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			struct ipv6_pinfo *np = inet6_sk(tunnel->sock);
131			seq_printf(m, " from %pI6c to %pI6c\n",
132				&np->saddr, &np->daddr);
133		} else
134#endif
135		seq_printf(m, " from %pI4 to %pI4\n",
136			   &inet->inet_saddr, &inet->inet_daddr);
137		if (tunnel->encap == L2TP_ENCAPTYPE_UDP)
138			seq_printf(m, " source port %hu, dest port %hu\n",
139				   ntohs(inet->inet_sport), ntohs(inet->inet_dport));
140	}
141	seq_printf(m, " L2TPv%d, %s\n", tunnel->version,
142		   tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" :
143		   tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" :
144		   "");
145	seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count,
146		   tunnel->sock ? atomic_read(&tunnel->sock->sk_refcnt) : 0,
147		   atomic_read(&tunnel->ref_count));
148
149	seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n",
150		   tunnel->debug,
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));
157
158	if (tunnel->show != NULL)
159		tunnel->show(m, tunnel);
160}
161
162static 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);
173	seq_printf(m, "   refcnt %d\n", atomic_read(&session->ref_count));
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
206	seq_printf(m, "   %hu/%hu tx %ld/%ld/%ld rx %ld/%ld/%ld\n",
207		   session->nr, session->ns,
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));
214
215	if (session->show != NULL)
216		session->show(m, session);
217}
218
219static 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 */
240	if (pd->session == NULL)
241		l2tp_dfs_seq_tunnel_show(m, pd->tunnel);
242	else
243		l2tp_dfs_seq_session_show(m, pd->session);
244
245out:
246	return 0;
247}
248
249static const struct seq_operations l2tp_dfs_seq_ops = {
250	.start		= l2tp_dfs_seq_start,
251	.next		= l2tp_dfs_seq_next,
252	.stop		= l2tp_dfs_seq_stop,
253	.show		= l2tp_dfs_seq_show,
254};
255
256static int l2tp_dfs_seq_open(struct inode *inode, struct file *file)
257{
258	struct l2tp_dfs_seq_data *pd;
259	struct seq_file *seq;
260	int rc = -ENOMEM;
261
262	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
263	if (pd == NULL)
264		goto out;
265
266	/* Derive the network namespace from the pid opening the
267	 * file.
268	 */
269	pd->net = get_net_ns_by_pid(current->pid);
270	if (IS_ERR(pd->net)) {
271		rc = PTR_ERR(pd->net);
272		goto err_free_pd;
273	}
274
275	rc = seq_open(file, &l2tp_dfs_seq_ops);
276	if (rc)
277		goto err_free_net;
278
279	seq = file->private_data;
280	seq->private = pd;
281
282out:
283	return rc;
284
285err_free_net:
286	put_net(pd->net);
287err_free_pd:
288	kfree(pd);
289	goto out;
290}
291
292static int l2tp_dfs_seq_release(struct inode *inode, struct file *file)
293{
294	struct l2tp_dfs_seq_data *pd;
295	struct seq_file *seq;
296
297	seq = file->private_data;
298	pd = seq->private;
299	if (pd->net)
300		put_net(pd->net);
301	kfree(pd);
302	seq_release(inode, file);
303
304	return 0;
305}
306
307static const struct file_operations l2tp_dfs_fops = {
308	.owner		= THIS_MODULE,
309	.open		= l2tp_dfs_seq_open,
310	.read		= seq_read,
311	.llseek		= seq_lseek,
312	.release	= l2tp_dfs_seq_release,
313};
314
315static int __init l2tp_debugfs_init(void)
316{
317	int rc = 0;
318
319	rootdir = debugfs_create_dir("l2tp", NULL);
320	if (IS_ERR(rootdir)) {
321		rc = PTR_ERR(rootdir);
322		rootdir = NULL;
323		goto out;
324	}
325
326	tunnels = debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops);
327	if (tunnels == NULL)
328		rc = -EIO;
329
330	pr_info("L2TP debugfs support\n");
331
332out:
333	if (rc)
334		pr_warn("unable to init\n");
335
336	return rc;
337}
338
339static void __exit l2tp_debugfs_exit(void)
340{
341	debugfs_remove(tunnels);
342	debugfs_remove(rootdir);
343}
344
345module_init(l2tp_debugfs_init);
346module_exit(l2tp_debugfs_exit);
347
348MODULE_LICENSE("GPL");
349MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
350MODULE_DESCRIPTION("L2TP debugfs driver");
351MODULE_VERSION("1.0");
352