net/ipv6/datagram.c

   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
  36 static bool ipv6_mapped_addr_any(const struct in6_addr *a)
  37 {
  38         return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
  39 }
  40
  41 static 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         int oif = sk->sk_bound_dev_if;
  46
  47         memset(fl6, 0, sizeof(*fl6));
  48         fl6->flowi6_proto = sk->sk_protocol;
  49         fl6->daddr = sk->sk_v6_daddr;
  50         fl6->saddr = np->saddr;
  51         fl6->flowi6_mark = sk->sk_mark;
  52         fl6->fl6_dport = inet->inet_dport;
  53         fl6->fl6_sport = inet->inet_sport;
  54         fl6->flowlabel = ip6_make_flowinfo(np->tclass, np->flow_label);
  55         fl6->flowi6_uid = sk->sk_uid;
  56
  57         if (!oif)
  58                 oif = np->sticky_pktinfo.ipi6_ifindex;
  59
  60         if (!oif) {
  61                 if (ipv6_addr_is_multicast(&fl6->daddr))
  62                         oif = np->mcast_oif;
  63                 else
  64                         oif = np->ucast_oif;
  65         }
  66
  67         fl6->flowi6_oif = oif;
  68         security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
  69 }
  70
  71 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
  72 {
  73         struct ip6_flowlabel *flowlabel = NULL;
  74         struct in6_addr *final_p, final;
  75         struct ipv6_txoptions *opt;
  76         struct dst_entry *dst;
  77         struct inet_sock *inet = inet_sk(sk);
  78         struct ipv6_pinfo *np = inet6_sk(sk);
  79         struct flowi6 fl6;
  80         int err = 0;
  81
  82         if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
  83                 flowlabel = fl6_sock_lookup(sk, np->flow_label);
  84                 if (IS_ERR(flowlabel))
  85                         return -EINVAL;
  86         }
  87         ip6_datagram_flow_key_init(&fl6, sk);
  88
  89         rcu_read_lock();
  90         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
  91         final_p = fl6_update_dst(&fl6, opt, &final);
  92         rcu_read_unlock();
  93
  94         dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
  95         if (IS_ERR(dst)) {
  96                 err = PTR_ERR(dst);
  97                 goto out;
  98         }
  99
 100         if (fix_sk_saddr) {
 101                 if (ipv6_addr_any(&np->saddr))
 102                         np->saddr = fl6.saddr;
 103
 104                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 105                         sk->sk_v6_rcv_saddr = fl6.saddr;
 106                         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 107                         if (sk->sk_prot->rehash)
 108                                 sk->sk_prot->rehash(sk);
 109                 }
 110         }
 111
 112         ip6_sk_dst_store_flow(sk, dst, &fl6);
 113
 114 out:
 115         fl6_sock_release(flowlabel);
 116         return err;
 117 }
 118
 119 void ip6_datagram_release_cb(struct sock *sk)
 120 {
 121         struct dst_entry *dst;
 122
 123         if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 124                 return;
 125
 126         rcu_read_lock();
 127         dst = __sk_dst_get(sk);
 128         if (!dst || !dst->obsolete ||
 129             dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
 130                 rcu_read_unlock();
 131                 return;
 132         }
 133         rcu_read_unlock();
 134
 135         ip6_datagram_dst_update(sk, false);
 136 }
 137 EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
 138
 139 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
 140                            int addr_len)
 141 {
 142         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
 143         struct inet_sock        *inet = inet_sk(sk);
 144         struct ipv6_pinfo       *np = inet6_sk(sk);
 145         struct in6_addr         *daddr, old_daddr;
 146         __be32                  fl6_flowlabel = 0;
 147         __be32                  old_fl6_flowlabel;
 148         __be16                  old_dport;
 149         int                     addr_type;
 150         int                     err;
 151
 152         if (usin->sin6_family == AF_INET) {
 153                 if (ipv6_only_sock(sk))
 154                         return -EAFNOSUPPORT;
 155                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
 156                 goto ipv4_connected;
 157         }
 158
 159         if (addr_len < SIN6_LEN_RFC2133)
 160                 return -EINVAL;
 161
 162         if (usin->sin6_family != AF_INET6)
 163                 return -EAFNOSUPPORT;
 164
 165         if (np->sndflow)
