net: proc: change proc_net_remove to remove_proc_entry
[linux-3.10.git] / net / l2tp / l2tp_eth.c
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, l2tp_eth_dev_setup);
250         if (!dev) {
251                 rc = -ENOMEM;
252                 goto out_del_session;
253         }
254
255         dev_net_set(dev, net);
256         if (session->mtu == 0)
257                 session->mtu = dev->mtu - session->hdr_len;
258         dev->mtu = session->mtu;
259         dev->needed_headroom += session->hdr_len;
260
261         priv = netdev_priv(dev);
262         priv->dev = dev;
263         priv->session = session;
264         INIT_LIST_HEAD(&priv->list);
265
266         priv->tunnel_sock = tunnel->sock;
267         session->recv_skb = l2tp_eth_dev_recv;
268         session->session_close = l2tp_eth_delete;
269 #if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
270         session->show = l2tp_eth_show;
271 #endif
272
273         spriv = l2tp_session_priv(session);
274         spriv->dev = dev;
275
276         rc = register_netdev(dev);
277         if (rc < 0)
278                 goto out_del_dev;
279
280         __module_get(THIS_MODULE);
281         /* Must be done after register_netdev() */
282         strlcpy(session->ifname, dev->name, IFNAMSIZ);
283
284         dev_hold(dev);
285         pn = l2tp_eth_pernet(dev_net(dev));
286         spin_lock(&pn->l2tp_eth_lock);
287         list_add(&priv->list, &pn->l2tp_eth_dev_list);
288         spin_unlock(&pn->l2tp_eth_lock);
289
290         return 0;
291
292 out_del_dev:
293         free_netdev(dev);
294         spriv->dev = NULL;
295 out_del_session:
296         l2tp_session_delete(session);
297 out:
298         return rc;
299 }
300
301 static __net_init int l2tp_eth_init_net(struct net *net)
302 {
303         struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id);
304
305         INIT_LIST_HEAD(&pn->l2tp_eth_dev_list);
306         spin_lock_init(&pn->l2tp_eth_lock);
307
308         return 0;
309 }
310
311 static struct pernet_operations l2tp_eth_net_ops = {
312         .init = l2tp_eth_init_net,
313         .id   = &l2tp_eth_net_id,
314         .size = sizeof(struct l2tp_eth_net),
315 };
316
317
318 static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = {
319         .session_create = l2tp_eth_create,
320         .session_delete = l2tp_session_delete,
321 };
322
323
324 static int __init l2tp_eth_init(void)
325 {
326         int err = 0;
327
328         err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops);
329         if (err)
330                 goto out;
331
332         err = register_pernet_device(&l2tp_eth_net_ops);
333         if (err)
334                 goto out_unreg;
335
336         pr_info("L2TP ethernet pseudowire support (L2TPv3)\n");
337
338         return 0;
339
340 out_unreg:
341         l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
342 out:
343         return err;
344 }
345
346 static void __exit l2tp_eth_exit(void)
347 {
348         unregister_pernet_device(&l2tp_eth_net_ops);
349         l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
350 }
351
352 module_init(l2tp_eth_init);
353 module_exit(l2tp_eth_exit);
354
355 MODULE_LICENSE("GPL");
356 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
357 MODULE_DESCRIPTION("L2TP ethernet pseudowire driver");
358 MODULE_VERSION("1.0");