[linux.git] / net / l2tp / l2tp_debugfs.c

/*
 * L2TP subsystem debugfs
 *
 * Copyright (c) 2010 Katalix Systems Ltd
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/socket.h>
#include <linux/hash.h>
#include <linux/l2tp.h>
#include <linux/in.h>
#include <linux/etherdevice.h>
#include <linux/spinlock.h>
#include <linux/debugfs.h>
#include <net/sock.h>
#include <net/ip.h>
#include <net/icmp.h>
#include <net/udp.h>
#include <net/inet_common.h>
#include <net/inet_hashtables.h>
#include <net/tcp_states.h>
#include <net/protocol.h>
#include <net/xfrm.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>

#include "l2tp_core.h"

static struct dentry *rootdir;
static struct dentry *tunnels;

struct l2tp_dfs_seq_data {
	struct net *net;
	int tunnel_idx;			/* current tunnel */
	int session_idx;		/* index of session within current tunnel */
	struct l2tp_tunnel *tunnel;
	struct l2tp_session *session;	/* NULL means get next tunnel */
};

static void l2tp_dfs_next_tunnel(struct l2tp_dfs_seq_data *pd)
{
	pd->tunnel = l2tp_tunnel_find_nth(pd->net, pd->tunnel_idx);
	pd->tunnel_idx++;
}

static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd)
{
	pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx);
	pd->session_idx++;

	if (pd->session == NULL) {
		pd->session_idx = 0;
		l2tp_dfs_next_tunnel(pd);
	}

}

static void *l2tp_dfs_seq_start(struct seq_file *m, loff_t *offs)
{
	struct l2tp_dfs_seq_data *pd = SEQ_START_TOKEN;
	loff_t pos = *offs;

	if (!pos)
		goto out;

	BUG_ON(m->private == NULL);
	pd = m->private;

	if (pd->tunnel == NULL)
		l2tp_dfs_next_tunnel(pd);
	else
		l2tp_dfs_next_session(pd);

	/* NULL tunnel and session indicates end of list */
	if ((pd->tunnel == NULL) && (pd->session == NULL))
		pd = NULL;

out:
	return pd;
}


static void *l2tp_dfs_seq_next(struct seq_file *m, void *v, loff_t *pos)
{
	(*pos)++;
	return NULL;
}

static void l2tp_dfs_seq_stop(struct seq_file *p, void *v)
{
	/* nothing to do */
}

static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v)
{
	struct l2tp_tunnel *tunnel = v;
	int session_count = 0;
	int hash;
	struct hlist_node *walk;
	struct hlist_node *tmp;

	read_lock_bh(&tunnel->hlist_lock);
	for (hash = 0; hash < L2TP_HASH_SIZE; hash++) {
		hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
			struct l2tp_session *session;

			session = hlist_entry(walk, struct l2tp_session, hlist);
			if (session->session_id == 0)
				continue;

			session_count++;
		}
	}
	read_unlock_bh(&tunnel->hlist_lock);

	seq_printf(m, "\nTUNNEL %u peer %u", tunnel->tunnel_id, tunnel->peer_tunnel_id);
	if (tunnel->sock) {
		struct inet_sock *inet = inet_sk(tunnel->sock);

#if IS_ENABLED(CONFIG_IPV6)
		if (tunnel->sock->sk_family == AF_INET6) {
			const struct ipv6_pinfo *np = inet6_sk(tunnel->sock);

			seq_printf(m, " from %pI6c to %pI6c\n",
				&np->saddr, &tunnel->sock->sk_v6_daddr);
		} else
#endif
		seq_printf(m, " from %pI4 to %pI4\n",
			   &inet->inet_saddr, &inet->inet_daddr);
		if (tunnel->encap == L2TP_ENCAPTYPE_UDP)
			seq_printf(m, " source port %hu, dest port %hu\n",
				   ntohs(inet->inet_sport), ntohs(inet->inet_dport));
	}
	seq_printf(m, " L2TPv%d, %s\n", tunnel->version,
		   tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" :
		   tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" :
		   "");
	seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count,
		   tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0,
		   refcount_read(&tunnel->ref_count));
	seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n",
		   tunnel->debug,
		   atomic_long_read(&tunnel->stats.tx_packets),
		   atomic_long_read(&tunnel->stats.tx_bytes),
		   atomic_long_read(&tunnel->stats.tx_errors),
		   atomic_long_read(&tunnel->stats.rx_packets),
		   atomic_long_read(&tunnel->stats.rx_bytes),
		   atomic_long_read(&tunnel->stats.rx_errors));

