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"
54 /* "Do not compress usage text if uncompressed text is small
55 * and we don't include bunzip2 code for other reasons"
57 * Useful for mass one-applet rebuild (bunzip2 code is ~2.7k).
59 * Unlike BUNZIP2, if FEATURE_SEAMLESS_BZ2 is on, bunzip2 code is built but
60 * still may be unused if none of the selected applets calls open_zipped()
61 * or its friends; we test for (FEATURE_SEAMLESS_BZ2 && <APPLET>) instead.
62 * For example, only if TAR and FEATURE_SEAMLESS_BZ2 are both selected,
63 * then bunzip2 code will be linked in anyway, and disabling help compression
64 * would be not optimal:
66 #if UNPACKED_USAGE_LENGTH < 4*1024 \
67 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_TAR) \
68 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_MODPROBE) \
69 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_INSMOD) \
70 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_DEPMOD) \
71 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_MAN) \
74 # undef ENABLE_FEATURE_COMPRESS_USAGE
75 # define ENABLE_FEATURE_COMPRESS_USAGE 0
79 unsigned FAST_FUNC string_array_len(char **argv)
90 #if ENABLE_SHOW_USAGE && !ENABLE_FEATURE_COMPRESS_USAGE
91 static const char usage_messages[] ALIGN1 = UNPACKED_USAGE;
93 # define usage_messages 0
96 #if ENABLE_FEATURE_COMPRESS_USAGE
98 static const char packed_usage[] ALIGN1 = { PACKED_USAGE };
99 # include "bb_archive.h"
100 static const char *unpack_usage_messages(void)
106 i = start_bunzip(&bd,
108 /* inbuf: */ packed_usage,
109 /* len: */ sizeof(packed_usage));
110 /* read_bunzip can longjmp to start_bunzip, and ultimately
111 * end up here with i != 0 on read data errors! Not trivial */
113 /* Cannot use xmalloc: will leak bd in NOFORK case! */
114 outbuf = malloc_or_warn(sizeof(UNPACKED_USAGE));
116 read_bunzip(bd, outbuf, sizeof(UNPACKED_USAGE));
121 # define dealloc_usage_messages(s) free(s)
125 # define unpack_usage_messages() usage_messages
126 # define dealloc_usage_messages(s) ((void)(s))
128 #endif /* FEATURE_COMPRESS_USAGE */
131 void FAST_FUNC bb_show_usage(void)
133 if (ENABLE_SHOW_USAGE) {
134 #ifdef SINGLE_APPLET_STR
135 /* Imagine that this applet is "true". Dont suck in printf! */
136 const char *usage_string = unpack_usage_messages();
138 if (*usage_string == '\b') {
139 full_write2_str("No help available.\n\n");
141 full_write2_str("Usage: "SINGLE_APPLET_STR" ");
142 full_write2_str(usage_string);
143 full_write2_str("\n\n");
145 if (ENABLE_FEATURE_CLEAN_UP)
146 dealloc_usage_messages((char*)usage_string);
149 const char *usage_string = p = unpack_usage_messages();
150 int ap = find_applet_by_name(applet_name);
152 if (ap < 0) /* never happens, paranoia */
155 while (*p++) continue;
158 full_write2_str(bb_banner);
159 full_write2_str(" multi-call binary.\n");
161 full_write2_str("\nNo help available.\n\n");
163 full_write2_str("\nUsage: ");
164 full_write2_str(applet_name);
165 full_write2_str(" ");
167 full_write2_str("\n");
169 if (ENABLE_FEATURE_CLEAN_UP)
170 dealloc_usage_messages((char*)usage_string);
176 int FAST_FUNC find_applet_by_name(const char *name)
182 /* The commented-out word-at-a-time code is ~40% faster, but +160 bytes.
183 * "Faster" here saves ~0.5 microsecond of real time - not worth it.
