1/* vi: set sw=4 ts=4: */
2/*
3 * Utility routines.
4 *
5 * 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.
8 *
9 * 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.
13 */
14
15/* 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#include "busybox.h"
30#include <assert.h>
31#include <malloc.h>
32/* Try to pull in PAGE_SIZE */
33#ifdef __linux__
34# include <sys/user.h>
35#endif
36#ifdef __GNU__ /* Hurd */
37# include <mach/vm_param.h>
38#endif
39
40
41/* Declare <applet>_main() */
42#define PROTOTYPES
43#include "applets.h"
44#undef PROTOTYPES
45
46
47/* Include generated applet names, pointers to <applet>_main, etc */
48#include "applet_tables.h"
49/* ...and if applet_tables generator says we have only one applet... */
50#ifdef SINGLE_APPLET_MAIN
51# undef ENABLE_FEATURE_INDIVIDUAL
52# define ENABLE_FEATURE_INDIVIDUAL 1
53# undef IF_FEATURE_INDIVIDUAL
54# define IF_FEATURE_INDIVIDUAL(...) __VA_ARGS__
55#endif
56
57
58#include "usage_compressed.h"
59
60#if ENABLE_SHOW_USAGE && !ENABLE_FEATURE_COMPRESS_USAGE
61static const char usage_messages[] ALIGN1 = UNPACKED_USAGE;
62#else
63# define usage_messages 0
64#endif
65
66#if ENABLE_FEATURE_COMPRESS_USAGE
67
68static const char packed_usage[] ALIGN1 = { PACKED_USAGE };
69# include "unarchive.h"
70static const char *unpack_usage_messages(void)
71{
72	char *outbuf = NULL;
73	bunzip_data *bd;
74	int i;
75
76	i = start_bunzip(&bd,
77			/* src_fd: */ -1,
78			/* inbuf:  */ (void *)packed_usage,
79			/* len:    */ sizeof(packed_usage));
80	/* read_bunzip can longjmp to start_bunzip, and ultimately
81	 * end up here with i != 0 on read data errors! Not trivial */
82	if (!i) {
83		/* Cannot use xmalloc: will leak bd in NOFORK case! */
84		outbuf = malloc_or_warn(sizeof(UNPACKED_USAGE));
85		if (outbuf)
86			read_bunzip(bd, outbuf, sizeof(UNPACKED_USAGE));
87	}
88	dealloc_bunzip(bd);
89	return outbuf;
90}
91# define dealloc_usage_messages(s) free(s)
92
93#else
94
95# define unpack_usage_messages() usage_messages
96# define dealloc_usage_messages(s) ((void)(s))
97
98#endif /* FEATURE_COMPRESS_USAGE */
99
100
101void FAST_FUNC bb_show_usage(void)
102{
103	if (ENABLE_SHOW_USAGE) {
104#ifdef SINGLE_APPLET_STR
105		/* Imagine that this applet is "true". Dont suck in printf! */
106		const char *p;
107		const char *usage_string = p = unpack_usage_messages();
108
109		if (*p == '\b') {
110			full_write2_str("No help available.\n\n");
111		} else {
112			full_write2_str("Usage: "SINGLE_APPLET_STR" ");
113			full_write2_str(p);
114			full_write2_str("\n\n");
115		}
116		if (ENABLE_FEATURE_CLEAN_UP)
117			dealloc_usage_messages((char*)usage_string);
118#else
119		const char *p;
120		const char *usage_string = p = unpack_usage_messages();
121		int ap = find_applet_by_name(applet_name);
122
123		if (ap < 0) /* never happens, paranoia */
124			xfunc_die();
125		while (ap) {
126			while (*p++) continue;
127			ap--;
128		}
129		full_write2_str(bb_banner);
130		full_write2_str(" multi-call binary.\n");
131		if (*p == '\b')
132			full_write2_str("\nNo help available.\n\n");
133		else {
134			full_write2_str("\nUsage: ");
135			full_write2_str(applet_name);
136			full_write2_str(" ");
137			full_write2_str(p);
138			full_write2_str("\n\n");
139		}
140		if (ENABLE_FEATURE_CLEAN_UP)
141			dealloc_usage_messages((char*)usage_string);
