path: root/miscutils/devfsd.c (plain)
blob: 99bdc72b8714093a48b7610c2d96aead04f038dc

1	/* vi: set sw=4 ts=4: */
2	/*
3	* Licensed under GPLv2 or later, see file LICENSE in this source tree.
4	*/
5
6	/*
7	devfsd implementation for busybox
8
9	Copyright (C) 2003 by Tito Ragusa <farmatito@tiscali.it>
10
11	Busybox version is based on some previous work and ideas
12	Copyright (C) [2003] by [Matteo Croce] <3297627799@wind.it>
13
14	devfsd.c
15
16	Main file for devfsd (devfs daemon for Linux).
17
18	Copyright (C) 1998-2002 Richard Gooch
19
20	devfsd.h
21
22	Header file for devfsd (devfs daemon for Linux).
23
24	Copyright (C) 1998-2000 Richard Gooch
25
26	compat_name.c
27
28	Compatibility name file for devfsd (build compatibility names).
29
30	Copyright (C) 1998-2002 Richard Gooch
31
32	expression.c
33
34	This code provides Borne Shell-like expression expansion.
35
36	Copyright (C) 1997-1999 Richard Gooch
37
38	This program is free software; you can redistribute it and/or modify
39	it under the terms of the GNU General Public License as published by
40	the Free Software Foundation; either version 2 of the License, or
41	(at your option) any later version.
42
43	This program is distributed in the hope that it will be useful,
44	but WITHOUT ANY WARRANTY; without even the implied warranty of
45	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
46	GNU General Public License for more details.
47
48	You should have received a copy of the GNU General Public License
49	along with this program; if not, write to the Free Software
50	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
51
52	Richard Gooch may be reached by email at rgooch@atnf.csiro.au
53	The postal address is:
54	Richard Gooch, c/o ATNF, P. O. Box 76, Epping, N.S.W., 2121, Australia.
55	*/
56	//config:config DEVFSD
57	//config: bool "devfsd (obsolete)"
58	//config: default n
59	//config: select PLATFORM_LINUX
60	//config: select FEATURE_SYSLOG
61	//config: help
62	//config: This is deprecated and should NOT be used anymore.
63	//config: Use linux >= 2.6 (optionally with hotplug) and mdev instead!
64	//config: See docs/mdev.txt for detailed instructions on how to use mdev
65	//config: instead.
66	//config:
67	//config: Provides compatibility with old device names on a devfs systems.
68	//config: You should set it to true if you have devfs enabled.
69	//config: The following keywords in devsfd.conf are supported:
70	//config: "CLEAR_CONFIG", "INCLUDE", "OPTIONAL_INCLUDE", "RESTORE",
71	//config: "PERMISSIONS", "EXECUTE", "COPY", "IGNORE",
72	//config: "MKOLDCOMPAT", "MKNEWCOMPAT","RMOLDCOMPAT", "RMNEWCOMPAT".
73	//config:
74	//config: But only if they are written UPPERCASE!!!!!!!!
75	//config:
76	//config:config DEVFSD_MODLOAD
77	//config: bool "Adds support for MODLOAD keyword in devsfd.conf"
78	//config: default y
79	//config: depends on DEVFSD
80	//config: help
81	//config: This actually doesn't work with busybox modutils but needs
82	//config: the external modutils.
83	//config:
84	//config:config DEVFSD_FG_NP
85	//config: bool "Enables the -fg and -np options"
86	//config: default y
87	//config: depends on DEVFSD
88	//config: help
89	//config: -fg Run the daemon in the foreground.
90	//config: -np Exit after parsing the configuration file.
91	//config: Do not poll for events.
92	//config:
93	//config:config DEVFSD_VERBOSE
94	//config: bool "Increases logging (and size)"
95	//config: default y
96	//config: depends on DEVFSD
97	//config: help
98	//config: Increases logging to stderr or syslog.
99	//config:
100	//config:config FEATURE_DEVFS
101	//config: bool "Use devfs names for all devices (obsolete)"
102	//config: default n
103	//config: select PLATFORM_LINUX
104	//config: help
105	//config: This is obsolete and should NOT be used anymore.
106	//config: Use linux >= 2.6 (optionally with hotplug) and mdev instead!
107	//config:
108	//config: For legacy systems -- if there is no way around devfsd -- this
109	//config: tells busybox to look for names like /dev/loop/0 instead of
110	//config: /dev/loop0. If your /dev directory has normal names instead of
111	//config: devfs names, you don't want this.
112
113	//applet:IF_DEVFSD(APPLET(devfsd, BB_DIR_SBIN, BB_SUID_DROP))
114
115	//kbuild:lib-$(CONFIG_DEVFSD) += devfsd.o
116
117	//usage:#define devfsd_trivial_usage
118	//usage: "mntpnt [-v]" IF_DEVFSD_FG_NP("[-fg][-np]")
119	//usage:#define devfsd_full_usage "\n\n"
120	//usage: "Manage devfs permissions and old device name symlinks\n"
121	//usage: "\n mntpnt The mount point where devfs is mounted"
122	//usage: "\n -v Print the protocol version numbers for devfsd"
123	//usage: "\n and the kernel-side protocol version and exit"
124	//usage: IF_DEVFSD_FG_NP(
125	//usage: "\n -fg Run in foreground"
126	//usage: "\n -np Exit after parsing the configuration file"
127	//usage: "\n and processing synthetic REGISTER events,"
128	//usage: "\n don't poll for events"
129	//usage: )
130
131	#include "libbb.h"
132	#include "xregex.h"
133	#include <syslog.h>
134
135	#include <sys/un.h>
136	#include <sys/sysmacros.h>
137
138	/* Various defines taken from linux/major.h */
139	#define IDE0_MAJOR 3
140	#define IDE1_MAJOR 22
141	#define IDE2_MAJOR 33
142	#define IDE3_MAJOR 34
143	#define IDE4_MAJOR 56
144	#define IDE5_MAJOR 57
145	#define IDE6_MAJOR 88
146	#define IDE7_MAJOR 89
147	#define IDE8_MAJOR 90
148	#define IDE9_MAJOR 91
149
150
151	/* Various defines taken from linux/devfs_fs.h */
152	#define DEVFSD_PROTOCOL_REVISION_KERNEL 5
153	#define DEVFSD_IOCTL_BASE 'd'
154	/* These are the various ioctls */
155	#define DEVFSDIOC_GET_PROTO_REV _IOR(DEVFSD_IOCTL_BASE, 0, int)
156	#define DEVFSDIOC_SET_EVENT_MASK _IOW(DEVFSD_IOCTL_BASE, 2, int)
157	#define DEVFSDIOC_RELEASE_EVENT_QUEUE _IOW(DEVFSD_IOCTL_BASE, 3, int)
158	#define DEVFSDIOC_SET_CONFIG_DEBUG_MASK _IOW(DEVFSD_IOCTL_BASE, 4, int)
159	#define DEVFSD_NOTIFY_REGISTERED 0
160	#define DEVFSD_NOTIFY_UNREGISTERED 1
161	#define DEVFSD_NOTIFY_ASYNC_OPEN 2
162	#define DEVFSD_NOTIFY_CLOSE 3
163	#define DEVFSD_NOTIFY_LOOKUP 4
164	#define DEVFSD_NOTIFY_CHANGE 5
165	#define DEVFSD_NOTIFY_CREATE 6
166	#define DEVFSD_NOTIFY_DELETE 7
167	#define DEVFS_PATHLEN 1024
168	/* Never change this otherwise the binary interface will change */
169
170	struct devfsd_notify_struct {
171	/* Use native C types to ensure same types in kernel and user space */
172	unsigned int type; /* DEVFSD_NOTIFY_* value */
173	unsigned int mode; /* Mode of the inode or device entry */
174	unsigned int major; /* Major number of device entry */
175	unsigned int minor; /* Minor number of device entry */
176	unsigned int uid; /* Uid of process, inode or device entry */
177	unsigned int gid; /* Gid of process, inode or device entry */
178	unsigned int overrun_count; /* Number of lost events */
179	unsigned int namelen; /* Number of characters not including '\0' */
180	/* The device name MUST come last */
181	char devname[DEVFS_PATHLEN]; /* This will be '\0' terminated */
182	};
183
184	#define BUFFER_SIZE 16384
185	#define DEVFSD_VERSION "1.3.25"
186	#define CONFIG_FILE "/etc/devfsd.conf"
187	#define MODPROBE "/sbin/modprobe"
188	#define MODPROBE_SWITCH_1 "-k"
189	#define MODPROBE_SWITCH_2 "-C"
190	#define CONFIG_MODULES_DEVFS "/etc/modules.devfs"
191	#define MAX_ARGS (6 + 1)
192	#define MAX_SUBEXPR 10
193	#define STRING_LENGTH 255
194
195	/* for get_uid_gid() */
196	#define UID 0
197	#define GID 1
198
199	/* fork_and_execute() */
200	# define DIE 1
201	# define NO_DIE 0
202
203	/* for dir_operation() */
204	#define RESTORE 0
205	#define SERVICE 1
206	#define READ_CONFIG 2
207
208	/* Update only after changing code to reflect new protocol */
209	#define DEVFSD_PROTOCOL_REVISION_DAEMON 5
210
211	/* Compile-time check */
212	#if DEVFSD_PROTOCOL_REVISION_KERNEL != DEVFSD_PROTOCOL_REVISION_DAEMON
213	#error protocol version mismatch. Update your kernel headers
214	#endif
215
216	#define AC_PERMISSIONS 0
217	#define AC_MODLOAD 1
218	#define AC_EXECUTE 2
219	#define AC_MFUNCTION 3 /* not supported by busybox */
220	#define AC_CFUNCTION 4 /* not supported by busybox */
221	#define AC_COPY 5
222	#define AC_IGNORE 6
223	#define AC_MKOLDCOMPAT 7
224	#define AC_MKNEWCOMPAT 8
