summaryrefslogtreecommitdiff
path: root/src/resolve/resolved-bus.c
AgeCommit message (Collapse)Author
2016-02-01resolved: rework what ResolveHostname() with family == AF_UNSPEC meansLennart Poettering
Previously, if a hostanem is resolved with AF_UNSPEC specified, this would be used as indication to resolve both an AF_INET and an AF_INET6 address. With this change this logic is altered: an AF_INET address is only resolved if there's actually a routable IPv4 address on the specific interface, and similar an AF_INET6 address is only resolved if there's a routable IPv6 address. With this in place, it's ensured that the returned data is actually connectable by applications. This logic mimics glibc's resolver behaviour. Note that if the client asks explicitly for AF_INET or AF_INET6 it will get what it asked for. This also simplifies the logic how it is determined whether a specific lookup shall take place on a scope. Specifically, the checks with dns_scope_good_key() are now moved out of the transaction code and into the query code, so that we don't even create a transaction object on a specific scope if we cannot execute the resolution on it anyway.
2016-01-26resolved: teach resolved the difference between "routing" and "search" domainsLennart Poettering
Following the changes to expose the "routing" and "search" domain concepts in networkd, actually make resolved use them. It will now use routing domains exclusively for making DNS routing decisions, and use search domains additionally for extending single-label names.
2016-01-25resolved: replace DNS_TRANSACTION_RESOURCES by DNS_TRANSACTION_ERRNOLennart Poettering
Whenever we encounter an OS error we did not expect, we so far put the transaction into DNS_TRANSACTION_RESOURCES state. Rename this state to DNS_TRANSACTION_ERRNO, and save + propagate the actual system error to the caller. This should make error messages triggered by system errors much more readable by the user.
2016-01-25resolved: properly handle LLMNR/TCP connection errorsLennart Poettering
The LLMNR spec suggests to do do reverse address lookups by doing direct LLMNR/TCP connections to the indicated address, instead of doing any LLMNR multicast queries. When we do this and the peer doesn't actually implement LLMNR this will result in a TCP connection error, which we need to handle. In contrast to most LLMNR lookups this will give us a quick response on whether we can find a suitable name. Report this as new transaction state, since this should mostly be treated like an NXDOMAIN rcode, except that it's not one.
2016-01-25resolved: fix rcode formatting string lengthLennart Poettering
Since we honour the edns rcode extension we need more than 4 bits to format it. To avoid further confusion, derive the right length from the type.
2016-01-25resolved: log each time we increase the DNSSEC verdict countersLennart Poettering
Also, don't consider RRs that aren't primary to the lookups we do as relevant to the lookups.
2016-01-25resolved: get rid of unnecessary if checkLennart Poettering
DNS_ANSWER_FOREACH() can deal with NULL answers anyway, let's simplify our code here.
2016-01-25resolve: generate a nice clean error when clients try to resolve a name when ↵Lennart Poettering
the network is down
2016-01-19resolved: rework DNSSECSupported propertyLennart Poettering
Not only report whether the server actually supports DNSSEC, but also first check whether DNSSEC is actually enabled for it in our local configuration. Also, export a per-link DNSSECSupported property in addition to the existing manager-wide property.
2016-01-19resolved: add SetLinkXYZ() method counterparts on the Link objectLennart Poettering
So far, we exposed SetLinkXYZ() on the Manager interface, to set a couple of link properties. This adds similar calls SetXYZ() on the Link interface, and makes sure the former is little more than a shortcut to the latter. SetLinkXYZ() has the benefit of not requiring a GetLink() round trip for setting these properties, while the method actually belongs to the Link objects, and this change corrects that.
2016-01-19resolved: expose bus objects for each LinkLennart Poettering
The link objects expose as properties the current settings made with SetLinkDNS() and related calls, plus some more information.
