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); 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 l2tp_session_dec_refcount(session); 217 goto discard; 218 219 discard_put: 220 sock_put(sk); 221 222 discard: 223 kfree_skb(skb); 224 return 0; 225 } 226 227 static int l2tp_ip6_open(struct sock *sk) 228 { 229 /* Prevent autobind. We don't have ports. */ 230 inet_sk(sk)->inet_num = IPPROTO_L2TP; 231 232 write_lock_bh(&l2tp_ip6_lock); 233 sk_add_node(sk, &l2tp_ip6_table); 234 write_unlock_bh(&l2tp_ip6_lock); 235 236 return 0; 237 } 238 239 static void l2tp_ip6_close(struct sock *sk, long timeout) 240 { 241 write_lock_bh(&l2tp_ip6_lock); 242 hlist_del_init(&sk->sk_bind_node); 243 sk_del_node_init(sk); 244 write_unlock_bh(&l2tp_ip6_lock); 245 246 sk_common_release(sk); 247 } 248 249 static void l2tp_ip6_destroy_sock(struct sock *sk) 250 { 251 struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); 252 253 lock_sock(sk); 254 ip6_flush_pending_frames(sk); 255 release_sock(sk); 256 257 if (tunnel) { 258 l2tp_tunnel_closeall(tunnel); 259 sock_put(sk); 260 } 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 *uaddr_len, 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 *uaddr_len = sizeof(*lsa); 453 return 0; 454 } 455 456 static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) 457 { 458 int rc; 459 460 /* Charge it to the socket, dropping if the queue is full. */ 461 rc = sock_queue_rcv_skb(sk, skb); 462 if (rc < 0) 463 goto drop; 464 465 return 0; 466 467 drop: 468 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); 469 kfree_skb(skb); 470 return -1; 471 } 472 473 static int l2tp_ip6_push_pending_frames(struct sock *sk) 474 { 475 struct sk_buff *skb; 476 __be32 *transhdr = NULL; 477 int err = 0; 478 479 skb = skb_peek(&sk->sk_write_queue); 480 if (skb == NULL) 481 goto out; 482 483 transhdr = (__be32 *)skb_transport_header(skb); 484 *transhdr = 0; 485 486 err = ip6_push_pending_frames(sk); 487 488 out: 489 return err; 490 } 491 492 /* Userspace will call sendmsg() on the tunnel socket to send L2TP 493 * control frames. 494 */ 495 static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 496 { 497 struct ipv6_txoptions opt_space; 498 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 499 struct in6_addr *daddr, *final_p, final; 500 struct ipv6_pinfo *np = inet6_sk(sk); 501 struct ipv6_txoptions *opt_to_free = NULL; 502 struct ipv6_txoptions *opt = NULL; 503 struct ip6_flowlabel *flowlabel = NULL; 504 struct dst_entry *dst = NULL; 505 struct flowi6 fl6; 506 struct sockcm_cookie sockc_unused = {0}; 507 struct ipcm6_cookie ipc6; 508 int addr_len = msg->msg_namelen; 509 int transhdrlen = 4; /* zero session-id */ 510 int ulen = len + transhdrlen; 511 int err; 512 513 /* Rough check on arithmetic overflow, 514 better check is made in ip6_append_data(). 515 */ 516 if (len > INT_MAX) 517 return -EMSGSIZE; 518 519 /* Mirror BSD error message compatibility */ 520 if (msg->msg_flags & MSG_OOB) 521 return -EOPNOTSUPP; 522 523 /* 524 * Get and verify the address. 525 */ 526 memset(&fl6, 0, sizeof(fl6)); 527 528 fl6.flowi6_mark = sk->sk_mark; 529 fl6.flowi6_uid = sk->sk_uid; 530 531 ipc6.hlimit = -1; 532 ipc6.tclass = -1; 533 ipc6.dontfrag = -1; 534 535 if (lsa) { 536 if (addr_len < SIN6_LEN_RFC2133) 537 return -EINVAL; 538 539 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) 540 return -EAFNOSUPPORT; 541 542 daddr = &lsa->l2tp_addr; 543 if (np->sndflow) { 544 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; 545 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 546 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 547 if (flowlabel == NULL) 548 return -EINVAL; 549 } 550 } 551 552 /* 553 * Otherwise it will be difficult to maintain 554 * sk->sk_dst_cache. 