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 FEATURE_SYSLOG
60 //config: help
61 //config: This is deprecated and should NOT be used anymore.
62 //config: Use linux >= 2.6 (optionally with hotplug) and mdev instead!
63 //config: See docs/mdev.txt for detailed instructions on how to use mdev
64 //config: instead.
65 //config:
66 //config: Provides compatibility with old device names on a devfs systems.
67 //config: You should set it to true if you have devfs enabled.
68 //config: The following keywords in devsfd.conf are supported:
69 //config: "CLEAR_CONFIG", "INCLUDE", "OPTIONAL_INCLUDE", "RESTORE",
70 //config: "PERMISSIONS", "EXECUTE", "COPY", "IGNORE",
71 //config: "MKOLDCOMPAT", "MKNEWCOMPAT","RMOLDCOMPAT", "RMNEWCOMPAT".
72 //config:
73 //config: But only if they are written UPPERCASE!!!!!!!!
74 //config:
75 //config:config DEVFSD_MODLOAD
76 //config: bool "Adds support for MODLOAD keyword in devsfd.conf"
77 //config: default y
78 //config: depends on DEVFSD
79 //config: help
80 //config: This actually doesn't work with busybox modutils but needs
81 //config: the external modutils.
82 //config:
83 //config:config DEVFSD_FG_NP
84 //config: bool "Enable the -fg and -np options"
85 //config: default y
86 //config: depends on DEVFSD
87 //config: help
88 //config: -fg Run the daemon in the foreground.
89 //config: -np Exit after parsing config. Do not poll for events.
90 //config:
91 //config:config DEVFSD_VERBOSE
92 //config: bool "Increases logging (and size)"
93 //config: default y
94 //config: depends on DEVFSD
95 //config: help
96 //config: Increases logging to stderr or syslog.
97 //config:
98 //config:config FEATURE_DEVFS
99 //config: bool "Use devfs names for all devices (obsolete)"
100 //config: default n
101 //config: help
102 //config: This is obsolete and should NOT be used anymore.
103 //config: Use linux >= 2.6 (optionally with hotplug) and mdev instead!
104 //config:
105 //config: For legacy systems -- if there is no way around devfsd -- this
106 //config: tells busybox to look for names like /dev/loop/0 instead of
107 //config: /dev/loop0. If your /dev directory has normal names instead of
108 //config: devfs names, you don't want this.
109
110 //applet:IF_DEVFSD(APPLET(devfsd, BB_DIR_SBIN, BB_SUID_DROP))
111
112 //kbuild:lib-$(CONFIG_DEVFSD) += devfsd.o
113
114 //usage:#define devfsd_trivial_usage
115 //usage: "mntpnt [-v]" IF_DEVFSD_FG_NP("[-fg][-np]")
116 //usage:#define devfsd_full_usage "\n\n"
117 //usage: "Manage devfs permissions and old device name symlinks\n"
118 //usage: "\n mntpnt The mount point where devfs is mounted"
119 //usage: "\n -v Print the protocol version numbers for devfsd"
120 //usage: "\n and the kernel-side protocol version and exit"
121 //usage: IF_DEVFSD_FG_NP(
122 //usage: "\n -fg Run in foreground"
123 //usage: "\n -np Exit after parsing the configuration file"
124 //usage: "\n and processing synthetic REGISTER events,"
125 //usage: "\n don't poll for events"
126 //usage: )
127
128 #include "libbb.h"
129 #include "xregex.h"
130 #include <syslog.h>
131
132 #include <sys/un.h>
133 #include <sys/sysmacros.h>
134
135 /* Various defines taken from linux/major.h */
136 #define IDE0_MAJOR 3
137 #define IDE1_MAJOR 22
138 #define IDE2_MAJOR 33
139 #define IDE3_MAJOR 34
140 #define IDE4_MAJOR 56
141 #define IDE5_MAJOR 57
142 #define IDE6_MAJOR 88
143 #define IDE7_MAJOR 89
144 #define IDE8_MAJOR 90
145 #define IDE9_MAJOR 91
146
147
148 /* Various defines taken from linux/devfs_fs.h */
149 #define DEVFSD_PROTOCOL_REVISION_KERNEL 5
150 #define DEVFSD_IOCTL_BASE 'd'
151 /* These are the various ioctls */
152 #define DEVFSDIOC_GET_PROTO_REV _IOR(DEVFSD_IOCTL_BASE, 0, int)
153 #define DEVFSDIOC_SET_EVENT_MASK _IOW(DEVFSD_IOCTL_BASE, 2, int)
154 #define DEVFSDIOC_RELEASE_EVENT_QUEUE _IOW(DEVFSD_IOCTL_BASE, 3, int)
155 #define DEVFSDIOC_SET_CONFIG_DEBUG_MASK _IOW(DEVFSD_IOCTL_BASE, 4, int)
156 #define DEVFSD_NOTIFY_REGISTERED 0
157 #define DEVFSD_NOTIFY_UNREGISTERED 1
158 #define DEVFSD_NOTIFY_ASYNC_OPEN 2
159 #define DEVFSD_NOTIFY_CLOSE 3
160 #define DEVFSD_NOTIFY_LOOKUP 4
161 #define DEVFSD_NOTIFY_CHANGE 5
162 #define DEVFSD_NOTIFY_CREATE 6
163 #define DEVFSD_NOTIFY_DELETE 7
164 #define DEVFS_PATHLEN 1024
165 /* Never change this otherwise the binary interface will change */
166
167 struct devfsd_notify_struct {
168 /* Use native C types to ensure same types in kernel and user space */
169 unsigned int type; /* DEVFSD_NOTIFY_* value */
170 unsigned int mode; /* Mode of the inode or device entry */
171 unsigned int major; /* Major number of device entry */
172 unsigned int minor; /* Minor number of device entry */
173 unsigned int uid; /* Uid of process, inode or device entry */
174 unsigned int gid; /* Gid of process, inode or device entry */
175 unsigned int overrun_count; /* Number of lost events */
176 unsigned int namelen; /* Number of characters not including '\0' */
177 /* The device name MUST come last */
178 char devname[DEVFS_PATHLEN]; /* This will be '\0' terminated */
179 };
180
181 #define BUFFER_SIZE 16384
182 #define DEVFSD_VERSION "1.3.25"
183 #define CONFIG_FILE "/etc/devfsd.conf"
184 #define MODPROBE "/sbin/modprobe"
185 #define MODPROBE_SWITCH_1 "-k"
186 #define MODPROBE_SWITCH_2 "-C"
187 #define CONFIG_MODULES_DEVFS "/etc/modules.devfs"
188 #define MAX_ARGS (6 + 1)
189 #define MAX_SUBEXPR 10
190 #define STRING_LENGTH 255
191
192 /* for get_uid_gid() */
193 #define UID 0
194 #define GID 1
195
196 /* fork_and_execute() */
197 # define DIE 1
198 # define NO_DIE 0
199
200 /* for dir_operation() */
201 #define RESTORE 0
202 #define SERVICE 1
203 #define READ_CONFIG 2
204
205 /* Update only after changing code to reflect new protocol */
206 #define DEVFSD_PROTOCOL_REVISION_DAEMON 5
207
208 /* Compile-time check */
209 #if DEVFSD_PROTOCOL_REVISION_KERNEL != DEVFSD_PROTOCOL_REVISION_DAEMON
210 #error protocol version mismatch. Update your kernel headers
211 #endif
212
213 #define AC_PERMISSIONS 0
214 #define AC_MODLOAD 1
215 #define AC_EXECUTE 2
216 #define AC_MFUNCTION 3 /* not supported by busybox */
217 #define AC_CFUNCTION 4 /* not supported by busybox */
218 #define AC_COPY 5
219 #define AC_IGNORE 6
220 #define AC_MKOLDCOMPAT 7
221 #define AC_MKNEWCOMPAT 8
222 #define AC_RMOLDCOMPAT 9
223 #define AC_RMNEWCOMPAT 10
224 #define AC_RESTORE 11
225
226 struct permissions_type {
227 mode_t mode;
228 uid_t uid;
229 gid_t gid;
230 };
231
232 struct execute_type {
233 char *argv[MAX_ARGS + 1]; /* argv[0] must always be the programme */
234 };
235
236 struct copy_type {
237 const char *source;
238 const char *destination;
239 };
240
241 struct action_type {
242 unsigned int what;
243 unsigned int when;
244 };
245
246 struct config_entry_struct {
247 struct action_type action;
248 regex_t preg;
249 union
250 {
251 struct permissions_type permissions;
252 struct execute_type execute;
253 struct copy_type copy;
254 }
255 u;
256 struct config_entry_struct *next;
257 };
258
259 struct get_variable_info {
260 const struct devfsd_notify_struct *info;
261 const char *devname;
262 char devpath[STRING_LENGTH];
263 };
264
265 static void dir_operation(int , const char * , int, unsigned long*);
266 static void service(struct stat statbuf, char *path);
267 static int st_expr_expand(char *, unsigned, const char *, const char *(*)(const char *, void *), void *);
268 static const char *get_old_name(const char *, unsigned, char *, unsigned, unsigned);
269 static int mksymlink(const char *oldpath, const char *newpath);
270 static void read_config_file(char *path, int optional, unsigned long *event_mask);
271 static void process_config_line(const char *, unsigned long *);
272 static int do_servicing(int, unsigned long);
273 static void service_name(const struct devfsd_notify_struct *);
274 static void action_permissions(const struct devfsd_notify_struct *, const struct config_entry_struct *);
275 static void action_execute(const struct devfsd_notify_struct *, const struct config_entry_struct *,
276 const regmatch_t *, unsigned);
277 static void action_modload(const struct devfsd_notify_struct *info, const struct config_entry_struct *entry);
278 static void action_copy(const struct devfsd_notify_struct *, const struct config_entry_struct *,
279 const regmatch_t *, unsigned);
280 static void action_compat(const struct devfsd_notify_struct *, unsigned);
281 static void free_config(void);
282 static void restore(char *spath, struct stat source_stat, int rootlen);
283 static int copy_inode(const char *, const struct stat *, mode_t, const char *, const struct stat *);
284 static mode_t get_mode(const char *);
285 static void signal_handler(int);
