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)
 165                 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
 166
 167         if (!fl6.flowi6_oif && (addr_type&IPV6_ADDR_MULTICAST))
 168                 fl6.flowi6_oif = np->mcast_oif;
 169
 170         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 171
 172         rcu_read_lock();
 173         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
 174         final_p = fl6_update_dst(&fl6, opt, &final);
 175         rcu_read_unlock();
 176
 177         dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
 178         err = 0;
 179         if (IS_ERR(dst)) {
 180                 err = PTR_ERR(dst);
 181                 goto out;
 182         }
 183
 184         /* source address lookup done in ip6_dst_lookup */
 185
 186         if (ipv6_addr_any(&np->saddr))
 187                 ipv6_addr_copy(&np->saddr, &fl6.saddr);
 188
 189         if (ipv6_addr_any(&np->rcv_saddr)) {
 190                 ipv6_addr_copy(&np->rcv_saddr, &fl6.saddr);
 191                 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 192                 if (sk->sk_prot->rehash)
 193                         sk->sk_prot->rehash(sk);
 194         }
 195
 196         ip6_dst_store(sk, dst,
 197                       ipv6_addr_equal(&fl6.daddr, &np->daddr) ?
 198                       &np->daddr : NULL,
 199 #ifdef CONFIG_IPV6_SUBTREES
 200                       ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
 201                       &np->saddr :
 202 #endif
 203                       NULL);
 204
 205         sk->sk_state = TCP_ESTABLISHED;
 206 out:
 207         fl6_sock_release(flowlabel);
 208         return err;
 209 }
 210
 211 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 212 {
 213         int res;
 214
 215         lock_sock(sk);
 216         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 217         release_sock(sk);
 218         return res;
 219 }
 220
 221 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 222                      __be16 port, u32 info, u8 *payload)
 223 {
 224         struct ipv6_pinfo *np  = inet6_sk(sk);
 225         struct icmp6hdr *icmph = icmp6_hdr(skb);
 226         struct sock_exterr_skb *serr;
 227
 228         if (!np->recverr)
 229                 return;
 230
 231         skb = skb_clone(skb, GFP_ATOMIC);
 232         if (!skb)
 233                 return;
 234
 235         skb->protocol = htons(ETH_P_IPV6);
 236
 237         serr = SKB_EXT_ERR(skb);
 238         serr->ee.ee_errno = err;
 239         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 240         serr->ee.ee_type = icmph->icmp6_type;
 241         serr->ee.ee_code = icmph->icmp6_code;
 242         serr->ee.ee_pad = 0;
 243         serr->ee.ee_info = info;
 244         serr->ee.ee_data = 0;
 245         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 246                                   skb_network_header(skb);
 247         serr->port = port;
 248
 249         __skb_pull(skb, payload - skb->data);
 250         skb_reset_transport_header(skb);
 251
 252         if (sock_queue_err_skb(sk, skb))
 253                 kfree_skb(skb);
 254 }
 255
 256 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 257 {
 258         struct ipv6_pinfo *np = inet6_sk(sk);
 259         struct sock_exterr_skb *serr;
 260         struct ipv6hdr *iph;
 261         struct sk_buff *skb;
 262
 263         if (!np->recverr)
 264                 return;
 265
 266         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 267         if (!skb)
 268                 return;
 269
 270         skb->protocol = htons(ETH_P_IPV6);
 271
 272         skb_put(skb, sizeof(struct ipv6hdr));
 273         skb_reset_network_header(skb);
 274         iph = ipv6_hdr(skb);
 275         ipv6_addr_copy(&iph->daddr, &fl6->daddr);
 276
 277         serr = SKB_EXT_ERR(skb);
 278         serr->ee.ee_errno = err;
 279         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 280         serr->ee.ee_type = 0;
 281         serr->ee.ee_code = 0;
 282         serr->ee.ee_pad = 0;
 283         serr->ee.ee_info = info;
 284         serr->ee.ee_data = 0;
 285         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 286         serr->port = fl6->fl6_dport;
 287
 288         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 289         skb_reset_transport_header(skb);
 290
 291         if (sock_queue_err_skb(sk, skb))
 292                 kfree_skb(skb);
 293 }
 294
 295 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 296 {
 297         struct ipv6_pinfo *np = inet6_sk(sk);
 298         struct ipv6hdr *iph;
 299         struct sk_buff *skb;
 300         struct ip6_mtuinfo *mtu_info;
 301
 302         if (!np->rxopt.bits.rxpmtu)
 303                 return;
 304
 305         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 306         if (!skb)
 307                 return;
 308
 309         skb_put(skb, sizeof(struct ipv6hdr));
 310         skb_reset_network_header(skb);
 311         iph = ipv6_hdr(skb);
 312         ipv6_addr_copy(&iph->daddr, &fl6->daddr);
 313
 314         mtu_info = IP6CBMTU(skb);
 315
 316         mtu_info->ip6m_mtu = mtu;
 317         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 318         mtu_info->ip6m_addr.sin6_port = 0;
 319         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 320         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 321         ipv6_addr_copy(&mtu_info->ip6m_addr.sin6_addr, &ipv6_hdr(skb)->daddr);
 322
 323         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 324         skb_reset_transport_header(skb);
