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"
56 /* "Do not compress usage text if uncompressed text is small
57 * and we don't include bunzip2 code for other reasons"
59 * Useful for mass one-applet rebuild (bunzip2 code is ~2.7k).
61 * Unlike BUNZIP2, if FEATURE_SEAMLESS_BZ2 is on, bunzip2 code is built but
62 * still may be unused if none of the selected applets calls open_zipped()
63 * or its friends; we test for (FEATURE_SEAMLESS_BZ2 && <APPLET>) instead.
64 * For example, only if TAR and FEATURE_SEAMLESS_BZ2 are both selected,
65 * then bunzip2 code will be linked in anyway, and disabling help compression
66 * would be not optimal:
68 #if UNPACKED_USAGE_LENGTH < 4*1024 \
69 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_TAR) \
70 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_MODPROBE) \
71 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_INSMOD) \
72 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_DEPMOD) \
73 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_MAN) \
76 # undef ENABLE_FEATURE_COMPRESS_USAGE
77 # define ENABLE_FEATURE_COMPRESS_USAGE 0
81 unsigned FAST_FUNC string_array_len(char **argv)
92 #if ENABLE_SHOW_USAGE && !ENABLE_FEATURE_COMPRESS_USAGE
93 static const char usage_messages[] ALIGN1 = UNPACKED_USAGE;
95 # define usage_messages 0
98 #if ENABLE_FEATURE_COMPRESS_USAGE
100 static const char packed_usage[] ALIGN1 = { PACKED_USAGE };
101 # include "bb_archive.h"
102 static const char *unpack_usage_messages(void)
108 i = start_bunzip(&bd,
110 /* inbuf: */ packed_usage,
111 /* len: */ sizeof(packed_usage));
112 /* read_bunzip can longjmp to start_bunzip, and ultimately
113 * end up here with i != 0 on read data errors! Not trivial */
115 /* Cannot use xmalloc: will leak bd in NOFORK case! */
116 outbuf = malloc_or_warn(sizeof(UNPACKED_USAGE));
118 read_bunzip(bd, outbuf, sizeof(UNPACKED_USAGE));
123 # define dealloc_usage_messages(s) free(s)
127 # define unpack_usage_messages() usage_messages
128 # define dealloc_usage_messages(s) ((void)(s))
130 #endif /* FEATURE_COMPRESS_USAGE */
133 void FAST_FUNC bb_show_usage(void)
135 if (ENABLE_SHOW_USAGE) {
136 #ifdef SINGLE_APPLET_STR
137 /* Imagine that this applet is "true". Dont suck in printf! */
138 const char *usage_string = unpack_usage_messages();
140 if (*usage_string == '\b') {
141 full_write2_str("No help available.\n\n");
143 full_write2_str("Usage: "SINGLE_APPLET_STR" ");
144 full_write2_str(usage_string);
145 full_write2_str("\n\n");
147 if (ENABLE_FEATURE_CLEAN_UP)
148 dealloc_usage_messages((char*)usage_string);
151 const char *usage_string = p = unpack_usage_messages();
152 int ap = find_applet_by_name(applet_name);
154 if (ap < 0) /* never happens, paranoia */
157 while (*p++) continue;
160 full_write2_str(bb_banner);
161 full_write2_str(" multi-call binary.\n");
163 full_write2_str("\nNo help available.\n\n");
165 full_write2_str("\nUsage: ");
166 full_write2_str(applet_name);
167 full_write2_str(" ");
169 full_write2_str("\n");
171 if (ENABLE_FEATURE_CLEAN_UP)
172 dealloc_usage_messages((char*)usage_string);
178 int FAST_FUNC find_applet_by_name(const char *name)
184 /* The commented-out word-at-a-time code is ~40% faster, but +160 bytes.
185 * "Faster" here saves ~0.5 microsecond of real time - not worth it.
