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/tcp_states.h> 29 #include <net/protocol.h> 30 #include <net/xfrm.h> 31 32 #include <net/transp_v6.h> 33 #include <net/addrconf.h> 34 #include <net/ip6_route.h> 35 36 #include "l2tp_core.h" 37 38 struct l2tp_ip6_sock { 39 /* inet_sock has to be the first member of l2tp_ip6_sock */ 40 struct inet_sock inet; 41 42 u32 conn_id; 43 u32 peer_conn_id; 44 45 /* ipv6_pinfo has to be the last member of l2tp_ip6_sock, see 46 inet6_sk_generic */ 47 struct ipv6_pinfo inet6; 48 }; 49 50 static DEFINE_RWLOCK(l2tp_ip6_lock); 51 static struct hlist_head l2tp_ip6_table; 52 static struct hlist_head l2tp_ip6_bind_table; 53 54 static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk) 55 { 56 return (struct l2tp_ip6_sock *)sk; 57 } 58 59 static struct sock *__l2tp_ip6_bind_lookup(struct net *net, 60 struct in6_addr *laddr, 61 int dif, u32 tunnel_id) 62 { 63 struct hlist_node *node; 64 struct sock *sk; 65 66 sk_for_each_bound(sk, node, &l2tp_ip6_bind_table) { 67 struct in6_addr *addr = inet6_rcv_saddr(sk); 68 struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk); 69 70 if (l2tp == NULL) 71 continue; 72 73 if ((l2tp->conn_id == tunnel_id) && 74 net_eq(sock_net(sk), net) && 75 !(addr && ipv6_addr_equal(addr, laddr)) && 76 !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)) 77 goto found; 78 } 79 80 sk = NULL; 81 found: 82 return sk; 83 } 84 85 static inline struct sock *l2tp_ip6_bind_lookup(struct net *net, 86 struct in6_addr *laddr, 87 int dif, u32 tunnel_id) 88 { 89 struct sock *sk = __l2tp_ip6_bind_lookup(net, laddr, dif, tunnel_id); 90 if (sk) 91 sock_hold(sk); 92 93 return sk; 94 } 95 96 /* When processing receive frames, there are two cases to 97 * consider. Data frames consist of a non-zero session-id and an 98 * optional cookie. Control frames consist of a regular L2TP header 99 * preceded by 32-bits of zeros. 100 * 101 * L2TPv3 Session Header Over IP 102 * 103 * 0 1 2 3 104 * 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 1 105 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 106 * | Session ID | 107 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 108 * | Cookie (optional, maximum 64 bits)... 109 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 110 * | 111 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 112 * 113 * L2TPv3 Control Message Header Over IP 114 * 115 * 0 1 2 3 116 * 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 1 117 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 118 * | (32 bits of zeros) | 119 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 120 * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length | 121 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 122 * | Control Connection ID | 123 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 124 * | Ns | Nr | 125 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 126 * 127 * All control frames are passed to userspace. 128 */ 129 static int l2tp_ip6_recv(struct sk_buff *skb) 130 { 131 struct sock *sk; 132 u32 session_id; 133 u32 tunnel_id; 134 unsigned char *ptr, *optr; 135 struct l2tp_session *session; 136 struct l2tp_tunnel *tunnel = NULL; 137 int length; 138 139 /* Point to L2TP header */ 140 optr = ptr = skb->data; 141 142 if (!pskb_may_pull(skb, 4)) 143 goto discard; 144 145 session_id = ntohl(*((__be32 *) ptr)); 146 ptr += 4; 147 148 /* RFC3931: L2TP/IP packets have the first 4 bytes containing 149 * the session_id. If it is 0, the packet is a L2TP control 150 * frame and the session_id value can be discarded. 