286 static const char *get_variable(const char *, void *);
287 static int make_dir_tree(const char *);
288 static int expand_expression(char *, unsigned, const char *, const char *(*)(const char *, void *), void *,
289 const char *, const regmatch_t *, unsigned);
290 static void expand_regexp(char *, size_t, const char *, const char *, const regmatch_t *, unsigned);
291 static const char *expand_variable( char *, unsigned, unsigned *, const char *,
292 const char *(*)(const char *, void *), void *);
293 static const char *get_variable_v2(const char *, const char *(*)(const char *, void *), void *);
294 static char get_old_ide_name(unsigned, unsigned);
295 static char *write_old_sd_name(char *, unsigned, unsigned, const char *);
296
297 /* busybox functions */
298 static int get_uid_gid(int flag, const char *string);
299 static void safe_memcpy(char * dest, const char * src, int len);
300 static unsigned int scan_dev_name_common(const char *d, unsigned int n, int addendum, const char *ptr);
301 static unsigned int scan_dev_name(const char *d, unsigned int n, const char *ptr);
302
303 /* Structs and vars */
304 static struct config_entry_struct *first_config = NULL;
305 static struct config_entry_struct *last_config = NULL;
306 static char *mount_point = NULL;
307 static volatile int caught_signal = FALSE;
308 static volatile int caught_sighup = FALSE;
309 static struct initial_symlink_struct {
310 const char *dest;
311 const char *name;
312 } initial_symlinks[] = {
313 {"/proc/self/fd", "fd"},
314 {"fd/0", "stdin"},
315 {"fd/1", "stdout"},
316 {"fd/2", "stderr"},
317 {NULL, NULL},
318 };
319
320 static struct event_type {
321 unsigned int type; /* The DEVFSD_NOTIFY_* value */
322 const char *config_name; /* The name used in the config file */
323 } event_types[] = {
324 {DEVFSD_NOTIFY_REGISTERED, "REGISTER"},
325 {DEVFSD_NOTIFY_UNREGISTERED, "UNREGISTER"},
326 {DEVFSD_NOTIFY_ASYNC_OPEN, "ASYNC_OPEN"},
327 {DEVFSD_NOTIFY_CLOSE, "CLOSE"},
328 {DEVFSD_NOTIFY_LOOKUP, "LOOKUP"},
329 {DEVFSD_NOTIFY_CHANGE, "CHANGE"},
330 {DEVFSD_NOTIFY_CREATE, "CREATE"},
331 {DEVFSD_NOTIFY_DELETE, "DELETE"},
332 {0xffffffff, NULL}
333 };
334
335 /* Busybox messages */
336
337 static const char bb_msg_proto_rev[] ALIGN1 = "protocol revision";
338 static const char bb_msg_bad_config[] ALIGN1 = "bad %s config file: %s";
339 static const char bb_msg_small_buffer[] ALIGN1 = "buffer too small";
340 static const char bb_msg_variable_not_found[] ALIGN1 = "variable: %s not found";
341
342 /* Busybox stuff */
343 #if ENABLE_DEVFSD_VERBOSE || ENABLE_DEBUG
344 #define info_logger(p, fmt, args...) bb_info_msg(fmt, ## args)
345 #define simple_info_logger(p, msg) bb_simple_info_msg(msg)
346 #define msg_logger(p, fmt, args...) bb_error_msg(fmt, ## args)
347 #define simple_msg_logger(p, msg) bb_simple_error_msg(msg)
348 #define msg_logger_and_die(p, fmt, args...) bb_error_msg_and_die(fmt, ## args)
349 #define simple_msg_logger_and_die(p, msg) bb_simple_error_msg_and_die(msg)
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 simple_info_logger(p, msg)
355 #define msg_logger(p, fmt, args...)
356 #define simple_msg_logger(p, msg)
357 #define msg_logger_and_die(p, fmt, args...) exit(EXIT_FAILURE)
358 #define simple_msg_logger_and_die(p, msg) exit(EXIT_FAILURE)
359 #define error_logger(p, fmt, args...)
360 #define error_logger_and_die(p, fmt, args...) exit(EXIT_FAILURE)
361 #endif
362
safe_memcpy(char * dest,const char * src,int len)363 static void safe_memcpy(char *dest, const char *src, int len)
364 {
365 memcpy(dest, src, len);
366 dest[len] = '\0';
367 }
368
scan_dev_name_common(const char * d,unsigned int n,int addendum,const char * ptr)369 static unsigned int scan_dev_name_common(const char *d, unsigned int n, int addendum, const char *ptr)
370 {
371 if (d[n - 4] == 'd' && d[n - 3] == 'i' && d[n - 2] == 's' && d[n - 1] == 'c')
372 return 2 + addendum;
373 if (d[n - 2] == 'c' && d[n - 1] == 'd')
374 return 3 + addendum;
375 if (ptr[0] == 'p' && ptr[1] == 'a' && ptr[2] == 'r' && ptr[3] == 't')
376 return 4 + addendum;
377 if (ptr[n - 2] == 'm' && ptr[n - 1] == 't')
378 return 5 + addendum;
379 return 0;
380 }
381
scan_dev_name(const char * d,unsigned int n,const char * ptr)382 static unsigned int scan_dev_name(const char *d, unsigned int n, const char *ptr)
383 {
384 if (d[0] == 's' && d[1] == 'c' && d[2] == 's' && d[3] == 'i' && d[4] == '/') {
385 if (d[n - 7] == 'g' && d[n - 6] == 'e' && d[n - 5] == 'n'
386 && d[n - 4] == 'e' && d[n - 3] == 'r' && d[n - 2] == 'i' && d[n - 1] == 'c'
387 )
388 return 1;
389 return scan_dev_name_common(d, n, 0, ptr);
390 }
391 if (d[0] == 'i' && d[1] == 'd' && d[2] == 'e' && d[3] == '/'
392 && d[4] == 'h' && d[5] == 'o' && d[6] == 's' && d[7] == 't'
393 )
394 return scan_dev_name_common(d, n, 4, ptr);
395 if (d[0] == 's' && d[1] == 'b' && d[2] == 'p' && d[3] == '/')
396 return 10;
397 if (d[0] == 'v' && d[1] == 'c' && d[2] == 'c' && d[3] == '/')
398 return 11;
399 if (d[0] == 'p' && d[1] == 't' && d[2] == 'y' && d[3] == '/')
400 return 12;
401 return 0;
402 }
403
404 /* Public functions follow */
405
406 int devfsd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
devfsd_main(int argc,char ** argv)407 int devfsd_main(int argc, char **argv)
408 {
409 int print_version = FALSE;
410 int do_daemon = TRUE;
411 int no_polling = FALSE;
412 int do_scan;
413 int fd, proto_rev, count;
414 unsigned long event_mask = 0;
415 struct sigaction new_action;
416 struct initial_symlink_struct *curr;
417
418 if (argc < 2)
419 bb_show_usage();
420
421 for (count = 2; count < argc; ++count) {
422 if (argv[count][0] == '-') {
423 if (argv[count][1] == 'v' && !argv[count][2]) /* -v */
424 print_version = TRUE;
425 else if (ENABLE_DEVFSD_FG_NP && argv[count][1] == 'f'
426 && argv[count][2] == 'g' && !argv[count][3]) /* -fg */
427 do_daemon = FALSE;
428 else if (ENABLE_DEVFSD_FG_NP && argv[count][1] == 'n'
429 && argv[count][2] == 'p' && !argv[count][3]) /* -np */
430 no_polling = TRUE;
431 else
432 bb_show_usage();
433 }
434 }
435
436 mount_point = bb_simplify_path(argv[1]);
437
438 xchdir(mount_point);
439
440 fd = xopen(".devfsd", O_RDONLY);
441 close_on_exec_on(fd);
442 xioctl(fd, DEVFSDIOC_GET_PROTO_REV, &proto_rev);
443
444 /*setup initial entries */
445 for (curr = initial_symlinks; curr->dest != NULL; ++curr)
446 symlink(curr->dest, curr->name);
447
448 /* NB: The check for CONFIG_FILE is done in read_config_file() */
449
450 if (print_version || (DEVFSD_PROTOCOL_REVISION_DAEMON != proto_rev)) {
451 printf("%s v%s\nDaemon %s:\t%d\nKernel-side %s:\t%d\n",
452 applet_name, DEVFSD_VERSION, bb_msg_proto_rev,
453 DEVFSD_PROTOCOL_REVISION_DAEMON, bb_msg_proto_rev, proto_rev);
454 if (DEVFSD_PROTOCOL_REVISION_DAEMON != proto_rev)
455 bb_error_msg_and_die("%s mismatch!", bb_msg_proto_rev);
456 exit(EXIT_SUCCESS); /* -v */
457 }
458 /* Tell kernel we are special(i.e. we get to see hidden entries) */
459 xioctl(fd, DEVFSDIOC_SET_EVENT_MASK, 0);
460
461 /* Set up SIGHUP and SIGUSR1 handlers */
462 sigemptyset(&new_action.sa_mask);
463 new_action.sa_flags = 0;
464 new_action.sa_handler = signal_handler;
465 sigaction_set(SIGHUP, &new_action);
466 sigaction_set(SIGUSR1, &new_action);
467
468 printf("%s v%s started for %s\n", applet_name, DEVFSD_VERSION, mount_point);
469
470 /* Set umask so that mknod(2), open(2) and mkdir(2) have complete control over permissions */
471 umask(0);
472 read_config_file((char*)CONFIG_FILE, FALSE, &event_mask);
473 /* Do the scan before forking, so that boot scripts see the finished product */
474 dir_operation(SERVICE, mount_point, 0, NULL);
475
476 if (ENABLE_DEVFSD_FG_NP && no_polling)
477 exit(EXIT_SUCCESS);
478
479 if (ENABLE_DEVFSD_VERBOSE || ENABLE_DEBUG)
480 logmode = LOGMODE_BOTH;
481 else if (do_daemon == TRUE)
482 logmode = LOGMODE_SYSLOG;
483 /* This is the default */
484 /*else
485 logmode = LOGMODE_STDIO; */
486
487 if (do_daemon) {
488 /* Release so that the child can grab it */
489 xioctl(fd, DEVFSDIOC_RELEASE_EVENT_QUEUE, 0);
490 bb_daemonize_or_rexec(0, argv);
491 } else if (ENABLE_DEVFSD_FG_NP) {
492 setpgid(0, 0); /* Become process group leader */
493 }
494
495 while (TRUE) {
496 do_scan = do_servicing(fd, event_mask);
497
498 free_config();
499 read_config_file((char*)CONFIG_FILE, FALSE, &event_mask);
500 if (do_scan)
501 dir_operation(SERVICE, mount_point, 0, NULL);
502 }
503 if (ENABLE_FEATURE_CLEAN_UP) free(mount_point);
504 } /* End Function main */
505
506
507 /* Private functions follow */
508
read_config_file(char * path,int optional,unsigned long * event_mask)509 static void read_config_file(char *path, int optional, unsigned long *event_mask)
510 /* [SUMMARY] Read a configuration database.
