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| author | jet2tlf <jet2tlf@gmail.com> | 2024-06-03 05:43:21 +0000 |
|---|---|---|
| committer | jet2tlf <jet2tlf@gmail.com> | 2024-06-03 05:43:21 +0000 |
| commit | ddaa6d76691453203459038a35aae5aa086dfad4 (patch) | |
| tree | 54a651954fa57bd9cdf190ffc9aab4e71fc0e425 /app/message.go | |
| parent | 57e0aa0ac0c6efd1dd50b354826cc21b6a5ffdc1 (diff) | |
| download | dns-server-go-ddaa6d76691453203459038a35aae5aa086dfad4.tar.gz dns-server-go-ddaa6d76691453203459038a35aae5aa086dfad4.zip | |
codecrafters submit [skip ci]
Diffstat (limited to 'app/message.go')
| -rw-r--r-- | app/message.go | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/app/message.go b/app/message.go index 0604d0e..931a6f0 100644 --- a/app/message.go +++ b/app/message.go @@ -89,3 +89,21 @@ func (m *DNSMessage) AddAnswer(a DNSAnswer) { func MakeAnswer(name []byte, rdata []byte) DNSAnswer { return DNSAnswer{Name: name, Type: 1, Class: 1, TTL: 60, RDLength: uint16(len(rdata)), RData: rdata} } + +func ParseHeader(buf []byte) DNSHeader { + return DNSHeader{ + ID: binary.BigEndian.Uint16(buf[0:2]), + QR: uint8(buf[2] >> 7), + OPCODE: uint8(buf[2] >> 3 & 0x0f), + AA: uint8(buf[2] >> 2 & 0x01), + TC: uint8(buf[2] >> 1 & 0x01), + RD: uint8(buf[2] & 0x01), + RA: uint8(buf[3] >> 7), + Z: uint8(buf[3] >> 4 & 0x07), + RCODE: uint8(buf[3] & 0x0f), + QDCOUNT: binary.BigEndian.Uint16(buf[4:6]), + ANCOUNT: binary.BigEndian.Uint16(buf[6:8]), + NSCOUNT: binary.BigEndian.Uint16(buf[8:10]), + ARCOUNT: binary.BigEndian.Uint16(buf[10:12]), + } +} |