555 */ 556 if (sk->sk_state == TCP_ESTABLISHED && 557 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 558 daddr = &sk->sk_v6_daddr; 559 560 if (addr_len >= sizeof(struct sockaddr_in6) && 561 lsa->l2tp_scope_id && 562 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) 563 fl6.flowi6_oif = lsa->l2tp_scope_id; 564 } else { 565 if (sk->sk_state != TCP_ESTABLISHED) 566 return -EDESTADDRREQ; 567 568 daddr = &sk->sk_v6_daddr; 569 fl6.flowlabel = np->flow_label; 570 } 571 572 if (fl6.flowi6_oif == 0) 573 fl6.flowi6_oif = sk->sk_bound_dev_if; 574 575 if (msg->msg_controllen) { 576 opt = &opt_space; 577 memset(opt, 0, sizeof(struct ipv6_txoptions)); 578 opt->tot_len = sizeof(struct ipv6_txoptions); 579 ipc6.opt = opt; 580 581 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, 582 &sockc_unused); 583 if (err < 0) { 584 fl6_sock_release(flowlabel); 585 return err; 586 } 587 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { 588 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 589 if (flowlabel == NULL) 590 return -EINVAL; 591 } 592 if (!(opt->opt_nflen|opt->opt_flen)) 593 opt = NULL; 594 } 595 596 if (!opt) { 597 opt = txopt_get(np); 598 opt_to_free = opt; 599 } 600 if (flowlabel) 601 opt = fl6_merge_options(&opt_space, flowlabel, opt); 602 opt = ipv6_fixup_options(&opt_space, opt); 603 ipc6.opt = opt; 604 605 fl6.flowi6_proto = sk->sk_protocol; 606 if (!ipv6_addr_any(daddr)) 607 fl6.daddr = *daddr; 608 else 609 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 610 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 611 fl6.saddr = np->saddr; 612 613 final_p = fl6_update_dst(&fl6, opt, &final); 614 615 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 616 fl6.flowi6_oif = np->mcast_oif; 617 else if (!fl6.flowi6_oif) 618 fl6.flowi6_oif = np->ucast_oif; 619 620 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 621 622 if (ipc6.tclass < 0) 623 ipc6.tclass = np->tclass; 624 625 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); 626 627 dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 628 if (IS_ERR(dst)) { 629 err = PTR_ERR(dst); 630 goto out; 631 } 632 633 if (ipc6.hlimit < 0) 634 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 635 636 if (ipc6.dontfrag < 0) 637 ipc6.dontfrag = np->dontfrag; 638 639 if (msg->msg_flags & MSG_CONFIRM) 640 goto do_confirm; 641 642 back_from_confirm: 643 lock_sock(sk); 644 err = ip6_append_data(sk, ip_generic_getfrag, msg, 645 ulen, transhdrlen, &ipc6, 646 &fl6, (struct rt6_info *)dst, 647 msg->msg_flags, &sockc_unused); 648 if (err) 649 ip6_flush_pending_frames(sk); 650 else if (!(msg->msg_flags & MSG_MORE)) 651 err = l2tp_ip6_push_pending_frames(sk); 652 release_sock(sk); 653 done: 654 dst_release(dst); 655 out: 656 fl6_sock_release(flowlabel); 657 txopt_put(opt_to_free); 658 659 return err < 0 ? err : len; 660 661 do_confirm: 662 if (msg->msg_flags & MSG_PROBE) 663 dst_confirm_neigh(dst, &fl6.daddr); 664 if (!(msg->msg_flags & MSG_PROBE) || len) 665 goto back_from_confirm; 666 err = 0; 667 goto done; 668 } 669 670 static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 671 int noblock, int flags, int *addr_len) 672 { 673 struct ipv6_pinfo *np = inet6_sk(sk); 674 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 675 size_t copied = 0; 676 int err = -EOPNOTSUPP; 677 struct sk_buff *skb; 678 679 if (flags & MSG_OOB) 680 goto out; 681 682 if (addr_len) 683 *addr_len = sizeof(*lsa); 684 685 if (flags & MSG_ERRQUEUE) 686 return ipv6_recv_error(sk, msg, len, addr_len); 687 688 skb = skb_recv_datagram(sk, flags, noblock, &err); 689 if (!skb) 690 goto out; 