e82670723a6084682b85f396359c077502227ea2
[project/procd.git] / initd / mkdev.c
1 /*
2 * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
3 * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU Lesser General Public License version 2.1
7 * as published by the Free Software Foundation
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 */
14
15 #define _DEFAULT_SOURCE
16
17 #include <sys/stat.h>
18 #include <sys/types.h>
19
20 #include <stdio.h>
21 #include <string.h>
22 #include <stdlib.h>
23 #include <unistd.h>
24 #include <stdbool.h>
25 #include <dirent.h>
26 #include <limits.h>
27 #include <fnmatch.h>
28
29 #include "init.h"
30
31 static char **patterns;
32 static int n_patterns;
33 static char buf[PATH_MAX];
34 static char buf2[PATH_MAX];
35 static unsigned int mode = 0600;
36
37 static bool find_pattern(const char *name)
38 {
39 int i;
40
41 for (i = 0; i < n_patterns; i++)
42 if (!fnmatch(patterns[i], name, 0))
43 return true;
44
45 return false;
46 }
47
48 static void make_dev(const char *path, bool block, int major, int minor)
49 {
50 unsigned int oldumask = umask(0);
51 unsigned int _mode = mode | (block ? S_IFBLK : S_IFCHR);
52
53 DEBUG(4, "Creating %s device %s(%d,%d)\n",
54 block ? "block" : "character",
55 path, major, minor);
56
57 mknod(path, _mode, makedev(major, minor));
58 umask(oldumask);
59 }
60
61 static void find_devs(bool block)
62 {
63 char *path = block ? "/sys/dev/block" : "/sys/dev/char";
64 struct dirent *dp;
65 DIR *dir;
66
67 dir = opendir(path);
68 if (!dir)
69 return;
70
71 path = buf2 + sprintf(buf2, "%s/", path);
72 while ((dp = readdir(dir)) != NULL) {
73 char *c;
74 int major = 0, minor = 0;
75 int len;
76
77 if (dp->d_type != DT_LNK)
78 continue;
79
80 if (sscanf(dp->d_name, "%d:%d", &major, &minor) != 2)
81 continue;
82
83 strcpy(path, dp->d_name);
84 len = readlink(buf2, buf, sizeof(buf));
85 if (len <= 0)
86 continue;
87
88 buf[len] = 0;
89 if (!find_pattern(buf))
90 continue;
91
92 c = strrchr(buf, '/');
93 if (!c)
94 continue;
95
96 c++;
97 make_dev(c, block, major, minor);
98 }
99 closedir(dir);
100 }
101
102 static char *add_pattern(const char *name)
103 {
104 char *str = malloc(strlen(name) + 2);
105
106 str[0] = '*';
107 strcpy(str + 1, name);
108 return str;
109 }
110
111 int mkdev(const char *name, int _mode)
112 {
113 char *pattern;
114
115 if (chdir("/dev"))
116 return 1;
117
118 pattern = add_pattern(name);
119 patterns = &pattern;
120 mode = _mode;
121 n_patterns = 1;
122 find_devs(true);
123 find_devs(false);
124 free(pattern);
125 return chdir("/");
126 }