bb_askpass: handle Ctrl-C, restore termoios on Ctrl-C.

sulogin: remove alarm handling, as it is redundant there.
code shrink. After all differences cancel out:

   text    data     bss     dec     hex filename
 777543    1000    9532  788075   c066b busybox_old
 777543    1000    9532  788075   c066b busybox_unstripped

2 files changed, 50 insertions, 47 deletions

diff --git a/libbb/bb_askpass.c b/libbb/bb_askpass.c
index 435314e..fd12f92 100644
--- a/libbb/bb_askpass.c
+++ b/libbb/bb_askpass.c
@@ -17,7 +17,7 @@ static void askpass_timeout(int ATTRIBUTE_UNUSED ignore)
 {
 }
 
-char *bb_askpass(int timeout, const char * prompt)
+char *bb_askpass(int timeout, const char *prompt)
 {
 	/* Was static char[BIGNUM] */
 	enum { sizeof_passwd = 128 };
@@ -25,35 +25,36 @@ char *bb_askpass(int timeout, const char * prompt)
 
 	char *ret;
 	int i;
-	struct sigaction sa;
-	struct termios old, new;
+	struct sigaction sa, oldsa;
+	struct termios tio, oldtio;
 
 	if (!passwd)
 		passwd = xmalloc(sizeof_passwd);
 	memset(passwd, 0, sizeof_passwd);
 
-	tcgetattr(STDIN_FILENO, &old);
+	tcgetattr(STDIN_FILENO, &oldtio);
 	tcflush(STDIN_FILENO, TCIFLUSH);
+	tio = oldtio;
+	tio.c_iflag &= ~(IUCLC|IXON|IXOFF|IXANY);
+	tio.c_lflag &= ~(ECHO|ECHOE|ECHOK|ECHONL|TOSTOP);
+	tcsetattr(STDIN_FILENO, TCSANOW, &tio);
 
-	fputs(prompt, stdout);
-	fflush(stdout);
-
-	tcgetattr(STDIN_FILENO, &new);
-	new.c_iflag &= ~(IUCLC|IXON|IXOFF|IXANY);
-	new.c_lflag &= ~(ECHO|ECHOE|ECHOK|ECHONL|TOSTOP);
-	tcsetattr(STDIN_FILENO, TCSANOW, &new);
-
+	memset(&sa, 0, sizeof(sa));
+	/* sa.sa_flags = 0; - no SA_RESTART! */
+	/* SIGINT and SIGALRM will interrupt read below */
+	sa.sa_handler = askpass_timeout;
+	sigaction(SIGINT, &sa, &oldsa);
 	if (timeout) {
-		sa.sa_flags = 0;
-		sa.sa_handler = askpass_timeout;
 		sigaction(SIGALRM, &sa, NULL);
 		alarm(timeout);
 	}
 
+	fputs(prompt, stdout);
+	fflush(stdout);
 	ret = NULL;
-	/* On timeout, read will hopefully be interrupted by SIGALRM,
+	/* On timeout or Ctrl-C, read will hopefully be interrupted,
 	 * and we return NULL */
-	if (read(STDIN_FILENO, passwd, sizeof_passwd-1) > 0) {
+	if (read(STDIN_FILENO, passwd, sizeof_passwd - 1) > 0) {
 		ret = passwd;
 		i = 0;
 		/* Last byte is guaranteed to be 0
@@ -67,8 +68,9 @@ char *bb_askpass(int timeout, const char * prompt)
 	if (timeout) {
 		alarm(0);
 	}
+	sigaction(SIGINT, &oldsa, NULL);
 
-	tcsetattr(STDIN_FILENO, TCSANOW, &old);
+	tcsetattr(STDIN_FILENO, TCSANOW, &oldtio);
 	bb_putchar('\n');
 	fflush(stdout);
 	return ret;
diff --git a/loginutils/sulogin.c b/loginutils/sulogin.c
index 7f100a1..f633fbb 100644
--- a/loginutils/sulogin.c
+++ b/loginutils/sulogin.c
@@ -9,29 +9,26 @@
 
 #include "libbb.h"
 
-static const char *const forbid[] = {
-	"ENV",
-	"BASH_ENV",
-	"HOME",
-	"IFS",
-	"PATH",
-	"SHELL",
-	"LD_LIBRARY_PATH",
-	"LD_PRELOAD",
-	"LD_TRACE_LOADED_OBJECTS",
-	"LD_BIND_NOW",
-	"LD_AOUT_LIBRARY_PATH",
-	"LD_AOUT_PRELOAD",
-	"LD_NOWARN",
-	"LD_KEEPDIR",
-	(char *) 0
-};
-
-
-static void catchalarm(int ATTRIBUTE_UNUSED junk)
-{
-	exit(EXIT_FAILURE);
-}
+static const char forbid[] ALIGN1 =
+	"ENV" "\0"
+	"BASH_ENV" "\0"
+	"HOME" "\0"
+	"IFS" "\0"
+	"PATH" "\0"
+	"SHELL" "\0"
+	"LD_LIBRARY_PATH" "\0"
+	"LD_PRELOAD" "\0"
+	"LD_TRACE_LOADED_OBJECTS" "\0"
+	"LD_BIND_NOW" "\0"
+	"LD_AOUT_LIBRARY_PATH" "\0"
+	"LD_AOUT_PRELOAD" "\0"
+	"LD_NOWARN" "\0"
+	"LD_KEEPDIR" "\0";
+
+//static void catchalarm(int ATTRIBUTE_UNUSED junk)
+//{
+//	exit(EXIT_FAILURE);
+//}
 
 
 int sulogin_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
@@ -40,7 +37,7 @@ int sulogin_main(int argc, char **argv)
 	char *cp;
 	int timeout = 0;
 	char *timeout_arg;
-	const char *const *p;
+	const char *p;
 	struct passwd *pwd;
 	const char *shell;
 #if ENABLE_FEATURE_SHADOWPASSWDS
@@ -71,10 +68,14 @@ int sulogin_main(int argc, char **argv)
 	}
 
 	/* Clear out anything dangerous from the environment */
-	for (p = forbid; *p; p++)
-		unsetenv(*p);
+	p = forbid;
+	do {
+		unsetenv(p);
+		p += strlen(p) + 1;
+	} while (*p);
 
-	signal(SIGALRM, catchalarm);
+// bb_askpass() already handles this
+//	signal(SIGALRM, catchalarm);
 
 	pwd = getpwuid(0);
 	if (!pwd) {
@@ -105,7 +106,7 @@ int sulogin_main(int argc, char **argv)
 		bb_error_msg("login incorrect");
 	}
 	memset(cp, 0, strlen(cp));
-	signal(SIGALRM, SIG_DFL);
+//	signal(SIGALRM, SIG_DFL);
 
 	bb_info_msg("System Maintenance Mode");
 
@@ -122,6 +123,6 @@ int sulogin_main(int argc, char **argv)
 	/* Exec login shell with no additional parameters. Never returns. */
 	run_shell(shell, 1, NULL, NULL);
 
-auth_error:
-	bb_error_msg_and_die("no password entry for 'root'");
+ auth_error:
+	bb_error_msg_and_die("no password entry for root");
 }