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 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
  37 {
  38         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
  39         struct inet_sock        *inet = inet_sk(sk);
  40         struct ipv6_pinfo       *np = inet6_sk(sk);
  41         struct in6_addr         *daddr, *final_p, final;
  42         struct dst_entry        *dst;
  43         struct flowi            fl;
  44         struct ip6_flowlabel    *flowlabel = NULL;
  45         struct ipv6_txoptions   *opt;
  46         int                     addr_type;
  47         int                     err;
  48
  49         if (usin->sin6_family == AF_INET) {
  50                 if (__ipv6_only_sock(sk))
  51                         return -EAFNOSUPPORT;
  52                 err = ip4_datagram_connect(sk, uaddr, addr_len);
  53                 goto ipv4_connected;
  54         }
  55
  56         if (addr_len < SIN6_LEN_RFC2133)
  57                 return -EINVAL;
  58
  59         if (usin->sin6_family != AF_INET6)
  60                 return -EAFNOSUPPORT;
  61
  62         memset(&fl, 0, sizeof(fl));
  63         if (np->sndflow) {
  64                 fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
  65                 if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
  66                         flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
  67                         if (flowlabel == NULL)
  68                                 return -EINVAL;
  69                         ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
  70                 }
  71         }
  72
  73         addr_type = ipv6_addr_type(&usin->sin6_addr);
  74
  75         if (addr_type == IPV6_ADDR_ANY) {
  76                 /*
  77                  *      connect to self
  78                  */
  79                 usin->sin6_addr.s6_addr[15] = 0x01;
  80         }
  81
  82         daddr = &usin->sin6_addr;
  83
  84         if (addr_type == IPV6_ADDR_MAPPED) {
  85                 struct sockaddr_in sin;
  86
  87                 if (__ipv6_only_sock(sk)) {
  88                         err = -ENETUNREACH;
  89                         goto out;
  90                 }
  91                 sin.sin_family = AF_INET;
  92                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
  93                 sin.sin_port = usin->sin6_port;
  94
  95                 err = ip4_datagram_connect(sk,
  96                                            (struct sockaddr*) &sin,
  97                                            sizeof(sin));
  98
  99 ipv4_connected:
 100                 if (err)
 101                         goto out;
 102
 103                 ipv6_addr_set_v4mapped(inet->inet_daddr, &np->daddr);
 104
 105                 if (ipv6_addr_any(&np->saddr))
 106                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 107
 108                 if (ipv6_addr_any(&np->rcv_saddr)) {
 109                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 110                                                &np->rcv_saddr);
 111                         if (sk->sk_prot->rehash)
 112                                 sk->sk_prot->rehash(sk);
 113                 }
 114
 115                 goto out;
 116         }
 117
 118         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 119                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 120                     usin->sin6_scope_id) {
 121                         if (sk->sk_bound_dev_if &&
 122                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 123                                 err = -EINVAL;
 124                                 goto out;
 125                         }
 126                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 127                 }
 128
 129                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 130                         sk->sk_bound_dev_if = np->mcast_oif;
 131
 132                 /* Connect to link-local address requires an interface */
 133                 if (!sk->sk_bound_dev_if) {
 134                         err = -EINVAL;
 135                         goto out;
 136                 }
 137         }
 138
 139         ipv6_addr_copy(&np->daddr, daddr);
 140         np->flow_label = fl.fl6_flowlabel;
 141
 142         inet->inet_dport = usin->sin6_port;
 143
 144         /*
 145          *      Check for a route to destination an obtain the
 146          *      destination cache for it.
 147          */
 148
 149         fl.proto = sk->sk_protocol;
 150         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 151         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 152         fl.oif = sk->sk_bound_dev_if;
 153         fl.mark = sk->sk_mark;
 154         fl.fl_ip_dport = inet->inet_dport;
 155         fl.fl_ip_sport = inet->inet_sport;
 156
 157         if (!fl.oif && (addr_type&IPV6_ADDR_MULTICAST))
 158                 fl.oif = np->mcast_oif;
 159
 160         security_sk_classify_flow(sk, &fl);
 161
 162         opt = flowlabel ? flowlabel->opt : np->opt;
 163         final_p = fl6_update_dst(&fl, opt, &final);
 164
 165         err = ip6_dst_lookup(sk, &dst, &fl);
 166         if (err)
 167                 goto out;
 168         if (final_p)
 169                 ipv6_addr_copy(&fl.fl6_dst, final_p);
 170
 171         err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);
 172         if (err < 0) {
 173                 if (err == -EREMOTE)
 174                         err = ip6_dst_blackhole(sk, &dst, &fl);
 175                 if (err < 0)
 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, &fl.fl6_src);
 183
 184         if (ipv6_addr_any(&np->rcv_saddr)) {
 185                 ipv6_addr_copy(&np->rcv_saddr, &fl.fl6_src);
 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(&fl.fl6_dst, &np->daddr) ?
