[mirror_ubuntu-kernels.git] / net / l2tp / l2tp_debugfs.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * L2TP subsystem debugfs
 *
 * Copyright (c) 2010 Katalix Systems Ltd
 */

#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)
{
	/* Drop reference taken during previous invocation */
	if (pd->session)
		l2tp_session_dec_refcount(pd->session);

	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_session()
	 * or l2tp_dfs_next_tunnel().
	 */
	if (pd->session) {
		l2tp_session_dec_refcount(pd->session);
		pd->session = NULL;
	}
	if (pd->tunnel) {
		l2tp_tunnel_dec_refcount(pd->tunnel);
		pd->tunnel = 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));
}

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 0/0/%c/%c/-/%s %08x %u\n",
		   session->recv_seq ? 'R' : '-',
		   session->send_seq ? 'S' : '-',
		   session->lns_mode ? "LNS" : "LAC",
		   session->debug,
		   jiffies_to_msecs(session->reorder_timeout));
	seq_printf(m, "   offset 0 l2specific %hu/%hu\n",
		   session->l2specific_type, l2tp_get_l2specific_len(session));
	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;
	}

	if (!pd->session)
		l2tp_dfs_seq_tunnel_show(m, pd->tunnel);
	else
		l2tp_dfs_seq_session_show(m, 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
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
0ad66140 JC	2	/*
	3	* L2TP subsystem debugfs
	4	*
	5	* Copyright (c) 2010 Katalix Systems Ltd
0ad66140 JC	6	*/
0ad66140 JC	7
a4ca44fa JP	8	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
a4ca44fa JP	9
0ad66140 JC	10	#include <linux/module.h>
	11	#include <linux/skbuff.h>
	12	#include <linux/socket.h>
	13	#include <linux/hash.h>
	14	#include <linux/l2tp.h>
	15	#include <linux/in.h>
	16	#include <linux/etherdevice.h>
	17	#include <linux/spinlock.h>
	18	#include <linux/debugfs.h>
	19	#include <net/sock.h>
	20	#include <net/ip.h>
	21	#include <net/icmp.h>
	22	#include <net/udp.h>
	23	#include <net/inet_common.h>
	24	#include <net/inet_hashtables.h>
	25	#include <net/tcp_states.h>
	26	#include <net/protocol.h>
	27	#include <net/xfrm.h>
	28	#include <net/net_namespace.h>
	29	#include <net/netns/generic.h>
	30
	31	#include "l2tp_core.h"
	32
	33	static struct dentry *rootdir;
	34	static struct dentry *tunnels;
	35
	36	struct l2tp_dfs_seq_data {
	37	struct net *net;
	38	int tunnel_idx; /* current tunnel */
	39	int session_idx; /* index of session within current tunnel */
	40	struct l2tp_tunnel *tunnel;
	41	struct l2tp_session session; / NULL means get next tunnel */
	42	};
	43
	44	static void l2tp_dfs_next_tunnel(struct l2tp_dfs_seq_data *pd)
	45	{
f726214d GN	46	/* Drop reference taken during previous invocation */
	47	if (pd->tunnel)
	48	l2tp_tunnel_dec_refcount(pd->tunnel);
	49
	50	pd->tunnel = l2tp_tunnel_get_nth(pd->net, pd->tunnel_idx);
0ad66140 JC	51	pd->tunnel_idx++;
	52	}
	53
	54	static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd)
	55	{
83494407 GN	56	/* Drop reference taken during previous invocation */
	57	if (pd->session)
	58	l2tp_session_dec_refcount(pd->session);
	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	{
f726214d GN	103	struct l2tp_dfs_seq_data *pd = v;
	104
	105	if (!pd \|\| pd == SEQ_START_TOKEN)
	106	return;
	107
83494407 GN	108	/* Drop reference taken by last invocation of l2tp_dfs_next_session()
	109	* or l2tp_dfs_next_tunnel().
