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 */
37 /* Declare <applet>_main() */
42 /* Include generated applet names, pointers to <applet>_main, etc */
43 #include "applet_tables.h"
44 /* ...and if applet_tables generator says we have only one applet... */
45 #ifdef SINGLE_APPLET_MAIN
46 # undef ENABLE_FEATURE_INDIVIDUAL
47 # define ENABLE_FEATURE_INDIVIDUAL 1
48 # undef IF_FEATURE_INDIVIDUAL
49 # define IF_FEATURE_INDIVIDUAL(...) __VA_ARGS__
52 #include "usage_compressed.h"
55 /* "Do not compress usage text if uncompressed text is small
56 * and we don't include bunzip2 code for other reasons"
58 * Useful for mass one-applet rebuild (bunzip2 code is ~2.7k).
60 * Unlike BUNZIP2, if FEATURE_SEAMLESS_BZ2 is on, bunzip2 code is built but
61 * still may be unused if none of the selected applets calls open_zipped()
62 * or its friends; we test for (FEATURE_SEAMLESS_BZ2 && <APPLET>) instead.
63 * For example, only if TAR and FEATURE_SEAMLESS_BZ2 are both selected,
64 * then bunzip2 code will be linked in anyway, and disabling help compression
65 * would be not optimal:
67 #if UNPACKED_USAGE_LENGTH < 4*1024 \
68 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_TAR) \
69 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_MODPROBE) \
70 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_INSMOD) \
71 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_DEPMOD) \
72 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_MAN) \
75 # undef ENABLE_FEATURE_COMPRESS_USAGE
76 # define ENABLE_FEATURE_COMPRESS_USAGE 0
80 unsigned FAST_FUNC string_array_len(char **argv)
91 #if ENABLE_SHOW_USAGE && !ENABLE_FEATURE_COMPRESS_USAGE
92 static const char usage_messages[] ALIGN1 = UNPACKED_USAGE;
94 # define usage_messages 0
97 #if ENABLE_FEATURE_COMPRESS_USAGE
99 static const char packed_usage[] ALIGN1 = { PACKED_USAGE };
100 # include "bb_archive.h"
101 static const char *unpack_usage_messages(void)
107 i = start_bunzip(&bd,
109 /* inbuf: */ packed_usage,
110 /* len: */ sizeof(packed_usage));
111 /* read_bunzip can longjmp to start_bunzip, and ultimately
112 * end up here with i != 0 on read data errors! Not trivial */
114 /* Cannot use xmalloc: will leak bd in NOFORK case! */
115 outbuf = malloc_or_warn(sizeof(UNPACKED_USAGE));
117 read_bunzip(bd, outbuf, sizeof(UNPACKED_USAGE));
122 # define dealloc_usage_messages(s) free(s)
126 # define unpack_usage_messages() usage_messages
127 # define dealloc_usage_messages(s) ((void)(s))
129 #endif /* FEATURE_COMPRESS_USAGE */
132 void FAST_FUNC bb_show_usage(void)
134 if (ENABLE_SHOW_USAGE) {
135 #ifdef SINGLE_APPLET_STR
136 /* Imagine that this applet is "true". Dont suck in printf! */
137 const char *usage_string = unpack_usage_messages();
139 if (*usage_string == '\b') {
140 full_write2_str("No help available.\n\n");
142 full_write2_str("Usage: "SINGLE_APPLET_STR" ");
143 full_write2_str(usage_string);
144 full_write2_str("\n\n");
146 if (ENABLE_FEATURE_CLEAN_UP)
147 dealloc_usage_messages((char*)usage_string);
150 const char *usage_string = p = unpack_usage_messages();
151 int ap = find_applet_by_name(applet_name);
153 if (ap < 0) /* never happens, paranoia */
156 while (*p++) continue;
159 full_write2_str(bb_banner);
160 full_write2_str(" multi-call binary.\n");
162 full_write2_str("\nNo help available.\n\n");
164 full_write2_str("\nUsage: ");
165 full_write2_str(applet_name);
166 full_write2_str(" ");
168 full_write2_str("\n");
170 if (ENABLE_FEATURE_CLEAN_UP)
171 dealloc_usage_messages((char*)usage_string);
177 int FAST_FUNC find_applet_by_name(const char *name)
183 /* The commented-out word-at-a-time code is ~40% faster, but +160 bytes.
