l2tp_eth.c 7.2 KB

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  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. #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12. #include <linux/module.h>
  13. #include <linux/skbuff.h>
  14. #include <linux/socket.h>
  15. #include <linux/hash.h>
  16. #include <linux/l2tp.h>
  17. #include <linux/in.h>
  18. #include <linux/etherdevice.h>
  19. #include <linux/spinlock.h>
  20. #include <net/sock.h>
  21. #include <net/ip.h>
  22. #include <net/icmp.h>
  23. #include <net/udp.h>
  24. #include <net/inet_common.h>
  25. #include <net/inet_hashtables.h>
  26. #include <net/tcp_states.h>
  27. #include <net/protocol.h>
  28. #include <net/xfrm.h>
  29. #include <net/net_namespace.h>
  30. #include <net/netns/generic.h>
  31. #include "l2tp_core.h"
  32. /* Default device name. May be overridden by name specified by user */
  33. #define L2TP_ETH_DEV_NAME "l2tpeth%d"
  34. /* via netdev_priv() */
  35. struct l2tp_eth {
  36. struct net_device *dev;
  37. struct sock *tunnel_sock;
  38. struct l2tp_session *session;
  39. struct list_head list;
  40. };
  41. /* via l2tp_session_priv() */
  42. struct l2tp_eth_sess {
  43. struct net_device *dev;
  44. };
  45. /* per-net private data for this module */
  46. static unsigned int l2tp_eth_net_id;
  47. struct l2tp_eth_net {
  48. struct list_head l2tp_eth_dev_list;
  49. spinlock_t l2tp_eth_lock;
  50. };
  51. static inline struct l2tp_eth_net *l2tp_eth_pernet(struct net *net)
  52. {
  53. return net_generic(net, l2tp_eth_net_id);
  54. }
  55. static int l2tp_eth_dev_init(struct net_device *dev)
  56. {
  57. struct l2tp_eth *priv = netdev_priv(dev);
  58. priv->dev = dev;
  59. eth_hw_addr_random(dev);
  60. memset(&dev->broadcast[0], 0xff, 6);
  61. return 0;
  62. }
  63. static void l2tp_eth_dev_uninit(struct net_device *dev)
  64. {
  65. struct l2tp_eth *priv = netdev_priv(dev);
  66. struct l2tp_eth_net *pn = l2tp_eth_pernet(dev_net(dev));
  67. spin_lock(&pn->l2tp_eth_lock);
  68. list_del_init(&priv->list);
  69. spin_unlock(&pn->l2tp_eth_lock);
  70. dev_put(dev);
  71. }
  72. static int l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev)
  73. {
  74. struct l2tp_eth *priv = netdev_priv(dev);
  75. struct l2tp_session *session = priv->session;
  76. l2tp_xmit_skb(session, skb, session->hdr_len);
  77. dev->stats.tx_bytes += skb->len;
  78. dev->stats.tx_packets++;
  79. return 0;
  80. }
  81. static struct net_device_ops l2tp_eth_netdev_ops = {
  82. .ndo_init = l2tp_eth_dev_init,
  83. .ndo_uninit = l2tp_eth_dev_uninit,
  84. .ndo_start_xmit = l2tp_eth_dev_xmit,
  85. };
  86. static void l2tp_eth_dev_setup(struct net_device *dev)
  87. {
  88. ether_setup(dev);
  89. dev->priv_flags &= ~IFF_TX_SKB_SHARING;
  90. dev->netdev_ops = &l2tp_eth_netdev_ops;
  91. dev->destructor = free_netdev;
  92. }
  93. static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
  94. {
  95. struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
  96. struct net_device *dev = spriv->dev;
  97. if (session->debug & L2TP_MSG_DATA) {
  98. unsigned int length;
  99. u8 *ptr = skb->data;
  100. length = min(32u, skb->len);
  101. if (!pskb_may_pull(skb, length))
  102. goto error;
  103. pr_debug("%s: eth recv\n", session->name);
  104. print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
  105. }
  106. if (!pskb_may_pull(skb, sizeof(ETH_HLEN)))
  107. goto error;
  108. secpath_reset(skb);
  109. /* checksums verified by L2TP */
  110. skb->ip_summed = CHECKSUM_NONE;
  111. skb_dst_drop(skb);
  112. nf_reset(skb);
  113. if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) {
  114. dev->stats.rx_packets++;
  115. dev->stats.rx_bytes += data_len;
  116. } else
  117. dev->stats.rx_errors++;
  118. return;
  119. error:
  120. dev->stats.rx_errors++;
  121. kfree_skb(skb);
  122. }
  123. static void l2tp_eth_delete(struct l2tp_session *session)
  124. {
  125. struct l2tp_eth_sess *spriv;
  126. struct net_device *dev;
  127. if (session) {
  128. spriv = l2tp_session_priv(session);
  129. dev = spriv->dev;
  130. if (dev) {
  131. unregister_netdev(dev);
  132. spriv->dev = NULL;
  133. }
  134. }
