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         err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);
 179         if (err < 0) {
 180                 if (err == -EREMOTE)
 181                         err = ip6_dst_blackhole(sk, &dst, &fl);
 182                 if (err < 0)
 183                         goto out;
 184         }
 185
 186         /* source address lookup done in ip6_dst_lookup */
 187
 188         if (ipv6_addr_any(&np->saddr))
 189                 ipv6_addr_copy(&np->saddr, &fl.fl6_src);
 190
 191         if (ipv6_addr_any(&np->rcv_saddr)) {
 192                 ipv6_addr_copy(&np->rcv_saddr, &fl.fl6_src);
 193                 inet->rcv_saddr = LOOPBACK4_IPV6;
 194         }
 195
 196         ip6_dst_store(sk, dst,
 197                       ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
 198                       &np->daddr : NULL,
 199 #ifdef CONFIG_IPV6_SUBTREES
 200                       ipv6_addr_equal(&fl.fl6_src, &np->saddr) ?
 201                       &np->saddr :
 202 #endif
 203                       NULL);
 204
 205         sk->sk_state = TCP_ESTABLISHED;
 206 out:
 207         fl6_sock_release(flowlabel);
 208         return err;
 209 }
 210
 211 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 212                      __be16 port, u32 info, u8 *payload)
 213 {
 214         struct ipv6_pinfo *np  = inet6_sk(sk);
 215         struct icmp6hdr *icmph = icmp6_hdr(skb);
 216         struct sock_exterr_skb *serr;
 217
 218         if (!np->recverr)
 219                 return;
 220
 221         skb = skb_clone(skb, GFP_ATOMIC);
 222         if (!skb)
 223                 return;
 224
 225         serr = SKB_EXT_ERR(skb);
 226         serr->ee.ee_errno = err;
 227         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 228         serr->ee.ee_type = icmph->icmp6_type;
 229         serr->ee.ee_code = icmph->icmp6_code;
 230         serr->ee.ee_pad = 0;
 231         serr->ee.ee_info = info;
 232         serr->ee.ee_data = 0;
 233         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 234                                   skb_network_header(skb);
 235         serr->port = port;
 236
 237         __skb_pull(skb, payload - skb->data);
 238         skb_reset_transport_header(skb);
 239
 240         if (sock_queue_err_skb(sk, skb))
 241                 kfree_skb(skb);
 242 }
 243
 244 void ipv6_local_error(struct sock *sk, int err, struct flowi *fl, u32 info)
 245 {
 246         struct ipv6_pinfo *np = inet6_sk(sk);
 247         struct sock_exterr_skb *serr;
 248         struct ipv6hdr *iph;
 249         struct sk_buff *skb;
 250
 251         if (!np->recverr)
 252                 return;
 253
 254         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 255         if (!skb)
 256                 return;
 257
 258         skb_put(skb, sizeof(struct ipv6hdr));
 259         skb_reset_network_header(skb);
 260         iph = ipv6_hdr(skb);
 261         ipv6_addr_copy(&iph->daddr, &fl->fl6_dst);
 262
 263         serr = SKB_EXT_ERR(skb);
 264         serr->ee.ee_errno = err;
 265         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 266         serr->ee.ee_type = 0;
 267         serr->ee.ee_code = 0;
 268         serr->ee.ee_pad = 0;
 269         serr->ee.ee_info = info;
 270         serr->ee.ee_data = 0;
 271         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 272         serr->port = fl->fl_ip_dport;
 273
 274         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 275         skb_reset_transport_header(skb);
 276
 277         if (sock_queue_err_skb(sk, skb))
 278                 kfree_skb(skb);
 279 }
 280
 281 /*
 282  *      Handle MSG_ERRQUEUE
 283  */
 284 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
 285 {
 286         struct ipv6_pinfo *np = inet6_sk(sk);
 287         struct sock_exterr_skb *serr;
 288         struct sk_buff *skb, *skb2;
 289         struct sockaddr_in6 *sin;
 290         struct {
 291                 struct sock_extended_err ee;
 292                 struct sockaddr_in6      offender;
 293         } errhdr;
 294         int err;
 295         int copied;
 296
 297         err = -EAGAIN;
 298         skb = skb_dequeue(&sk->sk_error_queue);
 299         if (skb == NULL)
 300                 goto out;
 301
 302         copied = skb->len;
 303         if (copied > len) {
 304                 msg->msg_flags |= MSG_TRUNC;
 305                 copied = len;
 306         }
 307         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 308         if (err)
 309                 goto out_free_skb;
 310
 311         sock_recv_timestamp(msg, sk, skb);
 312
 313         serr = SKB_EXT_ERR(skb);
 314
 315         sin = (struct sockaddr_in6 *)msg->msg_name;
 316         if (sin) {
 317                 const unsigned char *nh = skb_network_header(skb);
