Merge pull request #111 from ifupdown-ng/feature/deprecate-brctl

vlan aware bridging

Makefile

@@ -138,6 +138,7 @@ install: all
 	${SCDOC} < $< > $@
 
 MANPAGES_5 = \
+	doc/ifupdown-ng.conf.5 \
 	doc/interfaces.5 \
 	doc/interfaces-bond.5 \
 	doc/interfaces-batman.5 \

cmd/ifquery.c

@@ -272,6 +272,12 @@ ifquery_main(int argc, char *argv[])
 		return EXIT_FAILURE;
 	}
 
+	if (!lif_compat_apply(&collection))
+	{
+		fprintf(stderr, "%s: failed to apply compatibility glue\n", argv0);
+		return EXIT_FAILURE;
+	}
+
 	/* --list --state is not allowed */
 	if (listing && (listing_stat || listing_running))
 		generic_usage(self_applet, EXIT_FAILURE);

dist/ifupdown-ng.conf.example

@@ -17,6 +17,22 @@ allow_addon_scripts = 1
 # templates.  Valid values are 0 and 1, the default is 1.
 allow_any_iface_as_template = 1
 
+# compat_create_interfaces:
+# Denotes where or not to create interfaces when compat_* settings are
+# active and it would be necessary to create an interface to be fully
+# compliant.  This could happen when inheriting bridge VLAN settings to
+# an interface within a bridges bridge-ports setting but no interface
+# stanza is found.  Valid values are 0 and 1, the default is 1.
+compat_create_interfaces = 1
+
+# compat_ifupdown2_bridge_ports_inherit_vlans:
+# In ifupdown2 <bridge-vids> as well as the <bridge-pvid> set on a bridge
+# interface will be inherited by all member ports if not set explicitly.
+# When set to 1 ifupdown-ng behaves the same way and will internally copy
+# both options from the bridge member ports if they are not set on the
+# member port. Valid values are 0 and 1, the default is 1.
+compat_ifupdown2_bridge_ports_inherit_vlans = 1
+
 # implicit_template_conversion:
 # In some legacy configs, a template may be declared as an iface, and
 # ifupdown-ng automatically converts those declarations to a proper

doc/ADMIN-GUIDE.md

@@ -60,6 +60,20 @@ Currently the following settings are supported in
   in order to require inheritance from specified templates.
   Valid values are `0` and `1`, the default is `1`.
 
+* `compat_create_interfaces`:
+  Denotes where or not to create interfaces when compat\_* settings are
+  active and it would be necessary to create an interface to be fully
+  compliant.  This could happen when inheriting bridge VLAN settings to
+  an interface within a bridges bridge-ports setting but no interface
+  stanza is found.  Valid values are `0` and `1`, the default is `1`.
+
+* `compat_ifupdown2_bridge_ports_inherit_vlans`: In ifupdown2 `bridge-vids`
+  as well as the <bridge-pvid> set on a bridge interface will be inherited
+  by all member ports if not set explicitly.  When set to `1` ifupdown-ng
+  behaves the same way and will internally copy both options from the
+  bridge member ports if they are not set on the member port.
+  Valid values are `0` and `1`, the default is `1`.
+
 * `implicit_template_conversion`: In some legacy configs, a template
   may be declared as an iface, and ifupdown-ng automatically converts
   those declarations to a proper template.  If this setting is

doc/ifdown.scd

@@ -54,8 +54,9 @@ configured in the configuration database.
 
 # SEE ALSO
 
-*ifup*(8)++
+*ifupdown-ng.conf*(5)
-*ifquery*(8)++
+*ifup*(8)
+*ifquery*(8)
 *interfaces*(5)
 
 # AUTHORS

doc/ifup.scd

@@ -57,8 +57,9 @@ configured in the configuration database.
 
