From 7c6befc7c3cae040c58f7d5d19b0276ec3d4e0cb Mon Sep 17 00:00:00 2001
From: Matthias Schiffer <mschiffer@universe-factory.net>
Date: Sun, 7 Mar 2021 20:47:27 +0100
Subject: [PATCH] gluon-mesh-vpn-fastd: add L2TP offload support

---
 package/features                               |  7 ++++++-
 package/gluon-mesh-vpn-fastd-l2tp/Makefile     | 13 +++++++++++++
 .../files/lib/gluon/mesh-vpn/fastd/l2tp        |  0
 .../files/lib/gluon/mesh-vpn/fastd/.keep       |  0
 .../lib/gluon/upgrade/400-mesh-vpn-fastd       | 18 ++++++++++++++++++
 5 files changed, 37 insertions(+), 1 deletion(-)
 create mode 100644 package/gluon-mesh-vpn-fastd-l2tp/Makefile
 create mode 100644 package/gluon-mesh-vpn-fastd-l2tp/files/lib/gluon/mesh-vpn/fastd/l2tp
 create mode 100644 package/gluon-mesh-vpn-fastd/files/lib/gluon/mesh-vpn/fastd/.keep

diff --git a/package/features b/package/features
index c6e94a1a..da68b369 100644
--- a/package/features
+++ b/package/features
@@ -16,7 +16,12 @@ when(_'web-wizard' and _'autoupdater', {
 	'gluon-config-mode-autoupdater',
 })
 
-when(_'web-wizard' and (_'mesh-vpn-fastd' or _'mesh-vpn-tunneldigger' or _'mesh-vpn-wireguard'), {
+when(_'web-wizard' and (
+	_'mesh-vpn-fastd' or
+	_'mesh-vpn-fastd-l2tp' or
+	_'mesh-vpn-tunneldigger' or
+	_'mesh-vpn-wireguard'
+), {
 	'gluon-config-mode-mesh-vpn',
 })
 
diff --git a/package/gluon-mesh-vpn-fastd-l2tp/Makefile b/package/gluon-mesh-vpn-fastd-l2tp/Makefile
new file mode 100644
index 00000000..8eb5f6ec
--- /dev/null
+++ b/package/gluon-mesh-vpn-fastd-l2tp/Makefile
@@ -0,0 +1,13 @@
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=gluon-mesh-vpn-fastd-l2tp
+PKG_VERSION:=1
+
+include ../gluon.mk
+
+define Package/gluon-mesh-vpn-fastd-l2tp
+  TITLE:=Support for connecting meshes via fastd (with L2TP kernel offloading)
+  DEPENDS:=+gluon-core +gluon-mesh-vpn-fastd +kmod-l2tp-eth +@GLUON_SPECIALIZE_KERNEL:KERNEL_L2TP
+endef
+
+$(eval $(call BuildPackageGluon,gluon-mesh-vpn-fastd-l2tp))
diff --git a/package/gluon-mesh-vpn-fastd-l2tp/files/lib/gluon/mesh-vpn/fastd/l2tp b/package/gluon-mesh-vpn-fastd-l2tp/files/lib/gluon/mesh-vpn/fastd/l2tp
new file mode 100644
index 00000000..e69de29b
diff --git a/package/gluon-mesh-vpn-fastd/files/lib/gluon/mesh-vpn/fastd/.keep b/package/gluon-mesh-vpn-fastd/files/lib/gluon/mesh-vpn/fastd/.keep
new file mode 100644
index 00000000..e69de29b
diff --git a/package/gluon-mesh-vpn-fastd/luasrc/lib/gluon/upgrade/400-mesh-vpn-fastd b/package/gluon-mesh-vpn-fastd/luasrc/lib/gluon/upgrade/400-mesh-vpn-fastd
index 1af8218e..c8898755 100755
--- a/package/gluon-mesh-vpn-fastd/luasrc/lib/gluon/upgrade/400-mesh-vpn-fastd
+++ b/package/gluon-mesh-vpn-fastd/luasrc/lib/gluon/upgrade/400-mesh-vpn-fastd
@@ -5,6 +5,7 @@ local util = require 'gluon.util'
 local vpn_core = require 'gluon.mesh-vpn'
 
 local uci = require('simple-uci').cursor()
+local unistd = require 'posix.unistd'
 
 
 local syslog_level = uci:get('fastd', 'mesh_vpn', 'syslog_level') or 'verbose'
@@ -52,9 +53,19 @@ uci:section('fastd', 'fastd', 'mesh_vpn', {
 	secure_handshakes = true,
 	method = methods,
 	packet_mark = 1,
+	persist_interface = true,
+	offload_l2tp = false,
 	status_socket = '/var/run/fastd.mesh_vpn.socket',
 })
+uci:delete('fastd', 'mesh_vpn', 'peer_limit')
 
+-- L2TP offload support
+if unistd.access('/lib/gluon/mesh-vpn/fastd/l2tp') then
+	uci:set('fastd', 'mesh_vpn', 'mode', 'multitap')
+	uci:set('fastd', 'mesh_vpn', 'persist_interface', false)
+	uci:set('fastd', 'mesh_vpn', 'offload_l2tp', true)
+	uci:set('fastd', 'mesh_vpn', 'peer_limit', 1)
+end
 
 -- Collect list of groups that have peers with 'preserve' flag
 local preserve_groups = {}
@@ -96,6 +107,7 @@ local function add_peer(group, name, config)
 		enabled = true,
 		net = 'mesh_vpn',
 		group = group,
+		interface = 'mesh-vpn',
 		key = config.key,
 		remote = config.remotes,
 	})
@@ -125,5 +137,11 @@ end
 
 add_groups('mesh_vpn', site.mesh_vpn.fastd.groups())
 
+-- Update preserved peers as well
+uci:foreach('fastd', 'peer', function(peer)
+	if peer.net == 'mesh_vpn' then
+		uci:set('fastd', peer['.name'], 'interface', 'mesh-vpn')
+	end
+end)
 
 uci:save('fastd')