1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* L2TPv3 IP encapsulation support for IPv6 3 * 4 * Copyright (c) 2012 Katalix Systems Ltd 5 */ 6 7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 8 9 #include <linux/icmp.h> 10 #include <linux/module.h> 11 #include <linux/skbuff.h> 12 #include <linux/random.h> 13 #include <linux/socket.h> 14 #include <linux/l2tp.h> 15 #include <linux/in.h> 16 #include <linux/in6.h> 17 #include <net/sock.h> 18 #include <net/ip.h> 19 #include <net/icmp.h> 20 #include <net/udp.h> 21 #include <net/inet_common.h> 22 #include <net/tcp_states.h> 23 #include <net/protocol.h> 24 #include <net/xfrm.h> 25 26 #include <net/transp_v6.h> 27 #include <net/addrconf.h> 28 #include <net/ip6_route.h> 29 30 #include "l2tp_core.h" 31 32 struct l2tp_ip6_sock { 33 /* inet_sock has to be the first member of l2tp_ip6_sock */ 34 struct inet_sock inet; 35 36 u32 conn_id; 37 u32 peer_conn_id; 38 39 /* ipv6_pinfo has to be the last member of l2tp_ip6_sock, see 40 * inet6_sk_generic 41 */ 42 struct ipv6_pinfo inet6; 43 }; 44 45 static DEFINE_RWLOCK(l2tp_ip6_lock); 46 static struct hlist_head l2tp_ip6_table; 47 static struct hlist_head l2tp_ip6_bind_table; 48 49 static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk) 50 { 51 return (struct l2tp_ip6_sock *)sk; 52 } 53 54 static struct sock *__l2tp_ip6_bind_lookup(const struct net *net, 55 const struct in6_addr *laddr, 56 const struct in6_addr *raddr, 57 int dif, u32 tunnel_id) 58 { 59 struct sock *sk; 60 61 sk_for_each_bound(sk, &l2tp_ip6_bind_table) { 62 const struct in6_addr *sk_laddr = inet6_rcv_saddr(sk); 63 const struct in6_addr *sk_raddr = &sk->sk_v6_daddr; 64 const struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk); 65 66 if (!net_eq(sock_net(sk), net)) 67 continue; 68 69 if (sk->sk_bound_dev_if && dif && sk->sk_bound_dev_if != dif) 70 continue; 71 72 if (sk_laddr && !ipv6_addr_any(sk_laddr) && 73 !ipv6_addr_any(laddr) && !ipv6_addr_equal(sk_laddr, laddr)) 74 continue; 75 76 if (!ipv6_addr_any(sk_raddr) && raddr && 77 !ipv6_addr_any(raddr) && !ipv6_addr_equal(sk_raddr, raddr)) 78 continue; 79 80 if (l2tp->conn_id != tunnel_id) 81 continue; 82 83 goto found; 84 } 85 86 sk = NULL; 87 found: 88 return sk; 89 } 90 91 /* When processing receive frames, there are two cases to 92 * consider. Data frames consist of a non-zero session-id and an 93 * optional cookie. Control frames consist of a regular L2TP header 94 * preceded by 32-bits of zeros. 95 * 96 * L2TPv3 Session Header Over IP 97 * 98 * 0 1 2 3 99 * 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 1 100 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 101 * | Session ID | 102 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 103 * | Cookie (optional, maximum 64 bits)... 104 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 105 * | 106 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 107 * 108 * L2TPv3 Control Message Header Over IP 109 * 110 * 0 1 2 3 111 * 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 1 112 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 113 * | (32 bits of zeros) | 114 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 115 * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length | 116 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 117 * | Control Connection ID | 118 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 119 * | Ns | Nr | 120 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 121 * 122 * All control frames are passed to userspace. 