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
  23 #include <net/ipv6.h>
  24 #include <net/ndisc.h>
  25 #include <net/addrconf.h>
  26 #include <net/transp_v6.h>
  27 #include <net/ip6_route.h>
  28 #include <net/tcp_states.h>
  29 #include <net/dsfield.h>
  30 #include <net/sock_reuseport.h>
  31
  32 #include <linux/errqueue.h>
  33 #include <linux/uaccess.h>
  34
  35 static bool ipv6_mapped_addr_any(const struct in6_addr *a)
  36 {
  37         return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
  38 }
  39
  40 static void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
  41 {
  42         struct inet_sock *inet = inet_sk(sk);
  43         struct ipv6_pinfo *np = inet6_sk(sk);
  44
  45         memset(fl6, 0, sizeof(*fl6));
  46         fl6->flowi6_proto = sk->sk_protocol;
  47         fl6->daddr = sk->sk_v6_daddr;
  48         fl6->saddr = np->saddr;
  49         fl6->flowi6_oif = sk->sk_bound_dev_if;
  50         fl6->flowi6_mark = sk->sk_mark;
  51         fl6->fl6_dport = inet->inet_dport;
  52         fl6->fl6_sport = inet->inet_sport;
  53         fl6->flowlabel = np->flow_label;
  54         fl6->flowi6_uid = sk->sk_uid;
  55
  56         if (!fl6->flowi6_oif)
  57                 fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
  58
  59         if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr))
  60                 fl6->flowi6_oif = np->mcast_oif;
  61
  62         security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
  63 }
  64
  65 int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
  66 {
  67         struct ip6_flowlabel *flowlabel = NULL;
  68         struct in6_addr *final_p, final;
  69         struct ipv6_txoptions *opt;
  70         struct dst_entry *dst;
  71         struct inet_sock *inet = inet_sk(sk);
  72         struct ipv6_pinfo *np = inet6_sk(sk);
  73         struct flowi6 fl6;
  74         int err = 0;
  75
  76         if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
  77                 flowlabel = fl6_sock_lookup(sk, np->flow_label);
  78                 if (IS_ERR(flowlabel))
  79                         return -EINVAL;
  80         }
  81         ip6_datagram_flow_key_init(&fl6, sk);
  82
  83         rcu_read_lock();
  84         opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
  85         final_p = fl6_update_dst(&fl6, opt, &final);
  86         rcu_read_unlock();
  87
  88         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
  89         if (IS_ERR(dst)) {
  90                 err = PTR_ERR(dst);
  91                 goto out;
  92         }
  93
  94         if (fix_sk_saddr) {
  95                 if (ipv6_addr_any(&np->saddr))
  96                         np->saddr = fl6.saddr;
  97
  98                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
  99                         sk->sk_v6_rcv_saddr = fl6.saddr;
 100                         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 101                         if (sk->sk_prot->rehash)
 102                                 sk->sk_prot->rehash(sk);
 103                 }
 104         }
 105
 106         ip6_sk_dst_store_flow(sk, dst, &fl6);
 107
 108 out:
 109         fl6_sock_release(flowlabel);
 110         return err;
 111 }
 112
 113 void ip6_datagram_release_cb(struct sock *sk)
 114 {
 115         struct dst_entry *dst;
 116
 117         if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 118                 return;
 119
 120         rcu_read_lock();
 121         dst = __sk_dst_get(sk);
 122         if (!dst || !dst->obsolete ||
 123             dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
 124                 rcu_read_unlock();
 125                 return;
 126         }
 127         rcu_read_unlock();
 128
 129         ip6_datagram_dst_update(sk, false);
 130 }
 131 EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
 132
 133 int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
 134                            int addr_len)
 135 {
 136         struct sockaddr_in6     *usin = (struct sockaddr_in6 *) uaddr;
 137         struct inet_sock        *inet = inet_sk(sk);
 138         struct ipv6_pinfo       *np = inet6_sk(sk);
 139         struct in6_addr         *daddr, old_daddr;
