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.
14 /* We are trying to not use printf, this benefits the case when selected
15 * applets are really simple. Example:
19 * Currently defined functions:
20 * basename, false, true
23 * text data bss dec hex filename
24 * 4473 52 72 4597 11f5 busybox
26 * FEATURE_INSTALLER or FEATURE_SUID will still link printf routines in. :(
30 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
31 || defined(__APPLE__) \
33 # include <malloc.h> /* for mallopt */
36 /* Declare <applet>_main() */
41 /* Include generated applet names, pointers to <applet>_main, etc */
42 #include "applet_tables.h"
43 /* ...and if applet_tables generator says we have only one applet... */
44 #ifdef SINGLE_APPLET_MAIN
45 # undef ENABLE_FEATURE_INDIVIDUAL
46 # define ENABLE_FEATURE_INDIVIDUAL 1
47 # undef IF_FEATURE_INDIVIDUAL
48 # define IF_FEATURE_INDIVIDUAL(...) __VA_ARGS__
51 #include "usage_compressed.h"
53 #if ENABLE_ASH_EMBEDDED_SCRIPTS
54 # define DEFINE_script_names 1
55 # include "embedded_scripts.h"
57 # define NUM_SCRIPTS 0
60 # include "bb_archive.h"
61 static const char packed_scripts[] ALIGN1 = { PACKED_SCRIPTS };
64 /* "Do not compress usage text if uncompressed text is small
65 * and we don't include bunzip2 code for other reasons"
67 * Useful for mass one-applet rebuild (bunzip2 code is ~2.7k).
69 * Unlike BUNZIP2, if FEATURE_SEAMLESS_BZ2 is on, bunzip2 code is built but
70 * still may be unused if none of the selected applets calls open_zipped()
71 * or its friends; we test for (FEATURE_SEAMLESS_BZ2 && <APPLET>) instead.
72 * For example, only if TAR and FEATURE_SEAMLESS_BZ2 are both selected,
73 * then bunzip2 code will be linked in anyway, and disabling help compression
74 * would be not optimal:
76 #if UNPACKED_USAGE_LENGTH < 4*1024 \
77 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_TAR) \
78 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_MODPROBE) \
79 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_INSMOD) \
80 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_DEPMOD) \
81 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_MAN) \
84 # undef ENABLE_FEATURE_COMPRESS_USAGE
85 # define ENABLE_FEATURE_COMPRESS_USAGE 0
89 unsigned FAST_FUNC string_array_len(char **argv)
100 #if ENABLE_SHOW_USAGE && !ENABLE_FEATURE_COMPRESS_USAGE
101 static const char usage_messages[] ALIGN1 = UNPACKED_USAGE;
103 # define usage_messages 0
106 #if ENABLE_FEATURE_COMPRESS_USAGE
108 static const char packed_usage[] ALIGN1 = { PACKED_USAGE };
109 # include "bb_archive.h"
110 static const char *unpack_usage_messages(void)
117 /* Setup for I/O error handling via longjmp */
120 i = start_bunzip(&jmpbuf,
123 /* inbuf: */ packed_usage,
124 /* len: */ sizeof(packed_usage)
127 /* read_bunzip can longjmp and end up here with i != 0
128 * on read data errors! Not trivial */
130 /* Cannot use xmalloc: will leak bd in NOFORK case! */
131 outbuf = malloc_or_warn(sizeof(UNPACKED_USAGE));
133 read_bunzip(bd, outbuf, sizeof(UNPACKED_USAGE));
138 # define dealloc_usage_messages(s) free(s)
142 # define unpack_usage_messages() usage_messages
143 # define dealloc_usage_messages(s) ((void)(s))
145 #endif /* FEATURE_COMPRESS_USAGE */
148 void FAST_FUNC bb_show_usage(void)
150 if (ENABLE_SHOW_USAGE) {
151 #ifdef SINGLE_APPLET_STR
152 /* Imagine that this applet is "true". Dont suck in printf! */
153 const char *usage_string = unpack_usage_messages();
155 if (*usage_string == '\b') {
156 full_write2_str("No help available.\n\n");
158 full_write2_str("Usage: "SINGLE_APPLET_STR" ");
159 full_write2_str(usage_string);
160 full_write2_str("\n\n");
162 if (ENABLE_FEATURE_CLEAN_UP)
163 dealloc_usage_messages((char*)usage_string);
166 const char *usage_string = p = unpack_usage_messages();
167 int ap = find_applet_by_name(applet_name);
169 if (ap < 0) /* never happens, paranoia */
172 while (*p++) continue;
175 full_write2_str(bb_banner);
176 full_write2_str(" multi-call binary.\n");
178 full_write2_str("\nNo help available.\n\n");
180 full_write2_str("\nUsage: ");
181 full_write2_str(applet_name);
184 full_write2_str(" ");
187 full_write2_str("\n");
189 if (ENABLE_FEATURE_CLEAN_UP)
190 dealloc_usage_messages((char*)usage_string);
196 int FAST_FUNC find_applet_by_name(const char *name)
202 /* The commented-out word-at-a-time code is ~40% faster, but +160 bytes.
