blob: 86f85081c8f125e9279909416e5b707fb4eefcd5 [file] [log] [blame]
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +00001/* vi: set sw=4 ts=4: */
2/*
Denis Vlasenko724d1962007-10-10 14:41:07 +00003 * Utility routines.
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +00004 *
Denis Vlasenko724d1962007-10-10 14:41:07 +00005 * Copyright (C) tons of folks. Tracking down who wrote what
6 * isn't something I'm going to worry about... If you wrote something
7 * here, please feel free to acknowledge your work.
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +00008 *
Denis Vlasenko724d1962007-10-10 14:41:07 +00009 * Based in part on code from sash, Copyright (c) 1999 by David I. Bell
10 * Permission has been granted to redistribute this code under the GPL.
11 *
12 * Licensed under GPLv2 or later, see file License in this tarball for details.
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000013 */
14
Denis Vlasenko79cedcb2008-04-08 21:13:28 +000015/* We are trying to not use printf, this benefits the case when selected
16 * applets are really simple. Example:
17 *
18 * $ ./busybox
19 * ...
20 * Currently defined functions:
21 * basename, false, true
22 *
23 * $ size busybox
24 * text data bss dec hex filename
25 * 4473 52 72 4597 11f5 busybox
26 *
27 * FEATURE_INSTALLER or FEATURE_SUID will still link printf routines in. :(
28 */
29
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000030#include <assert.h>
31#include "busybox.h"
32
33
34/* Declare <applet>_main() */
35#define PROTOTYPES
36#include "applets.h"
37#undef PROTOTYPES
38
39#if ENABLE_SHOW_USAGE && !ENABLE_FEATURE_COMPRESS_USAGE
40/* Define usage_messages[] */
41static const char usage_messages[] ALIGN1 = ""
42#define MAKE_USAGE
43#include "usage.h"
44#include "applets.h"
45;
46#undef MAKE_USAGE
47#else
48#define usage_messages 0
49#endif /* SHOW_USAGE */
50
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000051
Denis Vlasenko32b2a9f2008-02-22 22:43:22 +000052/* Include generated applet names, pointers to <applet>_main, etc */
Denis Vlasenko1aa7e472007-11-28 06:49:03 +000053#include "applet_tables.h"
Denis Vlasenko468aea22008-04-01 14:47:57 +000054/* ...and if applet_tables generator says we have only one applet... */
55#ifdef SINGLE_APPLET_MAIN
56#undef ENABLE_FEATURE_INDIVIDUAL
57#define ENABLE_FEATURE_INDIVIDUAL 1
58#undef USE_FEATURE_INDIVIDUAL
59#define USE_FEATURE_INDIVIDUAL(...) __VA_ARGS__
60#endif
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000061
62
63#if ENABLE_FEATURE_COMPRESS_USAGE
64
65#include "usage_compressed.h"
66#include "unarchive.h"
67
68static const char *unpack_usage_messages(void)
69{
70 char *outbuf = NULL;
71 bunzip_data *bd;
72 int i;
73
74 i = start_bunzip(&bd,
75 /* src_fd: */ -1,
Denis Vlasenko55995022008-05-18 22:28:26 +000076 /* inbuf: */ (void *)packed_usage,
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000077 /* len: */ sizeof(packed_usage));
78 /* read_bunzip can longjmp to start_bunzip, and ultimately
79 * end up here with i != 0 on read data errors! Not trivial */
80 if (!i) {
81 /* Cannot use xmalloc: will leak bd in NOFORK case! */
82 outbuf = malloc_or_warn(SIZEOF_usage_messages);
83 if (outbuf)
84 read_bunzip(bd, outbuf, SIZEOF_usage_messages);
85 }
86 dealloc_bunzip(bd);
87 return outbuf;
88}
89#define dealloc_usage_messages(s) free(s)
90
91#else
92
93#define unpack_usage_messages() usage_messages
94#define dealloc_usage_messages(s) ((void)(s))
95
96#endif /* FEATURE_COMPRESS_USAGE */
97
98
Denis Vlasenko79cedcb2008-04-08 21:13:28 +000099static void full_write2_str(const char *str)
100{
Bernhard Reutner-Fischer5e25ddb2008-05-19 09:48:17 +0000101 full_write(STDERR_FILENO, str, strlen(str));
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000102}
103
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000104void bb_show_usage(void)
105{
106 if (ENABLE_SHOW_USAGE) {
Denis Vlasenko468aea22008-04-01 14:47:57 +0000107#ifdef SINGLE_APPLET_STR
108 /* Imagine that this applet is "true". Dont suck in printf! */
109 const char *p;
110 const char *usage_string = p = unpack_usage_messages();
111
112 if (*p == '\b') {
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000113 full_write2_str("\nNo help available.\n\n");
Denis Vlasenko468aea22008-04-01 14:47:57 +0000114 } else {
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000115 full_write2_str("\nUsage: "SINGLE_APPLET_STR" ");
116 full_write2_str(p);
117 full_write2_str("\n\n");
Denis Vlasenko468aea22008-04-01 14:47:57 +0000118 }
119 dealloc_usage_messages((char*)usage_string);
120#else
