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 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         opt = flowlabel ? flowlabel->opt : np->opt;
 170         final_p = fl6_update_dst(&fl6, opt, &final);
 171
 172         dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
 173         err = 0;
 174         if (IS_ERR(dst)) {
 175                 err = PTR_ERR(dst);
 176                 goto out;
 177         }
 178
 179         /* source address lookup done in ip6_dst_lookup */
 180
 181         if (ipv6_addr_any(&np->saddr))
 182                 ipv6_addr_copy(&np->saddr, &fl6.saddr);
 183
 184         if (ipv6_addr_any(&np->rcv_saddr)) {
 185                 ipv6_addr_copy(&np->rcv_saddr, &fl6.saddr);
 186                 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 187                 if (sk->sk_prot->rehash)
 188                         sk->sk_prot->rehash(sk);
 189         }
 190
 191         ip6_dst_store(sk, dst,
 192                       ipv6_addr_equal(&fl6.daddr, &np->daddr) ?
 193                       &np->daddr : NULL,
 194 #ifdef CONFIG_IPV6_SUBTREES
 195                       ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
 196                       &np->saddr :
 197 #endif
 198                       NULL);
 199
 200         sk->sk_state = TCP_ESTABLISHED;
 201 out:
 202         fl6_sock_release(flowlabel);
 203         return err;
 204 }
 205
 206 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 207                      __be16 port, u32 info, u8 *payload)
 208 {
 209         struct ipv6_pinfo *np  = inet6_sk(sk);
 210         struct icmp6hdr *icmph = icmp6_hdr(skb);
 211         struct sock_exterr_skb *serr;
 212
 213         if (!np->recverr)
 214                 return;
 215
 216         skb = skb_clone(skb, GFP_ATOMIC);
 217         if (!skb)
 218                 return;
 219
 220         skb->protocol = htons(ETH_P_IPV6);
 221
 222         serr = SKB_EXT_ERR(skb);
 223         serr->ee.ee_errno = err;
 224         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 225         serr->ee.ee_type = icmph->icmp6_type;
 226         serr->ee.ee_code = icmph->icmp6_code;
 227         serr->ee.ee_pad = 0;
 228         serr->ee.ee_info = info;
 229         serr->ee.ee_data = 0;
 230         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 231                                   skb_network_header(skb);
 232         serr->port = port;
 233
 234         __skb_pull(skb, payload - skb->data);
 235         skb_reset_transport_header(skb);
 236
 237         if (sock_queue_err_skb(sk, skb))
 238                 kfree_skb(skb);
 239 }
 240
 241 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 242 {
 243         struct ipv6_pinfo *np = inet6_sk(sk);
 244         struct sock_exterr_skb *serr;
 245         struct ipv6hdr *iph;
 246         struct sk_buff *skb;
 247
 248         if (!np->recverr)
 249                 return;
 250
 251         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 252         if (!skb)
 253                 return;
 254
 255         skb->protocol = htons(ETH_P_IPV6);
 256
 257         skb_put(skb, sizeof(struct ipv6hdr));
 258         skb_reset_network_header(skb);
 259         iph = ipv6_hdr(skb);
 260         ipv6_addr_copy(&iph->daddr, &fl6->daddr);
 261
 262         serr = SKB_EXT_ERR(skb);
 263         serr->ee.ee_errno = err;
 264         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 265         serr->ee.ee_type = 0;
 266         serr->ee.ee_code = 0;
 267         serr->ee.ee_pad = 0;
 268         serr->ee.ee_info = info;
 269         serr->ee.ee_data = 0;
 270         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 271         serr->port = fl6->fl6_dport;
 272
 273         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 274         skb_reset_transport_header(skb);
 275
 276         if (sock_queue_err_skb(sk, skb))
 277                 kfree_skb(skb);
 278 }
 279
 280 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 281 {
 282         struct ipv6_pinfo *np = inet6_sk(sk);
 283         struct ipv6hdr *iph;
 284         struct sk_buff *skb;
 285         struct ip6_mtuinfo *mtu_info;
 286
 287         if (!np->rxopt.bits.rxpmtu)
 288                 return;
 289
 290         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 291         if (!skb)
 292                 return;
 293
 294         skb_put(skb, sizeof(struct ipv6hdr));
 295         skb_reset_network_header(skb);
 296         iph = ipv6_hdr(skb);
 297         ipv6_addr_copy(&iph->daddr, &fl6->daddr);
 298
 299         mtu_info = IP6CBMTU(skb);
 300
 301         mtu_info->ip6m_mtu = mtu;
 302         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 303         mtu_info->ip6m_addr.sin6_port = 0;
 304         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 305         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 306         ipv6_addr_copy(&mtu_info->ip6m_addr.sin6_addr, &ipv6_hdr(skb)->daddr);
 307
 308         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 309         skb_reset_transport_header(skb);
 310
 311         skb = xchg(&np->rxpmtu, skb);
 312         kfree_skb(skb);
 313 }
 314
 315 /*
 316  *      Handle MSG_ERRQUEUE
 317  */
 318 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 319 {
 320         struct ipv6_pinfo *np = inet6_sk(sk);
 321         struct sock_exterr_skb *serr;
 322         struct sk_buff *skb, *skb2;
