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 == NULL)
  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 out:
 203         fl6_sock_release(flowlabel);
 204         return err;
 205 }
 206 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 207
 208 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 209                                  int addr_len)
 210 {
 211         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 212         if (sin6->sin6_family != AF_INET6)
 213                 return -EAFNOSUPPORT;
 214         return ip6_datagram_connect(sk, uaddr, addr_len);
 215 }
 216 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 217
 218 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 219                      __be16 port, u32 info, u8 *payload)
 220 {
 221         struct ipv6_pinfo *np  = inet6_sk(sk);
 222         struct icmp6hdr *icmph = icmp6_hdr(skb);
 223         struct sock_exterr_skb *serr;
 224
 225         if (!np->recverr)
 226                 return;
 227
 228         skb = skb_clone(skb, GFP_ATOMIC);
 229         if (!skb)
 230                 return;
 231
 232         skb->protocol = htons(ETH_P_IPV6);
 233
 234         serr = SKB_EXT_ERR(skb);
 235         serr->ee.ee_errno = err;
 236         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 237         serr->ee.ee_type = icmph->icmp6_type;
 238         serr->ee.ee_code = icmph->icmp6_code;
 239         serr->ee.ee_pad = 0;
 240         serr->ee.ee_info = info;
 241         serr->ee.ee_data = 0;
 242         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 243                                   skb_network_header(skb);
 244         serr->port = port;
 245
 246         __skb_pull(skb, payload - skb->data);
 247         skb_reset_transport_header(skb);
 248
 249         if (sock_queue_err_skb(sk, skb))
 250                 kfree_skb(skb);
 251 }
 252
 253 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 254 {
 255         struct ipv6_pinfo *np = inet6_sk(sk);
 256         struct sock_exterr_skb *serr;
 257         struct ipv6hdr *iph;
 258         struct sk_buff *skb;
 259
 260         if (!np->recverr)
 261                 return;
 262
 263         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 264         if (!skb)
 265                 return;
 266
 267         skb->protocol = htons(ETH_P_IPV6);
 268
 269         skb_put(skb, sizeof(struct ipv6hdr));
 270         skb_reset_network_header(skb);
 271         iph = ipv6_hdr(skb);
 272         iph->daddr = fl6->daddr;
 273
 274         serr = SKB_EXT_ERR(skb);
 275         serr->ee.ee_errno = err;
 276         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 277         serr->ee.ee_type = 0;
 278         serr->ee.ee_code = 0;
 279         serr->ee.ee_pad = 0;
 280         serr->ee.ee_info = info;
 281         serr->ee.ee_data = 0;
 282         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 283         serr->port = fl6->fl6_dport;
 284
 285         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 286         skb_reset_transport_header(skb);
 287
 288         if (sock_queue_err_skb(sk, skb))
 289                 kfree_skb(skb);
 290 }
 291
 292 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 293 {
 294         struct ipv6_pinfo *np = inet6_sk(sk);
 295         struct ipv6hdr *iph;
 296         struct sk_buff *skb;
 297         struct ip6_mtuinfo *mtu_info;
 298
 299         if (!np->rxopt.bits.rxpmtu)
 300                 return;
 301
 302         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 303         if (!skb)
 304                 return;
 305
 306         skb_put(skb, sizeof(struct ipv6hdr));
 307         skb_reset_network_header(skb);
 308         iph = ipv6_hdr(skb);
 309         iph->daddr = fl6->daddr;
 310
 311         mtu_info = IP6CBMTU(skb);
 312
 313         mtu_info->ip6m_mtu = mtu;
 314         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 315         mtu_info->ip6m_addr.sin6_port = 0;
 316         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 317         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 318         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 319
 320         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 321         skb_reset_transport_header(skb);
 322
 323         skb = xchg(&np->rxpmtu, skb);
 324         kfree_skb(skb);
 325 }
 326
 327 /*
 328  *      Handle MSG_ERRQUEUE
 329  */
 330 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 331 {
 332         struct ipv6_pinfo *np = inet6_sk(sk);
 333         struct sock_exterr_skb *serr;
 334         struct sk_buff *skb, *skb2;
 335         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 336         struct {
 337                 struct sock_extended_err ee;
 338                 struct sockaddr_in6      offender;
 339         } errhdr;
 340         int err;
 341         int copied;
 342
 343         err = -EAGAIN;
 344         skb = skb_dequeue(&sk->sk_error_queue);
 345         if (skb == NULL)
 346                 goto out;
 347
 348         copied = skb->len;
 349         if (copied > len) {
 350                 msg->msg_flags |= MSG_TRUNC;
 351                 copied = len;
 352         }
 353         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 354         if (err)
 355                 goto out_free_skb;
 356
 357         sock_recv_timestamp(msg, sk, skb);
 358
 359         serr = SKB_EXT_ERR(skb);
 360
 361         if (sin) {
