19 Úno
2023
19 Úno
'23
20:04
I ended up with error ....
local ffi = require('ffi')
local function DDR_SVCB(state, req)
local answer = req:ensure_answer()
if answer == nil then return nil end
local qry = req:current()
if qry.stype ~= kres.type.SVCB then
return state
end
ffi.C.kr_pkt_make_auth_header(answer)
answer:rcode(kres.rcode.NOERROR)
answer:begin(kres.section.ANSWER)
local msg = '1 resolver.example. alpn=dot ipv4hint=192.0.2.1
ipv6hint=2001:db8::1'
answer:put(qry.sname, 900, answer:qclass(), kres.type.SVCB,
string.char(#msg) .. msg)
answer:begin(kres.section.ADDITIONAL)
answer:put(qry.sname, 900, answer:qclass(), kres.type.A,
kres.str2ip('109.236.119.2'))
answer:put(qry.sname, 900, answer:qclass(), kres.type.A,
kres.str2ip('109.236.120.2'))
answer:put(qry.sname, 900, answer:qclass(), kres.type.AAAA,
kres.str2ip('2a02:6ca3:0:1::2'))
answer:put(qry.sname, 900, answer:qclass(), kres.type.AAAA,
kres.str2ip('2a02:6ca3:0:2::2'))
return kres.DONE
end
policy.add(policy.domains(DDR_SVCB, policy.todnames({'_testing.domain'})))
it results in
kdig _testing.domain @109.236.120.2 type64
;; ->>HEADER<<- opcode: QUERY; status: NOERROR; id: 63653
;; Flags: qr aa rd ra; QUERY: 1; ANSWER: 1; AUTHORITY: 0; ADDITIONAL: 4
;; QUESTION SECTION:
;; _testing.domain. IN SVCB
;; ANSWER SECTION:
;; WARNING: can't print whole section
;; ADDITIONAL SECTION:
_testing.domain. 900 IN A 109.236.119.2
_testing.domain. 900 IN A 109.236.120.2
_testing.domain. 900 IN AAAA 2a02:6ca3:0:1::2
_testing.domain. 900 IN AAAA 2a02:6ca3:0:2::2
;; Received 202 B
;; Time 2023-02-19 20:01:08 CET
;; From 109.236.120.2@53(UDP) in 0.2 ms
ne 19. 2. 2023 o 18:26 Blažej Krajňák <blazej.krajnak(a)gmail.com> napísal(a):
Hi there,
I'm trying to implement SVCB record "_dns.resolver.arpa" for DDR
mechanism for our AS50242 recursive resolvers.
When I look on Cloudflare or Google implementation, they answer with
"ADDITIONAL SECTION" also.
kdig _dns.resolver.arpa @8.8.8.8 type64
;; ->>HEADER<<- opcode: QUERY; status: NOERROR; id: 61402
;; Flags: qr aa rd ra; QUERY: 1; ANSWER: 2; AUTHORITY: 0; ADDITIONAL: 4
;; QUESTION SECTION:
;; _dns.resolver.arpa. IN SVCB
;; ANSWER SECTION:
_dns.resolver.arpa. 86400 IN SVCB 1 dns.google. alpn=dot
_dns.resolver.arpa. 86400 IN SVCB 2 dns.google. alpn=h2,h3
key7="/dns-query{?dns}"
;; ADDITIONAL SECTION:
dns.google. 86400 IN A 8.8.8.8
dns.google. 86400 IN A 8.8.4.4
dns.google. 86400 IN AAAA 2001:4860:4860::8888
dns.google. 86400 IN AAAA 2001:4860:4860::8844
In Knot Resolver documentation is an example how to answer for SVCB
request but without addition section.
policy.add(
policy.domains(
policy.ANSWER(
{ [kres.type.SVCB] = { rdata=kres.parse_rdata({
'SVCB 1 resolver.example. alpn=dot ipv4hint=192.0.2.1
ipv6hint=2001:db8::1',
'SVCB 2 resolver.example. mandatory=key65380 alpn=h2
key65380=/dns-query{?dns}',
}), ttl=5 } }
), { todname('_testing.domain') }))
Can anyone help me, how to add additional section to answer? Do we
need to use policy.custom_action(state, request)?
Thanks!
Blažej