linux/net/ipv6/datagram.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *      common UDP/RAW code
   4 *      Linux INET6 implementation
   5 *
   6 *      Authors:
   7 *      Pedro Roque             <roque@di.fc.ul.pt>
   8 */
   9
  10#include <linux/capability.h>
  11#include <linux/errno.h>
  12#include <linux/types.h>
  13#include <linux/kernel.h>
  14#include <linux/interrupt.h>
  15#include <linux/socket.h>
  16#include <linux/sockios.h>
  17#include <linux/in6.h>
  18#include <linux/ipv6.h>
  19#include <linux/route.h>
  20#include <linux/slab.h>
  21#include <linux/export.h>
  22#include <linux/icmp.h>
  23
  24#include <net/ipv6.h>
  25#include <net/ndisc.h>
  26#include <net/addrconf.h>
  27#include <net/transp_v6.h>
  28#include <net/ip6_route.h>
  29#include <net/tcp_states.h>
  30#include <net/dsfield.h>
  31#include <net/sock_reuseport.h>
  32
  33#include <linux/errqueue.h>
  34#include <linux/uaccess.h>
  35
  36static bool ipv6_mapped_addr_any(const struct in6_addr *a)
  37{
  38        return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
  39}
  40
  41static void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
  42{
  43        struct inet_sock *inet = inet_sk(sk);
  44        struct ipv6_pinfo *np = inet6_sk(sk);
  45
  46        memset(fl6, 0, sizeof(*fl6));
  47        fl6->flowi6_proto = sk->sk_protocol;
  48        fl6->daddr = sk->sk_v6_daddr;
  49        fl6->saddr = np->saddr;
  50        fl6->flowi6_oif = sk->sk_bound_dev_if;
  51        fl6->flowi6_mark = sk->sk_mark;
  52        fl6->fl6_dport = inet->inet_dport;
  53        fl6->fl6_sport = inet->inet_sport;
  54        fl6->flowlabel = np->flow_label;
  55        fl6->flowi6_uid = sk->sk_uid;
  56
  57        if (!fl6->flowi6_oif)
  58                fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
  59
  60        if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr))
  61                fl6->flowi6_oif = np->mcast_oif;
  62
  63        security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
  64}
  65
  66int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
  67{
  68        struct ip6_flowlabel *flowlabel = NULL;
  69        struct in6_addr *final_p, final;
  70        struct ipv6_txoptions *opt;
  71        struct dst_entry *dst;
  72        struct inet_sock *inet = inet_sk(sk);
  73        struct ipv6_pinfo *np = inet6_sk(sk);
  74        struct flowi6 fl6;
  75        int err = 0;
  76
  77        if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
  78                flowlabel = fl6_sock_lookup(sk, np->flow_label);
  79                if (IS_ERR(flowlabel))
  80                        return -EINVAL;
  81        }
  82        ip6_datagram_flow_key_init(&fl6, sk);
  83
  84        rcu_read_lock();
  85        opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
  86        final_p = fl6_update_dst(&fl6, opt, &final);
  87        rcu_read_unlock();
  88
  89        dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
  90        if (IS_ERR(dst)) {
  91                err = PTR_ERR(dst);
  92                goto out;
  93        }
  94
  95        if (fix_sk_saddr) {
  96                if (ipv6_addr_any(&np->saddr))
  97                        np->saddr = fl6.saddr;
  98
  99                if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 100                        sk->sk_v6_rcv_saddr = fl6.saddr;
 101                        inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 102                        if (sk->sk_prot->rehash)
 103                                sk->sk_prot->rehash(sk);
 104                }
 105        }
 106
 107        ip6_sk_dst_store_flow(sk, dst, &fl6);
 108
 109out:
 110        fl6_sock_release(flowlabel);
 111        return err;
 112}
 113
 114void ip6_datagram_release_cb(struct sock *sk)
 115{
 116        struct dst_entry *dst;
 117
 118        if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 119                return;
 120
 121        rcu_read_lock();
 122        dst = __sk_dst_get(sk);
 123        if (!dst || !dst->obsolete ||
 124            dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
 125                rcu_read_unlock();
 126                return;
 127        }
 128        rcu_read_unlock();
 129
 130        ip6_datagram_dst_update(sk, false);
 131}
 132EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
 133
 134int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
 135                           int addr_len)
