James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 1 | /* |
| 2 | * L2TPv3 IP encapsulation support |
| 3 | * |
| 4 | * Copyright (c) 2008,2009,2010 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 | |
Joe Perches | a4ca44f | 2012-05-16 09:55:56 +0000 | [diff] [blame] | 12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 13 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 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 <net/sock.h> |
| 22 | #include <net/ip.h> |
| 23 | #include <net/icmp.h> |
| 24 | #include <net/udp.h> |
| 25 | #include <net/inet_common.h> |
| 26 | #include <net/inet_hashtables.h> |
| 27 | #include <net/tcp_states.h> |
| 28 | #include <net/protocol.h> |
| 29 | #include <net/xfrm.h> |
| 30 | |
| 31 | #include "l2tp_core.h" |
| 32 | |
| 33 | struct l2tp_ip_sock { |
| 34 | /* inet_sock has to be the first member of l2tp_ip_sock */ |
| 35 | struct inet_sock inet; |
| 36 | |
James Chapman | c8657fd | 2012-04-29 21:48:48 +0000 | [diff] [blame] | 37 | u32 conn_id; |
| 38 | u32 peer_conn_id; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 39 | }; |
| 40 | |
| 41 | static DEFINE_RWLOCK(l2tp_ip_lock); |
| 42 | static struct hlist_head l2tp_ip_table; |
| 43 | static struct hlist_head l2tp_ip_bind_table; |
| 44 | |
| 45 | static inline struct l2tp_ip_sock *l2tp_ip_sk(const struct sock *sk) |
| 46 | { |
| 47 | return (struct l2tp_ip_sock *)sk; |
| 48 | } |
| 49 | |
| 50 | static struct sock *__l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id) |
| 51 | { |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 52 | struct sock *sk; |
| 53 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 54 | sk_for_each_bound(sk, &l2tp_ip_bind_table) { |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 55 | struct inet_sock *inet = inet_sk(sk); |
| 56 | struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk); |
| 57 | |
| 58 | if (l2tp == NULL) |
| 59 | continue; |
| 60 | |
| 61 | if ((l2tp->conn_id == tunnel_id) && |
Eric Dumazet | e83726b | 2010-10-21 04:39:09 -0700 | [diff] [blame] | 62 | net_eq(sock_net(sk), net) && |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 63 | !(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) && |
| 64 | !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)) |
| 65 | goto found; |
| 66 | } |
| 67 | |
| 68 | sk = NULL; |
| 69 | found: |
| 70 | return sk; |
| 71 | } |
| 72 | |
| 73 | static inline struct sock *l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id) |
| 74 | { |
| 75 | struct sock *sk = __l2tp_ip_bind_lookup(net, laddr, dif, tunnel_id); |
| 76 | if (sk) |
| 77 | sock_hold(sk); |
| 78 | |
| 79 | return sk; |
| 80 | } |
| 81 | |
| 82 | /* When processing receive frames, there are two cases to |
| 83 | * consider. Data frames consist of a non-zero session-id and an |
| 84 | * optional cookie. Control frames consist of a regular L2TP header |
| 85 | * preceded by 32-bits of zeros. |
| 86 | * |
| 87 | * L2TPv3 Session Header Over IP |
| 88 | * |
| 89 | * 0 1 2 3 |
| 90 | * 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 |
| 91 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 92 | * | Session ID | |
| 93 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 94 | * | Cookie (optional, maximum 64 bits)... |
| 95 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 96 | * | |
| 97 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 98 | * |
| 99 | * L2TPv3 Control Message Header Over IP |
| 100 | * |
| 101 | * 0 1 2 3 |
| 102 | * 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 |
| 103 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 104 | * | (32 bits of zeros) | |
