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 #include <sys/prctl.h>
39 #define PR_SET_NAME 15
42 #define PR_GET_NAME 16
45 /* Declare <applet>_main() */
50 /* Include generated applet names, pointers to <applet>_main, etc */
51 #include "applet_tables.h"
52 /* ...and if applet_tables generator says we have only one applet... */
53 #ifdef SINGLE_APPLET_MAIN
54 # undef ENABLE_FEATURE_INDIVIDUAL
55 # define ENABLE_FEATURE_INDIVIDUAL 1
56 # undef IF_FEATURE_INDIVIDUAL
57 # define IF_FEATURE_INDIVIDUAL(...) __VA_ARGS__
60 #include "usage_compressed.h"
63 /* "Do not compress usage text if uncompressed text is small
64 * and we don't include bunzip2 code for other reasons"
66 * Useful for mass one-applet rebuild (bunzip2 code is ~2.7k).
68 * Unlike BUNZIP2, if FEATURE_SEAMLESS_BZ2 is on, bunzip2 code is built but
69 * still may be unused if none of the selected applets calls open_zipped()
70 * or its friends; we test for (FEATURE_SEAMLESS_BZ2 && <APPLET>) instead.
71 * For example, only if TAR and FEATURE_SEAMLESS_BZ2 are both selected,
72 * then bunzip2 code will be linked in anyway, and disabling help compression
73 * would be not optimal:
75 #if UNPACKED_USAGE_LENGTH < 4*1024 \
76 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_TAR) \
77 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_MODPROBE) \
78 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_INSMOD) \
79 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_DEPMOD) \
80 && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_MAN) \
83 # undef ENABLE_FEATURE_COMPRESS_USAGE
84 # define ENABLE_FEATURE_COMPRESS_USAGE 0
88 unsigned FAST_FUNC string_array_len(char **argv)
99 #if ENABLE_SHOW_USAGE && !ENABLE_FEATURE_COMPRESS_USAGE
100 static const char usage_messages[] ALIGN1 = UNPACKED_USAGE;
102 # define usage_messages 0
105 #if ENABLE_FEATURE_COMPRESS_USAGE
107 static const char packed_usage[] ALIGN1 = { PACKED_USAGE };
108 # include "bb_archive.h"
109 static const char *unpack_usage_messages(void)
115 i = start_bunzip(&bd,
117 /* inbuf: */ packed_usage,
118 /* len: */ sizeof(packed_usage));
119 /* read_bunzip can longjmp to start_bunzip, and ultimately
120 * end up here with i != 0 on read data errors! Not trivial */
122 /* Cannot use xmalloc: will leak bd in NOFORK case! */
123 outbuf = malloc_or_warn(sizeof(UNPACKED_USAGE));
125 read_bunzip(bd, outbuf, sizeof(UNPACKED_USAGE));
130 # define dealloc_usage_messages(s) free(s)
134 # define unpack_usage_messages() usage_messages
135 # define dealloc_usage_messages(s) ((void)(s))
137 #endif /* FEATURE_COMPRESS_USAGE */
140 void FAST_FUNC bb_show_usage(void)
142 if (ENABLE_SHOW_USAGE) {
143 #ifdef SINGLE_APPLET_STR
144 /* Imagine that this applet is "true". Dont suck in printf! */
145 const char *usage_string = unpack_usage_messages();
147 if (*usage_string == '\b') {
148 full_write2_str("No help available.\n\n");
150 full_write2_str("Usage: "SINGLE_APPLET_STR" ");
151 full_write2_str(usage_string);
152 full_write2_str("\n\n");
154 if (ENABLE_FEATURE_CLEAN_UP)
155 dealloc_usage_messages((char*)usage_string);
158 const char *usage_string = p = unpack_usage_messages();
159 int ap = find_applet_by_name(applet_name);
161 if (ap < 0) /* never happens, paranoia */
164 while (*p++) continue;
167 full_write2_str(bb_banner);
168 full_write2_str(" multi-call binary.\n");
170 full_write2_str("\nNo help available.\n\n");
172 full_write2_str("\nUsage: ");
173 full_write2_str(applet_name);
174 full_write2_str(" ");
176 full_write2_str("\n");
178 if (ENABLE_FEATURE_CLEAN_UP)
179 dealloc_usage_messages((char*)usage_string);
185 int FAST_FUNC find_applet_by_name(const char *name)
191 /* The commented-out word-at-a-time code is ~40% faster, but +160 bytes.
