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_get(net, NULL, session_id, true); 160 if (!session) 161 goto discard; 162 163 tunnel = session->tunnel; 164 if (!tunnel) 165 goto discard_sess; 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_sess; 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 l2tp_session_dec_refcount(session); 183 184 return 0; 185 186 pass_up: 187 /* Get the tunnel_id from the L2TP header */ 188 if (!pskb_may_pull(skb, 12)) 189 goto discard; 190 191 if ((skb->data[0] & 0xc0) != 0xc0) 192 goto discard; 193 194 tunnel_id = ntohl(*(__be32 *) &skb->data[4]); 195 tunnel = l2tp_tunnel_find(net, tunnel_id); 196 if (tunnel) { 197 sk = tunnel->sock; 198 sock_hold(sk); 199 } else { 200 struct ipv6hdr *iph = ipv6_hdr(skb); 201 202 read_lock_bh(&l2tp_ip6_lock); 203 sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr, 204 inet6_iif(skb), tunnel_id); 205 if (!sk) { 206 read_unlock_bh(&l2tp_ip6_lock); 207 goto discard; 208 } 209 210 sock_hold(sk); 211 read_unlock_bh(&l2tp_ip6_lock); 212 } 213 214 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 215 goto discard_put; 216 217 nf_reset(skb); 218 219 return sk_receive_skb(sk, skb, 1); 220 221 discard_sess: 222 if (session->deref) 223 session->deref(session); 224 l2tp_session_dec_refcount(session); 225 goto discard; 226 227 discard_put: 228 sock_put(sk); 229 230 discard: 231 kfree_skb(skb); 232 return 0; 233 } 234 235 static int l2tp_ip6_open(struct sock *sk) 236 { 237 /* Prevent autobind. We don't have ports. */ 238 inet_sk(sk)->inet_num = IPPROTO_L2TP; 239 240 write_lock_bh(&l2tp_ip6_lock); 241 sk_add_node(sk, &l2tp_ip6_table); 242 write_unlock_bh(&l2tp_ip6_lock); 243 244 return 0; 245 } 246 247 static void l2tp_ip6_close(struct sock *sk, long timeout) 248 { 249 write_lock_bh(&l2tp_ip6_lock); 250 hlist_del_init(&sk->sk_bind_node); 251 sk_del_node_init(sk); 252 write_unlock_bh(&l2tp_ip6_lock); 253 254 sk_common_release(sk); 255 } 256 257 static void l2tp_ip6_destroy_sock(struct sock *sk) 258 { 259 struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); 260 261 lock_sock(sk); 262 ip6_flush_pending_frames(sk); 263 release_sock(sk); 264 265 if (tunnel) { 266 l2tp_tunnel_closeall(tunnel); 267 sock_put(sk); 268 } 269 270 inet6_destroy_sock(sk); 271 } 272 273 static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 274 { 275 struct inet_sock *inet = inet_sk(sk); 276 struct ipv6_pinfo *np = inet6_sk(sk); 277 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; 278 struct net *net = sock_net(sk); 279 __be32 v4addr = 0; 280 int bound_dev_if; 281 int addr_type; 282 int err; 283 284 if (addr->l2tp_family != AF_INET6) 285 return -EINVAL; 286 if (addr_len < sizeof(*addr)) 287 return -EINVAL; 288 289 addr_type = ipv6_addr_type(&addr->l2tp_addr); 290 291 /* l2tp_ip6 sockets are IPv6 only */ 292 if (addr_type == IPV6_ADDR_MAPPED) 293 return -EADDRNOTAVAIL; 294 295 /* L2TP is point-point, not multicast */ 296 if (addr_type & IPV6_ADDR_MULTICAST) 297 return -EADDRNOTAVAIL; 298 299 lock_sock(sk); 300 301 err = -EINVAL; 302 if (!sock_flag(sk, SOCK_ZAPPED)) 303 goto out_unlock; 304 305 if (sk->sk_state != TCP_CLOSE) 306 goto out_unlock; 307 308 bound_dev_if = sk->sk_bound_dev_if; 309 310 /* Check if the address belongs to the host. */ 311 rcu_read_lock(); 312 if (addr_type != IPV6_ADDR_ANY) { 313 struct net_device *dev = NULL; 314 315 if (addr_type & IPV6_ADDR_LINKLOCAL) { 316 if (addr->l2tp_scope_id) 317 bound_dev_if = addr->l2tp_scope_id; 318 319 /* Binding to link-local address requires an 320 * interface. 