203 * "Faster" here saves ~0.5 microsecond of real time - not worth it.
205 #if 0 /*BB_UNALIGNED_MEMACCESS_OK && BB_LITTLE_ENDIAN*/
208 /* Handle all names < 2 chars long early */
210 return -1; /* "" is not a valid applet name */
211 if (name[1] == '\0') {
213 return -1; /* 1-char name is not valid */
215 return -1; /* 1-char name which isn't "[" is not valid */
216 /* applet "[" is always applet #0: */
223 #if KNOWN_APPNAME_OFFSETS <= 0
226 max = NUM_APPLETS * KNOWN_APPNAME_OFFSETS;
227 for (j = ARRAY_SIZE(applet_nameofs)-1; j >= 0; j--) {
228 const char *pp = applet_names + applet_nameofs[j];
229 if (strcmp(name, pp) >= 0) {
230 //bb_error_msg("name:'%s' >= pp:'%s'", name, pp);
232 i = max - NUM_APPLETS;
237 max /= (unsigned)KNOWN_APPNAME_OFFSETS;
238 i /= (unsigned)KNOWN_APPNAME_OFFSETS;
239 //bb_error_msg("name:'%s' starting from:'%s' i:%u max:%u", name, p, i, max);
242 /* Open-coded linear search without strcmp/strlen calls for speed */
244 #if 0 /*BB_UNALIGNED_MEMACCESS_OK && BB_LITTLE_ENDIAN*/
245 /* skip "[\0" name, it's surely not it */
246 if (ENABLE_TEST && LONE_CHAR(p, '['))
248 /* All remaining applet names in p[] are at least 2 chars long */
249 /* name[] is also at least 2 chars long */
251 n32 = (name[0] << 0) | (name[1] << 8) | (name[2] << 16);
256 /* Quickly check match of the first 3 bytes */
257 move_from_unaligned32(p32, p);
259 if ((p32 & 0x00ffffff) != n32) {
260 /* Most likely case: 3 first bytes do not match */
262 if ((p32 & 0x00ff0000) == '\0')
263 continue; // p[2] was NUL
265 if ((p32 & 0xff000000) == '\0')
266 continue; // p[3] was NUL
267 /* p[0..3] aren't matching and none is NUL, check the rest */
273 /* Unlikely branch: first 3 bytes ([0..2]) match */
274 if ((p32 & 0x00ff0000) == '\0') {
275 /* name is 2-byte long, it is full match */
276 //bb_error_msg("found:'%s' i:%u", name, i);
279 /* Check remaining bytes [3..NUL] */
282 while (ch == name[j]) {
284 //bb_error_msg("found:'%s' i:%u", name, i);
290 /* Not a match. Skip it, including NUL */
301 /* Do we see "name\0" in applet_names[p] position? */
302 while ((ch = *p) == name[j]) {
304 //bb_error_msg("found:'%s' i:%u", name, i);
311 * p => 1st non-matching char in applet_names[],
312 * skip to and including NUL.