511 <path> The path to read the database from. If this is a directory, all
512 entries in that directory will be read(except hidden entries).
513 <optional> If TRUE, the routine will silently ignore a missing config file.
514 <event_mask> The event mask is written here. This is not initialised.
515 [RETURNS] Nothing.
516 */
517 {
518 struct stat statbuf;
519 FILE *fp;
520 char buf[STRING_LENGTH];
521 char *line = NULL;
522 char *p;
523
524 if (stat(path, &statbuf) == 0) {
525 /* Don't read 0 length files: ignored */
526 /*if (statbuf.st_size == 0)
527 return;*/
528 if (S_ISDIR(statbuf.st_mode)) {
529 p = bb_simplify_path(path);
530 dir_operation(READ_CONFIG, p, 0, event_mask);
531 free(p);
532 return;
533 }
534 fp = fopen_for_read(path);
535 if (fp != NULL) {
536 while (fgets(buf, STRING_LENGTH, fp) != NULL) {
537 /* Skip whitespace */
538 line = buf;
539 line = skip_whitespace(line);
540 if (line[0] == '\0' || line[0] == '#')
541 continue;
542 process_config_line(line, event_mask);
543 }
544 fclose(fp);
545 } else {
546 goto read_config_file_err;
547 }
548 } else {
549 read_config_file_err:
550 if (optional == 0 && errno == ENOENT)
551 error_logger_and_die(LOG_ERR, "read config file: %s", path);
552 }
553 } /* End Function read_config_file */
554
process_config_line(const char * line,unsigned long * event_mask)555 static void process_config_line(const char *line, unsigned long *event_mask)
556 /* [SUMMARY] Process a line from a configuration file.
557 <line> The configuration line.
558 <event_mask> The event mask is written here. This is not initialised.
559 [RETURNS] Nothing.
560 */
561 {
562 int num_args, count;
563 struct config_entry_struct *new;
564 char p[MAX_ARGS][STRING_LENGTH];
565 char when[STRING_LENGTH], what[STRING_LENGTH];
566 char name[STRING_LENGTH];
567 const char *msg = "";
568 char *ptr;
569 int i;
570
571 /* !!!! Only Uppercase Keywords in devsfd.conf */
572 static const char options[] ALIGN1 =
573 "CLEAR_CONFIG\0""INCLUDE\0""OPTIONAL_INCLUDE\0"
574 "RESTORE\0""PERMISSIONS\0""MODLOAD\0""EXECUTE\0"
575 "COPY\0""IGNORE\0""MKOLDCOMPAT\0""MKNEWCOMPAT\0"
576 "RMOLDCOMPAT\0""RMNEWCOMPAT\0";
577
578 for (count = 0; count < MAX_ARGS; ++count)
579 p[count][0] = '\0';
580 num_args = sscanf(line, "%s %s %s %s %s %s %s %s %s %s",
581 when, name, what,
582 p[0], p[1], p[2], p[3], p[4], p[5], p[6]);
583
584 i = index_in_strings(options, when);
585
586 /* "CLEAR_CONFIG" */
587 if (i == 0) {
588 free_config();
589 *event_mask = 0;
590 return;
591 }
592
593 if (num_args < 2)
594 goto process_config_line_err;
595
596 /* "INCLUDE" & "OPTIONAL_INCLUDE" */
597 if (i == 1 || i == 2) {
598 st_expr_expand(name, STRING_LENGTH, name, get_variable, NULL);
599 info_logger(LOG_INFO, "%sinclude: %s", (toupper(when[0]) == 'I') ? "": "optional_", name);
600 read_config_file(name, (toupper(when[0]) == 'I') ? FALSE : TRUE, event_mask);
601 return;
602 }
603 /* "RESTORE" */
604 if (i == 3) {
605 dir_operation(RESTORE, name, strlen(name),NULL);
606 return;
607 }
608 if (num_args < 3)
609 goto process_config_line_err;
610
611 new = xzalloc(sizeof *new);
612
613 for (count = 0; event_types[count].config_name != NULL; ++count) {
614 if (strcasecmp(when, event_types[count].config_name) != 0)
615 continue;
616 new->action.when = event_types[count].type;
617 break;
618 }
619 if (event_types[count].config_name == NULL) {
620 msg = "WHEN in";
621 goto process_config_line_err;
622 }
623
624 i = index_in_strings(options, what);
625
626 switch (i) {
627 case 4: /* "PERMISSIONS" */
628 new->action.what = AC_PERMISSIONS;
629 /* Get user and group */
630 ptr = strchr(p[0], '.');
631 if (ptr == NULL) {
632 msg = "UID.GID";
633 goto process_config_line_err; /*"missing '.' in UID.GID"*/
634 }
635
636 *ptr++ = '\0';
637 new->u.permissions.uid = get_uid_gid(UID, p[0]);
638 new->u.permissions.gid = get_uid_gid(GID, ptr);
639 /* Get mode */
640 new->u.permissions.mode = get_mode(p[1]);
641 break;
642 case 5: /* MODLOAD */
643 /*This action will pass "/dev/$devname"(i.e. "/dev/" prefixed to
644 the device name) to the module loading facility. In addition,
645 the /etc/modules.devfs configuration file is used.*/
646 if (ENABLE_DEVFSD_MODLOAD)
647 new->action.what = AC_MODLOAD;
648 break;
649 case 6: /* EXECUTE */
650 new->action.what = AC_EXECUTE;
651 num_args -= 3;
652
653 for (count = 0; count < num_args; ++count)
654 new->u.execute.argv[count] = xstrdup(p[count]);
655
656 new->u.execute.argv[num_args] = NULL;
657 break;
658 case 7: /* COPY */
659 new->action.what = AC_COPY;
660 num_args -= 3;
661 if (num_args != 2)
662 goto process_config_line_err; /* missing path and function in line */
663
664 new->u.copy.source = xstrdup(p[0]);
665 new->u.copy.destination = xstrdup(p[1]);
666 break;
667 case 8: /* IGNORE */
668 /* FALLTROUGH */
669 case 9: /* MKOLDCOMPAT */
670 /* FALLTROUGH */
671 case 10: /* MKNEWCOMPAT */
672 /* FALLTROUGH */
673 case 11:/* RMOLDCOMPAT */
674 /* FALLTROUGH */
675 case 12: /* RMNEWCOMPAT */
676 /* AC_IGNORE 6
677 AC_MKOLDCOMPAT 7
678 AC_MKNEWCOMPAT 8
679 AC_RMOLDCOMPAT 9
680 AC_RMNEWCOMPAT 10*/
681 new->action.what = i - 2;
682 break;
683 default:
684 msg = "WHAT in";
685 goto process_config_line_err;
686 /*esac*/
687 } /* switch (i) */
688
689 xregcomp(&new->preg, name, REG_EXTENDED);
690
691 *event_mask |= 1 << new->action.when;
692 new->next = NULL;
693 if (first_config == NULL)
694 first_config = new;
695 else
696 last_config->next = new;
697 last_config = new;
698 return;
699
700 process_config_line_err:
701 msg_logger_and_die(LOG_ERR, bb_msg_bad_config, msg, line);
702 } /* End Function process_config_line */
703
do_servicing(int fd,unsigned long event_mask)704 static int do_servicing(int fd, unsigned long event_mask)
705 /* [SUMMARY] Service devfs changes until a signal is received.
706 <fd> The open control file.
707 <event_mask> The event mask.
708 [RETURNS] TRUE if SIGHUP was caught, else FALSE.
