net/ipv6/datagram.c

   1 /*
   2  *      common UDP/RAW code
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 #include <linux/capability.h>
  15 #include <linux/errno.h>
  16 #include <linux/types.h>
  17 #include <linux/kernel.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/socket.h>
  20 #include <linux/sockios.h>
  21 #include <linux/in6.h>
  22 #include <linux/ipv6.h>
  23 #include <linux/route.h>
  24 #include <linux/slab.h>
  25 #include <linux/export.h>
  26
  27 #include <net/ipv6.h>
  28 #include <net/ndisc.h>
  29 #include <net/addrconf.h>
  30 #include <net/transp_v6.h>
  31 #include <net/ip6_route.h>
  32 #include <net/tcp_states.h>
  33 #include <net/dsfield.h>
  34
  35 #include <linux/errqueue.h>
  36 #include <linux/uaccess.h>
  37
  38 static bool ipv6_mapped_addr_any(const struct in6_addr *a)
  39 {
  40         return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
  41 }
  42
  43 static void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
  44 {
  45         struct inet_sock *inet = inet_sk(sk);
  46         struct ipv6_pinfo *np = inet6_sk(sk);
  47
  48         memset(fl6, 0, sizeof(*fl6));
  49         fl6->flowi6_proto = sk->sk_protocol;
  50         fl6->daddr = sk->sk_v6_daddr;
  51         fl6->saddr = np->saddr;
  52         fl6->flowi6_oif = sk->sk_bound_dev_if;
  53         fl6->flowi6_mark = sk->sk_mark;
  54         fl6->fl6_dport = inet->inet_dport;
  55         fl6->fl6_sport = inet->inet_sport;
  56         fl6->flowlabel = np->flow_label;
  57         fl6->flowi6_uid = sk->sk_uid;
  58
  59         if (!fl6->flowi6_oif)
  60                 fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
  61
  62         if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr))
  63                 fl6->flowi6_oif = np->mcast_oif;
  64
  65         security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
  66 }
  67
  68 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
  69 {
  70         struct ip6_flowlabel *flowlabel = NULL;
  71         struct in6_addr *final_p, final;
  72         struct ipv6_txoptions *opt;
  73         struct dst_entry *dst;
  74         struct inet_sock *inet = inet_sk(sk);
  75         struct ipv6_pinfo *np = inet6_sk(sk);
  76         struct flowi6 fl6;
  77         int err = 0;
  78
  79         if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
  80                 flowlabel = fl6_sock_lookup(sk, np->flow_label);
  81                 if (!flowlabel)
  82                         return -EINVAL;
  83         }
  84         ip6_datagram_flow_key_init(&fl6, sk);
  85
  86         rcu_read_lock();
  87         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
  88         final_p = fl6_update_dst(&fl6, opt, &final);
  89         rcu_read_unlock();
  90
  91         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
  92         if (IS_ERR(dst)) {
  93                 err = PTR_ERR(dst);
  94                 goto out;
  95         }
  96
  97         if (fix_sk_saddr) {
  98                 if (ipv6_addr_any(&np->saddr))
  99                         np->saddr = fl6.saddr;
 100
 101                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 102                         sk->sk_v6_rcv_saddr = fl6.saddr;
 103                         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 104                         if (sk->sk_prot->rehash)
 105                                 sk->sk_prot->rehash(sk);
 106                 }
 107         }
 108
 109         ip6_dst_store(sk, dst,
 110                       ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
 111                       &sk->sk_v6_daddr : NULL,
 112 #ifdef CONFIG_IPV6_SUBTREES
 113                       ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
 114                       &np->saddr :
 115 #endif
 116                       NULL);
 117
 118 out:
 119         fl6_sock_release(flowlabel);
 120         return err;
 121 }
 122
 123 void ip6_datagram_release_cb(struct sock *sk)
 124 {
 125         struct dst_entry *dst;
 126
 127         if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 128                 return;
 129
 130         rcu_read_lock();
 131         dst = __sk_dst_get(sk);
 132         if (!dst || !dst->obsolete ||
 133             dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
 134                 rcu_read_unlock();
 135                 return;
 136         }
 137         rcu_read_unlock();
 138
