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)
  75                                return -EINVAL;
  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, &sk->sk_v6_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(&sk->sk_v6_rcv_saddr) ||
 116                    ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 117                        ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 118                                               &sk->sk_v6_rcv_saddr);
 119                        if (sk->sk_prot->rehash)
 120                                sk->sk_prot->rehash(sk);
 121                }
 122
 123                goto out;
 124        }
 125
 126        if (__ipv6_addr_needs_scope_id(addr_type)) {
 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        sk->sk_v6_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 = sk->sk_v6_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);
 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(&sk->sk_v6_rcv_saddr)) {
 186                sk->sk_v6_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, &sk->sk_v6_daddr) ?
 194                      &sk->sk_v6_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;
 202        ip6_set_txhash(sk);
 203out:
 204        fl6_sock_release(flowlabel);
 205        return err;
 206}
 207EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 208
 209int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 210                                 int addr_len)
 211{
 212        DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 213        if (sin6->sin6_family != AF_INET6)
 214                return -EAFNOSUPPORT;
 215        return ip6_datagram_connect(sk, uaddr, addr_len);
 216}
 217EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 218
 219void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 220                     __be16 port, u32 info, u8 *payload)
 221{
 222        struct ipv6_pinfo *np  = inet6_sk(sk);
 223        struct icmp6hdr *icmph = icmp6_hdr(skb);
 224        struct sock_exterr_skb *serr;
 225
 226        if (!np->recverr)
 227                return;
 228
 229        skb = skb_clone(skb, GFP_ATOMIC);
 230        if (!skb)
 231                return;
 232
 233        skb->protocol = htons(ETH_P_IPV6);
 234
 235        serr = SKB_EXT_ERR(skb);
 236        serr->ee.ee_errno = err;
 237        serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 238        serr->ee.ee_type = icmph->icmp6_type;
 239        serr->ee.ee_code = icmph->icmp6_code;
 240        serr->ee.ee_pad = 0;
 241        serr->ee.ee_info = info;
 242        serr->ee.ee_data = 0;
 243        serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 244                                  skb_network_header(skb);
 245        serr->port = port;
 246
 247        __skb_pull(skb, payload - skb->data);
 248        skb_reset_transport_header(skb);
 249
 250        if (sock_queue_err_skb(sk, skb))
 251                kfree_skb(skb);
 252}
 253
 254void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 255{
 256        struct ipv6_pinfo *np = inet6_sk(sk);
 257        struct sock_exterr_skb *serr;
 258        struct ipv6hdr *iph;
 259        struct sk_buff *skb;
 260
 261        if (!np->recverr)
 262                return;
 263
 264        skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 265        if (!skb)
 266                return;
 267
 268        skb->protocol = htons(ETH_P_IPV6);
 269
 270        skb_put(skb, sizeof(struct ipv6hdr));
 271        skb_reset_network_header(skb);
 272        iph = ipv6_hdr(skb);
 273        iph->daddr = fl6->daddr;
 274
 275        serr = SKB_EXT_ERR(skb);
 276        serr->ee.ee_errno = err;
 277        serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 278        serr->ee.ee_type = 0;
 279        serr->ee.ee_code = 0;
 280        serr->ee.ee_pad = 0;
 281        serr->ee.ee_info = info;
 282        serr->ee.ee_data = 0;
 283        serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 284        serr->port = fl6->fl6_dport;
 285
 286        __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 287        skb_reset_transport_header(skb);
 288
 289        if (sock_queue_err_skb(sk, skb))
 290                kfree_skb(skb);
 291}
 292
 293void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 294{
 295        struct ipv6_pinfo *np = inet6_sk(sk);
 296        struct ipv6hdr *iph;
 297        struct sk_buff *skb;
 298        struct ip6_mtuinfo *mtu_info;
 299
 300        if (!np->rxopt.bits.rxpmtu)
 301                return;
 302
 303        skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 304        if (!skb)
 305                return;
 306
 307        skb_put(skb, sizeof(struct ipv6hdr));
 308        skb_reset_network_header(skb);
 309        iph = ipv6_hdr(skb);
 310        iph->daddr = fl6->daddr;
 311
 312        mtu_info = IP6CBMTU(skb);
 313
 314        mtu_info->ip6m_mtu = mtu;
 315        mtu_info->ip6m_addr.sin6_family = AF_INET6;
 316        mtu_info->ip6m_addr.sin6_port = 0;
 317        mtu_info->ip6m_addr.sin6_flowinfo = 0;
 318        mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 319        mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 320
 321        __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 322        skb_reset_transport_header(skb);
 323
 324        skb = xchg(&np->rxpmtu, skb);
 325        kfree_skb(skb);
 326}
 327
 328/* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 329 *
 330 * At one point, excluding local errors was a quick test to identify icmp/icmp6
 331 * errors. This is no longer true, but the test remained, so the v6 stack,
 332 * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 333 *
 334 * Timestamp code paths do not initialize the fields expected by cmsg:
 335 * the PKTINFO fields in skb->cb[]. Fill those in here.
