Add find_interface_by_mac()

git-svn-id: https://shorewall.svn.sourceforge.net/svnroot/shorewall/trunk@2516 fbd18981-670d-0410-9b5c-8dc0c1a9a2bb

Shorewall/changelog.txt

@@ -7,6 +7,8 @@ Changes in 2.5.3
 
 3) Set COMMAND=restore in restore-base.
 
+4) Implement find_interface_by_mac()
+
 Changes in 2.5.2
 
 1) Allow port lists in /etc/sorewall/accounting.

Shorewall/functions

@@ -798,6 +798,27 @@ find_interface_by_address() {
     [ -n "$dev" ] && echo $dev
 }
 
+#
+# Find the interface with the passed MAC address
+#
+
+find_interface_by_mac() {
+    local mac=$1 first second rest dev
+
+    ip link ls | while read first second rest; do
+	case $first in
+	    *:)
+                dev=$second
+		;;
+	    *)
+	        if [ "$second" = $mac ]; then
+		    echo ${dev%:}
+		    return
+		fi
+	esac
+    done
+}
+
 #
 # Find interface addresses--returns the set of addresses assigned to the passed
 # device

Shorewall/releasenotes.txt

@@ -16,6 +16,23 @@ New Features in Shorewall 2.5.3
     scripts. The value of this variable is sometimes of interest to
     programmers providing custom /etc/shorewall/tcstart scripts.
 
+4)  If you have problems with ethernet interfaces switching names when
+    your system is rebooted, you can now work around the problem. For
+    each interface, select a shell variable name and set the variable
+    to the value echoed by the 'find_interface_by_mac' function.
+
+    Example: To set EXT_IF to the interface with MAC address
+    00:02:e3:08:55:fa, in /etc/shorewall/params:
+
+	EXT_IF=$(find_interface_by_mac 00:02:e3:08:55:fa)
+
+    Now simple use $EXT_IF any time that you wish to refer to that
+    interface.
+
+    WARNING: If you have this problem, you will not wish to use the
+    "-f" option in the Shorewall SysV init script (usually named
+    /etc/init.d/shorewall).
+
 Problems Corrected in 2.5.2:
 
 1) You may now include port lists in in the /etc/shorewall/accounting