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         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 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 207 {
 208         int res;
 209
 210         lock_sock(sk);
 211         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 212         release_sock(sk);
 213         return res;
 214 }
 215
 216 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 217                      __be16 port, u32 info, u8 *payload)
 218 {
 219         struct ipv6_pinfo *np  = inet6_sk(sk);
 220         struct icmp6hdr *icmph = icmp6_hdr(skb);
 221         struct sock_exterr_skb *serr;
 222
 223         if (!np->recverr)
 224                 return;
 225
 226         skb = skb_clone(skb, GFP_ATOMIC);
 227         if (!skb)
 228                 return;
 229
 230         skb->protocol = htons(ETH_P_IPV6);
 231
 232         serr = SKB_EXT_ERR(skb);
 233         serr->ee.ee_errno = err;
 234         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 235         serr->ee.ee_type = icmph->icmp6_type;
 236         serr->ee.ee_code = icmph->icmp6_code;
 237         serr->ee.ee_pad = 0;
 238         serr->ee.ee_info = info;
 239         serr->ee.ee_data = 0;
 240         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 241                                   skb_network_header(skb);
 242         serr->port = port;
 243
 244         __skb_pull(skb, payload - skb->data);
 245         skb_reset_transport_header(skb);
 246
 247         if (sock_queue_err_skb(sk, skb))
 248                 kfree_skb(skb);
 249 }
 250
 251 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 252 {
 253         struct ipv6_pinfo *np = inet6_sk(sk);
 254         struct sock_exterr_skb *serr;
 255         struct ipv6hdr *iph;
 256         struct sk_buff *skb;
 257
 258         if (!np->recverr)
 259                 return;
 260
 261         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 262         if (!skb)
 263                 return;
 264
 265         skb->protocol = htons(ETH_P_IPV6);
 266
 267         skb_put(skb, sizeof(struct ipv6hdr));
 268         skb_reset_network_header(skb);
 269         iph = ipv6_hdr(skb);
 270         ipv6_addr_copy(&iph->daddr, &fl6->daddr);
 271
 272         serr = SKB_EXT_ERR(skb);
 273         serr->ee.ee_errno = err;
 274         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 275         serr->ee.ee_type = 0;
 276         serr->ee.ee_code = 0;
 277         serr->ee.ee_pad = 0;
 278         serr->ee.ee_info = info;
 279         serr->ee.ee_data = 0;
 280         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 281         serr->port = fl6->fl6_dport;
 282
 283         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 284         skb_reset_transport_header(skb);
 285
 286         if (sock_queue_err_skb(sk, skb))
 287                 kfree_skb(skb);
 288 }
 289
 290 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 291 {
 292         struct ipv6_pinfo *np = inet6_sk(sk);
 293         struct ipv6hdr *iph;
 294         struct sk_buff *skb;
 295         struct ip6_mtuinfo *mtu_info;
 296
 297         if (!np->rxopt.bits.rxpmtu)
 298                 return;
 299
 300         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 301         if (!skb)
 302                 return;
 303
 304         skb_put(skb, sizeof(struct ipv6hdr));
 305         skb_reset_network_header(skb);
 306         iph = ipv6_hdr(skb);
 307         ipv6_addr_copy(&iph->daddr, &fl6->daddr);
 308
 309         mtu_info = IP6CBMTU(skb);
 310
 311         mtu_info->ip6m_mtu = mtu;
 312         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 313         mtu_info->ip6m_addr.sin6_port = 0;
 314         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 315         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 316         ipv6_addr_copy(&mtu_info->ip6m_addr.sin6_addr, &ipv6_hdr(skb)->daddr);
 317
 318         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 319         skb_reset_transport_header(skb);
 320
 321         skb = xchg(&np->rxpmtu, skb);
 322         kfree_skb(skb);
 323 }
 324
 325 /*
 326  *      Handle MSG_ERRQUEUE
 327  */
 328 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 329 {
 330         struct ipv6_pinfo *np = inet6_sk(sk);
 331         struct sock_exterr_skb *serr;
 332         struct sk_buff *skb, *skb2;
 333         struct sockaddr_in6 *sin;
 334         struct {
 335                 struct sock_extended_err ee;
 336                 struct sockaddr_in6      offender;
 337         } errhdr;
 338         int err;
 339         int copied;
 340
 341         err = -EAGAIN;
 342         skb = skb_dequeue(&sk->sk_error_queue);
 343         if (skb == NULL)
 344                 goto out;
 345
 346         copied = skb->len;
 347         if (copied > len) {
 348                 msg->msg_flags |= MSG_TRUNC;
 349                 copied = len;
 350         }
 351         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 352         if (err)
 353                 goto out_free_skb;
 354