324 void lbb_prepare(const char *applet
325 IF_FEATURE_INDIVIDUAL(, char **argv))
326 MAIN_EXTERNALLY_VISIBLE;
327 void lbb_prepare(const char *applet
328 IF_FEATURE_INDIVIDUAL(, char **argv))
331 (*(int **)&bb_errno) = __errno_location();
334 applet_name = applet;
336 if (ENABLE_LOCALE_SUPPORT)
337 setlocale(LC_ALL, "");
339 #if ENABLE_FEATURE_INDIVIDUAL
340 /* Redundant for busybox (run_applet_and_exit covers that case)
341 * but needed for "individual applet" mode */
344 && strcmp(argv[1], "--help") == 0
345 && !is_prefixed_with(applet, "busybox")
347 /* Special case. POSIX says "test --help"
348 * should be no different from e.g. "test --foo". */
349 if (!ENABLE_TEST || strcmp(applet_name, "test") != 0)
355 /* The code below can well be in applets/applets.c, as it is used only
356 * for busybox binary, not "individual" binaries.
357 * However, keeping it here and linking it into libbusybox.so
358 * (together with remaining tiny applets/applets.o)
359 * makes it possible to avoid --whole-archive at link time.
360 * This makes (shared busybox) + libbusybox smaller.
361 * (--gc-sections would be even better....)
364 const char *applet_name;
370 /* If not built as a single-applet executable... */
371 #if !defined(SINGLE_APPLET_MAIN)
373 IF_FEATURE_SUID(static uid_t ruid;) /* real uid */
375 # if ENABLE_FEATURE_SUID_CONFIG
377 static struct suid_config_t {
378 /* next ptr must be first: this struct needs to be llist-compatible */
379 struct suid_config_t *m_next;
380 struct bb_uidgid_t m_ugid;
385 static bool suid_cfg_readable;
387 /* libbb candidate */
388 static char *get_trimmed_slice(char *s, char *e)
390 /* First, consider the value at e to be nul and back up until we
391 * reach a non-space char. Set the char after that (possibly at
392 * the original e) to nul. */
400 /* Next, advance past all leading space and return a ptr to the
401 * first non-space char; possibly the terminating nul. */
402 return skip_whitespace(s);
405 static void parse_config_file(void)
407 /* Don't depend on the tools to combine strings. */
408 static const char config_file[] ALIGN1 = "/etc/busybox.conf";
410 struct suid_config_t *sct_head;
419 if (ruid == 0) /* run by root - don't need to even read config file */
422 if ((stat(config_file, &st) != 0) /* No config file? */
423 || !S_ISREG(st.st_mode) /* Not a regular file? */
424 || (st.st_uid != 0) /* Not owned by root? */
425 || (st.st_mode & (S_IWGRP | S_IWOTH)) /* Writable by non-root? */
426 || !(f = fopen_for_read(config_file)) /* Cannot open? */
431 suid_cfg_readable = 1;
439 if (!fgets(buffer, sizeof(buffer), f)) { /* Are we done? */
441 //if (ferror(f)) { /* Make sure it wasn't a read error. */
442 // errmsg = "reading";
446 suid_config = sct_head; /* Success, so set the pointer. */
451 lc++; /* Got a (partial) line. */
453 /* If a line is too long for our buffer, we consider it an error.
454 * The following test does mistreat one corner case though.
