[PATCH v3] wireguard: Make IPv6 addrs available for automatic prefix assignment

[Daniel Gröber]

Currently when assigning IPv6 addresses with large prefixes to a wireguard
interface, like

    config interface 'wg'
            option proto 'wireguard'
            list addresses 'fd::/48'

and having, say, a LAN interface such as

    config interface 'lan'
            option proto 'static'
            option ip6assign '60'

as is default the interface does not automatically receive the wg
interface's prefix.

For this to happen the proto needs to use proto_add_ipv6_prefix to register
the fact that a prefix is available for assignment which is simple enough.

Note that the addresses configured here usually include a non-zero host
part but currently netifd handles this poorly when more than one interface
should receive a sub-prefix.

Signed-off-by: Daniel Gröber <dxld at darkboxed.org>
---
v3: Bump PKG_RELEASE, remove mention of netifd patch from commit msg.

The required netifd fix can be found in "[PATCH netifd] interface-ip:
Normalise prefix address using netmask before using it" (Message-Id:
<20201125173536.1175-1-dxld at darkboxed.org>).

 package/network/utils/wireguard-tools/Makefile           | 2 +-
 package/network/utils/wireguard-tools/files/wireguard.sh | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/package/network/utils/wireguard-tools/Makefile b/package/network/utils/wireguard-tools/Makefile
index 3cdbaa785c..c42ea4f492 100644
--- a/package/network/utils/wireguard-tools/Makefile
+++ b/package/network/utils/wireguard-tools/Makefile
@@ -12,7 +12,7 @@ include $(INCLUDE_DIR)/kernel.mk
 PKG_NAME:=wireguard-tools
 
 PKG_VERSION:=1.0.20200827
-PKG_RELEASE:=2
+PKG_RELEASE:=3
 
 PKG_SOURCE:=wireguard-tools-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=https://git.zx2c4.com/wireguard-tools/snapshot/
diff --git a/package/network/utils/wireguard-tools/files/wireguard.sh b/package/network/utils/wireguard-tools/files/wireguard.sh
index 63261aea71..a18d09eaed 100644
--- a/package/network/utils/wireguard-tools/files/wireguard.sh
+++ b/package/network/utils/wireguard-tools/files/wireguard.sh
@@ -151,6 +151,7 @@ proto_wireguard_setup() {
 		case "${address}" in
 			*:*/*)
 				proto_add_ipv6_address "${address%%/*}" "${address##*/}"
+				proto_add_ipv6_prefix "${address}"
 				;;
 			*.*/*)
 				proto_add_ipv4_address "${address%%/*}" "${address##*/}"
-- 
2.20.1