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             <[email protected]>
   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,
  42                                        const struct sock *sk)
  43 {
  44         const struct inet_sock *inet = inet_sk(sk);
  45         const struct ipv6_pinfo *np = inet6_sk(sk);
  46         int oif = sk->sk_bound_dev_if;
  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_mark = sk->sk_mark;
  53         fl6->fl6_dport = inet->inet_dport;
  54         fl6->fl6_sport = inet->inet_sport;
  55         fl6->flowlabel = ip6_make_flowinfo(np->tclass, np->flow_label);
  56         fl6->flowi6_uid = sk->sk_uid;
  57
  58         if (!oif)
  59                 oif = np->sticky_pktinfo.ipi6_ifindex;
  60
  61         if (!oif) {
  62                 if (ipv6_addr_is_multicast(&fl6->daddr))
  63                         oif = READ_ONCE(np->mcast_oif);
  64                 else
  65                         oif = READ_ONCE(np->ucast_oif);
  66         }
  67
  68         fl6->flowi6_oif = oif;
  69         security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
  70 }
  71
  72 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
  73 {
  74         struct ip6_flowlabel *flowlabel = NULL;
  75         struct in6_addr *final_p, final;
  76         struct ipv6_txoptions *opt;
  77         struct dst_entry *dst;
  78         struct inet_sock *inet = inet_sk(sk);
  79         struct ipv6_pinfo *np = inet6_sk(sk);
  80         struct flowi6 fl6;
  81         int err = 0;
  82
  83         if (inet6_test_bit(SNDFLOW, sk) &&
  84             (np->flow_label & IPV6_FLOWLABEL_MASK)) {
  85                 flowlabel = fl6_sock_lookup(sk, np->flow_label);
  86                 if (IS_ERR(flowlabel))
  87                         return -EINVAL;
  88         }
  89         ip6_datagram_flow_key_init(&fl6, sk);
  90
  91         rcu_read_lock();
  92         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
  93         final_p = fl6_update_dst(&fl6, opt, &final);
  94         rcu_read_unlock();
  95
  96         dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
  97         if (IS_ERR(dst)) {
  98                 err = PTR_ERR(dst);
  99                 goto out;
 100         }
 101
 102         if (fix_sk_saddr) {
 103                 if (ipv6_addr_any(&np->saddr))
 104                         np->saddr = fl6.saddr;
 105
 106                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 107                         sk->sk_v6_rcv_saddr = fl6.saddr;
 108                         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 109                         if (sk->sk_prot->rehash)
 110                                 sk->sk_prot->rehash(sk);
 111                 }
 112         }
 113
 114         ip6_sk_dst_store_flow(sk, dst, &fl6);
 115
 116 out:
 117         fl6_sock_release(flowlabel);
 118         return err;
 119 }
 120
 121 void ip6_datagram_release_cb(struct sock *sk)
 122 {
 123         struct dst_entry *dst;
 124
 125         if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 126                 return;
 127
 128         rcu_read_lock();
 129         dst = __sk_dst_get(sk);
 130         if (!dst || !dst->obsolete ||
 131             dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
 132                 rcu_read_unlock();
 133                 return;
 134         }
 135         rcu_read_unlock();
 136
 137         ip6_datagram_dst_update(sk, false);
 138 }
 139 EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
 140
 141 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
 142                            int addr_len)
 143 {
 144         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
 145         struct inet_sock        *inet = inet_sk(sk);
 146         struct ipv6_pinfo       *np = inet6_sk(sk);
 147         struct in6_addr         *daddr, old_daddr;
 148         __be32                  fl6_flowlabel = 0;
 149         __be32                  old_fl6_flowlabel;
 150         __be16                  old_dport;
 151         int                     addr_type;
 152         int                     err;
 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 (inet6_test_bit(SNDFLOW, sk))
 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
 200 ipv4_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_dev_equal_l3scope(sk, usin->sin6_scope_id)) {
 225                                 err = -EINVAL;
 226                                 goto out;
 227                         }
 228                         WRITE_ONCE(sk->sk_bound_dev_if, usin->sin6_scope_id);
 229                 }
 230
 231                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 232                         WRITE_ONCE(sk->sk_bound_dev_if, READ_ONCE(np->mcast_oif));
 233
 234                 /* Connect to link-local address requires an interface */
 235                 if (!sk->sk_bound_dev_if) {
 236                         err = -EINVAL;
 237                         goto out;
 238                 }
 239         }
 240
 241         /* save the current peer information before updating it */
 242         old_daddr = sk->sk_v6_daddr;
 243         old_fl6_flowlabel = np->flow_label;
 244         old_dport = inet->inet_dport;
 245
 246         sk->sk_v6_daddr = *daddr;
 247         np->flow_label = fl6_flowlabel;
 248         inet->inet_dport = usin->sin6_port;
 249
 250         /*
 251          *      Check for a route to destination an obtain the
 252          *      destination cache for it.
