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 <linux/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
  43static void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
  44{
  45        struct inet_sock *inet = inet_sk(sk);
  46        struct ipv6_pinfo *np = inet6_sk(sk);
  47
  48        memset(fl6, 0, sizeof(*fl6));
  49        fl6->flowi6_proto = sk->sk_protocol;
  50        fl6->daddr = sk->sk_v6_daddr;
  51        fl6->saddr = np->saddr;
  52        fl6->flowi6_oif = sk->sk_bound_dev_if;
  53        fl6->flowi6_mark = sk->sk_mark;
  54        fl6->fl6_dport = inet->inet_dport;
  55        fl6->fl6_sport = inet->inet_sport;
  56        fl6->flowlabel = np->flow_label;
  57        fl6->flowi6_uid = sk->sk_uid;
  58
  59        if (!fl6->flowi6_oif)
  60                fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
  61
  62        if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr))
  63                fl6->flowi6_oif = np->mcast_oif;
  64
  65        security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
  66}
  67
  68int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
  69{
  70        struct ip6_flowlabel *flowlabel = NULL;
  71        struct in6_addr *final_p, final;
  72        struct ipv6_txoptions *opt;
  73        struct dst_entry *dst;
  74        struct inet_sock *inet = inet_sk(sk);
  75        struct ipv6_pinfo *np = inet6_sk(sk);
  76        struct flowi6 fl6;
  77        int err = 0;
  78
  79        if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
  80                flowlabel = fl6_sock_lookup(sk, np->flow_label);
  81                if (!flowlabel)
  82                        return -EINVAL;
  83        }
  84        ip6_datagram_flow_key_init(&fl6, sk);
  85
  86        rcu_read_lock();
  87        opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
  88        final_p = fl6_update_dst(&fl6, opt, &final);
  89        rcu_read_unlock();
  90
  91        dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
  92        if (IS_ERR(dst)) {
  93                err = PTR_ERR(dst);
  94                goto out;
  95        }
  96
  97        if (fix_sk_saddr) {
  98                if (ipv6_addr_any(&np->saddr))
  99                        np->saddr = fl6.saddr;
 100
 101                if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 102                        sk->sk_v6_rcv_saddr = fl6.saddr;
 103                        inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 104                        if (sk->sk_prot->rehash)
 105                                sk->sk_prot->rehash(sk);
 106                }
 107        }
 108
 109        ip6_dst_store(sk, dst,
 110                      ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
 111                      &sk->sk_v6_daddr : NULL,
 112#ifdef CONFIG_IPV6_SUBTREES
 113                      ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
 114                      &np->saddr :
 115#endif
 116                      NULL);
 117
 118out:
 119        fl6_sock_release(flowlabel);
 120        return err;
 121}
 122
 123void ip6_datagram_release_cb(struct sock *sk)
 124{
 125        struct dst_entry *dst;
 126
 127        if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 128                return;
 129
 130        rcu_read_lock();
 131        dst = __sk_dst_get(sk);
 132        if (!dst || !dst->obsolete ||
 133            dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
 134                rcu_read_unlock();
 135                return;
 136        }
 137        rcu_read_unlock();
 138
 139        ip6_datagram_dst_update(sk, false);
 140}
 141EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
 142
 143int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
 144                           int addr_len)
 145{
 146        struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
 147        struct inet_sock        *inet = inet_sk(sk);
 148        struct ipv6_pinfo       *np = inet6_sk(sk);
 149        struct in6_addr         *daddr;
 150        int                     addr_type;
 151        int                     err;
 152        __be32                  fl6_flowlabel = 0;
 153
 154        if (usin->sin6_family == AF_INET) {
 155                if (__ipv6_only_sock(sk))
 156                        return -EAFNOSUPPORT;
 157                err = __ip4_datagram_connect(sk, uaddr, addr_len);
 158                goto ipv4_connected;
 159        }
 160
 161        if (addr_len < SIN6_LEN_RFC2133)
 162                return -EINVAL;
 163
 164        if (usin->sin6_family != AF_INET6)
 165                return -EAFNOSUPPORT;
 166
 167        if (np->sndflow)
 168                fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 169
 170        if (ipv6_addr_any(&usin->sin6_addr)) {
 171                /*
 172                 *      connect to self
 173                 */
 174                if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
 175                        ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
 176                                               &usin->sin6_addr);
 177                else
 178                        usin->sin6_addr = in6addr_loopback;
 179        }
 180
 181        addr_type = ipv6_addr_type(&usin->sin6_addr);
 182
 183        daddr = &usin->sin6_addr;
 184
 185        if (addr_type & IPV6_ADDR_MAPPED) {
 186                struct sockaddr_in sin;
 187
 188                if (__ipv6_only_sock(sk)) {
 189                        err = -ENETUNREACH;