142#endif
143	}
144	xfunc_die();
145}
146
147#if NUM_APPLETS > 8
148/* NB: any char pointer will work as well, not necessarily applet_names */
149static int applet_name_compare(const void *name, const void *v)
150{
151	int i = (const char *)v - applet_names;
152	return strcmp(name, APPLET_NAME(i));
153}
154#endif
155int FAST_FUNC find_applet_by_name(const char *name)
156{
157#if NUM_APPLETS > 8
158	/* Do a binary search to find the applet entry given the name. */
159	const char *p;
160	p = bsearch(name, applet_names, ARRAY_SIZE(applet_main), 1, applet_name_compare);
161	if (!p)
162		return -1;
163	return p - applet_names;
164#else
165	/* A version which does not pull in bsearch */
166	int i = 0;
167	const char *p = applet_names;
168	while (i < NUM_APPLETS) {
169		if (strcmp(name, p) == 0)
170			return i;
171		p += strlen(p) + 1;
172		i++;
173	}
174	return -1;
175#endif
176}
177
178
179void lbb_prepare(const char *applet
180		IF_FEATURE_INDIVIDUAL(, char **argv))
181				MAIN_EXTERNALLY_VISIBLE;
182void lbb_prepare(const char *applet
183		IF_FEATURE_INDIVIDUAL(, char **argv))
184{
185#ifdef __GLIBC__
186	(*(int **)&bb_errno) = __errno_location();
187	barrier();
188#endif
189	applet_name = applet;
190
191	/* Set locale for everybody except 'init' */
192	if (ENABLE_LOCALE_SUPPORT && getpid() != 1)
193		setlocale(LC_ALL, "");
194
195#if ENABLE_FEATURE_INDIVIDUAL
196	/* Redundant for busybox (run_applet_and_exit covers that case)
197	 * but needed for "individual applet" mode */
198	if (argv[1]
199	 && !argv[2]
200	 && strcmp(argv[1], "--help") == 0
201	 && strncmp(applet, "busybox", 7) != 0
202	) {
203		/* Special case. POSIX says "test --help"
204		 * should be no different from e.g. "test --foo".  */
205		if (!ENABLE_TEST || strcmp(applet_name, "test") != 0)
206			bb_show_usage();
207	}
208#endif
209}
210
211/* The code below can well be in applets/applets.c, as it is used only
212 * for busybox binary, not "individual" binaries.
213 * However, keeping it here and linking it into libbusybox.so
214 * (together with remaining tiny applets/applets.o)
215 * makes it possible to avoid --whole-archive at link time.
216 * This makes (shared busybox) + libbusybox smaller.
217 * (--gc-sections would be even better....)
218 */
219
220const char *applet_name;
221#if !BB_MMU
222bool re_execed;
223#endif
224
225
226/* If not built as a single-applet executable... */
227#if !defined(SINGLE_APPLET_MAIN)
228
229IF_FEATURE_SUID(static uid_t ruid;)  /* real uid */
230
231#if ENABLE_FEATURE_SUID_CONFIG
232
233/* applets[] is const, so we have to define this "override" structure */
234static struct BB_suid_config {
235	int m_applet;
236	uid_t m_uid;
237	gid_t m_gid;
238	mode_t m_mode;
239	struct BB_suid_config *m_next;
240} *suid_config;
241
242static bool suid_cfg_readable;
243
244/* check if u is member of group g */
245static int ingroup(uid_t u, gid_t g)
246{
247	struct group *grp = getgrgid(g);
248
249	if (grp) {
250		char **mem;
251
252		for (mem = grp->gr_mem; *mem; mem++) {
253			struct passwd *pwd = getpwnam(*mem);
254
255			if (pwd && (pwd->pw_uid == u))
256				return 1;
257		}
258	}
259	return 0;
260}
261
262/* This should probably be a libbb routine.  In that case,
263 * I'd probably rename it to something like bb_trimmed_slice.
