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 pd->tunnel = l2tp_tunnel_find_nth(pd->net, pd->tunnel_idx);
51 pd->tunnel_idx++;
52 }
53
54 static 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
66 static 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
86 out:
87 return pd;
88 }
89
90
91 static void *l2tp_dfs_seq_next(struct seq_file *m, void *v, loff_t *pos)
92 {
93 (*pos)++;
94 return NULL;
95 }
96
97 static void l2tp_dfs_seq_stop(struct seq_file *p, void *v)
98 {
99 /* nothing to do */
100 }
101
102 static 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 const struct ipv6_pinfo *np = inet6_sk(tunnel->sock);
131
132 seq_printf(m, " from %pI6c to %pI6c\n",
133 &np->saddr, &tunnel->sock->sk_v6_daddr);
134 } else
135 #endif
136 seq_printf(m, " from %pI4 to %pI4\n",
137 &inet->inet_saddr, &inet->inet_daddr);
138 if (tunnel->encap == L2TP_ENCAPTYPE_UDP)
139 seq_printf(m, " source port %hu, dest port %hu\n",
140 ntohs(inet->inet_sport), ntohs(inet->inet_dport));
141 }
142 seq_printf(m, " L2TPv%d, %s\n", tunnel->version,
143 tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" :
144 tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" :
145 "");
146 seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count,
147 tunnel->sock ? atomic_read(&tunnel->sock->sk_refcnt) : 0,
148 atomic_read(&tunnel->ref_count));
149
150 seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n",
151 tunnel->debug,
152 atomic_long_read(&tunnel->stats.tx_packets),
153 atomic_long_read(&tunnel->stats.tx_bytes),
154 atomic_long_read(&tunnel->stats.tx_errors),
155 atomic_long_read(&tunnel->stats.rx_packets),
156 atomic_long_read(&tunnel->stats.rx_bytes),
157 atomic_long_read(&tunnel->stats.rx_errors));
158
159 if (tunnel->show != NULL)
160 tunnel->show(m, tunnel);
161 }
162
163 static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v)
164 {
165 struct l2tp_session *session = v;
166
167 seq_printf(m, " SESSION %u, peer %u, %s\n", session->session_id,
168 session->peer_session_id,
169 session->pwtype == L2TP_PWTYPE_ETH ? "ETH" :
170 session->pwtype == L2TP_PWTYPE_PPP ? "PPP" :
171 "");
172 if (session->send_seq || session->recv_seq)
173 seq_printf(m, " nr %hu, ns %hu\n", session->nr, session->ns);
174 seq_printf(m, " refcnt %d\n", atomic_read(&session->ref_count));
175 seq_printf(m, " config %d/%d/%c/%c/%s/%s %08x %u\n",
176 session->mtu, session->mru,
177 session->recv_seq ? 'R' : '-',
178 session->send_seq ? 'S' : '-',
179 session->data_seq == 1 ? "IPSEQ" :
180 session->data_seq == 2 ? "DATASEQ" : "-",
181 session->lns_mode ? "LNS" : "LAC",
182 session->debug,
183 jiffies_to_msecs(session->reorder_timeout));
184 seq_printf(m, " offset %hu l2specific %hu/%hu\n",
185 session->offset, session->l2specific_type, session->l2specific_len);
186 if (session->cookie_len) {
187 seq_printf(m, " cookie %02x%02x%02x%02x",
188 session->cookie[0], session->cookie[1],
189 session->cookie[2], session->cookie[3]);
190 if (session->cookie_len == 8)
191 seq_printf(m, "%02x%02x%02x%02x",
192 session->cookie[4], session->cookie[5],
193 session->cookie[6], session->cookie[7]);
194 seq_printf(m, "\n");
195 }
196 if (session->peer_cookie_len) {
197 seq_printf(m, " peer cookie %02x%02x%02x%02x",
198 session->peer_cookie[0], session->peer_cookie[1],
199 session->peer_cookie[2], session->peer_cookie[3]);
200 if (session->peer_cookie_len == 8)
201 seq_printf(m, "%02x%02x%02x%02x",
202 session->peer_cookie[4], session->peer_cookie[5],
203 session->peer_cookie[6], session->peer_cookie[7]);
204 seq_printf(m, "\n");
205 }
206
207 seq_printf(m, " %hu/%hu tx %ld/%ld/%ld rx %ld/%ld/%ld\n",
208 session->nr, session->ns,
209 atomic_long_read(&session->stats.tx_packets),
