git.oblomov.eu Git - 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  *      $Id: datagram.c,v 1.24 2002/02/01 22:01:04 davem Exp $
   9  *
  10  *      This program is free software; you can redistribute it and/or
  11  *      modify it under the terms of the GNU General Public License
  12  *      as published by the Free Software Foundation; either version
  13  *      2 of the License, or (at your option) any later version.
  14  */
  15
  16 #include <linux/capability.h>
  17 #include <linux/errno.h>
  18 #include <linux/types.h>
  19 #include <linux/kernel.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/socket.h>
  22 #include <linux/sockios.h>
  23 #include <linux/in6.h>
  24 #include <linux/ipv6.h>
  25 #include <linux/route.h>
  26
  27 #include <net/ipv6.h>
  28 #include <net/ndisc.h>
  29 #include <net/addrconf.h>
  30 #include <net/transp_v6.h>
  31 #include <net/ip6_route.h>
  32 #include <net/tcp_states.h>
  33
  34 #include <linux/errqueue.h>
  35 #include <asm/uaccess.h>
  36
  37 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
  38 {
  39         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
  40         struct inet_sock        *inet = inet_sk(sk);
  41         struct ipv6_pinfo       *np = inet6_sk(sk);
  42         struct in6_addr         *daddr, *final_p = NULL, final;
  43         struct dst_entry        *dst;
  44         struct flowi            fl;
  45         struct ip6_flowlabel    *flowlabel = NULL;
  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(&np->daddr, 0, 0, htonl(0x0000ffff), inet->daddr);
 104
 105                 if (ipv6_addr_any(&np->saddr)) {
 106                         ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000ffff),
 107                                       inet->saddr);
 108                 }
 109
 110                 if (ipv6_addr_any(&np->rcv_saddr)) {
 111                         ipv6_addr_set(&np->rcv_saddr, 0, 0, htonl(0x0000ffff),
 112                                       inet->rcv_saddr);
 113                 }
 114                 goto out;
 115         }
 116
 117         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 118                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 119                     usin->sin6_scope_id) {
 120                         if (sk->sk_bound_dev_if &&
 121                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 122                                 err = -EINVAL;
 123                                 goto out;
 124                         }
 125                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 126                 }
 127
 128                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 129                         sk->sk_bound_dev_if = np->mcast_oif;
 130
 131                 /* Connect to link-local address requires an interface */
 132                 if (!sk->sk_bound_dev_if) {
 133                         err = -EINVAL;
 134                         goto out;
 135                 }
 136         }
 137
 138         ipv6_addr_copy(&np->daddr, daddr);
 139         np->flow_label = fl.fl6_flowlabel;
 140
 141         inet->dport = usin->sin6_port;
 142
 143         /*
 144          *      Check for a route to destination an obtain the
 145          *      destination cache for it.
 146          */
 147
 148         fl.proto = sk->sk_protocol;
 149         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 150         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 151         fl.oif = sk->sk_bound_dev_if;
 152         fl.fl_ip_dport = inet->dport;
 153         fl.fl_ip_sport = inet->sport;
 154
 155         if (!fl.oif && (addr_type&IPV6_ADDR_MULTICAST))
 156                 fl.oif = np->mcast_oif;
 157
 158         security_sk_classify_flow(sk, &fl);
 159
 160         if (flowlabel) {
 161                 if (flowlabel->opt && flowlabel->opt->srcrt) {
 162                         struct rt0_hdr *rt0 = (struct rt0_hdr *) flowlabel->opt->srcrt;
 163                         ipv6_addr_copy(&final, &fl.fl6_dst);
 164                         ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 165                         final_p = &final;
 166                 }
 167         } else if (np->opt && np->opt->srcrt) {
 168                 struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
 169                 ipv6_addr_copy(&final, &fl.fl6_dst);
 170                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 171                 final_p = &final;
 172         }
 173
 174         err = ip6_dst_lookup(sk, &dst, &fl);
 175         if (err)
 176                 goto out;
 177         if (final_p)
 178                 ipv6_addr_copy(&fl.fl6_dst, final_p);
 179
 180         if ((err = __xfrm_lookup(&dst, &fl, sk, XFRM_LOOKUP_WAIT)) < 0) {
 181                 if (err == -EREMOTE)
 182                         err = ip6_dst_blackhole(sk, &dst, &fl);
 183                 if (err < 0)
 184                         goto out;
 185         }
 186
 187         /* source address lookup done in ip6_dst_lookup */
 188
 189         if (ipv6_addr_any(&np->saddr))
 190                 ipv6_addr_copy(&np->saddr, &fl.fl6_src);
 191
 192         if (ipv6_addr_any(&np->rcv_saddr)) {
 193                 ipv6_addr_copy(&np->rcv_saddr, &fl.fl6_src);
 194                 inet->rcv_saddr = LOOPBACK4_IPV6;
 195         }
 196
 197         ip6_dst_store(sk, dst,
 198                       ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
 199                       &np->daddr : NULL,
 200 #ifdef CONFIG_IPV6_SUBTREES
 201                       ipv6_addr_equal(&fl.fl6_src, &np->saddr) ?
