1 /* 2 * L2TPv3 IP encapsulation support for IPv6 3 * 4 * Copyright (c) 2012 Katalix Systems Ltd 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 13 14 #include <linux/icmp.h> 15 #include <linux/module.h> 16 #include <linux/skbuff.h> 17 #include <linux/random.h> 18 #include <linux/socket.h> 19 #include <linux/l2tp.h> 20 #include <linux/in.h> 21 #include <linux/in6.h> 22 #include <net/sock.h> 23 #include <net/ip.h> 24 #include <net/icmp.h> 25 #include <net/udp.h> 26 #include <net/inet_common.h> 27 #include <net/inet_hashtables.h> 28 #include <net/inet6_hashtables.h> 29 #include <net/tcp_states.h> 30 #include <net/protocol.h> 31 #include <net/xfrm.h> 32 33 #include <net/transp_v6.h> 34 #include <net/addrconf.h> 35 #include <net/ip6_route.h> 36 37 #include "l2tp_core.h" 38 39 struct l2tp_ip6_sock { 40 /* inet_sock has to be the first member of l2tp_ip6_sock */ 41 struct inet_sock inet; 42 43 u32 conn_id; 44 u32 peer_conn_id; 45 46 /* ipv6_pinfo has to be the last member of l2tp_ip6_sock, see 47 inet6_sk_generic */ 48 struct ipv6_pinfo inet6; 49 }; 50 51 static DEFINE_RWLOCK(l2tp_ip6_lock); 52 static struct hlist_head l2tp_ip6_table; 53 static struct hlist_head l2tp_ip6_bind_table; 54 55 static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk) 56 { 57 return (struct l2tp_ip6_sock *)sk; 58 } 59 60 static struct sock *__l2tp_ip6_bind_lookup(struct net *net, 61 struct in6_addr *laddr, 62 int dif, u32 tunnel_id) 63 { 64 struct sock *sk; 65 66 sk_for_each_bound(sk, &l2tp_ip6_bind_table) { 67 const struct in6_addr *addr = inet6_rcv_saddr(sk); 68 struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk); 69 70 if (l2tp == NULL) 71 continue; 72 73 if ((l2tp->conn_id == tunnel_id) && 74 net_eq(sock_net(sk), net) && 75 !(addr && ipv6_addr_equal(addr, laddr)) && 76 !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)) 77 goto found; 78 } 79 80 sk = NULL; 81 found: 82 return sk; 83 } 84 85 static inline struct sock *l2tp_ip6_bind_lookup(struct net *net, 86 struct in6_addr *laddr, 87 int dif, u32 tunnel_id) 88 { 89 struct sock *sk = __l2tp_ip6_bind_lookup(net, laddr, dif, tunnel_id); 90 if (sk) 91 sock_hold(sk); 92 93 return sk; 94 } 95 96 /* When processing receive frames, there are two cases to 97 * consider. Data frames consist of a non-zero session-id and an 98 * optional cookie. Control frames consist of a regular L2TP header 99 * preceded by 32-bits of zeros. 100 * 101 * L2TPv3 Session Header Over IP 102 * 103 * 0 1 2 3 104 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 105 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 106 * | Session ID | 107 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 108 * | Cookie (optional, maximum 64 bits)... 109 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 110 * | 111 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 112 * 113 * L2TPv3 Control Message Header Over IP 114 * 115 * 0 1 2 3 116 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 117 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 118 * | (32 bits of zeros) | 119 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 120 * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length | 121 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 122 * | Control Connection ID | 123 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 124 * | Ns | Nr | 125 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 126 * 127 * All control frames are passed to userspace. 