151 */ 152 if (session_id == 0) { 153 __skb_pull(skb, 4); 154 goto pass_up; 155 } 156 157 /* Ok, this is a data packet. Lookup the session. */ 158 session = l2tp_session_find(&init_net, NULL, session_id); 159 if (session == NULL) 160 goto discard; 161 162 tunnel = session->tunnel; 163 if (tunnel == NULL) 164 goto discard; 165 166 /* Trace packet contents, if enabled */ 167 if (tunnel->debug & L2TP_MSG_DATA) { 168 length = min(32u, skb->len); 169 if (!pskb_may_pull(skb, length)) 170 goto discard; 171 172 pr_debug("%s: ip recv\n", tunnel->name); 173 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); 174 } 175 176 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, 177 tunnel->recv_payload_hook); 178 return 0; 179 180 pass_up: 181 /* Get the tunnel_id from the L2TP header */ 182 if (!pskb_may_pull(skb, 12)) 183 goto discard; 184 185 if ((skb->data[0] & 0xc0) != 0xc0) 186 goto discard; 187 188 tunnel_id = ntohl(*(__be32 *) &skb->data[4]); 189 tunnel = l2tp_tunnel_find(&init_net, tunnel_id); 190 if (tunnel != NULL) 191 sk = tunnel->sock; 192 else { 193 struct ipv6hdr *iph = ipv6_hdr(skb); 194 195 read_lock_bh(&l2tp_ip6_lock); 196 sk = __l2tp_ip6_bind_lookup(&init_net, &iph->daddr, 197 0, tunnel_id); 198 read_unlock_bh(&l2tp_ip6_lock); 199 } 200 201 if (sk == NULL) 202 goto discard; 203 204 sock_hold(sk); 205 206 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 207 goto discard_put; 208 209 nf_reset(skb); 210 211 return sk_receive_skb(sk, skb, 1); 212 213 discard_put: 214 sock_put(sk); 215 216 discard: 217 kfree_skb(skb); 218 return 0; 219 } 220 221 static int l2tp_ip6_open(struct sock *sk) 222 { 223 /* Prevent autobind. We don't have ports. */ 224 inet_sk(sk)->inet_num = IPPROTO_L2TP; 225 226 write_lock_bh(&l2tp_ip6_lock); 227 sk_add_node(sk, &l2tp_ip6_table); 228 write_unlock_bh(&l2tp_ip6_lock); 229 230 return 0; 231 } 232 233 static void l2tp_ip6_close(struct sock *sk, long timeout) 234 { 235 write_lock_bh(&l2tp_ip6_lock); 236 hlist_del_init(&sk->sk_bind_node); 237 sk_del_node_init(sk); 238 write_unlock_bh(&l2tp_ip6_lock); 239 240 sk_common_release(sk); 241 } 242 243 static void l2tp_ip6_destroy_sock(struct sock *sk) 244 { 245 lock_sock(sk); 246 ip6_flush_pending_frames(sk); 247 release_sock(sk); 248 249 inet6_destroy_sock(sk); 250 } 251 252 static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 253 { 254 struct inet_sock *inet = inet_sk(sk); 255 struct ipv6_pinfo *np = inet6_sk(sk); 256 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; 257 __be32 v4addr = 0; 258 int addr_type; 259 int err; 260 261 if (addr_len < sizeof(*addr)) 262 return -EINVAL; 263 264 addr_type = ipv6_addr_type(&addr->l2tp_addr); 265 266 /* l2tp_ip6 sockets are IPv6 only */ 267 if (addr_type == IPV6_ADDR_MAPPED) 268 return -EADDRNOTAVAIL; 269 270 /* L2TP is point-point, not multicast */ 271 if (addr_type & IPV6_ADDR_MULTICAST) 272 return -EADDRNOTAVAIL; 273 274 err = -EADDRINUSE; 275 read_lock_bh(&l2tp_ip6_lock); 276 if (__l2tp_ip6_bind_lookup(&init_net, &addr->l2tp_addr, 277 