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mtd: powernv_flash: Remove pointless goto in driver init
[linux-2.6/btrfs-unstable.git] / net / l2tp / l2tp_eth.c
blob87da9ef61860886d9bf5cc668524ef8b48a60c31
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 #include <linux/ip.h>
34 #include <linux/ipv6.h>
35 #include <linux/udp.h>
36
37 #include "l2tp_core.h"
38
39 /* Default device name. May be overridden by name specified by user */
40 #define L2TP_ETH_DEV_NAME "l2tpeth%d"
41
42 /* via netdev_priv() */
43 struct l2tp_eth {
44 struct net_device *dev;
45 struct sock *tunnel_sock;
46 struct l2tp_session *session;
47 struct list_head list;
48 atomic_long_t tx_bytes;
49 atomic_long_t tx_packets;
50 atomic_long_t tx_dropped;
51 atomic_long_t rx_bytes;
52 atomic_long_t rx_packets;
53 atomic_long_t rx_errors;
54 };
55
56 /* via l2tp_session_priv() */
57 struct l2tp_eth_sess {
58 struct net_device *dev;
59 };
60
61 /* per-net private data for this module */
62 static unsigned int l2tp_eth_net_id;
63 struct l2tp_eth_net {
64 struct list_head l2tp_eth_dev_list;
65 spinlock_t l2tp_eth_lock;
66 };
67
68 static inline struct l2tp_eth_net *l2tp_eth_pernet(struct net *net)
69 {
70 return net_generic(net, l2tp_eth_net_id);
71 }
72
73 static int l2tp_eth_dev_init(struct net_device *dev)
74 {
75 struct l2tp_eth *priv = netdev_priv(dev);
76
77 priv->dev = dev;
78 eth_hw_addr_random(dev);
79 eth_broadcast_addr(dev->broadcast);
80 netdev_lockdep_set_classes(dev);
81
82 return 0;
83 }
84
85 static void l2tp_eth_dev_uninit(struct net_device *dev)
86 {
87 struct l2tp_eth *priv = netdev_priv(dev);
88 struct l2tp_eth_net *pn = l2tp_eth_pernet(dev_net(dev));
89
90 spin_lock(&pn->l2tp_eth_lock);
91 list_del_init(&priv->list);
92 spin_unlock(&pn->l2tp_eth_lock);
93 dev_put(dev);
94 }
95
96 static int l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev)
97 {
98 struct l2tp_eth *priv = netdev_priv(dev);
99 struct l2tp_session *session = priv->session;
100 unsigned int len = skb->len;
101 int ret = l2tp_xmit_skb(session, skb, session->hdr_len);
102
103 if (likely(ret == NET_XMIT_SUCCESS)) {
104 atomic_long_add(len, &priv->tx_bytes);
105 atomic_long_inc(&priv->tx_packets);
106 } else {
107 atomic_long_inc(&priv->tx_dropped);
108 }
109 return NETDEV_TX_OK;
110 }
111
112 static void l2tp_eth_get_stats64(struct net_device *dev,
113 struct rtnl_link_stats64 *stats)
114 {
115 struct l2tp_eth *priv = netdev_priv(dev);
116
117 stats->tx_bytes = (unsigned long) atomic_long_read(&priv->tx_bytes);
118 stats->tx_packets = (unsigned long) atomic_long_read(&priv->tx_packets);
119 stats->tx_dropped = (unsigned long) atomic_long_read(&priv->tx_dropped);
120 stats->rx_bytes = (unsigned long) atomic_long_read(&priv->rx_bytes);
121 stats->rx_packets = (unsigned long) atomic_long_read(&priv->rx_packets);
122 stats->rx_errors = (unsigned long) atomic_long_read(&priv->rx_errors);
123
124 }
125
126 static const struct net_device_ops l2tp_eth_netdev_ops = {
127 .ndo_init = l2tp_eth_dev_init,
128 .ndo_uninit = l2tp_eth_dev_uninit,
129 .ndo_start_xmit = l2tp_eth_dev_xmit,
130 .ndo_get_stats64 = l2tp_eth_get_stats64,