 253          */
 254
 255         err = ip6_datagram_dst_update(sk, true);
 256         if (err) {
 257                 /* Restore the socket peer info, to keep it consistent with
 258                  * the old socket state
 259                  */
 260                 sk->sk_v6_daddr = old_daddr;
 261                 np->flow_label = old_fl6_flowlabel;
 262                 inet->inet_dport = old_dport;
 263                 goto out;
 264         }
 265
 266         reuseport_has_conns_set(sk);
 267         sk->sk_state = TCP_ESTABLISHED;
 268         sk_set_txhash(sk);
 269 out:
 270         return err;
 271 }
 272 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 273
 274 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 275 {
 276         int res;
 277
 278         lock_sock(sk);
 279         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 280         release_sock(sk);
 281         return res;
 282 }
 283 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 284
 285 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 286                                  int addr_len)
 287 {
 288         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 289         if (sin6->sin6_family != AF_INET6)
 290                 return -EAFNOSUPPORT;
 291         return ip6_datagram_connect(sk, uaddr, addr_len);
 292 }
 293 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 294
 295 static void ipv6_icmp_error_rfc4884(const struct sk_buff *skb,
 296                                     struct sock_ee_data_rfc4884 *out)
 297 {
 298         switch (icmp6_hdr(skb)->icmp6_type) {
 299         case ICMPV6_TIME_EXCEED:
 300         case ICMPV6_DEST_UNREACH:
 301                 ip_icmp_error_rfc4884(skb, out, sizeof(struct icmp6hdr),
 302                                       icmp6_hdr(skb)->icmp6_datagram_len * 8);
 303         }
 304 }
 305
 306 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 307                      __be16 port, u32 info, u8 *payload)
 308 {
 309         struct icmp6hdr *icmph = icmp6_hdr(skb);
 310         struct sock_exterr_skb *serr;
 311
 312         if (!inet6_test_bit(RECVERR6, sk))
 313                 return;
 314
 315         skb = skb_clone(skb, GFP_ATOMIC);
 316         if (!skb)
 317                 return;
 318
 319         skb->protocol = htons(ETH_P_IPV6);
 320
 321         serr = SKB_EXT_ERR(skb);
 322         serr->ee.ee_errno = err;
 323         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 324         serr->ee.ee_type = icmph->icmp6_type;
 325         serr->ee.ee_code = icmph->icmp6_code;
 326         serr->ee.ee_pad = 0;
 327         serr->ee.ee_info = info;
 328         serr->ee.ee_data = 0;
 329         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 330                                   skb_network_header(skb);
 331         serr->port = port;
 332
 333         __skb_pull(skb, payload - skb->data);
 334
 335         if (inet6_test_bit(RECVERR6_RFC4884, sk))
 336                 ipv6_icmp_error_rfc4884(skb, &serr->ee.ee_rfc4884);
 337
 338         skb_reset_transport_header(skb);
 339
 340         if (sock_queue_err_skb(sk, skb))
 341                 kfree_skb(skb);
 342 }
 343 EXPORT_SYMBOL_GPL(ipv6_icmp_error);
 344
 345 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 346 {
 347         struct sock_exterr_skb *serr;
 348         struct ipv6hdr *iph;
 349         struct sk_buff *skb;
 350
 351         if (!inet6_test_bit(RECVERR6, sk))
 352                 return;
 353
 354         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 355         if (!skb)
 356                 return;
 357
 358         skb->protocol = htons(ETH_P_IPV6);
 359
 360         skb_put(skb, sizeof(struct ipv6hdr));
 361         skb_reset_network_header(skb);
 362         iph = ipv6_hdr(skb);
 363         iph->daddr = fl6->daddr;
 364         ip6_flow_hdr(iph, 0, 0);
 365
 366         serr = SKB_EXT_ERR(skb);
 367         serr->ee.ee_errno = err;
 368         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 369         serr->ee.ee_type = 0;
 370         serr->ee.ee_code = 0;
 371         serr->ee.ee_pad = 0;
 372         serr->ee.ee_info = info;
 373         serr->ee.ee_data = 0;
 374         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 375         serr->port = fl6->fl6_dport;
 376
 377         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 378         skb_reset_transport_header(skb);
 379
 380         if (sock_queue_err_skb(sk, skb))
 381                 kfree_skb(skb);
 382 }
 383
 384 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 385 {
 386         struct ipv6_pinfo *np = inet6_sk(sk);
 387         struct ipv6hdr *iph;
 388         struct sk_buff *skb;
 389         struct ip6_mtuinfo *mtu_info;
 390
 391         if (!np->rxopt.bits.rxpmtu)
 392                 return;
 393
 394         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 395         if (!skb)
 396                 return;
 397
