Commit | Line | Data |
---|---|---|
ba412080 SE |
1 | /* Copyright (C) 2010-2016 B.A.T.M.A.N. contributors: |
2 | * | |
3 | * Marek Lindner | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of version 2 of the GNU General Public | |
7 | * License as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but | |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. | |
16 | */ | |
17 | ||
18 | #include "log.h" | |
19 | #include "main.h" | |
20 | ||
21 | #include <linux/compiler.h> | |
22 | #include <linux/debugfs.h> | |
23 | #include <linux/errno.h> | |
24 | #include <linux/export.h> | |
25 | #include <linux/fcntl.h> | |
26 | #include <linux/fs.h> | |
27 | #include <linux/jiffies.h> | |
28 | #include <linux/kernel.h> | |
29 | #include <linux/module.h> | |
30 | #include <linux/poll.h> | |
31 | #include <linux/sched.h> /* for linux/wait.h */ | |
32 | #include <linux/slab.h> | |
33 | #include <linux/spinlock.h> | |
34 | #include <linux/stat.h> | |
35 | #include <linux/stddef.h> | |
36 | #include <linux/types.h> | |
37 | #include <linux/uaccess.h> | |
38 | #include <linux/wait.h> | |
39 | #include <stdarg.h> | |
40 | ||
41 | #define BATADV_LOG_BUFF_MASK (batadv_log_buff_len - 1) | |
42 | ||
43 | static const int batadv_log_buff_len = BATADV_LOG_BUF_LEN; | |
44 | ||
45 | static char *batadv_log_char_addr(struct batadv_priv_debug_log *debug_log, | |
46 | size_t idx) | |
47 | { | |
48 | return &debug_log->log_buff[idx & BATADV_LOG_BUFF_MASK]; | |
49 | } | |
50 | ||
51 | static void batadv_emit_log_char(struct batadv_priv_debug_log *debug_log, | |
52 | char c) | |
53 | { | |
54 | char *char_addr; | |
55 | ||
56 | char_addr = batadv_log_char_addr(debug_log, debug_log->log_end); | |
57 | *char_addr = c; | |
58 | debug_log->log_end++; | |
59 | ||
60 | if (debug_log->log_end - debug_log->log_start > batadv_log_buff_len) | |
61 | debug_log->log_start = debug_log->log_end - batadv_log_buff_len; | |
62 | } | |
63 | ||
64 | __printf(2, 3) | |
65 | static int batadv_fdebug_log(struct batadv_priv_debug_log *debug_log, | |
66 | const char *fmt, ...) | |
67 | { | |
68 | va_list args; | |
69 | static char debug_log_buf[256]; | |
70 | char *p; | |
71 | ||
72 | if (!debug_log) | |
73 | return 0; | |
74 | ||
75 | spin_lock_bh(&debug_log->lock); | |
76 | va_start(args, fmt); | |
77 | vscnprintf(debug_log_buf, sizeof(debug_log_buf), fmt, args); | |
78 | va_end(args); | |
79 | ||
80 | for (p = debug_log_buf; *p != 0; p++) | |
81 | batadv_emit_log_char(debug_log, *p); | |
82 | ||
83 | spin_unlock_bh(&debug_log->lock); | |
84 | ||
85 | wake_up(&debug_log->queue_wait); | |
86 | ||
87 | return 0; | |
88 | } | |
89 | ||
90 | int batadv_debug_log(struct batadv_priv *bat_priv, const char *fmt, ...) | |
91 | { | |
92 | va_list args; | |
93 | char tmp_log_buf[256]; | |
94 | ||
95 | va_start(args, fmt); | |
96 | vscnprintf(tmp_log_buf, sizeof(tmp_log_buf), fmt, args); | |
97 | batadv_fdebug_log(bat_priv->debug_log, "[%10u] %s", | |
98 | jiffies_to_msecs(jiffies), tmp_log_buf); | |
99 | va_end(args); | |
100 | ||
101 | return 0; | |
102 | } | |
103 | ||
104 | static int batadv_log_open(struct inode *inode, struct file *file) | |
105 | { | |
106 | if (!try_module_get(THIS_MODULE)) | |
107 | return -EBUSY; | |
108 | ||
109 | nonseekable_open(inode, file); | |
110 | file->private_data = inode->i_private; | |
111 | return 0; | |
112 | } | |
113 | ||
