1 /* vi: set sw=4 ts=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.
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 GPL.
12 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
15 /* We are trying to not use printf, this benefits the case when selected
16 * applets are really simple. Example:
20 * Currently defined functions:
21 * basename, false, true
24 * text data bss dec hex filename
25 * 4473 52 72 4597 11f5 busybox
27 * FEATURE_INSTALLER or FEATURE_SUID will still link printf routines in. :(
31 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
32 || defined(__APPLE__) \
34 # include <malloc.h> /* for mallopt */
38 /* Declare <applet>_main() */
43 /* Include generated applet names, pointers to <applet>_main, etc */
44 #include "applet_tables.h"
45 /* ...and if applet_tables generator says we have only one applet... */
46 #ifdef SINGLE_APPLET_MAIN
47 # undef ENABLE_FEATURE_INDIVIDUAL
48 # define ENABLE_FEATURE_INDIVIDUAL 1
49 # undef IF_FEATURE_INDIVIDUAL
50 # define IF_FEATURE_INDIVIDUAL(...) __VA_ARGS__
53 #include "usage_compressed.h"
55 #if ENABLE_SHOW_USAGE && !ENABLE_FEATURE_COMPRESS_USAGE
56 static const char usage_messages[] ALIGN1 = UNPACKED_USAGE;
58 # define usage_messages 0
61 #if ENABLE_FEATURE_COMPRESS_USAGE
63 static const char packed_usage[] ALIGN1 = { PACKED_USAGE };
64 # include "bb_archive.h"
65 static const char *unpack_usage_messages(void)
73 /* inbuf: */ packed_usage,
74 /* len: */ sizeof(packed_usage));
75 /* read_bunzip can longjmp to start_bunzip, and ultimately
76 * end up here with i != 0 on read data errors! Not trivial */
78 /* Cannot use xmalloc: will leak bd in NOFORK case! */
79 outbuf = malloc_or_warn(sizeof(UNPACKED_USAGE));
81 read_bunzip(bd, outbuf, sizeof(UNPACKED_USAGE));
86 # define dealloc_usage_messages(s) free(s)
90 # define unpack_usage_messages() usage_messages
91 # define dealloc_usage_messages(s) ((void)(s))
93 #endif /* FEATURE_COMPRESS_USAGE */
96 void FAST_FUNC bb_show_usage(void)
98 if (ENABLE_SHOW_USAGE) {
99 #ifdef SINGLE_APPLET_STR
100 /* Imagine that this applet is "true". Dont suck in printf! */
101 const char *usage_string = unpack_usage_messages();
103 if (*usage_string == '\b') {
104 full_write2_str("No help available.\n\n");
106 full_write2_str("Usage: "SINGLE_APPLET_STR" ");
107 full_write2_str(usage_string);
108 full_write2_str("\n\n");
110 if (ENABLE_FEATURE_CLEAN_UP)
111 dealloc_usage_messages((char*)usage_string);
114 const char *usage_string = p = unpack_usage_messages();
115 int ap = find_applet_by_name(applet_name);
117 if (ap < 0) /* never happens, paranoia */
120 while (*p++) continue;
123 full_write2_str(bb_banner);
124 full_write2_str(" multi-call binary.\n");
126 full_write2_str("\nNo help available.\n\n");
128 full_write2_str("\nUsage: ");
129 full_write2_str(applet_name);
130 full_write2_str(" ");
132 full_write2_str("\n");
134 if (ENABLE_FEATURE_CLEAN_UP)
135 dealloc_usage_messages((char*)usage_string);
141 int FAST_FUNC find_applet_by_name(const char *name)
147 /* The commented-out word-at-a-time code is ~40% faster, but +160 bytes.
148 * "Faster" here saves ~0.5 microsecond of real time - not worth it.
