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#include <net/dsfield.h>
  34
  35#include <linux/errqueue.h>
  36#include <asm/uaccess.h>
  37
  38static bool ipv6_mapped_addr_any(const struct in6_addr *a)
  39{
  40        return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
  41}
  42
  43int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
  44{
  45        struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
  46        struct inet_sock        *inet = inet_sk(sk);
  47        struct ipv6_pinfo       *np = inet6_sk(sk);
  48        struct in6_addr         *daddr, *final_p, final;
  49        struct dst_entry        *dst;
  50        struct flowi6           fl6;
  51        struct ip6_flowlabel    *flowlabel = NULL;
  52        struct ipv6_txoptions   *opt;
  53        int                     addr_type;
  54        int                     err;
  55
  56        if (usin->sin6_family == AF_INET) {
  57                if (__ipv6_only_sock(sk))
  58                        return -EAFNOSUPPORT;
  59                err = ip4_datagram_connect(sk, uaddr, addr_len);
  60                goto ipv4_connected;
  61        }
  62
  63        if (addr_len < SIN6_LEN_RFC2133)
  64                return -EINVAL;
  65
  66        if (usin->sin6_family != AF_INET6)
  67                return -EAFNOSUPPORT;
  68
  69        memset(&fl6, 0, sizeof(fl6));
  70        if (np->sndflow) {
  71                fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
  72                if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
  73                        flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
  74                        if (flowlabel == NULL)
  75                                return -EINVAL;
  76                        usin->sin6_addr = flowlabel->dst;
  77                }
  78        }
  79
  80        addr_type = ipv6_addr_type(&usin->sin6_addr);
  81
  82        if (addr_type == IPV6_ADDR_ANY) {
  83                /*
  84                 *      connect to self
  85                 */
  86                usin->sin6_addr.s6_addr[15] = 0x01;
  87        }
  88
  89        daddr = &usin->sin6_addr;
  90
  91        if (addr_type == IPV6_ADDR_MAPPED) {
  92                struct sockaddr_in sin;
  93
  94                if (__ipv6_only_sock(sk)) {
  95                        err = -ENETUNREACH;
  96                        goto out;
  97                }
  98                sin.sin_family = AF_INET;
  99                sin.sin_addr.s_addr = daddr->s6_addr32[3];
 100                sin.sin_port = usin->sin6_port;
 101
 102                err = ip4_datagram_connect(sk,
 103                                           (struct sockaddr *) &sin,
 104                                           sizeof(sin));
 105
 106ipv4_connected:
 107                if (err)
 108                        goto out;
 109
 110                ipv6_addr_set_v4mapped(inet->inet_daddr, &np->daddr);
 111
 112                if (ipv6_addr_any(&np->saddr) ||
 113                    ipv6_mapped_addr_any(&np->saddr))
 114                        ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 115
 116                if (ipv6_addr_any(&np->rcv_saddr) ||
 117                    ipv6_mapped_addr_any(&np->rcv_saddr)) {
 118                        ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 119                                               &np->rcv_saddr);
 120                        if (sk->sk_prot->rehash)
 121                                sk->sk_prot->rehash(sk);
 122                }
 123
 124                goto out;
 125        }
 126
 127        if (__ipv6_addr_needs_scope_id(addr_type)) {
 128                if (addr_len >= sizeof(struct sockaddr_in6) &&
 129                    usin->sin6_scope_id) {
 130                        if (sk->sk_bound_dev_if &&
 131                            sk->sk_bound_dev_if != usin->sin6_scope_id) {
 132                                err = -EINVAL;
 133                                goto out;
 134                        }
 135                        sk->sk_bound_dev_if = usin->sin6_scope_id;
 136                }
 137
 138                if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 139                        sk->sk_bound_dev_if = np->mcast_oif;
 140
 141                /* Connect to link-local address requires an interface */
 142                if (!sk->sk_bound_dev_if) {
 143                        err = -EINVAL;
 144                        goto out;
 145                }
 146        }
 147
 148        np->daddr = *daddr;
 149        np->flow_label = fl6.flowlabel;
 150
 151        inet->inet_dport = usin->sin6_port;
 152
 153        /*
 154         *      Check for a route to destination an obtain the
 155         *      destination cache for it.
