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 #include <linux/slab.h>
  25
  26 #include <net/ipv6.h>
  27 #include <net/ndisc.h>
  28 #include <net/addrconf.h>
  29 #include <net/transp_v6.h>
  30 #include <net/ip6_route.h>
  31 #include <net/tcp_states.h>
  32
  33 #include <linux/errqueue.h>
  34 #include <asm/uaccess.h>
  35
  36 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
  37 {
  38         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
  39         struct inet_sock        *inet = inet_sk(sk);
  40         struct ipv6_pinfo       *np = inet6_sk(sk);
  41         struct in6_addr         *daddr, *final_p, final;
  42         struct dst_entry        *dst;
  43         struct flowi            fl;
  44         struct ip6_flowlabel    *flowlabel = NULL;
  45         struct ipv6_txoptions   *opt;
  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_v4mapped(inet->inet_daddr, &np->daddr);
 104
 105                 if (ipv6_addr_any(&np->saddr))
 106                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 107
 108                 if (ipv6_addr_any(&np->rcv_saddr))
 109                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 110                                                &np->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->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.mark = sk->sk_mark;
 151         fl.fl_ip_dport = inet->inet_dport;
 152         fl.fl_ip_sport = inet->inet_sport;
 153
 154         if (!fl.oif && (addr_type&IPV6_ADDR_MULTICAST))
 155                 fl.oif = np->mcast_oif;
 156
 157         security_sk_classify_flow(sk, &fl);
 158
 159         opt = flowlabel ? flowlabel->opt : np->opt;
 160         final_p = fl6_update_dst(&fl, opt, &final);
 161
 162         err = ip6_dst_lookup(sk, &dst, &fl);
 163         if (err)
 164                 goto out;
 165         if (final_p)
 166                 ipv6_addr_copy(&fl.fl6_dst, final_p);
 167
 168         err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);
 169         if (err < 0) {
 170                 if (err == -EREMOTE)
 171                         err = ip6_dst_blackhole(sk, &dst, &fl);
 172                 if (err < 0)
 173                         goto out;
 174         }
 175
 176         /* source address lookup done in ip6_dst_lookup */
 177
 178         if (ipv6_addr_any(&np->saddr))
 179                 ipv6_addr_copy(&np->saddr, &fl.fl6_src);
 180
 181         if (ipv6_addr_any(&np->rcv_saddr)) {
 182                 ipv6_addr_copy(&np->rcv_saddr, &fl.fl6_src);
 183                 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 184         }
 185
 186         ip6_dst_store(sk, dst,
 187                       ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
 188                       &np->daddr : NULL,
 189 #ifdef CONFIG_IPV6_SUBTREES
 190                       ipv6_addr_equal(&fl.fl6_src, &np->saddr) ?
 191                       &np->saddr :
 192 #endif
 193                       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                      __be16 port, u32 info, u8 *payload)
 203 {
 204         struct ipv6_pinfo *np  = inet6_sk(sk);
 205         struct icmp6hdr *icmph = icmp6_hdr(skb);
 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         skb->protocol = htons(ETH_P_IPV6);
 216
 217         serr = SKB_EXT_ERR(skb);
 218         serr->ee.ee_errno = err;
 219         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 220         serr->ee.ee_type = icmph->icmp6_type;
 221         serr->ee.ee_code = icmph->icmp6_code;
 222         serr->ee.ee_pad = 0;
 223         serr->ee.ee_info = info;
 224         serr->ee.ee_data = 0;
 225         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 226                                   skb_network_header(skb);
 227         serr->port = port;
 228
 229         __skb_pull(skb, payload - skb->data);
 230         skb_reset_transport_header(skb);
 231
 232         if (sock_queue_err_skb(sk, skb))
 233                 kfree_skb(skb);
 234 }
 235
 236 void ipv6_local_error(struct sock *sk, int err, struct flowi *fl, u32 info)
 237 {
 238         struct ipv6_pinfo *np = inet6_sk(sk);
 239         struct sock_exterr_skb *serr;
 240         struct ipv6hdr *iph;
 241         struct sk_buff *skb;
 242
 243         if (!np->recverr)
 244                 return;
 245
 246         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 247         if (!skb)
 248                 return;
 249
 250         skb->protocol = htons(ETH_P_IPV6);
 251
 252         skb_put(skb, sizeof(struct ipv6hdr));
 253         skb_reset_network_header(skb);
 254         iph = ipv6_hdr(skb);
 255         ipv6_addr_copy(&iph->daddr, &fl->fl6_dst);
 256
