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
  26 #include <net/ipv6.h>
  27 #include <net/ndisc.h>
  28 #include <net/addrconf.h>
  29 #include <net/transp_v6.h>
  30 #include <net/ip6_route.h>
  31 #include <net/tcp_states.h>
  32
  33 #include <linux/errqueue.h>
  34 #include <asm/uaccess.h>
  35
  36 static inline int ipv6_mapped_addr_any(const struct in6_addr *a)
  37 {
  38         return (ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0));
  39 }
  40
  41 static int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
  42 {
  43         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
  44         struct inet_sock        *inet = inet_sk(sk);
  45         struct ipv6_pinfo       *np = inet6_sk(sk);
  46         struct in6_addr         *daddr, *final_p, final;
  47         struct dst_entry        *dst;
  48         struct flowi6           fl6;
  49         struct ip6_flowlabel    *flowlabel = NULL;
  50         struct ipv6_txoptions   *opt;
  51         int                     addr_type;
  52         int                     err;
  53
  54         if (usin->sin6_family == AF_INET) {
  55                 if (__ipv6_only_sock(sk))
  56                         return -EAFNOSUPPORT;
  57                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
  58                 goto ipv4_connected;
  59         }
  60
  61         if (addr_len < SIN6_LEN_RFC2133)
  62                 return -EINVAL;
  63
  64         if (usin->sin6_family != AF_INET6)
  65                 return -EAFNOSUPPORT;
  66
  67         memset(&fl6, 0, sizeof(fl6));
  68         if (np->sndflow) {
  69                 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
  70                 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
  71                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
  72                         if (flowlabel == NULL)
  73                                 return -EINVAL;
  74                         ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
  75                 }
  76         }
  77
  78         addr_type = ipv6_addr_type(&usin->sin6_addr);
  79
  80         if (addr_type == IPV6_ADDR_ANY) {
  81                 /*
  82                  *      connect to self
  83                  */
  84                 usin->sin6_addr.s6_addr[15] = 0x01;
  85         }
  86
  87         daddr = &usin->sin6_addr;
  88
  89         if (addr_type == IPV6_ADDR_MAPPED) {
  90                 struct sockaddr_in sin;
  91
  92                 if (__ipv6_only_sock(sk)) {
  93                         err = -ENETUNREACH;
  94                         goto out;
  95                 }
  96                 sin.sin_family = AF_INET;
  97                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
  98                 sin.sin_port = usin->sin6_port;
  99
 100                 err = __ip4_datagram_connect(sk,
 101                                              (struct sockaddr *) &sin,
 102                                              sizeof(sin));
 103
 104 ipv4_connected:
 105                 if (err)
 106                         goto out;
 107
 108                 ipv6_addr_set_v4mapped(inet->inet_daddr, &np->daddr);
 109
 110                 if (ipv6_addr_any(&np->saddr) ||
 111                     ipv6_mapped_addr_any(&np->saddr))
 112                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 113
 114                 if (ipv6_addr_any(&np->rcv_saddr) ||
 115                     ipv6_mapped_addr_any(&np->rcv_saddr)) {
 116                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 117                                                &np->rcv_saddr);
 118                         if (sk->sk_prot->rehash)
 119                                 sk->sk_prot->rehash(sk);
 120                 }
 121
 122                 goto out;
 123         }
 124
 125         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 126                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 127                     usin->sin6_scope_id) {
 128                         if (sk->sk_bound_dev_if &&
 129                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 130                                 err = -EINVAL;
 131                                 goto out;
 132                         }
 133                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 134                 }
 135
 136                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 137                         sk->sk_bound_dev_if = np->mcast_oif;
 138
 139                 /* Connect to link-local address requires an interface */
 140                 if (!sk->sk_bound_dev_if) {
 141                         err = -EINVAL;
 142                         goto out;
 143                 }
 144         }
 145
 146         ipv6_addr_copy(&np->daddr, daddr);
 147         np->flow_label = fl6.flowlabel;
 148
 149         inet->inet_dport = usin->sin6_port;
 150
 151         /*
 152          *      Check for a route to destination an obtain the
 153          *      destination cache for it.