709 */
710 {
711 ssize_t bytes;
712 struct devfsd_notify_struct info;
713
714 /* (void*) cast is only in order to match prototype */
715 xioctl(fd, DEVFSDIOC_SET_EVENT_MASK, (void*)event_mask);
716 while (!caught_signal) {
717 errno = 0;
718 bytes = read(fd, (char *) &info, sizeof info);
719 if (caught_signal)
720 break; /* Must test for this first */
721 if (errno == EINTR)
722 continue; /* Yes, the order is important */
723 if (bytes < 1)
724 break;
725 service_name(&info);
726 }
727 if (caught_signal) {
728 int c_sighup = caught_sighup;
729
730 caught_signal = FALSE;
731 caught_sighup = FALSE;
732 return c_sighup;
733 }
734 simple_msg_logger_and_die(LOG_ERR, "read error on control file");
735 } /* End Function do_servicing */
736
service_name(const struct devfsd_notify_struct * info)737 static void service_name(const struct devfsd_notify_struct *info)
738 /* [SUMMARY] Service a single devfs change.
739 <info> The devfs change.
740 [RETURNS] Nothing.
741 */
742 {
743 unsigned int n;
744 regmatch_t mbuf[MAX_SUBEXPR];
745 struct config_entry_struct *entry;
746
747 if (ENABLE_DEBUG && info->overrun_count > 0)
748 msg_logger(LOG_ERR, "lost %u events", info->overrun_count);
749
750 /* Discard lookups on "/dev/log" and "/dev/initctl" */
751 if (info->type == DEVFSD_NOTIFY_LOOKUP
752 && ((info->devname[0] == 'l' && info->devname[1] == 'o'
753 && info->devname[2] == 'g' && !info->devname[3])
754 || (info->devname[0] == 'i' && info->devname[1] == 'n'
755 && info->devname[2] == 'i' && info->devname[3] == 't'
756 && info->devname[4] == 'c' && info->devname[5] == 't'
757 && info->devname[6] == 'l' && !info->devname[7]))
758 )
759 return;
760
761 for (entry = first_config; entry != NULL; entry = entry->next) {
762 /* First check if action matches the type, then check if name matches */
763 if (info->type != entry->action.when
764 || regexec(&entry->preg, info->devname, MAX_SUBEXPR, mbuf, 0) != 0)
765 continue;
766 for (n = 0;(n < MAX_SUBEXPR) && (mbuf[n].rm_so != -1); ++n)
767 /* VOID */;
768
769 switch (entry->action.what) {
770 case AC_PERMISSIONS:
771 action_permissions(info, entry);
772 break;
773 case AC_MODLOAD:
774 if (ENABLE_DEVFSD_MODLOAD)
775 action_modload(info, entry);
776 break;
777 case AC_EXECUTE:
778 action_execute(info, entry, mbuf, n);
779 break;
780 case AC_COPY:
781 action_copy(info, entry, mbuf, n);
782 break;
783 case AC_IGNORE:
784 return;
785 /*break;*/
786 case AC_MKOLDCOMPAT:
787 case AC_MKNEWCOMPAT:
788 case AC_RMOLDCOMPAT:
789 case AC_RMNEWCOMPAT:
790 action_compat(info, entry->action.what);
791 break;
792 default:
793 simple_msg_logger_and_die(LOG_ERR, "Unknown action");
794 }
795 }
796 } /* End Function service_name */
797
action_permissions(const struct devfsd_notify_struct * info,const struct config_entry_struct * entry)798 static void action_permissions(const struct devfsd_notify_struct *info,
799 const struct config_entry_struct *entry)
800 /* [SUMMARY] Update permissions for a device entry.
801 <info> The devfs change.
802 <entry> The config file entry.
803 [RETURNS] Nothing.
804 */
805 {
806 struct stat statbuf;
807
808 if (stat(info->devname, &statbuf) != 0
809 || chmod(info->devname, (statbuf.st_mode & S_IFMT) | (entry->u.permissions.mode & ~S_IFMT)) != 0
810 || chown(info->devname, entry->u.permissions.uid, entry->u.permissions.gid) != 0
811 )
812 error_logger(LOG_ERR, "Can't chmod or chown: %s", info->devname);
813 } /* End Function action_permissions */
814
action_modload(const struct devfsd_notify_struct * info,const struct config_entry_struct * entry UNUSED_PARAM)815 static void action_modload(const struct devfsd_notify_struct *info,
816 const struct config_entry_struct *entry UNUSED_PARAM)
817 /* [SUMMARY] Load a module.
818 <info> The devfs change.
819 <entry> The config file entry.
820 [RETURNS] Nothing.
821 */
822 {
823 char *argv[6];
824
825 argv[0] = (char*)MODPROBE;
826 argv[1] = (char*)MODPROBE_SWITCH_1; /* "-k" */
827 argv[2] = (char*)MODPROBE_SWITCH_2; /* "-C" */
828 argv[3] = (char*)CONFIG_MODULES_DEVFS;
829 argv[4] = concat_path_file("/dev", info->devname); /* device */
830 argv[5] = NULL;
831
832 spawn_and_wait(argv);
833 free(argv[4]);
834 } /* End Function action_modload */
835
action_execute(const struct devfsd_notify_struct * info,const struct config_entry_struct * entry,const regmatch_t * regexpr,unsigned int numexpr)836 static void action_execute(const struct devfsd_notify_struct *info,
837 const struct config_entry_struct *entry,
838 const regmatch_t *regexpr, unsigned int numexpr)
839 /* [SUMMARY] Execute a programme.
840 <info> The devfs change.
841 <entry> The config file entry.
842 <regexpr> The number of subexpression(start, end) offsets within the
843 device name.
844 <numexpr> The number of elements within <<regexpr>>.
845 [RETURNS] Nothing.
846 */
847 {
848 unsigned int count;
849 struct get_variable_info gv_info;
850 char *argv[MAX_ARGS + 1];
851 char largv[MAX_ARGS + 1][STRING_LENGTH];
852
853 gv_info.info = info;
854 gv_info.devname = info->devname;
855 snprintf(gv_info.devpath, sizeof(gv_info.devpath), "%s/%s", mount_point, info->devname);
856 for (count = 0; entry->u.execute.argv[count] != NULL; ++count) {
857 expand_expression(largv[count], STRING_LENGTH,
858 entry->u.execute.argv[count],
859 get_variable, &gv_info,
860 gv_info.devname, regexpr, numexpr);
861 argv[count] = largv[count];
862 }
863 argv[count] = NULL;
864 spawn_and_wait(argv);
865 } /* End Function action_execute */
866
867
action_copy(const struct devfsd_notify_struct * info,const struct config_entry_struct * entry,const regmatch_t * regexpr,unsigned int numexpr)868 static void action_copy(const struct devfsd_notify_struct *info,
869 const struct config_entry_struct *entry,
870 const regmatch_t *regexpr, unsigned int numexpr)
871 /* [SUMMARY] Copy permissions.
872 <info> The devfs change.
873 <entry> The config file entry.
874 <regexpr> This list of subexpression(start, end) offsets within the
875 device name.
876 <numexpr> The number of elements in <<regexpr>>.
877 [RETURNS] Nothing.
878 */
879 {
880 mode_t new_mode;
881 struct get_variable_info gv_info;
882 struct stat source_stat, dest_stat;
883 char source[STRING_LENGTH], destination[STRING_LENGTH];
884 int ret = 0;
885
886 dest_stat.st_mode = 0;
887
888 if ((info->type == DEVFSD_NOTIFY_CHANGE) && S_ISLNK(info->mode))
889 return;
890 gv_info.info = info;
891 gv_info.devname = info->devname;
892
893 snprintf(gv_info.devpath, sizeof(gv_info.devpath), "%s/%s", mount_point, info->devname);
894 expand_expression(source, STRING_LENGTH, entry->u.copy.source,
895 get_variable, &gv_info, gv_info.devname,
896 regexpr, numexpr);
897
898 expand_expression(destination, STRING_LENGTH, entry->u.copy.destination,
899 get_variable, &gv_info, gv_info.devname,
900 regexpr, numexpr);
901
902 if (!make_dir_tree(destination) || lstat(source, &source_stat) != 0)
903 return;
904 lstat(destination, &dest_stat);
905 new_mode = source_stat.st_mode & ~S_ISVTX;
906 if (info->type == DEVFSD_NOTIFY_CREATE)
907 new_mode |= S_ISVTX;
908 else if ((info->type == DEVFSD_NOTIFY_CHANGE) &&(dest_stat.st_mode & S_ISVTX))
909 new_mode |= S_ISVTX;
910 ret = copy_inode(destination, &dest_stat, new_mode, source, &source_stat);
911 if (ENABLE_DEBUG && ret && (errno != EEXIST))
912 error_logger(LOG_ERR, "copy_inode: %s to %s", source, destination);
913 } /* End Function action_copy */
914
action_compat(const struct devfsd_notify_struct * info,unsigned int action)915 static void action_compat(const struct devfsd_notify_struct *info, unsigned int action)
916 /* [SUMMARY] Process a compatibility request.
917 <info> The devfs change.
918 <action> The action to take.
919 [RETURNS] Nothing.