 202                       &np->saddr :
 203 #endif
 204                       NULL);
 205
 206         sk->sk_state = TCP_ESTABLISHED;
 207 out:
 208         fl6_sock_release(flowlabel);
 209         return err;
 210 }
 211
 212 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 213                      __be16 port, u32 info, u8 *payload)
 214 {
 215         struct ipv6_pinfo *np  = inet6_sk(sk);
 216         struct icmp6hdr *icmph = icmp6_hdr(skb);
 217         struct sock_exterr_skb *serr;
 218
 219         if (!np->recverr)
 220                 return;
 221
 222         skb = skb_clone(skb, GFP_ATOMIC);
 223         if (!skb)
 224                 return;
 225
 226         serr = SKB_EXT_ERR(skb);
 227         serr->ee.ee_errno = err;
 228         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 229         serr->ee.ee_type = icmph->icmp6_type;
 230         serr->ee.ee_code = icmph->icmp6_code;
 231         serr->ee.ee_pad = 0;
 232         serr->ee.ee_info = info;
 233         serr->ee.ee_data = 0;
 234         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 235                                   skb_network_header(skb);
 236         serr->port = port;
 237
 238         __skb_pull(skb, payload - skb->data);
 239         skb_reset_transport_header(skb);
 240
 241         if (sock_queue_err_skb(sk, skb))
 242                 kfree_skb(skb);
 243 }
 244
 245 void ipv6_local_error(struct sock *sk, int err, struct flowi *fl, u32 info)
 246 {
 247         struct ipv6_pinfo *np = inet6_sk(sk);
 248         struct sock_exterr_skb *serr;
 249         struct ipv6hdr *iph;
 250         struct sk_buff *skb;
 251
 252         if (!np->recverr)
 253                 return;
 254
 255         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 256         if (!skb)
 257                 return;
 258
 259         skb_put(skb, sizeof(struct ipv6hdr));
 260         skb_reset_network_header(skb);
 261         iph = ipv6_hdr(skb);
 262         ipv6_addr_copy(&iph->daddr, &fl->fl6_dst);
 263
 264         serr = SKB_EXT_ERR(skb);
 265         serr->ee.ee_errno = err;
 266         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 267         serr->ee.ee_type = 0;
 268         serr->ee.ee_code = 0;
 269         serr->ee.ee_pad = 0;
 270         serr->ee.ee_info = info;
 271         serr->ee.ee_data = 0;
 272         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 273         serr->port = fl->fl_ip_dport;
 274
 275         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 276         skb_reset_transport_header(skb);
 277
 278         if (sock_queue_err_skb(sk, skb))
 279                 kfree_skb(skb);
 280 }
 281
 282 /*
 283  *      Handle MSG_ERRQUEUE
 284  */
 285 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
 286 {
 287         struct ipv6_pinfo *np = inet6_sk(sk);
 288         struct sock_exterr_skb *serr;
 289         struct sk_buff *skb, *skb2;
 290         struct sockaddr_in6 *sin;
 291         struct {
 292                 struct sock_extended_err ee;
 293                 struct sockaddr_in6      offender;
 294         } errhdr;
 295         int err;
 296         int copied;
 297
 298         err = -EAGAIN;
 299         skb = skb_dequeue(&sk->sk_error_queue);
 300         if (skb == NULL)
 301                 goto out;
 302
 303         copied = skb->len;
 304         if (copied > len) {
 305                 msg->msg_flags |= MSG_TRUNC;
 306                 copied = len;
 307         }
 308         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 309         if (err)
 310                 goto out_free_skb;
 311
 312         sock_recv_timestamp(msg, sk, skb);
 313
 314         serr = SKB_EXT_ERR(skb);
 315
 316         sin = (struct sockaddr_in6 *)msg->msg_name;
 317         if (sin) {
 318                 const unsigned char *nh = skb_network_header(skb);
 319                 sin->sin6_family = AF_INET6;
 320                 sin->sin6_flowinfo = 0;
 321                 sin->sin6_port = serr->port;
 322                 sin->sin6_scope_id = 0;
 323                 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
 324                         ipv6_addr_copy(&sin->sin6_addr,
 325                                   (struct in6_addr *)(nh + serr->addr_offset));
 326                         if (np->sndflow)
 327                                 sin->sin6_flowinfo =