225	#define AC_RMOLDCOMPAT 9
226	#define AC_RMNEWCOMPAT 10
227	#define AC_RESTORE 11
228
229	struct permissions_type {
230	mode_t mode;
231	uid_t uid;
232	gid_t gid;
233	};
234
235	struct execute_type {
236	char *argv[MAX_ARGS + 1]; /* argv[0] must always be the programme */
237	};
238
239	struct copy_type {
240	const char *source;
241	const char *destination;
242	};
243
244	struct action_type {
245	unsigned int what;
246	unsigned int when;
247	};
248
249	struct config_entry_struct {
250	struct action_type action;
251	regex_t preg;
252	union
253	{
254	struct permissions_type permissions;
255	struct execute_type execute;
256	struct copy_type copy;
257	}
258	u;
259	struct config_entry_struct *next;
260	};
261
262	struct get_variable_info {
263	const struct devfsd_notify_struct *info;
264	const char *devname;
265	char devpath[STRING_LENGTH];
266	};
267
268	static void dir_operation(int , const char * , int, unsigned long*);
269	static void service(struct stat statbuf, char *path);
270	static int st_expr_expand(char *, unsigned, const char *, const char *(*)(const char *, void *), void *);
271	static const char *get_old_name(const char *, unsigned, char *, unsigned, unsigned);
272	static int mksymlink(const char *oldpath, const char *newpath);
273	static void read_config_file(char *path, int optional, unsigned long *event_mask);
274	static void process_config_line(const char *, unsigned long *);
275	static int do_servicing(int, unsigned long);
276	static void service_name(const struct devfsd_notify_struct *);
277	static void action_permissions(const struct devfsd_notify_struct *, const struct config_entry_struct *);
278	static void action_execute(const struct devfsd_notify_struct *, const struct config_entry_struct *,
279	const regmatch_t *, unsigned);
280	static void action_modload(const struct devfsd_notify_struct *info, const struct config_entry_struct *entry);
281	static void action_copy(const struct devfsd_notify_struct *, const struct config_entry_struct *,
282	const regmatch_t *, unsigned);
283	static void action_compat(const struct devfsd_notify_struct *, unsigned);
284	static void free_config(void);
285	static void restore(char *spath, struct stat source_stat, int rootlen);
286	static int copy_inode(const char *, const struct stat *, mode_t, const char *, const struct stat *);
287	static mode_t get_mode(const char *);
288	static void signal_handler(int);
289	static const char *get_variable(const char *, void *);
290	static int make_dir_tree(const char *);
291	static int expand_expression(char *, unsigned, const char *, const char *(*)(const char *, void *), void *,
292	const char *, const regmatch_t *, unsigned);
293	static void expand_regexp(char *, size_t, const char *, const char *, const regmatch_t *, unsigned);
294	static const char *expand_variable( char *, unsigned, unsigned *, const char *,
295	const char *(*)(const char *, void *), void *);
296	static const char *get_variable_v2(const char *, const char *(*)(const char *, void *), void *);
297	static char get_old_ide_name(unsigned, unsigned);
298	static char *write_old_sd_name(char *, unsigned, unsigned, const char *);
299
300	/* busybox functions */
301	static int get_uid_gid(int flag, const char *string);
302	static void safe_memcpy(char * dest, const char * src, int len);
303	static unsigned int scan_dev_name_common(const char *d, unsigned int n, int addendum, const char *ptr);
304	static unsigned int scan_dev_name(const char *d, unsigned int n, const char *ptr);
305
306	/* Structs and vars */
307	static struct config_entry_struct *first_config = NULL;
308	static struct config_entry_struct *last_config = NULL;
309	static char *mount_point = NULL;
310	static volatile int caught_signal = FALSE;
311	static volatile int caught_sighup = FALSE;
312	static struct initial_symlink_struct {
313	const char *dest;
314	const char *name;
315	} initial_symlinks[] = {
316	{"/proc/self/fd", "fd"},
317	{"fd/0", "stdin"},
318	{"fd/1", "stdout"},
319	{"fd/2", "stderr"},
320	{NULL, NULL},
321	};
322
323	static struct event_type {
324	unsigned int type; /* The DEVFSD_NOTIFY_* value */
325	const char *config_name; /* The name used in the config file */
326	} event_types[] = {
327	{DEVFSD_NOTIFY_REGISTERED, "REGISTER"},
328	{DEVFSD_NOTIFY_UNREGISTERED, "UNREGISTER"},
329	{DEVFSD_NOTIFY_ASYNC_OPEN, "ASYNC_OPEN"},
330	{DEVFSD_NOTIFY_CLOSE, "CLOSE"},
331	{DEVFSD_NOTIFY_LOOKUP, "LOOKUP"},
332	{DEVFSD_NOTIFY_CHANGE, "CHANGE"},
333	{DEVFSD_NOTIFY_CREATE, "CREATE"},
334	{DEVFSD_NOTIFY_DELETE, "DELETE"},
335	{0xffffffff, NULL}
336	};
337
338	/* Busybox messages */
339
340	static const char bb_msg_proto_rev[] ALIGN1 = "protocol revision";
341	static const char bb_msg_bad_config[] ALIGN1 = "bad %s config file: %s";
342	static const char bb_msg_small_buffer[] ALIGN1 = "buffer too small";
343	static const char bb_msg_variable_not_found[] ALIGN1 = "variable: %s not found";
344
345	/* Busybox stuff */
346	#if ENABLE_DEVFSD_VERBOSE || ENABLE_DEBUG
347	#define info_logger(p, fmt, args...) bb_error_msg(fmt, ## args)
348	#define msg_logger(p, fmt, args...) bb_error_msg(fmt, ## args)
349	#define msg_logger_and_die(p, fmt, args...) bb_error_msg_and_die(fmt, ## args)
350	#define error_logger(p, fmt, args...) bb_perror_msg(fmt, ## args)
351	#define error_logger_and_die(p, fmt, args...) bb_perror_msg_and_die(fmt, ## args)
352	#else
353	#define info_logger(p, fmt, args...)
354	#define msg_logger(p, fmt, args...)
355	#define msg_logger_and_die(p, fmt, args...) exit(EXIT_FAILURE)
356	#define error_logger(p, fmt, args...)
357	#define error_logger_and_die(p, fmt, args...) exit(EXIT_FAILURE)
358	#endif
359
360	static void safe_memcpy(char *dest, const char *src, int len)
361	{
362	memcpy(dest , src, len);
363	dest[len] = '\0';
364	}
365
366	static unsigned int scan_dev_name_common(const char *d, unsigned int n, int addendum, const char *ptr)
367	{
368	if (d[n - 4] == 'd' && d[n - 3] == 'i' && d[n - 2] == 's' && d[n - 1] == 'c')
369	return 2 + addendum;
370	if (d[n - 2] == 'c' && d[n - 1] == 'd')
371	return 3 + addendum;
372	if (ptr[0] == 'p' && ptr[1] == 'a' && ptr[2] == 'r' && ptr[3] == 't')
373	return 4 + addendum;
374	if (ptr[n - 2] == 'm' && ptr[n - 1] == 't')
375	return 5 + addendum;
376	return 0;
377	}
378
379	static unsigned int scan_dev_name(const char *d, unsigned int n, const char *ptr)
380	{
381	if (d[0] == 's' && d[1] == 'c' && d[2] == 's' && d[3] == 'i' && d[4] == '/') {
382	if (d[n - 7] == 'g' && d[n - 6] == 'e' && d[n - 5] == 'n'
383	&& d[n - 4] == 'e' && d[n - 3] == 'r' && d[n - 2] == 'i' && d[n - 1] == 'c'
384	)
385	return 1;
386	return scan_dev_name_common(d, n, 0, ptr);
387	}
388	if (d[0] == 'i' && d[1] == 'd' && d[2] == 'e' && d[3] == '/'
389	&& d[4] == 'h' && d[5] == 'o' && d[6] == 's' && d[7] == 't'
390	)
391	return scan_dev_name_common(d, n, 4, ptr);
392	if (d[0] == 's' && d[1] == 'b' && d[2] == 'p' && d[3] == '/')
393	return 10;
394	if (d[0] == 'v' && d[1] == 'c' && d[2] == 'c' && d[3] == '/')
395	return 11;
396	if (d[0] == 'p' && d[1] == 't' && d[2] == 'y' && d[3] == '/')
397	return 12;
398	return 0;
399	}
400
401	/* Public functions follow */
402
403	int devfsd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
404	int devfsd_main(int argc, char **argv)
405	{
406	int print_version = FALSE;
407	int do_daemon = TRUE;
408	int no_polling = FALSE;
409	int do_scan;
410	int fd, proto_rev, count;
411	unsigned long event_mask = 0;
412	struct sigaction new_action;
413	struct initial_symlink_struct *curr;
414
415	if (argc < 2)
416	bb_show_usage();
417
418	for (count = 2; count < argc; ++count) {
419	if (argv[count][0] == '-') {
420	if (argv[count][1] == 'v' && !argv[count][2]) /* -v */
421	print_version = TRUE;
422	else if (ENABLE_DEVFSD_FG_NP && argv[count][1] == 'f'
423	&& argv[count][2] == 'g' && !argv[count][3]) /* -fg */
424	do_daemon = FALSE;
425	else if (ENABLE_DEVFSD_FG_NP && argv[count][1] == 'n'
426	&& argv[count][2] == 'p' && !argv[count][3]) /* -np */
427	no_polling = TRUE;
428	else
429	bb_show_usage();
430	}
431	}
432
433	mount_point = bb_simplify_path(argv[1]);
434
435	xchdir(mount_point);
436
437	fd = xopen(".devfsd", O_RDONLY);