	if (tunnel->show != NULL)
		tunnel->show(m, tunnel);
}

static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v)
{
	struct l2tp_session *session = v;

	seq_printf(m, "  SESSION %u, peer %u, %s\n", session->session_id,
		   session->peer_session_id,
		   session->pwtype == L2TP_PWTYPE_ETH ? "ETH" :
		   session->pwtype == L2TP_PWTYPE_PPP ? "PPP" :
		   "");
	if (session->send_seq || session->recv_seq)
		seq_printf(m, "   nr %hu, ns %hu\n", session->nr, session->ns);
	seq_printf(m, "   refcnt %d\n", refcount_read(&session->ref_count));
	seq_printf(m, "   config %d/%d/%c/%c/%s/%s %08x %u\n",
		   session->mtu, session->mru,
		   session->recv_seq ? 'R' : '-',
		   session->send_seq ? 'S' : '-',
		   session->data_seq == 1 ? "IPSEQ" :
		   session->data_seq == 2 ? "DATASEQ" : "-",
		   session->lns_mode ? "LNS" : "LAC",
		   session->debug,
		   jiffies_to_msecs(session->reorder_timeout));
	seq_printf(m, "   offset %hu l2specific %hu/%hu\n",
		   session->offset, session->l2specific_type, session->l2specific_len);
	if (session->cookie_len) {
		seq_printf(m, "   cookie %02x%02x%02x%02x",
			   session->cookie[0], session->cookie[1],
			   session->cookie[2], session->cookie[3]);
		if (session->cookie_len == 8)
			seq_printf(m, "%02x%02x%02x%02x",
				   session->cookie[4], session->cookie[5],
				   session->cookie[6], session->cookie[7]);
		seq_printf(m, "\n");
	}
	if (session->peer_cookie_len) {
		seq_printf(m, "   peer cookie %02x%02x%02x%02x",
			   session->peer_cookie[0], session->peer_cookie[1],
			   session->peer_cookie[2], session->peer_cookie[3]);
		if (session->peer_cookie_len == 8)
			seq_printf(m, "%02x%02x%02x%02x",
				   session->peer_cookie[4], session->peer_cookie[5],
				   session->peer_cookie[6], session->peer_cookie[7]);
		seq_printf(m, "\n");
	}

	seq_printf(m, "   %hu/%hu tx %ld/%ld/%ld rx %ld/%ld/%ld\n",
		   session->nr, session->ns,
		   atomic_long_read(&session->stats.tx_packets),
		   atomic_long_read(&session->stats.tx_bytes),
		   atomic_long_read(&session->stats.tx_errors),
		   atomic_long_read(&session->stats.rx_packets),
		   atomic_long_read(&session->stats.rx_bytes),
		   atomic_long_read(&session->stats.rx_errors));

	if (session->show != NULL)
		session->show(m, session);
}

static int l2tp_dfs_seq_show(struct seq_file *m, void *v)
{
	struct l2tp_dfs_seq_data *pd = v;

	/* display header on line 1 */
	if (v == SEQ_START_TOKEN) {
		seq_puts(m, "TUNNEL ID, peer ID from IP to IP\n");
		seq_puts(m, " L2TPv2/L2TPv3, UDP/IP\n");
		seq_puts(m, " sessions session-count, refcnt refcnt/sk->refcnt\n");
		seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
		seq_puts(m, "  SESSION ID, peer ID, PWTYPE\n");
		seq_puts(m, "   refcnt cnt\n");
		seq_puts(m, "   offset OFFSET l2specific TYPE/LEN\n");
		seq_puts(m, "   [ cookie ]\n");
		seq_puts(m, "   [ peer cookie ]\n");
		seq_puts(m, "   config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n");
		seq_puts(m, "   nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
		goto out;
	}

