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(const struct net *net, 61 const struct in6_addr *laddr, 62 const struct in6_addr *raddr, 63 int dif, u32 tunnel_id) 64 { 65 struct sock *sk; 66 67 sk_for_each_bound(sk, &l2tp_ip6_bind_table) { 68 const struct in6_addr *sk_laddr = inet6_rcv_saddr(sk); 69 const struct in6_addr *sk_raddr = &sk->sk_v6_daddr; 70 const struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk); 71 72 if (!net_eq(sock_net(sk), net)) 73 continue; 74 75 if (sk->sk_bound_dev_if && dif && sk->sk_bound_dev_if != dif) 76 continue; 77 78 if (sk_laddr && !ipv6_addr_any(sk_laddr) && 79 !ipv6_addr_any(laddr) && !ipv6_addr_equal(sk_laddr, laddr)) 80 continue; 81 82 if (!ipv6_addr_any(sk_raddr) && raddr && 83 !ipv6_addr_any(raddr) && !ipv6_addr_equal(sk_raddr, raddr)) 84 continue; 85 86 if (l2tp->conn_id != tunnel_id) 87 continue; 88 89 goto found; 90 } 91 92 sk = NULL; 93 found: 94 return sk; 95 } 96 97 /* When processing receive frames, there are two cases to 98 * consider. Data frames consist of a non-zero session-id and an 99 * optional cookie. Control frames consist of a regular L2TP header 100 * preceded by 32-bits of zeros. 101 * 102 * L2TPv3 Session Header Over IP 103 * 104 * 0 1 2 3 105 * 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 1 106 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 107 * | Session ID | 108 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 109 * | Cookie (optional, maximum 64 bits)... 110 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 111 * | 112 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 113 * 114 * L2TPv3 Control Message Header Over IP 115 * 116 * 0 1 2 3 117 * 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 1 118 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 119 * | (32 bits of zeros) | 120 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 121 * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length | 122 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 123 * | Control Connection ID | 124 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 125 * | Ns | Nr | 126 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 127 * 128 * All control frames are passed to userspace. 129 */ 130 static int l2tp_ip6_recv(struct sk_buff *skb) 131 { 132 struct net *net = dev_net(skb->dev); 133 struct sock *sk; 134 u32 session_id; 135 u32 tunnel_id; 136 unsigned char *ptr, *optr; 137 struct l2tp_session *session; 138 struct l2tp_tunnel *tunnel = NULL; 139 struct ipv6hdr *iph; 140 int length; 141 142 if (!pskb_may_pull(skb, 4)) 143 goto discard; 144 145 /* Point to L2TP header */ 146 optr = ptr = skb->data; 147 session_id = ntohl(*((__be32 *) ptr)); 148 ptr += 4; 149 150 /* RFC3931: L2TP/IP packets have the first 4 bytes containing 151 * the session_id. If it is 0, the packet is a L2TP control 152 * frame and the session_id value can be discarded. 153 */ 154 if (session_id == 0) { 155 __skb_pull(skb, 4); 156 goto pass_up; 157 } 158 159 /* Ok, this is a data packet. Lookup the session. */ 160 session = l2tp_session_get(net, NULL, session_id); 161 if (!session) 162 goto discard; 163 164 tunnel = session->tunnel; 165 if (!tunnel) 166 goto discard_sess; 167 168 /* Trace packet contents, if enabled */ 169 if (tunnel->debug & L2TP_MSG_DATA) { 170 length = min(32u, skb->len); 171 if (!pskb_may_pull(skb, length)) 172 goto discard_sess; 173 174 /* Point to L2TP header */ 175 optr = ptr = skb->data; 176 ptr += 4; 177 pr_debug("%s: ip recv\n", tunnel->name); 178 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); 179 } 180 181 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, 182 tunnel->recv_payload_hook); 183 l2tp_session_dec_refcount(session); 184 185 return 0; 186 187 pass_up: 188 /* Get the tunnel_id from the L2TP header */ 189 if (!pskb_may_pull(skb, 