264 */
265static char *get_trimmed_slice(char *s, char *e)
266{
267	/* First, consider the value at e to be nul and back up until we
268	 * reach a non-space char.  Set the char after that (possibly at
269	 * the original e) to nul. */
270	while (e-- > s) {
271		if (!isspace(*e)) {
272			break;
273		}
274	}
275	e[1] = '\0';
276
277	/* Next, advance past all leading space and return a ptr to the
278	 * first non-space char; possibly the terminating nul. */
279	return skip_whitespace(s);
280}
281
282/* Don't depend on the tools to combine strings. */
283static const char config_file[] ALIGN1 = "/etc/busybox.conf";
284
285/* We don't supply a value for the nul, so an index adjustment is
286 * necessary below.  Also, we use unsigned short here to save some
287 * space even though these are really mode_t values. */
288static const unsigned short mode_mask[] ALIGN2 = {
289	/*  SST     sst                 xxx         --- */
290	S_ISUID,    S_ISUID|S_IXUSR,    S_IXUSR,    0,	/* user */
291	S_ISGID,    S_ISGID|S_IXGRP,    S_IXGRP,    0,	/* group */
292	0,          S_IXOTH,            S_IXOTH,    0	/* other */
293};
294
295#define parse_error(x)  do { errmsg = x; goto pe_label; } while (0)
296
297static void parse_config_file(void)
298{
299	struct BB_suid_config *sct_head;
300	struct BB_suid_config *sct;
301	int applet_no;
302	FILE *f;
303	const char *errmsg;
304	char *s;
305	char *e;
306	int i;
307	unsigned lc;
308	smallint section;
309	char buffer[256];
310	struct stat st;
311
312	assert(!suid_config); /* Should be set to NULL by bss init. */
313
314	ruid = getuid();
315	if (ruid == 0) /* run by root - don't need to even read config file */
316		return;
317
318	if ((stat(config_file, &st) != 0)       /* No config file? */
319	 || !S_ISREG(st.st_mode)                /* Not a regular file? */
320	 || (st.st_uid != 0)                    /* Not owned by root? */
321	 || (st.st_mode & (S_IWGRP | S_IWOTH))  /* Writable by non-root? */
322	 || !(f = fopen_for_read(config_file))      /* Cannot open? */
323	) {
324		return;
325	}
326
327	suid_cfg_readable = 1;
328	sct_head = NULL;
329	section = lc = 0;
330
331	while (1) {
332		s = buffer;
333
334		if (!fgets(s, sizeof(buffer), f)) { /* Are we done? */
335// why?
336			if (ferror(f)) {   /* Make sure it wasn't a read error. */
337				parse_error("reading");
338			}
339			fclose(f);
340			suid_config = sct_head;	/* Success, so set the pointer. */
341			return;
342		}
343
344		lc++;					/* Got a (partial) line. */
345
346		/* If a line is too long for our buffer, we consider it an error.
347		 * The following test does mistreat one corner case though.
348		 * If the final line of the file does not end with a newline and
349		 * yet exactly fills the buffer, it will be treated as too long
350		 * even though there isn't really a problem.  But it isn't really
351		 * worth adding code to deal with such an unlikely situation, and
352		 * we do err on the side of caution.  Besides, the line would be
353		 * too long if it did end with a newline. */
354		if (!strchr(s, '\n') && !feof(f)) {
355			parse_error("line too long");
356		}
357
358		/* Trim leading and trailing whitespace, ignoring comments, and
359		 * check if the resulting string is empty. */
360		s = get_trimmed_slice(s, strchrnul(s, '#'));
361		if (!*s) {
362			continue;
363		}
364
365		/* Check for a section header. */
366
367		if (*s == '[') {
368			/* Unlike the old code, we ignore leading and trailing
369			 * whitespace for the section name.  We also require that
370			 * there are no stray characters after the closing bracket. */
371			e = strchr(s, ']');
372			if (!e   /* Missing right bracket? */
373			 || e[1] /* Trailing characters? */
374			 || !*(s = get_trimmed_slice(s+1, e)) /* Missing name? */
375			) {
376				parse_error("section header");
377			}
378			/* Right now we only have one section so just check it.