 190                        goto out;
 191                }
 192                sin.sin_family = AF_INET;
 193                sin.sin_addr.s_addr = daddr->s6_addr32[3];
 194                sin.sin_port = usin->sin6_port;
 195
 196                err = __ip4_datagram_connect(sk,
 197                                             (struct sockaddr *) &sin,
 198                                             sizeof(sin));
 199
 200ipv4_connected:
 201                if (err)
 202                        goto out;
 203
 204                ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 205
 206                if (ipv6_addr_any(&np->saddr) ||
 207                    ipv6_mapped_addr_any(&np->saddr))
 208                        ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 209
 210                if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 211                    ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 212                        ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 213                                               &sk->sk_v6_rcv_saddr);
 214                        if (sk->sk_prot->rehash)
 215                                sk->sk_prot->rehash(sk);
 216                }
 217
 218                goto out;
 219        }
 220
 221        if (__ipv6_addr_needs_scope_id(addr_type)) {
 222                if (addr_len >= sizeof(struct sockaddr_in6) &&
 223                    usin->sin6_scope_id) {
 224                        if (sk->sk_bound_dev_if &&
 225                            sk->sk_bound_dev_if != usin->sin6_scope_id) {
 226                                err = -EINVAL;
 227                                goto out;
 228                        }
 229                        sk->sk_bound_dev_if = usin->sin6_scope_id;
 230                }
 231
 232                if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 233                        sk->sk_bound_dev_if = np->mcast_oif;
 234
 235                /* Connect to link-local address requires an interface */
 236                if (!sk->sk_bound_dev_if) {
 237                        err = -EINVAL;
 238                        goto out;
 239                }
 240        }
 241
 242        sk->sk_v6_daddr = *daddr;
 243        np->flow_label = fl6_flowlabel;
 244
 245        inet->inet_dport = usin->sin6_port;
 246
 247        /*
 248         *      Check for a route to destination an obtain the
 249         *      destination cache for it.
 250         */
 251
 252        err = ip6_datagram_dst_update(sk, true);
 253        if (err) {
 254                /* Reset daddr and dport so that udp_v6_early_demux()
 255                 * fails to find this socket
 256                 */
 257                memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
 258                inet->inet_dport = 0;
 259                goto out;
 260        }
 261
 262        sk->sk_state = TCP_ESTABLISHED;
 263        sk_set_txhash(sk);
 264out:
 265        return err;
 266}
 267EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 268
 269int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 270{
 271        int res;
 272
 273        lock_sock(sk);
 274        res = __ip6_datagram_connect(sk, uaddr, addr_len);
 275        release_sock(sk);
 276        return res;
 277}
 278EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 279
 280int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 281                                 int addr_len)
 282{
 283        DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 284        if (sin6->sin6_family != AF_INET6)
 285                return -EAFNOSUPPORT;
 286        return ip6_datagram_connect(sk, uaddr, addr_len);
 287}
 288EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 289
 290void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 291                     __be16 port, u32 info, u8 *payload)
 292{
 293        struct ipv6_pinfo *np  = inet6_sk(sk);
 294        struct icmp6hdr *icmph = icmp6_hdr(skb);
 295        struct sock_exterr_skb *serr;
 296
 297        if (!np->recverr)
 298                return;
 299
 300        skb = skb_clone(skb, GFP_ATOMIC);
 301        if (!skb)
 302                return;
 303
 304        skb->protocol = htons(ETH_P_IPV6);
 305
 306        serr = SKB_EXT_ERR(skb);
 307        serr->ee.ee_errno = err;
 308        serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 309        serr->ee.ee_type = icmph->icmp6_type;
 310        serr->ee.ee_code = icmph->icmp6_code;
 311        serr->ee.ee_pad = 0;
 312        serr->ee.ee_info = info;
 313        serr->ee.ee_data = 0;
 314        serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 315                                  skb_network_header(skb);
 316        serr->port = port;
 317
 318        __skb_pull(skb, payload - skb->data);
 319        skb_reset_transport_header(skb);
 320
 321        if (sock_queue_err_skb(sk, skb))
 322                kfree_skb(skb);
 323}
 324
 325void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 326{
 327        const struct ipv6_pinfo *np = inet6_sk(sk);
 328        struct sock_exterr_skb *serr;
 329        struct ipv6hdr *iph;
 330        struct sk_buff *skb;
 331
 332        if (!np->recverr)
 333                return;
 334
 335        skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 336        if (!skb)
 337                return;
 338
 339        skb->protocol = htons(ETH_P_IPV6);
 340
 341        skb_put(skb, sizeof(struct ipv6hdr));
 342        skb_reset_network_header(skb);