455 * If the final line of the file does not end with a newline and
456 * yet exactly fills the buffer, it will be treated as too long
457 * even though there isn't really a problem. But it isn't really
458 * worth adding code to deal with such an unlikely situation, and
459 * we do err on the side of caution. Besides, the line would be
460 * too long if it did end with a newline. */
461 if (!strchr(s, '\n') && !feof(f)) {
462 errmsg = "line too long";
466 /* Trim leading and trailing whitespace, ignoring comments, and
467 * check if the resulting string is empty. */
468 s = get_trimmed_slice(s, strchrnul(s, '#'));
473 /* Check for a section header. */
476 /* Unlike the old code, we ignore leading and trailing
477 * whitespace for the section name. We also require that
478 * there are no stray characters after the closing bracket. */
479 char *e = strchr(s, ']');
480 if (!e /* Missing right bracket? */
481 || e[1] /* Trailing characters? */
482 || !*(s = get_trimmed_slice(s+1, e)) /* Missing name? */
484 errmsg = "section header";
487 /* Right now we only have one section so just check it.
488 * If more sections are added in the future, please don't
489 * resort to cascading ifs with multiple strcasecmp calls.
490 * That kind of bloated code is all too common. A loop
491 * and a string table would be a better choice unless the
492 * number of sections is very small. */
493 if (strcasecmp(s, "SUID") == 0) {
497 section = -1; /* Unknown section so set to skip. */
501 /* Process sections. */
503 if (section == 1) { /* SUID */
504 /* Since we trimmed leading and trailing space above, we're
505 * now looking for strings of the form
506 * <key>[::space::]*=[::space::]*<value>
507 * where both key and value could contain inner whitespace. */
509 /* First get the key (an applet name in our case). */
510 char *e = strchr(s, '=');
512 s = get_trimmed_slice(s, e);
514 if (!e || !*s) { /* Missing '=' or empty key. */
519 /* Ok, we have an applet name. Process the rhs if this
520 * applet is currently built in and ignore it otherwise.
521 * Note: this can hide config file bugs which only pop
522 * up when the busybox configuration is changed. */
523 applet_no = find_applet_by_name(s);
524 if (applet_no >= 0) {
526 struct suid_config_t *sct;
528 /* Note: We currently don't check for duplicates!
529 * The last config line for each applet will be the
530 * one used since we insert at the head of the list.
531 * I suppose this could be considered a feature. */
532 sct = xzalloc(sizeof(*sct));
533 sct->m_applet = applet_no;
535 sct->m_next = sct_head;
538 /* Get the specified mode. */
540 e = skip_whitespace(e+1);
542 for (i = 0; i < 3; i++) {
543 /* There are 4 chars for each of user/group/other.
544 * "x-xx" instead of "x-" are to make
545 * "idx > 3" check catch invalid chars.
547 static const char mode_chars[] ALIGN1 = "Ssx-" "Ssx-" "x-xx";
548 static const unsigned short mode_mask[] ALIGN2 = {
549 S_ISUID, S_ISUID|S_IXUSR, S_IXUSR, 0, /* Ssx- */
550 S_ISGID, S_ISGID|S_IXGRP, S_IXGRP, 0, /* Ssx- */
553 const char *q = strchrnul(mode_chars + 4*i, *e);
554 unsigned idx = q - (mode_chars + 4*i);
559 sct->m_mode |= mode_mask[q - mode_chars];
563 /* Now get the user/group info. */
565 s = skip_whitespace(e);
566 /* Default is 0.0, else parse USER.GROUP: */
568 /* We require whitespace between mode and USER.GROUP */
569 if ((s == e) || !(e = strchr(s, '.'))) {
573 *e = ':'; /* get_uidgid needs USER:GROUP syntax */
574 if (get_uidgid(&sct->m_ugid, s) == 0) {
575 errmsg = "unknown user/group";
583 /* Unknown sections are ignored. */
585 /* Encountering configuration lines prior to seeing a
586 * section header is treated as an error. This is how
587 * the old code worked, but it may not be desirable.