	/* Show the tunnel or session context */
	if (!pd->session) {
		l2tp_dfs_seq_tunnel_show(m, pd->tunnel);
	} else {
		l2tp_dfs_seq_session_show(m, pd->session);
		l2tp_session_dec_refcount(pd->session);
	}

out:
	return 0;
}

static const struct seq_operations l2tp_dfs_seq_ops = {
	.start		= l2tp_dfs_seq_start,
	.next		= l2tp_dfs_seq_next,
	.stop		= l2tp_dfs_seq_stop,
	.show		= l2tp_dfs_seq_show,
};

static int l2tp_dfs_seq_open(struct inode *inode, struct file *file)
{
	struct l2tp_dfs_seq_data *pd;
	struct seq_file *seq;
	int rc = -ENOMEM;

	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
	if (pd == NULL)
		goto out;

	/* Derive the network namespace from the pid opening the
	 * file.
	 */
	pd->net = get_net_ns_by_pid(current->pid);
	if (IS_ERR(pd->net)) {
		rc = PTR_ERR(pd->net);
		goto err_free_pd;
	}

	rc = seq_open(file, &l2tp_dfs_seq_ops);
	if (rc)
		goto err_free_net;

	seq = file->private_data;
	seq->private = pd;

out:
	return rc;

err_free_net:
	put_net(pd->net);
err_free_pd:
	kfree(pd);
	goto out;
}

static int l2tp_dfs_seq_release(struct inode *inode, struct file *file)
{
	struct l2tp_dfs_seq_data *pd;
	struct seq_file *seq;

	seq = file->private_data;
	pd = seq->private;
	if (pd->net)
		put_net(pd->net);
	kfree(pd);
	seq_release(inode, file);

	return 0;
}

static const struct file_operations l2tp_dfs_fops = {
	.owner		= THIS_MODULE,
	.open		= l2tp_dfs_seq_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= l2tp_dfs_seq_release,
};

static int __init l2tp_debugfs_init(void)
{
	int rc = 0;

	rootdir = debugfs_create_dir("l2tp", NULL);
	if (IS_ERR(rootdir)) {
		rc = PTR_ERR(rootdir);
		rootdir = NULL;
		goto out;
	}

	tunnels = debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops);
	if (tunnels == NULL)
		rc = -EIO;

	pr_info("L2TP debugfs support\n");

out:
	if (rc)
		pr_warn("unable to init\n");

	return rc;
}

static void __exit l2tp_debugfs_exit(void)
{
	debugfs_remove(tunnels);
	debugfs_remove(rootdir);
}