 140         __be32                  fl6_flowlabel = 0;
 141         __be32                  old_fl6_flowlabel;
 142         __be16                  old_dport;
 143         int                     addr_type;
 144         int                     err;
 145
 146         if (usin->sin6_family == AF_INET) {
 147                 if (__ipv6_only_sock(sk))
 148                         return -EAFNOSUPPORT;
 149                 err = __ip4_datagram_connect(sk, uaddr, addr_len);
 150                 goto ipv4_connected;
 151         }
 152
 153         if (addr_len < SIN6_LEN_RFC2133)
 154                 return -EINVAL;
 155
 156         if (usin->sin6_family != AF_INET6)
 157                 return -EAFNOSUPPORT;
 158
 159         if (np->sndflow)
 160                 fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 161
 162         if (ipv6_addr_any(&usin->sin6_addr)) {
 163                 /*
 164                  *      connect to self
 165                  */
 166                 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
 167                         ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
 168                                                &usin->sin6_addr);
 169                 else
 170                         usin->sin6_addr = in6addr_loopback;
 171         }
 172
 173         addr_type = ipv6_addr_type(&usin->sin6_addr);
 174
 175         daddr = &usin->sin6_addr;
 176
 177         if (addr_type & IPV6_ADDR_MAPPED) {
 178                 struct sockaddr_in sin;
 179
 180                 if (__ipv6_only_sock(sk)) {
 181                         err = -ENETUNREACH;
 182                         goto out;
 183                 }
 184                 sin.sin_family = AF_INET;
 185                 sin.sin_addr.s_addr = daddr->s6_addr32[3];
 186                 sin.sin_port = usin->sin6_port;
 187
 188                 err = __ip4_datagram_connect(sk,
 189                                              (struct sockaddr *) &sin,
 190                                              sizeof(sin));
 191
 192 ipv4_connected:
 193                 if (err)
 194                         goto out;
 195
 196                 ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 197
 198                 if (ipv6_addr_any(&np->saddr) ||
 199                     ipv6_mapped_addr_any(&np->saddr))
 200                         ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 201
 202                 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 203                     ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 204                         ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 205                                                &sk->sk_v6_rcv_saddr);
 206                         if (sk->sk_prot->rehash)
 207                                 sk->sk_prot->rehash(sk);
 208                 }
 209
 210                 goto out;
 211         }
 212
 213         if (__ipv6_addr_needs_scope_id(addr_type)) {
 214                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 215                     usin->sin6_scope_id) {
 216                         if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id)) {
 217                                 err = -EINVAL;
 218                                 goto out;
 219                         }
 220                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 221                 }
 222
 223                 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 224                         sk->sk_bound_dev_if = np->mcast_oif;
 225
 226                 /* Connect to link-local address requires an interface */
 227                 if (!sk->sk_bound_dev_if) {
 228                         err = -EINVAL;
 229                         goto out;
 230                 }
 231         }
 232
 233         /* save the current peer information before updating it */
 234         old_daddr = sk->sk_v6_daddr;
 235         old_fl6_flowlabel = np->flow_label;
 236         old_dport = inet->inet_dport;
 237
 238         sk->sk_v6_daddr = *daddr;
 239         np->flow_label = fl6_flowlabel;
 240         inet->inet_dport = usin->sin6_port;
 241
 242         /*
 243          *      Check for a route to destination an obtain the
 244          *      destination cache for it.