 136{
 137        struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
 138        struct inet_sock        *inet = inet_sk(sk);
 139        struct ipv6_pinfo       *np = inet6_sk(sk);
 140        struct in6_addr         *daddr, old_daddr;
 141        __be32                  fl6_flowlabel = 0;
 142        __be32                  old_fl6_flowlabel;
 143        __be16                  old_dport;
 144        int                     addr_type;
 145        int                     err;
 146
 147        if (usin->sin6_family == AF_INET) {
 148                if (ipv6_only_sock(sk))
 149                        return -EAFNOSUPPORT;
 150                err = __ip4_datagram_connect(sk, uaddr, addr_len);
 151                goto ipv4_connected;
 152        }
 153
 154        if (addr_len < SIN6_LEN_RFC2133)
 155                return -EINVAL;
 156
 157        if (usin->sin6_family != AF_INET6)
 158                return -EAFNOSUPPORT;
 159
 160        if (np->sndflow)
 161                fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 162
 163        if (ipv6_addr_any(&usin->sin6_addr)) {
 164                /*
 165                 *      connect to self
 166                 */
 167                if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
 168                        ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
 169                                               &usin->sin6_addr);
 170                else
 171                        usin->sin6_addr = in6addr_loopback;
 172        }
 173
 174        addr_type = ipv6_addr_type(&usin->sin6_addr);
 175
 176        daddr = &usin->sin6_addr;
 177
 178        if (addr_type & IPV6_ADDR_MAPPED) {
 179                struct sockaddr_in sin;
 180
 181                if (ipv6_only_sock(sk)) {
 182                        err = -ENETUNREACH;
 183                        goto out;
 184                }
 185                sin.sin_family = AF_INET;
 186                sin.sin_addr.s_addr = daddr->s6_addr32[3];
 187                sin.sin_port = usin->sin6_port;
 188
 189                err = __ip4_datagram_connect(sk,
 190                                             (struct sockaddr *) &sin,
 191                                             sizeof(sin));
 192
 193ipv4_connected:
 194                if (err)
 195                        goto out;
 196
 197                ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 198
 199                if (ipv6_addr_any(&np->saddr) ||
 200                    ipv6_mapped_addr_any(&np->saddr))
 201                        ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 202
 203                if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 204                    ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 205                        ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 206                                               &sk->sk_v6_rcv_saddr);
 207                        if (sk->sk_prot->rehash)
 208                                sk->sk_prot->rehash(sk);
 209                }
 210
 211                goto out;
 212        }
 213
 214        if (__ipv6_addr_needs_scope_id(addr_type)) {
 215                if (addr_len >= sizeof(struct sockaddr_in6) &&
 216                    usin->sin6_scope_id) {
 217                        if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id)) {
 218                                err = -EINVAL;
 219                                goto out;
 220                        }
 221                        WRITE_ONCE(sk->sk_bound_dev_if, usin->sin6_scope_id);
 222                }
 223
 224                if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 225                        WRITE_ONCE(sk->sk_bound_dev_if, np->mcast_oif);
 226
 227                /* Connect to link-local address requires an interface */
 228                if (!sk->sk_bound_dev_if) {
 229                        err = -EINVAL;
 230                        goto out;
 231                }
 232        }
 233
 234        /* save the current peer information before updating it */
 235        old_daddr = sk->sk_v6_daddr;
 236        old_fl6_flowlabel = np->flow_label;
 237        old_dport = inet->inet_dport;
 238
 239        sk->sk_v6_daddr = *daddr;
 240        np->flow_label = fl6_flowlabel;
 241        inet->inet_dport = usin->sin6_port;
 242
 243        /*
 244         *      Check for a route to destination an obtain the
 245         *      destination cache for it.
