scripts/ci/setup_bridge.sh: Add

The script helps to setup a bridge for qemu to connect to the
local network

Signed-off-by: Filip Gołaś <filip.golas@3mdeb.com>

scripts/ci/setup_bridge.sh

@@ -0,0 +1,68 @@
+#!/usr/bin/env bash
+
+# SPDX-FileCopyrightText: 2025 3mdeb <contact@3mdeb.com>
+#
+# SPDX-License-Identifier: Apache-2.0
+
+INTERFACE=$1
+DEL=$2
+BR_NAME=br0
+
+function print_help {
+    echo ""
+    echo "Usage: $0 <interface> [del]"
+    echo ""
+    echo "The script creates a bridged interface that will be connected"
+    echo "to a network of given <interface>. The given interface is"
+    echo "toggled down."
+    echo ""
+    echo "Use optional [del] option to delete the bridge and restore"
+    echo "the original interface"
+    echo ""
+    echo "Examples:"
+    echo "  Set up bridge interface:"
+    echo "    $0 enp0s1"
+    echo "  Remove bridge and restore original interface:"
+    echo "    $0 enp0s1 del"
+}
+
+if [[ -z $INTERFACE ]]; then
+    print_help
+    exit 1
+fi
+
+ip link show $INTERFACE &> /dev/null
+if [[ $? -ne 0 ]]; then
+    print_help
+    exit 1
+fi
+
+if [[ $DEL == "del" ]]; then
+    ip link show $BR_NAME &> /dev/null
+    if [[ $? -ne 0 ]]; then
+        echo "Bridge interface $BR_NAME does not exist"
+        exit 0
+    fi
+
+    BR_IP=$(ip addr show $BR_NAME | awk '/inet / {print $2}')
+
+    echo "Deleting $BR_NAME IP: $BR_IP on $INTERFACE"
+
+    ip link del $BR_NAME
+    ip link set $INTERFACE up
+else
+    ip link show $BR_NAME &> /dev/null
+    if [[ $? -eq 0 ]]; then
+        echo "Bridge interface $BR_NAME already exists"
+        exit 0
+    fi
+    BR_IP=$(ip addr show $INTERFACE | awk '/inet / {print $2}')
+
+    echo "Setting up interface $BR_NAME IP: $BR_IP on $INTERFACE"
+
+    ip link add name $BR_NAME type bridge
+    ip link set $INTERFACE master $BR_NAME
+    ip addr flush dev $INTERFACE
+    ip link set $BR_NAME up
+    ip addr add $BR_IP dev $BR_NAME
+fi