150 #if 0 /*BB_UNALIGNED_MEMACCESS_OK && BB_LITTLE_ENDIAN*/
153 /* Handle all names < 2 chars long early */
155 return -1; /* "" is not a valid applet name */
156 if (name[1] == '\0') {
158 return -1; /* 1-char name is not valid */
160 return -1; /* 1-char name which isn't "[" is not valid */
161 /* applet "[" is always applet #0: */
168 #if KNOWN_APPNAME_OFFSETS <= 0
171 max = NUM_APPLETS * KNOWN_APPNAME_OFFSETS;
172 for (j = ARRAY_SIZE(applet_nameofs)-1; j >= 0; j--) {
173 const char *pp = applet_names + applet_nameofs[j];
174 if (strcmp(name, pp) >= 0) {
175 //bb_error_msg("name:'%s' >= pp:'%s'", name, pp);
177 i = max - NUM_APPLETS;
182 max /= (unsigned)KNOWN_APPNAME_OFFSETS;
183 i /= (unsigned)KNOWN_APPNAME_OFFSETS;
184 //bb_error_msg("name:'%s' starting from:'%s' i:%u max:%u", name, p, i, max);
187 /* Open-coded linear search without strcmp/strlen calls for speed */
189 #if 0 /*BB_UNALIGNED_MEMACCESS_OK && BB_LITTLE_ENDIAN*/
190 /* skip "[\0" name, it's surely not it */
191 if (ENABLE_TEST && LONE_CHAR(p, '['))
193 /* All remaining applet names in p[] are at least 2 chars long */
194 /* name[] is also at least 2 chars long */
196 n32 = (name[0] << 0) | (name[1] << 8) | (name[2] << 16);
201 /* Quickly check match of the first 3 bytes */
202 move_from_unaligned32(p32, p);
204 if ((p32 & 0x00ffffff) != n32) {
205 /* Most likely case: 3 first bytes do not match */
207 if ((p32 & 0x00ff0000) == '\0')
208 continue; // p[2] was NUL
210 if ((p32 & 0xff000000) == '\0')
211 continue; // p[3] was NUL
212 /* p[0..3] aren't matching and none is NUL, check the rest */
218 /* Unlikely branch: first 3 bytes ([0..2]) match */
219 if ((p32 & 0x00ff0000) == '\0') {
220 /* name is 2-byte long, it is full match */
221 //bb_error_msg("found:'%s' i:%u", name, i);
224 /* Check remaining bytes [3..NUL] */
227 while (ch == name[j]) {
229 //bb_error_msg("found:'%s' i:%u", name, i);
235 /* Not a match. Skip it, including NUL */
246 /* Do we see "name\0" in applet_names[p] position? */
247 while ((ch = *p) == name[j]) {
249 //bb_error_msg("found:'%s' i:%u", name, i);
256 * p => 1st non-matching char in applet_names[],
257 * skip to and including NUL.
269 void lbb_prepare(const char *applet
270 IF_FEATURE_INDIVIDUAL(, char **argv))
271 MAIN_EXTERNALLY_VISIBLE;
272 void lbb_prepare(const char *applet
273 IF_FEATURE_INDIVIDUAL(, char **argv))
276 (*(int **)&bb_errno) = __errno_location();
279 applet_name = applet;
281 if (ENABLE_LOCALE_SUPPORT)
282 setlocale(LC_ALL, "");
284 #if ENABLE_FEATURE_INDIVIDUAL
285 /* Redundant for busybox (run_applet_and_exit covers that case)
286 * but needed for "individual applet" mode */
289 && strcmp(argv[1], "--help") == 0
290 && !is_prefixed_with(applet, "busybox")
292 /* Special case. POSIX says "test --help"
293 * should be no different from e.g. "test --foo". */
294 if (!ENABLE_TEST || strcmp(applet_name, "test") != 0)
300 /* The code below can well be in applets/applets.c, as it is used only
301 * for busybox binary, not "individual" binaries.
302 * However, keeping it here and linking it into libbusybox.so
303 * (together with remaining tiny applets/applets.o)
304 * makes it possible to avoid --whole-archive at link time.
305 * This makes (shared busybox) + libbusybox smaller.
306 * (--gc-sections would be even better....)
