linux/net/ipv6/datagram.c
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   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#include <linux/export.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
  37static bool ipv6_mapped_addr_any(const struct in6_addr *a)
  38{
  39        return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
  40}
  41
  42int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
  43{
  44        struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
  45        struct inet_sock        *inet = inet_sk(sk);
  46        struct ipv6_pinfo       *np = inet6_sk(sk);
  47        struct in6_addr         *daddr, *final_p, final;
  48        struct dst_entry        *dst;
  49        struct flowi6           fl6;
  50        struct ip6_flowlabel    *flowlabel = NULL;
  51        struct ipv6_txoptions   *opt;
  52        int                     addr_type;
  53        int                     err;
  54
  55        if (usin->sin6_family == AF_INET) {
  56                if (__ipv6_only_sock(sk))
  57                        return -EAFNOSUPPORT;
  58                err = ip4_datagram_connect(sk, uaddr, addr_len);
  59                goto ipv4_connected;
  60        }
  61
  62        if (addr_len < SIN6_LEN_RFC2133)
  63                return -EINVAL;
  64
  65        if (usin->sin6_family != AF_INET6)
  66                return -EAFNOSUPPORT;
  67
  68        memset(&fl6, 0, sizeof(fl6));
  69        if (np->sndflow) {
  70                fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
  71                if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
  72                        flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
  73                        if (flowlabel == NULL)
  74                                return -EINVAL;
  75                        usin->sin6_addr = flowlabel->dst;
  76                }
  77        }
  78
  79        addr_type = ipv6_addr_type(&usin->sin6_addr);
  80
  81        if (addr_type == IPV6_ADDR_ANY) {
  82                /*
  83                 *      connect to self
  84                 */
  85                usin->sin6_addr.s6_addr[15] = 0x01;
  86        }
  87
  88        daddr = &usin->sin6_addr;
  89
  90        if (addr_type == IPV6_ADDR_MAPPED) {
  91                struct sockaddr_in sin;
  92
  93                if (__ipv6_only_sock(sk)) {
  94                        err = -ENETUNREACH;
  95                        goto out;
  96                }
  97                sin.sin_family = AF_INET;
  98                sin.sin_addr.s_addr = daddr->s6_addr32[3];
  99                sin.sin_port = usin->sin6_port;
 100
 101                err = ip4_datagram_connect(sk,
 102                                           (struct sockaddr *) &sin,
 103                                           sizeof(sin));
 104
 105ipv4_connected:
 106                if (err)
 107                        goto out;
 108
 109                ipv6_addr_set_v4mapped(inet->inet_daddr, &np->daddr);
 110
 111                if (ipv6_addr_any(&np->saddr) ||
 112                    ipv6_mapped_addr_any(&np->saddr))
 113                        ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 114
 115                if (ipv6_addr_any(&np->rcv_saddr) ||
 116                    ipv6_mapped_addr_any(&np->rcv_saddr)) {
 117                        ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 118                                               &np->rcv_saddr);
 119                        if (sk->sk_prot->rehash)
 120                                sk->sk_prot->rehash(sk);
 121                }
 122
 123                goto out;
 124        }
 125
 126        if (addr_type&IPV6_ADDR_LINKLOCAL) {
 127                if (addr_len >= sizeof(struct sockaddr_in6) &&
 128                    usin->sin6_scope_id) {
 129                        if (sk->sk_bound_dev_if &&
 130                            sk->sk_bound_dev_if != usin->sin6_scope_id) {
 131                                err = -EINVAL;
 132                                goto out;
 133                        }
 134                        sk->sk_bound_dev_if = usin->sin6_scope_id;
 135                }
 136
 137                if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 138                        sk->sk_bound_dev_if = np->mcast_oif;
 139
 140                /* Connect to link-local address requires an interface */
 141                if (!sk->sk_bound_dev_if) {
 142                        err = -EINVAL;
 143                        goto out;
 144                }
 145        }
 146
 147        np->daddr = *daddr;
 148        np->flow_label = fl6.flowlabel;
 149
 150        inet->inet_dport = usin->sin6_port;
 151
 152        /*
 153         *      Check for a route to destination an obtain the
 154         *      destination cache for it.