 139         ip6_datagram_dst_update(sk, false);
 140 }
 141 EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
 142
 143 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
 144                            int addr_len)
 145 {
 146         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
 147         struct inet_sock        *inet = inet_sk(sk);
 148         struct ipv6_pinfo       *np = inet6_sk(sk);
 149         struct in6_addr         *daddr;
 150         int                     addr_type;
 151         int                     err;
 152         __be32                  fl6_flowlabel = 0;
 153
 154         if (usin->sin6_family == AF_INET) {
 155                 if (__ipv6_only_sock(sk))
 156                         return -EAFNOSUPPORT;
 157                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
 158                 goto ipv4_connected;
 159         }
 160
 161         if (addr_len < SIN6_LEN_RFC2133)
 162                 return -EINVAL;
 163
 164         if (usin->sin6_family != AF_INET6)
 165                 return -EAFNOSUPPORT;
 166
 167         if (np->sndflow)
 168                 fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 169
 170         if (ipv6_addr_any(&usin->sin6_addr)) {
 171                 /*
 172                  *      connect to self
 173                  */
 174                 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
 175                         ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
 176                                                &usin->sin6_addr);
 177                 else
 178                         usin->sin6_addr = in6addr_loopback;
 179         }
 180
 181         addr_type = ipv6_addr_type(&usin->sin6_addr);
 182
 183         daddr = &usin->sin6_addr;
 184
 185         if (addr_type & IPV6_ADDR_MAPPED) {
 186                 struct sockaddr_in sin;
 187
 188                 if (__ipv6_only_sock(sk)) {
 189                         err = -ENETUNREACH;
 190                         goto out;
 191                 }
 192                 sin.sin_family = AF_INET;
 193                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
 194                 sin.sin_port = usin->sin6_port;
 195
 196                 err = __ip4_datagram_connect(sk,
 197                                              (struct sockaddr *) &sin,
 198                                              sizeof(sin));
 199
 200 ipv4_connected:
 201                 if (err)
 202                         goto out;
 203
 204                 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 205
 206                 if (ipv6_addr_any(&np->saddr) ||
 207                     ipv6_mapped_addr_any(&np->saddr))
 208                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 209
 210                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 211                     ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 212                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 213                                                &sk->sk_v6_rcv_saddr);
 214                         if (sk->sk_prot->rehash)
 215                                 sk->sk_prot->rehash(sk);
 216                 }
 217
 218                 goto out;
 219         }
 220
 221         if (__ipv6_addr_needs_scope_id(addr_type)) {
 222                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 223                     usin->sin6_scope_id) {
 224                         if (sk->sk_bound_dev_if &&
 225                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 226                                 err = -EINVAL;
 227                                 goto out;
 228                         }
 229                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 230                 }
 231
 232                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 233                         sk->sk_bound_dev_if = np->mcast_oif;
 234
 235                 /* Connect to link-local address requires an interface */
 236                 if (!sk->sk_bound_dev_if) {
 237                         err = -EINVAL;
 238                         goto out;
 239                 }
 240         }
 241
 242         sk->sk_v6_daddr = *daddr;
 243         np->flow_label = fl6_flowlabel;
 244
 245         inet->inet_dport = usin->sin6_port;
 246
 247         /*
 248          *      Check for a route to destination an obtain the
 249          *      destination cache for it.