sk->sk_bound_dev_if, addr->l2tp_conn_id)) 278 goto out_in_use; 279 read_unlock_bh(&l2tp_ip6_lock); 280 281 lock_sock(sk); 282 283 err = -EINVAL; 284 if (sk->sk_state != TCP_CLOSE) 285 goto out_unlock; 286 287 /* Check if the address belongs to the host. */ 288 rcu_read_lock(); 289 if (addr_type != IPV6_ADDR_ANY) { 290 struct net_device *dev = NULL; 291 292 if (addr_type & IPV6_ADDR_LINKLOCAL) { 293 if (addr_len >= sizeof(struct sockaddr_in6) && 294 addr->l2tp_scope_id) { 295 /* Override any existing binding, if another 296 * one is supplied by user. 297 */ 298 sk->sk_bound_dev_if = addr->l2tp_scope_id; 299 } 300 301 /* Binding to link-local address requires an 302 interface */ 303 if (!sk->sk_bound_dev_if) 304 goto out_unlock_rcu; 305 306 err = -ENODEV; 307 dev = dev_get_by_index_rcu(sock_net(sk), 308 sk->sk_bound_dev_if); 309 if (!dev) 310 goto out_unlock_rcu; 311 } 312 313 /* ipv4 addr of the socket is invalid. Only the 314 * unspecified and mapped address have a v4 equivalent. 315 */ 316 v4addr = LOOPBACK4_IPV6; 317 err = -EADDRNOTAVAIL; 318 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) 319 goto out_unlock_rcu; 320 } 321 rcu_read_unlock(); 322 323 inet->inet_rcv_saddr = inet->inet_saddr = v4addr; 324 np->rcv_saddr = addr->l2tp_addr; 325 np->saddr = addr->l2tp_addr; 326 327 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; 328 329 write_lock_bh(&l2tp_ip6_lock); 330 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 331 sk_del_node_init(sk); 332 write_unlock_bh(&l2tp_ip6_lock); 333 334 release_sock(sk); 335 return 0; 336 337 out_unlock_rcu: 338 rcu_read_unlock(); 339 out_unlock: 340 release_sock(sk); 341 return err; 342 343 out_in_use: 344 read_unlock_bh(&l2tp_ip6_lock); 345 return err; 346 } 347 348 static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, 349 int addr_len) 350 { 351 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr; 352 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; 353 struct in6_addr *daddr; 354 int addr_type; 355 int rc; 356 357 if (addr_len < sizeof(*lsa)) 358 return -EINVAL; 359 360 addr_type = ipv6_addr_type(&usin->sin6_addr); 361 if (addr_type & IPV6_ADDR_MULTICAST) 362 return -EINVAL; 363 364 if (addr_type & IPV6_ADDR_MAPPED) { 365 daddr = &usin->sin6_addr; 366 if (ipv4_is_multicast(daddr->s6_addr32[3])) 367 return -EINVAL; 368 } 369 370 rc = ip6_datagram_connect(sk, uaddr, addr_len); 371 372 lock_sock(sk); 373 374 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; 375 376 write_lock_bh(&l2tp_ip6_lock); 377 hlist_del_init(&sk->sk_bind_node); 378 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 379 write_unlock_bh(&l2tp_ip6_lock); 380 381 release_sock(sk); 382 383 return rc; 384 } 385 386 static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, 387 int *uaddr_len, int peer) 388 { 389 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; 390 struct sock *sk = sock->sk; 391 struct ipv6_pinfo *np = inet6_sk(sk); 392 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); 393 394 lsa->l2tp_family = AF_INET6; 395 lsa->l2tp_flowinfo = 0; 396 lsa->l2tp_scope_id = 0; 397 if (peer) { 398 if (!lsk->peer_conn_id) 399 return -ENOTCONN; 400 lsa->l2tp_conn_id = lsk->peer_conn_id; 401 lsa->l2tp_addr = np->daddr; 402 if (np->sndflow) 403 lsa->l2tp_flowinfo = np->flow_label; 404 } else { 405 if (ipv6_addr_any(&np->rcv_saddr)) 406 lsa->l2tp_addr = np->saddr; 407 else 408 lsa->l2tp_addr = np->rcv_saddr; 409 410 lsa->l2tp_conn_id = lsk->conn_id; 411 } 412 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 413 lsa->l2tp_scope_id = sk->sk_bound_dev_if; 414 *uaddr_len = sizeof(*lsa); 415 return 0; 416 } 417 418 static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) 419 { 420 int rc; 421 422 /* Charge it to the socket, dropping if the queue is full. */ 423 rc = sock_queue_rcv_skb(sk, skb); 424 if (rc < 0) 425 goto drop; 426 427 return 0; 428 429 drop: 430 IP_INC_STATS(&init_net, IPSTATS_MIB_INDISCARDS); 431 kfree_skb(skb); 432 return -1; 433 } 434 435 static int l2tp_ip6_push_pending_frames(struct sock *sk) 436 { 437 struct sk_buff *skb; 438 __be32 *transhdr = NULL; 439 int err = 0; 440 441 skb = skb_peek(&sk->sk_write_queue); 442 if (skb == NULL) 443 goto out; 444 445 transhdr = (__be32 *)skb_transport_header(skb); 446 *transhdr = 0; 447 448 err = ip6_push_pending_frames(sk); 449 450 out: 451 return err; 452 } 453 454 /* Userspace will call sendmsg() on the tunnel socket to send L2TP 455 * control frames. 456 */ 457 static int l2tp_ip6_sendmsg(struct kiocb *iocb, struct sock *sk, 458 struct msghdr *msg, size_t len) 459 { 460 struct ipv6_txoptions opt_space; 461 struct sockaddr_l2tpip6 *lsa = 462 (struct sockaddr_l2tpip6 *) msg->msg_name; 463 struct in6_addr *daddr, *final_p, final; 464 struct ipv6_pinfo *np = inet6_sk(sk); 465 struct ipv6_txoptions *opt = NULL; 466 struct ip6_flowlabel *flowlabel = NULL; 467 struct dst_entry *dst = NULL; 468 struct flowi6 fl6; 469 int addr_len = msg->msg_namelen; 470 int hlimit = -1; 471 int tclass = -1; 472 int dontfrag = -1; 473 int transhdrlen = 4; /* zero session-id */ 474 int ulen = len + transhdrlen; 475 int err; 476 477 /* Rough check on arithmetic overflow, 478 better check is made in ip6_append_data(). 479 */ 480 if (len > INT_MAX) 481 return -EMSGSIZE; 482 483 /* Mirror BSD error message compatibility */ 484 if (msg->msg_flags & MSG_OOB) 485 return -EOPNOTSUPP; 486 487 /* 488 * Get and verify the address. 489 */ 490 memset(&fl6, 0, sizeof(fl6)); 491 492 fl6.flowi6_mark = sk->sk_mark; 493 494 if (lsa) { 495 if (addr_len < SIN6_LEN_RFC2133) 496 return -EINVAL; 497 498 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) 499 return -EAFNOSUPPORT; 500 501 daddr = &lsa->l2tp_addr; 502 if (np->sndflow) { 503 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; 504 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 505 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 506 if (flowlabel == NULL) 507 return -EINVAL; 508 daddr = &flowlabel->dst; 509 } 510 } 511 512 /* 513 * Otherwise it will be difficult to maintain 514 * sk->sk_dst_cache. 515 */ 516 if (sk->sk_state == TCP_ESTABLISHED && 517 ipv6_addr_equal(daddr, &np->daddr)) 518 daddr = &np->daddr; 519 520 if (addr_len >= sizeof(struct sockaddr_in6) && 521 lsa->l2tp_scope_id && 522 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) 523 fl6.flowi6_oif = lsa->l2tp_scope_id; 524 } else { 525 if (sk->sk_state != TCP_ESTABLISHED) 526 return -EDESTADDRREQ; 527 528 daddr = &np->daddr; 529 fl6.flowlabel = np->flow_label; 530 } 531 532 if (fl6.flowi6_oif == 0) 533 fl6.flowi6_oif = sk->sk_bound_dev_if; 534 535 if (msg->msg_controllen) { 536 opt = &opt_space; 537 memset(opt, 0, sizeof(struct ipv6_txoptions)); 538 opt->tot_len = sizeof(struct ipv6_txoptions); 539 540 err = datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt, 541 &hlimit, &tclass, &dontfrag); 542 if (err < 0) { 543 fl6_sock_release(flowlabel); 544 return err; 545 } 546 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { 547 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 548 if (flowlabel == NULL) 549 return -EINVAL; 550 } 551 if (!(opt->opt_nflen|opt->opt_flen)) 552 opt = NULL; 553 } 554 555 if (opt == NULL) 556 opt = np->opt; 557 if (flowlabel) 558 opt = fl6_merge_options(&opt_space, flowlabel, opt); 559 opt = ipv6_fixup_options(&opt_space, opt); 560 561 fl6.flowi6_proto = sk->sk_protocol; 562 if (!ipv6_addr_any(daddr)) 563 fl6.daddr = *daddr; 564 else 565 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 566 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 567 fl6.saddr = np->saddr; 568 569 final_p = fl6_update_dst(&fl6, opt, &final); 570 571 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 572 fl6.flowi6_oif = np->mcast_oif; 573 else if (!fl6.flowi6_oif) 574 fl6.flowi6_oif = np->ucast_oif; 575 576 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 577 578 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true); 579 if (IS_ERR(dst)) { 580 err = PTR_ERR(dst); 581 goto out; 582 } 583 584 if (hlimit < 0) { 585 if (ipv6_addr_is_multicast(&fl6.daddr)) 586 hlimit = np->mcast_hops; 587 else 588 hlimit = np->hop_limit; 589 if (hlimit < 0) 590 hlimit = ip6_dst_hoplimit(dst); 591 } 592 593 if (tclass < 0) 594 tclass = np->tclass; 595 596 if (dontfrag < 0) 597 dontfrag = np->dontfrag; 598 599 if (msg->msg_flags & MSG_CONFIRM) 600 goto do_confirm; 601 602 back_from_confirm: 603 lock_sock(sk); 604 err = ip6_append_data(sk, ip_generic_getfrag, msg->msg_iov, 605 ulen, transhdrlen, hlimit, tclass, opt, 606 &fl6, (struct rt6_info *)dst, 607 msg->msg_flags, dontfrag); 608 if (err) 609 ip6_flush_pending_frames(sk); 610 else if (!(msg->msg_flags & MSG_MORE)) 611 err = l2tp_ip6_push_pending_frames(sk); 612 release_sock(sk); 613 done: 614 dst_release(dst); 615 out: 616 fl6_sock_release(flowlabel); 617 618 return err < 0 ? err : len; 619 620 do_confirm: 621 dst_confirm(dst); 622 if (!(msg->msg_flags & MSG_PROBE) || len) 623 goto back_from_confirm; 624 err = 0; 625 goto done; 626 } 627 628 static int l2tp_ip6_recvmsg(struct kiocb *iocb, struct sock *sk, 629 struct msghdr *msg, size_t len, int noblock, 630 int flags, int *addr_len) 631 { 632 struct inet_sock *inet = inet_sk(sk); 633 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)msg->msg_name; 634 size_t copied = 0; 635 int err = -EOPNOTSUPP; 636 struct sk_buff *skb; 637 638 if (flags & MSG_OOB) 639 goto out; 640 641 if (addr_len) 642 *addr_len = sizeof(*lsa); 643 644 if (flags & MSG_ERRQUEUE) 645 return ipv6_recv_error(sk, msg, len); 646 647 skb = skb_recv_datagram(sk, flags, noblock, &err); 648 if (!skb) 649 goto out; 650 651 copied = skb->len; 652 if (len < copied) { 653 msg->msg_flags |= MSG_TRUNC; 654 copied = len; 655 } 656 657 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 658 if (err) 659 goto done; 660 661 sock_recv_timestamp(msg, sk, skb); 662 663 /* Copy the address. */ 664 if (lsa) { 665 