187 #if 0 /*BB_UNALIGNED_MEMACCESS_OK && BB_LITTLE_ENDIAN*/
190 /* Handle all names < 2 chars long early */
192 return -1; /* "" is not a valid applet name */
193 if (name[1] == '\0') {
195 return -1; /* 1-char name is not valid */
197 return -1; /* 1-char name which isn't "[" is not valid */
198 /* applet "[" is always applet #0: */
205 #if KNOWN_APPNAME_OFFSETS <= 0
208 max = NUM_APPLETS * KNOWN_APPNAME_OFFSETS;
209 for (j = ARRAY_SIZE(applet_nameofs)-1; j >= 0; j--) {
210 const char *pp = applet_names + applet_nameofs[j];
211 if (strcmp(name, pp) >= 0) {
212 //bb_error_msg("name:'%s' >= pp:'%s'", name, pp);
214 i = max - NUM_APPLETS;
219 max /= (unsigned)KNOWN_APPNAME_OFFSETS;
220 i /= (unsigned)KNOWN_APPNAME_OFFSETS;
221 //bb_error_msg("name:'%s' starting from:'%s' i:%u max:%u", name, p, i, max);
224 /* Open-coded linear search without strcmp/strlen calls for speed */
226 #if 0 /*BB_UNALIGNED_MEMACCESS_OK && BB_LITTLE_ENDIAN*/
227 /* skip "[\0" name, it's surely not it */
228 if (ENABLE_TEST && LONE_CHAR(p, '['))
230 /* All remaining applet names in p[] are at least 2 chars long */
231 /* name[] is also at least 2 chars long */
233 n32 = (name[0] << 0) | (name[1] << 8) | (name[2] << 16);
238 /* Quickly check match of the first 3 bytes */
239 move_from_unaligned32(p32, p);
241 if ((p32 & 0x00ffffff) != n32) {
242 /* Most likely case: 3 first bytes do not match */
244 if ((p32 & 0x00ff0000) == '\0')
245 continue; // p[2] was NUL
247 if ((p32 & 0xff000000) == '\0')
248 continue; // p[3] was NUL
249 /* p[0..3] aren't matching and none is NUL, check the rest */
255 /* Unlikely branch: first 3 bytes ([0..2]) match */
256 if ((p32 & 0x00ff0000) == '\0') {
257 /* name is 2-byte long, it is full match */
258 //bb_error_msg("found:'%s' i:%u", name, i);
261 /* Check remaining bytes [3..NUL] */
264 while (ch == name[j]) {
266 //bb_error_msg("found:'%s' i:%u", name, i);
272 /* Not a match. Skip it, including NUL */
283 /* Do we see "name\0" in applet_names[p] position? */
284 while ((ch = *p) == name[j]) {
286 //bb_error_msg("found:'%s' i:%u", name, i);
293 * p => 1st non-matching char in applet_names[],
294 * skip to and including NUL.
306 void lbb_prepare(const char *applet
307 IF_FEATURE_INDIVIDUAL(, char **argv))
308 MAIN_EXTERNALLY_VISIBLE;
309 void lbb_prepare(const char *applet
310 IF_FEATURE_INDIVIDUAL(, char **argv))
313 (*(int **)&bb_errno) = __errno_location();
316 applet_name = applet;
318 if (ENABLE_LOCALE_SUPPORT)
319 setlocale(LC_ALL, "");
321 #if ENABLE_FEATURE_INDIVIDUAL
322 /* Redundant for busybox (run_applet_and_exit covers that case)
323 * but needed for "individual applet" mode */
326 && strcmp(argv[1], "--help") == 0
327 && !is_prefixed_with(applet, "busybox")
329 /* Special case. POSIX says "test --help"
330 * should be no different from e.g. "test --foo". */
331 if (!ENABLE_TEST || strcmp(applet_name, "test") != 0)
337 /* The code below can well be in applets/applets.c, as it is used only
338 * for busybox binary, not "individual" binaries.
339 * However, keeping it here and linking it into libbusybox.so
340 * (together with remaining tiny applets/applets.o)
341 * makes it possible to avoid --whole-archive at link time.
342 * This makes (shared busybox) + libbusybox smaller.
343 * (--gc-sections would be even better....)