12)) 190 goto discard; 191 192 if ((skb->data[0] & 0xc0) != 0xc0) 193 goto discard; 194 195 tunnel_id = ntohl(*(__be32 *) &skb->data[4]); 196 iph = ipv6_hdr(skb); 197 198 read_lock_bh(&l2tp_ip6_lock); 199 sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr, 200 inet6_iif(skb), tunnel_id); 201 if (!sk) { 202 read_unlock_bh(&l2tp_ip6_lock); 203 goto discard; 204 } 205 sock_hold(sk); 206 read_unlock_bh(&l2tp_ip6_lock); 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_sess: 216 l2tp_session_dec_refcount(session); 217 goto discard; 218 219 discard_put: 220 sock_put(sk); 221 222 discard: 223 kfree_skb(skb); 224 return 0; 225 } 226 227 static int l2tp_ip6_open(struct sock *sk) 228 { 229 /* Prevent autobind. We don't have ports. */ 230 inet_sk(sk)->inet_num = IPPROTO_L2TP; 231 232 write_lock_bh(&l2tp_ip6_lock); 233 sk_add_node(sk, &l2tp_ip6_table); 234 write_unlock_bh(&l2tp_ip6_lock); 235 236 return 0; 237 } 238 239 static void l2tp_ip6_close(struct sock *sk, long timeout) 240 { 241 write_lock_bh(&l2tp_ip6_lock); 242 hlist_del_init(&sk->sk_bind_node); 243 sk_del_node_init(sk); 244 write_unlock_bh(&l2tp_ip6_lock); 245 246 sk_common_release(sk); 247 } 248 249 static void l2tp_ip6_destroy_sock(struct sock *sk) 250 { 251 struct l2tp_tunnel *tunnel = sk->sk_user_data; 252 253 lock_sock(sk); 254 ip6_flush_pending_frames(sk); 255 release_sock(sk); 256 257 if (tunnel) 258 l2tp_tunnel_delete(tunnel); 259 260 inet6_destroy_sock(sk); 261 } 262 263 static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 264 { 265 struct inet_sock *inet = inet_sk(sk); 266 struct ipv6_pinfo *np = inet6_sk(sk); 267 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; 268 struct net *net = sock_net(sk); 269 __be32 v4addr = 0; 270 int bound_dev_if; 271 int addr_type; 272 int err; 273 274 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 lock_sock(sk); 290 291 err = -EINVAL; 292 if (!sock_flag(sk, SOCK_ZAPPED)) 293 goto out_unlock; 294 295 if (sk->sk_state != TCP_CLOSE) 296 goto out_unlock; 297 298 bound_dev_if = sk->sk_bound_dev_if; 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->l2tp_scope_id) 307 bound_dev_if = addr->l2tp_scope_id; 308 309 /* Binding to link-local address requires an 310 * interface. 311 */ 312 if (!bound_dev_if) 313 goto out_unlock_rcu; 314 315 err = -ENODEV; 316 dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); 317 if (!dev) 318 goto out_unlock_rcu; 319 } 320 321 /* ipv4 addr of the socket is invalid. Only the 322 * unspecified and mapped address have a v4 equivalent. 323 */ 324 v4addr = LOOPBACK4_IPV6; 325 err = -EADDRNOTAVAIL; 326 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) 327 goto out_unlock_rcu; 328 } 329 rcu_read_unlock(); 330 331 write_lock_bh(&l2tp_ip6_lock); 332 if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, 333 addr->l2tp_conn_id)) { 334 write_unlock_bh(&l2tp_ip6_lock); 335 err = -EADDRINUSE; 336 goto out_unlock; 337 } 338 339 inet->inet_saddr = v4addr; 340 inet->inet_rcv_saddr = v4addr; 341 sk->sk_bound_dev_if = bound_dev_if; 342 sk->sk_v6_rcv_saddr = addr->l2tp_addr; 343 np->saddr = addr->l2tp_addr; 344 345 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; 346 347 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 348 sk_del_node_init(sk); 349 write_unlock_bh(&l2tp_ip6_lock); 350 351 sock_reset_flag(sk, SOCK_ZAPPED); 352 release_sock(sk); 353 return 0; 354 355 out_unlock_rcu: 356 rcu_read_unlock(); 357 out_unlock: 358 release_sock(sk); 359 360 return err; 361 } 362 363 static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, 364 int addr_len) 365 { 366 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr; 367 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; 368 struct in6_addr *daddr; 369 int addr_type; 370 int rc; 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 