busybox/libbb/appletlib.c

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2007-10-09 01:02:12 +05:30
/* vi: set sw=4 ts=4: */
/*
* Utility routines.
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*
* Copyright (C) tons of folks. Tracking down who wrote what
* isn't something I'm going to worry about... If you wrote something
* here, please feel free to acknowledge your work.
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*
* Based in part on code from sash, Copyright (c) 1999 by David I. Bell
* Permission has been granted to redistribute this code under GPL.
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
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*/
/* We are trying to not use printf, this benefits the case when selected
* applets are really simple. Example:
*
* $ ./busybox
* ...
* Currently defined functions:
* basename, false, true
*
* $ size busybox
* text data bss dec hex filename
* 4473 52 72 4597 11f5 busybox
*
* FEATURE_INSTALLER or FEATURE_SUID will still link printf routines in. :(
*/
#include "busybox.h"
#if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
|| defined(__APPLE__) \
)
# include <malloc.h> /* for mallopt */
#endif
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/* Declare <applet>_main() */
#define PROTOTYPES
#include "applets.h"
#undef PROTOTYPES
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/* Include generated applet names, pointers to <applet>_main, etc */
#include "applet_tables.h"
/* ...and if applet_tables generator says we have only one applet... */
#ifdef SINGLE_APPLET_MAIN
# undef ENABLE_FEATURE_INDIVIDUAL
# define ENABLE_FEATURE_INDIVIDUAL 1
# undef IF_FEATURE_INDIVIDUAL
# define IF_FEATURE_INDIVIDUAL(...) __VA_ARGS__
#endif
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#include "usage_compressed.h"
#if ENABLE_FEATURE_SH_EMBEDDED_SCRIPTS
Treat custom and applet scripts as applets BusyBox has support for embedded shell scripts. Two types can be distinguished: custom scripts and scripts implementing applets. Custom scripts should be placed in the 'embed' directory at build time. They are given a default applet configuration and appear as applets to the user but no further configuration is possible. Applet scripts are integrated with the BusyBox build system and are intended to be used to ship standard applets that just happen to be implemented as scripts. They can be configured at build time and appear just like native applets. Such scripts should be placed in the 'applets_sh' directory. A stub C program should be written to provide the usual applet configuration details and placed in a suitable subsystem directory. It may be helpful to have a configuration option to enable any dependencies the script requires: see the 'nologin' applet for an example. function old new delta scripted_main - 41 +41 applet_names 2773 2781 +8 applet_main 1600 1604 +4 i2cdetect_main 672 674 +2 applet_suid 100 101 +1 applet_install_loc 200 201 +1 applet_flags 100 101 +1 packed_usage 33180 33179 -1 tryexec 159 152 -7 evalcommand 1661 1653 -8 script_names 9 - -9 packed_scripts 123 114 -9 complete_cmd_dir_file 826 811 -15 shellexec 271 254 -17 find_command 1007 990 -17 busybox_main 642 624 -18 run_applet_and_exit 100 78 -22 find_script_by_name 51 - -51 ------------------------------------------------------------------------------ (add/remove: 1/2 grow/shrink: 6/9 up/down: 58/-174) Total: -116 bytes text data bss dec hex filename 950034 477 7296 957807 e9d6f busybox_old 949918 477 7296 957691 e9cfb busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-11-17 23:18:14 +05:30
# define DEFINE_SCRIPT_DATA 1
# include "embedded_scripts.h"
#else
# define NUM_SCRIPTS 0
#endif
#if NUM_SCRIPTS > 0
# include "bb_archive.h"
static const char packed_scripts[] ALIGN1 = { PACKED_SCRIPTS };
#endif
/* "Do not compress usage text if uncompressed text is small
* and we don't include bunzip2 code for other reasons"
*
* Useful for mass one-applet rebuild (bunzip2 code is ~2.7k).
*
* Unlike BUNZIP2, if FEATURE_SEAMLESS_BZ2 is on, bunzip2 code is built but
* still may be unused if none of the selected applets calls open_zipped()
* or its friends; we test for (FEATURE_SEAMLESS_BZ2 && <APPLET>) instead.
* For example, only if TAR and FEATURE_SEAMLESS_BZ2 are both selected,
* then bunzip2 code will be linked in anyway, and disabling help compression
* would be not optimal:
*/
#if UNPACKED_USAGE_LENGTH < 4*1024 \
&& !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_TAR) \
&& !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_MODPROBE) \
&& !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_INSMOD) \
&& !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_DEPMOD) \
&& !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_MAN) \
&& !ENABLE_BUNZIP2 \
&& !ENABLE_BZCAT
# undef ENABLE_FEATURE_COMPRESS_USAGE
# define ENABLE_FEATURE_COMPRESS_USAGE 0
#endif
unsigned FAST_FUNC string_array_len(char **argv)
{
char **start = argv;
while (*argv)
argv++;
return argv - start;
}
#if ENABLE_SHOW_USAGE && !ENABLE_FEATURE_COMPRESS_USAGE
static const char usage_messages[] ALIGN1 = UNPACKED_USAGE;
#else
# define usage_messages 0
#endif
#if ENABLE_FEATURE_COMPRESS_USAGE
static const char packed_usage[] ALIGN1 = { PACKED_USAGE };
# include "bb_archive.h"
# define unpack_usage_messages() \
unpack_bz2_data(packed_usage, sizeof(packed_usage), sizeof(UNPACKED_USAGE))
# define dealloc_usage_messages(s) free(s)
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#else
# define unpack_usage_messages() usage_messages
# define dealloc_usage_messages(s) ((void)(s))
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#endif /* FEATURE_COMPRESS_USAGE */
void FAST_FUNC bb_show_usage(void)
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{
if (ENABLE_SHOW_USAGE) {
#ifdef SINGLE_APPLET_STR
/* Imagine that this applet is "true". Dont link in printf! */
const char *usage_string = unpack_usage_messages();
if (usage_string) {
if (*usage_string == '\b') {
full_write2_str("No help available\n");
} else {
full_write2_str("Usage: "SINGLE_APPLET_STR" ");
full_write2_str(usage_string);
full_write2_str("\n");
}
if (ENABLE_FEATURE_CLEAN_UP)
dealloc_usage_messages((char*)usage_string);
}
#else
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const char *p;
const char *usage_string = p = unpack_usage_messages();
int ap = find_applet_by_name(applet_name);
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if (ap < 0 || usage_string == NULL)
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xfunc_die();
while (ap) {
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while (*p++) continue;
ap--;
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}
full_write2_str(bb_banner);
full_write2_str(" multi-call binary.\n"); /* common string */
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if (*p == '\b')
full_write2_str("\nNo help available\n");
else {
full_write2_str("\nUsage: ");
full_write2_str(applet_name);
if (p[0]) {
if (p[0] != '\n')
full_write2_str(" ");
full_write2_str(p);
}
full_write2_str("\n");
}
if (ENABLE_FEATURE_CLEAN_UP)
dealloc_usage_messages((char*)usage_string);
#endif
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}
xfunc_die();
}
int FAST_FUNC find_applet_by_name(const char *name)
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{
unsigned i, max;
int j;
const char *p;
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2016-03-30 04:12:05 +05:30
/* The commented-out word-at-a-time code is ~40% faster, but +160 bytes.
