1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * L2TPv3 IP encapsulation support for IPv6 4 * 5 * Copyright (c) 2012 Katalix Systems Ltd 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/icmp.h> 11 #include <linux/module.h> 12 #include <linux/skbuff.h> 13 #include <linux/random.h> 14 #include <linux/socket.h> 15 #include <linux/l2tp.h> 16 #include <linux/in.h> 17 #include <linux/in6.h> 18 #include <net/sock.h> 19 #include <net/ip.h> 20 #include <net/icmp.h> 21 #include <net/udp.h> 22 #include <net/inet_common.h> 23 #include <net/tcp_states.h> 24 #include <net/protocol.h> 25 #include <net/xfrm.h> 26 27 #include <net/transp_v6.h> 28 #include <net/addrconf.h> 29 #include <net/ip6_route.h> 30 31 #include "l2tp_core.h" 32 33 struct l2tp_ip6_sock { 34 /* inet_sock has to be the first member of l2tp_ip6_sock */ 35 struct inet_sock inet; 36 37 u32 conn_id; 38 u32 peer_conn_id; 39 40 /* ipv6_pinfo has to be the last member of l2tp_ip6_sock, see 41 inet6_sk_generic */ 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 = ptr = skb->data; 141 session_id = ntohl(*((__be32 *) ptr)); 142 ptr += 4; 143 144 /* RFC3931: L2TP/IP packets have the first 4 bytes containing 145 * the session_id. If it is 0, the packet is a L2TP control 146 * frame and the session_id value can be discarded. 147 */ 148 if (session_id == 0) { 149 __skb_pull(skb, 4); 150 goto pass_up; 151 } 152 153 /* Ok, this is a data packet. Lookup the session. */ 154 session = l2tp_session_get(net, session_id); 155 if (!session) 156 goto discard; 157 158 tunnel = session->tunnel; 159 if (!tunnel) 160 goto discard_sess; 161 162 /* Trace packet contents, if enabled */ 163 if (tunnel->debug & L2TP_MSG_DATA) { 164 length = min(32u, skb->len); 165 if (!pskb_may_pull(skb, length)) 166 goto discard_sess; 167 168 /* Point to L2TP header */ 169 optr = ptr = skb->data; 170 ptr += 4; 171 pr_debug("%s: ip recv\n", tunnel->name); 172 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); 173 } 174 175 if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) 176 goto discard_sess; 177 178 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len); 179 l2tp_session_dec_refcount(session); 180 181 return 0; 182 183 pass_up: 184 /* Get the tunnel_id from the L2TP header */ 185 if (!pskb_may_pull(skb, 12)) 186 goto discard; 187 188 if ((skb->data[0] & 0xc0) != 0xc0) 189 goto discard; 190 191 tunnel_id = ntohl(*(__be32 *) &skb->data[4]); 192 iph = ipv6_hdr(skb); 193 194 read_lock_bh(&l2tp_ip6_lock); 195 sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr, 196 inet6_iif(skb), tunnel_id); 197 if (!sk) { 198 read_unlock_bh(&l2tp_ip6_lock); 199 goto discard; 200 } 201 sock_hold(sk); 202 read_unlock_bh(&l2tp_ip6_lock); 203 204 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 205 goto discard_put; 206 207 nf_reset_ct(skb); 208 209 return sk_receive_skb(sk, skb, 1); 210 211 discard_sess: 212 l2tp_session_dec_refcount(session); 213 goto discard; 214 215 discard_put: 216 sock_put(sk); 217 218 discard: 219 kfree_skb(skb); 220 return 0; 221 } 222 223 static int l2tp_ip6_hash(struct sock *sk) 224 { 225 if (sk_unhashed(sk)) { 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_unhash(struct sock *sk) 234 { 235 if (sk_unhashed(sk)) 236 return; 237 write_lock_bh(&l2tp_ip6_lock); 238 sk_del_node_init(sk); 239 write_unlock_bh(&l2tp_ip6_lock); 240 } 241 242 static int l2tp_ip6_open(struct sock *sk) 243 { 244 /* Prevent autobind. We don't have ports. */ 245 inet_sk(sk)->inet_num = IPPROTO_L2TP; 246 247 l2tp_ip6_hash(sk); 248 return 0; 249 } 250 251 static void l2tp_ip6_close(struct sock *sk, long timeout) 252 { 253 