128 */ 129 static int l2tp_ip6_recv(struct sk_buff *skb) 130 { 131 struct sock *sk; 132 u32 session_id; 133 u32 tunnel_id; 134 unsigned char *ptr, *optr; 135 struct l2tp_session *session; 136 struct l2tp_tunnel *tunnel = NULL; 137 int length; 138 139 /* Point to L2TP header */ 140 optr = ptr = skb->data; 141 142 if (!pskb_may_pull(skb, 4)) 143 goto discard; 144 145 session_id = ntohl(*((__be32 *) ptr)); 146 ptr += 4; 147 148 /* RFC3931: L2TP/IP packets have the first 4 bytes containing 149 * the session_id. If it is 0, the packet is a L2TP control 150 * frame and the session_id value can be discarded. 151 */ 152 if (session_id == 0) { 153 __skb_pull(skb, 4); 154 goto pass_up; 155 } 156 157 /* Ok, this is a data packet. Lookup the session. */ 158 session = l2tp_session_find(&init_net, NULL, session_id); 159 if (session == NULL) 160 goto discard; 161 162 tunnel = session->tunnel; 163 if (tunnel == NULL) 164 goto discard; 165 166 /* Trace packet contents, if enabled */ 167 if (tunnel->debug & L2TP_MSG_DATA) { 168 length = min(32u, skb->len); 169 if (!pskb_may_pull(skb, length)) 170 goto discard; 171 172 pr_debug("%s: ip recv\n", tunnel->name); 173 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); 174 } 175 176 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, 177 tunnel->recv_payload_hook); 178 return 0; 179 180 pass_up: 181 /* Get the tunnel_id from the L2TP header */ 182 if (!pskb_may_pull(skb, 12)) 183 goto discard; 184 185 if ((skb->data[0] & 0xc0) != 0xc0) 186 goto discard; 187 188 tunnel_id = ntohl(*(__be32 *) &skb->data[4]); 189 tunnel = l2tp_tunnel_find(&init_net, tunnel_id); 190 if (tunnel != NULL) 191 sk = tunnel->sock; 192 else { 193 struct ipv6hdr *iph = ipv6_hdr(skb); 194 195 read_lock_bh(&l2tp_ip6_lock); 196 sk = __l2tp_ip6_bind_lookup(&init_net, &iph->daddr, 197 0, tunnel_id); 198 read_unlock_bh(&l2tp_ip6_lock); 199 } 200 201 if (sk == NULL) 202 goto discard; 203 204 sock_hold(sk); 205 206 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 207 goto discard_put; 208 209 nf_reset(skb); 210 211 return sk_receive_skb(sk, skb, 1); 212 213 discard_put: 214 sock_put(sk); 215 216 discard: 217 kfree_skb(skb); 218 return 0; 219 } 220 221 static int l2tp_ip6_open(struct sock *sk) 222 { 223 /* Prevent autobind. We don't have ports. */ 224 inet_sk(sk)->inet_num = IPPROTO_L2TP; 225 226 write_lock_bh(&l2tp_ip6_lock); 227 sk_add_node(sk, &l2tp_ip6_table); 228 write_unlock_bh(&l2tp_ip6_lock); 229 230 return 0; 231 } 232 233 static void l2tp_ip6_close(struct sock *sk, long timeout) 234 { 235 write_lock_bh(&l2tp_ip6_lock); 236 hlist_del_init(&sk->sk_bind_node); 237 sk_del_node_init(sk); 238 write_unlock_bh(&l2tp_ip6_lock); 239 240 sk_common_release(sk); 241 } 242 243 static void l2tp_ip6_destroy_sock(struct sock *sk) 244 { 245 struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); 246 247 lock_sock(sk); 248 ip6_flush_pending_frames(sk); 249 release_sock(sk); 250 251 if (tunnel) { 252 l2tp_tunnel_closeall(tunnel); 253 sock_put(sk); 254 } 255 256 inet6_destroy_sock(sk); 257 } 258 259 static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 260 { 261 struct inet_sock *inet = inet_sk(sk); 262 struct ipv6_pinfo *np = inet6_sk(sk); 263 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; 264 __be32 v4addr = 0; 265 int addr_type; 266 int err; 267 268 if (!sock_flag(sk, SOCK_ZAPPED)) 269 return -EINVAL; 270 if (addr->l2tp_family != AF_INET6) 271 return -EINVAL; 272 if (addr_len < sizeof(*addr)) 273 return -EINVAL; 274 275 addr_type = ipv6_addr_type(&addr->l2tp_addr); 276 277 /* l2tp_ip6 sockets are IPv6 only */ 278 if (addr_type == IPV6_ADDR_MAPPED) 279 return -EADDRNOTAVAIL; 280 281 /* L2TP is point-point, not multicast */ 282 if (addr_type & IPV6_ADDR_MULTICAST) 283 return -EADDRNOTAVAIL; 284 285 err = -EADDRINUSE; 286 read_lock_bh(&l2tp_ip6_lock); 287 if (__l2tp_ip6_bind_lookup(&init_net, &addr->l2tp_addr, 288 sk->sk_bound_dev_if, addr->l2tp_conn_id)) 289 goto out_in_use; 290 read_unlock_bh(&l2tp_ip6_lock); 291 292 lock_sock(sk); 293 294 err = -EINVAL; 295 if (sk->sk_state != TCP_CLOSE) 296 goto out_unlock; 297 298 /* Check if the address belongs to the host. */ 299 rcu_read_lock(); 300 if (addr_type != IPV6_ADDR_ANY) { 301 struct net_device *dev = NULL; 302 303 if (addr_type & IPV6_ADDR_LINKLOCAL) { 304 if (addr_len >= sizeof(struct sockaddr_in6) && 305 addr->l2tp_scope_id) { 306 /* Override any existing binding, if another 307 * one is supplied by user. 308 */ 309 sk->sk_bound_dev_if = addr->l2tp_scope_id; 310 } 311 312 /* Binding to link-local address requires an 313 interface */ 314 if (!sk->sk_bound_dev_if) 315 goto out_unlock_rcu; 316 317 err = -ENODEV; 318 dev = dev_get_by_index_rcu(sock_net(sk), 319 sk->sk_bound_dev_if); 320 if (!dev) 321 goto out_unlock_rcu; 322 } 323 324 /* ipv4 addr of the socket is invalid. Only the 325 * unspecified and mapped address have a v4 equivalent. 326 */ 327 v4addr = LOOPBACK4_IPV6; 328 err = -EADDRNOTAVAIL; 329 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) 330 goto out_unlock_rcu; 331 } 332 rcu_read_unlock(); 333 334 inet->inet_rcv_saddr = inet->inet_saddr = v4addr; 335 sk->sk_v6_rcv_saddr = addr->l2tp_addr; 336 np->saddr = addr->l2tp_addr; 337 338 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; 339 340 write_lock_bh(&l2tp_ip6_lock); 341 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 342 sk_del_node_init(sk); 343 write_unlock_bh(&l2tp_ip6_lock); 344 345 sock_reset_flag(sk, SOCK_ZAPPED); 346 release_sock(sk); 347 return 0; 348 349 out_unlock_rcu: 350 rcu_read_unlock(); 351 out_unlock: 352 release_sock(sk); 353 return err; 354 355 out_in_use: 356 read_unlock_bh(&l2tp_ip6_lock); 357 return err; 358 } 359 360 static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, 361 int addr_len) 362 { 363 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr; 364 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; 365 struct in6_addr *daddr; 366 int addr_type; 367 int rc; 368 369 if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */ 370 return -EINVAL; 371 372 if (addr_len < sizeof(*lsa)) 373 return -EINVAL; 374 375 if (usin->sin6_family != AF_INET6) 376 return -EINVAL; 377 378 addr_type = ipv6_addr_type(&usin->sin6_addr); 379 if (addr_type & IPV6_ADDR_MULTICAST) 380 return -EINVAL; 381 382 if (addr_type & IPV6_ADDR_MAPPED) { 383 daddr = &usin->sin6_addr; 384 if (ipv4_is_multicast(daddr->s6_addr32[3])) 385 return -EINVAL; 386 } 387 388 rc = ip6_datagram_connect(sk, uaddr, addr_len); 389 390 lock_sock(sk); 391 392 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; 393 394 write_lock_bh(&l2tp_ip6_lock); 395 hlist_del_init(&sk->sk_bind_node); 396 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 397 write_unlock_bh(&l2tp_ip6_lock); 398 399 release_sock(sk); 400 401 return rc; 402 } 403 404 static int l2tp_ip6_disconnect(struct sock *sk, int flags) 405 { 406 if (sock_flag(sk, SOCK_ZAPPED)) 407 return 0; 408 409 return udp_disconnect(sk, flags); 410 } 411 412 