Diff of /tags/mkinitrd-6_2_0/util-linux/mdev.c

Parent Directory | Revision Log | Patch

	revision 532 by niro, Sat Sep 1 22:45:15 2007 UTC	revision 816 by niro, Fri Apr 24 18:33:46 2009 UTC
#	Line 9	Line 9
9	* Licensed under GPL version 2, see file LICENSE in this tarball for details.	* Licensed under GPL version 2, see file LICENSE in this tarball for details.
10	*/	*/
11
12	#include "busybox.h"	#include "libbb.h"
13	#include "xregex.h"	#include "xregex.h"
14
15	#define DEV_PATH "/dev"	struct globals {
	struct mdev_globals
	{
16	int root_major, root_minor;	int root_major, root_minor;
17	} mdev_globals;	};
18		#define G (*(struct globals*)&bb_common_bufsiz1)
19		#define root_major (G.root_major)
20		#define root_minor (G.root_minor)
21
22		/* Prevent infinite loops in /sys symlinks */
23		#define MAX_SYSFS_DEPTH 3
24
25		/* We use additional 64+ bytes in make_device() */
26		#define SCRATCH_SIZE 80
27
28		#if ENABLE_FEATURE_MDEV_RENAME
29		/* Builds an alias path.
30		* This function potentionally reallocates the alias parameter.
31		*/
32		static char *build_alias(char *alias, const char *device_name)
33		{
34		char *dest;
35
36	#define bbg mdev_globals	/* ">bar/": rename to bar/device_name */
37		/* ">bar[/]baz": rename to bar[/]baz */
38		dest = strrchr(alias, '/');
39		if (dest) { /* ">bar/[baz]" ? */
40		*dest = '\0'; /* mkdir bar */
41		bb_make_directory(alias, 0755, FILEUTILS_RECUR);
42		*dest = '/';
43		if (dest[1] == '\0') { /* ">bar/" => ">bar/device_name" */
44		dest = alias;
45		alias = concat_path_file(alias, device_name);
46		free(dest);
47		}
48		}
49
50		return alias;
51		}
52		#endif
53
54	/* mknod in /dev based on a path like "/sys/block/hda/hda1" */	/* mknod in /dev based on a path like "/sys/block/hda/hda1" */
55		/* NB: "mdev -s" may call us many times, do not leak memory/fds! */
56	static void make_device(char *path, int delete)	static void make_device(char *path, int delete)
57	{	{
58	char *device_name;	const char *device_name;
59	int major, minor, type, len;	int major, minor, type, len;
60	int mode = 0660;	int mode = 0660;
61	uid_t uid = 0;	#if ENABLE_FEATURE_MDEV_CONF
62	gid_t gid = 0;	struct bb_uidgid_t ugid = { 0, 0 };
63	char *temp = path + strlen(path);	parser_t *parser;
64		char *tokens[5];
65		#endif
66		#if ENABLE_FEATURE_MDEV_EXEC
67	char *command = NULL;	char *command = NULL;
68		#endif
69		#if ENABLE_FEATURE_MDEV_RENAME
70		char *alias = NULL;
71		char aliaslink = aliaslink; /* for compiler */
72		#endif
73		char *dev_maj_min = path + strlen(path);
74
75		/* Force the configuration file settings exactly. */
76		umask(0);
77
78	/* Try to read major/minor string.  Note that the kernel puts \n after	/* Try to read major/minor string.  Note that the kernel puts \n after
79	* the data, so we don't need to worry about null terminating the string	* the data, so we don't need to worry about null terminating the string
80	* because sscanf() will stop at the first nondigit, which \n is.  We	* because sscanf() will stop at the first nondigit, which \n is.
81	* also depend on path having writeable space after it. */	* We also depend on path having writeable space after it.