 355         sock_recv_timestamp(msg, sk, skb);
 356
 357         serr = SKB_EXT_ERR(skb);
 358
 359         sin = (struct sockaddr_in6 *)msg->msg_name;
 360         if (sin) {
 361                 const unsigned char *nh = skb_network_header(skb);
 362                 sin->sin6_family = AF_INET6;
 363                 sin->sin6_flowinfo = 0;
 364                 sin->sin6_port = serr->port;
 365                 sin->sin6_scope_id = 0;
 366                 if (skb->protocol == htons(ETH_P_IPV6)) {
 367                         ipv6_addr_copy(&sin->sin6_addr,
 368                                   (struct in6_addr *)(nh + serr->addr_offset));
 369                         if (np->sndflow)
 370                                 sin->sin6_flowinfo =
 371                                         (*(__be32 *)(nh + serr->addr_offset - 24) &
 372                                          IPV6_FLOWINFO_MASK);
 373                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 374                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 375                 } else {
 376                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 377                                                &sin->sin6_addr);
 378                 }
 379                 *addr_len = sizeof(*sin);
 380         }
 381
 382         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 383         sin = &errhdr.offender;
 384         memset(sin, 0, sizeof(*sin));
 385
 386         if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
 387                 sin->sin6_family = AF_INET6;
 388                 if (skb->protocol == htons(ETH_P_IPV6)) {
 389                         ipv6_addr_copy(&sin->sin6_addr, &ipv6_hdr(skb)->saddr);
 390                         if (np->rxopt.all)
 391                                 datagram_recv_ctl(sk, msg, skb);
 392                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 393                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 394                 } else {
 395                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 396                                                &sin->sin6_addr);
 397                         if (inet_sk(sk)->cmsg_flags)
 398                                 ip_cmsg_recv(msg, skb);
 399                 }
 400         }
 401
 402         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 403
 404         /* Now we could try to dump offended packet options */
 405
 406         msg->msg_flags |= MSG_ERRQUEUE;
 407         err = copied;
 408
 409         /* Reset and regenerate socket error */
 410         spin_lock_bh(&sk->sk_error_queue.lock);
 411         sk->sk_err = 0;
 412         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
 413                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
 414                 spin_unlock_bh(&sk->sk_error_queue.lock);
 415                 sk->sk_error_report(sk);
 416         } else {
 417                 spin_unlock_bh(&sk->sk_error_queue.lock);
 418         }
 419
 420 out_free_skb:
 421         kfree_skb(skb);
 422 out:
 423         return err;
 424 }
 425
 426 /*
 427  *      Handle IPV6_RECVPATHMTU
 428  */
 429 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 430                      int *addr_len)
 431 {
 432         struct ipv6_pinfo *np = inet6_sk(sk);
 433         struct sk_buff *skb;
 434         struct sockaddr_in6 *sin;
 435         struct ip6_mtuinfo mtu_info;
 436         int err;
 437         int copied;
 438
 439         err = -EAGAIN;
 440         skb = xchg(&np->rxpmtu, NULL);
 441         if (skb == NULL)
 442                 goto out;
 443
 444         copied = skb->len;
 445         if (copied > len) {
 446                 msg->msg_flags |= MSG_TRUNC;
 447                 copied = len;
 448         }
 449         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 450         if (err)
 451                 goto out_free_skb;
 452
 453         sock_recv_timestamp(msg, sk, skb);
 454
 455         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 456
 457         sin = (struct sockaddr_in6 *)msg->msg_name;
 458         if (sin) {
 459                 sin->sin6_family = AF_INET6;
 460                 sin->sin6_flowinfo = 0;
 461                 sin->sin6_port = 0;
 462                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 463                 ipv6_addr_copy(&sin->sin6_addr, &mtu_info.ip6m_addr.sin6_addr);
 464                 *addr_len = sizeof(*sin);
 465         }
 466
 467         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 468
 469         err = copied;
 470
 471 out_free_skb:
 472         kfree_skb(skb);
 473 out:
 474         return err;
 475 }
 476
 477
 478 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
 479 {
 480         struct ipv6_pinfo *np = inet6_sk(sk);
 481         struct inet6_skb_parm *opt = IP6CB(skb);
 482         unsigned char *nh = skb_network_header(skb);
 483
 484         if (np->rxopt.bits.rxinfo) {
 485                 struct in6_pktinfo src_info;
 486