 336 */
 337static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 338                                      struct sock_exterr_skb *serr)
 339{
 340        if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 341            serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 342                return true;
 343
 344        if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 345                return false;
 346
 347        if (!skb->dev)
 348                return false;
 349
 350        if (skb->protocol == htons(ETH_P_IPV6))
 351                IP6CB(skb)->iif = skb->dev->ifindex;
 352        else
 353                PKTINFO_SKB_CB(skb)->ipi_ifindex = skb->dev->ifindex;
 354
 355        return true;
 356}
 357
 358/*
 359 *      Handle MSG_ERRQUEUE
 360 */
 361int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 362{
 363        struct ipv6_pinfo *np = inet6_sk(sk);
 364        struct sock_exterr_skb *serr;
 365        struct sk_buff *skb;
 366        DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 367        struct {
 368                struct sock_extended_err ee;
 369                struct sockaddr_in6      offender;
 370        } errhdr;
 371        int err;
 372        int copied;
 373
 374        err = -EAGAIN;
 375        skb = sock_dequeue_err_skb(sk);
 376        if (!skb)
 377                goto out;
 378
 379        copied = skb->len;
 380        if (copied > len) {
 381                msg->msg_flags |= MSG_TRUNC;
 382                copied = len;
 383        }
 384        err = skb_copy_datagram_msg(skb, 0, msg, copied);
 385        if (err)
 386                goto out_free_skb;
 387
 388        sock_recv_timestamp(msg, sk, skb);
 389
 390        serr = SKB_EXT_ERR(skb);
 391
 392        if (sin && serr->port) {
 393                const unsigned char *nh = skb_network_header(skb);
 394                sin->sin6_family = AF_INET6;
 395                sin->sin6_flowinfo = 0;
 396                sin->sin6_port = serr->port;
 397                if (skb->protocol == htons(ETH_P_IPV6)) {
 398                        const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 399                                                                  struct ipv6hdr, daddr);
 400                        sin->sin6_addr = ip6h->daddr;
 401                        if (np->sndflow)
 402                                sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 403                        sin->sin6_scope_id =
 404                                ipv6_iface_scope_id(&sin->sin6_addr,
 405                                                    IP6CB(skb)->iif);
 406                } else {
 407                        ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 408                                               &sin->sin6_addr);
 409                        sin->sin6_scope_id = 0;
 410                }
 411                *addr_len = sizeof(*sin);
 412        }
 413
 414        memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 415        sin = &errhdr.offender;
 416        memset(sin, 0, sizeof(*sin));
 417
 418        if (ip6_datagram_support_cmsg(skb, serr)) {
 419                sin->sin6_family = AF_INET6;
 420                if (np->rxopt.all)
 421                        ip6_datagram_recv_common_ctl(sk, msg, skb);
 422                if (skb->protocol == htons(ETH_P_IPV6)) {
 423                        sin->sin6_addr = ipv6_hdr(skb)->saddr;
 424                        if (np->rxopt.all)
 425                                ip6_datagram_recv_specific_ctl(sk, msg, skb);
 426                        sin->sin6_scope_id =
 427                                ipv6_iface_scope_id(&sin->sin6_addr,
 428                                                    IP6CB(skb)->iif);
 429                } else {
 430                        ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 431                                               &sin->sin6_addr);
 432                        if (inet_sk(sk)->cmsg_flags)
 433                                ip_cmsg_recv(msg, skb);
 434                }
 435        }
 436
 437        put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 438
 439        /* Now we could try to dump offended packet options */
 440