 246         */
 247
 248        err = ip6_datagram_dst_update(sk, true);
 249        if (err) {
 250                /* Restore the socket peer info, to keep it consistent with
 251                 * the old socket state
 252                 */
 253                sk->sk_v6_daddr = old_daddr;
 254                np->flow_label = old_fl6_flowlabel;
 255                inet->inet_dport = old_dport;
 256                goto out;
 257        }
 258
 259        reuseport_has_conns(sk, true);
 260        sk->sk_state = TCP_ESTABLISHED;
 261        sk_set_txhash(sk);
 262out:
 263        return err;
 264}
 265EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 266
 267int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 268{
 269        int res;
 270
 271        lock_sock(sk);
 272        res = __ip6_datagram_connect(sk, uaddr, addr_len);
 273        release_sock(sk);
 274        return res;
 275}
 276EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 277
 278int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 279                                 int addr_len)
 280{
 281        DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 282        if (sin6->sin6_family != AF_INET6)
 283                return -EAFNOSUPPORT;
 284        return ip6_datagram_connect(sk, uaddr, addr_len);
 285}
 286EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 287
 288static void ipv6_icmp_error_rfc4884(const struct sk_buff *skb,
 289                                    struct sock_ee_data_rfc4884 *out)
 290{
 291        switch (icmp6_hdr(skb)->icmp6_type) {
 292        case ICMPV6_TIME_EXCEED:
 293        case ICMPV6_DEST_UNREACH:
 294                ip_icmp_error_rfc4884(skb, out, sizeof(struct icmp6hdr),
 295                                      icmp6_hdr(skb)->icmp6_datagram_len * 8);
 296        }
 297}
 298
 299void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 300                     __be16 port, u32 info, u8 *payload)
 301{
 302        struct ipv6_pinfo *np  = inet6_sk(sk);
 303        struct icmp6hdr *icmph = icmp6_hdr(skb);
 304        struct sock_exterr_skb *serr;
 305
 306        if (!np->recverr)
 307                return;
 308
 309        skb = skb_clone(skb, GFP_ATOMIC);
 310        if (!skb)
 311                return;
 312
 313        skb->protocol = htons(ETH_P_IPV6);
 314
 315        serr = SKB_EXT_ERR(skb);
 316        serr->ee.ee_errno = err;
 317        serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 318        serr->ee.ee_type = icmph->icmp6_type;
 319        serr->ee.ee_code = icmph->icmp6_code;
 320        serr->ee.ee_pad = 0;
 321        serr->ee.ee_info = info;
 322        serr->ee.ee_data = 0;
 323        serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 324                                  skb_network_header(skb);
 325        serr->port = port;
 326
 327        __skb_pull(skb, payload - skb->data);
 328
 329        if (inet6_sk(sk)->recverr_rfc4884)
 330                ipv6_icmp_error_rfc4884(skb, &serr->ee.ee_rfc4884);
 331
 332        skb_reset_transport_header(skb);
 333
 334        if (sock_queue_err_skb(sk, skb))
 335                kfree_skb(skb);
 336}
 337
 338void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 339{
 340        const struct ipv6_pinfo *np = inet6_sk(sk);
 341        struct sock_exterr_skb *serr;
 342        struct ipv6hdr *iph;
 343        struct sk_buff *skb;
 344
 345        if (!np->recverr)
 346                return;
 347
 348        skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 349        if (!skb)
 350                return;
 351
 352        skb->protocol = htons(ETH_P_IPV6);
 353
 354        skb_put(skb, sizeof(struct ipv6hdr));
 355        skb_reset_network_header(skb);
 356        iph = ipv6_hdr(skb);
 357        iph->daddr = fl6->daddr;
 358        ip6_flow_hdr(iph, 0, 0);
 359
 360        serr = SKB_EXT_ERR(skb);
 361        serr->ee.ee_errno = err;
 362        serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 363        serr->ee.ee_type = 0;
 364        serr->ee.ee_code = 0;
 365        serr->ee.ee_pad = 0;
 366        serr->ee.ee_info = info;
 367        serr->ee.ee_data = 0;
 368        serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 369        serr->port = fl6->fl6_dport;
 370
 371        __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 372        skb_reset_transport_header(skb);
 373
 374        if (sock_queue_err_skb(sk, skb))
 375                kfree_skb(skb);
 376}
 377
 378void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 379{
 380        struct ipv6_pinfo *np = inet6_sk(sk);
 381        struct ipv6hdr *iph;
 382        struct sk_buff *skb;
 383        struct ip6_mtuinfo *mtu_info;
 384
 385        if (!np->rxopt.bits.rxpmtu)
 386                return;
 387
 388        skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 389        if (!skb)
 390                return;
 391
 392        skb_put(skb, sizeof(struct ipv6hdr));
