Add a new option to ftpd(8), "-h", to disable printing any

host-specific information in FTP server messages (so paranoid
admins can sleep at night :-)

PR:		bin/16705
MFC after:	1 week

3 files changed, 25 insertions, 6 deletions

diff --git a/libexec/ftpd/ftpcmd.y b/libexec/ftpd/ftpcmd.y
index 261ffd0..b74c1fd 100644
--- a/libexec/ftpd/ftpcmd.y
+++ b/libexec/ftpd/ftpcmd.y
@@ -75,6 +75,7 @@ static const char rcsid[] =
 #include "pathnames.h"
 
 extern	union sockunion data_dest, his_addr;
+extern	int hostinfo;
 extern	int logged_in;
 extern	struct passwd *pw;
 extern	int guest;
@@ -1554,7 +1555,10 @@ help(struct tab *ctab, char *s)
 			printf("\r\n");
 		}
 		(void) fflush(stdout);
-		reply(214, "Direct comments to ftp-bugs@%s.", hostname);
+		if (hostinfo)
+			reply(214, "Direct comments to ftp-bugs@%s.", hostname);
+		else
+			reply(214, "End.");
 		return;
 	}
 	upper(s);
diff --git a/libexec/ftpd/ftpd.8 b/libexec/ftpd/ftpd.8
index 491c177..5bf7c00 100644
--- a/libexec/ftpd/ftpd.8
+++ b/libexec/ftpd/ftpd.8
@@ -40,7 +40,7 @@
 .Nd Internet File Transfer Protocol server
 .Sh SYNOPSIS
 .Nm
-.Op Fl 46ADdEMmOoRrSUvW
+.Op Fl 46ADdEhMmOoRrSUvW
 .Op Fl l Op Fl l
 .Op Fl a Ar address
 .Op Fl P Ar port
@@ -108,6 +108,9 @@ Debugging information is written to the syslog using
 .It Fl E
 Disable the EPSV command.
 This is useful for servers behind older firewalls.
+.It Fl h
+Disable printing host-specific information, such as the
+server software version or hostname, in server messages.
 .It Fl l
 Each successful and failed
 .Xr ftp 1
diff --git a/libexec/ftpd/ftpd.c b/libexec/ftpd/ftpd.c
index 3d60f42..bc96d2d 100644
--- a/libexec/ftpd/ftpd.c
+++ b/libexec/ftpd/ftpd.c
@@ -116,6 +116,7 @@ union sockunion pasv_addr;
 int	daemon_mode;
 int	data;
 int	dataport;
+int	hostinfo = 1;	/* print host-specific info in messages */
 int	logged_in;
 struct	passwd *pw;
 char	*homedir;
@@ -299,7 +300,8 @@ main(int argc, char *argv[], char **envp)
 #endif /* OLD_SETPROCTITLE */
 
 
-	while ((ch = getopt(argc, argv, "46a:AdDElmMoOp:P:rRSt:T:u:UvW")) != -1) {
+	while ((ch = getopt(argc, argv,
+	                    "46a:AdDEhlmMoOp:P:rRSt:T:u:UvW")) != -1) {
 		switch (ch) {
 		case '4':
 			enable_v4 = 1;
@@ -331,6 +333,10 @@ main(int argc, char *argv[], char **envp)
 			noepsv = 1;
 			break;
 
+		case 'h':
+			hostinfo = 0;
+			break;
+
 		case 'l':
 			logging++;	/* > 1 == extra logging */
 			break;
@@ -638,7 +644,10 @@ main(int argc, char *argv[], char **envp)
 	(void) gethostname(hostname, MAXHOSTNAMELEN - 1);
 	hostname[MAXHOSTNAMELEN - 1] = '\0';
 #endif
-	reply(220, "%s FTP server (%s) ready.", hostname, version);
+	if (hostinfo)
+		reply(220, "%s FTP server (%s) ready.", hostname, version);
+	else
+		reply(220, "FTP server ready.");
 	for (;;)
 		(void) yyparse();
 	/* NOTREACHED */
@@ -2228,8 +2237,11 @@ statcmd(void)
 	char hname[NI_MAXHOST];
 	int ispassive;
 
-	lreply(211, "%s FTP server status:", hostname);
-	printf("     %s\r\n", version);
+	if (hostinfo) {
+		lreply(211, "%s FTP server status:", hostname);
+		printf("     %s\r\n", version);
+	} else
+		lreply(211, "FTP server status:");
 	printf("     Connected to %s", remotehost);
 	if (!getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
 			 hname, sizeof(hname) - 1, NULL, 0, NI_NUMERICHOST)) {