920 */
921 {
922 int ret;
923 const char *compat_name = NULL;
924 const char *dest_name = info->devname;
925 const char *ptr;
926 char compat_buf[STRING_LENGTH], dest_buf[STRING_LENGTH];
927 int mode, host, bus, target, lun;
928 unsigned int i;
929 char rewind_;
930 /* 1 to 5 "scsi/" , 6 to 9 "ide/host" */
931 static const char *const fmt[] = {
932 NULL ,
933 "sg/c%db%dt%du%d", /* scsi/generic */
934 "sd/c%db%dt%du%d", /* scsi/disc */
935 "sr/c%db%dt%du%d", /* scsi/cd */
936 "sd/c%db%dt%du%dp%d", /* scsi/part */
937 "st/c%db%dt%du%dm%d%c", /* scsi/mt */
938 "ide/hd/c%db%dt%du%d", /* ide/host/disc */
939 "ide/cd/c%db%dt%du%d", /* ide/host/cd */
940 "ide/hd/c%db%dt%du%dp%d", /* ide/host/part */
941 "ide/mt/c%db%dt%du%d%s", /* ide/host/mt */
942 NULL
943 };
944
945 /* First construct compatibility name */
946 switch (action) {
947 case AC_MKOLDCOMPAT:
948 case AC_RMOLDCOMPAT:
949 compat_name = get_old_name(info->devname, info->namelen, compat_buf, info->major, info->minor);
950 break;
951 case AC_MKNEWCOMPAT:
952 case AC_RMNEWCOMPAT:
953 ptr = bb_basename(info->devname);
954 i = scan_dev_name(info->devname, info->namelen, ptr);
955
956 /* nothing found */
957 if (i == 0 || i > 9)
958 return;
959
960 sscanf(info->devname + ((i < 6) ? 5 : 4), "host%d/bus%d/target%d/lun%d/", &host, &bus, &target, &lun);
961 snprintf(dest_buf, sizeof(dest_buf), "../%s", info->devname + (( i > 5) ? 4 : 0));
962 dest_name = dest_buf;
963 compat_name = compat_buf;
964
965
966 /* 1 == scsi/generic 2 == scsi/disc 3 == scsi/cd 6 == ide/host/disc 7 == ide/host/cd */
967 if (i == 1 || i == 2 || i == 3 || i == 6 || i ==7)
968 sprintf(compat_buf, fmt[i], host, bus, target, lun);
969
970 /* 4 == scsi/part 8 == ide/host/part */
971 if (i == 4 || i == 8)
972 sprintf(compat_buf, fmt[i], host, bus, target, lun, atoi(ptr + 4));
973
974 /* 5 == scsi/mt */
975 if (i == 5) {
976 rewind_ = info->devname[info->namelen - 1];
977 if (rewind_ != 'n')
978 rewind_ = '\0';
979 mode=0;
980 if (ptr[2] == 'l' /*108*/ || ptr[2] == 'm'/*109*/)
981 mode = ptr[2] - 107; /* 1 or 2 */
982 if (ptr[2] == 'a')
983 mode = 3;
984 sprintf(compat_buf, fmt[i], host, bus, target, lun, mode, rewind_);
985 }
986
987 /* 9 == ide/host/mt */
988 if (i == 9)
989 snprintf(compat_buf, sizeof(compat_buf), fmt[i], host, bus, target, lun, ptr + 2);
990 /* esac */
991 } /* switch (action) */
992
993 if (compat_name == NULL)
994 return;
995
996 /* Now decide what to do with it */
997 switch (action) {
998 case AC_MKOLDCOMPAT:
999 case AC_MKNEWCOMPAT:
1000 mksymlink(dest_name, compat_name);
1001 break;
1002 case AC_RMOLDCOMPAT:
1003 case AC_RMNEWCOMPAT:
1004 ret = unlink(compat_name);
1005 if (ENABLE_DEBUG && ret)
1006 error_logger(LOG_ERR, "unlink: %s", compat_name);
1007 break;
1008 /*esac*/
1009 } /* switch (action) */
1010 } /* End Function action_compat */
1011
restore(char * spath,struct stat source_stat,int rootlen)1012 static void restore(char *spath, struct stat source_stat, int rootlen)
1013 {
1014 char *dpath;
1015 struct stat dest_stat;
1016
1017 dest_stat.st_mode = 0;
1018 dpath = concat_path_file(mount_point, spath + rootlen);
1019 lstat(dpath, &dest_stat);
1020 free(dpath);
1021 if (S_ISLNK(source_stat.st_mode) || (source_stat.st_mode & S_ISVTX))
1022 copy_inode(dpath, &dest_stat, (source_stat.st_mode & ~S_ISVTX), spath, &source_stat);
1023
1024 if (S_ISDIR(source_stat.st_mode))
1025 dir_operation(RESTORE, spath, rootlen, NULL);
1026 }
1027
1028
copy_inode(const char * destpath,const struct stat * dest_stat,mode_t new_mode,const char * sourcepath,const struct stat * source_stat)1029 static int copy_inode(const char *destpath, const struct stat *dest_stat,
1030 mode_t new_mode,
1031 const char *sourcepath, const struct stat *source_stat)
1032 /* [SUMMARY] Copy an inode.
1033 <destpath> The destination path. An existing inode may be deleted.
1034 <dest_stat> The destination stat(2) information.
1035 <new_mode> The desired new mode for the destination.
1036 <sourcepath> The source path.
1037 <source_stat> The source stat(2) information.
1038 [RETURNS] TRUE on success, else FALSE.
1039 */
1040 {
1041 int source_len, dest_len;
1042 char source_link[STRING_LENGTH], dest_link[STRING_LENGTH];
1043 int fd, val;
1044 struct sockaddr_un un_addr;
1045 char symlink_val[STRING_LENGTH];
1046
1047 if ((source_stat->st_mode & S_IFMT) ==(dest_stat->st_mode & S_IFMT)) {
1048 /* Same type */
1049 if (S_ISLNK(source_stat->st_mode)) {
1050 source_len = readlink(sourcepath, source_link, STRING_LENGTH - 1);
1051 if ((source_len < 0)
1052 || (dest_len = readlink(destpath, dest_link, STRING_LENGTH - 1)) < 0
1053 )
1054 return FALSE;
1055 source_link[source_len] = '\0';
1056 dest_link[dest_len] = '\0';
1057 if ((source_len != dest_len) || (strcmp(source_link, dest_link) != 0)) {
1058 unlink(destpath);
1059 symlink(source_link, destpath);
1060 }
1061 return TRUE;
1062 } /* Else not a symlink */
1063 chmod(destpath, new_mode & ~S_IFMT);
1064 chown(destpath, source_stat->st_uid, source_stat->st_gid);
1065 return TRUE;
1066 }
1067 /* Different types: unlink and create */
1068 unlink(destpath);
1069 switch (source_stat->st_mode & S_IFMT) {
1070 case S_IFSOCK:
1071 fd = socket(AF_UNIX, SOCK_STREAM, 0);
1072 if (fd < 0)
1073 break;
1074 un_addr.sun_family = AF_UNIX;
1075 snprintf(un_addr.sun_path, sizeof(un_addr.sun_path), "%s", destpath);
1076 val = bind(fd, (struct sockaddr *) &un_addr, (int) sizeof un_addr);
1077 close(fd);
1078 if (val != 0 || chmod(destpath, new_mode & ~S_IFMT) != 0)
1079 break;
1080 goto do_chown;
1081 case S_IFLNK:
1082 val = readlink(sourcepath, symlink_val, STRING_LENGTH - 1);
1083 if (val < 0)
1084 break;
1085 symlink_val[val] = '\0';
1086 if (symlink(symlink_val, destpath) == 0)
1087 return TRUE;
1088 break;
1089 case S_IFREG:
1090 fd = open(destpath, O_RDONLY | O_CREAT, new_mode & ~S_IFMT);
1091 if (fd < 0)
1092 break;
1093 close(fd);
1094 if (chmod(destpath, new_mode & ~S_IFMT) != 0)
1095 break;
1096 goto do_chown;
1097 case S_IFBLK:
1098 case S_IFCHR:
1099 case S_IFIFO:
1100 if (mknod(destpath, new_mode, source_stat->st_rdev) != 0)
1101 break;
1102 goto do_chown;
1103 case S_IFDIR:
1104 if (mkdir(destpath, new_mode & ~S_IFMT) != 0)
1105 break;
1106 do_chown:
1107 if (chown(destpath, source_stat->st_uid, source_stat->st_gid) == 0)
1108 return TRUE;
1109 /*break;*/
1110 }
1111 return FALSE;
1112 } /* End Function copy_inode */
1113
free_config(void)1114 static void free_config(void)
1115 /* [SUMMARY] Free the configuration information.
1116 [RETURNS] Nothing.
1117 */
1118 {
1119 struct config_entry_struct *c_entry;
1120 void *next;
1121
1122 for (c_entry = first_config; c_entry != NULL; c_entry = next) {
1123 unsigned int count;
1124
1125 next = c_entry->next;
1126 regfree(&c_entry->preg);
1127 if (c_entry->action.what == AC_EXECUTE) {
1128 for (count = 0; count < MAX_ARGS; ++count) {
1129 if (c_entry->u.execute.argv[count] == NULL)
1130 break;
1131 free(c_entry->u.execute.argv[count]);
1132 }
1133 }
1134 free(c_entry);
1135 }
1136 first_config = NULL;
1137 last_config = NULL;
1138 } /* End Function free_config */
1139
get_uid_gid(int flag,const char * string)1140 static int get_uid_gid(int flag, const char *string)
1141 /* [SUMMARY] Convert a string to a UID or GID value.
1142 <flag> "UID" or "GID".
1143 <string> The string.
1144 [RETURNS] The UID or GID value.