438	close_on_exec_on(fd);
439	xioctl(fd, DEVFSDIOC_GET_PROTO_REV, &proto_rev);
440
441	/*setup initial entries */
442	for (curr = initial_symlinks; curr->dest != NULL; ++curr)
443	symlink(curr->dest, curr->name);
444
445	/* NB: The check for CONFIG_FILE is done in read_config_file() */
446
447	if (print_version || (DEVFSD_PROTOCOL_REVISION_DAEMON != proto_rev)) {
448	printf("%s v%s\nDaemon %s:\t%d\nKernel-side %s:\t%d\n",
449	applet_name, DEVFSD_VERSION, bb_msg_proto_rev,
450	DEVFSD_PROTOCOL_REVISION_DAEMON, bb_msg_proto_rev, proto_rev);
451	if (DEVFSD_PROTOCOL_REVISION_DAEMON != proto_rev)
452	bb_error_msg_and_die("%s mismatch!", bb_msg_proto_rev);
453	exit(EXIT_SUCCESS); /* -v */
454	}
455	/* Tell kernel we are special(i.e. we get to see hidden entries) */
456	xioctl(fd, DEVFSDIOC_SET_EVENT_MASK, 0);
457
458	/* Set up SIGHUP and SIGUSR1 handlers */
459	sigemptyset(&new_action.sa_mask);
460	new_action.sa_flags = 0;
461	new_action.sa_handler = signal_handler;
462	sigaction_set(SIGHUP, &new_action);
463	sigaction_set(SIGUSR1, &new_action);
464
465	printf("%s v%s started for %s\n", applet_name, DEVFSD_VERSION, mount_point);
466
467	/* Set umask so that mknod(2), open(2) and mkdir(2) have complete control over permissions */
468	umask(0);
469	read_config_file((char*)CONFIG_FILE, FALSE, &event_mask);
470	/* Do the scan before forking, so that boot scripts see the finished product */
471	dir_operation(SERVICE, mount_point, 0, NULL);
472
473	if (ENABLE_DEVFSD_FG_NP && no_polling)
474	exit(EXIT_SUCCESS);
475
476	if (ENABLE_DEVFSD_VERBOSE || ENABLE_DEBUG)
477	logmode = LOGMODE_BOTH;
478	else if (do_daemon == TRUE)
479	logmode = LOGMODE_SYSLOG;
480	/* This is the default */
481	/*else
482	logmode = LOGMODE_STDIO; */
483
484	if (do_daemon) {
485	/* Release so that the child can grab it */
486	xioctl(fd, DEVFSDIOC_RELEASE_EVENT_QUEUE, 0);
487	bb_daemonize_or_rexec(0, argv);
488	} else if (ENABLE_DEVFSD_FG_NP) {
489	setpgid(0, 0); /* Become process group leader */
490	}
491
492	while (TRUE) {
493	do_scan = do_servicing(fd, event_mask);
494
495	free_config();
496	read_config_file((char*)CONFIG_FILE, FALSE, &event_mask);
497	if (do_scan)
498	dir_operation(SERVICE, mount_point, 0, NULL);
499	}
500	if (ENABLE_FEATURE_CLEAN_UP) free(mount_point);
501	} /* End Function main */
502
503
504	/* Private functions follow */
505
506	static void read_config_file(char *path, int optional, unsigned long *event_mask)
507	/* [SUMMARY] Read a configuration database.
508	<path> The path to read the database from. If this is a directory, all
509	entries in that directory will be read(except hidden entries).
510	<optional> If TRUE, the routine will silently ignore a missing config file.
511	<event_mask> The event mask is written here. This is not initialised.
512	[RETURNS] Nothing.
513	*/
514	{
515	struct stat statbuf;
516	FILE *fp;
517	char buf[STRING_LENGTH];
518	char *line = NULL;
519	char *p;
520
521	if (stat(path, &statbuf) == 0) {
522	/* Don't read 0 length files: ignored */
523	/*if (statbuf.st_size == 0)
524	return;*/
525	if (S_ISDIR(statbuf.st_mode)) {
526	p = bb_simplify_path(path);
527	dir_operation(READ_CONFIG, p, 0, event_mask);
528	free(p);
529	return;
530	}
531	fp = fopen_for_read(path);
532	if (fp != NULL) {
533	while (fgets(buf, STRING_LENGTH, fp) != NULL) {
534	/* Skip whitespace */
535	line = buf;
536	line = skip_whitespace(line);
537	if (line[0] == '\0' || line[0] == '#')
538	continue;
539	process_config_line(line, event_mask);
540	}
541	fclose(fp);
542	} else {
543	goto read_config_file_err;
544	}
545	} else {
546	read_config_file_err:
547	if (optional == 0 && errno == ENOENT)
548	error_logger_and_die(LOG_ERR, "read config file: %s", path);
549	}
550	} /* End Function read_config_file */
551
552	static void process_config_line(const char *line, unsigned long *event_mask)
553	/* [SUMMARY] Process a line from a configuration file.
554	<line> The configuration line.
555	<event_mask> The event mask is written here. This is not initialised.
556	[RETURNS] Nothing.
557	*/
558	{
559	int num_args, count;
560	struct config_entry_struct *new;
561	char p[MAX_ARGS][STRING_LENGTH];
562	char when[STRING_LENGTH], what[STRING_LENGTH];
563	char name[STRING_LENGTH];
564	const char *msg = "";
565	char *ptr;
566	int i;
567
568	/* !!!! Only Uppercase Keywords in devsfd.conf */
569	static const char options[] ALIGN1 =
570	"CLEAR_CONFIG\0""INCLUDE\0""OPTIONAL_INCLUDE\0"
571	"RESTORE\0""PERMISSIONS\0""MODLOAD\0""EXECUTE\0"
572	"COPY\0""IGNORE\0""MKOLDCOMPAT\0""MKNEWCOMPAT\0"
573	"RMOLDCOMPAT\0""RMNEWCOMPAT\0";
574
575	for (count = 0; count < MAX_ARGS; ++count)
576	p[count][0] = '\0';
577	num_args = sscanf(line, "%s %s %s %s %s %s %s %s %s %s",
578	when, name, what,
579	p[0], p[1], p[2], p[3], p[4], p[5], p[6]);
580
581	i = index_in_strings(options, when);
582
583	/* "CLEAR_CONFIG" */
584	if (i == 0) {
585	free_config();
586	*event_mask = 0;
587	return;
588	}
589
590	if (num_args < 2)
591	goto process_config_line_err;
592
593	/* "INCLUDE" & "OPTIONAL_INCLUDE" */
594	if (i == 1 || i == 2) {
595	st_expr_expand(name, STRING_LENGTH, name, get_variable, NULL);
596	info_logger(LOG_INFO, "%sinclude: %s", (toupper(when[0]) == 'I') ? "": "optional_", name);
597	read_config_file(name, (toupper(when[0]) == 'I') ? FALSE : TRUE, event_mask);
598	return;
599	}
600	/* "RESTORE" */
601	if (i == 3) {
602	dir_operation(RESTORE, name, strlen(name),NULL);
603	return;
604	}
605	if (num_args < 3)
606	goto process_config_line_err;
607
608	new = xzalloc(sizeof *new);
609
610	for (count = 0; event_types[count].config_name != NULL; ++count) {
611	if (strcasecmp(when, event_types[count].config_name) != 0)
612	continue;
613	new->action.when = event_types[count].type;
614	break;
615	}
616	if (event_types[count].config_name == NULL) {
617	msg = "WHEN in";
618	goto process_config_line_err;
619	}
620
621	i = index_in_strings(options, what);
622
623	switch (i) {
624	case 4: /* "PERMISSIONS" */
625	new->action.what = AC_PERMISSIONS;
626	/* Get user and group */
627	ptr = strchr(p[0], '.');
628	if (ptr == NULL) {
629	msg = "UID.GID";
630	goto process_config_line_err; /*"missing '.' in UID.GID"*/
631	}
632
633	*ptr++ = '\0';
634	new->u.permissions.uid = get_uid_gid(UID, p[0]);
635	new->u.permissions.gid = get_uid_gid(GID, ptr);
636	/* Get mode */
637	new->u.permissions.mode = get_mode(p[1]);
638	break;
639	case 5: /* MODLOAD */
640	/*This action will pass "/dev/$devname"(i.e. "/dev/" prefixed to
641	the device name) to the module loading facility. In addition,
642	the /etc/modules.devfs configuration file is used.*/
643	if (ENABLE_DEVFSD_MODLOAD)
644	new->action.what = AC_MODLOAD;
645	break;
646	case 6: /* EXECUTE */
647	new->action.what = AC_EXECUTE;
648	num_args -= 3;
649
650	for (count = 0; count < num_args; ++count)
651	new->u.execute.argv[count] = xstrdup(p[count]);
652
653	new->u.execute.argv[num_args] = NULL;
654	break;
655	case 7: /* COPY */
656	new->action.what = AC_COPY;
657	num_args -= 3;
658	if (num_args != 2)
659	goto process_config_line_err; /* missing path and function in line */
660
661	new->u.copy.source = xstrdup(p[0]);
662	new->u.copy.destination = xstrdup(p[1]);
663	break;
664	case 8: /* IGNORE */
665	/* FALLTROUGH */
666	case 9: /* MKOLDCOMPAT */
667	/* FALLTROUGH */
668	case 10: /* MKNEWCOMPAT */
669	/* FALLTROUGH */
670	case 11:/* RMOLDCOMPAT */
671	/* FALLTROUGH */
672	case 12: /* RMNEWCOMPAT */
673	/* AC_IGNORE 6
674	AC_MKOLDCOMPAT 7
675	AC_MKNEWCOMPAT 8
676	AC_RMOLDCOMPAT 9
677	AC_RMNEWCOMPAT 10*/
678	new->action.what = i - 2;
679	break;
680	default:
681	msg = "WHAT in";
682	goto process_config_line_err;
683	/*esac*/
684	} /* switch (i) */
685
686	xregcomp(&new->preg, name, REG_EXTENDED);
687
688	*event_mask |= 1 << new->action.when;
689	new->next = NULL;
690	if (first_config == NULL)
691	first_config = new;
692	else
693	last_config->next = new;
694	last_config = new;
695	return;
696
697	process_config_line_err:
698	msg_logger_and_die(LOG_ERR, bb_msg_bad_config, msg , line);
699	} /* End Function process_config_line */
700
701	static int do_servicing(int fd, unsigned long event_mask)
702	/* [SUMMARY] Service devfs changes until a signal is received.
