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 int length; 140 141 if (!pskb_may_pull(skb, 4)) 142 goto discard; 143 144 /* Point to L2TP header */ 145 optr = ptr = skb->data; 146 session_id = ntohl(*((__be32 *) ptr)); 147 ptr += 4; 148 149 /* RFC3931: L2TP/IP packets have the first 4 bytes containing 150 * the session_id. If it is 0, the packet is a L2TP control 151 * frame and the session_id value can be discarded. 152 */ 153 if (session_id == 0) { 154 __skb_pull(skb, 4); 155 goto pass_up; 156 } 157 158 /* Ok, this is a data packet. Lookup the session. */ 159 session = l2tp_session_find(net, NULL, session_id); 160 if (session == NULL) 161 goto discard; 162 163 tunnel = session->tunnel; 164 if (tunnel == NULL) 165 goto discard; 166 167 /* Trace packet contents, if enabled */ 168 if (tunnel->debug & L2TP_MSG_DATA) { 169 length = min(32u, skb->len); 170 if (!pskb_may_pull(skb, length)) 171 goto discard; 172 173 /* Point to L2TP header */ 174 optr = ptr = skb->data; 175 ptr += 4; 176 pr_debug("%s: ip recv\n", tunnel->name); 177 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); 178 } 179 180 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, 181 tunnel->recv_payload_hook); 182 return 0; 183 184 pass_up: 185 /* Get the tunnel_id from the L2TP header */ 186 if (!pskb_may_pull(skb, 12)) 187 goto discard; 188 189 if ((skb->data[0] & 0xc0) != 0xc0) 190 goto discard; 191 192 tunnel_id = ntohl(*(__be32 *) &skb->data[4]); 193 tunnel = l2tp_tunnel_find(net, tunnel_id); 194 if (tunnel != NULL) 195 sk = tunnel->sock; 196 else { 197 struct ipv6hdr *iph = ipv6_hdr(skb); 198 199 read_lock_bh(&l2tp_ip6_lock); 200 sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr, 201 inet6_iif(skb), tunnel_id); 202 if (!sk) { 203 read_unlock_bh(&l2tp_ip6_lock); 204 goto discard; 205 } 206 207 sock_hold(sk); 208 read_unlock_bh(&l2tp_ip6_lock); 209 } 210 211 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 212 goto discard_put; 213 214 nf_reset(skb); 215 216 return sk_receive_skb(sk, skb, 1); 217 218 discard_put: 219 sock_put(sk); 220 221 discard: 222 kfree_skb(skb); 223 return 0; 224 } 225 226 static int l2tp_ip6_open(struct sock *sk) 227 { 228 /* Prevent autobind. We don't have ports. */ 229 inet_sk(sk)->inet_num = IPPROTO_L2TP; 230 231 write_lock_bh(&l2tp_ip6_lock); 232 sk_add_node(sk, &l2tp_ip6_table); 233 write_unlock_bh(&l2tp_ip6_lock); 234 235 return 0; 236 } 237 238 static void l2tp_ip6_close(struct sock *sk, long timeout) 239 { 240 write_lock_bh(&l2tp_ip6_lock); 241 hlist_del_init(&sk->sk_bind_node); 242 sk_del_node_init(sk); 243 write_unlock_bh(&l2tp_ip6_lock); 244 245 sk_common_release(sk); 246 } 247 248 static void l2tp_ip6_destroy_sock(struct sock *sk) 249 { 250 struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); 251 252 lock_sock(sk); 253 ip6_flush_pending_frames(sk); 254 release_sock(sk); 255 256 if (tunnel) { 257 l2tp_tunnel_closeall(tunnel); 258 sock_put(sk); 259 } 260 261 inet6_destroy_sock(sk); 262 } 263 264 static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 265 { 266 struct inet_sock *inet = inet_sk(sk); 267 struct ipv6_pinfo *np = inet6_sk(sk); 268 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; 269 struct net *net = sock_net(sk); 270 __be32 v4addr = 0; 271 int bound_dev_if; 272 int addr_type; 273 int err; 274 275 if (addr->l2tp_family != AF_INET6) 276 return -EINVAL; 277 if (addr_len < sizeof(*addr)) 278 return -EINVAL; 279 280 addr_type = ipv6_addr_type(&addr->l2tp_addr); 281 282 /* l2tp_ip6 sockets are IPv6 only */ 283 if (addr_type == IPV6_ADDR_MAPPED) 284 return -EADDRNOTAVAIL; 285 286 /* L2TP is point-point, not multicast */ 287 if (addr_type & IPV6_ADDR_MULTICAST) 288 return -EADDRNOTAVAIL; 289 290 lock_sock(sk); 291 292 err = -EINVAL; 293 if (!sock_flag(sk, SOCK_ZAPPED)) 294 goto out_unlock; 295 296 if (sk->sk_state != TCP_CLOSE) 297 goto out_unlock; 298 299 bound_dev_if = sk->sk_bound_dev_if; 300 301 /* Check if the address belongs to the host. */ 302 rcu_read_lock(); 303 if (addr_type != IPV6_ADDR_ANY) { 304 struct net_device *dev = NULL; 305 306 if (addr_type & IPV6_ADDR_LINKLOCAL) { 307 if (addr->l2tp_scope_id) 308 bound_dev_if = addr->l2tp_scope_id; 309 310 /* Binding to link-local address requires an 311 * interface. 312 */ 313 if (!bound_dev_if) 314 goto out_unlock_rcu; 315 316 err = -ENODEV; 317 dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); 318 if (!dev) 319 goto out_unlock_rcu; 320 } 321 322 /* ipv4 addr of the socket is invalid. Only the 323 * unspecified and mapped address have a v4 equivalent. 324 */ 325 v4addr = LOOPBACK4_IPV6; 326 err = -EADDRNOTAVAIL; 327 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) 328 goto out_unlock_rcu; 329 } 330 rcu_read_unlock(); 331 332 write_lock_bh(&l2tp_ip6_lock); 333 if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, 334 addr->l2tp_conn_id)) { 335 write_unlock_bh(&l2tp_ip6_lock); 336 err = -EADDRINUSE; 337 goto out_unlock; 338 } 339 340 inet->inet_saddr = v4addr; 341 inet->inet_rcv_saddr = v4addr; 342 sk->sk_bound_dev_if = bound_dev_if; 343 sk->sk_v6_rcv_saddr = addr->l2tp_addr; 344 np->saddr = addr->l2tp_addr; 345 346 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; 347 348 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 349 sk_del_node_init(sk); 350 write_unlock_bh(&l2tp_ip6_lock); 351 352 sock_reset_flag(sk, SOCK_ZAPPED); 353 release_sock(sk); 354 return 0; 355 356 out_unlock_rcu: 357 rcu_read_unlock(); 358 out_unlock: 359 release_sock(sk); 360 361 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 (addr_len < sizeof(*lsa)) 374 return -EINVAL; 375 376 if (usin->sin6_family != AF_INET6) 377 return -EINVAL; 378 379 addr_type = ipv6_addr_type(&usin->sin6_addr); 380 if (addr_type & IPV6_ADDR_MULTICAST) 381 return -EINVAL; 382 383 if (addr_type & IPV6_ADDR_MAPPED) { 384 daddr = &usin->sin6_addr; 385 if (ipv4_is_multicast(daddr->s6_addr32[3])) 386 return -EINVAL; 387 } 388 389 lock_sock(sk); 390 391 /* Must bind first - autobinding does not work */ 392 if (sock_flag(sk, SOCK_ZAPPED)) { 393 rc = -EINVAL; 394 goto out_sk; 395 } 396 397 rc = __ip6_datagram_connect(sk, uaddr, addr_len); 398 if (rc < 0) 399 goto out_sk; 400 401 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; 402 403 write_lock_bh(&l2tp_ip6_lock); 404 hlist_del_init(&sk->sk_bind_node); 405 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 406 write_unlock_bh(&l2tp_ip6_lock); 407 408 out_sk: 409 release_sock(sk); 410 411 return rc; 412 } 413 