309 const char *applet_name;
315 /* If not built as a single-applet executable... */
316 #if !defined(SINGLE_APPLET_MAIN)
318 IF_FEATURE_SUID(static uid_t ruid;) /* real uid */
320 # if ENABLE_FEATURE_SUID_CONFIG
322 static struct suid_config_t {
323 /* next ptr must be first: this struct needs to be llist-compatible */
324 struct suid_config_t *m_next;
325 struct bb_uidgid_t m_ugid;
330 static bool suid_cfg_readable;
332 /* check if u is member of group g */
333 static int ingroup(uid_t u, gid_t g)
335 struct group *grp = getgrgid(g);
338 for (mem = grp->gr_mem; *mem; mem++) {
339 struct passwd *pwd = getpwnam(*mem);
340 if (pwd && (pwd->pw_uid == u))
347 /* libbb candidate */
348 static char *get_trimmed_slice(char *s, char *e)
350 /* First, consider the value at e to be nul and back up until we
351 * reach a non-space char. Set the char after that (possibly at
352 * the original e) to nul. */
360 /* Next, advance past all leading space and return a ptr to the
361 * first non-space char; possibly the terminating nul. */
362 return skip_whitespace(s);
365 static void parse_config_file(void)
367 /* Don't depend on the tools to combine strings. */
368 static const char config_file[] ALIGN1 = "/etc/busybox.conf";
370 struct suid_config_t *sct_head;
379 if (ruid == 0) /* run by root - don't need to even read config file */
382 if ((stat(config_file, &st) != 0) /* No config file? */
383 || !S_ISREG(st.st_mode) /* Not a regular file? */
384 || (st.st_uid != 0) /* Not owned by root? */
385 || (st.st_mode & (S_IWGRP | S_IWOTH)) /* Writable by non-root? */
386 || !(f = fopen_for_read(config_file)) /* Cannot open? */
391 suid_cfg_readable = 1;
399 if (!fgets(buffer, sizeof(buffer), f)) { /* Are we done? */
401 //if (ferror(f)) { /* Make sure it wasn't a read error. */
402 // errmsg = "reading";
406 suid_config = sct_head; /* Success, so set the pointer. */
411 lc++; /* Got a (partial) line. */
413 /* If a line is too long for our buffer, we consider it an error.
414 * The following test does mistreat one corner case though.
415 * If the final line of the file does not end with a newline and
416 * yet exactly fills the buffer, it will be treated as too long
417 * even though there isn't really a problem. But it isn't really
418 * worth adding code to deal with such an unlikely situation, and
419 * we do err on the side of caution. Besides, the line would be
420 * too long if it did end with a newline. */
421 if (!strchr(s, '\n') && !feof(f)) {
422 errmsg = "line too long";
426 /* Trim leading and trailing whitespace, ignoring comments, and
427 * check if the resulting string is empty. */
428 s = get_trimmed_slice(s, strchrnul(s, '#'));
433 /* Check for a section header. */
436 /* Unlike the old code, we ignore leading and trailing
437 * whitespace for the section name. We also require that
438 * there are no stray characters after the closing bracket. */
439 char *e = strchr(s, ']');
440 if (!e /* Missing right bracket? */
441 || e[1] /* Trailing characters? */
442 || !*(s = get_trimmed_slice(s+1, e)) /* Missing name? */
444 errmsg = "section header";
447 /* Right now we only have one section so just check it.
448 * If more sections are added in the future, please don't
449 * resort to cascading ifs with multiple strcasecmp calls.
450 * That kind of bloated code is all too common. A loop
451 * and a string table would be a better choice unless the
452 * number of sections is very small. */
453 if (strcasecmp(s, "SUID") == 0) {
457 section = -1; /* Unknown section so set to skip. */
461 /* Process sections. */
463 if (section == 1) { /* SUID */
464 /* Since we trimmed leading and trailing space above, we're
465 * now looking for strings of the form
466 * <key>[::space::]*=[::space::]*<value>
467 * where both key and value could contain inner whitespace. */
469 /* First get the key (an applet name in our case). */
470 char *e = strchr(s, '=');
472 s = get_trimmed_slice(s, e);
474 if (!e || !*s) { /* Missing '=' or empty key. */
479 /* Ok, we have an applet name. Process the rhs if this
480 * applet is currently built in and ignore it otherwise.
481 * Note: this can hide config file bugs which only pop
482 * up when the busybox configuration is changed. */
483 applet_no = find_applet_by_name(s);
484 if (applet_no >= 0) {
486 struct suid_config_t *sct;
488 /* Note: We currently don't check for duplicates!
489 * The last config line for each applet will be the
490 * one used since we insert at the head of the list.
491 * I suppose this could be considered a feature. */
492 sct = xzalloc(sizeof(*sct));
493 sct->m_applet = applet_no;
495 sct->m_next = sct_head;
498 /* Get the specified mode. */
500 e = skip_whitespace(e+1);
502 for (i = 0; i < 3; i++) {
503 /* There are 4 chars for each of user/group/other.
504 * "x-xx" instead of "x-" are to make
505 * "idx > 3" check catch invalid chars.
