scratch/dns-server/packet.go (view raw)
| 1 | package main |
| 2 | |
| 3 | import "bytes" |
| 4 | |
| 5 | type Packet struct { |
| 6 | Header Header |
| 7 | Questions []Question |
| 8 | Answers []Record |
| 9 | Authorities []Record |
| 10 | Resources []Record |
| 11 | } |
| 12 | |
| 13 | func ParsePacket(packet []byte) (Packet, error) { |
| 14 | r := bytes.NewReader(packet) |
| 15 | |
| 16 | var err error |
| 17 | var p Packet |
| 18 | |
| 19 | p.Header, err = ReadHeader(r) |
| 20 | if err != nil { |
| 21 | return Packet{}, err |
| 22 | } |
| 23 | |
| 24 | // TODO: don't do int(Questions) ???? |
| 25 | for i := 0; i < int(p.Header.Questions); i++ { |
| 26 | q, err := ReadQuestion(r, packet) |
| 27 | if err != nil { |
| 28 | return Packet{}, err |
| 29 | } |
| 30 | p.Questions = append(p.Questions, q) |
| 31 | } |
| 32 | |
| 33 | for i := 0; i < int(p.Header.Answers); i++ { |
| 34 | a, err := ReadRecord(r, packet) |
| 35 | if err != nil { |
| 36 | return Packet{}, err |
| 37 | } |
| 38 | p.Answers = append(p.Answers, a) |
| 39 | } |
| 40 | |
| 41 | for i := 0; i < int(p.Header.AuthoritativeEntries); i++ { |
| 42 | ae, err := ReadRecord(r, packet) |
| 43 | if err != nil { |
| 44 | return Packet{}, err |
| 45 | } |
| 46 | p.Authorities = append(p.Authorities, ae) |
| 47 | } |
| 48 | |
| 49 | for i := 0; i < int(p.Header.ResourceEntries); i++ { |
| 50 | re, err := ReadRecord(r, packet) |
| 51 | if err != nil { |
| 52 | return Packet{}, err |
| 53 | } |
| 54 | p.Resources = append(p.Resources, re) |
| 55 | } |
| 56 | |
| 57 | return p, nil |
| 58 | } |