 155         */
 156
 157        fl6.flowi6_proto = sk->sk_protocol;
 158        fl6.daddr = np->daddr;
 159        fl6.saddr = np->saddr;
 160        fl6.flowi6_oif = sk->sk_bound_dev_if;
 161        fl6.flowi6_mark = sk->sk_mark;
 162        fl6.fl6_dport = inet->inet_dport;
 163        fl6.fl6_sport = inet->inet_sport;
 164
 165        if (!fl6.flowi6_oif && (addr_type&IPV6_ADDR_MULTICAST))
 166                fl6.flowi6_oif = np->mcast_oif;
 167
 168        security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 169
 170        opt = flowlabel ? flowlabel->opt : np->opt;
 171        final_p = fl6_update_dst(&fl6, opt, &final);
 172
 173        dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
 174        err = 0;
 175        if (IS_ERR(dst)) {
 176                err = PTR_ERR(dst);
 177                goto out;
 178        }
 179
 180        /* source address lookup done in ip6_dst_lookup */
 181
 182        if (ipv6_addr_any(&np->saddr))
 183                np->saddr = fl6.saddr;
 184
 185        if (ipv6_addr_any(&np->rcv_saddr)) {
 186                np->rcv_saddr = fl6.saddr;
 187                inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 188                if (sk->sk_prot->rehash)
 189                        sk->sk_prot->rehash(sk);
 190        }
 191
 192        ip6_dst_store(sk, dst,
 193                      ipv6_addr_equal(&fl6.daddr, &np->daddr) ?
 194                      &np->daddr : NULL,
 195#ifdef CONFIG_IPV6_SUBTREES
 196                      ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
 197                      &np->saddr :
 198#endif
 199                      NULL);
 200
 201        sk->sk_state = TCP_ESTABLISHED;
 202out:
 203        fl6_sock_release(flowlabel);
 204        return err;
 205}
 206EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 207
 208void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 209                     __be16 port, u32 info, u8 *payload)
 210{
 211        struct ipv6_pinfo *np  = inet6_sk(sk);
 212        struct icmp6hdr *icmph = icmp6_hdr(skb);
 213        struct sock_exterr_skb *serr;
 214
 215        if (!np->recverr)
 216                return;
 217
 218        skb = skb_clone(skb, GFP_ATOMIC);
 219        if (!skb)
 220                return;
 221
 222        skb->protocol = htons(ETH_P_IPV6);
 223
 224        serr = SKB_EXT_ERR(skb);
 225        serr->ee.ee_errno = err;
 226        serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 227        serr->ee.ee_type = icmph->icmp6_type;
 228        serr->ee.ee_code = icmph->icmp6_code;
 229        serr->ee.ee_pad = 0;
 230        serr->ee.ee_info = info;
 231        serr->ee.ee_data = 0;
 232        serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 233                                  skb_network_header(skb);
 234        serr->port = port;
 235
 236        __skb_pull(skb, payload - skb->data);
 237        skb_reset_transport_header(skb);
 238
 239        if (sock_queue_err_skb(sk, skb))
 240                kfree_skb(skb);
 241}
 242
 243void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 244{
 245        struct ipv6_pinfo *np = inet6_sk(sk);
 246        struct sock_exterr_skb *serr;
 247        struct ipv6hdr *iph;
 248        struct sk_buff *skb;
 249
 250        if (!np->recverr)
 251                return;
 252
 253        skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 254        if (!skb)
 255                return;
 256
 257        skb->protocol = htons(ETH_P_IPV6);
 258
 259        skb_put(skb, sizeof(struct ipv6hdr));
 260        skb_reset_network_header(skb);
 261        iph = ipv6_hdr(skb);
 262        iph->daddr = fl6->daddr;
 263
 264        serr = SKB_EXT_ERR(skb);
 265        serr->ee.ee_errno = err;
 266        serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 267        serr->ee.ee_type = 0;
 268        serr->ee.ee_code = 0;
 269        serr->ee.ee_pad = 0;
 270        serr->ee.ee_info = info;
 271        serr->ee.ee_data = 0;
 272        serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 273        serr->port = fl6->fl6_dport;
 274
 275        __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 276        skb_reset_transport_header(skb);
 277
 278        if (sock_queue_err_skb(sk, skb))
 279                kfree_skb(skb);
 280}
 281
 282void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 283{
 284        struct ipv6_pinfo *np = inet6_sk(sk);
 285        struct ipv6hdr *iph;
 286        struct sk_buff *skb;
 287        struct ip6_mtuinfo *mtu_info;
 288
 289        if (!np->rxopt.bits.rxpmtu)
 290                return;
 291
 292        skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 293        if (!skb)
 294                return;
 295
 296        skb_put(skb, sizeof(struct ipv6hdr));
 297        skb_reset_network_header(skb);
 298        iph = ipv6_hdr(skb);
 299        iph->daddr = fl6->daddr;
 300
 301        mtu_info = IP6CBMTU(skb);
 302
 303        mtu_info->ip6m_mtu = mtu;
 304        mtu_info->ip6m_addr.sin6_family = AF_INET6;
 305        mtu_info->ip6m_addr.sin6_port = 0;
 306        mtu_info->ip6m_addr.sin6_flowinfo = 0;
 307        mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 308        mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 309
 310        __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 311        skb_reset_transport_header(skb);
 312
 313        skb = xchg(&np->rxpmtu, skb);
 314        kfree_skb(skb);
 315}
 316
 317/*
 318 *      Handle MSG_ERRQUEUE