* "Faster" here saves ~0.5 microsecond of real time - not worth it.
*/
#if 0 /*BB_UNALIGNED_MEMACCESS_OK && BB_LITTLE_ENDIAN*/
uint32_t n32;
/* Handle all names < 2 chars long early */
if (name[0] == '\0')
return -1; /* "" is not a valid applet name */
if (name[1] == '\0') {
if (!ENABLE_TEST)
return -1; /* 1-char name is not valid */
if (name[0] != ']')
return -1; /* 1-char name which isn't "[" is not valid */
/* applet "[" is always applet #0: */
return 0;
}
#endif
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2016-03-30 04:12:05 +05:30
p = applet_names;
i = 0;
#if KNOWN_APPNAME_OFFSETS <= 0
max = NUM_APPLETS;
#else
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2016-03-30 04:12:05 +05:30
max = NUM_APPLETS * KNOWN_APPNAME_OFFSETS;
for (j = ARRAY_SIZE(applet_nameofs)-1; j >= 0; j--) {
const char *pp = applet_names + applet_nameofs[j];
if (strcmp(name, pp) >= 0) {
//bb_error_msg("name:'%s' >= pp:'%s'", name, pp);
p = pp;
i = max - NUM_APPLETS;
break;
}
max -= NUM_APPLETS;
}
max /= (unsigned)KNOWN_APPNAME_OFFSETS;
i /= (unsigned)KNOWN_APPNAME_OFFSETS;
//bb_error_msg("name:'%s' starting from:'%s' i:%u max:%u", name, p, i, max);
#endif
/* Open-coded linear search without strcmp/strlen calls for speed */
#if 0 /*BB_UNALIGNED_MEMACCESS_OK && BB_LITTLE_ENDIAN*/
/* skip "[\0" name, it's surely not it */
if (ENABLE_TEST && LONE_CHAR(p, '['))
i++, p += 2;
/* All remaining applet names in p[] are at least 2 chars long */
/* name[] is also at least 2 chars long */
n32 = (name[0] << 0) | (name[1] << 8) | (name[2] << 16);
while (i < max) {
uint32_t p32;
char ch;
/* Quickly check match of the first 3 bytes */
move_from_unaligned32(p32, p);
p += 3;
if ((p32 & 0x00ffffff) != n32) {
/* Most likely case: 3 first bytes do not match */
i++;
if ((p32 & 0x00ff0000) == '\0')
continue; // p[2] was NUL
p++;
if ((p32 & 0xff000000) == '\0')
continue; // p[3] was NUL
/* p[0..3] aren't matching and none is NUL, check the rest */
while (*p++ != '\0')
continue;
continue;
}
/* Unlikely branch: first 3 bytes ([0..2]) match */
if ((p32 & 0x00ff0000) == '\0') {
/* name is 2-byte long, it is full match */
//bb_error_msg("found:'%s' i:%u", name, i);
return i;
}
/* Check remaining bytes [3..NUL] */
ch = (p32 >> 24);
j = 3;
while (ch == name[j]) {
if (ch == '\0') {
//bb_error_msg("found:'%s' i:%u", name, i);
return i;
}
ch = *++p;
j++;
}
/* Not a match. Skip it, including NUL */
while (ch != '\0')
ch = *++p;
p++;
i++;
}
return -1;
#else
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2016-03-30 04:12:05 +05:30
while (i < max) {
char ch;
j = 0;
/* Do we see "name\0" in applet_names[p] position? */
while ((ch = *p) == name[j]) {
if (ch == '\0') {
//bb_error_msg("found:'%s' i:%u", name, i);
return i; /* yes */
}
p++;
j++;
}
/* No.
* p => 1st non-matching char in applet_names[],
* skip to and including NUL.
*/
while (ch != '\0')
ch = *++p;
p++;
i++;
}
return -1;
#endif
2007-10-09 01:02:12 +05:30
}
void lbb_prepare(const char *applet
IF_FEATURE_INDIVIDUAL(, char **argv))
MAIN_EXTERNALLY_VISIBLE;
void lbb_prepare(const char *applet
IF_FEATURE_INDIVIDUAL(, char **argv))
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{
#ifdef __GLIBC__
(*(int **)&bb_errno) = __errno_location();
barrier();
2007-10-09 01:02:12 +05:30
#endif
applet_name = applet;
2007-10-09 01:02:12 +05:30
if (ENABLE_LOCALE_SUPPORT)
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setlocale(LC_ALL, "");
#if ENABLE_FEATURE_INDIVIDUAL
/* Redundant for busybox (run_applet_and_exit covers that case)
* but needed for "individual applet" mode */
if (argv[1]
&& !argv[2]
&& strcmp(argv[1], "--help") == 0
libbb: introduce and use is_prefixed_with() function old new delta is_prefixed_with - 18 +18 complete_username 78 77 -1 man_main 737 735 -2 fsck_device 429 427 -2 unpack_ar_archive 80 76 -4 strip_unsafe_prefix 105 101 -4 singlemount 1054 1050 -4 rtc_adjtime_is_utc 90 86 -4 resolve_mount_spec 88 84 -4 parse_one_line 1029 1025 -4 parse_conf 1460 1456 -4 may_wakeup 83 79 -4 loadkmap_main 219 215 -4 get_irqs_from_stat 103 99 -4 get_header_cpio 913 909 -4 findfs_main 79 75 -4 fbsplash_main 1230 1226 -4 load_crontab 776 771 -5 expand_vars_to_list 1151 1146 -5 date_main 881 876 -5 skip_dev_pfx 30 24 -6 make_device 2199 2193 -6 complete_cmd_dir_file 773 767 -6 run_applet_and_exit 715 708 -7 uudecode_main 321 313 -8 pwdx_main 197 189 -8 execute 568 560 -8 i2cdetect_main 1186 1176 -10 procps_scan 1242 1230 -12 procps_read_smaps 1017 1005 -12 process_module 746 734 -12 patch_main 1903 1891 -12 nfsmount 3572 3560 -12 stack_machine 126 112 -14 process_timer_stats 449 435 -14 match_fstype 111 97 -14 do_ipaddr 1344 1330 -14 open_list_and_close 359 343 -16 get_header_tar 1795 1779 -16 prepend_new_eth_table 340 323 -17 fsck_main 1811 1794 -17 find_iface_state 56 38 -18 dnsd_main 1321 1303 -18 base_device 179 158 -21 find_keyword 104 82 -22 handle_incoming_and_exit 2785 2762 -23 parse_and_put_prompt 774 746 -28 modinfo 347 317 -30 find_action 204 171 -33 update_passwd 1470 1436 -34 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 0/49 up/down: 18/-540) Total: -522 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-03-12 22:18:34 +05:30
&& !is_prefixed_with(applet, "busybox")
) {
/* Special case. POSIX says "test --help"
* should be no different from e.g. "test --foo". */
if (!ENABLE_TEST || strcmp(applet_name, "test") != 0)
bb_show_usage();
}
#endif
2007-10-09 01:02:12 +05:30
}
/* The code below can well be in applets/applets.c, as it is used only
* for busybox binary, not "individual" binaries.