 362                 const unsigned char *nh = skb_network_header(skb);
 363                 sin->sin6_family = AF_INET6;
 364                 sin->sin6_flowinfo = 0;
 365                 sin->sin6_port = serr->port;
 366                 if (skb->protocol == htons(ETH_P_IPV6)) {
 367                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 368                                                                   struct ipv6hdr, daddr);
 369                         sin->sin6_addr = ip6h->daddr;
 370                         if (np->sndflow)
 371                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 372                         sin->sin6_scope_id =
 373                                 ipv6_iface_scope_id(&sin->sin6_addr,
 374                                                     IP6CB(skb)->iif);
 375                 } else {
 376                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 377                                                &sin->sin6_addr);
 378                         sin->sin6_scope_id = 0;
 379                 }
 380                 *addr_len = sizeof(*sin);
 381         }
 382
 383         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 384         sin = &errhdr.offender;
 385         sin->sin6_family = AF_UNSPEC;
 386         if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
 387                 sin->sin6_family = AF_INET6;
 388                 sin->sin6_flowinfo = 0;
 389                 sin->sin6_port = 0;
 390                 if (np->rxopt.all)
 391                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 392                 if (skb->protocol == htons(ETH_P_IPV6)) {
 393                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 394                         if (np->rxopt.all)
 395                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 396                         sin->sin6_scope_id =
 397                                 ipv6_iface_scope_id(&sin->sin6_addr,
 398                                                     IP6CB(skb)->iif);
 399                 } else {
 400                         struct inet_sock *inet = inet_sk(sk);
 401
 402                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 403                                                &sin->sin6_addr);
 404                         sin->sin6_scope_id = 0;
 405                         if (inet->cmsg_flags)
 406                                 ip_cmsg_recv(msg, skb);
 407                 }
 408         }
 409
 410         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 411
 412         /* Now we could try to dump offended packet options */
 413
 414         msg->msg_flags |= MSG_ERRQUEUE;
 415         err = copied;
 416
 417         /* Reset and regenerate socket error */
 418         spin_lock_bh(&sk->sk_error_queue.lock);
 419         sk->sk_err = 0;
 420         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
 421                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
 422                 spin_unlock_bh(&sk->sk_error_queue.lock);
 423                 sk->sk_error_report(sk);
 424         } else {
 425                 spin_unlock_bh(&sk->sk_error_queue.lock);
 426         }
 427
 428 out_free_skb:
 429         kfree_skb(skb);
 430 out:
 431         return err;
 432 }
 433 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 434
 435 /*
 436  *      Handle IPV6_RECVPATHMTU
 437  */
 438 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 439                      int *addr_len)
 440 {
 441         struct ipv6_pinfo *np = inet6_sk(sk);
 442         struct sk_buff *skb;
 443         struct ip6_mtuinfo mtu_info;
 444         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 445         int err;
 446         int copied;
 447
 448         err = -EAGAIN;
 449         skb = xchg(&np->rxpmtu, NULL);
 450         if (skb == NULL)
 451                 goto out;
 452
 453         copied = skb->len;
 454         if (copied > len) {
 455                 msg->msg_flags |= MSG_TRUNC;
 456                 copied = len;
 457         }
 458         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 459         if (err)
 460                 goto out_free_skb;
 461
 462         sock_recv_timestamp(msg, sk, skb);
 463
 464         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 465
 466         if (sin) {
 467                 sin->sin6_family = AF_INET6;
 468                 sin->sin6_flowinfo = 0;
 469                 sin->sin6_port = 0;
 470                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 471                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 472                 *addr_len = sizeof(*sin);
 473         }
 474
 475         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 476
 477         err = copied;
 478
 479 out_free_skb:
 480         kfree_skb(skb);
 481 out:
 482         return err;
 483 }
 484
 485
 486 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 487                                  struct sk_buff *skb)
 488 {
 489         struct ipv6_pinfo *np = inet6_sk(sk);
 490         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 491
 492         if (np->rxopt.bits.rxinfo) {
 493                 struct in6_pktinfo src_info;
 494
 495                 if (is_ipv6) {
 496                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 497                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 498                 } else {
 499                         src_info.ipi6_ifindex =