1145 */
1146 {
1147 struct passwd *pw_ent;
1148 struct group *grp_ent;
1149 const char *msg;
1150
1151 if (isdigit(string[0]) || ((string[0] == '-') && isdigit(string[1])))
1152 return atoi(string);
1153
1154 if (flag == UID && (pw_ent = getpwnam(string)) != NULL)
1155 return pw_ent->pw_uid;
1156
1157 if (ENABLE_DEVFSD_VERBOSE)
1158 msg = "user";
1159
1160 if (flag == GID) {
1161 if ((grp_ent = getgrnam(string)) != NULL)
1162 return grp_ent->gr_gid;
1163 if (ENABLE_DEVFSD_VERBOSE)
1164 msg = "group";
1165 }
1166
1167 if (ENABLE_DEVFSD_VERBOSE)
1168 msg_logger(LOG_ERR, "unknown %s: %s, defaulting to %cid=0", msg, string, msg[0]);
1169 return 0;
1170 }/* End Function get_uid_gid */
1171
get_mode(const char * string)1172 static mode_t get_mode(const char *string)
1173 /* [SUMMARY] Convert a string to a mode value.
1174 <string> The string.
1175 [RETURNS] The mode value.
1176 */
1177 {
1178 mode_t mode;
1179 int i;
1180
1181 if (isdigit(string[0]))
1182 return strtoul(string, NULL, 8);
1183 if (strlen(string) != 9)
1184 msg_logger_and_die(LOG_ERR, "bad mode: %s", string);
1185
1186 mode = 0;
1187 i = S_IRUSR;
1188 while (i > 0) {
1189 if (string[0] == 'r' || string[0] == 'w' || string[0] == 'x')
1190 mode += i;
1191 i = i / 2;
1192 string++;
1193 }
1194 return mode;
1195 } /* End Function get_mode */
1196
signal_handler(int sig)1197 static void signal_handler(int sig)
1198 {
1199 caught_signal = TRUE;
1200 if (sig == SIGHUP)
1201 caught_sighup = TRUE;
1202
1203 info_logger(LOG_INFO, "Caught signal %d", sig);
1204 } /* End Function signal_handler */
1205
get_variable(const char * variable,void * info)1206 static const char *get_variable(const char *variable, void *info)
1207 {
1208 static char *hostname;
1209
1210 struct get_variable_info *gv_info = info;
1211 const char *field_names[] = {
1212 "hostname", "mntpt", "devpath", "devname", "uid", "gid", "mode",
1213 NULL, mount_point, gv_info->devpath, gv_info->devname, NULL
1214 };
1215 int i;
1216
1217 if (!hostname)
1218 hostname = safe_gethostname();
1219 field_names[7] = hostname;
1220
1221 /* index_in_str_array returns i>=0 */
1222 i = index_in_str_array(field_names, variable);
1223
1224 if (i > 6 || i < 0 || (i > 1 && gv_info == NULL))
1225 return NULL;
1226 if (i >= 0 && i <= 3)
1227 return field_names[i + 7];
1228
1229 if (i == 4)
1230 return auto_string(xasprintf("%u", gv_info->info->uid));
1231 if (i == 5)
1232 return auto_string(xasprintf("%u", gv_info->info->gid));
1233 /* i == 6 */
1234 return auto_string(xasprintf("%o", gv_info->info->mode));
1235 } /* End Function get_variable */
1236
service(struct stat statbuf,char * path)1237 static void service(struct stat statbuf, char *path)
1238 {
1239 struct devfsd_notify_struct info;
1240
1241 memset(&info, 0, sizeof info);
1242 info.type = DEVFSD_NOTIFY_REGISTERED;
1243 info.mode = statbuf.st_mode;
1244 info.major = major(statbuf.st_rdev);
1245 info.minor = minor(statbuf.st_rdev);
1246 info.uid = statbuf.st_uid;
1247 info.gid = statbuf.st_gid;
1248 snprintf(info.devname, sizeof(info.devname), "%s", path + strlen(mount_point) + 1);
1249 info.namelen = strlen(info.devname);
1250 service_name(&info);
1251 if (S_ISDIR(statbuf.st_mode))
1252 dir_operation(SERVICE, path, 0, NULL);
1253 }
1254
dir_operation(int type,const char * dir_name,int var,unsigned long * event_mask)1255 static void dir_operation(int type, const char * dir_name, int var, unsigned long *event_mask)
1256 /* [SUMMARY] Scan a directory tree and generate register events on leaf nodes.
1257 <flag> To choose which function to perform
1258 <dp> The directory pointer. This is closed upon completion.
1259 <dir_name> The name of the directory.
1260 <rootlen> string length parameter.
1261 [RETURNS] Nothing.
1262 */
1263 {
1264 struct stat statbuf;
1265 DIR *dp;
1266 struct dirent *de;
1267 char *path;
1268
1269 dp = warn_opendir(dir_name);
1270 if (dp == NULL)
1271 return;
1272
1273 while ((de = readdir(dp)) != NULL) {
1274
1275 if (de->d_name && DOT_OR_DOTDOT(de->d_name))
1276 continue;
1277 path = concat_path_file(dir_name, de->d_name);
1278 if (lstat(path, &statbuf) == 0) {
1279 switch (type) {
1280 case SERVICE:
1281 service(statbuf, path);
1282 break;
1283 case RESTORE:
1284 restore(path, statbuf, var);
1285 break;
1286 case READ_CONFIG:
1287 read_config_file(path, var, event_mask);
1288 break;
1289 }
1290 }
1291 free(path);
1292 }
1293 closedir(dp);
1294 } /* End Function do_scan_and_service */
1295
mksymlink(const char * oldpath,const char * newpath)1296 static int mksymlink(const char *oldpath, const char *newpath)
1297 /* [SUMMARY] Create a symlink, creating intervening directories as required.
1298 <oldpath> The string contained in the symlink.
1299 <newpath> The name of the new symlink.
1300 [RETURNS] 0 on success, else -1.
1301 */
1302 {
1303 if (!make_dir_tree(newpath))
1304 return -1;
1305
1306 if (symlink(oldpath, newpath) != 0) {
1307 if (errno != EEXIST)
1308 return -1;
1309 }
1310 return 0;
1311 } /* End Function mksymlink */
1312
1313
make_dir_tree(const char * path)1314 static int make_dir_tree(const char *path)
1315 /* [SUMMARY] Creating intervening directories for a path as required.
1316 <path> The full pathname(including the leaf node).
1317 [RETURNS] TRUE on success, else FALSE.
1318 */
1319 {
1320 if (bb_make_directory(dirname((char *)path), -1, FILEUTILS_RECUR) == -1)
1321 return FALSE;
1322 return TRUE;
1323 } /* End Function make_dir_tree */
1324
expand_expression(char * output,unsigned int outsize,const char * input,const char * (* get_variable_func)(const char * variable,void * info),void * info,const char * devname,const regmatch_t * ex,unsigned int numexp)1325 static int expand_expression(char *output, unsigned int outsize,
1326 const char *input,
1327 const char *(*get_variable_func)(const char *variable, void *info),
1328 void *info,
1329 const char *devname,
1330 const regmatch_t *ex, unsigned int numexp)
1331 /* [SUMMARY] Expand environment variables and regular subexpressions in string.
1332 <output> The output expanded expression is written here.
1333 <length> The size of the output buffer.
1334 <input> The input expression. This may equal <<output>>.
1335 <get_variable> A function which will be used to get variable values. If
1336 this returns NULL, the environment is searched instead. If this is NULL,
1337 only the environment is searched.
1338 <info> An arbitrary pointer passed to <<get_variable>>.
1339 <devname> Device name; specifically, this is the string that contains all
1340 of the regular subexpressions.
1341 <ex> Array of start / end offsets into info->devname for each subexpression
1342 <numexp> Number of regular subexpressions found in <<devname>>.
1343 [RETURNS] TRUE on success, else FALSE.
1344 */
1345 {
1346 char temp[STRING_LENGTH];
1347
1348 if (!st_expr_expand(temp, STRING_LENGTH, input, get_variable_func, info))
1349 return FALSE;
1350 expand_regexp(output, outsize, temp, devname, ex, numexp);
1351 return TRUE;
1352 } /* End Function expand_expression */
1353
expand_regexp(char * output,size_t outsize,const char * input,const char * devname,const regmatch_t * ex,unsigned int numex)1354 static void expand_regexp(char *output, size_t outsize, const char *input,
1355 const char *devname,
1356 const regmatch_t *ex, unsigned int numex)
1357 /* [SUMMARY] Expand all occurrences of the regular subexpressions \0 to \9.
1358 <output> The output expanded expression is written here.
1359 <outsize> The size of the output buffer.
1360 <input> The input expression. This may NOT equal <<output>>, because
1361 supporting that would require yet another string-copy. However, it's not
1362 hard to write a simple wrapper function to add this functionality for those
1363 few cases that need it.
1364 <devname> Device name; specifically, this is the string that contains all
1365 of the regular subexpressions.
1366 <ex> An array of start and end offsets into <<devname>>, one for each
1367 subexpression
1368 <numex> Number of subexpressions in the offset-array <<ex>>.
1369 [RETURNS] Nothing.