123 */ 124 static int l2tp_ip6_recv(struct sk_buff *skb) 125 { 126 struct net *net = dev_net(skb->dev); 127 struct sock *sk; 128 u32 session_id; 129 u32 tunnel_id; 130 unsigned char *ptr, *optr; 131 struct l2tp_session *session; 132 struct l2tp_tunnel *tunnel = NULL; 133 struct ipv6hdr *iph; 134 int length; 135 136 if (!pskb_may_pull(skb, 4)) 137 goto discard; 138 139 /* Point to L2TP header */ 140 optr = skb->data; 141 ptr = skb->data; 142 session_id = ntohl(*((__be32 *)ptr)); 143 ptr += 4; 144 145 /* RFC3931: L2TP/IP packets have the first 4 bytes containing 146 * the session_id. If it is 0, the packet is a L2TP control 147 * frame and the session_id value can be discarded. 148 */ 149 if (session_id == 0) { 150 __skb_pull(skb, 4); 151 goto pass_up; 152 } 153 154 /* Ok, this is a data packet. Lookup the session. */ 155 session = l2tp_session_get(net, session_id); 156 if (!session) 157 goto discard; 158 159 tunnel = session->tunnel; 160 if (!tunnel) 161 goto discard_sess; 162 163 /* Trace packet contents, if enabled */ 164 if (tunnel->debug & L2TP_MSG_DATA) { 165 length = min(32u, skb->len); 166 if (!pskb_may_pull(skb, length)) 167 goto discard_sess; 168 169 /* Point to L2TP header */ 170 optr = skb->data; 171 ptr = skb->data; 172 ptr += 4; 173 pr_debug("%s: ip recv\n", tunnel->name); 174 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); 175 } 176 177 if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) 178 goto discard_sess; 179 180 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len); 181 l2tp_session_dec_refcount(session); 182 183 return 0; 184 185 pass_up: 186 /* Get the tunnel_id from the L2TP header */ 187 if (!pskb_may_pull(skb, 12)) 188 goto discard; 189 190 if ((skb->data[0] & 0xc0) != 0xc0) 191 goto discard; 192 193 tunnel_id = ntohl(*(__be32 *)&skb->data[4]); 194 iph = ipv6_hdr(skb); 195 196 read_lock_bh(&l2tp_ip6_lock); 197 sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr, 198 inet6_iif(skb), tunnel_id); 199 if (!sk) { 200 read_unlock_bh(&l2tp_ip6_lock); 201 goto discard; 202 } 203 sock_hold(sk); 204 read_unlock_bh(&l2tp_ip6_lock); 205 206 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 207 goto discard_put; 208 209 nf_reset_ct(skb); 210 211 return sk_receive_skb(sk, skb, 1); 212 213 discard_sess: 214 l2tp_session_dec_refcount(session); 215 goto discard; 216 217 discard_put: 218 sock_put(sk); 219 220 discard: 221 kfree_skb(skb); 222 return 0; 223 } 224 225 static int l2tp_ip6_hash(struct sock *sk) 226 { 227 if (sk_unhashed(sk)) { 228 write_lock_bh(&l2tp_ip6_lock); 229 sk_add_node(sk, &l2tp_ip6_table); 230 write_unlock_bh(&l2tp_ip6_lock); 231 } 232 return 0; 233 } 234 235 static void l2tp_ip6_unhash(struct sock *sk) 236 { 237 if (sk_unhashed(sk)) 238 return; 239 write_lock_bh(&l2tp_ip6_lock); 240 sk_del_node_init(sk); 241 write_unlock_bh(&l2tp_ip6_lock); 242 } 243 244 static int l2tp_ip6_open(struct sock *sk) 245 { 246 /* Prevent autobind. We don't have ports. */ 247 inet_sk(sk)->inet_num = IPPROTO_L2TP; 248 249 l2tp_ip6_hash(sk); 250 return 0; 251 } 252 253 static void l2tp_ip6_close(struct sock *sk, long timeout) 254 { 255 write_lock_bh(&l2tp_ip6_lock); 256 hlist_del_init(&sk->sk_bind_node); 257 sk_del_node_init(sk); 258 write_unlock_bh(&l2tp_ip6_lock); 259 260 sk_common_release(sk); 261 } 262 263 static void l2tp_ip6_destroy_sock(struct sock *sk) 264 { 265 struct l2tp_tunnel *tunnel = sk->sk_user_data; 266 267 lock_sock(sk); 268 ip6_flush_pending_frames(sk); 269 release_sock(sk); 270 271 if (tunnel) 272 l2tp_tunnel_delete(tunnel); 273 274 inet6_destroy_sock(sk); 275 } 276 277 static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 278 { 279 struct inet_sock *inet = inet_sk(sk); 280 struct ipv6_pinfo *np = inet6_sk(sk); 281 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *)uaddr; 282 struct net *net = sock_net(sk); 283 __be32 v4addr = 0; 284 int bound_dev_if; 285 int addr_type; 286 int err; 287 288 if (addr->l2tp_family != AF_INET6) 289 return -EINVAL; 290 if (addr_len < sizeof(*addr)) 291 return -EINVAL; 292 293 addr_type = ipv6_addr_type(&addr->l2tp_addr); 294 295 /* l2tp_ip6 sockets are IPv6 only */ 296 if (addr_type == IPV6_ADDR_MAPPED) 297 return -EADDRNOTAVAIL; 298 299 /* L2TP is point-point, not multicast */ 300 if (addr_type & IPV6_ADDR_MULTICAST) 301 return -EADDRNOTAVAIL; 302 303 lock_sock(sk); 304 305 err = -EINVAL; 306 if (!sock_flag(sk, SOCK_ZAPPED)) 307 goto out_unlock; 308 309 if (sk->sk_state != TCP_CLOSE) 310 goto out_unlock; 311 312 bound_dev_if = sk->sk_bound_dev_if; 313 314 /* Check if the address belongs to the host. */ 315 rcu_read_lock(); 316 if (addr_type != IPV6_ADDR_ANY) { 317 struct net_device *dev = NULL; 318 319 if (addr_type & IPV6_ADDR_LINKLOCAL) { 320 if (addr->l2tp_scope_id) 321 bound_dev_if = addr->l2tp_scope_id; 322 323 /* Binding to link-local address requires an 324 * interface. 325 */ 326 if (!bound_dev_if) 327 goto out_unlock_rcu; 328 329 err = -ENODEV; 330 dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); 331 if (!dev) 332 goto out_unlock_rcu; 333 } 334 335 /* ipv4 addr of the socket is invalid. Only the 336 * unspecified and mapped address have a v4 equivalent. 337 */ 338 v4addr = LOOPBACK4_IPV6; 339 err = -EADDRNOTAVAIL; 340 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) 341 goto out_unlock_rcu; 342 } 343 rcu_read_unlock(); 344 345 write_lock_bh(&l2tp_ip6_lock); 346 if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, 347 addr->l2tp_conn_id)) { 348 write_unlock_bh(&l2tp_ip6_lock); 349 err = -EADDRINUSE; 350 goto out_unlock; 351 } 352 353 inet->inet_saddr = v4addr; 354 inet->inet_rcv_saddr = v4addr; 355 sk->sk_bound_dev_if = bound_dev_if; 356 sk->sk_v6_rcv_saddr = addr->l2tp_addr; 357 np->saddr = addr->l2tp_addr; 358 359 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; 360 361 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 362 sk_del_node_init(sk); 363 write_unlock_bh(&l2tp_ip6_lock); 364 365 sock_reset_flag(sk, SOCK_ZAPPED); 366 release_sock(sk); 367 return 0; 368 369 out_unlock_rcu: 370 rcu_read_unlock(); 371 out_unlock: 372 release_sock(sk); 373 374 return err; 375 } 376 377 static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, 378 int addr_len) 379 { 380 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; 381 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr; 382 struct in6_addr *daddr; 383 int addr_type; 384 int rc; 385 386 if (addr_len < sizeof(*lsa)) 387 return -EINVAL; 388 389 if (usin->sin6_family != AF_INET6) 390 return -EINVAL; 391 392 addr_type = ipv6_addr_type(&usin->sin6_addr); 393 if (addr_type & IPV6_ADDR_MULTICAST) 394 return -EINVAL; 395 396 if (addr_type & IPV6_ADDR_MAPPED) { 397 daddr = &usin->sin6_addr; 398 if (ipv4_is_multicast(daddr->s6_addr32[3])) 399 return -EINVAL; 400 } 401 402 lock_sock(sk); 403 404 /* Must bind first - autobinding does not work */ 405 if (sock_flag(sk, SOCK_ZAPPED)) { 406 rc = -EINVAL; 407 goto out_sk; 408 } 409 410 rc = __ip6_datagram_connect(sk, uaddr, addr_len); 411 if (rc < 0) 412 goto out_sk; 413 414 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; 415 416 write_lock_bh(&l2tp_ip6_lock); 417 hlist_del_init(&sk->sk_bind_node); 418 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 419 write_unlock_bh(&l2tp_ip6_lock); 420 421 out_sk: 422 release_sock(sk); 423 424 return rc; 425 } 426 427 static int l2tp_ip6_disconnect(struct sock *sk, int flags) 428 { 429 if (sock_flag(sk, SOCK_ZAPPED)) 430 return 0; 431 432 return __udp_disconnect(sk, flags); 433 } 434 435 static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, 436 int peer) 437 { 438 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; 439 struct sock *sk = sock->sk; 440 struct ipv6_pinfo *np = inet6_sk(sk); 441 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); 442 443 lsa->l2tp_family = AF_INET6; 444 lsa->l2tp_flowinfo = 0; 445 lsa->l2tp_scope_id = 0; 446 lsa->l2tp_unused = 0; 447 if (peer) { 448 if (!lsk->peer_conn_id) 449 return -ENOTCONN; 450 lsa->l2tp_conn_id = lsk->peer_conn_id; 451 lsa->l2tp_addr = sk->sk_v6_daddr; 452 if (np->sndflow) 453 lsa->l2tp_flowinfo = np->flow_label; 454 } else { 455 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 456 lsa->l2tp_addr = np->saddr; 457 else 458 lsa->l2tp_addr = sk->sk_v6_rcv_saddr; 459 460 lsa->l2tp_conn_id = lsk->conn_id; 461 } 462 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 463 lsa->l2tp_scope_id = sk->sk_bound_dev_if; 464 return sizeof(*lsa); 465 } 466 467 static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) 468 { 469 int rc; 470 471 /* Charge it to the socket, dropping if the queue is full. */ 472 rc = sock_queue_rcv_skb(sk, skb); 473 if (rc < 0) 474 goto drop; 475 476 return 0; 477 478 drop: 479 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); 480 kfree_skb(skb); 481 return -1; 482 } 483 484 static int l2tp_ip6_push_pending_frames(struct sock *sk) 485 { 486 struct sk_buff *skb; 487 __be32 *transhdr = NULL; 488 int err = 0; 489 490 skb = skb_peek(&sk->sk_write_queue); 491 if (!skb) 492 goto out; 493 494 transhdr = (__be32 *)skb_transport_header(skb); 495 *transhdr = 0; 496 497 err = ip6_push_pending_frames(sk); 498 499 out: 500 return err; 501 } 502 503 /* Userspace will call sendmsg() on the tunnel socket to send L2TP 504 * control frames. 505 */ 506 static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 507 { 508 struct ipv6_txoptions opt_space; 509 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 510 struct in6_addr *daddr, *final_p, final; 511 struct ipv6_pinfo *np = inet6_sk(sk); 512 struct ipv6_txoptions *opt_to_free = NULL; 513 struct ipv6_txoptions *opt = NULL; 514 struct ip6_flowlabel *flowlabel = NULL; 515 struct dst_entry *dst = NULL; 516 struct flowi6 fl6; 517 struct ipcm6_cookie ipc6; 518 int addr_len = msg->msg_namelen; 519 int transhdrlen = 4; /* zero session-id */ 520 int ulen = len + transhdrlen; 521 int err; 522 523 /* Rough check on arithmetic overflow, 524 * better check is made in ip6_append_data(). 