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>
= display default is no longer in cylinders
= +sizeC is no longer supported
= add +sizeT suffix - terabytes are here
= K,M,G,T and k,m,g,t suffixes all are binary, not decimal
= +sizeM results in last sector +(size * 1Mbyte - 1), not +(size * 1Mbyte)
= fix comparison to "YES" answer for sgi/sun
function old new delta
read_int 492 519 +27
fdisk_main 2644 2640 -4
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 27/-4) Total: 23 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Kconfig-language.txt was deleted in commit 4fa499a17b back in 2006.
Move to docs/ as suggested by Xabier Oneca:
http://lists.busybox.net/pipermail/busybox/2014-May/080914.html
Also update references to it everywhere.
Signed-off-by: Kartik Agaram <akkartik@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
fdisk from util-linux 2.31 (maybe earlier) does not print this.
function old new delta
check_consistency 449 399 -50
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-t, -S and -G each take mandatory integer arguments. getopt32long()'s
option string syntax for this type of argument is 'c:+', however nsenter's
opt_str uses 'c+', which specifies two options 'c' and '+' which do not
take arguments. This means that giving a target PID causes nsenter to
exit and print the usage string:
# nsenter -t1 sh
nsenter: unrecognized option: 1
BusyBox v1.27.2 (2017-12-12 10:41:50 GMT) multi-call binary.
...
The long form options are also broken:
# nsenter --setuid=1000 --setgid=1000 sh
BusyBox v1.29.0.git (2018-05-04 13:56:49 UTC) multi-call binary.
...
`nsenter --target=<pid> sh` parses correctly and appears to work, but
<pid> is ignored and set to 0. This doesn't raise an error unless one
of the namespace arguments is also given:
# ./busybox_unstripped nsenter --target=42 sh
# exit
# ./busybox_unstripped nsenter -n --target=42 sh
BusyBox v1.29.0.git (2018-05-04 13:56:49 UTC) multi-call binary.
...
This has caused problems in a couple of places:
https://github.com/linuxkit/linuxkit/issues/567https://github.com/gliderlabs/docker-alpine/issues/359https://github.com/kontena/pharos-cluster/pull/81
Signed-off-by: Euan Harris <euan.harris@docker.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
In nsenter from util-linux, the long version of the -n option is
--net=<path>. BusyBox's version expects --network=<path>, so scripts
and examples written for util-linux's version cause BusyBox's version
to exit with the usage message.
Confusingly, until commit 036585a911, the usage message erroneously
claimed that the long option was indeed called --net; after that commit
long options are not listed at all.
Signed-off-by: Euan Harris <euan.harris@docker.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Kernel will surely inform us in FITRIM does not make sense on a given file.
function old new delta
fstrim_main 241 221 -20
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
While at it, add -t to --help, and fix comments which say that -t is ignored
function old new delta
packed_usage 32427 32444 +17
umount_main 558 552 -6
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 17/-6) Total: 11 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Add support for LittleFS to blkid. Not included if FEATURE_BLKID_TYPE
is not selected (neither UUID nor label).
LittleFS is a small fail-safe filesystem designed for embedded
systems. It has strong copy-on-write guarantees and storage on disk
is always kept in a valid state. It also provides a form of dynamic
wear levelling for systems that can not fit a full flash translation
layer. (https://github.com/geky/littlefs)
ARM has introduced it in its Mbed OS 5.7, so it starts to gain focus.
(https://os.mbed.com/blog/entry/littlefs-high-integrity-embedded-fs/)
function old new delta
volume_id_probe_lfs - 62 +62
fs1 20 24 +4
Signed-off-by: Sven-Göran Bergh <sgb@systemaxion.se>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
"-c, --no-canonicalize: Do not canonicalize paths."
As busybox doesn't canonicalize paths in the first place it is safe to ignore
this option.
See https://github.com/systemd/systemd/issues/7786
Signed-off-by: Shawn Landden <slandden@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
FEATURE_GETOPT_LONG made dependent on LONG_OPTS.
