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
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 {
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);
55 pd->tunnel_idx++;
56 }
57
58 static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd)
59 {
60 /* Drop reference taken during previous invocation */
61 if (pd->session)
62 l2tp_session_dec_refcount(pd->session);
63
64 pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx);
65 pd->session_idx++;
66
67 if (pd->session == NULL) {
68 pd->session_idx = 0;
69 l2tp_dfs_next_tunnel(pd);
70 }
71
72 }
73
74 static void *l2tp_dfs_seq_start(struct seq_file *m, loff_t *offs)
75 {
76 struct l2tp_dfs_seq_data *pd = SEQ_START_TOKEN;
77 loff_t pos = *offs;
78
79 if (!pos)
80 goto out;
81
82 BUG_ON(m->private == NULL);
83 pd = m->private;
84
85 if (pd->tunnel == NULL)
86 l2tp_dfs_next_tunnel(pd);
87 else
88 l2tp_dfs_next_session(pd);
89
90 /* NULL tunnel and session indicates end of list */
91 if ((pd->tunnel == NULL) && (pd->session == NULL))
92 pd = NULL;
93
94 out:
95 return pd;
96 }
97
98
99 static void *l2tp_dfs_seq_next(struct seq_file *m, void *v, loff_t *pos)
100 {
101 (*pos)++;
102 return NULL;
103 }
104
105 static void l2tp_dfs_seq_stop(struct seq_file *p, void *v)
106 {
107 struct l2tp_dfs_seq_data *pd = v;
108
109 if (!pd || pd == SEQ_START_TOKEN)
110 return;
111
112 /* Drop reference taken by last invocation of l2tp_dfs_next_session()
113 * or l2tp_dfs_next_tunnel().
114 */
115 if (pd->session) {
116 l2tp_session_dec_refcount(pd->session);
117 pd->session = NULL;
118 }
119 if (pd->tunnel) {
120 l2tp_tunnel_dec_refcount(pd->tunnel);
121 pd->tunnel = NULL;
122 }
123 }
124
125 static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v)
126 {
127 struct l2tp_tunnel *tunnel = v;
128 int session_count = 0;
129 int hash;
130 struct hlist_node *walk;
131 struct hlist_node *tmp;
132
133 read_lock_bh(&tunnel->hlist_lock);
134 for (hash = 0; hash < L2TP_HASH_SIZE; hash++) {
135 hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
136 struct l2tp_session *session;
137
138 session = hlist_entry(walk, struct l2tp_session, hlist);
139 if (session->session_id == 0)
140 continue;
141
142 session_count++;
143 }
144 }
145 read_unlock_bh(&tunnel->hlist_lock);
146
147 seq_printf(m, "\nTUNNEL %u peer %u", tunnel->tunnel_id, tunnel->peer_tunnel_id);
148 if (tunnel->sock) {
149 struct inet_sock *inet = inet_sk(tunnel->sock);
150
151 #if IS_ENABLED(CONFIG_IPV6)
152 if (tunnel->sock->sk_family == AF_INET6) {
153 const struct ipv6_pinfo *np = inet6_sk(tunnel->sock);
154
155 seq_printf(m, " from %pI6c to %pI6c\n",
156 &np->saddr, &tunnel->sock->sk_v6_daddr);
157 } else
158 #endif
159 seq_printf(m, " from %pI4 to %pI4\n",
160 &inet->inet_saddr, &inet->inet_daddr);
161 if (tunnel->encap == L2TP_ENCAPTYPE_UDP)
162 seq_printf(m, " source port %hu, dest port %hu\n",
163 ntohs(inet->inet_sport), ntohs(inet->inet_dport));
164 }
165 seq_printf(m, " L2TPv%d, %s\n", tunnel->version,
166 tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" :
167 tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" :
168 "");
169 seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count,
170 tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0,
171 refcount_read(&tunnel->ref_count));
172 seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n",
173 tunnel->debug,
174 atomic_long_read(&tunnel->stats.tx_packets),
175 atomic_long_read(&tunnel->stats.tx_bytes),
176 atomic_long_read(&tunnel->stats.tx_errors),
177 atomic_long_read(&tunnel->stats.rx_packets),