 319 */
 320int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
 321{
 322        struct ipv6_pinfo *np = inet6_sk(sk);
 323        struct sock_exterr_skb *serr;
 324        struct sk_buff *skb, *skb2;
 325        struct sockaddr_in6 *sin;
 326        struct {
 327                struct sock_extended_err ee;
 328                struct sockaddr_in6      offender;
 329        } errhdr;
 330        int err;
 331        int copied;
 332
 333        err = -EAGAIN;
 334        skb = skb_dequeue(&sk->sk_error_queue);
 335        if (skb == NULL)
 336                goto out;
 337
 338        copied = skb->len;
 339        if (copied > len) {
 340                msg->msg_flags |= MSG_TRUNC;
 341                copied = len;
 342        }
 343        err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 344        if (err)
 345                goto out_free_skb;
 346
 347        sock_recv_timestamp(msg, sk, skb);
 348
 349        serr = SKB_EXT_ERR(skb);
 350
 351        sin = (struct sockaddr_in6 *)msg->msg_name;
 352        if (sin) {
 353                const unsigned char *nh = skb_network_header(skb);
 354                sin->sin6_family = AF_INET6;
 355                sin->sin6_flowinfo = 0;
 356                sin->sin6_port = serr->port;
 357                sin->sin6_scope_id = 0;
 358                if (skb->protocol == htons(ETH_P_IPV6)) {
 359                        sin->sin6_addr =
 360                                *(struct in6_addr *)(nh + serr->addr_offset);
 361                        if (np->sndflow)
 362                                sin->sin6_flowinfo =
 363                                        (*(__be32 *)(nh + serr->addr_offset - 24) &
 364                                         IPV6_FLOWINFO_MASK);
 365                        if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 366                                sin->sin6_scope_id = IP6CB(skb)->iif;
 367                } else {
 368                        ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 369                                               &sin->sin6_addr);
 370                }
 371        }
 372
 373        memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 374        sin = &errhdr.offender;
 375        sin->sin6_family = AF_UNSPEC;
 376        if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
 377                sin->sin6_family = AF_INET6;
 378                sin->sin6_flowinfo = 0;
 379                sin->sin6_scope_id = 0;
 380                if (skb->protocol == htons(ETH_P_IPV6)) {
 381                        sin->sin6_addr = ipv6_hdr(skb)->saddr;
 382                        if (np->rxopt.all)
 383                                datagram_recv_ctl(sk, msg, skb);
 384                        if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 385                                sin->sin6_scope_id = IP6CB(skb)->iif;
 386                } else {
 387                        struct inet_sock *inet = inet_sk(sk);
 388
 389                        ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 390                                               &sin->sin6_addr);
 391                        if (inet->cmsg_flags)
 392                                ip_cmsg_recv(msg, skb);
 393                }
 394        }
 395
 396        put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 397
 398        /* Now we could try to dump offended packet options */
 399
 400        msg->msg_flags |= MSG_ERRQUEUE;
 401        err = copied;
 402
 403        /* Reset and regenerate socket error */
 404        spin_lock_bh(&sk->sk_error_queue.lock);
 405        sk->sk_err = 0;
 406        if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
 407                sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
 408                spin_unlock_bh(&sk->sk_error_queue.lock);
 409                sk->sk_error_report(sk);
 410        } else {
 411                spin_unlock_bh(&sk->sk_error_queue.lock);
 412        }
 413
 414out_free_skb:
 415        kfree_skb(skb);
 416out:
 417        return err;
 418}
 419EXPORT_SYMBOL_GPL(ipv6_recv_error);
 420
 421/*
 422 *      Handle IPV6_RECVPATHMTU
 423 */
 424int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len)
 425{
 426        struct ipv6_pinfo *np = inet6_sk(sk);
 427        struct sk_buff *skb;
 428        struct sockaddr_in6 *sin;
 429        struct ip6_mtuinfo mtu_info;
 430        int err;
 431        int copied;
 432
 433        err = -EAGAIN;
 434        skb = xchg(&np->rxpmtu, NULL);
 435        if (skb == NULL)
 436                goto out;
 437
 438        copied = skb->len;
 439        if (copied > len) {
 440                msg->msg_flags |= MSG_TRUNC;
 441                copied = len;
 442        }
 443        err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 444        if (err)
 445                goto out_free_skb;
 446
 447        sock_recv_timestamp(msg, sk, skb);
 448
 449        memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 450
 451        sin = (struct sockaddr_in6 *)msg->msg_name;
 452        if (sin) {
 453                sin->sin6_family = AF_INET6;
 454                sin->sin6_flowinfo = 0;
 455                sin->sin6_port = 0;
 456                sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 457                sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 458        }
 459
 460        put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 461
 462        err = copied;
 463
