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 (!sock_flag(sk, SOCK_ZAPPED)) 262 return -EINVAL; 263 if (addr->l2tp_family != AF_INET6) 264 return -EINVAL; 265 if (addr_len < sizeof(*addr)) 266 return -EINVAL; 267 268 addr_type = ipv6_addr_type(&addr->l2tp_addr); 269 270 /* l2tp_ip6 sockets are IPv6 only */ 271 if (addr_type == IPV6_ADDR_MAPPED) 272 return -EADDRNOTAVAIL; 273 274 /* L2TP is point-point, not multicast */ 275 if (addr_type & IPV6_ADDR_MULTICAST) 276 return -EADDRNOTAVAIL; 277 278 err = -EADDRINUSE; 279 read_lock_bh(&l2tp_ip6_lock); 280 if (__l2tp_ip6_bind_lookup(&init_net, &addr->l2tp_addr, 281 sk->sk_bound_dev_if, addr->l2tp_conn_id)) 282 goto out_in_use; 283 read_unlock_bh(&l2tp_ip6_lock); 284 285 lock_sock(sk); 286 287 err = -EINVAL; 288 if (sk->sk_state != TCP_CLOSE) 289 goto out_unlock; 290 291 /* Check if the address belongs to the host. */ 292 rcu_read_lock(); 293 if (addr_type != IPV6_ADDR_ANY) { 294 struct net_device *dev = NULL; 295 296 if (addr_type & IPV6_ADDR_LINKLOCAL) { 297 if (addr_len >= sizeof(struct sockaddr_in6) && 298 addr->l2tp_scope_id) { 299 /* Override any existing binding, if another 300 * one is supplied by user. 301 */ 302 sk->sk_bound_dev_if = addr->l2tp_scope_id; 303 } 304 305 /* Binding to link-local address requires an 306 interface */ 307 if (!sk->sk_bound_dev_if) 308 goto out_unlock_rcu; 309 310 err = -ENODEV; 311 dev = dev_get_by_index_rcu(sock_net(sk), 312 sk->sk_bound_dev_if); 313 if (!dev) 314 goto out_unlock_rcu; 315 } 316 317 /* ipv4 addr of the socket is invalid. Only the 318 * unspecified and mapped address have a v4 equivalent. 319 */ 320 v4addr = LOOPBACK4_IPV6; 321 err = -EADDRNOTAVAIL; 322 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) 323 goto out_unlock_rcu; 324 } 325 rcu_read_unlock(); 326 327 inet->inet_rcv_saddr = inet->inet_saddr = v4addr; 328 np->rcv_saddr = addr->l2tp_addr; 329 np->saddr = addr->l2tp_addr; 330 331 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; 332 333 write_lock_bh(&l2tp_ip6_lock); 334 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 335 sk_del_node_init(sk); 336 write_unlock_bh(&l2tp_ip6_lock); 337 338 sock_reset_flag(sk, SOCK_ZAPPED); 339 release_sock(sk); 340 return 0; 341 342 out_unlock_rcu: 343 rcu_read_unlock(); 344 out_unlock: 345 release_sock(sk); 346 return err; 347 348 out_in_use: 349 read_unlock_bh(&l2tp_ip6_lock); 350 return err; 351 } 352 353 static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, 354 int addr_len) 355 { 356 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr; 357 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; 358 struct in6_addr *daddr; 359 int addr_type; 360 int rc; 361 362 if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */ 363 return -EINVAL; 364 365 if (addr_len < sizeof(*lsa)) 366 return -EINVAL; 367 368 addr_type = ipv6_addr_type(&usin->sin6_addr); 369 if (addr_type & IPV6_ADDR_MULTICAST) 370 return -EINVAL; 371 372 if (addr_type & IPV6_ADDR_MAPPED) { 373 daddr = &usin->sin6_addr; 374 if (ipv4_is_multicast(daddr->s6_addr32[3])) 375 return -EINVAL; 376 } 377 378 rc = ip6_datagram_connect(sk, uaddr, addr_len); 379 380 lock_sock(sk); 381 382 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; 383 384 write_lock_bh(&l2tp_ip6_lock); 385 hlist_del_init(&sk->sk_bind_node); 386 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 387 write_unlock_bh(&l2tp_ip6_lock); 388 389 release_sock(sk); 390 391 return rc; 392 } 393 394 static int l2tp_ip6_disconnect(struct sock *sk, int flags) 395 { 396 if (sock_flag(sk, SOCK_ZAPPED)) 397 return 0; 398 399 return udp_disconnect(sk, flags); 400 } 401 402 static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, 403 int *uaddr_len, int peer) 404 { 405 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; 406 struct sock *sk = sock->sk; 407 struct ipv6_pinfo *np = inet6_sk(sk); 408 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); 409 410 lsa->l2tp_family = AF_INET6; 411 lsa->l2tp_flowinfo = 0; 412 lsa->l2tp_scope_id = 0; 413 lsa->l2tp_unused = 0; 414 if (peer) { 415 if (!lsk->peer_conn_id) 416 return -ENOTCONN; 417 lsa->l2tp_conn_id = lsk->peer_conn_id; 418 lsa->l2tp_addr = np->daddr; 419 if (np->sndflow) 420 lsa->l2tp_flowinfo = np->flow_label; 421 } else { 422 if (ipv6_addr_any(&np->rcv_saddr)) 423 lsa->l2tp_addr = np->saddr; 424 else 425 lsa->l2tp_addr = np->rcv_saddr; 426 427 lsa->l2tp_conn_id = lsk->conn_id; 428 } 429 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 430 lsa->l2tp_scope_id = sk->sk_bound_dev_if; 431 *uaddr_len = sizeof(*lsa); 432 return 0; 433 } 434 435 static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) 436 { 437 int rc; 438 439 /* Charge it to the socket, dropping if the queue is full. */ 440 rc = sock_queue_rcv_skb(sk, skb); 441 if (rc < 0) 442 goto drop; 443 444 return 0; 445 446 drop: 447 IP_INC_STATS(&init_net, IPSTATS_MIB_INDISCARDS); 448 kfree_skb(skb); 449 return -1; 450 } 451 452 static int l2tp_ip6_push_pending_frames(struct sock *sk) 453 { 454 struct sk_buff *skb; 455 __be32 *transhdr = NULL; 456 int err = 0; 457 458 skb = skb_peek(&sk->sk_write_queue); 459 if (skb == NULL) 460 goto out; 461 462 transhdr = (__be32 *)skb_transport_header(skb); 463 *transhdr = 0; 464 465 err = ip6_push_pending_frames(sk); 466 467 out: 468 return err; 469 } 470 471 /* Userspace will call sendmsg() on the tunnel socket to send L2TP 472 * control frames. 473 */ 474 static int l2tp_ip6_sendmsg(struct kiocb *iocb, struct sock *sk, 475 struct msghdr *msg, size_t len) 476 { 477 struct ipv6_txoptions opt_space; 478 struct sockaddr_l2tpip6 *lsa = 479 (struct sockaddr_l2tpip6 *) msg->msg_name; 480 struct in6_addr *daddr, *final_p, final; 481 struct ipv6_pinfo *np = inet6_sk(sk); 482 struct ipv6_txoptions *opt = NULL; 483 struct ip6_flowlabel *flowlabel = NULL; 484 struct dst_entry *dst = NULL; 485 struct flowi6 fl6; 486 int addr_len = msg->msg_namelen; 487 int hlimit = -1; 488 int tclass = -1; 489 int dontfrag = -1; 490 int transhdrlen = 4; /* zero session-id */ 491 int ulen = len + transhdrlen; 492 int err; 493 494 /* Rough check on arithmetic overflow, 495 better check is made in ip6_append_data(). 496 */ 497 if (len > INT_MAX) 498 return -EMSGSIZE; 499 500 /* Mirror BSD error message compatibility */ 501 if (msg->msg_flags & MSG_OOB) 502 return -EOPNOTSUPP; 503 504 /* 505 * Get and verify the address. 506 */ 507 memset(&fl6, 0, sizeof(fl6)); 508 509 fl6.flowi6_mark = sk->sk_mark; 510 511 if (lsa) { 512 if (addr_len < SIN6_LEN_RFC2133) 513 return -EINVAL; 514 515 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) 516 return -EAFNOSUPPORT; 517 518 daddr = &lsa->l2tp_addr; 519 if (np->sndflow) { 520 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; 521 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 522 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 523 if (flowlabel == NULL) 524 return -EINVAL; 525 daddr = &flowlabel->dst; 526 } 527 } 528 529 /* 530 * Otherwise it will be difficult to maintain 531 * sk->sk_dst_cache. 