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v4.17
  1/*
  2 * L2TP subsystem debugfs
  3 *
  4 * Copyright (c) 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 <linux/debugfs.h>
 23#include <net/sock.h>
 24#include <net/ip.h>
 25#include <net/icmp.h>
 26#include <net/udp.h>
 27#include <net/inet_common.h>
 28#include <net/inet_hashtables.h>
 29#include <net/tcp_states.h>
 30#include <net/protocol.h>
 31#include <net/xfrm.h>
 32#include <net/net_namespace.h>
 33#include <net/netns/generic.h>
 34
 35#include "l2tp_core.h"
 36
 37static struct dentry *rootdir;
 38static struct dentry *tunnels;
 39
 40struct l2tp_dfs_seq_data {
 41	struct net *net;
 42	int tunnel_idx;			/* current tunnel */
 43	int session_idx;		/* index of session within current tunnel */
 44	struct l2tp_tunnel *tunnel;
 45	struct l2tp_session *session;	/* NULL means get next tunnel */
 46};
 47
 48static void l2tp_dfs_next_tunnel(struct l2tp_dfs_seq_data *pd)
 49{
 50	/* Drop reference taken during previous invocation */
 51	if (pd->tunnel)
 52		l2tp_tunnel_dec_refcount(pd->tunnel);
 53
 54	pd->tunnel = l2tp_tunnel_get_nth(pd->net, pd->tunnel_idx);
 55	pd->tunnel_idx++;
 56}
 57
 58static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd)
 59{
 60	pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx);
 61	pd->session_idx++;
 62
 63	if (pd->session == NULL) {
 64		pd->session_idx = 0;
 65		l2tp_dfs_next_tunnel(pd);
 66	}
 67
 68}
 69
 70static void *l2tp_dfs_seq_start(struct seq_file *m, loff_t *offs)
 71{
 72	struct l2tp_dfs_seq_data *pd = SEQ_START_TOKEN;
 73	loff_t pos = *offs;
 74
 75	if (!pos)
 76		goto out;
 77
 78	BUG_ON(m->private == NULL);
 79	pd = m->private;
 80
 81	if (pd->tunnel == NULL)
 82		l2tp_dfs_next_tunnel(pd);
 83	else
 84		l2tp_dfs_next_session(pd);
 85
 86	/* NULL tunnel and session indicates end of list */
 87	if ((pd->tunnel == NULL) && (pd->session == NULL))
 88		pd = NULL;
 89
 90out:
 91	return pd;
 92}
 93
 94
 95static void *l2tp_dfs_seq_next(struct seq_file *m, void *v, loff_t *pos)
 96{
 97	(*pos)++;
 98	return NULL;
 99}
100
101static void l2tp_dfs_seq_stop(struct seq_file *p, void *v)
102{
103	struct l2tp_dfs_seq_data *pd = v;
104
105	if (!pd || pd == SEQ_START_TOKEN)
106		return;
107
108	/* Drop reference taken by last invocation of l2tp_dfs_next_tunnel() */
109	if (pd->tunnel) {
110		l2tp_tunnel_dec_refcount(pd->tunnel);
111		pd->tunnel = NULL;
112		pd->session = NULL;
113	}
114}
115
116static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v)
117{
118	struct l2tp_tunnel *tunnel = v;
119	int session_count = 0;
120	int hash;
121	struct hlist_node *walk;
122	struct hlist_node *tmp;
123
124	read_lock_bh(&tunnel->hlist_lock);
125	for (hash = 0; hash < L2TP_HASH_SIZE; hash++) {
126		hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
127			struct l2tp_session *session;
128
129			session = hlist_entry(walk, struct l2tp_session, hlist);
130			if (session->session_id == 0)
131				continue;
132
133			session_count++;
134		}
135	}
136	read_unlock_bh(&tunnel->hlist_lock);
137
138	seq_printf(m, "\nTUNNEL %u peer %u", tunnel->tunnel_id, tunnel->peer_tunnel_id);
139	if (tunnel->sock) {
140		struct inet_sock *inet = inet_sk(tunnel->sock);
141
142#if IS_ENABLED(CONFIG_IPV6)
143		if (tunnel->sock->sk_family == AF_INET6) {
144			const struct ipv6_pinfo *np = inet6_sk(tunnel->sock);
145