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000121 const char *p;
122 const char *usage_string = p = unpack_usage_messages();
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000123 int ap = find_applet_by_name(applet_name);
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000124
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000125 if (ap < 0) /* never happens, paranoia */
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000126 xfunc_die();
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000127 while (ap) {
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000128 while (*p++) continue;
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000129 ap--;
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000130 }
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000131 full_write2_str(bb_banner);
132 full_write2_str(" multi-call binary\n");
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000133 if (*p == '\b')
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000134 full_write2_str("\nNo help available.\n\n");
135 else {
136 full_write2_str("\nUsage: ");
137 full_write2_str(applet_name);
138 full_write2_str(" ");
139 full_write2_str(p);
140 full_write2_str("\n\n");
141 }
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000142 dealloc_usage_messages((char*)usage_string);
Denis Vlasenko468aea22008-04-01 14:47:57 +0000143#endif
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000144 }
145 xfunc_die();
146}
147
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000148#if NUM_APPLETS > 8
Denis Vlasenko745cd172007-11-29 03:31:20 +0000149/* NB: any char pointer will work as well, not necessarily applet_names */
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000150static int applet_name_compare(const void *name, const void *v)
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000151{
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000152 int i = (const char *)v - applet_names;
153 return strcmp(name, APPLET_NAME(i));
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000154}
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000155#endif
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000156int find_applet_by_name(const char *name)
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000157{
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000158#if NUM_APPLETS > 8
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000159 /* Do a binary search to find the applet entry given the name. */
Denis Vlasenko745cd172007-11-29 03:31:20 +0000160 const char *p;
161 p = bsearch(name, applet_names, ARRAY_SIZE(applet_main), 1, applet_name_compare);
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000162 if (!p)
163 return -1;
164 return p - applet_names;
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000165#else
166 /* A version which does not pull in bsearch */
167 int i = 0;
168 const char *p = applet_names;
169 while (i < NUM_APPLETS) {
170 if (strcmp(name, p) == 0)
171 return i;
172 p += strlen(p) + 1;
173 i++;
174 }
175 return -1;
176#endif
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000177}
178
179
Denis Vlasenko68404f12008-03-17 09:00:54 +0000180void lbb_prepare(const char *applet
181 USE_FEATURE_INDIVIDUAL(, char **argv))
Denis Vlasenko468aea22008-04-01 14:47:57 +0000182 MAIN_EXTERNALLY_VISIBLE;
183void lbb_prepare(const char *applet
184 USE_FEATURE_INDIVIDUAL(, char **argv))
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000185{
186#ifdef __GLIBC__
187 (*(int **)&bb_errno) = __errno_location();
Denis Vlasenko574f2f42008-02-27 18:41:59 +0000188 barrier();
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000189#endif
Denis Vlasenko15cb4a42007-10-11 10:06:26 +0000190 applet_name = applet;
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000191
192 /* Set locale for everybody except 'init' */
193 if (ENABLE_LOCALE_SUPPORT && getpid() != 1)
194 setlocale(LC_ALL, "");
195
Denis Vlasenko82d38da2007-10-10 14:38:47 +0000196#if ENABLE_FEATURE_INDIVIDUAL
197 /* Redundant for busybox (run_applet_and_exit covers that case)
198 * but needed for "individual applet" mode */
Denis Vlasenkod419a9f2007-10-08 20:45:42 +0000199 if (argv[1] && strcmp(argv[1], "--help") == 0)
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000200 bb_show_usage();
Denis Vlasenko82d38da2007-10-10 14:38:47 +0000201#endif
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000202}
Denis Vlasenko724d1962007-10-10 14:41:07 +0000203
204/* The code below can well be in applets/applets.c, as it is used only
205 * for busybox binary, not "individual" binaries.
