1 /* 2 * L2TPv3 ethernet pseudowire driver 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 12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 13 14 #include <linux/module.h> 15 #include <linux/skbuff.h> 16 #include <linux/socket.h> 17 #include <linux/hash.h> 18 #include <linux/l2tp.h> 19 #include <linux/in.h> 20 #include <linux/etherdevice.h> 21 #include <linux/spinlock.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 #include <net/net_namespace.h> 32 #include <net/netns/generic.h> 33 34 #include "l2tp_core.h" 35 36 /* Default device name. May be overridden by name specified by user */ 37 #define L2TP_ETH_DEV_NAME "l2tpeth%d" 38 39 /* via netdev_priv() */ 40 struct l2tp_eth { 41 struct net_device *dev; 42 struct sock *tunnel_sock; 43 struct l2tp_session *session; 44 struct list_head list; 45 atomic_long_t tx_bytes; 46 atomic_long_t tx_packets; 47 atomic_long_t tx_dropped; 48 atomic_long_t rx_bytes; 49 atomic_long_t rx_packets; 50 atomic_long_t rx_errors; 51 }; 52 53 /* via l2tp_session_priv() */ 54 struct l2tp_eth_sess { 55 struct net_device *dev; 56 }; 57 58 /* per-net private data for this module */ 59 static unsigned int l2tp_eth_net_id; 60 struct l2tp_eth_net { 61 struct list_head l2tp_eth_dev_list; 62 spinlock_t l2tp_eth_lock; 63 }; 64 65 static inline struct l2tp_eth_net *l2tp_eth_pernet(struct net *net) 66 { 67 return net_generic(net, l2tp_eth_net_id); 68 } 69 70 static struct lock_class_key l2tp_eth_tx_busylock; 71 static struct lock_class_key l2tp_qdisc_running_key; 72 73 static int l2tp_eth_dev_init(struct net_device *dev) 74 { 75 struct l2tp_eth *priv = netdev_priv(dev); 76 77 priv->dev = dev; 78 eth_hw_addr_random(dev); 79 eth_broadcast_addr(dev->broadcast); 80 dev->qdisc_tx_busylock = &l2tp_eth_tx_busylock; 81 dev->qdisc_running_key = &l2tp_qdisc_running_key; 82 83 return 0; 84 } 85 86 static void l2tp_eth_dev_uninit(struct net_device *dev) 87 { 88 struct l2tp_eth *priv = netdev_priv(dev); 89 struct l2tp_eth_net *pn = l2tp_eth_pernet(dev_net(dev)); 90 91 spin_lock(&pn->l2tp_eth_lock); 92 list_del_init(&priv->list); 93 spin_unlock(&pn->l2tp_eth_lock); 94 dev_put(dev); 95 } 96 97 static int l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev) 98 { 99 struct l2tp_eth *priv = netdev_priv(dev); 100 struct l2tp_session *session = priv->session; 101 unsigned int len = skb->len; 102 int ret = l2tp_xmit_skb(session, skb, session->hdr_len); 103 104 if (likely(ret == NET_XMIT_SUCCESS)) { 105 atomic_long_add(len, &priv->tx_bytes); 106 atomic_long_inc(&priv->tx_packets); 107 } else { 108 atomic_long_inc(&priv->tx_dropped); 109 } 110 return NETDEV_TX_OK; 111 } 112 113 static struct rtnl_link_stats64 *l2tp_eth_get_stats64(struct net_device *dev, 114 struct rtnl_link_stats64 *stats) 115 { 116 struct l2tp_eth *priv = netdev_priv(dev); 117 118 stats->tx_bytes = atomic_long_read(&priv->tx_bytes); 119 stats->tx_packets = atomic_long_read(&priv->tx_packets); 120 stats->tx_dropped = atomic_long_read(&priv->tx_dropped); 121 stats->rx_bytes = atomic_long_read(&priv->rx_bytes); 122 stats->rx_packets = atomic_long_read(&priv->rx_packets); 123 stats->rx_errors = atomic_long_read(&priv->rx_errors); 124 return stats; 125 } 126 127 128 static struct net_device_ops l2tp_eth_netdev_ops = { 129 .ndo_init = l2tp_eth_dev_init, 130 .ndo_uninit = l2tp_eth_dev_uninit, 131 .ndo_start_xmit = l2tp_eth_dev_xmit, 132 .ndo_get_stats64 = l2tp_eth_get_stats64, 133 .ndo_set_mac_address = eth_mac_addr, 134 }; 135 136 static void l2tp_eth_dev_setup(struct net_device *dev) 137 { 138 ether_setup(dev); 139 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 140 dev->features |= NETIF_F_LLTX; 141 dev->netdev_ops = &l2tp_eth_netdev_ops; 142 dev->destructor = free_netdev; 143 } 144 145 static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len) 146 { 147 struct l2tp_eth_sess *spriv = l2tp_session_priv(session); 148 struct net_device *dev = spriv->dev; 149 struct l2tp_eth *priv = netdev_priv(dev); 150 151 if (session->debug & L2TP_MSG_DATA) { 152 unsigned int length; 153 154 length = min(32u, skb->len); 155 if (!pskb_may_pull(skb, length)) 156 goto error; 157 158 pr_debug("%s: eth recv\n", session->name); 159 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length); 160 } 161 162 if (!pskb_may_pull(skb, ETH_HLEN)) 163 goto error; 164 165 secpath_reset(skb); 166 167 /* checksums verified by L2TP */ 168 skb->ip_summed = CHECKSUM_NONE; 169 170 skb_dst_drop(skb); 171 nf_reset(skb); 172 173 if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) { 174 atomic_long_inc(&priv->rx_packets); 175 