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