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 if (!pskb_may_pull(skb, 4)) 140 goto discard; 141 142 /* Point to L2TP header */ 143 optr = ptr = skb->data; 144 session_id = ntohl(*((__be32 *) ptr)); 145 ptr += 4; 146 147 /* RFC3931: L2TP/IP packets have the first 4 bytes containing 148 * the session_id. If it is 0, the packet is a L2TP control 149 * frame and the session_id value can be discarded. 150 */ 151 if (session_id == 0) { 152 __skb_pull(skb, 4); 153 goto pass_up; 154 } 155 156 /* Ok, this is a data packet. Lookup the session. */ 157 session = l2tp_session_find(&init_net, NULL, session_id); 158 if (session == NULL) 159 goto discard; 160 161 tunnel = session->tunnel; 162 if (tunnel == NULL) 163 goto discard; 164 165 /* Trace packet contents, if enabled */ 166 if (tunnel->debug & L2TP_MSG_DATA) { 167 length = min(32u, skb->len); 168 if (!pskb_may_pull(skb, length)) 169 goto discard; 170 171 /* Point to L2TP header */ 172 optr = ptr = skb->data; 173 ptr += 4; 174 pr_debug("%s: ip recv\n", tunnel->name); 175 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); 176 } 177 178 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, 179 tunnel->recv_payload_hook); 180 return 0; 181 182 pass_up: 183 /* Get the tunnel_id from the L2TP header */ 184 if (!pskb_may_pull(skb, 12)) 185 goto discard; 186 187 if ((skb->data[0] & 0xc0) != 0xc0) 188 goto discard; 189 190 tunnel_id = ntohl(*(__be32 *) &skb->data[4]); 191 tunnel = l2tp_tunnel_find(&init_net, tunnel_id); 192 if (tunnel != NULL) 193 sk = tunnel->sock; 194 else { 195 struct ipv6hdr *iph = ipv6_hdr(skb); 196 197 read_lock_bh(&l2tp_ip6_lock); 198 sk = __l2tp_ip6_bind_lookup(&init_net, &iph->daddr, 199 0, tunnel_id); 200 read_unlock_bh(&l2tp_ip6_lock); 201 } 202 203 if (sk == NULL) 204 goto discard; 205 206 sock_hold(sk); 207 208 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 209 goto discard_put; 210 211 nf_reset(skb); 212 213 return sk_receive_skb(sk, skb, 1); 214 215 discard_put: 216 sock_put(sk); 217 218 discard: 219 kfree_skb(skb); 220 return 0; 221 } 222 223 static int l2tp_ip6_open(struct sock *sk) 224 { 225 /* Prevent autobind. We don't have ports. */ 226 inet_sk(sk)->inet_num = IPPROTO_L2TP; 227 228 write_lock_bh(&l2tp_ip6_lock); 229 sk_add_node(sk, &l2tp_ip6_table); 230 write_unlock_bh(&l2tp_ip6_lock); 231 232 return 0; 233 } 234 235 static void l2tp_ip6_close(struct sock *sk, long timeout) 236 { 237 write_lock_bh(&l2tp_ip6_lock); 238 hlist_del_init(&sk->sk_bind_node); 239 sk_del_node_init(sk); 240 write_unlock_bh(&l2tp_ip6_lock); 241 242 sk_common_release(sk); 243 } 244 245 static void l2tp_ip6_destroy_sock(struct sock *sk) 246 { 247 struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); 248 249 lock_sock(sk); 250 ip6_flush_pending_frames(sk); 251 release_sock(sk); 252 253 if (tunnel) { 254 l2tp_tunnel_closeall(tunnel); 255 sock_put(sk); 256 } 257 258 inet6_destroy_sock(sk); 259 } 260 261 static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 262 { 263 struct inet_sock *inet = inet_sk(sk); 264 struct ipv6_pinfo *np = inet6_sk(sk); 265 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; 266 __be32 v4addr = 0; 267 int addr_type; 268 int err; 269 270 if (!sock_flag(sk, SOCK_ZAPPED)) 271 return -EINVAL; 272 if (addr->l2tp_family != AF_INET6) 273 return -EINVAL; 274 if (addr_len < sizeof(*addr)) 275 return -EINVAL; 276 277 addr_type = ipv6_addr_type(&addr->l2tp_addr); 278 279 /* l2tp_ip6 sockets are IPv6 only */ 280 