 323         struct sockaddr_in6 *sin;
 324         struct {
 325                 struct sock_extended_err ee;
 326                 struct sockaddr_in6      offender;
 327         } errhdr;
 328         int err;
 329         int copied;
 330
 331         err = -EAGAIN;
 332         skb = skb_dequeue(&sk->sk_error_queue);
 333         if (skb == NULL)
 334                 goto out;
 335
 336         copied = skb->len;
 337         if (copied > len) {
 338                 msg->msg_flags |= MSG_TRUNC;
 339                 copied = len;
 340         }
 341         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 342         if (err)
 343                 goto out_free_skb;
 344
 345         sock_recv_timestamp(msg, sk, skb);
 346
 347         serr = SKB_EXT_ERR(skb);
 348
 349         sin = (struct sockaddr_in6 *)msg->msg_name;
 350         if (sin) {
 351                 const unsigned char *nh = skb_network_header(skb);
 352                 sin->sin6_family = AF_INET6;
 353                 sin->sin6_flowinfo = 0;
 354                 sin->sin6_port = serr->port;
 355                 sin->sin6_scope_id = 0;
 356                 if (skb->protocol == htons(ETH_P_IPV6)) {
 357                         ipv6_addr_copy(&sin->sin6_addr,
 358                                   (struct in6_addr *)(nh + serr->addr_offset));
 359                         if (np->sndflow)
 360                                 sin->sin6_flowinfo =
 361                                         (*(__be32 *)(nh + serr->addr_offset - 24) &
 362                                          IPV6_FLOWINFO_MASK);
 363                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 364                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 365                 } else {
 366                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 367                                                &sin->sin6_addr);
 368                 }
 369                 *addr_len = sizeof(*sin);
 370         }
 371
 372         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 373         sin = &errhdr.offender;
 374         memset(sin, 0, sizeof(*sin));
 375
 376         if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
 377                 sin->sin6_family = AF_INET6;
 378                 if (skb->protocol == htons(ETH_P_IPV6)) {
 379                         ipv6_addr_copy(&sin->sin6_addr, &ipv6_hdr(skb)->saddr);
 380                         if (np->rxopt.all)
 381                                 datagram_recv_ctl(sk, msg, skb);
 382                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 383                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 384                 } else {
 385                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 386                                                &sin->sin6_addr);
 387                         if (inet_sk(sk)->cmsg_flags)
 388                                 ip_cmsg_recv(msg, skb);
 389                 }
 390         }
 391
 392         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 393
 394         /* Now we could try to dump offended packet options */
 395
 396         msg->msg_flags |= MSG_ERRQUEUE;
 397         err = copied;
 398
 399         /* Reset and regenerate socket error */
 400         spin_lock_bh(&sk->sk_error_queue.lock);
 401         sk->sk_err = 0;
 402         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
 403                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
 404                 spin_unlock_bh(&sk->sk_error_queue.lock);
 405                 sk->sk_error_report(sk);
 406         } else {
 407                 spin_unlock_bh(&sk->sk_error_queue.lock);
 408         }
 409
 410 out_free_skb:
 411         kfree_skb(skb);
 412 out:
 413         return err;
 414 }
 415
 416 /*
 417  *      Handle IPV6_RECVPATHMTU
 418  */
 419 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 420                      int *addr_len)
 421 {
 422         struct ipv6_pinfo *np = inet6_sk(sk);
 423         struct sk_buff *skb;
 424         struct sockaddr_in6 *sin;
 425         struct ip6_mtuinfo mtu_info;
 426         int err;
 427         int copied;
 428
 429         err = -EAGAIN;
 430         skb = xchg(&np->rxpmtu, NULL);
 431         if (skb == NULL)
 432                 goto out;
 433
 434         copied = skb->len;
 435         if (copied > len) {
 436                 msg->msg_flags |= MSG_TRUNC;
 437                 copied = len;
 438         }
 439         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 440         if (err)
 441                 goto out_free_skb;
 442
 443         sock_recv_timestamp(msg, sk, skb);
 444
 445         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 446
 447         sin = (struct sockaddr_in6 *)msg->msg_name;
 448         if (sin) {
 449                 sin->sin6_family = AF_INET6;
 450                 sin->sin6_flowinfo = 0;
 451                 sin->sin6_port = 0;
 452                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 453                 ipv6_addr_copy(&sin->sin6_addr, &mtu_info.ip6m_addr.sin6_addr);
 454                 *addr_len = sizeof(*sin);
 455         }
 456
 457         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 458
 459         err = copied;
 460
 461 out_free_skb:
 462         kfree_skb(skb);
 463 out:
 464         return err;
 465 }
 466