static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, 413 int *uaddr_len, int peer) 414 { 415 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; 416 struct sock *sk = sock->sk; 417 struct ipv6_pinfo *np = inet6_sk(sk); 418 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); 419 420 lsa->l2tp_family = AF_INET6; 421 lsa->l2tp_flowinfo = 0; 422 lsa->l2tp_scope_id = 0; 423 lsa->l2tp_unused = 0; 424 if (peer) { 425 if (!lsk->peer_conn_id) 426 return -ENOTCONN; 427 lsa->l2tp_conn_id = lsk->peer_conn_id; 428 lsa->l2tp_addr = sk->sk_v6_daddr; 429 if (np->sndflow) 430 lsa->l2tp_flowinfo = np->flow_label; 431 } else { 432 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 433 lsa->l2tp_addr = np->saddr; 434 else 435 lsa->l2tp_addr = sk->sk_v6_rcv_saddr; 436 437 lsa->l2tp_conn_id = lsk->conn_id; 438 } 439 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 440 lsa->l2tp_scope_id = sk->sk_bound_dev_if; 441 *uaddr_len = sizeof(*lsa); 442 return 0; 443 } 444 445 static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) 446 { 447 int rc; 448 449 /* Charge it to the socket, dropping if the queue is full. */ 450 rc = sock_queue_rcv_skb(sk, skb); 451 if (rc < 0) 452 goto drop; 453 454 return 0; 455 456 drop: 457 IP_INC_STATS(&init_net, IPSTATS_MIB_INDISCARDS); 458 kfree_skb(skb); 459 return -1; 460 } 461 462 static int l2tp_ip6_push_pending_frames(struct sock *sk) 463 { 464 struct sk_buff *skb; 465 __be32 *transhdr = NULL; 466 int err = 0; 467 468 skb = skb_peek(&sk->sk_write_queue); 469 if (skb == NULL) 470 goto out; 471 472 transhdr = (__be32 *)skb_transport_header(skb); 473 *transhdr = 0; 474 475 err = ip6_push_pending_frames(sk); 476 477 out: 478 return err; 479 } 480 481 /* Userspace will call sendmsg() on the tunnel socket to send L2TP 482 * control frames. 483 */ 484 static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 485 { 486 struct ipv6_txoptions opt_space; 487 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 488 struct in6_addr *daddr, *final_p, final; 489 struct ipv6_pinfo *np = inet6_sk(sk); 490 struct ipv6_txoptions *opt_to_free = NULL; 491 struct ipv6_txoptions *opt = NULL; 492 struct ip6_flowlabel *flowlabel = NULL; 493 struct dst_entry *dst = NULL; 494 struct flowi6 fl6; 495 int addr_len = msg->msg_namelen; 496 int hlimit = -1; 497 int tclass = -1; 498 int dontfrag = -1; 499 int transhdrlen = 4; /* zero session-id */ 500 int ulen = len + transhdrlen; 501 int err; 502 503 /* Rough check on arithmetic overflow, 504 better check is made in ip6_append_data(). 505 */ 506 if (len > INT_MAX) 507 return -EMSGSIZE; 508 509 /* Mirror BSD error message compatibility */ 510 if (msg->msg_flags & MSG_OOB) 511 return -EOPNOTSUPP; 512 513 /* 514 * Get and verify the address. 515 */ 516 memset(&fl6, 0, sizeof(fl6)); 517 518 fl6.flowi6_mark = sk->sk_mark; 519 520 if (lsa) { 521 if (addr_len < SIN6_LEN_RFC2133) 522 return -EINVAL; 523 524 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) 525 return -EAFNOSUPPORT; 526 527 daddr = &lsa->l2tp_addr; 528 if (np->sndflow) { 529 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; 530 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 531 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 532 if (flowlabel == NULL) 533 return -EINVAL; 534 } 535 } 536 537 /* 538 * Otherwise it will be difficult to maintain 539 * sk->sk_dst_cache. 