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_v4mapped(inet->inet_daddr, &np->daddr);
 102
 103                 if (ipv6_addr_any(&np->saddr))
 104                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 105
 106                 if (ipv6_addr_any(&np->rcv_saddr))
 107                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 108                                                &np->rcv_saddr);
 109
 110                 goto out;
 111         }
 112
 113         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 114                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 115                     usin->sin6_scope_id) {
 116                         if (sk->sk_bound_dev_if &&
 117                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 118                                 err = -EINVAL;
 119                                 goto out;
 120                         }
 121                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 122                 }
 123
 124                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 125                         sk->sk_bound_dev_if = np->mcast_oif;
 126
 127                 /* Connect to link-local address requires an interface */
 128                 if (!sk->sk_bound_dev_if) {
 129                         err = -EINVAL;
 130                         goto out;
 131                 }
 132         }
 133
 134         ipv6_addr_copy(&np->daddr, daddr);
 135         np->flow_label = fl.fl6_flowlabel;
 136
 137         inet->inet_dport = usin->sin6_port;
 138
 139         /*
 140          *      Check for a route to destination an obtain the
 141          *      destination cache for it.
 142          */
 143
 144         fl.proto = sk->sk_protocol;
 145         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 146         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 147         fl.oif = sk->sk_bound_dev_if;
 148         fl.mark = sk->sk_mark;
 149         fl.fl_ip_dport = inet->inet_dport;
 150         fl.fl_ip_sport = inet->inet_sport;
 151
 152         if (!fl.oif && (addr_type&IPV6_ADDR_MULTICAST))
 153                 fl.oif = np->mcast_oif;
 154
 155         security_sk_classify_flow(sk, &fl);
 156
 157         if (flowlabel) {
 158                 if (flowlabel->opt && flowlabel->opt->srcrt) {
 159                         struct rt0_hdr *rt0 = (struct rt0_hdr *) flowlabel->opt->srcrt;
 160                         ipv6_addr_copy(&final, &fl.fl6_dst);
 161                         ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 162                         final_p = &final;
 163                 }
 164         } else if (np->opt && np->opt->srcrt) {
 165                 struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
 166                 ipv6_addr_copy(&final, &fl.fl6_dst);
 167                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 168                 final_p = &final;
 169         }
 170
 171         err = ip6_dst_lookup(sk, &dst, &fl);
 172         if (err)
 173                 goto out;
 174         if (final_p)
 175                 ipv6_addr_copy(&fl.fl6_dst, final_p);
 176
 177         err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);
 178         if (err < 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->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_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 332                                                &sin->sin6_addr);
 333                 }
 334         }
 335
 336         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 337         sin = &errhdr.offender;
 338         sin->sin6_family = AF_UNSPEC;
 339         if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
 340                 sin->sin6_family = AF_INET6;
 341                 sin->sin6_flowinfo = 0;
 342                 sin->sin6_scope_id = 0;
 343                 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
 344                         ipv6_addr_copy(&sin->sin6_addr, &ipv6_hdr(skb)->saddr);
 345                         if (np->rxopt.all)
 346                                 datagram_recv_ctl(sk, msg, skb);
 347                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 348                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 349                 } else {
 350                         struct inet_sock *inet = inet_sk(sk);
 351
 352                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 353                                                &sin->sin6_addr);
 354                         if (inet->cmsg_flags)
 355                                 ip_cmsg_recv(msg, skb);
 356                 }
 357         }
 358
 359         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 360
 361         /* Now we could try to dump offended packet options */
 362
 363         msg->msg_flags |= MSG_ERRQUEUE;
 364         err = copied;
 365
 366         /* Reset and regenerate socket error */
 367         spin_lock_bh(&sk->sk_error_queue.lock);
 368         sk->sk_err = 0;
 369         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
 370                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
 371                 spin_unlock_bh(&sk->sk_error_queue.lock);
 372                 sk->sk_error_report(sk);
 373         } else {
 374                 spin_unlock_bh(&sk->sk_error_queue.lock);
 375         }
 376
 377 out_free_skb:
 378         kfree_skb(skb);
 379 out:
 380         return err;
 381 }
 382
 383
 384
 385 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
 386 {
 387         struct ipv6_pinfo *np = inet6_sk(sk);
 388         struct inet6_skb_parm *opt = IP6CB(skb);
 389         unsigned char *nh = skb_network_header(skb);
 390
 391         if (np->rxopt.bits.rxinfo) {
 392                 struct in6_pktinfo src_info;
 393
 394                 src_info.ipi6_ifindex = opt->iif;
 395                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 396                 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
 397         }
 398
 399         if (np->rxopt.bits.rxhlim) {
 400                 int hlim = ipv6_hdr(skb)->hop_limit;
 401                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 402         }
 403
 404         if (np->rxopt.bits.rxtclass) {
 405                 int tclass = (ntohl(*(__be32 *)ipv6_hdr(skb)) >> 20) & 0xff;
 406                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 407         }
 408
 409         if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
 410                 __be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
 411                 put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 412         }
 413
 414         /* HbH is allowed only once */
 415         if (np->rxopt.bits.hopopts && opt->hop) {
 416                 u8 *ptr = nh + opt->hop;
 417                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 418         }
 419
 420         if (opt->lastopt &&
 421             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 422                 /*
 423                  * Silly enough, but we need to reparse in order to
 424                  * report extension headers (except for HbH)
 425                  * in order.