 193                       &np->daddr : NULL,
 194 #ifdef CONFIG_IPV6_SUBTREES
 195                       ipv6_addr_equal(&fl.fl6_src, &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 flowi *fl, 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, &fl->fl6_dst);
 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 = fl->fl_ip_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 flowi *fl, 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, &fl->fl6_dst);
 298
 299         mtu_info = IP6CBMTU(skb);
 300         if (!mtu_info) {
 301                 kfree_skb(skb);
 302                 return;
 303         }
 304
 305         mtu_info->ip6m_mtu = mtu;
 306         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 307         mtu_info->ip6m_addr.sin6_port = 0;
 308         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 309         mtu_info->ip6m_addr.sin6_scope_id = fl->oif;
 310         ipv6_addr_copy(&mtu_info->ip6m_addr.sin6_addr, &ipv6_hdr(skb)->daddr);
 311
 312         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 313         skb_reset_transport_header(skb);
 314
 315         skb = xchg(&np->rxpmtu, skb);
 316         kfree_skb(skb);
 317 }
 318
 319 /*
 320  *      Handle MSG_ERRQUEUE
 321  */
 322 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
 323 {
 324         struct ipv6_pinfo *np = inet6_sk(sk);
 325         struct sock_exterr_skb *serr;
 326         struct sk_buff *skb, *skb2;
 327         struct sockaddr_in6 *sin;
 328         struct {
 329                 struct sock_extended_err ee;
 330                 struct sockaddr_in6      offender;
 331         } errhdr;
 332         int err;
 333         int copied;
 334
 335         err = -EAGAIN;
 336         skb = skb_dequeue(&sk->sk_error_queue);
 337         if (skb == NULL)
 338                 goto out;
 339
 340         copied = skb->len;
 341         if (copied > len) {
 342                 msg->msg_flags |= MSG_TRUNC;
 343                 copied = len;
 344         }
 345         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 346         if (err)
 347                 goto out_free_skb;
 348
 349         sock_recv_timestamp(msg, sk, skb);
 350
 351         serr = SKB_EXT_ERR(skb);
 352
 353         sin = (struct sockaddr_in6 *)msg->msg_name;
 354         if (sin) {
 355                 const unsigned char *nh = skb_network_header(skb);
 356                 sin->sin6_family = AF_INET6;
 357                 sin->sin6_flowinfo = 0;
 358                 sin->sin6_port = serr->port;
 359                 sin->sin6_scope_id = 0;
 360                 if (skb->protocol == htons(ETH_P_IPV6)) {
 361                         ipv6_addr_copy(&sin->sin6_addr,
 362                                   (struct in6_addr *)(nh + serr->addr_offset));
 363                         if (np->sndflow)
 364                                 sin->sin6_flowinfo =
 365                                         (*(__be32 *)(nh + serr->addr_offset - 24) &
 366                                          IPV6_FLOWINFO_MASK);
 367                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 368                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 369                 } else {
 370                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 371                                                &sin->sin6_addr);
 372                 }
 373         }
 374
 375         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 376         sin = &errhdr.offender;
 377         sin->sin6_family = AF_UNSPEC;
 378         if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
 379                 sin->sin6_family = AF_INET6;
 380                 sin->sin6_flowinfo = 0;
 381                 sin->sin6_scope_id = 0;
 382                 if (skb->protocol == htons(ETH_P_IPV6)) {
 383                         ipv6_addr_copy(&sin->sin6_addr, &ipv6_hdr(skb)->saddr);
 384                         if (np->rxopt.all)
 385                                 datagram_recv_ctl(sk, msg, skb);
 386                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 387                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 388                 } else {
 389                         struct inet_sock *inet = inet_sk(sk);
 390
 391                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 392                                                &sin->sin6_addr);
 393                         if (inet->cmsg_flags)
 394                                 ip_cmsg_recv(msg, skb);
 395                 }
 396         }
 397
 398         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 399
 400         /* Now we could try to dump offended packet options */
 401
 402         msg->msg_flags |= MSG_ERRQUEUE;
 403         err = copied;
 404
 405         /* Reset and regenerate socket error */
 406         spin_lock_bh(&sk->sk_error_queue.lock);
 407         sk->sk_err = 0;
 408         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
 409                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
 410                 spin_unlock_bh(&sk->sk_error_queue.lock);
 411                 sk->sk_error_report(sk);
 412         } else {
 413                 spin_unlock_bh(&sk->sk_error_queue.lock);
 414         }
 415
 416 out_free_skb:
 417         kfree_skb(skb);
 418 out:
 419         return err;
 420 }
 421
 422 /*
 423  *      Handle IPV6_RECVPATHMTU
 424  */
 425 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len)
 426 {
 427         struct ipv6_pinfo *np = inet6_sk(sk);
 428         struct sk_buff *skb;
 429         struct sockaddr_in6 *sin;
 430         struct ip6_mtuinfo mtu_info;
 431         int err;
 432         int copied;
 433
 434         err = -EAGAIN;
 435         skb = xchg(&np->rxpmtu, NULL);
 436         if (skb == NULL)
 437                 goto out;
 438
 439         copied = skb->len;
 440         if (copied > len) {
 441                 msg->msg_flags |= MSG_TRUNC;
 442                 copied = len;
 443         }
 444         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 445         if (err)
 446                 goto out_free_skb;
