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