414 static int l2tp_ip6_disconnect(struct sock *sk, int flags) 415 { 416 if (sock_flag(sk, SOCK_ZAPPED)) 417 return 0; 418 419 return __udp_disconnect(sk, flags); 420 } 421 422 static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, 423 int *uaddr_len, int peer) 424 { 425 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; 426 struct sock *sk = sock->sk; 427 struct ipv6_pinfo *np = inet6_sk(sk); 428 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); 429 430 lsa->l2tp_family = AF_INET6; 431 lsa->l2tp_flowinfo = 0; 432 lsa->l2tp_scope_id = 0; 433 lsa->l2tp_unused = 0; 434 if (peer) { 435 if (!lsk->peer_conn_id) 436 return -ENOTCONN; 437 lsa->l2tp_conn_id = lsk->peer_conn_id; 438 lsa->l2tp_addr = sk->sk_v6_daddr; 439 if (np->sndflow) 440 lsa->l2tp_flowinfo = np->flow_label; 441 } else { 442 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 443 lsa->l2tp_addr = np->saddr; 444 else 445 lsa->l2tp_addr = sk->sk_v6_rcv_saddr; 446 447 lsa->l2tp_conn_id = lsk->conn_id; 448 } 449 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 450 lsa->l2tp_scope_id = sk->sk_bound_dev_if; 451 *uaddr_len = sizeof(*lsa); 452 return 0; 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 sockcm_cookie sockc_unused = {0}; 506 struct ipcm6_cookie ipc6; 507 int addr_len = msg->msg_namelen; 508 int transhdrlen = 4; /* zero session-id */ 509 int ulen = len + transhdrlen; 510 int err; 511 512 /* Rough check on arithmetic overflow, 513 better check is made in ip6_append_data(). 514 */ 515 if (len > INT_MAX) 516 return -EMSGSIZE; 517 518 /* Mirror BSD error message compatibility */ 519 if (msg->msg_flags & MSG_OOB) 520 return -EOPNOTSUPP; 521 522 /* 523 * Get and verify the address. 524 */ 525 memset(&fl6, 0, sizeof(fl6)); 526 527 fl6.flowi6_mark = sk->sk_mark; 528 fl6.flowi6_uid = sk->sk_uid; 529 530 ipc6.hlimit = -1; 531 ipc6.tclass = -1; 532 ipc6.dontfrag = -1; 533 534 if (lsa) { 535 if (addr_len < SIN6_LEN_RFC2133) 536 return -EINVAL; 537 538 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) 539 return -EAFNOSUPPORT; 540 541 daddr = &lsa->l2tp_addr; 542 if (np->sndflow) { 543 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; 544 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 545 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 546 if (flowlabel == NULL) 547 return -EINVAL; 548 } 549 } 550 551 /* 552 * Otherwise it will be difficult to maintain 553 * sk->sk_dst_cache. 554 */ 555 if (sk->sk_state == TCP_ESTABLISHED && 556 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 557 daddr = &sk->sk_v6_daddr; 558 559 if (addr_len >= sizeof(struct sockaddr_in6) && 560 lsa->l2tp_scope_id && 561 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) 562 fl6.flowi6_oif = lsa->l2tp_scope_id; 563 } else { 564 if (sk->sk_state != TCP_ESTABLISHED) 565 return -EDESTADDRREQ; 566 567 daddr = &sk->sk_v6_daddr; 568 fl6.flowlabel = np->flow_label; 569 } 570 571 if (fl6.flowi6_oif == 0) 572 fl6.flowi6_oif = sk->sk_bound_dev_if; 573 574 if (msg->msg_controllen) { 575 opt = &opt_space; 576 memset(opt, 0, sizeof(struct ipv6_txoptions)); 577 opt->tot_len = sizeof(struct ipv6_txoptions); 578 ipc6.opt = opt; 579 580 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, 581 &sockc_unused); 582 if (err < 0) { 583 fl6_sock_release(flowlabel); 584 return err; 585 } 586 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { 587 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 588 if (flowlabel == NULL) 589 return -EINVAL; 590 } 591 if (!