = -EINVAL;
 961                         goto exit_f;
 962                 }
 963         }
 964
 965 exit_f:
 966         return err;
 967 }
 968 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
 969
 970 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
 971                              __u16 srcp, __u16 destp, int bucket)
 972 {
 973         const struct in6_addr *dest, *src;
 974
 975         dest  = &sp->sk_v6_daddr;
 976         src   = &sp->sk_v6_rcv_saddr;
 977         seq_printf(seq,
 978                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
 979                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
 980                    bucket,
 981                    src->s6_addr32[0], src->s6_addr32[1],
 982                    src->s6_addr32[2], src->s6_addr32[3], srcp,
 983                    dest->s6_addr32[0], dest->s6_addr32[1],
 984                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
 985                    sp->sk_state,
 986                    sk_wmem_alloc_get(sp),
 987                    sk_rmem_alloc_get(sp),
 988                    0, 0L, 0,
 989                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
 990                    0,
 991                    sock_i_ino(sp),
 992                    atomic_read(&sp->sk_refcnt), sp,
 993                    atomic_read(&sp->sk_drops));
 994 }