 487                 src_info.ipi6_ifindex = opt->iif;
 488                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 489                 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
 490         }
 491
 492         if (np->rxopt.bits.rxhlim) {
 493                 int hlim = ipv6_hdr(skb)->hop_limit;
 494                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 495         }
 496
 497         if (np->rxopt.bits.rxtclass) {
 498                 int tclass = (ntohl(*(__be32 *)ipv6_hdr(skb)) >> 20) & 0xff;
 499                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 500         }
 501
 502         if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
 503                 __be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
 504                 put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 505         }
 506
 507         /* HbH is allowed only once */
 508         if (np->rxopt.bits.hopopts && opt->hop) {
 509                 u8 *ptr = nh + opt->hop;
 510                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 511         }
 512
 513         if (opt->lastopt &&
 514             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 515                 /*
 516                  * Silly enough, but we need to reparse in order to
 517                  * report extension headers (except for HbH)
 518                  * in order.
 519                  *
 520                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 521                  * (and WILL NOT be) defined because
 522                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 523                  */
 524                 unsigned int off = sizeof(struct ipv6hdr);
 525                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 526
 527                 while (off <= opt->lastopt) {
 528                         unsigned len;
 529                         u8 *ptr = nh + off;
 530
 531                         switch(nexthdr) {
 532                         case IPPROTO_DSTOPTS:
 533                                 nexthdr = ptr[0];
 534                                 len = (ptr[1] + 1) << 3;
 535                                 if (np->rxopt.bits.dstopts)
 536                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 537                                 break;
 538                         case IPPROTO_ROUTING:
 539                                 nexthdr = ptr[0];
 540                                 len = (ptr[1] + 1) << 3;
 541                                 if (np->rxopt.bits.srcrt)
 542                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 543                                 break;
 544                         case IPPROTO_AH:
 545                                 nexthdr = ptr[0];
 546                                 len = (ptr[1] + 2) << 2;
 547                                 break;
 548                         default:
 549                                 nexthdr = ptr[0];
 550                                 len = (ptr[1] + 1) << 3;
 551                                 break;
 552                         }
 553
 554                         off += len;
 555                 }
 556         }
 557
 558         /* socket options in old style */
 559         if (np->rxopt.bits.rxoinfo) {
 560                 struct in6_pktinfo src_info;
 561
 562                 src_info.ipi6_ifindex = opt->iif;
 563                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 564                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 565         }
 566         if (np->rxopt.bits.rxohlim) {
 567                 int hlim = ipv6_hdr(skb)->hop_limit;
 568                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 569         }
 570         if (np->rxopt.bits.ohopopts && opt->hop) {
 571                 u8 *ptr = nh + opt->hop;
 572                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 573         }
 574         if (np->rxopt.bits.odstopts && opt->dst0) {
 575                 u8 *ptr = nh + opt->dst0;
 576                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 577         }
 578         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 579                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 580                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 581         }
 582         if (np->rxopt.bits.odstopts && opt->dst1) {
 583                 u8 *ptr = nh + opt->dst1;
 584                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 585         }
 586         if (np->rxopt.bits.rxorigdstaddr) {
 587                 struct sockaddr_in6 sin6;
 588                 u16 *ports = (u16 *) skb_transport_header(skb);
 589
 590                 if (skb_transport_offset(skb) + 4 <= skb->len) {
 591                         /* All current transport protocols have the port numbers in the
 592                          * first four bytes of the transport header and this function is
 593                          * written with this assumption in mind.