(opt->opt_nflen|opt->opt_flen)) 592 opt = NULL; 593 } 594 595 if (!opt) { 596 opt = txopt_get(np); 597 opt_to_free = opt; 598 } 599 if (flowlabel) 600 opt = fl6_merge_options(&opt_space, flowlabel, opt); 601 opt = ipv6_fixup_options(&opt_space, opt); 602 ipc6.opt = opt; 603 604 fl6.flowi6_proto = sk->sk_protocol; 605 if (!ipv6_addr_any(daddr)) 606 fl6.daddr = *daddr; 607 else 608 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 609 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 610 fl6.saddr = np->saddr; 611 612 final_p = fl6_update_dst(&fl6, opt, &final); 613 614 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 615 fl6.flowi6_oif = np->mcast_oif; 616 else if (!fl6.flowi6_oif) 617 fl6.flowi6_oif = np->ucast_oif; 618 619 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 620 621 if (ipc6.tclass < 0) 622 ipc6.tclass = np->tclass; 623 624 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); 625 626 dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 627 if (IS_ERR(dst)) { 628 err = PTR_ERR(dst); 629 goto out; 630 } 631 632 if (ipc6.hlimit < 0) 633 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 634 635 if (ipc6.dontfrag < 0) 636 ipc6.dontfrag = np->dontfrag; 637 638 if (msg->msg_flags & MSG_CONFIRM) 639 goto do_confirm; 640 641 back_from_confirm: 642 lock_sock(sk); 643 err = ip6_append_data(sk, ip_generic_getfrag, msg, 644 ulen, transhdrlen, &ipc6, 645 &fl6, (struct rt6_info *)dst, 646 msg->msg_flags, &sockc_unused); 647 if (err) 648 ip6_flush_pending_frames(sk); 649 else if (!(msg->msg_flags & MSG_MORE)) 650 err = l2tp_ip6_push_pending_frames(sk); 651 release_sock(sk); 652 done: 653 dst_release(dst); 654 out: 655 fl6_sock_release(flowlabel); 656 txopt_put(opt_to_free); 657 658 return err < 0 ? err : len; 659 660 do_confirm: 661 if (msg->msg_flags & MSG_PROBE) 662 dst_confirm_neigh(dst, &fl6.daddr); 663 if (!(msg->msg_flags & MSG_PROBE) || len) 664 goto back_from_confirm; 665 err = 0; 666 goto done; 667 } 668 669 static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 670 int noblock, int flags, int *addr_len) 671 { 672 struct ipv6_pinfo *np = inet6_sk(sk); 673 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 674 size_t copied = 0; 675 int err = -EOPNOTSUPP; 676 struct sk_buff *skb; 677 678 if (flags & MSG_OOB) 679 goto out; 680 681 if (addr_len) 682 *addr_len = sizeof(*lsa); 683 684 if (flags & MSG_ERRQUEUE) 685 return ipv6_recv_error(sk, msg, len, addr_len); 686 687 skb = skb_recv_datagram(sk, flags, noblock, &err); 688 if (!skb) 689 goto out; 690 691 copied = skb->len; 692 if (len < copied) { 693 msg->msg_flags |= MSG_TRUNC; 694 copied = len; 695 } 696 697 err = skb_copy_datagram_msg(skb, 0, msg, copied); 698 if (err) 699 goto done; 700 701 sock_recv_timestamp(msg, sk, skb); 702 703 /* Copy the address. */ 704 if (lsa) { 705 lsa->l2tp_family = AF_INET6; 706 lsa->l2tp_unused = 0; 707 lsa->l2tp_addr = ipv6_hdr(skb)->saddr; 708 lsa->l2tp_flowinfo = 0; 709 lsa->l2tp_scope_id = 0; 710 