185 #if 0 /*BB_UNALIGNED_MEMACCESS_OK && BB_LITTLE_ENDIAN*/
188 /* Handle all names < 2 chars long early */
190 return -1; /* "" is not a valid applet name */
191 if (name[1] == '\0') {
193 return -1; /* 1-char name is not valid */
195 return -1; /* 1-char name which isn't "[" is not valid */
196 /* applet "[" is always applet #0: */
203 #if KNOWN_APPNAME_OFFSETS <= 0
206 max = NUM_APPLETS * KNOWN_APPNAME_OFFSETS;
207 for (j = ARRAY_SIZE(applet_nameofs)-1; j >= 0; j--) {
208 const char *pp = applet_names + applet_nameofs[j];
209 if (strcmp(name, pp) >= 0) {
210 //bb_error_msg("name:'%s' >= pp:'%s'", name, pp);
212 i = max - NUM_APPLETS;
217 max /= (unsigned)KNOWN_APPNAME_OFFSETS;
218 i /= (unsigned)KNOWN_APPNAME_OFFSETS;
219 //bb_error_msg("name:'%s' starting from:'%s' i:%u max:%u", name, p, i, max);
222 /* Open-coded linear search without strcmp/strlen calls for speed */
224 #if 0 /*BB_UNALIGNED_MEMACCESS_OK && BB_LITTLE_ENDIAN*/
225 /* skip "[\0" name, it's surely not it */
226 if (ENABLE_TEST && LONE_CHAR(p, '['))
228 /* All remaining applet names in p[] are at least 2 chars long */
229 /* name[] is also at least 2 chars long */
231 n32 = (name[0] << 0) | (name[1] << 8) | (name[2] << 16);
236 /* Quickly check match of the first 3 bytes */
237 move_from_unaligned32(p32, p);
239 if ((p32 & 0x00ffffff) != n32) {
240 /* Most likely case: 3 first bytes do not match */
242 if ((p32 & 0x00ff0000) == '\0')
243 continue; // p[2] was NUL
245 if ((p32 & 0xff000000) == '\0')
246 continue; // p[3] was NUL
247 /* p[0..3] aren't matching and none is NUL, check the rest */
253 /* Unlikely branch: first 3 bytes ([0..2]) match */
254 if ((p32 & 0x00ff0000) == '\0') {
255 /* name is 2-byte long, it is full match */
256 //bb_error_msg("found:'%s' i:%u", name, i);
259 /* Check remaining bytes [3..NUL] */
262 while (ch == name[j]) {
264 //bb_error_msg("found:'%s' i:%u", name, i);
270 /* Not a match. Skip it, including NUL */
281 /* Do we see "name\0" in applet_names[p] position? */
282 while ((ch = *p) == name[j]) {
284 //bb_error_msg("found:'%s' i:%u", name, i);
291 * p => 1st non-matching char in applet_names[],
292 * skip to and including NUL.
304 void lbb_prepare(const char *applet
305 IF_FEATURE_INDIVIDUAL(, char **argv))
306 MAIN_EXTERNALLY_VISIBLE;
307 void lbb_prepare(const char *applet
308 IF_FEATURE_INDIVIDUAL(, char **argv))
311 (*(int **)&bb_errno) = __errno_location();
314 applet_name = applet;
316 if (ENABLE_LOCALE_SUPPORT)
317 setlocale(LC_ALL, "");
319 #if ENABLE_FEATURE_INDIVIDUAL
320 /* Redundant for busybox (run_applet_and_exit covers that case)
321 * but needed for "individual applet" mode */
324 && strcmp(argv[1], "--help") == 0
325 && !is_prefixed_with(applet, "busybox")
327 /* Special case. POSIX says "test --help"
328 * should be no different from e.g. "test --foo". */
329 if (!ENABLE_TEST || strcmp(applet_name, "test") != 0)
335 /* The code below can well be in applets/applets.c, as it is used only
336 * for busybox binary, not "individual" binaries.
337 * However, keeping it here and linking it into libbusybox.so
338 * (together with remaining tiny applets/applets.o)
339 * makes it possible to avoid --whole-archive at link time.
340 * This makes (shared busybox) + libbusybox smaller.
341 * (--gc-sections would be even better....)
