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 void 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 } 121 122 static const struct net_device_ops l2tp_eth_netdev_ops = { 123 .ndo_init = l2tp_eth_dev_init, 124 .ndo_uninit = l2tp_eth_dev_uninit, 125 .ndo_start_xmit = l2tp_eth_dev_xmit, 126 .ndo_get_stats64 = l2tp_eth_get_stats64, 127 .ndo_set_mac_address = eth_mac_addr, 128 }; 129 130 static void l2tp_eth_dev_setup(struct net_device *dev) 131 { 132 ether_setup(dev); 133 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 134 dev->features |= NETIF_F_LLTX; 135 dev->netdev_ops = &l2tp_eth_netdev_ops; 136 dev->destructor = free_netdev; 137 } 138 139 static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len) 140 { 141 struct l2tp_eth_sess *spriv = l2tp_session_priv(session); 142 struct net_device *dev = spriv->dev; 143 struct l2tp_eth *priv = netdev_priv(dev); 144 145 if (session->debug & L2TP_MSG_DATA) { 146 unsigned int length; 147 148 length = min(32u, skb->len); 149 if (!pskb_may_pull(skb, length)) 150 goto error; 151 152 pr_debug("%s: eth recv\n", session->name); 153 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length); 154 } 155 156 if (!pskb_may_pull(skb, ETH_HLEN)) 157 goto error; 158 159 secpath_reset(skb); 160 161 /* checksums verified by L2TP */ 162 skb->ip_summed = CHECKSUM_NONE; 163 164 skb_dst_drop(skb); 165 nf_reset(skb); 166 167 if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) { 168 atomic_long_inc(&priv->rx_packets); 169 atomic_long_add(data_len, &priv->rx_bytes); 170 } else { 171 atomic_long_inc(&priv->rx_errors); 172 } 173 return; 174 175 error: 176 atomic_long_inc(&priv->rx_errors); 177 kfree_skb(skb); 178 } 179 180 static void l2tp_eth_delete(struct l2tp_session *session) 181 { 182 struct l2tp_eth_sess *spriv; 183 struct net_device *dev; 184 185 if (session) { 186 spriv = l2tp_session_priv(session); 187 dev = spriv->dev; 188 if (dev) { 189 unregister_netdev(dev); 190 spriv->dev = NULL; 191 module_put(THIS_MODULE); 192 } 193 } 194 } 195 196 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS) 197 static void l2tp_eth_show(struct seq_file *m, void *arg) 198 { 199 struct l2tp_session *session = arg; 200 struct l2tp_eth_sess *spriv = l2tp_session_priv(session); 201 struct net_device *dev = spriv->dev; 202 203 seq_printf(m, " interface %s\n", dev->name); 204 } 205 #endif 206 207 static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) 208 { 209 struct net_device *dev; 210 char name[IFNAMSIZ]; 211 struct l2tp_tunnel *tunnel; 212 struct l2tp_session *session; 213 struct l2tp_eth *priv; 214 struct l2tp_eth_sess *spriv; 215 int rc; 216 struct l2tp_eth_net *pn; 217 218 tunnel = l2tp_tunnel_find(net, tunnel_id); 219 if (!tunnel) { 220 rc = -ENODEV; 221 goto out; 222 } 223 224 if (cfg->ifname) { 225 dev = dev_get_by_name(net, cfg->ifname); 226 if (dev) { 227 dev_put(dev); 228 rc = -EEXIST; 229 goto out; 230 } 231 strlcpy(name, cfg->ifname, IFNAMSIZ); 232 } else 233 strcpy(name, L2TP_ETH_DEV_NAME); 234 235 session = l2tp_session_create(sizeof(*spriv), tunnel, session_id, 236 peer_session_id, cfg); 237 if (IS_ERR(session)) { 238 rc = PTR_ERR(session); 239 goto out; 240 } 241 242 dev = alloc_netdev(sizeof(*priv), name, NET_NAME_UNKNOWN, 243 l2tp_eth_dev_setup); 244 if (!dev) { 245 rc = -ENOMEM; 246 goto out_del_session; 247 } 248 249 dev_net_set(dev, net); 250 if (session->mtu == 0) 251 session->mtu = dev->mtu - session->hdr_len; 252 dev->mtu = session->mtu; 253 dev->needed_headroom += session->hdr_len; 254 dev->min_mtu = 0; 255 dev->max_mtu = ETH_MAX_MTU; 256 257 priv = netdev_priv(dev); 258 priv->dev = dev; 259 priv->session = session; 260 INIT_LIST_HEAD(&priv->list); 261 262 priv->tunnel_sock = tunnel->sock; 263 session->recv_skb = l2tp_eth_dev_recv; 264 session->session_close = l2tp_eth_delete; 265 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS) 266 session->show = l2tp_eth_show; 267 #endif 268 269 spriv = l2tp_session_priv(session); 270 spriv->dev = dev; 271 272 rc = register_netdev(dev); 273 if (rc < 0) 274 goto out_del_dev; 275 276 __module_get(THIS_MODULE); 277 /* Must be done after register_netdev() */ 278 strlcpy(session->ifname, dev->name, IFNAMSIZ); 279 280 dev_hold(dev); 281 pn = l2tp_eth_pernet(dev_net(dev)); 282 spin_lock(&pn->l2tp_eth_lock); 283 list_add(&priv->list, &pn->l2tp_eth_dev_list); 284 spin_unlock(&pn->l2tp_eth_lock); 285 286 return 0; 287 288 out_del_dev: 289 free_netdev(dev); 290 spriv->dev = NULL; 291 out_del_session: 292 l2tp_session_delete(session); 293 out: 294 return rc; 295 } 296 297 static __net_init int l2tp_eth_init_net(struct net *net) 298 { 299 struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id); 300 301 INIT_LIST_HEAD(&pn->l2tp_eth_dev_list); 302 spin_lock_init(&pn->l2tp_eth_lock); 303 304 return 0; 305 } 306 307 static struct pernet_operations l2tp_eth_net_ops = { 308 .init = l2tp_eth_init_net, 309 .id = &l2tp_eth_net_id, 310 .size = sizeof(struct l2tp_eth_net), 311 }; 312 313 314 static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = { 315 .session_create = l2tp_eth_create, 316 .session_delete = l2tp_session_delete, 317 }; 318 319 320 static int __init l2tp_eth_init(void) 321 { 322 int err = 0; 323 324 err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops); 325 if (err) 326 goto out; 327 328 err = register_pernet_device(&l2tp_eth_net_ops); 329 if (err) 330 goto out_unreg; 331 332 pr_info("L2TP ethernet pseudowire support (L2TPv3)\n"); 333 334 return 0; 335 336 out_unreg: 337 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); 338 out: 339 return err; 340 } 341 342 static void __exit l2tp_eth_exit(void) 343 { 344 unregister_pernet_device(&l2tp_eth_net_ops); 345 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); 346 } 347 348 module_init(l2tp_eth_init); 349 module_exit(l2tp_eth_exit); 350 351 MODULE_LICENSE("GPL"); 352 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 353 MODULE_DESCRIPTION("L2TP ethernet pseudowire driver"); 354 MODULE_VERSION("1.0"); 355 MODULE_ALIAS_L2TP_PWTYPE(5); 356