346 const char *applet_name;
352 /* If not built as a single-applet executable... */
353 #if !defined(SINGLE_APPLET_MAIN)
355 IF_FEATURE_SUID(static uid_t ruid;) /* real uid */
357 # if ENABLE_FEATURE_SUID_CONFIG
359 static struct suid_config_t {
360 /* next ptr must be first: this struct needs to be llist-compatible */
361 struct suid_config_t *m_next;
362 struct bb_uidgid_t m_ugid;
367 static bool suid_cfg_readable;
369 /* libbb candidate */
370 static char *get_trimmed_slice(char *s, char *e)
372 /* First, consider the value at e to be nul and back up until we
373 * reach a non-space char. Set the char after that (possibly at
374 * the original e) to nul. */
382 /* Next, advance past all leading space and return a ptr to the
383 * first non-space char; possibly the terminating nul. */
384 return skip_whitespace(s);
387 static void parse_config_file(void)
389 /* Don't depend on the tools to combine strings. */
390 static const char config_file[] ALIGN1 = "/etc/busybox.conf";
392 struct suid_config_t *sct_head;
401 if (ruid == 0) /* run by root - don't need to even read config file */
404 if ((stat(config_file, &st) != 0) /* No config file? */
405 || !S_ISREG(st.st_mode) /* Not a regular file? */
406 || (st.st_uid != 0) /* Not owned by root? */
407 || (st.st_mode & (S_IWGRP | S_IWOTH)) /* Writable by non-root? */
408 || !(f = fopen_for_read(config_file)) /* Cannot open? */
413 suid_cfg_readable = 1;
421 if (!fgets(buffer, sizeof(buffer), f)) { /* Are we done? */
423 //if (ferror(f)) { /* Make sure it wasn't a read error. */
424 // errmsg = "reading";
428 suid_config = sct_head; /* Success, so set the pointer. */
433 lc++; /* Got a (partial) line. */
435 /* If a line is too long for our buffer, we consider it an error.
436 * The following test does mistreat one corner case though.
437 * If the final line of the file does not end with a newline and
438 * yet exactly fills the buffer, it will be treated as too long
439 * even though there isn't really a problem. But it isn't really
440 * worth adding code to deal with such an unlikely situation, and
441 * we do err on the side of caution. Besides, the line would be
442 * too long if it did end with a newline. */
443 if (!strchr(s, '\n') && !feof(f)) {
444 errmsg = "line too long";
448 /* Trim leading and trailing whitespace, ignoring comments, and
449 * check if the resulting string is empty. */
450 s = get_trimmed_slice(s, strchrnul(s, '#'));
455 /* Check for a section header. */
458 /* Unlike the old code, we ignore leading and trailing
459 * whitespace for the section name. We also require that
460 * there are no stray characters after the closing bracket. */
461 char *e = strchr(s, ']');
462 if (!e /* Missing right bracket? */
463 || e[1] /* Trailing characters? */
464 || !*(s = get_trimmed_slice(s+1, e)) /* Missing name? */
466 errmsg = "section header";
469 /* Right now we only have one section so just check it.
470 * If more sections are added in the future, please don't
471 * resort to cascading ifs with multiple strcasecmp calls.
472 * That kind of bloated code is all too common. A loop
473 * and a string table would be a better choice unless the
474 * number of sections is very small. */
475 if (strcasecmp(s, "SUID") == 0) {
479 section = -1; /* Unknown section so set to skip. */
483 /* Process sections. */
485 if (section == 1) { /* SUID */
486 /* Since we trimmed leading and trailing space above, we're
487 * now looking for strings of the form
488 * <key>[::space::]*=[::space::]*<value>
489 * where both key and value could contain inner whitespace. */
491 /* First get the key (an applet name in our case). */
492 char *e = strchr(s, '=');
494 s = get_trimmed_slice(s, e);
496 if (!e || !*s) { /* Missing '=' or empty key. */
501 /* Ok, we have an applet name. Process the rhs if this
502 * applet is currently built in and ignore it otherwise.
503 * Note: this can hide config file bugs which only pop
504 * up when the busybox configuration is changed. */
505 applet_no = find_applet_by_name(s);
506 if (applet_no >= 0) {
508 struct suid_config_t *sct;
510 /* Note: We currently don't check for duplicates!
511 * The last config line for each applet will be the
512 * one used since we insert at the head of the list.