507 static const char mode_chars[] ALIGN1 = "Ssx-" "Ssx-" "x-xx";
508 static const unsigned short mode_mask[] ALIGN2 = {
509 S_ISUID, S_ISUID|S_IXUSR, S_IXUSR, 0, /* Ssx- */
510 S_ISGID, S_ISGID|S_IXGRP, S_IXGRP, 0, /* Ssx- */
513 const char *q = strchrnul(mode_chars + 4*i, *e);
514 unsigned idx = q - (mode_chars + 4*i);
519 sct->m_mode |= mode_mask[q - mode_chars];
523 /* Now get the user/group info. */
525 s = skip_whitespace(e);
526 /* Default is 0.0, else parse USER.GROUP: */
528 /* We require whitespace between mode and USER.GROUP */
529 if ((s == e) || !(e = strchr(s, '.'))) {
533 *e = ':'; /* get_uidgid needs USER:GROUP syntax */
534 if (get_uidgid(&sct->m_ugid, s) == 0) {
535 errmsg = "unknown user/group";
543 /* Unknown sections are ignored. */
545 /* Encountering configuration lines prior to seeing a
546 * section header is treated as an error. This is how
547 * the old code worked, but it may not be desirable.
548 * We may want to simply ignore such lines in case they
549 * are used in some future version of busybox. */
551 errmsg = "keyword outside section";
558 bb_error_msg("parse error in %s, line %u: %s", config_file, lc, errmsg);
560 /* Release any allocated memory before returning. */
561 llist_free((llist_t*)sct_head, NULL);
564 static inline void parse_config_file(void)
566 IF_FEATURE_SUID(ruid = getuid();)
568 # endif /* FEATURE_SUID_CONFIG */
571 # if ENABLE_FEATURE_SUID
572 static void check_suid(int applet_no)
574 gid_t rgid; /* real gid */
576 if (ruid == 0) /* set by parse_config_file() */
577 return; /* run by root - no need to check more */
580 # if ENABLE_FEATURE_SUID_CONFIG
581 if (suid_cfg_readable) {
583 struct suid_config_t *sct;
586 for (sct = suid_config; sct; sct = sct->m_next) {
587 if (sct->m_applet == applet_no)
590 goto check_need_suid;
592 /* Is this user allowed to run this applet? */
594 if (sct->m_ugid.uid == ruid)
597 else if ((sct->m_ugid.gid == rgid) || ingroup(ruid, sct->m_ugid.gid))
598 /* same group / in group */
600 if (!(m & S_IXOTH)) /* is x bit not set? */
601 bb_error_msg_and_die("you have no permission to run this applet");
603 /* We set effective AND saved ids. If saved-id is not set
604 * like we do below, seteuid(0) can still later succeed! */
606 /* Are we directed to change gid
607 * (APPLET = *s* USER.GROUP or APPLET = *S* USER.GROUP)?
609 if (sct->m_mode & S_ISGID)
610 rgid = sct->m_ugid.gid;
611 /* else: we will set egid = rgid, thus dropping sgid effect */
612 if (setresgid(-1, rgid, rgid))
613 bb_perror_msg_and_die("setresgid");
615 /* Are we directed to change uid
616 * (APPLET = s** USER.GROUP or APPLET = S** USER.GROUP)?
619 if (sct->m_mode & S_ISUID)
620 uid = sct->m_ugid.uid;
621 /* else: we will set euid = ruid, thus dropping suid effect */
622 if (setresuid(-1, uid, uid))
623 bb_perror_msg_and_die("setresuid");
627 # if !ENABLE_FEATURE_SUID_CONFIG_QUIET
629 static bool onetime = 0;
633 bb_error_msg("using fallback suid method");
639 if (APPLET_SUID(applet_no) == BB_SUID_REQUIRE) {
640 /* Real uid is not 0. If euid isn't 0 too, suid bit
641 * is most probably not set on our executable */
643 bb_error_msg_and_die("must be suid to work properly");
644 } else if (APPLET_SUID(applet_no) == BB_SUID_DROP) {
645 xsetgid(rgid); /* drop all privileges */
648 # if ENABLE_FEATURE_SUID_CONFIG
650 llist_free((llist_t*)suid_config, NULL);
654 # define check_suid(x) ((void)0)
655 # endif /* FEATURE_SUID */
658 # if ENABLE_FEATURE_INSTALLER
659 static const char usr_bin [] ALIGN1 = "/usr/bin/";
