1 /* vi: set sw=4 ts=4: */
4 * mdev - Mini udev for busybox
6 * Copyright 2005 Rob Landley <rob@landley.net>
7 * Copyright 2005 Frank Sorenson <frank@tuxrocks.com>
9 * Licensed under GPL version 2, see file LICENSE in this tarball for details.
16 int root_major, root_minor;
18 #define G (*(struct globals*)&bb_common_bufsiz1)
19 #define root_major (G.root_major)
20 #define root_minor (G.root_minor)
22 #define MAX_SYSFS_DEPTH 3 /* prevent infinite loops in /sys symlinks */
24 /* mknod in /dev based on a path like "/sys/block/hda/hda1" */
25 static void make_device(char *path, int delete)
27 const char *device_name;
28 int major, minor, type, len;
32 char *temp = path + strlen(path);
35 /* Try to read major/minor string. Note that the kernel puts \n after
36 * the data, so we don't need to worry about null terminating the string
37 * because sscanf() will stop at the first nondigit, which \n is. We
38 * also depend on path having writeable space after it. */
42 len = open_read_close(path, temp + 1, 64);
47 /* Determine device name, type, major and minor */
49 device_name = bb_basename(path);
50 type = path[5]=='c' ? S_IFCHR : S_IFBLK;
52 /* If we have a config file, look up permissions for this device */
54 if (ENABLE_FEATURE_MDEV_CONF) {
55 char *conf, *pos, *end;
58 /* mmap the config file */
59 fd = open("/etc/mdev.conf", O_RDONLY);
62 len = xlseek(fd, 0, SEEK_END);
63 conf = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
69 /* Loop through lines in mmaped file*/
70 for (pos=conf; pos-conf<len;) {
75 /* find end of this line */
76 for (end=pos; end-conf<len && *end!='\n'; end++)
79 /* Three fields: regex, uid:gid, mode */
80 for (field=0; field < (3 + ENABLE_FEATURE_MDEV_EXEC);
84 while (pos<end && isspace(*pos)) pos++;
85 if (pos==end || *pos=='#') break;
87 end2<end && !isspace(*end2) && *end2!='#'; end2++)
91 /* Regex to match this device */
93 char *regex = xstrndup(pos, end2-pos);
99 xregcomp(&match,regex, REG_EXTENDED);
100 result = regexec(&match, device_name, 1, &off, 0);
104 /* If not this device, skip rest of line */
105 if (result || off.rm_so
106 || off.rm_eo != strlen(device_name))
115 for (s=pos; s<end2 && *s!=':'; s++)
117 if (s == end2) break;
120 uid = strtoul(pos, &s2, 10);
123 char *_unam = xstrndup(pos, s-pos);
124 pass = getpwnam(_unam);
131 gid = strtoul(s, &s2, 10);
134 char *_grnam = xstrndup(s, end2-s);
135 grp = getgrnam(_grnam);
144 mode = strtoul(pos, &pos, 8);
145 if (pos != end2) break;
147 if (ENABLE_FEATURE_MDEV_EXEC && field == 3) {
149 const char *s = "@$*";
151 s2 = strchr(s, *pos++);
157 if ((s2-s+1) & (1<<delete))
158 command = xstrndup(pos, end-pos);
164 /* Did everything parse happily? */
166 if (field > 2) break;
167 if (field) bb_error_msg_and_die("bad line %d",line);
173 end_parse: /* nothing */ ;
178 if (sscanf(temp, "%d:%d", &major, &minor) != 2) return;
179 if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
180 bb_perror_msg_and_die("mknod %s", device_name);
182 if (major == root_major && minor == root_minor)
183 symlink(device_name, "root");
185 if (ENABLE_FEATURE_MDEV_CONF) chown(device_name, uid, gid);
188 /* setenv will leak memory, so use putenv */