 154          */
 155
 156         fl6.flowi6_proto = sk->sk_protocol;
 157         ipv6_addr_copy(&fl6.daddr, &np->daddr);
 158         ipv6_addr_copy(&fl6.saddr, &np->saddr);
 159         fl6.flowi6_oif = sk->sk_bound_dev_if;
 160         fl6.flowi6_mark = sk->sk_mark;
 161         fl6.fl6_dport = inet->inet_dport;
 162         fl6.fl6_sport = inet->inet_sport;
 163
 164         if (!fl6.flowi6_oif && (addr_type&IPV6_ADDR_MULTICAST))
 165                 fl6.flowi6_oif = np->mcast_oif;
 166
 167         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 168
 169         rcu_read_lock();
 170         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
 171         final_p = fl6_update_dst(&fl6, opt, &final);
 172         rcu_read_unlock();
 173
 174         dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
 175         err = 0;
 176         if (IS_ERR(dst)) {
 177                 err = PTR_ERR(dst);
 178                 goto out;
 179         }
 180
 181         /* source address lookup done in ip6_dst_lookup */
 182
 183         if (ipv6_addr_any(&np->saddr))
 184                 ipv6_addr_copy(&np->saddr, &fl6.saddr);
 185
 186         if (ipv6_addr_any(&np->rcv_saddr)) {
 187                 ipv6_addr_copy(&np->rcv_saddr, &fl6.saddr);
 188                 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 189                 if (sk->sk_prot->rehash)
 190                         sk->sk_prot->rehash(sk);
 191         }
 192
 193         ip6_dst_store(sk, dst,
 194                       ipv6_addr_equal(&fl6.daddr, &np->daddr) ?
 195                       &np->daddr : NULL,
 196 #ifdef CONFIG_IPV6_SUBTREES
 197                       ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
 198                       &np->saddr :
 199 #endif
 200                       NULL);
 201
 202         sk->sk_state = TCP_ESTABLISHED;
 203 out:
 204         fl6_sock_release(flowlabel);
 205         return err;
 206 }
 207
 208 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 209 {
 210         int res;
 211
 212         lock_sock(sk);
 213         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 214         release_sock(sk);
 215         return res;
 216 }
 217
 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         ipv6_addr_copy(&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         ipv6_addr_copy(&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         ipv6_addr_copy(&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         struct sockaddr_in6 *sin;
 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         sin = (struct sockaddr_in6 *)msg->msg_name;
 362         if (sin) {
 363                 const unsigned char *nh = skb_network_header(skb);
 364                 sin->sin6_family = AF_INET6;
 365                 sin->sin6_flowinfo = 0;
 366                 sin->sin6_port = serr->port;
 367                 sin->sin6_scope_id = 0;
 368                 if (skb->protocol == htons(ETH_P_IPV6)) {
 369                         ipv6_addr_copy(&sin->sin6_addr,
 370                                   (struct in6_addr *)(nh + serr->addr_offset));
 371                         if (np->sndflow)
 372                                 sin->sin6_flowinfo =
 373                                         (*(__be32 *)(nh + serr->addr_offset - 24) &
 374                                          IPV6_FLOWINFO_MASK);
 375                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 376                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 377                 } else {
 378                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 379                                                &sin->sin6_addr);
 380                 }
 381                 *addr_len = sizeof(*sin);
 382         }
 383
 384         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 385         sin = &errhdr.offender;
 386         memset(sin, 0, sizeof(*sin));
 387
 388         if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
 389                 sin->sin6_family = AF_INET6;
 390                 if (skb->protocol == htons(ETH_P_IPV6)) {
 391                         ipv6_addr_copy(&sin->sin6_addr, &ipv6_hdr(skb)->saddr);
 392                         if (np->rxopt.all)
 393                                 datagram_recv_ctl(sk, msg, skb);
 394                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 395                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 396                 } else {
 397                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 398                                                &sin->sin6_addr);
 399                         if (inet_sk(sk)->cmsg_flags)
 400                                 ip_cmsg_recv(msg, skb);
 401                 }
 402         }
 403
 404         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 405
 406         /* Now we could try to dump offended packet options */
 407
 408         msg->msg_flags |= MSG_ERRQUEUE;
 409         err = copied;
 410
 411         /* Reset and regenerate socket error */
 412         spin_lock_bh(&sk->sk_error_queue.lock);
 413         sk->sk_err = 0;
 414         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
 415                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
 416                 spin_unlock_bh(&sk->sk_error_queue.lock);
 417                 sk->sk_error_report(sk);
 418         } else {
 419                 spin_unlock_bh(&sk->sk_error_queue.lock);
 420         }
 421
 422 out_free_skb:
 423         kfree_skb(skb);
 424 out:
 425         return err;
 426 }
 427
 428 /*
 429  *      Handle IPV6_RECVPATHMTU
 430  */
 431 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 432                      int *addr_len)
 433 {
 434         struct ipv6_pinfo *np = inet6_sk(sk);
 435         struct sk_buff *skb;
 436         struct sockaddr_in6 *sin;
 437         struct ip6_mtuinfo mtu_info;
 438         int err;
 439         int copied;
 440
 441         err = -EAGAIN;
 442         skb = xchg(&np->rxpmtu, NULL);
 443         if (skb == NULL)
 444                 goto out;
 445
 446         copied = skb->len;
 447         if (copied > len) {
 448                 msg->msg_flags |= MSG_TRUNC;
 449                 copied = len;
 450         }