184 * "Faster" here saves ~0.5 microsecond of real time - not worth it.
186 #if 0 /*BB_UNALIGNED_MEMACCESS_OK && BB_LITTLE_ENDIAN*/
189 /* Handle all names < 2 chars long early */
191 return -1; /* "" is not a valid applet name */
192 if (name[1] == '\0') {
194 return -1; /* 1-char name is not valid */
196 return -1; /* 1-char name which isn't "[" is not valid */
197 /* applet "[" is always applet #0: */
204 #if KNOWN_APPNAME_OFFSETS <= 0
207 max = NUM_APPLETS * KNOWN_APPNAME_OFFSETS;
208 for (j = ARRAY_SIZE(applet_nameofs)-1; j >= 0; j--) {
209 const char *pp = applet_names + applet_nameofs[j];
210 if (strcmp(name, pp) >= 0) {
211 //bb_error_msg("name:'%s' >= pp:'%s'", name, pp);
213 i = max - NUM_APPLETS;
218 max /= (unsigned)KNOWN_APPNAME_OFFSETS;
219 i /= (unsigned)KNOWN_APPNAME_OFFSETS;
220 //bb_error_msg("name:'%s' starting from:'%s' i:%u max:%u", name, p, i, max);
223 /* Open-coded linear search without strcmp/strlen calls for speed */
225 #if 0 /*BB_UNALIGNED_MEMACCESS_OK && BB_LITTLE_ENDIAN*/
226 /* skip "[\0" name, it's surely not it */
227 if (ENABLE_TEST && LONE_CHAR(p, '['))
229 /* All remaining applet names in p[] are at least 2 chars long */
230 /* name[] is also at least 2 chars long */
232 n32 = (name[0] << 0) | (name[1] << 8) | (name[2] << 16);
237 /* Quickly check match of the first 3 bytes */
238 move_from_unaligned32(p32, p);
240 if ((p32 & 0x00ffffff) != n32) {
241 /* Most likely case: 3 first bytes do not match */
243 if ((p32 & 0x00ff0000) == '\0')
244 continue; // p[2] was NUL
246 if ((p32 & 0xff000000) == '\0')
247 continue; // p[3] was NUL
248 /* p[0..3] aren't matching and none is NUL, check the rest */
254 /* Unlikely branch: first 3 bytes ([0..2]) match */
255 if ((p32 & 0x00ff0000) == '\0') {
256 /* name is 2-byte long, it is full match */
257 //bb_error_msg("found:'%s' i:%u", name, i);
260 /* Check remaining bytes [3..NUL] */
263 while (ch == name[j]) {
265 //bb_error_msg("found:'%s' i:%u", name, i);
271 /* Not a match. Skip it, including NUL */
282 /* Do we see "name\0" in applet_names[p] position? */
283 while ((ch = *p) == name[j]) {
285 //bb_error_msg("found:'%s' i:%u", name, i);
292 * p => 1st non-matching char in applet_names[],
293 * skip to and including NUL.
305 void lbb_prepare(const char *applet
306 IF_FEATURE_INDIVIDUAL(, char **argv))
307 MAIN_EXTERNALLY_VISIBLE;
308 void lbb_prepare(const char *applet
309 IF_FEATURE_INDIVIDUAL(, char **argv))
312 (*(int **)&bb_errno) = __errno_location();
315 applet_name = applet;
317 if (ENABLE_LOCALE_SUPPORT)
318 setlocale(LC_ALL, "");
320 #if ENABLE_FEATURE_INDIVIDUAL
321 /* Redundant for busybox (run_applet_and_exit covers that case)
322 * but needed for "individual applet" mode */
325 && strcmp(argv[1], "--help") == 0
326 && !is_prefixed_with(applet, "busybox")
328 /* Special case. POSIX says "test --help"
329 * should be no different from e.g. "test --foo". */
330 if (!ENABLE_TEST || strcmp(applet_name, "test") != 0)
336 /* The code below can well be in applets/applets.c, as it is used only
337 * for busybox binary, not "individual" binaries.
338 * However, keeping it here and linking it into libbusybox.so
339 * (together with remaining tiny applets/applets.o)
340 * makes it possible to avoid --whole-archive at link time.