 257         serr = SKB_EXT_ERR(skb);
 258         serr->ee.ee_errno = err;
 259         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 260         serr->ee.ee_type = 0;
 261         serr->ee.ee_code = 0;
 262         serr->ee.ee_pad = 0;
 263         serr->ee.ee_info = info;
 264         serr->ee.ee_data = 0;
 265         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 266         serr->port = fl->fl_ip_dport;
 267
 268         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 269         skb_reset_transport_header(skb);
 270
 271         if (sock_queue_err_skb(sk, skb))
 272                 kfree_skb(skb);
 273 }
 274
 275 void ipv6_local_rxpmtu(struct sock *sk, struct flowi *fl, u32 mtu)
 276 {
 277         struct ipv6_pinfo *np = inet6_sk(sk);
 278         struct ipv6hdr *iph;
 279         struct sk_buff *skb;
 280         struct ip6_mtuinfo *mtu_info;
 281
 282         if (!np->rxopt.bits.rxpmtu)
 283                 return;
 284
 285         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 286         if (!skb)
 287                 return;
 288
 289         skb_put(skb, sizeof(struct ipv6hdr));
 290         skb_reset_network_header(skb);
 291         iph = ipv6_hdr(skb);
 292         ipv6_addr_copy(&iph->daddr, &fl->fl6_dst);
 293
 294         mtu_info = IP6CBMTU(skb);
 295         if (!mtu_info) {
 296                 kfree_skb(skb);
 297                 return;
 298         }
 299
 300         mtu_info->ip6m_mtu = mtu;
 301         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 302         mtu_info->ip6m_addr.sin6_port = 0;
 303         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 304         mtu_info->ip6m_addr.sin6_scope_id = fl->oif;
 305         ipv6_addr_copy(&mtu_info->ip6m_addr.sin6_addr, &ipv6_hdr(skb)->daddr);
 306
 307         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 308         skb_reset_transport_header(skb);
 309
 310         skb = xchg(&np->rxpmtu, skb);
 311         kfree_skb(skb);
 312 }
 313
 314 /*
 315  *      Handle MSG_ERRQUEUE
 316  */
 317 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
 318 {
 319         struct ipv6_pinfo *np = inet6_sk(sk);
 320         struct sock_exterr_skb *serr;
 321         struct sk_buff *skb, *skb2;
 322         struct sockaddr_in6 *sin;
 323         struct {
 324                 struct sock_extended_err ee;
 325                 struct sockaddr_in6      offender;
 326         } errhdr;
 327         int err;
 328         int copied;
 329
 330         err = -EAGAIN;
 331         skb = skb_dequeue(&sk->sk_error_queue);
 332         if (skb == NULL)
 333                 goto out;
 334
 335         copied = skb->len;
 336         if (copied > len) {
 337                 msg->msg_flags |= MSG_TRUNC;
 338                 copied = len;
 339         }
 340         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 341         if (err)
 342                 goto out_free_skb;
 343
 344         sock_recv_timestamp(msg, sk, skb);
 345
 346         serr = SKB_EXT_ERR(skb);
 347
 348         sin = (struct sockaddr_in6 *)msg->msg_name;
 349         if (sin) {
 350                 const unsigned char *nh = skb_network_header(skb);
 351                 sin->sin6_family = AF_INET6;
 352                 sin->sin6_flowinfo = 0;
 353                 sin->sin6_port = serr->port;
 354                 sin->sin6_scope_id = 0;
 355                 if (skb->protocol == htons(ETH_P_IPV6)) {
 356                         ipv6_addr_copy(&sin->sin6_addr,
 357                                   (struct in6_addr *)(nh + serr->addr_offset));
 358                         if (np->sndflow)
 359                                 sin->sin6_flowinfo =
 360                                         (*(__be32 *)(nh + serr->addr_offset - 24) &
 361                                          IPV6_FLOWINFO_MASK);
 362                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 363                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 364                 } else {
 365                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 366                                                &sin->sin6_addr);
 367                 }
 368         }
 369
 370         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 371         sin = &errhdr.offender;
 372         sin->sin6_family = AF_UNSPEC;
 373         if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
 374                 sin->sin6_family = AF_INET6;
 375                 sin->sin6_flowinfo = 0;
 376                 sin->sin6_scope_id = 0;
 377                 if (skb->protocol == htons(ETH_P_IPV6)) {
 378                         ipv6_addr_copy(&sin->sin6_addr, &ipv6_hdr(skb)->saddr);
