net/ipv6/datagram.c

   1 /*
   2  *      common UDP/RAW code
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      $Id: datagram.c,v 1.24 2002/02/01 22:01:04 davem Exp $
   9  *
  10  *      This program is free software; you can redistribute it and/or
  11  *      modify it under the terms of the GNU General Public License
  12  *      as published by the Free Software Foundation; either version
  13  *      2 of the License, or (at your option) any later version.
  14  */
  15
  16 #include <linux/errno.h>
  17 #include <linux/types.h>
  18 #include <linux/kernel.h>
  19 #include <linux/sched.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/socket.h>
  22 #include <linux/sockios.h>
  23 #include <linux/in6.h>
  24 #include <linux/ipv6.h>
  25 #include <linux/route.h>
  26
  27 #include <net/ipv6.h>
  28 #include <net/ndisc.h>
  29 #include <net/addrconf.h>
  30 #include <net/transp_v6.h>
  31 #include <net/ip6_route.h>
  32 #include <net/tcp_states.h>
  33
  34 #include <linux/errqueue.h>
  35 #include <asm/uaccess.h>
  36
  37 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
  38 {
  39         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
  40         struct inet_sock        *inet = inet_sk(sk);
  41         struct ipv6_pinfo       *np = inet6_sk(sk);
  42         struct in6_addr         *daddr, *final_p = NULL, final;
  43         struct dst_entry        *dst;
  44         struct flowi            fl;
  45         struct ip6_flowlabel    *flowlabel = NULL;
  46         int                     addr_type;
  47         int                     err;
  48
  49         if (usin->sin6_family == AF_INET) {
  50                 if (__ipv6_only_sock(sk))
  51                         return -EAFNOSUPPORT;
  52                 err = ip4_datagram_connect(sk, uaddr, addr_len);
  53                 goto ipv4_connected;
  54         }
  55
  56         if (addr_len < SIN6_LEN_RFC2133)
  57                 return -EINVAL;
  58
  59         if (usin->sin6_family != AF_INET6)
  60                 return -EAFNOSUPPORT;
  61
  62         memset(&fl, 0, sizeof(fl));
  63         if (np->sndflow) {
  64                 fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
  65                 if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
  66                         flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
  67                         if (flowlabel == NULL)
  68                                 return -EINVAL;
  69                         ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
  70                 }
  71         }
  72
  73         addr_type = ipv6_addr_type(&usin->sin6_addr);
  74
  75         if (addr_type == IPV6_ADDR_ANY) {
  76                 /*
  77                  *      connect to self
  78                  */
  79                 usin->sin6_addr.s6_addr[15] = 0x01;
  80         }
  81
  82         daddr = &usin->sin6_addr;
  83
  84         if (addr_type == IPV6_ADDR_MAPPED) {
  85                 struct sockaddr_in sin;
  86
  87                 if (__ipv6_only_sock(sk)) {
  88                         err = -ENETUNREACH;
  89                         goto out;
  90                 }
  91                 sin.sin_family = AF_INET;
  92                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
  93                 sin.sin_port = usin->sin6_port;
  94
  95                 err = ip4_datagram_connect(sk,
  96                                            (struct sockaddr*) &sin,
  97                                            sizeof(sin));
  98
  99 ipv4_connected:
 100                 if (err)
 101                         goto out;
 102
 103                 ipv6_addr_set(&np->daddr, 0, 0, htonl(0x0000ffff), inet->daddr);
 104
 105                 if (ipv6_addr_any(&np->saddr)) {
 106                         ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000ffff),
 107                                       inet->saddr);
 108                 }
 109
 110                 if (ipv6_addr_any(&np->rcv_saddr)) {
 111                         ipv6_addr_set(&np->rcv_saddr, 0, 0, htonl(0x0000ffff),
 112                                       inet->rcv_saddr);
 113                 }
 114                 goto out;
 115         }
 116
 117         if (addr_type&IPV6_ADDR_LINKLOCAL) {
 118                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 119                     usin->sin6_scope_id) {
 120                         if (sk->sk_bound_dev_if &&
 121                             sk->sk_bound_dev_if != usin->sin6_scope_id) {
 122                                 err = -EINVAL;
 123                                 goto out;
 124                         }
 125                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 126                         if (!sk->sk_bound_dev_if &&
 127                             (addr_type & IPV6_ADDR_MULTICAST))
 128                                 fl.oif = np->mcast_oif;
 129                 }
 130
 131                 /* Connect to link-local address requires an interface */
 132                 if (!sk->sk_bound_dev_if) {
 133                         err = -EINVAL;
 134                         goto out;
 135                 }
 136         }
 137
 138         ipv6_addr_copy(&np->daddr, daddr);
 139         np->flow_label = fl.fl6_flowlabel;
 140
 141         inet->dport = usin->sin6_port;
 142
 143         /*
 144          *      Check for a route to destination an obtain the
 145          *      destination cache for it.