 343        iph = ipv6_hdr(skb);
 344        iph->daddr = fl6->daddr;
 345
 346        serr = SKB_EXT_ERR(skb);
 347        serr->ee.ee_errno = err;
 348        serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 349        serr->ee.ee_type = 0;
 350        serr->ee.ee_code = 0;
 351        serr->ee.ee_pad = 0;
 352        serr->ee.ee_info = info;
 353        serr->ee.ee_data = 0;
 354        serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 355        serr->port = fl6->fl6_dport;
 356
 357        __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 358        skb_reset_transport_header(skb);
 359
 360        if (sock_queue_err_skb(sk, skb))
 361                kfree_skb(skb);
 362}
 363
 364void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 365{
 366        struct ipv6_pinfo *np = inet6_sk(sk);
 367        struct ipv6hdr *iph;
 368        struct sk_buff *skb;
 369        struct ip6_mtuinfo *mtu_info;
 370
 371        if (!np->rxopt.bits.rxpmtu)
 372                return;
 373
 374        skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 375        if (!skb)
 376                return;
 377
 378        skb_put(skb, sizeof(struct ipv6hdr));
 379        skb_reset_network_header(skb);
 380        iph = ipv6_hdr(skb);
 381        iph->daddr = fl6->daddr;
 382
 383        mtu_info = IP6CBMTU(skb);
 384
 385        mtu_info->ip6m_mtu = mtu;
 386        mtu_info->ip6m_addr.sin6_family = AF_INET6;
 387        mtu_info->ip6m_addr.sin6_port = 0;
 388        mtu_info->ip6m_addr.sin6_flowinfo = 0;
 389        mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 390        mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 391
 392        __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 393        skb_reset_transport_header(skb);
 394
 395        skb = xchg(&np->rxpmtu, skb);
 396        kfree_skb(skb);
 397}
 398
 399/* For some errors we have valid addr_offset even with zero payload and
 400 * zero port. Also, addr_offset should be supported if port is set.
 401 */
 402static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 403{
 404        return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 405               serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 406               serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 407}
 408
 409/* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 410 *
 411 * At one point, excluding local errors was a quick test to identify icmp/icmp6
 412 * errors. This is no longer true, but the test remained, so the v6 stack,
 413 * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 414 */
 415static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 416                                      struct sock_exterr_skb *serr)
 417{
 418        if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 419            serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 420                return true;
 421
 422        if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 423                return false;
 424
 425        if (!IP6CB(skb)->iif)
 426                return false;
 427
 428        return true;
 429}
 430
 431/*
 432 *      Handle MSG_ERRQUEUE
 433 */
 434int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 435{
 436        struct ipv6_pinfo *np = inet6_sk(sk);
 437        struct sock_exterr_skb *serr;
 438        struct sk_buff *skb;
 439        DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 440        struct {
 441                struct sock_extended_err ee;
 442                struct sockaddr_in6      offender;
 443        } errhdr;
 444        int err;
 445        int copied;
 446
 447        err = -EAGAIN;
 448        skb = sock_dequeue_err_skb(sk);
 449        if (!skb)
 450                goto out;
 451
 452        copied = skb->len;
 453        if (copied > len) {
 454                msg->msg_flags |= MSG_TRUNC;
 455                copied = len;
 456        }
 457        err = skb_copy_datagram_msg(skb, 0, msg, copied);
 458        if (unlikely(err)) {
 459                kfree_skb(skb);
 460                return err;
 461        }
 462        sock_recv_timestamp(msg, sk, skb);
 463
 464        serr = SKB_EXT_ERR(skb);
 465
 466        if (sin && ipv6_datagram_support_addr(serr)) {
 467                const unsigned char *nh = skb_network_header(skb);
 468                sin->sin6_family = AF_INET6;
 469                sin->sin6_flowinfo = 0;
 470                sin->sin6_port = serr->port;
 471                if (skb->protocol == htons(ETH_P_IPV6)) {
 472                        const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 473                                                                  struct ipv6hdr, daddr);
 474                        sin->sin6_addr = ip6h->daddr;
 475                        if (np->sndflow)
 476                                sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 477                        sin->sin6_scope_id =
 478                                ipv6_iface_scope_id(&sin->sin6_addr,
 479                                                    IP6CB(skb)->iif);
 480                } else {
 481                        ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 482                                               &sin->sin6_addr);
 483                        sin->sin6_scope_id = 0;
 484                }
 485                *addr_len = sizeof(*sin);
 486        }
 487
 488        memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 489        sin = &errhdr.offender;