 393        skb_reset_network_header(skb);
 394        iph = ipv6_hdr(skb);
 395        iph->daddr = fl6->daddr;
 396
 397        mtu_info = IP6CBMTU(skb);
 398
 399        mtu_info->ip6m_mtu = mtu;
 400        mtu_info->ip6m_addr.sin6_family = AF_INET6;
 401        mtu_info->ip6m_addr.sin6_port = 0;
 402        mtu_info->ip6m_addr.sin6_flowinfo = 0;
 403        mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 404        mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 405
 406        __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 407        skb_reset_transport_header(skb);
 408
 409        skb = xchg(&np->rxpmtu, skb);
 410        kfree_skb(skb);
 411}
 412
 413/* For some errors we have valid addr_offset even with zero payload and
 414 * zero port. Also, addr_offset should be supported if port is set.
 415 */
 416static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 417{
 418        return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 419               serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 420               serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 421}
 422
 423/* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 424 *
 425 * At one point, excluding local errors was a quick test to identify icmp/icmp6
 426 * errors. This is no longer true, but the test remained, so the v6 stack,
 427 * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 428 */
 429static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 430                                      struct sock_exterr_skb *serr)
 431{
 432        if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 433            serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 434                return true;
 435
 436        if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 437                return false;
 438
 439        if (!IP6CB(skb)->iif)
 440                return false;
 441
 442        return true;
 443}
 444
 445/*
 446 *      Handle MSG_ERRQUEUE
 447 */
 448int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 449{
 450        struct ipv6_pinfo *np = inet6_sk(sk);
 451        struct sock_exterr_skb *serr;
 452        struct sk_buff *skb;
 453        DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 454        struct {
 455                struct sock_extended_err ee;
 456                struct sockaddr_in6      offender;
 457        } errhdr;
 458        int err;
 459        int copied;
 460
 461        err = -EAGAIN;
 462        skb = sock_dequeue_err_skb(sk);
 463        if (!skb)
 464                goto out;
 465
 466        copied = skb->len;
 467        if (copied > len) {
 468                msg->msg_flags |= MSG_TRUNC;
 469                copied = len;
 470        }
 471        err = skb_copy_datagram_msg(skb, 0, msg, copied);
 472        if (unlikely(err)) {
 473                kfree_skb(skb);
 474                return err;
 475        }
 476        sock_recv_timestamp(msg, sk, skb);
 477
 478        serr = SKB_EXT_ERR(skb);
 479
 480        if (sin && ipv6_datagram_support_addr(serr)) {
 481                const unsigned char *nh = skb_network_header(skb);
 482                sin->sin6_family = AF_INET6;
 483                sin->sin6_flowinfo = 0;
 484                sin->sin6_port = serr->port;
 485                if (skb->protocol == htons(ETH_P_IPV6)) {
 486                        const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 487                                                                  struct ipv6hdr, daddr);
 488                        sin->sin6_addr = ip6h->daddr;
 489                        if (np->sndflow)
 490                                sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 491                        sin->sin6_scope_id =
 492                                ipv6_iface_scope_id(&sin->sin6_addr,
 493                                                    IP6CB(skb)->iif);
 494                } else {
 495                        ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 496                                               &sin->sin6_addr);
 497                        sin->sin6_scope_id = 0;
 498                }
 499                *addr_len = sizeof(*sin);
 500        }
 501
 502        memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 503        sin = &errhdr.offender;
 504        memset(sin, 0, sizeof(*sin));
 505
 506        if (ip6_datagram_support_cmsg(skb, serr)) {
 507                sin->sin6_family = AF_INET6;
 508                if (np->rxopt.all)
 509                        ip6_datagram_recv_common_ctl(sk, msg, skb);
 510                if (skb->protocol == htons(ETH_P_IPV6)) {
 511                        sin->sin6_addr = ipv6_hdr(skb)->saddr;
 512                        if (np->rxopt.all)
 513                                ip6_datagram_recv_specific_ctl(sk, msg, skb);
 514                        sin->sin6_scope_id =