 325
 326         skb = xchg(&np->rxpmtu, skb);
 327         kfree_skb(skb);
 328 }
 329
 330 /*
 331  *      Handle MSG_ERRQUEUE
 332  */
 333 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 334 {
 335         struct ipv6_pinfo *np = inet6_sk(sk);
 336         struct sock_exterr_skb *serr;
 337         struct sk_buff *skb, *skb2;
 338         struct sockaddr_in6 *sin;
 339         struct {
 340                 struct sock_extended_err ee;
 341                 struct sockaddr_in6      offender;
 342         } errhdr;
 343         int err;
 344         int copied;
 345
 346         err = -EAGAIN;
 347         skb = skb_dequeue(&sk->sk_error_queue);
 348         if (skb == NULL)
 349                 goto out;
 350
 351         copied = skb->len;
 352         if (copied > len) {
 353                 msg->msg_flags |= MSG_TRUNC;
 354                 copied = len;
 355         }
 356         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 357         if (err)
 358                 goto out_free_skb;
 359
 360         sock_recv_timestamp(msg, sk, skb);
 361
 362         serr = SKB_EXT_ERR(skb);
 363
 364         sin = (struct sockaddr_in6 *)msg->msg_name;
 365         if (sin) {
 366                 const unsigned char *nh = skb_network_header(skb);
 367                 sin->sin6_family = AF_INET6;
 368                 sin->sin6_flowinfo = 0;
 369                 sin->sin6_port = serr->port;
 370                 sin->sin6_scope_id = 0;
 371                 if (skb->protocol == htons(ETH_P_IPV6)) {
 372                         ipv6_addr_copy(&sin->sin6_addr,
 373                                   (struct in6_addr *)(nh + serr->addr_offset));
 374                         if (np->sndflow)
 375                                 sin->sin6_flowinfo =
 376                                         (*(__be32 *)(nh + serr->addr_offset - 24) &
 377                                          IPV6_FLOWINFO_MASK);
 378                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 379                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 380                 } else {
 381                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 382                                                &sin->sin6_addr);
 383                 }
 384                 *addr_len = sizeof(*sin);
 385         }
 386
 387         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 388         sin = &errhdr.offender;
 389         memset(sin, 0, sizeof(*sin));
 390
 391         if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
 392                 sin->sin6_family = AF_INET6;
 393                 if (skb->protocol == htons(ETH_P_IPV6)) {
 394                         ipv6_addr_copy(&sin->sin6_addr, &ipv6_hdr(skb)->saddr);
 395                         if (np->rxopt.all)
 396                                 datagram_recv_ctl(sk, msg, skb);
 397                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 398                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 399                 } else {
 400                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 401                                                &sin->sin6_addr);
 402                         if (inet_sk(sk)->cmsg_flags)
 403                                 ip_cmsg_recv(msg, skb);
 404                 }
 405         }
 406
 407         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 408
 409         /* Now we could try to dump offended packet options */
 410
 411         msg->msg_flags |= MSG_ERRQUEUE;
 412         err = copied;
 413
 414         /* Reset and regenerate socket error */
 415         spin_lock_bh(&sk->sk_error_queue.lock);
 416         sk->sk_err = 0;
 417         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
 418                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
 419                 spin_unlock_bh(&sk->sk_error_queue.lock);
 420                 sk->sk_error_report(sk);
 421         } else {
 422                 spin_unlock_bh(&sk->sk_error_queue.lock);
 423         }
 424
 425 out_free_skb:
 426         kfree_skb(skb);
 427 out:
 428         return err;
 429 }
 430
 431 /*
 432  *      Handle IPV6_RECVPATHMTU
 433  */
 434 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 435                      int *addr_len)
 436 {
 437         struct ipv6_pinfo *np = inet6_sk(sk);
 438         struct sk_buff *skb;
 439         struct sockaddr_in6 *sin;
 440         struct ip6_mtuinfo mtu_info;
 441         int err;
 442         int copied;
 443
 444         err = -EAGAIN;
 445         skb = xchg(&np->rxpmtu, NULL);
 446         if (skb == NULL)
 447                 goto out;
 448
 449         copied = skb->len;
 450         if (copied > len) {
 451                 msg->msg_flags |= MSG_TRUNC;
 452                 copied = len;
 453         }
 454         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 455         if (err)
 456                 goto out_free_skb;
 457
 458         sock_recv_timestamp(msg, sk, skb);
 459
 460         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 461
 462         sin = (struct sockaddr_in6 *)msg->msg_name;
 463         if (sin) {
 464                 sin->sin6_family = AF_INET6;
 465                 sin->sin6_flowinfo = 0;
 466                 sin->sin6_port = 0;
 467                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 468                 ipv6_addr_copy(&sin->sin6_addr, &mtu_info.ip6m_addr.sin6_addr);
 469                 *addr_len = sizeof(*sin);
 470         }
 471
