private static void ProcessControlDirective(DnsZoneParseContext context)
{
var token = context.Tokens.Dequeue();
var directive = token.StringValue;
switch (directive.ToUpperInvariant())
{
case "ORIGIN":
context.Origin = context.ReadAndResolveDomainName();
break;
case "INCLUDE":
var firstToken = context.Tokens.Dequeue();
var secondToken = context.Tokens.Dequeue();
if (secondToken.Type == TokenType.NewLine)
{
ProcessIncludeDirective(context, context.Origin, firstToken.StringValue);
}
else
{
context.Tokens.Dequeue(); //end of line
ProcessIncludeDirective(context, secondToken.StringValue, firstToken.StringValue);
}
break;
case "TTL":
context.DefaultTtl = context.ReadTimeSpan();
break;
default:
throw new NotSupportedException($"Unknown control directive '{directive}'");
}
}
private static void Process(DnsZoneParseContext context)
{
while (!context.IsEof)
{
var token = context.Tokens.Peek();
switch (token.Type)
{
case TokenType.NewLine:
context.Tokens.Dequeue();
break;
case TokenType.Control:
ProcessControlDirective(context);
break;
case TokenType.Whitespace:
case TokenType.Literal:
ParseResourceRecord(context);
break;
default:
throw new NotSupportedException($"not supported type {token.Type}");
}
}
}
private static void ProcessIncludeDirective(DnsZoneParseContext context, string origin, string fileName)
{
var childContext = context.CreateChildContext(fileName);
childContext.Origin = context.ResolveDomainName(origin);
Process(childContext);
context.Zone.Add(childContext.Zone);
}
public static DnsZoneFile Parse(IDnsSource source)
{
var tokenizer = new Tokenizer();
var fileSource = new FileSource {
Content = source.LoadContent(null)
};
var tokens = tokenizer.Read(fileSource).ToArray();
var context = new DnsZoneParseContext(tokens, source);
Process(context);
return(context.Zone);
}
private static void ParseResourceRecord(DnsZoneParseContext context)
{
string @class;
TimeSpan?ttl;
var nameToken = context.Tokens.Dequeue();
var name = nameToken.Type != TokenType.Whitespace ? nameToken.StringValue : "";
if (context.TryParseClass(out @class))
{
context.TryParseTtl(out ttl);
}
else if (context.TryParseTtl(out ttl))
{
context.TryParseClass(out @class);
}
var type = context.ReadResourceRecordType();
//An RRT.NULL return indicates we encountered some kind of
//whitespace instead of the ReadResourceRecordType.
if (type == ResourceRecordType.NULL)
{
return;
}
string domainName;
try {
domainName = context.ResolveDomainName(!string.IsNullOrWhiteSpace(name) ? name : context.PrevName);
} catch (ArgumentException exc) {
throw new TokenException(exc.Message, nameToken);
}
var record = DnsZoneUtils.CreateRecord(type);
record.Name = domainName;
record.Class = !string.IsNullOrWhiteSpace(@class) ? @class : context.PrevClass;
record.Ttl = context.GetTimeSpan(ttl);
record.AcceptVistor(_reader, context);
context.Zone.Records.Add(record);
context.PrevName = name;
if (!string.IsNullOrWhiteSpace(@class))
{
context.PrevClass = @class;
}
}
private static void ParseResourceRecord(DnsZoneParseContext context)
{
string @class;
TimeSpan?ttl;
var nameToken = context.Tokens.Dequeue();
var name = nameToken.Type != TokenType.Whitespace ? nameToken.StringValue : "";
if (context.TryParseClass(out @class))
{
context.TryParseTtl(out ttl);
}
else if (context.TryParseTtl(out ttl))
{
context.TryParseClass(out @class);
}
var type = context.ReadResourceRecordType();
var record = DnsZoneUtils.CreateRecord(type);
record.Name = context.ResolveDomainName(!string.IsNullOrWhiteSpace(name) ? name : context.PrevName);
record.Class = !string.IsNullOrWhiteSpace(@class) ? @class : context.PrevClass;
record.Ttl = context.GetTimeSpan(ttl);
record.AcceptVistor(_reader, context);
context.Zone.Records.Add(record);
context.PrevName = name;
if (!string.IsNullOrWhiteSpace(@class))
{
context.PrevClass = @class;
}
}
private static void ParseResourceRecord(DnsZoneParseContext context)
{
string @class = null;
TimeSpan?ttl = null;
if (context.Tokens.Count == 0)
{
return;
}
string name = null;
var nameToken = context.Tokens.Dequeue();
if (nameToken.Type == TokenType.Literal)
{
name = nameToken.StringValue;
}
else if (nameToken.Type == TokenType.Whitespace)
{
var preview = context.Tokens.Peek();
if (preview.Type == TokenType.NewLine || preview.Type == TokenType.NewLine)
{
context.Tokens.Dequeue();
return;
}
name = "";
}
else if (nameToken.Type == TokenType.Comments)
{
return;
}
else if (nameToken.Type == TokenType.NewLine)
{
return;
}
while (@class == null || ttl == null)
{
if (context.Tokens.Count == 0)
{
if (string.IsNullOrWhiteSpace(name))
{
return;
}
else
{
throw new TokenException("missing record type", nameToken);
}
}
var token = context.Tokens.Peek();
if (token.Type == TokenType.Literal)
{
if (@class == null)
{
if (context.TryParseClass(out @class))
{
continue;
}
}
if (@ttl == null)
{
if (context.TryParseTtl(out ttl))
{
continue;
}
}
break;
}
else if (token.Type == TokenType.Comments || token.Type == TokenType.NewLine)
{
throw new TokenException("missing record type", token);
}
else
{
throw new TokenException("unexpected token", token);
}
}
var type = context.ReadResourceRecordType();
string domainName;
try {
domainName = context.ResolveDomainName(!string.IsNullOrWhiteSpace(name) ? name : context.PrevName);
} catch (ArgumentException exc) {
throw new TokenException(exc.Message, nameToken);
}
var record = DnsZoneUtils.CreateRecord(type);
record.Name = domainName;
record.Class = !string.IsNullOrWhiteSpace(@class) ? @class : context.PrevClass;
record.Ttl = context.GetTimeSpan(ttl);
record.AcceptVistor(_reader, context);
context.Zone.Records.Add(record);
if (!string.IsNullOrWhiteSpace(name))
{
context.PrevName = name;
}
if (!string.IsNullOrWhiteSpace(@class))
{
context.PrevClass = @class;
}
}
