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Union type for FilePath and HostName. Specify FilePath to "resolv.conf" or numeric IP address in String form.

Warning: Only numeric IP addresses are valid RCHostNames.

Example (using Google's public DNS cache):

>>> let cache = RCHostName "8.8.8.8"

Type for resolver configuration. The easiest way to construct a ResolvConf object is to modify the defaultResolvConf.

Return a default ResolvConf:

• resolvInfo is RCFilePath "/etc/resolv.conf".

  • resolvTimeout is 3,000,000 micro seconds.
  • resolvRetry is 3.
  • resolvBufsize is 512. (obsoleted)

Example (use Google's public DNS cache instead of resolv.conf):

>>> let cache = RCHostName "8.8.8.8"
>>> let rc = defaultResolvConf { resolvInfo = cache }

Abstract data type of DNS Resolver seed. When implementing a DNS cache, this should be re-used.

Make a ResolvSeed from a ResolvConf.

Examples:

>>> rs <- makeResolvSeed defaultResolvConf

Abstract data type of DNS Resolver When implementing a DNS cache, this MUST NOT be re-used.

Giving a thread-safe Resolver to the function of the second argument. A socket for UDP is opened inside and is surely closed.

Giving thread-safe Resolvers to the function of the second argument. Sockets for UDP are opened inside and are surely closed.

Look up resource records for a domain, collecting the results from the ANSWER section of the response.

We repeat an example from Network.DNS.Lookup:

>>> let hostname = Data.ByteString.Char8.pack "www.example.com"
>>> rs <- makeResolvSeed defaultResolvConf
>>> withResolver rs $ \resolver -> lookup resolver hostname A
Right [93.184.216.119]

Look up resource records for a domain, collecting the results from the AUTHORITY section of the response.

Look up a name and return the entire DNS Response. Sample output is included below, however it is not tested -- the sequence number is unpredictable (it has to be!).

The example code:

  let hostname = Data.ByteString.Char8.pack "www.example.com"
  rs <- makeResolvSeed defaultResolvConf
  withResolver rs $ resolver -> lookupRaw resolver hostname A
  

And the (formatted) expected output:

  Right (DNSFormat
          { header = DNSHeader
                       { identifier = 1,
                         flags = DNSFlags
                                   { qOrR = QR_Response,
                                     opcode = OP_STD,
                                     authAnswer = False,
                                     trunCation = False,
                                     recDesired = True,
                                     recAvailable = True,
                                     rcode = NoErr },
                         qdCount = 1,
                         anCount = 1,
                         nsCount = 0,
                         arCount = 0},
            question = [Question { qname = "www.example.com.",
                                   qtype = A}],
            answer = [ResourceRecord {rrname = "www.example.com.",
                                      rrtype = A,
                                      rrttl = 800,
                                      rdlen = 4,
                                      rdata = 93.184.216.119}],
            authority = [],
            additional = []})
 

Like lookupRaw except that no unknown RDATA records are not split up into Ints.

Extract necessary information from DNSFormat