 472         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 473
 474         err = copied;
 475
 476 out_free_skb:
 477         kfree_skb(skb);
 478 out:
 479         return err;
 480 }
 481
 482
 483 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
 484 {
 485         struct ipv6_pinfo *np = inet6_sk(sk);
 486         struct inet6_skb_parm *opt = IP6CB(skb);
 487         unsigned char *nh = skb_network_header(skb);
 488
 489         if (np->rxopt.bits.rxinfo) {
 490                 struct in6_pktinfo src_info;
 491
 492                 src_info.ipi6_ifindex = opt->iif;
 493                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 494                 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
 495         }
 496
 497         if (np->rxopt.bits.rxhlim) {
 498                 int hlim = ipv6_hdr(skb)->hop_limit;
 499                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 500         }
 501
 502         if (np->rxopt.bits.rxtclass) {
 503                 int tclass = (ntohl(*(__be32 *)ipv6_hdr(skb)) >> 20) & 0xff;
 504                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 505         }
 506
 507         if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
 508                 __be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
 509                 put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 510         }
 511
 512         /* HbH is allowed only once */
 513         if (np->rxopt.bits.hopopts && opt->hop) {
 514                 u8 *ptr = nh + opt->hop;
 515                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 516         }
 517
 518         if (opt->lastopt &&
 519             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 520                 /*
 521                  * Silly enough, but we need to reparse in order to
 522                  * report extension headers (except for HbH)
 523                  * in order.
 524                  *
 525                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 526                  * (and WILL NOT be) defined because
 527                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 528                  */
 529                 unsigned int off = sizeof(struct ipv6hdr);
 530                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 531
 532                 while (off <= opt->lastopt) {
 533                         unsigned len;
 534                         u8 *ptr = nh + off;
 535
 536                         switch(nexthdr) {
 537                         case IPPROTO_DSTOPTS:
 538                                 nexthdr = ptr[0];
 539                                 len = (ptr[1] + 1) << 3;
 540                                 if (np->rxopt.bits.dstopts)
 541                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 542                                 break;
 543                         case IPPROTO_ROUTING:
 544                                 nexthdr = ptr[0];
 545                                 len = (ptr[1] + 1) << 3;
 546                                 if (np->rxopt.bits.srcrt)
 547                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 548                                 break;
 549                         case IPPROTO_AH:
 550                                 nexthdr = ptr[0];
 551                                 len = (ptr[1] + 2) << 2;
 552                                 break;
 553                         default:
 554                                 nexthdr = ptr[0];
 555                                 len = (ptr[1] + 1) << 3;
 556                                 break;
 557                         }
 558
 559                         off += len;
 560                 }
 561         }
 562
 563         /* socket options in old style */
 564         if (np->rxopt.bits.rxoinfo) {
 565                 struct in6_pktinfo src_info;
 566
 567                 src_info.ipi6_ifindex = opt->iif;
 568                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 569                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 570         }
 571         if (np->rxopt.bits.rxohlim) {
 572                 int hlim = ipv6_hdr(skb)->hop_limit;
 573                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 574         }
 575         if (np->rxopt.bits.ohopopts && opt->hop) {
 576                 u8 *ptr = nh + opt->hop;
 577                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 578         }
 579         if (np->rxopt.bits.odstopts && opt->dst0) {
 580                 u8 *ptr = nh + opt->dst0;
 581                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 582         }
 583         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 584                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 585                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 586         }
 587         if (np->rxopt.bits.odstopts && opt->dst1) {
 588                 u8 *ptr = nh + opt->dst1;
 589                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 590         }
 591         if (np->rxopt.bits.rxorigdstaddr) {
 592                 struct sockaddr_in6 sin6;
 593                 u16 *ports = (u16 *) skb_transport_header(skb);
 594
 595                 if (skb_transport_offset(skb) + 4 <= skb->len) {
 596                         /* All current transport protocols have the port numbers in the
 597                          * first four bytes of the transport header and this function is
 598                          * written with this assumption in mind.