 250          */
 251
 252         err = ip6_datagram_dst_update(sk, true);
 253         if (err) {
 254                 /* Reset daddr and dport so that udp_v6_early_demux()
 255                  * fails to find this socket
 256                  */
 257                 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
 258                 inet->inet_dport = 0;
 259                 goto out;
 260         }
 261
 262         sk->sk_state = TCP_ESTABLISHED;
 263         sk_set_txhash(sk);
 264 out:
 265         return err;
 266 }
 267 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 268
 269 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 270 {
 271         int res;
 272
 273         lock_sock(sk);
 274         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 275         release_sock(sk);
 276         return res;
 277 }
 278 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 279
 280 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 281                                  int addr_len)
 282 {
 283         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 284         if (sin6->sin6_family != AF_INET6)
 285                 return -EAFNOSUPPORT;
 286         return ip6_datagram_connect(sk, uaddr, addr_len);
 287 }
 288 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 289
 290 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 291                      __be16 port, u32 info, u8 *payload)
 292 {
 293         struct ipv6_pinfo *np  = inet6_sk(sk);
 294         struct icmp6hdr *icmph = icmp6_hdr(skb);
 295         struct sock_exterr_skb *serr;
 296
 297         if (!np->recverr)
 298                 return;
 299
 300         skb = skb_clone(skb, GFP_ATOMIC);
 301         if (!skb)
 302                 return;
 303
 304         skb->protocol = htons(ETH_P_IPV6);
 305
 306         serr = SKB_EXT_ERR(skb);
 307         serr->ee.ee_errno = err;
 308         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 309         serr->ee.ee_type = icmph->icmp6_type;
 310         serr->ee.ee_code = icmph->icmp6_code;
 311         serr->ee.ee_pad = 0;
 312         serr->ee.ee_info = info;
 313         serr->ee.ee_data = 0;
 314         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 315                                   skb_network_header(skb);
 316         serr->port = port;
 317
 318         __skb_pull(skb, payload - skb->data);
 319         skb_reset_transport_header(skb);
 320
 321         if (sock_queue_err_skb(sk, skb))
 322                 kfree_skb(skb);
 323 }
 324
 325 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 326 {
 327         const struct ipv6_pinfo *np = inet6_sk(sk);
 328         struct sock_exterr_skb *serr;
 329         struct ipv6hdr *iph;
 330         struct sk_buff *skb;
 331
 332         if (!np->recverr)
 333                 return;
 334
 335         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 336         if (!skb)
 337                 return;
 338
 339         skb->protocol = htons(ETH_P_IPV6);
 340
 341         skb_put(skb, sizeof(struct ipv6hdr));
 342         skb_reset_network_header(skb);
 343         iph = ipv6_hdr(skb);
 344         iph->daddr = fl6->daddr;
 345
 346         serr = SKB_EXT_ERR(skb);
 347         serr->ee.ee_errno = err;
 348         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 349         serr->ee.ee_type = 0;
 350         serr->ee.ee_code = 0;
 351         serr->ee.ee_pad = 0;
 352         serr->ee.ee_info = info;
 353         serr->ee.ee_data = 0;
 354         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 355         serr->port = fl6->fl6_dport;
 356
 357         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 358         skb_reset_transport_header(skb);
 359
 360         if (sock_queue_err_skb(sk, skb))
 361                 kfree_skb(skb);
 362 }
 363
 364 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 365 {
 366         struct ipv6_pinfo *np = inet6_sk(sk);
 367         struct ipv6hdr *iph;
 368         struct sk_buff *skb;
 369         struct ip6_mtuinfo *mtu_info;
 370
 371         if (!np->rxopt.bits.rxpmtu)
 372                 return;
 373
 374         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 375         if (!skb)
 376                 return;
 377
 378         skb_put(skb, sizeof(struct ipv6hdr));
 379         skb_reset_network_header(skb);
 380         iph = ipv6_hdr(skb);
 381         iph->daddr = fl6->daddr;
 382
 383         mtu_info = IP6CBMTU(skb);
 384
 385         mtu_info->ip6m_mtu = mtu;
 386         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 387         mtu_info->ip6m_addr.sin6_port = 0;
 388         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 389         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 390         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 391
 392         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 393         skb_reset_transport_header(skb);
 394
 395         skb = xchg(&np->rxpmtu, skb);
 396         kfree_skb(skb);
 397 }
 398
 399 /* For some errors we have valid addr_offset even with zero payload and
 400  * zero port. Also, addr_offset should be supported if port is set.