 # SEE ALSO
 
-*ifdown*(8)++
+*ifupdown-ng.conf*(5)
-*ifquery*(8)++
+*ifdown*(8)
+*ifquery*(8)
 *interfaces*(5)
 
 # AUTHORS

doc/ifupdown-ng.conf.scd

@@ -0,0 +1,70 @@
+ifupdown-ng.conf(5)
+
+# NAME
+
+*ifupdown-ng.conf* - Global configuration file for ifupdown-ng
+
+# DESCRIPTION
+
+ifupdown-ng allows to configure some parts of it's behaviour via global
+configuration options.
+
+# GENERAL CONFIGURATION OPTIONS
+
+*allow_addon_scripts* _bool_
+	Enable support for /etc/if-X.d addon scripts.  These are used for
+	compatibility with legacy setups, and may be disabled for
+	performance improvements in setups where only ifupdown-ng executors
+	are used.  Valid values are _0_ and _1_, the default is _1_.
+
+*use_hostname_for_dhcp* _bool_
+	Automatically learn the hostname property, used for DHCP
+	configuration by querying the system hostname using uname(2).
+	This is basically equivalent to `hostname $(hostname)` without
+	having to specify any configuration.  Valid values are _0_ and
+	_1_, the default is _1_.
+
+# TEMPLATE RELATED OPTIONS
+
+*allow_any_iface_as_template* _bool_
+	Enable any interface to act as a template for another interface.
+	This is presently the default, but is deprecated.  An admin may
+	choose to disable this setting in order to require inheritance
+	from specified templates.  Valid values are _0_ and _1_, the
+	default is _1_.
+
+*implicit_template_conversion* _bool_
+	In some legacy configs, a template may be declared as an iface, and
+	ifupdown-ng automatically converts those declarations to a proper
+	template.  If this setting is disabled, inheritance will continue
+	to work against non-template interfaces without converting them to
+	a template.  Valid values are _0_ and _1_, the default is _1_.
+
+# COMPATIBILITY RELATED OPTIONS
+
+*compat_create_interfaces* _bool_
+	Denotes where or not to create interfaces when compat_* settings are
+	active and it would be necessary to create an interface to be fully
+	compliant.  This could happen when inheriting bridge VLAN settings to
+	an interface within a bridges bridge-ports setting but no interface
+	stanza is found.  Valid values are _0_ and _1_, the default is _1_.
+
+compat_ifupdown2_bridge_ports_inherit_vlans _bool_
+	In ifupdown2 <bridge-vids> as well as the <bridge-pvid> set on a
+	bridge interface will be inherited by all member ports if not set
+	explicitly.  When set to 1 ifupdown-ng behaves the same way and will
+	internally copy both options from the bridge member ports if they
+	are not set on the member port.  Valid values are _0_ and _1_, the
+	default is _1_.
+
+# FILES
+
+/etc/network/ifupdown-ng.conf
+
+# SEE ALSO
+
+*interfaces*(5)
+
+# AUTHORS
+
+Maximilian Wilhelm <max@sdn.clinic>

doc/interfaces-bridge.scd

@@ -27,6 +27,11 @@ See *ip-link*(8) for more details about the options listed below.
 	removed from the Forwarding DataBase (FDB) after not having
 	seen a frame with this source address.
 
+*bridge-vlan-aware* _bool_
+	Denotes wether or not the bridge should be aware of 802.1q VLANs.
+	_bool_ can be given as _yes_/_no_ or _0_/_1_.  The defaul is _no_.
+	See related options for configuring vlan-aware bridges, below.
+
 # SPANNING TREE RELATED BRIDGE OPTIONS
 
 *bridge-stp* _state_
@@ -52,6 +57,51 @@ See *ip-link*(8) for more details about the options listed below.
 	after reception of its last STP hello message. Valid values
 	are between 6 and 40.
 