write_lock_bh(&l2tp_ip6_lock); 254 hlist_del_init(&sk->sk_bind_node); 255 sk_del_node_init(sk); 256 write_unlock_bh(&l2tp_ip6_lock); 257 258 sk_common_release(sk); 259 } 260 261 static void l2tp_ip6_destroy_sock(struct sock *sk) 262 { 263 struct l2tp_tunnel *tunnel = sk->sk_user_data; 264 265 lock_sock(sk); 266 ip6_flush_pending_frames(sk); 267 release_sock(sk); 268 269 if (tunnel) 270 l2tp_tunnel_delete(tunnel); 271 272 inet6_destroy_sock(sk); 273 } 274 275 static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 276 { 277 struct inet_sock *inet = inet_sk(sk); 278 struct ipv6_pinfo *np = inet6_sk(sk); 279 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; 280 struct net *net = sock_net(sk); 281 __be32 v4addr = 0; 282 int bound_dev_if; 283 int addr_type; 284 int err; 285 286 if (addr->l2tp_family != AF_INET6) 287 return -EINVAL; 288 if (addr_len < sizeof(*addr)) 289 return -EINVAL; 290 291 addr_type = ipv6_addr_type(&addr->l2tp_addr); 292 293 /* l2tp_ip6 sockets are IPv6 only */ 294 if (addr_type == IPV6_ADDR_MAPPED) 295 return -EADDRNOTAVAIL; 296 297 /* L2TP is point-point, not multicast */ 298 if (addr_type & IPV6_ADDR_MULTICAST) 299 return -EADDRNOTAVAIL; 300 301 lock_sock(sk); 302 303 err = -EINVAL; 304 if (!sock_flag(sk, SOCK_ZAPPED)) 305 goto out_unlock; 306 307 if (sk->sk_state != TCP_CLOSE) 308 goto out_unlock; 309 310 bound_dev_if = sk->sk_bound_dev_if; 311 312 /* Check if the address belongs to the host. */ 313 rcu_read_lock(); 314 if (addr_type != IPV6_ADDR_ANY) { 315 struct net_device *dev = NULL; 316 317 if (addr_type & IPV6_ADDR_LINKLOCAL) { 318 if (addr->l2tp_scope_id) 319 bound_dev_if = addr->l2tp_scope_id; 320 321 /* Binding to link-local address requires an 322 * interface. 323 */ 324 if (!bound_dev_if) 325 goto out_unlock_rcu; 326 327 err = -ENODEV; 328 dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); 329 if (!dev) 330 goto out_unlock_rcu; 331 } 332 333 /* ipv4 addr of the socket is invalid. Only the 334 * unspecified and mapped address have a v4 equivalent. 335 */ 336 v4addr = LOOPBACK4_IPV6; 337 err = -EADDRNOTAVAIL; 338 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) 339 goto out_unlock_rcu; 340 } 341 rcu_read_unlock(); 342 343 write_lock_bh(&l2tp_ip6_lock); 344 if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, 345 addr->l2tp_conn_id)) { 346 write_unlock_bh(&l2tp_ip6_lock); 347 err = -EADDRINUSE; 348 goto out_unlock; 349 } 350 351 inet->inet_saddr = v4addr; 352 inet->inet_rcv_saddr = v4addr; 353 sk->sk_bound_dev_if = bound_dev_if; 354 sk->sk_v6_rcv_saddr = addr->l2tp_addr; 355 np->saddr = addr->l2tp_addr; 356 357 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; 358 359 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 360 sk_del_node_init(sk); 361 write_unlock_bh(&l2tp_ip6_lock); 362 363 sock_reset_flag(sk, SOCK_ZAPPED); 364 release_sock(sk); 365 return 0; 366 367 out_unlock_rcu: 368 rcu_read_unlock(); 369 out_unlock: 370 release_sock(sk); 371 372 return err; 373 } 374 375 static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, 376 int addr_len) 377 { 378 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr; 379 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; 380 struct in6_addr *daddr; 381 int addr_type; 382 int rc; 383 384 if (addr_len < sizeof(*lsa)) 385 return -EINVAL; 386 387 if (usin->sin6_family != AF_INET6) 388 return -EINVAL; 389 390 addr_type = ipv6_addr_type(&usin->sin6_addr); 391 if (addr_type & IPV6_ADDR_MULTICAST) 392 return -EINVAL; 393 394 if (addr_type & IPV6_ADDR_MAPPED) { 395 daddr = &usin->sin6_addr; 396 if (ipv4_is_multicast(daddr->s6_addr32[3])) 397 return -EINVAL; 398 } 399 400 lock_sock(sk); 401 402 /* Must bind first - autobinding does not work */ 403 if (sock_flag(sk, SOCK_ZAPPED)) { 404 rc = -EINVAL; 405 goto out_sk; 406 } 407 408 rc = __ip6_datagram_connect(sk, uaddr, addr_len); 409 if (rc < 0) 410 goto out_sk; 411 412 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; 413 414 write_lock_bh(&l2tp_ip6_lock); 415 hlist_del_init(&sk->sk_bind_node); 416 sk_add_bind_node(sk, &l2tp_ip6_bind_table); 417 write_unlock_bh(&l2tp_ip6_lock); 418 419 out_sk: 420 release_sock(sk); 421 422 return rc; 423 } 424 425 static int l2tp_ip6_disconnect(struct sock *sk, int flags) 426 { 427 if (sock_flag(sk, SOCK_ZAPPED)) 428 return 0; 429 430 return __udp_disconnect(sk, flags); 431 } 432 433 static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, 434 int peer) 435 { 436 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; 437 struct sock *sk = sock->sk; 438 struct ipv6_pinfo *np = inet6_sk(sk); 439 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); 440 441 lsa->l2tp_family = AF_INET6; 442 lsa->l2tp_flowinfo = 0; 443 lsa->l2tp_scope_id = 0; 444 lsa->l2tp_unused = 0; 445 if (peer) { 446 if (!lsk->peer_conn_id) 447 return -ENOTCONN; 448 lsa->l2tp_conn_id = lsk->peer_conn_id; 449 lsa->l2tp_addr = sk->sk_v6_daddr; 450 if (np->sndflow) 451 lsa->l2tp_flowinfo = np->flow_label; 452 } else { 453 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 454 lsa->l2tp_addr = np->saddr; 455 else 456 lsa->l2tp_addr = sk->sk_v6_rcv_saddr; 457 458 lsa->l2tp_conn_id = lsk->conn_id; 459 } 460 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 461 lsa->l2tp_scope_id = sk->sk_bound_dev_if; 462 return sizeof(*lsa); 463 } 464 465 static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) 466 { 467 int rc; 468 469 /* Charge it to the socket, dropping if the queue is full. */ 470 rc = sock_queue_rcv_skb(sk, skb); 471 if (rc < 0) 472 goto drop; 473 474 return 0; 475 476 drop: 477 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); 478 kfree_skb(skb); 479 return -1; 480 } 481 482 static int l2tp_ip6_push_pending_frames(struct sock *sk) 483 { 484 struct sk_buff *skb; 485 __be32 *transhdr = NULL; 486 int err = 0; 487 488 skb = skb_peek(&sk->sk_write_queue); 489 if (skb == NULL) 490 goto out; 491 492 transhdr = (__be32 *)skb_transport_header(skb); 493 *transhdr = 0; 494 495 err = ip6_push_pending_frames(sk); 496 497 out: 498 return err; 499 } 500 501 /* Userspace will call sendmsg() on the tunnel socket to send L2TP 502 * control frames. 503 */ 504 static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 505 { 506 struct ipv6_txoptions opt_space; 507 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 508 struct in6_addr *daddr, *final_p, final; 509 struct ipv6_pinfo *np = inet6_sk(sk); 510 struct ipv6_txoptions *opt_to_free = NULL; 511 struct ipv6_txoptions *opt = NULL; 512 struct ip6_flowlabel *flowlabel = NULL; 513 struct dst_entry *dst = NULL; 514 struct flowi6 fl6; 515 struct ipcm6_cookie ipc6; 516 int addr_len = msg->msg_namelen; 517 int transhdrlen = 4; /* zero session-id */ 518 int ulen = len + transhdrlen; 519 int err; 520 521 /* Rough check on arithmetic overflow, 522 better check is made in ip6_append_data(). 523 */ 524 if (len > INT_MAX) 525 return -EMSGSIZE; 526 527 /* Mirror BSD error message compatibility */ 528 if (msg->msg_flags & MSG_OOB) 529 return -EOPNOTSUPP; 530 531 /* 532 * Get and verify the address. 533 */ 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 /* 559 * Otherwise it will be difficult to maintain 560 * sk->sk_dst_cache. 