snowflake-proxy: NAT type detection fails on reboot

[MatzFan]

Package Name

snowflake-proxy

Maintainer

(@PolynomialDivision)

OpenWrt Version

25.12.0-rc5

OpenWrt Target/Subtarget

mediatek/filogic

Steps to Reproduce

• install snowflake-proxy
• add -ephemeral-ports-range 32768:60999 as a command parameter in the start_service() function in the init script
• add a firewall rule to allow incoming IPv4 & IPv6 UDP traffic on the above port range on the WAN interface:

• # /etc/init.d/snowflake-proxy restart
• # logread|grep snowflake-proxy

Observe after the line "Proxy starting" the line "NAT type: unrestricted"

• reboot the router

The logs should report "NAT type: unrestricted" again.

Actual Behaviour

After a reboot logs say "NAT type: unknown".

I've reported the bug at the Tor Project's snowflake repo and been advised to report it here too. We suspect NAT type detection is failing because the STUN server probe test is conducted before the WAN connection is up.

Adding sleep 10 to the beginning of the start_service() function seems to fix it, but I expect there is a better way of waiting for a network connection.

Thanks for making this package available btw.

Confirmation Checklist

• The package is maintained in this repository.
• I understand that issues related to the base OpenWrt repository or LuCI repository will be closed.
• I am reporting an issue for OpenWrt, not an unsupported fork.

[brada4]

Try this #28434 (comment)

[MatzFan]

Thanks @brada4, I added the line ubus -t 60 wait_for network.interface.wan at the top of the start_service() function and below that ubus call network.interface.wan status. In the logs I now see the JSON returned from the latter with "up": false.

Is it possible to parse ubus messages in a wait_for statement, or do I instead need a read loop parsing the status? Maybe something like:

until ["$(ubus call network.interface.wan status)" | jsonfilter -e '@["up"]']
do
    sleep 1
done

Totally new to ash & ubus so any help much appreciated.

[PolynomialDivision]

Try adding that ubus -t 60 wait_for network.interface.wan in the boot() like done here:
https://github.com/openwrt/packages/blob/master/net/dhtd/files/dhtd.init#L9-L13

[MatzFan]

@PolynomialDivision thanks. I tried that with the same result; "up" is still false. However, adding a small delay (to wait for a PPPoE connection in my case) seems to do the trick. Through multiple reboots I now get NAT type "unrestricted" almost every time with this:

boot() {
	# Wait for wan interface
	ubus -t 120 wait_for network.interface.wan 2>/dev/null
	sleep 10
	rc_procd start_service
}

Would you accept a PR for this change?

[PolynomialDivision]

I don't like the sleep. Please try an interface trigger, or write yourself a trigger. Something like:

service_triggers() {
    procd_add_interface_trigger "interface.*.up" wan /etc/init.d/snowflake-proxy reload
}

or similar.

[PolynomialDivision]

Maybe not "up", you can specify different states. Look for:

ubus call network.interface.wan status
``