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7db7d9f3 | 1 | // SPDX-License-Identifier: GPL-2.0 |
6b1aea8c | 2 | /* Copyright (C) 2010-2018 B.A.T.M.A.N. contributors: |
ba412080 SE |
3 | * |
4 | * Marek Lindner | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of version 2 of the GNU General Public | |
8 | * License as published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but | |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, see <http://www.gnu.org/licenses/>. | |
17 | */ | |
18 | ||
19 | #include "log.h" | |
20 | #include "main.h" | |
21 | ||
22 | #include <linux/compiler.h> | |
23 | #include <linux/debugfs.h> | |
24 | #include <linux/errno.h> | |
48881ed5 | 25 | #include <linux/eventpoll.h> |
ba412080 SE |
26 | #include <linux/export.h> |
27 | #include <linux/fcntl.h> | |
28 | #include <linux/fs.h> | |
b92b94ac | 29 | #include <linux/gfp.h> |
ba412080 SE |
30 | #include <linux/jiffies.h> |
31 | #include <linux/kernel.h> | |
32 | #include <linux/module.h> | |
33 | #include <linux/poll.h> | |
34 | #include <linux/sched.h> /* for linux/wait.h */ | |
35 | #include <linux/slab.h> | |
36 | #include <linux/spinlock.h> | |
ba412080 SE |
37 | #include <linux/stddef.h> |
38 | #include <linux/types.h> | |
39 | #include <linux/uaccess.h> | |
40 | #include <linux/wait.h> | |
41 | #include <stdarg.h> | |
42 | ||
43 | #define BATADV_LOG_BUFF_MASK (batadv_log_buff_len - 1) | |
44 | ||
45 | static const int batadv_log_buff_len = BATADV_LOG_BUF_LEN; | |
46 | ||
47 | static char *batadv_log_char_addr(struct batadv_priv_debug_log *debug_log, | |
48 | size_t idx) | |
49 | { | |
50 | return &debug_log->log_buff[idx & BATADV_LOG_BUFF_MASK]; | |
51 | } | |
52 | ||
53 | static void batadv_emit_log_char(struct batadv_priv_debug_log *debug_log, | |
54 | char c) | |
55 | { | |
56 | char *char_addr; | |
57 | ||
58 | char_addr = batadv_log_char_addr(debug_log, debug_log->log_end); | |
59 | *char_addr = c; | |
60 | debug_log->log_end++; | |
61 | ||
62 | if (debug_log->log_end - debug_log->log_start > batadv_log_buff_len) | |
63 | debug_log->log_start = debug_log->log_end - batadv_log_buff_len; | |
64 | } | |
65 | ||
66 | __printf(2, 3) | |
67 | static int batadv_fdebug_log(struct batadv_priv_debug_log *debug_log, | |
68 | const char *fmt, ...) | |
69 | { | |
70 | va_list args; | |
71 | static char debug_log_buf[256]; | |
72 | char *p; | |
73 | ||
74 | if (!debug_log) | |
75 | return 0; | |
76 | ||
77 | spin_lock_bh(&debug_log->lock); | |
78 | va_start(args, fmt); | |
79 | vscnprintf(debug_log_buf, sizeof(debug_log_buf), fmt, args); | |
80 | va_end(args); | |
81 | ||
82 | for (p = debug_log_buf; *p != 0; p++) | |
83 | batadv_emit_log_char(debug_log, *p); | |
84 | ||
85 | spin_unlock_bh(&debug_log->lock); | |
86 | ||
87 | wake_up(&debug_log->queue_wait); | |
88 | ||
89 | return 0; | |
90 | } | |
91 | ||
ff15c27c SE |
92 | /** |
93 | * batadv_debug_log() - Add debug log entry | |
94 | * @bat_priv: the bat priv with all the soft interface information | |
95 | * @fmt: format string | |
96 | * | |
97 | * Return: 0 on success or negative error number in case of failure | |
98 | */ | |
ba412080 SE |
99 | int batadv_debug_log(struct batadv_priv *bat_priv, const char *fmt, ...) |
100 | { | |
101 | va_list args; | |
102 | char tmp_log_buf[256]; | |
103 | ||
104 | va_start(args, fmt); | |
105 | vscnprintf(tmp_log_buf, sizeof(tmp_log_buf), fmt, args); | |
106 | batadv_fdebug_log(bat_priv->debug_log, "[%10u] %s", | |
107 | jiffies_to_msecs(jiffies), tmp_log_buf); | |
108 | va_end(args); | |
109 | ||
110 | return 0; | |
111 | } | |
112 | ||
113 | static int batadv_log_open(struct inode *inode, struct file *file) | |
114 | { | |
115 | if (!try_module_get(THIS_MODULE)) | |
116 | return -EBUSY; | |
117 | ||
118 | nonseekable_open(inode, file); | |
119 | file->private_data = inode->i_private; | |
120 | return 0; | |
121 | } | |
122 | ||
