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GRONG is a DNS (Domain Name System) authoritative name server.It is more a research project than a production-ready program.
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GRONG (Gross and ROugh Nameserver written in Go) is a DNS (Domain Name System) authoritative name server. It is intended as a research project and is not probably suitable for use on the wild Internet. MAY NOT BE SUITABLE ON A PRODUCTION SITE. YOU HAVE BEEN WARNED!!! Disclaimer: I've never been to this city <http://en.wikipedia.org/wiki/Grong> GRONG can only be used as an authoritative name server (like, for instance, nsd), not as a recursive one. GRONG provides a general DNS engine, the front-end, which receives packets, parses them and sends a proper response, and several possible back-ends (named "responders") which generates a response, given the query. Some are provided with GRONG and you are welcome to write others. The official source is <http://github.com/bortzmeyer/grong> Usage ***** ./grong [-address="[ADDRESS]:PORT"] [-debug=N] [-nodaemon] [-domain="DOMAIN NAME"] Run with -help to see the defaults (and the other, less common, options) The -address option takes either a port (in the syntax ":NNN"), in that case GRONG listens on all IP addresses, or one address (in the syntax "x.y.z.T:NNN" for IPv4 and "[xxxx:yyyy::zzzz]:NNN" for IPv6). There is currently no way to listen on some (but not all) of the IP addresses. The -domain option takes a domain name, which will be the name of the zone for which the name server will be authoritative for. Not all responders use it. The back-end is choosen at compile-time only (I have no idea about the support for dynamic linking in Go) Among the provided responders: * rude-responder: responds REFUSED to every query * reflector-responder: responds with the IP address of the client (for TXT requests, in text form, for A or AAAA requests, as binary). -domain indicates the zone name it uses (e.g. whoami.example.net) * as112: an AS 112 name server (see <http://www.as112.net/>) For the person who compiles ************************** You need a working Go <http://golang.org> environment. Today, only the gc compiler is supported. To choose a responder (here, foobar-responder): make clean ln -sf foobar-responder.go responder.go make mv ./server /where/you/want/grong-foobar For the person who writes a responder ************************************ The interface of the responder is: It must be in package "responder" and imports package "types". Read "types.go" first, it contains useful constants (named from the RFC 1035). The front-end checks that the request is a query and, if so, calls the responder. The prototype is: func Respond(query types.DNSquery, config map[string]interface{}) types.DNSresponse To see what is available for you in the query, see the description of type DNSquery. Important: the query name (Qname) is always in lowercase, to ease comparisons. In the DNSresponse, RRs (Resource Records) have to be in the wire format (the front-end does not know the format of the RR, to keep it generic). For instance, data in TXT RR has to be {length, value}. There are some utilities functions in types to help you to do so. The map named "config" above gives you access to global variables. You can never be sure what variables are defined so it is careful to test their existence before using them. Typical variables (read the source code of server.go to find others) are: * debug: an integer for the debug level (0 = no debug, 1 = a bit of debug, etc). Always set. * servername: if set, a string identifying this specific name server (for instance "cdg1.a.ns.example.net"). * zonename: if set, the name of the zone currently served (for instance "myself.example.net") Since the map stores various types (the "interface{}", which means the empty interface, something which is fulfilled by every possible object), you often have to convert data with the reflect package. For instance, to get the integer value of debug: debug, exists := myconfig["debug"] if exists { debugi := reflect.NewValue(debug).(*reflect.IntValue).Get() } The responder must also provide a function: func Init(firstoption int) which will be called at server startup and which can be used to process additional command-line flags (see as112.go for a good example) or any other stuff. Implementation notes ******************** One goroutine is run for every DNS request. Makes the code much simpler and easier to read but may explain the fact that performance are behind BIND. TODO **** Finish the AS112 responder (SOA and NS records) The ability to listen to more than one address (but not all). Can I give several -address option to the flag module? If so, it probably just means firing several udpListeners and several tcpListeners. Since it interacts with the IPv4/IPv6 listening abilities, we may have to wait for the solution of <http://code.google.com/p/go/issues/detail?id=679>. Debugging of Go runtime performance issues, hit it harder with queryperf! Test with gccgo Implements version.server (and version.bind and hostname.bind ?) See if we can replace a good part of package "types" by standard package net/ <http://golang.org/src/pkg/net/dnsmsg.go> It does not seem easy, the dns* files do not export anything outside of package net, they are meant for internal use only. Daemonizing seems very difficult with Go <http://groups.google.com/group/golang-nuts/browse_thread/thread/2b29d93b90501a4b/95242bfb7ae0549e> In the mean time, nohup + & + disown seems the only solution. Provide an example at least for Debian, using start-stop-daemon? A name server with data, for instance able to serve a zone with a simple setup, one SOA, a few NS, and one A record for www.$ORIGIN. The list of zones (all with identical data) and the IP address of the Web server being taken from a file or on the command-line. Configuration file. What is idiomatic in Go? .INI ? <https://github.com/cthom06/go-rproxy> uses JSON. Continue hardening against rogue packets. See the example test-scapy.py in the distribution. Michael Hoisie had a very good suggestion to turn GRONG into a package. He plans: 1) all the source files should have a common package, like "grong". there shouldn't be a main package 2) there could be a Responder interface, that looks like: type Responder interface { Respond(query.DNSquery) DNSresponse } And all the various responders would implement this. 3) The Makefile would have a format like (except modified for Grong): http://github.com/hoisie/web.go/blob/master/Makefile 4) Instead of main() method, there would be a method like Run( resp Responder ) that takes a responder and starts the server Rewrite a good part of Grong to use Go DNS? https://github.com/miekg/godns DNSSEC (no, I'm joking) Author ****** Stéphane Bortzmeyer <stephane+grong@bortzmeyer.org> License ******* This is free software. Free as in free speech, not as in free beer. See the actual license in LICENSE
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GRONG is a DNS (Domain Name System) authoritative name server.It is more a research project than a production-ready program.
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