* However, keeping it here and linking it into libbusybox.so
* (together with remaining tiny applets/applets.o)
* makes it possible to avoid --whole-archive at link time.
* This makes (shared busybox) + libbusybox smaller.
* (--gc-sections would be even better....)
*/
const char *applet_name;
#if !BB_MMU
bool re_execed;
#endif
2008-04-29 05:40:27 +05:30
/* If not built as a single-applet executable... */
#if !defined(SINGLE_APPLET_MAIN)
IF_FEATURE_SUID(static uid_t ruid;) /* real uid */
# if ENABLE_FEATURE_SUID_CONFIG
static struct suid_config_t {
/* next ptr must be first: this struct needs to be llist-compatible */
struct suid_config_t *m_next;
struct bb_uidgid_t m_ugid;
int m_applet;
mode_t m_mode;
} *suid_config;
static bool suid_cfg_readable;
/* libbb candidate */
static char *get_trimmed_slice(char *s, char *e)
{
/* First, consider the value at e to be nul and back up until we
* reach a non-space char. Set the char after that (possibly at
* the original e) to nul. */
while (e-- > s) {
if (!isspace(*e)) {
break;
}
}
e[1] = '\0';
/* Next, advance past all leading space and return a ptr to the
* first non-space char; possibly the terminating nul. */
return skip_whitespace(s);
}
static void parse_config_file(void)
{
/* Don't depend on the tools to combine strings. */
static const char config_file[] ALIGN1 = "/etc/busybox.conf";
struct suid_config_t *sct_head;
int applet_no;
FILE *f;
const char *errmsg;
unsigned lc;
smallint section;
struct stat st;
ruid = getuid();
if (ruid == 0) /* run by root - don't need to even read config file */
return;
if ((stat(config_file, &st) != 0) /* No config file? */
|| !S_ISREG(st.st_mode) /* Not a regular file? */
|| (st.st_uid != 0) /* Not owned by root? */
|| (st.st_mode & (S_IWGRP | S_IWOTH)) /* Writable by non-root? */
|| !(f = fopen_for_read(config_file)) /* Cannot open? */
) {
return;
}
suid_cfg_readable = 1;
sct_head = NULL;
section = lc = 0;
while (1) {
char buffer[256];
char *s;
if (!fgets(buffer, sizeof(buffer), f)) { /* Are we done? */
// Looks like bloat
//if (ferror(f)) { /* Make sure it wasn't a read error. */
// errmsg = "reading";
// goto pe_label;
//}
fclose(f);
suid_config = sct_head; /* Success, so set the pointer. */
return;
}
s = buffer;
lc++; /* Got a (partial) line. */
/* If a line is too long for our buffer, we consider it an error.
* The following test does mistreat one corner case though.
* If the final line of the file does not end with a newline and
* yet exactly fills the buffer, it will be treated as too long
* even though there isn't really a problem. But it isn't really
* worth adding code to deal with such an unlikely situation, and
* we do err on the side of caution. Besides, the line would be
* too long if it did end with a newline. */
if (!strchr(s, '\n') && !feof(f)) {
errmsg = "line too long";
goto pe_label;
}
/* Trim leading and trailing whitespace, ignoring comments, and
* check if the resulting string is empty. */
s = get_trimmed_slice(s, strchrnul(s, '#'));
if (!*s) {
continue;
}
/* Check for a section header. */
if (*s == '[') {
/* Unlike the old code, we ignore leading and trailing
* whitespace for the section name. We also require that
* there are no stray characters after the closing bracket. */
char *e = strchr(s, ']');
if (!e /* Missing right bracket? */
|| e[1] /* Trailing characters? */
|| !*(s = get_trimmed_slice(s+1, e)) /* Missing name? */
) {
errmsg = "section header";
goto pe_label;
}
/* Right now we only have one section so just check it.
* If more sections are added in the future, please don't
* resort to cascading ifs with multiple strcasecmp calls.
* That kind of bloated code is all too common. A loop
* and a string table would be a better choice unless the
* number of sections is very small. */
if (strcasecmp(s, "SUID") == 0) {
section = 1;
continue;
}
section = -1; /* Unknown section so set to skip. */
continue;
}
/* Process sections. */
if (section == 1) { /* SUID */
/* Since we trimmed leading and trailing space above, we're
* now looking for strings of the form
* <key>[::space::]*=[::space::]*<value>
* where both key and value could contain inner whitespace. */
/* First get the key (an applet name in our case). */
char *e = strchr(s, '=');
if (e) {
s = get_trimmed_slice(s, e);
}
if (!e || !*s) { /* Missing '=' or empty key. */
errmsg = "keyword";
goto pe_label;
}
/* Ok, we have an applet name. Process the rhs if this
* applet is currently built in and ignore it otherwise.
* Note: this can hide config file bugs which only pop
* up when the busybox configuration is changed. */
applet_no = find_applet_by_name(s);
if (applet_no >= 0) {
unsigned i;
struct suid_config_t *sct;
/* Note: We currently don't check for duplicates!
* The last config line for each applet will be the
* one used since we insert at the head of the list.