703	<fd> The open control file.
704	<event_mask> The event mask.
705	[RETURNS] TRUE if SIGHUP was caught, else FALSE.
706	*/
707	{
708	ssize_t bytes;
709	struct devfsd_notify_struct info;
710
711	/* (void*) cast is only in order to match prototype */
712	xioctl(fd, DEVFSDIOC_SET_EVENT_MASK, (void*)event_mask);
713	while (!caught_signal) {
714	errno = 0;
715	bytes = read(fd, (char *) &info, sizeof info);
716	if (caught_signal)
717	break; /* Must test for this first */
718	if (errno == EINTR)
719	continue; /* Yes, the order is important */
720	if (bytes < 1)
721	break;
722	service_name(&info);
723	}
724	if (caught_signal) {
725	int c_sighup = caught_sighup;
726
727	caught_signal = FALSE;
728	caught_sighup = FALSE;
729	return c_sighup;
730	}
731	msg_logger_and_die(LOG_ERR, "read error on control file");
732	} /* End Function do_servicing */
733
734	static void service_name(const struct devfsd_notify_struct *info)
735	/* [SUMMARY] Service a single devfs change.
736	<info> The devfs change.
737	[RETURNS] Nothing.
738	*/
739	{
740	unsigned int n;
741	regmatch_t mbuf[MAX_SUBEXPR];
742	struct config_entry_struct *entry;
743
744	if (ENABLE_DEBUG && info->overrun_count > 0)
745	msg_logger(LOG_ERR, "lost %u events", info->overrun_count);
746
747	/* Discard lookups on "/dev/log" and "/dev/initctl" */
748	if (info->type == DEVFSD_NOTIFY_LOOKUP
749	&& ((info->devname[0] == 'l' && info->devname[1] == 'o'
750	&& info->devname[2] == 'g' && !info->devname[3])
751	|| (info->devname[0] == 'i' && info->devname[1] == 'n'
752	&& info->devname[2] == 'i' && info->devname[3] == 't'
753	&& info->devname[4] == 'c' && info->devname[5] == 't'
754	&& info->devname[6] == 'l' && !info->devname[7]))
755	)
756	return;
757
758	for (entry = first_config; entry != NULL; entry = entry->next) {
759	/* First check if action matches the type, then check if name matches */
760	if (info->type != entry->action.when
761	|| regexec(&entry->preg, info->devname, MAX_SUBEXPR, mbuf, 0) != 0)
762	continue;
763	for (n = 0;(n < MAX_SUBEXPR) && (mbuf[n].rm_so != -1); ++n)
764	/* VOID */;
765
766	switch (entry->action.what) {
767	case AC_PERMISSIONS:
768	action_permissions(info, entry);
769	break;
770	case AC_MODLOAD:
771	if (ENABLE_DEVFSD_MODLOAD)
772	action_modload(info, entry);
773	break;
774	case AC_EXECUTE:
775	action_execute(info, entry, mbuf, n);
776	break;
777	case AC_COPY:
778	action_copy(info, entry, mbuf, n);
779	break;
780	case AC_IGNORE:
781	return;
782	/*break;*/
783	case AC_MKOLDCOMPAT:
784	case AC_MKNEWCOMPAT:
785	case AC_RMOLDCOMPAT:
786	case AC_RMNEWCOMPAT:
787	action_compat(info, entry->action.what);
788	break;
789	default:
790	msg_logger_and_die(LOG_ERR, "Unknown action");
791	}
792	}
793	} /* End Function service_name */
794
795	static void action_permissions(const struct devfsd_notify_struct *info,
796	const struct config_entry_struct *entry)
797	/* [SUMMARY] Update permissions for a device entry.
798	<info> The devfs change.
799	<entry> The config file entry.
800	[RETURNS] Nothing.
801	*/
802	{
803	struct stat statbuf;
804
805	if (stat(info->devname, &statbuf) != 0
806	|| chmod(info->devname, (statbuf.st_mode & S_IFMT) | (entry->u.permissions.mode & ~S_IFMT)) != 0
807	|| chown(info->devname, entry->u.permissions.uid, entry->u.permissions.gid) != 0
808	)
809	error_logger(LOG_ERR, "Can't chmod or chown: %s", info->devname);
810	} /* End Function action_permissions */
811
812	static void action_modload(const struct devfsd_notify_struct *info,
813	const struct config_entry_struct *entry UNUSED_PARAM)
814	/* [SUMMARY] Load a module.
815	<info> The devfs change.
816	<entry> The config file entry.
817	[RETURNS] Nothing.
818	*/
819	{
820	char *argv[6];
821
822	argv[0] = (char*)MODPROBE;
823	argv[1] = (char*)MODPROBE_SWITCH_1; /* "-k" */
824	argv[2] = (char*)MODPROBE_SWITCH_2; /* "-C" */
825	argv[3] = (char*)CONFIG_MODULES_DEVFS;
826	argv[4] = concat_path_file("/dev", info->devname); /* device */
827	argv[5] = NULL;
828
829	spawn_and_wait(argv);
830	free(argv[4]);
831	} /* End Function action_modload */
832
833	static void action_execute(const struct devfsd_notify_struct *info,
834	const struct config_entry_struct *entry,
835	const regmatch_t *regexpr, unsigned int numexpr)
836	/* [SUMMARY] Execute a programme.
837	<info> The devfs change.
838	<entry> The config file entry.
839	<regexpr> The number of subexpression(start, end) offsets within the
840	device name.
841	<numexpr> The number of elements within <<regexpr>>.
842	[RETURNS] Nothing.
843	*/
844	{
845	unsigned int count;
846	struct get_variable_info gv_info;
847	char *argv[MAX_ARGS + 1];
848	char largv[MAX_ARGS + 1][STRING_LENGTH];
849
850	gv_info.info = info;
851	gv_info.devname = info->devname;
852	snprintf(gv_info.devpath, sizeof(gv_info.devpath), "%s/%s", mount_point, info->devname);
853	for (count = 0; entry->u.execute.argv[count] != NULL; ++count) {
854	expand_expression(largv[count], STRING_LENGTH,
855	entry->u.execute.argv[count],
856	get_variable, &gv_info,
857	gv_info.devname, regexpr, numexpr);
858	argv[count] = largv[count];
859	}
860	argv[count] = NULL;
861	spawn_and_wait(argv);
862	} /* End Function action_execute */
863
864
865	static void action_copy(const struct devfsd_notify_struct *info,
866	const struct config_entry_struct *entry,
867	const regmatch_t *regexpr, unsigned int numexpr)
868	/* [SUMMARY] Copy permissions.
869	<info> The devfs change.
870	<entry> The config file entry.
871	<regexpr> This list of subexpression(start, end) offsets within the
872	device name.
873	<numexpr> The number of elements in <<regexpr>>.
874	[RETURNS] Nothing.
875	*/
876	{
877	mode_t new_mode;
878	struct get_variable_info gv_info;
879	struct stat source_stat, dest_stat;
880	char source[STRING_LENGTH], destination[STRING_LENGTH];
881	int ret = 0;
882
883	dest_stat.st_mode = 0;
884
885	if ((info->type == DEVFSD_NOTIFY_CHANGE) && S_ISLNK(info->mode))
886	return;
887	gv_info.info = info;
888	gv_info.devname = info->devname;
889
890	snprintf(gv_info.devpath, sizeof(gv_info.devpath), "%s/%s", mount_point, info->devname);
891	expand_expression(source, STRING_LENGTH, entry->u.copy.source,
892	get_variable, &gv_info, gv_info.devname,
893	regexpr, numexpr);
894
895	expand_expression(destination, STRING_LENGTH, entry->u.copy.destination,
896	get_variable, &gv_info, gv_info.devname,
897	regexpr, numexpr);
898
899	if (!make_dir_tree(destination) || lstat(source, &source_stat) != 0)
900	return;
901	lstat(destination, &dest_stat);
902	new_mode = source_stat.st_mode & ~S_ISVTX;
903	if (info->type == DEVFSD_NOTIFY_CREATE)
904	new_mode |= S_ISVTX;
905	else if ((info->type == DEVFSD_NOTIFY_CHANGE) &&(dest_stat.st_mode & S_ISVTX))
906	new_mode |= S_ISVTX;
907	ret = copy_inode(destination, &dest_stat, new_mode, source, &source_stat);
908	if (ENABLE_DEBUG && ret && (errno != EEXIST))
909	error_logger(LOG_ERR, "copy_inode: %s to %s", source, destination);
910	} /* End Function action_copy */
911
912	static void action_compat(const struct devfsd_notify_struct *info, unsigned int action)
913	/* [SUMMARY] Process a compatibility request.