 146          */
 147
 148         fl.proto = sk->sk_protocol;
 149         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 150         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 151         fl.oif = sk->sk_bound_dev_if;
 152         fl.fl_ip_dport = inet->dport;
 153         fl.fl_ip_sport = inet->sport;
 154
 155         if (!fl.oif && (addr_type&IPV6_ADDR_MULTICAST))
 156                 fl.oif = np->mcast_oif;
 157
 158         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, 0)) < 0)
 179                 goto out;
 180
 181         /* source address lookup done in ip6_dst_lookup */
 182
 183         if (ipv6_addr_any(&np->saddr))
 184                 ipv6_addr_copy(&np->saddr, &fl.fl6_src);
 185
 186         if (ipv6_addr_any(&np->rcv_saddr)) {
 187                 ipv6_addr_copy(&np->rcv_saddr, &fl.fl6_src);
 188                 inet->rcv_saddr = LOOPBACK4_IPV6;
 189         }
 190
 191         ip6_dst_store(sk, dst,
 192                       ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
 193                       &np->daddr : NULL);
 194
 195         sk->sk_state = TCP_ESTABLISHED;
 196 out:
 197         fl6_sock_release(flowlabel);
 198         return err;
 199 }
 200
 201 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 202                      u16 port, u32 info, u8 *payload)
 203 {
 204         struct ipv6_pinfo *np  = inet6_sk(sk);
 205         struct icmp6hdr *icmph = (struct icmp6hdr *)skb->h.raw;
 206         struct sock_exterr_skb *serr;
 207
 208         if (!np->recverr)
 209                 return;
 210
 211         skb = skb_clone(skb, GFP_ATOMIC);
 212         if (!skb)
 213                 return;
 214
 215         serr = SKB_EXT_ERR(skb);
 216         serr->ee.ee_errno = err;
 217         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 218         serr->ee.ee_type = icmph->icmp6_type;
 219         serr->ee.ee_code = icmph->icmp6_code;
 220         serr->ee.ee_pad = 0;
 221         serr->ee.ee_info = info;
 222         serr->ee.ee_data = 0;
 223         serr->addr_offset = (u8*)&(((struct ipv6hdr*)(icmph+1))->daddr) - skb->nh.raw;
 224         serr->port = port;
 225
 226         skb->h.raw = payload;
 227         __skb_pull(skb, payload - skb->data);
 228
 229         if (sock_queue_err_skb(sk, skb))
 230                 kfree_skb(skb);
 231 }
 232
 233 void ipv6_local_error(struct sock *sk, int err, struct flowi *fl, u32 info)
 234 {
 235         struct ipv6_pinfo *np = inet6_sk(sk);
 236         struct sock_exterr_skb *serr;
 237         struct ipv6hdr *iph;
 238         struct sk_buff *skb;
 239
 240         if (!np->recverr)
 241                 return;
 242
 243         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 244         if (!skb)
 245                 return;
 246
 247         iph = (struct ipv6hdr*)skb_put(skb, sizeof(struct ipv6hdr));
 248         skb->nh.ipv6h = iph;
 249         ipv6_addr_copy(&iph->daddr, &fl->fl6_dst);
 250
 251         serr = SKB_EXT_ERR(skb);
 252         serr->ee.ee_errno = err;
 253         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 254         serr->ee.ee_type = 0;
 255         serr->ee.ee_code = 0;
 256         serr->ee.ee_pad = 0;
 257         serr->ee.ee_info = info;
 258         serr->ee.ee_data = 0;
 259         serr->addr_offset = (u8*)&iph->daddr - skb->nh.raw;
 260         serr->port = fl->fl_ip_dport;
 261
 262         skb->h.raw = skb->tail;
 263         __skb_pull(skb, skb->tail - skb->data);
 264
 265         if (sock_queue_err_skb(sk, skb))
 266                 kfree_skb(skb);
 267 }
 268
 269 /*
 270  *      Handle MSG_ERRQUEUE
 271  */
 272 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
 273 {
 274         struct ipv6_pinfo *np = inet6_sk(sk);
 275         struct sock_exterr_skb *serr;
 276         struct sk_buff *skb, *skb2;
 277         struct sockaddr_in6 *sin;
 278         struct {
 279                 struct sock_extended_err ee;
 280                 struct sockaddr_in6      offender;
 281         } errhdr;
 282         int err;
 283         int copied;
 284
 285         err = -EAGAIN;
 286         skb = skb_dequeue(&sk->sk_error_queue);
 287         if (skb == NULL)
 288                 goto out;
 289
 290         copied = skb->len;
 291         if (copied > len) {
 292                 msg->msg_flags |= MSG_TRUNC;
 293                 copied = len;
 294         }
 295         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 296         if (err)
 297                 goto out_free_skb;
 298
 299         sock_recv_timestamp(msg, sk, skb);