 500                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 501                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 502                                                &src_info.ipi6_addr);
 503                 }
 504                 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
 505         }
 506 }
 507
 508 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 509                                     struct sk_buff *skb)
 510 {
 511         struct ipv6_pinfo *np = inet6_sk(sk);
 512         struct inet6_skb_parm *opt = IP6CB(skb);
 513         unsigned char *nh = skb_network_header(skb);
 514
 515         if (np->rxopt.bits.rxhlim) {
 516                 int hlim = ipv6_hdr(skb)->hop_limit;
 517                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 518         }
 519
 520         if (np->rxopt.bits.rxtclass) {
 521                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 522                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 523         }
 524
 525         if (np->rxopt.bits.rxflow) {
 526                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 527                 if (flowinfo)
 528                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 529         }
 530
 531         /* HbH is allowed only once */
 532         if (np->rxopt.bits.hopopts && opt->hop) {
 533                 u8 *ptr = nh + opt->hop;
 534                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 535         }
 536
 537         if (opt->lastopt &&
 538             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 539                 /*
 540                  * Silly enough, but we need to reparse in order to
 541                  * report extension headers (except for HbH)
 542                  * in order.
 543                  *
 544                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 545                  * (and WILL NOT be) defined because
 546                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 547                  */
 548                 unsigned int off = sizeof(struct ipv6hdr);
 549                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 550
 551                 while (off <= opt->lastopt) {
 552                         unsigned int len;
 553                         u8 *ptr = nh + off;
 554
 555                         switch (nexthdr) {
 556                         case IPPROTO_DSTOPTS:
 557                                 nexthdr = ptr[0];
 558                                 len = (ptr[1] + 1) << 3;
 559                                 if (np->rxopt.bits.dstopts)
 560                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 561                                 break;
 562                         case IPPROTO_ROUTING:
 563                                 nexthdr = ptr[0];
 564                                 len = (ptr[1] + 1) << 3;
 565                                 if (np->rxopt.bits.srcrt)
 566                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 567                                 break;
 568                         case IPPROTO_AH:
 569                                 nexthdr = ptr[0];
 570                                 len = (ptr[1] + 2) << 2;
 571                                 break;
 572                         default:
 573                                 nexthdr = ptr[0];
 574                                 len = (ptr[1] + 1) << 3;
 575                                 break;
 576                         }
 577
 578                         off += len;
 579                 }
 580         }
 581
 582         /* socket options in old style */
 583         if (np->rxopt.bits.rxoinfo) {
 584                 struct in6_pktinfo src_info;
 585
 586                 src_info.ipi6_ifindex = opt->iif;
 587                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 588                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 589         }
 590         if (np->rxopt.bits.rxohlim) {
 591                 int hlim = ipv6_hdr(skb)->hop_limit;
 592                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 593         }
 594         if (np->rxopt.bits.ohopopts && opt->hop) {
 595                 u8 *ptr = nh + opt->hop;
 596                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 597         }
 598         if (np->rxopt.bits.odstopts && opt->dst0) {
 599                 u8 *ptr = nh + opt->dst0;
 600                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 601         }
 602         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 603                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 604                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 605         }
 606         if (np->rxopt.bits.odstopts && opt->dst1) {
 607                 u8 *ptr = nh + opt->dst1;
 608                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 609         }
 610         if (np->rxopt.bits.rxorigdstaddr) {
 611                 struct sockaddr_in6 sin6;
 612                 __be16 *ports = (__be16 *) skb_transport_header(skb);
 613
 614                 if (skb_transport_offset(skb) + 4 <= skb->len) {
 615                         /* All current transport protocols have the port numbers in the
 616                          * first four bytes of the transport header and this function is
 617                          * written with this assumption in mind.