 490        memset(sin, 0, sizeof(*sin));
 491
 492        if (ip6_datagram_support_cmsg(skb, serr)) {
 493                sin->sin6_family = AF_INET6;
 494                if (np->rxopt.all)
 495                        ip6_datagram_recv_common_ctl(sk, msg, skb);
 496                if (skb->protocol == htons(ETH_P_IPV6)) {
 497                        sin->sin6_addr = ipv6_hdr(skb)->saddr;
 498                        if (np->rxopt.all)
 499                                ip6_datagram_recv_specific_ctl(sk, msg, skb);
 500                        sin->sin6_scope_id =
 501                                ipv6_iface_scope_id(&sin->sin6_addr,
 502                                                    IP6CB(skb)->iif);
 503                } else {
 504                        ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 505                                               &sin->sin6_addr);
 506                        if (inet_sk(sk)->cmsg_flags)
 507                                ip_cmsg_recv(msg, skb);
 508                }
 509        }
 510
 511        put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 512
 513        /* Now we could try to dump offended packet options */
 514
 515        msg->msg_flags |= MSG_ERRQUEUE;
 516        err = copied;
 517
 518        consume_skb(skb);
 519out:
 520        return err;
 521}
 522EXPORT_SYMBOL_GPL(ipv6_recv_error);
 523
 524/*
 525 *      Handle IPV6_RECVPATHMTU
 526 */
 527int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 528                     int *addr_len)
 529{
 530        struct ipv6_pinfo *np = inet6_sk(sk);
 531        struct sk_buff *skb;
 532        struct ip6_mtuinfo mtu_info;
 533        DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 534        int err;
 535        int copied;
 536
 537        err = -EAGAIN;
 538        skb = xchg(&np->rxpmtu, NULL);
 539        if (!skb)
 540                goto out;
 541
 542        copied = skb->len;
 543        if (copied > len) {
 544                msg->msg_flags |= MSG_TRUNC;
 545                copied = len;
 546        }
 547        err = skb_copy_datagram_msg(skb, 0, msg, copied);
 548        if (err)
 549                goto out_free_skb;
 550
 551        sock_recv_timestamp(msg, sk, skb);
 552
 553        memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 554
 555        if (sin) {
 556                sin->sin6_family = AF_INET6;
 557                sin->sin6_flowinfo = 0;
 558                sin->sin6_port = 0;
 559                sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 560                sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 561                *addr_len = sizeof(*sin);
 562        }
 563
 564        put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 565
 566        err = copied;
 567
 568out_free_skb:
 569        kfree_skb(skb);
 570out:
 571        return err;
 572}
 573
 574
 575void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 576                                 struct sk_buff *skb)
 577{
 578        struct ipv6_pinfo *np = inet6_sk(sk);
 579        bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 580
 581        if (np->rxopt.bits.rxinfo) {
 582                struct in6_pktinfo src_info;
 583
 584                if (is_ipv6) {
 585                        src_info.ipi6_ifindex = IP6CB(skb)->iif;
 586                        src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 587                } else {
 588                        src_info.ipi6_ifindex =
 589                                PKTINFO_SKB_CB(skb)->ipi_ifindex;
 590                        ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 591                                               &src_info.ipi6_addr);
 592                }
 593
 594                if (src_info.ipi6_ifindex >= 0)
 595                        put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 596                                 sizeof(src_info), &src_info);
 597        }
 598}
 599
 600void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 601                                    struct sk_buff *skb)
 602{
 603        struct ipv6_pinfo *np = inet6_sk(sk);
 604        struct inet6_skb_parm *opt = IP6CB(skb);
 605        unsigned char *nh = skb_network_header(skb);
 606
 607        if (np->rxopt.bits.rxhlim) {
 608                int hlim = ipv6_hdr(skb)->hop_limit;
 609                put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 610        }
 611
 612        if (np->rxopt.bits.rxtclass) {
 613                int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 614                put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 615        }
 616
 617        if (np->rxopt.bits.rxflow) {
 618                __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 619                if (flowinfo)
 620                        put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 621        }
 622
 623        /* HbH is allowed only once */
 624        if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 625                u8 *ptr = nh + sizeof(struct ipv6hdr);
 626                put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 627        }
 628
 629        if (opt->lastopt &&
 630            (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 631                /*
 632                 * Silly enough, but we need to reparse in order to
 633                 * report extension headers (except for HbH)
 634                 * in order.
