src: allow to use variables in flowtable and chain devices

This patch adds support for using variables for devices in the chain and
flowtable definitions, eg.

 define if_main = lo

 table netdev filter1 {
    chain Main_Ingress1 {
        type filter hook ingress device $if_main priority -500; policy accept;
    }
 }

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

2 files changed, 43 insertions, 0 deletions

diff --git a/tests/shell/testcases/flowtable/0012flowtable_variable_0 b/tests/shell/testcases/flowtable/0012flowtable_variable_0
new file mode 100755
index 00000000..8e334224
--- /dev/null
+++ b/tests/shell/testcases/flowtable/0012flowtable_variable_0
@@ -0,0 +1,29 @@
+#!/bin/bash
+
+set -e
+
+ip link add name dummy1 type dummy
+
+EXPECTED="define if_main = { lo, dummy1 }
+
+table filter1 {
+	flowtable Main_ft1 {
+		hook ingress priority filter
+		counter
+		devices = \$if_main
+	}
+}"
+
+$NFT -f - <<< $EXPECTED
+
+EXPECTED="define if_main = \"lo\"
+
+table filter2 {
+	flowtable Main_ft2 {
+		hook ingress priority filter
+		counter
+		devices = { \$if_main, dummy1 }
+	}
+}"
+
+$NFT -f - <<< $EXPECTED
diff --git a/tests/shell/testcases/flowtable/dumps/0012flowtable_variable_0.nft b/tests/shell/testcases/flowtable/dumps/0012flowtable_variable_0.nft
new file mode 100644
index 00000000..1cbb2f11
--- /dev/null
+++ b/tests/shell/testcases/flowtable/dumps/0012flowtable_variable_0.nft
@@ -0,0 +1,14 @@
+table ip filter1 {
+	flowtable Main_ft1 {
+		hook ingress priority filter
+		devices = { dummy1, lo }
+		counter
+	}
+}
+table ip filter2 {
+	flowtable Main_ft2 {
+		hook ingress priority filter
+		devices = { dummy1, lo }
+		counter
+	}
+}