192 * "Faster" here saves ~0.5 microsecond of real time - not worth it.
194 #if 0 /*BB_UNALIGNED_MEMACCESS_OK && BB_LITTLE_ENDIAN*/
197 /* Handle all names < 2 chars long early */
199 return -1; /* "" is not a valid applet name */
200 if (name[1] == '\0') {
202 return -1; /* 1-char name is not valid */
204 return -1; /* 1-char name which isn't "[" is not valid */
205 /* applet "[" is always applet #0: */
212 #if KNOWN_APPNAME_OFFSETS <= 0
215 max = NUM_APPLETS * KNOWN_APPNAME_OFFSETS;
216 for (j = ARRAY_SIZE(applet_nameofs)-1; j >= 0; j--) {
217 const char *pp = applet_names + applet_nameofs[j];
218 if (strcmp(name, pp) >= 0) {
219 //bb_error_msg("name:'%s' >= pp:'%s'", name, pp);
221 i = max - NUM_APPLETS;
226 max /= (unsigned)KNOWN_APPNAME_OFFSETS;
227 i /= (unsigned)KNOWN_APPNAME_OFFSETS;
228 //bb_error_msg("name:'%s' starting from:'%s' i:%u max:%u", name, p, i, max);
231 /* Open-coded linear search without strcmp/strlen calls for speed */
233 #if 0 /*BB_UNALIGNED_MEMACCESS_OK && BB_LITTLE_ENDIAN*/
234 /* skip "[\0" name, it's surely not it */
235 if (ENABLE_TEST && LONE_CHAR(p, '['))
237 /* All remaining applet names in p[] are at least 2 chars long */
238 /* name[] is also at least 2 chars long */
240 n32 = (name[0] << 0) | (name[1] << 8) | (name[2] << 16);
245 /* Quickly check match of the first 3 bytes */
246 move_from_unaligned32(p32, p);
248 if ((p32 & 0x00ffffff) != n32) {
249 /* Most likely case: 3 first bytes do not match */
251 if ((p32 & 0x00ff0000) == '\0')
252 continue; // p[2] was NUL
254 if ((p32 & 0xff000000) == '\0')
255 continue; // p[3] was NUL
256 /* p[0..3] aren't matching and none is NUL, check the rest */
262 /* Unlikely branch: first 3 bytes ([0..2]) match */
263 if ((p32 & 0x00ff0000) == '\0') {
264 /* name is 2-byte long, it is full match */
265 //bb_error_msg("found:'%s' i:%u", name, i);
268 /* Check remaining bytes [3..NUL] */
271 while (ch == name[j]) {
273 //bb_error_msg("found:'%s' i:%u", name, i);
279 /* Not a match. Skip it, including NUL */
290 /* Do we see "name\0" in applet_names[p] position? */
291 while ((ch = *p) == name[j]) {
293 //bb_error_msg("found:'%s' i:%u", name, i);
300 * p => 1st non-matching char in applet_names[],
301 * skip to and including NUL.
313 void lbb_prepare(const char *applet
314 IF_FEATURE_INDIVIDUAL(, char **argv))
315 MAIN_EXTERNALLY_VISIBLE;
316 void lbb_prepare(const char *applet
317 IF_FEATURE_INDIVIDUAL(, char **argv))
320 (*(int **)&bb_errno) = __errno_location();
323 applet_name = applet;
325 if (ENABLE_LOCALE_SUPPORT)
326 setlocale(LC_ALL, "");
328 #if ENABLE_FEATURE_INDIVIDUAL
329 /* Redundant for busybox (run_applet_and_exit covers that case)
330 * but needed for "individual applet" mode */
333 && strcmp(argv[1], "--help") == 0
334 && !is_prefixed_with(applet, "busybox")
336 /* Special case. POSIX says "test --help"
337 * should be no different from e.g. "test --foo". */
338 if (!ENABLE_TEST || strcmp(applet_name, "test") != 0)
344 /* The code below can well be in applets/applets.c, as it is used only
345 * for busybox binary, not "individual" binaries.
346 * However, keeping it here and linking it into libbusybox.so
347 * (together with remaining tiny applets/applets.o)
348 * makes it possible to avoid --whole-archive at link time.