532 */ 533 if (sk->sk_state == TCP_ESTABLISHED && 534 ipv6_addr_equal(daddr, &np->daddr)) 535 daddr = &np->daddr; 536 537 if (addr_len >= sizeof(struct sockaddr_in6) && 538 lsa->l2tp_scope_id && 539 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) 540 fl6.flowi6_oif = lsa->l2tp_scope_id; 541 } else { 542 if (sk->sk_state != TCP_ESTABLISHED) 543 return -EDESTADDRREQ; 544 545 daddr = &np->daddr; 546 fl6.flowlabel = np->flow_label; 547 } 548 549 if (fl6.flowi6_oif == 0) 550 fl6.flowi6_oif = sk->sk_bound_dev_if; 551 552 if (msg->msg_controllen) { 553 opt = &opt_space; 554 memset(opt, 0, sizeof(struct ipv6_txoptions)); 555 opt->tot_len = sizeof(struct ipv6_txoptions); 556 557 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt, 558 &hlimit, &tclass, &dontfrag); 559 if (err < 0) { 560 fl6_sock_release(flowlabel); 561 return err; 562 } 563 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { 564 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 565 if (flowlabel == NULL) 566 return -EINVAL; 567 } 568 if (!(opt->opt_nflen|opt->opt_flen)) 569 opt = NULL; 570 } 571 572 if (opt == NULL) 573 opt = np->opt; 574 if (flowlabel) 575 opt = fl6_merge_options(&opt_space, flowlabel, opt); 576 opt = ipv6_fixup_options(&opt_space, opt); 577 578 fl6.flowi6_proto = sk->sk_protocol; 579 if (!ipv6_addr_any(daddr)) 580 fl6.daddr = *daddr; 581 else 582 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 583 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 584 fl6.saddr = np->saddr; 585 586 final_p = fl6_update_dst(&fl6, opt, &final); 587 588 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 589 fl6.flowi6_oif = np->mcast_oif; 590 else if (!fl6.flowi6_oif) 591 fl6.flowi6_oif = np->ucast_oif; 592 593 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 594 595 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true); 596 if (IS_ERR(dst)) { 597 err = PTR_ERR(dst); 598 goto out; 599 } 600 601 if (hlimit < 0) { 602 if (ipv6_addr_is_multicast(&fl6.daddr)) 603 hlimit = np->mcast_hops; 604 else 605 hlimit = np->hop_limit; 606 if (hlimit < 0) 607 hlimit = ip6_dst_hoplimit(dst); 608 } 609 610 if (tclass < 0) 611 tclass = np->tclass; 612 613 if (dontfrag < 0) 614 dontfrag = np->dontfrag; 615 616 if (msg->msg_flags & MSG_CONFIRM) 617 goto do_confirm; 618 619 back_from_confirm: 620 lock_sock(sk); 621 err = ip6_append_data(sk, ip_generic_getfrag, msg->msg_iov, 622 ulen, transhdrlen, hlimit, tclass, opt, 623 &fl6, (struct rt6_info *)dst, 624 msg->msg_flags, dontfrag); 625 if (err) 626 ip6_flush_pending_frames(sk); 627 else if (!(msg->msg_flags & MSG_MORE)) 628 err = l2tp_ip6_push_pending_frames(sk); 629 release_sock(sk); 630 done: 631 dst_release(dst); 632 out: 633 fl6_sock_release(flowlabel); 634 635 return err < 0 ? err : len; 636 637 do_confirm: 638 dst_confirm(dst); 639 if (!(msg->msg_flags & MSG_PROBE) || len) 640 goto back_from_confirm; 641 err = 0; 642 goto done; 643 } 644 645 static int l2tp_ip6_recvmsg(struct kiocb *iocb, struct sock *sk, 646 struct msghdr *msg, size_t len, int noblock, 647 int flags, int *addr_len) 648 { 649 struct ipv6_pinfo *np = inet6_sk(sk); 650 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)msg->msg_name; 651 size_t copied = 0; 652 int err = -EOPNOTSUPP; 653 struct sk_buff *skb; 654 655 if (flags & MSG_OOB) 656 goto out; 657 658 if (addr_len) 659 *addr_len = sizeof(*lsa); 660 661 if (flags & MSG_ERRQUEUE) 662 return ipv6_recv_error(sk, msg, len); 663 664 skb = skb_recv_datagram(sk, flags, noblock, &err); 665 if (!skb) 666 goto out; 667 668 copied = skb->len; 669 if (len < copied) { 670 msg->msg_flags |= MSG_TRUNC; 671 copied = len; 672 } 673 674 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 675 if (err) 676 goto done; 677 678 sock_recv_timestamp(msg, sk, skb); 679 680 /* Copy the address. */ 681 if (lsa) { 682 lsa->l2tp_family = AF_INET6; 683 lsa->l2tp_unused = 0; 684 lsa->l2tp_addr = ipv6_hdr(skb)->saddr; 685 lsa->l2tp_flowinfo = 0; 686 lsa->l2tp_scope_id = 0; 687 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 688 lsa->l2tp_scope_id = IP6CB(skb)->iif; 689 } 690 691 if (np->rxopt.all) 692 ip6_datagram_recv_ctl(sk, msg, skb); 693 694 if (flags & MSG_TRUNC) 695 copied = skb->len; 696 done: 697 skb_free_datagram(sk, skb); 698 out: 699 return err ? err : copied; 700 } 701 702 static struct proto l2tp_ip6_prot = { 703 .name = "L2TP/IPv6", 704 .owner = THIS_MODULE, 705 .init = l2tp_ip6_open, 706 .close = l2tp_ip6_close, 707 .bind = l2tp_ip6_bind, 708 .connect = l2tp_ip6_connect, 709 .disconnect = l2tp_ip6_disconnect, 710 .ioctl = udp_ioctl, 711 .destroy = l2tp_ip6_destroy_sock, 712 .setsockopt = ipv6_setsockopt, 713 .getsockopt = ipv6_getsockopt, 714 .sendmsg = l2tp_ip6_sendmsg, 715 .recvmsg = l2tp_ip6_recvmsg, 716 .backlog_rcv = l2tp_ip6_backlog_recv, 717 .hash = inet_hash, 718 .unhash = inet_unhash, 719 .obj_size = sizeof(struct l2tp_ip6_sock), 720 #ifdef CONFIG_COMPAT 721 .compat_setsockopt = compat_ipv6_setsockopt, 722 .compat_getsockopt = compat_ipv6_getsockopt, 723 #endif 724 }; 725 726 static const struct proto_ops l2tp_ip6_ops = { 727 .family = PF_INET6, 728 .owner = THIS_MODULE, 729 .release = inet6_release, 730 .bind = inet6_bind, 731 .connect = inet_dgram_connect, 732 .socketpair = sock_no_socketpair, 733 .accept = sock_no_accept, 734 .getname = l2tp_ip6_getname, 735 .poll = datagram_poll, 736 .ioctl = inet6_ioctl, 737 .listen = sock_no_listen, 738 .shutdown = inet_shutdown, 739 .setsockopt = sock_common_setsockopt, 740 .getsockopt = sock_common_getsockopt, 741 .sendmsg = inet_sendmsg, 742 .recvmsg = sock_common_recvmsg, 743 .mmap = sock_no_mmap, 744 .sendpage = sock_no_sendpage, 745 #ifdef CONFIG_COMPAT 746 .compat_setsockopt = compat_sock_common_setsockopt, 747 .compat_getsockopt = compat_sock_common_getsockopt, 748 #endif 749 }; 750 751 static struct inet_protosw l2tp_ip6_protosw = { 752 .type = SOCK_DGRAM, 753 .protocol = IPPROTO_L2TP, 754 .prot = &l2tp_ip6_prot, 755 .ops = &l2tp_ip6_ops, 756 .no_check = 0, 757 }; 758 759 static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { 760 .handler = l2tp_ip6_recv, 761 }; 762 763 static int __init l2tp_ip6_init(void) 764 { 765 int err; 766 767 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); 768 769 err = proto_register(&l2tp_ip6_prot, 1); 770 if (err != 0) 771 goto out; 772 773 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 774 if (err) 775 goto out1; 776 777 inet6_register_protosw(&l2tp_ip6_protosw); 778 return 0; 779 780 out1: 781 proto_unregister(&l2tp_ip6_prot); 782 out: 783 return err; 784 } 785 786 static void __exit l2tp_ip6_exit(void) 787 { 788 inet6_unregister_protosw(&l2tp_ip6_protosw); 789 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 790 proto_unregister(&l2tp_ip6_prot); 791 } 792 793 module_init(l2tp_ip6_init); 794 module_exit(l2tp_ip6_exit); 795 796 MODULE_LICENSE("GPL"); 797 MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); 798 MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); 799 MODULE_VERSION("1.0"); 800 801 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like 802 * enums 803 */ 804 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); 805