 398         skb_put(skb, sizeof(struct ipv6hdr));
 399         skb_reset_network_header(skb);
 400         iph = ipv6_hdr(skb);
 401         iph->daddr = fl6->daddr;
 402
 403         mtu_info = IP6CBMTU(skb);
 404
 405         mtu_info->ip6m_mtu = mtu;
 406         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 407         mtu_info->ip6m_addr.sin6_port = 0;
 408         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 409         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 410         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 411
 412         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 413         skb_reset_transport_header(skb);
 414
 415         skb = xchg(&np->rxpmtu, skb);
 416         kfree_skb(skb);
 417 }
 418
 419 /* For some errors we have valid addr_offset even with zero payload and
 420  * zero port. Also, addr_offset should be supported if port is set.
 421  */
 422 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 423 {
 424         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 425                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 426                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 427 }
 428
 429 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 430  *
 431  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 432  * errors. This is no longer true, but the test remained, so the v6 stack,
 433  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 434  */
 435 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 436                                       struct sock_exterr_skb *serr)
 437 {
 438         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 439             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 440                 return true;
 441
 442         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 443                 return false;
 444
 445         if (!IP6CB(skb)->iif)
 446                 return false;
 447
 448         return true;
 449 }
 450
 451 /*
 452  *      Handle MSG_ERRQUEUE
 453  */
 454 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 455 {
 456         struct ipv6_pinfo *np = inet6_sk(sk);
 457         struct sock_exterr_skb *serr;
 458         struct sk_buff *skb;
 459         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 460         struct {
 461                 struct sock_extended_err ee;
 462                 struct sockaddr_in6      offender;
 463         } errhdr;
 464         int err;
 465         int copied;
 466
 467         err = -EAGAIN;
 468         skb = sock_dequeue_err_skb(sk);
 469         if (!skb)
 470                 goto out;
 471
 472         copied = skb->len;
 473         if (copied > len) {
 474                 msg->msg_flags |= MSG_TRUNC;
 475                 copied = len;
 476         }
 477         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 478         if (unlikely(err)) {
 479                 kfree_skb(skb);
 480                 return err;
 481         }
 482         sock_recv_timestamp(msg, sk, skb);
 483
 484         serr = SKB_EXT_ERR(skb);
 485
 486         if (sin && ipv6_datagram_support_addr(serr)) {
 487                 const unsigned char *nh = skb_network_header(skb);
 488                 sin->sin6_family = AF_INET6;
 489                 sin->sin6_flowinfo = 0;
 490                 sin->sin6_port = serr->port;
 491                 if (skb->protocol == htons(ETH_P_IPV6)) {
 492                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 493                                                                   struct ipv6hdr, daddr);
 494                         sin->sin6_addr = ip6h->daddr;
 495                         if (inet6_test_bit(SNDFLOW, sk))
 496                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 497                         sin->sin6_scope_id =
 498                                 ipv6_iface_scope_id(&sin->sin6_addr,
 499                                                     IP6CB(skb)->iif);
 500                 } else {
 501                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 502                                                &sin->sin6_addr);
 503                         sin->sin6_scope_id = 0;
 504                 }
 505                 *addr_len = sizeof(*sin);
 506         }
 507
 508         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 509         sin = &errhdr.offender;
 510         memset(sin, 0, sizeof(*sin));
 511
 512         if (ip6_datagram_support_cmsg(skb, serr)) {
 513                 sin->sin6_family = AF_INET6;
 514                 if (np->rxopt.all)
 515                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 516                 if (skb->protocol == htons(ETH_P_IPV6)) {
 517                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 518                         if (np->rxopt.all)
 519                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 520                         sin->sin6_scope_id =