 635                 *
 636                 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 637                 * (and WILL NOT be) defined because
 638                 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 639                 */
 640                unsigned int off = sizeof(struct ipv6hdr);
 641                u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 642
 643                while (off <= opt->lastopt) {
 644                        unsigned int len;
 645                        u8 *ptr = nh + off;
 646
 647                        switch (nexthdr) {
 648                        case IPPROTO_DSTOPTS:
 649                                nexthdr = ptr[0];
 650                                len = (ptr[1] + 1) << 3;
 651                                if (np->rxopt.bits.dstopts)
 652                                        put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 653                                break;
 654                        case IPPROTO_ROUTING:
 655                                nexthdr = ptr[0];
 656                                len = (ptr[1] + 1) << 3;
 657                                if (np->rxopt.bits.srcrt)
 658                                        put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 659                                break;
 660                        case IPPROTO_AH:
 661                                nexthdr = ptr[0];
 662                                len = (ptr[1] + 2) << 2;
 663                                break;
 664                        default:
 665                                nexthdr = ptr[0];
 666                                len = (ptr[1] + 1) << 3;
 667                                break;
 668                        }
 669
 670                        off += len;
 671                }
 672        }
 673
 674        /* socket options in old style */
 675        if (np->rxopt.bits.rxoinfo) {
 676                struct in6_pktinfo src_info;
 677
 678                src_info.ipi6_ifindex = opt->iif;
 679                src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 680                put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 681        }
 682        if (np->rxopt.bits.rxohlim) {
 683                int hlim = ipv6_hdr(skb)->hop_limit;
 684                put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 685        }
 686        if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 687                u8 *ptr = nh + sizeof(struct ipv6hdr);
 688                put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 689        }
 690        if (np->rxopt.bits.odstopts && opt->dst0) {
 691                u8 *ptr = nh + opt->dst0;
 692                put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 693        }
 694        if (np->rxopt.bits.osrcrt && opt->srcrt) {
 695                struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 696                put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 697        }
 698        if (np->rxopt.bits.odstopts && opt->dst1) {
 699                u8 *ptr = nh + opt->dst1;
 700                put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 701        }
 702        if (np->rxopt.bits.rxorigdstaddr) {
 703                struct sockaddr_in6 sin6;
 704                __be16 *ports = (__be16 *) skb_transport_header(skb);
 705
 706                if (skb_transport_offset(skb) + 4 <= (int)skb->len) {
 707                        /* All current transport protocols have the port numbers in the
 708                         * first four bytes of the transport header and this function is
 709                         * written with this assumption in mind.