588 * We may want to simply ignore such lines in case they
589 * are used in some future version of busybox. */
591 errmsg = "keyword outside section";
598 bb_error_msg("parse error in %s, line %u: %s", config_file, lc, errmsg);
600 /* Release any allocated memory before returning. */
601 llist_free((llist_t*)sct_head, NULL);
604 static inline void parse_config_file(void)
606 IF_FEATURE_SUID(ruid = getuid();)
608 # endif /* FEATURE_SUID_CONFIG */
611 # if ENABLE_FEATURE_SUID && NUM_APPLETS > 0
612 # if ENABLE_FEATURE_SUID_CONFIG
613 /* check if u is member of group g */
614 static int ingroup(uid_t u, gid_t g)
616 struct group *grp = getgrgid(g);
619 for (mem = grp->gr_mem; *mem; mem++) {
620 struct passwd *pwd = getpwnam(*mem);
621 if (pwd && (pwd->pw_uid == u))
629 static void check_suid(int applet_no)
631 gid_t rgid; /* real gid */
633 if (ruid == 0) /* set by parse_config_file() */
634 return; /* run by root - no need to check more */
637 # if ENABLE_FEATURE_SUID_CONFIG
638 if (suid_cfg_readable) {
640 struct suid_config_t *sct;
643 for (sct = suid_config; sct; sct = sct->m_next) {
644 if (sct->m_applet == applet_no)
647 goto check_need_suid;
649 /* Is this user allowed to run this applet? */
651 if (sct->m_ugid.uid == ruid)
654 else if ((sct->m_ugid.gid == rgid) || ingroup(ruid, sct->m_ugid.gid))
655 /* same group / in group */
657 if (!(m & S_IXOTH)) /* is x bit not set? */
658 bb_error_msg_and_die("you have no permission to run this applet");
660 /* We set effective AND saved ids. If saved-id is not set
661 * like we do below, seteuid(0) can still later succeed! */
663 /* Are we directed to change gid
664 * (APPLET = *s* USER.GROUP or APPLET = *S* USER.GROUP)?
666 if (sct->m_mode & S_ISGID)
667 rgid = sct->m_ugid.gid;
668 /* else: we will set egid = rgid, thus dropping sgid effect */
669 if (setresgid(-1, rgid, rgid))
670 bb_perror_msg_and_die("setresgid");
672 /* Are we directed to change uid
673 * (APPLET = s** USER.GROUP or APPLET = S** USER.GROUP)?
676 if (sct->m_mode & S_ISUID)
677 uid = sct->m_ugid.uid;
678 /* else: we will set euid = ruid, thus dropping suid effect */
679 if (setresuid(-1, uid, uid))
680 bb_perror_msg_and_die("setresuid");
684 # if !ENABLE_FEATURE_SUID_CONFIG_QUIET
686 static bool onetime = 0;
690 bb_error_msg("using fallback suid method");
696 if (APPLET_SUID(applet_no) == BB_SUID_REQUIRE) {
697 /* Real uid is not 0. If euid isn't 0 too, suid bit
698 * is most probably not set on our executable */
700 bb_error_msg_and_die("must be suid to work properly");
701 } else if (APPLET_SUID(applet_no) == BB_SUID_DROP) {
703 * Drop all privileges.
705 * Don't check for errors: in normal use, they are impossible,
706 * and in special cases, exiting is harmful. Example:
707 * 'unshare --user' when user's shell is also from busybox.
709 * 'unshare --user' creates a new user namespace without any
710 * uid mappings. Thus, busybox binary is setuid nobody:nogroup
711 * within the namespace, as that is the only user. However,
712 * since no uids are mapped, calls to setgid/setuid
713 * fail (even though they would do nothing).