lsa->l2tp_family = AF_INET6; 666 lsa->l2tp_unused = 0; 667 lsa->l2tp_addr = ipv6_hdr(skb)->saddr; 668 lsa->l2tp_flowinfo = 0; 669 lsa->l2tp_scope_id = 0; 670 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 671 lsa->l2tp_scope_id = IP6CB(skb)->iif; 672 } 673 674 if (inet->cmsg_flags) 675 ip_cmsg_recv(msg, skb); 676 677 if (flags & MSG_TRUNC) 678 copied = skb->len; 679 done: 680 skb_free_datagram(sk, skb); 681 out: 682 return err ? err : copied; 683 } 684 685 static struct proto l2tp_ip6_prot = { 686 .name = "L2TP/IPv6", 687 .owner = THIS_MODULE, 688 .init = l2tp_ip6_open, 689 .close = l2tp_ip6_close, 690 .bind = l2tp_ip6_bind, 691 .connect = l2tp_ip6_connect, 692 .disconnect = udp_disconnect, 693 .ioctl = udp_ioctl, 694 .destroy = l2tp_ip6_destroy_sock, 695 .setsockopt = ipv6_setsockopt, 696 .getsockopt = ipv6_getsockopt, 697 .sendmsg = l2tp_ip6_sendmsg, 698 .recvmsg = l2tp_ip6_recvmsg, 699 .backlog_rcv = l2tp_ip6_backlog_recv, 700 .hash = inet_hash, 701 .unhash = inet_unhash, 702 .obj_size = sizeof(struct l2tp_ip6_sock), 703 #ifdef CONFIG_COMPAT 704 .compat_setsockopt = compat_ipv6_setsockopt, 705 .compat_getsockopt = compat_ipv6_getsockopt, 706 #endif 707 }; 708 709 static const struct proto_ops l2tp_ip6_ops = { 710 .family = PF_INET6, 711 .owner = THIS_MODULE, 712 .release = inet6_release, 713 .bind = inet6_bind, 714 .connect = inet_dgram_connect, 715 .socketpair = sock_no_socketpair, 716 .accept = sock_no_accept, 717 .getname = l2tp_ip6_getname, 718 .poll = datagram_poll, 719 .ioctl = inet6_ioctl, 720 .listen = sock_no_listen, 721 .shutdown = inet_shutdown, 722 .setsockopt = sock_common_setsockopt, 723 .getsockopt = sock_common_getsockopt, 724 .sendmsg = inet_sendmsg, 725 .recvmsg = sock_common_recvmsg, 726 .mmap = sock_no_mmap, 727 .sendpage = sock_no_sendpage, 728 #ifdef CONFIG_COMPAT 729 .compat_setsockopt = compat_sock_common_setsockopt, 730 .compat_getsockopt = compat_sock_common_getsockopt, 731 #endif 732 }; 733 734 static struct inet_protosw l2tp_ip6_protosw = { 735 .type = SOCK_DGRAM, 736 .protocol = IPPROTO_L2TP, 737 .prot = &l2tp_ip6_prot, 738 .ops = &l2tp_ip6_ops, 739 .no_check = 0, 740 }; 741 742 static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { 743 .handler = l2tp_ip6_recv, 744 }; 745 746 static int __init l2tp_ip6_init(void) 747 { 748 int err; 749 750 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); 751 752 err = proto_register(&l2tp_ip6_prot, 1); 753 if (err != 0) 754 goto out; 755 756 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 757 if (err) 758 goto out1; 759 760 inet6_register_protosw(&l2tp_ip6_protosw); 761 return 0; 762 763 out1: 764 proto_unregister(&l2tp_ip6_prot); 765 out: 766 return err; 767 } 768 769 static void __exit l2tp_ip6_exit(void) 770 { 771 inet6_unregister_protosw(&l2tp_ip6_protosw); 772 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 773 proto_unregister(&l2tp_ip6_prot); 774 } 775 776 module_init(l2tp_ip6_init); 777 module_exit(l2tp_ip6_exit); 778 779 MODULE_LICENSE("GPL"); 780 MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); 781 MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); 782 MODULE_VERSION("1.0"); 783 784 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like 785 * enums 786 */ 787 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); 788