321 */ 322 if (!bound_dev_if) 323 goto out_unlock_rcu; 324 325 err = -ENODEV; 326 dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); 327 if (!dev) 328 goto out_unlock_rcu; 329 } 330 331 /* ipv4 addr of the socket is invalid. Only the 332 * unspecified and mapped address have a v4 equivalent. 333 */ 334 v4addr = LOOPBACK4_IPV6; 335 err = -EADDRNOTAVAIL; 336 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) 337 goto out_unlock_rcu; 338 } 339 rcu_read_unlock(); 340 341 write_lock_bh(&l2tp_ip6_lock); 342 if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, 343 addr->l2tp_conn_id)) { 344 write_unlock_bh(&l2tp_ip6_lock); 345 err = -EADDRINUSE; 346 goto out_unlock; 347 } 348 349 inet->inet_saddr = v4addr; 350 inet->inet_rcv_saddr = v4addr; 351 sk->sk_bound_dev_if = bound_dev_if; 352 sk->sk_v6_rcv_saddr = addr->l2tp_addr; 353 np->saddr = addr->l2tp_addr; 354 355 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; 356 357 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 358 sk_del_node_init(sk); 359 write_unlock_bh(&l2tp_ip6_lock); 360 361 sock_reset_flag(sk, SOCK_ZAPPED); 362 release_sock(sk); 363 return 0; 364 365 out_unlock_rcu: 366 rcu_read_unlock(); 367 out_unlock: 368 release_sock(sk); 369 370 return err; 371 } 372 373 static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, 374 int addr_len) 375 { 376 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr; 377 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; 378 struct in6_addr *daddr; 379 int addr_type; 380 int rc; 381 382 if (addr_len < sizeof(*lsa)) 383 return -EINVAL; 384 385 if (usin->sin6_family != AF_INET6) 386 return -EINVAL; 387 388 addr_type = ipv6_addr_type(&usin->sin6_addr); 389 if (addr_type & IPV6_ADDR_MULTICAST) 390 return -EINVAL; 391 392 if (addr_type & IPV6_ADDR_MAPPED) { 393 daddr = &usin->sin6_addr; 394 if (ipv4_is_multicast(daddr->s6_addr32[3])) 395 return -EINVAL; 396 } 397 398 lock_sock(sk); 399 400 /* Must bind first - autobinding does not work */ 401 if (sock_flag(sk, SOCK_ZAPPED)) { 402 rc = -EINVAL; 403 goto out_sk; 404 } 405 406 rc = __ip6_datagram_connect(sk, uaddr, addr_len); 407 if (rc < 0) 408 goto out_sk; 409 410 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; 411 412 write_lock_bh(&l2tp_ip6_lock); 413 hlist_del_init(&sk->sk_bind_node); 414 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 415 write_unlock_bh(&l2tp_ip6_lock); 416 417 out_sk: 418 release_sock(sk); 419 420 return rc; 421 } 422 423 static int l2tp_ip6_disconnect(struct sock *sk, int flags) 424 { 425 if (sock_flag(sk, SOCK_ZAPPED)) 426 return 0; 427 428 return __udp_disconnect(sk, flags); 429 } 430 431 static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, 432 int *uaddr_len, int peer) 433 { 434 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; 435 struct sock *sk = sock->sk; 436 struct ipv6_pinfo *np = inet6_sk(sk); 437 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); 438 439 lsa->l2tp_family = AF_INET6; 440 lsa->l2tp_flowinfo = 0; 441 lsa->l2tp_scope_id = 0; 442 lsa->l2tp_unused = 0; 443 if (peer) { 444 if (!lsk->peer_conn_id) 445 return -ENOTCONN; 446 lsa->l2tp_conn_id = lsk->peer_conn_id; 447 lsa->l2tp_addr = sk->sk_v6_daddr; 448 if (np->sndflow) 449 lsa->l2tp_flowinfo = np->flow_label; 450 } else { 451 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 452 lsa->l2tp_addr = np->saddr; 453 else 454 lsa->l2tp_addr = sk->sk_v6_rcv_saddr; 455 456 lsa->l2tp_conn_id = lsk->conn_id; 457 } 458 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 459 lsa->l2tp_scope_id = sk->sk_bound_dev_if; 460 *uaddr_len = sizeof(*lsa); 461 return 0; 462 } 463 464 static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) 465 { 466 int rc; 467 468 /* Charge it to the socket, dropping if the queue is full. */ 469 rc = sock_queue_rcv_skb(sk, skb); 470 if (rc < 0) 471 goto drop; 472 473 return 0; 474 475 drop: 476 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); 477 kfree_skb(skb); 478 return -1; 479 } 480 481 static int l2tp_ip6_push_pending_frames(struct sock *sk) 482 { 483 struct sk_buff *skb; 484 __be32 *transhdr = NULL; 485 int err = 0; 486 487 skb = skb_peek(&sk->sk_write_queue); 488 if (skb == NULL) 489 goto out; 490 491 transhdr = (__be32 *)skb_transport_header(skb); 492 *transhdr = 0; 493 494 err = ip6_push_pending_frames(sk); 495 496 out: 497 return err; 498 } 499 500 /* Userspace will call sendmsg() on the tunnel socket to send L2TP 501 * control frames. 502 */ 503 static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 504 { 505 struct ipv6_txoptions opt_space; 506 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 507 struct in6_addr *daddr, *final_p, final; 508 struct ipv6_pinfo *np = inet6_sk(sk); 509 struct ipv6_txoptions *opt_to_free = NULL; 510 struct ipv6_txoptions *opt = NULL; 511 struct ip6_flowlabel *flowlabel = NULL; 512 struct dst_entry *dst = NULL; 513 struct flowi6 fl6; 514 struct sockcm_cookie sockc_unused = {0}; 515 struct ipcm6_cookie ipc6; 516 int addr_len = msg->msg_namelen; 517 int transhdrlen = 4; /* zero session-id */ 518 int ulen = len + transhdrlen; 519 int err; 520 521 /* Rough check on arithmetic overflow, 522 better check is made in ip6_append_data(). 523 */ 524 if (len > INT_MAX) 525 return -EMSGSIZE; 526 527 /* Mirror BSD error message compatibility */ 528 if (msg->msg_flags & MSG_OOB) 529 return -EOPNOTSUPP; 530 531 /* 532 * Get and verify the address. 533 */ 534 memset(&fl6, 0, sizeof(fl6)); 535 536 fl6.flowi6_mark = sk->sk_mark; 537 fl6.flowi6_uid = sk->sk_uid; 538 539 ipc6.hlimit = -1; 540 ipc6.tclass = -1; 541 ipc6.dontfrag = -1; 542 543 if (lsa) { 544 if (addr_len < SIN6_LEN_RFC2133) 545 return -EINVAL; 546 547 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) 548 return -EAFNOSUPPORT; 549 550 daddr = &lsa->l2tp_addr; 551 if (np->sndflow) { 552 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; 553 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 554 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 555 if (flowlabel == NULL) 556 return -EINVAL; 557 } 558 } 559 560 /* 561 * Otherwise it will be difficult to maintain 562 * sk->sk_dst_cache. 