 166                 fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 167
 168         if (ipv6_addr_any(&usin->sin6_addr)) {
 169                 /*
 170                  *      connect to self
 171                  */
 172                 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
 173                         ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
 174                                                &usin->sin6_addr);
 175                 else
 176                         usin->sin6_addr = in6addr_loopback;
 177         }
 178
 179         addr_type = ipv6_addr_type(&usin->sin6_addr);
 180
 181         daddr = &usin->sin6_addr;
 182
 183         if (addr_type & IPV6_ADDR_MAPPED) {
 184                 struct sockaddr_in sin;
 185
 186                 if (ipv6_only_sock(sk)) {
 187                         err = -ENETUNREACH;
 188                         goto out;
 189                 }
 190                 sin.sin_family = AF_INET;
 191                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
 192                 sin.sin_port = usin->sin6_port;
 193
 194                 err = __ip4_datagram_connect(sk,
 195                                              (struct sockaddr *) &sin,
 196                                              sizeof(sin));
 197
 198 ipv4_connected:
 199                 if (err)
 200                         goto out;
 201
 202                 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 203
 204                 if (ipv6_addr_any(&np->saddr) ||
 205                     ipv6_mapped_addr_any(&np->saddr))
 206                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 207
 208                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 209                     ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 210                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 211                                                &sk->sk_v6_rcv_saddr);
 212                         if (sk->sk_prot->rehash)
 213                                 sk->sk_prot->rehash(sk);
 214                 }
 215
 216                 goto out;
 217         }
 218
 219         if (__ipv6_addr_needs_scope_id(addr_type)) {
 220                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 221                     usin->sin6_scope_id) {
 222                         if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id)) {
 223                                 err = -EINVAL;
 224                                 goto out;
 225                         }
 226                         WRITE_ONCE(sk->sk_bound_dev_if, usin->sin6_scope_id);
 227                 }
 228
 229                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 230                         WRITE_ONCE(sk->sk_bound_dev_if, np->mcast_oif);
 231
 232                 /* Connect to link-local address requires an interface */
 233                 if (!sk->sk_bound_dev_if) {
 234                         err = -EINVAL;
 235                         goto out;
 236                 }
 237         }
 238
 239         /* save the current peer information before updating it */
 240         old_daddr = sk->sk_v6_daddr;
 241         old_fl6_flowlabel = np->flow_label;
 242         old_dport = inet->inet_dport;
 243
 244         sk->sk_v6_daddr = *daddr;
 245         np->flow_label = fl6_flowlabel;
 246         inet->inet_dport = usin->sin6_port;
 247
 248         /*
 249          *      Check for a route to destination an obtain the
 250          *      destination cache for it.
 251          */
 252
 253         err = ip6_datagram_dst_update(sk, true);
 254         if (err) {
 255                 /* Restore the socket peer info, to keep it consistent with
 256                  * the old socket state
 257                  */
 258                 sk->sk_v6_daddr = old_daddr;
 259                 np->flow_label = old_fl6_flowlabel;
 260                 inet->inet_dport = old_dport;
 261                 goto out;
 262         }
 263
 264         reuseport_has_conns_set(sk);
 265         sk->sk_state = TCP_ESTABLISHED;
 266         sk_set_txhash(sk);
 267 out:
 268         return err;
 269 }
 270 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 271
 272 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 273 {
 274         int res;
 275
 276         lock_sock(sk);
 277         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 278         release_sock(sk);
 279         return res;
 280 }
 281 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 282
 283 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 284                                  int addr_len)
 285 {
 286         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 287         if (sin6->sin6_family != AF_INET6)