 594                          */
 595
 596                         sin6.sin6_family = AF_INET6;
 597                         ipv6_addr_copy(&sin6.sin6_addr, &ipv6_hdr(skb)->daddr);
 598                         sin6.sin6_port = ports[1];
 599                         sin6.sin6_flowinfo = 0;
 600                         sin6.sin6_scope_id = 0;
 601
 602                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 603                 }
 604         }
 605         return 0;
 606 }
 607
 608 int datagram_send_ctl(struct net *net, struct sock *sk,
 609                       struct msghdr *msg, struct flowi6 *fl6,
 610                       struct ipv6_txoptions *opt,
 611                       int *hlimit, int *tclass, int *dontfrag)
 612 {
 613         struct in6_pktinfo *src_info;
 614         struct cmsghdr *cmsg;
 615         struct ipv6_rt_hdr *rthdr;
 616         struct ipv6_opt_hdr *hdr;
 617         int len;
 618         int err = 0;
 619
 620         for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 621                 int addr_type;
 622
 623                 if (!CMSG_OK(msg, cmsg)) {
 624                         err = -EINVAL;
 625                         goto exit_f;
 626                 }
 627
 628                 if (cmsg->cmsg_level != SOL_IPV6)
 629                         continue;
 630
 631                 switch (cmsg->cmsg_type) {
 632                 case IPV6_PKTINFO:
 633                 case IPV6_2292PKTINFO:
 634                     {
 635                         struct net_device *dev = NULL;
 636
 637                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 638                                 err = -EINVAL;
 639                                 goto exit_f;
 640                         }
 641
 642                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 643
 644                         if (src_info->ipi6_ifindex) {
 645                                 if (fl6->flowi6_oif &&
 646                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 647                                         return -EINVAL;
 648                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 649                         }
 650
 651                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 652
 653                         rcu_read_lock();
 654                         if (fl6->flowi6_oif) {
 655                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 656                                 if (!dev) {
 657                                         rcu_read_unlock();
 658                                         return -ENODEV;
 659                                 }
 660                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 661                                 rcu_read_unlock();
 662                                 return -EINVAL;
 663                         }
 664
 665                         if (addr_type != IPV6_ADDR_ANY) {
 666                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 667                                 if (!inet_sk(sk)->transparent &&
 668                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 669                                                    strict ? dev : NULL, 0))
 670                                         err = -EINVAL;
 671                                 else
 672                                         ipv6_addr_copy(&fl6->saddr, &src_info->ipi6_addr);
 673                         }
 674
 675                         rcu_read_unlock();
 676
 677                         if (err)
 678                                 goto exit_f;
 679
 680                         break;
 681                     }
 682
 683                 case IPV6_FLOWINFO:
 684                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 685                                 err = -EINVAL;
 686                                 goto exit_f;
 687                         }
 688
 689                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 690                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 691                                         err = -EINVAL;
 692                                         goto exit_f;
 693                                 }
 694                         }
 695                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 696                         break;
 697
 698                 case IPV6_2292HOPOPTS:
 699                 case IPV6_HOPOPTS:
 700                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 701                                 err = -EINVAL;
 702                                 goto exit_f;
 703                         }
 704
 705                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 706                         len = ((hdr->hdrlen + 1) << 3);
 707                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 708                                 err = -EINVAL;
 709                                 goto exit_f;
 710                         }
 711                         if (!capable(CAP_NET_RAW)) {
 712                                 err = -EPERM;
 713                                 goto exit_f;
 714                         }
 715                         opt->opt_nflen += len;
 716                         opt->hopopt = hdr;
 717                         break;
 718
 719                 case IPV6_2292DSTOPTS:
 720                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 721                                 err = -EINVAL;
 722                                 goto exit_f;
 723                         }
 724
 725                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 726                         len = ((hdr->hdrlen + 1) << 3);
 727                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 728                                 err = -EINVAL;
 729                                 goto exit_f;
 730                         }
 731                         if (!capable(CAP_NET_RAW)) {
 732                                 err = -EPERM;
