Bugfix: disable REUSEADDR socket option for passive data sockets.

src/sbbs3/ftpsrvr.c

@@ -2338,6 +2338,7 @@ static void ctrl_thread(void* arg)
 	BOOL		local_fsys=FALSE;
 	BOOL		alias_dir;
 	BOOL		append;
+	BOOL		reuseaddr;
 	FILE*		fp;
 	FILE*		alias_fp;
 	SOCKET		sock;
@@ -2876,6 +2877,14 @@ static void ctrl_thread(void* arg)
 				continue;
 			}
 
+			reuseaddr=FALSE;
+			if((result=setsockopt(pasv_sock,SOL_SOCKET,SO_REUSEADDR,(char*)&reuseaddr,sizeof(reuseaddr)))!=0) {
+				lprintf(LOG_WARNING,"%04d !PASV ERROR %d disabling REUSEADDR socket option"
+					,sock,ERROR_VALUE);
+				sockprintf(sock,"425 Error %d disabling REUSEADDR socket option", ERROR_VALUE);
+				continue;
+			}
+
 			if(startup->options&FTP_OPT_DEBUG_DATA)
 				lprintf(LOG_DEBUG,"%04d PASV DATA socket %d opened",sock,pasv_sock);