206 * However, keeping it here and linking it into libbusybox.so
207 * (together with remaining tiny applets/applets.o)
208 * makes it possible to avoid --whole-archive at link time.
209 * This makes (shared busybox) + libbusybox smaller.
210 * (--gc-sections would be even better....)
211 */
212
213const char *applet_name;
214#if !BB_MMU
215bool re_execed;
216#endif
217
Denis Vlasenko468aea22008-04-01 14:47:57 +0000218
Denis Vlasenko10f6fb12008-04-29 00:10:27 +0000219/* If not built as a single-applet executable... */
220#if !defined(SINGLE_APPLET_MAIN)
Denis Vlasenko468aea22008-04-01 14:47:57 +0000221
Denis Vlasenko724d1962007-10-10 14:41:07 +0000222USE_FEATURE_SUID(static uid_t ruid;) /* real uid */
223
224#if ENABLE_FEATURE_SUID_CONFIG
225
226/* applets[] is const, so we have to define this "override" structure */
227static struct BB_suid_config {
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000228 int m_applet;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000229 uid_t m_uid;
230 gid_t m_gid;
231 mode_t m_mode;
232 struct BB_suid_config *m_next;
233} *suid_config;
234
235static bool suid_cfg_readable;
236
237/* check if u is member of group g */
238static int ingroup(uid_t u, gid_t g)
239{
240 struct group *grp = getgrgid(g);
241
242 if (grp) {
243 char **mem;
244
245 for (mem = grp->gr_mem; *mem; mem++) {
246 struct passwd *pwd = getpwnam(*mem);
247
248 if (pwd && (pwd->pw_uid == u))
249 return 1;
250 }
251 }
252 return 0;
253}
254
255/* This should probably be a libbb routine. In that case,
256 * I'd probably rename it to something like bb_trimmed_slice.
257 */
258static char *get_trimmed_slice(char *s, char *e)
259{
260 /* First, consider the value at e to be nul and back up until we
261 * reach a non-space char. Set the char after that (possibly at
262 * the original e) to nul. */
263 while (e-- > s) {
264 if (!isspace(*e)) {
265 break;
266 }
267 }
268 e[1] = '\0';
269
270 /* Next, advance past all leading space and return a ptr to the
271 * first non-space char; possibly the terminating nul. */
272 return skip_whitespace(s);
273}
274
275/* Don't depend on the tools to combine strings. */
276static const char config_file[] ALIGN1 = "/etc/busybox.conf";
277
278/* We don't supply a value for the nul, so an index adjustment is
279 * necessary below. Also, we use unsigned short here to save some
280 * space even though these are really mode_t values. */
281static const unsigned short mode_mask[] ALIGN2 = {
282 /* SST sst xxx --- */
283 S_ISUID, S_ISUID|S_IXUSR, S_IXUSR, 0, /* user */
284 S_ISGID, S_ISGID|S_IXGRP, S_IXGRP, 0, /* group */
285 0, S_IXOTH, S_IXOTH, 0 /* other */
286};
287
288#define parse_error(x) do { errmsg = x; goto pe_label; } while (0)
289
290static void parse_config_file(void)
291{
292 struct BB_suid_config *sct_head;
293 struct BB_suid_config *sct;
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000294 int applet_no;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000295 FILE *f;
296 const char *errmsg;
297 char *s;
298 char *e;
299 int i;
300 unsigned lc;
301 smallint section;
302 char buffer[256];
303 struct stat st;
304
305 assert(!suid_config); /* Should be set to NULL by bss init. */
306
307 ruid = getuid();
308 if (ruid == 0) /* run by root - don't need to even read config file */