691 692 copied = skb->len; 693 if (len < copied) { 694 msg->msg_flags |= MSG_TRUNC; 695 copied = len; 696 } 697 698 err = skb_copy_datagram_msg(skb, 0, msg, copied); 699 if (err) 700 goto done; 701 702 sock_recv_timestamp(msg, sk, skb); 703 704 /* Copy the address. */ 705 if (lsa) { 706 lsa->l2tp_family = AF_INET6; 707 lsa->l2tp_unused = 0; 708 lsa->l2tp_addr = ipv6_hdr(skb)->saddr; 709 lsa->l2tp_flowinfo = 0; 710 lsa->l2tp_scope_id = 0; 711 lsa->l2tp_conn_id = 0; 712 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 713 lsa->l2tp_scope_id = inet6_iif(skb); 714 } 715 716 if (np->rxopt.all) 717 ip6_datagram_recv_ctl(sk, msg, skb); 718 719 if (flags & MSG_TRUNC) 720 copied = skb->len; 721 done: 722 skb_free_datagram(sk, skb); 723 out: 724 return err ? err : copied; 725 } 726 727 static struct proto l2tp_ip6_prot = { 728 .name = "L2TP/IPv6", 729 .owner = THIS_MODULE, 730 .init = l2tp_ip6_open, 731 .close = l2tp_ip6_close, 732 .bind = l2tp_ip6_bind, 733 .connect = l2tp_ip6_connect, 734 .disconnect = l2tp_ip6_disconnect, 735 .ioctl = l2tp_ioctl, 736 .destroy = l2tp_ip6_destroy_sock, 737 .setsockopt = ipv6_setsockopt, 738 .getsockopt = ipv6_getsockopt, 739 .sendmsg = l2tp_ip6_sendmsg, 740 .recvmsg = l2tp_ip6_recvmsg, 741 .backlog_rcv = l2tp_ip6_backlog_recv, 742 .hash = inet6_hash, 743 .unhash = inet_unhash, 744 .obj_size = sizeof(struct l2tp_ip6_sock), 745 #ifdef CONFIG_COMPAT 746 .compat_setsockopt = compat_ipv6_setsockopt, 747 .compat_getsockopt = compat_ipv6_getsockopt, 748 #endif 749 }; 750 751 static const struct proto_ops l2tp_ip6_ops = { 752 .family = PF_INET6, 753 .owner = THIS_MODULE, 754 .release = inet6_release, 755 .bind = inet6_bind, 756 .connect = inet_dgram_connect, 757 .socketpair = sock_no_socketpair, 758 .accept = sock_no_accept, 759 .getname = l2tp_ip6_getname, 760 .poll = datagram_poll, 761 .ioctl = inet6_ioctl, 762 .listen = sock_no_listen, 763 .shutdown = inet_shutdown, 764 .setsockopt = sock_common_setsockopt, 765 .getsockopt = sock_common_getsockopt, 766 .sendmsg = inet_sendmsg, 767 .recvmsg = sock_common_recvmsg, 768 .mmap = sock_no_mmap, 769 .sendpage = sock_no_sendpage, 770 #ifdef CONFIG_COMPAT 771 .compat_setsockopt = compat_sock_common_setsockopt, 772 .compat_getsockopt = compat_sock_common_getsockopt, 773 #endif 774 }; 775 776 static struct inet_protosw l2tp_ip6_protosw = { 777 .type = SOCK_DGRAM, 778 .protocol = IPPROTO_L2TP, 779 .prot = &l2tp_ip6_prot, 780 .ops = &l2tp_ip6_ops, 781 }; 782 783 static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { 784 .handler = l2tp_ip6_recv, 785 }; 786 787 static int __init l2tp_ip6_init(void) 788 { 789 int err; 790 791 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); 792 793 err = proto_register(&l2tp_ip6_prot, 1); 794 if (err != 0) 795 goto out; 796 797 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 798 if (err) 799 goto out1; 800 801 inet6_register_protosw(&l2tp_ip6_protosw); 802 return 0; 803 804 out1: 805 proto_unregister(&l2tp_ip6_prot); 806 out: 807 return err; 808 } 809 810 static void __exit l2tp_ip6_exit(void) 811 { 812 inet6_unregister_protosw(&l2tp_ip6_protosw); 813 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 814 proto_unregister(&l2tp_ip6_prot); 815 } 816 817 module_init(l2tp_ip6_init); 818 module_exit(l2tp_ip6_exit); 819 820 MODULE_LICENSE("GPL"); 821 MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); 822 MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); 823 MODULE_VERSION("1.0"); 824 825 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like 826 * enums 827 */ 828 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); 829 MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); 830