 515                                ipv6_iface_scope_id(&sin->sin6_addr,
 516                                                    IP6CB(skb)->iif);
 517                } else {
 518                        ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 519                                               &sin->sin6_addr);
 520                        if (inet_sk(sk)->cmsg_flags)
 521                                ip_cmsg_recv(msg, skb);
 522                }
 523        }
 524
 525        put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 526
 527        /* Now we could try to dump offended packet options */
 528
 529        msg->msg_flags |= MSG_ERRQUEUE;
 530        err = copied;
 531
 532        consume_skb(skb);
 533out:
 534        return err;
 535}
 536EXPORT_SYMBOL_GPL(ipv6_recv_error);
 537
 538/*
 539 *      Handle IPV6_RECVPATHMTU
 540 */
 541int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 542                     int *addr_len)
 543{
 544        struct ipv6_pinfo *np = inet6_sk(sk);
 545        struct sk_buff *skb;
 546        struct ip6_mtuinfo mtu_info;
 547        DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 548        int err;
 549        int copied;
 550
 551        err = -EAGAIN;
 552        skb = xchg(&np->rxpmtu, NULL);
 553        if (!skb)
 554                goto out;
 555
 556        copied = skb->len;
 557        if (copied > len) {
 558                msg->msg_flags |= MSG_TRUNC;
 559                copied = len;
 560        }
 561        err = skb_copy_datagram_msg(skb, 0, msg, copied);
 562        if (err)
 563                goto out_free_skb;
 564
 565        sock_recv_timestamp(msg, sk, skb);
 566
 567        memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 568
 569        if (sin) {
 570                sin->sin6_family = AF_INET6;
 571                sin->sin6_flowinfo = 0;
 572                sin->sin6_port = 0;
 573                sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 574                sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 575                *addr_len = sizeof(*sin);
 576        }
 577
 578        put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 579
 580        err = copied;
 581
 582out_free_skb:
 583        kfree_skb(skb);
 584out:
 585        return err;
 586}
 587
 588
 589void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 590                                 struct sk_buff *skb)
 591{
 592        struct ipv6_pinfo *np = inet6_sk(sk);
 593        bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 594
 595        if (np->rxopt.bits.rxinfo) {
 596                struct in6_pktinfo src_info;
 597
 598                if (is_ipv6) {
 599                        src_info.ipi6_ifindex = IP6CB(skb)->iif;
 600                        src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 601                } else {
 602                        src_info.ipi6_ifindex =
 603                                PKTINFO_SKB_CB(skb)->ipi_ifindex;
 604                        ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 605                                               &src_info.ipi6_addr);
 606                }
 607
 608                if (src_info.ipi6_ifindex >= 0)
 609                        put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 610                                 sizeof(src_info), &src_info);
 611        }
 612}
 613
 614void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 615                                    struct sk_buff *skb)
 616{
 617        struct ipv6_pinfo *np = inet6_sk(sk);
 618        struct inet6_skb_parm *opt = IP6CB(skb);
 619        unsigned char *nh = skb_network_header(skb);
 620
 621        if (np->rxopt.bits.rxhlim) {
 622                int hlim = ipv6_hdr(skb)->hop_limit;
 623                put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 624        }
 625
 626        if (np->rxopt.bits.rxtclass) {
 627                int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 628                put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 629        }
 630
 631        if (np->rxopt.bits.rxflow) {
 632                __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 633                if (flowinfo)
 634                        put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 635        }
 636
 637        /* HbH is allowed only once */
 638        if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 639                u8 *ptr = nh + sizeof(struct ipv6hdr);
 640                put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 641        }
 642
 643        if (opt->lastopt &&
 644            (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 645                /*
 646                 * Silly enough, but we need to reparse in order to
 647                 * report extension headers (except for HbH)
 648                 * in order.