 328                                         (*(__be32 *)(nh + serr->addr_offset - 24) &
 329                                          IPV6_FLOWINFO_MASK);
 330                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 331                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 332                 } else {
 333                         ipv6_addr_set(&sin->sin6_addr, 0, 0,
 334                                       htonl(0xffff),
 335                                       *(__be32 *)(nh + serr->addr_offset));
 336                 }
 337         }
 338
 339         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 340         sin = &errhdr.offender;
 341         sin->sin6_family = AF_UNSPEC;
 342         if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
 343                 sin->sin6_family = AF_INET6;
 344                 sin->sin6_flowinfo = 0;
 345                 sin->sin6_scope_id = 0;
 346                 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
 347                         ipv6_addr_copy(&sin->sin6_addr, &ipv6_hdr(skb)->saddr);
 348                         if (np->rxopt.all)
 349                                 datagram_recv_ctl(sk, msg, skb);
 350                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 351                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 352                 } else {
 353                         struct inet_sock *inet = inet_sk(sk);
 354
 355                         ipv6_addr_set(&sin->sin6_addr, 0, 0,
 356                                       htonl(0xffff), ip_hdr(skb)->saddr);
 357                         if (inet->cmsg_flags)
 358                                 ip_cmsg_recv(msg, skb);
 359                 }
 360         }
 361
 362         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 363
 364         /* Now we could try to dump offended packet options */
 365
 366         msg->msg_flags |= MSG_ERRQUEUE;
 367         err = copied;
 368
 369         /* Reset and regenerate socket error */
 370         spin_lock_bh(&sk->sk_error_queue.lock);
 371         sk->sk_err = 0;
 372         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
 373                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
 374                 spin_unlock_bh(&sk->sk_error_queue.lock);
 375                 sk->sk_error_report(sk);
 376         } else {
 377                 spin_unlock_bh(&sk->sk_error_queue.lock);
 378         }
 379
 380 out_free_skb:
 381         kfree_skb(skb);
 382 out:
 383         return err;
 384 }
 385
 386
 387
 388 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
 389 {
 390         struct ipv6_pinfo *np = inet6_sk(sk);
 391         struct inet6_skb_parm *opt = IP6CB(skb);
 392         unsigned char *nh = skb_network_header(skb);
 393
 394         if (np->rxopt.bits.rxinfo) {
 395                 struct in6_pktinfo src_info;
 396
 397                 src_info.ipi6_ifindex = opt->iif;
 398                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 399                 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
 400         }
 401
 402         if (np->rxopt.bits.rxhlim) {
 403                 int hlim = ipv6_hdr(skb)->hop_limit;
 404                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 405         }
 406
 407         if (np->rxopt.bits.rxtclass) {
 408                 int tclass = (ntohl(*(__be32 *)ipv6_hdr(skb)) >> 20) & 0xff;
 409                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 410         }
 411
 412         if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
 413                 __be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
 414                 put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 415         }
 416
 417         /* HbH is allowed only once */
 418         if (np->rxopt.bits.hopopts && opt->hop) {
 419                 u8 *ptr = nh + opt->hop;
 420                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 421         }
 422
 423         if (opt->lastopt &&
 424             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 425                 /*
 426                  * Silly enough, but we need to reparse in order to
 427                  * report extension headers (except for HbH)
 428                  * in order.
