[Dnsmasq-discuss] force --local/--server protocol

Mr Dash Four mr.dash.four at googlemail.com
Sun Jan 6 15:00:48 GMT 2013


> It's certainly true of the code as-distributed. Making modifications to
> turn UDP-from-the-client intp TCP-to-the-server would be possible, but a
> non-trivial bit of coding.
>   
OK, suppose I have the following scenario:

My resolv.conf.dnsmasq (the file which dnsmasq uses to make dns queries) 
contains 2 "real" DNS servers: 10.1.1.1 and, say, 8.8.8.8. Lets assume 
that a client makes a request to dnsmasq using port udp:53. dnsmasq then 
queries the 1'st server - 10.1.1.1 (I have "strict-order" active, so the 
servers are tried in turn for every request) on 10.1.1.1:53 using udp. 
10.1.1.1 then responds with "response truncated" message (that is done 
on purpose so that dnsmasq, hopefully, tries 10.1.1.1:53 tcp instead). 
What would happen next:

a) dnsmasq tries the next dns server in turn - 8.8.8.8 in this case;
b) dnsmasq returns an error to the client;
c) dnsmasq tries again on 10.1.1.1:53 tcp and then responds with the 
answer to the client (note that the original request from the client to 
dnsmasq was done using udp);

If the answer is not c), is there any way I could force dnsmasq to 
follow the path in c) above?




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