 467
 468 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
 469 {
 470         struct ipv6_pinfo *np = inet6_sk(sk);
 471         struct inet6_skb_parm *opt = IP6CB(skb);
 472         unsigned char *nh = skb_network_header(skb);
 473
 474         if (np->rxopt.bits.rxinfo) {
 475                 struct in6_pktinfo src_info;
 476
 477                 src_info.ipi6_ifindex = opt->iif;
 478                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 479                 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
 480         }
 481
 482         if (np->rxopt.bits.rxhlim) {
 483                 int hlim = ipv6_hdr(skb)->hop_limit;
 484                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 485         }
 486
 487         if (np->rxopt.bits.rxtclass) {
 488                 int tclass = (ntohl(*(__be32 *)ipv6_hdr(skb)) >> 20) & 0xff;
 489                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 490         }
 491
 492         if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
 493                 __be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
 494                 put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 495         }
 496
 497         /* HbH is allowed only once */
 498         if (np->rxopt.bits.hopopts && opt->hop) {
 499                 u8 *ptr = nh + opt->hop;
 500                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 501         }
 502
 503         if (opt->lastopt &&
 504             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 505                 /*
 506                  * Silly enough, but we need to reparse in order to
 507                  * report extension headers (except for HbH)
 508                  * in order.
 509                  *
 510                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 511                  * (and WILL NOT be) defined because
 512                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 513                  */
 514                 unsigned int off = sizeof(struct ipv6hdr);
 515                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 516
 517                 while (off <= opt->lastopt) {
 518                         unsigned len;
 519                         u8 *ptr = nh + off;
 520
 521                         switch(nexthdr) {
 522                         case IPPROTO_DSTOPTS:
 523                                 nexthdr = ptr[0];
 524                                 len = (ptr[1] + 1) << 3;
 525                                 if (np->rxopt.bits.dstopts)
 526                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 527                                 break;
 528                         case IPPROTO_ROUTING:
 529                                 nexthdr = ptr[0];
 530                                 len = (ptr[1] + 1) << 3;
 531                                 if (np->rxopt.bits.srcrt)
 532                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 533                                 break;
 534                         case IPPROTO_AH:
 535                                 nexthdr = ptr[0];
 536                                 len = (ptr[1] + 2) << 2;
 537                                 break;
 538                         default:
 539                                 nexthdr = ptr[0];
 540                                 len = (ptr[1] + 1) << 3;
 541                                 break;
 542                         }
 543
 544                         off += len;
 545                 }
 546         }
 547
 548         /* socket options in old style */
 549         if (np->rxopt.bits.rxoinfo) {
 550                 struct in6_pktinfo src_info;
 551
 552                 src_info.ipi6_ifindex = opt->iif;
 553                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 554                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 555         }
 556         if (np->rxopt.bits.rxohlim) {
 557                 int hlim = ipv6_hdr(skb)->hop_limit;
 558                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 559         }
 560         if (np->rxopt.bits.ohopopts && opt->hop) {
 561                 u8 *ptr = nh + opt->hop;
 562                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 563         }
 564         if (np->rxopt.bits.odstopts && opt->dst0) {
 565                 u8 *ptr = nh + opt->dst0;
 566                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 567         }
 568         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 569                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 570                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 571         }
 572         if (np->rxopt.bits.odstopts && opt->dst1) {
 573                 u8 *ptr = nh + opt->dst1;
 574                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 575         }
 576         if (np->rxopt.bits.rxorigdstaddr) {
 577                 struct sockaddr_in6 sin6;
 578                 u16 *ports = (u16 *) skb_transport_header(skb);
 579
 580                 if (skb_transport_offset(skb) + 4 <= skb->len) {
 581                         /* All current transport protocols have the port numbers in the
 582                          * first four bytes of the transport header and this function is
 583                          * written with this assumption in mind.