 288                 return -EAFNOSUPPORT;
 289         return ip6_datagram_connect(sk, uaddr, addr_len);
 290 }
 291 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 292
 293 static void ipv6_icmp_error_rfc4884(const struct sk_buff *skb,
 294                                     struct sock_ee_data_rfc4884 *out)
 295 {
 296         switch (icmp6_hdr(skb)->icmp6_type) {
 297         case ICMPV6_TIME_EXCEED:
 298         case ICMPV6_DEST_UNREACH:
 299                 ip_icmp_error_rfc4884(skb, out, sizeof(struct icmp6hdr),
 300                                       icmp6_hdr(skb)->icmp6_datagram_len * 8);
 301         }
 302 }
 303
 304 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 305                      __be16 port, u32 info, u8 *payload)
 306 {
 307         struct ipv6_pinfo *np  = inet6_sk(sk);
 308         struct icmp6hdr *icmph = icmp6_hdr(skb);
 309         struct sock_exterr_skb *serr;
 310
 311         if (!np->recverr)
 312                 return;
 313
 314         skb = skb_clone(skb, GFP_ATOMIC);
 315         if (!skb)
 316                 return;
 317
 318         skb->protocol = htons(ETH_P_IPV6);
 319
 320         serr = SKB_EXT_ERR(skb);
 321         serr->ee.ee_errno = err;
 322         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 323         serr->ee.ee_type = icmph->icmp6_type;
 324         serr->ee.ee_code = icmph->icmp6_code;
 325         serr->ee.ee_pad = 0;
 326         serr->ee.ee_info = info;
 327         serr->ee.ee_data = 0;
 328         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 329                                   skb_network_header(skb);
 330         serr->port = port;
 331
 332         __skb_pull(skb, payload - skb->data);
 333
 334         if (inet6_sk(sk)->recverr_rfc4884)
 335                 ipv6_icmp_error_rfc4884(skb, &serr->ee.ee_rfc4884);
 336
 337         skb_reset_transport_header(skb);
 338
 339         if (sock_queue_err_skb(sk, skb))
 340                 kfree_skb(skb);
 341 }
 342
 343 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 344 {
 345         const struct ipv6_pinfo *np = inet6_sk(sk);
 346         struct sock_exterr_skb *serr;
 347         struct ipv6hdr *iph;
 348         struct sk_buff *skb;
 349
 350         if (!np->recverr)
 351                 return;
 352
 353         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 354         if (!skb)
 355                 return;
 356
 357         skb->protocol = htons(ETH_P_IPV6);
 358
 359         skb_put(skb, sizeof(struct ipv6hdr));
 360         skb_reset_network_header(skb);
 361         iph = ipv6_hdr(skb);
 362         iph->daddr = fl6->daddr;
 363         ip6_flow_hdr(iph, 0, 0);
 364
 365         serr = SKB_EXT_ERR(skb);
 366         serr->ee.ee_errno = err;
 367         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 368         serr->ee.ee_type = 0;
 369         serr->ee.ee_code = 0;
 370         serr->ee.ee_pad = 0;
 371         serr->ee.ee_info = info;
 372         serr->ee.ee_data = 0;
 373         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 374         serr->port = fl6->fl6_dport;
 375
 376         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 377         skb_reset_transport_header(skb);
 378
 379         if (sock_queue_err_skb(sk, skb))
 380                 kfree_skb(skb);
 381 }
 382
 383 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 384 {
 385         struct ipv6_pinfo *np = inet6_sk(sk);
 386         struct ipv6hdr *iph;
 387         struct sk_buff *skb;
 388         struct ip6_mtuinfo *mtu_info;
 389
 390         if (!np->rxopt.bits.rxpmtu)
 391                 return;
 392
 393         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 394         if (!skb)
 395                 return;
 396
 397         skb_put(skb, sizeof(struct ipv6hdr));
 398         skb_reset_network_header(skb);
 399         iph = ipv6_hdr(skb);
 400         iph->daddr = fl6->daddr;
 401
 402         mtu_info = IP6CBMTU(skb);
 403
 404         mtu_info->ip6m_mtu = mtu;
 405         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 406         mtu_info->ip6m_addr.sin6_port = 0;
 407         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 408         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 409         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 410
 411         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 412         skb_reset_transport_header(skb);
 413
 414         skb = xchg(&np->rxpmtu, skb);
 415         kfree_skb(skb);
 416 }
 417
 418 /* For some errors we have valid addr_offset even with zero payload and
 419  * zero port. Also, addr_offset should be supported if port is set.