 649                 *
 650                 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 651                 * (and WILL NOT be) defined because
 652                 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 653                 */
 654                unsigned int off = sizeof(struct ipv6hdr);
 655                u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 656
 657                while (off <= opt->lastopt) {
 658                        unsigned int len;
 659                        u8 *ptr = nh + off;
 660
 661                        switch (nexthdr) {
 662                        case IPPROTO_DSTOPTS:
 663                                nexthdr = ptr[0];
 664                                len = (ptr[1] + 1) << 3;
 665                                if (np->rxopt.bits.dstopts)
 666                                        put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 667                                break;
 668                        case IPPROTO_ROUTING:
 669                                nexthdr = ptr[0];
 670                                len = (ptr[1] + 1) << 3;
 671                                if (np->rxopt.bits.srcrt)
 672                                        put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 673                                break;
 674                        case IPPROTO_AH:
 675                                nexthdr = ptr[0];
 676                                len = (ptr[1] + 2) << 2;
 677                                break;
 678                        default:
 679                                nexthdr = ptr[0];
 680                                len = (ptr[1] + 1) << 3;
 681                                break;
 682                        }
 683
 684                        off += len;
 685                }
 686        }
 687
 688        /* socket options in old style */
 689        if (np->rxopt.bits.rxoinfo) {
 690                struct in6_pktinfo src_info;
 691
 692                src_info.ipi6_ifindex = opt->iif;
 693                src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 694                put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 695        }
 696        if (np->rxopt.bits.rxohlim) {
 697                int hlim = ipv6_hdr(skb)->hop_limit;
 698                put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 699        }
 700        if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 701                u8 *ptr = nh + sizeof(struct ipv6hdr);
 702                put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 703        }
 704        if (np->rxopt.bits.odstopts && opt->dst0) {
 705                u8 *ptr = nh + opt->dst0;
 706                put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 707        }
 708        if (np->rxopt.bits.osrcrt && opt->srcrt) {
 709                struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 710                put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 711        }
 712        if (np->rxopt.bits.odstopts && opt->dst1) {
 713                u8 *ptr = nh + opt->dst1;
 714                put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 715        }
 716        if (np->rxopt.bits.rxorigdstaddr) {
 717                struct sockaddr_in6 sin6;
 718                __be16 _ports[2], *ports;
 719
 720                ports = skb_header_pointer(skb, skb_transport_offset(skb),
 721                                           sizeof(_ports), &_ports);
 722                if (ports) {
 723                        /* All current transport protocols have the port numbers in the
 724                         * first four bytes of the transport header and this function is
 725                         * written with this assumption in mind.
 726                         */
 727                        sin6.sin6_family = AF_INET6;
 728                        sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 729                        sin6.sin6_port = ports[1];
 730                        sin6.sin6_flowinfo = 0;
 731                        sin6.sin6_scope_id =
 732                                ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 733                                                    opt->iif);
 734
 735                        put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 736                }
 737        }
 738        if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
 739                int val = opt->frag_max_size;
 740
 741                put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
 742        }
 743}
 744
 745void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 746                          struct sk_buff *skb)
 747{
 748        ip6_datagram_recv_common_ctl(sk, msg, skb);
 749        ip6_datagram_recv_specific_ctl(sk, msg, skb);
 750}
 751EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 752
 753int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 754                          struct msghdr *msg, struct flowi6 *fl6,
 755                          struct ipcm6_cookie *ipc6)
 756{
 757        struct in6_pktinfo *src_info;
 758        struct cmsghdr *cmsg;
 759        struct ipv6_rt_hdr *rthdr;
 760        struct ipv6_opt_hdr *hdr;
 761        struct ipv6_txoptions *opt = ipc6->opt;
 762        int len;
 763        int err = 0;
 764
 765        for_each_cmsghdr(cmsg, msg) {
 766                int addr_type;
 767
 768                if (!CMSG_OK(msg, cmsg)) {
 769                        err = -EINVAL;
 770                        goto exit_f;
 771                }
 772
 773                if (cmsg->cmsg_level == SOL_SOCKET) {
 774                        err = __sock_cmsg_send(sk, msg, cmsg, &ipc6->sockc);
 775                        if (err)
 776                                return err;
 777                        continue;
 778                }
 779
 780                if (cmsg->cmsg_level != SOL_IPV6)
