summaryrefslogtreecommitdiff
path: root/net/batman-adv/log.c
blob: f97849a8380be47b45cb9af53b60d525f211a5ab (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2010-2019  B.A.T.M.A.N. contributors:
 *
 * Marek Lindner
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include "log.h"
#include "main.h"

#include <linux/compiler.h>
#include <linux/debugfs.h>
#include <linux/errno.h>
#include <linux/eventpoll.h>
#include <linux/export.h>
#include <linux/fcntl.h>
#include <linux/fs.h>
#include <linux/gfp.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/poll.h>
#include <linux/sched.h> /* for linux/wait.h */
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/wait.h>
#include <stdarg.h>

#include "debugfs.h"
#include "trace.h"

#ifdef CONFIG_BATMAN_ADV_DEBUGFS

#define BATADV_LOG_BUFF_MASK (batadv_log_buff_len - 1)

static const int batadv_log_buff_len = BATADV_LOG_BUF_LEN;

static char *batadv_log_char_addr(struct batadv_priv_debug_log *debug_log,
				  size_t idx)
{
	return &debug_log->log_buff[idx & BATADV_LOG_BUFF_MASK];
}

static void batadv_emit_log_char(struct batadv_priv_debug_log *debug_log,
				 char c)
{
	char *char_addr;

	char_addr = batadv_log_char_addr(debug_log, debug_log->log_end);
	*char_addr = c;
	debug_log->log_end++;

	if (debug_log->log_end - debug_log->log_start > batadv_log_buff_len)
		debug_log->log_start = debug_log->log_end - batadv_log_buff_len;
}

__printf(2, 3)
static int batadv_fdebug_log(struct batadv_priv_debug_log *debug_log,
			     const char *fmt, ...)
{
	va_list args;
	static char debug_log_buf[256];
	char *p;

	if (!debug_log)
		return 0;

	spin_lock_bh(&debug_log->lock);
	va_start(args, fmt);
	vscnprintf(debug_log_buf, sizeof(debug_log_buf), fmt, args);
	va_end(args);

	for (p = debug_log_buf; *p != 0; p++)
		batadv_emit_log_char(debug_log, *p);

	spin_unlock_bh(&debug_log->lock);

	wake_up(&debug_log->queue_wait);

	return 0;
}

static int batadv_log_open(struct inode *inode, struct file *file)
{
	if (!try_module_get(THIS_MODULE))
		return -EBUSY;

	batadv_debugfs_deprecated(file,
				  "Use tracepoint batadv:batadv_dbg instead\n");

	nonseekable_open(inode, file);
	file->private_data = inode->i_private;
	return 0;
}

static int batadv_log_release(struct inode *inode, struct file *file)
{
	module_put(THIS_MODULE);
	return 0;
}

static bool batadv_log_empty(struct batadv_priv_debug_log *debug_log)
{
	return !(debug_log->log_start - debug_log->log_end);
}

static ssize_t batadv_log_read(struct file *file, char __user *buf,
			       size_t count, loff_t *ppos)
{
	struct batadv_priv *bat_priv = file->private_data;
	struct batadv_priv_debug_log *debug_log = bat_priv->debug_log;
	int error, i = 0;
	char *char_addr;
	char c;

	if ((file->f_flags & O_NONBLOCK) && batadv_log_empty(debug_log))
		return -EAGAIN;

	if (!buf)
		return -EINVAL;

	if (count == 0)
		return 0;

	if (!access_ok(VERIFY_WRITE, buf, count))
		return -EFAULT;

	error = wait_event_interruptible(debug_log->queue_wait,
					 (!batadv_log_empty(debug_log)));

	if (error)
		return error;

	spin_lock_bh(&debug_log->lock);

	while ((!error) && (i < count) &&
	       (debug_log->log_start != debug_log->log_end)) {
		char_addr = batadv_log_char_addr(debug_log,
						 debug_log->log_start);
		c = *char_addr;

		debug_log->log_start++;

		spin_unlock_bh(&debug_log->lock);

		error = __put_user(c, buf);

		spin_lock_bh(&debug_log->lock);

		buf++;
		i++;
	}

	spin_unlock_bh(&debug_log->lock);

	if (!error)
		return i;

	return error;
}

static __poll_t batadv_log_poll(struct file *file, poll_table *wait)
{
	struct batadv_priv *bat_priv = file->private_data;
	struct batadv_priv_debug_log *debug_log = bat_priv->debug_log;

	poll_wait(file, &debug_log->queue_wait, wait);

	if (!batadv_log_empty(debug_log))
		return EPOLLIN | EPOLLRDNORM;

	return 0;
}

static const struct file_operations batadv_log_fops = {
	.open           = batadv_log_open,
	.release        = batadv_log_release,
	.read           = batadv_log_read,
	.poll           = batadv_log_poll,
	.llseek         = no_llseek,
};

/**
 * batadv_debug_log_setup() - Initialize debug log
 * @bat_priv: the bat priv with all the soft interface information
 *
 * Return: 0 on success or negative error number in case of failure
 */
int batadv_debug_log_setup(struct batadv_priv *bat_priv)
{
	struct dentry *d;

	if (!bat_priv->debug_dir)
		goto err;

	bat_priv->debug_log = kzalloc(sizeof(*bat_priv->debug_log), GFP_ATOMIC);
	if (!bat_priv->debug_log)
		goto err;

	spin_lock_init(&bat_priv->debug_log->lock);
	init_waitqueue_head(&bat_priv->debug_log->queue_wait);

	d = debugfs_create_file("log", 0400, bat_priv->debug_dir, bat_priv,
				&batadv_log_fops);
	if (!d)
		goto err;

	return 0;

err:
	return -ENOMEM;
}

/**
 * batadv_debug_log_cleanup() - Destroy debug log
 * @bat_priv: the bat priv with all the soft interface information
 */
void batadv_debug_log_cleanup(struct batadv_priv *bat_priv)
{
	kfree(bat_priv->debug_log);
	bat_priv->debug_log = NULL;
}

#endif /* CONFIG_BATMAN_ADV_DEBUGFS */

/**
 * batadv_debug_log() - Add debug log entry
 * @bat_priv: the bat priv with all the soft interface information
 * @fmt: format string
 *
 * Return: 0 on success or negative error number in case of failure
 */
int batadv_debug_log(struct batadv_priv *bat_priv, const char *fmt, ...)
{
	struct va_format vaf;
	va_list args;

	va_start(args, fmt);

	vaf.fmt = fmt;
	vaf.va = &args;

#ifdef CONFIG_BATMAN_ADV_DEBUGFS
	batadv_fdebug_log(bat_priv->debug_log, "[%10u] %pV",
			  jiffies_to_msecs(jiffies), &vaf);
#endif

	trace_batadv_dbg(bat_priv, &vaf);

	va_end(args);

	return 0;
}