 401  */
 402 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 403 {
 404         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 405                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 406                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 407 }
 408
 409 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 410  *
 411  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 412  * errors. This is no longer true, but the test remained, so the v6 stack,
 413  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 414  */
 415 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 416                                       struct sock_exterr_skb *serr)
 417 {
 418         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 419             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 420                 return true;
 421
 422         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 423                 return false;
 424
 425         if (!IP6CB(skb)->iif)
 426                 return false;
 427
 428         return true;
 429 }
 430
 431 /*
 432  *      Handle MSG_ERRQUEUE
 433  */
 434 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 435 {
 436         struct ipv6_pinfo *np = inet6_sk(sk);
 437         struct sock_exterr_skb *serr;
 438         struct sk_buff *skb;
 439         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 440         struct {
 441                 struct sock_extended_err ee;
 442                 struct sockaddr_in6      offender;
 443         } errhdr;
 444         int err;
 445         int copied;
 446
 447         err = -EAGAIN;
 448         skb = sock_dequeue_err_skb(sk);
 449         if (!skb)
 450                 goto out;
 451
 452         copied = skb->len;
 453         if (copied > len) {
 454                 msg->msg_flags |= MSG_TRUNC;
 455                 copied = len;
 456         }
 457         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 458         if (unlikely(err)) {
 459                 kfree_skb(skb);
 460                 return err;
 461         }
 462         sock_recv_timestamp(msg, sk, skb);
 463
 464         serr = SKB_EXT_ERR(skb);
 465
 466         if (sin && ipv6_datagram_support_addr(serr)) {
 467                 const unsigned char *nh = skb_network_header(skb);
 468                 sin->sin6_family = AF_INET6;
 469                 sin->sin6_flowinfo = 0;
 470                 sin->sin6_port = serr->port;
 471                 if (skb->protocol == htons(ETH_P_IPV6)) {
 472                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 473                                                                   struct ipv6hdr, daddr);
 474                         sin->sin6_addr = ip6h->daddr;
 475                         if (np->sndflow)
 476                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 477                         sin->sin6_scope_id =
 478                                 ipv6_iface_scope_id(&sin->sin6_addr,
 479                                                     IP6CB(skb)->iif);
 480                 } else {
 481                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 482                                                &sin->sin6_addr);
 483                         sin->sin6_scope_id = 0;
 484                 }
 485                 *addr_len = sizeof(*sin);
 486         }
 487
 488         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 489         sin = &errhdr.offender;
 490         memset(sin, 0, sizeof(*sin));
 491
 492         if (ip6_datagram_support_cmsg(skb, serr)) {
 493                 sin->sin6_family = AF_INET6;
 494                 if (np->rxopt.all)
 495                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 496                 if (skb->protocol == htons(ETH_P_IPV6)) {
 497                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 498                         if (np->rxopt.all)
 499                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 500                         sin->sin6_scope_id =
 501                                 ipv6_iface_scope_id(&sin->sin6_addr,
 502                                                     IP6CB(skb)->iif);
 503                 } else {
 504                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 505                                                &sin->sin6_addr);
 506                         if (inet_sk(sk)->cmsg_flags)
 507                                 ip_cmsg_recv(msg, skb);
 508                 }
 509         }
 510
 511         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 512
 513         /* Now we could try to dump offended packet options */
 514
 515         msg->msg_flags |= MSG_ERRQUEUE;
 516         err = copied;
 517
 518         consume_skb(skb);
 519 out:
 520         return err;
 521 }
 522 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 523
 524 /*
 525  *      Handle IPV6_RECVPATHMTU
 526  */
 527 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 528                      int *addr_len)
 529 {
 530         struct ipv6_pinfo *np = inet6_sk(sk);
 531         struct sk_buff *skb;
 532         struct ip6_mtuinfo mtu_info;
 533         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 534         int err;
 535         int copied;
 536
 537         err = -EAGAIN;
 538         skb = xchg(&np->rxpmtu, NULL);
 539         if (!skb)
 540                 goto out;
 541
 542         copied = skb->len;
 543         if (copied > len) {
 544                 msg->msg_flags |= MSG_TRUNC;
 545                 copied = len;
 546         }
 547         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 548         if (err)
 549                 goto out_free_skb;
 550
 551         sock_recv_timestamp(msg, sk, skb);
 552
 553         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 554
 555         if (sin) {
 556                 sin->sin6_family = AF_INET6;
 557                 sin->sin6_flowinfo = 0;
 558                 sin->sin6_port = 0;
 559                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 560                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 561                 *addr_len = sizeof(*sin);
 562         }
 563
 564         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 565
 566         err = copied;
 567
 568 out_free_skb:
 569         kfree_skb(skb);
 570 out:
 571         return err;
 572 }
 573
 574
 575 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 576                                  struct sk_buff *skb)
 577 {
 578         struct ipv6_pinfo *np = inet6_sk(sk);
 579         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 580
 581         if (np->rxopt.bits.rxinfo) {
 582                 struct in6_pktinfo src_info;
 583
 584                 if (is_ipv6) {
 585                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 586                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 587                 } else {
 588                         src_info.ipi6_ifindex =
 589                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 590                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 591                                                &src_info.ipi6_addr);
 592                 }
 593
 594                 if (src_info.ipi6_ifindex >= 0)
 595                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 596                                  sizeof(src_info), &src_info);
 597         }
 598 }
 599
 600 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 601                                     struct sk_buff *skb)
 602 {
 603         struct ipv6_pinfo *np = inet6_sk(sk);
 604         struct inet6_skb_parm *opt = IP6CB(skb);
 605         unsigned char *nh = skb_network_header(skb);
 606
 607         if (np->rxopt.bits.rxhlim) {
 608                 int hlim = ipv6_hdr(skb)->hop_limit;
 609                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 610         }
 611
 612         if (np->rxopt.bits.rxtclass) {
 613                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 614                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 615         }
 616
 617         if (np->rxopt.bits.rxflow) {
 618                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 619                 if (flowinfo)
 620                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 621         }
 622
 623         /* HbH is allowed only once */
 624         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 625                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 626                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 627         }
 628
 629         if (opt->lastopt &&
 630             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 631                 /*
 632                  * Silly enough, but we need to reparse in order to
 633                  * report extension headers (except for HbH)
 634                  * in order.
