T959: XML/Python rewrite of "protocol igmp-proxy" and op-mode commands

Examples:
=========

CFG commands:

  vyos@vyos# set protocols igmp-proxy disable-quickleave
  vyos@vyos# set protocols igmp-proxy interface eth0 alt-subnet '172.16.35.0/24'
  vyos@vyos# set protocols igmp-proxy interface eth0 alt-subnet '172.31.0.0/24'
  vyos@vyos# set protocols igmp-proxy interface eth0 role 'upstream'
  vyos@vyos# set protocols igmp-proxy interface eth1 role 'downstream'

  vyos@vyos# show protocols
   igmp-proxy {
       disable-quickleave
       interface eth0 {
           alt-subnet 172.16.35.0/24
           alt-subnet 172.31.0.0/24
           role upstream
       }
       interface eth1 {
           role downstream
       }
   }

OP mode commands:
-----------------

  vyos@vyos:~$ show ip multicast interface
   Interface  BytesIn      PktsIn       BytesOut     PktsOut      Local
   eth0       0.0b         0            0.0b         0            xxx.xxx.xxx.65
   eth1       0.0b         0            0.0b         0            xxx.xxx.xx.201

  vyos@vyos:~$ show ip multicast mfc
  Group           Origin          Pkts         Bytes        Wrong   In      Out
  xxx.x.xx.1      xxx.xx.0.1      10           9.81KB       0       eth0    eth1
  xxx.x.xx.2      xxx.xx.0.1                                        --

8 files changed, 722 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index b7cf53896..a9926137c 100644
--- a/Makefile
+++ b/Makefile
@@ -28,6 +28,7 @@ op_mode_definitions:
 	rm -f $(OP_TMPL_DIR)/set/node.def
 	rm -f $(OP_TMPL_DIR)/show/node.def
 	rm -f $(OP_TMPL_DIR)/show/interfaces/node.def
+	rm -f $(OP_TMPL_DIR)/show/ip/node.def
 	rm -f $(OP_TMPL_DIR)/reset/node.def
 	rm -f $(OP_TMPL_DIR)/restart/node.def
 	rm -f $(OP_TMPL_DIR)/monitor/node.def
diff --git a/debian/control b/debian/control
index 05b4f5320..a68598fd5 100644
--- a/debian/control
+++ b/debian/control
@@ -46,6 +46,7 @@ Depends: python3,
   keepalived (>=2.0.5),
   wireguard,
   tftpd-hpa,
+  igmpproxy,
   ${shlibs:Depends},
   ${misc:Depends}
 Description: VyOS configuration scripts and data
diff --git a/debian/rules b/debian/rules
index 15dfec551..663aff4d9 100755
--- a/debian/rules
+++ b/debian/rules
@@ -64,3 +64,7 @@ override_dh_auto_install:
 	# Install data files
 	mkdir -p $(DIR)/$(VYOS_DATA_DIR)
 	cp -r data/* $(DIR)/$(VYOS_DATA_DIR)
+
+	# Install etc configuration files
+	mkdir -p $(DIR)/etc
+	cp -r src/etc/* $(DIR)/etc
diff --git a/interface-definitions/igmp-proxy.xml b/interface-definitions/igmp-proxy.xml
new file mode 100644
index 000000000..ab56019b4
--- /dev/null
+++ b/interface-definitions/igmp-proxy.xml
@@ -0,0 +1,100 @@
+<?xml version="1.0"?>
+<!-- IGMP Proxy  configuration -->
+<interfaceDefinition>
+  <node name="protocols">
+    <children>
+      <node name="igmp-proxy" owner="${vyos_conf_scripts_dir}/igmp_proxy.py">
+        <properties>
+          <help>Internet Group Management Protocol (IGMP) proxy parameters</help>
+          <priority>740</priority>
+        </properties>
+        <children>
+          <leafNode name="disable">
+            <properties>
+              <help>Option to disable IGMP proxy</help>
+              <valueless/>
+            </properties>
+          </leafNode>
+          <leafNode name="disable-quickleave">
+            <properties>
+              <help>Option to disable "quickleave"</help>
+              <valueless/>
+            </properties>
+          </leafNode>
+          <tagNode name="interface">
+            <properties>
+              <help>Interface for IGMP proxy [REQUIRED]</help>
+              <completionHelp>
+                <script>${vyos_completion_dir}/list_interfaces.py</script>
+              </completionHelp>
+            </properties>
+            <children>
+              <leafNode name="alt-subnet">
+                <properties>
+                  <help>Allowed unicast sources for multicast traffic to be proxy'ed</help>
+                  <valueHelp>
+                    <format>ipv4net</format>
+                    <description>IPv4 network</description>
+                  </valueHelp>
+                  <constraint>
+                    <validator name="ipv4-prefix"/>
+                  </constraint>
+                  <multi/>
+                </properties>
+              </leafNode>
+              <leafNode name="role">
+                <properties>
+                  <help>Role of this IGMP interface</help>
+                  <completionHelp>
+                    <list>upstream downstream disabled</list>