146			seq_printf(m, " from %pI6c to %pI6c\n",
147				&np->saddr, &tunnel->sock->sk_v6_daddr);
148		} else
149#endif
150		seq_printf(m, " from %pI4 to %pI4\n",
151			   &inet->inet_saddr, &inet->inet_daddr);
152		if (tunnel->encap == L2TP_ENCAPTYPE_UDP)
153			seq_printf(m, " source port %hu, dest port %hu\n",
154				   ntohs(inet->inet_sport), ntohs(inet->inet_dport));
155	}
156	seq_printf(m, " L2TPv%d, %s\n", tunnel->version,
157		   tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" :
158		   tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" :
159		   "");
160	seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count,
161		   tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0,
162		   refcount_read(&tunnel->ref_count));
 
163	seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n",
164		   tunnel->debug,
165		   atomic_long_read(&tunnel->stats.tx_packets),
166		   atomic_long_read(&tunnel->stats.tx_bytes),
167		   atomic_long_read(&tunnel->stats.tx_errors),
168		   atomic_long_read(&tunnel->stats.rx_packets),
169		   atomic_long_read(&tunnel->stats.rx_bytes),
170		   atomic_long_read(&tunnel->stats.rx_errors));
171
172	if (tunnel->show != NULL)
173		tunnel->show(m, tunnel);
174}
175
176static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v)
177{
178	struct l2tp_session *session = v;
179
180	seq_printf(m, "  SESSION %u, peer %u, %s\n", session->session_id,
181		   session->peer_session_id,
182		   session->pwtype == L2TP_PWTYPE_ETH ? "ETH" :
183		   session->pwtype == L2TP_PWTYPE_PPP ? "PPP" :
184		   "");
185	if (session->send_seq || session->recv_seq)
186		seq_printf(m, "   nr %hu, ns %hu\n", session->nr, session->ns);
187	seq_printf(m, "   refcnt %d\n", refcount_read(&session->ref_count));
188	seq_printf(m, "   config %d/%d/%c/%c/%s/%s %08x %u\n",
189		   session->mtu, session->mru,
190		   session->recv_seq ? 'R' : '-',
191		   session->send_seq ? 'S' : '-',
192		   session->data_seq == 1 ? "IPSEQ" :
193		   session->data_seq == 2 ? "DATASEQ" : "-",
194		   session->lns_mode ? "LNS" : "LAC",
195		   session->debug,
196		   jiffies_to_msecs(session->reorder_timeout));
197	seq_printf(m, "   offset 0 l2specific %hu/%hu\n",
198		   session->l2specific_type, l2tp_get_l2specific_len(session));
199	if (session->cookie_len) {
200		seq_printf(m, "   cookie %02x%02x%02x%02x",
201			   session->cookie[0], session->cookie[1],
202			   session->cookie[2], session->cookie[3]);
203		if (session->cookie_len == 8)
204			seq_printf(m, "%02x%02x%02x%02x",
205				   session->cookie[4], session->cookie[5],
206				   session->cookie[6], session->cookie[7]);
207		seq_printf(m, "\n");
208	}
209	if (session->peer_cookie_len) {
210		seq_printf(m, "   peer cookie %02x%02x%02x%02x",
211			   session->peer_cookie[0], session->peer_cookie[1],
212			   session->peer_cookie[2], session->peer_cookie[3]);
213		if (session->peer_cookie_len == 8)
214			seq_printf(m, "%02x%02x%02x%02x",
215				   session->peer_cookie[4], session->peer_cookie[5],
216				   session->peer_cookie[6], session->peer_cookie[7]);
217		seq_printf(m, "\n");
218	}
219
220	seq_printf(m, "   %hu/%hu tx %ld/%ld/%ld rx %ld/%ld/%ld\n",
221		   session->nr, session->ns,
222		   atomic_long_read(&session->stats.tx_packets),
223		   atomic_long_read(&session->stats.tx_bytes),
224		   atomic_long_read(&session->stats.tx_errors),