 710                         */
 711
 712                        sin6.sin6_family = AF_INET6;
 713                        sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 714                        sin6.sin6_port = ports[1];
 715                        sin6.sin6_flowinfo = 0;
 716                        sin6.sin6_scope_id =
 717                                ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 718                                                    opt->iif);
 719
 720                        put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 721                }
 722        }
 723        if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
 724                int val = opt->frag_max_size;
 725
 726                put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
 727        }
 728}
 729
 730void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 731                          struct sk_buff *skb)
 732{
 733        ip6_datagram_recv_common_ctl(sk, msg, skb);
 734        ip6_datagram_recv_specific_ctl(sk, msg, skb);
 735}
 736EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 737
 738int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 739                          struct msghdr *msg, struct flowi6 *fl6,
 740                          struct ipcm6_cookie *ipc6, struct sockcm_cookie *sockc)
 741{
 742        struct in6_pktinfo *src_info;
 743        struct cmsghdr *cmsg;
 744        struct ipv6_rt_hdr *rthdr;
 745        struct ipv6_opt_hdr *hdr;
 746        struct ipv6_txoptions *opt = ipc6->opt;
 747        int len;
 748        int err = 0;
 749
 750        for_each_cmsghdr(cmsg, msg) {
 751                int addr_type;
 752
 753                if (!CMSG_OK(msg, cmsg)) {
 754                        err = -EINVAL;
 755                        goto exit_f;
 756                }
 757
 758                if (cmsg->cmsg_level == SOL_SOCKET) {
 759                        err = __sock_cmsg_send(sk, msg, cmsg, sockc);
 760                        if (err)
 761                                return err;
 762                        continue;
 763                }
 764
 765                if (cmsg->cmsg_level != SOL_IPV6)
 766                        continue;
 767
 768                switch (cmsg->cmsg_type) {
 769                case IPV6_PKTINFO:
 770                case IPV6_2292PKTINFO:
 771                    {
 772                        struct net_device *dev = NULL;
 773
 774                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 775                                err = -EINVAL;
 776                                goto exit_f;
 777                        }
 778
 779                        src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 780
 781                        if (src_info->ipi6_ifindex) {
 782                                if (fl6->flowi6_oif &&
 783                                    src_info->ipi6_ifindex != fl6->flowi6_oif)
 784                                        return -EINVAL;
 785                                fl6->flowi6_oif = src_info->ipi6_ifindex;
 786                        }
 787
 788                        addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 789
 790                        rcu_read_lock();
 791                        if (fl6->flowi6_oif) {
 792                                dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 793                                if (!dev) {
 794                                        rcu_read_unlock();
 795                                        return -ENODEV;
 796                                }
 797                        } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 798                                rcu_read_unlock();
 799                                return -EINVAL;
 800                        }
 801
 802                        if (addr_type != IPV6_ADDR_ANY) {
 803                                int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 804                                if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 805                                    !ipv6_chk_addr(net, &src_info->ipi6_addr,
 806                                                   strict ? dev : NULL, 0) &&
 807                                    !ipv6_chk_acast_addr_src(net, dev,
 808                                                             &src_info->ipi6_addr))
 809                                        err = -EINVAL;
 810                                else
 811                                        fl6->saddr = src_info->ipi6_addr;
 812                        }
 813
 814                        rcu_read_unlock();
 815
 816                        if (err)
 817                                goto exit_f;
 818
 819                        break;
 820                    }
 821
 822                case IPV6_FLOWINFO:
 823                        if (cmsg->cmsg_len < CMSG_LEN(4)) {
 824                                err = -EINVAL;
 825                                goto exit_f;
 826                        }
 827
 828                        if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 829                                if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 830                                        err = -EINVAL;
 831                                        goto exit_f;
 832                                }
 833                        }
 834                        fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 835                        break;
 836
 837                case IPV6_2292HOPOPTS:
 838                case IPV6_HOPOPTS:
 839                        if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 840                                err = -EINVAL;
 841                                goto exit_f;
 842                        }
 843
 844                        hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 845                        len = ((hdr->hdrlen + 1) << 3);
 846                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 847                                err = -EINVAL;
 848                                goto exit_f;
 849                        }
 850                        if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 851                                err = -EPERM;
 852                                goto exit_f;
 853                        }
 854                        opt->opt_nflen += len;
 855                        opt->hopopt = hdr;
 856                        break;
 857
 858                case IPV6_2292DSTOPTS:
 859                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 860                                err = -EINVAL;
 861                                goto exit_f;
 862                        }
 863
 864                        hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 865                        len = ((hdr->hdrlen + 1) << 3);
 866                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 867                                err = -EINVAL;
 868                                goto exit_f;
 869                        }
 870                        if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 871                                err = -EPERM;