 441        msg->msg_flags |= MSG_ERRQUEUE;
 442        err = copied;
 443
 444out_free_skb:
 445        kfree_skb(skb);
 446out:
 447        return err;
 448}
 449EXPORT_SYMBOL_GPL(ipv6_recv_error);
 450
 451/*
 452 *      Handle IPV6_RECVPATHMTU
 453 */
 454int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 455                     int *addr_len)
 456{
 457        struct ipv6_pinfo *np = inet6_sk(sk);
 458        struct sk_buff *skb;
 459        struct ip6_mtuinfo mtu_info;
 460        DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 461        int err;
 462        int copied;
 463
 464        err = -EAGAIN;
 465        skb = xchg(&np->rxpmtu, NULL);
 466        if (!skb)
 467                goto out;
 468
 469        copied = skb->len;
 470        if (copied > len) {
 471                msg->msg_flags |= MSG_TRUNC;
 472                copied = len;
 473        }
 474        err = skb_copy_datagram_msg(skb, 0, msg, copied);
 475        if (err)
 476                goto out_free_skb;
 477
 478        sock_recv_timestamp(msg, sk, skb);
 479
 480        memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 481
 482        if (sin) {
 483                sin->sin6_family = AF_INET6;
 484                sin->sin6_flowinfo = 0;
 485                sin->sin6_port = 0;
 486                sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 487                sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 488                *addr_len = sizeof(*sin);
 489        }
 490
 491        put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 492
 493        err = copied;
 494
 495out_free_skb:
 496        kfree_skb(skb);
 497out:
 498        return err;
 499}
 500
 501
 502void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 503                                 struct sk_buff *skb)
 504{
 505        struct ipv6_pinfo *np = inet6_sk(sk);
 506        bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 507
 508        if (np->rxopt.bits.rxinfo) {
 509                struct in6_pktinfo src_info;
 510
 511                if (is_ipv6) {
 512                        src_info.ipi6_ifindex = IP6CB(skb)->iif;
 513                        src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 514                } else {
 515                        src_info.ipi6_ifindex =
 516                                PKTINFO_SKB_CB(skb)->ipi_ifindex;
 517                        ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 518                                               &src_info.ipi6_addr);
 519                }
 520
 521                if (src_info.ipi6_ifindex >= 0)
 522                        put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 523                                 sizeof(src_info), &src_info);
 524        }
 525}
 526
 527void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 528                                    struct sk_buff *skb)
 529{
 530        struct ipv6_pinfo *np = inet6_sk(sk);
 531        struct inet6_skb_parm *opt = IP6CB(skb);
 532        unsigned char *nh = skb_network_header(skb);
 533
 534        if (np->rxopt.bits.rxhlim) {
 535                int hlim = ipv6_hdr(skb)->hop_limit;
 536                put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 537        }
 538
 539        if (np->rxopt.bits.rxtclass) {
 540                int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 541                put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 542        }
 543
 544        if (np->rxopt.bits.rxflow) {
 545                __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 546                if (flowinfo)
 547                        put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 548        }
 549
 550        /* HbH is allowed only once */
 551        if (np->rxopt.bits.hopopts && opt->hop) {
 552                u8 *ptr = nh + opt->hop;
 553                put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 554        }
 555
 556        if (opt->lastopt &&
 557            (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 558                /*
 559                 * Silly enough, but we need to reparse in order to
 560                 * report extension headers (except for HbH)
 561                 * in order.
