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ac79cbb9 | 1 | /* Copyright (C) 2010-2017 B.A.T.M.A.N. contributors: |
ba412080 SE |
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> | |
ba412080 SE |
34 | #include <linux/stddef.h> |
35 | #include <linux/types.h> | |
36 | #include <linux/uaccess.h> | |
37 | #include <linux/wait.h> | |
38 | #include <stdarg.h> | |
39 | ||
40 | #define BATADV_LOG_BUFF_MASK (batadv_log_buff_len - 1) | |
41 | ||
42 | static const int batadv_log_buff_len = BATADV_LOG_BUF_LEN; | |
43 | ||
44 | static char *batadv_log_char_addr(struct batadv_priv_debug_log *debug_log, | |
45 | size_t idx) | |
46 | { | |
47 | return &debug_log->log_buff[idx & BATADV_LOG_BUFF_MASK]; | |
48 | } | |
49 | ||
50 | static void batadv_emit_log_char(struct batadv_priv_debug_log *debug_log, | |
51 | char c) | |
52 | { | |
53 | char *char_addr; | |
54 | ||
55 | char_addr = batadv_log_char_addr(debug_log, debug_log->log_end); | |
56 | *char_addr = c; | |
57 | debug_log->log_end++; | |
58 | ||
59 | if (debug_log->log_end - debug_log->log_start > batadv_log_buff_len) | |
60 | debug_log->log_start = debug_log->log_end - batadv_log_buff_len; | |
61 | } | |
62 | ||
63 | __printf(2, 3) | |
64 | static int batadv_fdebug_log(struct batadv_priv_debug_log *debug_log, | |
65 | const char *fmt, ...) | |
66 | { | |
67 | va_list args; | |
68 | static char debug_log_buf[256]; | |
69 | char *p; | |
70 | ||
71 | if (!debug_log) | |
72 | return 0; | |
73 | ||
74 | spin_lock_bh(&debug_log->lock); | |
75 | va_start(args, fmt); | |
76 | vscnprintf(debug_log_buf, sizeof(debug_log_buf), fmt, args); | |
77 | va_end(args); | |
78 | ||
79 | for (p = debug_log_buf; *p != 0; p++) | |
80 | batadv_emit_log_char(debug_log, *p); | |
81 | ||
82 | spin_unlock_bh(&debug_log->lock); | |
83 | ||
84 | wake_up(&debug_log->queue_wait); | |
85 | ||
86 | return 0; | |
87 | } | |
88 | ||
89 | int batadv_debug_log(struct batadv_priv *bat_priv, const char *fmt, ...) | |
90 | { | |
91 | va_list args; | |
92 | char tmp_log_buf[256]; | |
93 | ||
94 | va_start(args, fmt); | |
95 | vscnprintf(tmp_log_buf, sizeof(tmp_log_buf), fmt, args); | |
96 | batadv_fdebug_log(bat_priv->debug_log, "[%10u] %s", | |
97 | jiffies_to_msecs(jiffies), tmp_log_buf); | |
98 | va_end(args); | |
99 | ||
100 | return 0; | |
101 | } | |
102 | ||
103 | static int batadv_log_open(struct inode *inode, struct file *file) | |
104 | { | |
105 | if (!try_module_get(THIS_MODULE)) | |
106 | return -EBUSY; | |
107 | ||
108 | nonseekable_open(inode, file); | |
109 | file->private_data = inode->i_private; | |
110 | return 0; | |
111 | } | |
112 | ||
113 | static int batadv_log_release(struct inode *inode, struct file *file) | |
114 | { | |
115 | module_put(THIS_MODULE); | |
116 | return 0; | |
117 | } | |
118 | ||
119 | static bool batadv_log_empty(struct batadv_priv_debug_log *debug_log) | |
120 | { | |
121 | return !(debug_log->log_start - debug_log->log_end); | |
122 | } | |
123 | ||
124 | static ssize_t batadv_log_read(struct file *file, char __user *buf, | |
