SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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 = NULL, final;
  42         struct dst_entry        *dst;
  43         struct flowi            fl;
  44         struct ip6_flowlabel    *flowlabel = NULL;
  45         int                     addr_type;
  46         int                     err;
  47
  48         if (usin->sin6_family == AF_INET) {
  49                 if (__ipv6_only_sock(sk))
  50                         return -EAFNOSUPPORT;
  51                 err = ip4_datagram_connect(sk, uaddr, addr_len);
  52                 goto ipv4_connected;
  53         }
  54
  55         if (addr_len < SIN6_LEN_RFC2133)
  56                 return -EINVAL;
  57
  58         if (usin->sin6_family != AF_INET6)
  59                 return -EAFNOSUPPORT;
  60
  61         memset(&fl, 0, sizeof(fl));
  62         if (np->sndflow) {
  63                 fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
  64                 if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
  65                         flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
  66                         if (flowlabel == NULL)
  67                                 return -EINVAL;
  68                         ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
  69                 }
  70         }
  71
  72         addr_type = ipv6_addr_type(&usin->sin6_addr);
  73
  74         if (addr_type == IPV6_ADDR_ANY) {
  75                 /*
  76                  *      connect to self
  77                  */
  78                 usin->sin6_addr.s6_addr[15] = 0x01;
  79         }
  80
  81         daddr = &usin->sin6_addr;
  82
  83         if (addr_type == IPV6_ADDR_MAPPED) {
  84                 struct sockaddr_in sin;
  85
  86                 if (__ipv6_only_sock(sk)) {
  87                         err = -ENETUNREACH;
  88                         goto out;
  89                 }
  90                 sin.sin_family = AF_INET;
  91                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
  92                 sin.sin_port = usin->sin6_port;
  93
  94                 err = ip4_datagram_connect(sk,
  95                                            (struct sockaddr*) &sin,
  96                                            sizeof(sin));
  97
  98 ipv4_connected:
  99                 if (err)
 100                         goto out;
 101
 102                 ipv6_addr_set_v4mapped(inet->inet_daddr, &np->daddr);
 103
 104                 if (ipv6_addr_any(&np->saddr))
 105                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 106
 107                 if (ipv6_addr_any(&np->rcv_saddr))
 108                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 109                                                &np->rcv_saddr);
 110
 111                 goto out;
 112         }
 113
 114         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 115                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 116                     usin->sin6_scope_id) {
 117                         if (sk->sk_bound_dev_if &&
 118                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 119                                 err = -EINVAL;
 120                                 goto out;
 121                         }
 122                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 123                 }
 124
 125                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 126                         sk->sk_bound_dev_if = np->mcast_oif;
 127
 128                 /* Connect to link-local address requires an interface */
 129                 if (!sk->sk_bound_dev_if) {
 130                         err = -EINVAL;
 131                         goto out;
 132                 }
 133         }
 134
 135         ipv6_addr_copy(&np->daddr, daddr);
 136         np->flow_label = fl.fl6_flowlabel;
 137
 138         inet->inet_dport = usin->sin6_port;
 139
 140         /*
 141          *      Check for a route to destination an obtain the
 142          *      destination cache for it.
