summaryrefslogtreecommitdiffstats
path: root/src/libudev/libudev.c
blob: afadfe6993825b5f035e5c7ce3f983971f667641 (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
/***
  This file is part of systemd.

  Copyright 2008-2014 Kay Sievers <kay@vrfy.org>

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd 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
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <ctype.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "libudev.h"

#include "fd-util.h"
#include "libudev-private.h"
#include "missing.h"
#include "string-util.h"

/**
 * SECTION:libudev
 * @short_description: libudev context
 *
 * The context contains the default values read from the udev config file,
 * and is passed to all library operations.
 */

/**
 * udev:
 *
 * Opaque object representing the library context.
 */
struct udev {
        int refcount;
        void (*log_fn)(struct udev *udev,
                       int priority, const char *file, int line, const char *fn,
                       const char *format, va_list args);
        void *userdata;
};

/**
 * udev_get_userdata:
 * @udev: udev library context
 *
 * Retrieve stored data pointer from library context. This might be useful
 * to access from callbacks.
 *
 * Returns: stored userdata
 **/
_public_ void *udev_get_userdata(struct udev *udev) {
        if (udev == NULL)
                return NULL;
        return udev->userdata;
}

/**
 * udev_set_userdata:
 * @udev: udev library context
 * @userdata: data pointer
 *
 * Store custom @userdata in the library context.
 **/
_public_ void udev_set_userdata(struct udev *udev, void *userdata) {
        if (udev == NULL)
                return;
        udev->userdata = userdata;
}

/**
 * udev_new:
 *
 * Create udev library context. This reads the udev configuration
 * file, and fills in the default values.
 *
 * The initial refcount is 1, and needs to be decremented to
 * release the resources of the udev library context.
 *
 * Returns: a new udev library context
 **/
_public_ struct udev *udev_new(void) {
        struct udev *udev;
        _cleanup_fclose_ FILE *f = NULL;

        udev = new0(struct udev, 1);
        if (udev == NULL)
                return NULL;
        udev->refcount = 1;

        f = fopen("/etc/udev/udev.conf", "re");
        if (f != NULL) {
                char line[UTIL_LINE_SIZE];
                unsigned line_nr = 0;

                while (fgets(line, sizeof(line), f)) {
                        size_t len;
                        char *key;
                        char *val;

                        line_nr++;

                        /* find key */
                        key = line;
                        while (isspace(key[0]))
                                key++;

                        /* comment or empty line */
                        if (key[0] == '#' || key[0] == '\0')
                                continue;

                        /* split key/value */
                        val = strchr(key, '=');
                        if (val == NULL) {
                                log_debug("/etc/udev/udev.conf:%u: missing assignment,  skipping line.", line_nr);
                                continue;
                        }
                        val[0] = '\0';
                        val++;

                        /* find value */
                        while (isspace(val[0]))
                                val++;

                        /* terminate key */
                        len = strlen(key);
                        if (len == 0)
                                continue;
                        while (isspace(key[len-1]))
                                len--;
                        key[len] = '\0';

                        /* terminate value */
                        len = strlen(val);
                        if (len == 0)
                                continue;
                        while (isspace(val[len-1]))
                                len--;
                        val[len] = '\0';

                        if (len == 0)
                                continue;

                        /* unquote */
                        if (val[0] == '"' || val[0] == '\'') {
                                if (val[len-1] != val[0]) {
                                        log_debug("/etc/udev/udev.conf:%u: inconsistent quoting, skipping line.", line_nr);
                                        continue;
                                }
                                val[len-1] = '\0';
                                val++;
                        }

                        if (streq(key, "udev_log")) {
                                int prio;

                                prio = util_log_priority(val);
                                if (prio < 0)
                                        log_debug("/etc/udev/udev.conf:%u: invalid log level '%s', ignoring.", line_nr, val);
                                else
                                        log_set_max_level(prio);
                                continue;
                        }
                }
        }

        return udev;
}

/**
 * udev_ref:
 * @udev: udev library context
 *
 * Take a reference of the udev library context.
 *
 * Returns: the passed udev library context
 **/
_public_ struct udev *udev_ref(struct udev *udev) {
        if (udev == NULL)
                return NULL;
        udev->refcount++;
        return udev;
}

/**
 * udev_unref:
 * @udev: udev library context
 *
 * Drop a reference of the udev library context. If the refcount
 * reaches zero, the resources of the context will be released.
 *
 * Returns: the passed udev library context if it has still an active reference, or #NULL otherwise.
 **/
_public_ struct udev *udev_unref(struct udev *udev) {
        if (udev == NULL)
                return NULL;
        udev->refcount--;
        if (udev->refcount > 0)
                return udev;
        free(udev);
        return NULL;
}

/**
 * udev_set_log_fn:
 * @udev: udev library context
 * @log_fn: function to be called for log messages
 *
 * This function is deprecated.
 *
 **/
_public_ void udev_set_log_fn(struct udev *udev,
                     void (*log_fn)(struct udev *udev,
                                    int priority, const char *file, int line, const char *fn,
                                    const char *format, va_list args)) {
        return;
}

/**
 * udev_get_log_priority:
 * @udev: udev library context
 *
 * This function is deprecated.
 *
 **/
_public_ int udev_get_log_priority(struct udev *udev) {
        return log_get_max_level();
}

/**
 * udev_set_log_priority:
 * @udev: udev library context
 * @priority: the new log priority
 *
 * This function is deprecated.
 *
 **/
_public_ void udev_set_log_priority(struct udev *udev, int priority) {
        log_set_max_level(priority);
}