| 105 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 106 | * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length | |
| 107 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 108 | * | Control Connection ID | |
| 109 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 110 | * | Ns | Nr | |
| 111 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 112 | * |
| 113 | * All control frames are passed to userspace. |
| 114 | */ |
| 115 | static int l2tp_ip_recv(struct sk_buff *skb) |
| 116 | { |
David S. Miller | 9d6ddb1 | 2013-02-05 14:36:02 -0500 | [diff] [blame] | 117 | struct net *net = dev_net(skb->dev); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 118 | struct sock *sk; |
| 119 | u32 session_id; |
| 120 | u32 tunnel_id; |
| 121 | unsigned char *ptr, *optr; |
| 122 | struct l2tp_session *session; |
| 123 | struct l2tp_tunnel *tunnel = NULL; |
| 124 | int length; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 125 | |
| 126 | /* Point to L2TP header */ |
| 127 | optr = ptr = skb->data; |
| 128 | |
| 129 | if (!pskb_may_pull(skb, 4)) |
| 130 | goto discard; |
| 131 | |
| 132 | session_id = ntohl(*((__be32 *) ptr)); |
| 133 | ptr += 4; |
| 134 | |
| 135 | /* RFC3931: L2TP/IP packets have the first 4 bytes containing |
| 136 | * the session_id. If it is 0, the packet is a L2TP control |
| 137 | * frame and the session_id value can be discarded. |
| 138 | */ |
| 139 | if (session_id == 0) { |
| 140 | __skb_pull(skb, 4); |
| 141 | goto pass_up; |
| 142 | } |
| 143 | |
| 144 | /* Ok, this is a data packet. Lookup the session. */ |
David S. Miller | 9d6ddb1 | 2013-02-05 14:36:02 -0500 | [diff] [blame] | 145 | session = l2tp_session_find(net, NULL, session_id); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 146 | if (session == NULL) |
| 147 | goto discard; |
| 148 | |
| 149 | tunnel = session->tunnel; |
| 150 | if (tunnel == NULL) |
| 151 | goto discard; |
| 152 | |
| 153 | /* Trace packet contents, if enabled */ |
| 154 | if (tunnel->debug & L2TP_MSG_DATA) { |
| 155 | length = min(32u, skb->len); |
| 156 | if (!pskb_may_pull(skb, length)) |
| 157 | goto discard; |
| 158 | |
Joe Perches | a4ca44f | 2012-05-16 09:55:56 +0000 | [diff] [blame] | 159 | pr_debug("%s: ip recv\n", tunnel->name); |
| 160 | print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 161 | } |
| 162 | |
| 163 | l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, tunnel->recv_payload_hook); |
| 164 | |
| 165 | return 0; |
| 166 | |
| 167 | pass_up: |
| 168 | /* Get the tunnel_id from the L2TP header */ |
| 169 | if (!pskb_may_pull(skb, 12)) |
| 170 | goto discard; |
| 171 | |
| 172 | if ((skb->data[0] & 0xc0) != 0xc0) |
| 173 | goto discard; |
| 174 | |
| 175 | tunnel_id = ntohl(*(__be32 *) &skb->data[4]); |
David S. Miller | 9d6ddb1 | 2013-02-05 14:36:02 -0500 | [diff] [blame] | 176 | tunnel = l2tp_tunnel_find(net, tunnel_id); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 177 | if (tunnel != NULL) |
| 178 | sk = tunnel->sock; |
| 179 | else { |
| 180 | struct iphdr *iph = (struct iphdr *) skb_network_header(skb); |
| 181 | |
| 182 | read_lock_bh(&l2tp_ip_lock); |
David S. Miller | 9d6ddb1 | 2013-02-05 14:36:02 -0500 | [diff] [blame] | 183 | sk = __l2tp_ip_bind_lookup(net, iph->daddr, 0, tunnel_id); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 184 | read_unlock_bh(&l2tp_ip_lock); |
| 185 | } |
| 186 | |
| 187 | if (sk == NULL) |
| 188 | goto discard; |
| 189 | |
| 190 | sock_hold(sk); |
| 191 | |
| 192 | if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) |
| 193 | goto discard_put; |