189 char *s = xasprintf("MDEV=%s", device_name);
191 if (system(command) == -1)
192 bb_perror_msg_and_die("cannot run %s", command);
198 if (delete) unlink(device_name);
201 /* File callback for /sys/ traversal */
202 static int fileAction(const char *fileName, struct stat *statbuf,
203 void *userData, int depth)
205 size_t len = strlen(fileName) - 4;
206 char *scratch = userData;
208 if (strcmp(fileName + len, "/dev"))
211 strcpy(scratch, fileName);
213 make_device(scratch, 0);
218 /* Directory callback for /sys/ traversal */
219 static int dirAction(const char *fileName, struct stat *statbuf,
220 void *userData, int depth)
222 return (depth >= MAX_SYSFS_DEPTH ? SKIP : TRUE);
225 /* For the full gory details, see linux/Documentation/firmware_class/README
227 * Firmware loading works like this:
228 * - kernel sets FIRMWARE env var
229 * - userspace checks /lib/firmware/$FIRMWARE
230 * - userspace waits for /sys/$DEVPATH/loading to appear
231 * - userspace writes "1" to /sys/$DEVPATH/loading
232 * - userspace copies /lib/firmware/$FIRMWARE into /sys/$DEVPATH/data
233 * - userspace writes "0" (worked) or "-1" (failed) to /sys/$DEVPATH/loading
234 * - kernel loads firmware into device
236 static void load_firmware(const char *const firmware, const char *const sysfs_path)
239 int firmware_fd, loading_fd, data_fd;
241 /* check for $FIRMWARE from kernel */
242 /* XXX: dont bother: open(NULL) works same as open("no-such-file")
247 /* check for /lib/firmware/$FIRMWARE */
248 xchdir("/lib/firmware");
249 firmware_fd = xopen(firmware, O_RDONLY);
251 /* in case we goto out ... */
254 /* check for /sys/$DEVPATH/loading ... give 30 seconds to appear */
256 for (cnt = 0; cnt < 30; ++cnt) {
257 loading_fd = open("loading", O_WRONLY);
258 if (loading_fd == -1)
263 if (loading_fd == -1)
266 /* tell kernel we're loading by `echo 1 > /sys/$DEVPATH/loading` */
267 if (write(loading_fd, "1", 1) != 1)
270 /* load firmware by `cat /lib/firmware/$FIRMWARE > /sys/$DEVPATH/data */
271 data_fd = open("data", O_WRONLY);
274 cnt = bb_copyfd_eof(firmware_fd, data_fd);
276 /* tell kernel result by `echo [0|-1] > /sys/$DEVPATH/loading` */
278 write(loading_fd, "0", 1);
280 write(loading_fd, "-1", 2);
283 if (ENABLE_FEATURE_CLEAN_UP) {
290 int mdev_main(int argc, char **argv);
291 int mdev_main(int argc, char **argv)
295 RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
301 if (argc == 2 && !strcmp(argv[1],"-s")) {
305 root_major = major(st.st_dev);
306 root_minor = minor(st.st_dev);
308 recursive_action("/sys/block",
309 ACTION_RECURSE | ACTION_FOLLOWLINKS,
310 fileAction, dirAction, temp, 0);
312 recursive_action("/sys/class",
313 ACTION_RECURSE | ACTION_FOLLOWLINKS,
314 fileAction, dirAction, temp, 0);
319 action = getenv("ACTION");
320 env_path = getenv("DEVPATH");
321 if (!action || !env_path)
324 sprintf(temp, "/sys%s", env_path);
325 if (!strcmp(action, "remove"))
326 make_device(temp, 1);
327 else if (!strcmp(action, "add")) {
328 make_device(temp, 0);
330 if (ENABLE_FEATURE_MDEV_LOAD_FIRMWARE)
331 load_firmware(getenv("FIRMWARE"), temp);
335 if (ENABLE_FEATURE_CLEAN_UP) RELEASE_CONFIG_BUFFER(temp);