 599                          */
 600
 601                         sin6.sin6_family = AF_INET6;
 602                         ipv6_addr_copy(&sin6.sin6_addr, &ipv6_hdr(skb)->daddr);
 603                         sin6.sin6_port = ports[1];
 604                         sin6.sin6_flowinfo = 0;
 605                         sin6.sin6_scope_id = 0;
 606
 607                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 608                 }
 609         }
 610         return 0;
 611 }
 612
 613 int datagram_send_ctl(struct net *net, struct sock *sk,
 614                       struct msghdr *msg, struct flowi6 *fl6,
 615                       struct ipv6_txoptions *opt,
 616                       int *hlimit, int *tclass, int *dontfrag)
 617 {
 618         struct in6_pktinfo *src_info;
 619         struct cmsghdr *cmsg;
 620         struct ipv6_rt_hdr *rthdr;
 621         struct ipv6_opt_hdr *hdr;
 622         int len;
 623         int err = 0;
 624
 625         for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 626                 int addr_type;
 627
 628                 if (!CMSG_OK(msg, cmsg)) {
 629                         err = -EINVAL;
 630                         goto exit_f;
 631                 }
 632
 633                 if (cmsg->cmsg_level != SOL_IPV6)
 634                         continue;
 635
 636                 switch (cmsg->cmsg_type) {
 637                 case IPV6_PKTINFO:
 638                 case IPV6_2292PKTINFO:
 639                     {
 640                         struct net_device *dev = NULL;
 641
 642                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 643                                 err = -EINVAL;
 644                                 goto exit_f;
 645                         }
 646
 647                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 648
 649                         if (src_info->ipi6_ifindex) {
 650                                 if (fl6->flowi6_oif &&
 651                                     src_info->ipi6_ifindex != fl6->flowi6_oif)
 652                                         return -EINVAL;
 653                                 fl6->flowi6_oif = src_info->ipi6_ifindex;
 654                         }
 655
 656                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 657
 658                         rcu_read_lock();
 659                         if (fl6->flowi6_oif) {
 660                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 661                                 if (!dev) {
 662                                         rcu_read_unlock();
 663                                         return -ENODEV;
 664                                 }
 665                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 666                                 rcu_read_unlock();
 667                                 return -EINVAL;
 668                         }
 669
 670                         if (addr_type != IPV6_ADDR_ANY) {
 671                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 672                                 if (!inet_sk(sk)->transparent &&
 673                                     !ipv6_chk_addr(net, &src_info->ipi6_addr,
 674                                                    strict ? dev : NULL, 0))
 675                                         err = -EINVAL;
 676                                 else
 677                                         ipv6_addr_copy(&fl6->saddr, &src_info->ipi6_addr);
 678                         }
 679
 680                         rcu_read_unlock();
 681
 682                         if (err)
 683                                 goto exit_f;
 684
 685                         break;
 686                     }
 687
 688                 case IPV6_FLOWINFO:
 689                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 690                                 err = -EINVAL;
 691                                 goto exit_f;
 692                         }
 693
 694                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 695                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 696                                         err = -EINVAL;
 697                                         goto exit_f;
 698                                 }
 699                         }
 700                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 701                         break;
 702
 703                 case IPV6_2292HOPOPTS:
 704                 case IPV6_HOPOPTS:
 705                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 706                                 err = -EINVAL;
 707                                 goto exit_f;
 708                         }
 709
 710                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 711                         len = ((hdr->hdrlen + 1) << 3);
 712                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 713                                 err = -EINVAL;
 714                                 goto exit_f;
 715                         }
 716                         if (!capable(CAP_NET_RAW)) {
 717                                 err = -EPERM;
 718                                 goto exit_f;
 719                         }
 720                         opt->opt_nflen += len;
 721                         opt->hopopt = hdr;
 722                         break;
 723
 724                 case IPV6_2292DSTOPTS:
 725                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 726                                 err = -EINVAL;
 727                                 goto exit_f;
 728                         }
 729
 730                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 731                         len = ((hdr->hdrlen + 1) << 3);
 732                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 733                                 err = -EINVAL;
 734                                 goto exit_f;
 735                         }
 736                         if (!capable(CAP_NET_RAW)) {
 737                                 err = -EPERM;
