Esempio n. 1
0
        /// <summary>
        /// Parses a resource record from the packet passed.
        /// </summary>
        /// <param name="message">The message containing the record being parsed.</param>
        /// <param name="packet">The raw DNS message packet.</param>
        /// <param name="offset">
        /// The current offset in the packet.  Returns as the offset of the first byte
        /// after the record.
        /// </param>
        /// <returns>The resource record or <c>null</c> if there was an error.</returns>
        public static DnsRR Parse(DnsMessage message, byte[] packet, ref int offset)
        {
            string    qname;
            DnsRRType rrtype;
            DnsRR     rr;
            int       savePos;

            // Peek the qname and record type

            savePos = offset;

            if (!message.ReadName(packet, ref offset, out qname))
            {
                return(null);
            }

            rrtype = (DnsRRType)Helper.ReadInt16(packet, ref offset);
            offset = savePos;

            switch (rrtype)
            {
            case DnsRRType.A:

                rr = new A_RR();
                break;

            case DnsRRType.CNAME:

                rr = new CNAME_RR();
                break;

            case DnsRRType.NS:

                rr = new NS_RR();
                break;

            case DnsRRType.MX:

                rr = new MX_RR();
                break;

            case DnsRRType.SOA:

                rr = new SOA_RR();
                break;

            default:

                rr = new DnsRR();
                break;
            }

            if (!rr.Read(message, packet, ref offset))
            {
                return(null);
            }

            return(rr);
        }
Esempio n. 2
0
        /// <summary>
        /// This method parses the resource record from the packet beginning
        /// at the offset passed.
        /// </summary>
        /// <param name="message">The message containing the record being parsed.</param>
        /// <param name="packet">The packet buffer.</param>
        /// <param name="offset">
        /// The offset in the packet where the record is located.
        /// This parameter will return set to the offset of the first
        /// byte after the parsed record.
        /// </param>
        /// <returns>True on success.</returns>
        public bool Read(DnsMessage message, byte[] packet, ref int offset)
        {
            if (!message.ReadName(packet, ref offset, out rname))
            {
                return(false);
            }

            rrtype = (DnsRRType)Helper.ReadInt16(packet, ref offset);
            qclass = (DnsQClass)Helper.ReadInt16(packet, ref offset);
            ttl    = Helper.ReadInt32(packet, ref offset);

            return(ReadData(message, packet, ref offset));
        }
Esempio n. 3
0
        /// <summary>
        /// This method parses the resource record's (including its
        /// length from the packet beginning at the offset passed.
        /// </summary>
        /// <param name="message">The message containing the record being parsed.</param>
        /// <param name="packet">The packet buffer.</param>
        /// <param name="offset">
        /// The offset in the packet where the data will be read.
        /// This parameter will return set to the offset of the first
        /// byte after the parsed data.
        /// </param>
        /// <returns>True on success.</returns>
        protected override bool ReadData(DnsMessage message, byte[] packet, ref int offset)
        {
            int pos;
            int cb;

            cb  = Helper.ReadInt16(packet, ref offset);
            pos = offset;
            if (!message.ReadName(packet, ref offset, out cname))
            {
                return(false);
            }

            return(pos + cb == offset);
        }