+                  </completionHelp>
+                  <valueHelp>
+                    <format>upstream</format>
+                    <description>Upstream interface (only 1 allowed)</description>
+                  </valueHelp>
+                  <valueHelp>
+                    <format>downstream</format>
+                    <description>Downstream interface(s) (default)</description>
+                  </valueHelp>
+                  <valueHelp>
+                    <format>disabled</format>
+                    <description>Disabled interface</description>
+                  </valueHelp>
+                  <constraint>
+                    <regex>(upstream|downstream|disabled)</regex>
+                  </constraint>
+                </properties>
+              </leafNode>
+              <leafNode name="threshold">
+                <properties>
+                  <help>TTL threshold</help>
+                  <valueHelp>
+                    <format>1-255</format>
+                    <description>TTL threshold for the interfaces (default: 1)</description>
+                  </valueHelp>
+                  <constraint>
+                    <validator name="numeric" argument="--range 1-255"/>
+                  </constraint>
+                  <constraintErrorMessage>threshold must be between 1 and 255</constraintErrorMessage>
+                </properties>
+              </leafNode>
+              <leafNode name="whitelist">
+                <properties>
+                  <help>Group to whitelist</help>
+                  <valueHelp>
+                    <format>ipv4net</format>
+                    <description>IPv4 network</description>
+                  </valueHelp>
+                  <constraint>
+                    <validator name="ipv4-prefix"/>
+                  </constraint>
+                  <multi/>
+                </properties>
+              </leafNode>
+            </children>
+          </tagNode>
+        </children>
+      </node>
+    </children>
+  </node>
+</interfaceDefinition>
diff --git a/op-mode-definitions/show-ip-multicast.xml b/op-mode-definitions/show-ip-multicast.xml
new file mode 100644
index 000000000..07102bfa6
--- /dev/null
+++ b/op-mode-definitions/show-ip-multicast.xml
@@ -0,0 +1,30 @@
+<?xml version="1.0"?>
+<interfaceDefinition>
+  <node name="show">
+    <children>
+      <node name="ip">
+        <children>
+          <node name="multicast">
+            <properties>
+              <help>Show IP multicast</help>
+            </properties>
+            <children>
+              <leafNode name="interface">
+                <properties>
+                  <help>Show multicast interfaces</help>
+                </properties>
+                <command>if ps -C igmpproxy &amp;&gt;/dev/null; then ${vyos_op_scripts_dir}/show-igmpproxy.py --interface; else echo IGMP proxy not configured; fi</command>
+              </leafNode>
+              <leafNode name="mfc">
+                <properties>
+                  <help>Show multicast fowarding cache</help>
+                </properties>
+                <command>if ps -C igmpproxy &amp;&gt;/dev/null; then ${vyos_op_scripts_dir}/show-igmpproxy.py --mfc; else echo IGMP proxy not configured; fi</command>
+              </leafNode>
+            </children>
+          </node>
+        </children>
+      </node>
+    </children>
+  </node>
+</interfaceDefinition>
diff --git a/src/conf_mode/igmp_proxy.py b/src/conf_mode/igmp_proxy.py
new file mode 100755
index 000000000..b994369af
--- /dev/null
+++ b/src/conf_mode/igmp_proxy.py
@@ -0,0 +1,179 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2018 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+#
+
+import sys
+import os
+import jinja2
+
+from vyos.config import Config
+from vyos import ConfigError
+
+config_file = r'/etc/igmpproxy.conf'
+
+# Please be careful if you edit the template.
+config_tmpl = """
+########################################################
+#
+# autogenerated by igmp_proxy.py
+#
+#   The configuration file must define one upstream
+#   interface, and one or more downstream interfaces.
+#
+#   If multicast traffic originates outside the
+#   upstream subnet, the "altnet" option can be
+#   used in order to define legal multicast sources.
+#   (Se example...)
+#
+#   The "quickleave" should be used to avoid saturation
+#   of the upstream link. The option should only
+#   be used if it's absolutely nessecary to
+#   accurately imitate just one Client.