349 * This makes (shared busybox) + libbusybox smaller.
350 * (--gc-sections would be even better....)
353 const char *applet_name;
359 /* If not built as a single-applet executable... */
360 #if !defined(SINGLE_APPLET_MAIN)
362 IF_FEATURE_SUID(static uid_t ruid;) /* real uid */
364 # if ENABLE_FEATURE_SUID_CONFIG
366 static struct suid_config_t {
367 /* next ptr must be first: this struct needs to be llist-compatible */
368 struct suid_config_t *m_next;
369 struct bb_uidgid_t m_ugid;
374 static bool suid_cfg_readable;
376 /* libbb candidate */
377 static char *get_trimmed_slice(char *s, char *e)
379 /* First, consider the value at e to be nul and back up until we
380 * reach a non-space char. Set the char after that (possibly at
381 * the original e) to nul. */
389 /* Next, advance past all leading space and return a ptr to the
390 * first non-space char; possibly the terminating nul. */
391 return skip_whitespace(s);
394 static void parse_config_file(void)
396 /* Don't depend on the tools to combine strings. */
397 static const char config_file[] ALIGN1 = "/etc/busybox.conf";
399 struct suid_config_t *sct_head;
408 if (ruid == 0) /* run by root - don't need to even read config file */
411 if ((stat(config_file, &st) != 0) /* No config file? */
412 || !S_ISREG(st.st_mode) /* Not a regular file? */
413 || (st.st_uid != 0) /* Not owned by root? */
414 || (st.st_mode & (S_IWGRP | S_IWOTH)) /* Writable by non-root? */
415 || !(f = fopen_for_read(config_file)) /* Cannot open? */
420 suid_cfg_readable = 1;
428 if (!fgets(buffer, sizeof(buffer), f)) { /* Are we done? */
430 //if (ferror(f)) { /* Make sure it wasn't a read error. */
431 // errmsg = "reading";
435 suid_config = sct_head; /* Success, so set the pointer. */
440 lc++; /* Got a (partial) line. */
442 /* If a line is too long for our buffer, we consider it an error.
443 * The following test does mistreat one corner case though.
444 * If the final line of the file does not end with a newline and
445 * yet exactly fills the buffer, it will be treated as too long
446 * even though there isn't really a problem. But it isn't really
447 * worth adding code to deal with such an unlikely situation, and
448 * we do err on the side of caution. Besides, the line would be
449 * too long if it did end with a newline. */
450 if (!strchr(s, '\n') && !feof(f)) {
451 errmsg = "line too long";
455 /* Trim leading and trailing whitespace, ignoring comments, and
456 * check if the resulting string is empty. */
457 s = get_trimmed_slice(s, strchrnul(s, '#'));
462 /* Check for a section header. */
465 /* Unlike the old code, we ignore leading and trailing
466 * whitespace for the section name. We also require that
467 * there are no stray characters after the closing bracket. */
468 char *e = strchr(s, ']');
469 if (!e /* Missing right bracket? */
470 || e[1] /* Trailing characters? */
471 || !*(s = get_trimmed_slice(s+1, e)) /* Missing name? */
473 errmsg = "section header";
476 /* Right now we only have one section so just check it.
477 * If more sections are added in the future, please don't
478 * resort to cascading ifs with multiple strcasecmp calls.
479 * That kind of bloated code is all too common. A loop
480 * and a string table would be a better choice unless the
481 * number of sections is very small. */
482 if (strcasecmp(s, "SUID") == 0) {
486 section = -1; /* Unknown section so set to skip. */
490 /* Process sections. */
492 if (section == 1) { /* SUID */
493 /* Since we trimmed leading and trailing space above, we're
494 * now looking for strings of the form
495 * <key>[::space::]*=[::space::]*<value>
496 * where both key and value could contain inner whitespace. */
498 /* First get the key (an applet name in our case). */
499 char *e = strchr(s, '=');
501 s = get_trimmed_slice(s, e);
503 if (!e || !*s) { /* Missing '=' or empty key. */
508 /* Ok, we have an applet name. Process the rhs if this
509 * applet is currently built in and ignore it otherwise.
510 * Note: this can hide config file bugs which only pop
511 * up when the busybox configuration is changed. */
512 applet_no = find_applet_by_name(s);
513 if (applet_no >= 0) {
515 struct suid_config_t *sct;
517 /* Note: We currently don't check for duplicates!
