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, 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 if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) 182 goto discard_sess; 183 184 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len); 185 l2tp_session_dec_refcount(session); 186 187 return 0; 188 189 pass_up: 190 /* Get the tunnel_id from the L2TP header */ 191 if (!pskb_may_pull(skb, 12)) 192 goto discard; 193 194 if ((skb->data[0] & 0xc0) != 0xc0) 195 goto discard; 196 197 tunnel_id = ntohl(*(__be32 *) &skb->data[4]); 198 iph = ipv6_hdr(skb); 199 200 read_lock_bh(&l2tp_ip6_lock); 201 sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr, 202 inet6_iif(skb), tunnel_id); 203 if (!sk) { 204 read_unlock_bh(&l2tp_ip6_lock); 205 goto discard; 206 } 207 sock_hold(sk); 208 read_unlock_bh(&l2tp_ip6_lock); 209 210 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 211 goto discard_put; 212 213 nf_reset(skb); 214 215 return sk_receive_skb(sk, skb, 1); 216 217 discard_sess: 218 l2tp_session_dec_refcount(session); 219 goto discard; 220 221 discard_put: 222 sock_put(sk); 223 224 discard: 225 kfree_skb(skb); 226 return 0; 227 } 228 229 static int l2tp_ip6_open(struct sock *sk) 230 { 231 /* Prevent autobind. We don't have ports. */ 232 inet_sk(sk)->inet_num = IPPROTO_L2TP; 233 234 write_lock_bh(&l2tp_ip6_lock); 235 sk_add_node(sk, &l2tp_ip6_table); 236 write_unlock_bh(&l2tp_ip6_lock); 237 238 return 0; 239 } 240 241 static void l2tp_ip6_close(struct sock *sk, long timeout) 242 { 243 write_lock_bh(&l2tp_ip6_lock); 244 hlist_del_init(&sk->sk_bind_node); 245 sk_del_node_init(sk); 246 write_unlock_bh(&l2tp_ip6_lock); 247 248 sk_common_release(sk); 249 } 250 251 static void l2tp_ip6_destroy_sock(struct sock *sk) 252 { 253 struct l2tp_tunnel *tunnel = sk->sk_user_data; 254 255 lock_sock(sk); 256 ip6_flush_pending_frames(sk); 257 release_sock(sk); 258 259 if (tunnel) 260 l2tp_tunnel_delete(tunnel); 261 262 inet6_destroy_sock(sk); 263 } 264 265 static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 266 { 267 struct inet_sock *inet = inet_sk(sk); 268 struct ipv6_pinfo *np = inet6_sk(sk); 269 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; 270 struct net *net = sock_net(sk); 271 __be32 v4addr = 0; 272 int bound_dev_if; 273 int addr_type; 274 int err; 275 276 if (addr->l2tp_family != AF_INET6) 277 return -EINVAL; 278 if (addr_len < sizeof(*addr)) 279 return -EINVAL; 280 281 addr_type = ipv6_addr_type(&addr->l2tp_addr); 282 283 /* l2tp_ip6 sockets are IPv6 only */ 284 if (addr_type == IPV6_ADDR_MAPPED) 285 return -EADDRNOTAVAIL; 286 287 /* L2TP is point-point, not multicast */ 288 if (addr_type & IPV6_ADDR_MULTICAST) 289 return -EADDRNOTAVAIL; 290 291 lock_sock(sk); 292 293 err = -EINVAL; 294 if (!sock_flag(sk, SOCK_ZAPPED)) 295 goto out_unlock; 296 297 if (sk->sk_state != TCP_CLOSE) 298 goto out_unlock; 299 300 bound_dev_if = sk->sk_bound_dev_if; 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->l2tp_scope_id) 309 bound_dev_if = addr->l2tp_scope_id; 310 311 /* Binding to link-local address requires an 312 * interface. 313 */ 314 if (!bound_dev_if) 315 goto out_unlock_rcu; 316 317 err = -ENODEV; 318 dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); 319 if (!dev) 320 goto out_unlock_rcu; 321 } 322 323 /* ipv4 addr of the socket is invalid. Only the 324 * unspecified and mapped address have a v4 equivalent. 325 */ 326 v4addr = LOOPBACK4_IPV6; 327 err = -EADDRNOTAVAIL; 328 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) 329 goto out_unlock_rcu; 330 } 331 rcu_read_unlock(); 332 333 write_lock_bh(&l2tp_ip6_lock); 334 if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, 335 addr->l2tp_conn_id)) { 336 write_unlock_bh(&l2tp_ip6_lock); 337 err = -EADDRINUSE; 338 goto out_unlock; 339 } 340 341 inet->inet_saddr = v4addr; 342 inet->inet_rcv_saddr = v4addr; 343 sk->sk_bound_dev_if = bound_dev_if; 344 sk->sk_v6_rcv_saddr = addr->l2tp_addr; 345 np->saddr = addr->l2tp_addr; 346 347 