+#
+########################################################
+
+{% if not disable_quickleave -%}
+quickleave
+{% endif -%}
+
+{% for i in interface %}
+# Configuration for {{ i.interface }} ({{ i.role }} interface)
+{% if i.role == 'disabled' -%}
+phyint {{ i.interface }} disabled
+{%- else -%}
+phyint {{ i.interface }} {{ i.role }} ratelimit 0 threshold {{ i.threshold }}
+{%- endif -%}
+{%- for subnet in i.alt_subnet %}
+        altnet {{ subnet }}
+{%- endfor %}
+{%- for subnet in i.whitelist %}
+        whitelist {{ subnet }}
+{%- endfor %}
+{% endfor %}
+"""
+
+default_config_data = {
+    'disable': False,
+    'disable_quickleave': False,
+    'interface': [],
+}
+
+def get_config():
+    igmp_proxy = default_config_data
+    conf = Config()
+    if not conf.exists('protocols igmp-proxy'):
+        return None
+    else:
+        conf.set_level('protocols igmp-proxy')
+
+    # Network interfaces to listen on
+    if conf.exists('disable'):
+        igmp_proxy['disable'] = True
+
+    # Option to disable "quickleave"
+    if conf.exists('disable-quickleave'):
+        igmp_proxy['disable_quickleave'] = True
+
+    for intf in conf.list_nodes('interface'):
+        conf.set_level('protocols igmp-proxy interface {0}'.format(intf))
+        interface = {
+            'interface': intf,
+            'alt_subnet': [],
+            'role': 'downstream',
+            'threshold': '1',
+            'whitelist': []
+        }
+
+        if conf.exists('alt-subnet'):
+            interface['alt_subnet'] = conf.return_values('alt-subnet')
+
+        if conf.exists('role'):
+            interface['role'] = conf.return_value('role')
+
+        if conf.exists('threshold'):
+            interface['threshold'] = conf.return_value('threshold')
+
+        if conf.exists('whitelist'):
+            interface['whitelist'] = conf.return_values('whitelist')
+
+        # Append interface configuration to global configuration list
+        igmp_proxy['interface'].append(interface)
+
+    return igmp_proxy
+
+def verify(igmp_proxy):
+    # bail out early - looks like removal from running config
+    if igmp_proxy is None:
+        return None
+
+    # bail out early - service is disabled
+    if igmp_proxy['disable']:
+        return None
+
+    # at least two interfaces are required, one upstream and one downstream
+    if len(igmp_proxy['interface']) < 2:
+        raise ConfigError('Must define an upstream and at least 1 downstream interface!')
+
+    upstream = 0
+    for i in igmp_proxy['interface']:
+        if "upstream" == i['role']:
+            upstream += 1
+
+    if upstream == 0:
+        raise ConfigError('At least 1 upstream interface is required!')
+    elif upstream > 1:
+        raise ConfigError('Only 1 upstream interface allowed!')
+
+    return None
+
+def generate(igmp_proxy):
+    # bail out early - looks like removal from running config
+    if igmp_proxy is None:
+        return None
+
+    # bail out early - service is disabled, but inform user
+    if igmp_proxy['disable']:
+        print('Warning: IGMP Proxy will be deactivated because it is disabled')
+        return None
+
+    tmpl = jinja2.Template(config_tmpl)
+    config_text = tmpl.render(igmp_proxy)
+    with open(config_file, 'w') as f:
+        f.write(config_text)
+
+    return None
+
+def apply(igmp_proxy):
+    if igmp_proxy is None or igmp_proxy['disable']:
+         # IGMP Proxy support is removed in the commit
+         os.system('sudo systemctl stop igmpproxy.service')
+         if os.path.exists(config_file):
+             os.unlink(config_file)
+    else:
+        os.system('sudo systemctl restart igmpproxy.service')
+
+    return None
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        sys.exit(1)
diff --git a/src/etc/init.d/igmpproxy b/src/etc/init.d/igmpproxy
new file mode 100755
index 000000000..4a2c94a4d
--- /dev/null
+++ b/src/etc/init.d/igmpproxy
@@ -0,0 +1,166 @@
+#!/bin/sh
+### BEGIN INIT INFO
+# Provides:          igmpproxy
+# Required-Start:    $local_fs $network $remote_fs $syslog
+# Required-Stop:     $local_fs $network $remote_fs $syslog
+# Default-Start:     2 3 4 5
+# Default-Stop:      0 1 6
+# Short-Description: IGMP multicast routing daemon
+# Description:       IGMPproxy is a simple dynamic Multicast Routing Daemon
+#                    using only IGMP signalling. It's intended for simple
+#                    forwarding of Multicast traffic between networks.