  135. }
  136. #if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
  137. static void l2tp_eth_show(struct seq_file *m, void *arg)
  138. {
  139. struct l2tp_session *session = arg;
  140. struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
  141. struct net_device *dev = spriv->dev;
  142. seq_printf(m, " interface %s\n", dev->name);
  143. }
  144. #endif
  145. static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg)
  146. {
  147. struct net_device *dev;
  148. char name[IFNAMSIZ];
  149. struct l2tp_tunnel *tunnel;
  150. struct l2tp_session *session;
  151. struct l2tp_eth *priv;
  152. struct l2tp_eth_sess *spriv;
  153. int rc;
  154. struct l2tp_eth_net *pn;
  155. tunnel = l2tp_tunnel_find(net, tunnel_id);
  156. if (!tunnel) {
  157. rc = -ENODEV;
  158. goto out;
  159. }
  160. session = l2tp_session_find(net, tunnel, session_id);
  161. if (session) {
  162. rc = -EEXIST;
  163. goto out;
  164. }
  165. if (cfg->ifname) {
  166. dev = dev_get_by_name(net, cfg->ifname);
  167. if (dev) {
  168. dev_put(dev);
  169. rc = -EEXIST;
  170. goto out;
  171. }
  172. strlcpy(name, cfg->ifname, IFNAMSIZ);
  173. } else
  174. strcpy(name, L2TP_ETH_DEV_NAME);
  175. session = l2tp_session_create(sizeof(*spriv), tunnel, session_id,
  176. peer_session_id, cfg);
  177. if (!session) {
  178. rc = -ENOMEM;
  179. goto out;
  180. }
  181. dev = alloc_netdev(sizeof(*priv), name, l2tp_eth_dev_setup);
  182. if (!dev) {
  183. rc = -ENOMEM;
  184. goto out_del_session;
  185. }
  186. dev_net_set(dev, net);
  187. if (session->mtu == 0)
  188. session->mtu = dev->mtu - session->hdr_len;
  189. dev->mtu = session->mtu;
  190. dev->needed_headroom += session->hdr_len;
  191. priv = netdev_priv(dev);
  192. priv->dev = dev;
  193. priv->session = session;
  194. INIT_LIST_HEAD(&priv->list);
  195. priv->tunnel_sock = tunnel->sock;
  196. session->recv_skb = l2tp_eth_dev_recv;
  197. session->session_close = l2tp_eth_delete;
  198. #if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
  199. session->show = l2tp_eth_show;
  200. #endif
  201. spriv = l2tp_session_priv(session);
  202. spriv->dev = dev;
  203. rc = register_netdev(dev);
  204. if (rc < 0)
  205. goto out_del_dev;
  206. /* Must be done after register_netdev() */
  207. strlcpy(session->ifname, dev->name, IFNAMSIZ);
  208. dev_hold(dev);
  209. pn = l2tp_eth_pernet(dev_net(dev));
  210. spin_lock(&pn->l2tp_eth_lock);
  211. list_add(&priv->list, &pn->l2tp_eth_dev_list);
  212. spin_unlock(&pn->l2tp_eth_lock);
  213. return 0;
  214. out_del_dev:
  215. free_netdev(dev);
  216. out_del_session:
  217. l2tp_session_delete(session);
  218. out:
  219. return rc;
  220. }
  221. static __net_init int l2tp_eth_init_net(struct net *net)
  222. {
  223. struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id);
  224. INIT_LIST_HEAD(&pn->l2tp_eth_dev_list);
  225. spin_lock_init(&pn->l2tp_eth_lock);
  226. return 0;
  227. }
  228. static struct pernet_operations l2tp_eth_net_ops = {
  229. .init = l2tp_eth_init_net,
  230. .id = &l2tp_eth_net_id,
  231. .size = sizeof(struct l2tp_eth_net),
  232. };
  233. static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = {
  234. .session_create = l2tp_eth_create,
  235. .session_delete = l2tp_session_delete,
  236. };
  237. static int __init l2tp_eth_init(void)
  238. {
  239. int err = 0;
  240. err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops);
  241. if (err)
  242. goto out;
  243. err = register_pernet_device(&l2tp_eth_net_ops);
  244. if (err)
  245. goto out_unreg;
  246. pr_info("L2TP ethernet pseudowire support (L2TPv3)\n");
  247. return 0;
  248. out_unreg:
  249. l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
  250. out:
  251. return err;
  252. }
  253. static void __exit l2tp_eth_exit(void)
  254. {
  255. unregister_pernet_device(&l2tp_eth_net_ops);
  256. l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
  257. }
  258. module_init(l2tp_eth_init);
  259. module_exit(l2tp_eth_exit);
  260. MODULE_LICENSE("GPL");
  261. MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
  262. MODULE_DESCRIPTION("L2TP ethernet pseudowire driver");
  263. MODULE_VERSION("1.0");