 521                                 ipv6_iface_scope_id(&sin->sin6_addr,
 522                                                     IP6CB(skb)->iif);
 523                 } else {
 524                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 525                                                &sin->sin6_addr);
 526                         if (inet_cmsg_flags(inet_sk(sk)))
 527                                 ip_cmsg_recv(msg, skb);
 528                 }
 529         }
 530
 531         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 532
 533         /* Now we could try to dump offended packet options */
 534
 535         msg->msg_flags |= MSG_ERRQUEUE;
 536         err = copied;
 537
 538         consume_skb(skb);
 539 out:
 540         return err;
 541 }
 542 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 543
 544 /*
 545  *      Handle IPV6_RECVPATHMTU
 546  */
 547 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 548                      int *addr_len)
 549 {
 550         struct ipv6_pinfo *np = inet6_sk(sk);
 551         struct sk_buff *skb;
 552         struct ip6_mtuinfo mtu_info;
 553         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 554         int err;
 555         int copied;
 556
 557         err = -EAGAIN;
 558         skb = xchg(&np->rxpmtu, NULL);
 559         if (!skb)
 560                 goto out;
 561
 562         copied = skb->len;
 563         if (copied > len) {
 564                 msg->msg_flags |= MSG_TRUNC;
 565                 copied = len;
 566         }
 567         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 568         if (err)
 569                 goto out_free_skb;
 570
 571         sock_recv_timestamp(msg, sk, skb);
 572
 573         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 574
 575         if (sin) {
 576                 sin->sin6_family = AF_INET6;
 577                 sin->sin6_flowinfo = 0;
 578                 sin->sin6_port = 0;
 579                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 580                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 581                 *addr_len = sizeof(*sin);
 582         }
 583
 584         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 585
 586         err = copied;
 587
 588 out_free_skb:
 589         kfree_skb(skb);
 590 out:
 591         return err;
 592 }
 593
 594
 595 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 596                                  struct sk_buff *skb)
 597 {
 598         struct ipv6_pinfo *np = inet6_sk(sk);
 599         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 600
 601         if (np->rxopt.bits.rxinfo) {
 602                 struct in6_pktinfo src_info;
 603
 604                 if (is_ipv6) {
 605                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 606                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 607                 } else {
 608                         src_info.ipi6_ifindex =
 609                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 610                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 611                                                &src_info.ipi6_addr);
 612                 }
 613
 614                 if (src_info.ipi6_ifindex >= 0)
 615                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 616                                  sizeof(src_info), &src_info);
 617         }
 618 }
 619
 620 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 621                                     struct sk_buff *skb)
 622 {
 623         struct ipv6_pinfo *np = inet6_sk(sk);
 624         struct inet6_skb_parm *opt = IP6CB(skb);
 625         unsigned char *nh = skb_network_header(skb);
 626
 627         if (np->rxopt.bits.rxhlim) {
 628                 int hlim = ipv6_hdr(skb)->hop_limit;
 629                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 630         }
 631
 632         if (np->rxopt.bits.rxtclass) {
 633                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 634                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 635         }
 636
 637         if (np->rxopt.bits.rxflow) {
 638                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 639                 if (flowinfo)
 640                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 641         }
 642
 643         /* HbH is allowed only once */
 644         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 645                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 646                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 647         }
 648
 649         if (opt->lastopt &&
 650             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 651                 /*
 652                  * Silly enough, but we need to reparse in order to
 653                  * report extension headers (except for HbH)
 654                  * in order.