225		   atomic_long_read(&session->stats.rx_packets),
226		   atomic_long_read(&session->stats.rx_bytes),
227		   atomic_long_read(&session->stats.rx_errors));
228
229	if (session->show != NULL)
230		session->show(m, session);
231}
232
233static int l2tp_dfs_seq_show(struct seq_file *m, void *v)
234{
235	struct l2tp_dfs_seq_data *pd = v;
236
237	/* display header on line 1 */
238	if (v == SEQ_START_TOKEN) {
239		seq_puts(m, "TUNNEL ID, peer ID from IP to IP\n");
240		seq_puts(m, " L2TPv2/L2TPv3, UDP/IP\n");
241		seq_puts(m, " sessions session-count, refcnt refcnt/sk->refcnt\n");
242		seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
243		seq_puts(m, "  SESSION ID, peer ID, PWTYPE\n");
244		seq_puts(m, "   refcnt cnt\n");
245		seq_puts(m, "   offset OFFSET l2specific TYPE/LEN\n");
246		seq_puts(m, "   [ cookie ]\n");
247		seq_puts(m, "   [ peer cookie ]\n");
248		seq_puts(m, "   config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n");
249		seq_puts(m, "   nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
250		goto out;
251	}
252
253	/* Show the tunnel or session context */
254	if (!pd->session) {
255		l2tp_dfs_seq_tunnel_show(m, pd->tunnel);
256	} else {
257		l2tp_dfs_seq_session_show(m, pd->session);
258		l2tp_session_dec_refcount(pd->session);
259	}
260
261out:
262	return 0;
263}
264
265static const struct seq_operations l2tp_dfs_seq_ops = {
266	.start		= l2tp_dfs_seq_start,
267	.next		= l2tp_dfs_seq_next,
268	.stop		= l2tp_dfs_seq_stop,
269	.show		= l2tp_dfs_seq_show,
270};
271
272static int l2tp_dfs_seq_open(struct inode *inode, struct file *file)
273{
274	struct l2tp_dfs_seq_data *pd;
275	struct seq_file *seq;
276	int rc = -ENOMEM;
277
278	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
279	if (pd == NULL)
280		goto out;
281
282	/* Derive the network namespace from the pid opening the
283	 * file.
284	 */
285	pd->net = get_net_ns_by_pid(current->pid);
286	if (IS_ERR(pd->net)) {
287		rc = PTR_ERR(pd->net);
288		goto err_free_pd;
289	}
290
291	rc = seq_open(file, &l2tp_dfs_seq_ops);
292	if (rc)
293		goto err_free_net;
294
295	seq = file->private_data;
296	seq->private = pd;
297
298out:
299	return rc;
300
301err_free_net:
302	put_net(pd->net);
303err_free_pd:
304	kfree(pd);
305	goto out;
306}
307
308static int l2tp_dfs_seq_release(struct inode *inode, struct file *file)
309{
310	struct l2tp_dfs_seq_data *pd;
311	struct seq_file *seq;
312
313	seq = file->private_data;
314	pd = seq->private;
315	if (pd->net)
316		put_net(pd->net);
317	kfree(pd);
318	seq_release(inode, file);
319
320	return 0;
321}
322
323static const struct file_operations l2tp_dfs_fops = {
324	.owner		= THIS_MODULE,
325	.open		= l2tp_dfs_seq_open,
326	.read		= seq_read,
327	.llseek		= seq_lseek,
328	.release	= l2tp_dfs_seq_release,
329};
330
331static int __init l2tp_debugfs_init(void)
332{
333	int rc = 0;
334
335	rootdir = debugfs_create_dir("l2tp", NULL);
336	if (IS_ERR(rootdir)) {
337		rc = PTR_ERR(rootdir);
338		rootdir = NULL;
339		goto out;
340	}
341
342	tunnels = debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops);
343	if (tunnels == NULL)
344		rc = -EIO;
345
346	pr_info("L2TP debugfs support\n");
347
348out:
349	if (rc)
350		pr_warn("unable to init\n");
351
352	return rc;
353}
354
355static void __exit l2tp_debugfs_exit(void)
356{
357	debugfs_remove(tunnels);
358	debugfs_remove(rootdir);
359}
360