 635                  *
 636                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 637                  * (and WILL NOT be) defined because
 638                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 639                  */
 640                 unsigned int off = sizeof(struct ipv6hdr);
 641                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 642
 643                 while (off <= opt->lastopt) {
 644                         unsigned int len;
 645                         u8 *ptr = nh + off;
 646
 647                         switch (nexthdr) {
 648                         case IPPROTO_DSTOPTS:
 649                                 nexthdr = ptr[0];
 650                                 len = (ptr[1] + 1) << 3;
 651                                 if (np->rxopt.bits.dstopts)
 652                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 653                                 break;
 654                         case IPPROTO_ROUTING:
 655                                 nexthdr = ptr[0];
 656                                 len = (ptr[1] + 1) << 3;
 657                                 if (np->rxopt.bits.srcrt)
 658                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 659                                 break;
 660                         case IPPROTO_AH:
 661                                 nexthdr = ptr[0];
 662                                 len = (ptr[1] + 2) << 2;
 663                                 break;
 664                         default:
 665                                 nexthdr = ptr[0];
 666                                 len = (ptr[1] + 1) << 3;
 667                                 break;
 668                         }
 669
 670                         off += len;
 671                 }
 672         }
 673
 674         /* socket options in old style */
 675         if (np->rxopt.bits.rxoinfo) {
 676                 struct in6_pktinfo src_info;
 677
 678                 src_info.ipi6_ifindex = opt->iif;
 679                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 680                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 681         }
 682         if (np->rxopt.bits.rxohlim) {
 683                 int hlim = ipv6_hdr(skb)->hop_limit;
 684                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 685         }
 686         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 687                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 688                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 689         }
 690         if (np->rxopt.bits.odstopts && opt->dst0) {
 691                 u8 *ptr = nh + opt->dst0;
 692                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 693         }
 694         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 695                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 696                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 697         }
 698         if (np->rxopt.bits.odstopts && opt->dst1) {
 699                 u8 *ptr = nh + opt->dst1;
 700                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 701         }
 702         if (np->rxopt.bits.rxorigdstaddr) {
 703                 struct sockaddr_in6 sin6;
 704                 __be16 *ports = (__be16 *) skb_transport_header(skb);
 705
 706                 if (skb_transport_offset(skb) + 4 <= (int)skb->len) {
 707                         /* All current transport protocols have the port numbers in the
 708                          * first four bytes of the transport header and this function is
 709                          * written with this assumption in mind.