 655                  *
 656                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 657                  * (and WILL NOT be) defined because
 658                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 659                  */
 660                 unsigned int off = sizeof(struct ipv6hdr);
 661                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 662
 663                 while (off <= opt->lastopt) {
 664                         unsigned int len;
 665                         u8 *ptr = nh + off;
 666
 667                         switch (nexthdr) {
 668                         case IPPROTO_DSTOPTS:
 669                                 nexthdr = ptr[0];
 670                                 len = (ptr[1] + 1) << 3;
 671                                 if (np->rxopt.bits.dstopts)
 672                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 673                                 break;
 674                         case IPPROTO_ROUTING:
 675                                 nexthdr = ptr[0];
 676                                 len = (ptr[1] + 1) << 3;
 677                                 if (np->rxopt.bits.srcrt)
 678                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 679                                 break;
 680                         case IPPROTO_AH:
 681                                 nexthdr = ptr[0];
 682                                 len = (ptr[1] + 2) << 2;
 683                                 break;
 684                         default:
 685                                 nexthdr = ptr[0];
 686                                 len = (ptr[1] + 1) << 3;
 687                                 break;
 688                         }
 689
 690                         off += len;
 691                 }
 692         }
 693
 694         /* socket options in old style */
 695         if (np->rxopt.bits.rxoinfo) {
 696                 struct in6_pktinfo src_info;
 697
 698                 src_info.ipi6_ifindex = opt->iif;
 699                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 700                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 701         }
 702         if (np->rxopt.bits.rxohlim) {
 703                 int hlim = ipv6_hdr(skb)->hop_limit;
 704                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 705         }
 706         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 707                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 708                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 709         }
 710         if (np->rxopt.bits.odstopts && opt->dst0) {
 711                 u8 *ptr = nh + opt->dst0;
 712                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 713         }
 714         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 715                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 716                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 717         }
 718         if (np->rxopt.bits.odstopts && opt->dst1) {
 719                 u8 *ptr = nh + opt->dst1;
 720                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 721         }
 722         if (np->rxopt.bits.rxorigdstaddr) {
 723                 struct sockaddr_in6 sin6;
 724                 __be16 _ports[2], *ports;
 725
 726                 ports = skb_header_pointer(skb, skb_transport_offset(skb),
 727                                            sizeof(_ports), &_ports);
 728                 if (ports) {
 729                         /* All current transport protocols have the port numbers in the
 730                          * first four bytes of the transport header and this function is
 731                          * written with this assumption in mind.
 732                          */
 733                         sin6.sin6_family = AF_INET6;
 734                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 735                         sin6.sin6_port = ports[1];
 736                         sin6.sin6_flowinfo = 0;
 737                         sin6.sin6_scope_id =
 738                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 739                                                     opt->iif);
 740
 741                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 742                 }
 743         }
 744         if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
 745                 int val = opt->frag_max_size;
 746
 747                 put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
 748         }
 749 }
 750
 751 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 752                           struct sk_buff *skb)
 753 {
 754         ip6_datagram_recv_common_ctl(sk, msg, skb);
 755         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 756 }
 757 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 758
 759 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 760                           struct msghdr *msg, struct flowi6 *fl6,
 761                           struct ipcm6_cookie *ipc6)
 762 {
 763         struct in6_pktinfo *src_info;
 764         struct cmsghdr *cmsg;
 765         struct ipv6_rt_hdr *rthdr;
 766         struct ipv6_opt_hdr *hdr;
 767         struct ipv6_txoptions *opt = ipc6->opt;
 768         int len;
 769         int err = 0;
 770
 771         for_each_cmsghdr(cmsg, msg) {
 772                 int addr_type;
 773
 774                 if (!CMSG_OK(msg, cmsg)) {
 775                         err = -EINVAL;
 776                         goto exit_f;
 777                 }
 778
 779                 if (cmsg->cmsg_level == SOL_SOCKET) {
 780                         err = __sock_cmsg_send(sk, cmsg, &ipc6->sockc);
 781                         if (err)
 782                                 return err;
 783                         continue;
 784                 }
 785
 786                 if (cmsg->cmsg_level != SOL_IPV6)
 787                         continue;
 788
 789                 switch (cmsg->cmsg_type) {
 790                 case IPV6_PKTINFO:
 791                 case IPV6_2292PKTINFO:
 792                     {
 793                         struct net_device *dev = NULL;