 300
 301         serr = SKB_EXT_ERR(skb);
 302
 303         sin = (struct sockaddr_in6 *)msg->msg_name;
 304         if (sin) {
 305                 sin->sin6_family = AF_INET6;
 306                 sin->sin6_flowinfo = 0;
 307                 sin->sin6_port = serr->port;
 308                 sin->sin6_scope_id = 0;
 309                 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
 310                         ipv6_addr_copy(&sin->sin6_addr,
 311                           (struct in6_addr *)(skb->nh.raw + serr->addr_offset));
 312                         if (np->sndflow)
 313                                 sin->sin6_flowinfo = *(u32*)(skb->nh.raw + serr->addr_offset - 24) & IPV6_FLOWINFO_MASK;
 314                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 315                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 316                 } else {
 317                         ipv6_addr_set(&sin->sin6_addr, 0, 0,
 318                                       htonl(0xffff),
 319                                       *(u32*)(skb->nh.raw + serr->addr_offset));
 320                 }
 321         }
 322
 323         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 324         sin = &errhdr.offender;
 325         sin->sin6_family = AF_UNSPEC;
 326         if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
 327                 sin->sin6_family = AF_INET6;
 328                 sin->sin6_flowinfo = 0;
 329                 sin->sin6_scope_id = 0;
 330                 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
 331                         ipv6_addr_copy(&sin->sin6_addr, &skb->nh.ipv6h->saddr);
 332                         if (np->rxopt.all)
 333                                 datagram_recv_ctl(sk, msg, skb);
 334                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 335                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 336                 } else {
 337                         struct inet_sock *inet = inet_sk(sk);
 338
 339                         ipv6_addr_set(&sin->sin6_addr, 0, 0,
 340                                       htonl(0xffff),
 341                                       skb->nh.iph->saddr);
 342                         if (inet->cmsg_flags)
 343                                 ip_cmsg_recv(msg, skb);
 344                 }
 345         }
 346
 347         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 348
 349         /* Now we could try to dump offended packet options */
 350
 351         msg->msg_flags |= MSG_ERRQUEUE;
 352         err = copied;
 353
 354         /* Reset and regenerate socket error */
 355         spin_lock_bh(&sk->sk_error_queue.lock);
 356         sk->sk_err = 0;
 357         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
 358                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
 359                 spin_unlock_bh(&sk->sk_error_queue.lock);
 360                 sk->sk_error_report(sk);
 361         } else {
 362                 spin_unlock_bh(&sk->sk_error_queue.lock);
 363         }
 364
 365 out_free_skb:
 366         kfree_skb(skb);
 367 out:
 368         return err;
 369 }
 370
 371
 372
 373 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
 374 {
 375         struct ipv6_pinfo *np = inet6_sk(sk);
 376         struct inet6_skb_parm *opt = IP6CB(skb);
 377
 378         if (np->rxopt.bits.rxinfo) {
 379                 struct in6_pktinfo src_info;
 380
 381                 src_info.ipi6_ifindex = opt->iif;
 382                 ipv6_addr_copy(&src_info.ipi6_addr, &skb->nh.ipv6h->daddr);
 383                 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
 384         }
 385
 386         if (np->rxopt.bits.rxhlim) {
 387                 int hlim = skb->nh.ipv6h->hop_limit;
 388                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 389         }
 390
 391         if (np->rxopt.bits.rxtclass) {
 392                 int tclass = (ntohl(*(u32 *)skb->nh.ipv6h) >> 20) & 0xff;
 393                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 394         }
 395
 396         if (np->rxopt.bits.rxflow && (*(u32*)skb->nh.raw & IPV6_FLOWINFO_MASK)) {
 397                 u32 flowinfo = *(u32*)skb->nh.raw & IPV6_FLOWINFO_MASK;
 398                 put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 399         }
 400
 401         /* HbH is allowed only once */
 402         if (np->rxopt.bits.hopopts && opt->hop) {
 403                 u8 *ptr = skb->nh.raw + opt->hop;
 404                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 405         }