 447
 448         sock_recv_timestamp(msg, sk, skb);
 449
 450         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 451
 452         sin = (struct sockaddr_in6 *)msg->msg_name;
 453         if (sin) {
 454                 sin->sin6_family = AF_INET6;
 455                 sin->sin6_flowinfo = 0;
 456                 sin->sin6_port = 0;
 457                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 458                 ipv6_addr_copy(&sin->sin6_addr, &mtu_info.ip6m_addr.sin6_addr);
 459         }
 460
 461         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 462
 463         err = copied;
 464
 465 out_free_skb:
 466         kfree_skb(skb);
 467 out:
 468         return err;
 469 }
 470
 471
 472 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
 473 {
 474         struct ipv6_pinfo *np = inet6_sk(sk);
 475         struct inet6_skb_parm *opt = IP6CB(skb);
 476         unsigned char *nh = skb_network_header(skb);
 477
 478         if (np->rxopt.bits.rxinfo) {
 479                 struct in6_pktinfo src_info;
 480
 481                 src_info.ipi6_ifindex = opt->iif;
 482                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 483                 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
 484         }
 485
 486         if (np->rxopt.bits.rxhlim) {
 487                 int hlim = ipv6_hdr(skb)->hop_limit;
 488                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 489         }
 490
 491         if (np->rxopt.bits.rxtclass) {
 492                 int tclass = (ntohl(*(__be32 *)ipv6_hdr(skb)) >> 20) & 0xff;
 493                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 494         }
 495
 496         if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
 497                 __be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
 498                 put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 499         }
 500
 501         /* HbH is allowed only once */
 502         if (np->rxopt.bits.hopopts && opt->hop) {
 503                 u8 *ptr = nh + opt->hop;
 504                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 505         }
 506
 507         if (opt->lastopt &&
 508             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 509                 /*
 510                  * Silly enough, but we need to reparse in order to
 511                  * report extension headers (except for HbH)
 512                  * in order.
 513                  *
 514                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 515                  * (and WILL NOT be) defined because
 516                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 517                  */
 518                 unsigned int off = sizeof(struct ipv6hdr);
 519                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 520
 521                 while (off <= opt->lastopt) {
 522                         unsigned len;
 523                         u8 *ptr = nh + off;
 524
 525                         switch(nexthdr) {
 526                         case IPPROTO_DSTOPTS:
 527                                 nexthdr = ptr[0];
 528                                 len = (ptr[1] + 1) << 3;
 529                                 if (np->rxopt.bits.dstopts)
 530                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 531                                 break;
 532                         case IPPROTO_ROUTING:
 533                                 nexthdr = ptr[0];
 534                                 len = (ptr[1] + 1) << 3;
 535                                 if (np->rxopt.bits.srcrt)
 536                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 537                                 break;
 538                         case IPPROTO_AH:
 539                                 nexthdr = ptr[0];
 540                                 len = (ptr[1] + 2) << 2;
 541                                 break;
 542                         default:
 543                                 nexthdr = ptr[0];
 544                                 len = (ptr[1] + 1) << 3;
 545                                 break;
 546                         }
 547
 548                         off += len;
 549                 }
 550         }
 551
 552         /* socket options in old style */
 553         if (np->rxopt.bits.rxoinfo) {
 554                 struct in6_pktinfo src_info;
 555
 556                 src_info.ipi6_ifindex = opt->iif;
 557                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 558                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 559         }
 560         if (np->rxopt.bits.rxohlim) {
 561                 int hlim = ipv6_hdr(skb)->hop_limit;
 562                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 563         }
 564         if (np->rxopt.bits.ohopopts && opt->hop) {
 565                 u8 *ptr = nh + opt->hop;
 566                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 567         }
 568         if (np->rxopt.bits.odstopts && opt->dst0) {
 569                 u8 *ptr = nh + opt->dst0;
 570                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 571         }
 572         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 573                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 574                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 575         }
 576         if (np->rxopt.bits.odstopts && opt->dst1) {
 577                 u8 *ptr = nh + opt->dst1;
 578                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 579         }
 580         if (np->rxopt.bits.rxorigdstaddr) {
 581                 struct sockaddr_in6 sin6;
 582                 u16 *ports = (u16 *) skb_transport_header(skb);
 583
 584                 if (skb_transport_offset(skb) + 4 <= skb->len) {
 585                         /* All current transport protocols have the port numbers in the
 586                          * first four bytes of the transport header and this function is
 587                          * written with this assumption in mind.
