internal static NameServerCollection Create(
IEnumerable <DnsClient.DNS.RR> records, IEnumerable <DnsClient.DNS.RR> addresses = null)
{
// NS records from Authority Section
IEnumerable <DnsClient.DNS.Records.NS> nsRecords = records.Select <DnsClient.DNS.Records.NS>();
DnsClient.DNS.Records.NS ns1 = nsRecords.FirstOrDefault();
if (ns1 == null)
{
return(Empty);
}
// There are NS RRs.
NameServerCollection result = new NameServerCollection(
(DnsDomain)ns1.Base.NAME, nsRecords.Select(ns => new NameServer(
(DnsDomain)ns.Base.NAME, (DnsDomain)ns.NSDNAME)));
// Apply address records from Additional Section (A or AAAA) if any
if (addresses != null)
{
foreach (DnsClient.DNS.Records.Address addr in addresses.Select(
rr => rr as DnsClient.DNS.Records.Address).Where(a => a != null))
{
DnsDomain name = DnsDomain.Parse(addr.Base.NAME);
if (result.NameServers.ContainsKey(name))
{
result.NameServers[name].Addresses.Add(addr.ADDRESS);
}
}
}
return(result);
}
public bool Equals(DnsDomain obj)
{
if (obj == null)
{
return(false);
}
return(_Domain.Equals(obj._Domain));
}
public NetworkHost(string name)
{
if (name == null)
{
throw new ArgumentNullException("name", "Value cannot be null.");
}
_Name = DnsDomain.Parse(name);
_Addresses = new List <IPAddress>();
}
/// <summary>
/// Initialize a new instance of the Resolver class using default options.
/// </summary>
/// <param name="domain">The domain in question</param>
public DomainResolver(string domain)
{
if (String.IsNullOrEmpty(domain))
{
throw new ArgumentNullException("domain", "String value cannot be null or empty.");
}
_Options = Options.Default;
_Domain = (DnsDomain)domain;
}
/// <summary>
/// Initialize a new instance of the Resolver class using default options.
/// </summary>
/// <param name="domain">The domain in question</param>
public DomainResolver(DnsDomain domain)
{
if (object.ReferenceEquals(null, domain))
{
throw new ArgumentNullException("domain");
}
_Options = Options.Default;
_Domain = domain;
}
/// <summary>
/// Initialize a new instance of the Resolver class.
/// </summary>
/// <param name="options">Resolution options</param>
/// <param name="domain">The domain in question</param>
public DomainResolver(Options options, DnsDomain domain)
{
if (object.ReferenceEquals(null, options))
{
throw new ArgumentNullException("options");
}
if (object.ReferenceEquals(null, domain))
{
throw new ArgumentNullException("domain");
}
_Options = options;
_Domain = domain;
}
/// <summary>
/// Initialize a new instance of the Resolver class.
/// </summary>
/// <param name="options">Resolution options</param>
/// <param name="domain">The domain in question</param>
public DomainResolver(Options options, string domain)
{
if (object.ReferenceEquals(null, options))
{
throw new ArgumentNullException("options");
}
if (String.IsNullOrEmpty(domain))
{
throw new ArgumentNullException("domain", "String value cannot be null or empty.");
}
_Options = options;
_Domain = (DnsDomain)domain;
}
public NetworkHost(DnsDomain name, IEnumerable <IPAddress> addresses)
{
if (name == null)
{
throw new ArgumentNullException("name", "Value cannot be null.");
}
if (addresses == null)
{
throw new ArgumentNullException("addresses", "Value cannot be null.");
}
_Name = name;
_Addresses = new List <IPAddress>(addresses);
}
public override bool Equals(object obj)
{
DnsDomain n = obj as DnsDomain;
if ((object)n == null)
{
string s = obj as string;
if ((object)s == null)
{
return(false);
}
return(Equals(s));
}
return(Equals(n));
}
// Internal c'tor for RootServers.
// Create instances through Find().
internal NameServerCollection(DnsDomain zoneName,
IEnumerable <NameServer> nameservers)
{
if (object.ReferenceEquals(null, zoneName))
{
throw new ArgumentNullException("zoneName");
}
if (object.ReferenceEquals(null, nameservers))
{
throw new ArgumentNullException("nameservers");
}
_ZoneName = zoneName;
NameServers = nameservers.ToDictionary(s => s.Name, s => s);
}
internal static NameServerCollection Find(DnsDomain domain,
IEnumerable <DnsClient.DNS.RR> records, IEnumerable <DnsClient.DNS.RR> addresses)
{
// [RFC 1034]
// 5.3.3. Algorithm
//
// 2. Find the best servers to ask.
