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, 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 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 iph = ipv6_hdr(skb); 196 197 read_lock_bh(&l2tp_ip6_lock); 198 sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr, 199 inet6_iif(skb), tunnel_id); 200 if (!sk) { 201 read_unlock_bh(&l2tp_ip6_lock); 202 goto discard; 203 } 204 sock_hold(sk); 205 read_unlock_bh(&l2tp_ip6_lock); 206 207 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 208 goto discard_put; 209 210 nf_reset(skb); 211 212 return sk_receive_skb(sk, skb, 1); 213 214 discard_sess: 215 l2tp_session_dec_refcount(session); 216 goto discard; 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 = sk->sk_user_data; 251 252 lock_sock(sk); 253 ip6_flush_pending_frames(sk); 254 release_sock(sk); 255 256 if (tunnel) 257 l2tp_tunnel_delete(tunnel); 258 259 inet6_destroy_sock(sk); 260 } 261 262 static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 263 { 264 struct inet_sock *inet = inet_sk(sk); 265 struct ipv6_pinfo *np = inet6_sk(sk); 266 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; 267 struct net *net = sock_net(sk); 268 __be32 v4addr = 0; 269 int bound_dev_if; 270 int addr_type; 271 int err; 272 273 if (addr->l2tp_family != AF_INET6) 274 return -EINVAL; 275 if (addr_len < sizeof(*addr)) 276 return -EINVAL; 277 278 addr_type = ipv6_addr_type(&addr->l2tp_addr); 279 280 /* l2tp_ip6 sockets are IPv6 only */ 281 if (addr_type == IPV6_ADDR_MAPPED) 282 return -EADDRNOTAVAIL; 283 284 /* L2TP is point-point, not multicast */ 285 if (addr_type & IPV6_ADDR_MULTICAST) 286 return -EADDRNOTAVAIL; 287 288 lock_sock(sk); 289 290 err = -EINVAL; 291 if (!sock_flag(sk, SOCK_ZAPPED)) 292 goto out_unlock; 293 294 if (sk->sk_state != TCP_CLOSE) 295 goto out_unlock; 296 297 bound_dev_if = sk->sk_bound_dev_if; 298 299 /* Check if the address belongs to the host. */ 300 rcu_read_lock(); 301 if (addr_type != IPV6_ADDR_ANY) { 302 struct net_device *dev = NULL; 303 304 if (addr_type & IPV6_ADDR_LINKLOCAL) { 305 if (addr->l2tp_scope_id) 306 bound_dev_if = addr->l2tp_scope_id; 307 308 /* Binding to link-local address requires an 309 * interface. 310 */ 311 if (!bound_dev_if) 312 goto out_unlock_rcu; 313 314 err = -ENODEV; 315 dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); 316 if (!dev) 317 goto out_unlock_rcu; 318 } 319 320 /* ipv4 addr of the socket is invalid. Only the 321 * unspecified and mapped address have a v4 equivalent. 322 */ 323 v4addr = LOOPBACK4_IPV6; 324 err = -EADDRNOTAVAIL; 325 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) 326 goto out_unlock_rcu; 327 } 328 rcu_read_unlock(); 329 330 write_lock_bh(&l2tp_ip6_lock); 331 if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, 332 addr->l2tp_conn_id)) { 333 write_unlock_bh(&l2tp_ip6_lock); 334 err = -EADDRINUSE; 335 goto out_unlock; 336 } 337 338 inet->inet_saddr = v4addr; 339 inet->inet_rcv_saddr = v4addr; 340 sk->sk_bound_dev_if = bound_dev_if; 341 sk->sk_v6_rcv_saddr = addr->l2tp_addr; 342 np->saddr = addr->l2tp_addr; 343 344 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; 345 346 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 347 sk_del_node_init(sk); 348 write_unlock_bh(&l2tp_ip6_lock); 349 350 sock_reset_flag(sk, SOCK_ZAPPED); 351 release_sock(sk); 352 return 0; 353 354 out_unlock_rcu: 355 rcu_read_unlock(); 356 out_unlock: 357 release_sock(sk); 358 359 return err; 360 } 361 362 static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, 363 int addr_len) 364 { 365 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr; 366 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; 367 struct in6_addr *daddr; 368 int addr_type; 369 int rc; 370 371 if (addr_len < sizeof(*lsa)) 372 return -EINVAL; 373 374 if (usin->sin6_family != AF_INET6) 375 return -EINVAL; 376 377 addr_type = ipv6_addr_type(&usin->sin6_addr); 378 if (addr_type & IPV6_ADDR_MULTICAST) 379 return -EINVAL; 380 381 if (addr_type & IPV6_ADDR_MAPPED) { 382 daddr = &usin->sin6_addr; 383 if (ipv4_is_multicast(daddr->s6_addr32[3])) 384 return -EINVAL; 385 } 386 387 lock_sock(sk); 388 389 /* Must bind first - autobinding does not work */ 390 if (sock_flag(sk, SOCK_ZAPPED)) { 391 rc = -EINVAL; 392 goto out_sk; 393 } 394 395 rc = __ip6_datagram_connect(sk, uaddr, addr_len); 396 if (rc < 0) 397 goto out_sk; 398 399 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; 400 401 write_lock_bh(&l2tp_ip6_lock); 402 hlist_del_init(&sk->sk_bind_node); 403 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 404 write_unlock_bh(&l2tp_ip6_lock); 405 406 out_sk: 407 release_sock(sk); 408 409 return rc; 410 } 411 412 static int l2tp_ip6_disconnect(struct sock *sk, int flags) 413 { 414 if (sock_flag(sk, SOCK_ZAPPED)) 415 return 0; 416 417 return __udp_disconnect(sk, flags); 418 } 419 420 static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, 421 int peer) 422 { 423 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; 424 struct sock *sk = sock->sk; 425 struct ipv6_pinfo *np = inet6_sk(sk); 426 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); 427 428 lsa->l2tp_family = AF_INET6; 429 lsa->l2tp_flowinfo = 0; 430 lsa->l2tp_scope_id = 0; 431 lsa->l2tp_unused = 0; 432 if (peer) { 433 if (!lsk->peer_conn_id) 434 return -ENOTCONN; 435 lsa->l2tp_conn_id = lsk->peer_conn_id; 436 lsa->l2tp_addr = sk->sk_v6_daddr; 437 if (np->sndflow) 438 lsa->l2tp_flowinfo = np->flow_label; 439 } else { 440 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 441 lsa->l2tp_addr = np->saddr; 442 else 443 lsa->l2tp_addr = sk->sk_v6_rcv_saddr; 444 445 lsa->l2tp_conn_id = lsk->conn_id; 446 } 447 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 448 lsa->l2tp_scope_id = sk->sk_bound_dev_if; 449 return sizeof(*lsa); 450 } 451 452 static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) 453 { 454 int rc; 455 456 /* Charge it to the socket, dropping if the queue is full. */ 457 rc = sock_queue_rcv_skb(sk, skb); 458 if (rc < 0) 459 goto drop; 460 461 return 0; 462 463 drop: 464 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); 465 kfree_skb(skb); 466 return -1; 467 } 468 469 static int l2tp_ip6_push_pending_frames(struct sock *sk) 470 { 471 struct sk_buff *skb; 472 __be32 *transhdr = NULL; 473 int err = 0; 474 475 skb = skb_peek(&sk->sk_write_queue); 476 if (skb == NULL) 477 goto out; 478 479 transhdr = (__be32 *)skb_transport_header(skb); 480 *transhdr = 0; 481 482 err = ip6_push_pending_frames(sk); 483 484 out: 485 return err; 486 } 487 488 /* Userspace will call sendmsg() on the tunnel socket to send L2TP 489 * control frames. 490 */ 491 static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 492 { 493 struct ipv6_txoptions opt_space; 494 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 495 struct in6_addr *daddr, *final_p, final; 496 struct ipv6_pinfo *np = inet6_sk(sk); 497 struct ipv6_txoptions *opt_to_free = NULL; 498 struct ipv6_txoptions *opt = NULL; 499 struct ip6_flowlabel *flowlabel = NULL; 500 struct dst_entry *dst = NULL; 501 struct flowi6 fl6; 502 struct ipcm6_cookie ipc6; 503 int addr_len = msg->msg_namelen; 504 int transhdrlen = 4; /* zero session-id */ 505 int ulen = len + transhdrlen; 506 int err; 507 508 /* Rough check on arithmetic overflow, 509 better check is made in ip6_append_data(). 510 */ 511 if (len > INT_MAX) 512 return -EMSGSIZE; 513 514 /* Mirror BSD error message compatibility */ 515 if (msg->msg_flags & MSG_OOB) 516 return -EOPNOTSUPP; 517 518 /* 519 * Get and verify the address. 