660 static const char usr_sbin[] ALIGN1 = "/usr/sbin/";
661 static const char *const install_dir[] = {
662 &usr_bin [8], /* "/" */
663 &usr_bin [4], /* "/bin/" */
664 &usr_sbin[4] /* "/sbin/" */
665 # if !ENABLE_INSTALL_NO_USR
671 /* create (sym)links for each applet */
672 static void install_links(const char *busybox, int use_symbolic_links,
673 char *custom_install_dir)
676 * this should be consistent w/ the enum,
677 * busybox.h::bb_install_loc_t, or else... */
678 int (*lf)(const char *, const char *);
680 const char *appname = applet_names;
685 if (use_symbolic_links)
688 for (i = 0; i < ARRAY_SIZE(applet_main); i++) {
689 fpc = concat_path_file(
690 custom_install_dir ? custom_install_dir : install_dir[APPLET_INSTALL_LOC(i)],
692 // debug: bb_error_msg("%slinking %s to busybox",
693 // use_symbolic_links ? "sym" : "", fpc);
694 rc = lf(busybox, fpc);
695 if (rc != 0 && errno != EEXIST) {
696 bb_simple_perror_msg(fpc);
699 while (*appname++ != '\0')
703 # elif ENABLE_BUSYBOX
704 static void install_links(const char *busybox UNUSED_PARAM,
705 int use_symbolic_links UNUSED_PARAM,
706 char *custom_install_dir UNUSED_PARAM)
712 static void run_applet_and_exit(const char *name, char **argv) NORETURN;
714 /* If we were called as "busybox..." */
715 static int busybox_main(char **argv)
718 /* Called without arguments */
721 unsigned output_width;
724 if (ENABLE_FEATURE_AUTOWIDTH) {
725 /* Obtain the terminal width */
726 output_width = get_terminal_width(2);
730 full_write2_str(bb_banner); /* reuse const string */
731 full_write2_str(" multi-call binary.\n"); /* reuse */
733 "BusyBox is copyrighted by many authors between 1998-2015.\n"
734 "Licensed under GPLv2. See source distribution for detailed\n"
735 "copyright notices.\n"
737 "Usage: busybox [function [arguments]...]\n"
738 " or: busybox --list"IF_FEATURE_INSTALLER("[-full]")"\n"
739 IF_FEATURE_INSTALLER(
740 " or: busybox --install [-s] [DIR]\n"
742 " or: function [arguments]...\n"
744 IF_NOT_FEATURE_SH_STANDALONE(
745 "\tBusyBox is a multi-call binary that combines many common Unix\n"
746 "\tutilities into a single executable. Most people will create a\n"
747 "\tlink to busybox for each function they wish to use and BusyBox\n"
748 "\twill act like whatever it was invoked as.\n"
750 IF_FEATURE_SH_STANDALONE(
751 "\tBusyBox is a multi-call binary that combines many common Unix\n"
752 "\tutilities into a single executable. The shell in this build\n"
753 "\tis configured to run built-in utilities without $PATH search.\n"
754 "\tYou don't need to install a link to busybox for each utility.\n"
755 "\tTo run external program, use full path (/sbin/ip instead of ip).\n"
758 "Currently defined functions:\n"
762 /* prevent last comma to be in the very last pos */
765 int len2 = strlen(a) + 2;
766 if (col >= (int)output_width - len2) {
767 full_write2_str(",\n");
772 full_write2_str("\t");
774 full_write2_str(", ");
780 full_write2_str("\n\n");
784 if (is_prefixed_with(argv[1], "--list")) {
786 const char *a = applet_names;
789 # if ENABLE_FEATURE_INSTALLER
790 if (argv[1][6]) /* --list-full? */
791 full_write2_str(install_dir[APPLET_INSTALL_LOC(i)] + 1);
794 full_write2_str("\n");
802 if (ENABLE_FEATURE_INSTALLER && strcmp(argv[1], "--install") == 0) {
803 int use_symbolic_links;
806 busybox = xmalloc_readlink(bb_busybox_exec_path);
808 /* bb_busybox_exec_path is usually "/proc/self/exe".
809 * In chroot, readlink("/proc/self/exe") usually fails.
810 * In such case, better use argv[0] as symlink target
811 * if it is a full path name.