561 */ 562 if (sk->sk_state == TCP_ESTABLISHED && 563 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 564 daddr = &sk->sk_v6_daddr; 565 566 if (addr_len >= sizeof(struct sockaddr_in6) && 567 lsa->l2tp_scope_id && 568 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) 569 fl6.flowi6_oif = lsa->l2tp_scope_id; 570 } else { 571 if (sk->sk_state != TCP_ESTABLISHED) 572 return -EDESTADDRREQ; 573 574 daddr = &sk->sk_v6_daddr; 575 fl6.flowlabel = np->flow_label; 576 } 577 578 if (fl6.flowi6_oif == 0) 579 fl6.flowi6_oif = sk->sk_bound_dev_if; 580 581 if (msg->msg_controllen) { 582 opt = &opt_space; 583 memset(opt, 0, sizeof(struct ipv6_txoptions)); 584 opt->tot_len = sizeof(struct ipv6_txoptions); 585 ipc6.opt = opt; 586 587 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6); 588 if (err < 0) { 589 fl6_sock_release(flowlabel); 590 return err; 591 } 592 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { 593 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 594 if (IS_ERR(flowlabel)) 595 return -EINVAL; 596 } 597 if (!(opt->opt_nflen|opt->opt_flen)) 598 opt = NULL; 599 } 600 601 if (!opt) { 602 opt = txopt_get(np); 603 opt_to_free = opt; 604 } 605 if (flowlabel) 606 opt = fl6_merge_options(&opt_space, flowlabel, opt); 607 opt = ipv6_fixup_options(&opt_space, opt); 608 ipc6.opt = opt; 609 610 fl6.flowi6_proto = sk->sk_protocol; 611 if (!ipv6_addr_any(daddr)) 612 fl6.daddr = *daddr; 613 else 614 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 615 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 616 fl6.saddr = np->saddr; 617 618 final_p = fl6_update_dst(&fl6, opt, &final); 619 620 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 621 fl6.flowi6_oif = np->mcast_oif; 622 else if (!fl6.flowi6_oif) 623 fl6.flowi6_oif = np->ucast_oif; 624 625 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 626 627 if (ipc6.tclass < 0) 628 ipc6.tclass = np->tclass; 629 630 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); 631 632 dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p); 633 if (IS_ERR(dst)) { 634 err = PTR_ERR(dst); 635 goto out; 636 } 637 638 if (ipc6.hlimit < 0) 639 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 640 641 if (ipc6.dontfrag < 0) 642 ipc6.dontfrag = np->dontfrag; 643 644 if (msg->msg_flags & MSG_CONFIRM) 645 goto do_confirm; 646 647 back_from_confirm: 648 lock_sock(sk); 649 err = ip6_append_data(sk, ip_generic_getfrag, msg, 650 ulen, transhdrlen, &ipc6, 651 &fl6, (struct rt6_info *)dst, 652 msg->msg_flags); 653 if (err) 654 ip6_flush_pending_frames(sk); 655 else if (!(msg->msg_flags & MSG_MORE)) 656 err = l2tp_ip6_push_pending_frames(sk); 657 release_sock(sk); 658 done: 659 dst_release(dst); 660 out: 661 fl6_sock_release(flowlabel); 662 txopt_put(opt_to_free); 663 664 return err < 0 ? err : len; 665 666 do_confirm: 667 if (msg->msg_flags & MSG_PROBE) 668 dst_confirm_neigh(dst, &fl6.daddr); 669 if (!(msg->msg_flags & MSG_PROBE) || len) 670 goto back_from_confirm; 671 err = 0; 672 goto done; 673 } 674 675 static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 676 int noblock, int flags, int *addr_len) 677 { 678 struct ipv6_pinfo *np = inet6_sk(sk); 679 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 680 size_t copied = 0; 681 int err = -EOPNOTSUPP; 682 struct sk_buff *skb; 683 684 if (flags & MSG_OOB) 685 goto out; 686 687 if (flags & MSG_ERRQUEUE) 688 return ipv6_recv_error(sk, msg, len, addr_len); 689 690 skb = skb_recv_datagram(sk, flags, noblock, &err); 691 if (!skb) 692 goto out; 693 694 copied = skb->len; 695 if (len < copied) { 696 msg->msg_flags |= MSG_TRUNC; 697 copied = len; 698 } 699 700 err = skb_copy_datagram_msg(skb, 0, msg, copied); 