 245          */
 246
 247         err = ip6_datagram_dst_update(sk, true);
 248         if (err) {
 249                 /* Restore the socket peer info, to keep it consistent with
 250                  * the old socket state
 251                  */
 252                 sk->sk_v6_daddr = old_daddr;
 253                 np->flow_label = old_fl6_flowlabel;
 254                 inet->inet_dport = old_dport;
 255                 goto out;
 256         }
 257
 258         reuseport_has_conns(sk, true);
 259         sk->sk_state = TCP_ESTABLISHED;
 260         sk_set_txhash(sk);
 261 out:
 262         return err;
 263 }
 264 EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 265
 266 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 267 {
 268         int res;
 269
 270         lock_sock(sk);
 271         res = __ip6_datagram_connect(sk, uaddr, addr_len);
 272         release_sock(sk);
 273         return res;
 274 }
 275 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 276
 277 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 278                                  int addr_len)
 279 {
 280         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 281         if (sin6->sin6_family != AF_INET6)
 282                 return -EAFNOSUPPORT;
 283         return ip6_datagram_connect(sk, uaddr, addr_len);
 284 }
 285 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 286
 287 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 288                      __be16 port, u32 info, u8 *payload)
 289 {
 290         struct ipv6_pinfo *np  = inet6_sk(sk);
 291         struct icmp6hdr *icmph = icmp6_hdr(skb);
 292         struct sock_exterr_skb *serr;
 293
 294         if (!np->recverr)
 295                 return;
 296
 297         skb = skb_clone(skb, GFP_ATOMIC);
 298         if (!skb)
 299                 return;
 300
 301         skb->protocol = htons(ETH_P_IPV6);
 302
 303         serr = SKB_EXT_ERR(skb);
 304         serr->ee.ee_errno = err;
 305         serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 306         serr->ee.ee_type = icmph->icmp6_type;
 307         serr->ee.ee_code = icmph->icmp6_code;
 308         serr->ee.ee_pad = 0;
 309         serr->ee.ee_info = info;
 310         serr->ee.ee_data = 0;
 311         serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 312                                   skb_network_header(skb);
 313         serr->port = port;
 314
 315         __skb_pull(skb, payload - skb->data);
 316         skb_reset_transport_header(skb);
 317
 318         if (sock_queue_err_skb(sk, skb))
 319                 kfree_skb(skb);
 320 }
 321
 322 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 323 {
 324         const struct ipv6_pinfo *np = inet6_sk(sk);
 325         struct sock_exterr_skb *serr;
 326         struct ipv6hdr *iph;
 327         struct sk_buff *skb;
 328
 329         if (!np->recverr)
 330                 return;
 331
 332         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 333         if (!skb)
 334                 return;
 335
 336         skb->protocol = htons(ETH_P_IPV6);
 337
 338         skb_put(skb, sizeof(struct ipv6hdr));
 339         skb_reset_network_header(skb);
 340         iph = ipv6_hdr(skb);
 341         iph->daddr = fl6->daddr;
 342         ip6_flow_hdr(iph, 0, 0);
 343
 344         serr = SKB_EXT_ERR(skb);
 345         serr->ee.ee_errno = err;
 346         serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 347         serr->ee.ee_type = 0;
 348         serr->ee.ee_code = 0;
 349         serr->ee.ee_pad = 0;
 350         serr->ee.ee_info = info;
 351         serr->ee.ee_data = 0;
 352         serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 353         serr->port = fl6->fl6_dport;
 354
 355         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 356         skb_reset_transport_header(skb);
 357
 358         if (sock_queue_err_skb(sk, skb))
 359                 kfree_skb(skb);
 360 }
 361
 362 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 363 {
 364         struct ipv6_pinfo *np = inet6_sk(sk);
 365         struct ipv6hdr *iph;
 366         struct sk_buff *skb;
 367         struct ip6_mtuinfo *mtu_info;
 368
 369         if (!np->rxopt.bits.rxpmtu)
 370                 return;
 371
 372         skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 373         if (!skb)
 374                 return;
 375
 376         skb_put(skb, sizeof(struct ipv6hdr));
 377         skb_reset_network_header(skb);
 378         iph = ipv6_hdr(skb);
 379         iph->daddr = fl6->daddr;
 380
 381         mtu_info = IP6CBMTU(skb);
 382
 383         mtu_info->ip6m_mtu = mtu;
 384         mtu_info->ip6m_addr.sin6_family = AF_INET6;
 385         mtu_info->ip6m_addr.sin6_port = 0;
 386         mtu_info->ip6m_addr.sin6_flowinfo = 0;
 387         mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 388         mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 389
 390         __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 391         skb_reset_transport_header(skb);
 392
 393         skb = xchg(&np->rxpmtu, skb);
 394         kfree_skb(skb);
 395 }
 396
 397 /* For some errors we have valid addr_offset even with zero payload and
 398  * zero port. Also, addr_offset should be supported if port is set.
