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path: root/src/resolve/resolved-manager.h
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2016-06-24resolved: add option to disable caching (#3592)Martin Pitt
In some cases, caching DNS results locally is not desirable, a it makes DNS cache poisoning attacks a tad easier and also allows users on the system to determine whether or not a particular domain got visited by another user. Thus provide a new "Cache" resolved.conf option to disable it.
2016-06-21resolved: respond to local resolver requests on 127.0.0.53:53Lennart Poettering
In order to improve compatibility with local clients that speak DNS directly (and do not use NSS or our bus API) listen locally on 127.0.0.53:53 and process any queries made that way. Note that resolved does not implement a full DNS server on this port, but simply enough to allow normal, local clients to resolve RRs through resolved. Specifically it does not implement queries without the RD bit set (these are requests where recursive lookups are explicitly disabled), and neither queries with DNSSEC DO set in combination with DNSSEC CD (i.e. DNSSEC lookups with validation turned off). It also refuses zone transfers and obsolete RR types. All lookups done this way will be rejected with a clean error code, so that the client side can repeat the query with a reduced feature set. The code will set the DNSSEC AD flag however, depending on whether the data resolved has been validated (or comes from a local, trusted source). Lookups made via this mechanisms are propagated to LLMNR and mDNS as necessary, but this is only partially useful as DNS packets cannot carry IP scope data (i.e. the ifindex), and hence link-local addresses returned cannot be used properly (and given that LLMNR/mDNS are mostly about link-local communication this is quite a limitation). Also, given that DNS tends to use IDNA for non-ASCII names, while LLMNR/mDNS uses UTF-8 lookups cannot be mapped 1:1. In general this should improve compatibility with clients bypassing NSS but it is highly recommended for clients to instead use NSS or our native bus API. This patch also beefs up the DnsStream logic, as it reuses the code for local TCP listening. DnsStream now provides proper reference counting for its objects. In order to avoid feedback loops resolved will no silently ignore 127.0.0.53 specified as DNS server when reading configuration. resolved listens on 127.0.0.53:53 instead of 127.0.0.1:53 in order to leave the latter free for local, external DNS servers or forwarders. This also changes the "etc.conf" tmpfiles snippet to create a symlink from /etc/resolv.conf to /usr/lib/systemd/resolv.conf by default, thus making this stub the default mode of operation if /etc is not populated.
2016-06-21resolved: drop unused permit_domain_search variable from Manager objectLennart Poettering
2016-06-21resolved: make sure DNS configuration pushed in by the user stays around on ↵Lennart Poettering
restarts Let's make sure that all settings pushed in stay around when systemd-resolved is restarted.
2016-06-21resolved: make sure that route-only domains are never added to /etc/resolv.confLennart Poettering
After all, /etc/resolv.conf doesn't know the concept of "route-only domains", hence the domains should really not appear there.
2016-06-10resolved: also add a way to flush all caches via the busLennart Poettering
And expose it in "resolve-tool --flush-caches".
2016-06-10resolved: flush all caches if SIGUSR2 is receivedLennart Poettering
2016-02-10tree-wide: remove Emacs lines from all filesDaniel Mack
This should be handled fine now by .dir-locals.el, so need to carry that stuff in every file.
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.
2016-01-26networkd: rework Domains= settingLennart Poettering
Previously, .network files only knew a vaguely defined "Domains=" concept, for which the documentation declared it was the "DNS domain" for the network connection, without specifying what that means. With this the Domains setting is reworked, so that there are now "routing" domains and "search" domains. The former are to be used by resolved to route DNS request to specific network interfaces, the latter is to be used for searching single-label hostnames with (in addition to being used for routing). Both settings are configured in the "Domains=" setting. Normal domain names listed in it are now considered search domains (for compatibility with existing setups), while those prefixed with "~" are considered routing domains only. To route all lookups to a specific interface the routing domain "." may be used, referring to the root domain. An alternative syntax for this is the "*", as was already implemented before using the "wildcard" domain concept. This commit adds proper parsers for this new logic, and exposes this via the sd-network API. This information is not used by resolved yet, this will be added in a later commit.
2016-01-25resolved: synthesize RRs for data from /etc/hostsLennart Poettering
This way the difference between lookups via NSS and our native bus API should become minimal.
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.
2016-01-19resolved: 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.
2016-01-05resolved,networkd: add a per-interface DNSSEC settingLennart Poettering
This adds a DNSSEC= setting to .network files, and makes resolved honour them.
2016-01-05resolved,networkd: unify ResolveSupport enumLennart Poettering
networkd previously knew an enum "ResolveSupport" for configuring per-interface LLMNR support, resolved had a similar enum just called "Support", with the same value and similar pasers. Unify this, call the enum ResolveSupport, and port both daemons to it.