 143          */
 144
 145         fl.proto = sk->sk_protocol;
 146         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 147         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 148         fl.oif = sk->sk_bound_dev_if;
 149         fl.mark = sk->sk_mark;
 150         fl.fl_ip_dport = inet->inet_dport;
 151         fl.fl_ip_sport = inet->inet_sport;
 152
 153         if (!fl.oif && (addr_type&IPV6_ADDR_MULTICAST))
 154                 fl.oif = np->mcast_oif;
 155
 156         security_sk_classify_flow(sk, &fl);
 157
 158         if (flowlabel) {
 159                 if (flowlabel->opt && flowlabel->opt->srcrt) {
 160                         struct rt0_hdr *rt0 = (struct rt0_hdr *) flowlabel->opt->srcrt;
 161                         ipv6_addr_copy(&final, &fl.fl6_dst);
 162                         ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 163                         final_p = &final;
 164                 }
 165         } else if (np->opt && np->opt->srcrt) {
 166                 struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
 167                 ipv6_addr_copy(&final, &fl.fl6_dst);
 168                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 169                 final_p = &final;
 170         }
 171
 172         err = ip6_dst_lookup(sk, &dst, &fl);
 173         if (err)
 174                 goto out;
 175         if (final_p)
 176                 ipv6_addr_copy(&fl.fl6_dst, final_p);
 177
 178         err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);
 179         if (err < 0) {
 180                 if (err == -EREMOTE)
 181                         err = ip6_dst_blackhole(sk, &dst, &fl);
 182                 if (err < 0)
 183                         goto out;
 184         }
 185
 186         /* source address lookup done in ip6_dst_lookup */
 187
 188         if (ipv6_addr_any(&np->saddr))
 189                 ipv6_addr_copy(&np->saddr, &fl.fl6_src);
 190
 191         if (ipv6_addr_any(&np->rcv_saddr)) {
 192                 ipv6_addr_copy(&np->rcv_saddr, &fl.fl6_src);
 193                 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 194         }
 195
 196         ip6_dst_store(sk, dst,
 197                       ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
 198                       &np->daddr : NULL,
 199 #ifdef CONFIG_IPV6_SUBTREES
 200                       ipv6_addr_equal(&fl.fl6_src, &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 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 212                      __be16 port, u32 info, u8 *payload)
 213 {
 214         struct ipv6_pinfo *np  = inet6_sk(sk);
 215         struct icmp6hdr *icmph = icmp6_hdr(skb);
 216         struct sock_exterr_skb *serr;
 217
 218         if (!np->recverr)
 219                 return;
 220
 221         skb = skb_clone(skb, GFP_ATOMIC);
 222         if (!skb)
 223                 return;
 224
 225         serr = SKB_EXT_ERR(skb);
 226         serr->ee.ee_errno = err;
 227         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 228         serr->ee.ee_type = icmph->icmp6_type;
 229         serr->ee.ee_code = icmph->icmp6_code;
 230         serr->ee.ee_pad = 0;
 231         serr->ee.ee_info = info;
 232         serr->ee.ee_data = 0;
 233         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 234                                   skb_network_header(skb);
 235         serr->port = port;
 236
 237         __skb_pull(skb, payload - skb->data);
 238         skb_reset_transport_header(skb);
 239
 240         if (sock_queue_err_skb(sk, skb))
 241                 kfree_skb(skb);
 242 }
 243
 244 void ipv6_local_error(struct sock *sk, int err, struct flowi *fl, u32 info)
 245 {
 246         struct ipv6_pinfo *np = inet6_sk(sk);
 247         struct sock_exterr_skb *serr;
 248         struct ipv6hdr *iph;
 249         struct sk_buff *skb;
 250
 251         if (!np->recverr)
 252                 return;
 253
 254         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 255         if (!skb)
 256                 return;
 257
 258         skb_put(skb, sizeof(struct ipv6hdr));
 259         skb_reset_network_header(skb);
 260         iph = ipv6_hdr(skb);
 261         ipv6_addr_copy(&iph->daddr, &fl->fl6_dst);
 262
 263         serr = SKB_EXT_ERR(skb);
 264         serr->ee.ee_errno = err;
 265         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 266         serr->ee.ee_type = 0;
 267         serr->ee.ee_code = 0;
 268         serr->ee.ee_pad = 0;
 269         serr->ee.ee_info = info;
 270         serr->ee.ee_data = 0;
 271         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 272         serr->port = fl->fl_ip_dport;
 273
 274         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 275         skb_reset_transport_header(skb);
 276
 277         if (sock_queue_err_skb(sk, skb))
 278                 kfree_skb(skb);
 279 }
 280
 281 /*
 282  *      Handle MSG_ERRQUEUE
 283  */
 284 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
 285 {
 286         struct ipv6_pinfo *np = inet6_sk(sk);
 287         struct sock_exterr_skb *serr;
 288         struct sk_buff *skb, *skb2;
 289         struct sockaddr_in6 *sin;
 290         struct {
 291                 struct sock_extended_err ee;
 292                 struct sockaddr_in6      offender;
 293         } errhdr;
 294         int err;
 295         int copied;
 296
 297         err = -EAGAIN;