379			 * If more sections are added in the future, please don't
380			 * resort to cascading ifs with multiple strcasecmp calls.
381			 * That kind of bloated code is all too common.  A loop
382			 * and a string table would be a better choice unless the
383			 * number of sections is very small. */
384			if (strcasecmp(s, "SUID") == 0) {
385				section = 1;
386				continue;
387			}
388			section = -1;	/* Unknown section so set to skip. */
389			continue;
390		}
391
392		/* Process sections. */
393
394		if (section == 1) {		/* SUID */
395			/* Since we trimmed leading and trailing space above, we're
396			 * now looking for strings of the form
397			 *    <key>[::space::]*=[::space::]*<value>
398			 * where both key and value could contain inner whitespace. */
399
400			/* First get the key (an applet name in our case). */
401			e = strchr(s, '=');
402			if (e) {
403				s = get_trimmed_slice(s, e);
404			}
405			if (!e || !*s) {	/* Missing '=' or empty key. */
406				parse_error("keyword");
407			}
408
409			/* Ok, we have an applet name.  Process the rhs if this
410			 * applet is currently built in and ignore it otherwise.
411			 * Note: this can hide config file bugs which only pop
412			 * up when the busybox configuration is changed. */
413			applet_no = find_applet_by_name(s);
414			if (applet_no >= 0) {
415				/* Note: We currently don't check for duplicates!
416				 * The last config line for each applet will be the
417				 * one used since we insert at the head of the list.
418				 * I suppose this could be considered a feature. */
419				sct = xmalloc(sizeof(struct BB_suid_config));
420				sct->m_applet = applet_no;
421				sct->m_mode = 0;
422				sct->m_next = sct_head;
423				sct_head = sct;
424
425				/* Get the specified mode. */
426
427				e = skip_whitespace(e+1);
428
429				for (i = 0; i < 3; i++) {
430					/* There are 4 chars + 1 nul for each of user/group/other. */
431					static const char mode_chars[] ALIGN1 = "Ssx-\0" "Ssx-\0" "Ttx-";
432
433					const char *q;
434					q = strchrnul(mode_chars + 5*i, *e++);
435					if (!*q) {
436						parse_error("mode");
437					}
438					/* Adjust by -i to account for nul. */
439					sct->m_mode |= mode_mask[(q - mode_chars) - i];
440				}
441
442				/* Now get the the user/group info. */
443
444				s = skip_whitespace(e);
445
446				/* Note: we require whitespace between the mode and the
447				 * user/group info. */
448				if ((s == e) || !(e = strchr(s, '.'))) {
449					parse_error("<uid>.<gid>");
450				}
451				*e++ = '\0';
452
453				/* We can't use get_ug_id here since it would exit()
454				 * if a uid or gid was not found.  Oh well... */
455				sct->m_uid = bb_strtoul(s, NULL, 10);
456				if (errno) {
457					struct passwd *pwd = getpwnam(s);
458					if (!pwd) {
459						parse_error("user");
460					}
461					sct->m_uid = pwd->pw_uid;
462				}
463
464				sct->m_gid = bb_strtoul(e, NULL, 10);
465				if (errno) {
466					struct group *grp;
467					grp = getgrnam(e);
468					if (!grp) {
469						parse_error("group");
470					}
471					sct->m_gid = grp->gr_gid;
472				}
473			}
474			continue;
475		}
476
477		/* Unknown sections are ignored. */
478
479		/* Encountering configuration lines prior to seeing a
480		 * section header is treated as an error.  This is how
481		 * the old code worked, but it may not be desirable.