| 194 | |
| 195 | nf_reset(skb); |
| 196 | |
| 197 | return sk_receive_skb(sk, skb, 1); |
| 198 | |
| 199 | discard_put: |
| 200 | sock_put(sk); |
| 201 | |
| 202 | discard: |
| 203 | kfree_skb(skb); |
| 204 | return 0; |
| 205 | } |
| 206 | |
| 207 | static int l2tp_ip_open(struct sock *sk) |
| 208 | { |
| 209 | /* Prevent autobind. We don't have ports. */ |
| 210 | inet_sk(sk)->inet_num = IPPROTO_L2TP; |
| 211 | |
| 212 | write_lock_bh(&l2tp_ip_lock); |
| 213 | sk_add_node(sk, &l2tp_ip_table); |
| 214 | write_unlock_bh(&l2tp_ip_lock); |
| 215 | |
| 216 | return 0; |
| 217 | } |
| 218 | |
| 219 | static void l2tp_ip_close(struct sock *sk, long timeout) |
| 220 | { |
| 221 | write_lock_bh(&l2tp_ip_lock); |
| 222 | hlist_del_init(&sk->sk_bind_node); |
James Chapman | d1f224a | 2012-04-10 00:10:42 +0000 | [diff] [blame] | 223 | sk_del_node_init(sk); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 224 | write_unlock_bh(&l2tp_ip_lock); |
| 225 | sk_common_release(sk); |
| 226 | } |
| 227 | |
| 228 | static void l2tp_ip_destroy_sock(struct sock *sk) |
| 229 | { |
| 230 | struct sk_buff *skb; |
Tom Parkin | 9360631 | 2013-03-19 06:11:15 +0000 | [diff] [blame] | 231 | struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 232 | |
| 233 | while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) |
| 234 | kfree_skb(skb); |
| 235 | |
Tom Parkin | 9360631 | 2013-03-19 06:11:15 +0000 | [diff] [blame] | 236 | if (tunnel) { |
| 237 | l2tp_tunnel_closeall(tunnel); |
| 238 | sock_put(sk); |
| 239 | } |
| 240 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 241 | sk_refcnt_debug_dec(sk); |
| 242 | } |
| 243 | |
| 244 | static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) |
| 245 | { |
| 246 | struct inet_sock *inet = inet_sk(sk); |
| 247 | struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *) uaddr; |
David S. Miller | 9d6ddb1 | 2013-02-05 14:36:02 -0500 | [diff] [blame] | 248 | struct net *net = sock_net(sk); |
James Chapman | c51ce49 | 2012-05-29 03:30:42 +0000 | [diff] [blame] | 249 | int ret; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 250 | int chk_addr_ret; |
| 251 | |
James Chapman | c51ce49 | 2012-05-29 03:30:42 +0000 | [diff] [blame] | 252 | if (!sock_flag(sk, SOCK_ZAPPED)) |
| 253 | return -EINVAL; |
| 254 | if (addr_len < sizeof(struct sockaddr_l2tpip)) |
| 255 | return -EINVAL; |
| 256 | if (addr->l2tp_family != AF_INET) |
| 257 | return -EINVAL; |
| 258 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 259 | ret = -EADDRINUSE; |
| 260 | read_lock_bh(&l2tp_ip_lock); |
David S. Miller | 9d6ddb1 | 2013-02-05 14:36:02 -0500 | [diff] [blame] | 261 | if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr, |
| 262 | sk->sk_bound_dev_if, addr->l2tp_conn_id)) |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 263 | goto out_in_use; |
| 264 | |
| 265 | read_unlock_bh(&l2tp_ip_lock); |
| 266 | |
| 267 | lock_sock(sk); |
| 268 | if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_l2tpip)) |
| 269 | goto out; |
| 270 | |
David S. Miller | 9d6ddb1 | 2013-02-05 14:36:02 -0500 | [diff] [blame] | 271 | chk_addr_ret = inet_addr_type(net, addr->l2tp_addr.s_addr); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 272 | ret = -EADDRNOTAVAIL; |
| 273 | if (addr->l2tp_addr.s_addr && chk_addr_ret != RTN_LOCAL && |
| 274 | chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST) |
| 275 | goto out; |
| 276 | |
James Chapman | c9be48d | 2012-04-10 00:10:43 +0000 | [diff] [blame] | 277 | if (addr->l2tp_addr.s_addr) |
| 278 | inet->inet_rcv_saddr = inet->inet_saddr = addr->l2tp_addr.s_addr; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 279 | if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST) |
