From: Jonatan Schlag <jonatan.schlag@ipfire.org>
Date: Wed, 7 Jun 2017 06:24:34 +0000 (+0200)
Subject: util: add function mtu_is_valid
X-Git-Tag: 009~216
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=48a64768662a855fdc509127a7edb6c1a9e88def;p=network.git

util: add function mtu_is_valid

This function checks if an mtu is valid for a given IP protocol.

Signed-off-by: Jonatan Schlag <jonatan.schlag@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/functions/functions.util b/src/functions/functions.util
index 4b6f9566..b7e35c91 100644
--- a/src/functions/functions.util
+++ b/src/functions/functions.util
@@ -321,6 +321,24 @@ isipaddress() {
 	ip_is_valid ${addr}
 }
 
+mtu_is_valid() {
+	local proto=${1}
+	local mtu=${2}
+
+	case ${proto} in
+		ipv4)
+			[ ${mtu} -ge 576 ] && [ ${mtu} -le 9000 ]
+			;;
+		ipv6)
+			[ ${mtu} -ge 1280 ] && [ ${mtu} -le 9000 ]
+			;;
+		*)
+			error "${proto} is not a valid proto"
+			return ${EXIT_ERROR}
+			;;
+	esac
+}
+
 backtrace() {
 	local start=1