	110	*/
	111	if (pd->session) {
	112	l2tp_session_dec_refcount(pd->session);
	113	pd->session = NULL;
	114	}
5411b618	115	if (pd->tunnel) {
f726214d	116	l2tp_tunnel_dec_refcount(pd->tunnel);
5411b618	117	pd->tunnel = NULL;
5411b618	118	}
0ad66140 JC	119	}
	120
	121	static void l2tp_dfs_seq_tunnel_show(struct seq_file m, void v)
	122	{
	123	struct l2tp_tunnel *tunnel = v;
	124	int session_count = 0;
	125	int hash;
	126	struct hlist_node *walk;
	127	struct hlist_node *tmp;
	128
	129	read_lock_bh(&tunnel->hlist_lock);
	130	for (hash = 0; hash < L2TP_HASH_SIZE; hash++) {
	131	hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
	132	struct l2tp_session *session;
	133
	134	session = hlist_entry(walk, struct l2tp_session, hlist);
	135	if (session->session_id == 0)
	136	continue;
	137
	138	session_count++;
	139	}
	140	}
	141	read_unlock_bh(&tunnel->hlist_lock);
	142
	143	seq_printf(m, "\nTUNNEL %u peer %u", tunnel->tunnel_id, tunnel->peer_tunnel_id);
	144	if (tunnel->sock) {
	145	struct inet_sock *inet = inet_sk(tunnel->sock);
2121c3f5 CE	146
	147	#if IS_ENABLED(CONFIG_IPV6)
	148	if (tunnel->sock->sk_family == AF_INET6) {
efe4208f ED	149	const struct ipv6_pinfo *np = inet6_sk(tunnel->sock);
efe4208f ED	150
2121c3f5	151	seq_printf(m, " from %pI6c to %pI6c\n",
efe4208f	152	&np->saddr, &tunnel->sock->sk_v6_daddr);
2121c3f5 CE	153	} else
2121c3f5 CE	154	#endif
a4fbf841 JP	155	seq_printf(m, " from %pI4 to %pI4\n",
a4fbf841 JP	156	&inet->inet_saddr, &inet->inet_daddr);
0ad66140 JC	157	if (tunnel->encap == L2TP_ENCAPTYPE_UDP)
	158	seq_printf(m, " source port %hu, dest port %hu\n",
	159	ntohs(inet->inet_sport), ntohs(inet->inet_dport));
	160	}
	161	seq_printf(m, " L2TPv%d, %s\n", tunnel->version,
	162	tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" :
	163	tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" :
	164	"");
	165	seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count,
41c6d650	166	tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0,
fbea9e07	167	refcount_read(&tunnel->ref_count));
7b7c0719	168	seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n",
0ad66140	169	tunnel->debug,
7b7c0719 TP	170	atomic_long_read(&tunnel->stats.tx_packets),
	171	atomic_long_read(&tunnel->stats.tx_bytes),
	172	atomic_long_read(&tunnel->stats.tx_errors),
	173	atomic_long_read(&tunnel->stats.rx_packets),
	174	atomic_long_read(&tunnel->stats.rx_bytes),
	175	atomic_long_read(&tunnel->stats.rx_errors));
0ad66140 JC	176	}
	177
	178	static void l2tp_dfs_seq_session_show(struct seq_file m, void v)
	179	{
	180	struct l2tp_session *session = v;
	181
	182	seq_printf(m, " SESSION %u, peer %u, %s\n", session->session_id,
	183	session->peer_session_id,
	184	session->pwtype == L2TP_PWTYPE_ETH ? "ETH" :
	185	session->pwtype == L2TP_PWTYPE_PPP ? "PPP" :
	186	"");
	187	if (session->send_seq \|\| session->recv_seq)
	188	seq_printf(m, " nr %hu, ns %hu\n", session->nr, session->ns);
fbea9e07	189	seq_printf(m, " refcnt %d\n", refcount_read(&session->ref_count));
e9697e2e	190	seq_printf(m, " config 0/0/%c/%c/-/%s %08x %u\n",
0ad66140 JC	191	session->recv_seq ? 'R' : '-',
0ad66140 JC	192	session->send_seq ? 'S' : '-',
0ad66140 JC	193	session->lns_mode ? "LNS" : "LAC",
	194	session->debug,
	195	jiffies_to_msecs(session->reorder_timeout));
900631ee	196	seq_printf(m, " offset 0 l2specific %hu/%hu\n",
9afa6585	197	session->l2specific_type, l2tp_get_l2specific_len(session));
0ad66140 JC	198	if (session->cookie_len) {
	199	seq_printf(m, " cookie %02x%02x%02x%02x",
	200	session->cookie[0], session->cookie[1],
	201	session->cookie[2], session->cookie[3]);
	202	if (session->cookie_len == 8)
	203	seq_printf(m, "%02x%02x%02x%02x",
	204	session->cookie[4], session->cookie[5],
	205	session->cookie[6], session->cookie[7]);
	206	seq_printf(m, "\n");
	207	}
	208	if (session->peer_cookie_len) {
	209	seq_printf(m, " peer cookie %02x%02x%02x%02x",
	210	session->peer_cookie[0], session->peer_cookie[1],
	211	session->peer_cookie[2], session->peer_cookie[3]);
	212	if (session->peer_cookie_len == 8)
	213	seq_printf(m, "%02x%02x%02x%02x",
	214	session->peer_cookie[4], session->peer_cookie[5],