518 * The last config line for each applet will be the
519 * one used since we insert at the head of the list.
520 * I suppose this could be considered a feature. */
521 sct = xzalloc(sizeof(*sct));
522 sct->m_applet = applet_no;
524 sct->m_next = sct_head;
527 /* Get the specified mode. */
529 e = skip_whitespace(e+1);
531 for (i = 0; i < 3; i++) {
532 /* There are 4 chars for each of user/group/other.
533 * "x-xx" instead of "x-" are to make
534 * "idx > 3" check catch invalid chars.
536 static const char mode_chars[] ALIGN1 = "Ssx-" "Ssx-" "x-xx";
537 static const unsigned short mode_mask[] ALIGN2 = {
538 S_ISUID, S_ISUID|S_IXUSR, S_IXUSR, 0, /* Ssx- */
539 S_ISGID, S_ISGID|S_IXGRP, S_IXGRP, 0, /* Ssx- */
542 const char *q = strchrnul(mode_chars + 4*i, *e);
543 unsigned idx = q - (mode_chars + 4*i);
548 sct->m_mode |= mode_mask[q - mode_chars];
552 /* Now get the user/group info. */
554 s = skip_whitespace(e);
555 /* Default is 0.0, else parse USER.GROUP: */
557 /* We require whitespace between mode and USER.GROUP */
558 if ((s == e) || !(e = strchr(s, '.'))) {
562 *e = ':'; /* get_uidgid needs USER:GROUP syntax */
563 if (get_uidgid(&sct->m_ugid, s) == 0) {
564 errmsg = "unknown user/group";
572 /* Unknown sections are ignored. */
574 /* Encountering configuration lines prior to seeing a
575 * section header is treated as an error. This is how
576 * the old code worked, but it may not be desirable.
577 * We may want to simply ignore such lines in case they
578 * are used in some future version of busybox. */
580 errmsg = "keyword outside section";
587 bb_error_msg("parse error in %s, line %u: %s", config_file, lc, errmsg);
589 /* Release any allocated memory before returning. */
590 llist_free((llist_t*)sct_head, NULL);
593 static inline void parse_config_file(void)
595 IF_FEATURE_SUID(ruid = getuid();)
597 # endif /* FEATURE_SUID_CONFIG */
600 # if ENABLE_FEATURE_SUID && NUM_APPLETS > 0
601 # if ENABLE_FEATURE_SUID_CONFIG
602 /* check if u is member of group g */
603 static int ingroup(uid_t u, gid_t g)
605 struct group *grp = getgrgid(g);
608 for (mem = grp->gr_mem; *mem; mem++) {
609 struct passwd *pwd = getpwnam(*mem);
610 if (pwd && (pwd->pw_uid == u))
618 static void check_suid(int applet_no)
620 gid_t rgid; /* real gid */
622 if (ruid == 0) /* set by parse_config_file() */
623 return; /* run by root - no need to check more */
626 # if ENABLE_FEATURE_SUID_CONFIG
627 if (suid_cfg_readable) {
629 struct suid_config_t *sct;
632 for (sct = suid_config; sct; sct = sct->m_next) {
633 if (sct->m_applet == applet_no)
636 goto check_need_suid;
638 /* Is this user allowed to run this applet? */
640 if (sct->m_ugid.uid == ruid)
643 else if ((sct->m_ugid.gid == rgid) || ingroup(ruid, sct->m_ugid.gid))
644 /* same group / in group */
646 if (!(m & S_IXOTH)) /* is x bit not set? */
647 bb_error_msg_and_die("you have no permission to run this applet");
649 /* We set effective AND saved ids. If saved-id is not set
650 * like we do below, seteuid(0) can still later succeed! */
652 /* Are we directed to change gid
653 * (APPLET = *s* USER.GROUP or APPLET = *S* USER.GROUP)?
655 if (sct->m_mode & S_ISGID)
656 rgid = sct->m_ugid.gid;
657 /* else: we will set egid = rgid, thus dropping sgid effect */
658 if (setresgid(-1, rgid, rgid))
659 bb_perror_msg_and_die("setresgid");
661 /* Are we directed to change uid
662 * (APPLET = s** USER.GROUP or APPLET = S** USER.GROUP)?