813 if (argv[0][0] != '/')
814 bb_error_msg_and_die("'%s' is not an absolute path", argv[0]);
817 /* busybox --install [-s] [DIR]:
819 * DIR: directory to install links to
821 use_symbolic_links = (argv[2] && strcmp(argv[2], "-s") == 0 && ++argv);
822 install_links(busybox, use_symbolic_links, argv[2]);
826 if (strcmp(argv[1], "--help") == 0) {
827 /* "busybox --help [<applet>]" */
830 /* convert to "<applet> --help" */
834 /* "busybox <applet> arg1 arg2 ..." */
837 /* We support "busybox /a/path/to/applet args..." too. Allows for
838 * "#!/bin/busybox"-style wrappers */
839 applet_name = bb_get_last_path_component_nostrip(argv[0]);
840 run_applet_and_exit(applet_name, argv);
845 void FAST_FUNC run_applet_no_and_exit(int applet_no, char **argv)
852 /* Reinit some shared global data */
853 xfunc_error_retval = EXIT_FAILURE;
854 applet_name = bb_get_last_path_component_nostrip(argv[0]);
856 /* Special case. POSIX says "test --help"
857 * should be no different from e.g. "test --foo".
858 * Thus for "test", we skip --help check.
859 * "true" and "false" are also special.
862 # if defined APPLET_NO_test
863 && applet_no != APPLET_NO_test
865 # if defined APPLET_NO_true
866 && applet_no != APPLET_NO_true
868 # if defined APPLET_NO_false
869 && applet_no != APPLET_NO_false
872 if (argc == 2 && strcmp(argv[1], "--help") == 0) {
873 /* Make "foo --help" exit with 0: */
874 xfunc_error_retval = 0;
878 if (ENABLE_FEATURE_SUID)
879 check_suid(applet_no);
880 xfunc_error_retval = applet_main[applet_no](argc, argv);
881 /* Note: applet_main() may also not return (die on a xfunc or such) */
884 # endif /* NUM_APPLETS > 0 */
886 static NORETURN void run_applet_and_exit(const char *name, char **argv)
889 if (is_prefixed_with(name, "busybox"))
890 exit(busybox_main(argv));
893 /* find_applet_by_name() search is more expensive, so goes second */
895 int applet = find_applet_by_name(name);
897 run_applet_no_and_exit(applet, argv);
901 /*bb_error_msg_and_die("applet not found"); - links in printf */
902 full_write2_str(applet_name);
903 full_write2_str(": applet not found\n");
904 /* POSIX: "If a command is not found, the exit status shall be 127" */
908 #endif /* !defined(SINGLE_APPLET_MAIN) */
912 #if ENABLE_BUILD_LIBBUSYBOX
913 int lbb_main(char **argv)
915 int main(int argc UNUSED_PARAM, char **argv)
919 /* TODO: find a use for a block of memory between end of .bss
920 * and end of page. For example, I'm getting "_end:0x812e698 2408 bytes"
921 * - more than 2k of wasted memory (in this particular build)
922 * *per each running process*!
923 * (If your linker does not generate "_end" name, weak attribute
924 * makes &_end == NULL, end_len == 0 here.)
926 extern char _end[] __attribute__((weak));
927 unsigned end_len = (-(int)_end) & 0xfff;
928 printf("_end:%p %u bytes\n", &_end, end_len);
931 /* Tweak malloc for reduced memory consumption */
932 #ifdef M_TRIM_THRESHOLD
933 /* M_TRIM_THRESHOLD is the maximum amount of freed top-most memory
934 * to keep before releasing to the OS
935 * Default is way too big: 256k
937 mallopt(M_TRIM_THRESHOLD, 8 * 1024);
939 #ifdef M_MMAP_THRESHOLD
940 /* M_MMAP_THRESHOLD is the request size threshold for using mmap()
941 * Default is too big: 256k
943 mallopt(M_MMAP_THRESHOLD, 32 * 1024 - 256);
947 /* NOMMU re-exec trick sets high-order bit in first byte of name */
948 if (argv[0][0] & 0x80) {
954 #if defined(SINGLE_APPLET_MAIN)
955 /* Only one applet is selected in .config */
956 if (argv[1] && is_prefixed_with(argv[0], "busybox")) {
957 /* "busybox <applet> <params>" should still work as expected */
960 /* applet_names in this case is just "applet\0\0" */
961 lbb_prepare(applet_names IF_FEATURE_INDIVIDUAL(, argv));
962 return SINGLE_APPLET_MAIN(argc, argv);
964 lbb_prepare("busybox" IF_FEATURE_INDIVIDUAL(, argv));
967 if (argv[1] && is_prefixed_with(bb_basename(argv[0]), "busybox"))
970 applet_name = argv[0];
971 if (applet_name[0] == '-')
973 applet_name = bb_basename(applet_name);
975 parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */
977 run_applet_and_exit(applet_name, argv);