82		*/
83		major = -1;
84	if (!delete) {	if (!delete) {
85	strcat(path, "/dev");	strcpy(dev_maj_min, "/dev");
86	len = open_read_close(path, temp + 1, 64);	len = open_read_close(path, dev_maj_min + 1, 64);
87	*temp++ = 0;	*dev_maj_min++ = '\0';
88	if (len < 1) return;	if (len < 1) {
89		if (!ENABLE_FEATURE_MDEV_EXEC)
90		return;
91		/* no "dev" file, so just try to run script */
92		*dev_maj_min = '\0';
93		} else if (sscanf(dev_maj_min, "%u:%u", &major, &minor) != 2) {
94		major = -1;
95		}
96	}	}
97
98	/* Determine device name, type, major and minor */	/* Determine device name, type, major and minor */
99		device_name = bb_basename(path);
100		/* http://kernel.org/doc/pending/hotplug.txt says that only
101		* "/sys/block/..." is for block devices. "/sys/bus" etc is not.
102		* But since 2.6.25 block devices are also in /sys/class/block.
103		* We use strstr("/block/") to forestall future surprises. */
104		type = S_IFCHR;
105		if (strstr(path, "/block/"))
106		type = S_IFBLK;
107
108		#if ENABLE_FEATURE_MDEV_CONF
109		parser = config_open2("/etc/mdev.conf", fopen_for_read);
110
111		/* If we have config file, look up user settings */
112		while (config_read(parser, tokens, 4, 3, "# \t", PARSE_NORMAL)) {
113		regmatch_t off[1 + 9*ENABLE_FEATURE_MDEV_RENAME_REGEXP];
114		char *val;
115
116		/* Fields: regex uid:gid mode [alias] [cmd] */
117
118		/* 1st field: @<numeric maj,min>... */
119		if (tokens[0][0] == '@') {
120		/* @major,minor[-last] */
121		/* (useful when name is ambiguous:
122		* "/sys/class/usb/lp0" and
123		* "/sys/class/printer/lp0") */
124		int cmaj, cmin0, cmin1, sc;
125		if (major < 0)
126		continue; /* no dev, no match */
127		sc = sscanf(tokens[0], "@%u,%u-%u", &cmaj, &cmin0, &cmin1);
128		if (sc < 1 || major != cmaj
129		|| (sc == 2 && minor != cmin0)
130		|| (sc == 3 && (minor < cmin0 || minor > cmin1))
131		) {
132		continue; /* no match */
133		}
134		} else { /* ... or regex to match device name */
135		regex_t match;
136		int result;
137
138		/* Is this it? */
139		xregcomp(&match, tokens[0], REG_EXTENDED);
140		result = regexec(&match, device_name, ARRAY_SIZE(off), off, 0);
141		regfree(&match);
142
143		//bb_error_msg("matches:");
144		//for (int i = 0; i < ARRAY_SIZE(off); i++) {
145		// if (off[i].rm_so < 0) continue;
146		// bb_error_msg("match %d: '%.*s'\n", i,
147		// (int)(off[i].rm_eo - off[i].rm_so),
148		// device_name + off[i].rm_so);
149		//}
150
151		/* If not this device, skip rest of line */
152		/* (regexec returns whole pattern as "range" 0) */
153		if (result || off[0].rm_so
154		|| ((int)off[0].rm_eo != (int)strlen(device_name))
155		) {
156		continue;
157		}
158		}
159
160	device_name = strrchr(path, '/') + 1;	/* This line matches: stop parsing the file
161	type = path[5]=='c' ? S_IFCHR : S_IFBLK;	* after parsing the rest of fields */
	/* If we have a config file, look up permissions for this device */
	if (ENABLE_FEATURE_MDEV_CONF) {
	char *conf, *pos, *end;
	int line, fd;
	/* mmap the config file */
	fd = open("/etc/mdev.conf", O_RDONLY);
	if (fd < 0)
	goto end_parse;
	len = xlseek(fd, 0, SEEK_END);
	conf = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
	close(fd);
	if (!conf)
	goto end_parse;
	line = 0;
	/* Loop through lines in mmaped file*/
	for (pos=conf; pos-conf<len;) {
	int field;
	char *end2;
	line++;
	/* find end of this line */
	for (end=pos; end-conf<len && *end!='\n'; end++)
	;
	/* Three fields: regex, uid:gid, mode */
	for (field=0; field < (3 + ENABLE_FEATURE_MDEV_EXEC);
	field++)