482		 * We may want to simply ignore such lines in case they
483		 * are used in some future version of busybox. */
484		if (!section) {
485			parse_error("keyword outside section");
486		}
487
488	} /* while (1) */
489
490 pe_label:
491	fprintf(stderr, "Parse error in %s, line %d: %s\n",
492			config_file, lc, errmsg);
493
494	fclose(f);
495	/* Release any allocated memory before returning. */
496	while (sct_head) {
497		sct = sct_head->m_next;
498		free(sct_head);
499		sct_head = sct;
500	}
501}
502#else
503static inline void parse_config_file(void)
504{
505	IF_FEATURE_SUID(ruid = getuid();)
506}
507#endif /* FEATURE_SUID_CONFIG */
508
509
510#if ENABLE_FEATURE_SUID
511static void check_suid(int applet_no)
512{
513	gid_t rgid;  /* real gid */
514
515	if (ruid == 0) /* set by parse_config_file() */
516		return; /* run by root - no need to check more */
517	rgid = getgid();
518
519#if ENABLE_FEATURE_SUID_CONFIG
520	if (suid_cfg_readable) {
521		uid_t uid;
522		struct BB_suid_config *sct;
523		mode_t m;
524
525		for (sct = suid_config; sct; sct = sct->m_next) {
526			if (sct->m_applet == applet_no)
527				goto found;
528		}
529		goto check_need_suid;
530 found:
531		m = sct->m_mode;
532		if (sct->m_uid == ruid)
533			/* same uid */
534			m >>= 6;
535		else if ((sct->m_gid == rgid) || ingroup(ruid, sct->m_gid))
536			/* same group / in group */
537			m >>= 3;
538
539		if (!(m & S_IXOTH))           /* is x bit not set ? */
540			bb_error_msg_and_die("you have no permission to run this applet!");
541
542		/* _both_ sgid and group_exec have to be set for setegid */
543		if ((sct->m_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP))
544			rgid = sct->m_gid;
545		/* else (no setegid) we will set egid = rgid */
546
547		/* We set effective AND saved ids. If saved-id is not set
548		 * like we do below, seteiud(0) can still later succeed! */
549		if (setresgid(-1, rgid, rgid))
550			bb_perror_msg_and_die("setresgid");
551
552		/* do we have to set effective uid? */
553		uid = ruid;
554		if (sct->m_mode & S_ISUID)
555			uid = sct->m_uid;
556		/* else (no seteuid) we will set euid = ruid */
557
558		if (setresuid(-1, uid, uid))
559			bb_perror_msg_and_die("setresuid");
560		return;
561	}
562#if !ENABLE_FEATURE_SUID_CONFIG_QUIET
563	{
564		static bool onetime = 0;
565
566		if (!onetime) {
567			onetime = 1;
568			fprintf(stderr, "Using fallback suid method\n");
569		}
570	}
571#endif
572 check_need_suid:
573#endif
574	if (APPLET_SUID(applet_no) == _BB_SUID_REQUIRE) {
575		/* Real uid is not 0. If euid isn't 0 too, suid bit
576		 * is most probably not set on our executable */
577		if (geteuid())
578			bb_error_msg_and_die("must be suid to work properly");
579	} else if (APPLET_SUID(applet_no) == _BB_SUID_DROP) {
580		xsetgid(rgid);  /* drop all privileges */
581		xsetuid(ruid);
582	}
583}
584#else
585#define check_suid(x) ((void)0)
586#endif /* FEATURE_SUID */
587
588
589#if ENABLE_FEATURE_INSTALLER
590static const char usr_bin [] ALIGN1 = "/usr/bin/";
591static const char usr_sbin[] ALIGN1 = "/usr/sbin/";
592static const char *const install_dir[] = {
593	&usr_bin [8], /* "/" */
594	&usr_bin [4], /* "/bin/" */
595	&usr_sbin[4], /* "/sbin/" */
596	usr_bin,
597	usr_sbin
598};
599
600
601/* create (sym)links for each applet */
602static void install_links(const char *busybox, int use_symbolic_links,
