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
  25 #include <net/ipv6.h>
  26 #include <net/ndisc.h>
  27 #include <net/addrconf.h>
  28 #include <net/transp_v6.h>
  29 #include <net/ip6_route.h>
  30 #include <net/tcp_states.h>
  31
  32 #include <linux/errqueue.h>
  33 #include <asm/uaccess.h>
  34
  35 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
  36 {
  37         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
  38         struct inet_sock        *inet = inet_sk(sk);
  39         struct ipv6_pinfo       *np = inet6_sk(sk);
  40         struct in6_addr         *daddr, *final_p = NULL, final;
  41         struct dst_entry        *dst;
  42         struct flowi            fl;
  43         struct ip6_flowlabel    *flowlabel = NULL;
  44         int                     addr_type;
  45         int                     err;
  46
  47         if (usin->sin6_family == AF_INET) {
  48                 if (__ipv6_only_sock(sk))
  49                         return -EAFNOSUPPORT;
  50                 err = ip4_datagram_connect(sk, uaddr, addr_len);
  51                 goto ipv4_connected;
  52         }
  53
  54         if (addr_len < SIN6_LEN_RFC2133)
  55                 return -EINVAL;
  56
  57         if (usin->sin6_family != AF_INET6)
  58                 return -EAFNOSUPPORT;
  59
  60         memset(&fl, 0, sizeof(fl));
  61         if (np->sndflow) {
  62                 fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
  63                 if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
  64                         flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
  65                         if (flowlabel == NULL)
  66                                 return -EINVAL;
  67                         ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
  68                 }
  69         }
  70
  71         addr_type = ipv6_addr_type(&usin->sin6_addr);
  72
  73         if (addr_type == IPV6_ADDR_ANY) {
  74                 /*
  75                  *      connect to self
  76                  */
  77                 usin->sin6_addr.s6_addr[15] = 0x01;
  78         }
  79
  80         daddr = &usin->sin6_addr;
  81
  82         if (addr_type == IPV6_ADDR_MAPPED) {
  83                 struct sockaddr_in sin;
  84
  85                 if (__ipv6_only_sock(sk)) {
  86                         err = -ENETUNREACH;
  87                         goto out;
  88                 }
  89                 sin.sin_family = AF_INET;
  90                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
  91                 sin.sin_port = usin->sin6_port;
  92
  93                 err = ip4_datagram_connect(sk,
  94                                            (struct sockaddr*) &sin,
  95                                            sizeof(sin));
  96
  97 ipv4_connected:
  98                 if (err)
  99                         goto out;
 100
 101                 ipv6_addr_set(&np->daddr, 0, 0, htonl(0x0000ffff), inet->daddr);
 102
 103                 if (ipv6_addr_any(&np->saddr)) {
 104                         ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000ffff),
 105                                       inet->saddr);
 106                 }
 107
 108                 if (ipv6_addr_any(&np->rcv_saddr)) {
 109                         ipv6_addr_set(&np->rcv_saddr, 0, 0, htonl(0x0000ffff),
 110                                       inet->rcv_saddr);
 111                 }
 112                 goto out;
 113         }
 114
 115         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 116                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 117                     usin->sin6_scope_id) {
 118                         if (sk->sk_bound_dev_if &&
 119                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 120                                 err = -EINVAL;
 121                                 goto out;
 122                         }
 123                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 124                 }
 125
 126                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 127                         sk->sk_bound_dev_if = np->mcast_oif;
 128
 129                 /* Connect to link-local address requires an interface */
 130                 if (!sk->sk_bound_dev_if) {
 131                         err = -EINVAL;
 132                         goto out;
 133                 }
 134         }
 135
 136         ipv6_addr_copy(&np->daddr, daddr);
 137         np->flow_label = fl.fl6_flowlabel;
 138
 139         inet->dport = usin->sin6_port;
 140
 141         /*
 142          *      Check for a route to destination an obtain the
 143          *      destination cache for it.
 144          */
 145
 146         fl.proto = sk->sk_protocol;
 147         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 148         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 149         fl.oif = sk->sk_bound_dev_if;
 150         fl.fl_ip_dport = inet->dport;
 151         fl.fl_ip_sport = 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         if ((err = __xfrm_lookup(&dst, &fl, sk, XFRM_LOOKUP_WAIT)) < 0) {
 179                 if (err == -EREMOTE)
 180                         err = ip6_dst_blackhole(sk, &dst, &fl);
 181                 if (err < 0)
 182                         goto out;
 183         }
 184
 185         /* source address lookup done in ip6_dst_lookup */
 186
 187         if (ipv6_addr_any(&np->saddr))
 188                 ipv6_addr_copy(&np->saddr, &fl.fl6_src);
 189
 190         if (ipv6_addr_any(&np->rcv_saddr)) {
 191                 ipv6_addr_copy(&np->rcv_saddr, &fl.fl6_src);
 192                 inet->rcv_saddr = LOOPBACK4_IPV6;
 193         }
 194
 195         ip6_dst_store(sk, dst,
 196                       ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
 197                       &np->daddr : NULL,
 198 #ifdef CONFIG_IPV6_SUBTREES
 199                       ipv6_addr_equal(&fl.fl6_src, &np->saddr) ?
