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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 eth_broadcast_addr(dev->broadcast);
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 .ndo_set_mac_address = eth_mac_addr,
130};
131
132static void l2tp_eth_dev_setup(struct net_device *dev)
133{
134 ether_setup(dev);
135 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
136 dev->features |= NETIF_F_LLTX;
137 dev->netdev_ops = &l2tp_eth_netdev_ops;
138 dev->destructor = free_netdev;
139}
140
141static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
142{
143 struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
144 struct net_device *dev = spriv->dev;
145 struct l2tp_eth *priv = netdev_priv(dev);
146
147 if (session->debug & L2TP_MSG_DATA) {
148 unsigned int length;
149
150 length = min(32u, skb->len);
151 if (!pskb_may_pull(skb, length))
152 goto error;
153
154 pr_debug("%s: eth recv\n", session->name);
155 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length);
156 }
157
158 if (!pskb_may_pull(skb, ETH_HLEN))
159 goto error;
160
161 secpath_reset(skb);
162
163
164 skb->ip_summed = CHECKSUM_NONE;
165
166 skb_dst_drop(skb);
167 nf_reset(skb);
168
169 if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) {
170 atomic_long_inc(&priv->rx_packets);
171 atomic_long_add(data_len, &priv->rx_bytes);
172 } else {
173 atomic_long_inc(&priv->rx_errors);
174 }
175 return;
176
177error:
178 atomic_long_inc(&priv->rx_errors);
179 kfree_skb(skb);
180}
181
182static void l2tp_eth_delete(struct l2tp_session *session)
183{
184 struct l2tp_eth_sess *spriv;
185 struct net_device *dev;
186
187 if (session) {
188 spriv = l2tp_session_priv(session);
189 dev = spriv->dev;
190 if (dev) {
191 unregister_netdev(dev);
192 spriv->dev = NULL;
193 module_put(THIS_MODULE);
194 }
195 }
196}
197
198#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
199static void l2tp_eth_show(struct seq_file *m, void *arg)
200{
201 struct l2tp_session *session = arg;
202 struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
203 struct net_device *dev = spriv->dev;
204
205 seq_printf(m, " interface %s\n", dev->name);
206}
207#endif
208
209static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg)
210{
211 struct net_device *dev;
212 char name[IFNAMSIZ];
213 struct l2tp_tunnel *tunnel;
214 struct l2tp_session *session;
215 struct l2tp_eth *priv;
216 struct l2tp_eth_sess *spriv;
217 int rc;
218 struct l2tp_eth_net *pn;
219
220 tunnel = l2tp_tunnel_find(net, tunnel_id);
221 if (!tunnel) {
222 rc = -ENODEV;
223 goto out;
224 }
225
226 session = l2tp_session_find(net, tunnel, session_id);
227 if (session) {
228 rc = -EEXIST;
229 goto out;
230 }
231
232 if (cfg->ifname) {
233 dev = dev_get_by_name(net, cfg->ifname);
234 if (dev) {
235 dev_put(dev);
236 rc = -EEXIST;
237 goto out;
238 }
239 strlcpy(name, cfg->ifname, IFNAMSIZ);
240 } else
241 strcpy(name, L2TP_ETH_DEV_NAME);
242
243 session = l2tp_session_create(sizeof(*spriv), tunnel, session_id,
244 peer_session_id, cfg);
245 if (!session) {
246 rc = -ENOMEM;
247 goto out;
248 }
249
250 dev = alloc_netdev(sizeof(*priv), name, NET_NAME_UNKNOWN,
251 l2tp_eth_dev_setup);
252 if (!dev) {
253 rc = -ENOMEM;
254 goto out_del_session;
255 }
256
257 dev_net_set(dev, net);
258 if (session->mtu == 0)
259 session->mtu = dev->mtu - session->hdr_len;
260 dev->mtu = session->mtu;
261 dev->needed_headroom += session->hdr_len;
262
263 priv = netdev_priv(dev);
264 priv->dev = dev;
265 priv->session = session;
266 INIT_LIST_HEAD(&priv->list);
267
268 priv->tunnel_sock = tunnel->sock;
269 session->recv_skb = l2tp_eth_dev_recv;
270 session->session_close = l2tp_eth_delete;
271#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
272 session->show = l2tp_eth_show;
273#endif
274
275 spriv = l2tp_session_priv(session);
276 spriv->dev = dev;
277
278 rc = register_netdev(dev);
279 if (rc < 0)
280 goto out_del_dev;
281
282 __module_get(THIS_MODULE);
283
284 strlcpy(session->ifname, dev->name, IFNAMSIZ);
285
286 dev_hold(dev);
287 pn = l2tp_eth_pernet(dev_net(dev));
288 spin_lock(&pn->l2tp_eth_lock);
289 list_add(&priv->list, &pn->l2tp_eth_dev_list);
290 spin_unlock(&pn->l2tp_eth_lock);
291
292 return 0;
293
294out_del_dev:
295 free_netdev(dev);
296 spriv->dev = NULL;
297out_del_session:
298 l2tp_session_delete(session);
299out:
300 return rc;
301}
302
303static __net_init int l2tp_eth_init_net(struct net *net)
304{
305 struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id);
306
307 INIT_LIST_HEAD(&pn->l2tp_eth_dev_list);
308 spin_lock_init(&pn->l2tp_eth_lock);
309
310 return 0;
311}
312
313static struct pernet_operations l2tp_eth_net_ops = {
314 .init = l2tp_eth_init_net,
315 .id = &l2tp_eth_net_id,
316 .size = sizeof(struct l2tp_eth_net),
317};
318
319
320static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = {
321 .session_create = l2tp_eth_create,
322 .session_delete = l2tp_session_delete,
323};
324
325
326static int __init l2tp_eth_init(void)
327{
328 int err = 0;
329
330 err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops);
331 if (err)
332 goto out;
333
334 err = register_pernet_device(&l2tp_eth_net_ops);
335 if (err)
336 goto out_unreg;
337
338 pr_info("L2TP ethernet pseudowire support (L2TPv3)\n");
339
340 return 0;
341
342out_unreg:
343 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
344out:
345 return err;
346}
347
348static void __exit l2tp_eth_exit(void)
349{
350 unregister_pernet_device(&l2tp_eth_net_ops);
351 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
352}
353
354module_init(l2tp_eth_init);
355module_exit(l2tp_eth_exit);
356
357MODULE_LICENSE("GPL");
358MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
359MODULE_DESCRIPTION("L2TP ethernet pseudowire driver");
360MODULE_VERSION("1.0");
361
