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 }; 46 47 /* via l2tp_session_priv() */ 48 struct l2tp_eth_sess { 49 struct net_device *dev; 50 }; 51 52 /* per-net private data for this module */ 53 static unsigned int l2tp_eth_net_id; 54 struct l2tp_eth_net { 55 struct list_head l2tp_eth_dev_list; 56 spinlock_t l2tp_eth_lock; 57 }; 58 59 static inline struct l2tp_eth_net *l2tp_eth_pernet(struct net *net) 60 { 61 return net_generic(net, l2tp_eth_net_id); 62 } 63 64 static int l2tp_eth_dev_init(struct net_device *dev) 65 { 66 struct l2tp_eth *priv = netdev_priv(dev); 67 68 priv->dev = dev; 69 eth_hw_addr_random(dev); 70 memset(&dev->broadcast[0], 0xff, 6); 71 72 return 0; 73 } 74 75 static void l2tp_eth_dev_uninit(struct net_device *dev) 76 { 77 struct l2tp_eth *priv = netdev_priv(dev); 78 struct l2tp_eth_net *pn = l2tp_eth_pernet(dev_net(dev)); 79 80 spin_lock(&pn->l2tp_eth_lock); 81 list_del_init(&priv->list); 82 spin_unlock(&pn->l2tp_eth_lock); 83 dev_put(dev); 84 } 85 86 static int l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev) 87 { 88 struct l2tp_eth *priv = netdev_priv(dev); 89 struct l2tp_session *session = priv->session; 90 91 l2tp_xmit_skb(session, skb, session->hdr_len); 92 93 dev->stats.tx_bytes += skb->len; 94 dev->stats.tx_packets++; 95 96 return 0; 97 } 98 99 static struct net_device_ops l2tp_eth_netdev_ops = { 100 .ndo_init = l2tp_eth_dev_init, 101 .ndo_uninit = l2tp_eth_dev_uninit, 102 .ndo_start_xmit = l2tp_eth_dev_xmit, 103 }; 104 105 static void l2tp_eth_dev_setup(struct net_device *dev) 106 { 107 ether_setup(dev); 108 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 109 dev->netdev_ops = &l2tp_eth_netdev_ops; 110 dev->destructor = free_netdev; 111 } 112 113 static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len) 114 { 115 struct l2tp_eth_sess *spriv = l2tp_session_priv(session); 116 struct net_device *dev = spriv->dev; 117 118 if (session->debug & L2TP_MSG_DATA) { 119 unsigned int length; 120 u8 *ptr = skb->data; 121 122 length = min(32u, skb->len); 123 if (!pskb_may_pull(skb, length)) 124 goto error; 125 126 pr_debug("%s: eth recv\n", session->name); 127 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); 128 } 129 130 if (!pskb_may_pull(skb, sizeof(ETH_HLEN))) 131 goto error; 132 133 secpath_reset(skb); 134 135 /* checksums verified by L2TP */ 136 skb->ip_summed = CHECKSUM_NONE; 137 138 skb_dst_drop(skb); 139 nf_reset(skb); 140 141 if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) { 142 dev->stats.rx_packets++; 143 dev->stats.rx_bytes += data_len; 144 } else 145 dev->stats.rx_errors++; 146 147 return; 148 149 error: 150 dev->stats.rx_errors++; 151 kfree_skb(skb); 152 } 153 154 static void l2tp_eth_delete(struct l2tp_session *session) 155 { 156 struct l2tp_eth_sess *spriv; 157 struct net_device *dev; 158 159 if (session) { 160 spriv = l2tp_session_priv(session); 161 dev = spriv->dev; 162 if (dev) { 163 unregister_netdev(dev); 164 spriv->dev = NULL; 165 } 166 } 167 } 168 169 #if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE) 170 static void l2tp_eth_show(struct seq_file *m, void *arg) 171 { 172 struct l2tp_session *session = arg; 173 struct l2tp_eth_sess *spriv = l2tp_session_priv(session); 174 struct net_device *dev = spriv->dev; 175 176 seq_printf(m, " interface %s\n", dev->name); 177 } 178 #endif 179 180 static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) 181 { 182 struct net_device *dev; 183 char name[IFNAMSIZ]; 184 struct