 781                        continue;
 782
 783                switch (cmsg->cmsg_type) {
 784                case IPV6_PKTINFO:
 785                case IPV6_2292PKTINFO:
 786                    {
 787                        struct net_device *dev = NULL;
 788                        int src_idx;
 789
 790                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 791                                err = -EINVAL;
 792                                goto exit_f;
 793                        }
 794
 795                        src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 796                        src_idx = src_info->ipi6_ifindex;
 797
 798                        if (src_idx) {
 799                                if (fl6->flowi6_oif &&
 800                                    src_idx != fl6->flowi6_oif &&
 801                                    (READ_ONCE(sk->sk_bound_dev_if) != fl6->flowi6_oif ||
 802                                     !sk_dev_equal_l3scope(sk, src_idx)))
 803                                        return -EINVAL;
 804                                fl6->flowi6_oif = src_idx;
 805                        }
 806
 807                        addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 808
 809                        rcu_read_lock();
 810                        if (fl6->flowi6_oif) {
 811                                dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 812                                if (!dev) {
 813                                        rcu_read_unlock();
 814                                        return -ENODEV;
 815                                }
 816                        } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 817                                rcu_read_unlock();
 818                                return -EINVAL;
 819                        }
 820
 821                        if (addr_type != IPV6_ADDR_ANY) {
 822                                int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 823                                if (!ipv6_can_nonlocal_bind(net, inet_sk(sk)) &&
 824                                    !ipv6_chk_addr_and_flags(net, &src_info->ipi6_addr,
 825                                                             dev, !strict, 0,
 826                                                             IFA_F_TENTATIVE) &&
 827                                    !ipv6_chk_acast_addr_src(net, dev,
 828                                                             &src_info->ipi6_addr))
 829                                        err = -EINVAL;
 830                                else
 831                                        fl6->saddr = src_info->ipi6_addr;
 832                        }
 833
 834                        rcu_read_unlock();
 835
 836                        if (err)
 837                                goto exit_f;
 838
 839                        break;
 840                    }
 841
 842                case IPV6_FLOWINFO:
 843                        if (cmsg->cmsg_len < CMSG_LEN(4)) {
 844                                err = -EINVAL;
 845                                goto exit_f;
 846                        }
 847
 848                        if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 849                                if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 850                                        err = -EINVAL;
 851                                        goto exit_f;
 852                                }
 853                        }
 854                        fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 855                        break;
 856
 857                case IPV6_2292HOPOPTS:
 858                case IPV6_HOPOPTS:
 859                        if (opt->hopopt || 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                        opt->opt_nflen += len;
 875                        opt->hopopt = hdr;
 876                        break;
 877
 878                case IPV6_2292DSTOPTS:
 879                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 880                                err = -EINVAL;
 881                                goto exit_f;
 882                        }
 883
 884                        hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 885                        len = ((hdr->hdrlen + 1) << 3);
 886                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 887                                err = -EINVAL;
 888                                goto exit_f;
 889                        }
 890                        if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 891                                err = -EPERM;
 892                                goto exit_f;
 893                        }
 894                        if (opt->dst1opt) {
 895                                err = -EINVAL;
 896                                goto exit_f;
 897                        }
 898                        opt->opt_flen += len;
 899                        opt->dst1opt = hdr;
 900                        break;
 901
 902                case IPV6_DSTOPTS:
 903                case IPV6_RTHDRDSTOPTS:
 904                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 905                                err = -EINVAL;
 906                                goto exit_f;
 907                        }
 908
 909                        hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 910                        len = ((hdr->hdrlen + 1) << 3);
 911                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 912                                err = -EINVAL;
 913                                goto exit_f;
 914                        }
 915                        if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 916                                err = -EPERM;
 917                                goto exit_f;
 918                        }