 794                         int src_idx;
 795
 796                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 797                                 err = -EINVAL;
 798                                 goto exit_f;
 799                         }
 800
 801                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 802                         src_idx = src_info->ipi6_ifindex;
 803
 804                         if (src_idx) {
 805                                 if (fl6->flowi6_oif &&
 806                                     src_idx != fl6->flowi6_oif &&
 807                                     (READ_ONCE(sk->sk_bound_dev_if) != fl6->flowi6_oif ||
 808                                      !sk_dev_equal_l3scope(sk, src_idx)))
 809                                         return -EINVAL;
 810                                 fl6->flowi6_oif = src_idx;
 811                         }
 812
 813                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 814
 815                         rcu_read_lock();
 816                         if (fl6->flowi6_oif) {
 817                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 818                                 if (!dev) {
 819                                         rcu_read_unlock();
 820                                         return -ENODEV;
 821                                 }
 822                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 823                                 rcu_read_unlock();
 824                                 return -EINVAL;
 825                         }
 826
 827                         if (addr_type != IPV6_ADDR_ANY) {
 828                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 829                                 if (!ipv6_can_nonlocal_bind(net, inet_sk(sk)) &&
 830                                     !ipv6_chk_addr_and_flags(net, &src_info->ipi6_addr,
 831                                                              dev, !strict, 0,
 832                                                              IFA_F_TENTATIVE) &&
 833                                     !ipv6_chk_acast_addr_src(net, dev,
 834                                                              &src_info->ipi6_addr))
 835                                         err = -EINVAL;
 836                                 else
 837                                         fl6->saddr = src_info->ipi6_addr;
 838                         }
 839
 840                         rcu_read_unlock();
 841
 842                         if (err)
 843                                 goto exit_f;
 844
 845                         break;
 846                     }
 847
 848                 case IPV6_FLOWINFO:
 849                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 850                                 err = -EINVAL;
 851                                 goto exit_f;
 852                         }
 853
 854                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 855                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 856                                         err = -EINVAL;
 857                                         goto exit_f;
 858                                 }
 859                         }
 860                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 861                         break;
 862
 863                 case IPV6_2292HOPOPTS:
 864                 case IPV6_HOPOPTS:
 865                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 866                                 err = -EINVAL;
 867                                 goto exit_f;
 868                         }
 869
 870                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 871                         len = ((hdr->hdrlen + 1) << 3);
 872                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 873                                 err = -EINVAL;
 874                                 goto exit_f;
 875                         }
 876                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 877                                 err = -EPERM;
 878                                 goto exit_f;
 879                         }
 880                         opt->opt_nflen += len;
 881                         opt->hopopt = hdr;
 882                         break;
 883
 884                 case IPV6_2292DSTOPTS:
 885                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 886                                 err = -EINVAL;
 887                                 goto exit_f;
 888                         }
 889
 890                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 891                         len = ((hdr->hdrlen + 1) << 3);
 892                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 893                                 err = -EINVAL;
 894                                 goto exit_f;
 895                         }
 896                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 897                                 err = -EPERM;
 898                                 goto exit_f;
 899                         }
 900                         if (opt->dst1opt) {
 901                                 err = -EINVAL;
 902                                 goto exit_f;
 903                         }
 904                         opt->opt_flen += len;
 905                         opt->dst1opt = hdr;
 906                         break;
 907
 908                 case IPV6_DSTOPTS:
 909                 case IPV6_RTHDRDSTOPTS:
 910                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 911                                 err = -EINVAL;
 912                                 goto exit_f;
 913                         }
 914
 915                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 916                         len = ((hdr->hdrlen + 1) << 3);
 917                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 918                                 err = -EINVAL;
 919                                 goto exit_f;
 920                         }
 921                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 922                                 err = -EPERM;