	{
	/* Skip whitespace */
	while (pos<end && isspace(*pos)) pos++;
	if (pos==end || *pos=='#') break;
	for (end2=pos;
	end2<end && !isspace(*end2) && *end2!='#'; end2++)
	;
	if (field == 0) {
	/* Regex to match this device */
	char *regex = strndupa(pos, end2-pos);
	regex_t match;
	regmatch_t off;
	int result;
	/* Is this it? */
	xregcomp(&match,regex, REG_EXTENDED);
	result = regexec(&match, device_name, 1, &off, 0);
	regfree(&match);
	/* If not this device, skip rest of line */
	if (result || off.rm_so
	|| off.rm_eo != strlen(device_name))
	break;
	}
	if (field == 1) {
	/* uid:gid */
162
163	char *s, *s2;	/* 2nd field: uid:gid - device ownership */
164		parse_chown_usergroup_or_die(&ugid, tokens[1]);
165
166	/* Find : */	/* 3rd field: mode - device permissions */
167	for (s=pos; s<end2 && *s!=':'; s++)	mode = strtoul(tokens[2], NULL, 8);
	;
	if (s == end2) break;
	/* Parse UID */
	uid = strtoul(pos, &s2, 10);
	if (s != s2) {
	struct passwd *pass;
	pass = getpwnam(strndupa(pos, s-pos));
	if (!pass) break;
	uid = pass->pw_uid;
	}
	s++;
	/* parse GID */
	gid = strtoul(s, &s2, 10);
	if (end2 != s2) {
	struct group *grp;
	grp = getgrnam(strndupa(s, end2-s));
	if (!grp) break;
	gid = grp->gr_gid;
	}
	}
	if (field == 2) {
	/* mode */
168
169	mode = strtoul(pos, &pos, 8);	val = tokens[3];
170	if (pos != end2) break;	/* 4th field (opt): >alias */
171	}	#if ENABLE_FEATURE_MDEV_RENAME
172	if (ENABLE_FEATURE_MDEV_EXEC && field == 3) {	if (!val)
173	// Command to run	break;
174	char *s = "@$*", *s2;	aliaslink = *val;
175	s2 = strchr(s, *pos++);	if (aliaslink == '>' || aliaslink == '=') {
176	if (!s2) {	char *s;
177	// Force error	#if ENABLE_FEATURE_MDEV_RENAME_REGEXP
178	field = 1;	char *p;
179	break;	unsigned i, n;
180		#endif
181		char *a = val;
182		s = strchrnul(val, ' ');
183		val = (s[0] && s[1]) ? s+1 : NULL;
184		s[0] = '\0';
185		#if ENABLE_FEATURE_MDEV_RENAME_REGEXP
186		/* substitute %1..9 with off[1..9], if any */
187		n = 0;
188		s = a;
189		while (*s)
190		if (*s++ == '%')
191		n++;
192
193		p = alias = xzalloc(strlen(a) + n * strlen(device_name));
194		s = a + 1;
195		while (*s) {
196		*p = *s;
197		if ('%' == *s) {
198		i = (s[1] - '0');
199		if (i <= 9 && off[i].rm_so >= 0) {
200		n = off[i].rm_eo - off[i].rm_so;
201		strncpy(p, device_name + off[i].rm_so, n);
202		p += n - 1;
203		s++;
204	}	}
	if ((s2-s+1) & (1<<delete))
	command = xstrndup(pos, end-pos);
205	}	}
206		p++;
207		s++;
208		}
209		#else
210		alias = xstrdup(a + 1);
211		#endif
212		}
213		#endif /* ENABLE_FEATURE_MDEV_RENAME */
214
215	pos = end2;	#if ENABLE_FEATURE_MDEV_EXEC
216		/* The rest (opt): command to run */
217		if (!val)
218		break;
219		{
220		const char *s = "@$*";
221		const char *s2 = strchr(s, *val);
222
223		if (!s2)
224		bb_error_msg_and_die("bad line %u", parser->lineno);
225
226		/* Correlate the position in the "@$*" with the delete
227		* step so that we get the proper behavior:
228		* @cmd: run on create
229		* $cmd: run on delete
230		* *cmd: run on both
231		*/
232		if ((s2 - s + 1) /*1/2/3*/ & /*1/2*/ (1 + delete)) {
233		command = xstrdup(val + 1);
234	}	}
235		}
236		#endif
237		/* end of field parsing */
238		break; /* we found matching line, stop */
239		} /* end of "while line is read from /etc/mdev.conf" */
240
241	/* Did everything parse happily? */	config_close(parser);
242		#endif /* ENABLE_FEATURE_MDEV_CONF */
243
244	if (field > 2) break;	if (!delete && major >= 0) {
	if (field) bb_error_msg_and_die("bad line %d",line);
245
