[Dnsmasq-discuss] dnsmasq interaction with nonrecursive requests

[Petr Mensik]

Hi,

I was checking latest dnsmasq reponses to non-recursive queries. It
seems strange, it does not work as it should. Originally, I was checking
NXDOMAIN issue, reported on Fedora bug #1647464.

But this issue seems important, it makes difficult to use dnsmasq with
bigger resolvers like bind or unbound. It does skip even local defined
hosts, which I think should be responded always even without recursion
bit set.

This was tested first on released dnsmasq 2.80 in Fedora rawhide, then
on git compilation with version v2.80-53-g343b7b4. Both seems to be
incorrect.

# grep -w qeos-1 /etc/hosts
172.16.36.1    qeos-1

# dig @127.0.0.1 +norec qeos-1

; <<>> DiG 9.11.5-P4-RedHat-9.11.5-13.P4.fc31 <<>> @127.0.0.1 +norec qeos-1
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 50085
;; flags: qr ra; QUERY: 1, ANSWER: 0, AUTHORITY: 13, ADDITIONAL: 27

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;qeos-1.				IN	A

;; AUTHORITY SECTION:
.			498600	IN	NS	b.root-servers.net.
.			498600	IN	NS	m.root-servers.net.
.			498600	IN	NS	e.root-servers.net.
.			498600	IN	NS	f.root-servers.net.
.			498600	IN	NS	k.root-servers.net.
.			498600	IN	NS	l.root-servers.net.
.			498600	IN	NS	c.root-servers.net.
.			498600	IN	NS	d.root-servers.net.
.			498600	IN	NS	i.root-servers.net.
.			498600	IN	NS	g.root-servers.net.
.			498600	IN	NS	a.root-servers.net.
.			498600	IN	NS	h.root-servers.net.
.			498600	IN	NS	j.root-servers.net.

;; ADDITIONAL SECTION:
e.root-servers.net.	153695	IN	A	192.203.230.10
e.root-servers.net.	153695	IN	AAAA	2001:500:a8::e
h.root-servers.net.	153695	IN	A	198.97.190.53
h.root-servers.net.	153695	IN	AAAA	2001:500:1::53
l.root-servers.net.	585734	IN	A	199.7.83.42
l.root-servers.net.	153695	IN	AAAA	2001:500:9f::42
i.root-servers.net.	585699	IN	A	192.36.148.17
i.root-servers.net.	153695	IN	AAAA	2001:7fe::53
a.root-servers.net.	597264	IN	A	198.41.0.4
a.root-servers.net.	597264	IN	AAAA	2001:503:ba3e::2:30
d.root-servers.net.	153695	IN	A	199.7.91.13
d.root-servers.net.	153695	IN	AAAA	2001:500:2d::d
c.root-servers.net.	153695	IN	A	192.33.4.12
c.root-servers.net.	153695	IN	AAAA	2001:500:2::c
b.root-servers.net.	585695	IN	A	199.9.14.201
b.root-servers.net.	153695	IN	AAAA	2001:500:200::b
j.root-servers.net.	153695	IN	A	192.58.128.30
j.root-servers.net.	153695	IN	AAAA	2001:503:c27::2:30
k.root-servers.net.	586670	IN	A	193.0.14.129
k.root-servers.net.	153695	IN	AAAA	2001:7fd::1
g.root-servers.net.	153695	IN	A	192.112.36.4
g.root-servers.net.	153695	IN	AAAA	2001:500:12::d0d
m.root-servers.net.	153695	IN	A	202.12.27.33
m.root-servers.net.	153695	IN	AAAA	2001:dc3::35
f.root-servers.net.	153695	IN	A	192.5.5.241
f.root-servers.net.	153695	IN	AAAA	2001:500:2f::f

# dig @127.0.0.1 +rec qeos-1
; <<>> DiG 9.11.5-P4-RedHat-9.11.5-13.P4.fc31 <<>> @127.0.0.1 +rec qeos-1
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 50355
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;qeos-1.				IN	A

;; ANSWER SECTION:
qeos-1.			0	IN	A	172.16.36.1

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Pá dub 12 05:23:57 EDT 2019
;; MSG SIZE  rcvd: 51

1. https://bugzilla.redhat.com/show_bug.cgi?id=1647464

-- 
Petr Menšík
Software Engineer
Red Hat, http://www.redhat.com/
email: pemensik at redhat.com  PGP: 65C6C973