344 const char *applet_name;
350 /* If not built as a single-applet executable... */
351 #if !defined(SINGLE_APPLET_MAIN)
353 IF_FEATURE_SUID(static uid_t ruid;) /* real uid */
355 # if ENABLE_FEATURE_SUID_CONFIG
357 static struct suid_config_t {
358 /* next ptr must be first: this struct needs to be llist-compatible */
359 struct suid_config_t *m_next;
360 struct bb_uidgid_t m_ugid;
365 static bool suid_cfg_readable;
367 /* libbb candidate */
368 static char *get_trimmed_slice(char *s, char *e)
370 /* First, consider the value at e to be nul and back up until we
371 * reach a non-space char. Set the char after that (possibly at
372 * the original e) to nul. */
380 /* Next, advance past all leading space and return a ptr to the
381 * first non-space char; possibly the terminating nul. */
382 return skip_whitespace(s);
385 static void parse_config_file(void)
387 /* Don't depend on the tools to combine strings. */
388 static const char config_file[] ALIGN1 = "/etc/busybox.conf";
390 struct suid_config_t *sct_head;
399 if (ruid == 0) /* run by root - don't need to even read config file */
402 if ((stat(config_file, &st) != 0) /* No config file? */
403 || !S_ISREG(st.st_mode) /* Not a regular file? */
404 || (st.st_uid != 0) /* Not owned by root? */
405 || (st.st_mode & (S_IWGRP | S_IWOTH)) /* Writable by non-root? */
406 || !(f = fopen_for_read(config_file)) /* Cannot open? */
411 suid_cfg_readable = 1;
419 if (!fgets(buffer, sizeof(buffer), f)) { /* Are we done? */
421 //if (ferror(f)) { /* Make sure it wasn't a read error. */
422 // errmsg = "reading";
426 suid_config = sct_head; /* Success, so set the pointer. */
431 lc++; /* Got a (partial) line. */
433 /* If a line is too long for our buffer, we consider it an error.
434 * The following test does mistreat one corner case though.
435 * If the final line of the file does not end with a newline and
436 * yet exactly fills the buffer, it will be treated as too long
437 * even though there isn't really a problem. But it isn't really
438 * worth adding code to deal with such an unlikely situation, and
439 * we do err on the side of caution. Besides, the line would be
440 * too long if it did end with a newline. */
441 if (!strchr(s, '\n') && !feof(f)) {
442 errmsg = "line too long";
446 /* Trim leading and trailing whitespace, ignoring comments, and
447 * check if the resulting string is empty. */
448 s = get_trimmed_slice(s, strchrnul(s, '#'));
453 /* Check for a section header. */
456 /* Unlike the old code, we ignore leading and trailing
457 * whitespace for the section name. We also require that
458 * there are no stray characters after the closing bracket. */
459 char *e = strchr(s, ']');
460 if (!e /* Missing right bracket? */
461 || e[1] /* Trailing characters? */
462 || !*(s = get_trimmed_slice(s+1, e)) /* Missing name? */
464 errmsg = "section header";
467 /* Right now we only have one section so just check it.
468 * If more sections are added in the future, please don't
469 * resort to cascading ifs with multiple strcasecmp calls.
470 * That kind of bloated code is all too common. A loop
471 * and a string table would be a better choice unless the
472 * number of sections is very small. */
473 if (strcasecmp(s, "SUID") == 0) {
477 section = -1; /* Unknown section so set to skip. */
481 /* Process sections. */
483 if (section == 1) { /* SUID */
484 /* Since we trimmed leading and trailing space above, we're
485 * now looking for strings of the form
486 * <key>[::space::]*=[::space::]*<value>
487 * where both key and value could contain inner whitespace. */
489 /* First get the key (an applet name in our case). */
490 char *e = strchr(s, '=');
492 s = get_trimmed_slice(s, e);
494 if (!e || !*s) { /* Missing '=' or empty key. */
499 /* Ok, we have an applet name. Process the rhs if this
500 * applet is currently built in and ignore it otherwise.
501 * Note: this can hide config file bugs which only pop
502 * up when the busybox configuration is changed. */
503 applet_no = find_applet_by_name(s);
504 if (applet_no >= 0) {
506 struct suid_config_t *sct;
508 /* Note: We currently don't check for duplicates!
509 * The last config line for each applet will be the
510 * one used since we insert at the head of the list.