 298         skb = skb_dequeue(&sk->sk_error_queue);
 299         if (skb == NULL)
 300                 goto out;
 301
 302         copied = skb->len;
 303         if (copied > len) {
 304                 msg->msg_flags |= MSG_TRUNC;
 305                 copied = len;
 306         }
 307         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 308         if (err)
 309                 goto out_free_skb;
 310
 311         sock_recv_timestamp(msg, sk, skb);
 312
 313         serr = SKB_EXT_ERR(skb);
 314
 315         sin = (struct sockaddr_in6 *)msg->msg_name;
 316         if (sin) {
 317                 const unsigned char *nh = skb_network_header(skb);
 318                 sin->sin6_family = AF_INET6;
 319                 sin->sin6_flowinfo = 0;
 320                 sin->sin6_port = serr->port;
 321                 sin->sin6_scope_id = 0;
 322                 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
 323                         ipv6_addr_copy(&sin->sin6_addr,
 324                                   (struct in6_addr *)(nh + serr->addr_offset));
 325                         if (np->sndflow)
 326                                 sin->sin6_flowinfo =
 327                                         (*(__be32 *)(nh + serr->addr_offset - 24) &
 328                                          IPV6_FLOWINFO_MASK);
 329                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 330                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 331                 } else {
 332                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 333                                                &sin->sin6_addr);
 334                 }
 335         }
 336
 337         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 338         sin = &errhdr.offender;
 339         sin->sin6_family = AF_UNSPEC;
 340         if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
 341                 sin->sin6_family = AF_INET6;
 342                 sin->sin6_flowinfo = 0;
 343                 sin->sin6_scope_id = 0;
 344                 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
 345                         ipv6_addr_copy(&sin->sin6_addr, &ipv6_hdr(skb)->saddr);
 346                         if (np->rxopt.all)
 347                                 datagram_recv_ctl(sk, msg, skb);
 348                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 349                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 350                 } else {
 351                         struct inet_sock *inet = inet_sk(sk);
 352
 353                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 354                                                &sin->sin6_addr);
 355                         if (inet->cmsg_flags)
 356                                 ip_cmsg_recv(msg, skb);
 357                 }
 358         }
 359
 360         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 361
 362         /* Now we could try to dump offended packet options */
 363
 364         msg->msg_flags |= MSG_ERRQUEUE;
 365         err = copied;
 366
 367         /* Reset and regenerate socket error */
 368         spin_lock_bh(&sk->sk_error_queue.lock);
 369         sk->sk_err = 0;
 370         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
 371                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
 372                 spin_unlock_bh(&sk->sk_error_queue.lock);
 373                 sk->sk_error_report(sk);
 374         } else {
 375                 spin_unlock_bh(&sk->sk_error_queue.lock);
 376         }
 377
 378 out_free_skb:
 379         kfree_skb(skb);
 380 out:
 381         return err;
 382 }
 383
 384
 385
 386 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
 387 {
 388         struct ipv6_pinfo *np = inet6_sk(sk);
 389         struct inet6_skb_parm *opt = IP6CB(skb);
 390         unsigned char *nh = skb_network_header(skb);
 391
 392         if (np->rxopt.bits.rxinfo) {
 393                 struct in6_pktinfo src_info;
 394
 395                 src_info.ipi6_ifindex = opt->iif;
 396                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 397                 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
 398         }
 399
 400         if (np->rxopt.bits.rxhlim) {
 401                 int hlim = ipv6_hdr(skb)->hop_limit;
 402                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 403         }
 404
 405         if (np->rxopt.bits.rxtclass) {
 406                 int tclass = (ntohl(*(__be32 *)ipv6_hdr(skb)) >> 20) & 0xff;
 407                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 408         }
 409
 410         if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
 411                 __be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
 412                 put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 413         }
 414
 415         /* HbH is allowed only once */
 416         if (np->rxopt.bits.hopopts && opt->hop) {
 417                 u8 *ptr = nh + opt->hop;
 418                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 419         }
 420
 421         if (opt->lastopt &&
 422             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 423                 /*
 424                  * Silly enough, but we need to reparse in order to
 425                  * report extension headers (except for HbH)
 426                  * in order.
