From 3e31a807af42c07beebc539a3efa7476ba1ef096 Mon Sep 17 00:00:00 2001
From: Ari Johnson <ari@theari.com>
Date: Thu, 24 Sep 2015 17:19:59 -0400
Subject: [PATCH] TELNET_KEEPALIVE feature

---
 options.h.dist |  6 ++++++
 src/bsd.c      | 13 +++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/options.h.dist b/options.h.dist
index 4e01b87..f2908c8 100644
--- a/options.h.dist
+++ b/options.h.dist
@@ -153,6 +153,12 @@
 /* These are options specific to CobraMUSH.
  */
 
+/* Automatic keepalive for telnet-enabled connections */
+#define TELNET_KEEPALIVE /* */
+
+/* Keepalive timer interval (in seconds) */
+#define KEEPALIVE_INTERVAL 300
+
 /* Colored WHO */
 #define COLOREDWHO /* */
 
diff --git a/src/bsd.c b/src/bsd.c
index e260e99..39c81c1 100644
--- a/src/bsd.c
+++ b/src/bsd.c
@@ -4771,6 +4771,19 @@ inactivity_check(void)
        back, the client probably doesn't understand them */
     if ((d->conn_flags & CONN_TELNET_QUERY) && idle_for > 60)
       d->conn_flags &= ~CONN_TELNET_QUERY;
+
+#ifndef COMPILE_CONSOLE
+#ifdef TELNET_KEEPALIVE
+    if (idle_for && !(idle_for % KEEPALIVE_INTERVAL) &&
+        (d->conn_flags & CONN_TELNET)) {
+      tbuf[0] = IAC;
+      tbuf[1] = NOP;
+      tbuf[2] = '\0';
+      queue_newwrite(d, (unsigned char *) tbuf, 2);
+    }
+#endif /* TELNET_KEEPALIVE */
+#endif /* !COMPILE_CONSOLE */
+
     if(d->connected && GoodObject(d->player) && ((a = atr_get(d->player, "IDLE_TIMEOUT"))!=NULL)) {
 	    memset(tbuf, '\0', BUFFER_LEN);
 	    strncpy(tbuf, atr_value(a), BUFFER_LEN-1);
-- 
2.30.2