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 int l2tp_eth_dev_init(struct net_device *dev) 72 { 73 struct l2tp_eth *priv = netdev_priv(dev); 74 75 priv->dev = dev; 76 eth_hw_addr_random(dev); 77 memset(&dev->broadcast[0], 0xff, 6); 78 dev->qdisc_tx_busylock = &l2tp_eth_tx_busylock; 79 return 0; 80 } 81 82 static void l2tp_eth_dev_uninit(struct net_device *dev) 83 { 84 struct l2tp_eth *priv = netdev_priv(dev); 85 struct l2tp_eth_net *pn = l2tp_eth_pernet(dev_net(dev)); 86 87 spin_lock(&pn->l2tp_eth_lock); 88 list_del_init(&priv->list); 89 spin_unlock(&pn->l2tp_eth_lock); 90 dev_put(dev); 91 } 92 93 static int l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev) 94 { 95 struct l2tp_eth *priv = netdev_priv(dev); 96 struct l2tp_session *session = priv->session; 97 unsigned int len = skb->len; 98 int ret = l2tp_xmit_skb(session, skb, session->hdr_len); 99 100 if (likely(ret == NET_XMIT_SUCCESS)) { 101 atomic_long_add(len, &priv->tx_bytes); 102 atomic_long_inc(&priv->tx_packets); 103 } else { 104 atomic_long_inc(&priv->tx_dropped); 105 } 106 return NETDEV_TX_OK; 107 } 108 109 static struct rtnl_link_stats64 *l2tp_eth_get_stats64(struct net_device *dev, 110 struct rtnl_link_stats64 *stats) 111 { 112 struct l2tp_eth *priv = netdev_priv(dev); 113 114 stats->tx_bytes = atomic_long_read(&priv->tx_bytes); 115 stats->tx_packets = atomic_long_read(&priv->tx_packets); 116 stats->tx_dropped = atomic_long_read(&priv->tx_dropped); 117 stats->rx_bytes = atomic_long_read(&priv->rx_bytes); 118 stats->rx_packets = atomic_long_read(&priv->rx_packets); 119 stats->rx_errors = atomic_long_read(&priv->rx_errors); 120 return stats; 121 } 122 123 124 static struct net_device_ops l2tp_eth_netdev_ops = { 125 .ndo_init = l2tp_eth_dev_init, 126 .ndo_uninit = l2tp_eth_dev_uninit, 127 .ndo_start_xmit = l2tp_eth_dev_xmit, 128 .ndo_get_stats64 = l2tp_eth_get_stats64, 129 }; 130 131 static void l2tp_eth_dev_setup(struct net_device *dev) 132 { 133 ether_setup(dev); 134 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 135 dev->features |= NETIF_F_LLTX; 136 dev->netdev_ops = &l2tp_eth_netdev_ops; 137 dev->destructor = free_netdev; 138 } 139 140 static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len) 141 { 142 struct l2tp_eth_sess *spriv = l2tp_session_priv(session); 143 struct net_device *dev = spriv->dev; 144 struct l2tp_eth *priv = netdev_priv(dev); 145 146 if (session->debug & L2TP_MSG_DATA) { 147 unsigned int length; 148 149 length = min(32u, skb->len); 150 if (!pskb_may_pull(skb, length)) 151 goto error; 152 153 pr_debug("%s: eth recv\n", session->name); 154 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length); 155 } 156 157 if (!pskb_may_pull(skb, ETH_HLEN)) 158 goto error; 159 160 secpath_reset(skb); 161 162 /* checksums verified by L2TP */ 163 skb->ip_summed = CHECKSUM_NONE; 164 165 skb_dst_drop(skb); 166 nf_reset(skb); 167 168 if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) { 169 atomic_long_inc(&priv->rx_packets); 170 atomic_long_add(data_len, &priv->rx_bytes); 171 } else { 172 atomic_long_inc(&priv->rx_errors); 173 } 174 return; 175 176 error: 177 atomic_long_inc(&priv->rx_errors); 178 kfree_skb(skb); 179 } 180 181 static void l2tp_eth_delete(struct l2tp_session *session) 182 { 183 struct l2tp_eth_sess *spriv; 184 struct net_device *dev; 185 186 if (session) { 187 spriv = l2tp_session_priv(session); 188 dev = spriv->dev; 189 if (dev) { 190 unregister_netdev(dev); 191 spriv->dev = NULL; 192 module_put(THIS_MODULE); 193 } 194 } 195 } 196 197 #if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE) 198 static void l2tp_eth_show(struct seq_file *m, void *arg) 199 { 200 struct l2tp_session *session = arg; 201 struct l2tp_eth_sess *spriv = l2tp_session_priv(session); 202 struct net_device *dev = spriv->dev; 203 204 seq_printf(m, " interface %s\n", dev->name); 205 } 206 #endif 207 208 static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) 209 { 210 struct net_device *dev; 211 char name[IFNAMSIZ]; 212 struct l2tp_tunnel *tunnel; 213 struct l2tp_session *session; 214 struct l2tp_eth *priv; 215 struct l2tp_eth_sess *spriv; 216 int rc; 217 struct l2tp_eth_net *pn; 218 219 tunnel = l2tp_tunnel_find(net, tunnel_id); 220 if (!tunnel) { 221 rc = -ENODEV; 222 goto out; 223 } 224 225 session = l2tp_session_find(net, tunnel, session_id); 226 if (session) { 227 rc = -EEXIST; 228 goto out; 229 } 230 231 if (cfg->ifname) { 232 dev = dev_get_by_name(net, cfg->ifname); 233 if (dev) { 234 dev_put(dev); 235 rc = -EEXIST; 236 goto out; 237 } 238 strlcpy(name, cfg->ifname, IFNAMSIZ); 239 } else 240 strcpy(name, L2TP_ETH_DEV_NAME); 241 242 session = l2tp_session_create(sizeof(*spriv), tunnel, session_id, 243 peer_session_id, cfg); 244 if (!session) { 245 rc = -ENOMEM; 246 goto out; 247 } 248 249 dev = alloc_netdev(sizeof(*priv), name, NET_NAME_UNKNOWN, 250 l2tp_eth_dev_setup); 251 if (!dev) { 252 rc = -ENOMEM; 253 goto out_del_session; 254 } 255 256 dev_net_set(dev, net); 257 if (session->mtu == 0) 258 session->mtu = dev->mtu - session->hdr_len; 259 dev->mtu = session->mtu; 260 dev->needed_headroom += session->hdr_len; 261 262 priv = netdev_priv(dev); 263 priv->dev = dev; 264 priv->session = session; 265 INIT_LIST_HEAD(&priv->list); 266 267 priv->tunnel_sock = tunnel->sock; 268 session->recv_skb = l2tp_eth_dev_recv; 269 session->session_close = l2tp_eth_delete; 270 #if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE) 271 session->show = l2tp_eth_show; 272 #endif 273 274 spriv = l2tp_session_priv(session); 275 spriv->dev = dev; 276 277 rc = register_netdev(dev); 278 if (rc < 0) 279 goto out_del_dev; 280 281 __module_get(THIS_MODULE); 282 /* Must be done after register_netdev() */ 283 strlcpy(session->ifname, dev->name, IFNAMSIZ); 284 285 dev_hold(dev); 286 pn = l2tp_eth_pernet(dev_net(dev)); 287 spin_lock(&pn->l2tp_eth_lock); 288 list_add(&priv->list, &pn->l2tp_eth_dev_list); 289 spin_unlock(&pn->l2tp_eth_lock); 290 291 return 0; 292 293 out_del_dev: 294 free_netdev(dev); 295 spriv->dev = NULL; 296 out_del_session: 297 l2tp_session_delete(session); 298 out: 299 return rc; 300 } 301 302 static __net_init int l2tp_eth_init_net(struct net *net) 303 { 304 struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id); 305 306 INIT_LIST_HEAD(&pn->l2tp_eth_dev_list); 307 spin_lock_init(&pn->l2tp_eth_lock); 308 309 return 0; 310 } 311 312 static struct pernet_operations l2tp_eth_net_ops = { 313 .init = l2tp_eth_init_net, 314 .id = &l2tp_eth_net_id, 315 .size = sizeof(struct l2tp_eth_net), 316 }; 317 318 319 static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = { 320 .session_create = l2tp_eth_create, 321 .session_delete = l2tp_session_delete, 322 }; 323 324 325 static int __init l2tp_eth_init(void) 326 { 327 int err = 0; 328 329 err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops); 330 if (err) 331 goto out; 332 333 err = register_pernet_device(&l2tp_eth_net_ops); 334 if (err) 335 goto out_unreg; 336 337 pr_info("L2TP ethernet pseudowire support (L2TPv3)\n"); 338 339 return 0; 340 341 out_unreg: 342 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); 343 out: 344 return err; 345 } 346 347 static void __exit l2tp_eth_exit(void) 348 { 349 unregister_pernet_device(&l2tp_eth_net_ops); 350 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); 351 } 352 353 module_init(l2tp_eth_init); 354 module_exit(l2tp_eth_exit); 355 356 MODULE_LICENSE("GPL"); 357 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 358 MODULE_DESCRIPTION("L2TP ethernet pseudowire driver"); 359 MODULE_VERSION("1.0"); 360