246	/* Next line */	if (ENABLE_FEATURE_MDEV_RENAME)
247	pos = ++end;	unlink(device_name);
	}
	munmap(conf, len);
	end_parse: /* nothing */ ;
	}
248
	umask(0);
	if (!delete) {
	if (sscanf(temp, "%d:%d", &major, &minor) != 2) return;
249	if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)	if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
250	bb_perror_msg_and_die("mknod %s", device_name);	bb_perror_msg_and_die("mknod %s", device_name);
251
252	if (major == bbg.root_major && minor == bbg.root_minor)	if (major == root_major && minor == root_minor)
253	symlink(device_name, "root");	symlink(device_name, "root");
254
255	if (ENABLE_FEATURE_MDEV_CONF) chown(device_name, uid, gid);	#if ENABLE_FEATURE_MDEV_CONF
256		chown(device_name, ugid.uid, ugid.gid);
257
258		#if ENABLE_FEATURE_MDEV_RENAME
259		if (alias) {
260		alias = build_alias(alias, device_name);
261
262		/* move the device, and optionally
263		* make a symlink to moved device node */
264		if (rename(device_name, alias) == 0 && aliaslink == '>')
265		symlink(alias, device_name);
266
267		free(alias);
268		}
269		#endif
270		#endif
271	}	}
	if (command) {
	int rc;
	char *s;
272
273	s = xasprintf("MDEV=%s", device_name);	#if ENABLE_FEATURE_MDEV_EXEC
274	putenv(s);	if (command) {
275	rc = system(command);	/* setenv will leak memory, use putenv/unsetenv/free */
276	s[4] = 0;	char *s = xasprintf("MDEV=%s", device_name);
277	putenv(s);	putenv(s);
278		if (system(command) == -1)
279		bb_perror_msg_and_die("can't run '%s'", command);
280		s[4] = '\0';
281		unsetenv(s);
282	free(s);	free(s);
283	free(command);	free(command);
	if (rc == -1) bb_perror_msg_and_die("cannot run %s", command);
284	}	}
285	if (delete) unlink(device_name);	#endif
	}
286
287	/* Recursive search of /sys/block or /sys/class.  path must be a writeable	if (delete) {
288	* buffer of size PATH_MAX containing the directory string to start at. */	unlink(device_name);
289		/* At creation time, device might have been moved
290		* and a symlink might have been created. Undo that. */
291		#if ENABLE_FEATURE_MDEV_RENAME
292		if (alias) {
293		alias = build_alias(alias, device_name);
294		unlink(alias);
295		free(alias);
296		}
297		#endif
298		}
299		}
300
301	static void find_dev(char *path)	/* File callback for /sys/ traversal */
302		static int FAST_FUNC fileAction(const char *fileName,
303		struct stat *statbuf UNUSED_PARAM,
304		void *userData,
305		int depth UNUSED_PARAM)
306	{	{
307	DIR *dir;	size_t len = strlen(fileName) - 4; /* can't underflow */
308	size_t len = strlen(path);	char *scratch = userData;
	struct dirent *entry;
	dir = opendir(path);
	if (dir == NULL)
	return;
	while ((entry = readdir(dir)) != NULL) {
	struct stat st;
	/* Skip "." and ".." (also skips hidden files, which is ok) */
309
310	if (entry->d_name[0] == '.')	/* len check is for paranoid reasons */
311	continue;	if (strcmp(fileName + len, "/dev") != 0 || len >= PATH_MAX)
312		return FALSE;
313
314		strcpy(scratch, fileName);
315		scratch[len] = '\0';
316		make_device(scratch, 0);
317
318	// uClibc doesn't fill out entry->d_type reliably. so we use lstat().	return TRUE;
319		}
320
321	snprintf(path+len, PATH_MAX-len, "/%s", entry->d_name);	/* Directory callback for /sys/ traversal */
322	if (!lstat(path, &st) && S_ISDIR(st.st_mode)) find_dev(path);	static int FAST_FUNC dirAction(const char *fileName UNUSED_PARAM,
323	path[len] = 0;	struct stat *statbuf UNUSED_PARAM,
324		void *userData UNUSED_PARAM,
325		int depth)
326		{
327		return (depth >= MAX_SYSFS_DEPTH ? SKIP : TRUE);