module_init(l2tp_debugfs_init);
module_exit(l2tp_debugfs_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("James Chapman <[email protected]>");
MODULE_DESCRIPTION("L2TP debugfs driver");
MODULE_VERSION("1.0");
Commit	Line	Data
0ad66140 JC	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
a4ca44fa JP	12	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
a4ca44fa JP	13
0ad66140 JC	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
	37	static struct dentry *rootdir;
	38	static struct dentry *tunnels;
	39
	40	struct 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
	48	static 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
	54	static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd)
	55	{
a4346210	56	pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx);
0ad66140 JC	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
	66	static 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
	86	out:
	87	return pd;
	88	}
	89
	90
	91	static void l2tp_dfs_seq_next(struct seq_file m, void v, loff_t pos)
	92	{
	93	(*pos)++;
	94	return NULL;
	95	}
	96
	97	static void l2tp_dfs_seq_stop(struct seq_file p, void v)
	98	{
	99	/* nothing to do */
	100	}
	101
	102	static 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);
2121c3f5 CE	127
	128	#if IS_ENABLED(CONFIG_IPV6)
	129	if (tunnel->sock->sk_family == AF_INET6) {
efe4208f ED	130	const struct ipv6_pinfo *np = inet6_sk(tunnel->sock);
efe4208f ED	131
2121c3f5	132	seq_printf(m, " from %pI6c to %pI6c\n",
efe4208f	133	&np->saddr, &tunnel->sock->sk_v6_daddr);
2121c3f5 CE	134	} else
2121c3f5 CE	135	#endif
a4fbf841 JP	136	seq_printf(m, " from %pI4 to %pI4\n",
a4fbf841 JP	137	&inet->inet_saddr, &inet->inet_daddr);
0ad66140 JC	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,
41c6d650	147	tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0,
fbea9e07	148	refcount_read(&tunnel->ref_count));
7b7c0719	149	seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n",
0ad66140	150	tunnel->debug,
7b7c0719 TP	151	atomic_long_read(&tunnel->stats.tx_packets),
	152	atomic_long_read(&tunnel->stats.tx_bytes),
	153	atomic_long_read(&tunnel->stats.tx_errors),
	154	atomic_long_read(&tunnel->stats.rx_packets),
	155	atomic_long_read(&tunnel->stats.rx_bytes),
	156	atomic_long_read(&tunnel->stats.rx_errors));
0ad66140 JC	157
	158	if (tunnel->show != NULL)
	159	tunnel->show(m, tunnel);
	160	}
	161
	162	static void l2tp_dfs_seq_session_show(struct seq_file m, void v)
	163	{
	164	struct l2tp_session *session = v;
	165
	166	seq_printf(m, " SESSION %u, peer %u, %s\n", session->session_id,
	167	session->peer_session_id,
	168	session->pwtype == L2TP_PWTYPE_ETH ? "ETH" :
	169	session->pwtype == L2TP_PWTYPE_PPP ? "PPP" :
	170	"");
	171	if (session->send_seq \|\| session->recv_seq)
	172	seq_printf(m, " nr %hu, ns %hu\n", session->nr, session->ns);
fbea9e07	173	seq_printf(m, " refcnt %d\n", refcount_read(&session->ref_count));
0ad66140 JC	174	seq_printf(m, " config %d/%d/%c/%c/%s/%s %08x %u\n",
	175	session->mtu, session->mru,
	176	session->recv_seq ? 'R' : '-',
	177	session->send_seq ? 'S' : '-',
	178	session->data_seq == 1 ? "IPSEQ" :
	179	session->data_seq == 2 ? "DATASEQ" : "-",
	180	session->lns_mode ? "LNS" : "LAC",
	181	session->debug,
	182	jiffies_to_msecs(session->reorder_timeout));
	183	seq_printf(m, " offset %hu l2specific %hu/%hu\n",
	184	session->offset, session->l2specific_type, session->l2specific_len);
	185	if (session->cookie_len) {
	186	seq_printf(m, " cookie %02x%02x%02x%02x",
	187	session->cookie[0], session->cookie[1],
	188	session->cookie[2], session->cookie[3]);
	189	if (session->cookie_len == 8)
	190	seq_printf(m, "%02x%02x%02x%02x",
	191	session->cookie[4], session->cookie[5],
	192	session->cookie[6], session->cookie[7]);
	193	seq_printf(m, "\n");
	194	}
	195	if (session->peer_cookie_len) {
	196	seq_printf(m, " peer cookie %02x%02x%02x%02x",
	197	session->peer_cookie[0], session->peer_cookie[1],
	198	session->peer_cookie[2], session->peer_cookie[3]);
	199	if (session->peer_cookie_len == 8)
	200	seq_printf(m, "%02x%02x%02x%02x",
	201	session->peer_cookie[4], session->peer_cookie[5],
	202	session->peer_cookie[6], session->peer_cookie[7]);