| 280 | inet->inet_saddr = 0; /* Use device */ |
| 281 | sk_dst_reset(sk); |
| 282 | |
| 283 | l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id; |
| 284 | |
| 285 | write_lock_bh(&l2tp_ip_lock); |
| 286 | sk_add_bind_node(sk, &l2tp_ip_bind_table); |
| 287 | sk_del_node_init(sk); |
| 288 | write_unlock_bh(&l2tp_ip_lock); |
| 289 | ret = 0; |
James Chapman | c51ce49 | 2012-05-29 03:30:42 +0000 | [diff] [blame] | 290 | sock_reset_flag(sk, SOCK_ZAPPED); |
| 291 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 292 | out: |
| 293 | release_sock(sk); |
| 294 | |
| 295 | return ret; |
| 296 | |
| 297 | out_in_use: |
| 298 | read_unlock_bh(&l2tp_ip_lock); |
| 299 | |
| 300 | return ret; |
| 301 | } |
| 302 | |
| 303 | static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) |
| 304 | { |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 305 | struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr; |
James Chapman | de3c7a1 | 2012-04-29 21:48:47 +0000 | [diff] [blame] | 306 | int rc; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 307 | |
James Chapman | c51ce49 | 2012-05-29 03:30:42 +0000 | [diff] [blame] | 308 | if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */ |
| 309 | return -EINVAL; |
| 310 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 311 | if (addr_len < sizeof(*lsa)) |
James Chapman | de3c7a1 | 2012-04-29 21:48:47 +0000 | [diff] [blame] | 312 | return -EINVAL; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 313 | |
James Chapman | de3c7a1 | 2012-04-29 21:48:47 +0000 | [diff] [blame] | 314 | if (ipv4_is_multicast(lsa->l2tp_addr.s_addr)) |
| 315 | return -EINVAL; |
| 316 | |
| 317 | rc = ip4_datagram_connect(sk, uaddr, addr_len); |
| 318 | if (rc < 0) |
| 319 | return rc; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 320 | |
David S. Miller | 2f16270 | 2011-05-08 13:39:01 -0700 | [diff] [blame] | 321 | lock_sock(sk); |
| 322 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 323 | l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; |
| 324 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 325 | write_lock_bh(&l2tp_ip_lock); |
| 326 | hlist_del_init(&sk->sk_bind_node); |
| 327 | sk_add_bind_node(sk, &l2tp_ip_bind_table); |
| 328 | write_unlock_bh(&l2tp_ip_lock); |
| 329 | |
David S. Miller | 2f16270 | 2011-05-08 13:39:01 -0700 | [diff] [blame] | 330 | release_sock(sk); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 331 | return rc; |
| 332 | } |
| 333 | |
James Chapman | c51ce49 | 2012-05-29 03:30:42 +0000 | [diff] [blame] | 334 | static int l2tp_ip_disconnect(struct sock *sk, int flags) |
| 335 | { |
| 336 | if (sock_flag(sk, SOCK_ZAPPED)) |
| 337 | return 0; |
| 338 | |
| 339 | return udp_disconnect(sk, flags); |
| 340 | } |
| 341 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 342 | static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr, |
| 343 | int *uaddr_len, int peer) |
| 344 | { |
| 345 | struct sock *sk = sock->sk; |
| 346 | struct inet_sock *inet = inet_sk(sk); |
| 347 | struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk); |
| 348 | struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr; |
| 349 | |
| 350 | memset(lsa, 0, sizeof(*lsa)); |
| 351 | lsa->l2tp_family = AF_INET; |
| 352 | if (peer) { |
| 353 | if (!inet->inet_dport) |
| 354 | return -ENOTCONN; |
| 355 | lsa->l2tp_conn_id = lsk->peer_conn_id; |
| 356 | lsa->l2tp_addr.s_addr = inet->inet_daddr; |
| 357 | } else { |
| 358 | __be32 addr = inet->inet_rcv_saddr; |
| 359 | if (!addr) |