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.
2015-12-08resolved: add infrastructure for mDNS related socketsDaniel Mack
Just hook up mDNS listeners with an empty packet dispather function, introduce a config directive, man page updates etc.
2015-12-03resolved: add a simple trust anchor database as additional RR sourceLennart Poettering
When doing DNSSEC lookups we need to know one or more DS or DNSKEY RRs as trust anchors to validate lookups. With this change we add a compiled-in trust anchor database, serving the root DS key as of today, retrieved from: https://data.iana.org/root-anchors/root-anchors.xml The interface is kept generic, so that additional DS or DNSKEY RRs may be served via the same interface, for example by provisioning them locally in external files to support "islands" of security. The trust anchor database becomes the fourth source of RRs we maintain, besides, the network, the local cache, and the local zone.
2015-11-25resolved: split out calls to compile full list of dns servers and search domainsLennart Poettering
Let's split this out from the resolv.conf parser, so that this becomes generically useful.
2015-11-25resolved: enforce a maximum limit on both dns servers and search domainsLennart Poettering
2015-11-25resolved: add a generic DnsSearchDomain conceptLennart Poettering
With this change, we add a new object to resolved, "DnsSearchDomain=" which wraps a search domain. This is then used to introduce a global search domain list, in addition to the existing per-link search domain list which is reword to make use of this new object too. This is preparation for implement proper unicast DNS search domain support.
2015-11-25resolved: make sure FallbackDNS= overrides built-in servers, doesn't extend themLennart Poettering
Closes #342.
2015-11-25resolved: move dns server picking code from resolved-manager.c to ↵Lennart Poettering
resolved-dns-server.c
2015-11-25resolved: split out all code dealing with /etc/resolv.conf into its own .c fileLennart Poettering
No functional changes.
2015-11-25resolved: unify code for parsing dns server informationLennart Poettering
Let's use the same parser when parsing dns server information from /etc/resolv.conf and our native configuration file. Also, move all code that manages lists of dns servers to a single place. resolved-dns-server.c
2015-11-18tree-wide: sort includes in *.hThomas Hindoe Paaboel Andersen
This is a continuation of the previous include sort patch, which only sorted for .c files.
2015-08-26resolved: dump cache and zone contents to syslog on SIGUSR1Lennart Poettering
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.
2015-07-27resolved: scope - write() unicast DNS packetsTom Gundersen
As we have connect()ed to the desired DNS server, we no longer need to pass control messages manually when sending packets. Simplify the logic accordingly.
2015-07-14resolved: use one UDP socket per transactionTom Gundersen
We used to have one global socket, use one per transaction instead. This has the side-effect of giving us a random UDP port per transaction, and hence increasing the entropy and making cache poisoining significantly harder to achieve. We still reuse the same port number for packets belonging to the same transaction (resent packets).
2015-07-13resolved: move LLMNR related functions into separate fileDaniel Mack
2015-06-13sd-netlink: rename from sd-rtnlTom Gundersen
2015-02-23remove unused includesThomas Hindoe Paaboel Andersen
This patch removes includes that are not used. The removals were found with include-what-you-use which checks if any of the symbols from a header is in use.
2014-10-22resolved: simplify detection of packets from the loopback deviceLennart Poettering
We can simplify our code quite a bit if we explicitly check for the ifindex being 1 on Linux as a loopback check. Apparently, this is hardcoded on Linux on the kernel, and effectively exported to userspace via rtnl and such, hence we should be able to rely on it.
2014-08-12resolved: unify logic how we flush out DNS servers we learntLennart Poettering
2014-08-11resolved: verify all RRs when we come back from suspendLennart Poettering
2014-08-11resolved: implement full LLMNR conflict detection logicLennart Poettering
2014-08-04resolved: read the per-interface LLMNR setting from networkd and act on itLennart Poettering
2014-08-04resolved: when there's already somebody listening on the LLMNR ports, simple ↵Lennart Poettering
disable LLMNR and warn, but continue This allows us to run resolved inside an nspawn container that shares the network namespace with the host, if there's already an instance running.
2014-08-01resolved: flush cache each time we change to a different DNS serverLennart Poettering
2014-08-01resolved: read the system /etc/resolv.conf unless we wrote it ourselvesLennart Poettering
This way we integrate nicely with foreign network management stacks, such as NM.
2014-08-01resolved: rename resolved.h to resolved-manager.hLennart Poettering
After all it pretty much exlcusively containers definitions about the "Manager" object, hence let's call this the most obvious way.