 399  */
 400 static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 401 {
 402         return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 403                serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 404                serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 405 }
 406
 407 /* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 408  *
 409  * At one point, excluding local errors was a quick test to identify icmp/icmp6
 410  * errors. This is no longer true, but the test remained, so the v6 stack,
 411  * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 412  */
 413 static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 414                                       struct sock_exterr_skb *serr)
 415 {
 416         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 417             serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 418                 return true;
 419
 420         if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 421                 return false;
 422
 423         if (!IP6CB(skb)->iif)
 424                 return false;
 425
 426         return true;
 427 }
 428
 429 /*
 430  *      Handle MSG_ERRQUEUE
 431  */
 432 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 433 {
 434         struct ipv6_pinfo *np = inet6_sk(sk);
 435         struct sock_exterr_skb *serr;
 436         struct sk_buff *skb;
 437         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 438         struct {
 439                 struct sock_extended_err ee;
 440                 struct sockaddr_in6      offender;
 441         } errhdr;
 442         int err;
 443         int copied;
 444
 445         err = -EAGAIN;
 446         skb = sock_dequeue_err_skb(sk);
 447         if (!skb)
 448                 goto out;
 449
 450         copied = skb->len;
 451         if (copied > len) {
 452                 msg->msg_flags |= MSG_TRUNC;
 453                 copied = len;
 454         }
 455         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 456         if (unlikely(err)) {
 457                 kfree_skb(skb);
 458                 return err;
 459         }
 460         sock_recv_timestamp(msg, sk, skb);
 461
 462         serr = SKB_EXT_ERR(skb);
 463
 464         if (sin && ipv6_datagram_support_addr(serr)) {
 465                 const unsigned char *nh = skb_network_header(skb);
 466                 sin->sin6_family = AF_INET6;
 467                 sin->sin6_flowinfo = 0;
 468                 sin->sin6_port = serr->port;
 469                 if (skb->protocol == htons(ETH_P_IPV6)) {
 470                         const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 471                                                                   struct ipv6hdr, daddr);
 472                         sin->sin6_addr = ip6h->daddr;
 473                         if (np->sndflow)
 474                                 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 475                         sin->sin6_scope_id =
 476                                 ipv6_iface_scope_id(&sin->sin6_addr,
 477                                                     IP6CB(skb)->iif);
 478                 } else {
 479                         ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 480                                                &sin->sin6_addr);
 481                         sin->sin6_scope_id = 0;
 482                 }
 483                 *addr_len = sizeof(*sin);
 484         }
 485
 486         memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 487         sin = &errhdr.offender;
 488         memset(sin, 0, sizeof(*sin));
 489
 490         if (ip6_datagram_support_cmsg(skb, serr)) {
 491                 sin->sin6_family = AF_INET6;
 492                 if (np->rxopt.all)
 493                         ip6_datagram_recv_common_ctl(sk, msg, skb);
 494                 if (skb->protocol == htons(ETH_P_IPV6)) {
 495                         sin->sin6_addr = ipv6_hdr(skb)->saddr;
 496                         if (np->rxopt.all)
 497                                 ip6_datagram_recv_specific_ctl(sk, msg, skb);
 498                         sin->sin6_scope_id =
 499                                 ipv6_iface_scope_id(&sin->sin6_addr,
 500                                                     IP6CB(skb)->iif);
 501                 } else {
 502                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 503                                                &sin->sin6_addr);
 504                         if (inet_sk(sk)->cmsg_flags)
 505                                 ip_cmsg_recv(msg, skb);