 738                                 goto exit_f;
 739                         }
 740                         if (opt->dst1opt) {
 741                                 err = -EINVAL;
 742                                 goto exit_f;
 743                         }
 744                         opt->opt_flen += len;
 745                         opt->dst1opt = hdr;
 746                         break;
 747
 748                 case IPV6_DSTOPTS:
 749                 case IPV6_RTHDRDSTOPTS:
 750                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 751                                 err = -EINVAL;
 752                                 goto exit_f;
 753                         }
 754
 755                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 756                         len = ((hdr->hdrlen + 1) << 3);
 757                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 758                                 err = -EINVAL;
 759                                 goto exit_f;
 760                         }
 761                         if (!capable(CAP_NET_RAW)) {
 762                                 err = -EPERM;
 763                                 goto exit_f;
 764                         }
 765                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 766                                 opt->opt_flen += len;
 767                                 opt->dst1opt = hdr;
 768                         } else {
 769                                 opt->opt_nflen += len;
 770                                 opt->dst0opt = hdr;
 771                         }
 772                         break;
 773
 774                 case IPV6_2292RTHDR:
 775                 case IPV6_RTHDR:
 776                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 777                                 err = -EINVAL;
 778                                 goto exit_f;
 779                         }
 780
 781                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 782
 783                         switch (rthdr->type) {
 784 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 785                         case IPV6_SRCRT_TYPE_2:
 786                                 if (rthdr->hdrlen != 2 ||
 787                                     rthdr->segments_left != 1) {
 788                                         err = -EINVAL;
 789                                         goto exit_f;
 790                                 }
 791                                 break;
 792 #endif
 793                         default:
 794                                 err = -EINVAL;
 795                                 goto exit_f;
 796                         }
 797
 798                         len = ((rthdr->hdrlen + 1) << 3);
 799
 800                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 801                                 err = -EINVAL;
 802                                 goto exit_f;
 803                         }
 804
 805                         /* segments left must also match */
 806                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 807                                 err = -EINVAL;
 808                                 goto exit_f;
 809                         }
 810
 811                         opt->opt_nflen += len;
 812                         opt->srcrt = rthdr;
 813
 814                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 815                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 816
 817                                 opt->opt_nflen += dsthdrlen;
 818                                 opt->dst0opt = opt->dst1opt;
 819                                 opt->dst1opt = NULL;
 820                                 opt->opt_flen -= dsthdrlen;
 821                         }
 822
 823                         break;
 824
 825                 case IPV6_2292HOPLIMIT:
 826                 case IPV6_HOPLIMIT:
 827                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 828                                 err = -EINVAL;
 829                                 goto exit_f;
 830                         }
 831
 832                         *hlimit = *(int *)CMSG_DATA(cmsg);
 833                         if (*hlimit < -1 || *hlimit > 0xff) {
 834                                 err = -EINVAL;
 835                                 goto exit_f;
 836                         }
 837
 838                         break;
 839
 840                 case IPV6_TCLASS:
 841                     {
 842                         int tc;
 843
 844                         err = -EINVAL;
 845                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 846                                 goto exit_f;
 847                         }
 848
 849                         tc = *(int *)CMSG_DATA(cmsg);
 850                         if (tc < -1 || tc > 0xff)
 851                                 goto exit_f;
 852
 853                         err = 0;
 854                         *tclass = tc;
 855
 856                         break;
 857                     }
 858
 859                 case IPV6_DONTFRAG:
 860                     {
 861                         int df;
 862
 863                         err = -EINVAL;
 864                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 865                                 goto exit_f;
 866                         }
 867
 868                         df = *(int *)CMSG_DATA(cmsg);
 869                         if (df < 0 || df > 1)
 870                                 goto exit_f;
 871
 872                         err = 0;
 873                         *dontfrag = df;
 874
 875                         break;
 876                     }
 877                 default:
 878                         LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
 879                                        cmsg->cmsg_type);
 880                         err = -EINVAL;
 881                         goto exit_f;
 882                 }
 883         }
 884
 885 exit_f:
 886         return err;
 887 }