 406
 407         if (opt->lastopt &&
 408             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 409                 /*
 410                  * Silly enough, but we need to reparse in order to
 411                  * report extension headers (except for HbH)
 412                  * in order.
 413                  *
 414                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 415                  * (and WILL NOT be) defined because
 416                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 417                  */
 418                 unsigned int off = sizeof(struct ipv6hdr);
 419                 u8 nexthdr = skb->nh.ipv6h->nexthdr;
 420
 421                 while (off <= opt->lastopt) {
 422                         unsigned len;
 423                         u8 *ptr = skb->nh.raw + off;
 424
 425                         switch(nexthdr) {
 426                         case IPPROTO_DSTOPTS:
 427                                 nexthdr = ptr[0];
 428                                 len = (ptr[1] + 1) << 3;
 429                                 if (np->rxopt.bits.dstopts)
 430                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 431                                 break;
 432                         case IPPROTO_ROUTING:
 433                                 nexthdr = ptr[0];
 434                                 len = (ptr[1] + 1) << 3;
 435                                 if (np->rxopt.bits.srcrt)
 436                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 437                                 break;
 438                         case IPPROTO_AH:
 439                                 nexthdr = ptr[0];
 440                                 len = (ptr[1] + 1) << 2;
 441                                 break;
 442                         default:
 443                                 nexthdr = ptr[0];
 444                                 len = (ptr[1] + 1) << 3;
 445                                 break;
 446                         }
 447
 448                         off += len;
 449                 }
 450         }
 451
 452         /* socket options in old style */
 453         if (np->rxopt.bits.rxoinfo) {
 454                 struct in6_pktinfo src_info;
 455
 456                 src_info.ipi6_ifindex = opt->iif;
 457                 ipv6_addr_copy(&src_info.ipi6_addr, &skb->nh.ipv6h->daddr);
 458                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 459         }
 460         if (np->rxopt.bits.rxohlim) {
 461                 int hlim = skb->nh.ipv6h->hop_limit;
 462                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 463         }
 464         if (np->rxopt.bits.ohopopts && opt->hop) {
 465                 u8 *ptr = skb->nh.raw + opt->hop;
 466                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 467         }
 468         if (np->rxopt.bits.odstopts && opt->dst0) {
 469                 u8 *ptr = skb->nh.raw + opt->dst0;
 470                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 471         }
 472         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 473                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(skb->nh.raw + opt->srcrt);
 474                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 475         }
 476         if (np->rxopt.bits.odstopts && opt->dst1) {
 477                 u8 *ptr = skb->nh.raw + opt->dst1;
 478                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 479         }
 480         return 0;
 481 }
 482
 483 int datagram_send_ctl(struct msghdr *msg, struct flowi *fl,
 484                       struct ipv6_txoptions *opt,
 485                       int *hlimit, int *tclass)
 486 {
 487         struct in6_pktinfo *src_info;
 488         struct cmsghdr *cmsg;
 489         struct ipv6_rt_hdr *rthdr;
 490         struct ipv6_opt_hdr *hdr;
 491         int len;
 492         int err = 0;
 493
 494         for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 495                 int addr_type;
 496                 struct net_device *dev = NULL;
 497
 498                 if (!CMSG_OK(msg, cmsg)) {
 499                         err = -EINVAL;
 500                         goto exit_f;
 501                 }
 502
 503                 if (cmsg->cmsg_level != SOL_IPV6)
 504                         continue;
 505
 506                 switch (cmsg->cmsg_type) {
 507                 case IPV6_PKTINFO:
 508                 case IPV6_2292PKTINFO:
 509                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 510                                 err = -EINVAL;
 511                                 goto exit_f;
 512                         }
 513
 514                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 515
 516                         if (src_info->ipi6_ifindex) {
 517                                 if (fl->oif && src_info->ipi6_ifindex != fl->oif)
 518                                         return -EINVAL;
 519                                 fl->oif = src_info->ipi6_ifindex;
 520                         }
 521
 522                         addr_type = ipv6_addr_type(&src_info->ipi6_addr);
 523
 524                         if (addr_type == IPV6_ADDR_ANY)
 525                                 break;
 526
 527                         if (addr_type & IPV6_ADDR_LINKLOCAL) {
 528                                 if (!src_info->ipi6_ifindex)
 529                                         return -EINVAL;
 530                                 else {
 531                                         dev = dev_get_by_index(src_info->ipi6_ifindex);
 532                                         if (!dev)
 533                                                 return -ENODEV;
 534                                 }
 535                         }
 536                         if (!ipv6_chk_addr(&src_info->ipi6_addr, dev, 0)) {
 537                                 if (dev)
 538                                         dev_put(dev);
 539                                 err = -EINVAL;
 540                                 goto exit_f;
 541                         }
 542                         if (dev)
 543                                 dev_put(dev);
 544
 545                         ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
 546                         break;
 547
 548                 case IPV6_FLOWINFO:
 549                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 550                                 err = -EINVAL;
 551                                 goto exit_f;
 552                         }
 553
 554                         if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) {
 555                                 if ((fl->fl6_flowlabel^*(u32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 556                                         err = -EINVAL;
 557                                         goto exit_f;
 558                                 }
 559                         }
 560                         fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(u32 *)CMSG_DATA(cmsg);
 561                         break;
 562
 563                 case IPV6_2292HOPOPTS:
 564                 case IPV6_HOPOPTS:
 565                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 566                                 err = -EINVAL;
 567                                 goto exit_f;
 568                         }
 569
 570                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 571                         len = ((hdr->hdrlen + 1) << 3);
 572                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 573                                 err = -EINVAL;
 574                                 goto exit_f;
 575                         }
 576                         if (!capable(CAP_NET_RAW)) {
 577                                 err = -EPERM;
 578                                 goto exit_f;
 579                         }
 580                         opt->opt_nflen += len;
 581                         opt->hopopt = hdr;
 582                         break;
 583
 584                 case IPV6_2292DSTOPTS:
 585                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 586                                 err = -EINVAL;
 587                                 goto exit_f;
 588                         }
 589
 590                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 591                         len = ((hdr->hdrlen + 1) << 3);
 592                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 593                                 err = -EINVAL;
 594                                 goto exit_f;
 595                         }
 596                         if (!capable(CAP_NET_RAW)) {
 597                                 err = -EPERM;
 598                                 goto exit_f;
 599                         }
 600                         if (opt->dst1opt) {
 601                                 err = -EINVAL;
 602                                 goto exit_f;
 603                         }