309 return;
310
311 if ((stat(config_file, &st) != 0) /* No config file? */
312 || !S_ISREG(st.st_mode) /* Not a regular file? */
313 || (st.st_uid != 0) /* Not owned by root? */
314 || (st.st_mode & (S_IWGRP | S_IWOTH)) /* Writable by non-root? */
315 || !(f = fopen(config_file, "r")) /* Cannot open? */
316 ) {
317 return;
318 }
319
320 suid_cfg_readable = 1;
321 sct_head = NULL;
322 section = lc = 0;
323
324 while (1) {
325 s = buffer;
326
327 if (!fgets(s, sizeof(buffer), f)) { /* Are we done? */
Denis Vlasenkod02db892008-03-17 09:05:21 +0000328// why?
Denis Vlasenko724d1962007-10-10 14:41:07 +0000329 if (ferror(f)) { /* Make sure it wasn't a read error. */
330 parse_error("reading");
331 }
332 fclose(f);
333 suid_config = sct_head; /* Success, so set the pointer. */
334 return;
335 }
336
337 lc++; /* Got a (partial) line. */
338
339 /* If a line is too long for our buffer, we consider it an error.
340 * The following test does mistreat one corner case though.
341 * If the final line of the file does not end with a newline and
342 * yet exactly fills the buffer, it will be treated as too long
343 * even though there isn't really a problem. But it isn't really
344 * worth adding code to deal with such an unlikely situation, and
345 * we do err on the side of caution. Besides, the line would be
346 * too long if it did end with a newline. */
347 if (!strchr(s, '\n') && !feof(f)) {
348 parse_error("line too long");
349 }
350
351 /* Trim leading and trailing whitespace, ignoring comments, and
352 * check if the resulting string is empty. */
353 s = get_trimmed_slice(s, strchrnul(s, '#'));
354 if (!*s) {
355 continue;
356 }
357
358 /* Check for a section header. */
359
360 if (*s == '[') {
361 /* Unlike the old code, we ignore leading and trailing
362 * whitespace for the section name. We also require that
363 * there are no stray characters after the closing bracket. */
364 e = strchr(s, ']');
365 if (!e /* Missing right bracket? */
366 || e[1] /* Trailing characters? */
367 || !*(s = get_trimmed_slice(s+1, e)) /* Missing name? */
368 ) {
369 parse_error("section header");
370 }
371 /* Right now we only have one section so just check it.
372 * If more sections are added in the future, please don't
373 * resort to cascading ifs with multiple strcasecmp calls.
374 * That kind of bloated code is all too common. A loop
375 * and a string table would be a better choice unless the
376 * number of sections is very small. */
377 if (strcasecmp(s, "SUID") == 0) {
378 section = 1;
379 continue;
380 }
381 section = -1; /* Unknown section so set to skip. */
382 continue;
383 }
384
385 /* Process sections. */
386
387 if (section == 1) { /* SUID */
388 /* Since we trimmed leading and trailing space above, we're
389 * now looking for strings of the form
390 * <key>[::space::]*=[::space::]*<value>
391 * where both key and value could contain inner whitespace. */
392
393 /* First get the key (an applet name in our case). */
394 e = strchr(s, '=');
395 if (e) {
396 s = get_trimmed_slice(s, e);
397 }
398 if (!e || !*s) { /* Missing '=' or empty key. */
399 parse_error("keyword");
400 }
401
402 /* Ok, we have an applet name. Process the rhs if this
403 * applet is currently built in and ignore it otherwise.