665 if (sct->m_mode & S_ISUID)
666 uid = sct->m_ugid.uid;
667 /* else: we will set euid = ruid, thus dropping suid effect */
668 if (setresuid(-1, uid, uid))
669 bb_perror_msg_and_die("setresuid");
673 # if !ENABLE_FEATURE_SUID_CONFIG_QUIET
675 static bool onetime = 0;
679 bb_error_msg("using fallback suid method");
685 if (APPLET_SUID(applet_no) == BB_SUID_REQUIRE) {
686 /* Real uid is not 0. If euid isn't 0 too, suid bit
687 * is most probably not set on our executable */
689 bb_error_msg_and_die("must be suid to work properly");
690 } else if (APPLET_SUID(applet_no) == BB_SUID_DROP) {
692 * Drop all privileges.
694 * Don't check for errors: in normal use, they are impossible,
695 * and in special cases, exiting is harmful. Example:
696 * 'unshare --user' when user's shell is also from busybox.
698 * 'unshare --user' creates a new user namespace without any
699 * uid mappings. Thus, busybox binary is setuid nobody:nogroup
700 * within the namespace, as that is the only user. However,
701 * since no uids are mapped, calls to setgid/setuid
702 * fail (even though they would do nothing).
707 # if ENABLE_FEATURE_SUID_CONFIG
709 llist_free((llist_t*)suid_config, NULL);
713 # define check_suid(x) ((void)0)
714 # endif /* FEATURE_SUID */
717 # if ENABLE_FEATURE_INSTALLER
718 static const char usr_bin [] ALIGN1 = "/usr/bin/";
719 static const char usr_sbin[] ALIGN1 = "/usr/sbin/";
720 static const char *const install_dir[] = {
721 &usr_bin [8], /* "/" */
722 &usr_bin [4], /* "/bin/" */
723 &usr_sbin[4] /* "/sbin/" */
724 # if !ENABLE_INSTALL_NO_USR
730 /* create (sym)links for each applet */
731 static void install_links(const char *busybox, int use_symbolic_links,
732 char *custom_install_dir)
735 * this should be consistent w/ the enum,
736 * busybox.h::bb_install_loc_t, or else... */
737 int (*lf)(const char *, const char *);
739 const char *appname = applet_names;
744 if (use_symbolic_links)
747 for (i = 0; i < ARRAY_SIZE(applet_main); i++) {
748 fpc = concat_path_file(
749 custom_install_dir ? custom_install_dir : install_dir[APPLET_INSTALL_LOC(i)],
751 // debug: bb_error_msg("%slinking %s to busybox",
752 // use_symbolic_links ? "sym" : "", fpc);
753 rc = lf(busybox, fpc);
754 if (rc != 0 && errno != EEXIST) {
755 bb_simple_perror_msg(fpc);
758 while (*appname++ != '\0')
762 # elif ENABLE_BUSYBOX
763 static void install_links(const char *busybox UNUSED_PARAM,
764 int use_symbolic_links UNUSED_PARAM,
765 char *custom_install_dir UNUSED_PARAM)
770 static void run_applet_and_exit(const char *name, char **argv) NORETURN;
773 # if ENABLE_FEATURE_SH_STANDALONE && ENABLE_FEATURE_TAB_COMPLETION
775 * Insert "busybox" into applet table as well.
776 * This makes standalone shell tab-complete this name too.
777 * (Otherwise having "busybox" in applet table is not necessary,
778 * there is other code which routes "busyboxANY_SUFFIX" name
779 * to busybox_main()).