328		}
329
330	/* If there's a dev entry, mknod it */	/* For the full gory details, see linux/Documentation/firmware_class/README
331		*
332		* Firmware loading works like this:
333		* - kernel sets FIRMWARE env var
334		* - userspace checks /lib/firmware/$FIRMWARE
335		* - userspace waits for /sys/$DEVPATH/loading to appear
336		* - userspace writes "1" to /sys/$DEVPATH/loading
337		* - userspace copies /lib/firmware/$FIRMWARE into /sys/$DEVPATH/data
338		* - userspace writes "0" (worked) or "-1" (failed) to /sys/$DEVPATH/loading
339		* - kernel loads firmware into device
340		*/
341		static void load_firmware(const char *const firmware, const char *const sysfs_path)
342		{
343		int cnt;
344		int firmware_fd, loading_fd, data_fd;
345
346	if (!strcmp(entry->d_name, "dev")) make_device(path, 0);	/* check for /lib/firmware/$FIRMWARE */
347		xchdir("/lib/firmware");
348		firmware_fd = xopen(firmware, O_RDONLY);
349
350		/* in case we goto out ... */
351		data_fd = -1;
352
353		/* check for /sys/$DEVPATH/loading ... give 30 seconds to appear */
354		xchdir(sysfs_path);
355		for (cnt = 0; cnt < 30; ++cnt) {
356		loading_fd = open("loading", O_WRONLY);
357		if (loading_fd != -1)
358		goto loading;
359		sleep(1);
360	}	}
361		goto out;
362
363	closedir(dir);	loading:
364		/* tell kernel we're loading by `echo 1 > /sys/$DEVPATH/loading` */
365		if (full_write(loading_fd, "1", 1) != 1)
366		goto out;
367
368		/* load firmware by `cat /lib/firmware/$FIRMWARE > /sys/$DEVPATH/data */
369		data_fd = open("data", O_WRONLY);
370		if (data_fd == -1)
371		goto out;
372		cnt = bb_copyfd_eof(firmware_fd, data_fd);
373
374		/* tell kernel result by `echo [0|-1] > /sys/$DEVPATH/loading` */
375		if (cnt > 0)
376		full_write(loading_fd, "0", 1);
377		else
378		full_write(loading_fd, "-1", 2);
379
380		out:
381		if (ENABLE_FEATURE_CLEAN_UP) {
382		close(firmware_fd);
383		close(loading_fd);
384		close(data_fd);
385		}
386	}	}
387
388	int mdev_main(int argc, char *argv[])	int mdev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
389		int mdev_main(int argc UNUSED_PARAM, char **argv)
390	{	{
391	char *action;	RESERVE_CONFIG_BUFFER(temp, PATH_MAX + SCRATCH_SIZE);
	char *env_path;
	RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
	xchdir(DEV_PATH);
392
393	/* Scan */	/* We can be called as hotplug helper */
394		/* Kernel cannot provide suitable stdio fds for us, do it ourself */
395	if (argc == 2 && !strcmp(argv[1],"-s")) {	#if 1
396		bb_sanitize_stdio();
397		#else
398		/* Debug code */
399		/* Replace LOGFILE by other file or device name if you need */
400		#define LOGFILE "/dev/console"
401		/* Just making sure fd 0 is not closed,
402		* we don't really intend to read from it */
403		xmove_fd(xopen("/", O_RDONLY), STDIN_FILENO);
404		xmove_fd(xopen(LOGFILE, O_WRONLY|O_APPEND), STDOUT_FILENO);
405		xmove_fd(xopen(LOGFILE, O_WRONLY|O_APPEND), STDERR_FILENO);
406		#endif
407
408		xchdir("/dev");
409
410		if (argv[1] && !strcmp(argv[1], "-s")) {
411		/* Scan:
412		* mdev -s
413		*/
414	struct stat st;	struct stat st;
415
416	xstat("/", &st);	xstat("/", &st);
417	bbg.root_major = major(st.st_dev);	root_major = major(st.st_dev);
418	bbg.root_minor = minor(st.st_dev);	root_minor = minor(st.st_dev);
	strcpy(temp,"/sys/block");
	find_dev(temp);
	strcpy(temp,"/sys/class");
	find_dev(temp);
	/* Hotplug */
419
420		/* ACTION_FOLLOWLINKS is needed since in newer kernels
421		* /sys/block/loop* (for example) are symlinks to dirs,
422		* not real directories.