 318                 sin->sin6_family = AF_INET6;
 319                 sin->sin6_flowinfo = 0;
 320                 sin->sin6_port = serr->port;
 321                 sin->sin6_scope_id = 0;
 322                 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
 323                         ipv6_addr_copy(&sin->sin6_addr,
 324                                   (struct in6_addr *)(nh + serr->addr_offset));
 325                         if (np->sndflow)
 326                                 sin->sin6_flowinfo =
 327                                         (*(__be32 *)(nh + serr->addr_offset - 24) &
 328                                          IPV6_FLOWINFO_MASK);
 329                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 330                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 331                 } else {
 332                         ipv6_addr_set(&sin->sin6_addr, 0, 0,
 333                                       htonl(0xffff),
 334                                       *(__be32 *)(nh + serr->addr_offset));
 335                 }
 336         }
 337
 338         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 339         sin = &errhdr.offender;
 340         sin->sin6_family = AF_UNSPEC;
 341         if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
 342                 sin->sin6_family = AF_INET6;
 343                 sin->sin6_flowinfo = 0;
 344                 sin->sin6_scope_id = 0;
 345                 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
 346                         ipv6_addr_copy(&sin->sin6_addr, &ipv6_hdr(skb)->saddr);
 347                         if (np->rxopt.all)
 348                                 datagram_recv_ctl(sk, msg, skb);
 349                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 350                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 351                 } else {
 352                         struct inet_sock *inet = inet_sk(sk);
 353
 354                         ipv6_addr_set(&sin->sin6_addr, 0, 0,
 355                                       htonl(0xffff), ip_hdr(skb)->saddr);
 356                         if (inet->cmsg_flags)
 357                                 ip_cmsg_recv(msg, skb);
 358                 }
 359         }
 360
 361         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 362
 363         /* Now we could try to dump offended packet options */
 364
 365         msg->msg_flags |= MSG_ERRQUEUE;
 366         err = copied;
 367
 368         /* Reset and regenerate socket error */
 369         spin_lock_bh(&sk->sk_error_queue.lock);
 370         sk->sk_err = 0;
 371         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
 372                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
 373                 spin_unlock_bh(&sk->sk_error_queue.lock);
 374                 sk->sk_error_report(sk);
 375         } else {
 376                 spin_unlock_bh(&sk->sk_error_queue.lock);
 377         }
 378
 379 out_free_skb:
 380         kfree_skb(skb);
 381 out:
 382         return err;
 383 }
 384
 385
 386
 387 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
 388 {
 389         struct ipv6_pinfo *np = inet6_sk(sk);
 390         struct inet6_skb_parm *opt = IP6CB(skb);
 391         unsigned char *nh = skb_network_header(skb);
 392
 393         if (np->rxopt.bits.rxinfo) {
 394                 struct in6_pktinfo src_info;
 395
 396                 src_info.ipi6_ifindex = opt->iif;
 397                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 398                 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
 399         }
 400
 401         if (np->rxopt.bits.rxhlim) {
 402                 int hlim = ipv6_hdr(skb)->hop_limit;
 403                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 404         }
 405
 406         if (np->rxopt.bits.rxtclass) {
 407                 int tclass = (ntohl(*(__be32 *)ipv6_hdr(skb)) >> 20) & 0xff;
 408                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 409         }
 410
 411         if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
 412                 __be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
 413                 put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 414         }
 415
 416         /* HbH is allowed only once */
 417         if (np->rxopt.bits.hopopts && opt->hop) {
 418                 u8 *ptr = nh + opt->hop;
 419                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 420         }
 421
 422         if (opt->lastopt &&
 423             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 424                 /*
 425                  * Silly enough, but we need to reparse in order to
 426                  * report extension headers (except for HbH)
 427                  * in order.