341 * This makes (shared busybox) + libbusybox smaller.
342 * (--gc-sections would be even better....)
345 const char *applet_name;
351 /* If not built as a single-applet executable... */
352 #if !defined(SINGLE_APPLET_MAIN)
354 IF_FEATURE_SUID(static uid_t ruid;) /* real uid */
356 # if ENABLE_FEATURE_SUID_CONFIG
358 static struct suid_config_t {
359 /* next ptr must be first: this struct needs to be llist-compatible */
360 struct suid_config_t *m_next;
361 struct bb_uidgid_t m_ugid;
366 static bool suid_cfg_readable;
368 /* libbb candidate */
369 static char *get_trimmed_slice(char *s, char *e)
371 /* First, consider the value at e to be nul and back up until we
372 * reach a non-space char. Set the char after that (possibly at
373 * the original e) to nul. */
381 /* Next, advance past all leading space and return a ptr to the
382 * first non-space char; possibly the terminating nul. */
383 return skip_whitespace(s);
386 static void parse_config_file(void)
388 /* Don't depend on the tools to combine strings. */
389 static const char config_file[] ALIGN1 = "/etc/busybox.conf";
391 struct suid_config_t *sct_head;
400 if (ruid == 0) /* run by root - don't need to even read config file */
403 if ((stat(config_file, &st) != 0) /* No config file? */
404 || !S_ISREG(st.st_mode) /* Not a regular file? */
405 || (st.st_uid != 0) /* Not owned by root? */
406 || (st.st_mode & (S_IWGRP | S_IWOTH)) /* Writable by non-root? */
407 || !(f = fopen_for_read(config_file)) /* Cannot open? */
412 suid_cfg_readable = 1;
420 if (!fgets(buffer, sizeof(buffer), f)) { /* Are we done? */
422 //if (ferror(f)) { /* Make sure it wasn't a read error. */
423 // errmsg = "reading";
427 suid_config = sct_head; /* Success, so set the pointer. */
432 lc++; /* Got a (partial) line. */
434 /* If a line is too long for our buffer, we consider it an error.
435 * The following test does mistreat one corner case though.
436 * If the final line of the file does not end with a newline and
437 * yet exactly fills the buffer, it will be treated as too long
438 * even though there isn't really a problem. But it isn't really
439 * worth adding code to deal with such an unlikely situation, and
440 * we do err on the side of caution. Besides, the line would be
441 * too long if it did end with a newline. */
442 if (!strchr(s, '\n') && !feof(f)) {
443 errmsg = "line too long";
447 /* Trim leading and trailing whitespace, ignoring comments, and
448 * check if the resulting string is empty. */
449 s = get_trimmed_slice(s, strchrnul(s, '#'));
454 /* Check for a section header. */
457 /* Unlike the old code, we ignore leading and trailing
458 * whitespace for the section name. We also require that
459 * there are no stray characters after the closing bracket. */
460 char *e = strchr(s, ']');
461 if (!e /* Missing right bracket? */
462 || e[1] /* Trailing characters? */
463 || !*(s = get_trimmed_slice(s+1, e)) /* Missing name? */
465 errmsg = "section header";
468 /* Right now we only have one section so just check it.
469 * If more sections are added in the future, please don't
470 * resort to cascading ifs with multiple strcasecmp calls.
471 * That kind of bloated code is all too common. A loop
472 * and a string table would be a better choice unless the
473 * number of sections is very small. */
474 if (strcasecmp(s, "SUID") == 0) {
478 section = -1; /* Unknown section so set to skip. */
482 /* Process sections. */
484 if (section == 1) { /* SUID */
485 /* Since we trimmed leading and trailing space above, we're
486 * now looking for strings of the form
487 * <key>[::space::]*=[::space::]*<value>
488 * where both key and value could contain inner whitespace. */
490 /* First get the key (an applet name in our case). */
491 char *e = strchr(s, '=');
493 s = get_trimmed_slice(s, e);
495 if (!e || !*s) { /* Missing '=' or empty key. */
500 /* Ok, we have an applet name. Process the rhs if this
501 * applet is currently built in and ignore it otherwise.
502 * Note: this can hide config file bugs which only pop
503 * up when the busybox configuration is changed. */
504 applet_no = find_applet_by_name(s);
505 if (applet_no >= 0) {
507 struct suid_config_t *sct;
509 /* Note: We currently don't check for duplicates!