563 */ 564 if (sk->sk_state == TCP_ESTABLISHED && 565 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 566 daddr = &sk->sk_v6_daddr; 567 568 if (addr_len >= sizeof(struct sockaddr_in6) && 569 lsa->l2tp_scope_id && 570 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) 571 fl6.flowi6_oif = lsa->l2tp_scope_id; 572 } else { 573 if (sk->sk_state != TCP_ESTABLISHED) 574 return -EDESTADDRREQ; 575 576 daddr = &sk->sk_v6_daddr; 577 fl6.flowlabel = np->flow_label; 578 } 579 580 if (fl6.flowi6_oif == 0) 581 fl6.flowi6_oif = sk->sk_bound_dev_if; 582 583 if (msg->msg_controllen) { 584 opt = &opt_space; 585 memset(opt, 0, sizeof(struct ipv6_txoptions)); 586 opt->tot_len = sizeof(struct ipv6_txoptions); 587 ipc6.opt = opt; 588 589 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, 590 &sockc_unused); 591 if (err < 0) { 592 fl6_sock_release(flowlabel); 593 return err; 594 } 595 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { 596 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 597 if (flowlabel == NULL) 598 return -EINVAL; 599 } 600 if (!(opt->opt_nflen|opt->opt_flen)) 601 opt = NULL; 602 } 603 604 if (!opt) { 605 opt = txopt_get(np); 606 opt_to_free = opt; 607 } 608 if (flowlabel) 609 opt = fl6_merge_options(&opt_space, flowlabel, opt); 610 opt = ipv6_fixup_options(&opt_space, opt); 611 ipc6.opt = opt; 612 613 fl6.flowi6_proto = sk->sk_protocol; 614 if (!ipv6_addr_any(daddr)) 615 fl6.daddr = *daddr; 616 else 617 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 618 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 619 fl6.saddr = np->saddr; 620 621 final_p = fl6_update_dst(&fl6, opt, &final); 622 623 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 624 fl6.flowi6_oif = np->mcast_oif; 625 else if (!fl6.flowi6_oif) 626 fl6.flowi6_oif = np->ucast_oif; 627 628 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 629 630 if (ipc6.tclass < 0) 631 ipc6.tclass = np->tclass; 632 633 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); 634 635 dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 636 if (IS_ERR(dst)) { 637 err = PTR_ERR(dst); 638 goto out; 639 } 640 641 if (ipc6.hlimit < 0) 642 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 643 644 if (ipc6.dontfrag < 0) 645 ipc6.dontfrag = np->dontfrag; 646 647 if (msg->msg_flags & MSG_CONFIRM) 648 goto do_confirm; 649 650 back_from_confirm: 651 lock_sock(sk); 652 err = ip6_append_data(sk, ip_generic_getfrag, msg, 653 ulen, transhdrlen, &ipc6, 654 &fl6, (struct rt6_info *)dst, 655 msg->msg_flags, &sockc_unused); 656 if (err) 657 ip6_flush_pending_frames(sk); 658 else if (!(msg->msg_flags & MSG_MORE)) 659 err = l2tp_ip6_push_pending_frames(sk); 660 release_sock(sk); 661 done: 662 dst_release(dst); 663 out: 664 fl6_sock_release(flowlabel); 665 txopt_put(opt_to_free); 666 667 return err < 0 ? err : len; 668 669 do_confirm: 670 if (msg->msg_flags & MSG_PROBE) 671 dst_confirm_neigh(dst, &fl6.daddr); 672 if (!(msg->msg_flags & MSG_PROBE) || len) 673 goto back_from_confirm; 674 err = 0; 675 goto done; 676 } 677 678 static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 679 int noblock, int flags, int *addr_len) 680 { 681 struct ipv6_pinfo *np = inet6_sk(sk); 682 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 683 size_t copied = 0; 684 int err = -EOPNOTSUPP; 685 struct sk_buff *skb; 686 687 if (flags & MSG_OOB) 688 goto out; 689 690 if (addr_len) 691 *addr_len = sizeof(*lsa); 692 693 if (flags & MSG_ERRQUEUE) 694 return ipv6_recv_error(sk, msg, len, addr_len); 695 696 skb = skb_recv_datagram(sk, flags, noblock, &err); 697 if (!skb) 698 goto out; 699 700 copied = skb->len; 701 if (len < copied) { 702 msg->msg_flags |= MSG_TRUNC; 703 copied = len; 704 } 705 706 err = skb_copy_datagram_msg(skb, 0, msg, copied); 707 if (err) 708 goto done; 709 710 sock_recv_timestamp(msg, sk, skb); 711 712 /* Copy the address. */ 713 if (lsa) { 714 