	203	seq_printf(m, "\n");
	204	}
	205
7b7c0719	206	seq_printf(m, " %hu/%hu tx %ld/%ld/%ld rx %ld/%ld/%ld\n",
0ad66140	207	session->nr, session->ns,
7b7c0719 TP	208	atomic_long_read(&session->stats.tx_packets),
	209	atomic_long_read(&session->stats.tx_bytes),
	210	atomic_long_read(&session->stats.tx_errors),
	211	atomic_long_read(&session->stats.rx_packets),
	212	atomic_long_read(&session->stats.rx_bytes),
	213	atomic_long_read(&session->stats.rx_errors));
0ad66140 JC	214
	215	if (session->show != NULL)
	216	session->show(m, session);
	217	}
	218
	219	static int l2tp_dfs_seq_show(struct seq_file m, void v)
	220	{
	221	struct l2tp_dfs_seq_data *pd = v;
	222
	223	/* display header on line 1 */
	224	if (v == SEQ_START_TOKEN) {
	225	seq_puts(m, "TUNNEL ID, peer ID from IP to IP\n");
	226	seq_puts(m, " L2TPv2/L2TPv3, UDP/IP\n");
	227	seq_puts(m, " sessions session-count, refcnt refcnt/sk->refcnt\n");
	228	seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
	229	seq_puts(m, " SESSION ID, peer ID, PWTYPE\n");
	230	seq_puts(m, " refcnt cnt\n");
	231	seq_puts(m, " offset OFFSET l2specific TYPE/LEN\n");
	232	seq_puts(m, " [ cookie ]\n");
	233	seq_puts(m, " [ peer cookie ]\n");
	234	seq_puts(m, " config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n");
	235	seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
	236	goto out;
	237	}
	238
	239	/* Show the tunnel or session context */
e08293a4	240	if (!pd->session) {
0ad66140	241	l2tp_dfs_seq_tunnel_show(m, pd->tunnel);
e08293a4	242	} else {
0ad66140	243	l2tp_dfs_seq_session_show(m, pd->session);
e08293a4 GN	244	l2tp_session_dec_refcount(pd->session);
e08293a4 GN	245	}
0ad66140 JC	246
	247	out:
	248	return 0;
	249	}
	250
	251	static const struct seq_operations l2tp_dfs_seq_ops = {
	252	.start = l2tp_dfs_seq_start,
	253	.next = l2tp_dfs_seq_next,
	254	.stop = l2tp_dfs_seq_stop,
	255	.show = l2tp_dfs_seq_show,
	256	};
	257
	258	static int l2tp_dfs_seq_open(struct inode inode, struct file file)
	259	{
	260	struct l2tp_dfs_seq_data *pd;
	261	struct seq_file *seq;
	262	int rc = -ENOMEM;
	263
6f9b9018	264	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
0ad66140 JC	265	if (pd == NULL)
	266	goto out;
	267
	268	/* Derive the network namespace from the pid opening the
	269	* file.
	270	*/
	271	pd->net = get_net_ns_by_pid(current->pid);
	272	if (IS_ERR(pd->net)) {
b8f07a06	273	rc = PTR_ERR(pd->net);
0ad66140 JC	274	goto err_free_pd;
	275	}
	276
	277	rc = seq_open(file, &l2tp_dfs_seq_ops);
	278	if (rc)
	279	goto err_free_net;
	280
	281	seq = file->private_data;
	282	seq->private = pd;
	283
	284	out:
	285	return rc;
	286
	287	err_free_net:
	288	put_net(pd->net);
	289	err_free_pd:
	290	kfree(pd);
	291	goto out;
	292	}
	293
	294	static int l2tp_dfs_seq_release(struct inode inode, struct file file)
	295	{
	296	struct l2tp_dfs_seq_data *pd;
	297	struct seq_file *seq;
	298
	299	seq = file->private_data;
	300	pd = seq->private;
	301	if (pd->net)
	302	put_net(pd->net);
	303	kfree(pd);
	304	seq_release(inode, file);
	305
	306	return 0;
	307	}
	308
	309	static const struct file_operations l2tp_dfs_fops = {
	310	.owner = THIS_MODULE,
	311	.open = l2tp_dfs_seq_open,
	312	.read = seq_read,
	313	.llseek = seq_lseek,
	314	.release = l2tp_dfs_seq_release,
	315	};
	316
	317	static int __init l2tp_debugfs_init(void)
	318	{
	319	int rc = 0;
	320
	321	rootdir = debugfs_create_dir("l2tp", NULL);
	322	if (IS_ERR(rootdir)) {
	323	rc = PTR_ERR(rootdir);
	324	rootdir = NULL;
	325	goto out;
	326	}
	327
	328	tunnels = debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops);
	329	if (tunnels == NULL)
	330	rc = -EIO;
	331
a4ca44fa	332	pr_info("L2TP debugfs support\n");
0ad66140 JC	333
	334	out:
	335	if (rc)
a4ca44fa	336	pr_warn("unable to init\n");
0ad66140 JC	337
	338	return rc;
	339	}
	340
	341	static void __exit l2tp_debugfs_exit(void)
	342	{
	343	debugfs_remove(tunnels);
	344	debugfs_remove(rootdir);
	345	}
	346
	347	module_init(l2tp_debugfs_init);
	348	module_exit(l2tp_debugfs_exit);
	349
	350	MODULE_LICENSE("GPL");
	351	MODULE_AUTHOR("James Chapman <[email protected]>");
	352	MODULE_DESCRIPTION("L2TP debugfs driver");
	353	MODULE_VERSION("1.0");