internal static DnsDataResourceRecord Parse(DnsDatagram dns, int offsetInDns, out int numBytesRead)
{
DnsDomainName domainName;
DnsType type;
DnsClass dnsClass;
if (!DnsResourceRecord.TryParseBase(dns, offsetInDns, out domainName, out type, out dnsClass, out numBytesRead))
{
return((DnsDataResourceRecord)null);
}
if (offsetInDns + numBytesRead + 6 > dns.Length)
{
return((DnsDataResourceRecord)null);
}
int ttl = dns.ReadInt(offsetInDns + numBytesRead, Endianity.Big);
ushort num = dns.ReadUShort(offsetInDns + numBytesRead + 4, Endianity.Big);
numBytesRead += 6;
if (offsetInDns + numBytesRead + (int)num > dns.Length)
{
return((DnsDataResourceRecord)null);
}
DnsResourceData data = DnsResourceData.Read(dns, type, offsetInDns + numBytesRead, (int)num);
if (data == null)
{
return((DnsDataResourceRecord)null);
}
numBytesRead += (int)num;
if (type == DnsType.Opt)
{
return((DnsDataResourceRecord) new DnsOptResourceRecord(domainName, dnsClass, ttl, data));
}
return(new DnsDataResourceRecord(domainName, type, dnsClass, ttl, data));
}
internal static DnsDataResourceRecord Parse(DnsDatagram dns, int offsetInDns, out int numBytesRead)
{
DnsDomainName domainName;
DnsType type;
DnsClass dnsClass;
if (!TryParseBase(dns, offsetInDns, out domainName, out type, out dnsClass, out numBytesRead))
{
return(null);
}
if (offsetInDns + numBytesRead + MinimumLengthAfterBase > dns.Length)
{
return(null);
}
int ttl = dns.ReadInt(offsetInDns + numBytesRead + OffsetAfterBase.Ttl, Endianity.Big);
ushort dataLength = dns.ReadUShort(offsetInDns + numBytesRead + OffsetAfterBase.DataLength, Endianity.Big);
numBytesRead += MinimumLengthAfterBase;
if (offsetInDns + numBytesRead + dataLength > dns.Length)
{
return(null);
}
DnsResourceData data = DnsResourceData.Read(dns, type, offsetInDns + numBytesRead, dataLength);
if (data == null)
{
return(null);
}
numBytesRead += dataLength;
if (type == DnsType.Opt)
{
return(new DnsOptResourceRecord(domainName, dnsClass, ttl, data));
}
return(new DnsDataResourceRecord(domainName, type, dnsClass, ttl, data));
}