+# OPTIONS FOR VLAN-AWARE-BRIDGES
+
+The following options only have an effect on vlan-aware bridges and
+their ports.
+
+All settings can be applied on the bridge interface itself and all member
+port iface stanzas.  If applied on the bridge interface they take effect
+for the bridge interface itself and might be inherited to _bridge-ports_
+depending on the compatibility settings configured in *ifupdown-ng.conf*(5).
+
+Configuring VLAN options on the bridge interface might be required for
+setting up a VLAN interface to one of the VLANs carried within the bridge.
+See the EXAMPLES section for an example for this scenario.
+
+See *ifupdown-ng.conf*(5) for more information about compatiblity settings
+mentioned below.
+
+*bridge-access* _vlan ID_
+	Configure the given _vlan ID_ for untagged ingress and egress
+	on this interface.  The common description for this kind of
+	configuration is called "access port".
+
+*bridge-pvid* _vlan ID_
+	Denotes the _vlan ID_ to considered a PVID at ingress.
+	Any untagged frames received on this interface will be
+	assigned to this _vlan ID_.  The default PVID is _1_.
+
+	If compatibility to ifupdown2 bridge port inheritance is active
+	a _bridge-pvid_ set on the bridge will be inherited to any
+	interface configured in _bridge-ports_ without a _bridge-pvid_ set.
+
+*bridge-vids* _list of vlan IDs_
+	Denotes the space separated list of VLANs to be allowed tagged
+	ingress/egress on this interface.
+
+	If compatibility to ifupdown2 bridge port inheritance is active
+	a _bridge-vids_ set on the bridge will be inherited to any
+	interface configured in _bridge-ports_ without _bridge-vids_ set.
+
+*bridge-allow-untagged* _bool_
+	Denotes wether or not the bridge should allow untagged frames on
+	ingress as well as egress. If set to _no_ untagged frames will be
+	droppped on ingress and none will be sent. _bool_ can be given as
+	_yes_/_no_ or _0_/_1_.  The defaul is _yes_.
+
 # EXAMPLES
 