178 atomic_long_read(&tunnel->stats.rx_bytes),
179 atomic_long_read(&tunnel->stats.rx_errors));
180 }
181
182 static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v)
183 {
184 struct l2tp_session *session = v;
185
186 seq_printf(m, " SESSION %u, peer %u, %s\n", session->session_id,
187 session->peer_session_id,
188 session->pwtype == L2TP_PWTYPE_ETH ? "ETH" :
189 session->pwtype == L2TP_PWTYPE_PPP ? "PPP" :
190 "");
191 if (session->send_seq || session->recv_seq)
192 seq_printf(m, " nr %hu, ns %hu\n", session->nr, session->ns);
193 seq_printf(m, " refcnt %d\n", refcount_read(&session->ref_count));
194 seq_printf(m, " config 0/0/%c/%c/-/%s %08x %u\n",
195 session->recv_seq ? 'R' : '-',
196 session->send_seq ? 'S' : '-',
197 session->lns_mode ? "LNS" : "LAC",
198 session->debug,
199 jiffies_to_msecs(session->reorder_timeout));
200 seq_printf(m, " offset 0 l2specific %hu/%hu\n",
201 session->l2specific_type, l2tp_get_l2specific_len(session));
202 if (session->cookie_len) {
203 seq_printf(m, " cookie %02x%02x%02x%02x",
204 session->cookie[0], session->cookie[1],
205 session->cookie[2], session->cookie[3]);
206 if (session->cookie_len == 8)
207 seq_printf(m, "%02x%02x%02x%02x",
208 session->cookie[4], session->cookie[5],
209 session->cookie[6], session->cookie[7]);
210 seq_printf(m, "\n");
211 }
212 if (session->peer_cookie_len) {
213 seq_printf(m, " peer cookie %02x%02x%02x%02x",
214 session->peer_cookie[0], session->peer_cookie[1],
215 session->peer_cookie[2], session->peer_cookie[3]);
216 if (session->peer_cookie_len == 8)
217 seq_printf(m, "%02x%02x%02x%02x",
218 session->peer_cookie[4], session->peer_cookie[5],
219 session->peer_cookie[6], session->peer_cookie[7]);
220 seq_printf(m, "\n");
221 }
222
223 seq_printf(m, " %hu/%hu tx %ld/%ld/%ld rx %ld/%ld/%ld\n",
224 session->nr, session->ns,
225 atomic_long_read(&session->stats.tx_packets),
226 atomic_long_read(&session->stats.tx_bytes),
227 atomic_long_read(&session->stats.tx_errors),
228 atomic_long_read(&session->stats.rx_packets),
229 atomic_long_read(&session->stats.rx_bytes),
230 atomic_long_read(&session->stats.rx_errors));
231
232 if (session->show != NULL)
233 session->show(m, session);
234 }
235
236 static int l2tp_dfs_seq_show(struct seq_file *m, void *v)
237 {
238 struct l2tp_dfs_seq_data *pd = v;
239
240 /* display header on line 1 */
241 if (v == SEQ_START_TOKEN) {
242 seq_puts(m, "TUNNEL ID, peer ID from IP to IP\n");
243 seq_puts(m, " L2TPv2/L2TPv3, UDP/IP\n");
244 seq_puts(m, " sessions session-count, refcnt refcnt/sk->refcnt\n");
245 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
246 seq_puts(m, " SESSION ID, peer ID, PWTYPE\n");
247 seq_puts(m, " refcnt cnt\n");
248 seq_puts(m, " offset OFFSET l2specific TYPE/LEN\n");
249 seq_puts(m, " [ cookie ]\n");
250 seq_puts(m, " [ peer cookie ]\n");
251 seq_puts(m, " config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n");
252 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
253 goto out;
254 }
255
256 if (!pd->session)
257 l2tp_dfs_seq_tunnel_show(m, pd->tunnel);
258 else
259 l2tp_dfs_seq_session_show(m, pd->session);
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
278 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
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)) {
287 rc = PTR_ERR(pd->net);
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
346 pr_info("L2TP debugfs support\n");
347
348 out:
349 if (rc)
350 pr_warn("unable to init\n");
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");
368
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