 464out_free_skb:
 465        kfree_skb(skb);
 466out:
 467        return err;
 468}
 469
 470
 471int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
 472{
 473        struct ipv6_pinfo *np = inet6_sk(sk);
 474        struct inet6_skb_parm *opt = IP6CB(skb);
 475        unsigned char *nh = skb_network_header(skb);
 476
 477        if (np->rxopt.bits.rxinfo) {
 478                struct in6_pktinfo src_info;
 479
 480                src_info.ipi6_ifindex = opt->iif;
 481                src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 482                put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
 483        }
 484
 485        if (np->rxopt.bits.rxhlim) {
 486                int hlim = ipv6_hdr(skb)->hop_limit;
 487                put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 488        }
 489
 490        if (np->rxopt.bits.rxtclass) {
 491                int tclass = ipv6_tclass(ipv6_hdr(skb));
 492                put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 493        }
 494
 495        if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
 496                __be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
 497                put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 498        }
 499
 500        /* HbH is allowed only once */
 501        if (np->rxopt.bits.hopopts && opt->hop) {
 502                u8 *ptr = nh + opt->hop;
 503                put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 504        }
 505
 506        if (opt->lastopt &&
 507            (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 508                /*
 509                 * Silly enough, but we need to reparse in order to
 510                 * report extension headers (except for HbH)
 511                 * in order.
 512                 *
 513                 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 514                 * (and WILL NOT be) defined because
 515                 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 516                 */
 517                unsigned int off = sizeof(struct ipv6hdr);
 518                u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 519
 520                while (off <= opt->lastopt) {
 521                        unsigned int len;
 522                        u8 *ptr = nh + off;
 523
 524                        switch (nexthdr) {
 525                        case IPPROTO_DSTOPTS:
 526                                nexthdr = ptr[0];
 527                                len = (ptr[1] + 1) << 3;
 528                                if (np->rxopt.bits.dstopts)
 529                                        put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 530                                break;
 531                        case IPPROTO_ROUTING:
 532                                nexthdr = ptr[0];
 533                                len = (ptr[1] + 1) << 3;
 534                                if (np->rxopt.bits.srcrt)
 535                                        put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 536                                break;
 537                        case IPPROTO_AH:
 538                                nexthdr = ptr[0];
 539                                len = (ptr[1] + 2) << 2;
 540                                break;
 541                        default:
 542                                nexthdr = ptr[0];
 543                                len = (ptr[1] + 1) << 3;
 544                                break;
 545                        }
 546
 547                        off += len;
 548                }
 549        }
 550
 551        /* socket options in old style */
 552        if (np->rxopt.bits.rxoinfo) {
 553                struct in6_pktinfo src_info;
 554
 555                src_info.ipi6_ifindex = opt->iif;
 556                src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 557                put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 558        }
 559        if (np->rxopt.bits.rxohlim) {
 560                int hlim = ipv6_hdr(skb)->hop_limit;
 561                put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 562        }
 563        if (np->rxopt.bits.ohopopts && opt->hop) {
 564                u8 *ptr = nh + opt->hop;
 565                put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 566        }
 567        if (np->rxopt.bits.odstopts && opt->dst0) {
 568                u8 *ptr = nh + opt->dst0;
 569                put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 570        }
 571        if (np->rxopt.bits.osrcrt && opt->srcrt) {
 572                struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 573                put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 574        }
 575        if (np->rxopt.bits.odstopts && opt->dst1) {
 576                u8 *ptr = nh + opt->dst1;
 577                put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 578        }
 579        if (np->rxopt.bits.rxorigdstaddr) {
 580                struct sockaddr_in6 sin6;
 581                __be16 *ports = (__be16 *) skb_transport_header(skb);
 582
 583                if (skb_transport_offset(skb) + 4 <= skb->len) {
 584                        /* All current transport protocols have the port numbers in the
 585                         * first four bytes of the transport header and this function is
 586                         * written with this assumption in mind.