 562                 *
 563                 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 564                 * (and WILL NOT be) defined because
 565                 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 566                 */
 567                unsigned int off = sizeof(struct ipv6hdr);
 568                u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 569
 570                while (off <= opt->lastopt) {
 571                        unsigned int len;
 572                        u8 *ptr = nh + off;
 573
 574                        switch (nexthdr) {
 575                        case IPPROTO_DSTOPTS:
 576                                nexthdr = ptr[0];
 577                                len = (ptr[1] + 1) << 3;
 578                                if (np->rxopt.bits.dstopts)
 579                                        put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 580                                break;
 581                        case IPPROTO_ROUTING:
 582                                nexthdr = ptr[0];
 583                                len = (ptr[1] + 1) << 3;
 584                                if (np->rxopt.bits.srcrt)
 585                                        put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 586                                break;
 587                        case IPPROTO_AH:
 588                                nexthdr = ptr[0];
 589                                len = (ptr[1] + 2) << 2;
 590                                break;
 591                        default:
 592                                nexthdr = ptr[0];
 593                                len = (ptr[1] + 1) << 3;
 594                                break;
 595                        }
 596
 597                        off += len;
 598                }
 599        }
 600
 601        /* socket options in old style */
 602        if (np->rxopt.bits.rxoinfo) {
 603                struct in6_pktinfo src_info;
 604
 605                src_info.ipi6_ifindex = opt->iif;
 606                src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 607                put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 608        }
 609        if (np->rxopt.bits.rxohlim) {
 610                int hlim = ipv6_hdr(skb)->hop_limit;
 611                put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 612        }
 613        if (np->rxopt.bits.ohopopts && opt->hop) {
 614                u8 *ptr = nh + opt->hop;
 615                put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 616        }
 617        if (np->rxopt.bits.odstopts && opt->dst0) {
 618                u8 *ptr = nh + opt->dst0;
 619                put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 620        }
 621        if (np->rxopt.bits.osrcrt && opt->srcrt) {
 622                struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 623                put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 624        }
 625        if (np->rxopt.bits.odstopts && opt->dst1) {
 626                u8 *ptr = nh + opt->dst1;
 627                put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 628        }
 629        if (np->rxopt.bits.rxorigdstaddr) {
 630                struct sockaddr_in6 sin6;
 631                __be16 *ports = (__be16 *) skb_transport_header(skb);
 632
 633                if (skb_transport_offset(skb) + 4 <= skb->len) {
 634                        /* All current transport protocols have the port numbers in the
 635                         * first four bytes of the transport header and this function is
 636                         * written with this assumption in mind.
 637                         */
 638
 639                        sin6.sin6_family = AF_INET6;
 640                        sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 641                        sin6.sin6_port = ports[1];
 642                        sin6.sin6_flowinfo = 0;
 643                        sin6.sin6_scope_id =
 644                                ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 645                                                    opt->iif);
 646
 647                        put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 648                }
 649        }
 650}
 651
 652void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 653                          struct sk_buff *skb)
 654{
 655        ip6_datagram_recv_common_ctl(sk, msg, skb);
 656        ip6_datagram_recv_specific_ctl(sk, msg, skb);
 657}
 658EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 659
 660int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 661                          struct msghdr *msg, struct flowi6 *fl6,
 662                          struct ipv6_txoptions *opt,
 663                          int *hlimit, int *tclass, int *dontfrag)
 664{
 665        struct in6_pktinfo *src_info;
 666        struct cmsghdr *cmsg;
 667        struct ipv6_rt_hdr *rthdr;
 668        struct ipv6_opt_hdr *hdr;
 669        int len;
 670        int err = 0;
 671
 672        for_each_cmsghdr(cmsg, msg) {
 673                int addr_type;
 674
 675                if (!CMSG_OK(msg, cmsg)) {
 676                        err = -EINVAL;
 677                        goto exit_f;
 678                }
 679
 680                if (cmsg->cmsg_level != SOL_IPV6)
 681                        continue;
 682
 683                switch (cmsg->cmsg_type) {
 684                case IPV6_PKTINFO:
 685                case IPV6_2292PKTINFO:
 686                    {
 687                        struct net_device *dev = NULL;
 688
 689                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 690                                err = -EINVAL;
 691                                goto exit_f;
 692                        }
 693
 694                        src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 695