404 * Note: this can hide config file bugs which only pop
405 * up when the busybox configuration is changed. */
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000406 applet_no = find_applet_by_name(s);
407 if (applet_no >= 0) {
Denis Vlasenko724d1962007-10-10 14:41:07 +0000408 /* Note: We currently don't check for duplicates!
409 * The last config line for each applet will be the
410 * one used since we insert at the head of the list.
411 * I suppose this could be considered a feature. */
412 sct = xmalloc(sizeof(struct BB_suid_config));
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000413 sct->m_applet = applet_no;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000414 sct->m_mode = 0;
415 sct->m_next = sct_head;
416 sct_head = sct;
417
418 /* Get the specified mode. */
419
420 e = skip_whitespace(e+1);
421
422 for (i = 0; i < 3; i++) {
423 /* There are 4 chars + 1 nul for each of user/group/other. */
424 static const char mode_chars[] ALIGN1 = "Ssx-\0" "Ssx-\0" "Ttx-";
425
426 const char *q;
427 q = strchrnul(mode_chars + 5*i, *e++);
428 if (!*q) {
429 parse_error("mode");
430 }
431 /* Adjust by -i to account for nul. */
432 sct->m_mode |= mode_mask[(q - mode_chars) - i];
433 }
434
435 /* Now get the the user/group info. */
436
437 s = skip_whitespace(e);
438
439 /* Note: we require whitespace between the mode and the
440 * user/group info. */
441 if ((s == e) || !(e = strchr(s, '.'))) {
442 parse_error("<uid>.<gid>");
443 }
444 *e++ = '\0';
445
446 /* We can't use get_ug_id here since it would exit()
447 * if a uid or gid was not found. Oh well... */
448 sct->m_uid = bb_strtoul(s, NULL, 10);
449 if (errno) {
450 struct passwd *pwd = getpwnam(s);
451 if (!pwd) {
452 parse_error("user");
453 }
454 sct->m_uid = pwd->pw_uid;
455 }
456
457 sct->m_gid = bb_strtoul(e, NULL, 10);
458 if (errno) {
459 struct group *grp;
460 grp = getgrnam(e);
461 if (!grp) {
462 parse_error("group");
463 }
464 sct->m_gid = grp->gr_gid;
465 }
466 }
467 continue;
468 }
469
470 /* Unknown sections are ignored. */
471
472 /* Encountering configuration lines prior to seeing a
473 * section header is treated as an error. This is how
474 * the old code worked, but it may not be desirable.
475 * We may want to simply ignore such lines in case they
476 * are used in some future version of busybox. */
477 if (!section) {
478 parse_error("keyword outside section");
479 }
480
481 } /* while (1) */
482
483 pe_label:
484 fprintf(stderr, "Parse error in %s, line %d: %s\n",
485 config_file, lc, errmsg);
486
487 fclose(f);
488 /* Release any allocated memory before returning. */
489 while (sct_head) {
490 sct = sct_head->m_next;
491 free(sct_head);
492 sct_head = sct;
493 }
494}
495#else
496static inline void parse_config_file(void)
497{
498 USE_FEATURE_SUID(ruid = getuid();)
499}
500#endif /* FEATURE_SUID_CONFIG */
501
502
503#if ENABLE_FEATURE_SUID
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000504static void check_suid(int applet_no)
Denis Vlasenko724d1962007-10-10 14:41:07 +0000505{
506 gid_t rgid; /* real gid */
507
508 if (ruid == 0) /* set by parse_config_file() */
509 return; /* run by root - no need to check more */
510 rgid = getgid();
511
512#if ENABLE_FEATURE_SUID_CONFIG
513 if (suid_cfg_readable) {
514 uid_t uid;
515 struct BB_suid_config *sct;
516 mode_t m;
517
518 for (sct = suid_config; sct; sct = sct->m_next) {
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000519 if (sct->m_applet == applet_no)
Denis Vlasenko724d1962007-10-10 14:41:07 +0000520 goto found;
521 }
