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 net *net = dev_net(skb->dev); 132 struct sock *sk; 133 u32 session_id; 134 u32 tunnel_id; 135 unsigned char *ptr, *optr; 136 struct l2tp_session *session; 137 struct l2tp_tunnel *tunnel = NULL; 138 int length; 139 140 if (!pskb_may_pull(skb, 4)) 141 goto discard; 142 143 /* Point to L2TP header */ 144 optr = ptr = skb->data; 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(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 /* Point to L2TP header */ 173 optr = ptr = skb->data; 174 ptr += 4; 175 pr_debug("%s: ip recv\n", tunnel->name); 176 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); 177 } 178 179 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, 180 tunnel->recv_payload_hook); 181 return 0; 182 183 pass_up: 184 /* Get the tunnel_id from the L2TP header */ 185 if (!pskb_may_pull(skb, 12)) 186 goto discard; 187 188 if ((skb->data[0] & 0xc0) != 0xc0) 189 goto discard; 190 191 tunnel_id = ntohl(*(__be32 *) &skb->data[4]); 192 tunnel = l2tp_tunnel_find(net, tunnel_id); 193 if (tunnel != NULL) 194 sk = tunnel->sock; 195 else { 196 struct ipv6hdr *iph = ipv6_hdr(skb); 197 198 read_lock_bh(&l2tp_ip6_lock); 199 sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, 200 0, tunnel_id); 201 read_unlock_bh(&l2tp_ip6_lock); 202 } 203 204 if (sk == NULL) 205 goto discard; 206 207 sock_hold(sk); 208 209 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 210 goto discard_put; 211 212 nf_reset(skb); 213 214 return sk_receive_skb(sk, skb, 1); 215 216 discard_put: 217 sock_put(sk); 218 219 discard: 220 kfree_skb(skb); 221 return 0; 222 } 223 224 static int l2tp_ip6_open(struct sock *sk) 225 { 226 /* Prevent autobind. We don't have ports. */ 227 inet_sk(sk)->inet_num = IPPROTO_L2TP; 228 229 write_lock_bh(&l2tp_ip6_lock); 230 sk_add_node(sk, &l2tp_ip6_table); 231 write_unlock_bh(&l2tp_ip6_lock); 232 233 return 0; 234 } 235 236 static void l2tp_ip6_close(struct sock *sk, long timeout) 237 { 238 write_lock_bh(&l2tp_ip6_lock); 239 hlist_del_init(&sk->sk_bind_node); 240 sk_del_node_init(sk); 241 write_unlock_bh(&l2tp_ip6_lock); 242 243 sk_common_release(sk); 244 } 245 246 static void l2tp_ip6_destroy_sock(struct sock *sk) 247 { 248 struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); 249 250 lock_sock(sk); 251 ip6_flush_pending_frames(sk); 252 release_sock(sk); 253 254 if (tunnel) { 255 l2tp_tunnel_closeall(tunnel); 256 sock_put(sk); 257 } 258 259 inet6_destroy_sock(sk); 260 } 261 262 static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 263 { 264 struct inet_sock *inet = inet_sk(sk); 265 struct ipv6_pinfo *np = inet6_sk(sk); 266 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; 267 struct net *net = sock_net(sk); 268 __be32 v4addr = 0; 269 int addr_type; 270 int err; 271 272 if (!sock_flag(sk, SOCK_ZAPPED)) 273 return -EINVAL; 274 if (addr->l2tp_family != AF_INET6) 275 return -EINVAL; 276 if (addr_len < sizeof(*addr)) 277 return -EINVAL; 278 279 addr_type = ipv6_addr_type(&addr->l2tp_addr); 280 281 /* l2tp_ip6 sockets are IPv6 only */ 282 if (addr_type == IPV6_ADDR_MAPPED) 283 return -EADDRNOTAVAIL; 284 285 /* L2TP is point-point, not multicast */ 286 if (addr_type & IPV6_ADDR_MULTICAST) 287 return -EADDRNOTAVAIL; 288 289 err = -EADDRINUSE; 290 read_lock_bh(&l2tp_ip6_lock); 291 if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, 292 sk->sk_bound_dev_if, addr->l2tp_conn_id)) 293 