 428                  *
 429                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 430                  * (and WILL NOT be) defined because
 431                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 432                  */
 433                 unsigned int off = sizeof(struct ipv6hdr);
 434                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 435
 436                 while (off <= opt->lastopt) {
 437                         unsigned len;
 438                         u8 *ptr = nh + off;
 439
 440                         switch(nexthdr) {
 441                         case IPPROTO_DSTOPTS:
 442                                 nexthdr = ptr[0];
 443                                 len = (ptr[1] + 1) << 3;
 444                                 if (np->rxopt.bits.dstopts)
 445                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 446                                 break;
 447                         case IPPROTO_ROUTING:
 448                                 nexthdr = ptr[0];
 449                                 len = (ptr[1] + 1) << 3;
 450                                 if (np->rxopt.bits.srcrt)
 451                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 452                                 break;
 453                         case IPPROTO_AH:
 454                                 nexthdr = ptr[0];
 455                                 len = (ptr[1] + 2) << 2;
 456                                 break;
 457                         default:
 458                                 nexthdr = ptr[0];
 459                                 len = (ptr[1] + 1) << 3;
 460                                 break;
 461                         }
 462
 463                         off += len;
 464                 }
 465         }
 466
 467         /* socket options in old style */
 468         if (np->rxopt.bits.rxoinfo) {
 469                 struct in6_pktinfo src_info;
 470
 471                 src_info.ipi6_ifindex = opt->iif;
 472                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 473                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 474         }
 475         if (np->rxopt.bits.rxohlim) {
 476                 int hlim = ipv6_hdr(skb)->hop_limit;
 477                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 478         }
 479         if (np->rxopt.bits.ohopopts && opt->hop) {
 480                 u8 *ptr = nh + opt->hop;
 481                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 482         }
 483         if (np->rxopt.bits.odstopts && opt->dst0) {
 484                 u8 *ptr = nh + opt->dst0;
 485                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 486         }
 487         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 488                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 489                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 490         }
 491         if (np->rxopt.bits.odstopts && opt->dst1) {
 492                 u8 *ptr = nh + opt->dst1;
 493                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 494         }
 495         return 0;
 496 }
 497
 498 int datagram_send_ctl(struct net *net,
 499                       struct msghdr *msg, struct flowi *fl,
 500                       struct ipv6_txoptions *opt,
 501                       int *hlimit, int *tclass)
 502 {
 503         struct in6_pktinfo *src_info;
 504         struct cmsghdr *cmsg;
 505         struct ipv6_rt_hdr *rthdr;
 506         struct ipv6_opt_hdr *hdr;
 507         int len;
 508         int err = 0;
 509
 510         for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 511                 int addr_type;
 512
 513                 if (!CMSG_OK(msg, cmsg)) {
 514                         err = -EINVAL;
 515                         goto exit_f;
 516                 }
 517
 518                 if (cmsg->cmsg_level != SOL_IPV6)
 519                         continue;
 520
 521                 switch (cmsg->cmsg_type) {
 522                 case IPV6_PKTINFO:
 523                 case IPV6_2292PKTINFO:
 524                     {
 525                         struct net_device *dev = NULL;
 526
 527                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 528                                 err = -EINVAL;
 529                                 goto exit_f;
 530                         }
 531
 532                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 533
 534                         if (src_info->ipi6_ifindex) {
 535                                 if (fl->oif && src_info->ipi6_ifindex != fl->oif)
 536                                         return -EINVAL;
 537                                 fl->oif = src_info->ipi6_ifindex;
 538                         }
 539
 540                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 541
 542                         if (fl->oif) {
 543                                 dev = dev_get_by_index(net, fl->oif);
 544                                 if (!dev)
 545                                         return -ENODEV;
 546                         } else if (addr_type & IPV6_ADDR_LINKLOCAL)
 547                                 return -EINVAL;
 548
 549                         if (addr_type != IPV6_ADDR_ANY) {
 550                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 551                                 if (!ipv6_chk_addr(net, &src_info->ipi6_addr,
 552                                                    strict ? dev : NULL, 0))
 553                                         err = -EINVAL;
 554                                 else
 555                                         ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
 556                         }
 557
 558                         if (dev)
 559                                 dev_put(dev);
 560
 561                         if (err)
 562                                 goto exit_f;
 563
 564                         break;
 565                     }
 566
 567                 case IPV6_FLOWINFO:
 568                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 569                                 err = -EINVAL;
 570                                 goto exit_f;
 571                         }
 572
 573                         if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) {
 574                                 if ((fl->fl6_flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 575                                         err = -EINVAL;
 576                                         goto exit_f;
 577                                 }
 578                         }
 579                         fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 580                         break;
 581
 582                 case IPV6_2292HOPOPTS:
 583                 case IPV6_HOPOPTS:
 584                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 585                                 err = -EINVAL;
 586                                 goto exit_f;
 587                         }
 588
 589                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 590                         len = ((hdr->hdrlen + 1) << 3);
 591                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 592                                 err = -EINVAL;
 593                                 goto exit_f;
 594                         }
 595                         if (!capable(CAP_NET_RAW)) {
 596                                 err = -EPERM;
 597                                 goto exit_f;
 598                         }
 599                         opt->opt_nflen += len;
 600                         opt->hopopt = hdr;
 601                         break;
 602
 603                 case IPV6_2292DSTOPTS:
 604                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 605                                 err = -EINVAL;
 606                                 goto exit_f;
 607                         }
 608
 609                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 610                         len = ((hdr->hdrlen + 1) << 3);
 611                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 612                                 err = -EINVAL;
 613                                 goto exit_f;
 614                         }
 615                         if (!capable(CAP_NET_RAW)) {
 616                                 err = -EPERM;
 617                                 goto exit_f;
 618                         }
 619                         if (opt->dst1opt) {
 620                                 err = -EINVAL;
 621                                 goto exit_f;
 622                         }
 623                         opt->opt_flen += len;
 624                         opt->dst1opt = hdr;
 625                         break;
 626
 627                 case IPV6_DSTOPTS:
 628                 case IPV6_RTHDRDSTOPTS:
 629                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 630                                 err = -EINVAL;
 631                                 goto exit_f;
 632                         }
 633
 634                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 635                         len = ((hdr->hdrlen + 1) << 3);
 636                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 637                                 err = -EINVAL;
 638                                 goto exit_f;
 639                         }
 640                         if (!capable(CAP_NET_RAW)) {
 641                                 err = -EPERM;
 642                                 goto exit_f;
 643                         }
 644                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 645                                 opt->opt_flen += len;
 646                                 opt->dst1opt = hdr;
 647                         } else {
 648                                 opt->opt_nflen += len;
 649                                 opt->dst0opt = hdr;
 650                         }
 651                         break;
 652
 653                 case IPV6_2292RTHDR:
 654                 case IPV6_RTHDR:
 655                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 656                                 err = -EINVAL;
 657                                 goto exit_f;
 658                         }
 659
 660                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 661
 662                         switch (rthdr->type) {
 663 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 664                         case IPV6_SRCRT_TYPE_2:
 665                                 if (rthdr->hdrlen != 2 ||
 666                                     rthdr->segments_left != 1) {
 667                                         err = -EINVAL;
 668                                         goto exit_f;
 669                                 }
 670                                 break;
 671 #endif
 672                         default:
 673                                 err = -EINVAL;
 674                                 goto exit_f;
 675                         }
 676
 677                         len = ((rthdr->hdrlen + 1) << 3);
 678
 679                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 680                                 err = -EINVAL;
 681                                 goto exit_f;
 682                         }
 683
 684                         /* segments left must also match */
 685                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 686                                 err = -EINVAL;
 687                                 goto exit_f;
 688                         }
 689
 690                         opt->opt_nflen += len;
 691                         opt->srcrt = rthdr;
 692
 693                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 694                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 695
 696                                 opt->opt_nflen += dsthdrlen;
 697                                 opt->dst0opt = opt->dst1opt;
 698                                 opt->dst1opt = NULL;
 699                                 opt->opt_flen -= dsthdrlen;
 700                         }
 701
 702                         break;
 703
 704                 case IPV6_2292HOPLIMIT:
 705                 case IPV6_HOPLIMIT:
 706                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 707                                 err = -EINVAL;
 708                                 goto exit_f;
 709                         }
 710
 711                         *hlimit = *(int *)CMSG_DATA(cmsg);
 712                         if (*hlimit < -1 || *hlimit > 0xff) {
 713                                 err = -EINVAL;
 714                                 goto exit_f;
 715                         }
 716
 717                         break;
 718
 719                 case IPV6_TCLASS:
 720                     {
 721                         int tc;
 722
 723                         err = -EINVAL;
 724                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 725                                 goto exit_f;
 726                         }
 727
 728                         tc = *(int *)CMSG_DATA(cmsg);
 729                         if (tc < -1 || tc > 0xff)
 730                                 goto exit_f;
 731
 732                         err = 0;
 733                         *tclass = tc;
 734
 735                         break;
 736                     }
 737                 default:
 738                         LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
 739                                        cmsg->cmsg_type);
 740                         err = -EINVAL;
 741                         goto exit_f;
 742                 }
 743         }
 744
 745 exit_f:
 746         return err;
 747 }