lsa->l2tp_family = AF_INET6; 715 lsa->l2tp_unused = 0; 716 lsa->l2tp_addr = ipv6_hdr(skb)->saddr; 717 lsa->l2tp_flowinfo = 0; 718 lsa->l2tp_scope_id = 0; 719 lsa->l2tp_conn_id = 0; 720 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 721 lsa->l2tp_scope_id = inet6_iif(skb); 722 } 723 724 if (np->rxopt.all) 725 ip6_datagram_recv_ctl(sk, msg, skb); 726 727 if (flags & MSG_TRUNC) 728 copied = skb->len; 729 done: 730 skb_free_datagram(sk, skb); 731 out: 732 return err ? err : copied; 733 } 734 735 static struct proto l2tp_ip6_prot = { 736 .name = "L2TP/IPv6", 737 .owner = THIS_MODULE, 738 .init = l2tp_ip6_open, 739 .close = l2tp_ip6_close, 740 .bind = l2tp_ip6_bind, 741 .connect = l2tp_ip6_connect, 742 .disconnect = l2tp_ip6_disconnect, 743 .ioctl = l2tp_ioctl, 744 .destroy = l2tp_ip6_destroy_sock, 745 .setsockopt = ipv6_setsockopt, 746 .getsockopt = ipv6_getsockopt, 747 .sendmsg = l2tp_ip6_sendmsg, 748 .recvmsg = l2tp_ip6_recvmsg, 749 .backlog_rcv = l2tp_ip6_backlog_recv, 750 .hash = inet6_hash, 751 .unhash = inet_unhash, 752 .obj_size = sizeof(struct l2tp_ip6_sock), 753 #ifdef CONFIG_COMPAT 754 .compat_setsockopt = compat_ipv6_setsockopt, 755 .compat_getsockopt = compat_ipv6_getsockopt, 756 #endif 757 }; 758 759 static const struct proto_ops l2tp_ip6_ops = { 760 .family = PF_INET6, 761 .owner = THIS_MODULE, 762 .release = inet6_release, 763 .bind = inet6_bind, 764 .connect = inet_dgram_connect, 765 .socketpair = sock_no_socketpair, 766 .accept = sock_no_accept, 767 .getname = l2tp_ip6_getname, 768 .poll = datagram_poll, 769 .ioctl = inet6_ioctl, 770 .listen = sock_no_listen, 771 .shutdown = inet_shutdown, 772 .setsockopt = sock_common_setsockopt, 773 .getsockopt = sock_common_getsockopt, 774 .sendmsg = inet_sendmsg, 775 .recvmsg = sock_common_recvmsg, 776 .mmap = sock_no_mmap, 777 .sendpage = sock_no_sendpage, 778 #ifdef CONFIG_COMPAT 779 .compat_setsockopt = compat_sock_common_setsockopt, 780 .compat_getsockopt = compat_sock_common_getsockopt, 781 #endif 782 }; 783 784 static struct inet_protosw l2tp_ip6_protosw = { 785 .type = SOCK_DGRAM, 786 .protocol = IPPROTO_L2TP, 787 .prot = &l2tp_ip6_prot, 788 .ops = &l2tp_ip6_ops, 789 }; 790 791 static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { 792 .handler = l2tp_ip6_recv, 793 }; 794 795 static int __init l2tp_ip6_init(void) 796 { 797 int err; 798 799 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); 800 801 err = proto_register(&l2tp_ip6_prot, 1); 802 if (err != 0) 803 goto out; 804 805 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 806 if (err) 807 goto out1; 808 809 inet6_register_protosw(&l2tp_ip6_protosw); 810 return 0; 811 812 out1: 813 proto_unregister(&l2tp_ip6_prot); 814 out: 815 return err; 816 } 817 818 static void __exit l2tp_ip6_exit(void) 819 { 820 inet6_unregister_protosw(&l2tp_ip6_protosw); 821 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 822 proto_unregister(&l2tp_ip6_prot); 823 } 824 825 module_init(l2tp_ip6_init); 826 module_exit(l2tp_ip6_exit); 827 828 MODULE_LICENSE("GPL"); 829 MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); 830 MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); 831 MODULE_VERSION("1.0"); 832 833 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like 834 * enums 835 */ 836 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); 837 MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); 838