goto out_in_use; 294 read_unlock_bh(&l2tp_ip6_lock); 295 296 lock_sock(sk); 297 298 err = -EINVAL; 299 if (sk->sk_state != TCP_CLOSE) 300 goto out_unlock; 301 302 /* Check if the address belongs to the host. */ 303 rcu_read_lock(); 304 if (addr_type != IPV6_ADDR_ANY) { 305 struct net_device *dev = NULL; 306 307 if (addr_type & IPV6_ADDR_LINKLOCAL) { 308 if (addr_len >= sizeof(struct sockaddr_in6) && 309 addr->l2tp_scope_id) { 310 /* Override any existing binding, if another 311 * one is supplied by user. 312 */ 313 sk->sk_bound_dev_if = addr->l2tp_scope_id; 314 } 315 316 /* Binding to link-local address requires an 317 interface */ 318 if (!sk->sk_bound_dev_if) 319 goto out_unlock_rcu; 320 321 err = -ENODEV; 322 dev = dev_get_by_index_rcu(sock_net(sk), 323 sk->sk_bound_dev_if); 324 if (!dev) 325 goto out_unlock_rcu; 326 } 327 328 /* ipv4 addr of the socket is invalid. Only the 329 * unspecified and mapped address have a v4 equivalent. 330 */ 331 v4addr = LOOPBACK4_IPV6; 332 err = -EADDRNOTAVAIL; 333 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) 334 goto out_unlock_rcu; 335 } 336 rcu_read_unlock(); 337 338 inet->inet_rcv_saddr = inet->inet_saddr = v4addr; 339 sk->sk_v6_rcv_saddr = addr->l2tp_addr; 340 np->saddr = addr->l2tp_addr; 341 342 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; 343 344 write_lock_bh(&l2tp_ip6_lock); 345 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 346 sk_del_node_init(sk); 347 write_unlock_bh(&l2tp_ip6_lock); 348 349 sock_reset_flag(sk, SOCK_ZAPPED); 350 release_sock(sk); 351 return 0; 352 353 out_unlock_rcu: 354 rcu_read_unlock(); 355 out_unlock: 356 release_sock(sk); 357 return err; 358 359 out_in_use: 360 read_unlock_bh(&l2tp_ip6_lock); 361 return err; 362 } 363 364 static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, 365 int addr_len) 366 { 367 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr; 368 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; 369 struct in6_addr *daddr; 370 int addr_type; 371 int rc; 372 373 if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */ 374 return -EINVAL; 375 376 if (addr_len < sizeof(*lsa)) 377 return -EINVAL; 378 379 if (usin->sin6_family != AF_INET6) 380 return -EINVAL; 381 382 addr_type = ipv6_addr_type(&usin->sin6_addr); 383 if (addr_type & IPV6_ADDR_MULTICAST) 384 return -EINVAL; 385 386 if (addr_type & IPV6_ADDR_MAPPED) { 387 daddr = &usin->sin6_addr; 388 if (ipv4_is_multicast(daddr->s6_addr32[3])) 389 return -EINVAL; 390 } 391 392 rc = ip6_datagram_connect(sk, uaddr, addr_len); 393 394 lock_sock(sk); 395 396 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; 397 398 write_lock_bh(&l2tp_ip6_lock); 399 hlist_del_init(&sk->sk_bind_node); 400 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 401 write_unlock_bh(&l2tp_ip6_lock); 402 403 release_sock(sk); 404 405 return rc; 406 } 407 408 static int l2tp_ip6_disconnect(struct sock *sk, int flags) 409 { 410 if (sock_flag(sk, SOCK_ZAPPED)) 411 return 0; 412 413 return udp_disconnect(sk, flags); 414 } 415 416 static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, 417 int *uaddr_len, int peer) 418 { 419 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; 420 struct sock *sk = sock->sk; 421 struct ipv6_pinfo *np = inet6_sk(sk); 422 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); 423 424 lsa->l2tp_family = AF_INET6; 425 lsa->l2tp_flowinfo = 0; 426 lsa->l2tp_scope_id = 0; 427 lsa->l2tp_unused = 0; 428 if (peer) { 429 if (!lsk->peer_conn_id) 430 return -ENOTCONN; 431 lsa->l2tp_conn_id = lsk->peer_conn_id; 432 lsa->l2tp_addr = sk->sk_v6_daddr; 433 if (np->sndflow) 434 lsa->l2tp_flowinfo = np->flow_label; 435 } else { 436 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 437 lsa->l2tp_addr = np->saddr; 438 else 439 lsa->l2tp_addr = sk->sk_v6_rcv_saddr; 440 441 lsa->l2tp_conn_id = lsk->conn_id; 442 } 443 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 444 lsa->l2tp_scope_id = sk->sk_bound_dev_if; 445 *uaddr_len = sizeof(*lsa); 446 return 0; 447 } 448 449 static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) 450 { 451 int rc; 452 453 /* Charge it to the socket, dropping if the queue is full. */ 454 rc = sock_queue_rcv_skb(sk, skb); 455 if (rc < 0) 456 goto drop; 457 458 return 0; 459 460 drop: 461 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); 462 kfree_skb(skb); 463 return -1; 464 } 465 466 static int l2tp_ip6_push_pending_frames(struct sock *sk) 467 { 468 struct sk_buff *skb; 469 __be32 *transhdr = NULL; 470 int err = 0; 471 472 skb = skb_peek(&sk->sk_write_queue); 473 if (skb == NULL) 474 goto out; 475 476 transhdr = (__be32 *)skb_transport_header(skb); 477 *transhdr = 0; 478 479 err = ip6_push_pending_frames(sk); 480 481 out: 482 return err; 483 } 484 485 /* Userspace will call sendmsg() on the tunnel socket to send L2TP 486 * control frames. 487 */ 488 static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 489 { 490 struct ipv6_txoptions opt_space; 491 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 492 struct in6_addr *daddr, *final_p, final; 493 struct ipv6_pinfo *np = inet6_sk(sk); 494 struct ipv6_txoptions *opt_to_free = NULL; 495 struct ipv6_txoptions *opt = NULL; 496 struct ip6_flowlabel *flowlabel = NULL; 497 struct dst_entry *dst = NULL; 498 struct flowi6 fl6; 499 struct sockcm_cookie sockc_unused = {0}; 500 struct ipcm6_cookie ipc6; 501 int addr_len = msg->msg_namelen; 502 int transhdrlen = 4; /* zero session-id */ 503 int ulen = len + transhdrlen; 504 int err; 505 506 /* Rough check on arithmetic overflow, 507 better check is made in ip6_append_data(). 508 */ 509 if (len > INT_MAX) 510 return -EMSGSIZE; 511 512 /* Mirror BSD error message compatibility */ 513 if (msg->msg_flags & MSG_OOB) 514 return -EOPNOTSUPP; 515 516 /* 517 * Get and verify the address. 518 */ 519 memset(&fl6, 0, sizeof(fl6)); 520 521 fl6.flowi6_mark = sk->sk_mark; 522 523 ipc6.hlimit = -1; 524 ipc6.tclass = -1; 525 ipc6.dontfrag = -1; 526 527 if (lsa) { 528 if (addr_len < SIN6_LEN_RFC2133) 529 return -EINVAL; 530 531 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) 532 return -EAFNOSUPPORT; 533 534 daddr = &lsa->l2tp_addr; 535 if (np->sndflow) { 536 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; 537 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 538 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 539 if (flowlabel == NULL) 540 return -EINVAL; 541 } 542 } 543 544 /* 545 * Otherwise it will be difficult to maintain 546 * sk->sk_dst_cache. 