 710                          */
 711
 712                         sin6.sin6_family = AF_INET6;
 713                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 714                         sin6.sin6_port = ports[1];
 715                         sin6.sin6_flowinfo = 0;
 716                         sin6.sin6_scope_id =
 717                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 718                                                     opt->iif);
 719
 720                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 721                 }
 722         }
 723         if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
 724                 int val = opt->frag_max_size;
 725
 726                 put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
 727         }
 728 }
 729
 730 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 731                           struct sk_buff *skb)
 732 {
 733         ip6_datagram_recv_common_ctl(sk, msg, skb);
 734         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 735 }
 736 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 737
 738 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 739                           struct msghdr *msg, struct flowi6 *fl6,
 740                           struct ipcm6_cookie *ipc6, struct sockcm_cookie *sockc)
 741 {
 742         struct in6_pktinfo *src_info;
 743         struct cmsghdr *cmsg;
 744         struct ipv6_rt_hdr *rthdr;
 745         struct ipv6_opt_hdr *hdr;
 746         struct ipv6_txoptions *opt = ipc6->opt;
 747         int len;
 748         int err = 0;
 749
 750         for_each_cmsghdr(cmsg, msg) {
 751                 int addr_type;
 752
 753                 if (!CMSG_OK(msg, cmsg)) {
 754                         err = -EINVAL;
 755                         goto exit_f;
 756                 }
 757
 758                 if (cmsg->cmsg_level == SOL_SOCKET) {
 759                         err = __sock_cmsg_send(sk, msg, cmsg, sockc);
 760                         if (err)
 761                                 return err;
 762                         continue;
 763                 }
 764
 765                 if (cmsg->cmsg_level != SOL_IPV6)
 766                         continue;
 767
 768                 switch (cmsg->cmsg_type) {
 769                 case IPV6_PKTINFO:
 770                 case IPV6_2292PKTINFO:
 771                     {
 772                         struct net_device *dev = NULL;
 773
 774                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 775                                 err = -EINVAL;
 776                                 goto exit_f;
 777                         }
 778
 779                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 780
 781                         if (src_info->ipi6_ifindex) {
 782                                 if (fl6->flowi6_oif &&
 783                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 784                                         return -EINVAL;
 785                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 786                         }
 787
 788                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 789
 790                         rcu_read_lock();
 791                         if (fl6->flowi6_oif) {
 792                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 793                                 if (!dev) {
 794                                         rcu_read_unlock();
 795                                         return -ENODEV;
 796                                 }
 797                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 798                                 rcu_read_unlock();
 799                                 return -EINVAL;
 800                         }
 801
 802                         if (addr_type != IPV6_ADDR_ANY) {
 803                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 804                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 805                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 806                                                    strict ? dev : NULL, 0) &&
 807                                     !ipv6_chk_acast_addr_src(net, dev,
 808                                                              &src_info->ipi6_addr))
 809                                         err = -EINVAL;
 810                                 else
 811                                         fl6->saddr = src_info->ipi6_addr;
 812                         }
 813
 814                         rcu_read_unlock();
 815
 816                         if (err)
 817                                 goto exit_f;
 818
 819                         break;
 820                     }
 821
 822                 case IPV6_FLOWINFO:
 823                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 824                                 err = -EINVAL;
 825                                 goto exit_f;
 826                         }
 827
 828                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 829                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 830                                         err = -EINVAL;
 831                                         goto exit_f;
 832                                 }
 833                         }
 834                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 835                         break;
 836
 837                 case IPV6_2292HOPOPTS:
 838                 case IPV6_HOPOPTS:
 839                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 840                                 err = -EINVAL;
 841                                 goto exit_f;
 842                         }
 843
 844                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 845                         len = ((hdr->hdrlen + 1) << 3);
 846                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 847                                 err = -EINVAL;
 848                                 goto exit_f;
 849                         }
 850                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 851                                 err = -EPERM;
 852                                 goto exit_f;
 853                         }
 854                         opt->opt_nflen += len;
 855                         opt->hopopt = hdr;
 856                         break;
 857
 858                 case IPV6_2292DSTOPTS:
 859                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 860                                 err = -EINVAL;
 861                                 goto exit_f;
 862                         }
 863
 864                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 865                         len = ((hdr->hdrlen + 1) << 3);
 866                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 867                                 err = -EINVAL;
 868                                 goto exit_f;
 869                         }
 870                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 871                                 err = -EPERM;
 872                                 goto exit_f;
 873                         }