210 atomic_long_read(&session->stats.tx_bytes),
211 atomic_long_read(&session->stats.tx_errors),
212 atomic_long_read(&session->stats.rx_packets),
213 atomic_long_read(&session->stats.rx_bytes),
214 atomic_long_read(&session->stats.rx_errors));
215
216 if (session->show != NULL)
217 session->show(m, session);
218 }
219
220 static int l2tp_dfs_seq_show(struct seq_file *m, void *v)
221 {
222 struct l2tp_dfs_seq_data *pd = v;
223
224 /* display header on line 1 */
225 if (v == SEQ_START_TOKEN) {
226 seq_puts(m, "TUNNEL ID, peer ID from IP to IP\n");
227 seq_puts(m, " L2TPv2/L2TPv3, UDP/IP\n");
228 seq_puts(m, " sessions session-count, refcnt refcnt/sk->refcnt\n");
229 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
230 seq_puts(m, " SESSION ID, peer ID, PWTYPE\n");
231 seq_puts(m, " refcnt cnt\n");
232 seq_puts(m, " offset OFFSET l2specific TYPE/LEN\n");
233 seq_puts(m, " [ cookie ]\n");
234 seq_puts(m, " [ peer cookie ]\n");
235 seq_puts(m, " config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n");
236 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
237 goto out;
238 }
239
240 /* Show the tunnel or session context */
241 if (pd->session == NULL)
242 l2tp_dfs_seq_tunnel_show(m, pd->tunnel);
243 else
244 l2tp_dfs_seq_session_show(m, pd->session);
245
246 out:
247 return 0;
248 }
249
250 static const struct seq_operations l2tp_dfs_seq_ops = {
251 .start = l2tp_dfs_seq_start,
252 .next = l2tp_dfs_seq_next,
253 .stop = l2tp_dfs_seq_stop,
254 .show = l2tp_dfs_seq_show,
255 };
256
257 static int l2tp_dfs_seq_open(struct inode *inode, struct file *file)
258 {
259 struct l2tp_dfs_seq_data *pd;
260 struct seq_file *seq;
261 int rc = -ENOMEM;
262
263 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
264 if (pd == NULL)
265 goto out;
266
267 /* Derive the network namespace from the pid opening the
268 * file.
269 */
270 pd->net = get_net_ns_by_pid(current->pid);
271 if (IS_ERR(pd->net)) {
272 rc = PTR_ERR(pd->net);
273 goto err_free_pd;
274 }
275
276 rc = seq_open(file, &l2tp_dfs_seq_ops);
277 if (rc)
278 goto err_free_net;
279
280 seq = file->private_data;
281 seq->private = pd;
282
283 out:
284 return rc;
285
286 err_free_net:
287 put_net(pd->net);
288 err_free_pd:
289 kfree(pd);
290 goto out;
291 }
292
293 static int l2tp_dfs_seq_release(struct inode *inode, struct file *file)
294 {
295 struct l2tp_dfs_seq_data *pd;
296 struct seq_file *seq;
297
298 seq = file->private_data;
299 pd = seq->private;
300 if (pd->net)
301 put_net(pd->net);
302 kfree(pd);
303 seq_release(inode, file);
304
305 return 0;
306 }
307
308 static const struct file_operations l2tp_dfs_fops = {
309 .owner = THIS_MODULE,
310 .open = l2tp_dfs_seq_open,
311 .read = seq_read,
312 .llseek = seq_lseek,
313 .release = l2tp_dfs_seq_release,
314 };
315
316 static int __init l2tp_debugfs_init(void)
317 {
318 int rc = 0;
319
320 rootdir = debugfs_create_dir("l2tp", NULL);
321 if (IS_ERR(rootdir)) {
322 rc = PTR_ERR(rootdir);
323 rootdir = NULL;
324 goto out;
325 }
326
327 tunnels = debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops);
328 if (tunnels == NULL)
329 rc = -EIO;
330
331 pr_info("L2TP debugfs support\n");
332
333 out:
334 if (rc)
335 pr_warn("unable to init\n");
336
337 return rc;
338 }
339
340 static void __exit l2tp_debugfs_exit(void)
341 {
342 debugfs_remove(tunnels);
343 debugfs_remove(rootdir);
344 }
345
346 module_init(l2tp_debugfs_init);
347 module_exit(l2tp_debugfs_exit);
348
349 MODULE_LICENSE("GPL");
350 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
351 MODULE_DESCRIPTION("L2TP debugfs driver");
352 MODULE_VERSION("1.0");
353
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