Denis Vlasenko15ca51e2007-10-29 19:25:45 +0000522 goto check_need_suid;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000523 found:
524 m = sct->m_mode;
525 if (sct->m_uid == ruid)
526 /* same uid */
527 m >>= 6;
528 else if ((sct->m_gid == rgid) || ingroup(ruid, sct->m_gid))
529 /* same group / in group */
530 m >>= 3;
531
532 if (!(m & S_IXOTH)) /* is x bit not set ? */
533 bb_error_msg_and_die("you have no permission to run this applet!");
534
535 /* _both_ sgid and group_exec have to be set for setegid */
536 if ((sct->m_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP))
537 rgid = sct->m_gid;
538 /* else (no setegid) we will set egid = rgid */
539
540 /* We set effective AND saved ids. If saved-id is not set
541 * like we do below, seteiud(0) can still later succeed! */
542 if (setresgid(-1, rgid, rgid))
543 bb_perror_msg_and_die("setresgid");
544
545 /* do we have to set effective uid? */
546 uid = ruid;
547 if (sct->m_mode & S_ISUID)
548 uid = sct->m_uid;
549 /* else (no seteuid) we will set euid = ruid */
550
551 if (setresuid(-1, uid, uid))
552 bb_perror_msg_and_die("setresuid");
553 return;
554 }
555#if !ENABLE_FEATURE_SUID_CONFIG_QUIET
556 {
557 static bool onetime = 0;
558
559 if (!onetime) {
560 onetime = 1;
561 fprintf(stderr, "Using fallback suid method\n");
562 }
563 }
564#endif
Denis Vlasenko15ca51e2007-10-29 19:25:45 +0000565 check_need_suid:
Denis Vlasenko724d1962007-10-10 14:41:07 +0000566#endif
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000567 if (APPLET_SUID(applet_no) == _BB_SUID_ALWAYS) {
Denis Vlasenko724d1962007-10-10 14:41:07 +0000568 /* Real uid is not 0. If euid isn't 0 too, suid bit
569 * is most probably not set on our executable */
570 if (geteuid())
Denis Vlasenko15ca51e2007-10-29 19:25:45 +0000571 bb_error_msg_and_die("must be suid to work properly");
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000572 } else if (APPLET_SUID(applet_no) == _BB_SUID_NEVER) {
Denis Vlasenko724d1962007-10-10 14:41:07 +0000573 xsetgid(rgid); /* drop all privileges */
574 xsetuid(ruid);
575 }
576}
577#else
578#define check_suid(x) ((void)0)
579#endif /* FEATURE_SUID */
580
581
582#if ENABLE_FEATURE_INSTALLER
583/* create (sym)links for each applet */
584static void install_links(const char *busybox, int use_symbolic_links)
585{
586 /* directory table
587 * this should be consistent w/ the enum,
588 * busybox.h::bb_install_loc_t, or else... */
589 static const char usr_bin [] ALIGN1 = "/usr/bin";
590 static const char usr_sbin[] ALIGN1 = "/usr/sbin";
591 static const char *const install_dir[] = {
592 &usr_bin [8], /* "", equivalent to "/" for concat_path_file() */
593 &usr_bin [4], /* "/bin" */
594 &usr_sbin[4], /* "/sbin" */
595 usr_bin,
596 usr_sbin
597 };
598
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000599 int (*lf)(const char *, const char *);
Denis Vlasenko724d1962007-10-10 14:41:07 +0000600 char *fpc;
Denis Vlasenko6b06cb82008-05-15 21:30:45 +0000601 unsigned i;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000602 int rc;
603
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000604 lf = link;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000605 if (use_symbolic_links)
606 lf = symlink;
607
Denis Vlasenko745cd172007-11-29 03:31:20 +0000608 for (i = 0; i < ARRAY_SIZE(applet_main); i++) {
Denis Vlasenko724d1962007-10-10 14:41:07 +0000609 fpc = concat_path_file(
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000610 install_dir[APPLET_INSTALL_LOC(i)],
611 APPLET_NAME(i));