 200                       &np->saddr :
 201 #endif
 202                       NULL);
 203
 204         sk->sk_state = TCP_ESTABLISHED;
 205 out:
 206         fl6_sock_release(flowlabel);
 207         return err;
 208 }
 209
 210 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 211                      __be16 port, u32 info, u8 *payload)
 212 {
 213         struct ipv6_pinfo *np  = inet6_sk(sk);
 214         struct icmp6hdr *icmph = icmp6_hdr(skb);
 215         struct sock_exterr_skb *serr;
 216
 217         if (!np->recverr)
 218                 return;
 219
 220         skb = skb_clone(skb, GFP_ATOMIC);
 221         if (!skb)
 222                 return;
 223
 224         serr = SKB_EXT_ERR(skb);
 225         serr->ee.ee_errno = err;
 226         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 227         serr->ee.ee_type = icmph->icmp6_type;
 228         serr->ee.ee_code = icmph->icmp6_code;
 229         serr->ee.ee_pad = 0;
 230         serr->ee.ee_info = info;
 231         serr->ee.ee_data = 0;
 232         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 233                                   skb_network_header(skb);
 234         serr->port = port;
 235
 236         __skb_pull(skb, payload - skb->data);
 237         skb_reset_transport_header(skb);
 238
 239         if (sock_queue_err_skb(sk, skb))
 240                 kfree_skb(skb);
 241 }
 242
 243 void ipv6_local_error(struct sock *sk, int err, struct flowi *fl, u32 info)
 244 {
 245         struct ipv6_pinfo *np = inet6_sk(sk);
 246         struct sock_exterr_skb *serr;
 247         struct ipv6hdr *iph;
 248         struct sk_buff *skb;
 249
 250         if (!np->recverr)
 251                 return;
 252
 253         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 254         if (!skb)
 255                 return;
 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 /*
 281  *      Handle MSG_ERRQUEUE
 282  */
 283 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
 284 {
 285         struct ipv6_pinfo *np = inet6_sk(sk);
 286         struct sock_exterr_skb *serr;
 287         struct sk_buff *skb, *skb2;
 288         struct sockaddr_in6 *sin;
 289         struct {
 290                 struct sock_extended_err ee;
 291                 struct sockaddr_in6      offender;
 292         } errhdr;
 293         int err;
 294         int copied;
 295
 296         err = -EAGAIN;
 297         skb = skb_dequeue(&sk->sk_error_queue);
 298         if (skb == NULL)
 299                 goto out;
 300
 301         copied = skb->len;
 302         if (copied > len) {
 303                 msg->msg_flags |= MSG_TRUNC;
 304                 copied = len;
 305         }
 306         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 307         if (err)
 308                 goto out_free_skb;
 309
 310         sock_recv_timestamp(msg, sk, skb);
 311
 312         serr = SKB_EXT_ERR(skb);
 313
 314         sin = (struct sockaddr_in6 *)msg->msg_name;
 315         if (sin) {
 316                 const unsigned char *nh = skb_network_header(skb);
 317                 sin->sin6_family = AF_INET6;
 318                 sin->sin6_flowinfo = 0;
 319                 sin->sin6_port = serr->port;
 320                 sin->sin6_scope_id = 0;
 321                 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
 322                         ipv6_addr_copy(&sin->sin6_addr,
 323                                   (struct in6_addr *)(nh + serr->addr_offset));
 324                         if (np->sndflow)
 325                                 sin->sin6_flowinfo =
 326                                         (*(__be32 *)(nh + serr->addr_offset - 24) &
 327                                          IPV6_FLOWINFO_MASK);
 328                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 329                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 330                 } else {
 331                         ipv6_addr_set(&sin->sin6_addr, 0, 0,
 332                                       htonl(0xffff),
 333                                       *(__be32 *)(nh + serr->addr_offset));
 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(&sin->sin6_addr, 0, 0,
 354                                       htonl(0xffff), ip_hdr(skb)->saddr);
 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                         if (fl->oif) {
 542                                 dev = dev_get_by_index(net, fl->oif);
 543                                 if (!dev)
 544                                         return -ENODEV;
 545                         } else if (addr_type & IPV6_ADDR_LINKLOCAL)
 546                                 return -EINVAL;
 547
 548                         if (addr_type != IPV6_ADDR_ANY) {
 549                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 550                                 if (!ipv6_chk_addr(net, &src_info->ipi6_addr,
 551                                                    strict ? dev : NULL, 0))
 552                                         err = -EINVAL;
 553                                 else
 554                                         ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
 555                         }
 556
 557                         if (dev)
 558                                 dev_put(dev);
 559
 560                         if (err)
 561                                 goto exit_f;
 562
 563                         break;
 564                     }
 565
 566                 case IPV6_FLOWINFO:
 567                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 568                                 err = -EINVAL;
 569                                 goto exit_f;
 570                         }
 571
 572                         if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) {
 573                                 if ((fl->fl6_flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 574                                         err = -EINVAL;
 575                                         goto exit_f;
 576                                 }
 577                         }
 578                         fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 579                         break;
 580
 581                 case IPV6_2292HOPOPTS:
 582                 case IPV6_HOPOPTS:
 583                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 584                                 err = -EINVAL;
 585                                 goto exit_f;
 586                         }