+### END INIT INFO
+
+# Author: Pali Rohár <pali.rohar@gmail.com>
+
+# Do NOT "set -e"
+
+# PATH should only include /usr/* if it runs after the mountnfs.sh script
+PATH=/sbin:/usr/sbin:/bin:/usr/bin
+DESC="igmpproxy"
+NAME=igmpproxy
+DAEMON=/sbin/igmpproxy
+DAEMON_ARGS="/etc/igmpproxy.conf"
+PIDFILE=/var/run/$NAME.pid
+SCRIPTNAME=/etc/init.d/$NAME
+
+# Exit if the package is not installed
+[ -x "$DAEMON" ] || exit 0
+
+# Read configuration variable file if it is present
+[ -r /etc/default/$NAME ] && . /etc/default/$NAME
+
+# Load the VERBOSE setting and other rcS variables
+. /lib/init/vars.sh
+
+# Define LSB log_* functions.
+# Depend on lsb-base (>= 3.2-14) to ensure that this file is present
+# and status_of_proc is working.
+. /lib/lsb/init-functions
+
+#
+# Function that starts the daemon/service
+#
+do_start()
+{
+	# Return
+	#   0 if daemon has been started
+	#   1 if daemon was already running
+	#   2 if daemon could not be started
+	start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON --test > /dev/null \
+		|| return 1
+	start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON -b -m -- \
+		$DAEMON_OPTS $DAEMON_ARGS \
+		|| return 2
+	# The above code will not work for interpreted scripts, use the next
+	# six lines below instead (Ref: #643337, start-stop-daemon(8) )
+	#start-stop-daemon --start --quiet --pidfile $PIDFILE --startas $DAEMON \
+	#	--name $NAME --test > /dev/null \
+	#	|| return 1
+	#start-stop-daemon --start --quiet --pidfile $PIDFILE --startas $DAEMON \
+	#	--name $NAME -- $DAEMON_ARGS \
+	#	|| return 2
+
+	# Add code here, if necessary, that waits for the process to be ready
+	# to handle requests from services started subsequently which depend
+	# on this one.  As a last resort, sleep for some time.
+}
+
+#
+# Function that stops the daemon/service
+#
+do_stop()
+{
+	# Return
+	#   0 if daemon has been stopped
+	#   1 if daemon was already stopped
+	#   2 if daemon could not be stopped
+	#   other if a failure occurred
+	start-stop-daemon --stop --quiet --retry=TERM/30/KILL/5 --pidfile $PIDFILE --name $NAME
+	RETVAL="$?"
+	[ "$RETVAL" = 2 ] && return 2
+	# Wait for children to finish too if this is a daemon that forks
+	# and if the daemon is only ever run from this initscript.
+	# If the above conditions are not satisfied then add some other code
+	# that waits for the process to drop all resources that could be
+	# needed by services started subsequently.  A last resort is to
+	# sleep for some time.
+	start-stop-daemon --stop --quiet --oknodo --retry=0/30/KILL/5 --exec $DAEMON
+	[ "$?" = 2 ] && return 2
+	# Many daemons don't delete their pidfiles when they exit.
+	rm -f $PIDFILE
+	return "$RETVAL"
+}
+
+#
+# Function that sends a SIGHUP to the daemon/service
+#
+do_reload() {
+	#
+	# If the daemon can reload its configuration without
+	# restarting (for example, when it is sent a SIGHUP),
+	# then implement that here.
+	#
+	start-stop-daemon --stop --signal 1 --quiet --pidfile $PIDFILE --name $NAME
+	return 0
+}
+
+case "$1" in
+  start)
+	[ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC " "$NAME"
+	do_start
+	case "$?" in
+		0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
+		2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
+	esac
+	;;
+  stop)
+	[ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC" "$NAME"
+	do_stop
+	case "$?" in
+		0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
+		2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
+	esac
+	;;
+  status)
+	status_of_proc "$DAEMON" "$NAME" && exit 0 || exit $?
+	;;
+  #reload|force-reload)
+	#
+	# If do_reload() is not implemented then leave this commented out
+	# and leave 'force-reload' as an alias for 'restart'.
+	#
+	#log_daemon_msg "Reloading $DESC" "$NAME"
+	#do_reload
+	#log_end_msg $?