if (addr_type == IPV6_ADDR_MAPPED) 281 return -EADDRNOTAVAIL; 282 283 /* L2TP is point-point, not multicast */ 284 if (addr_type & IPV6_ADDR_MULTICAST) 285 return -EADDRNOTAVAIL; 286 287 err = -EADDRINUSE; 288 read_lock_bh(&l2tp_ip6_lock); 289 if (__l2tp_ip6_bind_lookup(&init_net, &addr->l2tp_addr, 290 sk->sk_bound_dev_if, addr->l2tp_conn_id)) 291 goto out_in_use; 292 read_unlock_bh(&l2tp_ip6_lock); 293 294 lock_sock(sk); 295 296 err = -EINVAL; 297 if (sk->sk_state != TCP_CLOSE) 298 goto out_unlock; 299 300 /* Check if the address belongs to the host. */ 301 rcu_read_lock(); 302 if (addr_type != IPV6_ADDR_ANY) { 303 struct net_device *dev = NULL; 304 305 if (addr_type & IPV6_ADDR_LINKLOCAL) { 306 if (addr_len >= sizeof(struct sockaddr_in6) && 307 addr->l2tp_scope_id) { 308 /* Override any existing binding, if another 309 * one is supplied by user. 310 */ 311 sk->sk_bound_dev_if = addr->l2tp_scope_id; 312 } 313 314 /* Binding to link-local address requires an 315 interface */ 316 if (!sk->sk_bound_dev_if) 317 goto out_unlock_rcu; 318 319 err = -ENODEV; 320 dev = dev_get_by_index_rcu(sock_net(sk), 321 sk->sk_bound_dev_if); 322 if (!dev) 323 goto out_unlock_rcu; 324 } 325 326 /* ipv4 addr of the socket is invalid. Only the 327 * unspecified and mapped address have a v4 equivalent. 328 */ 329 v4addr = LOOPBACK4_IPV6; 330 err = -EADDRNOTAVAIL; 331 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) 332 goto out_unlock_rcu; 333 } 334 rcu_read_unlock(); 335 336 inet->inet_rcv_saddr = inet->inet_saddr = v4addr; 337 sk->sk_v6_rcv_saddr = addr->l2tp_addr; 338 np->saddr = addr->l2tp_addr; 339 340 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; 341 342 write_lock_bh(&l2tp_ip6_lock); 343 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 344 sk_del_node_init(sk); 345 write_unlock_bh(&l2tp_ip6_lock); 346 347 sock_reset_flag(sk, SOCK_ZAPPED); 348 release_sock(sk); 349 return 0; 350 351 out_unlock_rcu: 352 rcu_read_unlock(); 353 out_unlock: 354 release_sock(sk); 355 return err; 356 357 out_in_use: 358 read_unlock_bh(&l2tp_ip6_lock); 359 return err; 360 } 361 362 static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, 363 int addr_len) 364 { 365 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr; 366 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; 367 struct in6_addr *daddr; 368 int addr_type; 369 int rc; 370 371 if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */ 372 return -EINVAL; 373 374 if (addr_len < sizeof(*lsa)) 375 return -EINVAL; 376 377 if (usin->sin6_family != AF_INET6) 378 return -EINVAL; 379 380 addr_type = ipv6_addr_type(&usin->sin6_addr); 381 if (addr_type & IPV6_ADDR_MULTICAST) 382 return -EINVAL; 383 384 if (addr_type & IPV6_ADDR_MAPPED) { 385 daddr = &usin->sin6_addr; 386 if (ipv4_is_multicast(daddr->s6_addr32[3])) 387 return -EINVAL; 388 } 389 390 rc = ip6_datagram_connect(sk, uaddr, addr_len); 391 392 lock_sock(sk); 393 394 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; 395 396 write_lock_bh(&l2tp_ip6_lock); 397 hlist_del_init(&sk->sk_bind_node); 398 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 399 write_unlock_bh(&l2tp_ip6_lock); 400 401 release_sock(sk); 402 403 return rc; 404 } 405 406 static int l2tp_ip6_disconnect(struct sock *sk, int flags) 407 { 408 if (sock_flag(sk, SOCK_ZAPPED)) 409 return 0; 410 411 return udp_disconnect(sk, flags); 412 } 413 414 static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, 415 int *uaddr_len, int