| 360 | addr = inet->inet_saddr; |
| 361 | lsa->l2tp_conn_id = lsk->conn_id; |
| 362 | lsa->l2tp_addr.s_addr = addr; |
| 363 | } |
| 364 | *uaddr_len = sizeof(*lsa); |
| 365 | return 0; |
| 366 | } |
| 367 | |
| 368 | static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb) |
| 369 | { |
| 370 | int rc; |
| 371 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 372 | /* Charge it to the socket, dropping if the queue is full. */ |
| 373 | rc = sock_queue_rcv_skb(sk, skb); |
| 374 | if (rc < 0) |
| 375 | goto drop; |
| 376 | |
| 377 | return 0; |
| 378 | |
| 379 | drop: |
David S. Miller | 9d6ddb1 | 2013-02-05 14:36:02 -0500 | [diff] [blame] | 380 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 381 | kfree_skb(skb); |
| 382 | return -1; |
| 383 | } |
| 384 | |
| 385 | /* Userspace will call sendmsg() on the tunnel socket to send L2TP |
| 386 | * control frames. |
| 387 | */ |
Ying Xue | 1b78414 | 2015-03-02 15:37:48 +0800 | [diff] [blame] | 388 | static int l2tp_ip_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 389 | { |
| 390 | struct sk_buff *skb; |
| 391 | int rc; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 392 | struct inet_sock *inet = inet_sk(sk); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 393 | struct rtable *rt = NULL; |
David S. Miller | fdbb0f0 | 2011-05-08 13:48:37 -0700 | [diff] [blame] | 394 | struct flowi4 *fl4; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 395 | int connected = 0; |
| 396 | __be32 daddr; |
| 397 | |
David S. Miller | 2f16270 | 2011-05-08 13:39:01 -0700 | [diff] [blame] | 398 | lock_sock(sk); |
| 399 | |
| 400 | rc = -ENOTCONN; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 401 | if (sock_flag(sk, SOCK_DEAD)) |
David S. Miller | 2f16270 | 2011-05-08 13:39:01 -0700 | [diff] [blame] | 402 | goto out; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 403 | |
| 404 | /* Get and verify the address. */ |
| 405 | if (msg->msg_name) { |
Steffen Hurrle | 342dfc3 | 2014-01-17 22:53:15 +0100 | [diff] [blame] | 406 | DECLARE_SOCKADDR(struct sockaddr_l2tpip *, lip, msg->msg_name); |
David S. Miller | 2f16270 | 2011-05-08 13:39:01 -0700 | [diff] [blame] | 407 | rc = -EINVAL; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 408 | if (msg->msg_namelen < sizeof(*lip)) |
David S. Miller | 2f16270 | 2011-05-08 13:39:01 -0700 | [diff] [blame] | 409 | goto out; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 410 | |
| 411 | if (lip->l2tp_family != AF_INET) { |
David S. Miller | 2f16270 | 2011-05-08 13:39:01 -0700 | [diff] [blame] | 412 | rc = -EAFNOSUPPORT; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 413 | if (lip->l2tp_family != AF_UNSPEC) |
David S. Miller | 2f16270 | 2011-05-08 13:39:01 -0700 | [diff] [blame] | 414 | goto out; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 415 | } |
| 416 | |
| 417 | daddr = lip->l2tp_addr.s_addr; |
| 418 | } else { |
Sasha Levin | 84768edbb | 2012-05-02 03:58:43 +0000 | [diff] [blame] | 419 | rc = -EDESTADDRREQ; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 420 | if (sk->sk_state != TCP_ESTABLISHED) |
Sasha Levin | 84768edbb | 2012-05-02 03:58:43 +0000 | [diff] [blame] | 421 | goto out; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 422 | |
| 423 | daddr = inet->inet_daddr; |
| 424 | connected = 1; |
| 425 | } |
| 426 | |
| 427 | /* Allocate a socket buffer */ |
| 428 | rc = -ENOMEM; |
| 429 | skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) + |
| 430 | 4 + len, 0, GFP_KERNEL); |
| 431 | if (!skb) |
| 432 | goto error; |
| 433 | |
| 434 | /* Reserve space for headers, putting IP header on 4-byte boundary. */ |