781 //usage:#define busybox_trivial_usage NOUSAGE_STR
782 //usage:#define busybox_full_usage ""
783 //applet:IF_BUSYBOX(IF_FEATURE_SH_STANDALONE(IF_FEATURE_TAB_COMPLETION(APPLET(busybox, BB_DIR_BIN, BB_SUID_MAYBE))))
784 int busybox_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
786 # define busybox_main(argc,argv) busybox_main(argv)
789 int busybox_main(int argc UNUSED_PARAM, char **argv)
792 /* Called without arguments */
795 unsigned output_width;
797 output_width = get_terminal_width(2);
800 full_write2_str(bb_banner); /* reuse const string */
801 full_write2_str(" multi-call binary.\n"); /* reuse */
803 "BusyBox is copyrighted by many authors between 1998-2015.\n"
804 "Licensed under GPLv2. See source distribution for detailed\n"
805 "copyright notices.\n"
807 "Usage: busybox [function [arguments]...]\n"
808 " or: busybox --list"IF_FEATURE_INSTALLER("[-full]")"\n"
809 IF_FEATURE_INSTALLER(
810 " or: busybox --install [-s] [DIR]\n"
812 " or: function [arguments]...\n"
814 IF_NOT_FEATURE_SH_STANDALONE(
815 "\tBusyBox is a multi-call binary that combines many common Unix\n"
816 "\tutilities into a single executable. Most people will create a\n"
817 "\tlink to busybox for each function they wish to use and BusyBox\n"
818 "\twill act like whatever it was invoked as.\n"
820 IF_FEATURE_SH_STANDALONE(
821 "\tBusyBox is a multi-call binary that combines many common Unix\n"
822 "\tutilities into a single executable. The shell in this build\n"
823 "\tis configured to run built-in utilities without $PATH search.\n"
824 "\tYou don't need to install a link to busybox for each utility.\n"
825 "\tTo run external program, use full path (/sbin/ip instead of ip).\n"
828 "Currently defined functions:\n"
832 /* prevent last comma to be in the very last pos */
835 int len2 = strlen(a) + 2;
836 if (col >= (int)output_width - len2) {
837 full_write2_str(",\n");
842 full_write2_str("\t");
844 full_write2_str(", ");
850 full_write2_str("\n");
854 if (is_prefixed_with(argv[1], "--list")) {
856 const char *a = applet_names;
859 # if ENABLE_FEATURE_INSTALLER
860 if (argv[1][6]) /* --list-full? */
861 full_write2_str(install_dir[APPLET_INSTALL_LOC(i)] + 1);
864 full_write2_str("\n");
872 if (ENABLE_FEATURE_INSTALLER && strcmp(argv[1], "--install") == 0) {
873 int use_symbolic_links;
876 busybox = xmalloc_readlink(bb_busybox_exec_path);
878 /* bb_busybox_exec_path is usually "/proc/self/exe".
879 * In chroot, readlink("/proc/self/exe") usually fails.
880 * In such case, better use argv[0] as symlink target
881 * if it is a full path name.
883 if (argv[0][0] != '/')
884 bb_error_msg_and_die("'%s' is not an absolute path", argv[0]);
887 /* busybox --install [-s] [DIR]:
889 * DIR: directory to install links to
891 use_symbolic_links = (argv[2] && strcmp(argv[2], "-s") == 0 && ++argv);
892 install_links(busybox, use_symbolic_links, argv[2]);
896 if (strcmp(argv[1], "--help") == 0) {
897 /* "busybox --help [<applet>]" */
900 /* convert to "<applet> --help" */
904 /* "busybox <applet> arg1 arg2 ..." */
907 /* We support "busybox /a/path/to/applet args..." too. Allows for
908 * "#!/bin/busybox"-style wrappers */
909 applet_name = bb_get_last_path_component_nostrip(argv[0]);
910 run_applet_and_exit(applet_name, argv);
914 #if defined(__linux__) && (NUM_APPLETS > 1)
915 void FAST_FUNC set_task_comm(const char *comm)
917 /* okay if too long (truncates) */
918 prctl(PR_SET_NAME, (long)comm, 0, 0, 0);
923 void FAST_FUNC run_applet_no_and_exit(int applet_no, const char *name, char **argv)
925 int argc = string_array_len(argv);
927 /* Reinit some shared global data */
928 xfunc_error_retval = EXIT_FAILURE;
930 * We do not use argv[0]: do not want to repeat massaging of
931 * "-/sbin/halt" -> "halt", for example.
935 /* Special case. POSIX says "test --help"
936 * should be no different from e.g. "test --foo".
937 * Thus for "test", we skip --help check.
938 * "true" and "false" are also special.