 584                          */
 585
 586                         sin6.sin6_family = AF_INET6;
 587                         ipv6_addr_copy(&sin6.sin6_addr, &ipv6_hdr(skb)->daddr);
 588                         sin6.sin6_port = ports[1];
 589                         sin6.sin6_flowinfo = 0;
 590                         sin6.sin6_scope_id = 0;
 591
 592                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 593                 }
 594         }
 595         return 0;
 596 }
 597
 598 int datagram_send_ctl(struct net *net, struct sock *sk,
 599                       struct msghdr *msg, struct flowi6 *fl6,
 600                       struct ipv6_txoptions *opt,
 601                       int *hlimit, int *tclass, int *dontfrag)
 602 {
 603         struct in6_pktinfo *src_info;
 604         struct cmsghdr *cmsg;
 605         struct ipv6_rt_hdr *rthdr;
 606         struct ipv6_opt_hdr *hdr;
 607         int len;
 608         int err = 0;
 609
 610         for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 611                 int addr_type;
 612
 613                 if (!CMSG_OK(msg, cmsg)) {
 614                         err = -EINVAL;
 615                         goto exit_f;
 616                 }
 617
 618                 if (cmsg->cmsg_level != SOL_IPV6)
 619                         continue;
 620
 621                 switch (cmsg->cmsg_type) {
 622                 case IPV6_PKTINFO:
 623                 case IPV6_2292PKTINFO:
 624                     {
 625                         struct net_device *dev = NULL;
 626
 627                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 628                                 err = -EINVAL;
 629                                 goto exit_f;
 630                         }
 631
 632                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 633
 634                         if (src_info->ipi6_ifindex) {
 635                                 if (fl6->flowi6_oif &&
 636                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 637                                         return -EINVAL;
 638                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 639                         }
 640
 641                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 642
 643                         rcu_read_lock();
 644                         if (fl6->flowi6_oif) {
 645                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 646                                 if (!dev) {
 647                                         rcu_read_unlock();
 648                                         return -ENODEV;
 649                                 }
 650                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 651                                 rcu_read_unlock();
 652                                 return -EINVAL;
 653                         }
 654
 655                         if (addr_type != IPV6_ADDR_ANY) {
 656                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 657                                 if (!inet_sk(sk)->transparent &&
 658                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 659                                                    strict ? dev : NULL, 0))
 660                                         err = -EINVAL;
 661                                 else
 662                                         ipv6_addr_copy(&fl6->saddr, &src_info->ipi6_addr);
 663                         }
 664
 665                         rcu_read_unlock();
 666
 667                         if (err)
 668                                 goto exit_f;
 669
 670                         break;
 671                     }
 672
 673                 case IPV6_FLOWINFO:
 674                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 675                                 err = -EINVAL;
 676                                 goto exit_f;
 677                         }
 678
 679                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 680                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 681                                         err = -EINVAL;
 682                                         goto exit_f;
 683                                 }
 684                         }
 685                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 686                         break;
 687
 688                 case IPV6_2292HOPOPTS:
 689                 case IPV6_HOPOPTS:
 690                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 691                                 err = -EINVAL;
 692                                 goto exit_f;
 693                         }
 694
 695                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 696                         len = ((hdr->hdrlen + 1) << 3);
 697                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 698                                 err = -EINVAL;
 699                                 goto exit_f;
 700                         }
 701                         if (!capable(CAP_NET_RAW)) {
 702                                 err = -EPERM;
 703                                 goto exit_f;
 704                         }
 705                         opt->opt_nflen += len;
 706                         opt->hopopt = hdr;
 707                         break;
 708
 709                 case IPV6_2292DSTOPTS:
 710                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 711                                 err = -EINVAL;
 712                                 goto exit_f;
 713                         }
 714
 715                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 716                         len = ((hdr->hdrlen + 1) << 3);
 717                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 718                                 err = -EINVAL;