513 * I suppose this could be considered a feature. */
514 sct = xzalloc(sizeof(*sct));
515 sct->m_applet = applet_no;
517 sct->m_next = sct_head;
520 /* Get the specified mode. */
522 e = skip_whitespace(e+1);
524 for (i = 0; i < 3; i++) {
525 /* There are 4 chars for each of user/group/other.
526 * "x-xx" instead of "x-" are to make
527 * "idx > 3" check catch invalid chars.
529 static const char mode_chars[] ALIGN1 = "Ssx-" "Ssx-" "x-xx";
530 static const unsigned short mode_mask[] ALIGN2 = {
531 S_ISUID, S_ISUID|S_IXUSR, S_IXUSR, 0, /* Ssx- */
532 S_ISGID, S_ISGID|S_IXGRP, S_IXGRP, 0, /* Ssx- */
535 const char *q = strchrnul(mode_chars + 4*i, *e);
536 unsigned idx = q - (mode_chars + 4*i);
541 sct->m_mode |= mode_mask[q - mode_chars];
545 /* Now get the user/group info. */
547 s = skip_whitespace(e);
548 /* Default is 0.0, else parse USER.GROUP: */
550 /* We require whitespace between mode and USER.GROUP */
551 if ((s == e) || !(e = strchr(s, '.'))) {
555 *e = ':'; /* get_uidgid needs USER:GROUP syntax */
556 if (get_uidgid(&sct->m_ugid, s) == 0) {
557 errmsg = "unknown user/group";
565 /* Unknown sections are ignored. */
567 /* Encountering configuration lines prior to seeing a
568 * section header is treated as an error. This is how
569 * the old code worked, but it may not be desirable.
570 * We may want to simply ignore such lines in case they
571 * are used in some future version of busybox. */
573 errmsg = "keyword outside section";
580 bb_error_msg("parse error in %s, line %u: %s", config_file, lc, errmsg);
582 /* Release any allocated memory before returning. */
583 llist_free((llist_t*)sct_head, NULL);
586 static inline void parse_config_file(void)
588 IF_FEATURE_SUID(ruid = getuid();)
590 # endif /* FEATURE_SUID_CONFIG */
593 # if ENABLE_FEATURE_SUID && NUM_APPLETS > 0
594 # if ENABLE_FEATURE_SUID_CONFIG
595 /* check if u is member of group g */
596 static int ingroup(uid_t u, gid_t g)
598 struct group *grp = getgrgid(g);
601 for (mem = grp->gr_mem; *mem; mem++) {
602 struct passwd *pwd = getpwnam(*mem);
603 if (pwd && (pwd->pw_uid == u))
611 static void check_suid(int applet_no)
613 gid_t rgid; /* real gid */
615 if (ruid == 0) /* set by parse_config_file() */
616 return; /* run by root - no need to check more */
619 # if ENABLE_FEATURE_SUID_CONFIG
620 if (suid_cfg_readable) {
622 struct suid_config_t *sct;
625 for (sct = suid_config; sct; sct = sct->m_next) {
626 if (sct->m_applet == applet_no)
629 goto check_need_suid;
631 /* Is this user allowed to run this applet? */
633 if (sct->m_ugid.uid == ruid)
636 else if ((sct->m_ugid.gid == rgid) || ingroup(ruid, sct->m_ugid.gid))
637 /* same group / in group */
639 if (!(m & S_IXOTH)) /* is x bit not set? */
640 bb_error_msg_and_die("you have no permission to run this applet");
642 /* We set effective AND saved ids. If saved-id is not set
643 * like we do below, seteuid(0) can still later succeed! */
645 /* Are we directed to change gid
646 * (APPLET = *s* USER.GROUP or APPLET = *S* USER.GROUP)?
648 if (sct->m_mode & S_ISGID)
649 rgid = sct->m_ugid.gid;
650 /* else: we will set egid = rgid, thus dropping sgid effect */
651 if (setresgid(-1, rgid, rgid))
652 bb_perror_msg_and_die("setresgid");
654 /* Are we directed to change uid
655 * (APPLET = s** USER.GROUP or APPLET = S** USER.GROUP)?