 420  */
 421 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 422 {
 423         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 424                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 425                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 426 }
 427
 428 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 429  *
 430  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 431  * errors. This is no longer true, but the test remained, so the v6 stack,
 432  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 433  */
 434 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 435                                       struct sock_exterr_skb *serr)
 436 {
 437         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 438             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 439                 return true;
 440
 441         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 442                 return false;
 443
 444         if (!IP6CB(skb)->iif)
 445                 return false;
 446
 447         return true;
 448 }
 449
 450 /*
 451  *      Handle MSG_ERRQUEUE
 452  */
 453 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 454 {
 455         struct ipv6_pinfo *np = inet6_sk(sk);
 456         struct sock_exterr_skb *serr;
 457         struct sk_buff *skb;
 458         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 459         struct {
 460                 struct sock_extended_err ee;
 461                 struct sockaddr_in6      offender;
 462         } errhdr;
 463         int err;
 464         int copied;
 465
 466         err = -EAGAIN;
 467         skb = sock_dequeue_err_skb(sk);
 468         if (!skb)
 469                 goto out;
 470
 471         copied = skb->len;
 472         if (copied > len) {
 473                 msg->msg_flags |= MSG_TRUNC;
 474                 copied = len;
 475         }
 476         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 477         if (unlikely(err)) {
 478                 kfree_skb(skb);
 479                 return err;
 480         }
 481         sock_recv_timestamp(msg, sk, skb);
 482
 483         serr = SKB_EXT_ERR(skb);
 484
 485         if (sin && ipv6_datagram_support_addr(serr)) {
 486                 const unsigned char *nh = skb_network_header(skb);
 487                 sin->sin6_family = AF_INET6;
 488                 sin->sin6_flowinfo = 0;
 489                 sin->sin6_port = serr->port;
 490                 if (skb->protocol == htons(ETH_P_IPV6)) {
 491                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 492                                                                   struct ipv6hdr, daddr);
 493                         sin->sin6_addr = ip6h->daddr;
 494                         if (np->sndflow)
 495                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 496                         sin->sin6_scope_id =
 497                                 ipv6_iface_scope_id(&sin->sin6_addr,
 498                                                     IP6CB(skb)->iif);
 499                 } else {
 500                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 501                                                &sin->sin6_addr);
 502                         sin->sin6_scope_id = 0;
 503                 }
 504                 *addr_len = sizeof(*sin);
 505         }
 506
 507         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 508         sin = &errhdr.offender;
 509         memset(sin, 0, sizeof(*sin));
 510
 511         if (ip6_datagram_support_cmsg(skb, serr)) {
 512                 sin->sin6_family = AF_INET6;
 513                 if (np->rxopt.all)
 514                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 515                 if (skb->protocol == htons(ETH_P_IPV6)) {
 516                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 517                         if (np->rxopt.all)
 518                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 519                         sin->sin6_scope_id =
 520                                 ipv6_iface_scope_id(&sin->sin6_addr,
 521                                                     IP6CB(skb)->iif);
 522                 } else {
 523                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 524                                                &sin->sin6_addr);
 525                         if (inet_sk(sk)->cmsg_flags)
 526                                 ip_cmsg_recv(msg, skb);
 527                 }
 528         }
 529
 530         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 531
 532         /* Now we could try to dump offended packet options */
 533
 534         msg->msg_flags |= MSG_ERRQUEUE;
 535         err = copied;
 536
 537         consume_skb(skb);
 538 out:
 539         return err;
 540 }
 541 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 542
 543 /*
 544  *      Handle IPV6_RECVPATHMTU
 545  */
 546 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 547                      int *addr_len)
 548 {
 549         struct ipv6_pinfo *np = inet6_sk(sk);
 550         struct sk_buff *skb;
 551         struct ip6_mtuinfo mtu_info;
 552         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 553         int err;
 554         int copied;
 555
 556         err = -EAGAIN;
 557         skb = xchg(&np->rxpmtu, NULL);
 558         if (!skb)
 559                 goto out;
 560
 561         copied = skb->len;
 562         if (copied > len) {
 563                 msg->msg_flags |= MSG_TRUNC;
 564                 copied = len;
 565         }
 566         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 567         if (err)
 568                 goto out_free_skb;
 569
 570         sock_recv_timestamp(msg, sk, skb);
 571
 572         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 573
 574         if (sin) {
 575                 sin->sin6_family = AF_INET6;
 576                 sin->sin6_flowinfo = 0;
 577                 sin->sin6_port = 0;
 578                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 579                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 580                 *addr_len = sizeof(*sin);
 581         }
 582
 583         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 584
 585         err = copied;
 586
 587 out_free_skb:
 588         kfree_skb(skb);
 589 out:
 590         return err;
 591 }
 592
 593
 594 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 595                                  struct sk_buff *skb)
 596 {
 597         struct ipv6_pinfo *np = inet6_sk(sk);
 598         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 599
 600         if (np->rxopt.bits.rxinfo) {
 601                 struct in6_pktinfo src_info;
 602
 603                 if (is_ipv6) {
 604                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 605                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 606                 } else {
 607                         src_info.ipi6_ifindex =
 608                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 609                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 610                                                &src_info.ipi6_addr);
 611                 }
 612
 613                 if (src_info.ipi6_ifindex >= 0)
 614                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 615                                  sizeof(src_info), &src_info);
 616         }
 617 }
 618
 619 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 620                                     struct sk_buff *skb)
 621 {
 622         struct ipv6_pinfo *np = inet6_sk(sk);
 623         struct inet6_skb_parm *opt = IP6CB(skb);
 624         unsigned char *nh = skb_network_header(skb);
 625
 626         if (np->rxopt.bits.rxhlim) {
 627                 int hlim = ipv6_hdr(skb)->hop_limit;
 628                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 629         }
 630
 631         if (np->rxopt.bits.rxtclass) {
 632                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 633                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 634         }
 635
 636         if (np->rxopt.bits.rxflow) {
 637                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 638                 if (flowinfo)
 639                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 640         }
 641
 642         /* HbH is allowed only once */
 643         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 644                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 645                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 646         }
 647
 648         if (opt->lastopt &&
 649             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 650                 /*
 651                  * Silly enough, but we need to reparse in order to
 652                  * report extension headers (except for HbH)
 653                  * in order.