 156         */
 157
 158        fl6.flowi6_proto = sk->sk_protocol;
 159        fl6.daddr = np->daddr;
 160        fl6.saddr = np->saddr;
 161        fl6.flowi6_oif = sk->sk_bound_dev_if;
 162        fl6.flowi6_mark = sk->sk_mark;
 163        fl6.fl6_dport = inet->inet_dport;
 164        fl6.fl6_sport = inet->inet_sport;
 165
 166        if (!fl6.flowi6_oif && (addr_type&IPV6_ADDR_MULTICAST))
 167                fl6.flowi6_oif = np->mcast_oif;
 168
 169        security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 170
 171        opt = flowlabel ? flowlabel->opt : np->opt;
 172        final_p = fl6_update_dst(&fl6, opt, &final);
 173
 174        dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
 175        err = 0;
 176        if (IS_ERR(dst)) {
 177                err = PTR_ERR(dst);
 178                goto out;
 179        }
 180
 181        /* source address lookup done in ip6_dst_lookup */
 182
 183        if (ipv6_addr_any(&np->saddr))
 184                np->saddr = fl6.saddr;
 185
 186        if (ipv6_addr_any(&np->rcv_saddr)) {
 187                np->rcv_saddr = fl6.saddr;
 188                inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 189                if (sk->sk_prot->rehash)
 190                        sk->sk_prot->rehash(sk);
 191        }
 192
 193        ip6_dst_store(sk, dst,
 194                      ipv6_addr_equal(&fl6.daddr, &np->daddr) ?
 195                      &np->daddr : NULL,
 196#ifdef CONFIG_IPV6_SUBTREES
 197                      ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
 198                      &np->saddr :
 199#endif
 200                      NULL);
 201
 202        sk->sk_state = TCP_ESTABLISHED;
 203out:
 204        fl6_sock_release(flowlabel);
 205        return err;
 206}
 207EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 208
 209void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 210                     __be16 port, u32 info, u8 *payload)
 211{
 212        struct ipv6_pinfo *np  = inet6_sk(sk);
 213        struct icmp6hdr *icmph = icmp6_hdr(skb);
 214        struct sock_exterr_skb *serr;
 215
 216        if (!np->recverr)
 217                return;
 218
 219        skb = skb_clone(skb, GFP_ATOMIC);
 220        if (!skb)
 221                return;
 222
 223        skb->protocol = htons(ETH_P_IPV6);
 224
 225        serr = SKB_EXT_ERR(skb);
 226        serr->ee.ee_errno = err;
 227        serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 228        serr->ee.ee_type = icmph->icmp6_type;
 229        serr->ee.ee_code = icmph->icmp6_code;
 230        serr->ee.ee_pad = 0;
 231        serr->ee.ee_info = info;
 232        serr->ee.ee_data = 0;
 233        serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 234                                  skb_network_header(skb);
 235        serr->port = port;
 236
 237        __skb_pull(skb, payload - skb->data);
 238        skb_reset_transport_header(skb);
 239
 240        if (sock_queue_err_skb(sk, skb))
 241                kfree_skb(skb);
 242}
 243
 244void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 245{
 246        struct ipv6_pinfo *np = inet6_sk(sk);
 247        struct sock_exterr_skb *serr;
 248        struct ipv6hdr *iph;
 249        struct sk_buff *skb;
 250
 251        if (!np->recverr)
 252                return;
 253
 254        skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 255        if (!skb)
 256                return;
 257
 258        skb->protocol = htons(ETH_P_IPV6);
 259
 260        skb_put(skb, sizeof(struct ipv6hdr));
 261        skb_reset_network_header(skb);
 262        iph = ipv6_hdr(skb);
 263        iph->daddr = fl6->daddr;
 264
 265        serr = SKB_EXT_ERR(skb);
 266        serr->ee.ee_errno = err;
 267        serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 268        serr->ee.ee_type = 0;
 269        serr->ee.ee_code = 0;
 270        serr->ee.ee_pad = 0;
 271        serr->ee.ee_info = info;
 272        serr->ee.ee_data = 0;
 273        serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 274        serr->port = fl6->fl6_dport;
 275
 276        __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 277        skb_reset_transport_header(skb);
 278
 279        if (sock_queue_err_skb(sk, skb))
 280                kfree_skb(skb);
 281}
 282
 283void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 284{
 285        struct ipv6_pinfo *np = inet6_sk(sk);
 286        struct ipv6hdr *iph;
 287        struct sk_buff *skb;
 288        struct ip6_mtuinfo *mtu_info;
 289
 290        if (!np->rxopt.bits.rxpmtu)
 291                return;
 292
 293        skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 294        if (!skb)
 295                return;
 296
 297        skb_put(skb, sizeof(struct ipv6hdr));
 298        skb_reset_network_header(skb);
 299        iph = ipv6_hdr(skb);
 300        iph->daddr = fl6->daddr;
 301
 302        mtu_info = IP6CBMTU(skb);
 303
 304        mtu_info->ip6m_mtu = mtu;
 305        mtu_info->ip6m_addr.sin6_family = AF_INET6;
 306        mtu_info->ip6m_addr.sin6_port = 0;
 307        mtu_info->ip6m_addr.sin6_flowinfo = 0;
 308        mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 309        mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 310
 311        __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 312        skb_reset_transport_header(skb);
 313
 314        skb = xchg(&np->rxpmtu, skb);
 315        kfree_skb(skb);
 316}
 317
 318/*
 319 *      Handle MSG_ERRQUEUE
 320 */
 321int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