658 if (sct->m_mode & S_ISUID)
659 uid = sct->m_ugid.uid;
660 /* else: we will set euid = ruid, thus dropping suid effect */
661 if (setresuid(-1, uid, uid))
662 bb_perror_msg_and_die("setresuid");
666 # if !ENABLE_FEATURE_SUID_CONFIG_QUIET
668 static bool onetime = 0;
672 bb_error_msg("using fallback suid method");
678 if (APPLET_SUID(applet_no) == BB_SUID_REQUIRE) {
679 /* Real uid is not 0. If euid isn't 0 too, suid bit
680 * is most probably not set on our executable */
682 bb_error_msg_and_die("must be suid to work properly");
683 } else if (APPLET_SUID(applet_no) == BB_SUID_DROP) {
685 * Drop all privileges.
687 * Don't check for errors: in normal use, they are impossible,
688 * and in special cases, exiting is harmful. Example:
689 * 'unshare --user' when user's shell is also from busybox.
691 * 'unshare --user' creates a new user namespace without any
692 * uid mappings. Thus, busybox binary is setuid nobody:nogroup
693 * within the namespace, as that is the only user. However,
694 * since no uids are mapped, calls to setgid/setuid
695 * fail (even though they would do nothing).
700 # if ENABLE_FEATURE_SUID_CONFIG
702 llist_free((llist_t*)suid_config, NULL);
706 # define check_suid(x) ((void)0)
707 # endif /* FEATURE_SUID */
710 # if ENABLE_FEATURE_INSTALLER
711 static const char usr_bin [] ALIGN1 = "/usr/bin/";
712 static const char usr_sbin[] ALIGN1 = "/usr/sbin/";
713 static const char *const install_dir[] = {
714 &usr_bin [8], /* "/" */
715 &usr_bin [4], /* "/bin/" */
716 &usr_sbin[4] /* "/sbin/" */
717 # if !ENABLE_INSTALL_NO_USR
723 /* create (sym)links for each applet */
724 static void install_links(const char *busybox, int use_symbolic_links,
725 char *custom_install_dir)
728 * this should be consistent w/ the enum,
729 * busybox.h::bb_install_loc_t, or else... */
730 int (*lf)(const char *, const char *);
732 const char *appname = applet_names;
737 if (use_symbolic_links)
740 for (i = 0; i < ARRAY_SIZE(applet_main); i++) {
741 fpc = concat_path_file(
742 custom_install_dir ? custom_install_dir : install_dir[APPLET_INSTALL_LOC(i)],
744 // debug: bb_error_msg("%slinking %s to busybox",
745 // use_symbolic_links ? "sym" : "", fpc);
746 rc = lf(busybox, fpc);
747 if (rc != 0 && errno != EEXIST) {
748 bb_simple_perror_msg(fpc);
751 while (*appname++ != '\0')
755 # elif ENABLE_BUSYBOX
756 static void install_links(const char *busybox UNUSED_PARAM,
757 int use_symbolic_links UNUSED_PARAM,
758 char *custom_install_dir UNUSED_PARAM)
763 static void run_applet_and_exit(const char *name, char **argv) NORETURN;
766 # if ENABLE_FEATURE_SH_STANDALONE && ENABLE_FEATURE_TAB_COMPLETION
768 * Insert "busybox" into applet table as well.
769 * This makes standalone shell tab-complete this name too.
770 * (Otherwise having "busybox" in applet table is not necessary,
771 * there is other code which routes "busyboxANY_SUFFIX" name
772 * to busybox_main()).