701 if (err) 702 goto done; 703 704 sock_recv_timestamp(msg, sk, skb); 705 706 /* Copy the address. */ 707 if (lsa) { 708 lsa->l2tp_family = AF_INET6; 709 lsa->l2tp_unused = 0; 710 lsa->l2tp_addr = ipv6_hdr(skb)->saddr; 711 lsa->l2tp_flowinfo = 0; 712 lsa->l2tp_scope_id = 0; 713 lsa->l2tp_conn_id = 0; 714 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 715 lsa->l2tp_scope_id = inet6_iif(skb); 716 *addr_len = sizeof(*lsa); 717 } 718 719 if (np->rxopt.all) 720 ip6_datagram_recv_ctl(sk, msg, skb); 721 722 if (flags & MSG_TRUNC) 723 copied = skb->len; 724 done: 725 skb_free_datagram(sk, skb); 726 out: 727 return err ? err : copied; 728 } 729 730 static struct proto l2tp_ip6_prot = { 731 .name = "L2TP/IPv6", 732 .owner = THIS_MODULE, 733 .init = l2tp_ip6_open, 734 .close = l2tp_ip6_close, 735 .bind = l2tp_ip6_bind, 736 .connect = l2tp_ip6_connect, 737 .disconnect = l2tp_ip6_disconnect, 738 .ioctl = l2tp_ioctl, 739 .destroy = l2tp_ip6_destroy_sock, 740 .setsockopt = ipv6_setsockopt, 741 .getsockopt = ipv6_getsockopt, 742 .sendmsg = l2tp_ip6_sendmsg, 743 .recvmsg = l2tp_ip6_recvmsg, 744 .backlog_rcv = l2tp_ip6_backlog_recv, 745 .hash = l2tp_ip6_hash, 746 .unhash = l2tp_ip6_unhash, 747 .obj_size = sizeof(struct l2tp_ip6_sock), 748 #ifdef CONFIG_COMPAT 749 .compat_setsockopt = compat_ipv6_setsockopt, 750 .compat_getsockopt = compat_ipv6_getsockopt, 751 #endif 752 }; 753 754 static const struct proto_ops l2tp_ip6_ops = { 755 .family = PF_INET6, 756 .owner = THIS_MODULE, 757 .release = inet6_release, 758 .bind = inet6_bind, 759 .connect = inet_dgram_connect, 760 .socketpair = sock_no_socketpair, 761 .accept = sock_no_accept, 762 .getname = l2tp_ip6_getname, 763 .poll = datagram_poll, 764 .ioctl = inet6_ioctl, 765 .gettstamp = sock_gettstamp, 766 .listen = sock_no_listen, 767 .shutdown = inet_shutdown, 768 .setsockopt = sock_common_setsockopt, 769 .getsockopt = sock_common_getsockopt, 770 .sendmsg = inet_sendmsg, 771 .recvmsg = sock_common_recvmsg, 772 .mmap = sock_no_mmap, 773 .sendpage = sock_no_sendpage, 774 #ifdef CONFIG_COMPAT 775 .compat_ioctl = inet6_compat_ioctl, 776 .compat_setsockopt = compat_sock_common_setsockopt, 777 .compat_getsockopt = compat_sock_common_getsockopt, 778 #endif 779 }; 780 781 static struct inet_protosw l2tp_ip6_protosw = { 782 .type = SOCK_DGRAM, 783 .protocol = IPPROTO_L2TP, 784 .prot = &l2tp_ip6_prot, 785 .ops = &l2tp_ip6_ops, 786 }; 787 788 static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { 789 .handler = l2tp_ip6_recv, 790 }; 791 792 static int __init l2tp_ip6_init(void) 793 { 794 int err; 795 796 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); 797 798 err = proto_register(&l2tp_ip6_prot, 1); 799 if (err != 0) 800 goto out; 801 802 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 803 if (err) 804 goto out1; 805 806 inet6_register_protosw(&l2tp_ip6_protosw); 807 return 0; 808 809 out1: 810 proto_unregister(&l2tp_ip6_prot); 811 out: 812 return err; 813 } 814 815 static void __exit l2tp_ip6_exit(void) 816 { 817 inet6_unregister_protosw(&l2tp_ip6_protosw); 818 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 819 proto_unregister(&l2tp_ip6_prot); 820 } 821 822 module_init(l2tp_ip6_init); 823 module_exit(l2tp_ip6_exit); 824 825 MODULE_LICENSE("GPL"); 826 MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); 827 MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); 828 MODULE_VERSION("1.0"); 829 830 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like 831 * enums 832 */ 833 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP); 834 MODULE_ALIAS_NET_PF_PROTO(PF_INET6, IPPROTO_L2TP); 835