1370 */
1371 {
1372 const char last_exp = '0' - 1 + numex;
1373 int c = -1;
1374
1375 /* Guarantee NULL termination by writing an explicit '\0' character into
1376 the very last byte */
1377 if (outsize)
1378 output[--outsize] = '\0';
1379 /* Copy the input string into the output buffer, replacing '\\' with '\'
1380 and '\0' .. '\9' with subexpressions 0 .. 9, if they exist. Other \x
1381 codes are deleted */
1382 while ((c != '\0') && (outsize != 0)) {
1383 c = *input;
1384 ++input;
1385 if (c == '\\') {
1386 c = *input;
1387 ++input;
1388 if (c != '\\') {
1389 if ((c >= '0') && (c <= last_exp)) {
1390 const regmatch_t *subexp = ex + (c - '0');
1391 unsigned int sublen = subexp->rm_eo - subexp->rm_so;
1392
1393 /* Range checking */
1394 if (sublen > outsize)
1395 sublen = outsize;
1396 strncpy(output, devname + subexp->rm_so, sublen);
1397 output += sublen;
1398 outsize -= sublen;
1399 }
1400 continue;
1401 }
1402 }
1403 *output = c;
1404 ++output;
1405 --outsize;
1406 } /* while */
1407 } /* End Function expand_regexp */
1408
1409
1410 /* from compat_name.c */
1411
1412 struct translate_struct {
1413 const char *match; /* The string to match to(up to length) */
1414 const char *format; /* Format of output, "%s" takes data past match string,
1415 NULL is effectively "%s"(just more efficient) */
1416 };
1417
1418 static struct translate_struct translate_table[] =
1419 {
1420 {"sound/", NULL},
1421 {"printers/", "lp%s"},
1422 {"v4l/", NULL},
1423 {"parports/", "parport%s"},
1424 {"fb/", "fb%s"},
1425 {"netlink/", NULL},
1426 {"loop/", "loop%s"},
1427 {"floppy/", "fd%s"},
1428 {"rd/", "ram%s"},
1429 {"md/", "md%s"}, /* Meta-devices */
1430 {"vc/", "tty%s"},
1431 {"misc/", NULL},
1432 {"isdn/", NULL},
1433 {"pg/", "pg%s"}, /* Parallel port generic ATAPI interface*/
1434 {"i2c/", "i2c-%s"},
1435 {"staliomem/", "staliomem%s"}, /* Stallion serial driver control */
1436 {"tts/E", "ttyE%s"}, /* Stallion serial driver */
1437 {"cua/E", "cue%s"}, /* Stallion serial driver callout */
1438 {"tts/R", "ttyR%s"}, /* Rocketport serial driver */
1439 {"cua/R", "cur%s"}, /* Rocketport serial driver callout */
1440 {"ip2/", "ip2%s"}, /* Computone serial driver control */
1441 {"tts/F", "ttyF%s"}, /* Computone serial driver */
1442 {"cua/F", "cuf%s"}, /* Computone serial driver callout */
1443 {"tts/C", "ttyC%s"}, /* Cyclades serial driver */
1444 {"cua/C", "cub%s"}, /* Cyclades serial driver callout */
1445 {"tts/", "ttyS%s"}, /* Generic serial: must be after others */
1446 {"cua/", "cua%s"}, /* Generic serial: must be after others */
1447 {"input/js", "js%s"}, /* Joystick driver */
1448 {NULL, NULL}
1449 };
1450
get_old_name(const char * devname,unsigned int namelen,char * buffer,unsigned int major,unsigned int minor)1451 const char *get_old_name(const char *devname, unsigned int namelen,
1452 char *buffer, unsigned int major, unsigned int minor)
1453 /* [SUMMARY] Translate a kernel-supplied name into an old name.
1454 <devname> The device name provided by the kernel.
1455 <namelen> The length of the name.
1456 <buffer> A buffer that may be used. This should be at least 128 bytes long.
1457 <major> The major number for the device.
1458 <minor> The minor number for the device.
1459 [RETURNS] A pointer to the old name if known, else NULL.
1460 */
1461 {
1462 const char *compat_name = NULL;
1463 const char *ptr;
1464 struct translate_struct *trans;
1465 unsigned int i;
1466 char mode;
1467 int indexx;
1468 const char *pty1;
1469 const char *pty2;
1470 /* 1 to 5 "scsi/" , 6 to 9 "ide/host", 10 sbp/, 11 vcc/, 12 pty/ */
1471 static const char *const fmt[] = {
1472 NULL ,
1473 "sg%u", /* scsi/generic */
1474 NULL, /* scsi/disc */
1475 "sr%u", /* scsi/cd */
1476 NULL, /* scsi/part */
1477 "nst%u%c", /* scsi/mt */
1478 "hd%c" , /* ide/host/disc */
1479 "hd%c" , /* ide/host/cd */
1480 "hd%c%s", /* ide/host/part */
1481 "%sht%d", /* ide/host/mt */
1482 "sbpcd%u", /* sbp/ */
1483 "vcs%s", /* vcc/ */
1484 "%cty%c%c", /* pty/ */
1485 NULL
1486 };
1487
1488 for (trans = translate_table; trans->match != NULL; ++trans) {
1489 char *after_match = is_prefixed_with(devname, trans->match);
1490 if (after_match) {
1491 if (trans->format == NULL)
1492 return after_match;
1493 sprintf(buffer, trans->format, after_match);
1494 return buffer;
1495 }
1496 }
1497
1498 ptr = bb_basename(devname);
1499 i = scan_dev_name(devname, namelen, ptr);
1500
1501 if (i > 0 && i < 13)
1502 compat_name = buffer;
1503 else
1504 return NULL;
1505
1506 /* 1 == scsi/generic, 3 == scsi/cd, 10 == sbp/ */
1507 if (i == 1 || i == 3 || i == 10)
1508 sprintf(buffer, fmt[i], minor);
1509
1510 /* 2 ==scsi/disc, 4 == scsi/part */
1511 if (i == 2 || i == 4)
1512 compat_name = write_old_sd_name(buffer, major, minor, ((i == 2) ? "" : (ptr + 4)));
1513
1514 /* 5 == scsi/mt */
1515 if (i == 5) {
1516 mode = ptr[2];
1517 if (mode == 'n')
1518 mode = '\0';
1519 sprintf(buffer, fmt[i], minor & 0x1f, mode);
1520 if (devname[namelen - 1] != 'n')
1521 ++compat_name;
1522 }
1523 /* 6 == ide/host/disc, 7 == ide/host/cd, 8 == ide/host/part */
1524 if (i == 6 || i == 7 || i == 8)
1525 /* last arg should be ignored for i == 6 or i== 7 */
1526 sprintf(buffer, fmt[i] , get_old_ide_name(major, minor), ptr + 4);
1527
1528 /* 9 == ide/host/mt */
1529 if (i == 9)
1530 sprintf(buffer, fmt[i], ptr + 2, minor & 0x7f);
1531
1532 /* 11 == vcc/ */
1533 if (i == 11) {
1534 sprintf(buffer, fmt[i], devname + 4);
1535 if (buffer[3] == '0')
1536 buffer[3] = '\0';
1537 }
1538 /* 12 == pty/ */
1539 if (i == 12) {
1540 pty1 = "pqrstuvwxyzabcde";
1541 pty2 = "0123456789abcdef";
1542 indexx = atoi(devname + 5);
1543 sprintf(buffer, fmt[i], (devname[4] == 'm') ? 'p' : 't', pty1[indexx >> 4], pty2[indexx & 0x0f]);
1544 }
1545 return compat_name;
1546 } /* End Function get_old_name */
1547
get_old_ide_name(unsigned int major,unsigned int minor)1548 static char get_old_ide_name(unsigned int major, unsigned int minor)
1549 /* [SUMMARY] Get the old IDE name for a device.
1550 <major> The major number for the device.
1551 <minor> The minor number for the device.
1552 [RETURNS] The drive letter.
1553 */
1554 {
1555 char letter = 'y'; /* 121 */
1556 char c = 'a'; /* 97 */
1557 int i = IDE0_MAJOR;
1558
1559 /* I hope it works like the previous code as it saves a few bytes. Tito ;P */
1560 do {
1561 if (i == IDE0_MAJOR || i == IDE1_MAJOR || i == IDE2_MAJOR
1562 || i == IDE3_MAJOR || i == IDE4_MAJOR || i == IDE5_MAJOR
1563 || i == IDE6_MAJOR || i == IDE7_MAJOR || i == IDE8_MAJOR
1564 || i == IDE9_MAJOR
1565 ) {
1566 if ((unsigned int)i == major) {
1567 letter = c;
1568 break;
1569 }
1570 c += 2;
1571 }
1572 i++;
1573 } while (i <= IDE9_MAJOR);
1574
1575 if (minor > 63)
1576 ++letter;
1577 return letter;
1578 } /* End Function get_old_ide_name */
1579
write_old_sd_name(char * buffer,unsigned int major,unsigned int minor,const char * part)1580 static char *write_old_sd_name(char *buffer,
1581 unsigned int major, unsigned int minor,
1582 const char *part)
1583 /* [SUMMARY] Write the old SCSI disc name to a buffer.
1584 <buffer> The buffer to write to.
1585 <major> The major number for the device.
1586 <minor> The minor number for the device.
1587 <part> The partition string. Must be "" for a whole-disc entry.
1588 [RETURNS] A pointer to the buffer on success, else NULL.
1589 */
1590 {
1591 unsigned int disc_index;
1592
1593 if (major == 8) {
1594 sprintf(buffer, "sd%c%s", 'a' + (minor >> 4), part);
1595 return buffer;
1596 }
1597 if ((major > 64) && (major < 72)) {
1598 disc_index = ((major - 64) << 4) +(minor >> 4);
1599 if (disc_index < 26)
1600 sprintf(buffer, "sd%c%s", 'a' + disc_index, part);
1601 else
1602 sprintf(buffer, "sd%c%c%s", 'a' +(disc_index / 26) - 1, 'a' + disc_index % 26, part);
1603 return buffer;
1604 }
1605 return NULL;
1606 } /* End Function write_old_sd_name */
1607
1608
1609 /* expression.c */
1610
1611 /*EXPERIMENTAL_FUNCTION*/
1612
st_expr_expand(char * output,unsigned int length,const char * input,const char * (* get_variable_func)(const char * variable,void * info),void * info)1613 int st_expr_expand(char *output, unsigned int length, const char *input,
1614 const char *(*get_variable_func)(const char *variable,
1615 void *info),
1616 void *info)
1617 /* [SUMMARY] Expand an expression using Borne Shell-like unquoted rules.