123 | static int batadv_log_release(struct inode *inode, struct file *file) | |
124 | { | |
125 | module_put(THIS_MODULE); | |
126 | return 0; | |
127 | } | |
128 | ||
129 | static bool batadv_log_empty(struct batadv_priv_debug_log *debug_log) | |
130 | { | |
131 | return !(debug_log->log_start - debug_log->log_end); | |
132 | } | |
133 | ||
134 | static ssize_t batadv_log_read(struct file *file, char __user *buf, | |
135 | size_t count, loff_t *ppos) | |
136 | { | |
137 | struct batadv_priv *bat_priv = file->private_data; | |
138 | struct batadv_priv_debug_log *debug_log = bat_priv->debug_log; | |
139 | int error, i = 0; | |
140 | char *char_addr; | |
141 | char c; | |
142 | ||
143 | if ((file->f_flags & O_NONBLOCK) && batadv_log_empty(debug_log)) | |
144 | return -EAGAIN; | |
145 | ||
146 | if (!buf) | |
147 | return -EINVAL; | |
148 | ||
149 | if (count == 0) | |
150 | return 0; | |
151 | ||
152 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
153 | return -EFAULT; | |
154 | ||
155 | error = wait_event_interruptible(debug_log->queue_wait, | |
156 | (!batadv_log_empty(debug_log))); | |
157 | ||
158 | if (error) | |
159 | return error; | |
160 | ||
161 | spin_lock_bh(&debug_log->lock); | |
162 | ||
163 | while ((!error) && (i < count) && | |
164 | (debug_log->log_start != debug_log->log_end)) { | |
165 | char_addr = batadv_log_char_addr(debug_log, | |
166 | debug_log->log_start); | |
167 | c = *char_addr; | |
168 | ||
169 | debug_log->log_start++; | |
170 | ||
171 | spin_unlock_bh(&debug_log->lock); | |
172 | ||
173 | error = __put_user(c, buf); | |
174 | ||
175 | spin_lock_bh(&debug_log->lock); | |
176 | ||
177 | buf++; | |
178 | i++; | |
179 | } | |
180 | ||
181 | spin_unlock_bh(&debug_log->lock); | |
182 | ||
183 | if (!error) | |
184 | return i; | |
185 | ||
186 | return error; | |
187 | } | |
188 | ||
ade994f4 | 189 | static __poll_t batadv_log_poll(struct file *file, poll_table *wait) |
ba412080 SE |
190 | { |
191 | struct batadv_priv *bat_priv = file->private_data; | |
192 | struct batadv_priv_debug_log *debug_log = bat_priv->debug_log; | |
193 | ||
194 | poll_wait(file, &debug_log->queue_wait, wait); | |
195 | ||
196 | if (!batadv_log_empty(debug_log)) | |
a9a08845 | 197 | return EPOLLIN | EPOLLRDNORM; |
ba412080 SE |
198 | |
199 | return 0; | |
200 | } | |
201 | ||
202 | static const struct file_operations batadv_log_fops = { | |
203 | .open = batadv_log_open, | |
204 | .release = batadv_log_release, | |
205 | .read = batadv_log_read, | |
206 | .poll = batadv_log_poll, | |
207 | .llseek = no_llseek, | |
208 | }; | |
209 | ||
ff15c27c SE |
210 | /** |
211 | * batadv_debug_log_setup() - Initialize debug log | |
212 | * @bat_priv: the bat priv with all the soft interface information | |
213 | * | |
214 | * Return: 0 on success or negative error number in case of failure | |
215 | */ | |
ba412080 SE |
216 | int batadv_debug_log_setup(struct batadv_priv *bat_priv) |
217 | { | |
218 | struct dentry *d; | |
219 | ||
220 | if (!bat_priv->debug_dir) | |
221 | goto err; | |
222 | ||
223 | bat_priv->debug_log = kzalloc(sizeof(*bat_priv->debug_log), GFP_ATOMIC); | |
224 | if (!bat_priv->debug_log) | |
225 | goto err; | |
226 | ||
227 | spin_lock_init(&bat_priv->debug_log->lock); | |
228 | init_waitqueue_head(&bat_priv->debug_log->queue_wait); | |
229 | ||
507b37cf | 230 | d = debugfs_create_file("log", 0400, bat_priv->debug_dir, bat_priv, |
ba412080 SE |
231 | &batadv_log_fops); |
232 | if (!d) | |
233 | goto err; | |
234 | ||
235 | return 0; | |
236 | ||
237 | err: | |
238 | return -ENOMEM; | |
239 | } | |
240 | ||
ff15c27c SE |
241 | /** |
242 | * batadv_debug_log_cleanup() - Destroy debug log | |
243 | * @bat_priv: the bat priv with all the soft interface information | |
244 | */ | |
ba412080 SE |
245 | void batadv_debug_log_cleanup(struct batadv_priv *bat_priv) |
246 | { | |
247 | kfree(bat_priv->debug_log); | |
248 | bat_priv->debug_log = NULL; | |
249 | } |