423		* (kernel's CONFIG_SYSFS_DEPRECATED makes them real dirs,
424		* but we can't enforce that on users) */
425		recursive_action("/sys/block",
426		ACTION_RECURSE | ACTION_FOLLOWLINKS,
427		fileAction, dirAction, temp, 0);
428		recursive_action("/sys/class",
429		ACTION_RECURSE | ACTION_FOLLOWLINKS,
430		fileAction, dirAction, temp, 0);
431	} else {	} else {
432		char *seq;
433		char *action;
434		char *env_path;
435		char seqbuf[sizeof(int)*3 + 2];
436		int seqlen = seqlen; /* for compiler */
437
438		/* Hotplug:
439		* env ACTION=... DEVPATH=... [SEQNUM=...] mdev
440		* ACTION can be "add" or "remove"
441		* DEVPATH is like "/block/sda" or "/class/input/mice"
442		*/
443	action = getenv("ACTION");	action = getenv("ACTION");
444	env_path = getenv("DEVPATH");	env_path = getenv("DEVPATH");
445	if (!action || !env_path)	if (!action || !env_path)
446	bb_show_usage();	bb_show_usage();
447
448	sprintf(temp, "/sys%s", env_path);	seq = getenv("SEQNUM");
449	if (!strcmp(action, "add")) make_device(temp,0);	if (seq) {
450	else if (!strcmp(action, "remove")) make_device(temp,1);	int timeout = 2000 / 32;
451		do {
452		seqlen = open_read_close("mdev.seq", seqbuf, sizeof(seqbuf-1));
453		if (seqlen < 0)
454		break;
455		seqbuf[seqlen] = '\0';
456		if (seqbuf[0] == '\n' /* seed file? */
457		|| strcmp(seq, seqbuf) == 0 /* correct idx? */
458		) {
459		break;
460		}
461		usleep(32*1000);
462		} while (--timeout);
463		}
464
465		snprintf(temp, PATH_MAX, "/sys%s", env_path);
466		if (!strcmp(action, "remove"))
467		make_device(temp, 1);
468		else if (!strcmp(action, "add")) {
469		make_device(temp, 0);
470
471		if (ENABLE_FEATURE_MDEV_LOAD_FIRMWARE) {
472		char *fw = getenv("FIRMWARE");
473		if (fw)
474		load_firmware(fw, temp);
475		}
476		}
477
478		if (seq && seqlen >= 0) {
479		xopen_xwrite_close("mdev.seq", utoa(xatou(seq) + 1));
480		}
481	}	}
482
483	if (ENABLE_FEATURE_CLEAN_UP) RELEASE_CONFIG_BUFFER(temp);	if (ENABLE_FEATURE_CLEAN_UP)
484		RELEASE_CONFIG_BUFFER(temp);
485
486	return 0;	return 0;
487	}	}

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Legend: Removed from v.532   changed lines   Added in v.816