 654                  *
 655                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 656                  * (and WILL NOT be) defined because
 657                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 658                  */
 659                 unsigned int off = sizeof(struct ipv6hdr);
 660                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 661
 662                 while (off <= opt->lastopt) {
 663                         unsigned int len;
 664                         u8 *ptr = nh + off;
 665
 666                         switch (nexthdr) {
 667                         case IPPROTO_DSTOPTS:
 668                                 nexthdr = ptr[0];
 669                                 len = (ptr[1] + 1) << 3;
 670                                 if (np->rxopt.bits.dstopts)
 671                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 672                                 break;
 673                         case IPPROTO_ROUTING:
 674                                 nexthdr = ptr[0];
 675                                 len = (ptr[1] + 1) << 3;
 676                                 if (np->rxopt.bits.srcrt)
 677                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 678                                 break;
 679                         case IPPROTO_AH:
 680                                 nexthdr = ptr[0];
 681                                 len = (ptr[1] + 2) << 2;
 682                                 break;
 683                         default:
 684                                 nexthdr = ptr[0];
 685                                 len = (ptr[1] + 1) << 3;
 686                                 break;
 687                         }
 688
 689                         off += len;
 690                 }
 691         }
 692
 693         /* socket options in old style */
 694         if (np->rxopt.bits.rxoinfo) {
 695                 struct in6_pktinfo src_info;
 696
 697                 src_info.ipi6_ifindex = opt->iif;
 698                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 699                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 700         }
 701         if (np->rxopt.bits.rxohlim) {
 702                 int hlim = ipv6_hdr(skb)->hop_limit;
 703                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 704         }
 705         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 706                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 707                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 708         }
 709         if (np->rxopt.bits.odstopts && opt->dst0) {
 710                 u8 *ptr = nh + opt->dst0;
 711                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 712         }
 713         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 714                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 715                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 716         }
 717         if (np->rxopt.bits.odstopts && opt->dst1) {
 718                 u8 *ptr = nh + opt->dst1;
 719                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 720         }
 721         if (np->rxopt.bits.rxorigdstaddr) {
 722                 struct sockaddr_in6 sin6;
 723                 __be16 _ports[2], *ports;
 724
 725                 ports = skb_header_pointer(skb, skb_transport_offset(skb),
 726                                            sizeof(_ports), &_ports);
 727                 if (ports) {
 728                         /* All current transport protocols have the port numbers in the
 729                          * first four bytes of the transport header and this function is
 730                          * written with this assumption in mind.