 451         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 452         if (err)
 453                 goto out_free_skb;
 454
 455         sock_recv_timestamp(msg, sk, skb);
 456
 457         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 458
 459         sin = (struct sockaddr_in6 *)msg->msg_name;
 460         if (sin) {
 461                 sin->sin6_family = AF_INET6;
 462                 sin->sin6_flowinfo = 0;
 463                 sin->sin6_port = 0;
 464                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 465                 ipv6_addr_copy(&sin->sin6_addr, &mtu_info.ip6m_addr.sin6_addr);
 466                 *addr_len = sizeof(*sin);
 467         }
 468
 469         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 470
 471         err = copied;
 472
 473 out_free_skb:
 474         kfree_skb(skb);
 475 out:
 476         return err;
 477 }
 478
 479
 480 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
 481 {
 482         struct ipv6_pinfo *np = inet6_sk(sk);
 483         struct inet6_skb_parm *opt = IP6CB(skb);
 484         unsigned char *nh = skb_network_header(skb);
 485
 486         if (np->rxopt.bits.rxinfo) {
 487                 struct in6_pktinfo src_info;
 488
 489                 src_info.ipi6_ifindex = opt->iif;
 490                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 491                 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
 492         }
 493
 494         if (np->rxopt.bits.rxhlim) {
 495                 int hlim = ipv6_hdr(skb)->hop_limit;
 496                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 497         }
 498
 499         if (np->rxopt.bits.rxtclass) {
 500                 int tclass = (ntohl(*(__be32 *)ipv6_hdr(skb)) >> 20) & 0xff;
 501                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 502         }
 503
 504         if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
 505                 __be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
 506                 put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 507         }
 508
 509         /* HbH is allowed only once */
 510         if (np->rxopt.bits.hopopts && opt->hop) {
 511                 u8 *ptr = nh + opt->hop;
 512                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 513         }
 514
 515         if (opt->lastopt &&
 516             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 517                 /*
 518                  * Silly enough, but we need to reparse in order to
 519                  * report extension headers (except for HbH)
 520                  * in order.
 521                  *
 522                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 523                  * (and WILL NOT be) defined because
 524                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 525                  */
 526                 unsigned int off = sizeof(struct ipv6hdr);
 527                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 528
 529                 while (off <= opt->lastopt) {
 530                         unsigned len;
 531                         u8 *ptr = nh + off;
 532
 533                         switch(nexthdr) {
 534                         case IPPROTO_DSTOPTS:
 535                                 nexthdr = ptr[0];
 536                                 len = (ptr[1] + 1) << 3;
 537                                 if (np->rxopt.bits.dstopts)
 538                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 539                                 break;
 540                         case IPPROTO_ROUTING:
 541                                 nexthdr = ptr[0];
 542                                 len = (ptr[1] + 1) << 3;
 543                                 if (np->rxopt.bits.srcrt)
 544                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 545                                 break;
 546                         case IPPROTO_AH:
 547                                 nexthdr = ptr[0];
 548                                 len = (ptr[1] + 2) << 2;
 549                                 break;
 550                         default:
 551                                 nexthdr = ptr[0];
 552                                 len = (ptr[1] + 1) << 3;
 553                                 break;
 554                         }
 555
 556                         off += len;
 557                 }
 558         }
 559
 560         /* socket options in old style */
 561         if (np->rxopt.bits.rxoinfo) {
 562                 struct in6_pktinfo src_info;
 563
 564                 src_info.ipi6_ifindex = opt->iif;
 565                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 566                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 567         }
 568         if (np->rxopt.bits.rxohlim) {
 569                 int hlim = ipv6_hdr(skb)->hop_limit;
 570                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 571         }
 572         if (np->rxopt.bits.ohopopts && opt->hop) {
 573                 u8 *ptr = nh + opt->hop;
 574                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 575         }
 576         if (np->rxopt.bits.odstopts && opt->dst0) {
 577                 u8 *ptr = nh + opt->dst0;
 578                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 579         }
 580         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 581                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 582                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 583         }
 584         if (np->rxopt.bits.odstopts && opt->dst1) {
 585                 u8 *ptr = nh + opt->dst1;
 586                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 587         }
 588         if (np->rxopt.bits.rxorigdstaddr) {
 589                 struct sockaddr_in6 sin6;
 590                 u16 *ports = (u16 *) skb_transport_header(skb);
 591
 592                 if (skb_transport_offset(skb) + 4 <= skb->len) {
 593                         /* All current transport protocols have the port numbers in the
 594                          * first four bytes of the transport header and this function is
 595                          * written with this assumption in mind.
