o Use writev() to send status on the backchannel instead of fdopen()ing

  fd 3 and using stdio.

o Add SIGINT/SIGQUIT signal handler for yp_chpass() now that getpass()
  is interuptible.

o Block SIGINT/SIGQUIT in krb_chpass() until it is made to clean up
  after itself properly.

1 files changed, 35 insertions, 14 deletions

diff --git a/libexec/login_chpass/login_chpass.c b/libexec/login_chpass/login_chpass.c
index 72e8ed93829..76b148444eb 100644
--- a/libexec/login_chpass/login_chpass.c
+++ b/libexec/login_chpass/login_chpass.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: login_chpass.c,v 1.3 2001/12/06 05:37:03 millert Exp $	*/
+/*	$OpenBSD: login_chpass.c,v 1.4 2001/12/07 04:22:41 millert Exp $	*/
 
 /*-
  * Copyright (c) 1995,1996 Berkeley Software Design, Inc. All rights reserved.
@@ -38,6 +38,7 @@
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <sys/file.h>
+#include <sys/uio.h>
 #include <sys/wait.h>
 
 #include <err.h>
@@ -70,10 +71,15 @@
 
 #define	_PATH_LOGIN_LCHPASS	"/usr/libexec/auth/login_lchpass"
 
+#define BACK_CHANNEL	3
+
+struct iovec iov[2] = { { BI_SILENT, sizeof(BI_SILENT) - 1 }, { "\n", 1 } };
+
 #ifdef  YP
 int	_yp_check __P((char **));
 char	*ypgetnewpasswd __P((struct passwd *, char **));
 struct passwd *ypgetpwnam __P((char *));
+void	kbintr __P((int));
 #endif
 
 #ifdef KERBEROS
@@ -166,7 +172,6 @@ void
 yp_chpass(username)
 	char *username;
 {
-	FILE *back;
 	char *master;
 	int r, rpcport, status;
 	struct yppasswd yppasswd;
@@ -175,10 +180,8 @@ yp_chpass(username)
 	CLIENT *client;
 	extern char *domain;
 
-	if (!(back = fdopen(3, "a")))  {
-		syslog(LOG_ERR, "reopening back channel: %m");
-		exit(1);
-	}
+	(void)signal(SIGINT, kbintr);
+	(void)signal(SIGQUIT, kbintr);
 
 	if ((r = yp_get_default_domain(&domain)) != 0) {
 		warnx("can't get local YP domain. Reason: %s", yperr_string(r));
@@ -219,7 +222,7 @@ yp_chpass(username)
 
 	if (*pw->pw_passwd == '\0') {
 		syslog(LOG_ERR, "%s attempting to add password", username);
-		fprintf(back, BI_SILENT "\n");
+		(void)writev(BACK_CHANNEL, iov, 2);
 		exit(0);
 	}
 
@@ -256,9 +259,27 @@ yp_chpass(username)
 	printf("The YP password has been changed on %s, the master YP passwd server.\n",
 	    master);
 	free(yppasswd.newpw.pw_passwd);
-	fprintf(back, BI_SILENT "\n");
+	(void)writev(BACK_CHANNEL, iov, 2);
 	exit(0);
 }
+
+void kbintr(signo)
+	int signo;
+{
+	char msg[] = "YP passwd database unchanged.\n";
+	struct iovec iv[3];
+	extern char *__progname;
+
+	iv[0].iov_base = __progname;
+	iv[0].iov_len = strlen(__progname);
+	iv[1].iov_base = ": ";
+	iv[1].iov_len = 2;
+	iv[2].iov_base = msg;
+	iv[2].iov_len = sizeof(msg) - 1;
+	writev(STDERR_FILENO, iv, 3);
+
+	_exit(1);
+}
 #endif
 
 #ifdef KERBEROS
@@ -268,16 +289,16 @@ krb_chpass(username, instance, argv)
 	char *instance;
 	char *argv[];
 {
-	FILE *back;
 	int rval;
 	char pword[MAX_KPW_LEN];
 	char tktstring[MAXPATHLEN];
 	krb_principal principal;
+	sigset_t set;
 
-	if (!(back = fdopen(3, "a")))  {
-		syslog(LOG_ERR, "reopening back channel: %m");
-		exit(1);
-	}
+	sigemptyset(&set);
+	sigaddset(&set, SIGINT);
+	sigaddset(&set, SIGQUIT);
+	(void)sigprocmask(SIG_BLOCK, &set, NULL);
 
 	memset(&principal, 0, sizeof(principal));
 	krb_get_default_principal(principal.name,
@@ -320,7 +341,7 @@ krb_chpass(username, instance, argv)
 	dest_tkt();
 
 	if (rval == 0)
-		fprintf(back, BI_SILENT "\n");
+		(void)writev(BACK_CHANNEL, iov, 2);
     	exit(rval);
 }
 #endif