 731                          */
 732                         sin6.sin6_family = AF_INET6;
 733                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 734                         sin6.sin6_port = ports[1];
 735                         sin6.sin6_flowinfo = 0;
 736                         sin6.sin6_scope_id =
 737                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 738                                                     opt->iif);
 739
 740                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 741                 }
 742         }
 743         if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
 744                 int val = opt->frag_max_size;
 745
 746                 put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
 747         }
 748 }
 749
 750 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 751                           struct sk_buff *skb)
 752 {
 753         ip6_datagram_recv_common_ctl(sk, msg, skb);
 754         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 755 }
 756 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 757
 758 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 759                           struct msghdr *msg, struct flowi6 *fl6,
 760                           struct ipcm6_cookie *ipc6)
 761 {
 762         struct in6_pktinfo *src_info;
 763         struct cmsghdr *cmsg;
 764         struct ipv6_rt_hdr *rthdr;
 765         struct ipv6_opt_hdr *hdr;
 766         struct ipv6_txoptions *opt = ipc6->opt;
 767         int len;
 768         int err = 0;
 769
 770         for_each_cmsghdr(cmsg, msg) {
 771                 int addr_type;
 772
 773                 if (!CMSG_OK(msg, cmsg)) {
 774                         err = -EINVAL;
 775                         goto exit_f;
 776                 }
 777
 778                 if (cmsg->cmsg_level == SOL_SOCKET) {
 779                         err = __sock_cmsg_send(sk, msg, cmsg, &ipc6->sockc);
 780                         if (err)
 781                                 return err;
 782                         continue;
 783                 }
 784
 785                 if (cmsg->cmsg_level != SOL_IPV6)
 786                         continue;
 787
 788                 switch (cmsg->cmsg_type) {
 789                 case IPV6_PKTINFO:
 790                 case IPV6_2292PKTINFO:
 791                     {
 792                         struct net_device *dev = NULL;
 793                         int src_idx;
 794
 795                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 796                                 err = -EINVAL;
 797                                 goto exit_f;
 798                         }
 799
 800                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 801                         src_idx = src_info->ipi6_ifindex;
 802
 803                         if (src_idx) {
 804                                 if (fl6->flowi6_oif &&
 805                                     src_idx != fl6->flowi6_oif &&
 806                                     (READ_ONCE(sk->sk_bound_dev_if) != fl6->flowi6_oif ||
 807                                      !sk_dev_equal_l3scope(sk, src_idx)))
 808                                         return -EINVAL;
 809                                 fl6->flowi6_oif = src_idx;
 810                         }
 811
 812                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 813
 814                         rcu_read_lock();
 815                         if (fl6->flowi6_oif) {
 816                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 817                                 if (!dev) {
 818                                         rcu_read_unlock();
 819                                         return -ENODEV;
 820                                 }
 821                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 822                                 rcu_read_unlock();
 823                                 return -EINVAL;
 824                         }
 825
 826                         if (addr_type != IPV6_ADDR_ANY) {
 827                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 828                                 if (!ipv6_can_nonlocal_bind(net, inet_sk(sk)) &&
 829                                     !ipv6_chk_addr_and_flags(net, &src_info->ipi6_addr,
 830                                                              dev, !strict, 0,
 831                                                              IFA_F_TENTATIVE) &&
 832                                     !ipv6_chk_acast_addr_src(net, dev,
 833                                                              &src_info->ipi6_addr))
 834                                         err = -EINVAL;
 835                                 else
 836                                         fl6->saddr = src_info->ipi6_addr;
 837                         }
 838
 839                         rcu_read_unlock();
 840
 841                         if (err)
 842                                 goto exit_f;
 843
 844                         break;
 845                     }
 846
 847                 case IPV6_FLOWINFO:
 848                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 849                                 err = -EINVAL;
 850                                 goto exit_f;
 851                         }
 852
 853                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 854                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 855                                         err = -EINVAL;
 856                                         goto exit_f;
 857                                 }
 858                         }
 859                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 860                         break;
 861
 862                 case IPV6_2292HOPOPTS:
 863                 case IPV6_HOPOPTS:
 864                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 865                                 err = -EINVAL;
 866                                 goto exit_f;
 867                         }
 868
 869                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 870                         len = ((hdr->hdrlen + 1) << 3);
 871                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 872                                 err = -EINVAL;
 873                                 goto exit_f;
 874                         }
 875                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 876                                 err = -EPERM;
 877                                 goto exit_f;
 878                         }
 879                         opt->opt_nflen += len;
 880                         opt->hopopt = hdr;
 881                         break;
 882
 883                 case IPV6_2292DSTOPTS:
 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 (opt->dst1opt) {
 900                                 err = -EINVAL;
 901                                 goto exit_f;
 902                         }