 874                         if (opt->dst1opt) {
 875                                 err = -EINVAL;
 876                                 goto exit_f;
 877                         }
 878                         opt->opt_flen += len;
 879                         opt->dst1opt = hdr;
 880                         break;
 881
 882                 case IPV6_DSTOPTS:
 883                 case IPV6_RTHDRDSTOPTS:
 884                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 885                                 err = -EINVAL;
 886                                 goto exit_f;
 887                         }
 888
 889                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 890                         len = ((hdr->hdrlen + 1) << 3);
 891                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 892                                 err = -EINVAL;
 893                                 goto exit_f;
 894                         }
 895                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 896                                 err = -EPERM;
 897                                 goto exit_f;
 898                         }
 899                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 900                                 opt->opt_flen += len;
 901                                 opt->dst1opt = hdr;
 902                         } else {
 903                                 opt->opt_nflen += len;
 904                                 opt->dst0opt = hdr;
 905                         }
 906                         break;
 907
 908                 case IPV6_2292RTHDR:
 909                 case IPV6_RTHDR:
 910                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 911                                 err = -EINVAL;
 912                                 goto exit_f;
 913                         }
 914
 915                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 916
 917                         switch (rthdr->type) {
 918 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 919                         case IPV6_SRCRT_TYPE_2:
 920                                 if (rthdr->hdrlen != 2 ||
 921                                     rthdr->segments_left != 1) {
 922                                         err = -EINVAL;
 923                                         goto exit_f;
 924                                 }
 925                                 break;
 926 #endif
 927                         default:
 928                                 err = -EINVAL;
 929                                 goto exit_f;
 930                         }
 931
 932                         len = ((rthdr->hdrlen + 1) << 3);
 933
 934                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 935                                 err = -EINVAL;
 936                                 goto exit_f;
 937                         }
 938
 939                         /* segments left must also match */
 940                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 941                                 err = -EINVAL;
 942                                 goto exit_f;
 943                         }
 944
 945                         opt->opt_nflen += len;
 946                         opt->srcrt = rthdr;
 947
 948                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 949                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 950
 951                                 opt->opt_nflen += dsthdrlen;
 952                                 opt->dst0opt = opt->dst1opt;
 953                                 opt->dst1opt = NULL;
 954                                 opt->opt_flen -= dsthdrlen;
 955                         }
 956
 957                         break;
 958
 959                 case IPV6_2292HOPLIMIT:
 960                 case IPV6_HOPLIMIT:
 961                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 962                                 err = -EINVAL;
 963                                 goto exit_f;
 964                         }
 965
 966                         ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 967                         if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 968                                 err = -EINVAL;
 969                                 goto exit_f;
 970                         }
 971
 972                         break;
 973
 974                 case IPV6_TCLASS:
 975                     {
 976                         int tc;
 977
 978                         err = -EINVAL;
 979                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 980                                 goto exit_f;
 981
 982                         tc = *(int *)CMSG_DATA(cmsg);
 983                         if (tc < -1 || tc > 0xff)
 984                                 goto exit_f;
 985
 986                         err = 0;
 987                         ipc6->tclass = tc;
 988
 989                         break;
 990                     }
 991
 992                 case IPV6_DONTFRAG:
 993                     {
 994                         int df;
 995
 996                         err = -EINVAL;
 997                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 998                                 goto exit_f;
 999
1000                         df = *(int *)CMSG_DATA(cmsg);
1001                         if (df < 0 || df > 1)
1002                                 goto exit_f;
1003
1004                         err = 0;
1005                         ipc6->dontfrag = df;
1006
1007                         break;
1008                     }
1009                 default:
1010                         net_dbg_ratelimited("invalid cmsg type: %d\n",
1011                                             cmsg->cmsg_type);
1012                         err = -EINVAL;
1013                         goto exit_f;
1014                 }
1015         }
1016
1017 exit_f:
1018         return err;
1019 }
1020 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1021
1022 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1023                              __u16 srcp, __u16 destp, int bucket)
1024 {
1025         const struct in6_addr *dest, *src;
1026
1027         dest  = &sp->sk_v6_daddr;
1028         src   = &sp->sk_v6_rcv_saddr;
1029         seq_printf(seq,
1030                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1031                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
1032                    bucket,
1033                    src->s6_addr32[0], src->s6_addr32[1],
1034                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1035                    dest->s6_addr32[0], dest->s6_addr32[1],
1036                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1037                    sp->sk_state,
1038                    sk_wmem_alloc_get(sp),
1039                    sk_rmem_alloc_get(sp),
1040                    0, 0L, 0,
1041                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1042                    0,
1043                    sock_i_ino(sp),
1044                    refcount_read(&sp->sk_refcnt), sp,
1045                    atomic_read(&sp->sk_drops));
1046 }