 322{
 323        struct ipv6_pinfo *np = inet6_sk(sk);
 324        struct sock_exterr_skb *serr;
 325        struct sk_buff *skb, *skb2;
 326        struct sockaddr_in6 *sin;
 327        struct {
 328                struct sock_extended_err ee;
 329                struct sockaddr_in6      offender;
 330        } errhdr;
 331        int err;
 332        int copied;
 333
 334        err = -EAGAIN;
 335        skb = skb_dequeue(&sk->sk_error_queue);
 336        if (skb == NULL)
 337                goto out;
 338
 339        copied = skb->len;
 340        if (copied > len) {
 341                msg->msg_flags |= MSG_TRUNC;
 342                copied = len;
 343        }
 344        err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 345        if (err)
 346                goto out_free_skb;
 347
 348        sock_recv_timestamp(msg, sk, skb);
 349
 350        serr = SKB_EXT_ERR(skb);
 351
 352        sin = (struct sockaddr_in6 *)msg->msg_name;
 353        if (sin) {
 354                const unsigned char *nh = skb_network_header(skb);
 355                sin->sin6_family = AF_INET6;
 356                sin->sin6_flowinfo = 0;
 357                sin->sin6_port = serr->port;
 358                if (skb->protocol == htons(ETH_P_IPV6)) {
 359                        const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 360                                                                  struct ipv6hdr, daddr);
 361                        sin->sin6_addr = ip6h->daddr;
 362                        if (np->sndflow)
 363                                sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 364                        sin->sin6_scope_id =
 365                                ipv6_iface_scope_id(&sin->sin6_addr,
 366                                                    IP6CB(skb)->iif);
 367                } else {
 368                        ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 369                                               &sin->sin6_addr);
 370                        sin->sin6_scope_id = 0;
 371                }
 372        }
 373
 374        memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 375        sin = &errhdr.offender;
 376        sin->sin6_family = AF_UNSPEC;
 377        if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
 378                sin->sin6_family = AF_INET6;
 379                sin->sin6_flowinfo = 0;
 380                if (skb->protocol == htons(ETH_P_IPV6)) {
 381                        sin->sin6_addr = ipv6_hdr(skb)->saddr;
 382                        if (np->rxopt.all)
 383                                ip6_datagram_recv_ctl(sk, msg, skb);
 384                        sin->sin6_scope_id =
 385                                ipv6_iface_scope_id(&sin->sin6_addr,
 386                                                    IP6CB(skb)->iif);
 387                } else {
 388                        struct inet_sock *inet = inet_sk(sk);
 389
 390                        ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 391                                               &sin->sin6_addr);
 392                        sin->sin6_scope_id = 0;
 393                        if (inet->cmsg_flags)
 394                                ip_cmsg_recv(msg, skb);
 395                }
 396        }
 397
 398        put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 399
 400        /* Now we could try to dump offended packet options */
 401
 402        msg->msg_flags |= MSG_ERRQUEUE;
 403        err = copied;
 404
 405        /* Reset and regenerate socket error */
 406        spin_lock_bh(&sk->sk_error_queue.lock);
 407        sk->sk_err = 0;
 408        if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
 409                sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
 410                spin_unlock_bh(&sk->sk_error_queue.lock);
 411                sk->sk_error_report(sk);
 412        } else {
 413                spin_unlock_bh(&sk->sk_error_queue.lock);
 414        }
 415
 416out_free_skb:
 417        kfree_skb(skb);
 418out:
 419        return err;
 420}
 421EXPORT_SYMBOL_GPL(ipv6_recv_error);
 422
 423/*
 424 *      Handle IPV6_RECVPATHMTU
 425 */
 426int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len)
 427{
 428        struct ipv6_pinfo *np = inet6_sk(sk);
 429        struct sk_buff *skb;
 430        struct sockaddr_in6 *sin;
 431        struct ip6_mtuinfo mtu_info;
 432        int err;
 433        int copied;
 434
 435        err = -EAGAIN;
 436        skb = xchg(&np->rxpmtu, NULL);
 437        if (skb == NULL)
 438                goto out;
 439
 440        copied = skb->len;
 441        if (copied > len) {
 442                msg->msg_flags |= MSG_TRUNC;
 443                copied = len;
 444        }
 445        err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 446        if (err)
 447                goto out_free_skb;
 448
 449        sock_recv_timestamp(msg, sk, skb);
 450
 451        memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 452
 453        sin = (struct sockaddr_in6 *)msg->msg_name;
 454        if (sin) {
 455                sin->sin6_family = AF_INET6;
 456                sin->sin6_flowinfo = 0;
 457                sin->sin6_port = 0;
 458                sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 459                sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 460        }
 461
 462        put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 463
 464        err = copied;
 465
 466out_free_skb:
 467        kfree_skb(skb);
 468out:
 469        return err;
 470}
 471
 472
 473int ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 474                          struct sk_buff *skb)
 475{
 476        struct ipv6_pinfo *np = inet6_sk(sk);
 477        struct inet6_skb_parm *opt = IP6CB(skb);
 478        unsigned char *nh = skb_network_header(skb);
 479
 480        if (np->rxopt.bits.rxinfo) {
 481                struct in6_pktinfo src_info;
 482
 483                src_info.ipi6_ifindex = opt->iif;
 484                src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 485                put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
 486        }
 487
 488        if (np->rxopt.bits.rxhlim) {
 489                int hlim = ipv6_hdr(skb)->hop_limit;
 490                put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 491        }
 492
 493        if (np->rxopt.bits.rxtclass) {
 494                int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 495                put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 496        }
 497
 498        if (np->rxopt.bits.rxflow) {
 499                __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 500                if (flowinfo)
 501                        put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 502        }
 503
 504        /* HbH is allowed only once */
 505        if (np->rxopt.bits.hopopts && opt->hop) {
 506                u8 *ptr = nh + opt->hop;
 507                put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 508        }
 509
 510        if (opt->lastopt &&
 511            (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 512                /*
 513                 * Silly enough, but we need to reparse in order to
 514                 * report extension headers (except for HbH)
 515                 * in order.
 516                 *
 517                 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 518                 * (and WILL NOT be) defined because
 519                 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 520                 */
 521                unsigned int off = sizeof(struct ipv6hdr);
 522                u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 523
 524                while (off <= opt->lastopt) {
 525                        unsigned int len;
 526                        u8 *ptr = nh + off;
 527
 528                        switch (nexthdr) {
 529                        case IPPROTO_DSTOPTS:
 530                                nexthdr = ptr[0];
 531                                len = (ptr[1] + 1) << 3;
 532                                if (np->rxopt.bits.dstopts)
 533                                        put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 534                                break;
 535                        case IPPROTO_ROUTING:
 536                                nexthdr = ptr[0];
 537                                len = (ptr[1] + 1) << 3;
 538                                if (np->rxopt.bits.srcrt)
 539                                        put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 540                                break;
 541                        case IPPROTO_AH:
 542                                nexthdr = ptr[0];
 543                                len = (ptr[1] + 2) << 2;
 544                                break;
 545                        default:
 546                                nexthdr = ptr[0];
 547                                len = (ptr[1] + 1) << 3;
 548                                break;
 549                        }
 550
 551                        off += len;
 552                }
 553        }
 554
 555        /* socket options in old style */
 556        if (np->rxopt.bits.rxoinfo) {
 557                struct in6_pktinfo src_info;
 558
 559                src_info.ipi6_ifindex = opt->iif;
 560                src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 561                put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 562        }
 563        if (np->rxopt.bits.rxohlim) {
 564                int hlim = ipv6_hdr(skb)->hop_limit;
 565                put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 566        }
 567        if (np->rxopt.bits.ohopopts && opt->hop) {
 568                u8 *ptr = nh + opt->hop;
 569                put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 570        }
 571        if (np->rxopt.bits.odstopts && opt->dst0) {
 572                u8 *ptr = nh + opt->dst0;
 573                put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 574        }
 575        if (np->rxopt.bits.osrcrt && opt->srcrt) {
 576                struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 577                put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 578        }
 579        if (np->rxopt.bits.odstopts && opt->dst1) {
 580                u8 *ptr = nh + opt->dst1;
 581                put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 582        }
 583        if (np->rxopt.bits.rxorigdstaddr) {
 584                struct sockaddr_in6 sin6;
 585                __be16 *ports = (__be16 *) skb_transport_header(skb);
 586
 587                if (skb_transport_offset(skb) + 4 <= skb->len) {
 588                        /* All current transport protocols have the port numbers in the
 589                         * first four bytes of the transport header and this function is
 590                         * written with this assumption in mind.