361module_init(l2tp_debugfs_init);
362module_exit(l2tp_debugfs_exit);
363
364MODULE_LICENSE("GPL");
365MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
366MODULE_DESCRIPTION("L2TP debugfs driver");
367MODULE_VERSION("1.0");
v4.10.11
  1/*
  2 * L2TP subsystem debugfs
  3 *
  4 * Copyright (c) 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 <linux/debugfs.h>
 23#include <net/sock.h>
 24#include <net/ip.h>
 25#include <net/icmp.h>
 26#include <net/udp.h>
 27#include <net/inet_common.h>
 28#include <net/inet_hashtables.h>
 29#include <net/tcp_states.h>
 30#include <net/protocol.h>
 31#include <net/xfrm.h>
 32#include <net/net_namespace.h>
 33#include <net/netns/generic.h>
 34
 35#include "l2tp_core.h"
 36
 37static struct dentry *rootdir;
 38static struct dentry *tunnels;
 39
 40struct l2tp_dfs_seq_data {
 41	struct net *net;
 42	int tunnel_idx;			/* current tunnel */
 43	int session_idx;		/* index of session within current tunnel */
 44	struct l2tp_tunnel *tunnel;
 45	struct l2tp_session *session;	/* NULL means get next tunnel */
 46};
 47
 48static void l2tp_dfs_next_tunnel(struct l2tp_dfs_seq_data *pd)
 49{
 50	pd->tunnel = l2tp_tunnel_find_nth(pd->net, pd->tunnel_idx);
 
 
 
 
 51	pd->tunnel_idx++;
 52}
 53
 54static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd)
 55{
 56	pd->session = l2tp_session_find_nth(pd->tunnel, pd->session_idx);
 57	pd->session_idx++;
 58
 59	if (pd->session == NULL) {
 60		pd->session_idx = 0;
 61		l2tp_dfs_next_tunnel(pd);
 62	}
 63
 64}
 65
 66static void *l2tp_dfs_seq_start(struct seq_file *m, loff_t *offs)
 67{
 68	struct l2tp_dfs_seq_data *pd = SEQ_START_TOKEN;
 69	loff_t pos = *offs;
 70
 71	if (!pos)
 72		goto out;
 73
 74	BUG_ON(m->private == NULL);
 75	pd = m->private;
 76
 77	if (pd->tunnel == NULL)
 78		l2tp_dfs_next_tunnel(pd);
 79	else
 80		l2tp_dfs_next_session(pd);
 81
 82	/* NULL tunnel and session indicates end of list */
 83	if ((pd->tunnel == NULL) && (pd->session == NULL))
 84		pd = NULL;
 85
 86out:
 87	return pd;
 88}
 89
 90
 91static void *l2tp_dfs_seq_next(struct seq_file *m, void *v, loff_t *pos)
 92{
 93	(*pos)++;
 94	return NULL;
 95}
 96
 97static void l2tp_dfs_seq_stop(struct seq_file *p, void *v)
 98{
 99	/* nothing to do */
 
 
 
 
 
 
 
 
 
 
100}
101
102static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v)
103{
104	struct l2tp_tunnel *tunnel = v;
105	int session_count = 0;
106	int hash;
107	struct hlist_node *walk;
108	struct hlist_node *tmp;
109
110	read_lock_bh(&tunnel->hlist_lock);
111	for (hash = 0; hash < L2TP_HASH_SIZE; hash++) {
112		hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
113			struct l2tp_session *session;
114
115			session = hlist_entry(walk, struct l2tp_session, hlist);
116			if (session->session_id == 0)
117				continue;
118
119			session_count++;
120		}
121	}
122	read_unlock_bh(&tunnel->hlist_lock);
123
124	seq_printf(m, "\nTUNNEL %u peer %u", tunnel->tunnel_id, tunnel->peer_tunnel_id);
125	if (tunnel->sock) {
126		struct inet_sock *inet = inet_sk(tunnel->sock);
127
128#if IS_ENABLED(CONFIG_IPV6)
129		if (tunnel->sock->sk_family == AF_INET6) {
130			const struct ipv6_pinfo *np = inet6_sk(tunnel->sock);
131
132			seq_printf(m, " from %pI6c to %pI6c\n",
133				&np->saddr, &tunnel->sock->sk_v6_daddr);
134		} else
135#endif
136		seq_printf(m, " from %pI4 to %pI4\n",
137			   &inet->inet_saddr, &inet->inet_daddr);