547 */ 548 if (sk->sk_state == TCP_ESTABLISHED && 549 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 550 daddr = &sk->sk_v6_daddr; 551 552 if (addr_len >= sizeof(struct sockaddr_in6) && 553 lsa->l2tp_scope_id && 554 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) 555 fl6.flowi6_oif = lsa->l2tp_scope_id; 556 } else { 557 if (sk->sk_state != TCP_ESTABLISHED) 558 return -EDESTADDRREQ; 559 560 daddr = &sk->sk_v6_daddr; 561 fl6.flowlabel = np->flow_label; 562 } 563 564 if (fl6.flowi6_oif == 0) 565 fl6.flowi6_oif = sk->sk_bound_dev_if; 566 567 if (msg->msg_controllen) { 568 opt = &opt_space; 569 memset(opt, 0, sizeof(struct ipv6_txoptions)); 570 opt->tot_len = sizeof(struct ipv6_txoptions); 571 ipc6.opt = opt; 572 573 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, 574 &sockc_unused); 575 if (err < 0) { 576 fl6_sock_release(flowlabel); 577 return err; 578 } 579 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { 580 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 581 if (flowlabel == NULL) 582 return -EINVAL; 583 } 584 if (!(opt->opt_nflen|opt->opt_flen)) 585 opt = NULL; 586 } 587 588 if (!opt) { 589 opt = txopt_get(np); 590 opt_to_free = opt; 591 } 592 if (flowlabel) 593 opt = fl6_merge_options(&opt_space, flowlabel, opt); 594 opt = ipv6_fixup_options(&opt_space, opt); 595 ipc6.opt = opt; 596 597 fl6.flowi6_proto = sk->sk_protocol; 598 if (!ipv6_addr_any(daddr)) 599 fl6.daddr = *daddr; 600 else 601 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 602 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 603 fl6.saddr = np->saddr; 604 605 final_p = fl6_update_dst(&fl6, opt, &final); 606 607 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 608 fl6.flowi6_oif = np->mcast_oif; 609 else if (!fl6.flowi6_oif) 610 fl6.flowi6_oif = np->ucast_oif; 611 612 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 613 614 if (ipc6.tclass < 0) 615 ipc6.tclass = np->tclass; 616 617 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); 618 619 dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 620 if (IS_ERR(dst)) { 621 err = PTR_ERR(dst); 622 goto out; 623 } 624 625 if (ipc6.hlimit < 0) 626 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 627 628 if (ipc6.dontfrag < 0) 629 ipc6.dontfrag = np->dontfrag; 630 631 if (msg->msg_flags & MSG_CONFIRM) 632 goto do_confirm; 633 634 back_from_confirm: 635 lock_sock(sk); 636 err = ip6_append_data(sk, ip_generic_getfrag, msg, 637 ulen, transhdrlen, &ipc6, 638 &fl6, (struct rt6_info *)dst, 639 msg->msg_flags, &sockc_unused); 640 if (err) 641 ip6_flush_pending_frames(sk); 642 else if (!(msg->msg_flags & MSG_MORE)) 643 err = l2tp_ip6_push_pending_frames(sk); 644 release_sock(sk); 645 done: 646 dst_release(dst); 647 out: 648 fl6_sock_release(flowlabel); 649 txopt_put(opt_to_free); 650 651 return err < 0 ? err : len; 652 653 do_confirm: 654 dst_confirm(dst); 655 if (!(msg->msg_flags & MSG_PROBE) || len) 656 goto back_from_confirm; 657 err = 0; 658 goto done; 659 } 660 661 static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 662 int noblock, int flags, int *addr_len) 663 { 664 struct ipv6_pinfo *np = inet6_sk(sk); 665 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 666 size_t copied = 0; 667 int err = -EOPNOTSUPP; 668 struct sk_buff *skb; 669 670 if (flags & MSG_OOB) 671 goto out; 672 673 if (addr_len) 674 *addr_len = sizeof(*lsa); 675 676 if (flags & MSG_ERRQUEUE) 677 return ipv6_recv_error(sk, msg, len, addr_len); 678 679 skb = skb_recv_datagram(sk, flags, noblock, &err); 680 if (!skb) 681 goto out; 682 683 copied = skb->len; 684 if (len < copied) { 685 msg->msg_flags |= MSG_TRUNC; 686 copied = len; 687 } 688 689 err = skb_copy_datagram_msg(skb, 0, msg, copied); 690 if (err) 691 goto done; 692 693 sock_recv_timestamp(msg, sk, skb); 694 695 /* Copy