dnsdist: Handle header-only responses, handle Refused as Servfail in the cache #4812

rgacogne · 2016-12-23T11:03:17Z

Short description

@rygl reported that Unbound sends Refused responses containing only the DNS header, and that we didn't parse these correctly.
This patch also makes the packet cache use the same custom TTL for Refused responses than for ServFail ones.

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I have:

read the CONTRIBUTING.md document
compiled and tested this code
included documentation (including possible behaviour changes)
documented the code
added regression tests

@rygl

@rygl reported that unbound at least sends `Refused` responses containing only the DNS header.

The check is done before inserting the response into the cache, but it feels safer to check it again before passing it to `memcpy()`. We check that the cached response is larger than `sizeof(dnsheader) + qname` afterwards, but the previous commit moved the header copy before that check.

rgacogne added 2 commits December 22, 2016 15:49

dnsdist: Handle responses with qdcount == 0

c8c3d4e

@rygl reported that unbound at least sends `Refused` responses containing only the DNS header.

dnsdist: Handle Refused as ServFail in the packet cache

2714396

rgacogne added defect dnsdist labels Dec 23, 2016

rgacogne added this to the dnsdist-1.1.0 milestone Dec 23, 2016

rgacogne merged commit 2ea1f87 into PowerDNS:master Dec 29, 2016

rgacogne deleted the dnsdist-qdcount-zero-responses branch December 29, 2016 12:21

dnsdist: Handle header-only responses, handle Refused as Servfail in the cache #4812

dnsdist: Handle header-only responses, handle Refused as Servfail in the cache #4812

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rgacogne commented Dec 23, 2016

Short description

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