510 * The last config line for each applet will be the
511 * one used since we insert at the head of the list.
512 * I suppose this could be considered a feature. */
513 sct = xzalloc(sizeof(*sct));
514 sct->m_applet = applet_no;
516 sct->m_next = sct_head;
519 /* Get the specified mode. */
521 e = skip_whitespace(e+1);
523 for (i = 0; i < 3; i++) {
524 /* There are 4 chars for each of user/group/other.
525 * "x-xx" instead of "x-" are to make
526 * "idx > 3" check catch invalid chars.
528 static const char mode_chars[] ALIGN1 = "Ssx-" "Ssx-" "x-xx";
529 static const unsigned short mode_mask[] ALIGN2 = {
530 S_ISUID, S_ISUID|S_IXUSR, S_IXUSR, 0, /* Ssx- */
531 S_ISGID, S_ISGID|S_IXGRP, S_IXGRP, 0, /* Ssx- */
534 const char *q = strchrnul(mode_chars + 4*i, *e);
535 unsigned idx = q - (mode_chars + 4*i);
540 sct->m_mode |= mode_mask[q - mode_chars];
544 /* Now get the user/group info. */
546 s = skip_whitespace(e);
547 /* Default is 0.0, else parse USER.GROUP: */
549 /* We require whitespace between mode and USER.GROUP */
550 if ((s == e) || !(e = strchr(s, '.'))) {
554 *e = ':'; /* get_uidgid needs USER:GROUP syntax */
555 if (get_uidgid(&sct->m_ugid, s) == 0) {
556 errmsg = "unknown user/group";
564 /* Unknown sections are ignored. */
566 /* Encountering configuration lines prior to seeing a
567 * section header is treated as an error. This is how
568 * the old code worked, but it may not be desirable.
569 * We may want to simply ignore such lines in case they
570 * are used in some future version of busybox. */
572 errmsg = "keyword outside section";
579 bb_error_msg("parse error in %s, line %u: %s", config_file, lc, errmsg);
581 /* Release any allocated memory before returning. */
582 llist_free((llist_t*)sct_head, NULL);
585 static inline void parse_config_file(void)
587 IF_FEATURE_SUID(ruid = getuid();)
589 # endif /* FEATURE_SUID_CONFIG */
592 # if ENABLE_FEATURE_SUID && NUM_APPLETS > 0
593 # if ENABLE_FEATURE_SUID_CONFIG
594 /* check if u is member of group g */
595 static int ingroup(uid_t u, gid_t g)
597 struct group *grp = getgrgid(g);
600 for (mem = grp->gr_mem; *mem; mem++) {
601 struct passwd *pwd = getpwnam(*mem);
602 if (pwd && (pwd->pw_uid == u))
610 static void check_suid(int applet_no)
612 gid_t rgid; /* real gid */
614 if (ruid == 0) /* set by parse_config_file() */
615 return; /* run by root - no need to check more */
618 # if ENABLE_FEATURE_SUID_CONFIG
619 if (suid_cfg_readable) {
621 struct suid_config_t *sct;
624 for (sct = suid_config; sct; sct = sct->m_next) {
625 if (sct->m_applet == applet_no)
628 goto check_need_suid;
630 /* Is this user allowed to run this applet? */
632 if (sct->m_ugid.uid == ruid)
635 else if ((sct->m_ugid.gid == rgid) || ingroup(ruid, sct->m_ugid.gid))
636 /* same group / in group */
638 if (!(m & S_IXOTH)) /* is x bit not set? */
639 bb_error_msg_and_die("you have no permission to run this applet");
641 /* We set effective AND saved ids. If saved-id is not set
642 * like we do below, seteuid(0) can still later succeed! */
644 /* Are we directed to change gid
645 * (APPLET = *s* USER.GROUP or APPLET = *S* USER.GROUP)?
647 if (sct->m_mode & S_ISGID)
648 rgid = sct->m_ugid.gid;
649 /* else: we will set egid = rgid, thus dropping sgid effect */
650 if (setresgid(-1, rgid, rgid))
651 bb_perror_msg_and_die("setresgid");
653 /* Are we directed to change uid
654 * (APPLET = s** USER.GROUP or APPLET = S** USER.GROUP)?