| 435 | skb_reserve(skb, 2 + NET_SKB_PAD); |
| 436 | skb_reset_network_header(skb); |
| 437 | skb_reserve(skb, sizeof(struct iphdr)); |
| 438 | skb_reset_transport_header(skb); |
| 439 | |
| 440 | /* Insert 0 session_id */ |
| 441 | *((__be32 *) skb_put(skb, 4)) = 0; |
| 442 | |
| 443 | /* Copy user data into skb */ |
Al Viro | 6ce8e9c | 2014-04-06 21:25:44 -0400 | [diff] [blame] | 444 | rc = memcpy_from_msg(skb_put(skb, len), msg, len); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 445 | if (rc < 0) { |
| 446 | kfree_skb(skb); |
| 447 | goto error; |
| 448 | } |
| 449 | |
David S. Miller | fdbb0f0 | 2011-05-08 13:48:37 -0700 | [diff] [blame] | 450 | fl4 = &inet->cork.fl.u.ip4; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 451 | if (connected) |
| 452 | rt = (struct rtable *) __sk_dst_check(sk, 0); |
| 453 | |
Eric Dumazet | 081b1b1 | 2011-06-11 22:27:09 +0000 | [diff] [blame] | 454 | rcu_read_lock(); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 455 | if (rt == NULL) { |
Eric Dumazet | 081b1b1 | 2011-06-11 22:27:09 +0000 | [diff] [blame] | 456 | const struct ip_options_rcu *inet_opt; |
Eric Dumazet | f6d8bd0 | 2011-04-21 09:45:37 +0000 | [diff] [blame] | 457 | |
David S. Miller | 778865a | 2011-04-28 13:54:06 -0700 | [diff] [blame] | 458 | inet_opt = rcu_dereference(inet->inet_opt); |
Eric Dumazet | f6d8bd0 | 2011-04-21 09:45:37 +0000 | [diff] [blame] | 459 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 460 | /* Use correct destination address if we have options. */ |
Eric Dumazet | f6d8bd0 | 2011-04-21 09:45:37 +0000 | [diff] [blame] | 461 | if (inet_opt && inet_opt->opt.srr) |
| 462 | daddr = inet_opt->opt.faddr; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 463 | |
David S. Miller | 78fbfd8 | 2011-03-12 00:00:52 -0500 | [diff] [blame] | 464 | /* If this fails, retransmit mechanism of transport layer will |
| 465 | * keep trying until route appears or the connection times |
| 466 | * itself out. |
| 467 | */ |
David S. Miller | fdbb0f0 | 2011-05-08 13:48:37 -0700 | [diff] [blame] | 468 | rt = ip_route_output_ports(sock_net(sk), fl4, sk, |
David S. Miller | 78fbfd8 | 2011-03-12 00:00:52 -0500 | [diff] [blame] | 469 | daddr, inet->inet_saddr, |
| 470 | inet->inet_dport, inet->inet_sport, |
| 471 | sk->sk_protocol, RT_CONN_FLAGS(sk), |
| 472 | sk->sk_bound_dev_if); |
| 473 | if (IS_ERR(rt)) |
| 474 | goto no_route; |
Eric Dumazet | 4399a4d | 2012-06-08 06:25:00 +0000 | [diff] [blame] | 475 | if (connected) { |
Eric Dumazet | 081b1b1 | 2011-06-11 22:27:09 +0000 | [diff] [blame] | 476 | sk_setup_caps(sk, &rt->dst); |
Eric Dumazet | 4399a4d | 2012-06-08 06:25:00 +0000 | [diff] [blame] | 477 | } else { |
| 478 | skb_dst_set(skb, &rt->dst); |
| 479 | goto xmit; |
| 480 | } |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 481 | } |
Eric Dumazet | 081b1b1 | 2011-06-11 22:27:09 +0000 | [diff] [blame] | 482 | |
| 483 | /* We dont need to clone dst here, it is guaranteed to not disappear. |
| 484 | * __dev_xmit_skb() might force a refcount if needed. |
| 485 | */ |
| 486 | skb_dst_set_noref(skb, &rt->dst); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 487 | |
Eric Dumazet | 4399a4d | 2012-06-08 06:25:00 +0000 | [diff] [blame] | 488 | xmit: |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 489 | /* Queue the packet to IP for output */ |
Eric Dumazet | b0270e9 | 2014-04-15 12:58:34 -0400 | [diff] [blame] | 490 | rc = ip_queue_xmit(sk, skb, &inet->cork.fl); |
Eric Dumazet | 081b1b1 | 2011-06-11 22:27:09 +0000 | [diff] [blame] | 491 | rcu_read_unlock(); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 492 | |