718 # if ENABLE_FEATURE_SUID_CONFIG
720 llist_free((llist_t*)suid_config, NULL);
724 # define check_suid(x) ((void)0)
725 # endif /* FEATURE_SUID */
728 # if ENABLE_FEATURE_INSTALLER
729 static const char usr_bin [] ALIGN1 = "/usr/bin/";
730 static const char usr_sbin[] ALIGN1 = "/usr/sbin/";
731 static const char *const install_dir[] = {
732 &usr_bin [8], /* "/" */
733 &usr_bin [4], /* "/bin/" */
734 &usr_sbin[4] /* "/sbin/" */
735 # if !ENABLE_INSTALL_NO_USR
741 /* create (sym)links for each applet */
742 static void install_links(const char *busybox, int use_symbolic_links,
743 char *custom_install_dir)
746 * this should be consistent w/ the enum,
747 * busybox.h::bb_install_loc_t, or else... */
748 int (*lf)(const char *, const char *);
750 const char *appname = applet_names;
755 if (use_symbolic_links)
758 for (i = 0; i < ARRAY_SIZE(applet_main); i++) {
759 fpc = concat_path_file(
760 custom_install_dir ? custom_install_dir : install_dir[APPLET_INSTALL_LOC(i)],
762 // debug: bb_error_msg("%slinking %s to busybox",
763 // use_symbolic_links ? "sym" : "", fpc);
764 rc = lf(busybox, fpc);
765 if (rc != 0 && errno != EEXIST) {
766 bb_simple_perror_msg(fpc);
769 while (*appname++ != '\0')
773 # elif ENABLE_BUSYBOX
774 static void install_links(const char *busybox UNUSED_PARAM,
775 int use_symbolic_links UNUSED_PARAM,
776 char *custom_install_dir UNUSED_PARAM)
781 static void run_applet_and_exit(const char *name, char **argv) NORETURN;
784 # if ENABLE_FEATURE_SH_STANDALONE && ENABLE_FEATURE_TAB_COMPLETION
786 * Insert "busybox" into applet table as well.
787 * This makes standalone shell tab-complete this name too.
788 * (Otherwise having "busybox" in applet table is not necessary,
789 * there is other code which routes "busyboxANY_SUFFIX" name
790 * to busybox_main()).
792 //usage:#define busybox_trivial_usage NOUSAGE_STR
793 //usage:#define busybox_full_usage ""
794 //applet:IF_BUSYBOX(IF_FEATURE_SH_STANDALONE(IF_FEATURE_TAB_COMPLETION(APPLET(busybox, BB_DIR_BIN, BB_SUID_MAYBE))))
795 int busybox_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
797 # define busybox_main(argc,argv) busybox_main(argv)
800 int busybox_main(int argc UNUSED_PARAM, char **argv)
803 /* Called without arguments */
806 unsigned output_width;
808 output_width = get_terminal_width(2);
811 full_write2_str(bb_banner); /* reuse const string */
812 full_write2_str(" multi-call binary.\n"); /* reuse */
814 "BusyBox is copyrighted by many authors between 1998-2015.\n"
815 "Licensed under GPLv2. See source distribution for detailed\n"
816 "copyright notices.\n"
818 "Usage: busybox [function [arguments]...]\n"
819 " or: busybox --list"IF_FEATURE_INSTALLER("[-full]")"\n"
820 IF_FEATURE_INSTALLER(
821 " or: busybox --install [-s] [DIR]\n"
823 " or: function [arguments]...\n"
825 IF_NOT_FEATURE_SH_STANDALONE(
826 "\tBusyBox is a multi-call binary that combines many common Unix\n"
827 "\tutilities into a single executable. Most people will create a\n"
828 "\tlink to busybox for each function they wish to use and BusyBox\n"
829 "\twill act like whatever it was invoked as.\n"
831 IF_FEATURE_SH_STANDALONE(
832 "\tBusyBox is a multi-call binary that combines many common Unix\n"
833 "\tutilities into a single executable. The shell in this build\n"
834 "\tis configured to run built-in utilities without $PATH search.\n"
835 "\tYou don't need to install a link to busybox for each utility.\n"
836 "\tTo run external program, use full path (/sbin/ip instead of ip).\n"
839 "Currently defined functions:\n"
843 /* prevent last comma to be in the very last pos */
846 int len2 = strlen(a) + 2;
847 if (col >= (int)output_width - len2) {
848 full_write2_str(",\n");
853 full_write2_str("\t");
855 full_write2_str(", ");
861 full_write2_str("\n");
865 if (is_prefixed_with(argv[1], "--list")) {
867 const char *a = applet_names;
870 # if ENABLE_FEATURE_INSTALLER
871 if (argv[1][6]) /* --list-full? */
872 full_write2_str(install_dir[APPLET_INSTALL_LOC(i)] + 1);
875 full_write2_str("\n");
883 if (ENABLE_FEATURE_INSTALLER && strcmp(argv[1], "--install") == 0) {
884 int use_symbolic_links;
887 busybox = xmalloc_readlink(bb_busybox_exec_path);
889 /* bb_busybox_exec_path is usually "/proc/self/exe".