657 if (sct->m_mode & S_ISUID)
658 uid = sct->m_ugid.uid;
659 /* else: we will set euid = ruid, thus dropping suid effect */
660 if (setresuid(-1, uid, uid))
661 bb_perror_msg_and_die("setresuid");
665 # if !ENABLE_FEATURE_SUID_CONFIG_QUIET
667 static bool onetime = 0;
671 bb_error_msg("using fallback suid method");
677 if (APPLET_SUID(applet_no) == BB_SUID_REQUIRE) {
678 /* Real uid is not 0. If euid isn't 0 too, suid bit
679 * is most probably not set on our executable */
681 bb_error_msg_and_die("must be suid to work properly");
682 } else if (APPLET_SUID(applet_no) == BB_SUID_DROP) {
684 * Drop all privileges.
686 * Don't check for errors: in normal use, they are impossible,
687 * and in special cases, exiting is harmful. Example:
688 * 'unshare --user' when user's shell is also from busybox.
690 * 'unshare --user' creates a new user namespace without any
691 * uid mappings. Thus, busybox binary is setuid nobody:nogroup
692 * within the namespace, as that is the only user. However,
693 * since no uids are mapped, calls to setgid/setuid
694 * fail (even though they would do nothing).
699 # if ENABLE_FEATURE_SUID_CONFIG
701 llist_free((llist_t*)suid_config, NULL);
705 # define check_suid(x) ((void)0)
706 # endif /* FEATURE_SUID */
709 # if ENABLE_FEATURE_INSTALLER
710 static const char usr_bin [] ALIGN1 = "/usr/bin/";
711 static const char usr_sbin[] ALIGN1 = "/usr/sbin/";
712 static const char *const install_dir[] = {
713 &usr_bin [8], /* "/" */
714 &usr_bin [4], /* "/bin/" */
715 &usr_sbin[4] /* "/sbin/" */
716 # if !ENABLE_INSTALL_NO_USR
722 /* create (sym)links for each applet */
723 static void install_links(const char *busybox, int use_symbolic_links,
724 char *custom_install_dir)
727 * this should be consistent w/ the enum,
728 * busybox.h::bb_install_loc_t, or else... */
729 int (*lf)(const char *, const char *);
731 const char *appname = applet_names;
736 if (use_symbolic_links)
739 for (i = 0; i < ARRAY_SIZE(applet_main); i++) {
740 fpc = concat_path_file(
741 custom_install_dir ? custom_install_dir : install_dir[APPLET_INSTALL_LOC(i)],
743 // debug: bb_error_msg("%slinking %s to busybox",
744 // use_symbolic_links ? "sym" : "", fpc);
745 rc = lf(busybox, fpc);
746 if (rc != 0 && errno != EEXIST) {
747 bb_simple_perror_msg(fpc);
750 while (*appname++ != '\0')
754 # elif ENABLE_BUSYBOX
755 static void install_links(const char *busybox UNUSED_PARAM,
756 int use_symbolic_links UNUSED_PARAM,
757 char *custom_install_dir UNUSED_PARAM)
762 static void run_applet_and_exit(const char *name, char **argv) NORETURN;
765 # if ENABLE_FEATURE_SH_STANDALONE && ENABLE_FEATURE_TAB_COMPLETION
767 * Insert "busybox" into applet table as well.
768 * This makes standalone shell tab-complete this name too.
769 * (Otherwise having "busybox" in applet table is not necessary,
770 * there is other code which routes "busyboxANY_SUFFIX" name
771 * to busybox_main()).