 719                                 goto exit_f;
 720                         }
 721                         if (!capable(CAP_NET_RAW)) {
 722                                 err = -EPERM;
 723                                 goto exit_f;
 724                         }
 725                         if (opt->dst1opt) {
 726                                 err = -EINVAL;
 727                                 goto exit_f;
 728                         }
 729                         opt->opt_flen += len;
 730                         opt->dst1opt = hdr;
 731                         break;
 732
 733                 case IPV6_DSTOPTS:
 734                 case IPV6_RTHDRDSTOPTS:
 735                         if (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 (!capable(CAP_NET_RAW)) {
 747                                 err = -EPERM;
 748                                 goto exit_f;
 749                         }
 750                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 751                                 opt->opt_flen += len;
 752                                 opt->dst1opt = hdr;
 753                         } else {
 754                                 opt->opt_nflen += len;
 755                                 opt->dst0opt = hdr;
 756                         }
 757                         break;
 758
 759                 case IPV6_2292RTHDR:
 760                 case IPV6_RTHDR:
 761                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 762                                 err = -EINVAL;
 763                                 goto exit_f;
 764                         }
 765
 766                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 767
 768                         switch (rthdr->type) {
 769 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 770                         case IPV6_SRCRT_TYPE_2:
 771                                 if (rthdr->hdrlen != 2 ||
 772                                     rthdr->segments_left != 1) {
 773                                         err = -EINVAL;
 774                                         goto exit_f;
 775                                 }
 776                                 break;
 777 #endif
 778                         default:
 779                                 err = -EINVAL;
 780                                 goto exit_f;
 781                         }
 782
 783                         len = ((rthdr->hdrlen + 1) << 3);
 784
 785                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 786                                 err = -EINVAL;
 787                                 goto exit_f;
 788                         }
 789
 790                         /* segments left must also match */
 791                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 792                                 err = -EINVAL;
 793                                 goto exit_f;
 794                         }
 795
 796                         opt->opt_nflen += len;
 797                         opt->srcrt = rthdr;
 798
 799                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 800                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 801
 802                                 opt->opt_nflen += dsthdrlen;
 803                                 opt->dst0opt = opt->dst1opt;
 804                                 opt->dst1opt = NULL;
 805                                 opt->opt_flen -= dsthdrlen;
 806                         }
 807
 808                         break;
 809
 810                 case IPV6_2292HOPLIMIT:
 811                 case IPV6_HOPLIMIT:
 812                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 813                                 err = -EINVAL;
 814                                 goto exit_f;
 815                         }
 816
 817                         *hlimit = *(int *)CMSG_DATA(cmsg);
 818                         if (*hlimit < -1 || *hlimit > 0xff) {
 819                                 err = -EINVAL;
 820                                 goto exit_f;
 821                         }
 822
 823                         break;
 824
 825                 case IPV6_TCLASS:
 826                     {
 827                         int tc;
 828
 829                         err = -EINVAL;
 830                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 831                                 goto exit_f;
 832                         }
 833
 834                         tc = *(int *)CMSG_DATA(cmsg);
 835                         if (tc < -1 || tc > 0xff)
 836                                 goto exit_f;
 837
 838                         err = 0;
 839                         *tclass = tc;
 840
 841                         break;
 842                     }
 843
 844                 case IPV6_DONTFRAG:
 845                     {
 846                         int df;
 847
 848                         err = -EINVAL;
 849                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 850                                 goto exit_f;
 851                         }
 852
 853                         df = *(int *)CMSG_DATA(cmsg);
 854                         if (df < 0 || df > 1)
 855                                 goto exit_f;
 856
 857                         err = 0;
 858                         *dontfrag = df;
 859
 860                         break;
 861                     }
 862                 default:
 863                         LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
 864                                        cmsg->cmsg_type);
 865                         err = -EINVAL;
 866                         goto exit_f;
 867                 }
 868         }
 869
 870 exit_f:
 871         return err;
 872 }