 596                          */
 597
 598                         sin6.sin6_family = AF_INET6;
 599                         ipv6_addr_copy(&sin6.sin6_addr, &ipv6_hdr(skb)->daddr);
 600                         sin6.sin6_port = ports[1];
 601                         sin6.sin6_flowinfo = 0;
 602                         sin6.sin6_scope_id = 0;
 603
 604                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 605                 }
 606         }
 607         return 0;
 608 }
 609
 610 int datagram_send_ctl(struct net *net, struct sock *sk,
 611                       struct msghdr *msg, struct flowi6 *fl6,
 612                       struct ipv6_txoptions *opt,
 613                       int *hlimit, int *tclass, int *dontfrag)
 614 {
 615         struct in6_pktinfo *src_info;
 616         struct cmsghdr *cmsg;
 617         struct ipv6_rt_hdr *rthdr;
 618         struct ipv6_opt_hdr *hdr;
 619         int len;
 620         int err = 0;
 621
 622         for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 623                 int addr_type;
 624
 625                 if (!CMSG_OK(msg, cmsg)) {
 626                         err = -EINVAL;
 627                         goto exit_f;
 628                 }
 629
 630                 if (cmsg->cmsg_level != SOL_IPV6)
 631                         continue;
 632
 633                 switch (cmsg->cmsg_type) {
 634                 case IPV6_PKTINFO:
 635                 case IPV6_2292PKTINFO:
 636                     {
 637                         struct net_device *dev = NULL;
 638
 639                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 640                                 err = -EINVAL;
 641                                 goto exit_f;
 642                         }
 643
 644                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 645
 646                         if (src_info->ipi6_ifindex) {
 647                                 if (fl6->flowi6_oif &&
 648                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 649                                         return -EINVAL;
 650                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 651                         }
 652
 653                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 654
 655                         rcu_read_lock();
 656                         if (fl6->flowi6_oif) {
 657                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 658                                 if (!dev) {
 659                                         rcu_read_unlock();
 660                                         return -ENODEV;
 661                                 }
 662                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 663                                 rcu_read_unlock();
 664                                 return -EINVAL;
 665                         }
 666
 667                         if (addr_type != IPV6_ADDR_ANY) {
 668                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 669                                 if (!inet_sk(sk)->transparent &&
 670                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 671                                                    strict ? dev : NULL, 0))
 672                                         err = -EINVAL;
 673                                 else
 674                                         ipv6_addr_copy(&fl6->saddr, &src_info->ipi6_addr);
 675                         }
 676
 677                         rcu_read_unlock();
 678
 679                         if (err)
 680                                 goto exit_f;
 681
 682                         break;
 683                     }
 684
 685                 case IPV6_FLOWINFO:
 686                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 687                                 err = -EINVAL;
 688                                 goto exit_f;
 689                         }
 690
 691                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 692                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 693                                         err = -EINVAL;
 694                                         goto exit_f;
 695                                 }
 696                         }
 697                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 698                         break;
 699
 700                 case IPV6_2292HOPOPTS:
 701                 case IPV6_HOPOPTS:
 702                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 703                                 err = -EINVAL;
 704                                 goto exit_f;
 705                         }
 706
 707                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 708                         len = ((hdr->hdrlen + 1) << 3);
 709                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 710                                 err = -EINVAL;
 711                                 goto exit_f;
 712                         }
 713                         if (!capable(CAP_NET_RAW)) {
 714                                 err = -EPERM;
 715                                 goto exit_f;
 716                         }
 717                         opt->opt_nflen += len;
 718                         opt->hopopt = hdr;
 719                         break;
 720
 721                 case IPV6_2292DSTOPTS:
 722                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 723                                 err = -EINVAL;
 724                                 goto exit_f;
 725                         }
 726
 727                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 728                         len = ((hdr->hdrlen + 1) << 3);
 729                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 730                                 err = -EINVAL;
 731                                 goto exit_f;
 732                         }
 733                         if (!capable(CAP_NET_RAW)) {
 734                                 err = -EPERM;