914	<info> The devfs change.
915	<action> The action to take.
916	[RETURNS] Nothing.
917	*/
918	{
919	int ret;
920	const char *compat_name = NULL;
921	const char *dest_name = info->devname;
922	const char *ptr;
923	char compat_buf[STRING_LENGTH], dest_buf[STRING_LENGTH];
924	int mode, host, bus, target, lun;
925	unsigned int i;
926	char rewind_;
927	/* 1 to 5 "scsi/" , 6 to 9 "ide/host" */
928	static const char *const fmt[] = {
929	NULL ,
930	"sg/c%db%dt%du%d", /* scsi/generic */
931	"sd/c%db%dt%du%d", /* scsi/disc */
932	"sr/c%db%dt%du%d", /* scsi/cd */
933	"sd/c%db%dt%du%dp%d", /* scsi/part */
934	"st/c%db%dt%du%dm%d%c", /* scsi/mt */
935	"ide/hd/c%db%dt%du%d", /* ide/host/disc */
936	"ide/cd/c%db%dt%du%d", /* ide/host/cd */
937	"ide/hd/c%db%dt%du%dp%d", /* ide/host/part */
938	"ide/mt/c%db%dt%du%d%s", /* ide/host/mt */
939	NULL
940	};
941
942	/* First construct compatibility name */
943	switch (action) {
944	case AC_MKOLDCOMPAT:
945	case AC_RMOLDCOMPAT:
946	compat_name = get_old_name(info->devname, info->namelen, compat_buf, info->major, info->minor);
947	break;
948	case AC_MKNEWCOMPAT:
949	case AC_RMNEWCOMPAT:
950	ptr = bb_basename(info->devname);
951	i = scan_dev_name(info->devname, info->namelen, ptr);
952
953	/* nothing found */
954	if (i == 0 || i > 9)
955	return;
956
957	sscanf(info->devname + ((i < 6) ? 5 : 4), "host%d/bus%d/target%d/lun%d/", &host, &bus, &target, &lun);
958	snprintf(dest_buf, sizeof(dest_buf), "../%s", info->devname + (( i > 5) ? 4 : 0));
959	dest_name = dest_buf;
960	compat_name = compat_buf;
961
962
963	/* 1 == scsi/generic 2 == scsi/disc 3 == scsi/cd 6 == ide/host/disc 7 == ide/host/cd */
964	if (i == 1 || i == 2 || i == 3 || i == 6 || i ==7)
965	sprintf(compat_buf, fmt[i], host, bus, target, lun);
966
967	/* 4 == scsi/part 8 == ide/host/part */
968	if (i == 4 || i == 8)
969	sprintf(compat_buf, fmt[i], host, bus, target, lun, atoi(ptr + 4));
970
971	/* 5 == scsi/mt */
972	if (i == 5) {
973	rewind_ = info->devname[info->namelen - 1];
974	if (rewind_ != 'n')
975	rewind_ = '\0';
976	mode=0;
977	if (ptr[2] == 'l' /*108*/ || ptr[2] == 'm'/*109*/)
978	mode = ptr[2] - 107; /* 1 or 2 */
979	if (ptr[2] == 'a')
980	mode = 3;
981	sprintf(compat_buf, fmt[i], host, bus, target, lun, mode, rewind_);
982	}
983
984	/* 9 == ide/host/mt */
985	if (i == 9)
986	snprintf(compat_buf, sizeof(compat_buf), fmt[i], host, bus, target, lun, ptr + 2);
987	/* esac */
988	} /* switch (action) */
989
990	if (compat_name == NULL)
991	return;
992
993	/* Now decide what to do with it */
994	switch (action) {
995	case AC_MKOLDCOMPAT:
996	case AC_MKNEWCOMPAT:
997	mksymlink(dest_name, compat_name);
998	break;
999	case AC_RMOLDCOMPAT:
1000	case AC_RMNEWCOMPAT:
1001	ret = unlink(compat_name);
1002	if (ENABLE_DEBUG && ret)
1003	error_logger(LOG_ERR, "unlink: %s", compat_name);
1004	break;
1005	/*esac*/
1006	} /* switch (action) */
1007	} /* End Function action_compat */
1008
1009	static void restore(char *spath, struct stat source_stat, int rootlen)
1010	{
1011	char *dpath;
1012	struct stat dest_stat;
1013
1014	dest_stat.st_mode = 0;
1015	dpath = concat_path_file(mount_point, spath + rootlen);
1016	lstat(dpath, &dest_stat);
1017	free(dpath);
1018	if (S_ISLNK(source_stat.st_mode) || (source_stat.st_mode & S_ISVTX))
1019	copy_inode(dpath, &dest_stat, (source_stat.st_mode & ~S_ISVTX), spath, &source_stat);
1020
1021	if (S_ISDIR(source_stat.st_mode))
1022	dir_operation(RESTORE, spath, rootlen, NULL);
1023	}
1024
1025
1026	static int copy_inode(const char *destpath, const struct stat *dest_stat,
1027	mode_t new_mode,
1028	const char *sourcepath, const struct stat *source_stat)
1029	/* [SUMMARY] Copy an inode.
1030	<destpath> The destination path. An existing inode may be deleted.
1031	<dest_stat> The destination stat(2) information.
1032	<new_mode> The desired new mode for the destination.
1033	<sourcepath> The source path.
1034	<source_stat> The source stat(2) information.
1035	[RETURNS] TRUE on success, else FALSE.
1036	*/
1037	{
1038	int source_len, dest_len;
1039	char source_link[STRING_LENGTH], dest_link[STRING_LENGTH];
1040	int fd, val;
1041	struct sockaddr_un un_addr;
1042	char symlink_val[STRING_LENGTH];
1043
1044	if ((source_stat->st_mode & S_IFMT) ==(dest_stat->st_mode & S_IFMT)) {
1045	/* Same type */
1046	if (S_ISLNK(source_stat->st_mode)) {
1047	source_len = readlink(sourcepath, source_link, STRING_LENGTH - 1);
1048	if ((source_len < 0)
1049	|| (dest_len = readlink(destpath, dest_link, STRING_LENGTH - 1)) < 0
1050	)
1051	return FALSE;
1052	source_link[source_len] = '\0';
1053	dest_link[dest_len] = '\0';
1054	if ((source_len != dest_len) || (strcmp(source_link, dest_link) != 0)) {
1055	unlink(destpath);
1056	symlink(source_link, destpath);
1057	}
1058	return TRUE;
1059	} /* Else not a symlink */
1060	chmod(destpath, new_mode & ~S_IFMT);
1061	chown(destpath, source_stat->st_uid, source_stat->st_gid);
1062	return TRUE;
1063	}
1064	/* Different types: unlink and create */
1065	unlink(destpath);
1066	switch (source_stat->st_mode & S_IFMT) {
1067	case S_IFSOCK:
1068	fd = socket(AF_UNIX, SOCK_STREAM, 0);
1069	if (fd < 0)
1070	break;
1071	un_addr.sun_family = AF_UNIX;
1072	snprintf(un_addr.sun_path, sizeof(un_addr.sun_path), "%s", destpath);
1073	val = bind(fd, (struct sockaddr *) &un_addr, (int) sizeof un_addr);
1074	close(fd);
1075	if (val != 0 || chmod(destpath, new_mode & ~S_IFMT) != 0)
1076	break;
1077	goto do_chown;
1078	case S_IFLNK:
1079	val = readlink(sourcepath, symlink_val, STRING_LENGTH - 1);
1080	if (val < 0)
1081	break;
1082	symlink_val[val] = '\0';
1083	if (symlink(symlink_val, destpath) == 0)
1084	return TRUE;
1085	break;
1086	case S_IFREG:
1087	fd = open(destpath, O_RDONLY | O_CREAT, new_mode & ~S_IFMT);
1088	if (fd < 0)
1089	break;
1090	close(fd);
1091	if (chmod(destpath, new_mode & ~S_IFMT) != 0)
1092	break;
1093	goto do_chown;
1094	case S_IFBLK:
1095	case S_IFCHR:
1096	case S_IFIFO:
1097	if (mknod(destpath, new_mode, source_stat->st_rdev) != 0)
1098	break;
1099	goto do_chown;
1100	case S_IFDIR:
1101	if (mkdir(destpath, new_mode & ~S_IFMT) != 0)
1102	break;
1103	do_chown:
1104	if (chown(destpath, source_stat->st_uid, source_stat->st_gid) == 0)
1105	return TRUE;
1106	/*break;*/
1107	}
1108	return FALSE;
1109	} /* End Function copy_inode */
1110
1111	static void free_config(void)
1112	/* [SUMMARY] Free the configuration information.
1113	[RETURNS] Nothing.
