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path: root/src/resolve/resolved-dns-question.c
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2015-12-10resolved: cache - do negative caching only on the canonical nameTom Gundersen
Apart from dropping redundant information, this fixes an issue where, due to broken DNS servers, we can only be certain of whether an apparent NODATA response is in fact an NXDOMAIN response after explicitly resolving the canonical name. This issue is outlined in RFC2308. Moreover, by caching NXDOMAIN for an existing name, we would mistakenly return NXDOMAIN for types which should not be redirected. I.e., a query for AAAA on test-nx-1.jklm.no correctly returns NXDOMAIN, but a query for CNAME should return the record and a query for DNAME should return NODATA. Note that this means we will not cache an NXDOMAIN response in the presence of redirection, meaning one redundant roundtrip in case the name is queried again.
2015-11-25resolved: fully support DNS search domainsLennart Poettering
This adds support for searching single-label hostnames in a set of configured search domains. A new object DnsQueryCandidate is added that links queries to scopes. It keeps track of the search domain last used for a query on a specific link. Whenever a host name was unsuccessfuly resolved on a scope all its transactions are flushed out and replaced by a new set, with the next search domain appended. This also adds a new flag SD_RESOLVED_NO_SEARCH to disable search domain behaviour. The "systemd-resolve-host" tool is updated to make this configurable via --search=. Fixes #1697
2015-11-25resolved: don't claim DnsQuestion have to have the same namesLennart Poettering
Wen DnsQuestion objects are used for DnsQuery objects all contained keys have to share the same name, but otherwise they generally don't have to, and this can actually happen in real-life because DnsPacket objects for mDNS use DnsQuestion for the question section. Hence, rename: dns_question_is_valid() to dns_question_is_valid_for_query(), since the name uniqueness check it does is only relevant when used for a query. Similar, rename dns_question_name() to dns_question_first_name(), to be more accurate, as this difference matters if we keys don#t have to share the same name.
2015-11-24resolved: implement client-side DNAME resolutionLennart Poettering
Most servers apparently always implicitly convert DNAME to CNAME, but some servers don't, hence implement this properly, as this is required by edns0.
2015-11-24question: drop dns_question_is_superset() which we don't use anymoreLennart Poettering
2015-11-23resolved: add ResolveService() bus call for resolving SRV and DNS-SD servicesLennart Poettering
This also adds client-side support for this to systemd-resolve-host. Note that the ResolveService() API can deal both with DNS-SD service (consisting of service name, type and domain), as well as classic SRV services (consisting just of a type and a domain), all exposed in the same call. This patch also reworks CNAME handling in order to reuse it between hostname, RR and service lookups. In contrast to Avahi and Bonjour, this new API will actually reolve the A/AAAA RRs the SRV RRs point to in one go (unless this is explicitly disabled). This normally comes for free, as these RRs are sent along the SRV responses anyway, hence let's make use of that. This makes the API considerably easier to use, as a single ResolveService() invocation will return all necessary data to pick a server and connect() to it. Note that this only implements the DNS-SD resolving step, it does not implement DNS-SD browsing, as that makes sense primarily on mDNS, due to its continuous nature.
2015-10-27util-lib: split out allocation calls into alloc-util.[ch]Lennart Poettering
2015-09-16resolved: rr - introduce dns_resource_key_new_redirect()Tom Gundersen
Takes a key and CNAME RR and returns the canonical RR of the right type. Make use of this in dns_question_redirect().
2015-08-21resolved: only maintain one question RR key per transactionLennart Poettering
Let's simplify things and only maintain a single RR key per transaction object, instead of a full DnsQuestion. Unicast DNS and LLMNR don't support multiple questions per packet anway, and Multicast DNS suggests coalescing questions beyond a single dns query, across the whole system.
2015-08-21resolved: make DnsQuestion logic handle NULL arrays as empty arraysLennart Poettering
Following our usual logic of treating NULL arrays as empty arrays (for example, see strv.c) do the same for questions too.
2015-07-28resolved: compare dns question arrays properlyLennart Poettering
Let's optimize things a bit and properly compare DNS question arrays, instead of checking if they are mutual supersets. This also makes ANY query handling more accurate.
2015-06-10resolve: move dns routines into sharedNick Owens
2014-07-30resolved: fix cname handlingLennart Poettering
2014-07-29resolved: when resolving an address PTR record via llmnr, make a tcp ↵Lennart Poettering
connection by default
2014-07-23resolved: implement negative cachingLennart Poettering
2014-07-23resolved: rework logic so that we can share transactions between queries of ↵Lennart Poettering
different clients