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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
37#define L2TP_ETH_DEV_NAME "l2tpeth%d"
38
39
40struct 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
54struct l2tp_eth_sess {
55 struct net_device *dev;
56};
57
58
59static unsigned int l2tp_eth_net_id;
60struct l2tp_eth_net {
61 struct list_head l2tp_eth_dev_list;
62 spinlock_t l2tp_eth_lock;
63};
64
65static inline struct l2tp_eth_net *l2tp_eth_pernet(struct net *net)
66{
67 return net_generic(net, l2tp_eth_net_id);
68}
69
70static struct lock_class_key l2tp_eth_tx_busylock;
71static 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
82static 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
93static 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
109static 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
124static 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
131static 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
140static 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
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
176error:
177 atomic_long_inc(&priv->rx_errors);
178 kfree_skb(skb);
179}
180
181static 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)
198static 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
208static 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
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
292out_del_dev:
293 free_netdev(dev);
294 spriv->dev = NULL;
295out_del_session:
296 l2tp_session_delete(session);
297out:
298 return rc;
299}
300
301static __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
311static 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
318static 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
324static 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
340out_unreg:
341 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
342out:
343 return err;
344}
345
346static 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
352module_init(l2tp_eth_init);
353module_exit(l2tp_eth_exit);
354
355MODULE_LICENSE("GPL");
356MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
357MODULE_DESCRIPTION("L2TP ethernet pseudowire driver");
358MODULE_VERSION("1.0");
359