* I suppose this could be considered a feature. */
sct = xzalloc(sizeof(*sct));
sct->m_applet = applet_no;
/*sct->m_mode = 0;*/
sct->m_next = sct_head;
sct_head = sct;
/* Get the specified mode. */
e = skip_whitespace(e+1);
for (i = 0; i < 3; i++) {
/* There are 4 chars for each of user/group/other.
* "x-xx" instead of "x-" are to make
* "idx > 3" check catch invalid chars.
*/
static const char mode_chars[] ALIGN1 = "Ssx-" "Ssx-" "x-xx";
static const unsigned short mode_mask[] ALIGN2 = {
S_ISUID, S_ISUID|S_IXUSR, S_IXUSR, 0, /* Ssx- */
S_ISGID, S_ISGID|S_IXGRP, S_IXGRP, 0, /* Ssx- */
S_IXOTH, 0 /* x- */
};
const char *q = strchrnul(mode_chars + 4*i, *e);
unsigned idx = q - (mode_chars + 4*i);
if (idx > 3) {
errmsg = "mode";
goto pe_label;
}
sct->m_mode |= mode_mask[q - mode_chars];
e++;
}
/* Now get the user/group info. */
s = skip_whitespace(e);
/* Default is 0.0, else parse USER.GROUP: */
if (*s) {
/* We require whitespace between mode and USER.GROUP */
if ((s == e) || !(e = strchr(s, '.'))) {
errmsg = "uid.gid";
goto pe_label;
}
*e = ':'; /* get_uidgid needs USER:GROUP syntax */
if (get_uidgid(&sct->m_ugid, s) == 0) {
errmsg = "unknown user/group";
goto pe_label;
}
}
}
continue;
}
/* Unknown sections are ignored. */
/* Encountering configuration lines prior to seeing a
* section header is treated as an error. This is how
* the old code worked, but it may not be desirable.
* We may want to simply ignore such lines in case they
* are used in some future version of busybox. */
if (!section) {
errmsg = "keyword outside section";
goto pe_label;
}
} /* while (1) */
pe_label:
fclose(f);
bb_error_msg("parse error in %s, line %u: %s", config_file, lc, errmsg);
/* Release any allocated memory before returning. */
llist_free((llist_t*)sct_head, NULL);
}
# else
static inline void parse_config_file(void)
{
IF_FEATURE_SUID(ruid = getuid();)
}
# endif /* FEATURE_SUID_CONFIG */
# if ENABLE_FEATURE_SUID && NUM_APPLETS > 0
# if ENABLE_FEATURE_SUID_CONFIG
/* check if u is member of group g */
static int ingroup(uid_t u, gid_t g)
{
struct group *grp = getgrgid(g);
if (grp) {
char **mem;
for (mem = grp->gr_mem; *mem; mem++) {
struct passwd *pwd = getpwnam(*mem);
if (pwd && (pwd->pw_uid == u))
return 1;
}
}
return 0;
}
# endif
static void check_suid(int applet_no)
{
gid_t rgid; /* real gid */
if (ruid == 0) /* set by parse_config_file() */
return; /* run by root - no need to check more */
rgid = getgid();
# if ENABLE_FEATURE_SUID_CONFIG
if (suid_cfg_readable) {
uid_t uid;
struct suid_config_t *sct;
mode_t m;
for (sct = suid_config; sct; sct = sct->m_next) {
if (sct->m_applet == applet_no)
goto found;
}
goto check_need_suid;
found:
/* Is this user allowed to run this applet? */
m = sct->m_mode;
if (sct->m_ugid.uid == ruid)
/* same uid */
m >>= 6;
else if ((sct->m_ugid.gid == rgid) || ingroup(ruid, sct->m_ugid.gid))
/* same group / in group */
m >>= 3;
if (!(m & S_IXOTH)) /* is x bit not set? */
bb_error_msg_and_die("you have no permission to run this applet");
/* We set effective AND saved ids. If saved-id is not set
* like we do below, seteuid(0) can still later succeed! */
/* Are we directed to change gid
* (APPLET = *s* USER.GROUP or APPLET = *S* USER.GROUP)?
*/
if (sct->m_mode & S_ISGID)
rgid = sct->m_ugid.gid;
/* else: we will set egid = rgid, thus dropping sgid effect */
if (setresgid(-1, rgid, rgid))
bb_perror_msg_and_die("setresgid");
/* Are we directed to change uid
* (APPLET = s** USER.GROUP or APPLET = S** USER.GROUP)?
*/
uid = ruid;
if (sct->m_mode & S_ISUID)
uid = sct->m_ugid.uid;
/* else: we will set euid = ruid, thus dropping suid effect */
if (setresuid(-1, uid, uid))
bb_perror_msg_and_die("setresuid");
goto ret;
}
# if !ENABLE_FEATURE_SUID_CONFIG_QUIET
{
static bool onetime = 0;
if (!onetime) {
onetime = 1;
bb_error_msg("using fallback suid method");
}
}
# endif
check_need_suid:
# endif
if (APPLET_SUID(applet_no) == BB_SUID_REQUIRE) {
/* Real uid is not 0. If euid isn't 0 too, suid bit
* is most probably not set on our executable */
if (geteuid())
bb_error_msg_and_die("must be suid to work properly");
} else if (APPLET_SUID(applet_no) == BB_SUID_DROP) {
/*
* Drop all privileges.
*
* Don't check for errors: in normal use, they are impossible,
* and in special cases, exiting is harmful. Example:
* 'unshare --user' when user's shell is also from busybox.
*
* 'unshare --user' creates a new user namespace without any
* uid mappings. Thus, busybox binary is setuid nobody:nogroup
* within the namespace, as that is the only user. However,
* since no uids are mapped, calls to setgid/setuid
* fail (even though they would do nothing).