lock_sock(sk); 389 390 /* Must bind first - autobinding does not work */ 391 if (sock_flag(sk, SOCK_ZAPPED)) { 392 rc = -EINVAL; 393 goto out_sk; 394 } 395 396 rc = __ip6_datagram_connect(sk, uaddr, addr_len); 397 if (rc < 0) 398 goto out_sk; 399 400 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; 401 402 write_lock_bh(&l2tp_ip6_lock); 403 hlist_del_init(&sk->sk_bind_node); 404 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 405 write_unlock_bh(&l2tp_ip6_lock); 406 407 out_sk: 408 release_sock(sk); 409 410 return rc; 411 } 412 413 static int l2tp_ip6_disconnect(struct sock *sk, int flags) 414 { 415 if (sock_flag(sk, SOCK_ZAPPED)) 416 return 0; 417 418 return __udp_disconnect(sk, flags); 419 } 420 421 static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, 422 int peer) 423 { 424 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; 425 struct sock *sk = sock->sk; 426 struct ipv6_pinfo *np = inet6_sk(sk); 427 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); 428 429 lsa->l2tp_family = AF_INET6; 430 lsa->l2tp_flowinfo = 0; 431 lsa->l2tp_scope_id = 0; 432 lsa->l2tp_unused = 0; 433 if (peer) { 434 if (!lsk->peer_conn_id) 435 return -ENOTCONN; 436 lsa->l2tp_conn_id = lsk->peer_conn_id; 437 lsa->l2tp_addr = sk->sk_v6_daddr; 438 if (np->sndflow) 439 lsa->l2tp_flowinfo = np->flow_label; 440 } else { 441 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 442 lsa->l2tp_addr = np->saddr; 443 else 444 lsa->l2tp_addr = sk->sk_v6_rcv_saddr; 445 446 lsa->l2tp_conn_id = lsk->conn_id; 447 } 448 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 449 lsa->l2tp_scope_id = sk->sk_bound_dev_if; 450 return sizeof(*lsa); 451 } 452 453 static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) 454 { 455 int rc; 456 457 /* Charge it to the socket, dropping if the queue is full. */ 458 rc = sock_queue_rcv_skb(sk, skb); 459 if (rc < 0) 460 goto drop; 461 462 return 0; 463 464 drop: 465 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); 466 kfree_skb(skb); 467 return -1; 468 } 469 470 static int l2tp_ip6_push_pending_frames(struct sock *sk) 471 { 472 struct sk_buff *skb; 473 __be32 *transhdr = NULL; 474 int err = 0; 475 476 skb = skb_peek(&sk->sk_write_queue); 477 if (skb == NULL) 478 goto out; 479 480 transhdr = (__be32 *)skb_transport_header(skb); 481 *transhdr = 0; 482 483 err = ip6_push_pending_frames(sk); 484 485 out: 486 return err; 487 } 488 489 /* Userspace will call sendmsg() on the tunnel socket to send L2TP 490 * control frames. 491 */ 492 static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 493 { 494 struct ipv6_txoptions opt_space; 495 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 496 struct in6_addr *daddr, *final_p, final; 497 struct ipv6_pinfo *np = inet6_sk(sk); 498 struct ipv6_txoptions *opt_to_free = NULL; 499 struct ipv6_txoptions *opt = NULL; 500 struct ip6_flowlabel *flowlabel = NULL; 501 struct dst_entry *dst = NULL; 502 struct flowi6 fl6; 503 struct sockcm_cookie sockc_unused = {0}; 504 struct ipcm6_cookie ipc6; 505 int addr_len = msg->msg_namelen; 506 int transhdrlen = 4; /* zero session-id */ 507 int ulen = len + transhdrlen; 508 int err; 509 510 /* Rough check on arithmetic overflow, 511 better check is made in ip6_append_data(). 512 */ 513 if (len > INT_MAX) 514 return -EMSGSIZE; 515 516 /* Mirror BSD error message compatibility */ 517 if (msg->msg_flags & MSG_OOB) 518 return -EOPNOTSUPP; 519 520 /* 521 * Get and verify the address. 522 */ 523 memset(&fl6, 0, sizeof(fl6)); 524 525 fl6.flowi6_mark = sk->sk_mark; 526 fl6.flowi6_uid = sk->sk_uid; 527 528 ipc6.hlimit = -1; 529 ipc6.tclass = -1; 530 ipc6.dontfrag = -1; 531 532 if (lsa) { 533 if (addr_len < SIN6_LEN_RFC2133) 534 return -EINVAL; 535 536 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) 537 return -EAFNOSUPPORT; 538 539 daddr = &lsa->l2tp_addr; 540 if (np->sndflow) { 541 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; 542 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 543 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 544 if (flowlabel == NULL) 545 return -EINVAL; 546 } 547 } 548 549 /* 550 * Otherwise it will be difficult to maintain 551 * sk->sk_dst_cache. 