2016-01-19resolved: rename a few props to closer match ther counterparts in the ↵Lennart Poettering
various configuration files
2016-01-19resolved: add bus API for configuring per-link DNS settingsLennart Poettering
This is useful for alternative network management solutions (such as NetworkManager) to push DNS configuration data into resolved. The calls will fail should networkd already have taken possesion of a link, so that the bus API is only available if we don't get the data from networkd.
2016-01-19resolve-host: show whether DNSSEC is supported or not in --statistics outputLennart Poettering
This should be generally useful information, hence show it.
2016-01-18resolved: rework IDNA logicLennart Poettering
Move IDNA logic out of the normal domain name processing, and into the bus frontend calls. Previously whenever comparing two domain names we'd implicitly do IDNA conversion so that "pöttering.de" and "xn--pttering-n4a.de" would be considered equal. This is problematic not only for DNSSEC, but actually also against he IDNA specs. Moreover it creates problems when encoding DNS-SD services in classic DNS. There, the specification suggests using UTF8 encoding for the actual service name, but apply IDNA encoding to the domain suffix. With this change IDNA conversion is done only: - When the user passes a non-ASCII hostname when resolving a host name using ResolveHostname() - When the user passes a non-ASCII domain suffix when resolving a service using ResolveService() No IDNA encoding is done anymore: - When the user does raw ResolveRecord() RR resolving - On the service part of a DNS-SD service name Previously, IDNA encoding was done when serializing names into packets, at a point where information whether something is a label that needs IDNA encoding or not was not available, but at a point whether it was known whether to generate a classic DNS packet (where IDNA applies), or an mDNS/LLMNR packet (where IDNA does not apply, and UTF8 is used instead for all host names). With this change each DnsQuery object will now maintain two copies of the DnsQuestion to ask: one encoded in IDNA for use with classic DNS, and one encoded in UTF8 for use with LLMNR and MulticastDNS.
2016-01-11resolved: improve query RR type error wording a bitLennart Poettering
2016-01-11resolved: refuse doing queries for known-obsolete RR typesLennart Poettering
Given how fragile DNS servers are with some DNS types, and given that we really should avoid confusing them with known-weird lookups, refuse doing lookups for known-obsolete RR types.
2016-01-11resolved: add missing case to switch statementLennart Poettering
2016-01-11resolved: don't attempt to send queries for DNSSEC RR types to servers not ↵Lennart Poettering
supporting them If we already degraded the feature level below DO don't bother with sending requests for DS, DNSKEY, RRSIG, NSEC, NSEC3 or NSEC3PARAM RRs. After all, we cannot do DNSSEC validation then anyway, and we better not press a legacy server like this with such modern concepts. This also has the benefit that when we try to validate a response we received using DNSSEC, and we detect a limited server support level while doing so, all further auxiliary DNSSEC queries will fail right-away.
2016-01-11resolved: when we get a TCP connection failure, try againLennart Poettering
Previously, when we couldn't connect to a DNS server via TCP we'd abort the whole transaction using a "connection-failure" state. This change removes that, and counts failed connections as "lost packet" events, so that we switch back to the UDP protocol again.
2016-01-11resolved: set a description on all our event sourcesLennart Poettering
2016-01-07resolved: query_process_cname - make fully recursiveTom Gundersen
This ensures we properly resolve the CNAME chain as far as we can, rather than only CNAME chains of length one.
2016-01-04resolved: explicitly handle case when the trust anchor is emptyLennart Poettering
Since we honour RFC5011 revoked keys it might happen we end up with an empty trust anchor, or one where there's no entry for the root left. With this patch the logic is changed what to do in this case. Before this patch we'd end up requesting the root DS, which returns with NODATA but a signed NSEC we cannot verify, since the trust anchor is empty after all. Thus we'd return a DNSSEC result of "missing-key", as we lack a verified version of the key. With this patch in place, look-ups for the root DS are explicitly recognized, and not passed on to the DNS servers. Instead, if downgrade-ok mode is on an unsigned NODATA response is synthesized, so that the validator code continues under the assumption the root zone was unsigned. If downgrade-ok mode is off a new transaction failure is generated, that makes this case recognizable.