 696                        if (src_info->ipi6_ifindex) {
 697                                if (fl6->flowi6_oif &&
 698                                    src_info->ipi6_ifindex != fl6->flowi6_oif)
 699                                        return -EINVAL;
 700                                fl6->flowi6_oif = src_info->ipi6_ifindex;
 701                        }
 702
 703                        addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 704
 705                        rcu_read_lock();
 706                        if (fl6->flowi6_oif) {
 707                                dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 708                                if (!dev) {
 709                                        rcu_read_unlock();
 710                                        return -ENODEV;
 711                                }
 712                        } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 713                                rcu_read_unlock();
 714                                return -EINVAL;
 715                        }
 716
 717                        if (addr_type != IPV6_ADDR_ANY) {
 718                                int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 719                                if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 720                                    !ipv6_chk_addr(net, &src_info->ipi6_addr,
 721                                                   strict ? dev : NULL, 0) &&
 722                                    !ipv6_chk_acast_addr_src(net, dev,
 723                                                             &src_info->ipi6_addr))
 724                                        err = -EINVAL;
 725                                else
 726                                        fl6->saddr = src_info->ipi6_addr;
 727                        }
 728
 729                        rcu_read_unlock();
 730
 731                        if (err)
 732                                goto exit_f;
 733
 734                        break;
 735                    }
 736
 737                case IPV6_FLOWINFO:
 738                        if (cmsg->cmsg_len < CMSG_LEN(4)) {
 739                                err = -EINVAL;
 740                                goto exit_f;
 741                        }
 742
 743                        if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 744                                if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 745                                        err = -EINVAL;
 746                                        goto exit_f;
 747                                }
 748                        }
 749                        fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 750                        break;
 751
 752                case IPV6_2292HOPOPTS:
 753                case IPV6_HOPOPTS:
 754                        if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 755                                err = -EINVAL;
 756                                goto exit_f;
 757                        }
 758
 759                        hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 760                        len = ((hdr->hdrlen + 1) << 3);
 761                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 762                                err = -EINVAL;
 763                                goto exit_f;
 764                        }
 765                        if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 766                                err = -EPERM;
 767                                goto exit_f;
 768                        }
 769                        opt->opt_nflen += len;
 770                        opt->hopopt = hdr;
 771                        break;
 772
 773                case IPV6_2292DSTOPTS:
 774                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 775                                err = -EINVAL;
 776                                goto exit_f;
 777                        }
 778
 779                        hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 780                        len = ((hdr->hdrlen + 1) << 3);
 781                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 782                                err = -EINVAL;
 783                                goto exit_f;
 784                        }
 785                        if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 786                                err = -EPERM;
 787                                goto exit_f;
 788                        }
 789                        if (opt->dst1opt) {
 790                                err = -EINVAL;
 791                                goto exit_f;
 792                        }
 793                        opt->opt_flen += len;
 794                        opt->dst1opt = hdr;
 795                        break;
 796
 797                case IPV6_DSTOPTS:
 798                case IPV6_RTHDRDSTOPTS:
 799                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 800                                err = -EINVAL;
 801                                goto exit_f;
 802                        }
 803
 804                        hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 805                        len = ((hdr->hdrlen + 1) << 3);
 806                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 807                                err = -EINVAL;
 808                                goto exit_f;
 809                        }
 810                        if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 811                                err = -EPERM;
 812                                goto exit_f;
 813                        }
 814                        if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 815                                opt->opt_flen += len;
