fix mail.mda so it handles system() exit value correctly

issue reported and diff tested by florian@

1 files changed, 14 insertions, 1 deletions

diff --git a/usr.sbin/smtpd/mail.mda.c b/usr.sbin/smtpd/mail.mda.c
index 64398c84f9c..f9fb32367a6 100644
--- a/usr.sbin/smtpd/mail.mda.c
+++ b/usr.sbin/smtpd/mail.mda.c
@@ -16,6 +16,7 @@
 
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/wait.h>
 
 #include <ctype.h>
 #include <err.h>
@@ -26,12 +27,14 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sysexits.h>
 #include <unistd.h>
 
 int
 main(int argc, char *argv[])
 {
 	int ch;
+	int ret;
 
 	if (! geteuid())
 		errx(1, "mail.mda: may not be executed as root");
@@ -51,5 +54,15 @@ main(int argc, char *argv[])
 	if (argc > 1)
 		errx(1, "mail.mda: only one command is supported");
 
-	return system(argv[0]) == 0 ? 0 : 1;
+	/* could not obtain a shell or could not obtain wait status,
+	 * tempfail */
+	if ((ret = system(argv[0])) == -1)
+		errx(EX_TEMPFAIL, "%s", strerror(errno));
+
+	/* not exited properly but we have no details,
+	 * tempfail */
+	if (! WIFEXITED(ret))
+		exit(EX_TEMPFAIL);
+
+	exit(WEXITSTATUS(ret));
 }