atomic_long_add(data_len, &priv->rx_bytes); 176 } else { 177 atomic_long_inc(&priv->rx_errors); 178 } 179 return; 180 181 error: 182 atomic_long_inc(&priv->rx_errors); 183 kfree_skb(skb); 184 } 185 186 static void l2tp_eth_delete(struct l2tp_session *session) 187 { 188 struct l2tp_eth_sess *spriv; 189 struct net_device *dev; 190 191 if (session) { 192 spriv = l2tp_session_priv(session); 193 dev = spriv->dev; 194 if (dev) { 195 unregister_netdev(dev); 196 spriv->dev = NULL; 197 module_put(THIS_MODULE); 198 } 199 } 200 } 201 202 #if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE) 203 static void l2tp_eth_show(struct seq_file *m, void *arg) 204 { 205 struct l2tp_session *session = arg; 206 struct l2tp_eth_sess *spriv = l2tp_session_priv(session); 207 struct net_device *dev = spriv->dev; 208 209 seq_printf(m, " interface %s\n", dev->name); 210 } 211 #endif 212 213 static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) 214 { 215 struct net_device *dev; 216 char name[IFNAMSIZ]; 217 struct l2tp_tunnel *tunnel; 218 struct l2tp_session *session; 219 struct l2tp_eth *priv; 220 struct l2tp_eth_sess *spriv; 221 int rc; 222 struct l2tp_eth_net *pn; 223 224 tunnel = l2tp_tunnel_find(net, tunnel_id); 225 if (!tunnel) { 226 rc = -ENODEV; 227 goto out; 228 } 229 230 session = l2tp_session_find(net, tunnel, session_id); 231 if (session) { 232 rc = -EEXIST; 233 goto out; 234 } 235 236 if (cfg->ifname) { 237 dev = dev_get_by_name(net, cfg->ifname); 238 if (dev) { 239 dev_put(dev); 240 rc = -EEXIST; 241 goto out; 242 } 243 strlcpy(name, cfg->ifname, IFNAMSIZ); 244 } else 245 strcpy(name, L2TP_ETH_DEV_NAME); 246 247 session = l2tp_session_create(sizeof(*spriv), tunnel, session_id, 248 peer_session_id, cfg); 249 if (!session) { 250 rc = -ENOMEM; 251 goto out; 252 } 253 254 dev = alloc_netdev(sizeof(*priv), name, NET_NAME_UNKNOWN, 255 l2tp_eth_dev_setup); 256 if (!dev) { 257 rc = -ENOMEM; 258 goto out_del_session; 259 } 260 261 dev_net_set(dev, net); 262 if (session->mtu == 0) 263 session->mtu = dev->mtu - session->hdr_len; 264 dev->mtu = session->mtu; 265 dev->needed_headroom += session->hdr_len; 266 267 priv = netdev_priv(dev); 268 priv->dev = dev; 269 priv->session = session; 270 INIT_LIST_HEAD(&priv->list); 271 272 priv->tunnel_sock = tunnel->sock; 273 session->recv_skb = l2tp_eth_dev_recv; 274 session->session_close = l2tp_eth_delete; 275 #if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE) 276 session->show = l2tp_eth_show; 277 #endif 278 279 spriv = l2tp_session_priv(session); 280 spriv->dev = dev; 281 282 rc = register_netdev(dev); 283 if (rc < 0) 284 goto out_del_dev; 285 286 __module_get(THIS_MODULE); 287 /* Must be done after register_netdev() */ 288 strlcpy(session->ifname, dev->name, IFNAMSIZ); 289 290 dev_hold(dev); 291 pn = l2tp_eth_pernet(dev_net(dev)); 292 spin_lock(&pn->l2tp_eth_lock); 293 list_add(&priv->list, &pn->l2tp_eth_dev_list); 294 spin_unlock(&pn->l2tp_eth_lock); 295 296 return 0; 297 298 out_del_dev: 299 free_netdev(dev); 300 spriv->dev = NULL; 301 out_del_session: 302 l2tp_session_delete(session); 303 out: 304 return rc; 305 } 306 307 static __net_init int l2tp_eth_init_net(struct net *net) 308 { 309 struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id); 310 311 INIT_LIST_HEAD(&pn->l2tp_eth_dev_list); 312 spin_lock_init(&pn->l2tp_eth_lock); 313 314 return 0; 315 } 316 317 static struct pernet_operations l2tp_eth_net_ops = { 318 .init = l2tp_eth_init_net, 319 .id = &l2tp_eth_net_id, 320 .size = sizeof(struct l2tp_eth_net), 321 }; 322 323 324 static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = { 325 .session_create = l2tp_eth_create, 326 .session_delete = l2tp_session_delete, 327 }; 328 329 330 static int __init l2tp_eth_init(void) 331 { 332 int err = 0; 333 334 err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops); 335 if (err) 336 goto out; 337 338 err = register_pernet_device(&l2tp_eth_net_ops); 339 if (err) 340 goto out_unreg; 341 342 pr_info("L2TP ethernet pseudowire support (L2TPv3)\n"); 343 344 return 0; 345 346 out_unreg: 347 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); 348 out: 349 return err; 350 } 351 352 static void __exit l2tp_eth_exit(void) 353 { 354 unregister_pernet_device(&l2tp_eth_net_ops); 355 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); 356 } 357 358 module_init(l2tp_eth_init); 359 module_exit(l2tp_eth_exit); 360 361 MODULE_LICENSE("GPL"); 362 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 363 MODULE_DESCRIPTION("L2TP ethernet pseudowire driver"); 364 MODULE_VERSION("1.0"); 365 MODULE_ALIAS_L2TP_PWTYPE(5); 366