+	#;;
+  restart|force-reload)
+	#
+	# If the "reload" option is implemented then remove the
+	# 'force-reload' alias
+	#
+	log_daemon_msg "Restarting $DESC" "$NAME"
+	do_stop
+	case "$?" in
+	  0|1)
+		do_start
+		case "$?" in
+			0) log_end_msg 0 ;;
+			1) log_end_msg 1 ;; # Old process is still running
+			*) log_end_msg 1 ;; # Failed to start
+		esac
+		;;
+	  *)
+		# Failed to stop
+		log_end_msg 1
+		;;
+	esac
+	;;
+  *)
+	#echo "Usage: $SCRIPTNAME {start|stop|restart|reload|force-reload}" >&2
+	echo "Usage: $SCRIPTNAME {start|stop|status|restart|force-reload}" >&2
+	exit 3
+	;;
+esac
+
+:
diff --git a/src/op_mode/show-igmpproxy.py b/src/op_mode/show-igmpproxy.py
new file mode 100755
index 000000000..a021fcdde
--- /dev/null
+++ b/src/op_mode/show-igmpproxy.py
@@ -0,0 +1,241 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2018 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# File: show-igmpproxy
+# Purpose:
+#    Display istatistics from IPv4 IGMP proxy.
+#    Used by the "run show ip multicast" command tree.
+
+import sys
+import jinja2
+import argparse
+import ipaddress
+import socket
+
+import vyos.config
+
+# Output Template for "show ip multicast interface" command
+#
+# Example:
+# Interface  BytesIn      PktsIn       BytesOut     PktsOut      Local
+# eth0       0.0b         0            0.0b         0            xxx.xxx.xxx.65
+# eth1       0.0b         0            0.0b         0            xxx.xxx.xx.201
+# eth0.3     0.0b         0            0.0b         0            xxx.xxx.x.7
+# tun1       0.0b         0            0.0b         0            xxx.xxx.xxx.2
+vif_out_tmpl = """
+{%- for r in data %}
+{{ "%-10s"|format(r.interface) }} {{ "%-12s"|format(r.bytes_in) }} {{ "%-12s"|format(r.pkts_in) }} {{ "%-12s"|format(r.bytes_out) }} {{ "%-12s"|format(r.pkts_out) }} {{ "%-15s"|format(r.loc) }}
+{%- endfor %}
+"""
+
+# Output Template for "show ip multicast mfc" command
+#
+# Example:
+# Group             Origin            In    Out           Pkts        Bytes        Wrong
+# xxx.xxx.xxx.250   xxx.xx.xxx.75     --
+# xxx.xxx.xx.124    xx.xxx.xxx.26     --
+mfc_out_tmpl = """
+{%- for r in data %}
+{{ "%-15s"|format(r.group) }} {{ "%-15s"|format(r.origin) }} {{ "%-12s"|format(r.pkts) }} {{ "%-12s"|format(r.bytes) }} {{ "%-12s"|format(r.wrong) }} {{ "%-10s"|format(r.iif) }} {{ "%-20s"|format(r.oifs|join(', ')) }}
+{%- endfor %}
+"""
+
+parser = argparse.ArgumentParser()
+parser.add_argument("--interface", action="store_true", help="Interface Statistics")
+parser.add_argument("--mfc", action="store_true", help="Multicast Forwarding Cache")
+
+def byte_string(size):
+    # convert size to integer
+    size = int(size)
+
+    # One Terrabyte
+    s_TB = 1024 * 1024 * 1024 * 1024
+    # One Gigabyte
+    s_GB = 1024 * 1024 * 1024
+    # One Megabyte
+    s_MB = 1024 * 1024
+    # One Kilobyte
+    s_KB = 1024
+    # One Byte
+    s_B  = 1
+
+    if size > s_TB:
+        return str(round((size/s_TB), 2)) + 'TB'
+    elif size > s_GB:
+        return str(round((size/s_GB), 2)) + 'GB'
+    elif size > s_MB:
+        return str(round((size/s_MB), 2)) + 'MB'
+    elif size > s_KB:
+        return str(round((size/s_KB), 2)) + 'KB'
+    else:
+        return str(round((size/s_B), 2)) + 'b'
+
+    return None
+
+def kernel2ip(addr):
+    """
+    Convert any given addr from Linux Kernel to a proper, IPv4 address
+    using the correct host byte order.