*/
setgid(rgid);
setuid(ruid);
}
# if ENABLE_FEATURE_SUID_CONFIG
ret: ;
llist_free((llist_t*)suid_config, NULL);
# endif
}
# else
# define check_suid(x) ((void)0)
# endif /* FEATURE_SUID */
# if ENABLE_FEATURE_INSTALLER
static const char usr_bin [] ALIGN1 = "/usr/bin/";
static const char usr_sbin[] ALIGN1 = "/usr/sbin/";
static const char *const install_dir[] = {
&usr_bin [8], /* "/" */
&usr_bin [4], /* "/bin/" */
&usr_sbin[4] /* "/sbin/" */
# if !ENABLE_INSTALL_NO_USR
,usr_bin
,usr_sbin
# endif
};
/* create (sym)links for each applet */
static void install_links(const char *busybox, int use_symbolic_links,
char *custom_install_dir)
{
/* directory table
* this should be consistent w/ the enum,
* busybox.h::bb_install_loc_t, or else... */
int (*lf)(const char *, const char *);
char *fpc;
const char *appname = applet_names;
unsigned i;
int rc;
lf = link;
if (use_symbolic_links)
lf = symlink;
for (i = 0; i < ARRAY_SIZE(applet_main); i++) {
fpc = concat_path_file(
custom_install_dir ? custom_install_dir : install_dir[APPLET_INSTALL_LOC(i)],
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2016-03-30 04:12:05 +05:30
appname);
// debug: bb_error_msg("%slinking %s to busybox",
// use_symbolic_links ? "sym" : "", fpc);
rc = lf(busybox, fpc);
if (rc != 0 && errno != EEXIST) {
bb_simple_perror_msg(fpc);
}
free(fpc);
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2016-03-30 04:12:05 +05:30
while (*appname++ != '\0')
continue;
}
}
# elif ENABLE_BUSYBOX
static void install_links(const char *busybox UNUSED_PARAM,
int use_symbolic_links UNUSED_PARAM,
char *custom_install_dir UNUSED_PARAM)
{
}
# endif
static void run_applet_and_exit(const char *name, char **argv) NORETURN;
# if NUM_SCRIPTS > 0
static int find_script_by_name(const char *name)
{
int i;
int applet = find_applet_by_name(name);
if (applet >= 0) {
for (i = 0; i < NUM_SCRIPTS; ++i)
if (applet_numbers[i] == applet)
return i;
}
return -1;
}
int scripted_main(int argc UNUSED_PARAM, char **argv)
{
int script = find_script_by_name(applet_name);
if (script >= 0)
#if ENABLE_ASH || ENABLE_SH_IS_ASH || ENABLE_BASH_IS_ASH
exit(ash_main(-script - 1, argv));
#elif ENABLE_HUSH || ENABLE_SH_IS_HUSH || ENABLE_BASH_IS_HUSH
exit(hush_main(-script - 1, argv));
#else
return 1;
#endif
return 0;
}
char* FAST_FUNC
get_script_content(unsigned n)
{
char *t = unpack_bz2_data(packed_scripts, sizeof(packed_scripts),
UNPACKED_SCRIPTS_LENGTH);
if (t) {
while (n != 0) {
while (*t++ != '\0')
continue;
n--;
}
}
return t;
}
# endif /* NUM_SCRIPTS > 0 */
# if ENABLE_BUSYBOX
# if ENABLE_FEATURE_SH_STANDALONE && ENABLE_FEATURE_TAB_COMPLETION
/*
* Insert "busybox" into applet table as well.
* This makes standalone shell tab-complete this name too.
* (Otherwise having "busybox" in applet table is not necessary,
* there is other code which routes "busyboxANY_SUFFIX" name
* to busybox_main()).
*/
//usage:#define busybox_trivial_usage NOUSAGE_STR
//usage:#define busybox_full_usage ""
//applet:IF_BUSYBOX(IF_FEATURE_SH_STANDALONE(IF_FEATURE_TAB_COMPLETION(APPLET(busybox, BB_DIR_BIN, BB_SUID_MAYBE))))
int busybox_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
# else
# define busybox_main(argc,argv) busybox_main(argv)
static
# endif
int busybox_main(int argc UNUSED_PARAM, char **argv)
{
if (!argv[1]) {
/* Called without arguments */
const char *a;
int col;
unsigned output_width;
help:
output_width = get_terminal_width(2);
dup2(1, 2);
full_write2_str(bb_banner); /* reuse const string */
full_write2_str(" multi-call binary.\n"); /* reuse */
full_write2_str(
"BusyBox is copyrighted by many authors between 1998-2015.\n"
"Licensed under GPLv2. See source distribution for detailed\n"
"copyright notices.\n"
"\n"
"Usage: busybox [function [arguments]...]\n"
" or: busybox --list"IF_FEATURE_INSTALLER("[-full]")"\n"
# if ENABLE_FEATURE_SHOW_SCRIPT && NUM_SCRIPTS > 0
" or: busybox --show SCRIPT\n"
# endif
IF_FEATURE_INSTALLER(
" or: busybox --install [-s] [DIR]\n"
)
" or: function [arguments]...\n"
"\n"
IF_NOT_FEATURE_SH_STANDALONE(
"\tBusyBox is a multi-call binary that combines many common Unix\n"
"\tutilities into a single executable. Most people will create a\n"
"\tlink to busybox for each function they wish to use and BusyBox\n"
"\twill act like whatever it was invoked as.\n"
)
IF_FEATURE_SH_STANDALONE(
"\tBusyBox is a multi-call binary that combines many common Unix\n"
"\tutilities into a single executable. The shell in this build\n"
"\tis configured to run built-in utilities without $PATH search.\n"
"\tYou don't need to install a link to busybox for each utility.\n"
"\tTo run external program, use full path (/sbin/ip instead of ip).\n"
)
"\n"
"Currently defined functions:\n"
);
col = 0;
/* prevent last comma to be in the very last pos */
output_width--;
a = applet_names;
Treat custom and applet scripts as applets BusyBox has support for embedded shell scripts. Two types can be distinguished: custom scripts and scripts implementing applets. Custom scripts should be placed in the 'embed' directory at build time. They are given a default applet configuration and appear as applets to the user but no further configuration is possible. Applet scripts are integrated with the BusyBox build system and are intended to be used to ship standard applets that just happen to be implemented as scripts. They can be configured at build time and appear just like native applets. Such scripts should be placed in the 'applets_sh' directory. A stub C program should be written to provide the usual applet configuration details and placed in a suitable subsystem directory. It may be helpful to have a configuration option to enable any dependencies the script requires: see the 'nologin' applet for an example. function old new delta scripted_main - 41 +41 applet_names 2773 2781 +8 applet_main 1600 1604 +4 i2cdetect_main 672 674 +2 applet_suid 100 101 +1 applet_install_loc 200 201 +1 applet_flags 100 101 +1 packed_usage 33180 33179 -1 tryexec 159 152 -7 evalcommand 1661 1653 -8 script_names 9 - -9 packed_scripts 123 114 -9 complete_cmd_dir_file 826 811 -15 shellexec 271 254 -17 find_command 1007 990 -17 busybox_main 642 624 -18 run_applet_and_exit 100 78 -22 find_script_by_name 51 - -51 ------------------------------------------------------------------------------ (add/remove: 1/2 grow/shrink: 6/9 up/down: 58/-174) Total: -116 bytes text data bss dec hex filename 950034 477 7296 957807 e9d6f busybox_old 949918 477 7296 957691 e9cfb busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-11-17 23:18:14 +05:30