peer) 416 { 417 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; 418 struct sock *sk = sock->sk; 419 struct ipv6_pinfo *np = inet6_sk(sk); 420 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); 421 422 lsa->l2tp_family = AF_INET6; 423 lsa->l2tp_flowinfo = 0; 424 lsa->l2tp_scope_id = 0; 425 lsa->l2tp_unused = 0; 426 if (peer) { 427 if (!lsk->peer_conn_id) 428 return -ENOTCONN; 429 lsa->l2tp_conn_id = lsk->peer_conn_id; 430 lsa->l2tp_addr = sk->sk_v6_daddr; 431 if (np->sndflow) 432 lsa->l2tp_flowinfo = np->flow_label; 433 } else { 434 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 435 lsa->l2tp_addr = np->saddr; 436 else 437 lsa->l2tp_addr = sk->sk_v6_rcv_saddr; 438 439 lsa->l2tp_conn_id = lsk->conn_id; 440 } 441 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 442 lsa->l2tp_scope_id = sk->sk_bound_dev_if; 443 *uaddr_len = sizeof(*lsa); 444 return 0; 445 } 446 447 static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) 448 { 449 int rc; 450 451 /* Charge it to the socket, dropping if the queue is full. */ 452 rc = sock_queue_rcv_skb(sk, skb); 453 if (rc < 0) 454 goto drop; 455 456 return 0; 457 458 drop: 459 IP_INC_STATS(&init_net, IPSTATS_MIB_INDISCARDS); 460 kfree_skb(skb); 461 return -1; 462 } 463 464 static int l2tp_ip6_push_pending_frames(struct sock *sk) 465 { 466 struct sk_buff *skb; 467 __be32 *transhdr = NULL; 468 int err = 0; 469 470 skb = skb_peek(&sk->sk_write_queue); 471 if (skb == NULL) 472 goto out; 473 474 transhdr = (__be32 *)skb_transport_header(skb); 475 *transhdr = 0; 476 477 err = ip6_push_pending_frames(sk); 478 479 out: 480 return err; 481 } 482 483 /* Userspace will call sendmsg() on the tunnel socket to send L2TP 484 * control frames. 485 */ 486 static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 487 { 488 struct ipv6_txoptions opt_space; 489 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 490 struct in6_addr *daddr, *final_p, final; 491 struct ipv6_pinfo *np = inet6_sk(sk); 492 struct ipv6_txoptions *opt_to_free = NULL; 493 struct ipv6_txoptions *opt = NULL; 494 struct ip6_flowlabel *flowlabel = NULL; 495 struct dst_entry *dst = NULL; 496 struct flowi6 fl6; 497 int addr_len = msg->msg_namelen; 498 int hlimit = -1; 499 int tclass = -1; 500 int dontfrag = -1; 501 int transhdrlen = 4; /* zero session-id */ 502 int ulen = len + transhdrlen; 503 int err; 504 505 /* Rough check on arithmetic overflow, 506 better check is made in ip6_append_data(). 507 */ 508 if (len > INT_MAX) 509 return -EMSGSIZE; 510 511 /* Mirror BSD error message compatibility */ 512 if (msg->msg_flags & MSG_OOB) 513 return -EOPNOTSUPP; 514 515 /* 516 * Get and verify the address. 517 */ 518 memset(&fl6, 0, sizeof(fl6)); 519 520 fl6.flowi6_mark = sk->sk_mark; 521 522 if (lsa) { 523 if (addr_len < SIN6_LEN_RFC2133) 524 return -EINVAL; 525 526 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) 527 return -EAFNOSUPPORT; 528 529 daddr = &lsa->l2tp_addr; 530 if (np->sndflow) { 531 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; 532 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 533 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 534 if (flowlabel == NULL) 535 return -EINVAL; 536 } 537 } 538 539 /* 540 * Otherwise it will be difficult to maintain 541 * sk->sk_dst_cache. 