 604                         opt->opt_flen += len;
 605                         opt->dst1opt = hdr;
 606                         break;
 607
 608                 case IPV6_DSTOPTS:
 609                 case IPV6_RTHDRDSTOPTS:
 610                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 611                                 err = -EINVAL;
 612                                 goto exit_f;
 613                         }
 614
 615                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 616                         len = ((hdr->hdrlen + 1) << 3);
 617                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 618                                 err = -EINVAL;
 619                                 goto exit_f;
 620                         }
 621                         if (!capable(CAP_NET_RAW)) {
 622                                 err = -EPERM;
 623                                 goto exit_f;
 624                         }
 625                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 626                                 opt->opt_flen += len;
 627                                 opt->dst1opt = hdr;
 628                         } else {
 629                                 opt->opt_nflen += len;
 630                                 opt->dst0opt = hdr;
 631                         }
 632                         break;
 633
 634                 case IPV6_2292RTHDR:
 635                 case IPV6_RTHDR:
 636                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 637                                 err = -EINVAL;
 638                                 goto exit_f;
 639                         }
 640
 641                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 642
 643                         /*
 644                          *      TYPE 0
 645                          */
 646                         if (rthdr->type) {
 647                                 err = -EINVAL;
 648                                 goto exit_f;
 649                         }
 650
 651                         len = ((rthdr->hdrlen + 1) << 3);
 652
 653                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 654                                 err = -EINVAL;
 655                                 goto exit_f;
 656                         }
 657
 658                         /* segments left must also match */
 659                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 660                                 err = -EINVAL;
 661                                 goto exit_f;
 662                         }
 663
 664                         opt->opt_nflen += len;
 665                         opt->srcrt = rthdr;
 666
 667                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 668                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 669
 670                                 opt->opt_nflen += dsthdrlen;
 671                                 opt->dst0opt = opt->dst1opt;
 672                                 opt->dst1opt = NULL;
 673                                 opt->opt_flen -= dsthdrlen;
 674                         }
 675
 676                         break;
 677
 678                 case IPV6_2292HOPLIMIT:
 679                 case IPV6_HOPLIMIT:
 680                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 681                                 err = -EINVAL;
 682                                 goto exit_f;
 683                         }
 684
 685                         *hlimit = *(int *)CMSG_DATA(cmsg);
 686                         break;
 687
 688                 case IPV6_TCLASS:
 689                     {
 690                         int tc;
 691
 692                         err = -EINVAL;
 693                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 694                                 goto exit_f;
 695                         }
 696
 697                         tc = *(int *)CMSG_DATA(cmsg);
 698                         if (tc < 0 || tc > 0xff)
 699                                 goto exit_f;
 700
 701                         err = 0;
 702                         *tclass = tc;
 703
 704                         break;
 705                     }
 706                 default:
 707                         LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
 708                                        cmsg->cmsg_type);
 709                         err = -EINVAL;
 710                         break;
 711                 };
 712         }
 713
 714 exit_f:
 715         return err;
 716 }