525 */ 526 if (len > INT_MAX) 527 return -EMSGSIZE; 528 529 /* Mirror BSD error message compatibility */ 530 if (msg->msg_flags & MSG_OOB) 531 return -EOPNOTSUPP; 532 533 /* Get and verify the address */ 534 memset(&fl6, 0, sizeof(fl6)); 535 536 fl6.flowi6_mark = sk->sk_mark; 537 fl6.flowi6_uid = sk->sk_uid; 538 539 ipcm6_init(&ipc6); 540 541 if (lsa) { 542 if (addr_len < SIN6_LEN_RFC2133) 543 return -EINVAL; 544 545 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) 546 return -EAFNOSUPPORT; 547 548 daddr = &lsa->l2tp_addr; 549 if (np->sndflow) { 550 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; 551 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) { 552 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 553 if (IS_ERR(flowlabel)) 554 return -EINVAL; 555 } 556 } 557 558 /* Otherwise it will be difficult to maintain 559 * sk->sk_dst_cache. 560 */ 561 if (sk->sk_state == TCP_ESTABLISHED && 562 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 563 daddr = &sk->sk_v6_daddr; 564 565 if (addr_len >= sizeof(struct sockaddr_in6) && 566 lsa->l2tp_scope_id && 567 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) 568 fl6.flowi6_oif = lsa->l2tp_scope_id; 569 } else { 570 if (sk->sk_state != TCP_ESTABLISHED) 571 return -EDESTADDRREQ; 572 573 daddr = &sk->sk_v6_daddr; 574 fl6.flowlabel = np->flow_label; 575 } 576 577 if (fl6.flowi6_oif == 0) 578 fl6.flowi6_oif = sk->sk_bound_dev_if; 579 580 if (msg->msg_controllen) { 581 opt = &opt_space; 582 memset(opt, 0, sizeof(struct ipv6_txoptions)); 583 opt->tot_len = sizeof(struct ipv6_txoptions); 584 ipc6.opt = opt; 585 586 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6); 587 if (err < 0) { 588 fl6_sock_release(flowlabel); 589 return err; 590 } 591 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { 592 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 593 if (IS_ERR(flowlabel)) 594 return -EINVAL; 595 } 596 if (!(opt->opt_nflen | opt->opt_flen)) 597 opt = NULL; 598 } 599 600 if (!opt) { 601 opt = txopt_get(np); 602 opt_to_free = opt; 603 } 604 if (flowlabel) 605 opt = fl6_merge_options(&opt_space, flowlabel, opt); 606 opt = ipv6_fixup_options(&opt_space, opt); 607 ipc6.opt = opt; 608 609 fl6.flowi6_proto = sk->sk_protocol; 610 if (!ipv6_addr_any(daddr)) 611 fl6.daddr = *daddr; 612 else 613 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 614 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 615 fl6.saddr = np->saddr; 616 617 final_p = fl6_update_dst(&fl6, opt, &final); 618 619 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 620 fl6.flowi6_oif = np->mcast_oif; 621 else if (!fl6.flowi6_oif) 622 fl6.flowi6_oif = np->ucast_oif; 623 624 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 625 626 if (ipc6.tclass < 0) 627 ipc6.tclass = np->tclass; 628 629 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); 630 631 dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p); 632 if (IS_ERR(dst)) { 633 err = PTR_ERR(dst); 634 goto out; 635 } 636 637 if (ipc6.hlimit < 0) 638 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 639 640 if (ipc6.dontfrag < 0) 641 ipc6.dontfrag = np->dontfrag; 642 643 if (msg->msg_flags & MSG_CONFIRM) 644 goto do_confirm; 645 646 back_from_confirm: 647 lock_sock(sk); 648 err = ip6_append_data(sk, ip_generic_getfrag, msg, 649 ulen, transhdrlen, &ipc6, 650 &fl6, (struct rt6_info *)dst, 651 msg->msg_flags); 652 if (err) 653 ip6_flush_pending_frames(sk); 654 else if (!(msg->msg_flags & MSG_MORE)) 655 err = l2tp_ip6_push_pending_frames(sk); 656 release_sock(sk); 657 done: 658 dst_release(dst); 659 out: 660 fl6_sock_release(flowlabel); 661 txopt_put(opt_to_free); 662 663 return err < 0 ? err : len; 664 665 do_confirm: 666 if (msg->msg_flags & MSG_PROBE) 667 dst_confirm_neigh(dst, &fl6.daddr); 668 if (!