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; 348 349 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 350 sk_del_node_init(sk); 351 write_unlock_bh(&l2tp_ip6_lock); 352 353 sock_reset_flag(sk, SOCK_ZAPPED); 354 release_sock(sk); 355 return 0; 356 357 out_unlock_rcu: 358 rcu_read_unlock(); 359 out_unlock: 360 release_sock(sk); 361 362 return err; 363 } 364 365 static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, 366 int addr_len) 367 { 368 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr; 369 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; 370 struct in6_addr *daddr; 371 int addr_type; 372 int rc; 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 lock_sock(sk); 391 392 /* Must bind first - autobinding does not work */ 393 if (sock_flag(sk, SOCK_ZAPPED)) { 394 rc = -EINVAL; 395 goto out_sk; 396 } 397 398 rc = __ip6_datagram_connect(sk, uaddr, addr_len); 399 if (rc < 0) 400 goto out_sk; 401 402 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; 403 404 write_lock_bh(&l2tp_ip6_lock); 405 hlist_del_init(&sk->sk_bind_node); 406 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 407 write_unlock_bh(&l2tp_ip6_lock); 408 409 out_sk: 410 release_sock(sk); 411 412 return rc; 413 } 414 415 static int l2tp_ip6_disconnect(struct sock *sk, int flags) 416 { 417 if (sock_flag(sk, SOCK_ZAPPED)) 418 return 0; 419 420 return __udp_disconnect(sk, flags); 421 } 422 423 static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, 424 int peer) 425 { 426 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; 427 struct sock *sk = sock->sk; 428 struct ipv6_pinfo *np = inet6_sk(sk); 429 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); 430 431 lsa->l2tp_family = AF_INET6; 432 lsa->l2tp_flowinfo = 0; 433 lsa->l2tp_scope_id = 0; 434 lsa->l2tp_unused = 0; 435 if (peer) { 436 if (!lsk->peer_conn_id) 437 return -ENOTCONN; 438 lsa->l2tp_conn_id = lsk->peer_conn_id; 439 lsa->l2tp_addr = sk->sk_v6_daddr; 440 if (np->sndflow) 441 lsa->l2tp_flowinfo = np->flow_label; 442 } else { 443 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 444 lsa->l2tp_addr = np->saddr; 445 else 446 lsa->l2tp_addr = sk->sk_v6_rcv_saddr; 447 448 lsa->l2tp_conn_id = lsk->conn_id; 449 } 450 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 451 lsa->l2tp_scope_id = sk->sk_bound_dev_if; 452 return sizeof(*lsa); 453 } 454 455 static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) 456 { 457 int rc; 458 459 /* Charge it to the socket, dropping if the queue is full. */ 460 rc = sock_queue_rcv_skb(sk, skb); 461 if (rc < 0) 462 goto drop; 463 464 return 0; 465 466 drop: 467 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); 468 kfree_skb(skb); 469 return -1; 470 } 471 472 static int l2tp_ip6_push_pending_frames(struct sock *sk) 473 { 474 struct sk_buff *skb; 475 __be32 *transhdr = NULL; 476 int err = 0; 477 478 skb = skb_peek(&sk->sk_write_queue); 479 if (skb == NULL) 480 goto out; 481 482 transhdr = (__be32 *)skb_transport_header(skb); 483 *transhdr = 0; 484 485 err = ip6_push_pending_frames(sk); 486 487 out: 488 return err; 489 } 490 491 /* Userspace will call sendmsg() on the tunnel socket to send L2TP 492 * control frames. 493 */ 494 static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 495 { 496 struct ipv6_txoptions opt_space; 497 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 498 struct in6_addr *daddr, *final_p, final; 499 struct ipv6_pinfo *np = inet6_sk(sk); 500 struct ipv6_txoptions *opt_to_free = NULL; 501 struct ipv6_txoptions *opt = NULL; 502 struct ip6_flowlabel *flowlabel = NULL; 503 struct dst_entry *dst = NULL; 504 struct flowi6 fl6; 505 struct ipcm6_cookie ipc6; 506 int addr_len = msg->msg_namelen; 507 int transhdrlen = 4; /* zero session-id */ 508 int ulen = len + transhdrlen; 509 int err; 510 511 /* Rough check on arithmetic overflow, 512 better check is made in ip6_append_data(). 513 */ 514 if (len > INT_MAX) 515 return -EMSGSIZE; 516 517 /* Mirror BSD error message compatibility */ 518 if (msg->msg_flags & MSG_OOB) 519 return -EOPNOTSUPP; 520 521 /* 522 * Get and verify the address. 