 618                          */
 619
 620                         sin6.sin6_family = AF_INET6;
 621                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 622                         sin6.sin6_port = ports[1];
 623                         sin6.sin6_flowinfo = 0;
 624                         sin6.sin6_scope_id =
 625                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 626                                                     opt->iif);
 627
 628                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 629                 }
 630         }
 631 }
 632
 633 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 634                           struct sk_buff *skb)
 635 {
 636         ip6_datagram_recv_common_ctl(sk, msg, skb);
 637         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 638 }
 639 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 640
 641 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 642                           struct msghdr *msg, struct flowi6 *fl6,
 643                           struct ipv6_txoptions *opt,
 644                           int *hlimit, int *tclass, int *dontfrag)
 645 {
 646         struct in6_pktinfo *src_info;
 647         struct cmsghdr *cmsg;
 648         struct ipv6_rt_hdr *rthdr;
 649         struct ipv6_opt_hdr *hdr;
 650         int len;
 651         int err = 0;
 652
 653         for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 654                 int addr_type;
 655
 656                 if (!CMSG_OK(msg, cmsg)) {
 657                         err = -EINVAL;
 658                         goto exit_f;
 659                 }
 660
 661                 if (cmsg->cmsg_level != SOL_IPV6)
 662                         continue;
 663
 664                 switch (cmsg->cmsg_type) {
 665                 case IPV6_PKTINFO:
 666                 case IPV6_2292PKTINFO:
 667                     {
 668                         struct net_device *dev = NULL;
 669
 670                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 671                                 err = -EINVAL;
 672                                 goto exit_f;
 673                         }
 674
 675                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 676
 677                         if (src_info->ipi6_ifindex) {
 678                                 if (fl6->flowi6_oif &&
 679                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 680                                         return -EINVAL;
 681                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 682                         }
 683
 684                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 685
 686                         rcu_read_lock();
 687                         if (fl6->flowi6_oif) {
 688                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 689                                 if (!dev) {
 690                                         rcu_read_unlock();
 691                                         return -ENODEV;
 692                                 }
 693                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 694                                 rcu_read_unlock();
 695                                 return -EINVAL;
 696                         }
 697
 698                         if (addr_type != IPV6_ADDR_ANY) {
 699                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 700                                 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 701                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 702                                                    strict ? dev : NULL, 0) &&
 703                                     !ipv6_chk_acast_addr_src(net, dev,
 704                                                              &src_info->ipi6_addr))
 705                                         err = -EINVAL;
 706                                 else
 707                                         fl6->saddr = src_info->ipi6_addr;
 708                         }
 709
 710                         rcu_read_unlock();
 711
 712                         if (err)
 713                                 goto exit_f;
 714
 715                         break;
 716                     }
 717
 718                 case IPV6_FLOWINFO:
 719                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 720                                 err = -EINVAL;
 721                                 goto exit_f;
 722                         }
 723
 724                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 725                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 726                                         err = -EINVAL;
 727                                         goto exit_f;
 728                                 }
 729                         }
 730                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 731                         break;
 732
 733                 case IPV6_2292HOPOPTS:
 734                 case IPV6_HOPOPTS:
 735                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 736                                 err = -EINVAL;
 737                                 goto exit_f;
 738                         }
 739
 740                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 741                         len = ((hdr->hdrlen + 1) << 3);
 742                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 743                                 err = -EINVAL;
 744                                 goto exit_f;
 745                         }
 746                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 747                                 err = -EPERM;
 748                                 goto exit_f;
 749                         }
 750                         opt->opt_nflen += len;
 751                         opt->hopopt = hdr;
 752                         break;
 753
 754                 case IPV6_2292DSTOPTS:
 755                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 756                                 err = -EINVAL;
 757                                 goto exit_f;
 758                         }
 759
 760                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 761                         len = ((hdr->hdrlen + 1) << 3);
 762                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 763                                 err = -EINVAL;
 764                                 goto exit_f;
 765                         }
 766                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 767                                 err = -EPERM;
 768                                 goto exit_f;
 769                         }
 770                         if (opt->dst1opt) {
 771                                 err = -EINVAL;
 772                                 goto exit_f;
 773                         }