 429                  *
 430                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 431                  * (and WILL NOT be) defined because
 432                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 433                  */
 434                 unsigned int off = sizeof(struct ipv6hdr);
 435                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 436
 437                 while (off <= opt->lastopt) {
 438                         unsigned len;
 439                         u8 *ptr = nh + off;
 440
 441                         switch(nexthdr) {
 442                         case IPPROTO_DSTOPTS:
 443                                 nexthdr = ptr[0];
 444                                 len = (ptr[1] + 1) << 3;
 445                                 if (np->rxopt.bits.dstopts)
 446                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 447                                 break;
 448                         case IPPROTO_ROUTING:
 449                                 nexthdr = ptr[0];
 450                                 len = (ptr[1] + 1) << 3;
 451                                 if (np->rxopt.bits.srcrt)
 452                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 453                                 break;
 454                         case IPPROTO_AH:
 455                                 nexthdr = ptr[0];
 456                                 len = (ptr[1] + 2) << 2;
 457                                 break;
 458                         default:
 459                                 nexthdr = ptr[0];
 460                                 len = (ptr[1] + 1) << 3;
 461                                 break;
 462                         }
 463
 464                         off += len;
 465                 }
 466         }
 467
 468         /* socket options in old style */
 469         if (np->rxopt.bits.rxoinfo) {
 470                 struct in6_pktinfo src_info;
 471
 472                 src_info.ipi6_ifindex = opt->iif;
 473                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 474                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 475         }
 476         if (np->rxopt.bits.rxohlim) {
 477                 int hlim = ipv6_hdr(skb)->hop_limit;
 478                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 479         }
 480         if (np->rxopt.bits.ohopopts && opt->hop) {
 481                 u8 *ptr = nh + opt->hop;
 482                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 483         }
 484         if (np->rxopt.bits.odstopts && opt->dst0) {
 485                 u8 *ptr = nh + opt->dst0;
 486                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 487         }
 488         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 489                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 490                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 491         }
 492         if (np->rxopt.bits.odstopts && opt->dst1) {
 493                 u8 *ptr = nh + opt->dst1;
 494                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 495         }
 496         return 0;
 497 }
 498
 499 int datagram_send_ctl(struct net *net,
 500                       struct msghdr *msg, struct flowi *fl,
 501                       struct ipv6_txoptions *opt,
 502                       int *hlimit, int *tclass)
 503 {
 504         struct in6_pktinfo *src_info;
 505         struct cmsghdr *cmsg;
 506         struct ipv6_rt_hdr *rthdr;
 507         struct ipv6_opt_hdr *hdr;
 508         int len;
 509         int err = 0;
 510
 511         for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 512                 int addr_type;
 513
 514                 if (!CMSG_OK(msg, cmsg)) {
 515                         err = -EINVAL;
 516                         goto exit_f;
 517                 }
 518
 519                 if (cmsg->cmsg_level != SOL_IPV6)
 520                         continue;
 521
 522                 switch (cmsg->cmsg_type) {
 523                 case IPV6_PKTINFO:
 524                 case IPV6_2292PKTINFO:
 525                     {
 526                         struct net_device *dev = NULL;
 527
 528                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 529                                 err = -EINVAL;
 530                                 goto exit_f;
 531                         }
 532
 533                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 534
 535                         if (src_info->ipi6_ifindex) {
 536                                 if (fl->oif && src_info->ipi6_ifindex != fl->oif)
 537                                         return -EINVAL;
 538                                 fl->oif = src_info->ipi6_ifindex;
 539                         }
 540
 541                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 542
 543                         if (fl->oif) {
 544                                 dev = dev_get_by_index(net, fl->oif);
 545                                 if (!dev)
 546                                         return -ENODEV;
 547                         } else if (addr_type & IPV6_ADDR_LINKLOCAL)
 548                                 return -EINVAL;
 549
 550                         if (addr_type != IPV6_ADDR_ANY) {
 551                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 552                                 if (!ipv6_chk_addr(net, &src_info->ipi6_addr,
 553                                                    strict ? dev : NULL, 0))
 554                                         err = -EINVAL;
 555                                 else
 556                                         ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
 557                         }
 558
 559                         if (dev)
 560                                 dev_put(dev);
 561
 562                         if (err)
 563                                 goto exit_f;
 564
 565                         break;
 566                     }
 567
 568                 case IPV6_FLOWINFO:
 569                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 570                                 err = -EINVAL;
 571                                 goto exit_f;
 572                         }
 573
 574                         if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) {
 575                                 if ((fl->fl6_flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 576                                         err = -EINVAL;
 577                                         goto exit_f;
 578                                 }
 579                         }
 580                         fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 581                         break;