523 */ 524 memset(&fl6, 0, sizeof(fl6)); 525 526 fl6.flowi6_mark = sk->sk_mark; 527 fl6.flowi6_uid = sk->sk_uid; 528 529 ipcm6_init(&ipc6); 530 531 if (lsa) { 532 if (addr_len < SIN6_LEN_RFC2133) 533 return -EINVAL; 534 535 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) 536 return -EAFNOSUPPORT; 537 538 daddr = &lsa->l2tp_addr; 539 if (np->sndflow) { 540 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; 541 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 542 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 543 if (flowlabel == NULL) 544 return -EINVAL; 545 } 546 } 547 548 /* 549 * Otherwise it will be difficult to maintain 550 * sk->sk_dst_cache. 551 */ 552 if (sk->sk_state == TCP_ESTABLISHED && 553 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 554 daddr = &sk->sk_v6_daddr; 555 556 if (addr_len >= sizeof(struct sockaddr_in6) && 557 lsa->l2tp_scope_id && 558 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) 559 fl6.flowi6_oif = lsa->l2tp_scope_id; 560 } else { 561 if (sk->sk_state != TCP_ESTABLISHED) 562 return -EDESTADDRREQ; 563 564 daddr = &sk->sk_v6_daddr; 565 fl6.flowlabel = np->flow_label; 566 } 567 568 if (fl6.flowi6_oif == 0) 569 fl6.flowi6_oif = sk->sk_bound_dev_if; 570 571 if (msg->msg_controllen) { 572 opt = &opt_space; 573 memset(opt, 0, sizeof(struct ipv6_txoptions)); 574 opt->tot_len = sizeof(struct ipv6_txoptions); 575 ipc6.opt = opt; 576 577 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6); 578 if (err < 0) { 579 fl6_sock_release(flowlabel); 580 return err; 581 } 582 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { 583 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 584 if (flowlabel == NULL) 585 return -EINVAL; 586 } 587 if (!(opt->opt_nflen|opt->opt_flen)) 588 opt = NULL; 589 } 590 591 if (!opt) { 592 opt = txopt_get(np); 593 opt_to_free = opt; 594 } 595 if (flowlabel) 596 opt = fl6_merge_options(&opt_space, flowlabel, opt); 597 opt = ipv6_fixup_options(&opt_space, opt); 598 ipc6.opt = opt; 599 600 fl6.flowi6_proto = sk->sk_protocol; 601 if (!ipv6_addr_any(daddr)) 602 fl6.daddr = *daddr; 603 else 604 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 605 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 606 fl6.saddr = np->saddr; 607 608 final_p = fl6_update_dst(&fl6, opt, &final); 609 610 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 611 fl6.flowi6_oif = np->mcast_oif; 612 else if (!fl6.flowi6_oif) 613 fl6.flowi6_oif = np->ucast_oif; 614 615 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 616 617 if (ipc6.tclass < 0) 618 ipc6.tclass = np->tclass; 619 620 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); 621 622 dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 623 if (IS_ERR(dst)) { 624 err = PTR_ERR(dst); 625 goto out; 626 } 627 628 if (ipc6.hlimit < 0) 629 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 630 631 if (ipc6.dontfrag < 0) 632 ipc6.dontfrag = np->dontfrag; 633 634 if (msg->msg_flags & MSG_CONFIRM) 635 goto do_confirm; 636 637 back_from_confirm: 638 lock_sock(sk); 639 err = ip6_append_data(sk, ip_generic_getfrag, msg, 640 ulen, transhdrlen, &ipc6, 641 &fl6, (struct rt6_info *)dst, 642 msg->msg_flags); 643 if (err) 644 ip6_flush_pending_frames(sk); 645 else if (!(msg->msg_flags & MSG_MORE)) 646 err = l2tp_ip6_push_pending_frames(sk); 647 release_sock(sk); 648 done: 649 dst_release(dst); 650 out: 651 fl6_sock_release(flowlabel); 652 txopt_put(opt_to_free); 653 654 return err < 0 ? err : len; 655 656 do_confirm: 657 if (msg->msg_flags & MSG_PROBE) 658 dst_confirm_neigh(dst, &fl6.daddr); 659 if (!