941 # if defined APPLET_NO_test
942 && applet_no != APPLET_NO_test
944 # if defined APPLET_NO_true
945 && applet_no != APPLET_NO_true
947 # if defined APPLET_NO_false
948 && applet_no != APPLET_NO_false
951 if (argc == 2 && strcmp(argv[1], "--help") == 0) {
952 /* Make "foo --help" exit with 0: */
953 xfunc_error_retval = 0;
957 if (ENABLE_FEATURE_SUID)
958 check_suid(applet_no);
959 xfunc_error_retval = applet_main[applet_no](argc, argv);
960 /* Note: applet_main() may also not return (die on a xfunc or such) */
963 # endif /* NUM_APPLETS > 0 */
965 # if ENABLE_BUSYBOX || NUM_APPLETS > 0
966 static NORETURN void run_applet_and_exit(const char *name, char **argv)
969 if (is_prefixed_with(name, "busybox"))
970 exit(busybox_main(/*unused:*/ 0, argv));
973 /* find_applet_by_name() search is more expensive, so goes second */
975 int applet = find_applet_by_name(name);
977 run_applet_no_and_exit(applet, name, argv);
981 /*bb_error_msg_and_die("applet not found"); - links in printf */
982 full_write2_str(applet_name);
983 full_write2_str(": applet not found\n");
984 /* POSIX: "If a command is not found, the exit status shall be 127" */
989 #endif /* !defined(SINGLE_APPLET_MAIN) */
992 #if ENABLE_BUILD_LIBBUSYBOX
993 int lbb_main(char **argv)
995 int main(int argc UNUSED_PARAM, char **argv)
999 /* TODO: find a use for a block of memory between end of .bss
1000 * and end of page. For example, I'm getting "_end:0x812e698 2408 bytes"
1001 * - more than 2k of wasted memory (in this particular build)
1002 * *per each running process*!
1003 * (If your linker does not generate "_end" name, weak attribute
1004 * makes &_end == NULL, end_len == 0 here.)
1006 extern char _end[] __attribute__((weak));
1007 unsigned end_len = (-(int)_end) & 0xfff;
1008 printf("_end:%p %u bytes\n", &_end, end_len);
1011 /* Tweak malloc for reduced memory consumption */
1012 #ifdef M_TRIM_THRESHOLD
1013 /* M_TRIM_THRESHOLD is the maximum amount of freed top-most memory
1014 * to keep before releasing to the OS
1015 * Default is way too big: 256k
1017 mallopt(M_TRIM_THRESHOLD, 8 * 1024);
1019 #ifdef M_MMAP_THRESHOLD
1020 /* M_MMAP_THRESHOLD is the request size threshold for using mmap()
1021 * Default is too big: 256k
1023 mallopt(M_MMAP_THRESHOLD, 32 * 1024 - 256);
1025 #if 0 /*def M_TOP_PAD*/
1026 /* When the program break is increased, then M_TOP_PAD bytes are added
1027 * to the sbrk(2) request. When the heap is trimmed because of free(3),
1028 * this much free space is preserved at the top of the heap.
1029 * glibc default seems to be way too big: 128k, but need to verify.
1031 mallopt(M_TOP_PAD, 8 * 1024);
1035 /* NOMMU re-exec trick sets high-order bit in first byte of name */
1036 if (argv[0][0] & 0x80) {
1042 #if defined(SINGLE_APPLET_MAIN)
1044 /* Only one applet is selected in .config */
1045 if (argv[1] && is_prefixed_with(argv[0], "busybox")) {
1046 /* "busybox <applet> <params>" should still work as expected */
1049 /* applet_names in this case is just "applet\0\0" */
1050 lbb_prepare(applet_names IF_FEATURE_INDIVIDUAL(, argv));
1051 # if ENABLE_BUILD_LIBBUSYBOX
1052 return SINGLE_APPLET_MAIN(string_array_len(argv), argv);
1054 return SINGLE_APPLET_MAIN(argc, argv);
1057 #elif !ENABLE_BUSYBOX && NUM_APPLETS == 0
1059 full_write2_str(bb_basename(argv[0]));
1060 full_write2_str(": no applets enabled\n");
1065 lbb_prepare("busybox" IF_FEATURE_INDIVIDUAL(, argv));
1066 # if !ENABLE_BUSYBOX
1067 if (argv[1] && is_prefixed_with(bb_basename(argv[0]), "busybox"))
1070 applet_name = argv[0];
1071 if (applet_name[0] == '-')
1073 applet_name = bb_basename(applet_name);
1075 /* If we are a result of execv("/proc/self/exe"), fix ugly comm of "exe" */
1076 if (ENABLE_FEATURE_SH_STANDALONE
1077 || ENABLE_FEATURE_PREFER_APPLETS
1080 if (NUM_APPLETS > 1)
1081 set_task_comm(applet_name);
1084 parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */
1085 run_applet_and_exit(applet_name, argv);