--- /usr/src/libexec/tftpd/tftpd.c.orig	Tue May 31 11:22:53 2005
+++ /usr/src/libexec/tftpd/tftpd.c	Fri May 12 07:28:28 2006
@@ -130,11 +130,13 @@
 	char *chroot_dir = NULL;
 	struct passwd *nobody;
 	const char *chuser = "nobody";
+	char *pp;
+	u_short startport = 0, endport = 0;
 
 	tzset();			/* syslog in localtime */
 
 	openlog("tftpd", LOG_PID | LOG_NDELAY, LOG_FTP);
-	while ((ch = getopt(argc, argv, "cClns:u:U:w")) != -1) {
+	while ((ch = getopt(argc, argv, "cClnp:s:u:U:w")) != -1) {
 		switch (ch) {
 		case 'c':
 			ipchroot = 1;
@@ -148,6 +150,17 @@
 		case 'n':
 			suppress_naks = 1;
 			break;
+		case 'p':
+			pp = strchr(optarg, (int)'-');
+			if (pp == NULL) {
+				startport = atoi(optarg);
+				endport = startport;
+			} else {
+				*pp++ = (char)0;
+				startport = atoi(optarg);
+				endport = atoi(pp);
+			}
+			break;
 		case 's':
 			chroot_dir = optarg;
 			break;
@@ -289,19 +302,7 @@
 	}
 
 	len = sizeof(me);
-	if (getsockname(0, (struct sockaddr *)&me, &len) == 0) {
-		switch (me.ss_family) {
-		case AF_INET:
-			((struct sockaddr_in *)&me)->sin_port = 0;
-			break;
-		case AF_INET6:
-			((struct sockaddr_in6 *)&me)->sin6_port = 0;
-			break;
-		default:
-			/* unsupported */
-			break;
-		}
-	} else {
+	if (getsockname(0, (struct sockaddr *)&me, &len) != 0) {
 		memset(&me, 0, sizeof(me));
 		me.ss_family = from.ss_family;
 		me.ss_len = from.ss_len;
@@ -314,9 +315,27 @@
 		syslog(LOG_ERR, "socket: %m");
 		exit(1);
 	}
-	if (bind(peer, (struct sockaddr *)&me, me.ss_len) < 0) {
-		syslog(LOG_ERR, "bind: %m");
-		exit(1);
+	while (1) {
+		switch (me.ss_family) {
+		case AF_INET:
+			((struct sockaddr_in *)&me)->sin_port = htons(startport);
+			break;
+		case AF_INET6:
+			((struct sockaddr_in6 *)&me)->sin6_port = htons(startport);
+			break;
+		default:
+			/* unsupported */
+			break;
+		}
+		if (bind(peer, (struct sockaddr *)&me, me.ss_len) < 0) {
+			if (errno == EADDRINUSE && startport < endport) {
+				startport++;
+				continue;
+			}
+			syslog(LOG_ERR, "bind: %m");
+			exit(1);
+		}
+		break;
 	}
 	if (connect(peer, (struct sockaddr *)&from, from.ss_len) < 0) {
 		syslog(LOG_ERR, "connect: %m");
--- /usr/src/libexec/tftpd/tftpd.8.orig	Wed Jul  7 13:57:14 2004
+++ /usr/src/libexec/tftpd/tftpd.8	Wed May 10 16:36:10 2006
@@ -147,6 +147,21 @@
 .It Fl n
 Suppress negative acknowledgement of requests for nonexistent
 relative filenames.
+.It Fl p Ar port-range
+Force
+.Nm
+to bind to a local udp port within the specified
+.Pa port-range .
+.Nm
+This is useful when the server is behind a firewall because it
+limits the size of hole that must be opened in the firewall for
+to function.  You can specify either a single port number, or
+a port range (two numbers separated by the '-' dash character).
+If you only use a single port, your tftp server will only be
+able to handle a single tftp session at a time.  If you use
+this option, it is recommended that you choose a large enough
+range to support as many concurrent tftp sessions as you
+ever expect to encounter.
 .It Fl s Ar directory
 Cause
 .Nm