138		if (tunnel->encap == L2TP_ENCAPTYPE_UDP)
139			seq_printf(m, " source port %hu, dest port %hu\n",
140				   ntohs(inet->inet_sport), ntohs(inet->inet_dport));
141	}
142	seq_printf(m, " L2TPv%d, %s\n", tunnel->version,
143		   tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" :
144		   tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" :
145		   "");
146	seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count,
147		   tunnel->sock ? atomic_read(&tunnel->sock->sk_refcnt) : 0,
148		   atomic_read(&tunnel->ref_count));
149
150	seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n",
151		   tunnel->debug,
152		   atomic_long_read(&tunnel->stats.tx_packets),
153		   atomic_long_read(&tunnel->stats.tx_bytes),
154		   atomic_long_read(&tunnel->stats.tx_errors),
155		   atomic_long_read(&tunnel->stats.rx_packets),
156		   atomic_long_read(&tunnel->stats.rx_bytes),
157		   atomic_long_read(&tunnel->stats.rx_errors));
158
159	if (tunnel->show != NULL)
160		tunnel->show(m, tunnel);
161}
162
163static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v)
164{
165	struct l2tp_session *session = v;
166
167	seq_printf(m, "  SESSION %u, peer %u, %s\n", session->session_id,
168		   session->peer_session_id,
169		   session->pwtype == L2TP_PWTYPE_ETH ? "ETH" :
170		   session->pwtype == L2TP_PWTYPE_PPP ? "PPP" :
171		   "");
172	if (session->send_seq || session->recv_seq)
173		seq_printf(m, "   nr %hu, ns %hu\n", session->nr, session->ns);
174	seq_printf(m, "   refcnt %d\n", atomic_read(&session->ref_count));
175	seq_printf(m, "   config %d/%d/%c/%c/%s/%s %08x %u\n",
176		   session->mtu, session->mru,
177		   session->recv_seq ? 'R' : '-',
178		   session->send_seq ? 'S' : '-',
179		   session->data_seq == 1 ? "IPSEQ" :
180		   session->data_seq == 2 ? "DATASEQ" : "-",
181		   session->lns_mode ? "LNS" : "LAC",
182		   session->debug,
183		   jiffies_to_msecs(session->reorder_timeout));
184	seq_printf(m, "   offset %hu l2specific %hu/%hu\n",
185		   session->offset, session->l2specific_type, session->l2specific_len);
186	if (session->cookie_len) {
187		seq_printf(m, "   cookie %02x%02x%02x%02x",
188			   session->cookie[0], session->cookie[1],
189			   session->cookie[2], session->cookie[3]);
190		if (session->cookie_len == 8)
191			seq_printf(m, "%02x%02x%02x%02x",
192				   session->cookie[4], session->cookie[5],
193				   session->cookie[6], session->cookie[7]);
194		seq_printf(m, "\n");
195	}
196	if (session->peer_cookie_len) {
197		seq_printf(m, "   peer cookie %02x%02x%02x%02x",
198			   session->peer_cookie[0], session->peer_cookie[1],
199			   session->peer_cookie[2], session->peer_cookie[3]);
200		if (session->peer_cookie_len == 8)
201			seq_printf(m, "%02x%02x%02x%02x",
202				   session->peer_cookie[4], session->peer_cookie[5],
203				   session->peer_cookie[6], session->peer_cookie[7]);
204		seq_printf(m, "\n");
205	}
206
207	seq_printf(m, "   %hu/%hu tx %ld/%ld/%ld rx %ld/%ld/%ld\n",
208		   session->nr, session->ns,
209		   atomic_long_read(&session->stats.tx_packets),
210		   atomic_long_read(&session->stats.tx_bytes),
211		   atomic_long_read(&session->stats.tx_errors),
212		   atomic_long_read(&session->stats.rx_packets),
213		   atomic_long_read(&session->stats.rx_bytes),
214		   atomic_long_read(&session->stats.rx_errors));
215
216	if (session->show != NULL)