 591                         */
 592
 593                        sin6.sin6_family = AF_INET6;
 594                        sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 595                        sin6.sin6_port = ports[1];
 596                        sin6.sin6_flowinfo = 0;
 597                        sin6.sin6_scope_id =
 598                                ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 599                                                    opt->iif);
 600
 601                        put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 602                }
 603        }
 604        return 0;
 605}
 606EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 607
 608int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 609                          struct msghdr *msg, struct flowi6 *fl6,
 610                          struct ipv6_txoptions *opt,
 611                          int *hlimit, int *tclass, int *dontfrag)
 612{
 613        struct in6_pktinfo *src_info;
 614        struct cmsghdr *cmsg;
 615        struct ipv6_rt_hdr *rthdr;
 616        struct ipv6_opt_hdr *hdr;
 617        int len;
 618        int err = 0;
 619
 620        for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 621                int addr_type;
 622
 623                if (!CMSG_OK(msg, cmsg)) {
 624                        err = -EINVAL;
 625                        goto exit_f;
 626                }
 627
 628                if (cmsg->cmsg_level != SOL_IPV6)
 629                        continue;
 630
 631                switch (cmsg->cmsg_type) {
 632                case IPV6_PKTINFO:
 633                case IPV6_2292PKTINFO:
 634                    {
 635                        struct net_device *dev = NULL;
 636
 637                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 638                                err = -EINVAL;
 639                                goto exit_f;
 640                        }
 641
 642                        src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 643
 644                        if (src_info->ipi6_ifindex) {
 645                                if (fl6->flowi6_oif &&
 646                                    src_info->ipi6_ifindex != fl6->flowi6_oif)
 647                                        return -EINVAL;
 648                                fl6->flowi6_oif = src_info->ipi6_ifindex;
 649                        }
 650
 651                        addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 652
 653                        rcu_read_lock();
 654                        if (fl6->flowi6_oif) {
 655                                dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 656                                if (!dev) {
 657                                        rcu_read_unlock();
 658                                        return -ENODEV;
 659                                }
 660                        } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 661                                rcu_read_unlock();
 662                                return -EINVAL;
 663                        }
 664
 665                        if (addr_type != IPV6_ADDR_ANY) {
 666                                int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 667                                if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 668                                    !ipv6_chk_addr(net, &src_info->ipi6_addr,
 669                                                   strict ? dev : NULL, 0))
 670                                        err = -EINVAL;
 671                                else
 672                                        fl6->saddr = src_info->ipi6_addr;
 673                        }
 674
 675                        rcu_read_unlock();
 676
 677                        if (err)
 678                                goto exit_f;
 679
 680                        break;
 681                    }
 682
 683                case IPV6_FLOWINFO:
 684                        if (cmsg->cmsg_len < CMSG_LEN(4)) {
 685                                err = -EINVAL;
 686                                goto exit_f;
 687                        }
 688
 689                        if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 690                                if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 691                                        err = -EINVAL;
 692                                        goto exit_f;
 693                                }
 694                        }
 695                        fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 696                        break;
 697
 698                case IPV6_2292HOPOPTS:
 699                case IPV6_HOPOPTS:
 700                        if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 701                                err = -EINVAL;
 702                                goto exit_f;
 703                        }
 704
 705                        hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 706                        len = ((hdr->hdrlen + 1) << 3);
 707                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 708                                err = -EINVAL;
 709                                goto exit_f;
 710                        }
 711                        if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 712                                err = -EPERM;
 713                                goto exit_f;
 714                        }
 715                        opt->opt_nflen += len;
 716                        opt->hopopt = hdr;
 717                        break;
 718
 719                case IPV6_2292DSTOPTS:
 720                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 721                                err = -EINVAL;
 722                                goto exit_f;
 723                        }
 724
 725                        hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 726                        len = ((hdr->hdrlen + 1) << 3);
 727                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 728                                err = -EINVAL;
 729                                goto exit_f;