 588                          */
 589
 590                         sin6.sin6_family = AF_INET6;
 591                         ipv6_addr_copy(&sin6.sin6_addr, &ipv6_hdr(skb)->daddr);
 592                         sin6.sin6_port = ports[1];
 593                         sin6.sin6_flowinfo = 0;
 594                         sin6.sin6_scope_id = 0;
 595
 596                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 597                 }
 598         }
 599         return 0;
 600 }
 601
 602 int datagram_send_ctl(struct net *net,
 603                       struct msghdr *msg, struct flowi *fl,
 604                       struct ipv6_txoptions *opt,
 605                       int *hlimit, int *tclass, int *dontfrag)
 606 {
 607         struct in6_pktinfo *src_info;
 608         struct cmsghdr *cmsg;
 609         struct ipv6_rt_hdr *rthdr;
 610         struct ipv6_opt_hdr *hdr;
 611         int len;
 612         int err = 0;
 613
 614         for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 615                 int addr_type;
 616
 617                 if (!CMSG_OK(msg, cmsg)) {
 618                         err = -EINVAL;
 619                         goto exit_f;
 620                 }
 621
 622                 if (cmsg->cmsg_level != SOL_IPV6)
 623                         continue;
 624
 625                 switch (cmsg->cmsg_type) {
 626                 case IPV6_PKTINFO:
 627                 case IPV6_2292PKTINFO:
 628                     {
 629                         struct net_device *dev = NULL;
 630
 631                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 632                                 err = -EINVAL;
 633                                 goto exit_f;
 634                         }
 635
 636                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 637
 638                         if (src_info->ipi6_ifindex) {
 639                                 if (fl->oif && src_info->ipi6_ifindex != fl->oif)
 640                                         return -EINVAL;
 641                                 fl->oif = src_info->ipi6_ifindex;
 642                         }
 643
 644                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 645
 646                         rcu_read_lock();
 647                         if (fl->oif) {
 648                                 dev = dev_get_by_index_rcu(net, fl->oif);
 649                                 if (!dev) {
 650                                         rcu_read_unlock();
 651                                         return -ENODEV;
 652                                 }
 653                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 654                                 rcu_read_unlock();
 655                                 return -EINVAL;
 656                         }
 657
 658                         if (addr_type != IPV6_ADDR_ANY) {
 659                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 660                                 if (!ipv6_chk_addr(net, &src_info->ipi6_addr,
 661                                                    strict ? dev : NULL, 0))
 662                                         err = -EINVAL;
 663                                 else
 664                                         ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
 665                         }
 666
 667                         rcu_read_unlock();
 668
 669                         if (err)
 670                                 goto exit_f;
 671
 672                         break;
 673                     }
 674
 675                 case IPV6_FLOWINFO:
 676                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 677                                 err = -EINVAL;
 678                                 goto exit_f;
 679                         }
 680
 681                         if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) {
 682                                 if ((fl->fl6_flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 683                                         err = -EINVAL;
 684                                         goto exit_f;
 685                                 }
 686                         }
 687                         fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 688                         break;
 689
 690                 case IPV6_2292HOPOPTS:
 691                 case IPV6_HOPOPTS:
 692                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 693                                 err = -EINVAL;
 694                                 goto exit_f;
 695                         }
 696
 697                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 698                         len = ((hdr->hdrlen + 1) << 3);
 699                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 700                                 err = -EINVAL;
 701                                 goto exit_f;
 702                         }
 703                         if (!capable(CAP_NET_RAW)) {
 704                                 err = -EPERM;
 705                                 goto exit_f;
 706                         }
 707                         opt->opt_nflen += len;
 708                         opt->hopopt = hdr;
 709                         break;
 710
 711                 case IPV6_2292DSTOPTS:
 712                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 713                                 err = -EINVAL;
 714                                 goto exit_f;
 715                         }
 716
 717                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 718                         len = ((hdr->hdrlen + 1) << 3);
 719                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 720                                 err = -EINVAL;
 721                                 goto exit_f;
 722                         }
 723                         if (!capable(CAP_NET_RAW)) {
 724                                 err = -EPERM;
 725                                 goto exit_f;