lsa->l2tp_conn_id = 0; 711 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 712 lsa->l2tp_scope_id = inet6_iif(skb); 713 } 714 715 if (np->rxopt.all) 716 ip6_datagram_recv_ctl(sk, msg, skb); 717 718 if (flags & MSG_TRUNC) 719 copied = skb->len; 720 done: 721 skb_free_datagram(sk, skb); 722 out: 723 return err ? err : copied; 724 } 725 726 static struct proto l2tp_ip6_prot = { 727 .name = "L2TP/IPv6", 728 .owner = THIS_MODULE, 729 .init = l2tp_ip6_open, 730 .close = l2tp_ip6_close, 731 .bind = l2tp_ip6_bind, 732 .connect = l2tp_ip6_connect, 733 .disconnect = l2tp_ip6_disconnect, 734 .ioctl = l2tp_ioctl, 735 .destroy = l2tp_ip6_destroy_sock, 736 .setsockopt = ipv6_setsockopt, 737 .getsockopt = ipv6_getsockopt, 738 .sendmsg = l2tp_ip6_sendmsg, 739 .recvmsg = l2tp_ip6_recvmsg, 740 .backlog_rcv = l2tp_ip6_backlog_recv, 741 .hash = inet6_hash, 742 .unhash = inet_unhash, 743 .obj_size = sizeof(struct l2tp_ip6_sock), 744 #ifdef CONFIG_COMPAT 745 .compat_setsockopt = compat_ipv6_setsockopt, 746 .compat_getsockopt = compat_ipv6_getsockopt, 747 #endif 748 }; 749 750 static const struct proto_ops l2tp_ip6_ops = { 751 .family = PF_INET6, 752 .owner = THIS_MODULE, 753 .release = inet6_release, 754 .bind = inet6_bind, 755 .connect = inet_dgram_connect, 756 .socketpair = sock_no_socketpair, 757 .accept = sock_no_accept, 758 .getname = l2tp_ip6_getname, 759 .poll = datagram_poll, 760 .ioctl = inet6_ioctl, 761 .listen = sock_no_listen, 762 .shutdown = inet_shutdown, 763 .setsockopt = sock_common_setsockopt, 764 .getsockopt = sock_common_getsockopt, 765 .sendmsg = inet_sendmsg, 766 .recvmsg = sock_common_recvmsg, 767 .mmap = sock_no_mmap, 768 .sendpage = sock_no_sendpage, 769 #ifdef CONFIG_COMPAT 770 .compat_setsockopt = compat_sock_common_setsockopt, 771 .compat_getsockopt = compat_sock_common_getsockopt, 772 #endif 773 }; 774 775 static struct inet_protosw l2tp_ip6_protosw = { 776 .type = SOCK_DGRAM, 777 .protocol = IPPROTO_L2TP, 778 .prot = &l2tp_ip6_prot, 779 .ops = &l2tp_ip6_ops, 780 }; 781 782 static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { 783 .handler = l2tp_ip6_recv, 784 }; 785 786 static int __init l2tp_ip6_init(void) 787 { 788 int err; 789 790 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); 791 792 err = proto_register(&l2tp_ip6_prot, 1); 793 if (err != 0) 794 goto out; 795 796 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 797 if (err) 798 goto out1; 799 800 inet6_register_protosw(&l2tp_ip6_protosw); 801 return 0; 802 803 out1: 804 proto_unregister(&l2tp_ip6_prot); 805 out: 806 return err; 807 } 808 809 static void __exit l2tp_ip6_exit(void) 810 { 811 inet6_unregister_protosw(&l2tp_ip6_protosw); 812 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 813 proto_unregister(&l2tp_ip6_prot); 814 } 815 816 module_init(l2tp_ip6_init); 817 module_exit(l2tp_ip6_exit); 818 819 MODULE_LICENSE("GPL"); 820 MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); 821 MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); 822 MODULE_VERSION("1.0"); 823 824 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like 825 * enums 826 */ 827 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); 828 MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); 829