217		session->show(m, session);
218}
219
220static int l2tp_dfs_seq_show(struct seq_file *m, void *v)
221{
222	struct l2tp_dfs_seq_data *pd = v;
223
224	/* display header on line 1 */
225	if (v == SEQ_START_TOKEN) {
226		seq_puts(m, "TUNNEL ID, peer ID from IP to IP\n");
227		seq_puts(m, " L2TPv2/L2TPv3, UDP/IP\n");
228		seq_puts(m, " sessions session-count, refcnt refcnt/sk->refcnt\n");
229		seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
230		seq_puts(m, "  SESSION ID, peer ID, PWTYPE\n");
231		seq_puts(m, "   refcnt cnt\n");
232		seq_puts(m, "   offset OFFSET l2specific TYPE/LEN\n");
233		seq_puts(m, "   [ cookie ]\n");
234		seq_puts(m, "   [ peer cookie ]\n");
235		seq_puts(m, "   config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n");
236		seq_puts(m, "   nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
237		goto out;
238	}
239
240	/* Show the tunnel or session context */
241	if (pd->session == NULL)
242		l2tp_dfs_seq_tunnel_show(m, pd->tunnel);
243	else
244		l2tp_dfs_seq_session_show(m, pd->session);
 
 
245
246out:
247	return 0;
248}
249
250static const struct seq_operations l2tp_dfs_seq_ops = {
251	.start		= l2tp_dfs_seq_start,
252	.next		= l2tp_dfs_seq_next,
253	.stop		= l2tp_dfs_seq_stop,
254	.show		= l2tp_dfs_seq_show,
255};
256
257static int l2tp_dfs_seq_open(struct inode *inode, struct file *file)
258{
259	struct l2tp_dfs_seq_data *pd;
260	struct seq_file *seq;
261	int rc = -ENOMEM;
262
263	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
264	if (pd == NULL)
265		goto out;
266
267	/* Derive the network namespace from the pid opening the
268	 * file.
269	 */
270	pd->net = get_net_ns_by_pid(current->pid);
271	if (IS_ERR(pd->net)) {
272		rc = PTR_ERR(pd->net);
273		goto err_free_pd;
274	}
275
276	rc = seq_open(file, &l2tp_dfs_seq_ops);
277	if (rc)
278		goto err_free_net;
279
280	seq = file->private_data;
281	seq->private = pd;
282
283out:
284	return rc;
285
286err_free_net:
287	put_net(pd->net);
288err_free_pd:
289	kfree(pd);
290	goto out;
291}
292
293static int l2tp_dfs_seq_release(struct inode *inode, struct file *file)
294{
295	struct l2tp_dfs_seq_data *pd;
296	struct seq_file *seq;
297
298	seq = file->private_data;
299	pd = seq->private;
300	if (pd->net)
301		put_net(pd->net);
302	kfree(pd);
303	seq_release(inode, file);
304
305	return 0;
306}
307
308static const struct file_operations l2tp_dfs_fops = {
309	.owner		= THIS_MODULE,
310	.open		= l2tp_dfs_seq_open,
311	.read		= seq_read,
312	.llseek		= seq_lseek,
313	.release	= l2tp_dfs_seq_release,
314};
315
316static int __init l2tp_debugfs_init(void)
317{
318	int rc = 0;
319
320	rootdir = debugfs_create_dir("l2tp", NULL);
321	if (IS_ERR(rootdir)) {
322		rc = PTR_ERR(rootdir);
323		rootdir = NULL;
324		goto out;
325	}
326
327	tunnels = debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops);
328	if (tunnels == NULL)
329		rc = -EIO;
330
331	pr_info("L2TP debugfs support\n");
332
333out:
334	if (rc)
335		pr_warn("unable to init\n");
336
337	return rc;
338}
339
340static void __exit l2tp_debugfs_exit(void)
341{
342	debugfs_remove(tunnels);
343	debugfs_remove(rootdir);
344}
345
346module_init(l2tp_debugfs_init);
347module_exit(l2tp_debugfs_exit);
348
349MODULE_LICENSE("GPL");
350MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
351MODULE_DESCRIPTION("L2TP debugfs driver");
352MODULE_VERSION("1.0");