From 827665279a8736a456e10ad820d995c5065d1d39 Mon Sep 17 00:00:00 2001
From: David Tomaschik <david@systemoverlord.com>
Date: Sun, 2 Aug 2020 21:55:19 -0700
Subject: [PATCH] Add qdisc_span script.

---
 bin/qdisc_span.sh | 48 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100755 bin/qdisc_span.sh

diff --git a/bin/qdisc_span.sh b/bin/qdisc_span.sh
new file mode 100755
index 0000000..8b29290
--- /dev/null
+++ b/bin/qdisc_span.sh
@@ -0,0 +1,48 @@
+#!/bin/bash
+
+set -ue
+
+ACTION="add"
+
+if [ "${1}" == "-d" ] ; then
+  ACTION="del"
+  shift
+fi
+
+BRIDGE="${1}"
+DEST="${2}"
+
+function setup_span {
+  if tc qdisc show dev "${1}" | grep -q 'qdisc ingress ffff' ; then
+    return 0
+  fi
+  tc qdisc add dev "${1}" ingress
+  tc filter add dev "${1}" parent ffff: protocol all u32 match u8 0 0 action mirred egress mirror dev "${DEST}"
+}
+
+function del_span {
+  tc qdisc del dev "${1}" ingress
+}
+
+function handle_iface {
+  case "${ACTION}" in
+    add)
+      setup_span "${1}"
+      ;;
+    del)
+      del_span "${1}"
+      ;;
+    *)
+      echo "Unknown action!"
+      exit 1
+      ;;
+  esac
+}
+
+function get_bridge_ifaces {
+  bridge link | grep "master ${1}" | cut -d: -f2 | cut -d@ -f1
+}
+
+for iface in $(get_bridge_ifaces "${BRIDGE}") ; do
+  handle_iface "$iface"
+done