 A simple layer 2 only bridge:
@@ -77,10 +127,46 @@ iface br0
 	address 2001:db8::42/64
 ```
 
+A layer 2 only vlan-aware bridge:
+
+```
+auto bond0
+iface bond0
+	bond-members eth0 eth1
+	bridge-vids 23 42 84 1337
+
+auto br0
+iface br0
+	bridge-ports bond0
+```
+
+A vlan-aware bridge with a VLAN interface on top:
+
+```
+auto eth0
+iface eth0
+	bridge-vids 23 42 84 1337
+
+auto br0
+iface br0
+	bridge-ports eth0
+	bridge-vlan-aware yes
+	bridge-vids 42
+
+auto vlan42
+iface vlan42
+	vlan-raw-device br0
+	#
+	address 192.0.2.42/24
+	address 2001:db8::42/64
+```
+
 # SEE ALSO
 
-*ip-link*(8)
 *interfaces*(5)
+*ifupdown-ng.conf*(5)
+*ip-link*(8)
+*bridge*(8)
 
 # AUTHORS
 

doc/interfaces.scd

@@ -216,6 +216,7 @@ iface eth0
 
 # SEE ALSO
 
+*ifupdown-ng.conf*(5)
 *ifup*(8)
 *ifdown*(8)
 *ifquery*(8)

executor-scripts/linux/bridge

@@ -1,6 +1,7 @@
 #!/bin/sh
 
 set -e
+[ -n "$VERBOSE" ] && set -x
 
 # Copyright (C) 2012, 2020 Natanael Copa <ncopa@alpinelinux.org>
 # Copyright (C) 2020 Ariadne Conill <ariadne@dereferenced.org>
@@ -14,6 +15,10 @@ set -e
 # implied.  In no event shall the authors be liable for any damages arising
 # from the use of this software.
 
+################################################################################
+#                        Bridge management functions                           #
+################################################################################
+
 all_ports_exist() {
 	local i=
 	for i in "$@"; do
@@ -52,13 +57,10 @@ all_ports() {
 add_ports() {
 	local port=
 	for port in $PORTS; do
-		if [ -x /etc/network/if-pre-up.d/vlan ]; then
-			env IFACE=$port /etc/network/if-pre-up.d/vlan
-		fi
 		if [ -n "$IF_BRIDGE_HW" ]; then
 			ip link set dev $port addr $IF_BRIDGE_HW
 		fi
-		brctl addif $IFACE $port && ip link set dev $port up
+		ip link set dev $port master $IFACE && ip link set dev $port up
 	done
 }
 
@@ -66,22 +68,17 @@ del_ports() {
 	local port=
 	for port in $PORTS; do
 		ip link set dev $port down
-		brctl delif $IFACE $port
+		ip link set dev $port nomaster
-		if [ -x /etc/network/ip-post-down.d/vlan ]; then
-			env IFACE=$port /etc/network/if-post-down.d/vlan
-		fi
 	done
 }
 
-set_bridge_opts() {
+set_bridge_opts_brctl() {
 	[ -n "$IF_BRIDGE_AGEING" ] \
 		&& brctl setageing $IFACE $IF_BRIDGE_AGEING
 	[ -n "$IF_BRIDGE_BRIDGEPRIO" ] \
 		&& brctl setbridgeprio $IFACE $IF_BRIDGE_BRIDGEPRIO
 	[ -n "$IF_BRIDGE_FD" ] \
 		&& brctl setfd $IFACE $IF_BRIDGE_FD
-	[ -n "$IF_BRIDGE_GCINT" ] \
-		&& brctl setgcint $IFACE $IF_BRIDGE_GCINT
 	[ -n "$IF_BRIDGE_HELLO" ] \
 		&& brctl sethello $IFACE $IF_BRIDGE_HELLO
 	[ -n "$IF_BRIDGE_MAXAGE" ] \
@@ -94,6 +91,44 @@ set_bridge_opts() {
 		&& brctl stp $IFACE $IF_BRIDGE_STP
 }
 
+yesno() {
+	case "$1" in
+	yes|YES|true|TRUE|1)
+		echo 1
+		;;
+	*)
+		echo 0
+		;;
+	esac
+}
+
+set_bridge_opts_iproute2() {
+	[ -n "$IF_BRIDGE_AGEING" ] \
+		&& ip link set dev $IFACE type bridge ageing_time $IF_BRIDGE_AGEING
+	[ -n "$IF_BRIDGE_BRIDGEPRIO" ] \
+		&& ip link set dev $IFACE type bridge priority $IF_BRIDGE_BRIDGEPRIO
+	[ -n "$IF_BRIDGE_FD" ] \
+		&& ip link set dev $IFACE type bridge forward_delay $IF_BRIDGE_FD
+	[ -n "$IF_BRIDGE_HELLO" ] \
+		&& ip link set dev $IFACE type bridge hello_time $IF_BRIDGE_HELLO
+	[ -n "$IF_BRIDGE_MAXAGE" ] \
+		&& ip link set dev $IFACE type bridge max_age $IF_BRIDGE_MAXAGE
+	[ -n "$IF_BRIDGE_PATHCOST" ] \
+		&& bridge link set dev $IFACE cost $IF_BRIDGE_PATHCOST