while (*a) {
int len2 = strlen(a) + 2;
if (col >= (int)output_width - len2) {
full_write2_str(",\n");
col = 0;
}
if (col == 0) {
col = 6;
full_write2_str("\t");
} else {
full_write2_str(", ");
}
Treat custom and applet scripts as applets BusyBox has support for embedded shell scripts. Two types can be distinguished: custom scripts and scripts implementing applets. Custom scripts should be placed in the 'embed' directory at build time. They are given a default applet configuration and appear as applets to the user but no further configuration is possible. Applet scripts are integrated with the BusyBox build system and are intended to be used to ship standard applets that just happen to be implemented as scripts. They can be configured at build time and appear just like native applets. Such scripts should be placed in the 'applets_sh' directory. A stub C program should be written to provide the usual applet configuration details and placed in a suitable subsystem directory. It may be helpful to have a configuration option to enable any dependencies the script requires: see the 'nologin' applet for an example. function old new delta scripted_main - 41 +41 applet_names 2773 2781 +8 applet_main 1600 1604 +4 i2cdetect_main 672 674 +2 applet_suid 100 101 +1 applet_install_loc 200 201 +1 applet_flags 100 101 +1 packed_usage 33180 33179 -1 tryexec 159 152 -7 evalcommand 1661 1653 -8 script_names 9 - -9 packed_scripts 123 114 -9 complete_cmd_dir_file 826 811 -15 shellexec 271 254 -17 find_command 1007 990 -17 busybox_main 642 624 -18 run_applet_and_exit 100 78 -22 find_script_by_name 51 - -51 ------------------------------------------------------------------------------ (add/remove: 1/2 grow/shrink: 6/9 up/down: 58/-174) Total: -116 bytes text data bss dec hex filename 950034 477 7296 957807 e9d6f busybox_old 949918 477 7296 957691 e9cfb busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-11-17 23:18:14 +05:30
full_write2_str(a);
col += len2;
a += len2 - 1;
}
full_write2_str("\n");
return 0;
}
# if ENABLE_FEATURE_SHOW_SCRIPT && NUM_SCRIPTS > 0
if (strcmp(argv[1], "--show") == 0) {
int n;
if (!argv[2])
bb_error_msg_and_die(bb_msg_requires_arg, "--show");
n = find_script_by_name(argv[2]);
if (n < 0)
bb_error_msg_and_die("script '%s' not found", argv[2]);
full_write1_str(get_script_content(n));
return 0;
}
# endif
libbb: introduce and use is_prefixed_with() function old new delta is_prefixed_with - 18 +18 complete_username 78 77 -1 man_main 737 735 -2 fsck_device 429 427 -2 unpack_ar_archive 80 76 -4 strip_unsafe_prefix 105 101 -4 singlemount 1054 1050 -4 rtc_adjtime_is_utc 90 86 -4 resolve_mount_spec 88 84 -4 parse_one_line 1029 1025 -4 parse_conf 1460 1456 -4 may_wakeup 83 79 -4 loadkmap_main 219 215 -4 get_irqs_from_stat 103 99 -4 get_header_cpio 913 909 -4 findfs_main 79 75 -4 fbsplash_main 1230 1226 -4 load_crontab 776 771 -5 expand_vars_to_list 1151 1146 -5 date_main 881 876 -5 skip_dev_pfx 30 24 -6 make_device 2199 2193 -6 complete_cmd_dir_file 773 767 -6 run_applet_and_exit 715 708 -7 uudecode_main 321 313 -8 pwdx_main 197 189 -8 execute 568 560 -8 i2cdetect_main 1186 1176 -10 procps_scan 1242 1230 -12 procps_read_smaps 1017 1005 -12 process_module 746 734 -12 patch_main 1903 1891 -12 nfsmount 3572 3560 -12 stack_machine 126 112 -14 process_timer_stats 449 435 -14 match_fstype 111 97 -14 do_ipaddr 1344 1330 -14 open_list_and_close 359 343 -16 get_header_tar 1795 1779 -16 prepend_new_eth_table 340 323 -17 fsck_main 1811 1794 -17 find_iface_state 56 38 -18 dnsd_main 1321 1303 -18 base_device 179 158 -21 find_keyword 104 82 -22 handle_incoming_and_exit 2785 2762 -23 parse_and_put_prompt 774 746 -28 modinfo 347 317 -30 find_action 204 171 -33 update_passwd 1470 1436 -34 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 0/49 up/down: 18/-540) Total: -522 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-03-12 22:18:34 +05:30
if (is_prefixed_with(argv[1], "--list")) {
unsigned i = 0;
const char *a = applet_names;
dup2(1, 2);
while (*a) {
# if ENABLE_FEATURE_INSTALLER
if (argv[1][6]) /* --list-full? */
full_write2_str(install_dir[APPLET_INSTALL_LOC(i)] + 1);
# endif
full_write2_str(a);
full_write2_str("\n");
i++;
while (*a++ != '\0')
continue;
}
return 0;
}
if (ENABLE_FEATURE_INSTALLER && strcmp(argv[1], "--install") == 0) {
int use_symbolic_links;
const char *busybox;
busybox = xmalloc_readlink(bb_busybox_exec_path);
if (!busybox) {
/* bb_busybox_exec_path is usually "/proc/self/exe".
* In chroot, readlink("/proc/self/exe") usually fails.
* In such case, better use argv[0] as symlink target
* if it is a full path name.
*/
if (argv[0][0] != '/')
bb_error_msg_and_die("'%s' is not an absolute path", argv[0]);
busybox = argv[0];
}
/* busybox --install [-s] [DIR]:
* -s: make symlinks
* DIR: directory to install links to
*/
use_symbolic_links = (argv[2] && strcmp(argv[2], "-s") == 0 && ++argv);
install_links(busybox, use_symbolic_links, argv[2]);
return 0;
}
if (strcmp(argv[1], "--help") == 0) {
/* "busybox --help [<applet>]" */
if (!argv[2])
goto help;
/* convert to "<applet> --help" */
argv[0] = argv[2];
argv[2] = NULL;
} else {
/* "busybox <applet> arg1 arg2 ..." */
argv++;
}
/* We support "busybox /a/path/to/applet args..." too. Allows for
* "#!/bin/busybox"-style wrappers */
applet_name = bb_get_last_path_component_nostrip(argv[0]);
run_applet_and_exit(applet_name, argv);
}
# endif
# if NUM_APPLETS > 0
void FAST_FUNC run_applet_no_and_exit(int applet_no, const char *name, char **argv)
{
int argc = string_array_len(argv);
/*
* We do not use argv[0]: do not want to repeat massaging of
* "-/sbin/halt" -> "halt", for example.