 735                                 goto exit_f;
 736                         }
 737                         if (opt->dst1opt) {
 738                                 err = -EINVAL;
 739                                 goto exit_f;
 740                         }
 741                         opt->opt_flen += len;
 742                         opt->dst1opt = hdr;
 743                         break;
 744
 745                 case IPV6_DSTOPTS:
 746                 case IPV6_RTHDRDSTOPTS:
 747                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 748                                 err = -EINVAL;
 749                                 goto exit_f;
 750                         }
 751
 752                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 753                         len = ((hdr->hdrlen + 1) << 3);
 754                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 755                                 err = -EINVAL;
 756                                 goto exit_f;
 757                         }
 758                         if (!capable(CAP_NET_RAW)) {
 759                                 err = -EPERM;
 760                                 goto exit_f;
 761                         }
 762                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 763                                 opt->opt_flen += len;
 764                                 opt->dst1opt = hdr;
 765                         } else {
 766                                 opt->opt_nflen += len;
 767                                 opt->dst0opt = hdr;
 768                         }
 769                         break;
 770
 771                 case IPV6_2292RTHDR:
 772                 case IPV6_RTHDR:
 773                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 774                                 err = -EINVAL;
 775                                 goto exit_f;
 776                         }
 777
 778                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 779
 780                         switch (rthdr->type) {
 781 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 782                         case IPV6_SRCRT_TYPE_2:
 783                                 if (rthdr->hdrlen != 2 ||
 784                                     rthdr->segments_left != 1) {
 785                                         err = -EINVAL;
 786                                         goto exit_f;
 787                                 }
 788                                 break;
 789 #endif
 790                         default:
 791                                 err = -EINVAL;
 792                                 goto exit_f;
 793                         }
 794
 795                         len = ((rthdr->hdrlen + 1) << 3);
 796
 797                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 798                                 err = -EINVAL;
 799                                 goto exit_f;
 800                         }
 801
 802                         /* segments left must also match */
 803                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 804                                 err = -EINVAL;
 805                                 goto exit_f;
 806                         }
 807
 808                         opt->opt_nflen += len;
 809                         opt->srcrt = rthdr;
 810
 811                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 812                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 813
 814                                 opt->opt_nflen += dsthdrlen;
 815                                 opt->dst0opt = opt->dst1opt;
 816                                 opt->dst1opt = NULL;
 817                                 opt->opt_flen -= dsthdrlen;
 818                         }
 819
 820                         break;
 821
 822                 case IPV6_2292HOPLIMIT:
 823                 case IPV6_HOPLIMIT:
 824                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 825                                 err = -EINVAL;
 826                                 goto exit_f;
 827                         }
 828
 829                         *hlimit = *(int *)CMSG_DATA(cmsg);
 830                         if (*hlimit < -1 || *hlimit > 0xff) {
 831                                 err = -EINVAL;
 832                                 goto exit_f;
 833                         }
 834
 835                         break;
 836
 837                 case IPV6_TCLASS:
 838                     {
 839                         int tc;
 840
 841                         err = -EINVAL;
 842                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 843                                 goto exit_f;
 844                         }
 845
 846                         tc = *(int *)CMSG_DATA(cmsg);
 847                         if (tc < -1 || tc > 0xff)
 848                                 goto exit_f;
 849
 850                         err = 0;
 851                         *tclass = tc;
 852
 853                         break;
 854                     }
 855
 856                 case IPV6_DONTFRAG:
 857                     {
 858                         int df;
 859
 860                         err = -EINVAL;
 861                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 862                                 goto exit_f;
 863                         }
 864
 865                         df = *(int *)CMSG_DATA(cmsg);
 866                         if (df < 0 || df > 1)
 867                                 goto exit_f;
 868
 869                         err = 0;
 870                         *dontfrag = df;
 871
 872                         break;
 873                     }
 874                 default:
 875                         LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
 876                                        cmsg->cmsg_type);
 877                         err = -EINVAL;
 878                         goto exit_f;
 879                 }
 880         }
 881
 882 exit_f:
 883         return err;
 884 }