 733                                 goto exit_f;
 734                         }
 735                         if (opt->dst1opt) {
 736                                 err = -EINVAL;
 737                                 goto exit_f;
 738                         }
 739                         opt->opt_flen += len;
 740                         opt->dst1opt = hdr;
 741                         break;
 742
 743                 case IPV6_DSTOPTS:
 744                 case IPV6_RTHDRDSTOPTS:
 745                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 746                                 err = -EINVAL;
 747                                 goto exit_f;
 748                         }
 749
 750                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 751                         len = ((hdr->hdrlen + 1) << 3);
 752                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 753                                 err = -EINVAL;
 754                                 goto exit_f;
 755                         }
 756                         if (!capable(CAP_NET_RAW)) {
 757                                 err = -EPERM;
 758                                 goto exit_f;
 759                         }
 760                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 761                                 opt->opt_flen += len;
 762                                 opt->dst1opt = hdr;
 763                         } else {
 764                                 opt->opt_nflen += len;
 765                                 opt->dst0opt = hdr;
 766                         }
 767                         break;
 768
 769                 case IPV6_2292RTHDR:
 770                 case IPV6_RTHDR:
 771                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 772                                 err = -EINVAL;
 773                                 goto exit_f;
 774                         }
 775
 776                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 777
 778                         switch (rthdr->type) {
 779 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 780                         case IPV6_SRCRT_TYPE_2:
 781                                 if (rthdr->hdrlen != 2 ||
 782                                     rthdr->segments_left != 1) {
 783                                         err = -EINVAL;
 784                                         goto exit_f;
 785                                 }
 786                                 break;
 787 #endif
 788                         default:
 789                                 err = -EINVAL;
 790                                 goto exit_f;
 791                         }
 792
 793                         len = ((rthdr->hdrlen + 1) << 3);
 794
 795                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 796                                 err = -EINVAL;
 797                                 goto exit_f;
 798                         }
 799
 800                         /* segments left must also match */
 801                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 802                                 err = -EINVAL;
 803                                 goto exit_f;
 804                         }
 805
 806                         opt->opt_nflen += len;
 807                         opt->srcrt = rthdr;
 808
 809                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 810                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 811
 812                                 opt->opt_nflen += dsthdrlen;
 813                                 opt->dst0opt = opt->dst1opt;
 814                                 opt->dst1opt = NULL;
 815                                 opt->opt_flen -= dsthdrlen;
 816                         }
 817
 818                         break;
 819
 820                 case IPV6_2292HOPLIMIT:
 821                 case IPV6_HOPLIMIT:
 822                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 823                                 err = -EINVAL;
 824                                 goto exit_f;
 825                         }
 826
 827                         *hlimit = *(int *)CMSG_DATA(cmsg);
 828                         if (*hlimit < -1 || *hlimit > 0xff) {
 829                                 err = -EINVAL;
 830                                 goto exit_f;
 831                         }
 832
 833                         break;
 834
 835                 case IPV6_TCLASS:
 836                     {
 837                         int tc;
 838
 839                         err = -EINVAL;
 840                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 841                                 goto exit_f;
 842                         }
 843
 844                         tc = *(int *)CMSG_DATA(cmsg);
 845                         if (tc < -1 || tc > 0xff)
 846                                 goto exit_f;
 847
 848                         err = 0;
 849                         *tclass = tc;
 850
 851                         break;
 852                     }
 853
 854                 case IPV6_DONTFRAG:
 855                     {
 856                         int df;
 857
 858                         err = -EINVAL;
 859                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 860                                 goto exit_f;
 861                         }
 862
 863                         df = *(int *)CMSG_DATA(cmsg);
 864                         if (df < 0 || df > 1)
 865                                 goto exit_f;
 866
 867                         err = 0;
 868                         *dontfrag = df;
 869
 870                         break;
 871                     }
 872                 default:
 873                         LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
 874                                        cmsg->cmsg_type);
 875                         err = -EINVAL;
 876                         goto exit_f;
 877                 }
 878         }
 879
 880 exit_f:
 881         return err;
 882 }