l2tp_tunnel *tunnel; 185 struct l2tp_session *session; 186 struct l2tp_eth *priv; 187 struct l2tp_eth_sess *spriv; 188 int rc; 189 struct l2tp_eth_net *pn; 190 191 tunnel = l2tp_tunnel_find(net, tunnel_id); 192 if (!tunnel) { 193 rc = -ENODEV; 194 goto out; 195 } 196 197 session = l2tp_session_find(net, tunnel, session_id); 198 if (session) { 199 rc = -EEXIST; 200 goto out; 201 } 202 203 if (cfg->ifname) { 204 dev = dev_get_by_name(net, cfg->ifname); 205 if (dev) { 206 dev_put(dev); 207 rc = -EEXIST; 208 goto out; 209 } 210 strlcpy(name, cfg->ifname, IFNAMSIZ); 211 } else 212 strcpy(name, L2TP_ETH_DEV_NAME); 213 214 session = l2tp_session_create(sizeof(*spriv), tunnel, session_id, 215 peer_session_id, cfg); 216 if (!session) { 217 rc = -ENOMEM; 218 goto out; 219 } 220 221 dev = alloc_netdev(sizeof(*priv), name, l2tp_eth_dev_setup); 222 if (!dev) { 223 rc = -ENOMEM; 224 goto out_del_session; 225 } 226 227 dev_net_set(dev, net); 228 if (session->mtu == 0) 229 session->mtu = dev->mtu - session->hdr_len; 230 dev->mtu = session->mtu; 231 dev->needed_headroom += session->hdr_len; 232 233 priv = netdev_priv(dev); 234 priv->dev = dev; 235 priv->session = session; 236 INIT_LIST_HEAD(&priv->list); 237 238 priv->tunnel_sock = tunnel->sock; 239 session->recv_skb = l2tp_eth_dev_recv; 240 session->session_close = l2tp_eth_delete; 241 #if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE) 242 session->show = l2tp_eth_show; 243 #endif 244 245 spriv = l2tp_session_priv(session); 246 spriv->dev = dev; 247 248 rc = register_netdev(dev); 249 if (rc < 0) 250 goto out_del_dev; 251 252 /* Must be done after register_netdev() */ 253 strlcpy(session->ifname, dev->name, IFNAMSIZ); 254 255 dev_hold(dev); 256 pn = l2tp_eth_pernet(dev_net(dev)); 257 spin_lock(&pn->l2tp_eth_lock); 258 list_add(&priv->list, &pn->l2tp_eth_dev_list); 259 spin_unlock(&pn->l2tp_eth_lock); 260 261 return 0; 262 263 out_del_dev: 264 free_netdev(dev); 265 out_del_session: 266 l2tp_session_delete(session); 267 out: 268 return rc; 269 } 270 271 static __net_init int l2tp_eth_init_net(struct net *net) 272 { 273 struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id); 274 275 INIT_LIST_HEAD(&pn->l2tp_eth_dev_list); 276 spin_lock_init(&pn->l2tp_eth_lock); 277 278 return 0; 279 } 280 281 static struct pernet_operations l2tp_eth_net_ops = { 282 .init = l2tp_eth_init_net, 283 .id = &l2tp_eth_net_id, 284 .size = sizeof(struct l2tp_eth_net), 285 }; 286 287 288 static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = { 289 .session_create = l2tp_eth_create, 290 .session_delete = l2tp_session_delete, 291 }; 292 293 294 static int __init l2tp_eth_init(void) 295 { 296 int err = 0; 297 298 err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops); 299 if (err) 300 goto out; 301 302 err = register_pernet_device(&l2tp_eth_net_ops); 303 if (err) 304 goto out_unreg; 305 306 pr_info("L2TP ethernet pseudowire support (L2TPv3)\n"); 307 308 return 0; 309 310 out_unreg: 311 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); 312 out: 313 return err; 314 } 315 316 static void __exit l2tp_eth_exit(void) 317 { 318 unregister_pernet_device(&l2tp_eth_net_ops); 319 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); 320 } 321 322 module_init(l2tp_eth_init); 323 module_exit(l2tp_eth_exit); 324 325 MODULE_LICENSE("GPL"); 326 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 327 MODULE_DESCRIPTION("L2TP ethernet pseudowire driver"); 328 MODULE_VERSION("1.0"); 329