131 .ndo_set_mac_address = eth_mac_addr,
132 };
133
134 static struct device_type l2tpeth_type = {
135 .name = "l2tpeth",
136 };
137
138 static void l2tp_eth_dev_setup(struct net_device *dev)
139 {
140 SET_NETDEV_DEVTYPE(dev, &l2tpeth_type);
141 ether_setup(dev);
142 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
143 dev->features |= NETIF_F_LLTX;
144 dev->netdev_ops = &l2tp_eth_netdev_ops;
145 dev->needs_free_netdev = true;
146 }
147
148 static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
149 {
150 struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
151 struct net_device *dev = spriv->dev;
152 struct l2tp_eth *priv = netdev_priv(dev);
153
154 if (session->debug & L2TP_MSG_DATA) {
155 unsigned int length;
156
157 length = min(32u, skb->len);
158 if (!pskb_may_pull(skb, length))
159 goto error;
160
161 pr_debug("%s: eth recv\n", session->name);
162 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length);
163 }
164
165 if (!pskb_may_pull(skb, ETH_HLEN))
166 goto error;
167
168 secpath_reset(skb);
169
170 /* checksums verified by L2TP */
171 skb->ip_summed = CHECKSUM_NONE;
172
173 skb_dst_drop(skb);
174 nf_reset(skb);
175
176 if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) {
177 atomic_long_inc(&priv->rx_packets);
178 atomic_long_add(data_len, &priv->rx_bytes);
179 } else {
180 atomic_long_inc(&priv->rx_errors);
181 }
182 return;
183
184 error:
185 atomic_long_inc(&priv->rx_errors);
186 kfree_skb(skb);
187 }
188
189 static void l2tp_eth_delete(struct l2tp_session *session)
190 {
191 struct l2tp_eth_sess *spriv;
192 struct net_device *dev;
193
194 if (session) {
195 spriv = l2tp_session_priv(session);
196 dev = spriv->dev;
197 if (dev) {
198 unregister_netdev(dev);
199 spriv->dev = NULL;
200 module_put(THIS_MODULE);
201 }
202 }
203 }
204
205 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
206 static void l2tp_eth_show(struct seq_file *m, void *arg)
207 {
208 struct l2tp_session *session = arg;
209 struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
210 struct net_device *dev = spriv->dev;
211
212 seq_printf(m, " interface %s\n", dev->name);
213 }
214 #endif
215
216 static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel,
217 struct l2tp_session *session,
218 struct net_device *dev)
219 {
220 unsigned int overhead = 0;
221 struct dst_entry *dst;
222 u32 l3_overhead = 0;
223
224 /* if the encap is UDP, account for UDP header size */
225 if (tunnel->encap == L2TP_ENCAPTYPE_UDP) {
226 overhead += sizeof(struct udphdr);
227 dev->needed_headroom += sizeof(struct udphdr);
228 }
229 if (session->mtu != 0) {
230 dev->mtu = session->mtu;
231 dev->needed_headroom += session->hdr_len;
232 return;
233 }
234 lock_sock(tunnel->sock);
235 l3_overhead = kernel_sock_ip_overhead(tunnel->sock);
236 release_sock(tunnel->sock);
237 if (l3_overhead == 0) {
238 /* L3 Overhead couldn't be identified, this could be
239 * because tunnel->sock was NULL or the socket's
240 * address family was not IPv4 or IPv6,
241 * dev mtu stays at 1500.
242 */
243 return;
244 }
245 /* Adjust MTU, factor overhead - underlay L3, overlay L2 hdr
246 * UDP overhead, if any, was already factored in above.