 379                         if (np->rxopt.all)
 380                                 datagram_recv_ctl(sk, msg, skb);
 381                         if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 382                                 sin->sin6_scope_id = IP6CB(skb)->iif;
 383                 } else {
 384                         struct inet_sock *inet = inet_sk(sk);
 385
 386                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 387                                                &sin->sin6_addr);
 388                         if (inet->cmsg_flags)
 389                                 ip_cmsg_recv(msg, skb);
 390                 }
 391         }
 392
 393         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 394
 395         /* Now we could try to dump offended packet options */
 396
 397         msg->msg_flags |= MSG_ERRQUEUE;
 398         err = copied;
 399
 400         /* Reset and regenerate socket error */
 401         spin_lock_bh(&sk->sk_error_queue.lock);
 402         sk->sk_err = 0;
 403         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
 404                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
 405                 spin_unlock_bh(&sk->sk_error_queue.lock);
 406                 sk->sk_error_report(sk);
 407         } else {
 408                 spin_unlock_bh(&sk->sk_error_queue.lock);
 409         }
 410
 411 out_free_skb:
 412         kfree_skb(skb);
 413 out:
 414         return err;
 415 }
 416
 417 /*
 418  *      Handle IPV6_RECVPATHMTU
 419  */
 420 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len)
 421 {
 422         struct ipv6_pinfo *np = inet6_sk(sk);
 423         struct sk_buff *skb;
 424         struct sockaddr_in6 *sin;
 425         struct ip6_mtuinfo mtu_info;
 426         int err;
 427         int copied;
 428
 429         err = -EAGAIN;
 430         skb = xchg(&np->rxpmtu, NULL);
 431         if (skb == NULL)
 432                 goto out;
 433
 434         copied = skb->len;
 435         if (copied > len) {
 436                 msg->msg_flags |= MSG_TRUNC;
 437                 copied = len;
 438         }
 439         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 440         if (err)
 441                 goto out_free_skb;
 442
 443         sock_recv_timestamp(msg, sk, skb);
 444
 445         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 446
 447         sin = (struct sockaddr_in6 *)msg->msg_name;
 448         if (sin) {
 449                 sin->sin6_family = AF_INET6;
 450                 sin->sin6_flowinfo = 0;
 451                 sin->sin6_port = 0;
 452                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 453                 ipv6_addr_copy(&sin->sin6_addr, &mtu_info.ip6m_addr.sin6_addr);
 454         }
 455
 456         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 457
 458         err = copied;
 459
 460 out_free_skb:
 461         kfree_skb(skb);
 462 out:
 463         return err;
 464 }
 465
 466
 467 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
 468 {
 469         struct ipv6_pinfo *np = inet6_sk(sk);
 470         struct inet6_skb_parm *opt = IP6CB(skb);
 471         unsigned char *nh = skb_network_header(skb);
 472
 473         if (np->rxopt.bits.rxinfo) {
 474                 struct in6_pktinfo src_info;
 475
 476                 src_info.ipi6_ifindex = opt->iif;
 477                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 478                 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
 479         }
 480
 481         if (np->rxopt.bits.rxhlim) {
 482                 int hlim = ipv6_hdr(skb)->hop_limit;
 483                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 484         }
 485
 486         if (np->rxopt.bits.rxtclass) {
 487                 int tclass = (ntohl(*(__be32 *)ipv6_hdr(skb)) >> 20) & 0xff;
 488                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 489         }
 490
 491         if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
 492                 __be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
 493                 put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 494         }
 495
 496         /* HbH is allowed only once */
 497         if (np->rxopt.bits.hopopts && opt->hop) {
 498                 u8 *ptr = nh + opt->hop;
 499                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 500         }
 501
 502         if (opt->lastopt &&
 503             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 504                 /*
 505                  * Silly enough, but we need to reparse in order to
 506                  * report extension headers (except for HbH)
 507                  * in order.