 587                         */
 588
 589                        sin6.sin6_family = AF_INET6;
 590                        sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 591                        sin6.sin6_port = ports[1];
 592                        sin6.sin6_flowinfo = 0;
 593                        sin6.sin6_scope_id = 0;
 594
 595                        put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 596                }
 597        }
 598        return 0;
 599}
 600
 601int datagram_send_ctl(struct net *net, struct sock *sk,
 602                      struct msghdr *msg, struct flowi6 *fl6,
 603                      struct ipv6_txoptions *opt,
 604                      int *hlimit, int *tclass, int *dontfrag)
 605{
 606        struct in6_pktinfo *src_info;
 607        struct cmsghdr *cmsg;
 608        struct ipv6_rt_hdr *rthdr;
 609        struct ipv6_opt_hdr *hdr;
 610        int len;
 611        int err = 0;
 612
 613        for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 614                int addr_type;
 615
 616                if (!CMSG_OK(msg, cmsg)) {
 617                        err = -EINVAL;
 618                        goto exit_f;
 619                }
 620
 621                if (cmsg->cmsg_level != SOL_IPV6)
 622                        continue;
 623
 624                switch (cmsg->cmsg_type) {
 625                case IPV6_PKTINFO:
 626                case IPV6_2292PKTINFO:
 627                    {
 628                        struct net_device *dev = NULL;
 629
 630                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 631                                err = -EINVAL;
 632                                goto exit_f;
 633                        }
 634
 635                        src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 636
 637                        if (src_info->ipi6_ifindex) {
 638                                if (fl6->flowi6_oif &&
 639                                    src_info->ipi6_ifindex != fl6->flowi6_oif)
 640                                        return -EINVAL;
 641                                fl6->flowi6_oif = src_info->ipi6_ifindex;
 642                        }
 643
 644                        addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 645
 646                        rcu_read_lock();
 647                        if (fl6->flowi6_oif) {
 648                                dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 649                                if (!dev) {
 650                                        rcu_read_unlock();
 651                                        return -ENODEV;
 652                                }
 653                        } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 654                                rcu_read_unlock();
 655                                return -EINVAL;
 656                        }
 657
 658                        if (addr_type != IPV6_ADDR_ANY) {
 659                                int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 660                                if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 661                                    !ipv6_chk_addr(net, &src_info->ipi6_addr,
 662                                                   strict ? dev : NULL, 0))
 663                                        err = -EINVAL;
 664                                else
 665                                        fl6->saddr = src_info->ipi6_addr;
 666                        }
 667
 668                        rcu_read_unlock();
 669
 670                        if (err)
 671                                goto exit_f;
 672
 673                        break;
 674                    }
 675
 676                case IPV6_FLOWINFO:
 677                        if (cmsg->cmsg_len < CMSG_LEN(4)) {
 678                                err = -EINVAL;
 679                                goto exit_f;
 680                        }
 681
 682                        if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 683                                if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 684                                        err = -EINVAL;
 685                                        goto exit_f;
 686                                }
 687                        }
 688                        fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 689                        break;
 690
 691                case IPV6_2292HOPOPTS:
 692                case IPV6_HOPOPTS:
 693                        if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 694                                err = -EINVAL;
 695                                goto exit_f;
 696                        }
 697
 698                        hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 699                        len = ((hdr->hdrlen + 1) << 3);
 700                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 701                                err = -EINVAL;
 702                                goto exit_f;
 703                        }
 704                        if (!capable(CAP_NET_RAW)) {
 705                                err = -EPERM;
 706                                goto exit_f;
 707                        }
 708                        opt->opt_nflen += len;
 709                        opt->hopopt = hdr;
 710                        break;
 711
 712                case IPV6_2292DSTOPTS:
 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 (opt->dst1opt) {
 729                                err = -EINVAL;
 730                                goto exit_f;
 731                        }
 732                        opt->opt_flen += len;
 733                        opt->dst1opt = hdr;