1618 <output> The output expanded expression is written here.
1619 <length> The size of the output buffer.
1620 <input> The input expression. This may equal <<output>>.
1621 <get_variable> A function which will be used to get variable values. If
1622 this returns NULL, the environment is searched instead. If this is NULL,
1623 only the environment is searched.
1624 <info> An arbitrary pointer passed to <<get_variable>>.
1625 [RETURNS] TRUE on success, else FALSE.
1626 */
1627 {
1628 char ch;
1629 unsigned int len;
1630 unsigned int out_pos = 0;
1631 const char *env;
1632 const char *ptr;
1633 struct passwd *pwent;
1634 char buffer[BUFFER_SIZE], tmp[STRING_LENGTH];
1635
1636 if (length > BUFFER_SIZE)
1637 length = BUFFER_SIZE;
1638 for (; TRUE; ++input) {
1639 switch (ch = *input) {
1640 case '$':
1641 /* Variable expansion */
1642 input = expand_variable(buffer, length, &out_pos, ++input, get_variable_func, info);
1643 if (input == NULL)
1644 return FALSE;
1645 break;
1646 case '~':
1647 /* Home directory expansion */
1648 ch = input[1];
1649 if (isspace(ch) ||(ch == '/') ||(ch == '\0')) {
1650 /* User's own home directory: leave separator for next time */
1651 env = getenv("HOME");
1652 if (env == NULL) {
1653 info_logger(LOG_INFO, bb_msg_variable_not_found, "HOME");
1654 return FALSE;
1655 }
1656 len = strlen(env);
1657 if (len + out_pos >= length)
1658 goto st_expr_expand_out;
1659 memcpy(buffer + out_pos, env, len + 1);
1660 out_pos += len;
1661 continue;
1662 }
1663 /* Someone else's home directory */
1664 for (ptr = ++input; !isspace(ch) && (ch != '/') && (ch != '\0'); ch = *++ptr)
1665 /* VOID */;
1666 len = ptr - input;
1667 if (len >= sizeof tmp)
1668 goto st_expr_expand_out;
1669 safe_memcpy(tmp, input, len);
1670 input = ptr - 1;
1671 pwent = getpwnam(tmp);
1672 if (pwent == NULL) {
1673 info_logger(LOG_INFO, "no pwent for: %s", tmp);
1674 return FALSE;
1675 }
1676 len = strlen(pwent->pw_dir);
1677 if (len + out_pos >= length)
1678 goto st_expr_expand_out;
1679 memcpy(buffer + out_pos, pwent->pw_dir, len + 1);
1680 out_pos += len;
1681 break;
1682 case '\0':
1683 /* Falltrough */
1684 default:
1685 if (out_pos >= length)
1686 goto st_expr_expand_out;
1687 buffer[out_pos++] = ch;
1688 if (ch == '\0') {
1689 memcpy(output, buffer, out_pos);
1690 return TRUE;
1691 }
1692 break;
1693 /* esac */
1694 }
1695 }
1696 return FALSE;
1697 st_expr_expand_out:
1698 simple_info_logger(LOG_INFO, bb_msg_small_buffer);
1699 return FALSE;
1700 } /* End Function st_expr_expand */
1701
1702
1703 /* Private functions follow */
1704
expand_variable(char * buffer,unsigned int length,unsigned int * out_pos,const char * input,const char * (* func)(const char * variable,void * info),void * info)1705 static const char *expand_variable(char *buffer, unsigned int length,
1706 unsigned int *out_pos, const char *input,
1707 const char *(*func)(const char *variable,
1708 void *info),
1709 void *info)
1710 /* [SUMMARY] Expand a variable.
1711 <buffer> The buffer to write to.
1712 <length> The length of the output buffer.
1713 <out_pos> The current output position. This is updated.
1714 <input> A pointer to the input character pointer.
1715 <func> A function which will be used to get variable values. If this
1716 returns NULL, the environment is searched instead. If this is NULL, only
1717 the environment is searched.
1718 <info> An arbitrary pointer passed to <<func>>.
1719 <errfp> Diagnostic messages are written here.
1720 [RETURNS] A pointer to the end of this subexpression on success, else NULL.
1721 */
1722 {
1723 char ch;
1724 int len;
1725 unsigned int open_braces;
1726 const char *env, *ptr;
1727 char tmp[STRING_LENGTH];
1728
1729 ch = input[0];
1730 if (ch == '$') {
1731 /* Special case for "$$": PID */
1732 sprintf(tmp, "%d", (int) getpid());
1733 len = strlen(tmp);
1734 if (len + *out_pos >= length)
1735 goto expand_variable_out;
1736
1737 memcpy(buffer + *out_pos, tmp, len + 1);
1738 out_pos += len;
1739 return input;
1740 }
1741 /* Ordinary variable expansion, possibly in braces */
1742 if (ch != '{') {
1743 /* Simple variable expansion */
1744 for (ptr = input; isalnum(ch) || (ch == '_') || (ch == ':'); ch = *++ptr)
1745 /* VOID */;
1746 len = ptr - input;
1747 if ((size_t)len >= sizeof tmp)
1748 goto expand_variable_out;
1749
1750 safe_memcpy(tmp, input, len);
1751 input = ptr - 1;
1752 env = get_variable_v2(tmp, func, info);
1753 if (env == NULL) {
1754 info_logger(LOG_INFO, bb_msg_variable_not_found, tmp);
1755 return NULL;
1756 }
1757 len = strlen(env);
1758 if (len + *out_pos >= length)
1759 goto expand_variable_out;
1760
1761 memcpy(buffer + *out_pos, env, len + 1);
1762 *out_pos += len;
1763 return input;
1764 }
1765 /* Variable in braces: check for ':' tricks */
1766 ch = *++input;
1767 for (ptr = input; isalnum(ch) || (ch == '_'); ch = *++ptr)
1768 /* VOID */;
1769 if (ch == '}') {
1770 /* Must be simple variable expansion with "${var}" */
1771 len = ptr - input;
1772 if ((size_t)len >= sizeof tmp)
1773 goto expand_variable_out;
1774
1775 safe_memcpy(tmp, input, len);
1776 ptr = expand_variable(buffer, length, out_pos, tmp, func, info);
1777 if (ptr == NULL)
1778 return NULL;
1779 return input + len;
1780 }
1781 if (ch != ':' || ptr[1] != '-') {
1782 simple_info_logger(LOG_INFO, "illegal char in var name");
1783 return NULL;
1784 }
1785 /* It's that handy "${var:-word}" expression. Check if var is defined */
1786 len = ptr - input;
1787 if ((size_t)len >= sizeof tmp)
1788 goto expand_variable_out;
1789
1790 safe_memcpy(tmp, input, len);
1791 /* Move input pointer to ':' */
1792 input = ptr;
1793 /* First skip to closing brace, taking note of nested expressions */
1794 ptr += 2;
1795 ch = ptr[0];
1796 for (open_braces = 1; open_braces > 0; ch = *++ptr) {
1797 switch (ch) {
1798 case '{':
1799 ++open_braces;
1800 break;
1801 case '}':
1802 --open_braces;
1803 break;
1804 case '\0':
1805 info_logger(LOG_INFO, "\"}\" not found in: %s", input);
1806 return NULL;
1807 default:
1808 break;
1809 }
1810 }
1811 --ptr;
1812 /* At this point ptr should point to closing brace of "${var:-word}" */
1813 env = get_variable_v2(tmp, func, info);
1814 if (env != NULL) {
1815 /* Found environment variable, so skip the input to the closing brace
1816 and return the variable */
1817 input = ptr;
1818 len = strlen(env);
1819 if (len + *out_pos >= length)
1820 goto expand_variable_out;
1821
1822 memcpy(buffer + *out_pos, env, len + 1);
1823 *out_pos += len;
1824 return input;
1825 }
1826 /* Environment variable was not found, so process word. Advance input
1827 pointer to start of word in "${var:-word}" */
1828 input += 2;
1829 len = ptr - input;
1830 if ((size_t)len >= sizeof tmp)
1831 goto expand_variable_out;
1832
1833 safe_memcpy(tmp, input, len);
1834 input = ptr;
1835 if (!st_expr_expand(tmp, STRING_LENGTH, tmp, func, info))
1836 return NULL;
1837 len = strlen(tmp);
1838 if (len + *out_pos >= length)
1839 goto expand_variable_out;
1840
1841 memcpy(buffer + *out_pos, tmp, len + 1);
1842 *out_pos += len;
1843 return input;
1844 expand_variable_out:
1845 simple_info_logger(LOG_INFO, bb_msg_small_buffer);
1846 return NULL;
1847 } /* End Function expand_variable */
1848
1849
get_variable_v2(const char * variable,const char * (* func)(const char * variable,void * info),void * info)1850 static const char *get_variable_v2(const char *variable,
1851 const char *(*func)(const char *variable, void *info),
1852 void *info)
1853 /* [SUMMARY] Get a variable from the environment or .
1854 <variable> The variable name.
1855 <func> A function which will be used to get the variable. If this returns
1856 NULL, the environment is searched instead. If this is NULL, only the
1857 environment is searched.
1858 [RETURNS] The value of the variable on success, else NULL.
1859 */
1860 {
1861 const char *value;
1862
1863 if (func != NULL) {
1864 value = (*func)(variable, info);
1865 if (value != NULL)
1866 return value;
1867 }
1868 return getenv(variable);
1869 } /* End Function get_variable */
1870
1871 /* END OF CODE */
1872