3 * mdev - Mini udev for busybox
5 * Copyright 2005 Rob Landley <rob@landley.net>
6 * Copyright 2005 Frank Sorenson <frank@tuxrocks.com>
8 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
19 #include <sys/types.h>
25 #define DEV_PATH "/dev"
26 #define MDEV_CONF "/etc/mdev.conf"
30 /* mknod in /dev based on a path like "/sys/block/hda/hda1" */
31 static void make_device(char *path)
33 char *device_name, *s;
34 int major, minor, type, len, fd;
39 RESERVE_CONFIG_BUFFER(temp, PATH_MAX);
41 /* Try to read major/minor string */
43 snprintf(temp, PATH_MAX, "%s/dev", path);
44 fd = open(temp, O_RDONLY);
45 len = read(fd, temp, PATH_MAX-1);
47 if (len < 1) goto end;
49 /* Determine device name, type, major and minor */
51 device_name = strrchr(path, '/') + 1;
52 type = strncmp(path+5, "block/", 6) ? S_IFCHR : S_IFBLK;
53 if (sscanf(temp, "%d:%d", &major, &minor) != 2)
56 /* If we have a config file, look up permissions for this device */
58 if (ENABLE_FEATURE_MDEV_CONF) {
59 char *conf, *pos, *end;
61 /* mmap the config file */
62 if (-1 != (fd=open(MDEV_CONF,O_RDONLY))) {
63 len = lseek(fd, 0, SEEK_END);
64 conf = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
68 /* Loop through lines in mmaped file*/
69 for (pos=conf; pos-conf<len;) {
74 /* find end of this line */
75 for(end=pos; end-conf<len && *end!='\n'; end++)
78 /* Three fields: regex, uid:gid, mode */
79 for (field=3; field; field--) {
81 while (pos<end && isspace(*pos))
83 if (pos==end || *pos=='#')
85 for (end2=pos; end2<end && !isspace(*end2) && *end2!='#'; end2++)
89 /* Regex to match this device */
92 char *regex = strndupa(pos,end2-pos);
98 xregcomp(&match,regex,REG_EXTENDED);
99 result = regexec(&match,device_name,1,&off,0);
102 /* If not this device, skip rest of line */
103 if (result || off.rm_so || off.rm_eo!=strlen(device_name))
114 for(s=pos; s<end2 && *s!=':'; s++)
120 uid = strtoul(pos,&s2,10);
123 pass = getpwnam(strndupa(pos,s-pos));
130 gid = strtoul(s,&s2,10);
133 grp = getgrnam(strndupa(s,end2-s));
143 mode = strtoul(pos,&pos,8);
153 /* Did everything parse happily? */
154 if (field && field!=3)
155 bb_error_msg_and_die("Bad line %d",line);
167 sprintf(temp, "%s/%s", DEV_PATH, device_name);
169 if (mknod(temp, mode | type, makedev(major, minor)) && errno != EEXIST)
170 bb_perror_msg_and_die("mknod %s failed", temp);
172 if (ENABLE_FEATURE_MDEV_CONF) chown(temp,uid,gid);
175 RELEASE_CONFIG_BUFFER(temp);
178 /* Recursive search of /sys/block or /sys/class. path must be a writeable
179 * buffer of size PATH_MAX containing the directory string to start at. */
181 static void find_dev(char *path)
184 size_t len = strlen(path);
185 struct dirent *entry;
187 if ((dir = opendir(path)) == NULL)
190 while ((entry = readdir(dir)) != NULL) {
192 /* Skip "." and ".." (also skips hidden files, which is ok) */
194 if (entry->d_name[0] == '.')
197 if (entry->d_type == DT_DIR) {
198 snprintf(path+len, PATH_MAX-len, "/%s", entry->d_name);
203 /* If there's a dev entry, mknod it */
205 if (!strcmp(entry->d_name, "dev")) make_device(path);
211 int mdev_main(int argc, char *argv[])
215 RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
219 if (argc == 2 && !strcmp(argv[1],"-s")) {
220 strcpy(temp,"/sys/block");
222 strcpy(temp,"/sys/class");
228 action = getenv("ACTION");
229 env_path = getenv("DEVPATH");
230 if (!action || !env_path)
233 if (!strcmp(action, "add")) {
234 sprintf(temp, "/sys%s", env_path);
236 } else if (!strcmp(action, "remove")) {
237 sprintf(temp, "%s/%s", DEV_PATH, strrchr(env_path, '/') + 1);
242 if (ENABLE_FEATURE_CLEAN_UP) RELEASE_CONFIG_BUFFER(temp);