(msg->msg_flags & MSG_PROBE) || len) 660 goto back_from_confirm; 661 err = 0; 662 goto done; 663 } 664 665 static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 666 int noblock, int flags, int *addr_len) 667 { 668 struct ipv6_pinfo *np = inet6_sk(sk); 669 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 670 size_t copied = 0; 671 int err = -EOPNOTSUPP; 672 struct sk_buff *skb; 673 674 if (flags & MSG_OOB) 675 goto out; 676 677 if (flags & MSG_ERRQUEUE) 678 return ipv6_recv_error(sk, msg, len, addr_len); 679 680 skb = skb_recv_datagram(sk, flags, noblock, &err); 681 if (!skb) 682 goto out; 683 684 copied = skb->len; 685 if (len < copied) { 686 msg->msg_flags |= MSG_TRUNC; 687 copied = len; 688 } 689 690 err = skb_copy_datagram_msg(skb, 0, msg, copied); 691 if (err) 692 goto done; 693 694 sock_recv_timestamp(msg, sk, skb); 695 696 /* Copy the address. */ 697 if (lsa) { 698 lsa->l2tp_family = AF_INET6; 699 lsa->l2tp_unused = 0; 700 lsa->l2tp_addr = ipv6_hdr(skb)->saddr; 701 lsa->l2tp_flowinfo = 0; 702 lsa->l2tp_scope_id = 0; 703 lsa->l2tp_conn_id = 0; 704 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 705 lsa->l2tp_scope_id = inet6_iif(skb); 706 *addr_len = sizeof(*lsa); 707 } 708 709 if (np->rxopt.all) 710 ip6_datagram_recv_ctl(sk, msg, skb); 711 712 if (flags & MSG_TRUNC) 713 copied = skb->len; 714 done: 715 skb_free_datagram(sk, skb); 716 out: 717 return err ? err : copied; 718 } 719 720 static struct proto l2tp_ip6_prot = { 721 .name = "L2TP/IPv6", 722 .owner = THIS_MODULE, 723 .init = l2tp_ip6_open, 724 .close = l2tp_ip6_close, 725 .bind = l2tp_ip6_bind, 726 .connect = l2tp_ip6_connect, 727 .disconnect = l2tp_ip6_disconnect, 728 .ioctl = l2tp_ioctl, 729 .destroy = l2tp_ip6_destroy_sock, 730 .setsockopt = ipv6_setsockopt, 731 .getsockopt = ipv6_getsockopt, 732 .sendmsg = l2tp_ip6_sendmsg, 733 .recvmsg = l2tp_ip6_recvmsg, 734 .backlog_rcv = l2tp_ip6_backlog_recv, 735 .hash = inet6_hash, 736 .unhash = inet_unhash, 737 .obj_size = sizeof(struct l2tp_ip6_sock), 738 #ifdef CONFIG_COMPAT 739 .compat_setsockopt = compat_ipv6_setsockopt, 740 .compat_getsockopt = compat_ipv6_getsockopt, 741 #endif 742 }; 743 744 static const struct proto_ops l2tp_ip6_ops = { 745 .family = PF_INET6, 746 .owner = THIS_MODULE, 747 .release = inet6_release, 748 .bind = inet6_bind, 749 .connect = inet_dgram_connect, 750 .socketpair = sock_no_socketpair, 751 .accept = sock_no_accept, 752 .getname = l2tp_ip6_getname, 753 .poll = datagram_poll, 754 .ioctl = inet6_ioctl, 755 .listen = sock_no_listen, 756 .shutdown = inet_shutdown, 757 .setsockopt = sock_common_setsockopt, 758 .getsockopt = sock_common_getsockopt, 759 .sendmsg = inet_sendmsg, 760 .recvmsg = sock_common_recvmsg, 761 .mmap = sock_no_mmap, 762 .sendpage = sock_no_sendpage, 763 #ifdef CONFIG_COMPAT 764 .compat_setsockopt = compat_sock_common_setsockopt, 765 .compat_getsockopt = compat_sock_common_getsockopt, 766 #endif 767 }; 768 769 static struct inet_protosw l2tp_ip6_protosw = { 770 .type = SOCK_DGRAM, 771 .protocol = IPPROTO_L2TP, 772 .prot = &l2tp_ip6_prot, 773 .ops = &l2tp_ip6_ops, 774 }; 775 776 static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { 777 .handler = l2tp_ip6_recv, 778 }; 779 780 static int __init l2tp_ip6_init(void) 781 { 782 int err; 783 784 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); 785 786 err = proto_register(&l2tp_ip6_prot, 1); 787 if (err != 0) 788 goto out; 789 790 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 791 if (err) 792 goto out1; 793 794 inet6_register_protosw(&l2tp_ip6_protosw); 795 return 0; 796 797 out1: 798 proto_unregister(&l2tp_ip6_prot); 799 out: 800 return err; 801 } 802 803 static void __exit l2tp_ip6_exit(void) 804 { 805 inet6_unregister_protosw(&l2tp_ip6_protosw); 806 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 807 proto_unregister(&l2tp_ip6_prot); 808 } 809 810 module_init(l2tp_ip6_init); 811 module_exit(l2tp_ip6_exit); 812 813 MODULE_LICENSE("GPL"); 814 MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); 815 MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); 816 MODULE_VERSION("1.0"); 817 818 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like 819 * enums 820 */ 821 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); 822 MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); 823