 774                         opt->opt_flen += len;
 775                         opt->dst1opt = hdr;
 776                         break;
 777
 778                 case IPV6_DSTOPTS:
 779                 case IPV6_RTHDRDSTOPTS:
 780                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 781                                 err = -EINVAL;
 782                                 goto exit_f;
 783                         }
 784
 785                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 786                         len = ((hdr->hdrlen + 1) << 3);
 787                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 788                                 err = -EINVAL;
 789                                 goto exit_f;
 790                         }
 791                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 792                                 err = -EPERM;
 793                                 goto exit_f;
 794                         }
 795                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 796                                 opt->opt_flen += len;
 797                                 opt->dst1opt = hdr;
 798                         } else {
 799                                 opt->opt_nflen += len;
 800                                 opt->dst0opt = hdr;
 801                         }
 802                         break;
 803
 804                 case IPV6_2292RTHDR:
 805                 case IPV6_RTHDR:
 806                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 807                                 err = -EINVAL;
 808                                 goto exit_f;
 809                         }
 810
 811                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 812
 813                         switch (rthdr->type) {
 814 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 815                         case IPV6_SRCRT_TYPE_2:
 816                                 if (rthdr->hdrlen != 2 ||
 817                                     rthdr->segments_left != 1) {
 818                                         err = -EINVAL;
 819                                         goto exit_f;
 820                                 }
 821                                 break;
 822 #endif
 823                         default:
 824                                 err = -EINVAL;
 825                                 goto exit_f;
 826                         }
 827
 828                         len = ((rthdr->hdrlen + 1) << 3);
 829
 830                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 831                                 err = -EINVAL;
 832                                 goto exit_f;
 833                         }
 834
 835                         /* segments left must also match */
 836                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 837                                 err = -EINVAL;
 838                                 goto exit_f;
 839                         }
 840
 841                         opt->opt_nflen += len;
 842                         opt->srcrt = rthdr;
 843
 844                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 845                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 846
 847                                 opt->opt_nflen += dsthdrlen;
 848                                 opt->dst0opt = opt->dst1opt;
 849                                 opt->dst1opt = NULL;
 850                                 opt->opt_flen -= dsthdrlen;
 851                         }
 852
 853                         break;
 854
 855                 case IPV6_2292HOPLIMIT:
 856                 case IPV6_HOPLIMIT:
 857                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 858                                 err = -EINVAL;
 859                                 goto exit_f;
 860                         }
 861
 862                         *hlimit = *(int *)CMSG_DATA(cmsg);
 863                         if (*hlimit < -1 || *hlimit > 0xff) {
 864                                 err = -EINVAL;
 865                                 goto exit_f;
 866                         }
 867
 868                         break;
 869
 870                 case IPV6_TCLASS:
 871                     {
 872                         int tc;
 873
 874                         err = -EINVAL;
 875                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 876                                 goto exit_f;
 877
 878                         tc = *(int *)CMSG_DATA(cmsg);
 879                         if (tc < -1 || tc > 0xff)
 880                                 goto exit_f;
 881
 882                         err = 0;
 883                         *tclass = tc;
 884
 885                         break;
 886                     }
 887
 888                 case IPV6_DONTFRAG:
 889                     {
 890                         int df;
 891
 892                         err = -EINVAL;
 893                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 894                                 goto exit_f;
 895
 896                         df = *(int *)CMSG_DATA(cmsg);
 897                         if (df < 0 || df > 1)
 898                                 goto exit_f;
 899
 900                         err = 0;
 901                         *dontfrag = df;
 902
 903                         break;
 904                     }
 905                 default:
 906                         LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
 907                                        cmsg->cmsg_type);
 908                         err = -EINVAL;
 909                         goto exit_f;
 910                 }
 911         }
 912
 913 exit_f:
 914         return err;
 915 }
 916 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
 917
 918 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
 919                              __u16 srcp, __u16 destp, int bucket)
 920 {
 921         const struct in6_addr *dest, *src;
 922
 923         dest  = &sp->sk_v6_daddr;
 924         src   = &sp->sk_v6_rcv_saddr;
 925         seq_printf(seq,
 926                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
 927                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
 928                    bucket,
 929                    src->s6_addr32[0], src->s6_addr32[1],
 930                    src->s6_addr32[2], src->s6_addr32[3], srcp,
 931                    dest->s6_addr32[0], dest->s6_addr32[1],
 932                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
 933                    sp->sk_state,
 934                    sk_wmem_alloc_get(sp),
 935                    sk_rmem_alloc_get(sp),
 936                    0, 0L, 0,
 937                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
 938                    0,
 939                    sock_i_ino(sp),
 940                    atomic_read(&sp->sk_refcnt), sp,
 941                    atomic_read(&sp->sk_drops));
 942 }