603		char *custom_install_dir)
604{
605	/* directory table
606	 * this should be consistent w/ the enum,
607	 * busybox.h::bb_install_loc_t, or else... */
608	int (*lf)(const char *, const char *);
609	char *fpc;
610	unsigned i;
611	int rc;
612
613	lf = link;
614	if (use_symbolic_links)
615		lf = symlink;
616
617	for (i = 0; i < ARRAY_SIZE(applet_main); i++) {
618		fpc = concat_path_file(
619				custom_install_dir ? custom_install_dir : install_dir[APPLET_INSTALL_LOC(i)],
620				APPLET_NAME(i));
621		// debug: bb_error_msg("%slinking %s to busybox",
622		//		use_symbolic_links ? "sym" : "", fpc);
623		rc = lf(busybox, fpc);
624		if (rc != 0 && errno != EEXIST) {
625			bb_simple_perror_msg(fpc);
626		}
627		free(fpc);
628	}
629}
630#else
631# define install_links(x,y,z) ((void)0)
632#endif
633
634/* If we were called as "busybox..." */
635static int busybox_main(char **argv)
636{
637	if (!argv[1]) {
638		/* Called without arguments */
639		const char *a;
640		int col;
641		unsigned output_width;
642 help:
643		output_width = 80;
644		if (ENABLE_FEATURE_AUTOWIDTH) {
645			/* Obtain the terminal width */
646			get_terminal_width_height(0, &output_width, NULL);
647		}
648
649		dup2(1, 2);
650		full_write2_str(bb_banner); /* reuse const string */
651		full_write2_str(" multi-call binary.\n"); /* reuse */
652		full_write2_str(
653			"Copyright (C) 1998-2009 Erik Andersen, Rob Landley, Denys Vlasenko\n"
654			"and others. Licensed under GPLv2.\n"
655			"See source distribution for full notice.\n"
656			"\n"
657			"Usage: busybox [function] [arguments]...\n"
658			"   or: function [arguments]...\n"
659			"\n"
660			"\tBusyBox is a multi-call binary that combines many common Unix\n"
661			"\tutilities into a single executable.  Most people will create a\n"
662			"\tlink to busybox for each function they wish to use and BusyBox\n"
663			"\twill act like whatever it was invoked as.\n"
664			"\n"
665			"Currently defined functions:\n"
666		);
667		col = 0;
668		a = applet_names;
669		/* prevent last comma to be in the very last pos */
670		output_width--;
671		while (*a) {
672			int len2 = strlen(a) + 2;
673			if (col >= (int)output_width - len2) {
674				full_write2_str(",\n");
675				col = 0;
676			}
677			if (col == 0) {
678				col = 6;
679				full_write2_str("\t");
680			} else {
681				full_write2_str(", ");
682			}
683			full_write2_str(a);
684			col += len2;
685			a += len2 - 1;
686		}
687		full_write2_str("\n\n");
688		return 0;
689	}
690
691	if (strncmp(argv[1], "--list", 6) == 0) {
692		unsigned i = 0;
693		const char *a = applet_names;
694		dup2(1, 2);
695		while (*a) {
696#if ENABLE_FEATURE_INSTALLER
697			if (argv[1][6]) /* --list-path? */
698				full_write2_str(install_dir[APPLET_INSTALL_LOC(i)] + 1);
699#endif
700			full_write2_str(a);
701			full_write2_str("\n");
702			i++;
703			a += strlen(a) + 1;
704		}
705		return 0;
706	}
707
708	if (ENABLE_FEATURE_INSTALLER && strcmp(argv[1], "--install") == 0) {
709		int use_symbolic_links;
710		const char *busybox;
711		busybox = xmalloc_readlink(bb_busybox_exec_path);
712		if (!busybox)
713			busybox = bb_busybox_exec_path;
714		/* busybox --install [-s] [DIR]: */
715		/* -s: make symlinks */
716		/* DIR: directory to install links to */
717		use_symbolic_links = (argv[2] && strcmp(argv[2], "-s") == 0 && argv++);