 582
 583                 case IPV6_2292HOPOPTS:
 584                 case IPV6_HOPOPTS:
 585                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 586                                 err = -EINVAL;
 587                                 goto exit_f;
 588                         }
 589
 590                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 591                         len = ((hdr->hdrlen + 1) << 3);
 592                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 593                                 err = -EINVAL;
 594                                 goto exit_f;
 595                         }
 596                         if (!capable(CAP_NET_RAW)) {
 597                                 err = -EPERM;
 598                                 goto exit_f;
 599                         }
 600                         opt->opt_nflen += len;
 601                         opt->hopopt = hdr;
 602                         break;
 603
 604                 case IPV6_2292DSTOPTS:
 605                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 606                                 err = -EINVAL;
 607                                 goto exit_f;
 608                         }
 609
 610                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 611                         len = ((hdr->hdrlen + 1) << 3);
 612                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 613                                 err = -EINVAL;
 614                                 goto exit_f;
 615                         }
 616                         if (!capable(CAP_NET_RAW)) {
 617                                 err = -EPERM;
 618                                 goto exit_f;
 619                         }
 620                         if (opt->dst1opt) {
 621                                 err = -EINVAL;
 622                                 goto exit_f;
 623                         }
 624                         opt->opt_flen += len;
 625                         opt->dst1opt = hdr;
 626                         break;
 627
 628                 case IPV6_DSTOPTS:
 629                 case IPV6_RTHDRDSTOPTS:
 630                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 631                                 err = -EINVAL;
 632                                 goto exit_f;
 633                         }
 634
 635                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 636                         len = ((hdr->hdrlen + 1) << 3);
 637                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 638                                 err = -EINVAL;
 639                                 goto exit_f;
 640                         }
 641                         if (!capable(CAP_NET_RAW)) {
 642                                 err = -EPERM;
 643                                 goto exit_f;
 644                         }
 645                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 646                                 opt->opt_flen += len;
 647                                 opt->dst1opt = hdr;
 648                         } else {
 649                                 opt->opt_nflen += len;
 650                                 opt->dst0opt = hdr;
 651                         }
 652                         break;
 653
 654                 case IPV6_2292RTHDR:
 655                 case IPV6_RTHDR:
 656                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 657                                 err = -EINVAL;
 658                                 goto exit_f;
 659                         }
 660
 661                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 662
 663                         switch (rthdr->type) {
 664 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 665                         case IPV6_SRCRT_TYPE_2:
 666                                 break;
 667 #endif
 668                         default:
 669                                 err = -EINVAL;
 670                                 goto exit_f;
 671                         }
 672
 673                         len = ((rthdr->hdrlen + 1) << 3);
 674
 675                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 676                                 err = -EINVAL;
 677                                 goto exit_f;
 678                         }
 679
 680                         /* segments left must also match */
 681                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 682                                 err = -EINVAL;
 683                                 goto exit_f;
 684                         }
 685
 686                         opt->opt_nflen += len;
 687                         opt->srcrt = rthdr;
 688
 689                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 690                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 691
 692                                 opt->opt_nflen += dsthdrlen;
 693                                 opt->dst0opt = opt->dst1opt;
 694                                 opt->dst1opt = NULL;
 695                                 opt->opt_flen -= dsthdrlen;
 696                         }
 697
 698                         break;
 699
 700                 case IPV6_2292HOPLIMIT:
 701                 case IPV6_HOPLIMIT:
 702                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 703                                 err = -EINVAL;
 704                                 goto exit_f;
 705                         }
 706
 707                         *hlimit = *(int *)CMSG_DATA(cmsg);
 708                         if (*hlimit < -1 || *hlimit > 0xff) {
 709                                 err = -EINVAL;
 710                                 goto exit_f;
 711                         }
 712
 713                         break;
 714
 715                 case IPV6_TCLASS:
 716                     {
 717                         int tc;
 718
 719                         err = -EINVAL;
 720                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 721                                 goto exit_f;
 722                         }
 723
 724                         tc = *(int *)CMSG_DATA(cmsg);
 725                         if (tc < -1 || tc > 0xff)
 726                                 goto exit_f;
 727
 728                         err = 0;
 729                         *tclass = tc;
 730
 731                         break;
 732                     }
 733                 default:
 734                         LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
 735                                        cmsg->cmsg_type);
 736                         err = -EINVAL;
 737                         break;
 738                 }
 739         }
 740
 741 exit_f:
 742         return err;
 743 }