 903                         opt->opt_flen += len;
 904                         opt->dst1opt = hdr;
 905                         break;
 906
 907                 case IPV6_DSTOPTS:
 908                 case IPV6_RTHDRDSTOPTS:
 909                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 910                                 err = -EINVAL;
 911                                 goto exit_f;
 912                         }
 913
 914                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 915                         len = ((hdr->hdrlen + 1) << 3);
 916                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 917                                 err = -EINVAL;
 918                                 goto exit_f;
 919                         }
 920                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 921                                 err = -EPERM;
 922                                 goto exit_f;
 923                         }
 924                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 925                                 opt->opt_flen += len;
 926                                 opt->dst1opt = hdr;
 927                         } else {
 928                                 opt->opt_nflen += len;
 929                                 opt->dst0opt = hdr;
 930                         }
 931                         break;
 932
 933                 case IPV6_2292RTHDR:
 934                 case IPV6_RTHDR:
 935                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 936                                 err = -EINVAL;
 937                                 goto exit_f;
 938                         }
 939
 940                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 941
 942                         switch (rthdr->type) {
 943 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 944                         case IPV6_SRCRT_TYPE_2:
 945                                 if (rthdr->hdrlen != 2 ||
 946                                     rthdr->segments_left != 1) {
 947                                         err = -EINVAL;
 948                                         goto exit_f;
 949                                 }
 950                                 break;
 951 #endif
 952                         default:
 953                                 err = -EINVAL;
 954                                 goto exit_f;
 955                         }
 956
 957                         len = ((rthdr->hdrlen + 1) << 3);
 958
 959                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 960                                 err = -EINVAL;
 961                                 goto exit_f;
 962                         }
 963
 964                         /* segments left must also match */
 965                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 966                                 err = -EINVAL;
 967                                 goto exit_f;
 968                         }
 969
 970                         opt->opt_nflen += len;
 971                         opt->srcrt = rthdr;
 972
 973                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 974                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 975
 976                                 opt->opt_nflen += dsthdrlen;
 977                                 opt->dst0opt = opt->dst1opt;
 978                                 opt->dst1opt = NULL;
 979                                 opt->opt_flen -= dsthdrlen;
 980                         }
 981
 982                         break;
 983
 984                 case IPV6_2292HOPLIMIT:
 985                 case IPV6_HOPLIMIT:
 986                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 987                                 err = -EINVAL;
 988                                 goto exit_f;
 989                         }
 990
 991                         ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 992                         if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 993                                 err = -EINVAL;
 994                                 goto exit_f;
 995                         }
 996
 997                         break;
 998
 999                 case IPV6_TCLASS:
1000                     {
1001                         int tc;
1002
1003                         err = -EINVAL;
1004                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1005                                 goto exit_f;
1006
1007                         tc = *(int *)CMSG_DATA(cmsg);
1008                         if (tc < -1 || tc > 0xff)
1009                                 goto exit_f;
1010
1011                         err = 0;
1012                         ipc6->tclass = tc;
1013
1014                         break;
1015                     }
1016
1017                 case IPV6_DONTFRAG:
1018                     {
1019                         int df;
1020
1021                         err = -EINVAL;
1022                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1023                                 goto exit_f;
1024
1025                         df = *(int *)CMSG_DATA(cmsg);
1026                         if (df < 0 || df > 1)
1027                                 goto exit_f;
1028
1029                         err = 0;
1030                         ipc6->dontfrag = df;
1031
1032                         break;
1033                     }
1034                 default:
1035                         net_dbg_ratelimited("invalid cmsg type: %d\n",
1036                                             cmsg->cmsg_type);
1037                         err = -EINVAL;
1038                         goto exit_f;
1039                 }
1040         }
1041
1042 exit_f:
1043         return err;
1044 }
1045 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1046
1047 void __ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1048                                __u16 srcp, __u16 destp, int rqueue, int bucket)
1049 {
1050         const struct in6_addr *dest, *src;
1051
1052         dest  = &sp->sk_v6_daddr;
1053         src   = &sp->sk_v6_rcv_saddr;
1054         seq_printf(seq,
1055                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1056                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u\n",
1057                    bucket,
1058                    src->s6_addr32[0], src->s6_addr32[1],
1059                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1060                    dest->s6_addr32[0], dest->s6_addr32[1],
1061                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1062                    sp->sk_state,
1063                    sk_wmem_alloc_get(sp),
1064                    rqueue,
1065                    0, 0L, 0,
1066                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1067                    0,
1068                    sock_i_ino(sp),
1069                    refcount_read(&sp->sk_refcnt), sp,
1070                    atomic_read(&sp->sk_drops));
1071 }