552 */ 553 if (sk->sk_state == TCP_ESTABLISHED && 554 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 555 daddr = &sk->sk_v6_daddr; 556 557 if (addr_len >= sizeof(struct sockaddr_in6) && 558 lsa->l2tp_scope_id && 559 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) 560 fl6.flowi6_oif = lsa->l2tp_scope_id; 561 } else { 562 if (sk->sk_state != TCP_ESTABLISHED) 563 return -EDESTADDRREQ; 564 565 daddr = &sk->sk_v6_daddr; 566 fl6.flowlabel = np->flow_label; 567 } 568 569 if (fl6.flowi6_oif == 0) 570 fl6.flowi6_oif = sk->sk_bound_dev_if; 571 572 if (msg->msg_controllen) { 573 opt = &opt_space; 574 memset(opt, 0, sizeof(struct ipv6_txoptions)); 575 opt->tot_len = sizeof(struct ipv6_txoptions); 576 ipc6.opt = opt; 577 578 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, 579 &sockc_unused); 580 if (err < 0) { 581 fl6_sock_release(flowlabel); 582 return err; 583 } 584 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { 585 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 586 if (flowlabel == NULL) 587 return -EINVAL; 588 } 589 if (!(opt->opt_nflen|opt->opt_flen)) 590 opt = NULL; 591 } 592 593 if (!opt) { 594 opt = txopt_get(np); 595 opt_to_free = opt; 596 } 597 if (flowlabel) 598 opt = fl6_merge_options(&opt_space, flowlabel, opt); 599 opt = ipv6_fixup_options(&opt_space, opt); 600 ipc6.opt = opt; 601 602 fl6.flowi6_proto = sk->sk_protocol; 603 if (!ipv6_addr_any(daddr)) 604 fl6.daddr = *daddr; 605 else 606 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 607 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 608 fl6.saddr = np->saddr; 609 610 final_p = fl6_update_dst(&fl6, opt, &final); 611 612 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 613 fl6.flowi6_oif = np->mcast_oif; 614 else if (!fl6.flowi6_oif) 615 fl6.flowi6_oif = np->ucast_oif; 616 617 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 618 619 if (ipc6.tclass < 0) 620 ipc6.tclass = np->tclass; 621 622 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); 623 624 dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 625 if (IS_ERR(dst)) { 626 err = PTR_ERR(dst); 627 goto out; 628 } 629 630 if (ipc6.hlimit < 0) 631 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 632 633 if (ipc6.dontfrag < 0) 634 ipc6.dontfrag = np->dontfrag; 635 636 if (msg->msg_flags & MSG_CONFIRM) 637 goto do_confirm; 638 639 back_from_confirm: 640 lock_sock(sk); 641 err = ip6_append_data(sk, ip_generic_getfrag, msg, 642 ulen, transhdrlen, &ipc6, 643 &fl6, (struct rt6_info *)dst, 644 msg->msg_flags, &sockc_unused); 645 if (err) 646 ip6_flush_pending_frames(sk); 647 else if (!(msg->msg_flags & MSG_MORE)) 648 err = l2tp_ip6_push_pending_frames(sk); 649 release_sock(sk); 650 done: 651 dst_release(dst); 652 out: 653 fl6_sock_release(flowlabel); 654 txopt_put(opt_to_free); 655 656 return err < 0 ? err : len; 657 658 do_confirm: 659 if (msg->msg_flags & MSG_PROBE) 660 dst_confirm_neigh(dst, &fl6.daddr); 661 if (!