 506                 }
 507         }
 508
 509         put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 510
 511         /* Now we could try to dump offended packet options */
 512
 513         msg->msg_flags |= MSG_ERRQUEUE;
 514         err = copied;
 515
 516         consume_skb(skb);
 517 out:
 518         return err;
 519 }
 520 EXPORT_SYMBOL_GPL(ipv6_recv_error);
 521
 522 /*
 523  *      Handle IPV6_RECVPATHMTU
 524  */
 525 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 526                      int *addr_len)
 527 {
 528         struct ipv6_pinfo *np = inet6_sk(sk);
 529         struct sk_buff *skb;
 530         struct ip6_mtuinfo mtu_info;
 531         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 532         int err;
 533         int copied;
 534
 535         err = -EAGAIN;
 536         skb = xchg(&np->rxpmtu, NULL);
 537         if (!skb)
 538                 goto out;
 539
 540         copied = skb->len;
 541         if (copied > len) {
 542                 msg->msg_flags |= MSG_TRUNC;
 543                 copied = len;
 544         }
 545         err = skb_copy_datagram_msg(skb, 0, msg, copied);
 546         if (err)
 547                 goto out_free_skb;
 548
 549         sock_recv_timestamp(msg, sk, skb);
 550
 551         memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 552
 553         if (sin) {
 554                 sin->sin6_family = AF_INET6;
 555                 sin->sin6_flowinfo = 0;
 556                 sin->sin6_port = 0;
 557                 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 558                 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 559                 *addr_len = sizeof(*sin);
 560         }
 561
 562         put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 563
 564         err = copied;
 565
 566 out_free_skb:
 567         kfree_skb(skb);
 568 out:
 569         return err;
 570 }
 571
 572
 573 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 574                                  struct sk_buff *skb)
 575 {
 576         struct ipv6_pinfo *np = inet6_sk(sk);
 577         bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 578
 579         if (np->rxopt.bits.rxinfo) {
 580                 struct in6_pktinfo src_info;
 581
 582                 if (is_ipv6) {
 583                         src_info.ipi6_ifindex = IP6CB(skb)->iif;
 584                         src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 585                 } else {
 586                         src_info.ipi6_ifindex =
 587                                 PKTINFO_SKB_CB(skb)->ipi_ifindex;
 588                         ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 589                                                &src_info.ipi6_addr);
 590                 }
 591
 592                 if (src_info.ipi6_ifindex >= 0)
 593                         put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 594                                  sizeof(src_info), &src_info);
 595         }
 596 }
 597
 598 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 599                                     struct sk_buff *skb)
 600 {
 601         struct ipv6_pinfo *np = inet6_sk(sk);
 602         struct inet6_skb_parm *opt = IP6CB(skb);
 603         unsigned char *nh = skb_network_header(skb);
 604
 605         if (np->rxopt.bits.rxhlim) {
 606                 int hlim = ipv6_hdr(skb)->hop_limit;
 607                 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 608         }
 609
 610         if (np->rxopt.bits.rxtclass) {
 611                 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 612                 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 613         }
 614
 615         if (np->rxopt.bits.rxflow) {
 616                 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 617                 if (flowinfo)
 618                         put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 619         }
 620
 621         /* HbH is allowed only once */
 622         if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 623                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 624                 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 625         }
 626
 627         if (opt->lastopt &&
 628             (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 629                 /*
 630                  * Silly enough, but we need to reparse in order to
 631                  * report extension headers (except for HbH)
 632                  * in order.