520 */ 521 memset(&fl6, 0, sizeof(fl6)); 522 523 fl6.flowi6_mark = sk->sk_mark; 524 fl6.flowi6_uid = sk->sk_uid; 525 526 ipcm6_init(&ipc6); 527 528 if (lsa) { 529 if (addr_len < SIN6_LEN_RFC2133) 530 return -EINVAL; 531 532 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) 533 return -EAFNOSUPPORT; 534 535 daddr = &lsa->l2tp_addr; 536 if (np->sndflow) { 537 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; 538 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 539 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 540 if (flowlabel == NULL) 541 return -EINVAL; 542 } 543 } 544 545 /* 546 * Otherwise it will be difficult to maintain 547 * sk->sk_dst_cache. 548 */ 549 if (sk->sk_state == TCP_ESTABLISHED && 550 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 551 daddr = &sk->sk_v6_daddr; 552 553 if (addr_len >= sizeof(struct sockaddr_in6) && 554 lsa->l2tp_scope_id && 555 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) 556 fl6.flowi6_oif = lsa->l2tp_scope_id; 557 } else { 558 if (sk->sk_state != TCP_ESTABLISHED) 559 return -EDESTADDRREQ; 560 561 daddr = &sk->sk_v6_daddr; 562 fl6.flowlabel = np->flow_label; 563 } 564 565 if (fl6.flowi6_oif == 0) 566 fl6.flowi6_oif = sk->sk_bound_dev_if; 567 568 if (msg->msg_controllen) { 569 opt = &opt_space; 570 memset(opt, 0, sizeof(struct ipv6_txoptions)); 571 opt->tot_len = sizeof(struct ipv6_txoptions); 572 ipc6.opt = opt; 573 574 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6); 575 if (err < 0) { 576 fl6_sock_release(flowlabel); 577 return err; 578 } 579 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { 580 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 581 if (flowlabel == NULL) 582 return -EINVAL; 583 } 584 if (!(opt->opt_nflen|opt->opt_flen)) 585 opt = NULL; 586 } 587 588 if (!opt) { 589 opt = txopt_get(np); 590 opt_to_free = opt; 591 } 592 if (flowlabel) 593 opt = fl6_merge_options(&opt_space, flowlabel, opt); 594 opt = ipv6_fixup_options(&opt_space, opt); 595 ipc6.opt = opt; 596 597 fl6.flowi6_proto = sk->sk_protocol; 598 if (!ipv6_addr_any(daddr)) 599 fl6.daddr = *daddr; 600 else 601 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 602 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 603 fl6.saddr = np->saddr; 604 605 final_p = fl6_update_dst(&fl6, opt, &final); 606 607 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 608 fl6.flowi6_oif = np->mcast_oif; 609 else if (!fl6.flowi6_oif) 610 fl6.flowi6_oif = np->ucast_oif; 611 612 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 613 614 if (ipc6.tclass < 0) 615 ipc6.tclass = np->tclass; 616 617 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); 618 619 dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 620 if (IS_ERR(dst)) { 621 err = PTR_ERR(dst); 622 goto out; 623 } 624 625 if (ipc6.hlimit < 0) 626 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 627 628 if (ipc6.dontfrag < 0) 629 ipc6.dontfrag = np->dontfrag; 630 631 if (msg->msg_flags & MSG_CONFIRM) 632 goto do_confirm; 633 634 back_from_confirm: 635 lock_sock(sk); 636 err = ip6_append_data(sk, ip_generic_getfrag, msg, 637 ulen, transhdrlen, &ipc6, 638 &fl6, (struct rt6_info *)dst, 639 msg->msg_flags); 640 if (err) 641 ip6_flush_pending_frames(sk); 642 else if (!(msg->msg_flags & MSG_MORE)) 643 err = l2tp_ip6_push_pending_frames(sk); 644 release_sock(sk); 645 done: 646 dst_release(dst); 647 out: 648 fl6_sock_release(flowlabel); 649 txopt_put(opt_to_free); 650 651 return err < 0 ? err : len; 652 653 do_confirm: 654 if (msg->msg_flags & MSG_PROBE) 655 dst_confirm_neigh(dst, &fl6.daddr); 656 if (!