+	[ -n "$IF_BRIDGE_PORTPRIO" ] \
+		&& bridge link set dev $IFACE priority $IF_BRIDGE_PORTPRIO
+	[ -n "$IF_BRIDGE_STP" ] \
+		&& ip link set dev $IFACE type bridge stp $(yesno $IF_BRIDGE_STP)
+	[ -n "$IF_BRIDGE_VLAN_AWARE" ] \
+		&& ip link set dev $IFACE type bridge vlan_filtering $(yesno $IF_BRIDGE_VLAN_AWARE)
+}
+
+set_bridge_opts() {
+	[ -x /sbin/bridge ] && set_bridge_opts_iproute2 && return 0
+	[ -x /sbin/brctl ] && set_bridge_opts_brctl && return 0
+}
+
+
 all_ports_ready() {
 	local port=
 	for port in $PORTS; do
@@ -123,7 +158,92 @@ wait_bridge() {
 	done
 }
 
-[ -z "$IF_BRIDGE_PORTS" ] && IF_BRIDGE_PORTS="$IF_REQUIRES"
+
+################################################################################
+#                     Bridge port management functions                         #
+################################################################################
+
+configure_access_port() {
+	port="$1"
+	vlan="$2"
+	self="$3"
+
+	# Cleans all existing VLANs (probably at least VLAN 1)
+	bridge vlan show dev ${port} | tail -n +2 | grep -v '^$' | sed -e "s/^${port}//" | while read vid flags; do
+		bridge vlan del vid "${vid}" dev "${port}" ${self}
+	done
+
+	bridge vlan add vid "${vlan}" pvid untagged dev "${port}" ${self}
+}
+
+configure_trunk_port() {
+	port="$1"
+	self="$2"
+
+	# Working on the bridge itself?
+	if [ "${self}" ]; then
+		allow_untagged="${IF_BRIDGE_ALLOW_UNTAGGED}"
+		pvid="${IF_BRIDGE_PVID}"
+		vids="${IF_BRIDGE_VIDS}"
+	else
+		allow_untagged=$(ifquery -p bridge-allow-untagged ${port} 2>/dev/null || true)
+		pvid=$(ifquery -p bridge-pvid ${port} 2>/dev/null || true)
+		vids=$(ifquery -p bridge-vids ${port} 2>/dev/null || true)
+	fi
+
+	# If bridge-allow-untagged if set to off, remove untagged VLAN. If it's
+	# one of our bridge-vids, it will be set again later.
+	if [ "${allow_untagged}" -a  "$(yesno ${allow_untagged})" = 0 ]; then
+		untagged_vid=$(bridge vlan show dev ${port} | tail -n +2 | grep -v '^$' | sed -e "s/^${port}//" | awk '/Untagged/ { print $1 }')
+		if [ "${untagged_vid}" ]; then
+			bridge vlan del vid "${untagged_vid}" dev "${port}" ${self}
+		fi
+	fi
+
+	# The vlan specified is to be considered a PVID at ingress.
+	# Any untagged frames will be assigned to this VLAN.
+	if [ "${pvid}" ]; then
+		cur_pvid=$(bridge vlan show dev ${port} | tail -n +2 | grep -v '^$' | sed -e "s/^${port}//" | awk '/PVID/ { print $1 }')
+		if [ "${cur_pvid}" ]; then
+			bridge vlan del vid ${cur_pvid} dev "${port}" ${self}
+		fi
+
+		bridge vlan add vid "${pvid}" dev "${port}" pvid untagged ${self}
+	fi
+
+	# Add regular tagged VLANs
+	for vid in ${vids}; do
+		bridge vlan add vid $vid dev "${port}" ${self}
+	done
+}
+
+# Configure VLANs on the bridge interface itself
+set_bridge_vlans() {
+	# Shall the bridge interface be an untagged port?
+	if [ "${IF_BRIDGE_ACCESS}" ]; then
+		configure_access_port "${IFACE}" "${IF_BRIDGE_ACCESS}" "self"
+
+	# Configure bridge interface as trunk port
+	else
+		configure_trunk_port "${IFACE}" "self"
+	fi
+}
+
+# Configure VLANs on the bridge-ports
+set_bridge_port_vlans() {
+	for port in ${PORTS}; do
+		access_vlan=$(ifquery -p bridge-access ${port} 2>/dev/null || true)
+
+		# Shall this prot interface be an untagged port?
+		if [ "${access_vlan}" ]; then
+			configure_access_port "${port}" "${access_vlan}"
+
+		# Configure port as trunk
+		else
+			configure_trunk_port "${port}"
+		fi
+	done