 587
 588                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 589                         len = ((hdr->hdrlen + 1) << 3);
 590                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 591                                 err = -EINVAL;
 592                                 goto exit_f;
 593                         }
 594                         if (!capable(CAP_NET_RAW)) {
 595                                 err = -EPERM;
 596                                 goto exit_f;
 597                         }
 598                         opt->opt_nflen += len;
 599                         opt->hopopt = hdr;
 600                         break;
 601
 602                 case IPV6_2292DSTOPTS:
 603                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 604                                 err = -EINVAL;
 605                                 goto exit_f;
 606                         }
 607
 608                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 609                         len = ((hdr->hdrlen + 1) << 3);
 610                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 611                                 err = -EINVAL;
 612                                 goto exit_f;
 613                         }
 614                         if (!capable(CAP_NET_RAW)) {
 615                                 err = -EPERM;
 616                                 goto exit_f;
 617                         }
 618                         if (opt->dst1opt) {
 619                                 err = -EINVAL;
 620                                 goto exit_f;
 621                         }
 622                         opt->opt_flen += len;
 623                         opt->dst1opt = hdr;
 624                         break;
 625
 626                 case IPV6_DSTOPTS:
 627                 case IPV6_RTHDRDSTOPTS:
 628                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 629                                 err = -EINVAL;
 630                                 goto exit_f;
 631                         }
 632
 633                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 634                         len = ((hdr->hdrlen + 1) << 3);
 635                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 636                                 err = -EINVAL;
 637                                 goto exit_f;
 638                         }
 639                         if (!capable(CAP_NET_RAW)) {
 640                                 err = -EPERM;
 641                                 goto exit_f;
 642                         }
 643                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 644                                 opt->opt_flen += len;
 645                                 opt->dst1opt = hdr;
 646                         } else {
 647                                 opt->opt_nflen += len;
 648                                 opt->dst0opt = hdr;
 649                         }
 650                         break;
 651
 652                 case IPV6_2292RTHDR:
 653                 case IPV6_RTHDR:
 654                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 655                                 err = -EINVAL;
 656                                 goto exit_f;
 657                         }
 658
 659                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 660
 661                         switch (rthdr->type) {
 662 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 663                         case IPV6_SRCRT_TYPE_2:
 664                                 break;
 665 #endif
 666                         default:
 667                                 err = -EINVAL;
 668                                 goto exit_f;
 669                         }
 670
 671                         len = ((rthdr->hdrlen + 1) << 3);
 672
 673                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 674                                 err = -EINVAL;
 675                                 goto exit_f;
 676                         }
 677
 678                         /* segments left must also match */
 679                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 680                                 err = -EINVAL;
 681                                 goto exit_f;
 682                         }
 683
 684                         opt->opt_nflen += len;
 685                         opt->srcrt = rthdr;
 686
 687                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 688                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 689
 690                                 opt->opt_nflen += dsthdrlen;
 691                                 opt->dst0opt = opt->dst1opt;
 692                                 opt->dst1opt = NULL;
 693                                 opt->opt_flen -= dsthdrlen;
 694                         }
 695
 696                         break;
 697
 698                 case IPV6_2292HOPLIMIT:
 699                 case IPV6_HOPLIMIT:
 700                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 701                                 err = -EINVAL;
 702                                 goto exit_f;
 703                         }
 704
 705                         *hlimit = *(int *)CMSG_DATA(cmsg);
 706                         if (*hlimit < -1 || *hlimit > 0xff) {
 707                                 err = -EINVAL;
 708                                 goto exit_f;
 709                         }
 710
 711                         break;
 712
 713                 case IPV6_TCLASS:
 714                     {
 715                         int tc;
 716
 717                         err = -EINVAL;
 718                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 719                                 goto exit_f;
 720                         }
 721
 722                         tc = *(int *)CMSG_DATA(cmsg);
 723                         if (tc < -1 || tc > 0xff)
 724                                 goto exit_f;
 725
 726                         err = 0;
 727                         *tclass = tc;
 728
 729                         break;
 730                     }
 731                 default:
 732                         LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
 733                                        cmsg->cmsg_type);
 734                         err = -EINVAL;
 735                         break;
 736                 }
 737         }
 738
 739 exit_f:
 740         return err;
 741 }