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