 919                        if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 920                                opt->opt_flen += len;
 921                                opt->dst1opt = hdr;
 922                        } else {
 923                                opt->opt_nflen += len;
 924                                opt->dst0opt = hdr;
 925                        }
 926                        break;
 927
 928                case IPV6_2292RTHDR:
 929                case IPV6_RTHDR:
 930                        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 931                                err = -EINVAL;
 932                                goto exit_f;
 933                        }
 934
 935                        rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 936
 937                        switch (rthdr->type) {
 938#if IS_ENABLED(CONFIG_IPV6_MIP6)
 939                        case IPV6_SRCRT_TYPE_2:
 940                                if (rthdr->hdrlen != 2 ||
 941                                    rthdr->segments_left != 1) {
 942                                        err = -EINVAL;
 943                                        goto exit_f;
 944                                }
 945                                break;
 946#endif
 947                        default:
 948                                err = -EINVAL;
 949                                goto exit_f;
 950                        }
 951
 952                        len = ((rthdr->hdrlen + 1) << 3);
 953
 954                        if (cmsg->cmsg_len < CMSG_LEN(len)) {
 955                                err = -EINVAL;
 956                                goto exit_f;
 957                        }
 958
 959                        /* segments left must also match */
 960                        if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 961                                err = -EINVAL;
 962                                goto exit_f;
 963                        }
 964
 965                        opt->opt_nflen += len;
 966                        opt->srcrt = rthdr;
 967
 968                        if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 969                                int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 970
 971                                opt->opt_nflen += dsthdrlen;
 972                                opt->dst0opt = opt->dst1opt;
 973                                opt->dst1opt = NULL;
 974                                opt->opt_flen -= dsthdrlen;
 975                        }
 976
 977                        break;
 978
 979                case IPV6_2292HOPLIMIT:
 980                case IPV6_HOPLIMIT:
 981                        if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 982                                err = -EINVAL;
 983                                goto exit_f;
 984                        }
 985
 986                        ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 987                        if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 988                                err = -EINVAL;
 989                                goto exit_f;
 990                        }
 991
 992                        break;
 993
 994                case IPV6_TCLASS:
 995                    {
 996                        int tc;
 997
 998                        err = -EINVAL;
 999                        if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1000                                goto exit_f;
1001
1002                        tc = *(int *)CMSG_DATA(cmsg);
1003                        if (tc < -1 || tc > 0xff)
1004                                goto exit_f;
1005
1006                        err = 0;
1007                        ipc6->tclass = tc;
1008
1009                        break;
1010                    }
1011
1012                case IPV6_DONTFRAG:
1013                    {
1014                        int df;
1015
1016                        err = -EINVAL;
1017                        if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1018                                goto exit_f;
1019
1020                        df = *(int *)CMSG_DATA(cmsg);
1021                        if (df < 0 || df > 1)
1022                                goto exit_f;
1023
1024                        err = 0;
1025                        ipc6->dontfrag = df;
1026
1027                        break;
1028                    }
1029                default:
1030                        net_dbg_ratelimited("invalid cmsg type: %d\n",
1031                                            cmsg->cmsg_type);
1032                        err = -EINVAL;
1033                        goto exit_f;
1034                }
1035        }
1036
1037exit_f:
1038        return err;
1039}
1040EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1041
1042void __ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1043                               __u16 srcp, __u16 destp, int rqueue, int bucket)
1044{
1045        const struct in6_addr *dest, *src;
1046
1047        dest  = &sp->sk_v6_daddr;
1048        src   = &sp->sk_v6_rcv_saddr;
1049        seq_printf(seq,
1050                   "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1051                   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u\n",
1052                   bucket,
1053                   src->s6_addr32[0], src->s6_addr32[1],
1054                   src->s6_addr32[2], src->s6_addr32[3], srcp,
1055                   dest->s6_addr32[0], dest->s6_addr32[1],
1056                   dest->s6_addr32[2], dest->s6_addr32[3], destp,
1057                   sp->sk_state,
1058                   sk_wmem_alloc_get(sp),
1059                   rqueue,
1060                   0, 0L, 0,
1061                   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1062                   0,
1063                   sock_i_ino(sp),
1064                   refcount_read(&sp->sk_refcnt), sp,
1065                   atomic_read(&sp->sk_drops));
1066}
1067