[Feature Request] HTTP/3 support in ODOH.

[przemyslaw0]

I would like to use ODOH with QUIC because it's faster than TCP.

[LeonardWalter]

I added support for this on the ODoH3 branch in my forked repo in this commit 28b86fa

0-RTT is not possible by default because ODoH must use HTTP POST requests. It is possible to force the use of 0-RTT even with POST requests when using a custom transport (which we do).
If you want to test that aswell you could just hard-code it by for example adding this after line 104 in dohclient.go

if opt.Use0RTT && opt.Transport == "quic" {
	opt.Method = "GET"
}
opt.Method = "POST"
opt.Use0RTT = true

[przemyslaw0]

@LeonardWalter

Your fork doesn't work:

$ ./routedns -l 6 ./routedns.toml 
time=2025-02-28T14:59:45.766-05:00 level=INFO msg="starting listener" id=local-udp-ipv6 protocol=udp addr=[::]:1053
time=2025-02-28T14:59:51.416-05:00 level=DEBUG msg="received query" id=local-udp-ipv6 client=127.0.0.1 qname=google.com. protocol=udp addr=[::]:1053
time=2025-02-28T14:59:51.416-05:00 level=DEBUG msg="forwarding query to resolver" id=local-udp-ipv6 client=127.0.0.1 qname=google.com. protocol=udp addr=[::]:1053 resolver=blocktest
time=2025-02-28T14:59:51.416-05:00 level=DEBUG msg="forwarding unmodified query to resolver" id=blocktest client=127.0.0.1 qtype=A qname=google.com. resolver=res
time=2025-02-28T14:59:51.416-05:00 level=DEBUG msg="querying upstream resolver" id=bootstrap-resolver client=127.0.0.1 qtype=AAAA qname=odoh.cloudflare-dns.com. resolver=[::1]:10053 protocol=udp
time=2025-02-28T14:59:51.417-05:00 level=DEBUG msg="opening connection" addr=[::1]:10053
time=2025-02-28T14:59:51.417-05:00 level=DEBUG msg="querying upstream resolver" id=bootstrap-resolver client=127.0.0.1 qtype=A qname=odoh.cloudflare-dns.com. resolver=[::1]:10053 protocol=udp
time=2025-02-28T14:59:51.417-05:00 level=DEBUG msg="sending query" addr=[::1]:10053 qname=odoh.cloudflare-dns.com.
time=2025-02-28T14:59:51.417-05:00 level=DEBUG msg="sending query" addr=[::1]:10053 qname=odoh.cloudflare-dns.com.
2025/02/28 14:59:51 failed to sufficiently increase receive buffer size (was: 208 kiB, wanted: 7168 kiB, got: 416 kiB). See https://github.com/quic-go/quic-go/wiki/UDP-Buffer-Sizes for details.
time=2025-02-28T14:59:51.767-05:00 level=ERROR msg="couldn't dial quic connection" error="CRYPTO_ERROR 0x128 (remote): tls: handshake failure"
time=2025-02-28T14:59:51.767-05:00 level=ERROR msg="failed to resolve" id=local-udp-ipv6 client=127.0.0.1 qname=google.com. protocol=udp addr=[::]:1053 error="Get \"https://odoh.cloudflare-dns.com/.well-known/odohconfigs\": CRYPTO_ERROR 0x128 (remote): tls: handshake failure"
time=2025-02-28T15:00:01.627-05:00 level=DEBUG msg="connection terminated by idle timeout" addr=[::1]:10053

[resolvers.res]
address = "https://odoh-noads-nl.alekberg.net/proxy"
protocol = "odoh"
target = "https://odoh.cloudflare-dns.com/dns-query"
transport = "quic"
target-config = ""

[LeonardWalter]

That is because the proxy and server you specified both don't support ODoH with quic. You need to set up your own proxy/server to use this.

As far as I am aware, there are currently no other implementations available of ODoH that support HTTP3 / quic