 923                                 goto exit_f;
 924                         }
 925                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 926                                 opt->opt_flen += len;
 927                                 opt->dst1opt = hdr;
 928                         } else {
 929                                 opt->opt_nflen += len;
 930                                 opt->dst0opt = hdr;
 931                         }
 932                         break;
 933
 934                 case IPV6_2292RTHDR:
 935                 case IPV6_RTHDR:
 936                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 937                                 err = -EINVAL;
 938                                 goto exit_f;
 939                         }
 940
 941                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 942
 943                         switch (rthdr->type) {
 944 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 945                         case IPV6_SRCRT_TYPE_2:
 946                                 if (rthdr->hdrlen != 2 ||
 947                                     rthdr->segments_left != 1) {
 948                                         err = -EINVAL;
 949                                         goto exit_f;
 950                                 }
 951                                 break;
 952 #endif
 953                         default:
 954                                 err = -EINVAL;
 955                                 goto exit_f;
 956                         }
 957
 958                         len = ((rthdr->hdrlen + 1) << 3);
 959
 960                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 961                                 err = -EINVAL;
 962                                 goto exit_f;
 963                         }
 964
 965                         /* segments left must also match */
 966                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 967                                 err = -EINVAL;
 968                                 goto exit_f;
 969                         }
 970
 971                         opt->opt_nflen += len;
 972                         opt->srcrt = rthdr;
 973
 974                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 975                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 976
 977                                 opt->opt_nflen += dsthdrlen;
 978                                 opt->dst0opt = opt->dst1opt;
 979                                 opt->dst1opt = NULL;
 980                                 opt->opt_flen -= dsthdrlen;
 981                         }
 982
 983                         break;
 984
 985                 case IPV6_2292HOPLIMIT:
 986                 case IPV6_HOPLIMIT:
 987                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 988                                 err = -EINVAL;
 989                                 goto exit_f;
 990                         }
 991
 992                         ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 993                         if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 994                                 err = -EINVAL;
 995                                 goto exit_f;
 996                         }
 997
 998                         break;
 999
1000                 case IPV6_TCLASS:
1001                     {
1002                         int tc;
1003
1004                         err = -EINVAL;
1005                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1006                                 goto exit_f;
1007
1008                         tc = *(int *)CMSG_DATA(cmsg);
1009                         if (tc < -1 || tc > 0xff)
1010                                 goto exit_f;
1011
1012                         err = 0;
1013                         ipc6->tclass = tc;
1014
1015                         break;
1016                     }
1017
1018                 case IPV6_DONTFRAG:
1019                     {
1020                         int df;
1021
1022                         err = -EINVAL;
1023                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1024                                 goto exit_f;
1025
1026                         df = *(int *)CMSG_DATA(cmsg);
1027                         if (df < 0 || df > 1)
1028                                 goto exit_f;
1029
1030                         err = 0;
1031                         ipc6->dontfrag = df;
1032
1033                         break;
1034                     }
1035                 default:
1036                         net_dbg_ratelimited("invalid cmsg type: %d\n",
1037                                             cmsg->cmsg_type);
1038                         err = -EINVAL;
1039                         goto exit_f;
1040                 }
1041         }
1042
1043 exit_f:
1044         return err;
1045 }
1046 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1047
1048 void __ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1049                                __u16 srcp, __u16 destp, int rqueue, int bucket)
1050 {
1051         const struct in6_addr *dest, *src;
1052
1053         dest  = &sp->sk_v6_daddr;
1054         src   = &sp->sk_v6_rcv_saddr;
1055         seq_printf(seq,
1056                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1057                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u\n",
1058                    bucket,
1059                    src->s6_addr32[0], src->s6_addr32[1],
1060                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1061                    dest->s6_addr32[0], dest->s6_addr32[1],
1062                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1063                    sp->sk_state,
1064                    sk_wmem_alloc_get(sp),
1065                    rqueue,
1066                    0, 0L, 0,
1067                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1068                    0,
1069                    sock_i_ino(sp),
1070                    refcount_read(&sp->sk_refcnt), sp,
1071                    atomic_read(&sp->sk_drops));
1072 }