247 */
248 overhead += session->hdr_len + ETH_HLEN + l3_overhead;
249
250 /* If PMTU discovery was enabled, use discovered MTU on L2TP device */
251 dst = sk_dst_get(tunnel->sock);
252 if (dst) {
253 /* dst_mtu will use PMTU if found, else fallback to intf MTU */
254 u32 pmtu = dst_mtu(dst);
255
256 if (pmtu != 0)
257 dev->mtu = pmtu;
258 dst_release(dst);
259 }
260 session->mtu = dev->mtu - overhead;
261 dev->mtu = session->mtu;
262 dev->needed_headroom += session->hdr_len;
263 }
264
265 static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel,
266 u32 session_id, u32 peer_session_id,
267 struct l2tp_session_cfg *cfg)
268 {
269 unsigned char name_assign_type;
270 struct net_device *dev;
271 char name[IFNAMSIZ];
272 struct l2tp_session *session;
273 struct l2tp_eth *priv;
274 struct l2tp_eth_sess *spriv;
275 int rc;
276 struct l2tp_eth_net *pn;
277
278 if (cfg->ifname) {
279 strlcpy(name, cfg->ifname, IFNAMSIZ);
280 name_assign_type = NET_NAME_USER;
281 } else {
282 strcpy(name, L2TP_ETH_DEV_NAME);
283 name_assign_type = NET_NAME_ENUM;
284 }
285
286 session = l2tp_session_create(sizeof(*spriv), tunnel, session_id,
287 peer_session_id, cfg);
288 if (IS_ERR(session)) {
289 rc = PTR_ERR(session);
290 goto out;
291 }
292
293 dev = alloc_netdev(sizeof(*priv), name, name_assign_type,
294 l2tp_eth_dev_setup);
295 if (!dev) {
296 rc = -ENOMEM;
297 goto out_del_session;
298 }
299
300 dev_net_set(dev, net);
301 dev->min_mtu = 0;
302 dev->max_mtu = ETH_MAX_MTU;
303 l2tp_eth_adjust_mtu(tunnel, session, dev);
304
305 priv = netdev_priv(dev);
306 priv->dev = dev;
307 priv->session = session;
308 INIT_LIST_HEAD(&priv->list);
309
310 priv->tunnel_sock = tunnel->sock;
311 session->recv_skb = l2tp_eth_dev_recv;
312 session->session_close = l2tp_eth_delete;
313 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS)
314 session->show = l2tp_eth_show;
315 #endif
316
317 spriv = l2tp_session_priv(session);
318 spriv->dev = dev;
319
320 rc = register_netdev(dev);
321 if (rc < 0)
322 goto out_del_dev;
323
324 __module_get(THIS_MODULE);
325 /* Must be done after register_netdev() */
326 strlcpy(session->ifname, dev->name, IFNAMSIZ);
327
328 dev_hold(dev);
329 pn = l2tp_eth_pernet(dev_net(dev));
330 spin_lock(&pn->l2tp_eth_lock);
331 list_add(&priv->list, &pn->l2tp_eth_dev_list);
332 spin_unlock(&pn->l2tp_eth_lock);
333
334 return 0;
335
336 out_del_dev:
337 free_netdev(dev);
338 spriv->dev = NULL;
339 out_del_session:
340 l2tp_session_delete(session);
341 out:
342 return rc;
343 }
344
345 static __net_init int l2tp_eth_init_net(struct net *net)
346 {
347 struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id);
348
349 INIT_LIST_HEAD(&pn->l2tp_eth_dev_list);
350 spin_lock_init(&pn->l2tp_eth_lock);
351
352 return 0;
353 }
354
355 static struct pernet_operations l2tp_eth_net_ops = {
356 .init = l2tp_eth_init_net,
357 .id = &l2tp_eth_net_id,
358 .size = sizeof(struct l2tp_eth_net),
359 };
360
361
362 static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = {
363 .session_create = l2tp_eth_create,
364 .session_delete = l2tp_session_delete,
365 };
366
367
368 static int __init l2tp_eth_init(void)
369 {
370 int err = 0;
371
372 err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops);
373 if (err)
374 goto out;
375
376 err = register_pernet_device(&l2tp_eth_net_ops);
377 if (err)
378 goto out_unreg;
379
380 pr_info("L2TP ethernet pseudowire support (L2TPv3)\n");
381
382 return 0;
383
384 out_unreg:
385 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
386 out:
387 return err;
388 }
389
390 static void __exit l2tp_eth_exit(void)
391 {
392 unregister_pernet_device(&l2tp_eth_net_ops);
393 l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
394 }
395
396 module_init(l2tp_eth_init);
397 module_exit(l2tp_eth_exit);
398
399 MODULE_LICENSE("GPL");
400 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
401 MODULE_DESCRIPTION("L2TP ethernet pseudowire driver");
402 MODULE_VERSION("1.0");
403 MODULE_ALIAS_L2TP_PWTYPE(5);
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