95fcoe: Add the rd.nofcoe option to disable the FCoE module from the command line

Images built with the fcoe module will always run the lldpad
service as part of their pre-trigger scripts if the network
is active. This prevents network installations in
environments where, for security reasons, LLDPDU frames
cause a switchport shutdown.

Add a new rd.nofcoe option to cause dracut to skip the
lldpad.sh script and the entire 95-fcoe module.

Signed-off-by: Patrick Talbert <ptalbert@redhat.com>

dracut.cmdline.7.asc

@@ -765,6 +765,9 @@ iscsistart -b --param node.session.timeo.replacement_timeout=30
 
 FCoE
 ~~~~
+**rd.nofcoe=0**::
+    disable FCoE and lldpad
+
 **fcoe=**__<edd|interface|MAC>__:__{dcb|nodcb}__:__{fabric|vn2vn}__::
     Try to connect to a FCoE SAN through the NIC specified by _<interface>_ or
     _<MAC>_ or EDD settings. The second argument specifies if DCB

modules.d/95fcoe/lldpad.sh

@@ -1,5 +1,10 @@
 #!/bin/bash
 
+if ! getargbool 0 rd.nofcoe ; then
+	info "rd.nofcoe=0: skipping lldpad activation"
+	exit 0
+fi
+
 # Note lldpad will stay running after switchroot, the system initscripts
 # are to kill it and start a new lldpad to take over. Data is transfered
 # between the 2 using a shm segment

modules.d/95fcoe/parse-fcoe.sh

@@ -13,6 +13,11 @@
 # fcoe=eth0:nodcb:vn2vn
 # fcoe=4a:3f:4c:04:f8:d7:nodcb:fabric
 
+if ! getargbool 0 rd.nofcoe ; then
+	info "rd.nofcoe=0: skipping fcoe"
+	exit 0
+fi
+
 [ -z "$fcoe" ] && fcoe=$(getarg fcoe=)
 
 # If it's not set we don't continue