+}
 
 case "$IF_BRIDGE_PORTS" in
 "")	;;
@@ -132,30 +252,53 @@ all)	PORTS=$(all_ports);;
 *)	PORTS="$IF_BRIDGE_PORTS";;
 esac
 
-[ -z "$PORTS" ] && ! env | grep -q "^IF_BRIDGE" && exit
-
 case "$PHASE" in
 depend)
-	echo "$PORTS"
+	# Called for the bridge interface
-	;;
+	if [ "${IF_BRIDGE_PORTS}" ]; then
-create)
+		echo "$PORTS"
-	if [ ! -d "/sys/class/net/${IFACE}" ]; then
-		brctl addbr "${IFACE}"
 	fi
 	;;
+
+create)
+	# Called for the bridge interface
+	if [ "${IF_BRIDGE_PORTS}" -a ! -d "/sys/class/net/${IFACE}" ]; then
+		ip link add "${IFACE}" type bridge
+	fi
+	;;
+
 pre-up)
-	wait_ports
+	# Called for the bridge interface
-	set_bridge_opts
+	if [ "${IF_BRIDGE_PORTS}" ]; then
-	add_ports
+		wait_ports
-	wait_bridge
+		set_bridge_opts
+		set_bridge_vlans
+		add_ports
+		set_bridge_port_vlans
+		wait_bridge
+
+	# Called for a bridge member port
+	elif [ "${IF_BRIDGE_VIDS}" -o "${IF_BRIDGE_PVID}" -o "${IF_BRIDGE_ACCESS}" -o "${IF_BRIDGE_ALLOW_UNTAGGED}" ]; then
+		# Eventually we want to configure VLAN settings of member ports here.
+		# The current execution model does not allow this, so this is a no-op
+		# for now and we work around this by configuring ports while configuring
+		# the bridge.
+		true
+	fi
 	;;
+
 post-down)
-	del_ports
+	# Called for the bridge interface
-	ip link set dev $IFACE down
+	if [ "${IF_BRIDGE_PORTS}" ]; then
+		del_ports
+		ip link set dev $IFACE down
+	fi
 	;;
+
 destroy)
-	if [ -d "/sys/class/net/${IFACE}" ]; then
+	# Called for the bridge interface
-		brctl delbr "${IFACE}"
+	if [ "${IF_BRIDGE_PORTS}" -a -d "/sys/class/net/${IFACE}" ]; then
+		ip link del "${IFACE}"
 	fi
 	;;
 esac

libifupdown/compat.c

@@ -14,14 +14,100 @@
  */
 
 #include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include "libifupdown/config-file.h"
 #include "libifupdown/dict.h"
+#include "libifupdown/interface.h"
+#include "libifupdown/tokenize.h"
+
+static bool
+compat_ifupdown2_bridge_ports_inherit_vlans(struct lif_dict *collection)
+{
+	struct lif_node *iter;
+
+	/* Loop through all interfaces and search for bridges */
+	LIF_DICT_FOREACH(iter, collection)
+	{
+		struct lif_dict_entry *entry = iter->data;
+		struct lif_interface *bridge = entry->data;
+
+		/* We only care for bridges */
+		if (!bridge->is_bridge)
+			continue;
+
+		struct lif_dict_entry *bridge_pvid = lif_dict_find(&bridge->vars, "bridge-pvid");
+		struct lif_dict_entry *bridge_vids = lif_dict_find(&bridge->vars, "bridge-vids");
+
+		/* If there's nothing to inherit here, carry on */
+		if (bridge_pvid == NULL && bridge_vids == NULL)
+			continue;
+
+		struct lif_dict_entry *bridge_ports_entry = lif_dict_find(&bridge->vars, "bridge-ports");
+
+		/* This SHOULD not happen, but better save than sorry */
+		if (bridge_ports_entry == NULL)
+			continue;
+
+		char bridge_ports_str[4096] = {};
+		strlcpy(bridge_ports_str, bridge_ports_entry->data, sizeof bridge_ports_str);
+
+		/* If there are no bridge-ports configured, carry on */
+		if (strcmp(bridge_ports_str, "none") == 0)
+			continue;
+
+		/* Loop over all bridge-ports and set bridge-pvid and bridge-vid if not set already */
+		char *bufp = bridge_ports_str;
+		for (char *tokenp = lif_next_token(&bufp); *tokenp; tokenp = lif_next_token(&bufp))
+		{
+			entry = lif_dict_find(collection, tokenp);
+
+			/* There might be interfaces give within the bridge-ports for which there is no
+			 * interface stanza. If this is the case, we add one, so we can inherit the