542 */ 543 if (sk->sk_state == TCP_ESTABLISHED && 544 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 545 daddr = &sk->sk_v6_daddr; 546 547 if (addr_len >= sizeof(struct sockaddr_in6) && 548 lsa->l2tp_scope_id && 549 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) 550 fl6.flowi6_oif = lsa->l2tp_scope_id; 551 } else { 552 if (sk->sk_state != TCP_ESTABLISHED) 553 return -EDESTADDRREQ; 554 555 daddr = &sk->sk_v6_daddr; 556 fl6.flowlabel = np->flow_label; 557 } 558 559 if (fl6.flowi6_oif == 0) 560 fl6.flowi6_oif = sk->sk_bound_dev_if; 561 562 if (msg->msg_controllen) { 563 opt = &opt_space; 564 memset(opt, 0, sizeof(struct ipv6_txoptions)); 565 opt->tot_len = sizeof(struct ipv6_txoptions); 566 567 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt, 568 &hlimit, &tclass, &dontfrag); 569 if (err < 0) { 570 fl6_sock_release(flowlabel); 571 return err; 572 } 573 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { 574 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 575 if (flowlabel == NULL) 576 return -EINVAL; 577 } 578 if (!(opt->opt_nflen|opt->opt_flen)) 579 opt = NULL; 580 } 581 582 if (!opt) { 583 opt = txopt_get(np); 584 opt_to_free = opt; 585 } 586 if (flowlabel) 587 opt = fl6_merge_options(&opt_space, flowlabel, opt); 588 opt = ipv6_fixup_options(&opt_space, opt); 589 590 fl6.flowi6_proto = sk->sk_protocol; 591 if (!ipv6_addr_any(daddr)) 592 fl6.daddr = *daddr; 593 else 594 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 595 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 596 fl6.saddr = np->saddr; 597 598 final_p = fl6_update_dst(&fl6, opt, &final); 599 600 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 601 fl6.flowi6_oif = np->mcast_oif; 602 else if (!fl6.flowi6_oif) 603 fl6.flowi6_oif = np->ucast_oif; 604 605 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 606 607 dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 608 if (IS_ERR(dst)) { 609 err = PTR_ERR(dst); 610 goto out; 611 } 612 613 if (hlimit < 0) 614 hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 615 616 if (tclass < 0) 617 tclass = np->tclass; 618 619 if (dontfrag < 0) 620 dontfrag = np->dontfrag; 621 622 if (msg->msg_flags & MSG_CONFIRM) 623 goto do_confirm; 624 625 back_from_confirm: 626 lock_sock(sk); 627 err = ip6_append_data(sk, ip_generic_getfrag, msg, 628 ulen, transhdrlen, hlimit, tclass, opt, 629 &fl6, (struct rt6_info *)dst, 630 msg->msg_flags, dontfrag); 631 if (err) 632 ip6_flush_pending_frames(sk); 633 else if (!(msg->msg_flags & MSG_MORE)) 634 err = l2tp_ip6_push_pending_frames(sk); 635 release_sock(sk); 636 done: 637 dst_release(dst); 638 out: 639 fl6_sock_release(flowlabel); 640 txopt_put(opt_to_free); 641 642 return err < 0 ? err : len; 643 644 do_confirm: 645 dst_confirm(dst); 646 if (!(msg->msg_flags & MSG_PROBE) || len) 647 goto back_from_confirm; 648 err = 0; 649 goto done; 650 } 651 652 static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 653 int noblock, int flags, int *addr_len) 654 { 655 struct ipv6_pinfo *np = inet6_sk(sk); 656 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 657 size_t copied = 0; 658 int err = -EOPNOTSUPP; 659 struct sk_buff *skb; 660 661 if (flags & MSG_OOB) 662 goto out; 663 664 if (addr_len) 665 *addr_len = sizeof(*lsa); 666 667 if (flags & MSG_ERRQUEUE) 668 return ipv6_recv_error(sk, msg, len, addr_len); 669 670 skb = skb_recv_datagram(sk, flags, noblock, &err); 671 if (!skb) 672 goto out; 673 674 copied = skb->len; 675 if (len < copied) { 676 msg->msg_flags |= MSG_TRUNC; 677 copied = len; 678 } 679 680 err = skb_copy_datagram_msg(skb, 0, msg, copied); 681 if (err) 682 goto done; 683 684 