Bug 52491

Peter Bieringer, while working to get IPv6 enabled on 'isdn0' like devices,
sent me two patches, which also/mostly contain some generic fixes too.

His comments enclosed.

-    log_isdnctrl pppbind $DEVICE
+    [ "$ENCAP" = "syncppp" ] && log_isdnctrl pppbind $DEVICE

pppbind makes no sense on using isdnX devices

+    # set netmask, if available
+    [ -n "$NETMASK" ] && netmask="netmask $NETMASK"
+
     # activate ISDN device
-    ifconfig $DEVICE $LOCAL_IP pointopoint $REMOTE_IP up >/dev/null 2>&1
+    ifconfig $DEVICE $LOCAL_IP pointopoint $REMOTE_IP $netmask up
>/dev/null 2>&1

[netmask doesn't matter that much on pointopoint links, but one could be
pedantic...]

-    [ -n "$ISDN_HOSTNAME" ] && options="$options hostname
$ISDN_HOSTNAME"
+    [ -n "$ISDN_HOSTNAME" ] && options="$options remotename
$ISDN_HOSTNAME"

option "hostname" isn't recognized by ipppd (ifup won't work)

-        route del default >/dev/null 2>&1
-        if [ -z "$REMOTE_IP" -o "$REMOTE_IP" = "0.0.0.0" ]; then
-            route add default $DEVICE >/dev/null 2>&1
-        else
-            route add default gw $REMOTE_IP >/dev/null 2>&1
-	fi
+       if  [ "$DEFROUTE" = "yes" ]; then
+               route del default >/dev/null 2>&1
+               if [ -z "$REMOTE_IP" -o "$REMOTE_IP" = "0.0.0.0" ]; then
+                   route add default $DEVICE >/dev/null 2>&1
+               else
+                   route add default gw $REMOTE_IP >/dev/null 2>&1
+               fi
+       fi

defaultroute is set on dialmode auto regardless the setting of
DEFROUTE. This breaks automatic P-t-P links to stub subnets.

[NOTE! Hopefully the isdn-config programs generate DEFROUTE=yes, else this
change would break for those enabling default route..]

And IPv6 additions:

+# Get global network configuration
+. /etc/sysconfig/network
+

[ probably should get the config from other locations too (the new
scheme).. ]

+    ## Setup IPv6
+    if [ "${NETWORKING_IPV6}" = "yes" ]; then
+	/etc/sysconfig/network-scripts/ifup-ipv6 $DEVICE
     fi

[ actually, this probably should be ${CONFIG} .. in this case it shouldn't
matter, but
with general ifup structure it might if you store the 
configs under /etc/sysconfig/networking/ with a different name ]

And similar for ifdown-ippp:

+# Shut down IPv6
+if [ "${NETWORKING_IPV6}" = "yes" ]; then
+    /etc/sysconfig/network-scripts/ifdown-ipv6 $DEVICE
 fi

[ $DEVICE => ${CONFIG} ]

( ipppd has a bug wrt. ipv6 but that's beside the point now :-)

Attaching his diffs.