 734                        break;
 735
 736                case IPV6_DSTOPTS:
 737                case IPV6_RTHDRDSTOPTS:
 738                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 739                                err = -EINVAL;
 740                                goto exit_f;
 741                        }
 742
 743                        hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 744                        len = ((hdr->hdrlen + 1) << 3);
 745                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 746                                err = -EINVAL;
 747                                goto exit_f;
 748                        }
 749                        if (!capable(CAP_NET_RAW)) {
 750                                err = -EPERM;
 751                                goto exit_f;
 752                        }
 753                        if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 754                                opt->opt_flen += len;
 755                                opt->dst1opt = hdr;
 756                        } else {
 757                                opt->opt_nflen += len;
 758                                opt->dst0opt = hdr;
 759                        }
 760                        break;
 761
 762                case IPV6_2292RTHDR:
 763                case IPV6_RTHDR:
 764                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 765                                err = -EINVAL;
 766                                goto exit_f;
 767                        }
 768
 769                        rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 770
 771                        switch (rthdr->type) {
 772#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
 773                        case IPV6_SRCRT_TYPE_2:
 774                                if (rthdr->hdrlen != 2 ||
 775                                    rthdr->segments_left != 1) {
 776                                        err = -EINVAL;
 777                                        goto exit_f;
 778                                }
 779                                break;
 780#endif
 781                        default:
 782                                err = -EINVAL;
 783                                goto exit_f;
 784                        }
 785
 786                        len = ((rthdr->hdrlen + 1) << 3);
 787
 788                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 789                                err = -EINVAL;
 790                                goto exit_f;
 791                        }
 792
 793                        /* segments left must also match */
 794                        if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 795                                err = -EINVAL;
 796                                goto exit_f;
 797                        }
 798
 799                        opt->opt_nflen += len;
 800                        opt->srcrt = rthdr;
 801
 802                        if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 803                                int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 804
 805                                opt->opt_nflen += dsthdrlen;
 806                                opt->dst0opt = opt->dst1opt;
 807                                opt->dst1opt = NULL;
 808                                opt->opt_flen -= dsthdrlen;
 809                        }
 810
 811                        break;
 812
 813                case IPV6_2292HOPLIMIT:
 814                case IPV6_HOPLIMIT:
 815                        if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 816                                err = -EINVAL;
 817                                goto exit_f;
 818                        }
 819
 820                        *hlimit = *(int *)CMSG_DATA(cmsg);
 821                        if (*hlimit < -1 || *hlimit > 0xff) {
 822                                err = -EINVAL;
 823                                goto exit_f;
 824                        }
 825
 826                        break;
 827
 828                case IPV6_TCLASS:
 829                    {
 830                        int tc;
 831
 832                        err = -EINVAL;
 833                        if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 834                                goto exit_f;
 835
 836                        tc = *(int *)CMSG_DATA(cmsg);
 837                        if (tc < -1 || tc > 0xff)
 838                                goto exit_f;
 839
 840                        err = 0;
 841                        *tclass = tc;
 842
 843                        break;
 844                    }
 845
 846                case IPV6_DONTFRAG:
 847                    {
 848                        int df;
 849
 850                        err = -EINVAL;
 851                        if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 852                                goto exit_f;
 853
 854                        df = *(int *)CMSG_DATA(cmsg);
 855                        if (df < 0 || df > 1)
 856                                goto exit_f;
 857
 858                        err = 0;
 859                        *dontfrag = df;
 860
 861                        break;
 862                    }
 863                default:
 864                        LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
 865                                       cmsg->cmsg_type);
 866                        err = -EINVAL;
 867                        goto exit_f;
 868                }
 869        }
 870
 871exit_f:
 872        return err;
 873}
 874EXPORT_SYMBOL_GPL(datagram_send_ctl);
 875
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