*/
applet_name = name;
/* Special case. POSIX says "test --help"
* should be no different from e.g. "test --foo".
* Thus for "test", we skip --help check.
* "true" and "false" are also special.
*/
if (1
# if defined APPLET_NO_test
&& applet_no != APPLET_NO_test
# endif
# if defined APPLET_NO_true
&& applet_no != APPLET_NO_true
# endif
# if defined APPLET_NO_false
&& applet_no != APPLET_NO_false
# endif
) {
if (argc == 2 && strcmp(argv[1], "--help") == 0) {
/* Make "foo --help" exit with 0: */
xfunc_error_retval = 0;
bb_show_usage();
}
}
if (ENABLE_FEATURE_SUID)
check_suid(applet_no);
xfunc_error_retval = applet_main[applet_no](argc, argv);
/* Note: applet_main() may also not return (die on a xfunc or such) */
xfunc_die();
}
# endif /* NUM_APPLETS > 0 */
Treat custom and applet scripts as applets BusyBox has support for embedded shell scripts. Two types can be distinguished: custom scripts and scripts implementing applets. Custom scripts should be placed in the 'embed' directory at build time. They are given a default applet configuration and appear as applets to the user but no further configuration is possible. Applet scripts are integrated with the BusyBox build system and are intended to be used to ship standard applets that just happen to be implemented as scripts. They can be configured at build time and appear just like native applets. Such scripts should be placed in the 'applets_sh' directory. A stub C program should be written to provide the usual applet configuration details and placed in a suitable subsystem directory. It may be helpful to have a configuration option to enable any dependencies the script requires: see the 'nologin' applet for an example. function old new delta scripted_main - 41 +41 applet_names 2773 2781 +8 applet_main 1600 1604 +4 i2cdetect_main 672 674 +2 applet_suid 100 101 +1 applet_install_loc 200 201 +1 applet_flags 100 101 +1 packed_usage 33180 33179 -1 tryexec 159 152 -7 evalcommand 1661 1653 -8 script_names 9 - -9 packed_scripts 123 114 -9 complete_cmd_dir_file 826 811 -15 shellexec 271 254 -17 find_command 1007 990 -17 busybox_main 642 624 -18 run_applet_and_exit 100 78 -22 find_script_by_name 51 - -51 ------------------------------------------------------------------------------ (add/remove: 1/2 grow/shrink: 6/9 up/down: 58/-174) Total: -116 bytes text data bss dec hex filename 950034 477 7296 957807 e9d6f busybox_old 949918 477 7296 957691 e9cfb busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-11-17 23:18:14 +05:30
# if ENABLE_BUSYBOX || NUM_APPLETS > 0
static NORETURN void run_applet_and_exit(const char *name, char **argv)
{
# if ENABLE_BUSYBOX
libbb: introduce and use is_prefixed_with() function old new delta is_prefixed_with - 18 +18 complete_username 78 77 -1 man_main 737 735 -2 fsck_device 429 427 -2 unpack_ar_archive 80 76 -4 strip_unsafe_prefix 105 101 -4 singlemount 1054 1050 -4 rtc_adjtime_is_utc 90 86 -4 resolve_mount_spec 88 84 -4 parse_one_line 1029 1025 -4 parse_conf 1460 1456 -4 may_wakeup 83 79 -4 loadkmap_main 219 215 -4 get_irqs_from_stat 103 99 -4 get_header_cpio 913 909 -4 findfs_main 79 75 -4 fbsplash_main 1230 1226 -4 load_crontab 776 771 -5 expand_vars_to_list 1151 1146 -5 date_main 881 876 -5 skip_dev_pfx 30 24 -6 make_device 2199 2193 -6 complete_cmd_dir_file 773 767 -6 run_applet_and_exit 715 708 -7 uudecode_main 321 313 -8 pwdx_main 197 189 -8 execute 568 560 -8 i2cdetect_main 1186 1176 -10 procps_scan 1242 1230 -12 procps_read_smaps 1017 1005 -12 process_module 746 734 -12 patch_main 1903 1891 -12 nfsmount 3572 3560 -12 stack_machine 126 112 -14 process_timer_stats 449 435 -14 match_fstype 111 97 -14 do_ipaddr 1344 1330 -14 open_list_and_close 359 343 -16 get_header_tar 1795 1779 -16 prepend_new_eth_table 340 323 -17 fsck_main 1811 1794 -17 find_iface_state 56 38 -18 dnsd_main 1321 1303 -18 base_device 179 158 -21 find_keyword 104 82 -22 handle_incoming_and_exit 2785 2762 -23 parse_and_put_prompt 774 746 -28 modinfo 347 317 -30 find_action 204 171 -33 update_passwd 1470 1436 -34 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 0/49 up/down: 18/-540) Total: -522 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-03-12 22:18:34 +05:30
if (is_prefixed_with(name, "busybox"))
exit(busybox_main(/*unused:*/ 0, argv));
# endif
# if NUM_APPLETS > 0
applet_tables: save space by removing applet name offsets The array applet_nameofs consumes two bytes per applet. It encodes nofork/noexec flags suid flags the offset of the applet name in the applet_name string Change the applet_table build tool to store the flags in two separate arrays (applet_flags and applet_suid). Replace applet_nameofs[] with a smaller version that only stores a limited number of offsets. This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC and APPLET_SUID. According to Valgrind the original find_applet_by_name required 353 cycles per call, averaged over all names. Adjusting the number of known offsets allows space to be traded off against execution time: KNOWN_OFFSETS cycles bytes (wrt KNOWN_OFFSETS = 0) 0 9057 - 2 4604 32 4 2407 75 8 1342 98 16 908 130 32 884 194 This patch uses KNOWN_OFFSETS = 8. v2: Remove some dead code from the applet_table tool; Treat the applet in the middle of the table as a special case. v3: Use the middle applet to adjust the start of the linear search as well as the last applet found. v4: Use an augmented linear search in find_applet_by_name. Drop the special treatment of the middle name from get_applet_name: most of the advantage now derives from the last stored value. v5: Don't store index in applet_nameofs, it can be calculated. v6: Tweaks by Denys function old new delta find_applet_by_name 25 125 +100 applet_suid - 92 +92 run_applet_no_and_exit 452 460 +8 run_applet_and_exit 695 697 +2 applet_name_compare 31 - -31 applet_nameofs 734 14 -720 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751) Total: -549 bytes text data bss dec hex filename 925464 906 17160 943530 e65aa busybox_old 924915 906 17160 942981 e6385 busybox_unstripped Signed-off-by: Ron Yorston <rmy@pobox.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2016-03-30 04:12:05 +05:30
/* find_applet_by_name() search is more expensive, so goes second */
{
int applet = find_applet_by_name(name);
if (applet >= 0)
run_applet_no_and_exit(applet, name, argv);
}
# endif
/*bb_error_msg_and_die("applet not found"); - links in printf */
full_write2_str(applet_name);
full_write2_str(": applet not found\n");
/* POSIX: "If a command is not found, the exit status shall be 127" */
exit(127);
}
# endif
2008-04-29 05:40:27 +05:30
#endif /* !defined(SINGLE_APPLET_MAIN) */
#if ENABLE_BUILD_LIBBUSYBOX
int lbb_main(char **argv)
#else
2008-07-05 14:48:54 +05:30
int main(int argc UNUSED_PARAM, char **argv)
#endif
{
#if 0
/* TODO: find a use for a block of memory between end of .bss
* and end of page. For example, I'm getting "_end:0x812e698 2408 bytes"
* - more than 2k of wasted memory (in this particular build)
* *per each running process*!
