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 int l2tp_eth_dev_init(struct net_device *dev) 71 { 72 struct l2tp_eth *priv = netdev_priv(dev); 73 74 priv->dev = dev; 75 eth_hw_addr_random(dev); 76 eth_broadcast_addr(dev->broadcast); 77 netdev_lockdep_set_classes(dev); 78 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 const 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 .ndo_set_mac_address = eth_mac_addr, 130 }; 131 132 static void l2tp_eth_dev_setup(struct net_device *dev) 133 { 134 ether_setup(dev); 135 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 136 dev->features |= NETIF_F_LLTX; 137 dev->netdev_ops = &l2tp_eth_netdev_ops; 138 dev->destructor = free_netdev; 139 } 140 141 static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len) 142 { 143 struct l2tp_eth_sess *spriv = l2tp_session_priv(session); 144 struct net_device *dev = spriv->dev; 145 struct l2tp_eth *priv = netdev_priv(dev); 146 147 if (session->debug & L2TP_MSG_DATA) { 148 unsigned int length; 149 150 length = min(32u, skb->len); 151 if (!pskb_may_pull(skb, length)) 152 goto error; 153 154 pr_debug("%s: eth recv\n", session->name); 155 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length); 156 } 157 158 if (!pskb_may_pull(skb, ETH_HLEN)) 159 goto error; 160 161 secpath_reset(skb); 162 163 /* checksums verified by L2TP */ 164 skb->ip_summed = CHECKSUM_NONE; 165 166 skb_dst_drop(skb); 167 nf_reset(skb); 168 169 if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) { 170 atomic_long_inc(&priv->rx_packets); 171 atomic_long_add(data_len, &priv->rx_bytes); 172 } else { 173 atomic_long_inc(&priv->rx_errors); 174 } 175 return; 176 177 error: 178 atomic_long_inc(&priv->rx_errors); 179 kfree_skb(skb); 180 } 181 182 static void l2tp_eth_delete(struct l2tp_session *session) 183 { 184 struct l2tp_eth_sess *spriv; 185 struct net_device *dev; 186 187 if (session) { 188 spriv = l2tp_session_priv(session); 189 dev = spriv->dev; 190 if (dev) { 191 unregister_netdev(dev); 192 spriv->dev = NULL; 193 module_put(THIS_MODULE); 194 } 195 } 196 } 197 198 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS) 199 static void l2tp_eth_show(struct seq_file *m, void *arg) 200 { 201 struct l2tp_session *session = arg; 202 struct l2tp_eth_sess *spriv = l2tp_session_priv(session); 203 struct net_device *dev = spriv->dev; 204 205 seq_printf(m, " interface %s\n", dev->name); 206 } 207 #endif 208 209 static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) 210 { 211 struct net_device *dev; 212 char name[IFNAMSIZ]; 213 struct l2tp_tunnel *tunnel; 214 struct l2tp_session *session; 215 struct l2tp_eth *priv; 216 struct l2tp_eth_sess *spriv; 217 int rc; 218 struct l2tp_eth_net *pn; 219 220 tunnel = l2tp_tunnel_find(net, tunnel_id); 221 if (!tunnel) { 222 rc = -ENODEV; 223 goto out; 224 } 225 226 session = l2tp_session_find(net, tunnel, session_id); 227 if (session) { 228 rc = -EEXIST; 229 goto out; 230 } 231 232 if (cfg->ifname) { 233 dev = dev_get_by_name(net, cfg->ifname); 234 if (dev) { 235 dev_put(dev); 236 rc = -EEXIST; 237 goto out; 238 } 239 strlcpy(name, cfg->ifname, IFNAMSIZ); 240 } else 241 strcpy(name, L2TP_ETH_DEV_NAME); 242 243 session = l2tp_session_create(sizeof(*spriv), tunnel, session_id, 244 peer_session_id, cfg); 245 if (!session) { 246 rc = -ENOMEM; 247 goto out; 248 } 249 250 dev = alloc_netdev(sizeof(*priv), name, NET_NAME_UNKNOWN, 251 l2tp_eth_dev_setup); 252 if (!dev) { 253 rc = -ENOMEM; 254 goto out_del_session; 255 } 256 257 dev_net_set(dev, net); 258 if (session->mtu == 0) 259 session->mtu = dev->mtu - session->hdr_len; 260 dev->mtu = session->mtu; 261 dev->needed_headroom += session->hdr_len; 262 dev->min_mtu = 0; 263 dev->max_mtu = ETH_MAX_MTU; 264 265 priv = netdev_priv(dev); 266 priv->dev = dev; 267 priv->session = session; 268 INIT_LIST_HEAD(&priv->list); 269 270 priv->tunnel_sock = tunnel->sock; 271 session->recv_skb = l2tp_eth_dev_recv; 272 session->session_close = l2tp_eth_delete; 273 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS) 274 session->show = l2tp_eth_show; 275 #endif 276 277 spriv = l2tp_session_priv(session); 278 spriv->dev = dev; 279 280 rc = register_netdev(dev); 281 if (rc < 0) 282 goto out_del_dev; 283 284 __module_get(THIS_MODULE); 285 /* Must be done after register_netdev() */ 286 strlcpy(session->ifname, dev->name, IFNAMSIZ); 287 288 dev_hold(dev); 289 pn = l2tp_eth_pernet(dev_net(dev)); 290 spin_lock(&pn->l2tp_eth_lock); 291 list_add(&priv->list, &pn->l2tp_eth_dev_list); 292 spin_unlock(&pn->l2tp_eth_lock); 293 294 return 0; 295 296 out_del_dev: 297 free_netdev(dev); 298 spriv->dev = NULL; 299 out_del_session: 300 l2tp_session_delete(session); 301 out: 302 return rc; 303 } 304 305 static __net_init int l2tp_eth_init_net(struct net *net) 306 { 307 struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id); 308 309 INIT_LIST_HEAD(&pn->l2tp_eth_dev_list); 310 spin_lock_init(&pn->l2tp_eth_lock); 311 312 return 0; 313 } 314 315 static struct pernet_operations l2tp_eth_net_ops = { 316 .init = l2tp_eth_init_net, 317 .id = &l2tp_eth_net_id, 318 .size = sizeof(struct l2tp_eth_net), 319 }; 320 321 322 static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = { 323 .session_create = l2tp_eth_create, 324 .session_delete = l2tp_session_delete, 325 }; 326 327 328 static int __init l2tp_eth_init(void) 329 { 330 int err = 0; 331 332 err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops); 333 if (err) 334 goto out; 335 336 err = register_pernet_device(&l2tp_eth_net_ops); 337 if (err) 338 goto out_unreg; 339 340 pr_info("L2TP ethernet pseudowire support (L2TPv3)\n"); 341 342 return 0; 343 344 out_unreg: 345 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); 346 out: 347 return err; 348 } 349 350 static void __exit l2tp_eth_exit(void) 351 { 352 unregister_pernet_device(&l2tp_eth_net_ops); 353 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); 354 } 355 356 module_init(l2tp_eth_init); 357 module_exit(l2tp_eth_exit); 358 359 MODULE_LICENSE("GPL"); 360 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 361 MODULE_DESCRIPTION("L2TP ethernet pseudowire driver"); 362 MODULE_VERSION("1.0"); 363 MODULE_ALIAS_L2TP_PWTYPE(5); 364