 508                  *
 509                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 510                  * (and WILL NOT be) defined because
 511                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 512                  */
 513                 unsigned int off = sizeof(struct ipv6hdr);
 514                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 515
 516                 while (off <= opt->lastopt) {
 517                         unsigned len;
 518                         u8 *ptr = nh + off;
 519
 520                         switch(nexthdr) {
 521                         case IPPROTO_DSTOPTS:
 522                                 nexthdr = ptr[0];
 523                                 len = (ptr[1] + 1) << 3;
 524                                 if (np->rxopt.bits.dstopts)
 525                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 526                                 break;
 527                         case IPPROTO_ROUTING:
 528                                 nexthdr = ptr[0];
 529                                 len = (ptr[1] + 1) << 3;
 530                                 if (np->rxopt.bits.srcrt)
 531                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 532                                 break;
 533                         case IPPROTO_AH:
 534                                 nexthdr = ptr[0];
 535                                 len = (ptr[1] + 2) << 2;
 536                                 break;
 537                         default:
 538                                 nexthdr = ptr[0];
 539                                 len = (ptr[1] + 1) << 3;
 540                                 break;
 541                         }
 542
 543                         off += len;
 544                 }
 545         }
 546
 547         /* socket options in old style */
 548         if (np->rxopt.bits.rxoinfo) {
 549                 struct in6_pktinfo src_info;
 550
 551                 src_info.ipi6_ifindex = opt->iif;
 552                 ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
 553                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 554         }
 555         if (np->rxopt.bits.rxohlim) {
 556                 int hlim = ipv6_hdr(skb)->hop_limit;
 557                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 558         }
 559         if (np->rxopt.bits.ohopopts && opt->hop) {
 560                 u8 *ptr = nh + opt->hop;
 561                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 562         }
 563         if (np->rxopt.bits.odstopts && opt->dst0) {
 564                 u8 *ptr = nh + opt->dst0;
 565                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 566         }
 567         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 568                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 569                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 570         }
 571         if (np->rxopt.bits.odstopts && opt->dst1) {
 572                 u8 *ptr = nh + opt->dst1;
 573                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 574         }
 575         return 0;
 576 }
 577
 578 int datagram_send_ctl(struct net *net,
 579                       struct msghdr *msg, struct flowi *fl,
 580                       struct ipv6_txoptions *opt,
 581                       int *hlimit, int *tclass, int *dontfrag)
 582 {
 583         struct in6_pktinfo *src_info;
 584         struct cmsghdr *cmsg;
 585         struct ipv6_rt_hdr *rthdr;
 586         struct ipv6_opt_hdr *hdr;
 587         int len;
 588         int err = 0;
 589
 590         for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 591                 int addr_type;
 592
 593                 if (!CMSG_OK(msg, cmsg)) {
 594                         err = -EINVAL;
 595                         goto exit_f;
 596                 }
 597
 598                 if (cmsg->cmsg_level != SOL_IPV6)
 599                         continue;
 600
 601                 switch (cmsg->cmsg_type) {
 602                 case IPV6_PKTINFO:
 603                 case IPV6_2292PKTINFO:
 604                     {
 605                         struct net_device *dev = NULL;
 606
 607                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 608                                 err = -EINVAL;
 609                                 goto exit_f;
 610                         }
 611
 612                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 613
 614                         if (src_info->ipi6_ifindex) {
 615                                 if (fl->oif && src_info->ipi6_ifindex != fl->oif)
 616                                         return -EINVAL;
 617                                 fl->oif = src_info->ipi6_ifindex;
 618                         }
 619
 620                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 621
 622                         rcu_read_lock();
 623                         if (fl->oif) {
 624                                 dev = dev_get_by_index_rcu(net, fl->oif);
 625                                 if (!dev) {
 626                                         rcu_read_unlock();
 627                                         return -ENODEV;
 628                                 }
 629                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 630                                 rcu_read_unlock();
 631                                 return -EINVAL;
 632                         }
 633
 634                         if (addr_type != IPV6_ADDR_ANY) {
 635                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 636                                 if (!ipv6_chk_addr(net, &src_info->ipi6_addr,
 637                                                    strict ? dev : NULL, 0))
 638                                         err = -EINVAL;
 639                                 else
 640                                         ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
 641                         }
 642
 643                         rcu_read_unlock();
 644
 645                         if (err)
 646                                 goto exit_f;
 647
 648                         break;
 649                     }
 650
 651                 case IPV6_FLOWINFO:
 652                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 653                                 err = -EINVAL;
 654                                 goto exit_f;
 655                         }
 656
 657                         if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) {
 658                                 if ((fl->fl6_flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 659                                         err = -EINVAL;
 660                                         goto exit_f;
 661                                 }
 662                         }
 663                         fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 664                         break;
 665
 666                 case IPV6_2292HOPOPTS:
 667                 case IPV6_HOPOPTS:
 668                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 669                                 err = -EINVAL;
 670                                 goto exit_f;
 671                         }
 672