| 493 | error: |
James Chapman | c8657fd | 2012-04-29 21:48:48 +0000 | [diff] [blame] | 494 | if (rc >= 0) |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 495 | rc = len; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 496 | |
David S. Miller | 2f16270 | 2011-05-08 13:39:01 -0700 | [diff] [blame] | 497 | out: |
| 498 | release_sock(sk); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 499 | return rc; |
| 500 | |
| 501 | no_route: |
Eric Dumazet | 081b1b1 | 2011-06-11 22:27:09 +0000 | [diff] [blame] | 502 | rcu_read_unlock(); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 503 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); |
| 504 | kfree_skb(skb); |
David S. Miller | 2f16270 | 2011-05-08 13:39:01 -0700 | [diff] [blame] | 505 | rc = -EHOSTUNREACH; |
| 506 | goto out; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 507 | } |
| 508 | |
Ying Xue | 1b78414 | 2015-03-02 15:37:48 +0800 | [diff] [blame] | 509 | static int l2tp_ip_recvmsg(struct sock *sk, struct msghdr *msg, |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 510 | size_t len, int noblock, int flags, int *addr_len) |
| 511 | { |
| 512 | struct inet_sock *inet = inet_sk(sk); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 513 | size_t copied = 0; |
| 514 | int err = -EOPNOTSUPP; |
Steffen Hurrle | 342dfc3 | 2014-01-17 22:53:15 +0100 | [diff] [blame] | 515 | DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 516 | struct sk_buff *skb; |
| 517 | |
| 518 | if (flags & MSG_OOB) |
| 519 | goto out; |
| 520 | |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 521 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
| 522 | if (!skb) |
| 523 | goto out; |
| 524 | |
| 525 | copied = skb->len; |
| 526 | if (len < copied) { |
| 527 | msg->msg_flags |= MSG_TRUNC; |
| 528 | copied = len; |
| 529 | } |
| 530 | |
David S. Miller | 51f3d02 | 2014-11-05 16:46:40 -0500 | [diff] [blame] | 531 | err = skb_copy_datagram_msg(skb, 0, msg, copied); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 532 | if (err) |
| 533 | goto done; |
| 534 | |
| 535 | sock_recv_timestamp(msg, sk, skb); |
| 536 | |
| 537 | /* Copy the address. */ |
| 538 | if (sin) { |
| 539 | sin->sin_family = AF_INET; |
| 540 | sin->sin_addr.s_addr = ip_hdr(skb)->saddr; |
| 541 | sin->sin_port = 0; |
| 542 | memset(&sin->sin_zero, 0, sizeof(sin->sin_zero)); |
Hannes Frederic Sowa | bceaa90 | 2013-11-18 04:20:45 +0100 | [diff] [blame] | 543 | *addr_len = sizeof(*sin); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 544 | } |
| 545 | if (inet->cmsg_flags) |
| 546 | ip_cmsg_recv(msg, skb); |
| 547 | if (flags & MSG_TRUNC) |
| 548 | copied = skb->len; |
| 549 | done: |
| 550 | skb_free_datagram(sk, skb); |
| 551 | out: |
James Chapman | c8657fd | 2012-04-29 21:48:48 +0000 | [diff] [blame] | 552 | return err ? err : copied; |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 553 | } |
| 554 | |
stephen hemminger | fc13084 | 2010-10-21 07:50:46 +0000 | [diff] [blame] | 555 | static struct proto l2tp_ip_prot = { |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 556 | .name = "L2TP/IP", |
| 557 | .owner = THIS_MODULE, |
| 558 | .init = l2tp_ip_open, |
| 559 | .close = l2tp_ip_close, |
| 560 | .bind = l2tp_ip_bind, |
| 561 | .connect = l2tp_ip_connect, |
James Chapman | c51ce49 | 2012-05-29 03:30:42 +0000 | [diff] [blame] | 562 | .disconnect = l2tp_ip_disconnect, |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 563 | .ioctl = udp_ioctl, |
| 564 | .destroy = l2tp_ip_destroy_sock, |
| 565 | .setsockopt = ip_setsockopt, |
| 566 | .getsockopt = ip_getsockopt, |
