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authorDenys Vlasenko <vda.linux@googlemail.com>2021-02-18 23:30:24 +0100
committerDenys Vlasenko <vda.linux@googlemail.com>2021-02-18 23:30:24 +0100
commit6bdfbc4cb5470f63d4905e89f89a9829af354316 (patch)
tree573f2b655d4944d4e5e9e7627f18c8a4bb1ebeaa /libbb
parent33745b1fc8cc6d41f4e708d67800d296668af2ce (diff)
downloadbusybox-6bdfbc4cb5470f63d4905e89f89a9829af354316.tar.gz
libbb: fix '--help' handling in FEATURE_SH_NOFORK=y
Most BusyBox applets respond to the '--help' option by printing a usage message. This is normally handled by busybox_main() so applet main routines don't have support for '--help'. In standalone shell mode with FEATURE_SH_NOFORK enabled nofork applets are invoked directly, bypassing busybox_main(). This results in inconsistent handling of '--help': - applets which call getopt() report "unrecognized option '--help'" and print help anyway; - realpath says "--help: No such file or directory" and doesn't print help; - usleep says "invalid number '--help'" and doesn't print help. Avoid inconsistency by checking for '--help' in run_nofork_applet(). Bug found by Ron Yorston. function old new delta show_usage_if_dash_dash_help - 70 +70 run_nofork_applet 347 362 +15 run_applet_no_and_exit 432 365 -67 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 1/1 up/down: 85/-67) Total: 18 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'libbb')
-rw-r--r--libbb/appletlib.c29
-rw-r--r--libbb/vfork_daemon_rexec.c5
2 files changed, 24 insertions, 10 deletions
diff --git a/libbb/appletlib.c b/libbb/appletlib.c
index 542211255..67c540abb 100644
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -905,16 +905,8 @@ int busybox_main(int argc UNUSED_PARAM, char **argv)
# endif
# if NUM_APPLETS > 0
-void FAST_FUNC run_applet_no_and_exit(int applet_no, const char *name, char **argv)
+void FAST_FUNC show_usage_if_dash_dash_help(int applet_no, 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.
@@ -931,15 +923,32 @@ void FAST_FUNC run_applet_no_and_exit(int applet_no, const char *name, char **ar
&& applet_no != APPLET_NO_false
# endif
) {
- if (argc == 2 && strcmp(argv[1], "--help") == 0) {
+ if (argv[1] && !argv[2] && strcmp(argv[1], "--help") == 0) {
/* Make "foo --help" exit with 0: */
xfunc_error_retval = 0;
bb_show_usage();
}
}
+}
+
+void FAST_FUNC run_applet_no_and_exit(int applet_no, const char *name, char **argv)
+{
+ int argc;
+
+ /*
+ * We do not use argv[0]: do not want to repeat massaging of
+ * "-/sbin/halt" -> "halt", for example.
+ */
+ applet_name = name;
+
+ show_usage_if_dash_dash_help(applet_no, argv);
+
if (ENABLE_FEATURE_SUID)
check_suid(applet_no);
+
+ argc = string_array_len(argv);
xfunc_error_retval = applet_main[applet_no](argc, argv);
+
/* Note: applet_main() may also not return (die on a xfunc or such) */
xfunc_die();
}
diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c
index 65271e84f..a49fe8e01 100644
--- a/libbb/vfork_daemon_rexec.c
+++ b/libbb/vfork_daemon_rexec.c
@@ -109,8 +109,13 @@ int FAST_FUNC run_nofork_applet(int applet_no, char **argv)
char *tmp_argv[argc+1];
memcpy(tmp_argv, argv, (argc+1) * sizeof(tmp_argv[0]));
applet_name = tmp_argv[0];
+
+ /* longjmp's (instead of returning) if --help is seen */
+ show_usage_if_dash_dash_help(applet_no, argv);
+
/* Finally we can call NOFORK applet's main() */
rc = applet_main[applet_no](argc, tmp_argv);
+
/* Important for shells: `which CMD` was failing */
fflush_all();
} else {