* (If your linker does not generate "_end" name, weak attribute
* makes &_end == NULL, end_len == 0 here.)
*/
extern char _end[] __attribute__((weak));
unsigned end_len = (-(int)_end) & 0xfff;
printf("_end:%p %u bytes\n", &_end, end_len);
#endif
/* Tweak malloc for reduced memory consumption */
#ifdef M_TRIM_THRESHOLD
/* M_TRIM_THRESHOLD is the maximum amount of freed top-most memory
* to keep before releasing to the OS
* Default is way too big: 256k
*/
mallopt(M_TRIM_THRESHOLD, 8 * 1024);
#endif
#ifdef M_MMAP_THRESHOLD
/* M_MMAP_THRESHOLD is the request size threshold for using mmap()
* Default is too big: 256k
*/
mallopt(M_MMAP_THRESHOLD, 32 * 1024 - 256);
#endif
#if 0 /*def M_TOP_PAD*/
/* When the program break is increased, then M_TOP_PAD bytes are added
* to the sbrk(2) request. When the heap is trimmed because of free(3),
* this much free space is preserved at the top of the heap.
* glibc default seems to be way too big: 128k, but need to verify.
*/
mallopt(M_TOP_PAD, 8 * 1024);
#endif
#if !BB_MMU
/* NOMMU re-exec trick sets high-order bit in first byte of name */
if (argv[0][0] & 0x80) {
re_execed = 1;
argv[0][0] &= 0x7f;
}
#endif
#if defined(SINGLE_APPLET_MAIN)
/* Only one applet is selected in .config */
libbb: introduce and use is_prefixed_with() function old new delta is_prefixed_with - 18 +18 complete_username 78 77 -1 man_main 737 735 -2 fsck_device 429 427 -2 unpack_ar_archive 80 76 -4 strip_unsafe_prefix 105 101 -4 singlemount 1054 1050 -4 rtc_adjtime_is_utc 90 86 -4 resolve_mount_spec 88 84 -4 parse_one_line 1029 1025 -4 parse_conf 1460 1456 -4 may_wakeup 83 79 -4 loadkmap_main 219 215 -4 get_irqs_from_stat 103 99 -4 get_header_cpio 913 909 -4 findfs_main 79 75 -4 fbsplash_main 1230 1226 -4 load_crontab 776 771 -5 expand_vars_to_list 1151 1146 -5 date_main 881 876 -5 skip_dev_pfx 30 24 -6 make_device 2199 2193 -6 complete_cmd_dir_file 773 767 -6 run_applet_and_exit 715 708 -7 uudecode_main 321 313 -8 pwdx_main 197 189 -8 execute 568 560 -8 i2cdetect_main 1186 1176 -10 procps_scan 1242 1230 -12 procps_read_smaps 1017 1005 -12 process_module 746 734 -12 patch_main 1903 1891 -12 nfsmount 3572 3560 -12 stack_machine 126 112 -14 process_timer_stats 449 435 -14 match_fstype 111 97 -14 do_ipaddr 1344 1330 -14 open_list_and_close 359 343 -16 get_header_tar 1795 1779 -16 prepend_new_eth_table 340 323 -17 fsck_main 1811 1794 -17 find_iface_state 56 38 -18 dnsd_main 1321 1303 -18 base_device 179 158 -21 find_keyword 104 82 -22 handle_incoming_and_exit 2785 2762 -23 parse_and_put_prompt 774 746 -28 modinfo 347 317 -30 find_action 204 171 -33 update_passwd 1470 1436 -34 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 0/49 up/down: 18/-540) Total: -522 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-03-12 22:18:34 +05:30
if (argv[1] && is_prefixed_with(argv[0], "busybox")) {
/* "busybox <applet> <params>" should still work as expected */
argv++;
}
/* applet_names in this case is just "applet\0\0" */
lbb_prepare(applet_names IF_FEATURE_INDIVIDUAL(, argv));
# if ENABLE_BUILD_LIBBUSYBOX
return SINGLE_APPLET_MAIN(string_array_len(argv), argv);
# else
return SINGLE_APPLET_MAIN(argc, argv);
# endif
#elif !ENABLE_BUSYBOX && NUM_APPLETS == 0
full_write2_str(bb_basename(argv[0]));
full_write2_str(": no applets enabled\n");
exit(127);
#else
lbb_prepare("busybox" IF_FEATURE_INDIVIDUAL(, argv));
# if !ENABLE_BUSYBOX
if (argv[1] && is_prefixed_with(bb_basename(argv[0]), "busybox"))
argv++;
# endif
applet_name = argv[0];
if (applet_name[0] == '-')
applet_name++;
applet_name = bb_basename(applet_name);
/* If we are a result of execv("/proc/self/exe"), fix ugly comm of "exe" */
if (ENABLE_FEATURE_SH_STANDALONE
|| ENABLE_FEATURE_PREFER_APPLETS
|| !BB_MMU
) {
if (NUM_APPLETS > 1)
set_task_comm(applet_name);
}
parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */
run_applet_and_exit(applet_name, argv);
#endif
}