| 567 | .sendmsg = l2tp_ip_sendmsg, |
| 568 | .recvmsg = l2tp_ip_recvmsg, |
| 569 | .backlog_rcv = l2tp_ip_backlog_recv, |
| 570 | .hash = inet_hash, |
| 571 | .unhash = inet_unhash, |
| 572 | .obj_size = sizeof(struct l2tp_ip_sock), |
| 573 | #ifdef CONFIG_COMPAT |
| 574 | .compat_setsockopt = compat_ip_setsockopt, |
| 575 | .compat_getsockopt = compat_ip_getsockopt, |
| 576 | #endif |
| 577 | }; |
| 578 | |
| 579 | static const struct proto_ops l2tp_ip_ops = { |
| 580 | .family = PF_INET, |
| 581 | .owner = THIS_MODULE, |
| 582 | .release = inet_release, |
| 583 | .bind = inet_bind, |
| 584 | .connect = inet_dgram_connect, |
| 585 | .socketpair = sock_no_socketpair, |
| 586 | .accept = sock_no_accept, |
| 587 | .getname = l2tp_ip_getname, |
| 588 | .poll = datagram_poll, |
| 589 | .ioctl = inet_ioctl, |
| 590 | .listen = sock_no_listen, |
| 591 | .shutdown = inet_shutdown, |
| 592 | .setsockopt = sock_common_setsockopt, |
| 593 | .getsockopt = sock_common_getsockopt, |
| 594 | .sendmsg = inet_sendmsg, |
| 595 | .recvmsg = sock_common_recvmsg, |
| 596 | .mmap = sock_no_mmap, |
| 597 | .sendpage = sock_no_sendpage, |
| 598 | #ifdef CONFIG_COMPAT |
| 599 | .compat_setsockopt = compat_sock_common_setsockopt, |
| 600 | .compat_getsockopt = compat_sock_common_getsockopt, |
| 601 | #endif |
| 602 | }; |
| 603 | |
| 604 | static struct inet_protosw l2tp_ip_protosw = { |
| 605 | .type = SOCK_DGRAM, |
| 606 | .protocol = IPPROTO_L2TP, |
| 607 | .prot = &l2tp_ip_prot, |
| 608 | .ops = &l2tp_ip_ops, |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 609 | }; |
| 610 | |
| 611 | static struct net_protocol l2tp_ip_protocol __read_mostly = { |
| 612 | .handler = l2tp_ip_recv, |
David S. Miller | 9d6ddb1 | 2013-02-05 14:36:02 -0500 | [diff] [blame] | 613 | .netns_ok = 1, |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 614 | }; |
| 615 | |
| 616 | static int __init l2tp_ip_init(void) |
| 617 | { |
| 618 | int err; |
| 619 | |
Joe Perches | a4ca44f | 2012-05-16 09:55:56 +0000 | [diff] [blame] | 620 | pr_info("L2TP IP encapsulation support (L2TPv3)\n"); |
James Chapman | 0d76751 | 2010-04-02 06:19:00 +0000 | [diff] [blame] | 621 | |
| 622 | err = proto_register(&l2tp_ip_prot, 1); |
| 623 | if (err != 0) |
| 624 | goto out; |
| 625 | |
| 626 | err = inet_add_protocol(&l2tp_ip_protocol, IPPROTO_L2TP); |
| 627 | if (err) |
| 628 | goto out1; |
| 629 | |
| 630 | inet_register_protosw(&l2tp_ip_protosw); |
| 631 | return 0; |
| 632 | |
| 633 | out1: |
| 634 | proto_unregister(&l2tp_ip_prot); |
| 635 | out: |
| 636 | return err; |
| 637 | } |
| 638 | |
| 639 | static void __exit l2tp_ip_exit(void) |
| 640 | { |
| 641 | inet_unregister_protosw(&l2tp_ip_protosw); |
| 642 | inet_del_protocol(&l2tp_ip_protocol, IPPROTO_L2TP); |
| 643 | proto_unregister(&l2tp_ip_prot); |
| 644 | } |
| 645 | |
| 646 | module_init(l2tp_ip_init); |
| 647 | module_exit(l2tp_ip_exit); |
| 648 | |
| 649 | MODULE_LICENSE("GPL"); |
| 650 | MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); |
| 651 | MODULE_DESCRIPTION("L2TP over IP"); |
| 652 | MODULE_VERSION("1.0"); |
Michal Marek | e8d34a88 | 2010-12-06 02:39:12 +0000 | [diff] [blame] | 653 | |
Lucas De Marchi | e9c5499 | 2011-04-26 23:28:26 -0700 | [diff] [blame] | 654 | /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like |
Michal Marek | e8d34a88 | 2010-12-06 02:39:12 +0000 | [diff] [blame] | 655 | * enums |
| 656 | */ |
| 657 | MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 2, IPPROTO_L2TP); |
stephen hemminger | 163c2e2 | 2015-09-23 21:33:35 -0700 | [diff] [blame] | 658 | MODULE_ALIAS_NET_PF_PROTO(PF_INET, IPPROTO_L2TP); |