 426                  *
 427                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 428                  * (and WILL NOT be) defined because
 429                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 430                  */
 431                 unsigned int off = sizeof(struct ipv6hdr);
 432                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 433
 434                 while (off <= opt->lastopt) {
 435                         unsigned len;
 436                         u8 *ptr = nh + off;
 437
 438                         switch(nexthdr) {
 439                         case IPPROTO_DSTOPTS:
 440                                 nexthdr = ptr[0];
 441                                 len = (ptr[1] + 1) << 3;
 442                                 if (np->rxopt.bits.dstopts)
 443                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 444                                 break;
 445                         case IPPROTO_ROUTING:
 446                                 nexthdr = ptr[0];
 447                                 len = (ptr[1] + 1) << 3;
 448                                 if (np->rxopt.bits.srcrt)
 449                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 450                                 break;
 451                         case IPPROTO_AH:
 452                                 nexthdr = ptr[0];
 453                                 len = (ptr[1] + 2) << 2;
 454                                 break;
 455                         default:
 456                                 nexthdr = ptr[0];
 457                                 len = (ptr[1] + 1) << 3;
 458                                 break;
 459                         }
 460
 461                         off += len;
 462                 }
 463         }
 464
 465         /* socket options in old style */
 466         if (np->rxopt.bits.rxoinfo) {
 467                 struct in6_pktinfo src_info;
 468
 469                 src_info.ipi6_ifindex = opt->iif;
 470                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 471                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 472         }
 473         if (np->rxopt.bits.rxohlim) {
 474                 int hlim = ipv6_hdr(skb)->hop_limit;
 475                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 476         }
 477         if (np->rxopt.bits.ohopopts && opt->hop) {
 478                 u8 *ptr = nh + opt->hop;
 479                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 480         }
 481         if (np->rxopt.bits.odstopts && opt->dst0) {
 482                 u8 *ptr = nh + opt->dst0;
 483                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 484         }
 485         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 486                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 487                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 488         }
 489         if (np->rxopt.bits.odstopts && opt->dst1) {
 490                 u8 *ptr = nh + opt->dst1;
 491                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 492         }
 493         return 0;
 494 }
 495
 496 int datagram_send_ctl(struct net *net,
 497                       struct msghdr *msg, struct flowi *fl,
 498                       struct ipv6_txoptions *opt,
 499                       int *hlimit, int *tclass)
 500 {
 501         struct in6_pktinfo *src_info;
 502         struct cmsghdr *cmsg;
 503         struct ipv6_rt_hdr *rthdr;
 504         struct ipv6_opt_hdr *hdr;
 505         int len;
 506         int err = 0;
 507
 508         for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 509                 int addr_type;
 510
 511                 if (!CMSG_OK(msg, cmsg)) {
 512                         err = -EINVAL;
 513                         goto exit_f;
 514                 }
 515
 516                 if (cmsg->cmsg_level != SOL_IPV6)
 517                         continue;
 518
 519                 switch (cmsg->cmsg_type) {
 520                 case IPV6_PKTINFO:
 521                 case IPV6_2292PKTINFO:
 522                     {
 523                         struct net_device *dev = NULL;
 524
 525                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 526                                 err = -EINVAL;
 527                                 goto exit_f;
 528                         }
 529
 530                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 531
 532                         if (src_info->ipi6_ifindex) {
 533                                 if (fl->oif && src_info->ipi6_ifindex != fl->oif)
 534                                         return -EINVAL;
 535                                 fl->oif = src_info->ipi6_ifindex;
 536                         }
 537
 538                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 539
 540                         rcu_read_lock();
 541                         if (fl->oif) {
 542                                 dev = dev_get_by_index_rcu(net, fl->oif);
 543                                 if (!dev) {
 544                                         rcu_read_unlock();
 545                                         return -ENODEV;
 546                                 }
 547                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 548                                 rcu_read_unlock();
 549                                 return -EINVAL;
 550                         }
 551
 552                         if (addr_type != IPV6_ADDR_ANY) {
 553                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 554                                 if (!ipv6_chk_addr(net, &src_info->ipi6_addr,
 555                                                    strict ? dev : NULL, 0))
 556                                         err = -EINVAL;
 557                                 else
 558                                         ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
 559                         }
 560
 561                         rcu_read_unlock();
 562
 563                         if (err)
 564                                 goto exit_f;
 565
 566                         break;
 567                     }
 568
 569                 case IPV6_FLOWINFO:
 570                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 571                                 err = -EINVAL;
 572                                 goto exit_f;
 573                         }
 574
 575                         if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) {
 576                                 if ((fl->fl6_flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 577                                         err = -EINVAL;
 578                                         goto exit_f;
 579                                 }
 580                         }
 581                         fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 582                         break;
 583
 584                 case IPV6_2292HOPOPTS:
 585                 case IPV6_HOPOPTS:
 586                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 587                                 err = -EINVAL;
 588                                 goto exit_f;
 589                         }
 590
 591                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 592                         len = ((hdr->hdrlen + 1) << 3);
 593                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 594                                 err = -EINVAL;
 595                                 goto exit_f;
 596                         }
 597                         if (!capable(CAP_NET_RAW)) {
 598                                 err = -EPERM;
 599                                 goto exit_f;
 600                         }
 601                         opt->opt_nflen += len;
 602                         opt->hopopt = hdr;
 603                         break;
 604
 605                 case IPV6_2292DSTOPTS:
 606                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 607                                 err = -EINVAL;
 608                                 goto exit_f;
 609                         }
 610
 611                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 612                         len = ((hdr->hdrlen + 1) << 3);
 613                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 614                                 err = -EINVAL;
 615                                 goto exit_f;
 616                         }
 617                         if (!capable(CAP_NET_RAW)) {
 618                                 err = -EPERM;
 619                                 goto exit_f;
 620                         }
 621                         if (opt->dst1opt) {
 622                                 err = -EINVAL;
 623                                 goto exit_f;
 624                         }
 625                         opt->opt_flen += len;
 626                         opt->dst1opt = hdr;
 627                         break;
 628
 629                 case IPV6_DSTOPTS:
 630                 case IPV6_RTHDRDSTOPTS:
 631                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 632                                 err = -EINVAL;
 633                                 goto exit_f;
 634                         }
 635
 636                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 637                         len = ((hdr->hdrlen + 1) << 3);
 638                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 639                                 err = -EINVAL;
 640                                 goto exit_f;
 641                         }
 642                         if (!capable(CAP_NET_RAW)) {
 643                                 err = -EPERM;
 644                                 goto exit_f;
 645                         }
 646                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 647                                 opt->opt_flen += len;
 648                                 opt->dst1opt = hdr;
 649                         } else {
 650                                 opt->opt_nflen += len;
 651                                 opt->dst0opt = hdr;
 652                         }
 653                         break;
 654
 655                 case IPV6_2292RTHDR:
 656                 case IPV6_RTHDR:
 657                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 658                                 err = -EINVAL;
 659                                 goto exit_f;
 660                         }
 661
 662                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 663
 664                         switch (rthdr->type) {
 665 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 666                         case IPV6_SRCRT_TYPE_2:
 667                                 if (rthdr->hdrlen != 2 ||
 668                                     rthdr->segments_left != 1) {
 669                                         err = -EINVAL;
 670                                         goto exit_f;
 671                                 }
 672                                 break;
 673 #endif
 674                         default:
 675                                 err = -EINVAL;
 676                                 goto exit_f;
 677                         }
 678
 679                         len = ((rthdr->hdrlen + 1) << 3);
 680
 681                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 682                                 err = -EINVAL;
 683                                 goto exit_f;
 684                         }
 685
 686                         /* segments left must also match */
 687                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 688                                 err = -EINVAL;
 689                                 goto exit_f;
 690                         }
 691
 692                         opt->opt_nflen += len;
 693                         opt->srcrt = rthdr;
 694
 695                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 696                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 697
 698                                 opt->opt_nflen += dsthdrlen;
 699                                 opt->dst0opt = opt->dst1opt;
 700                                 opt->dst1opt = NULL;
 701                                 opt->opt_flen -= dsthdrlen;
 702                         }
 703
 704                         break;
 705
 706                 case IPV6_2292HOPLIMIT:
 707                 case IPV6_HOPLIMIT:
 708                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 709                                 err = -EINVAL;
 710                                 goto exit_f;
 711                         }
 712
 713                         *hlimit = *(int *)CMSG_DATA(cmsg);
 714                         if (*hlimit < -1 || *hlimit > 0xff) {
 715                                 err = -EINVAL;
 716                                 goto exit_f;
 717                         }
 718
 719                         break;
 720
 721                 case IPV6_TCLASS:
 722                     {
 723                         int tc;
 724
 725                         err = -EINVAL;
 726                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 727                                 goto exit_f;
 728                         }
 729
 730                         tc = *(int *)CMSG_DATA(cmsg);
 731                         if (tc < -1 || tc > 0xff)
 732                                 goto exit_f;
 733
 734                         err = 0;
 735                         *tclass = tc;
 736
 737                         break;
 738                     }
 739                 default:
 740                         LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
 741                                        cmsg->cmsg_type);
 742                         err = -EINVAL;
 743                         goto exit_f;
 744                 }
 745         }
 746
 747 exit_f:
 748         return err;
 749 }