 673                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 674                         len = ((hdr->hdrlen + 1) << 3);
 675                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 676                                 err = -EINVAL;
 677                                 goto exit_f;
 678                         }
 679                         if (!capable(CAP_NET_RAW)) {
 680                                 err = -EPERM;
 681                                 goto exit_f;
 682                         }
 683                         opt->opt_nflen += len;
 684                         opt->hopopt = hdr;
 685                         break;
 686
 687                 case IPV6_2292DSTOPTS:
 688                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 689                                 err = -EINVAL;
 690                                 goto exit_f;
 691                         }
 692
 693                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 694                         len = ((hdr->hdrlen + 1) << 3);
 695                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 696                                 err = -EINVAL;
 697                                 goto exit_f;
 698                         }
 699                         if (!capable(CAP_NET_RAW)) {
 700                                 err = -EPERM;
 701                                 goto exit_f;
 702                         }
 703                         if (opt->dst1opt) {
 704                                 err = -EINVAL;
 705                                 goto exit_f;
 706                         }
 707                         opt->opt_flen += len;
 708                         opt->dst1opt = hdr;
 709                         break;
 710
 711                 case IPV6_DSTOPTS:
 712                 case IPV6_RTHDRDSTOPTS:
 713                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 714                                 err = -EINVAL;
 715                                 goto exit_f;
 716                         }
 717
 718                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 719                         len = ((hdr->hdrlen + 1) << 3);
 720                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 721                                 err = -EINVAL;
 722                                 goto exit_f;
 723                         }
 724                         if (!capable(CAP_NET_RAW)) {
 725                                 err = -EPERM;
 726                                 goto exit_f;
 727                         }
 728                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 729                                 opt->opt_flen += len;
 730                                 opt->dst1opt = hdr;
 731                         } else {
 732                                 opt->opt_nflen += len;
 733                                 opt->dst0opt = hdr;
 734                         }
 735                         break;
 736
 737                 case IPV6_2292RTHDR:
 738                 case IPV6_RTHDR:
 739                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 740                                 err = -EINVAL;
 741                                 goto exit_f;
 742                         }
 743
 744                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 745
 746                         switch (rthdr->type) {
 747 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 748                         case IPV6_SRCRT_TYPE_2:
 749                                 if (rthdr->hdrlen != 2 ||
 750                                     rthdr->segments_left != 1) {
 751                                         err = -EINVAL;
 752                                         goto exit_f;
 753                                 }
 754                                 break;
 755 #endif
 756                         default:
 757                                 err = -EINVAL;
 758                                 goto exit_f;
 759                         }
 760
 761                         len = ((rthdr->hdrlen + 1) << 3);
 762
 763                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 764                                 err = -EINVAL;
 765                                 goto exit_f;
 766                         }
 767
 768                         /* segments left must also match */
 769                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 770                                 err = -EINVAL;
 771                                 goto exit_f;
 772                         }
 773
 774                         opt->opt_nflen += len;
 775                         opt->srcrt = rthdr;
 776
 777                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 778                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 779
 780                                 opt->opt_nflen += dsthdrlen;
 781                                 opt->dst0opt = opt->dst1opt;
 782                                 opt->dst1opt = NULL;
 783                                 opt->opt_flen -= dsthdrlen;
 784                         }
 785
 786                         break;
 787
 788                 case IPV6_2292HOPLIMIT:
 789                 case IPV6_HOPLIMIT:
 790                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 791                                 err = -EINVAL;
 792                                 goto exit_f;
 793                         }
 794
 795                         *hlimit = *(int *)CMSG_DATA(cmsg);
 796                         if (*hlimit < -1 || *hlimit > 0xff) {
 797                                 err = -EINVAL;
 798                                 goto exit_f;
 799                         }
 800
 801                         break;
 802
 803                 case IPV6_TCLASS:
 804                     {
 805                         int tc;
 806
 807                         err = -EINVAL;
 808                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 809                                 goto exit_f;
 810                         }
 811
 812                         tc = *(int *)CMSG_DATA(cmsg);
 813                         if (tc < -1 || tc > 0xff)
 814                                 goto exit_f;
 815
 816                         err = 0;
 817                         *tclass = tc;
 818
 819                         break;
 820                     }
 821
 822                 case IPV6_DONTFRAG:
 823                     {
 824                         int df;
 825
 826                         err = -EINVAL;
 827                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 828                                 goto exit_f;
 829                         }
 830
 831                         df = *(int *)CMSG_DATA(cmsg);
 832                         if (df < 0 || df > 1)
 833                                 goto exit_f;
 834
 835                         err = 0;
 836                         *dontfrag = df;
 837
 838                         break;
 839                     }
 840                 default:
 841                         LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
 842                                        cmsg->cmsg_type);
 843                         err = -EINVAL;
 844                         goto exit_f;
 845                 }
 846         }
 847
 848 exit_f:
 849         return err;
 850 }