511 * I suppose this could be considered a feature. */
512 sct = xzalloc(sizeof(*sct));
513 sct->m_applet = applet_no;
515 sct->m_next = sct_head;
518 /* Get the specified mode. */
520 e = skip_whitespace(e+1);
522 for (i = 0; i < 3; i++) {
523 /* There are 4 chars for each of user/group/other.
524 * "x-xx" instead of "x-" are to make
525 * "idx > 3" check catch invalid chars.
527 static const char mode_chars[] ALIGN1 = "Ssx-" "Ssx-" "x-xx";
528 static const unsigned short mode_mask[] ALIGN2 = {
529 S_ISUID, S_ISUID|S_IXUSR, S_IXUSR, 0, /* Ssx- */
530 S_ISGID, S_ISGID|S_IXGRP, S_IXGRP, 0, /* Ssx- */
533 const char *q = strchrnul(mode_chars + 4*i, *e);
534 unsigned idx = q - (mode_chars + 4*i);
539 sct->m_mode |= mode_mask[q - mode_chars];
543 /* Now get the user/group info. */
545 s = skip_whitespace(e);
546 /* Default is 0.0, else parse USER.GROUP: */
548 /* We require whitespace between mode and USER.GROUP */
549 if ((s == e) || !(e = strchr(s, '.'))) {
553 *e = ':'; /* get_uidgid needs USER:GROUP syntax */
554 if (get_uidgid(&sct->m_ugid, s) == 0) {
555 errmsg = "unknown user/group";
563 /* Unknown sections are ignored. */
565 /* Encountering configuration lines prior to seeing a
566 * section header is treated as an error. This is how
567 * the old code worked, but it may not be desirable.
568 * We may want to simply ignore such lines in case they
569 * are used in some future version of busybox. */
571 errmsg = "keyword outside section";
578 bb_error_msg("parse error in %s, line %u: %s", config_file, lc, errmsg);
580 /* Release any allocated memory before returning. */
581 llist_free((llist_t*)sct_head, NULL);
584 static inline void parse_config_file(void)
586 IF_FEATURE_SUID(ruid = getuid();)
588 # endif /* FEATURE_SUID_CONFIG */
591 # if ENABLE_FEATURE_SUID && NUM_APPLETS > 0
592 # if ENABLE_FEATURE_SUID_CONFIG
593 /* check if u is member of group g */
594 static int ingroup(uid_t u, gid_t g)
596 struct group *grp = getgrgid(g);
599 for (mem = grp->gr_mem; *mem; mem++) {
600 struct passwd *pwd = getpwnam(*mem);
601 if (pwd && (pwd->pw_uid == u))
609 static void check_suid(int applet_no)
611 gid_t rgid; /* real gid */
613 if (ruid == 0) /* set by parse_config_file() */
614 return; /* run by root - no need to check more */
617 # if ENABLE_FEATURE_SUID_CONFIG
618 if (suid_cfg_readable) {
620 struct suid_config_t *sct;
623 for (sct = suid_config; sct; sct = sct->m_next) {
624 if (sct->m_applet == applet_no)
627 goto check_need_suid;
629 /* Is this user allowed to run this applet? */
631 if (sct->m_ugid.uid == ruid)
634 else if ((sct->m_ugid.gid == rgid) || ingroup(ruid, sct->m_ugid.gid))
635 /* same group / in group */
637 if (!(m & S_IXOTH)) /* is x bit not set? */
638 bb_error_msg_and_die("you have no permission to run this applet");
640 /* We set effective AND saved ids. If saved-id is not set
641 * like we do below, seteuid(0) can still later succeed! */
643 /* Are we directed to change gid
644 * (APPLET = *s* USER.GROUP or APPLET = *S* USER.GROUP)?
646 if (sct->m_mode & S_ISGID)
647 rgid = sct->m_ugid.gid;
648 /* else: we will set egid = rgid, thus dropping sgid effect */
649 if (setresgid(-1, rgid, rgid))
650 bb_perror_msg_and_die("setresgid");
652 /* Are we directed to change uid
653 * (APPLET = s** USER.GROUP or APPLET = S** USER.GROUP)?