 816                                opt->dst1opt = hdr;
 817                        } else {
 818                                opt->opt_nflen += len;
 819                                opt->dst0opt = hdr;
 820                        }
 821                        break;
 822
 823                case IPV6_2292RTHDR:
 824                case IPV6_RTHDR:
 825                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 826                                err = -EINVAL;
 827                                goto exit_f;
 828                        }
 829
 830                        rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 831
 832                        switch (rthdr->type) {
 833#if IS_ENABLED(CONFIG_IPV6_MIP6)
 834                        case IPV6_SRCRT_TYPE_2:
 835                                if (rthdr->hdrlen != 2 ||
 836                                    rthdr->segments_left != 1) {
 837                                        err = -EINVAL;
 838                                        goto exit_f;
 839                                }
 840                                break;
 841#endif
 842                        default:
 843                                err = -EINVAL;
 844                                goto exit_f;
 845                        }
 846
 847                        len = ((rthdr->hdrlen + 1) << 3);
 848
 849                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 850                                err = -EINVAL;
 851                                goto exit_f;
 852                        }
 853
 854                        /* segments left must also match */
 855                        if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 856                                err = -EINVAL;
 857                                goto exit_f;
 858                        }
 859
 860                        opt->opt_nflen += len;
 861                        opt->srcrt = rthdr;
 862
 863                        if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 864                                int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 865
 866                                opt->opt_nflen += dsthdrlen;
 867                                opt->dst0opt = opt->dst1opt;
 868                                opt->dst1opt = NULL;
 869                                opt->opt_flen -= dsthdrlen;
 870                        }
 871
 872                        break;
 873
 874                case IPV6_2292HOPLIMIT:
 875                case IPV6_HOPLIMIT:
 876                        if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 877                                err = -EINVAL;
 878                                goto exit_f;
 879                        }
 880
 881                        *hlimit = *(int *)CMSG_DATA(cmsg);
 882                        if (*hlimit < -1 || *hlimit > 0xff) {
 883                                err = -EINVAL;
 884                                goto exit_f;
 885                        }
 886
 887                        break;
 888
 889                case IPV6_TCLASS:
 890                    {
 891                        int tc;
 892
 893                        err = -EINVAL;
 894                        if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 895                                goto exit_f;
 896
 897                        tc = *(int *)CMSG_DATA(cmsg);
 898                        if (tc < -1 || tc > 0xff)
 899                                goto exit_f;
 900
 901                        err = 0;
 902                        *tclass = tc;
 903
 904                        break;
 905                    }
 906
 907                case IPV6_DONTFRAG:
 908                    {
 909                        int df;
 910
 911                        err = -EINVAL;
 912                        if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 913                                goto exit_f;
 914
 915                        df = *(int *)CMSG_DATA(cmsg);
 916                        if (df < 0 || df > 1)
 917                                goto exit_f;
 918
 919                        err = 0;
 920                        *dontfrag = df;
 921
 922                        break;
 923                    }
 924                default:
 925                        net_dbg_ratelimited("invalid cmsg type: %d\n",
 926                                            cmsg->cmsg_type);
 927                        err = -EINVAL;
 928                        goto exit_f;
 929                }
 930        }
 931
 932exit_f:
 933        return err;
 934}
 935EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
 936
 937void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
 938                             __u16 srcp, __u16 destp, int bucket)
 939{
 940        const struct in6_addr *dest, *src;
 941
 942        dest  = &sp->sk_v6_daddr;
 943        src   = &sp->sk_v6_rcv_saddr;
 944        seq_printf(seq,
 945                   "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
 946                   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
 947                   bucket,
 948                   src->s6_addr32[0], src->s6_addr32[1],
 949                   src->s6_addr32[2], src->s6_addr32[3], srcp,
 950                   dest->s6_addr32[0], dest->s6_addr32[1],
 951                   dest->s6_addr32[2], dest->s6_addr32[3], destp,
 952                   sp->sk_state,
 953                   sk_wmem_alloc_get(sp),
 954                   sk_rmem_alloc_get(sp),
 955                   0, 0L, 0,
 956                   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
 957                   0,
 958                   sock_i_ino(sp),
 959                   atomic_read(&sp->sk_refcnt), sp,
 960                   atomic_read(&sp->sk_drops));
 961}
 962