(msg->msg_flags & MSG_PROBE) || len) 662 goto back_from_confirm; 663 err = 0; 664 goto done; 665 } 666 667 static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 668 int noblock, int flags, int *addr_len) 669 { 670 struct ipv6_pinfo *np = inet6_sk(sk); 671 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 672 size_t copied = 0; 673 int err = -EOPNOTSUPP; 674 struct sk_buff *skb; 675 676 if (flags & MSG_OOB) 677 goto out; 678 679 if (addr_len) 680 *addr_len = sizeof(*lsa); 681 682 if (flags & MSG_ERRQUEUE) 683 return ipv6_recv_error(sk, msg, len, addr_len); 684 685 skb = skb_recv_datagram(sk, flags, noblock, &err); 686 if (!skb) 687 goto out; 688 689 copied = skb->len; 690 if (len < copied) { 691 msg->msg_flags |= MSG_TRUNC; 692 copied = len; 693 } 694 695 err = skb_copy_datagram_msg(skb, 0, msg, copied); 696 if (err) 697 goto done; 698 699 sock_recv_timestamp(msg, sk, skb); 700 701 /* Copy the address. */ 702 if (lsa) { 703 lsa->l2tp_family = AF_INET6; 704 lsa->l2tp_unused = 0; 705 lsa->l2tp_addr = ipv6_hdr(skb)->saddr; 706 lsa->l2tp_flowinfo = 0; 707 lsa->l2tp_scope_id = 0; 708 lsa->l2tp_conn_id = 0; 709 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 710 lsa->l2tp_scope_id = inet6_iif(skb); 711 } 712 713 if (np->rxopt.all) 714 ip6_datagram_recv_ctl(sk, msg, skb); 715 716 if (flags & MSG_TRUNC) 717 copied = skb->len; 718 done: 719 skb_free_datagram(sk, skb); 720 out: 721 return err ? err : copied; 722 } 723 724 static struct proto l2tp_ip6_prot = { 725 .name = "L2TP/IPv6", 726 .owner = THIS_MODULE, 727 .init = l2tp_ip6_open, 728 .close = l2tp_ip6_close, 729 .bind = l2tp_ip6_bind, 730 .connect = l2tp_ip6_connect, 731 .disconnect = l2tp_ip6_disconnect, 732 .ioctl = l2tp_ioctl, 733 .destroy = l2tp_ip6_destroy_sock, 734 .setsockopt = ipv6_setsockopt, 735 .getsockopt = ipv6_getsockopt, 736 .sendmsg = l2tp_ip6_sendmsg, 737 .recvmsg = l2tp_ip6_recvmsg, 738 .backlog_rcv = l2tp_ip6_backlog_recv, 739 .hash = inet6_hash, 740 .unhash = inet_unhash, 741 .obj_size = sizeof(struct l2tp_ip6_sock), 742 #ifdef CONFIG_COMPAT 743 .compat_setsockopt = compat_ipv6_setsockopt, 744 .compat_getsockopt = compat_ipv6_getsockopt, 745 #endif 746 }; 747 748 static const struct proto_ops l2tp_ip6_ops = { 749 .family = PF_INET6, 750 .owner = THIS_MODULE, 751 .release = inet6_release, 752 .bind = inet6_bind, 753 .connect = inet_dgram_connect, 754 .socketpair = sock_no_socketpair, 755 .accept = sock_no_accept, 756 .getname = l2tp_ip6_getname, 757 .poll_mask = datagram_poll_mask, 758 .ioctl = inet6_ioctl, 759 .listen = sock_no_listen, 760 .shutdown = inet_shutdown, 761 .setsockopt = sock_common_setsockopt, 762 .getsockopt = sock_common_getsockopt, 763 .sendmsg = inet_sendmsg, 764 .recvmsg = sock_common_recvmsg, 765 .mmap = sock_no_mmap, 766 .sendpage = sock_no_sendpage, 767 #ifdef CONFIG_COMPAT 768 .compat_setsockopt = compat_sock_common_setsockopt, 769 .compat_getsockopt = compat_sock_common_getsockopt, 770 #endif 771 }; 772 773 static struct inet_protosw l2tp_ip6_protosw = { 774 .type = SOCK_DGRAM, 775 .protocol = IPPROTO_L2TP, 776 .prot = &l2tp_ip6_prot, 777 .ops = &l2tp_ip6_ops, 778 }; 779 780 static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { 781 .handler = l2tp_ip6_recv, 782 }; 783 784 static int __init l2tp_ip6_init(void) 785 { 786 int err; 787 788 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); 789 790 err = proto_register(&l2tp_ip6_prot, 1); 791 if (err != 0) 792 goto out; 793 794 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 795 if (err) 796 goto out1; 797 798 inet6_register_protosw(&l2tp_ip6_protosw); 799 return 0; 800 801 out1: 802 proto_unregister(&l2tp_ip6_prot); 803 out: 804 return err; 805 } 806 807 static void __exit l2tp_ip6_exit(void) 808 { 809 inet6_unregister_protosw(&l2tp_ip6_protosw); 810 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 811 proto_unregister(&l2tp_ip6_prot); 812 } 813 814 module_init(l2tp_ip6_init); 815 module_exit(l2tp_ip6_exit); 816 817 MODULE_LICENSE("GPL"); 818 MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); 819 MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); 820 MODULE_VERSION("1.0"); 821 822 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like 823 * enums 824 */ 825 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); 826 MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); 827