[mirror_ubuntu-bionic-kernel.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)
{
	/* Drop reference taken during previous invocation */
	if (pd->tunnel)
		l2tp_tunnel_dec_refcount(pd->tunnel);

	pd->tunnel = l2tp_tunnel_get_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)
{
	struct l2tp_dfs_seq_data *pd = v;

	if (!pd || pd == SEQ_START_TOKEN)
		return;

	/* Drop reference taken by last invocation of l2tp_dfs_next_tunnel() */
	if (pd->tunnel) {
		l2tp_tunnel_dec_refcount(pd->tunnel);
		pd->tunnel = NULL;
		pd->session = NULL;
	}
}

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 <jchapman@katalix.com>");
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	{
1de2c79b GN	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);
0ad66140 JC	55	pd->tunnel_idx++;
	56	}
	57
	58	static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd)
	59	{
a4346210	60	pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx);
0ad66140 JC	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
	70	static 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
	90	out:
	91	return pd;
	92	}
	93
	94
	95	static void l2tp_dfs_seq_next(struct seq_file m, void v, loff_t pos)
	96	{
	97	(*pos)++;
	98	return NULL;
	99	}
	100
	101	static void l2tp_dfs_seq_stop(struct seq_file p, void v)
	102	{
1de2c79b GN	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() */
3e8f7ee4	109	if (pd->tunnel) {
1de2c79b	110	l2tp_tunnel_dec_refcount(pd->tunnel);
3e8f7ee4 GN	111	pd->tunnel = NULL;
	112	pd->session = NULL;
	113	}
0ad66140 JC	114	}
	115
	116	static 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);
2121c3f5 CE	141
	142	#if IS_ENABLED(CONFIG_IPV6)
	143	if (tunnel->sock->sk_family == AF_INET6) {
efe4208f ED	144	const struct ipv6_pinfo *np = inet6_sk(tunnel->sock);
efe4208f ED	145
2121c3f5	146	seq_printf(m, " from %pI6c to %pI6c\n",
efe4208f	147	&np->saddr, &tunnel->sock->sk_v6_daddr);
2121c3f5 CE	148	} else
2121c3f5 CE	149	#endif
a4fbf841 JP	150	seq_printf(m, " from %pI4 to %pI4\n",
a4fbf841 JP	151	&inet->inet_saddr, &inet->inet_daddr);
0ad66140 JC	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,
41c6d650	161	tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0,
fbea9e07	162	refcount_read(&tunnel->ref_count));
7b7c0719	163	seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n",
0ad66140	164	tunnel->debug,
7b7c0719 TP	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));
0ad66140 JC	171
	172	if (tunnel->show != NULL)
	173	tunnel->show(m, tunnel);
	174	}
	175
	176	static 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);
fbea9e07	187	seq_printf(m, " refcnt %d\n", refcount_read(&session->ref_count));
0ad66140 JC	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 %hu l2specific %hu/%hu\n",
	198	session->offset, session->l2specific_type, session->l2specific_len);
	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
7b7c0719	220	seq_printf(m, " %hu/%hu tx %ld/%ld/%ld rx %ld/%ld/%ld\n",
0ad66140	221	session->nr, session->ns,
7b7c0719 TP	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));
0ad66140 JC	228
	229	if (session->show != NULL)
	230	session->show(m, session);
	231	}
	232
	233	static 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 */
e08293a4	254	if (!pd->session) {
0ad66140	255	l2tp_dfs_seq_tunnel_show(m, pd->tunnel);
e08293a4	256	} else {
0ad66140	257	l2tp_dfs_seq_session_show(m, pd->session);
e08293a4 GN	258	l2tp_session_dec_refcount(pd->session);
e08293a4 GN	259	}
0ad66140 JC	260
	261	out:
	262	return 0;
	263	}
	264
	265	static 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
	272	static 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
6f9b9018	278	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
0ad66140 JC	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)) {
b8f07a06	287	rc = PTR_ERR(pd->net);
0ad66140 JC	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
	298	out:
	299	return rc;
	300
	301	err_free_net:
	302	put_net(pd->net);
	303	err_free_pd:
	304	kfree(pd);
	305	goto out;
	306	}
	307
	308	static 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
	323	static 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
	331	static 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
a4ca44fa	346	pr_info("L2TP debugfs support\n");
0ad66140 JC	347
	348	out:
	349	if (rc)
a4ca44fa	350	pr_warn("unable to init\n");
0ad66140 JC	351
	352	return rc;
	353	}
	354
	355	static void __exit l2tp_debugfs_exit(void)
	356	{
	357	debugfs_remove(tunnels);
	358	debugfs_remove(rootdir);
	359	}
	360
	361	module_init(l2tp_debugfs_init);
	362	module_exit(l2tp_debugfs_exit);
	363
	364	MODULE_LICENSE("GPL");
	365	MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
	366	MODULE_DESCRIPTION("L2TP debugfs driver");
	367	MODULE_VERSION("1.0");