718		install_links(busybox, use_symbolic_links, argv[2]);
719		return 0;
720	}
721
722	if (strcmp(argv[1], "--help") == 0) {
723		/* "busybox --help [<applet>]" */
724		if (!argv[2])
725			goto help;
726		/* convert to "<applet> --help" */
727		argv[0] = argv[2];
728		argv[2] = NULL;
729	} else {
730		/* "busybox <applet> arg1 arg2 ..." */
731		argv++;
732	}
733	/* We support "busybox /a/path/to/applet args..." too. Allows for
734	 * "#!/bin/busybox"-style wrappers */
735	applet_name = bb_get_last_path_component_nostrip(argv[0]);
736	run_applet_and_exit(applet_name, argv);
737
738	/*bb_error_msg_and_die("applet not found"); - sucks in printf */
739	full_write2_str(applet_name);
740	full_write2_str(": applet not found\n");
741	xfunc_die();
742}
743
744void FAST_FUNC run_applet_no_and_exit(int applet_no, char **argv)
745{
746	int argc = 1;
747
748	while (argv[argc])
749		argc++;
750
751	/* Reinit some shared global data */
752	xfunc_error_retval = EXIT_FAILURE;
753
754	applet_name = APPLET_NAME(applet_no);
755	if (argc == 2 && strcmp(argv[1], "--help") == 0) {
756		/* Special case. POSIX says "test --help"
757		 * should be no different from e.g. "test --foo".  */
758//TODO: just compare applet_no with APPLET_NO_test
759		if (!ENABLE_TEST || strcmp(applet_name, "test") != 0)
760			bb_show_usage();
761	}
762	if (ENABLE_FEATURE_SUID)
763		check_suid(applet_no);
764	exit(applet_main[applet_no](argc, argv));
765}
766
767void FAST_FUNC run_applet_and_exit(const char *name, char **argv)
768{
769	int applet = find_applet_by_name(name);
770	if (applet >= 0)
771		run_applet_no_and_exit(applet, argv);
772	if (!strncmp(name, "busybox", 7))
773		exit(busybox_main(argv));
774}
775
776#endif /* !defined(SINGLE_APPLET_MAIN) */
777
778
779
780#if ENABLE_BUILD_LIBBUSYBOX
781int lbb_main(char **argv)
782#else
783int main(int argc UNUSED_PARAM, char **argv)
784#endif
785{
786	/* Tweak malloc for reduced memory consumption */
787#ifndef PAGE_SIZE
788# define PAGE_SIZE (4*1024) /* guess */
789#endif
790#ifdef M_TRIM_THRESHOLD
791	/* M_TRIM_THRESHOLD is the maximum amount of freed top-most memory
792	 * to keep before releasing to the OS
793	 * Default is way too big: 256k
794	 */
795	mallopt(M_TRIM_THRESHOLD, 2 * PAGE_SIZE);
796#endif
797#ifdef M_MMAP_THRESHOLD
798	/* M_MMAP_THRESHOLD is the request size threshold for using mmap()
799	 * Default is too big: 256k
800	 */
801	mallopt(M_MMAP_THRESHOLD, 8 * PAGE_SIZE - 256);
802#endif
803
804#if defined(SINGLE_APPLET_MAIN)
805	/* Only one applet is selected by the user! */
806	/* applet_names in this case is just "applet\0\0" */
807	lbb_prepare(applet_names IF_FEATURE_INDIVIDUAL(, argv));
808	return SINGLE_APPLET_MAIN(argc, argv);
809#else
810	lbb_prepare("busybox" IF_FEATURE_INDIVIDUAL(, argv));
811
812#if !BB_MMU
813	/* NOMMU re-exec trick sets high-order bit in first byte of name */
814	if (argv[0][0] & 0x80) {
815		re_execed = 1;
816		argv[0][0] &= 0x7f;
817	}
818#endif
819	applet_name = argv[0];
820	if (applet_name[0] == '-')
821		applet_name++;
822	applet_name = bb_basename(applet_name);
823
824	parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */
825
826	run_applet_and_exit(applet_name, argv);
827
828	/*bb_error_msg_and_die("applet not found"); - sucks in printf */
829	full_write2_str(applet_name);
830	full_write2_str(": applet not found\n");
831	xfunc_die();
832#endif
833}
834