Add fake SNMP reset tool

The flush test sends an SNMP request to PDU to reset the
power on the hardware PC. As the flush test sends only one
type of request we don't need to parse it and can just wait
for any UDP packet and perform a hard reset of the VM.

Signed-off-by: Kostiantyn Kostiuk <[email protected]>

bin/fake-snmp-reset

@@ -0,0 +1,71 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+# Intended to be usable as a standalone script
+# it is not a part of the AutoHCK module
+
+require 'json'
+require 'logger'
+require 'socket'
+
+class SnmpReset
+  def initialize(logger, socket_file)
+    @logger = logger
+
+    @socket_file = socket_file
+
+    @qmp_connected = false
+  end
+
+  def connect_socket
+    @logger.info "Initializing QMP session for #{@socket_file}"
+    @qmp_socket = UNIXSocket.new(@socket_file)
+  end
+
+  def run
+    @logger.info 'Initializing UDP socket'
+    UDPSocket.open do |socket|
+      socket.bind('0.0.0.0', 'snmp')
+      @logger.info "Listening on #{socket.local_address.inspect_sockaddr}"
+
+      count = 0
+
+      loop do
+        _, addr = socket.recvfrom(512)
+
+        @logger.info "Received data from #{addr[3]}:#{addr[1]}"
+
+        unless @qmp_connected
+          connect_socket
+          send_cmd 'qmp_capabilities'
+          @qmp_connected = true
+        end
+
+        count += 1
+        send_cmd 'system_reset'
+        @logger.info "Rebooting... #{count}"
+      end
+    end
+  end
+
+  private
+
+  def send_cmd(cmd)
+    @logger.info "Sending #{cmd} via QMP"
+    @qmp_socket.write JSON.dump({ 'execute' => cmd })
+    @qmp_socket.flush
+
+    loop do
+      response = JSON.parse(@qmp_socket.readline)
+      break response['return'] if response.key?('return')
+      raise response['error'].to_s if response.key?('error')
+    end
+  end
+end
+
+log = Logger.new('fake-snmp-reset.txt')
+log.level = Logger::DEBUG
+log.info "START #{ARGV}"
+
+snmp = SnmpReset.new(log, ARGV[0])
+snmp.run