Keeping VPN interface status up-to-date in netifd/ubus/luci

Vavooon · February 1, 2023, 5:22pm

I'm trying to improve Zerotier support and faced some issues while working on netifd protocol handler.
Looks like the correct procedure to notify the system about interface status, including current IP address is following:

proto_init_update
proto_add_ipv4_address
proto_send_update

The problem I see here is that proto_add_ipv4_address function re-assigns IP address to the interface when interface status data reaches netifd.
Since Zerotier already assigns IP address to the interface, I'm rather looking for a way to update interface status with all the info (addresses, routes etc.) which is already assigned to the interface without extracting it with ip command and assigning again.

Currently I'm doing it in this way:

github.com/openwrt/packages

zerotier: implement netifd protocol support

openwrt:master ← Vavooon:zerotier-add-proto

opened 06:20PM - 11 Jul 22 UTC

Vavooon

+152 -1

Signed-off-by: Volodymyr Nazarchuk <vavooon@gmail.com> Maintainer: @mwarning … Compile tested: (mipsbe, 8dev Rambutan, OpenWrt v22.03.0-rc4) Run tested: (mipsbe, 8dev Rambutan, OpenWrt v22.03.0-rc4) Description: Currently Zerotier package uses own config file located under `/etc/config/zerotier`. Instead, this PR adds native `zerotier` protocol support which is based on existing service script, so it can be properly handled by `netifd`. Few new features compared to `zerotier` service are: - `zerotier-one` daemon is executed for each network separately with random port (`-p0` argument) - It supports consistent network interface naming, so you can have interface names like `zt0` I am not sure whether it is a good idea to remove existing `zerotier` service so I'm keeping it for now for backward compatibility, but let me know if it's better to remove it. Here's example interface definition inside `/etc/config/network`: ``` config interface 'zt0' option disabled '0' option proto 'zerotier' option network_id '**************' option config_path '/root/.zt-**************' option copy_config_path '1 ```

stangri · February 2, 2023, 3:22am

Have similar questions for nebula netifd support. I checked the source and it's not evident to me how to create a fully compliant netifd protocol.

jow · February 3, 2023, 9:42am

Conceptually, netifd must be the owner and authoritative source of layer 4 address settings. Protocols that configure IP addresses without involving netifd are not compliant and will lead to undefined behavior such as missing/stale status data, netifd clearing/reverting IP settings on config reload etc.

If the supervised protocol process does not support exposing effective address info without simultaneously configuring it then yes, the only way is extracting the settings and reapplying them through netifd.

Vavooon · February 12, 2023, 8:15pm

@stangri
I've improved IP addresses extraction from existing interface using JSON output from ip command.
You may use it for Nebula as well, if you want.

I'm not completely sure it extract all possible variables from output ($ptp for IPv4 and $preferred/$valid/$offlink/$class for IPv6)

IPv4 options:

github.com

bartve-enovation/netifd/blob/master/scripts/netifd-proto.sh#L105


      
          
          
	append PROTO_DNS_SEARCH "$address"
          }
          
          
proto_add_ipv4_address() {
          	local address="$1"
          	local mask="$2"
          	local broadcast="$3"
          	local ptp="$4"
          
          
	append PROTO_IPADDR "$address/$mask/$broadcast/$ptp"
          }
          
          
proto_add_ipv6_address() {
          	local address="$1"
          	local mask="$2"
          	local preferred="$3"
          	local valid="$4"
          	local offlink="$5"
          	local class="$6"

IPv6 options:

github.com

bartve-enovation/netifd/blob/master/scripts/netifd-proto.sh#L116


      
          }
          
          
proto_add_ipv6_address() {
          	local address="$1"
          	local mask="$2"
          	local preferred="$3"
          	local valid="$4"
          	local offlink="$5"
          	local class="$6"
          
          
	append PROTO_IP6ADDR "$address/$mask/$preferred/$valid/$offlink/$class"
          }
          
          
proto_add_ipv4_route() {
          	local target="$1"
          	local mask="$2"
          	local gw="$3"
          
          
	append PROTO_ROUTE "$target/$mask/$gw//"
          }

github.com/openwrt/packages

zerotier: implement netifd protocol support

openwrt:master ← Vavooon:zerotier-add-proto

opened 06:20PM - 11 Jul 22 UTC

Vavooon

+174 -1

Signed-off-by: Volodymyr Nazarchuk <vavooon@gmail.com> Maintainer: @mwarning … Compile tested: (mipsbe, 8dev Rambutan, OpenWrt v22.03.0-rc4) Run tested: (mipsbe, 8dev Rambutan, OpenWrt v22.03.0-rc4) Description: Currently Zerotier package uses own config file located under `/etc/config/zerotier`. Instead, this PR adds native `zerotier` protocol support which is based on existing service script, so it can be properly handled by `netifd`. Few new features compared to `zerotier` service are: - `zerotier-one` daemon is executed for each network separately with random port (`-p0` argument) - It supports consistent network interface naming, so you can have interface names like `zt0` I am not sure whether it is a good idea to remove existing `zerotier` service so I'm keeping it for now for backward compatibility, but let me know if it's better to remove it. Here's example interface definition inside `/etc/config/network`: ``` config interface 'zt0' option disabled '0' option proto 'zerotier' option network_id '**************' option config_path '/root/.zt-**************' option copy_config_path '1 ```