656 if (sct->m_mode & S_ISUID)
657 uid = sct->m_ugid.uid;
658 /* else: we will set euid = ruid, thus dropping suid effect */
659 if (setresuid(-1, uid, uid))
660 bb_perror_msg_and_die("setresuid");
664 # if !ENABLE_FEATURE_SUID_CONFIG_QUIET
666 static bool onetime = 0;
670 bb_error_msg("using fallback suid method");
676 if (APPLET_SUID(applet_no) == BB_SUID_REQUIRE) {
677 /* Real uid is not 0. If euid isn't 0 too, suid bit
678 * is most probably not set on our executable */
680 bb_error_msg_and_die("must be suid to work properly");
681 } else if (APPLET_SUID(applet_no) == BB_SUID_DROP) {
683 * Drop all privileges.
685 * Don't check for errors: in normal use, they are impossible,
686 * and in special cases, exiting is harmful. Example:
687 * 'unshare --user' when user's shell is also from busybox.
689 * 'unshare --user' creates a new user namespace without any
690 * uid mappings. Thus, busybox binary is setuid nobody:nogroup
691 * within the namespace, as that is the only user. However,
692 * since no uids are mapped, calls to setgid/setuid
693 * fail (even though they would do nothing).
698 # if ENABLE_FEATURE_SUID_CONFIG
700 llist_free((llist_t*)suid_config, NULL);
704 # define check_suid(x) ((void)0)
705 # endif /* FEATURE_SUID */
708 # if ENABLE_FEATURE_INSTALLER
709 static const char usr_bin [] ALIGN1 = "/usr/bin/";
710 static const char usr_sbin[] ALIGN1 = "/usr/sbin/";
711 static const char *const install_dir[] = {
712 &usr_bin [8], /* "/" */
713 &usr_bin [4], /* "/bin/" */
714 &usr_sbin[4] /* "/sbin/" */
715 # if !ENABLE_INSTALL_NO_USR
721 /* create (sym)links for each applet */
722 static void install_links(const char *busybox, int use_symbolic_links,
723 char *custom_install_dir)
726 * this should be consistent w/ the enum,
727 * busybox.h::bb_install_loc_t, or else... */
728 int (*lf)(const char *, const char *);
730 const char *appname = applet_names;
735 if (use_symbolic_links)
738 for (i = 0; i < ARRAY_SIZE(applet_main); i++) {
739 fpc = concat_path_file(
740 custom_install_dir ? custom_install_dir : install_dir[APPLET_INSTALL_LOC(i)],
742 // debug: bb_error_msg("%slinking %s to busybox",
743 // use_symbolic_links ? "sym" : "", fpc);
744 rc = lf(busybox, fpc);
745 if (rc != 0 && errno != EEXIST) {
746 bb_simple_perror_msg(fpc);
749 while (*appname++ != '\0')
753 # elif ENABLE_BUSYBOX
754 static void install_links(const char *busybox UNUSED_PARAM,
755 int use_symbolic_links UNUSED_PARAM,
756 char *custom_install_dir UNUSED_PARAM)
761 static void run_applet_and_exit(const char *name, char **argv) NORETURN;
764 # if ENABLE_FEATURE_SH_STANDALONE && ENABLE_FEATURE_TAB_COMPLETION
766 * Insert "busybox" into applet table as well.
767 * This makes standalone shell tab-complete this name too.
768 * (Otherwise having "busybox" in applet table is not necessary,
769 * there is other code which routes "busyboxANY_SUFFIX" name
770 * to busybox_main()).