774 //usage:#define busybox_trivial_usage NOUSAGE_STR
775 //usage:#define busybox_full_usage ""
776 //applet:IF_BUSYBOX(IF_FEATURE_SH_STANDALONE(IF_FEATURE_TAB_COMPLETION(APPLET(busybox, BB_DIR_BIN, BB_SUID_MAYBE))))
777 int busybox_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
779 # define busybox_main(argc,argv) busybox_main(argv)
782 int busybox_main(int argc UNUSED_PARAM, char **argv)
785 /* Called without arguments */
788 unsigned output_width;
790 output_width = get_terminal_width(2);
793 full_write2_str(bb_banner); /* reuse const string */
794 full_write2_str(" multi-call binary.\n"); /* reuse */
796 "BusyBox is copyrighted by many authors between 1998-2015.\n"
797 "Licensed under GPLv2. See source distribution for detailed\n"
798 "copyright notices.\n"
800 "Usage: busybox [function [arguments]...]\n"
801 " or: busybox --list"IF_FEATURE_INSTALLER("[-full]")"\n"
802 IF_FEATURE_INSTALLER(
803 " or: busybox --install [-s] [DIR]\n"
805 " or: function [arguments]...\n"
807 IF_NOT_FEATURE_SH_STANDALONE(
808 "\tBusyBox is a multi-call binary that combines many common Unix\n"
809 "\tutilities into a single executable. Most people will create a\n"
810 "\tlink to busybox for each function they wish to use and BusyBox\n"
811 "\twill act like whatever it was invoked as.\n"
813 IF_FEATURE_SH_STANDALONE(
814 "\tBusyBox is a multi-call binary that combines many common Unix\n"
815 "\tutilities into a single executable. The shell in this build\n"
816 "\tis configured to run built-in utilities without $PATH search.\n"
817 "\tYou don't need to install a link to busybox for each utility.\n"
818 "\tTo run external program, use full path (/sbin/ip instead of ip).\n"
821 "Currently defined functions:\n"
825 /* prevent last comma to be in the very last pos */
828 int len2 = strlen(a) + 2;
829 if (col >= (int)output_width - len2) {
830 full_write2_str(",\n");
835 full_write2_str("\t");
837 full_write2_str(", ");
843 full_write2_str("\n");
847 if (is_prefixed_with(argv[1], "--list")) {
849 const char *a = applet_names;
852 # if ENABLE_FEATURE_INSTALLER
853 if (argv[1][6]) /* --list-full? */
854 full_write2_str(install_dir[APPLET_INSTALL_LOC(i)] + 1);
857 full_write2_str("\n");
865 if (ENABLE_FEATURE_INSTALLER && strcmp(argv[1], "--install") == 0) {
866 int use_symbolic_links;
869 busybox = xmalloc_readlink(bb_busybox_exec_path);
871 /* bb_busybox_exec_path is usually "/proc/self/exe".
872 * In chroot, readlink("/proc/self/exe") usually fails.
873 * In such case, better use argv[0] as symlink target
874 * if it is a full path name.
876 if (argv[0][0] != '/')
877 bb_error_msg_and_die("'%s' is not an absolute path", argv[0]);
880 /* busybox --install [-s] [DIR]:
882 * DIR: directory to install links to
884 use_symbolic_links = (argv[2] && strcmp(argv[2], "-s") == 0 && ++argv);
885 install_links(busybox, use_symbolic_links, argv[2]);
889 if (strcmp(argv[1], "--help") == 0) {
890 /* "busybox --help [<applet>]" */
893 /* convert to "<applet> --help" */
897 /* "busybox <applet> arg1 arg2 ..." */
900 /* We support "busybox /a/path/to/applet args..." too. Allows for
901 * "#!/bin/busybox"-style wrappers */
902 applet_name = bb_get_last_path_component_nostrip(argv[0]);
903 run_applet_and_exit(applet_name, argv);
908 void FAST_FUNC run_applet_no_and_exit(int applet_no, const char *name, char **argv)
910 int argc = string_array_len(argv);
912 /* Reinit some shared global data */
913 xfunc_error_retval = EXIT_FAILURE;
915 * We do not use argv[0]: do not want to repeat massaging of
916 * "-/sbin/halt" -> "halt", for example.
920 /* Special case. POSIX says "test --help"
921 * should be no different from e.g. "test --foo".
922 * Thus for "test", we skip --help check.
923 * "true" and "false" are also special.