(msg->msg_flags & MSG_PROBE) || len) 669 goto back_from_confirm; 670 err = 0; 671 goto done; 672 } 673 674 static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 675 int noblock, int flags, int *addr_len) 676 { 677 struct ipv6_pinfo *np = inet6_sk(sk); 678 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 679 size_t copied = 0; 680 int err = -EOPNOTSUPP; 681 struct sk_buff *skb; 682 683 if (flags & MSG_OOB) 684 goto out; 685 686 if (flags & MSG_ERRQUEUE) 687 return ipv6_recv_error(sk, msg, len, addr_len); 688 689 skb = skb_recv_datagram(sk, flags, noblock, &err); 690 if (!skb) 691 goto out; 692 693 copied = skb->len; 694 if (len < copied) { 695 msg->msg_flags |= MSG_TRUNC; 696 copied = len; 697 } 698 699 err = skb_copy_datagram_msg(skb, 0, msg, copied); 700 if (err) 701 goto done; 702 703 sock_recv_timestamp(msg, sk, skb); 704 705 /* Copy the address. */ 706 if (lsa) { 707 lsa->l2tp_family = AF_INET6; 708 lsa->l2tp_unused = 0; 709 lsa->l2tp_addr = ipv6_hdr(skb)->saddr; 710 lsa->l2tp_flowinfo = 0; 711 lsa->l2tp_scope_id = 0; 712 lsa->l2tp_conn_id = 0; 713 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 714 lsa->l2tp_scope_id = inet6_iif(skb); 715 *addr_len = sizeof(*lsa); 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 = l2tp_ip6_hash, 745 .unhash = l2tp_ip6_unhash, 746 .obj_size = sizeof(struct l2tp_ip6_sock), 747 }; 748 749 static const struct proto_ops l2tp_ip6_ops = { 750 .family = PF_INET6, 751 .owner = THIS_MODULE, 752 .release = inet6_release, 753 .bind = inet6_bind, 754 .connect = inet_dgram_connect, 755 .socketpair = sock_no_socketpair, 756 .accept = sock_no_accept, 757 .getname = l2tp_ip6_getname, 758 .poll = datagram_poll, 759 .ioctl = inet6_ioctl, 760 .gettstamp = sock_gettstamp, 761 .listen = sock_no_listen, 762 .shutdown = inet_shutdown, 763 .setsockopt = sock_common_setsockopt, 764 .getsockopt = sock_common_getsockopt, 765 .sendmsg = inet_sendmsg, 766 .recvmsg = sock_common_recvmsg, 767 .mmap = sock_no_mmap, 768 .sendpage = sock_no_sendpage, 769 #ifdef CONFIG_COMPAT 770 .compat_ioctl = inet6_compat_ioctl, 771 #endif 772 }; 773 774 static struct inet_protosw l2tp_ip6_protosw = { 775 .type = SOCK_DGRAM, 776 .protocol = IPPROTO_L2TP, 777 .prot = &l2tp_ip6_prot, 778 .ops = &l2tp_ip6_ops, 779 }; 780 781 static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { 782 .handler = l2tp_ip6_recv, 783 }; 784 785 static int __init l2tp_ip6_init(void) 786 { 787 int err; 788 789 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); 790 791 err = proto_register(&l2tp_ip6_prot, 1); 792 if (err != 0) 793 goto out; 794 795 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 796 if (err) 797 goto out1; 798 799 inet6_register_protosw(&l2tp_ip6_protosw); 800 return 0; 801 802 out1: 803 proto_unregister(&l2tp_ip6_prot); 804 out: 805 return err; 806 } 807 808 static void __exit l2tp_ip6_exit(void) 809 { 810 inet6_unregister_protosw(&l2tp_ip6_protosw); 811 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 812 proto_unregister(&l2tp_ip6_prot); 813 } 814 815 module_init(l2tp_ip6_init); 816 module_exit(l2tp_ip6_exit); 817 818 MODULE_LICENSE("GPL"); 819 MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); 820 MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); 821 MODULE_VERSION("1.0"); 822 823 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like 824 * enums 825 */ 826 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); 827 MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); 828