 726                         }
 727                         if (opt->dst1opt) {
 728                                 err = -EINVAL;
 729                                 goto exit_f;
 730                         }
 731                         opt->opt_flen += len;
 732                         opt->dst1opt = hdr;
 733                         break;
 734
 735                 case IPV6_DSTOPTS:
 736                 case IPV6_RTHDRDSTOPTS:
 737                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 738                                 err = -EINVAL;
 739                                 goto exit_f;
 740                         }
 741
 742                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 743                         len = ((hdr->hdrlen + 1) << 3);
 744                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 745                                 err = -EINVAL;
 746                                 goto exit_f;
 747                         }
 748                         if (!capable(CAP_NET_RAW)) {
 749                                 err = -EPERM;
 750                                 goto exit_f;
 751                         }
 752                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 753                                 opt->opt_flen += len;
 754                                 opt->dst1opt = hdr;
 755                         } else {
 756                                 opt->opt_nflen += len;
 757                                 opt->dst0opt = hdr;
 758                         }
 759                         break;
 760
 761                 case IPV6_2292RTHDR:
 762                 case IPV6_RTHDR:
 763                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 764                                 err = -EINVAL;
 765                                 goto exit_f;
 766                         }
 767
 768                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 769
 770                         switch (rthdr->type) {
 771 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 772                         case IPV6_SRCRT_TYPE_2:
 773                                 if (rthdr->hdrlen != 2 ||
 774                                     rthdr->segments_left != 1) {
 775                                         err = -EINVAL;
 776                                         goto exit_f;
 777                                 }
 778                                 break;
 779 #endif
 780                         default:
 781                                 err = -EINVAL;
 782                                 goto exit_f;
 783                         }
 784
 785                         len = ((rthdr->hdrlen + 1) << 3);
 786
 787                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 788                                 err = -EINVAL;
 789                                 goto exit_f;
 790                         }
 791
 792                         /* segments left must also match */
 793                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 794                                 err = -EINVAL;
 795                                 goto exit_f;
 796                         }
 797
 798                         opt->opt_nflen += len;
 799                         opt->srcrt = rthdr;
 800
 801                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 802                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 803
 804                                 opt->opt_nflen += dsthdrlen;
 805                                 opt->dst0opt = opt->dst1opt;
 806                                 opt->dst1opt = NULL;
 807                                 opt->opt_flen -= dsthdrlen;
 808                         }
 809
 810                         break;
 811
 812                 case IPV6_2292HOPLIMIT:
 813                 case IPV6_HOPLIMIT:
 814                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 815                                 err = -EINVAL;
 816                                 goto exit_f;
 817                         }
 818
 819                         *hlimit = *(int *)CMSG_DATA(cmsg);
 820                         if (*hlimit < -1 || *hlimit > 0xff) {
 821                                 err = -EINVAL;
 822                                 goto exit_f;
 823                         }
 824
 825                         break;
 826
 827                 case IPV6_TCLASS:
 828                     {
 829                         int tc;
 830
 831                         err = -EINVAL;
 832                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 833                                 goto exit_f;
 834                         }
 835
 836                         tc = *(int *)CMSG_DATA(cmsg);
 837                         if (tc < -1 || tc > 0xff)
 838                                 goto exit_f;
 839
 840                         err = 0;
 841                         *tclass = tc;
 842
 843                         break;
 844                     }
 845
 846                 case IPV6_DONTFRAG:
 847                     {
 848                         int df;
 849
 850                         err = -EINVAL;
 851                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 852                                 goto exit_f;
 853                         }
 854
 855                         df = *(int *)CMSG_DATA(cmsg);
 856                         if (df < 0 || df > 1)
 857                                 goto exit_f;
 858
 859                         err = 0;
 860                         *dontfrag = df;
 861
 862                         break;
 863                     }
 864                 default:
 865                         LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
 866                                        cmsg->cmsg_type);
 867                         err = -EINVAL;
 868                         goto exit_f;
 869                 }
 870         }
 871
 872 exit_f:
 873         return err;
 874 }