540 */ 541 if (sk->sk_state == TCP_ESTABLISHED && 542 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 543 daddr = &sk->sk_v6_daddr; 544 545 if (addr_len >= sizeof(struct sockaddr_in6) && 546 lsa->l2tp_scope_id && 547 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) 548 fl6.flowi6_oif = lsa->l2tp_scope_id; 549 } else { 550 if (sk->sk_state != TCP_ESTABLISHED) 551 return -EDESTADDRREQ; 552 553 daddr = &sk->sk_v6_daddr; 554 fl6.flowlabel = np->flow_label; 555 } 556 557 if (fl6.flowi6_oif == 0) 558 fl6.flowi6_oif = sk->sk_bound_dev_if; 559 560 if (msg->msg_controllen) { 561 opt = &opt_space; 562 memset(opt, 0, sizeof(struct ipv6_txoptions)); 563 opt->tot_len = sizeof(struct ipv6_txoptions); 564 565 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt, 566 &hlimit, &tclass, &dontfrag); 567 if (err < 0) { 568 fl6_sock_release(flowlabel); 569 return err; 570 } 571 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { 572 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 573 if (flowlabel == NULL) 574 return -EINVAL; 575 } 576 if (!(opt->opt_nflen|opt->opt_flen)) 577 opt = NULL; 578 } 579 580 if (!opt) { 581 opt = txopt_get(np); 582 opt_to_free = opt; 583 } 584 if (flowlabel) 585 opt = fl6_merge_options(&opt_space, flowlabel, opt); 586 opt = ipv6_fixup_options(&opt_space, opt); 587 588 fl6.flowi6_proto = sk->sk_protocol; 589 if (!ipv6_addr_any(daddr)) 590 fl6.daddr = *daddr; 591 else 592 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 593 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 594 fl6.saddr = np->saddr; 595 596 final_p = fl6_update_dst(&fl6, opt, &final); 597 598 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 599 fl6.flowi6_oif = np->mcast_oif; 600 else if (!fl6.flowi6_oif) 601 fl6.flowi6_oif = np->ucast_oif; 602 603 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 604 605 dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 606 if (IS_ERR(dst)) { 607 err = PTR_ERR(dst); 608 goto out; 609 } 610 611 if (hlimit < 0) 612 hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 613 614 if (tclass < 0) 615 tclass = np->tclass; 616 617 if (dontfrag < 0) 618 dontfrag = np->dontfrag; 619 620 if (msg->msg_flags & MSG_CONFIRM) 621 goto do_confirm; 622 623 back_from_confirm: 624 lock_sock(sk); 625 err = ip6_append_data(sk, ip_generic_getfrag, msg, 626 ulen, transhdrlen, hlimit, tclass, opt, 627 &fl6, (struct rt6_info *)dst, 628 msg->msg_flags, dontfrag); 629 if (err) 630 ip6_flush_pending_frames(sk); 631 else if (!(msg->msg_flags & MSG_MORE)) 632 err = l2tp_ip6_push_pending_frames(sk); 633 release_sock(sk); 634 done: 635 dst_release(dst); 636 out: 637 fl6_sock_release(flowlabel); 638 txopt_put(opt_to_free); 639 640 return err < 0 ? err : len; 641 642 do_confirm: 643 dst_confirm(dst); 644 if (!(msg->msg_flags & MSG_PROBE) || len) 645 goto back_from_confirm; 646 err = 0; 647 goto done; 648 } 649 650 static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 651 int noblock, int flags, int *addr_len) 652 { 653 struct ipv6_pinfo *np = inet6_sk(sk); 654 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 655 size_t copied = 0; 656 int err = -EOPNOTSUPP; 657 struct sk_buff *skb; 658 659 if (flags & MSG_OOB) 660 goto out; 661 662 if (addr_len) 663 *addr_len = sizeof(*lsa); 664 665 if (flags & MSG_ERRQUEUE) 666 return ipv6_recv_error(sk, msg, len, addr_len); 667 668 skb = skb_recv_datagram(sk, flags, noblock, &err); 669 if (!skb) 670 goto out; 671 672 copied = skb->len; 673 if (len < copied) { 674 msg->msg_flags |= MSG_TRUNC; 675 copied = len; 676 } 677 678 err = skb_copy_datagram_msg(skb, 0, msg, copied); 679 if (err) 680 goto done; 