890 * In chroot, readlink("/proc/self/exe") usually fails.
891 * In such case, better use argv[0] as symlink target
892 * if it is a full path name.
894 if (argv[0][0] != '/')
895 bb_error_msg_and_die("'%s' is not an absolute path", argv[0]);
898 /* busybox --install [-s] [DIR]:
900 * DIR: directory to install links to
902 use_symbolic_links = (argv[2] && strcmp(argv[2], "-s") == 0 && ++argv);
903 install_links(busybox, use_symbolic_links, argv[2]);
907 if (strcmp(argv[1], "--help") == 0) {
908 /* "busybox --help [<applet>]" */
911 /* convert to "<applet> --help" */
915 /* "busybox <applet> arg1 arg2 ..." */
918 /* We support "busybox /a/path/to/applet args..." too. Allows for
919 * "#!/bin/busybox"-style wrappers */
920 applet_name = bb_get_last_path_component_nostrip(argv[0]);
921 run_applet_and_exit(applet_name, argv);
926 void FAST_FUNC run_applet_no_and_exit(int applet_no, const char *name, char **argv)
928 int argc = string_array_len(argv);
931 * We do not use argv[0]: do not want to repeat massaging of
932 * "-/sbin/halt" -> "halt", for example.
936 /* Special case. POSIX says "test --help"
937 * should be no different from e.g. "test --foo".
938 * Thus for "test", we skip --help check.
939 * "true" and "false" are also special.
942 # if defined APPLET_NO_test
943 && applet_no != APPLET_NO_test
945 # if defined APPLET_NO_true
946 && applet_no != APPLET_NO_true
948 # if defined APPLET_NO_false
949 && applet_no != APPLET_NO_false
952 if (argc == 2 && strcmp(argv[1], "--help") == 0) {
953 /* Make "foo --help" exit with 0: */
954 xfunc_error_retval = 0;
958 if (ENABLE_FEATURE_SUID)
959 check_suid(applet_no);
960 xfunc_error_retval = applet_main[applet_no](argc, argv);
961 /* Note: applet_main() may also not return (die on a xfunc or such) */
964 # endif /* NUM_APPLETS > 0 */
975 /* Setup for I/O error handling via longjmp */
978 i = start_bunzip(&jmpbuf,
981 /* inbuf: */ packed_scripts,
982 /* len: */ sizeof(packed_scripts)
985 /* read_bunzip can longjmp and end up here with i != 0
986 * on read data errors! Not trivial */
988 outbuf = xmalloc(UNPACKED_SCRIPTS_LENGTH);
989 read_bunzip(bd, outbuf, UNPACKED_SCRIPTS_LENGTH);
996 * In standalone shell mode we sometimes want the index of the script
997 * and sometimes the index offset by NUM_APPLETS.