 633                  *
 634                  * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 635                  * (and WILL NOT be) defined because
 636                  * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 637                  */
 638                 unsigned int off = sizeof(struct ipv6hdr);
 639                 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 640
 641                 while (off <= opt->lastopt) {
 642                         unsigned int len;
 643                         u8 *ptr = nh + off;
 644
 645                         switch (nexthdr) {
 646                         case IPPROTO_DSTOPTS:
 647                                 nexthdr = ptr[0];
 648                                 len = (ptr[1] + 1) << 3;
 649                                 if (np->rxopt.bits.dstopts)
 650                                         put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 651                                 break;
 652                         case IPPROTO_ROUTING:
 653                                 nexthdr = ptr[0];
 654                                 len = (ptr[1] + 1) << 3;
 655                                 if (np->rxopt.bits.srcrt)
 656                                         put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 657                                 break;
 658                         case IPPROTO_AH:
 659                                 nexthdr = ptr[0];
 660                                 len = (ptr[1] + 2) << 2;
 661                                 break;
 662                         default:
 663                                 nexthdr = ptr[0];
 664                                 len = (ptr[1] + 1) << 3;
 665                                 break;
 666                         }
 667
 668                         off += len;
 669                 }
 670         }
 671
 672         /* socket options in old style */
 673         if (np->rxopt.bits.rxoinfo) {
 674                 struct in6_pktinfo src_info;
 675
 676                 src_info.ipi6_ifindex = opt->iif;
 677                 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 678                 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 679         }
 680         if (np->rxopt.bits.rxohlim) {
 681                 int hlim = ipv6_hdr(skb)->hop_limit;
 682                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 683         }
 684         if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 685                 u8 *ptr = nh + sizeof(struct ipv6hdr);
 686                 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 687         }
 688         if (np->rxopt.bits.odstopts && opt->dst0) {
 689                 u8 *ptr = nh + opt->dst0;
 690                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 691         }
 692         if (np->rxopt.bits.osrcrt && opt->srcrt) {
 693                 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 694                 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 695         }
 696         if (np->rxopt.bits.odstopts && opt->dst1) {
 697                 u8 *ptr = nh + opt->dst1;
 698                 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 699         }
 700         if (np->rxopt.bits.rxorigdstaddr) {
 701                 struct sockaddr_in6 sin6;
 702                 __be16 _ports[2], *ports;
 703
 704                 ports = skb_header_pointer(skb, skb_transport_offset(skb),
 705                                            sizeof(_ports), &_ports);
 706                 if (ports) {
 707                         /* All current transport protocols have the port numbers in the
 708                          * first four bytes of the transport header and this function is
 709                          * written with this assumption in mind.
 710                          */
 711                         sin6.sin6_family = AF_INET6;
 712                         sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 713                         sin6.sin6_port = ports[1];
 714                         sin6.sin6_flowinfo = 0;
 715                         sin6.sin6_scope_id =
 716                                 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 717                                                     opt->iif);
 718
 719                         put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 720                 }
 721         }
 722         if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
 723                 int val = opt->frag_max_size;
 724
 725                 put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
 726         }
 727 }
 728
 729 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 730                           struct sk_buff *skb)
 731 {
 732         ip6_datagram_recv_common_ctl(sk, msg, skb);
 733         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 734 }
 735 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 736
 737 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 738                           struct msghdr *msg, struct flowi6 *fl6,
 739                           struct ipcm6_cookie *ipc6)
 740 {
 741         struct in6_pktinfo *src_info;
 742         struct cmsghdr *cmsg;
 743         struct ipv6_rt_hdr *rthdr;
 744         struct ipv6_opt_hdr *hdr;
 745         struct ipv6_txoptions *opt = ipc6->opt;
 746         int len;
 747         int err = 0;
 748
 749         for_each_cmsghdr(cmsg, msg) {
 750                 int addr_type;
 751
 752                 if (!CMSG_OK(msg, cmsg)) {
 753                         err = -EINVAL;
 754                         goto exit_f;
 755                 }
 756
 757                 if (cmsg->cmsg_level == SOL_SOCKET) {
 758                         err = __sock_cmsg_send(sk, msg, cmsg, &ipc6->sockc);
 759                         if (err)
 760                                 return err;
 761                         continue;
 762                 }
 763
 764                 if (cmsg->cmsg_level != SOL_IPV6)
 765                         continue;
 766
 767                 switch (cmsg->cmsg_type) {
 768                 case IPV6_PKTINFO:
 769                 case IPV6_2292PKTINFO:
 770                     {
 771                         struct net_device *dev = NULL;