the address. */ 696 if (lsa) { 697 lsa->l2tp_family = AF_INET6; 698 lsa->l2tp_unused = 0; 699 lsa->l2tp_addr = ipv6_hdr(skb)->saddr; 700 lsa->l2tp_flowinfo = 0; 701 lsa->l2tp_scope_id = 0; 702 lsa->l2tp_conn_id = 0; 703 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 704 lsa->l2tp_scope_id = inet6_iif(skb); 705 } 706 707 if (np->rxopt.all) 708 ip6_datagram_recv_ctl(sk, msg, skb); 709 710 if (flags & MSG_TRUNC) 711 copied = skb->len; 712 done: 713 skb_free_datagram(sk, skb); 714 out: 715 return err ? err : copied; 716 } 717 718 static struct proto l2tp_ip6_prot = { 719 .name = "L2TP/IPv6", 720 .owner = THIS_MODULE, 721 .init = l2tp_ip6_open, 722 .close = l2tp_ip6_close, 723 .bind = l2tp_ip6_bind, 724 .connect = l2tp_ip6_connect, 725 .disconnect = l2tp_ip6_disconnect, 726 .ioctl = udp_ioctl, 727 .destroy = l2tp_ip6_destroy_sock, 728 .setsockopt = ipv6_setsockopt, 729 .getsockopt = ipv6_getsockopt, 730 .sendmsg = l2tp_ip6_sendmsg, 731 .recvmsg = l2tp_ip6_recvmsg, 732 .backlog_rcv = l2tp_ip6_backlog_recv, 733 .hash = inet6_hash, 734 .unhash = inet_unhash, 735 .obj_size = sizeof(struct l2tp_ip6_sock), 736 #ifdef CONFIG_COMPAT 737 .compat_setsockopt = compat_ipv6_setsockopt, 738 .compat_getsockopt = compat_ipv6_getsockopt, 739 #endif 740 }; 741 742 static const struct proto_ops l2tp_ip6_ops = { 743 .family = PF_INET6, 744 .owner = THIS_MODULE, 745 .release = inet6_release, 746 .bind = inet6_bind, 747 .connect = inet_dgram_connect, 748 .socketpair = sock_no_socketpair, 749 .accept = sock_no_accept, 750 .getname = l2tp_ip6_getname, 751 .poll = datagram_poll, 752 .ioctl = inet6_ioctl, 753 .listen = sock_no_listen, 754 .shutdown = inet_shutdown, 755 .setsockopt = sock_common_setsockopt, 756 .getsockopt = sock_common_getsockopt, 757 .sendmsg = inet_sendmsg, 758 .recvmsg = sock_common_recvmsg, 759 .mmap = sock_no_mmap, 760 .sendpage = sock_no_sendpage, 761 #ifdef CONFIG_COMPAT 762 .compat_setsockopt = compat_sock_common_setsockopt, 763 .compat_getsockopt = compat_sock_common_getsockopt, 764 #endif 765 }; 766 767 static struct inet_protosw l2tp_ip6_protosw = { 768 .type = SOCK_DGRAM, 769 .protocol = IPPROTO_L2TP, 770 .prot = &l2tp_ip6_prot, 771 .ops = &l2tp_ip6_ops, 772 }; 773 774 static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { 775 .handler = l2tp_ip6_recv, 776 }; 777 778 static int __init l2tp_ip6_init(void) 779 { 780 int err; 781 782 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); 783 784 err = proto_register(&l2tp_ip6_prot, 1); 785 if (err != 0) 786 goto out; 787 788 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 789 if (err) 790 goto out1; 791 792 inet6_register_protosw(&l2tp_ip6_protosw); 793 return 0; 794 795 out1: 796 proto_unregister(&l2tp_ip6_prot); 797 out: 798 return err; 799 } 800 801 static void __exit l2tp_ip6_exit(void) 802 { 803 inet6_unregister_protosw(&l2tp_ip6_protosw); 804 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 805 proto_unregister(&l2tp_ip6_prot); 806 } 807 808 module_init(l2tp_ip6_init); 809 module_exit(l2tp_ip6_exit); 810 811 MODULE_LICENSE("GPL"); 812 MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); 813 MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); 814 MODULE_VERSION("1.0"); 815 816 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like 817 * enums 818 */ 819 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); 820 MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); 821