The folloving options are removed, now LONG_OPTS enables long options
for affected applets:
FEATURE_ENV_LONG_OPTIONS FEATURE_EXPAND_LONG_OPTIONS
FEATURE_UNEXPAND_LONG_OPTIONS FEATURE_MKDIR_LONG_OPTIONS
FEATURE_MV_LONG_OPTIONS FEATURE_RMDIR_LONG_OPTIONS
FEATURE_ADDGROUP_LONG_OPTIONS FEATURE_ADDUSER_LONG_OPTIONS
FEATURE_HWCLOCK_LONG_OPTIONS FEATURE_NSENTER_LONG_OPTS
FEATURE_CHCON_LONG_OPTIONS FEATURE_RUNCON_LONG_OPTIONS
They either had a small number of long options, or their long options are
essential.
Example: upstream addgroup and adduser have ONLY longopts,
we should probably go further and get rid
of non-standard short options.
To this end, make addgroup and adduser "select LONG_OPTS".
We had this breakage caused by us even in our own package!
#if ENABLE_LONG_OPTS || !ENABLE_ADDGROUP
/* We try to use --gid, not -g, because "standard" addgroup
* has no short option -g, it has only long --gid.
*/
argv[1] = (char*)"--gid";
#else
/* Breaks if system in fact does NOT use busybox addgroup */
argv[1] = (char*)"-g";
#endif
xargs: its lone longopt no longer depends on DESKTOP, only on LONG_OPTS.
hwclock TODO: get rid of incompatible -t, -l aliases to --systz, --localtime
Shorten help texts by omitting long option when short opt alternative exists.
Reduction of size comes from the fact that store of an immediate
(an address of longopts) to a fixed address (global variable)
is a longer insn than pushing that immediate or passing it in a register.
This effect is CPU-agnostic.
function old new delta
getopt32 1350 22 -1328
vgetopt32 - 1318 +1318
getopt32long - 24 +24
tftpd_main 562 567 +5
scan_recursive 376 380 +4
collect_cpu 545 546 +1
date_main 1096 1095 -1
hostname_main 262 259 -3
uname_main 259 255 -4
setpriv_main 362 358 -4
rmdir_main 191 187 -4
mv_main 562 558 -4
ipcalc_main 548 544 -4
ifenslave_main 641 637 -4
gzip_main 192 188 -4
gunzip_main 77 73 -4
fsfreeze_main 81 77 -4
flock_main 318 314 -4
deluser_main 337 333 -4
cp_main 374 370 -4
chown_main 175 171 -4
applet_long_options 4 - -4
xargs_main 894 889 -5
wget_main 2540 2535 -5
udhcpc_main 2767 2762 -5
touch_main 436 431 -5
tar_main 1014 1009 -5
start_stop_daemon_main 1033 1028 -5
sed_main 682 677 -5
script_main 1082 1077 -5
run_parts_main 330 325 -5
rtcwake_main 459 454 -5
od_main 2169 2164 -5
nl_main 201 196 -5
modprobe_main 773 768 -5
mkdir_main 160 155 -5
ls_main 568 563 -5
install_main 773 768 -5
hwclock_main 411 406 -5
getopt_main 622 617 -5
fstrim_main 256 251 -5
env_main 198 193 -5
dumpleases_main 635 630 -5
dpkg_main 3991 3986 -5
diff_main 1355 1350 -5
cryptpw_main 233 228 -5
cpio_main 593 588 -5
conspy_main 1135 1130 -5
chpasswd_main 313 308 -5
adduser_main 887 882 -5
addgroup_main 416 411 -5
ftpgetput_main 351 345 -6
get_terminal_width_height 242 234 -8
expand_main 690 680 -10
static.expand_longopts 18 - -18
static.unexpand_longopts 27 - -27
mkdir_longopts 28 - -28
env_longopts 30 - -30
static.ifenslave_longopts 34 - -34
mv_longopts 46 - -46
static.rmdir_longopts 48 - -48
packed_usage 31739 31687 -52
------------------------------------------------------------------------------
(add/remove: 2/8 grow/shrink: 3/49 up/down: 1352/-1840) Total: -488 bytes
text data bss dec hex filename
915681 485 6880 923046 e15a6 busybox_old
915428 485 6876 922789 e14a5 busybox_unstripped
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
The applets with "<applet> [opts] PROG ARGS" API very quickly exec
another program, noexec is okay for them:
chpst/envdir/envuidgid/softlimit/setuidgid
chroot
chrt
ionice
nice
nohup
setarch/linux32/linux64
taskset
cttyhack
"reset" and "sulogin" applets don't have this form, but also exec
another program at once, thus made noexec too.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Noticed while auditing nofork/noexec status
function old new delta
packed_usage 31777 31747 -30
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
With Linux 4.3, a new set of capabilities has been introduced with the
ambient capabilities. These aim to solve the problem that it was
impossible to grant run programs with elevated privileges across
non-root users. Quoting from capabilities(7):
This is a set of capabilities that are preserved across an execve(2)
of a program that is not privileged. The ambient capability set
obeys the invariant that no capability can ever be ambient if it is
not both permitted and inheritable.