+			 * bridge-vids/pvid to it. */
+			struct lif_interface *bridge_port;
+			if (entry)
+				bridge_port = entry->data;
+
+			else if (lif_config.compat_create_interfaces)
+			{
+				bridge_port = lif_interface_collection_find(collection, tokenp);
+				if (bridge_port == NULL)
+				{
+					fprintf(stderr, "Failed to add interface \"%s\"", tokenp);
+					return false;
+				}
+			}
+
+			/* We would have to creaet an interface, but shouldn't */
+			else
+			{
+				fprintf(stderr, "compat: Missing interface stanza for bridge-port \"%s\" but should not create one.\n",
+				        tokenp);
+				continue;
+			}
+
+			/* Maybe pimp bridge-pvid */
+			struct lif_dict_entry *port_pvid = lif_dict_find(&bridge_port->vars, "bridge-pvid");
+			if (bridge_pvid && !port_pvid)
+				lif_dict_add(&bridge_port->vars, "bridge-pvid", bridge_pvid->data);
+
+			/* Maybe pimp bridge-vids */
+			struct lif_dict_entry *port_vids = lif_dict_find(&bridge_port->vars, "bridge-vids");
+			if (bridge_vids && !port_vids)
+				lif_dict_add(&bridge_port->vars, "bridge-vids", bridge_vids->data);
+		}
+	}
+
+	return true;
+}
 
 extern bool
 lif_compat_apply(struct lif_dict *collection)
 {
-	(void) collection;
+	if (lif_config.compat_ifupdown2_bridge_ports_inherit_vlans &&
-
+	    !compat_ifupdown2_bridge_ports_inherit_vlans(collection))
-	/* Mangle interfaces according to some config options here */
+		return false;
 
 	return true;
 }

libifupdown/config-file.c

@@ -21,6 +21,8 @@
 struct lif_config_file lif_config = {
 	.allow_addon_scripts = true,
 	.allow_any_iface_as_template = true,
+	.compat_create_interfaces = true,
+	.compat_ifupdown2_bridge_ports_inherit_vlans = true,
 	.implicit_template_conversion = true,
 	.use_hostname_for_dhcp = true,
 };
@@ -31,7 +33,7 @@ set_bool_value(const char *key, const char *value, void *opaque)
 	(void) key;
 
 	if (*value == '1' ||
-		*value == 'Y' || *value == 'y' || 
+		*value == 'Y' || *value == 'y' ||
 		*value == 'T' || *value == 't')
 		*(bool *) opaque = true;
 	else if (*value == '0' ||
@@ -47,6 +49,8 @@ set_bool_value(const char *key, const char *value, void *opaque)
 static struct lif_config_handler handlers[] = {
 	{"allow_addon_scripts", set_bool_value, &lif_config.allow_addon_scripts},
 	{"allow_any_iface_as_template", set_bool_value, &lif_config.allow_any_iface_as_template},
+	{"compat_create_interfaces", set_bool_value, &lif_config.compat_create_interfaces},
+	{"compat_ifupdown2_bridge_ports_inherit_vlans", set_bool_value, &lif_config.compat_ifupdown2_bridge_ports_inherit_vlans},
 	{"implicit_template_conversion", set_bool_value, &lif_config.implicit_template_conversion},
 	{"use_hostname_for_dhcp", set_bool_value, &lif_config.use_hostname_for_dhcp},
 };

libifupdown/config-file.h

@@ -21,6 +21,8 @@
 struct lif_config_file {
 	bool allow_addon_scripts;
 	bool allow_any_iface_as_template;
+	bool compat_create_interfaces;
+	bool compat_ifupdown2_bridge_ports_inherit_vlans;
 	bool implicit_template_conversion;
 	bool use_hostname_for_dhcp;
 };

libifupdown/interface-file.c

@@ -206,6 +206,10 @@ handle_generic(struct lif_interface_file_parse_state *state, char *token, char *
 
 	token = maybe_remap_token(token);
 
+	/* This smells like a bridge */
+	if (strcmp(token, "bridge-ports") == 0)
+		state->cur_iface->is_bridge = true;
+
 	/* Skip any leading whitespaces in value for <token> */
 	while (isspace (*bufp))
 		bufp++;