 772                         int src_idx;
 773
 774                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 775                                 err = -EINVAL;
 776                                 goto exit_f;
 777                         }
 778
 779                         src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 780                         src_idx = src_info->ipi6_ifindex;
 781
 782                         if (src_idx) {
 783                                 if (fl6->flowi6_oif &&
 784                                     src_idx != fl6->flowi6_oif &&
 785                                     (sk->sk_bound_dev_if != fl6->flowi6_oif ||
 786                                      !sk_dev_equal_l3scope(sk, src_idx)))
 787                                         return -EINVAL;
 788                                 fl6->flowi6_oif = src_idx;
 789                         }
 790
 791                         addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 792
 793                         rcu_read_lock();
 794                         if (fl6->flowi6_oif) {
 795                                 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 796                                 if (!dev) {
 797                                         rcu_read_unlock();
 798                                         return -ENODEV;
 799                                 }
 800                         } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 801                                 rcu_read_unlock();
 802                                 return -EINVAL;
 803                         }
 804
 805                         if (addr_type != IPV6_ADDR_ANY) {
 806                                 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 807                                 if (!ipv6_can_nonlocal_bind(net, inet_sk(sk)) &&
 808                                     !ipv6_chk_addr_and_flags(net, &src_info->ipi6_addr,
 809                                                              dev, !strict, 0,
 810                                                              IFA_F_TENTATIVE) &&
 811                                     !ipv6_chk_acast_addr_src(net, dev,
 812                                                              &src_info->ipi6_addr))
 813                                         err = -EINVAL;
 814                                 else
 815                                         fl6->saddr = src_info->ipi6_addr;
 816                         }
 817
 818                         rcu_read_unlock();
 819
 820                         if (err)
 821                                 goto exit_f;
 822
 823                         break;
 824                     }
 825
 826                 case IPV6_FLOWINFO:
 827                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
 828                                 err = -EINVAL;
 829                                 goto exit_f;
 830                         }
 831
 832                         if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 833                                 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 834                                         err = -EINVAL;
 835                                         goto exit_f;
 836                                 }
 837                         }
 838                         fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 839                         break;
 840
 841                 case IPV6_2292HOPOPTS:
 842                 case IPV6_HOPOPTS:
 843                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 844                                 err = -EINVAL;
 845                                 goto exit_f;
 846                         }
 847
 848                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 849                         len = ((hdr->hdrlen + 1) << 3);
 850                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 851                                 err = -EINVAL;
 852                                 goto exit_f;
 853                         }
 854                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 855                                 err = -EPERM;
 856                                 goto exit_f;
 857                         }
 858                         opt->opt_nflen += len;
 859                         opt->hopopt = hdr;
 860                         break;
 861
 862                 case IPV6_2292DSTOPTS:
 863                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 864                                 err = -EINVAL;
 865                                 goto exit_f;
 866                         }
 867
 868                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 869                         len = ((hdr->hdrlen + 1) << 3);
 870                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 871                                 err = -EINVAL;
 872                                 goto exit_f;
 873                         }
 874                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 875                                 err = -EPERM;
 876                                 goto exit_f;
 877                         }
 878                         if (opt->dst1opt) {
 879                                 err = -EINVAL;
 880                                 goto exit_f;
 881                         }
 882                         opt->opt_flen += len;
 883                         opt->dst1opt = hdr;
 884                         break;
 885
 886                 case IPV6_DSTOPTS:
 887                 case IPV6_RTHDRDSTOPTS:
 888                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 889                                 err = -EINVAL;
 890                                 goto exit_f;
 891                         }
 892
 893                         hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 894                         len = ((hdr->hdrlen + 1) << 3);
 895                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 896                                 err = -EINVAL;
 897                                 goto exit_f;
 898                         }
