l2tp: Add debugfs files for dumping l2tp debug info
[linux-2.6.git] / net / l2tp / l2tp_debugfs.c
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
35 static struct dentry *rootdir;
36 static struct dentry *tunnels;
37
38 struct 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
46 static 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
52 static 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
64 static 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
84 out:
85         return pd;
86 }
87
88
89 static void *l2tp_dfs_seq_next(struct seq_file *m, void *v, loff_t *pos)
90 {
91         (*pos)++;
92         return NULL;
93 }
94
95 static void l2tp_dfs_seq_stop(struct seq_file *p, void *v)
96 {
97         /* nothing to do */
98 }
99
100 static 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 " NIPQUAD_FMT " to " NIPQUAD_FMT "\n",
126                            NIPQUAD(inet->inet_saddr), NIPQUAD(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
152 static 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
209 static 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
235 out:
236         return 0;
237 }
238
239 static 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
246 static 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
272 out:
273         return rc;
274
275 err_free_net:
276         put_net(pd->net);
277 err_free_pd:
278         kfree(pd);
279         goto out;
280 }
281
282 static 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
297 static 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
305 static 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
322 out:
323         if (rc)
324                 printk(KERN_WARNING "l2tp debugfs: unable to init\n");
325
326         return rc;
327 }
328
329 static void __exit l2tp_debugfs_exit(void)
330 {
331         debugfs_remove(tunnels);
332         debugfs_remove(rootdir);
333 }
334
335 module_init(l2tp_debugfs_init);
336 module_exit(l2tp_debugfs_exit);
337
338 MODULE_LICENSE("GPL");
339 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
340 MODULE_DESCRIPTION("L2TP debugfs driver");
341 MODULE_VERSION("1.0");