681 682 sock_recv_timestamp(msg, sk, skb); 683 684 /* Copy the address. */ 685 if (lsa) { 686 lsa->l2tp_family = AF_INET6; 687 lsa->l2tp_unused = 0; 688 lsa->l2tp_addr = ipv6_hdr(skb)->saddr; 689 lsa->l2tp_flowinfo = 0; 690 lsa->l2tp_scope_id = 0; 691 lsa->l2tp_conn_id = 0; 692 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 693 lsa->l2tp_scope_id = inet6_iif(skb); 694 } 695 696 if (np->rxopt.all) 697 ip6_datagram_recv_ctl(sk, msg, skb); 698 699 if (flags & MSG_TRUNC) 700 copied = skb->len; 701 done: 702 skb_free_datagram(sk, skb); 703 out: 704 return err ? err : copied; 705 } 706 707 static struct proto l2tp_ip6_prot = { 708 .name = "L2TP/IPv6", 709 .owner = THIS_MODULE, 710 .init = l2tp_ip6_open, 711 .close = l2tp_ip6_close, 712 .bind = l2tp_ip6_bind, 713 .connect = l2tp_ip6_connect, 714 .disconnect = l2tp_ip6_disconnect, 715 .ioctl = udp_ioctl, 716 .destroy = l2tp_ip6_destroy_sock, 717 .setsockopt = ipv6_setsockopt, 718 .getsockopt = ipv6_getsockopt, 719 .sendmsg = l2tp_ip6_sendmsg, 720 .recvmsg = l2tp_ip6_recvmsg, 721 .backlog_rcv = l2tp_ip6_backlog_recv, 722 .hash = inet6_hash, 723 .unhash = inet_unhash, 724 .obj_size = sizeof(struct l2tp_ip6_sock), 725 #ifdef CONFIG_COMPAT 726 .compat_setsockopt = compat_ipv6_setsockopt, 727 .compat_getsockopt = compat_ipv6_getsockopt, 728 #endif 729 }; 730 731 static const struct proto_ops l2tp_ip6_ops = { 732 .family = PF_INET6, 733 .owner = THIS_MODULE, 734 .release = inet6_release, 735 .bind = inet6_bind, 736 .connect = inet_dgram_connect, 737 .socketpair = sock_no_socketpair, 738 .accept = sock_no_accept, 739 .getname = l2tp_ip6_getname, 740 .poll = datagram_poll, 741 .ioctl = inet6_ioctl, 742 .listen = sock_no_listen, 743 .shutdown = inet_shutdown, 744 .setsockopt = sock_common_setsockopt, 745 .getsockopt = sock_common_getsockopt, 746 .sendmsg = inet_sendmsg, 747 .recvmsg = sock_common_recvmsg, 748 .mmap = sock_no_mmap, 749 .sendpage = sock_no_sendpage, 750 #ifdef CONFIG_COMPAT 751 .compat_setsockopt = compat_sock_common_setsockopt, 752 .compat_getsockopt = compat_sock_common_getsockopt, 753 #endif 754 }; 755 756 static struct inet_protosw l2tp_ip6_protosw = { 757 .type = SOCK_DGRAM, 758 .protocol = IPPROTO_L2TP, 759 .prot = &l2tp_ip6_prot, 760 .ops = &l2tp_ip6_ops, 761 }; 762 763 static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { 764 .handler = l2tp_ip6_recv, 765 }; 766 767 static int __init l2tp_ip6_init(void) 768 { 769 int err; 770 771 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); 772 773 err = proto_register(&l2tp_ip6_prot, 1); 774 if (err != 0) 775 goto out; 776 777 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 778 if (err) 779 goto out1; 780 781 inet6_register_protosw(&l2tp_ip6_protosw); 782 return 0; 783 784 out1: 785 proto_unregister(&l2tp_ip6_prot); 786 out: 787 return err; 788 } 789 790 static void __exit l2tp_ip6_exit(void) 791 { 792 inet6_unregister_protosw(&l2tp_ip6_protosw); 793 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 794 proto_unregister(&l2tp_ip6_prot); 795 } 796 797 module_init(l2tp_ip6_init); 798 module_exit(l2tp_ip6_exit); 799 800 MODULE_LICENSE("GPL"); 801 MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); 802 MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); 803 MODULE_VERSION("1.0"); 804 805 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like 806 * enums 807 */ 808 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); 809 MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); 810