1114	*/
1115	{
1116	struct config_entry_struct *c_entry;
1117	void *next;
1118
1119	for (c_entry = first_config; c_entry != NULL; c_entry = next) {
1120	unsigned int count;
1121
1122	next = c_entry->next;
1123	regfree(&c_entry->preg);
1124	if (c_entry->action.what == AC_EXECUTE) {
1125	for (count = 0; count < MAX_ARGS; ++count) {
1126	if (c_entry->u.execute.argv[count] == NULL)
1127	break;
1128	free(c_entry->u.execute.argv[count]);
1129	}
1130	}
1131	free(c_entry);
1132	}
1133	first_config = NULL;
1134	last_config = NULL;
1135	} /* End Function free_config */
1136
1137	static int get_uid_gid(int flag, const char *string)
1138	/* [SUMMARY] Convert a string to a UID or GID value.
1139	<flag> "UID" or "GID".
1140	<string> The string.
1141	[RETURNS] The UID or GID value.
1142	*/
1143	{
1144	struct passwd *pw_ent;
1145	struct group *grp_ent;
1146	const char *msg;
1147
1148	if (isdigit(string[0]) || ((string[0] == '-') && isdigit(string[1])))
1149	return atoi(string);
1150
1151	if (flag == UID && (pw_ent = getpwnam(string)) != NULL)
1152	return pw_ent->pw_uid;
1153
1154	if (ENABLE_DEVFSD_VERBOSE)
1155	msg = "user";
1156
1157	if (flag == GID) {
1158	if ((grp_ent = getgrnam(string)) != NULL)
1159	return grp_ent->gr_gid;
1160	if (ENABLE_DEVFSD_VERBOSE)
1161	msg = "group";
1162	}
1163
1164	if (ENABLE_DEVFSD_VERBOSE)
1165	msg_logger(LOG_ERR, "unknown %s: %s, defaulting to %cid=0", msg, string, msg[0]);
1166	return 0;
1167	}/* End Function get_uid_gid */
1168
1169	static mode_t get_mode(const char *string)
1170	/* [SUMMARY] Convert a string to a mode value.
1171	<string> The string.
1172	[RETURNS] The mode value.
1173	*/
1174	{
1175	mode_t mode;
1176	int i;
1177
1178	if (isdigit(string[0]))
1179	return strtoul(string, NULL, 8);
1180	if (strlen(string) != 9)
1181	msg_logger_and_die(LOG_ERR, "bad mode: %s", string);
1182
1183	mode = 0;
1184	i = S_IRUSR;
1185	while (i > 0) {
1186	if (string[0] == 'r' || string[0] == 'w' || string[0] == 'x')
1187	mode += i;
1188	i = i / 2;
1189	string++;
1190	}
1191	return mode;
1192	} /* End Function get_mode */
1193
1194	static void signal_handler(int sig)
1195	{
1196	caught_signal = TRUE;
1197	if (sig == SIGHUP)
1198	caught_sighup = TRUE;
1199
1200	info_logger(LOG_INFO, "Caught signal %d", sig);
1201	} /* End Function signal_handler */
1202
1203	static const char *get_variable(const char *variable, void *info)
1204	{
1205	static char *hostname;
1206
1207	struct get_variable_info *gv_info = info;
1208	const char *field_names[] = {
1209	"hostname", "mntpt", "devpath", "devname", "uid", "gid", "mode",
1210	NULL, mount_point, gv_info->devpath, gv_info->devname, NULL
1211	};
1212	int i;
1213
1214	if (!hostname)
1215	hostname = safe_gethostname();
1216	field_names[7] = hostname;
1217
1218	/* index_in_str_array returns i>=0 */
1219	i = index_in_str_array(field_names, variable);
1220
1221	if (i > 6 || i < 0 || (i > 1 && gv_info == NULL))
1222	return NULL;
1223	if (i >= 0 && i <= 3)
1224	return field_names[i + 7];
1225
1226	if (i == 4)
1227	return auto_string(xasprintf("%u", gv_info->info->uid));
1228	if (i == 5)
1229	return auto_string(xasprintf("%u", gv_info->info->gid));
1230	/* i == 6 */
1231	return auto_string(xasprintf("%o", gv_info->info->mode));
1232	} /* End Function get_variable */
1233
1234	static void service(struct stat statbuf, char *path)
1235	{
1236	struct devfsd_notify_struct info;
1237
1238	memset(&info, 0, sizeof info);
1239	info.type = DEVFSD_NOTIFY_REGISTERED;
1240	info.mode = statbuf.st_mode;
1241	info.major = major(statbuf.st_rdev);
1242	info.minor = minor(statbuf.st_rdev);
1243	info.uid = statbuf.st_uid;
1244	info.gid = statbuf.st_gid;
1245	snprintf(info.devname, sizeof(info.devname), "%s", path + strlen(mount_point) + 1);
1246	info.namelen = strlen(info.devname);
1247	service_name(&info);
1248	if (S_ISDIR(statbuf.st_mode))
1249	dir_operation(SERVICE, path, 0, NULL);
1250	}
1251
1252	static void dir_operation(int type, const char * dir_name, int var, unsigned long *event_mask)
1253	/* [SUMMARY] Scan a directory tree and generate register events on leaf nodes.
1254	<flag> To choose which function to perform
1255	<dp> The directory pointer. This is closed upon completion.
1256	<dir_name> The name of the directory.
1257	<rootlen> string length parameter.
1258	[RETURNS] Nothing.
1259	*/
1260	{
1261	struct stat statbuf;
1262	DIR *dp;
1263	struct dirent *de;
1264	char *path;
1265
1266	dp = warn_opendir(dir_name);
1267	if (dp == NULL)
1268	return;
1269
1270	while ((de = readdir(dp)) != NULL) {
1271
1272	if (de->d_name && DOT_OR_DOTDOT(de->d_name))
1273	continue;
1274	path = concat_path_file(dir_name, de->d_name);
1275	if (lstat(path, &statbuf) == 0) {
1276	switch (type) {
1277	case SERVICE:
1278	service(statbuf, path);
1279	break;
1280	case RESTORE:
1281	restore(path, statbuf, var);
1282	break;
1283	case READ_CONFIG:
1284	read_config_file(path, var, event_mask);
1285	break;
1286	}
1287	}
1288	free(path);
1289	}
1290	closedir(dp);
1291	} /* End Function do_scan_and_service */
1292
1293	static int mksymlink(const char *oldpath, const char *newpath)
1294	/* [SUMMARY] Create a symlink, creating intervening directories as required.
1295	<oldpath> The string contained in the symlink.
1296	<newpath> The name of the new symlink.
1297	[RETURNS] 0 on success, else -1.
1298	*/
1299	{
1300	if (!make_dir_tree(newpath))
1301	return -1;
1302
1303	if (symlink(oldpath, newpath) != 0) {
1304	if (errno != EEXIST)
1305	return -1;
1306	}
1307	return 0;
1308	} /* End Function mksymlink */
1309
1310
1311	static int make_dir_tree(const char *path)
1312	/* [SUMMARY] Creating intervening directories for a path as required.
1313	<path> The full pathname(including the leaf node).
1314	[RETURNS] TRUE on success, else FALSE.
1315	*/
1316	{
1317	if (bb_make_directory(dirname((char *)path), -1, FILEUTILS_RECUR) == -1)
1318	return FALSE;
1319	return TRUE;
1320	} /* End Function make_dir_tree */
1321
1322	static int expand_expression(char *output, unsigned int outsize,
1323	const char *input,
1324	const char *(*get_variable_func)(const char *variable, void *info),
1325	void *info,
1326	const char *devname,
1327	const regmatch_t *ex, unsigned int numexp)
1328	/* [SUMMARY] Expand environment variables and regular subexpressions in string.
1329	<output> The output expanded expression is written here.
1330	<length> The size of the output buffer.
1331	<input> The input expression. This may equal <<output>>.
1332	<get_variable> A function which will be used to get variable values. If
1333	this returns NULL, the environment is searched instead. If this is NULL,
1334	only the environment is searched.
1335	<info> An arbitrary pointer passed to <<get_variable>>.
1336	<devname> Device name; specifically, this is the string that contains all
1337	of the regular subexpressions.
1338	<ex> Array of start / end offsets into info->devname for each subexpression
1339	<numexp> Number of regular subexpressions found in <<devname>>.
1340	[RETURNS] TRUE on success, else FALSE.
1341	*/
1342	{
1343	char temp[STRING_LENGTH];
1344
1345	if (!st_expr_expand(temp, STRING_LENGTH, input, get_variable_func, info))
1346	return FALSE;
1347	expand_regexp(output, outsize, temp, devname, ex, numexp);
1348	return TRUE;
1349	} /* End Function expand_expression */
1350
1351	static void expand_regexp(char *output, size_t outsize, const char *input,
1352	const char *devname,
1353	const regmatch_t *ex, unsigned int numex)
1354	/* [SUMMARY] Expand all occurrences of the regular subexpressions \0 to \9.
1355	<output> The output expanded expression is written here.
1356	<outsize> The size of the output buffer.
1357	<input> The input expression. This may NOT equal <<output>>, because
1358	supporting that would require yet another string-copy. However, it's not
1359	hard to write a simple wrapper function to add this functionality for those
1360	few cases that need it.
1361	<devname> Device name; specifically, this is the string that contains all
1362	of the regular subexpressions.
1363	<ex> An array of start and end offsets into <<devname>>, one for each
1364	subexpression
1365	<numex> Number of subexpressions in the offset-array <<ex>>.
1366	[RETURNS] Nothing.