773 //usage:#define busybox_trivial_usage NOUSAGE_STR
774 //usage:#define busybox_full_usage ""
775 //applet:IF_BUSYBOX(IF_FEATURE_SH_STANDALONE(IF_FEATURE_TAB_COMPLETION(APPLET(busybox, BB_DIR_BIN, BB_SUID_MAYBE))))
776 int busybox_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
778 # define busybox_main(argc,argv) busybox_main(argv)
781 int busybox_main(int argc UNUSED_PARAM, char **argv)
784 /* Called without arguments */
787 unsigned output_width;
789 output_width = get_terminal_width(2);
792 full_write2_str(bb_banner); /* reuse const string */
793 full_write2_str(" multi-call binary.\n"); /* reuse */
795 "BusyBox is copyrighted by many authors between 1998-2015.\n"
796 "Licensed under GPLv2. See source distribution for detailed\n"
797 "copyright notices.\n"
799 "Usage: busybox [function [arguments]...]\n"
800 " or: busybox --list"IF_FEATURE_INSTALLER("[-full]")"\n"
801 IF_FEATURE_INSTALLER(
802 " or: busybox --install [-s] [DIR]\n"
804 " or: function [arguments]...\n"
806 IF_NOT_FEATURE_SH_STANDALONE(
807 "\tBusyBox is a multi-call binary that combines many common Unix\n"
808 "\tutilities into a single executable. Most people will create a\n"
809 "\tlink to busybox for each function they wish to use and BusyBox\n"
810 "\twill act like whatever it was invoked as.\n"
812 IF_FEATURE_SH_STANDALONE(
813 "\tBusyBox is a multi-call binary that combines many common Unix\n"
814 "\tutilities into a single executable. The shell in this build\n"
815 "\tis configured to run built-in utilities without $PATH search.\n"
816 "\tYou don't need to install a link to busybox for each utility.\n"
817 "\tTo run external program, use full path (/sbin/ip instead of ip).\n"
820 "Currently defined functions:\n"
824 /* prevent last comma to be in the very last pos */
827 int len2 = strlen(a) + 2;
828 if (col >= (int)output_width - len2) {
829 full_write2_str(",\n");
834 full_write2_str("\t");
836 full_write2_str(", ");
842 full_write2_str("\n");
846 if (is_prefixed_with(argv[1], "--list")) {
848 const char *a = applet_names;
851 # if ENABLE_FEATURE_INSTALLER
852 if (argv[1][6]) /* --list-full? */
853 full_write2_str(install_dir[APPLET_INSTALL_LOC(i)] + 1);
856 full_write2_str("\n");
864 if (ENABLE_FEATURE_INSTALLER && strcmp(argv[1], "--install") == 0) {
865 int use_symbolic_links;
868 busybox = xmalloc_readlink(bb_busybox_exec_path);
870 /* bb_busybox_exec_path is usually "/proc/self/exe".
871 * In chroot, readlink("/proc/self/exe") usually fails.
872 * In such case, better use argv[0] as symlink target
873 * if it is a full path name.
875 if (argv[0][0] != '/')
876 bb_error_msg_and_die("'%s' is not an absolute path", argv[0]);
879 /* busybox --install [-s] [DIR]:
881 * DIR: directory to install links to
883 use_symbolic_links = (argv[2] && strcmp(argv[2], "-s") == 0 && ++argv);
884 install_links(busybox, use_symbolic_links, argv[2]);
888 if (strcmp(argv[1], "--help") == 0) {
889 /* "busybox --help [<applet>]" */
892 /* convert to "<applet> --help" */
896 /* "busybox <applet> arg1 arg2 ..." */
899 /* We support "busybox /a/path/to/applet args..." too. Allows for
900 * "#!/bin/busybox"-style wrappers */
901 applet_name = bb_get_last_path_component_nostrip(argv[0]);
902 run_applet_and_exit(applet_name, argv);
907 void FAST_FUNC run_applet_no_and_exit(int applet_no, const char *name, char **argv)
909 int argc = string_array_len(argv);
912 * We do not use argv[0]: do not want to repeat massaging of
913 * "-/sbin/halt" -> "halt", for example.
917 /* Special case. POSIX says "test --help"
918 * should be no different from e.g. "test --foo".
919 * Thus for "test", we skip --help check.
920 * "true" and "false" are also special.