 899                         if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 900                                 err = -EPERM;
 901                                 goto exit_f;
 902                         }
 903                         if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 904                                 opt->opt_flen += len;
 905                                 opt->dst1opt = hdr;
 906                         } else {
 907                                 opt->opt_nflen += len;
 908                                 opt->dst0opt = hdr;
 909                         }
 910                         break;
 911
 912                 case IPV6_2292RTHDR:
 913                 case IPV6_RTHDR:
 914                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 915                                 err = -EINVAL;
 916                                 goto exit_f;
 917                         }
 918
 919                         rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 920
 921                         switch (rthdr->type) {
 922 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 923                         case IPV6_SRCRT_TYPE_2:
 924                                 if (rthdr->hdrlen != 2 ||
 925                                     rthdr->segments_left != 1) {
 926                                         err = -EINVAL;
 927                                         goto exit_f;
 928                                 }
 929                                 break;
 930 #endif
 931                         default:
 932                                 err = -EINVAL;
 933                                 goto exit_f;
 934                         }
 935
 936                         len = ((rthdr->hdrlen + 1) << 3);
 937
 938                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
 939                                 err = -EINVAL;
 940                                 goto exit_f;
 941                         }
 942
 943                         /* segments left must also match */
 944                         if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 945                                 err = -EINVAL;
 946                                 goto exit_f;
 947                         }
 948
 949                         opt->opt_nflen += len;
 950                         opt->srcrt = rthdr;
 951
 952                         if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 953                                 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 954
 955                                 opt->opt_nflen += dsthdrlen;
 956                                 opt->dst0opt = opt->dst1opt;
 957                                 opt->dst1opt = NULL;
 958                                 opt->opt_flen -= dsthdrlen;
 959                         }
 960
 961                         break;
 962
 963                 case IPV6_2292HOPLIMIT:
 964                 case IPV6_HOPLIMIT:
 965                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 966                                 err = -EINVAL;
 967                                 goto exit_f;
 968                         }
 969
 970                         ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 971                         if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 972                                 err = -EINVAL;
 973                                 goto exit_f;
 974                         }
 975
 976                         break;
 977
 978                 case IPV6_TCLASS:
 979                     {
 980                         int tc;
 981
 982                         err = -EINVAL;
 983                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 984                                 goto exit_f;
 985
 986                         tc = *(int *)CMSG_DATA(cmsg);
 987                         if (tc < -1 || tc > 0xff)
 988                                 goto exit_f;
 989
 990                         err = 0;
 991                         ipc6->tclass = tc;
 992
 993                         break;
 994                     }
 995
 996                 case IPV6_DONTFRAG:
 997                     {
 998                         int df;
 999
1000                         err = -EINVAL;
1001                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1002                                 goto exit_f;
1003
1004                         df = *(int *)CMSG_DATA(cmsg);
1005                         if (df < 0 || df > 1)
1006                                 goto exit_f;
1007
1008                         err = 0;
1009                         ipc6->dontfrag = df;
1010
1011                         break;
1012                     }
1013                 default:
1014                         net_dbg_ratelimited("invalid cmsg type: %d\n",
1015                                             cmsg->cmsg_type);
1016                         err = -EINVAL;
1017                         goto exit_f;
1018                 }
1019         }
1020
1021 exit_f:
1022         return err;
1023 }
1024 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1025
1026 void __ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1027                                __u16 srcp, __u16 destp, int rqueue, int bucket)
1028 {
1029         const struct in6_addr *dest, *src;
1030
1031         dest  = &sp->sk_v6_daddr;
1032         src   = &sp->sk_v6_rcv_saddr;
1033         seq_printf(seq,
1034                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1035                    "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u\n",
1036                    bucket,
1037                    src->s6_addr32[0], src->s6_addr32[1],
1038                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1039                    dest->s6_addr32[0], dest->s6_addr32[1],
1040                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1041                    sp->sk_state,
1042                    sk_wmem_alloc_get(sp),
1043                    rqueue,
1044                    0, 0L, 0,
1045                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1046                    0,
1047                    sock_i_ino(sp),
1048                    refcount_read(&sp->sk_refcnt), sp,
1049                    atomic_read(&sp->sk_drops));
1050 }