1367	*/
1368	{
1369	const char last_exp = '0' - 1 + numex;
1370	int c = -1;
1371
1372	/* Guarantee NULL termination by writing an explicit '\0' character into
1373	the very last byte */
1374	if (outsize)
1375	output[--outsize] = '\0';
1376	/* Copy the input string into the output buffer, replacing '\\' with '\'
1377	and '\0' .. '\9' with subexpressions 0 .. 9, if they exist. Other \x
1378	codes are deleted */
1379	while ((c != '\0') && (outsize != 0)) {
1380	c = *input;
1381	++input;
1382	if (c == '\\') {
1383	c = *input;
1384	++input;
1385	if (c != '\\') {
1386	if ((c >= '0') && (c <= last_exp)) {
1387	const regmatch_t *subexp = ex + (c - '0');
1388	unsigned int sublen = subexp->rm_eo - subexp->rm_so;
1389
1390	/* Range checking */
1391	if (sublen > outsize)
1392	sublen = outsize;
1393	strncpy(output, devname + subexp->rm_so, sublen);
1394	output += sublen;
1395	outsize -= sublen;
1396	}
1397	continue;
1398	}
1399	}
1400	*output = c;
1401	++output;
1402	--outsize;
1403	} /* while */
1404	} /* End Function expand_regexp */
1405
1406
1407	/* from compat_name.c */
1408
1409	struct translate_struct {
1410	const char *match; /* The string to match to(up to length) */
1411	const char *format; /* Format of output, "%s" takes data past match string,
1412	NULL is effectively "%s"(just more efficient) */
1413	};
1414
1415	static struct translate_struct translate_table[] =
1416	{
1417	{"sound/", NULL},
1418	{"printers/", "lp%s"},
1419	{"v4l/", NULL},
1420	{"parports/", "parport%s"},
1421	{"fb/", "fb%s"},
1422	{"netlink/", NULL},
1423	{"loop/", "loop%s"},
1424	{"floppy/", "fd%s"},
1425	{"rd/", "ram%s"},
1426	{"md/", "md%s"}, /* Meta-devices */
1427	{"vc/", "tty%s"},
1428	{"misc/", NULL},
1429	{"isdn/", NULL},
1430	{"pg/", "pg%s"}, /* Parallel port generic ATAPI interface*/
1431	{"i2c/", "i2c-%s"},
1432	{"staliomem/", "staliomem%s"}, /* Stallion serial driver control */
1433	{"tts/E", "ttyE%s"}, /* Stallion serial driver */
1434	{"cua/E", "cue%s"}, /* Stallion serial driver callout */
1435	{"tts/R", "ttyR%s"}, /* Rocketport serial driver */
1436	{"cua/R", "cur%s"}, /* Rocketport serial driver callout */
1437	{"ip2/", "ip2%s"}, /* Computone serial driver control */
1438	{"tts/F", "ttyF%s"}, /* Computone serial driver */
1439	{"cua/F", "cuf%s"}, /* Computone serial driver callout */
1440	{"tts/C", "ttyC%s"}, /* Cyclades serial driver */
1441	{"cua/C", "cub%s"}, /* Cyclades serial driver callout */
1442	{"tts/", "ttyS%s"}, /* Generic serial: must be after others */
1443	{"cua/", "cua%s"}, /* Generic serial: must be after others */
1444	{"input/js", "js%s"}, /* Joystick driver */
1445	{NULL, NULL}
1446	};
1447
1448	const char *get_old_name(const char *devname, unsigned int namelen,
1449	char *buffer, unsigned int major, unsigned int minor)
1450	/* [SUMMARY] Translate a kernel-supplied name into an old name.
1451	<devname> The device name provided by the kernel.
1452	<namelen> The length of the name.
1453	<buffer> A buffer that may be used. This should be at least 128 bytes long.
1454	<major> The major number for the device.
1455	<minor> The minor number for the device.
1456	[RETURNS] A pointer to the old name if known, else NULL.
1457	*/
1458	{
1459	const char *compat_name = NULL;
1460	const char *ptr;
1461	struct translate_struct *trans;
1462	unsigned int i;
1463	char mode;
1464	int indexx;
1465	const char *pty1;
1466	const char *pty2;
1467	/* 1 to 5 "scsi/" , 6 to 9 "ide/host", 10 sbp/, 11 vcc/, 12 pty/ */
1468	static const char *const fmt[] = {
1469	NULL ,
1470	"sg%u", /* scsi/generic */
1471	NULL, /* scsi/disc */
1472	"sr%u", /* scsi/cd */
1473	NULL, /* scsi/part */
1474	"nst%u%c", /* scsi/mt */
1475	"hd%c" , /* ide/host/disc */
1476	"hd%c" , /* ide/host/cd */
1477	"hd%c%s", /* ide/host/part */
1478	"%sht%d", /* ide/host/mt */
1479	"sbpcd%u", /* sbp/ */
1480	"vcs%s", /* vcc/ */
1481	"%cty%c%c", /* pty/ */
1482	NULL
1483	};
1484
1485	for (trans = translate_table; trans->match != NULL; ++trans) {
1486	char *after_match = is_prefixed_with(devname, trans->match);
1487	if (after_match) {
1488	if (trans->format == NULL)
1489	return after_match;
1490	sprintf(buffer, trans->format, after_match);
1491	return buffer;
1492	}
1493	}
1494
1495	ptr = bb_basename(devname);
1496	i = scan_dev_name(devname, namelen, ptr);
1497
1498	if (i > 0 && i < 13)
1499	compat_name = buffer;
1500	else
1501	return NULL;
1502
1503	/* 1 == scsi/generic, 3 == scsi/cd, 10 == sbp/ */
1504	if (i == 1 || i == 3 || i == 10)
1505	sprintf(buffer, fmt[i], minor);
1506
1507	/* 2 ==scsi/disc, 4 == scsi/part */
1508	if (i == 2 || i == 4)
1509	compat_name = write_old_sd_name(buffer, major, minor, ((i == 2) ? "" : (ptr + 4)));
1510
1511	/* 5 == scsi/mt */
1512	if (i == 5) {
1513	mode = ptr[2];
1514	if (mode == 'n')
1515	mode = '\0';
1516	sprintf(buffer, fmt[i], minor & 0x1f, mode);
1517	if (devname[namelen - 1] != 'n')
1518	++compat_name;
1519	}
1520	/* 6 == ide/host/disc, 7 == ide/host/cd, 8 == ide/host/part */
1521	if (i == 6 || i == 7 || i == 8)
1522	/* last arg should be ignored for i == 6 or i== 7 */
1523	sprintf(buffer, fmt[i] , get_old_ide_name(major, minor), ptr + 4);
1524
1525	/* 9 == ide/host/mt */
1526	if (i == 9)
1527	sprintf(buffer, fmt[i], ptr + 2, minor & 0x7f);
1528
1529	/* 11 == vcc/ */
1530	if (i == 11) {
1531	sprintf(buffer, fmt[i], devname + 4);
1532	if (buffer[3] == '0')
1533	buffer[3] = '\0';
1534	}
1535	/* 12 == pty/ */
1536	if (i == 12) {
1537	pty1 = "pqrstuvwxyzabcde";
1538	pty2 = "0123456789abcdef";
1539	indexx = atoi(devname + 5);
1540	sprintf(buffer, fmt[i], (devname[4] == 'm') ? 'p' : 't', pty1[indexx >> 4], pty2[indexx & 0x0f]);
1541	}
1542	return compat_name;
1543	} /* End Function get_old_name */
1544
1545	static char get_old_ide_name(unsigned int major, unsigned int minor)
1546	/* [SUMMARY] Get the old IDE name for a device.
1547	<major> The major number for the device.
1548	<minor> The minor number for the device.
1549	[RETURNS] The drive letter.
1550	*/
1551	{
1552	char letter = 'y'; /* 121 */
1553	char c = 'a'; /* 97 */
1554	int i = IDE0_MAJOR;
1555
1556	/* I hope it works like the previous code as it saves a few bytes. Tito ;P */
1557	do {
1558	if (i == IDE0_MAJOR || i == IDE1_MAJOR || i == IDE2_MAJOR
1559	|| i == IDE3_MAJOR || i == IDE4_MAJOR || i == IDE5_MAJOR
1560	|| i == IDE6_MAJOR || i == IDE7_MAJOR || i == IDE8_MAJOR
1561	|| i == IDE9_MAJOR
1562	) {
1563	if ((unsigned int)i == major) {
1564	letter = c;
1565	break;
1566	}
1567	c += 2;
1568	}
1569	i++;
1570	} while (i <= IDE9_MAJOR);
1571
1572	if (minor > 63)
1573	++letter;
1574	return letter;
1575	} /* End Function get_old_ide_name */
1576
1577	static char *write_old_sd_name(char *buffer,
1578	unsigned int major, unsigned int minor,
1579	const char *part)
1580	/* [SUMMARY] Write the old SCSI disc name to a buffer.
1581	<buffer> The buffer to write to.
1582	<major> The major number for the device.
1583	<minor> The minor number for the device.
1584	<part> The partition string. Must be "" for a whole-disc entry.
1585	[RETURNS] A pointer to the buffer on success, else NULL.
1586	*/
1587	{
1588	unsigned int disc_index;
1589
1590	if (major == 8) {
1591	sprintf(buffer, "sd%c%s", 'a' + (minor >> 4), part);
1592	return buffer;
1593	}
1594	if ((major > 64) && (major < 72)) {
1595	disc_index = ((major - 64) << 4) +(minor >> 4);
1596	if (disc_index < 26)
1597	sprintf(buffer, "sd%c%s", 'a' + disc_index, part);
1598	else
1599	sprintf(buffer, "sd%c%c%s", 'a' +(disc_index / 26) - 1, 'a' + disc_index % 26, part);
1600	return buffer;
1601	}
1602	return NULL;
1603	} /* End Function write_old_sd_name */
1604
1605
1606	/* expression.c */
1607
1608	/*EXPERIMENTAL_FUNCTION*/
1609
1610	int st_expr_expand(char *output, unsigned int length, const char *input,
1611	const char *(*get_variable_func)(const char *variable,
1612	void *info),
1613	void *info)
1614	/* [SUMMARY] Expand an expression using Borne Shell-like unquoted rules.