 427                  *
 428                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 429                  * (and WILL NOT be) defined because
 430                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 431                  */
 432                 unsigned int off = sizeof(struct ipv6hdr);
 433                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 434
 435                 while (off <= opt->lastopt) {
 436                         unsigned len;
 437                         u8 *ptr = nh + off;
 438
 439                         switch(nexthdr) {
 440                         case IPPROTO_DSTOPTS:
 441                                 nexthdr = ptr[0];
 442                                 len = (ptr[1] + 1) << 3;
 443                                 if (np->rxopt.bits.dstopts)
 444                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 445                                 break;
 446                         case IPPROTO_ROUTING:
 447                                 nexthdr = ptr[0];
 448                                 len = (ptr[1] + 1) << 3;
 449                                 if (np->rxopt.bits.srcrt)
 450                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 451                                 break;
 452                         case IPPROTO_AH:
 453                                 nexthdr = ptr[0];
 454                                 len = (ptr[1] + 2) << 2;
 455                                 break;
 456                         default:
 457                                 nexthdr = ptr[0];
 458                                 len = (ptr[1] + 1) << 3;
 459                                 break;
 460                         }
 461
 462                         off += len;
 463                 }
 464         }
 465
 466         /* socket options in old style */
 467         if (np->rxopt.bits.rxoinfo) {
 468                 struct in6_pktinfo src_info;
 469
 470                 src_info.ipi6_ifindex = opt->iif;
 471                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 472                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 473         }
 474         if (np->rxopt.bits.rxohlim) {
 475                 int hlim = ipv6_hdr(skb)->hop_limit;
 476                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 477         }
 478         if (np->rxopt.bits.ohopopts && opt->hop) {
 479                 u8 *ptr = nh + opt->hop;
 480                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 481         }
 482         if (np->rxopt.bits.odstopts && opt->dst0) {
 483                 u8 *ptr = nh + opt->dst0;
 484                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 485         }
 486         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 487                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 488                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 489         }
 490         if (np->rxopt.bits.odstopts && opt->dst1) {
 491                 u8 *ptr = nh + opt->dst1;
 492                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 493         }
 494         return 0;
 495 }
 496
 497 int datagram_send_ctl(struct net *net,
 498                       struct msghdr *msg, struct flowi *fl,
 499                       struct ipv6_txoptions *opt,
 500                       int *hlimit, int *tclass)
 501 {
 502         struct in6_pktinfo *src_info;
 503         struct cmsghdr *cmsg;
 504         struct ipv6_rt_hdr *rthdr;
 505         struct ipv6_opt_hdr *hdr;
 506         int len;
 507         int err = 0;
 508
 509         for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 510                 int addr_type;
 511
 512                 if (!CMSG_OK(msg, cmsg)) {
 513                         err = -EINVAL;
 514                         goto exit_f;
 515                 }
 516
 517                 if (cmsg->cmsg_level != SOL_IPV6)
 518                         continue;
 519
 520                 switch (cmsg->cmsg_type) {
 521                 case IPV6_PKTINFO:
 522                 case IPV6_2292PKTINFO:
 523                     {
 524                         struct net_device *dev = NULL;
 525
 526                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 527                                 err = -EINVAL;
 528                                 goto exit_f;
 529                         }
 530
 531                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 532
 533                         if (src_info->ipi6_ifindex) {
 534                                 if (fl->oif && src_info->ipi6_ifindex != fl->oif)
 535                                         return -EINVAL;
 536                                 fl->oif = src_info->ipi6_ifindex;
 537                         }
 538
 539                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 540
 541                         rcu_read_lock();
 542                         if (fl->oif) {
 543                                 dev = dev_get_by_index_rcu(net, fl->oif);
 544                                 if (!dev) {
 545                                         rcu_read_unlock();
 546                                         return -ENODEV;
 547                                 }
 548                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 549                                 rcu_read_unlock();
 550                                 return -EINVAL;
 551                         }
 552
 553                         if (addr_type != IPV6_ADDR_ANY) {
 554                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 555                                 if (!ipv6_chk_addr(net, &src_info->ipi6_addr,
 556                                                    strict ? dev : NULL, 0))
 557                                         err = -EINVAL;
 558                                 else
 559                                         ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
 560                         }
 561
 562                         rcu_read_unlock();
 563
 564                         if (err)
 565                                 goto exit_f;
 566
 567                         break;
 568                     }
 569
 570                 case IPV6_FLOWINFO:
 571                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 572                                 err = -EINVAL;
 573                                 goto exit_f;
 574                         }
 575
 576                         if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) {
 577                                 if ((fl->fl6_flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 578                                         err = -EINVAL;
 579                                         goto exit_f;
 580                                 }
 581                         }
 582                         fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 583                         break;
 584
 585                 case IPV6_2292HOPOPTS:
 586                 case IPV6_HOPOPTS:
 587                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 588                                 err = -EINVAL;
 589                                 goto exit_f;
 590                         }
 591
 592                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 593                         len = ((hdr->hdrlen + 1) << 3);
 594                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 595                                 err = -EINVAL;
 596                                 goto exit_f;
 597                         }
 598                         if (!capable(CAP_NET_RAW)) {
 599                                 err = -EPERM;
 600                                 goto exit_f;
 601                         }
 602                         opt->opt_nflen += len;
 603                         opt->hopopt = hdr;
 604                         break;
 605
 606                 case IPV6_2292DSTOPTS:
 607                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 608                                 err = -EINVAL;
 609                                 goto exit_f;
 610                         }
 611
 612                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 613                         len = ((hdr->hdrlen + 1) << 3);
 614                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 615                                 err = -EINVAL;
 616                                 goto exit_f;
 617                         }
 618                         if (!capable(CAP_NET_RAW)) {
 619                                 err = -EPERM;
 620                                 goto exit_f;
 621                         }
 622                         if (opt->dst1opt) {
 623                                 err = -EINVAL;
 624                                 goto exit_f;
 625                         }
 626                         opt->opt_flen += len;
 627                         opt->dst1opt = hdr;
 628                         break;
 629
 630                 case IPV6_DSTOPTS:
 631                 case IPV6_RTHDRDSTOPTS:
 632                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 633                                 err = -EINVAL;
 634                                 goto exit_f;
 635                         }
 636
 637                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 638                         len = ((hdr->hdrlen + 1) << 3);
 639                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 640                                 err = -EINVAL;
 641                                 goto exit_f;
 642                         }
 643                         if (!capable(CAP_NET_RAW)) {
 644                                 err = -EPERM;
 645                                 goto exit_f;
 646                         }
 647                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 648                                 opt->opt_flen += len;
 649                                 opt->dst1opt = hdr;
 650                         } else {
 651                                 opt->opt_nflen += len;
 652                                 opt->dst0opt = hdr;
 653                         }
 654                         break;
 655
 656                 case IPV6_2292RTHDR:
 657                 case IPV6_RTHDR:
 658                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 659                                 err = -EINVAL;
 660                                 goto exit_f;
 661                         }
 662
 663                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 664
 665                         switch (rthdr->type) {
 666 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 667                         case IPV6_SRCRT_TYPE_2:
 668                                 if (rthdr->hdrlen != 2 ||
 669                                     rthdr->segments_left != 1) {
 670                                         err = -EINVAL;
 671                                         goto exit_f;
 672                                 }
 673                                 break;
 674 #endif
 675                         default:
 676                                 err = -EINVAL;
 677                                 goto exit_f;
 678                         }
 679
 680                         len = ((rthdr->hdrlen + 1) << 3);
 681
 682                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 683                                 err = -EINVAL;
 684                                 goto exit_f;
 685                         }
 686
 687                         /* segments left must also match */
 688                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 689                                 err = -EINVAL;
 690                                 goto exit_f;
 691                         }
 692
 693                         opt->opt_nflen += len;
 694                         opt->srcrt = rthdr;
 695
 696                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 697                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 698
 699                                 opt->opt_nflen += dsthdrlen;
 700                                 opt->dst0opt = opt->dst1opt;
 701                                 opt->dst1opt = NULL;
 702                                 opt->opt_flen -= dsthdrlen;
 703                         }
 704
 705                         break;
 706
 707                 case IPV6_2292HOPLIMIT:
 708                 case IPV6_HOPLIMIT:
 709                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 710                                 err = -EINVAL;
 711                                 goto exit_f;
 712                         }
 713
 714                         *hlimit = *(int *)CMSG_DATA(cmsg);
 715                         if (*hlimit < -1 || *hlimit > 0xff) {
 716                                 err = -EINVAL;
 717                                 goto exit_f;
 718                         }
 719
 720                         break;
 721
 722                 case IPV6_TCLASS:
 723                     {
 724                         int tc;
 725
 726                         err = -EINVAL;
 727                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 728                                 goto exit_f;
 729                         }
 730
 731                         tc = *(int *)CMSG_DATA(cmsg);
 732                         if (tc < -1 || tc > 0xff)
 733                                 goto exit_f;
 734
 735                         err = 0;
 736                         *tclass = tc;
 737
 738                         break;
 739                     }
 740                 default:
 741                         LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
 742                                        cmsg->cmsg_type);
 743                         err = -EINVAL;
 744                         goto exit_f;
 745                 }
 746         }
 747
 748 exit_f:
 749         return err;
 750 }