1000 find_script_by_name(const char *arg)
1002 const char *s = script_names;
1006 if (strcmp(arg, s) == 0)
1009 while (*s++ != '\0')
1016 get_script_content(unsigned n)
1018 char *t = unpack_scripts();
1021 while (*t++ != '\0')
1028 # endif /* NUM_SCRIPTS > 0 */
1030 # if ENABLE_BUSYBOX || NUM_APPLETS > 0 || NUM_SCRIPTS > 0
1031 static NORETURN void run_applet_and_exit(const char *name, char **argv)
1034 if (is_prefixed_with(name, "busybox"))
1035 exit(busybox_main(/*unused:*/ 0, argv));
1037 # if NUM_APPLETS > 0
1038 /* find_applet_by_name() search is more expensive, so goes second */
1040 int applet = find_applet_by_name(name);
1042 run_applet_no_and_exit(applet, name, argv);
1045 # if NUM_SCRIPTS > 0
1047 int script = find_script_by_name(name);
1049 exit(ash_main(-script - 1, argv));
1053 /*bb_error_msg_and_die("applet not found"); - links in printf */
1054 full_write2_str(applet_name);
1055 full_write2_str(": applet not found\n");
1056 /* POSIX: "If a command is not found, the exit status shall be 127" */
1061 #endif /* !defined(SINGLE_APPLET_MAIN) */
1064 #if ENABLE_BUILD_LIBBUSYBOX
1065 int lbb_main(char **argv)
1067 int main(int argc UNUSED_PARAM, char **argv)
1071 /* TODO: find a use for a block of memory between end of .bss
1072 * and end of page. For example, I'm getting "_end:0x812e698 2408 bytes"
1073 * - more than 2k of wasted memory (in this particular build)
1074 * *per each running process*!
1075 * (If your linker does not generate "_end" name, weak attribute
1076 * makes &_end == NULL, end_len == 0 here.)
1078 extern char _end[] __attribute__((weak));
1079 unsigned end_len = (-(int)_end) & 0xfff;
1080 printf("_end:%p %u bytes\n", &_end, end_len);
1083 /* Tweak malloc for reduced memory consumption */
1084 #ifdef M_TRIM_THRESHOLD
1085 /* M_TRIM_THRESHOLD is the maximum amount of freed top-most memory
1086 * to keep before releasing to the OS
1087 * Default is way too big: 256k
1089 mallopt(M_TRIM_THRESHOLD, 8 * 1024);
1091 #ifdef M_MMAP_THRESHOLD
1092 /* M_MMAP_THRESHOLD is the request size threshold for using mmap()
1093 * Default is too big: 256k
1095 mallopt(M_MMAP_THRESHOLD, 32 * 1024 - 256);
1097 #if 0 /*def M_TOP_PAD*/
1098 /* When the program break is increased, then M_TOP_PAD bytes are added
1099 * to the sbrk(2) request. When the heap is trimmed because of free(3),
1100 * this much free space is preserved at the top of the heap.
1101 * glibc default seems to be way too big: 128k, but need to verify.
1103 mallopt(M_TOP_PAD, 8 * 1024);
1107 /* NOMMU re-exec trick sets high-order bit in first byte of name */
1108 if (argv[0][0] & 0x80) {
1114 #if defined(SINGLE_APPLET_MAIN)
1116 /* Only one applet is selected in .config */
1117 if (argv[1] && is_prefixed_with(argv[0], "busybox")) {
1118 /* "busybox <applet> <params>" should still work as expected */
1121 /* applet_names in this case is just "applet\0\0" */
1122 lbb_prepare(applet_names IF_FEATURE_INDIVIDUAL(, argv));
1123 # if ENABLE_BUILD_LIBBUSYBOX
1124 return SINGLE_APPLET_MAIN(string_array_len(argv), argv);
1126 return SINGLE_APPLET_MAIN(argc, argv);
1129 #elif !ENABLE_BUSYBOX && NUM_APPLETS == 0
1131 full_write2_str(bb_basename(argv[0]));
1132 full_write2_str(": no applets enabled\n");
1137 lbb_prepare("busybox" IF_FEATURE_INDIVIDUAL(, argv));
1138 # if !ENABLE_BUSYBOX
1139 if (argv[1] && is_prefixed_with(bb_basename(argv[0]), "busybox"))
1142 applet_name = argv[0];
1143 if (applet_name[0] == '-')
1145 applet_name = bb_basename(applet_name);
1147 /* If we are a result of execv("/proc/self/exe"), fix ugly comm of "exe" */
1148 if (ENABLE_FEATURE_SH_STANDALONE
1149 || ENABLE_FEATURE_PREFER_APPLETS
1152 if (NUM_APPLETS > 1)
1153 set_task_comm(applet_name);
1156 parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */
1157 run_applet_and_exit(applet_name, argv);