//
// Step 2 looks for a name server to ask for the required data. The
// general strategy is to look for locally-available name server RRs,
// starting at SNAME, then the parent domain name of SNAME, the
// grandparent, and so on toward the root. Thus if SNAME were
// Mockapetris.ISI.EDU, this step would look for NS RRs for
// Mockapetris.ISI.EDU, then ISI.EDU, then EDU, and then . (the root).
// These NS RRs list the names of hosts for a zone at or above SNAME. Copy
// the names into SLIST.
// NS records from Authority Section above domain (SNAME)
IEnumerable <DnsClient.DNS.Records.NS> nservers = records.Select <
DnsClient.DNS.Records.NS>().Where(ns => domain.IsBelow(ns.Base.NAME));
if (!nservers.Any())
{
return(Empty);
}
// There are relevant NS RRs.
NameServerCollection result = new NameServerCollection(
domain, nservers.Select(ns => new NameServer(
(DnsDomain)ns.Base.NAME, (DnsDomain)ns.NSDNAME)));
// Apply address records from Additional Section (A or AAAA) if any
if (!object.ReferenceEquals(null, addresses))
{
foreach (DnsClient.DNS.Records.Address addr in addresses.Select <
DnsClient.DNS.Records.Address>())
{
DnsDomain hostname = (DnsDomain)addr.Base.NAME;
if (result.NameServers.ContainsKey(hostname))
{
result.NameServers[hostname].Addresses.Add(addr.ADDRESS);
}
}
}
return(result);
}
/// <summary>
/// Randomly select one item from the collection of name servers (resolved items prefered).
/// <para>The method is invalid for an empty set of name servers.</para>
/// </summary>
/// <returns></returns>
public NameServer SelectAny()
{
if (IsEmpty)
{
throw new InvalidOperationException(
"The method is invalid for an empty set of name servers.");
}
// At least one name server exists.
NameServer selected = null;
Random r = new Random((int)DateTime.Now.Ticks ^ DateTime.Now.Millisecond);
// Try selecting on each name level, from highest to lowest.
foreach (IGrouping <int, NameServer> nsg in Groupings)
{
int c = nsg.Count(), resc;
if (c == 0)
{
continue;
}
// prefer resolved servers
IEnumerable <NameServer> resolved = NameServers.Values.Where(
ns => ns.IsResolved);
if ((resc = resolved.Count()) > 0)
{
selected = resolved.ElementAt(r.Next(0, resc));
}
else
{
// get any
selected = nsg.ElementAt(r.Next(0, c));
}
}
// selected cannot be null
SelectedName = selected.Name;
return(selected);
}
/// <summary>
/// Mark one item in the collection of name servers as the selected one.
/// <para>The method is invalid for an empty set of name servers.</para>
/// </summary>
/// <param name="selected"></param>
public void SelectOne(NameServer selected)
{
if (IsEmpty)
{
throw new InvalidOperationException(
"The method is invalid for an empty set of name servers.");
}
if (object.ReferenceEquals(null, selected))
{
throw new ArgumentNullException("selected");
}
try
{
SelectedName = NameServers[selected.Name].Name;
}
catch (Exception ex)
{
throw new ArgumentException(
"The given name server was not found in the collection.", "selected", ex);
}
}
public static bool TryParse(string input, out DnsDomain domain)
{
if (object.ReferenceEquals(null, input))
{
throw new ArgumentNullException("input");
}
domain = null;
input = input.Trim();
if (input.Equals("."))
{
domain = Root;
return(true);
}
if (input.Length == 0)
{
return(false);
}
if (input.Length > 255)
{
return(false);
}
if (input[input.Length - 1] == '.')
{
input = input.Substring(0, input.Length - 1);
}
IEnumerable <DnsLabel> labels = input.Split('.').Select(s => DnsLabel.Parse(s));
domain = new DnsDomain(labels.Reverse(), String.Join(".", labels.Select(a => (a.ToString())).ToArray()) + '.');
return(true);
}
public NameServer(DnsDomain name)
: base(name)
{
this.Zone = null;
}
internal DomainResolver(DomainResolver resolver, DnsDomain domain)
{
_Options = resolver.Options;
_Domain = domain;
}
//public NameServer(string name)
// : base(name)
//{
// this.Zone = null;
//}
//public NameServer(DnsDomain name, IEnumerable<IPAddress> addresses)
// : base(name, addresses)
//{
//}
public NameServer(DnsDomain zone, DnsDomain name)
: base(name)
{
this.Zone = zone;
}
public bool IsBelow(DnsDomain domain)
{
return(this._Domain.EndsWith(domain._Domain));
}
public NameServer(DnsDomain zone, DnsDomain name, IEnumerable <IPAddress> addresses)
: base(name, addresses)
{
this.Zone = zone;
}
// Empty c'tor
private NameServerCollection()
{
_ZoneName = null;
NameServers = new Dictionary <DnsDomain, NameServer>();
}
