Bring async receive_udp ignore_errors in line with the sync one - #1297
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rthalley merged 1 commit intoAug 29, 2026
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ignore_errors means "discard the datagram and keep listening for a valid response", but dns.asyncquery.receive_udp() passed continue_on_error to from_wire(), so a datagram with a valid header and an unparsable body was returned with its errors recorded instead of being skipped. Also removes the ignore_errors parameter added to dns.asyncquery.receive_tcp() at the same time; dns.query.receive_tcp() has no such parameter and nothing passes it.
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Differential fuzz of
dns.queryagainstdns.asyncqueryover 400 response datagrams: 120 diverged, every one withignore_errors=True. A control restricted to well-formed wire gave 0/400 before and after.Two datagrams into each twin: a valid header plus trailing junk, then a clean NXDOMAIN response.
The sync twin discards the unparsable datagram and keeps listening, as its docstring promises ("ignore format errors or response mismatches and keep listening for a valid response"), which the async docstring defers to. The async twin returns it with the parse errors recorded.
Blame puts both bodies at f66e25b (2024-02-09).
dns/asyncquery.py:161is 864308a (#1248), which addedcontinue_on_error=ignore_errorsto the async twin only;dns/query.pywas not touched.Do53Nameserver.queryand.async_queryboth passignore_errors=Truefor UDP, sodns.resolveranddns.asyncresolverdisagree on a damaged or injected response. Nothing in dnspython readsMessage.errors, so a salvaged message reaches the resolver looking clean.After the change the same fuzz gives 0 across four seeds.
The
receive_tcphunk is separable: #1248 also gave the asyncreceive_tcpanignore_errorsparameter the sync one lacks and no caller passes. Neither has shipped in a release.test_unparsable_wire_is_skipped_not_salvagedis added to both suites. The async one fails without the source change; the sync one passes either way and pins the authoritative behaviour.