772 //usage:#define busybox_trivial_usage NOUSAGE_STR
773 //usage:#define busybox_full_usage ""
774 //applet:IF_BUSYBOX(IF_FEATURE_SH_STANDALONE(IF_FEATURE_TAB_COMPLETION(APPLET(busybox, BB_DIR_BIN, BB_SUID_MAYBE))))
775 int busybox_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
777 # define busybox_main(argc,argv) busybox_main(argv)
780 int busybox_main(int argc UNUSED_PARAM, char **argv)
783 /* Called without arguments */
786 unsigned output_width;
788 output_width = get_terminal_width(2);
791 full_write2_str(bb_banner); /* reuse const string */
792 full_write2_str(" multi-call binary.\n"); /* reuse */
794 "BusyBox is copyrighted by many authors between 1998-2015.\n"
795 "Licensed under GPLv2. See source distribution for detailed\n"
796 "copyright notices.\n"
798 "Usage: busybox [function [arguments]...]\n"
799 " or: busybox --list"IF_FEATURE_INSTALLER("[-full]")"\n"
800 IF_FEATURE_INSTALLER(
801 " or: busybox --install [-s] [DIR]\n"
803 " or: function [arguments]...\n"
805 IF_NOT_FEATURE_SH_STANDALONE(
806 "\tBusyBox is a multi-call binary that combines many common Unix\n"
807 "\tutilities into a single executable. Most people will create a\n"
808 "\tlink to busybox for each function they wish to use and BusyBox\n"
809 "\twill act like whatever it was invoked as.\n"
811 IF_FEATURE_SH_STANDALONE(
812 "\tBusyBox is a multi-call binary that combines many common Unix\n"
813 "\tutilities into a single executable. The shell in this build\n"
814 "\tis configured to run built-in utilities without $PATH search.\n"
815 "\tYou don't need to install a link to busybox for each utility.\n"
816 "\tTo run external program, use full path (/sbin/ip instead of ip).\n"
819 "Currently defined functions:\n"
823 /* prevent last comma to be in the very last pos */
826 int len2 = strlen(a) + 2;
827 if (col >= (int)output_width - len2) {
828 full_write2_str(",\n");
833 full_write2_str("\t");
835 full_write2_str(", ");
841 full_write2_str("\n");
845 if (is_prefixed_with(argv[1], "--list")) {
847 const char *a = applet_names;
850 # if ENABLE_FEATURE_INSTALLER
851 if (argv[1][6]) /* --list-full? */
852 full_write2_str(install_dir[APPLET_INSTALL_LOC(i)] + 1);
855 full_write2_str("\n");
863 if (ENABLE_FEATURE_INSTALLER && strcmp(argv[1], "--install") == 0) {
864 int use_symbolic_links;
867 busybox = xmalloc_readlink(bb_busybox_exec_path);
869 /* bb_busybox_exec_path is usually "/proc/self/exe".
870 * In chroot, readlink("/proc/self/exe") usually fails.
871 * In such case, better use argv[0] as symlink target
872 * if it is a full path name.
874 if (argv[0][0] != '/')
875 bb_error_msg_and_die("'%s' is not an absolute path", argv[0]);
878 /* busybox --install [-s] [DIR]:
880 * DIR: directory to install links to
882 use_symbolic_links = (argv[2] && strcmp(argv[2], "-s") == 0 && ++argv);
883 install_links(busybox, use_symbolic_links, argv[2]);
887 if (strcmp(argv[1], "--help") == 0) {
888 /* "busybox --help [<applet>]" */
891 /* convert to "<applet> --help" */
895 /* "busybox <applet> arg1 arg2 ..." */
898 /* We support "busybox /a/path/to/applet args..." too. Allows for
899 * "#!/bin/busybox"-style wrappers */
900 applet_name = bb_get_last_path_component_nostrip(argv[0]);
901 run_applet_and_exit(applet_name, argv);
906 void FAST_FUNC run_applet_no_and_exit(int applet_no, const char *name, char **argv)
908 int argc = string_array_len(argv);
911 * We do not use argv[0]: do not want to repeat massaging of
912 * "-/sbin/halt" -> "halt", for example.
916 /* Special case. POSIX says "test --help"
917 * should be no different from e.g. "test --foo".
918 * Thus for "test", we skip --help check.
919 * "true" and "false" are also special.
