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