926 # if defined APPLET_NO_test
927 && applet_no != APPLET_NO_test
929 # if defined APPLET_NO_true
930 && applet_no != APPLET_NO_true
932 # if defined APPLET_NO_false
933 && applet_no != APPLET_NO_false
936 if (argc == 2 && strcmp(argv[1], "--help") == 0) {
937 /* Make "foo --help" exit with 0: */
938 xfunc_error_retval = 0;
942 if (ENABLE_FEATURE_SUID)
943 check_suid(applet_no);
944 xfunc_error_retval = applet_main[applet_no](argc, argv);
945 /* Note: applet_main() may also not return (die on a xfunc or such) */
948 # endif /* NUM_APPLETS > 0 */
950 # if ENABLE_BUSYBOX || NUM_APPLETS > 0
951 static NORETURN void run_applet_and_exit(const char *name, char **argv)
954 if (is_prefixed_with(name, "busybox"))
955 exit(busybox_main(/*unused:*/ 0, argv));
958 /* find_applet_by_name() search is more expensive, so goes second */
960 int applet = find_applet_by_name(name);
962 run_applet_no_and_exit(applet, name, argv);
966 /*bb_error_msg_and_die("applet not found"); - links in printf */
967 full_write2_str(applet_name);
968 full_write2_str(": applet not found\n");
969 /* POSIX: "If a command is not found, the exit status shall be 127" */
974 #endif /* !defined(SINGLE_APPLET_MAIN) */
977 #if ENABLE_BUILD_LIBBUSYBOX
978 int lbb_main(char **argv)
980 int main(int argc UNUSED_PARAM, char **argv)
984 /* TODO: find a use for a block of memory between end of .bss
985 * and end of page. For example, I'm getting "_end:0x812e698 2408 bytes"
986 * - more than 2k of wasted memory (in this particular build)
987 * *per each running process*!
988 * (If your linker does not generate "_end" name, weak attribute
989 * makes &_end == NULL, end_len == 0 here.)
991 extern char _end[] __attribute__((weak));
992 unsigned end_len = (-(int)_end) & 0xfff;
993 printf("_end:%p %u bytes\n", &_end, end_len);
996 /* Tweak malloc for reduced memory consumption */
997 #ifdef M_TRIM_THRESHOLD
998 /* M_TRIM_THRESHOLD is the maximum amount of freed top-most memory
999 * to keep before releasing to the OS
1000 * Default is way too big: 256k
1002 mallopt(M_TRIM_THRESHOLD, 8 * 1024);
1004 #ifdef M_MMAP_THRESHOLD
1005 /* M_MMAP_THRESHOLD is the request size threshold for using mmap()
1006 * Default is too big: 256k
1008 mallopt(M_MMAP_THRESHOLD, 32 * 1024 - 256);
1010 #if 0 /*def M_TOP_PAD*/
1011 /* When the program break is increased, then M_TOP_PAD bytes are added
1012 * to the sbrk(2) request. When the heap is trimmed because of free(3),
1013 * this much free space is preserved at the top of the heap.
1014 * glibc default seems to be way too big: 128k, but need to verify.
1016 mallopt(M_TOP_PAD, 8 * 1024);
1020 /* NOMMU re-exec trick sets high-order bit in first byte of name */
1021 if (argv[0][0] & 0x80) {
1027 #if defined(SINGLE_APPLET_MAIN)
1029 /* Only one applet is selected in .config */
1030 if (argv[1] && is_prefixed_with(argv[0], "busybox")) {
1031 /* "busybox <applet> <params>" should still work as expected */
1034 /* applet_names in this case is just "applet\0\0" */
1035 lbb_prepare(applet_names IF_FEATURE_INDIVIDUAL(, argv));
1036 # if ENABLE_BUILD_LIBBUSYBOX
1037 return SINGLE_APPLET_MAIN(string_array_len(argv), argv);
1039 return SINGLE_APPLET_MAIN(argc, argv);
1042 #elif !ENABLE_BUSYBOX && NUM_APPLETS == 0
1044 full_write2_str(bb_basename(argv[0]));
1045 full_write2_str(": no applets enabled\n");
1050 lbb_prepare("busybox" IF_FEATURE_INDIVIDUAL(, argv));
1051 # if !ENABLE_BUSYBOX
1052 if (argv[1] && is_prefixed_with(bb_basename(argv[0]), "busybox"))
1055 applet_name = argv[0];
1056 if (applet_name[0] == '-')
1058 applet_name = bb_basename(applet_name);
1059 parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */
1060 run_applet_and_exit(applet_name, argv);