	215	session->peer_cookie[6], session->peer_cookie[7]);
	216	seq_printf(m, "\n");
	217	}
	218
7b7c0719	219	seq_printf(m, " %hu/%hu tx %ld/%ld/%ld rx %ld/%ld/%ld\n",
0ad66140	220	session->nr, session->ns,
7b7c0719 TP	221	atomic_long_read(&session->stats.tx_packets),
	222	atomic_long_read(&session->stats.tx_bytes),
	223	atomic_long_read(&session->stats.tx_errors),
	224	atomic_long_read(&session->stats.rx_packets),
	225	atomic_long_read(&session->stats.rx_bytes),
	226	atomic_long_read(&session->stats.rx_errors));
0ad66140 JC	227
	228	if (session->show != NULL)
	229	session->show(m, session);
	230	}
	231
	232	static int l2tp_dfs_seq_show(struct seq_file m, void v)
	233	{
	234	struct l2tp_dfs_seq_data *pd = v;
	235
	236	/* display header on line 1 */
	237	if (v == SEQ_START_TOKEN) {
	238	seq_puts(m, "TUNNEL ID, peer ID from IP to IP\n");
	239	seq_puts(m, " L2TPv2/L2TPv3, UDP/IP\n");
	240	seq_puts(m, " sessions session-count, refcnt refcnt/sk->refcnt\n");
	241	seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
	242	seq_puts(m, " SESSION ID, peer ID, PWTYPE\n");
	243	seq_puts(m, " refcnt cnt\n");
863def15	244	seq_puts(m, " offset OFFSET l2specific TYPE/LEN\n");
0ad66140 JC	245	seq_puts(m, " [ cookie ]\n");
	246	seq_puts(m, " [ peer cookie ]\n");
	247	seq_puts(m, " config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n");
	248	seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
	249	goto out;
	250	}
	251
83494407	252	if (!pd->session)
0ad66140	253	l2tp_dfs_seq_tunnel_show(m, pd->tunnel);
83494407	254	else
0ad66140 JC	255	l2tp_dfs_seq_session_show(m, pd->session);
	256
	257	out:
	258	return 0;
	259	}
	260
	261	static const struct seq_operations l2tp_dfs_seq_ops = {
	262	.start = l2tp_dfs_seq_start,
	263	.next = l2tp_dfs_seq_next,
	264	.stop = l2tp_dfs_seq_stop,
	265	.show = l2tp_dfs_seq_show,
	266	};
	267
	268	static int l2tp_dfs_seq_open(struct inode inode, struct file file)
	269	{
	270	struct l2tp_dfs_seq_data *pd;
	271	struct seq_file *seq;
	272	int rc = -ENOMEM;
	273
6f9b9018	274	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
0ad66140 JC	275	if (pd == NULL)
	276	goto out;
	277
	278	/* Derive the network namespace from the pid opening the
	279	* file.
	280	*/
	281	pd->net = get_net_ns_by_pid(current->pid);
	282	if (IS_ERR(pd->net)) {
b8f07a06	283	rc = PTR_ERR(pd->net);
0ad66140 JC	284	goto err_free_pd;
	285	}
	286
	287	rc = seq_open(file, &l2tp_dfs_seq_ops);
	288	if (rc)
	289	goto err_free_net;
	290
	291	seq = file->private_data;
	292	seq->private = pd;
	293
	294	out:
	295	return rc;
	296
	297	err_free_net:
	298	put_net(pd->net);
	299	err_free_pd:
	300	kfree(pd);
	301	goto out;
	302	}
	303
	304	static int l2tp_dfs_seq_release(struct inode inode, struct file file)
	305	{
	306	struct l2tp_dfs_seq_data *pd;
	307	struct seq_file *seq;
	308
	309	seq = file->private_data;
	310	pd = seq->private;
	311	if (pd->net)
	312	put_net(pd->net);
	313	kfree(pd);
	314	seq_release(inode, file);
	315
	316	return 0;
	317	}
	318
	319	static const struct file_operations l2tp_dfs_fops = {
	320	.owner = THIS_MODULE,
	321	.open = l2tp_dfs_seq_open,
	322	.read = seq_read,
	323	.llseek = seq_lseek,
	324	.release = l2tp_dfs_seq_release,
	325	};
	326
	327	static int __init l2tp_debugfs_init(void)
	328	{
	329	int rc = 0;
	330
	331	rootdir = debugfs_create_dir("l2tp", NULL);
	332	if (IS_ERR(rootdir)) {
	333	rc = PTR_ERR(rootdir);
	334	rootdir = NULL;
	335	goto out;
	336	}
	337
	338	tunnels = debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops);
	339	if (tunnels == NULL)
	340	rc = -EIO;
	341
a4ca44fa	342	pr_info("L2TP debugfs support\n");
0ad66140 JC	343
	344	out:
	345	if (rc)
a4ca44fa	346	pr_warn("unable to init\n");
0ad66140 JC	347
	348	return rc;
	349	}
	350
	351	static void __exit l2tp_debugfs_exit(void)
	352	{
	353	debugfs_remove(tunnels);
	354	debugfs_remove(rootdir);
	355	}
	356
	357	module_init(l2tp_debugfs_init);
	358	module_exit(l2tp_debugfs_exit);
	359
	360	MODULE_LICENSE("GPL");
	361	MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
	362	MODULE_DESCRIPTION("L2TP debugfs driver");
	363	MODULE_VERSION("1.0");