(msg->msg_flags & MSG_PROBE) || len) 657 goto back_from_confirm; 658 err = 0; 659 goto done; 660 } 661 662 static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 663 int noblock, int flags, int *addr_len) 664 { 665 struct ipv6_pinfo *np = inet6_sk(sk); 666 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 667 size_t copied = 0; 668 int err = -EOPNOTSUPP; 669 struct sk_buff *skb; 670 671 if (flags & MSG_OOB) 672 goto out; 673 674 if (addr_len) 675 *addr_len = sizeof(*lsa); 676 677 if (flags & MSG_ERRQUEUE) 678 return ipv6_recv_error(sk, msg, len, addr_len); 679 680 skb = skb_recv_datagram(sk, flags, noblock, &err); 681 if (!skb) 682 goto out; 683 684 copied = skb->len; 685 if (len < copied) { 686 msg->msg_flags |= MSG_TRUNC; 687 copied = len; 688 } 689 690 err = skb_copy_datagram_msg(skb, 0, msg, copied); 691 if (err) 692 goto done; 693 694 sock_recv_timestamp(msg, sk, skb); 695 696 /* Copy the address. */ 697 if (lsa) { 698 lsa->l2tp_family = AF_INET6; 699 lsa->l2tp_unused = 0; 700 lsa->l2tp_addr = ipv6_hdr(skb)->saddr; 701 lsa->l2tp_flowinfo = 0; 702 lsa->l2tp_scope_id = 0; 703 lsa->l2tp_conn_id = 0; 704 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 705 lsa->l2tp_scope_id = inet6_iif(skb); 706 } 707 708 if (np->rxopt.all) 709 ip6_datagram_recv_ctl(sk, msg, skb); 710 711 if (flags & MSG_TRUNC) 712 copied = skb->len; 713 done: 714 skb_free_datagram(sk, skb); 715 out: 716 return err ? err : copied; 717 } 718 719 static struct proto l2tp_ip6_prot = { 720 .name = "L2TP/IPv6", 721 .owner = THIS_MODULE, 722 .init = l2tp_ip6_open, 723 .close = l2tp_ip6_close, 724 .bind = l2tp_ip6_bind, 725 .connect = l2tp_ip6_connect, 726 .disconnect = l2tp_ip6_disconnect, 727 .ioctl = l2tp_ioctl, 728 .destroy = l2tp_ip6_destroy_sock, 729 .setsockopt = ipv6_setsockopt, 730 .getsockopt = ipv6_getsockopt, 731 .sendmsg = l2tp_ip6_sendmsg, 732 .recvmsg = l2tp_ip6_recvmsg, 733 .backlog_rcv = l2tp_ip6_backlog_recv, 734 .hash = inet6_hash, 735 .unhash = inet_unhash, 736 .obj_size = sizeof(struct l2tp_ip6_sock), 737 #ifdef CONFIG_COMPAT 738 .compat_setsockopt = compat_ipv6_setsockopt, 739 .compat_getsockopt = compat_ipv6_getsockopt, 740 #endif 741 }; 742 743 static const struct proto_ops l2tp_ip6_ops = { 744 .family = PF_INET6, 745 .owner = THIS_MODULE, 746 .release = inet6_release, 747 .bind = inet6_bind, 748 .connect = inet_dgram_connect, 749 .socketpair = sock_no_socketpair, 750 .accept = sock_no_accept, 751 .getname = l2tp_ip6_getname, 752 .poll = datagram_poll, 753 .ioctl = inet6_ioctl, 754 .listen = sock_no_listen, 755 .shutdown = inet_shutdown, 756 .setsockopt = sock_common_setsockopt, 757 .getsockopt = sock_common_getsockopt, 758 .sendmsg = inet_sendmsg, 759 .recvmsg = sock_common_recvmsg, 760 .mmap = sock_no_mmap, 761 .sendpage = sock_no_sendpage, 762 #ifdef CONFIG_COMPAT 763 .compat_setsockopt = compat_sock_common_setsockopt, 764 .compat_getsockopt = compat_sock_common_getsockopt, 765 #endif 766 }; 767 768 static struct inet_protosw l2tp_ip6_protosw = { 769 .type = SOCK_DGRAM, 770 .protocol = IPPROTO_L2TP, 771 .prot = &l2tp_ip6_prot, 772 .ops = &l2tp_ip6_ops, 773 }; 774 775 static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { 776 .handler = l2tp_ip6_recv, 777 }; 778 779 static int __init l2tp_ip6_init(void) 780 { 781 int err; 782 783 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); 784 785 err = proto_register(&l2tp_ip6_prot, 1); 786 if (err != 0) 787 goto out; 788 789 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 790 if (err) 791 goto out1; 792 793 inet6_register_protosw(&l2tp_ip6_protosw); 794 return 0; 795 796 out1: 797 proto_unregister(&l2tp_ip6_prot); 798 out: 799 return err; 800 } 801 802 static void __exit l2tp_ip6_exit(void) 803 { 804 inet6_unregister_protosw(&l2tp_ip6_protosw); 805 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 806 proto_unregister(&l2tp_ip6_prot); 807 } 808 809 module_init(l2tp_ip6_init); 810 module_exit(l2tp_ip6_exit); 811 812 MODULE_LICENSE("GPL"); 813 MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); 814 MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); 815 MODULE_VERSION("1.0"); 816 817 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like 818 * enums 819 */ 820 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); 821 MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); 822