+    """
+
+    # Convert from hex 'FE000A0A' to decimal '4261415434'
+    addr = int(addr, 16)
+    # Kernel ABI _always_ uses network byteorder
+    addr = socket.ntohl(addr)
+
+    return ipaddress.IPv4Address( addr )
+
+def do_mr_vif():
+    """
+    Read contents of file /proc/net/ip_mr_vif and print a more human
+    friendly version to the command line. IPv4 addresses present as
+    32bit integers in hex format are converted to IPv4 notation, too.
+    """
+
+    with open('/proc/net/ip_mr_vif', 'r') as f:
+        lines = len(f.readlines())
+        if lines < 2:
+            return None
+
+    result = {
+        'data': []
+    }
+
+    # Build up table format string
+    table_format = {
+        'interface': 'Interface',
+        'pkts_in'  : 'PktsIn',
+        'pkts_out' : 'PktsOut',
+        'bytes_in' : 'BytesIn',
+        'bytes_out': 'BytesOut',
+        'loc'      : 'Local'
+    }
+    result['data'].append(table_format)
+
+    # read and parse information from /proc filesystema
+    with open('/proc/net/ip_mr_vif', 'r') as f:
+        header_line = next(f)
+        for line in f:
+            data = {
+                'interface': line.split()[1],
+                'pkts_in'  : line.split()[3],
+                'pkts_out' : line.split()[5],
+
+                # convert raw byte number to something more human readable
+                # Note: could be replaced by Python3 hurry.filesize module
+                'bytes_in' : byte_string( line.split()[2] ),
+                'bytes_out': byte_string( line.split()[4] ),
+
+                # convert IP address from hex 'FE000A0A' to decimal '4261415434'
+                'loc'      : kernel2ip( line.split()[7] ),
+            }
+            result['data'].append(data)
+
+    return result
+
+def do_mr_mfc():
+    """
+    Read contents of file /proc/net/ip_mr_cache and print a more human
+    friendly version to the command line. IPv4 addresses present as
+    32bit integers in hex format are converted to IPv4 notation, too.
+    """
+
+    with open('/proc/net/ip_mr_cache', 'r') as f:
+        lines = len(f.readlines())
+        if lines < 2:
+            return None
+
+    # We need this to convert from interface index to a real interface name
+    # Thus we also skip the format identifier on list index 0
+    vif = do_mr_vif()['data'][1:]
+
+    result = {
+        'data': []
+    }
+
+    # Build up table format string
+    table_format = {
+        'group' : 'Group',
+        'origin': 'Origin',
+        'iif'   : 'In',
+        'oifs'  : ['Out'],
+        'pkts'  : 'Pkts',
+        'bytes' : 'Bytes',
+        'wrong' : 'Wrong'
+    }
+    result['data'].append(table_format)
+
+    # read and parse information from /proc filesystem
+    with open('/proc/net/ip_mr_cache', 'r') as f:
+        header_line = next(f)
+        for line in f:
+            data = {
+                # convert IP address from hex 'FE000A0A' to decimal '4261415434'
+                'group' : kernel2ip( line.split()[0] ),
+                'origin': kernel2ip( line.split()[1] ),
+
+                'iif'   : '--',
+                'pkts'  : '',
+                'bytes' : '',
+                'wrong' : '',
+                'oifs'  : []
+            }
+
+            iif = int( line.split()[2] )
+            if not ((iif == -1) or (iif == 65535)):
+                data['pkts']  = line.split()[3]
+                data['bytes'] = byte_string( line.split()[4] )
+                data['wrong'] = line.split()[5]
+
+                # convert index to real interface name
+                data['iif']  = vif[iif]['interface']
+
+                # convert each output interface index to a real interface name
+                for oif in line.split()[6:]:
+                    idx = int( oif.split(':')[0] )
+                    data['oifs'].append( vif[idx]['interface'] )
+
+            result['data'].append(data)
+
+    return result
+
+if __name__ == '__main__':
+    args = parser.parse_args()
+
+    # Do nothing if service is not configured
+    c = vyos.config.Config()
+    if not c.exists_effective('protocols igmp-proxy'):
+        print("IGMP proxy is not configured")
+        sys.exit(0)
+
+    if args.interface:
+        data = do_mr_vif()
+        if data:
+            tmpl = jinja2.Template(vif_out_tmpl)
+            print(tmpl.render(data))
+
+        sys.exit(0)
+    elif args.mfc:
+        data = do_mr_mfc()
+        if data:
+            tmpl = jinja2.Template(mfc_out_tmpl)
+            print(tmpl.render(data))
+
+        sys.exit(0)
+    else:
+        parser.print_help()
+        sys.exit(1)
+