Denis Vlasenko745cd172007-11-29 03:31:20 +0000612 // debug: bb_error_msg("%slinking %s to busybox",
613 // use_symbolic_links ? "sym" : "", fpc);
Denis Vlasenko724d1962007-10-10 14:41:07 +0000614 rc = lf(busybox, fpc);
615 if (rc != 0 && errno != EEXIST) {
616 bb_simple_perror_msg(fpc);
617 }
618 free(fpc);
619 }
620}
621#else
622#define install_links(x,y) ((void)0)
623#endif /* FEATURE_INSTALLER */
624
625/* If we were called as "busybox..." */
626static int busybox_main(char **argv)
627{
628 if (!argv[1]) {
629 /* Called without arguments */
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000630 const char *a;
Denis Vlasenko55995022008-05-18 22:28:26 +0000631 unsigned col, output_width;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000632 help:
633 output_width = 80;
634 if (ENABLE_FEATURE_AUTOWIDTH) {
635 /* Obtain the terminal width */
636 get_terminal_width_height(0, &output_width, NULL);
637 }
638 /* leading tab and room to wrap */
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000639 output_width -= MAX_APPLET_NAME_LEN + 8;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000640
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000641 full_write2_str(bb_banner); /* reuse const string... */
642 full_write2_str(" multi-call binary\n"
Bernhard Reutner-Fischer15ce7f52008-04-24 10:35:50 +0000643 "Copyright (C) 1998-2008 Erik Andersen, Rob Landley, Denys Vlasenko\n"
Denis Vlasenkofcfb5c02007-12-24 12:16:24 +0000644 "and others. Licensed under GPLv2.\n"
645 "See source distribution for full notice.\n"
Denis Vlasenko724d1962007-10-10 14:41:07 +0000646 "\n"
647 "Usage: busybox [function] [arguments]...\n"
Denis Vlasenkofcfb5c02007-12-24 12:16:24 +0000648 " or: function [arguments]...\n"
Denis Vlasenko724d1962007-10-10 14:41:07 +0000649 "\n"
650 "\tBusyBox is a multi-call binary that combines many common Unix\n"
651 "\tutilities into a single executable. Most people will create a\n"
652 "\tlink to busybox for each function they wish to use and BusyBox\n"
653 "\twill act like whatever it was invoked as!\n"
Denis Vlasenkofcfb5c02007-12-24 12:16:24 +0000654 "\n"
655 "Currently defined functions:\n");
Denis Vlasenko724d1962007-10-10 14:41:07 +0000656 col = 0;
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000657 a = applet_names;
658 while (*a) {
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000659 int len;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000660 if (col > output_width) {
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000661 full_write2_str(",\n");
Denis Vlasenko724d1962007-10-10 14:41:07 +0000662 col = 0;
663 }
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000664 full_write2_str(col ? ", " : "\t");
665 full_write2_str(a);
666 len = strlen(a);
667 col += len + 2;
668 a += len + 1;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000669 }
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000670 full_write2_str("\n\n");
Denis Vlasenko724d1962007-10-10 14:41:07 +0000671 return 0;
672 }
673
674 if (ENABLE_FEATURE_INSTALLER && strcmp(argv[1], "--install") == 0) {
675 const char *busybox;
676 busybox = xmalloc_readlink(bb_busybox_exec_path);
677 if (!busybox)
678 busybox = bb_busybox_exec_path;
679 /* -s makes symlinks */
680 install_links(busybox, argv[2] && strcmp(argv[2], "-s") == 0);
681 return 0;
682 }
683
684 if (strcmp(argv[1], "--help") == 0) {
685 /* "busybox --help [<applet>]" */
686 if (!argv[2])
687 goto help;
688 /* convert to "<applet> --help" */
689 argv[0] = argv[2];
690 argv[2] = NULL;
691 } else {
692 /* "busybox <applet> arg1 arg2 ..." */
693 argv++;