 872                                goto exit_f;
 873                        }
 874                        if (opt->dst1opt) {
 875                                err = -EINVAL;
 876                                goto exit_f;
 877                        }
 878                        opt->opt_flen += len;
 879                        opt->dst1opt = hdr;
 880                        break;
 881
 882                case IPV6_DSTOPTS:
 883                case IPV6_RTHDRDSTOPTS:
 884                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 885                                err = -EINVAL;
 886                                goto exit_f;
 887                        }
 888
 889                        hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 890                        len = ((hdr->hdrlen + 1) << 3);
 891                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 892                                err = -EINVAL;
 893                                goto exit_f;
 894                        }
 895                        if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 896                                err = -EPERM;
 897                                goto exit_f;
 898                        }
 899                        if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 900                                opt->opt_flen += len;
 901                                opt->dst1opt = hdr;
 902                        } else {
 903                                opt->opt_nflen += len;
 904                                opt->dst0opt = hdr;
 905                        }
 906                        break;
 907
 908                case IPV6_2292RTHDR:
 909                case IPV6_RTHDR:
 910                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 911                                err = -EINVAL;
 912                                goto exit_f;
 913                        }
 914
 915                        rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 916
 917                        switch (rthdr->type) {
 918#if IS_ENABLED(CONFIG_IPV6_MIP6)
 919                        case IPV6_SRCRT_TYPE_2:
 920                                if (rthdr->hdrlen != 2 ||
 921                                    rthdr->segments_left != 1) {
 922                                        err = -EINVAL;
 923                                        goto exit_f;
 924                                }
 925                                break;
 926#endif
 927                        default:
 928                                err = -EINVAL;
 929                                goto exit_f;
 930                        }
 931
 932                        len = ((rthdr->hdrlen + 1) << 3);
 933
 934                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 935                                err = -EINVAL;
 936                                goto exit_f;
 937                        }
 938
 939                        /* segments left must also match */
 940                        if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 941                                err = -EINVAL;
 942                                goto exit_f;
 943                        }
 944
 945                        opt->opt_nflen += len;
 946                        opt->srcrt = rthdr;
 947
 948                        if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 949                                int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 950
 951                                opt->opt_nflen += dsthdrlen;
 952                                opt->dst0opt = opt->dst1opt;
 953                                opt->dst1opt = NULL;
 954                                opt->opt_flen -= dsthdrlen;
 955                        }
 956
 957                        break;
 958
 959                case IPV6_2292HOPLIMIT:
 960                case IPV6_HOPLIMIT:
 961                        if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 962                                err = -EINVAL;
 963                                goto exit_f;
 964                        }
 965
 966                        ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 967                        if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 968                                err = -EINVAL;
 969                                goto exit_f;
 970                        }
 971
 972                        break;
 973
 974                case IPV6_TCLASS:
 975                    {
 976                        int tc;
 977
 978                        err = -EINVAL;
 979                        if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 980                                goto exit_f;
 981
 982                        tc = *(int *)CMSG_DATA(cmsg);
 983                        if (tc < -1 || tc > 0xff)
 984                                goto exit_f;
 985
 986                        err = 0;
 987                        ipc6->tclass = tc;
 988
 989                        break;
 990                    }
 991
 992                case IPV6_DONTFRAG:
 993                    {
 994                        int df;
 995
 996                        err = -EINVAL;
 997                        if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 998                                goto exit_f;
 999
1000                        df = *(int *)CMSG_DATA(cmsg);
1001                        if (df < 0 || df > 1)
1002                                goto exit_f;
1003
1004                        err = 0;
1005                        ipc6->dontfrag = df;
1006
1007                        break;
1008                    }
1009                default:
1010                        net_dbg_ratelimited("invalid cmsg type: %d\n",
1011                                            cmsg->cmsg_type);
1012                        err = -EINVAL;
1013                        goto exit_f;
1014                }
1015        }
1016
1017exit_f:
1018        return err;
1019}
1020EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1021
1022void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1023                             __u16 srcp, __u16 destp, int bucket)
1024{
1025        const struct in6_addr *dest, *src;
1026
1027        dest  = &sp->sk_v6_daddr;
1028        src   = &sp->sk_v6_rcv_saddr;
1029        seq_printf(seq,
1030                   "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1031                   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
1032                   bucket,
1033                   src->s6_addr32[0], src->s6_addr32[1],
1034                   src->s6_addr32[2], src->s6_addr32[3], srcp,
1035                   dest->s6_addr32[0], dest->s6_addr32[1],
1036                   dest->s6_addr32[2], dest->s6_addr32[3], destp,
1037                   sp->sk_state,
1038                   sk_wmem_alloc_get(sp),
1039                   sk_rmem_alloc_get(sp),
1040                   0, 0L, 0,
1041                   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1042                   0,
1043                   sock_i_ino(sp),
1044                   refcount_read(&sp->sk_refcnt), sp,
1045                   atomic_read(&sp->sk_drops));
1046}
1047