923 # if defined APPLET_NO_test
924 && applet_no != APPLET_NO_test
926 # if defined APPLET_NO_true
927 && applet_no != APPLET_NO_true
929 # if defined APPLET_NO_false
930 && applet_no != APPLET_NO_false
933 if (argc == 2 && strcmp(argv[1], "--help") == 0) {
934 /* Make "foo --help" exit with 0: */
935 xfunc_error_retval = 0;
939 if (ENABLE_FEATURE_SUID)
940 check_suid(applet_no);
941 xfunc_error_retval = applet_main[applet_no](argc, argv);
942 /* Note: applet_main() may also not return (die on a xfunc or such) */
945 # endif /* NUM_APPLETS > 0 */
947 # if ENABLE_BUSYBOX || NUM_APPLETS > 0
948 static NORETURN void run_applet_and_exit(const char *name, char **argv)
951 if (is_prefixed_with(name, "busybox"))
952 exit(busybox_main(/*unused:*/ 0, argv));
955 /* find_applet_by_name() search is more expensive, so goes second */
957 int applet = find_applet_by_name(name);
959 run_applet_no_and_exit(applet, name, argv);
963 /*bb_error_msg_and_die("applet not found"); - links in printf */
964 full_write2_str(applet_name);
965 full_write2_str(": applet not found\n");
966 /* POSIX: "If a command is not found, the exit status shall be 127" */
971 #endif /* !defined(SINGLE_APPLET_MAIN) */
974 #if ENABLE_BUILD_LIBBUSYBOX
975 int lbb_main(char **argv)
977 int main(int argc UNUSED_PARAM, char **argv)
981 /* TODO: find a use for a block of memory between end of .bss
982 * and end of page. For example, I'm getting "_end:0x812e698 2408 bytes"
983 * - more than 2k of wasted memory (in this particular build)
984 * *per each running process*!
985 * (If your linker does not generate "_end" name, weak attribute
986 * makes &_end == NULL, end_len == 0 here.)
988 extern char _end[] __attribute__((weak));
989 unsigned end_len = (-(int)_end) & 0xfff;
990 printf("_end:%p %u bytes\n", &_end, end_len);
993 /* Tweak malloc for reduced memory consumption */
994 #ifdef M_TRIM_THRESHOLD
995 /* M_TRIM_THRESHOLD is the maximum amount of freed top-most memory
996 * to keep before releasing to the OS
997 * Default is way too big: 256k
999 mallopt(M_TRIM_THRESHOLD, 8 * 1024);
1001 #ifdef M_MMAP_THRESHOLD
1002 /* M_MMAP_THRESHOLD is the request size threshold for using mmap()
1003 * Default is too big: 256k
1005 mallopt(M_MMAP_THRESHOLD, 32 * 1024 - 256);
1007 #if 0 /*def M_TOP_PAD*/
1008 /* When the program break is increased, then M_TOP_PAD bytes are added
1009 * to the sbrk(2) request. When the heap is trimmed because of free(3),
1010 * this much free space is preserved at the top of the heap.
1011 * glibc default seems to be way too big: 128k, but need to verify.
1013 mallopt(M_TOP_PAD, 8 * 1024);
1017 /* NOMMU re-exec trick sets high-order bit in first byte of name */
1018 if (argv[0][0] & 0x80) {
1024 #if defined(SINGLE_APPLET_MAIN)
1026 /* Only one applet is selected in .config */
1027 if (argv[1] && is_prefixed_with(argv[0], "busybox")) {
1028 /* "busybox <applet> <params>" should still work as expected */
1031 /* applet_names in this case is just "applet\0\0" */
1032 lbb_prepare(applet_names IF_FEATURE_INDIVIDUAL(, argv));
1033 # if ENABLE_BUILD_LIBBUSYBOX
1034 return SINGLE_APPLET_MAIN(string_array_len(argv), argv);
1036 return SINGLE_APPLET_MAIN(argc, argv);
1039 #elif !ENABLE_BUSYBOX && NUM_APPLETS == 0
1041 full_write2_str(bb_basename(argv[0]));
1042 full_write2_str(": no applets enabled\n");
1047 lbb_prepare("busybox" IF_FEATURE_INDIVIDUAL(, argv));
1048 # if !ENABLE_BUSYBOX
1049 if (argv[1] && is_prefixed_with(bb_basename(argv[0]), "busybox"))
1052 applet_name = argv[0];
1053 if (applet_name[0] == '-')
1055 applet_name = bb_basename(applet_name);
1057 /* If we are a result of execv("/proc/self/exe"), fix ugly comm of "exe" */
1058 if (ENABLE_FEATURE_SH_STANDALONE
1059 || ENABLE_FEATURE_PREFER_APPLETS
1062 if (NUM_APPLETS > 1)
1063 set_task_comm(applet_name);
1066 parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */
1067 run_applet_and_exit(applet_name, argv);