1615	<output> The output expanded expression is written here.
1616	<length> The size of the output buffer.
1617	<input> The input expression. This may equal <<output>>.
1618	<get_variable> A function which will be used to get variable values. If
1619	this returns NULL, the environment is searched instead. If this is NULL,
1620	only the environment is searched.
1621	<info> An arbitrary pointer passed to <<get_variable>>.
1622	[RETURNS] TRUE on success, else FALSE.
1623	*/
1624	{
1625	char ch;
1626	unsigned int len;
1627	unsigned int out_pos = 0;
1628	const char *env;
1629	const char *ptr;
1630	struct passwd *pwent;
1631	char buffer[BUFFER_SIZE], tmp[STRING_LENGTH];
1632
1633	if (length > BUFFER_SIZE)
1634	length = BUFFER_SIZE;
1635	for (; TRUE; ++input) {
1636	switch (ch = *input) {
1637	case '$':
1638	/* Variable expansion */
1639	input = expand_variable(buffer, length, &out_pos, ++input, get_variable_func, info);
1640	if (input == NULL)
1641	return FALSE;
1642	break;
1643	case '~':
1644	/* Home directory expansion */
1645	ch = input[1];
1646	if (isspace(ch) ||(ch == '/') ||(ch == '\0')) {
1647	/* User's own home directory: leave separator for next time */
1648	env = getenv("HOME");
1649	if (env == NULL) {
1650	info_logger(LOG_INFO, bb_msg_variable_not_found, "HOME");
1651	return FALSE;
1652	}
1653	len = strlen(env);
1654	if (len + out_pos >= length)
1655	goto st_expr_expand_out;
1656	memcpy(buffer + out_pos, env, len + 1);
1657	out_pos += len;
1658	continue;
1659	}
1660	/* Someone else's home directory */
1661	for (ptr = ++input; !isspace(ch) && (ch != '/') && (ch != '\0'); ch = *++ptr)
1662	/* VOID */;
1663	len = ptr - input;
1664	if (len >= sizeof tmp)
1665	goto st_expr_expand_out;
1666	safe_memcpy(tmp, input, len);
1667	input = ptr - 1;
1668	pwent = getpwnam(tmp);
1669	if (pwent == NULL) {
1670	info_logger(LOG_INFO, "no pwent for: %s", tmp);
1671	return FALSE;
1672	}
1673	len = strlen(pwent->pw_dir);
1674	if (len + out_pos >= length)
1675	goto st_expr_expand_out;
1676	memcpy(buffer + out_pos, pwent->pw_dir, len + 1);
1677	out_pos += len;
1678	break;
1679	case '\0':
1680	/* Falltrough */
1681	default:
1682	if (out_pos >= length)
1683	goto st_expr_expand_out;
1684	buffer[out_pos++] = ch;
1685	if (ch == '\0') {
1686	memcpy(output, buffer, out_pos);
1687	return TRUE;
1688	}
1689	break;
1690	/* esac */
1691	}
1692	}
1693	return FALSE;
1694	st_expr_expand_out:
1695	info_logger(LOG_INFO, bb_msg_small_buffer);
1696	return FALSE;
1697	} /* End Function st_expr_expand */
1698
1699
1700	/* Private functions follow */
1701
1702	static const char *expand_variable(char *buffer, unsigned int length,
1703	unsigned int *out_pos, const char *input,
1704	const char *(*func)(const char *variable,
1705	void *info),
1706	void *info)
1707	/* [SUMMARY] Expand a variable.
1708	<buffer> The buffer to write to.
1709	<length> The length of the output buffer.
1710	<out_pos> The current output position. This is updated.
1711	<input> A pointer to the input character pointer.
1712	<func> A function which will be used to get variable values. If this
1713	returns NULL, the environment is searched instead. If this is NULL, only
1714	the environment is searched.
1715	<info> An arbitrary pointer passed to <<func>>.
1716	<errfp> Diagnostic messages are written here.
1717	[RETURNS] A pointer to the end of this subexpression on success, else NULL.
1718	*/
1719	{
1720	char ch;
1721	int len;
1722	unsigned int open_braces;
1723	const char *env, *ptr;
1724	char tmp[STRING_LENGTH];
1725
1726	ch = input[0];
1727	if (ch == '$') {
1728	/* Special case for "$$": PID */
1729	sprintf(tmp, "%d", (int) getpid());
1730	len = strlen(tmp);
1731	if (len + *out_pos >= length)
1732	goto expand_variable_out;
1733
1734	memcpy(buffer + *out_pos, tmp, len + 1);
1735	out_pos += len;
1736	return input;
1737	}
1738	/* Ordinary variable expansion, possibly in braces */
1739	if (ch != '{') {
1740	/* Simple variable expansion */
1741	for (ptr = input; isalnum(ch) || (ch == '_') || (ch == ':'); ch = *++ptr)
1742	/* VOID */;
1743	len = ptr - input;
1744	if ((size_t)len >= sizeof tmp)
1745	goto expand_variable_out;
1746
1747	safe_memcpy(tmp, input, len);
1748	input = ptr - 1;
1749	env = get_variable_v2(tmp, func, info);
1750	if (env == NULL) {
1751	info_logger(LOG_INFO, bb_msg_variable_not_found, tmp);
1752	return NULL;
1753	}
1754	len = strlen(env);
1755	if (len + *out_pos >= length)
1756	goto expand_variable_out;
1757
1758	memcpy(buffer + *out_pos, env, len + 1);
1759	*out_pos += len;
1760	return input;
1761	}
1762	/* Variable in braces: check for ':' tricks */
1763	ch = *++input;
1764	for (ptr = input; isalnum(ch) || (ch == '_'); ch = *++ptr)
1765	/* VOID */;
1766	if (ch == '}') {
1767	/* Must be simple variable expansion with "${var}" */
1768	len = ptr - input;
1769	if ((size_t)len >= sizeof tmp)
1770	goto expand_variable_out;
1771
1772	safe_memcpy(tmp, input, len);
1773	ptr = expand_variable(buffer, length, out_pos, tmp, func, info);
1774	if (ptr == NULL)
1775	return NULL;
1776	return input + len;
1777	}
1778	if (ch != ':' || ptr[1] != '-') {
1779	info_logger(LOG_INFO, "illegal char in var name");
1780	return NULL;
1781	}
1782	/* It's that handy "${var:-word}" expression. Check if var is defined */
1783	len = ptr - input;
1784	if ((size_t)len >= sizeof tmp)
1785	goto expand_variable_out;
1786
1787	safe_memcpy(tmp, input, len);
1788	/* Move input pointer to ':' */
1789	input = ptr;
1790	/* First skip to closing brace, taking note of nested expressions */
1791	ptr += 2;
1792	ch = ptr[0];
1793	for (open_braces = 1; open_braces > 0; ch = *++ptr) {
1794	switch (ch) {
1795	case '{':
1796	++open_braces;
1797	break;
1798	case '}':
1799	--open_braces;
1800	break;
1801	case '\0':
1802	info_logger(LOG_INFO, "\"}\" not found in: %s", input);
1803	return NULL;
1804	default:
1805	break;
1806	}
1807	}
1808	--ptr;
1809	/* At this point ptr should point to closing brace of "${var:-word}" */
1810	env = get_variable_v2(tmp, func, info);
1811	if (env != NULL) {
1812	/* Found environment variable, so skip the input to the closing brace
1813	and return the variable */
1814	input = ptr;
1815	len = strlen(env);
1816	if (len + *out_pos >= length)
1817	goto expand_variable_out;
1818
1819	memcpy(buffer + *out_pos, env, len + 1);
1820	*out_pos += len;
1821	return input;
1822	}
1823	/* Environment variable was not found, so process word. Advance input
1824	pointer to start of word in "${var:-word}" */
1825	input += 2;
1826	len = ptr - input;
1827	if ((size_t)len >= sizeof tmp)
1828	goto expand_variable_out;
1829
1830	safe_memcpy(tmp, input, len);
1831	input = ptr;
1832	if (!st_expr_expand(tmp, STRING_LENGTH, tmp, func, info))
1833	return NULL;
1834	len = strlen(tmp);
1835	if (len + *out_pos >= length)
1836	goto expand_variable_out;
1837
1838	memcpy(buffer + *out_pos, tmp, len + 1);
1839	*out_pos += len;
1840	return input;
1841	expand_variable_out:
1842	info_logger(LOG_INFO, bb_msg_small_buffer);
1843	return NULL;
1844	} /* End Function expand_variable */
1845
1846
1847	static const char *get_variable_v2(const char *variable,
1848	const char *(*func)(const char *variable, void *info),
1849	void *info)
1850	/* [SUMMARY] Get a variable from the environment or .
1851	<variable> The variable name.
1852	<func> A function which will be used to get the variable. If this returns
1853	NULL, the environment is searched instead. If this is NULL, only the
1854	environment is searched.
1855	[RETURNS] The value of the variable on success, else NULL.
1856	*/
1857	{
1858	const char *value;
1859
1860	if (func != NULL) {
1861	value = (*func)(variable, info);
1862	if (value != NULL)
1863	return value;
1864	}
1865	return getenv(variable);
1866	} /* End Function get_variable */
1867
1868	/* END OF CODE */
1869