Add handle to control global TCP keepalives and turn them on as

default.

Despite their name it doesn't keep TCP sessions alive, it kills
them if the other end has gone AWOL.  This happens a lot with
clients which use NAT, dynamic IP assignment or which has a 2^32
* 10^-3 seconds upper bound on their uptime.

There is no detectable increase in network trafic because of this:
two minimal TCP packets every two hours for a live TCP connection.

Many servers already enable keepalives themselves.

The host requirements RFC is 10 years old, and doesn't know about
the loosing clients of todays InterNet.

5 files changed, 30 insertions, 5 deletions

diff --git a/etc/rc.d/netoptions b/etc/rc.d/netoptions
index a10e8fd..ef6bc08 100644
--- a/etc/rc.d/netoptions
+++ b/etc/rc.d/netoptions
@@ -1,6 +1,6 @@
 #!/bin/sh -
 #
-#	$Id: rc.network,v 1.43 1999/04/10 10:56:58 des Exp $
+#	$Id: rc.network,v 1.44 1999/04/12 15:26:41 brian Exp $
 #	From: @(#)netstart	5.9 (Berkeley) 3/30/91
 
 # Note that almost all the user-configurable behavior is no longer in
@@ -180,6 +180,11 @@ network_pass1() {
 	    sysctl -w net.inet.ip.accept_sourceroute=1 >/dev/null 2>&1
     fi
 
+    if [ "X$tcp_keepalive" = X"YES" ]; then
+	    echo -n ' TCP keepalive=YES'
+	    sysctl -w net.inet.tcp.always_keepalive=1 >/dev/null 2>&1
+    fi
+
     if [ "X$ipxgateway_enable" = X"YES" ]; then
 	    echo -n ' IPX gateway=YES'
 	    sysctl -w net.ipx.ipx.ipxforwarding=1 >/dev/null 2>&1
diff --git a/etc/rc.d/network1 b/etc/rc.d/network1
index a10e8fd..ef6bc08 100644
--- a/etc/rc.d/network1
+++ b/etc/rc.d/network1
@@ -1,6 +1,6 @@
 #!/bin/sh -
 #
-#	$Id: rc.network,v 1.43 1999/04/10 10:56:58 des Exp $
+#	$Id: rc.network,v 1.44 1999/04/12 15:26:41 brian Exp $
 #	From: @(#)netstart	5.9 (Berkeley) 3/30/91
 
 # Note that almost all the user-configurable behavior is no longer in
@@ -180,6 +180,11 @@ network_pass1() {
 	    sysctl -w net.inet.ip.accept_sourceroute=1 >/dev/null 2>&1
     fi
 
+    if [ "X$tcp_keepalive" = X"YES" ]; then
+	    echo -n ' TCP keepalive=YES'
+	    sysctl -w net.inet.tcp.always_keepalive=1 >/dev/null 2>&1
+    fi
+
     if [ "X$ipxgateway_enable" = X"YES" ]; then
 	    echo -n ' IPX gateway=YES'
 	    sysctl -w net.ipx.ipx.ipxforwarding=1 >/dev/null 2>&1
diff --git a/etc/rc.d/network2 b/etc/rc.d/network2
index a10e8fd..ef6bc08 100644
--- a/etc/rc.d/network2
+++ b/etc/rc.d/network2
@@ -1,6 +1,6 @@
 #!/bin/sh -
 #
-#	$Id: rc.network,v 1.43 1999/04/10 10:56:58 des Exp $
+#	$Id: rc.network,v 1.44 1999/04/12 15:26:41 brian Exp $
 #	From: @(#)netstart	5.9 (Berkeley) 3/30/91
 
 # Note that almost all the user-configurable behavior is no longer in
@@ -180,6 +180,11 @@ network_pass1() {
 	    sysctl -w net.inet.ip.accept_sourceroute=1 >/dev/null 2>&1
     fi
 
+    if [ "X$tcp_keepalive" = X"YES" ]; then
+	    echo -n ' TCP keepalive=YES'
+	    sysctl -w net.inet.tcp.always_keepalive=1 >/dev/null 2>&1
+    fi
+
     if [ "X$ipxgateway_enable" = X"YES" ]; then
 	    echo -n ' IPX gateway=YES'
 	    sysctl -w net.ipx.ipx.ipxforwarding=1 >/dev/null 2>&1
diff --git a/etc/rc.d/network3 b/etc/rc.d/network3
index a10e8fd..ef6bc08 100644
--- a/etc/rc.d/network3
+++ b/etc/rc.d/network3
@@ -1,6 +1,6 @@
 #!/bin/sh -
 #
-#	$Id: rc.network,v 1.43 1999/04/10 10:56:58 des Exp $
+#	$Id: rc.network,v 1.44 1999/04/12 15:26:41 brian Exp $
 #	From: @(#)netstart	5.9 (Berkeley) 3/30/91
 
 # Note that almost all the user-configurable behavior is no longer in
@@ -180,6 +180,11 @@ network_pass1() {
 	    sysctl -w net.inet.ip.accept_sourceroute=1 >/dev/null 2>&1
     fi
 
+    if [ "X$tcp_keepalive" = X"YES" ]; then
+	    echo -n ' TCP keepalive=YES'
+	    sysctl -w net.inet.tcp.always_keepalive=1 >/dev/null 2>&1
+    fi
+
     if [ "X$ipxgateway_enable" = X"YES" ]; then
 	    echo -n ' IPX gateway=YES'
 	    sysctl -w net.ipx.ipx.ipxforwarding=1 >/dev/null 2>&1
diff --git a/etc/rc.d/routing b/etc/rc.d/routing
index a10e8fd..ef6bc08 100644
--- a/etc/rc.d/routing
+++ b/etc/rc.d/routing
@@ -1,6 +1,6 @@
 #!/bin/sh -
 #
-#	$Id: rc.network,v 1.43 1999/04/10 10:56:58 des Exp $
+#	$Id: rc.network,v 1.44 1999/04/12 15:26:41 brian Exp $
 #	From: @(#)netstart	5.9 (Berkeley) 3/30/91
 
 # Note that almost all the user-configurable behavior is no longer in
@@ -180,6 +180,11 @@ network_pass1() {
 	    sysctl -w net.inet.ip.accept_sourceroute=1 >/dev/null 2>&1
     fi
 
+    if [ "X$tcp_keepalive" = X"YES" ]; then
+	    echo -n ' TCP keepalive=YES'
+	    sysctl -w net.inet.tcp.always_keepalive=1 >/dev/null 2>&1
+    fi
+
     if [ "X$ipxgateway_enable" = X"YES" ]; then
 	    echo -n ' IPX gateway=YES'
 	    sysctl -w net.ipx.ipx.ipxforwarding=1 >/dev/null 2>&1