922 # if defined APPLET_NO_test
923 && applet_no != APPLET_NO_test
925 # if defined APPLET_NO_true
926 && applet_no != APPLET_NO_true
928 # if defined APPLET_NO_false
929 && applet_no != APPLET_NO_false
932 if (argc == 2 && strcmp(argv[1], "--help") == 0) {
933 /* Make "foo --help" exit with 0: */
934 xfunc_error_retval = 0;
938 if (ENABLE_FEATURE_SUID)
939 check_suid(applet_no);
940 xfunc_error_retval = applet_main[applet_no](argc, argv);
941 /* Note: applet_main() may also not return (die on a xfunc or such) */
944 # endif /* NUM_APPLETS > 0 */
946 # if ENABLE_BUSYBOX || NUM_APPLETS > 0
947 static NORETURN void run_applet_and_exit(const char *name, char **argv)
950 if (is_prefixed_with(name, "busybox"))
951 exit(busybox_main(/*unused:*/ 0, argv));
954 /* find_applet_by_name() search is more expensive, so goes second */
956 int applet = find_applet_by_name(name);
958 run_applet_no_and_exit(applet, name, argv);
962 /*bb_error_msg_and_die("applet not found"); - links in printf */
963 full_write2_str(applet_name);
964 full_write2_str(": applet not found\n");
965 /* POSIX: "If a command is not found, the exit status shall be 127" */
970 #endif /* !defined(SINGLE_APPLET_MAIN) */
973 #if ENABLE_BUILD_LIBBUSYBOX
974 int lbb_main(char **argv)
976 int main(int argc UNUSED_PARAM, char **argv)
980 /* TODO: find a use for a block of memory between end of .bss
981 * and end of page. For example, I'm getting "_end:0x812e698 2408 bytes"
982 * - more than 2k of wasted memory (in this particular build)
983 * *per each running process*!
984 * (If your linker does not generate "_end" name, weak attribute
985 * makes &_end == NULL, end_len == 0 here.)
987 extern char _end[] __attribute__((weak));
988 unsigned end_len = (-(int)_end) & 0xfff;
989 printf("_end:%p %u bytes\n", &_end, end_len);
992 /* Tweak malloc for reduced memory consumption */
993 #ifdef M_TRIM_THRESHOLD
994 /* M_TRIM_THRESHOLD is the maximum amount of freed top-most memory
995 * to keep before releasing to the OS
996 * Default is way too big: 256k
998 mallopt(M_TRIM_THRESHOLD, 8 * 1024);
1000 #ifdef M_MMAP_THRESHOLD
1001 /* M_MMAP_THRESHOLD is the request size threshold for using mmap()
1002 * Default is too big: 256k
1004 mallopt(M_MMAP_THRESHOLD, 32 * 1024 - 256);
1006 #if 0 /*def M_TOP_PAD*/
1007 /* When the program break is increased, then M_TOP_PAD bytes are added
1008 * to the sbrk(2) request. When the heap is trimmed because of free(3),
1009 * this much free space is preserved at the top of the heap.
1010 * glibc default seems to be way too big: 128k, but need to verify.
1012 mallopt(M_TOP_PAD, 8 * 1024);
1016 /* NOMMU re-exec trick sets high-order bit in first byte of name */
1017 if (argv[0][0] & 0x80) {
1023 #if defined(SINGLE_APPLET_MAIN)
1025 /* Only one applet is selected in .config */
1026 if (argv[1] && is_prefixed_with(argv[0], "busybox")) {
1027 /* "busybox <applet> <params>" should still work as expected */
1030 /* applet_names in this case is just "applet\0\0" */
1031 lbb_prepare(applet_names IF_FEATURE_INDIVIDUAL(, argv));
1032 # if ENABLE_BUILD_LIBBUSYBOX
1033 return SINGLE_APPLET_MAIN(string_array_len(argv), argv);
1035 return SINGLE_APPLET_MAIN(argc, argv);
1038 #elif !ENABLE_BUSYBOX && NUM_APPLETS == 0
1040 full_write2_str(bb_basename(argv[0]));
1041 full_write2_str(": no applets enabled\n");
1046 lbb_prepare("busybox" IF_FEATURE_INDIVIDUAL(, argv));
1047 # if !ENABLE_BUSYBOX
1048 if (argv[1] && is_prefixed_with(bb_basename(argv[0]), "busybox"))
1051 applet_name = argv[0];
1052 if (applet_name[0] == '-')
1054 applet_name = bb_basename(applet_name);
1056 /* If we are a result of execv("/proc/self/exe"), fix ugly comm of "exe" */
1057 if (ENABLE_FEATURE_SH_STANDALONE
1058 || ENABLE_FEATURE_PREFER_APPLETS
1061 if (NUM_APPLETS > 1)
1062 set_task_comm(applet_name);
1065 parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */
1066 run_applet_and_exit(applet_name, argv);