2016-01-04resolved: introduce a proper bus error for DNSSEC validation errorsLennart Poettering
2015-12-29resolved: properly handle SRV RRs with the DNS root as hostnameLennart Poettering
2015-12-26resolved: generate an explicit transaction error when we cannot reach server ↵Lennart Poettering
via TCP Previously, if we couldn't reach a server via UDP we'd generate an MAX_ATTEMPTS transaction result, but if we couldn't reach it via TCP we'd generate a RESOURCES transaction result. While it is OK to generate two different errors I think, "RESOURCES" is certainly a misnomer. Introduce a new transaction result "CONNECTION_FAILURE" instead.
2015-12-26resolved: gather statistics about resolved namesLennart Poettering
This collects statistical data about transactions, dnssec verifications and the cache, and exposes it over the bus. The systemd-resolve-host tool learns new options to query these statistics and reset them.
2015-12-18resolved: propagate the DNSSEC result from the transaction to the query and ↵Lennart Poettering
the the bus client It's useful to generate useful errors, so let's do that.
2015-12-18resolved: rename DNS_TRANSACTION_FAILURE → DNS_TRANSACTION_RCODE_FAILURELennart Poettering
We have many types of failure for a transaction, and DNS_TRANSACTION_FAILURE was just one specific one of them, if the server responded with a non-zero RCODE. Hence let's rename this, to indicate which kind of failure this actually refers to.
2015-12-11resolved: generalize DNS RR type validity checksLennart Poettering
Check the validity of RR types as we parse or receive data from IPC clients, and use the same code for all of them.
2015-12-10resolved: chase DNSKEY/DS RRs when doing look-ups with DNSSEC enabledLennart Poettering
This adds initial support for validating RRSIG/DNSKEY/DS chains when doing lookups. Proof-of-non-existance, or proof-of-unsigned-zones is not implemented yet. With this change DnsTransaction objects will generate additional DnsTransaction objects when looking for DNSKEY or DS RRs to validate an RRSIG on a response. DnsTransaction objects are thus created for three reasons now: 1) Because a user asked for something to be resolved, i.e. requested by a DnsQuery/DnsQueryCandidate object. 2) As result of LLMNR RR probing, requested by a DnsZoneItem. 3) Because another DnsTransaction requires the requested RRs for validation of its own response. DnsTransactions are shared between all these users, and are GC automatically as soon as all of these users don't need a specific transaction anymore. To unify the handling of these three reasons for existance for a DnsTransaction, a new common naming is introduced: each DnsTransaction now tracks its "owners" via a Set* object named "notify_xyz", containing all owners to notify on completion. A new DnsTransaction state is introduced called "VALIDATING" that is entered after a response has been receieved which needs to be validated, as long as we are still waiting for the DNSKEY/DS RRs from other DnsTransactions. This patch will request the DNSKEY/DS RRs bottom-up, and then validate them top-down. Caching of RRs is now only done after verification, so that the cache is not poisoned with known invalid data. The "DnsAnswer" object gained a substantial number of new calls, since we need to add/remove RRs to it dynamically now.
2015-12-03resolved: add a concept of "authenticated" responsesLennart Poettering
This adds a new SD_RESOLVED_AUTHENTICATED flag for responses we return on the bus. When set, then the data has been authenticated. For now this mostly reflects the DNSSEC AD bit, if DNSSEC=trust is set. As soon as the client-side validation is complete it will be hooked up to this flag too. We also set this bit whenver we generated the data ourselves, for example, because it originates in our local LLMNR zone, or from the built-in trust anchor database. The "systemd-resolve-host" tool has been updated to show the flag state for the data it shows.
2015-12-02resolved: port ResolveRecord() bus call implementation to ↵Lennart Poettering
dns_resource_record_to_wire_format() Now that we have dns_resource_record_to_wire_format() we can generate the RR serialization we return to bus clients in ResolveRecord() with it. We pass the RR data along in the original form, not the DNSSEC canonical form, since that would mean we'd lose RR name casing, which is however important to keep for DNS-SD services and similar.