sock_recv_timestamp(msg, sk, skb); 685 686 /* Copy the address. */ 687 if (lsa) { 688 lsa->l2tp_family = AF_INET6; 689 lsa->l2tp_unused = 0; 690 lsa->l2tp_addr = ipv6_hdr(skb)->saddr; 691 lsa->l2tp_flowinfo = 0; 692 lsa->l2tp_scope_id = 0; 693 lsa->l2tp_conn_id = 0; 694 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 695 lsa->l2tp_scope_id = inet6_iif(skb); 696 } 697 698 if (np->rxopt.all) 699 ip6_datagram_recv_ctl(sk, msg, skb); 700 701 if (flags & MSG_TRUNC) 702 copied = skb->len; 703 done: 704 skb_free_datagram(sk, skb); 705 out: 706 return err ? err : copied; 707 } 708 709 static struct proto l2tp_ip6_prot = { 710 .name = "L2TP/IPv6", 711 .owner = THIS_MODULE, 712 .init = l2tp_ip6_open, 713 .close = l2tp_ip6_close, 714 .bind = l2tp_ip6_bind, 715 .connect = l2tp_ip6_connect, 716 .disconnect = l2tp_ip6_disconnect, 717 .ioctl = udp_ioctl, 718 .destroy = l2tp_ip6_destroy_sock, 719 .setsockopt = ipv6_setsockopt, 720 .getsockopt = ipv6_getsockopt, 721 .sendmsg = l2tp_ip6_sendmsg, 722 .recvmsg = l2tp_ip6_recvmsg, 723 .backlog_rcv = l2tp_ip6_backlog_recv, 724 .hash = inet6_hash, 725 .unhash = inet_unhash, 726 .obj_size = sizeof(struct l2tp_ip6_sock), 727 #ifdef CONFIG_COMPAT 728 .compat_setsockopt = compat_ipv6_setsockopt, 729 .compat_getsockopt = compat_ipv6_getsockopt, 730 #endif 731 }; 732 733 static const struct proto_ops l2tp_ip6_ops = { 734 .family = PF_INET6, 735 .owner = THIS_MODULE, 736 .release = inet6_release, 737 .bind = inet6_bind, 738 .connect = inet_dgram_connect, 739 .socketpair = sock_no_socketpair, 740 .accept = sock_no_accept, 741 .getname = l2tp_ip6_getname, 742 .poll = datagram_poll, 743 .ioctl = inet6_ioctl, 744 .listen = sock_no_listen, 745 .shutdown = inet_shutdown, 746 .setsockopt = sock_common_setsockopt, 747 .getsockopt = sock_common_getsockopt, 748 .sendmsg = inet_sendmsg, 749 .recvmsg = sock_common_recvmsg, 750 .mmap = sock_no_mmap, 751 .sendpage = sock_no_sendpage, 752 #ifdef CONFIG_COMPAT 753 .compat_setsockopt = compat_sock_common_setsockopt, 754 .compat_getsockopt = compat_sock_common_getsockopt, 755 #endif 756 }; 757 758 static struct inet_protosw l2tp_ip6_protosw = { 759 .type = SOCK_DGRAM, 760 .protocol = IPPROTO_L2TP, 761 .prot = &l2tp_ip6_prot, 762 .ops = &l2tp_ip6_ops, 763 }; 764 765 static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { 766 .handler = l2tp_ip6_recv, 767 }; 768 769 static int __init l2tp_ip6_init(void) 770 { 771 int err; 772 773 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); 774 775 err = proto_register(&l2tp_ip6_prot, 1); 776 if (err != 0) 777 goto out; 778 779 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 780 if (err) 781 goto out1; 782 783 inet6_register_protosw(&l2tp_ip6_protosw); 784 return 0; 785 786 out1: 787 proto_unregister(&l2tp_ip6_prot); 788 out: 789 return err; 790 } 791 792 static void __exit l2tp_ip6_exit(void) 793 { 794 inet6_unregister_protosw(&l2tp_ip6_protosw); 795 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 796 proto_unregister(&l2tp_ip6_prot); 797 } 798 799 module_init(l2tp_ip6_init); 800 module_exit(l2tp_ip6_exit); 801 802 MODULE_LICENSE("GPL"); 803 MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); 804 MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); 805 MODULE_VERSION("1.0"); 806 807 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like 808 * enums 809 */ 810 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); 811 MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); 812