114 | static int batadv_log_release(struct inode *inode, struct file *file) | |
115 | { | |
116 | module_put(THIS_MODULE); | |
117 | return 0; | |
118 | } | |
119 | ||
120 | static bool batadv_log_empty(struct batadv_priv_debug_log *debug_log) | |
121 | { | |
122 | return !(debug_log->log_start - debug_log->log_end); | |
123 | } | |
124 | ||
125 | static ssize_t batadv_log_read(struct file *file, char __user *buf, | |
126 | size_t count, loff_t *ppos) | |
127 | { | |
128 | struct batadv_priv *bat_priv = file->private_data; | |
129 | struct batadv_priv_debug_log *debug_log = bat_priv->debug_log; | |
130 | int error, i = 0; | |
131 | char *char_addr; | |
132 | char c; | |
133 | ||
134 | if ((file->f_flags & O_NONBLOCK) && batadv_log_empty(debug_log)) | |
135 | return -EAGAIN; | |
136 | ||
137 | if (!buf) | |
138 | return -EINVAL; | |
139 | ||
140 | if (count == 0) | |
141 | return 0; | |
142 | ||
143 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
144 | return -EFAULT; | |
145 | ||
146 | error = wait_event_interruptible(debug_log->queue_wait, | |
147 | (!batadv_log_empty(debug_log))); | |
148 | ||
149 | if (error) | |
150 | return error; | |
151 | ||
152 | spin_lock_bh(&debug_log->lock); | |
153 | ||
154 | while ((!error) && (i < count) && | |
155 | (debug_log->log_start != debug_log->log_end)) { | |
156 | char_addr = batadv_log_char_addr(debug_log, | |
157 | debug_log->log_start); | |
158 | c = *char_addr; | |
159 | ||
160 | debug_log->log_start++; | |
161 | ||
162 | spin_unlock_bh(&debug_log->lock); | |
163 | ||
164 | error = __put_user(c, buf); | |
165 | ||
166 | spin_lock_bh(&debug_log->lock); | |
167 | ||
168 | buf++; | |
169 | i++; | |
170 | } | |
171 | ||
172 | spin_unlock_bh(&debug_log->lock); | |
173 | ||
174 | if (!error) | |
175 | return i; | |
176 | ||
177 | return error; | |
178 | } | |
179 | ||
180 | static unsigned int batadv_log_poll(struct file *file, poll_table *wait) | |
181 | { | |
182 | struct batadv_priv *bat_priv = file->private_data; | |
183 | struct batadv_priv_debug_log *debug_log = bat_priv->debug_log; | |
184 | ||
185 | poll_wait(file, &debug_log->queue_wait, wait); | |
186 | ||
187 | if (!batadv_log_empty(debug_log)) | |
188 | return POLLIN | POLLRDNORM; | |
189 | ||
190 | return 0; | |
191 | } | |
192 | ||
193 | static const struct file_operations batadv_log_fops = { | |
194 | .open = batadv_log_open, | |
195 | .release = batadv_log_release, | |
196 | .read = batadv_log_read, | |
197 | .poll = batadv_log_poll, | |
198 | .llseek = no_llseek, | |
199 | }; | |
200 | ||
201 | int batadv_debug_log_setup(struct batadv_priv *bat_priv) | |
202 | { | |
203 | struct dentry *d; | |
204 | ||
205 | if (!bat_priv->debug_dir) | |
206 | goto err; | |
207 | ||
208 | bat_priv->debug_log = kzalloc(sizeof(*bat_priv->debug_log), GFP_ATOMIC); | |
209 | if (!bat_priv->debug_log) | |
210 | goto err; | |
211 | ||
212 | spin_lock_init(&bat_priv->debug_log->lock); | |
213 | init_waitqueue_head(&bat_priv->debug_log->queue_wait); | |
214 | ||
215 | d = debugfs_create_file("log", S_IFREG | S_IRUSR, | |
216 | bat_priv->debug_dir, bat_priv, | |
217 | &batadv_log_fops); | |
218 | if (!d) | |
219 | goto err; | |
220 | ||
221 | return 0; | |
222 | ||
223 | err: | |
224 | return -ENOMEM; | |
225 | } | |
226 | ||
227 | void batadv_debug_log_cleanup(struct batadv_priv *bat_priv) | |
228 | { | |
229 | kfree(bat_priv->debug_log); | |
230 | bat_priv->debug_log = NULL; | |
231 | } |