2015-11-27tree-wide: expose "p"-suffix unref calls in public APIs to make gcc cleanup easyLennart Poettering
GLIB has recently started to officially support the gcc cleanup attribute in its public API, hence let's do the same for our APIs. With this patch we'll define an xyz_unrefp() call for each public xyz_unref() call, to make it easy to use inside a __attribute__((cleanup())) expression. Then, all code is ported over to make use of this. The new calls are also documented in the man pages, with examples how to use them (well, I only added docs where the _unref() call itself already had docs, and the examples, only cover sd_bus_unrefp() and sd_event_unrefp()). This also renames sd_lldp_free() to sd_lldp_unref(), since that's how we tend to call our destructors these days. Note that this defines no public macro that wraps gcc's attribute and makes it easier to use. While I think it's our duty in the library to make our stuff easy to use, I figure it's not our duty to make gcc's own features easy to use on its own. Most likely, client code which wants to make use of this should define its own: #define _cleanup_(function) __attribute__((cleanup(function))) Or similar, to make the gcc feature easier to use. Making this logic public has the benefit that we can remove three header files whose only purpose was to define these functions internally. See #2008.
2015-11-27resolved: fix buildLennart Poettering
2015-11-26Merge pull request #2031 from poettering/resolved-search-domainsTom Gundersen
resolved. Fully implement search domains for single-label names
2015-11-26resolved: bus - follow CNAME chains when resolving addressesTom Gundersen
It may be unexpected to find a CNAME record when doing a reverse lookup, as we expect to find a PTR record directly. However, it is explicitly supported according to <https://tools.ietf.org/html/rfc2181#section-10.2>, and there seems to be no benefit to not supporting it.
2015-11-25dns-domain: change dns_srv_type_is_valid() return value to boolLennart Poettering
For similar reasons as dns_name_is_root() got changed in the previous commit.
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: expose some properties on the busLennart Poettering
For now, let's just expose the LLMNR hostname currently in use; a combined list of all dns servers with their interface indexes; a combined list of all search domains with their interface indexes.
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: remove unused variableThomas Hindoe Paaboel Andersen
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: cache - handle CNAME redirectionTom Gundersen
CNAME records are special in the way they are treated by DNS servers, and our cache should mimic that behavior: In case a domain name has an alias, its CNAME record is returned in place of any other. Our cache was not doing this despite caching the CNAME records, this entailed needless lookups to re-resolve the CNAME.
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().
2015-08-24resolved: remove duplicate handling of "no servers" query resultLennart Poettering
So far we handled immediate "no server" query results differently from "no server" results we ran into during operation: the former would cause the dns_query_go() call to fail with ESRCH, the later would result in the query completion callback to be called. Remove the duplicate codepaths, by always going through the completion callback. This allows us to remove quite a number of lines for handling the ESRCH. This commit should not alter behaviour at all.
2015-08-21resolved: when passing RRs across the bus, make sure not to use name compressionLennart Poettering
We explicitly need to turn off name compression when marshalling or demarshalling RRs for bus transfer, since they otherwise refer to packet offsets that reference packets that are not transmitted themselves.
2015-08-21resolved: rework synthesizing logicLennart Poettering
With this change we'll now also generate synthesized RRs for the local LLMNR hostname (first label of system hostname), the local mDNS hostname (first label of system hostname suffixed with .local), the "gateway" hostname and all the reverse PTRs. This hence takes over part of what nss-myhostname already implemented. Local hostnames resolve to the set of local IP addresses. Since the addresses are possibly on different interfaces it is necessary to change the internal DnsAnswer object to track per-RR interface indexes, and to change the bus API to always return the interface per-address rather than per-reply. This change also patches the existing clients for resolved accordingly (nss-resolve + systemd-resolve-host). This also changes the routing logic for queries slightly: we now ensure that the local hostname is never resolved via LLMNR, thus making it trustable on the local system.
2015-06-10resolve: move dns routines into sharedNick Owens