694 }
695 /* We support "busybox /a/path/to/applet args..." too. Allows for
696 * "#!/bin/busybox"-style wrappers */
697 applet_name = bb_get_last_path_component_nostrip(argv[0]);
698 run_applet_and_exit(applet_name, argv);
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000699
700 /*bb_error_msg_and_die("applet not found"); - sucks in printf */
701 full_write2_str(applet_name);
702 full_write2_str(": applet not found\n");
703 xfunc_die();
Denis Vlasenko724d1962007-10-10 14:41:07 +0000704}
705
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000706void run_applet_no_and_exit(int applet_no, char **argv)
Denis Vlasenko724d1962007-10-10 14:41:07 +0000707{
708 int argc = 1;
709
710 while (argv[argc])
711 argc++;
712
713 /* Reinit some shared global data */
Denis Vlasenko724d1962007-10-10 14:41:07 +0000714 xfunc_error_retval = EXIT_FAILURE;
715
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000716 applet_name = APPLET_NAME(applet_no);
Denis Vlasenko724d1962007-10-10 14:41:07 +0000717 if (argc == 2 && !strcmp(argv[1], "--help"))
718 bb_show_usage();
719 if (ENABLE_FEATURE_SUID)
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000720 check_suid(applet_no);
Denis Vlasenko745cd172007-11-29 03:31:20 +0000721 exit(applet_main[applet_no](argc, argv));
Denis Vlasenko724d1962007-10-10 14:41:07 +0000722}
723
724void run_applet_and_exit(const char *name, char **argv)
725{
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000726 int applet = find_applet_by_name(name);
727 if (applet >= 0)
728 run_applet_no_and_exit(applet, argv);
Denis Vlasenko724d1962007-10-10 14:41:07 +0000729 if (!strncmp(name, "busybox", 7))
730 exit(busybox_main(argv));
731}
732
Denis Vlasenko10f6fb12008-04-29 00:10:27 +0000733#endif /* !defined(SINGLE_APPLET_MAIN) */
Denis Vlasenko468aea22008-04-01 14:47:57 +0000734
735
Denis Vlasenko724d1962007-10-10 14:41:07 +0000736
737#if ENABLE_BUILD_LIBBUSYBOX
Denis Vlasenko85c24712008-03-17 09:04:04 +0000738int lbb_main(char **argv)
Denis Vlasenko724d1962007-10-10 14:41:07 +0000739#else
Denis Vlasenko68404f12008-03-17 09:00:54 +0000740int main(int argc ATTRIBUTE_UNUSED, char **argv)
Denis Vlasenko724d1962007-10-10 14:41:07 +0000741#endif
742{
Denis Vlasenko10f6fb12008-04-29 00:10:27 +0000743#if defined(SINGLE_APPLET_MAIN)
Denis Vlasenko468aea22008-04-01 14:47:57 +0000744 /* Only one applet is selected by the user! */
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000745 /* applet_names in this case is just "applet\0\0" */
746 lbb_prepare(applet_names USE_FEATURE_INDIVIDUAL(, argv));
Denis Vlasenko468aea22008-04-01 14:47:57 +0000747 return SINGLE_APPLET_MAIN(argc, argv);
748#else
Denis Vlasenko68404f12008-03-17 09:00:54 +0000749 lbb_prepare("busybox" USE_FEATURE_INDIVIDUAL(, argv));
Denis Vlasenko724d1962007-10-10 14:41:07 +0000750
751#if !BB_MMU
752 /* NOMMU re-exec trick sets high-order bit in first byte of name */
753 if (argv[0][0] & 0x80) {
754 re_execed = 1;
755 argv[0][0] &= 0x7f;
756 }
757#endif
758 applet_name = argv[0];
759 if (applet_name[0] == '-')
760 applet_name++;
761 applet_name = bb_basename(applet_name);
762
763 parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */
764
765 run_applet_and_exit(applet_name, argv);
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000766
767 /*bb_error_msg_and_die("applet not found"); - sucks in printf */
768 full_write2_str(applet_name);
769 full_write2_str(": applet not found\n");
770 xfunc_die();
Denis Vlasenko468aea22008-04-01 14:47:57 +0000771#endif
Denis Vlasenko724d1962007-10-10 14:41:07 +0000772}