 730                        }
 731                        if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 732                                err = -EPERM;
 733                                goto exit_f;
 734                        }
 735                        if (opt->dst1opt) {
 736                                err = -EINVAL;
 737                                goto exit_f;
 738                        }
 739                        opt->opt_flen += len;
 740                        opt->dst1opt = hdr;
 741                        break;
 742
 743                case IPV6_DSTOPTS:
 744                case IPV6_RTHDRDSTOPTS:
 745                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 746                                err = -EINVAL;
 747                                goto exit_f;
 748                        }
 749
 750                        hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 751                        len = ((hdr->hdrlen + 1) << 3);
 752                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 753                                err = -EINVAL;
 754                                goto exit_f;
 755                        }
 756                        if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 757                                err = -EPERM;
 758                                goto exit_f;
 759                        }
 760                        if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 761                                opt->opt_flen += len;
 762                                opt->dst1opt = hdr;
 763                        } else {
 764                                opt->opt_nflen += len;
 765                                opt->dst0opt = hdr;
 766                        }
 767                        break;
 768
 769                case IPV6_2292RTHDR:
 770                case IPV6_RTHDR:
 771                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 772                                err = -EINVAL;
 773                                goto exit_f;
 774                        }
 775
 776                        rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 777
 778                        switch (rthdr->type) {
 779#if IS_ENABLED(CONFIG_IPV6_MIP6)
 780                        case IPV6_SRCRT_TYPE_2:
 781                                if (rthdr->hdrlen != 2 ||
 782                                    rthdr->segments_left != 1) {
 783                                        err = -EINVAL;
 784                                        goto exit_f;
 785                                }
 786                                break;
 787#endif
 788                        default:
 789                                err = -EINVAL;
 790                                goto exit_f;
 791                        }
 792
 793                        len = ((rthdr->hdrlen + 1) << 3);
 794
 795                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 796                                err = -EINVAL;
 797                                goto exit_f;
 798                        }
 799
 800                        /* segments left must also match */
 801                        if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 802                                err = -EINVAL;
 803                                goto exit_f;
 804                        }
 805
 806                        opt->opt_nflen += len;
 807                        opt->srcrt = rthdr;
 808
 809                        if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 810                                int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 811
 812                                opt->opt_nflen += dsthdrlen;
 813                                opt->dst0opt = opt->dst1opt;
 814                                opt->dst1opt = NULL;
 815                                opt->opt_flen -= dsthdrlen;
 816                        }
 817
 818                        break;
 819
 820                case IPV6_2292HOPLIMIT:
 821                case IPV6_HOPLIMIT:
 822                        if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 823                                err = -EINVAL;
 824                                goto exit_f;
 825                        }
 826
 827                        *hlimit = *(int *)CMSG_DATA(cmsg);
 828                        if (*hlimit < -1 || *hlimit > 0xff) {
 829                                err = -EINVAL;
 830                                goto exit_f;
 831                        }
 832
 833                        break;
 834
 835                case IPV6_TCLASS:
 836                    {
 837                        int tc;
 838
 839                        err = -EINVAL;
 840                        if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 841                                goto exit_f;
 842
 843                        tc = *(int *)CMSG_DATA(cmsg);
 844                        if (tc < -1 || tc > 0xff)
 845                                goto exit_f;
 846
 847                        err = 0;
 848                        *tclass = tc;
 849
 850                        break;
 851                    }
 852
 853                case IPV6_DONTFRAG:
 854                    {
 855                        int df;
 856
 857                        err = -EINVAL;
 858                        if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 859                                goto exit_f;
 860
 861                        df = *(int *)CMSG_DATA(cmsg);
 862                        if (df < 0 || df > 1)
 863                                goto exit_f;
 864
 865                        err = 0;
 866                        *dontfrag = df;
 867
 868                        break;
 869                    }
 870                default:
 871                        LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
 872                                       cmsg->cmsg_type);
 873                        err = -EINVAL;
 874                        goto exit_f;
 875                }
 876        }
 877
 878exit_f:
 879        return err;
 880}
 881EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
 882