With this new set of capabilities it is now possible to run an
executable with elevated privileges as a different user, making it much
easier to do proper privilege separation.
Note though that the `--ambient-caps` switch is not part of any released
version of util-linux, yet. It has been applied in 0c92194ee (setpriv:
support modifying the set of ambient capabilities, 2017-06-24) and will
probably be part of v2.31.
function old new delta
parse_cap - 174 +174
setpriv_main 1246 1301 +55
.rodata 146307 146347 +40
static.setpriv_longopts 40 55 +15
packed_usage 32092 32079 -13
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
The main use case of setpriv is to modify the current state of
privileges available to the calling process and spawn a new executable
with the modified, new state. Next to the already supported case of
modifying the no-new-privs flag, util-linux also supports to modify
capability sets.
This commit introduces to add or drop capabilities from the set of
inheritable capabilities. Quoting from capabilities(7):
This is a set of capabilities preserved across an execve(2).
Inheritable capabilities remain inheritable when executing any
program, and inheritable capabilities are added to the permitted set
when executing a program that has the corresponding bits set in the
file inheritable set.
As such, inheritable capabilities enable executing files with certain
privileges if the file itself has these privileges set. Note though that
inheritable capabilities are dropped across execve when running as a
non-root user.
function old new delta
getcaps - 237 +237
setpriv_main 1129 1246 +117
.rodata 146198 146307 +109
static.setpriv_longopts 29 40 +11
packed_usage 32107 32092 -15
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
As with the previous commit, this commit introduces the ability to dump
the set of ambient capabilities.
function old new delta
setpriv_main 982 1129 +147
.rodata 146148 146198 +50
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
As with the previous commit, this one implements the ability to dump the
capability bounding set.
function old new delta
setpriv_main 838 982 +144
.rodata 146101 146148 +47
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
The setpriv executable from util-linux also dumps out information on the
different capability sets known by the kernel. By default, these are the
inheritable capabilities, bounding capabilities and (not yet released)
the ambient capabilities, which have been introduced with Linux 4.3.
This patch introduces the ability to dump the set of inheritable
capabilities.
By default, setpriv(1) identifies capabilities by their human-readable
name, for example 'net_admin'. For unknown capabilities, though, it does
instead use the capability's value, for example 'cap_12', which is
equivalent to 'net_admin'. As there is no kernel interface to retrieve
capability names by their index, we have to declare these ourselves,
which adds to setpriv's size.
To counteract, using the human-readble name has been made configurable.
The following sizes are with the 'FEATURE_SETPRIV_CAPABILITY_NAMES'
enabled:
function old new delta
.rodata 145969 146405 +436
setpriv_main 467 842 +375
capabilities - 304 +304
And with 'FEATURE_SETPRIV_CAPABILITY_NAMES' disabled:
function old new delta
setpriv_main 467 838 +371
.rodata 145969 146101 +132
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Introduce the ability to dump the state of the no-new-privs flag, which
states whethere it is allowed to grant new privileges.
function old new delta
setpriv_main 419 467 +48
.rodata 145926 145969 +43
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