125 | size_t count, loff_t *ppos) | |
126 | { | |
127 | struct batadv_priv *bat_priv = file->private_data; | |
128 | struct batadv_priv_debug_log *debug_log = bat_priv->debug_log; | |
129 | int error, i = 0; | |
130 | char *char_addr; | |
131 | char c; | |
132 | ||
133 | if ((file->f_flags & O_NONBLOCK) && batadv_log_empty(debug_log)) | |
134 | return -EAGAIN; | |
135 | ||
136 | if (!buf) | |
137 | return -EINVAL; | |
138 | ||
139 | if (count == 0) | |
140 | return 0; | |
141 | ||
142 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
143 | return -EFAULT; | |
144 | ||
145 | error = wait_event_interruptible(debug_log->queue_wait, | |
146 | (!batadv_log_empty(debug_log))); | |
147 | ||
148 | if (error) | |
149 | return error; | |
150 | ||
151 | spin_lock_bh(&debug_log->lock); | |
152 | ||
153 | while ((!error) && (i < count) && | |
154 | (debug_log->log_start != debug_log->log_end)) { | |
155 | char_addr = batadv_log_char_addr(debug_log, | |
156 | debug_log->log_start); | |
157 | c = *char_addr; | |
158 | ||
159 | debug_log->log_start++; | |
160 | ||
161 | spin_unlock_bh(&debug_log->lock); | |
162 | ||
163 | error = __put_user(c, buf); | |
164 | ||
165 | spin_lock_bh(&debug_log->lock); | |
166 | ||
167 | buf++; | |
168 | i++; | |
169 | } | |
170 | ||
171 | spin_unlock_bh(&debug_log->lock); | |
172 | ||
173 | if (!error) | |
174 | return i; | |
175 | ||
176 | return error; | |
177 | } | |
178 | ||
179 | static unsigned int batadv_log_poll(struct file *file, poll_table *wait) | |
180 | { | |
181 | struct batadv_priv *bat_priv = file->private_data; | |
182 | struct batadv_priv_debug_log *debug_log = bat_priv->debug_log; | |
183 | ||
184 | poll_wait(file, &debug_log->queue_wait, wait); | |
185 | ||
186 | if (!batadv_log_empty(debug_log)) | |
187 | return POLLIN | POLLRDNORM; | |
188 | ||
189 | return 0; | |
190 | } | |
191 | ||
192 | static const struct file_operations batadv_log_fops = { | |
193 | .open = batadv_log_open, | |
194 | .release = batadv_log_release, | |
195 | .read = batadv_log_read, | |
196 | .poll = batadv_log_poll, | |
197 | .llseek = no_llseek, | |
198 | }; | |
199 | ||
200 | int batadv_debug_log_setup(struct batadv_priv *bat_priv) | |
201 | { | |
202 | struct dentry *d; | |
203 | ||
204 | if (!bat_priv->debug_dir) | |
205 | goto err; | |
206 | ||
207 | bat_priv->debug_log = kzalloc(sizeof(*bat_priv->debug_log), GFP_ATOMIC); | |
208 | if (!bat_priv->debug_log) | |
209 | goto err; | |
210 | ||
211 | spin_lock_init(&bat_priv->debug_log->lock); | |
212 | init_waitqueue_head(&bat_priv->debug_log->queue_wait); | |
213 | ||
507b37cf | 214 | d = debugfs_create_file("log", 0400, bat_priv->debug_dir, bat_priv, |
ba412080 SE |
215 | &batadv_log_fops); |
216 | if (!d) | |
217 | goto err; | |
218 | ||
219 | return 0; | |
220 | ||
221 | err: | |
222 | return -ENOMEM; | |
223 | } | |
224 | ||
225 | void batadv_debug_log_cleanup(struct batadv_priv *bat_priv) | |
226 | { | |
227 | kfree(bat_priv->debug_log); | |
228 | bat_priv->debug_log = NULL; | |
229 | } |