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, 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
  66 int 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
 109 out:
 110         fl6_sock_release(flowlabel);
 111         return err;
 112 }
 113
 114 void 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 }
 132 EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
 133
 134 int __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
 193 ipv4_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                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 222                 }
 223
 224                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 225                         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);
 262 out:
 263         return err;
 264 }
 265 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 266
 267 int 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 }
 276 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 277
 278 int 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 }
 286 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 287
 288 static 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
 299 void 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
 338 void 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
 378 void 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  */
 416 static 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  */
 429 static 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  */
 448 int 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);
 533 out:
 534         return err;
 535 }
 536 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 537
 538 /*
 539  *      Handle IPV6_RECVPATHMTU
 540  */
 541 int 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
 582 out_free_skb:
 583         kfree_skb(skb);
 584 out:
 585         return err;
 586 }
 587
 588
 589 void 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
 614 void 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
 745 void 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 }
 751 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 752
 753 int 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                                     (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
1037 exit_f:
1038         return err;
1039 }
1040 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1041
1042 void __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 }