commit de0ee9781f1a9dc39f34bf012c85bb8ef6438179
parent ac0bbf61fe81b5d097be816471b5b166591691b4
Author: Oliver Lowe <o@olowe.co>
Date: Sun, 4 Aug 2024 20:00:54 +1000
pcap: rename parser.go to pcap
There's no mention of any parsers, and we only have one file
containing both encoding and decoding pcap data.
Diffstat:
3 files changed, 122 insertions(+), 123 deletions(-)
diff --git a/pcap/parser.go b/pcap/parser.go
@@ -1,123 +0,0 @@
-package pcap
-
-import (
- "bytes"
- "encoding/binary"
- "fmt"
- "io"
- "time"
-)
-
-const (
- magicLittleEndian uint32 = 0xa1b2c3d4
- magicBigEndian uint32 = 0xd4c3b2a1
-)
-
-type GlobalHeader struct {
- VersionMajor uint16
- VersionMinor uint16
- ThisZone int32
- SigFigs uint32
- SnapLen uint32
- Network uint32
-}
-
-type Header struct {
- Time time.Time
- OrigLen uint32
-}
-
-type header struct {
- Seconds uint32
- SubSeconds uint32 // micro or nanoseconds
- InclLen uint32
- OrigLen uint32
-}
-
-type Packet struct {
- Header Header
- Data []byte
-}
-
-type File struct {
- Header GlobalHeader
- Packets []Packet
-}
-
-func decode(reader io.Reader) (*File, error) {
- var magic uint32
- if err := binary.Read(reader, binary.NativeEndian, &magic); err != nil {
- return nil, fmt.Errorf("read magic number: %w", err)
- }
- if magic != magicLittleEndian && magic != magicBigEndian {
- return nil, fmt.Errorf("unknown magic number %#x", magic)
- }
-
- var gheader GlobalHeader
- if err := binary.Read(reader, binary.LittleEndian, &gheader); err != nil {
- return nil, fmt.Errorf("read global header: %w", err)
- }
-
- var packets []Packet
- for i := 1; ; i++ {
- var h header
- err := binary.Read(reader, binary.LittleEndian, &h)
- if err == io.EOF {
- break
- } else if err != nil {
- return nil, fmt.Errorf("packet %d: read header: %w", i, err)
- }
- hh := Header{
- Time: time.Unix(int64(h.Seconds), int64(h.SubSeconds)*1000),
- OrigLen: h.OrigLen,
- }
-
- data := make([]byte, h.InclLen)
- if _, err = io.ReadFull(reader, data); err != nil {
- return nil, fmt.Errorf("packet %d: read data: %w", i, err)
- }
-
- packets = append(packets, Packet{
- Header: hh,
- Data: data,
- })
- }
-
- return &File{
- Header: gheader,
- Packets: packets,
- }, nil
-}
-
-func encode(file *File) ([]byte, error) {
- b := make([]byte, 4)
- binary.NativeEndian.PutUint32(b, magicLittleEndian)
- buf := bytes.NewBuffer(b)
- if err := binary.Write(buf, binary.LittleEndian, &file.Header); err != nil {
- return nil, fmt.Errorf("global header: %v", err)
- }
-
- for i, p := range file.Packets {
- sec, nsec := timestamp(p.Header.Time)
- h := header{
- Seconds: sec,
- SubSeconds: nsec / 1000,
- InclLen: uint32(len(p.Data)),
- OrigLen: p.Header.OrigLen,
- }
- if err := binary.Write(buf, binary.LittleEndian, h); err != nil {
- return nil, fmt.Errorf("packet %d: header: %v", i, err)
- }
- if _, err := buf.Write(p.Data); err != nil {
- return nil, fmt.Errorf("packet %d: data: %v", i, err)
- }
- }
-
- return buf.Bytes(), nil
-}
-
-func timestamp(t time.Time) (seconds, nanoSeconds uint32) {
- seconds = uint32(t.Unix())
- nanoSeconds = uint32(t.UnixNano() - t.Unix()*1e9)
- return
-}
diff --git a/pcap/pcap.go b/pcap/pcap.go
@@ -3,3 +3,125 @@
//
// [pcap-savefile(5)]: https://www.tcpdump.org/manpages/pcap-savefile.5.txt
package pcap
+
+import (
+ "bytes"
+ "encoding/binary"
+ "fmt"
+ "io"
+ "time"
+)
+
+const (
+ magicLittleEndian uint32 = 0xa1b2c3d4
+ magicBigEndian uint32 = 0xd4c3b2a1
+)
+
+type GlobalHeader struct {
+ VersionMajor uint16
+ VersionMinor uint16
+ ThisZone int32
+ SigFigs uint32
+ SnapLen uint32
+ Network uint32
+}
+
+type Header struct {
+ Time time.Time
+ OrigLen uint32
+}
+
+type header struct {
+ Seconds uint32
+ SubSeconds uint32 // micro or nanoseconds
+ InclLen uint32
+ OrigLen uint32
+}
+
+type Packet struct {
+ Header Header
+ Data []byte
+}
+
+type File struct {
+ Header GlobalHeader
+ Packets []Packet
+}
+
+func decode(reader io.Reader) (*File, error) {
+ var magic uint32
+ if err := binary.Read(reader, binary.NativeEndian, &magic); err != nil {
+ return nil, fmt.Errorf("read magic number: %w", err)
+ }
+ if magic != magicLittleEndian && magic != magicBigEndian {
+ return nil, fmt.Errorf("unknown magic number %#x", magic)
+ }
+
+ var gheader GlobalHeader
+ if err := binary.Read(reader, binary.LittleEndian, &gheader); err != nil {
+ return nil, fmt.Errorf("read global header: %w", err)
+ }
+
+ var packets []Packet
+ for i := 1; ; i++ {
+ var h header
+ err := binary.Read(reader, binary.LittleEndian, &h)
+ if err == io.EOF {
+ break
+ } else if err != nil {
+ return nil, fmt.Errorf("packet %d: read header: %w", i, err)
+ }
+ hh := Header{
+ Time: time.Unix(int64(h.Seconds), int64(h.SubSeconds)*1000),
+ OrigLen: h.OrigLen,
+ }
+
+ data := make([]byte, h.InclLen)
+ if _, err = io.ReadFull(reader, data); err != nil {
+ return nil, fmt.Errorf("packet %d: read data: %w", i, err)
+ }
+
+ packets = append(packets, Packet{
+ Header: hh,
+ Data: data,
+ })
+ }
+
+ return &File{
+ Header: gheader,
+ Packets: packets,
+ }, nil
+}
+
+func encode(file *File) ([]byte, error) {
+ b := make([]byte, 4)
+ binary.NativeEndian.PutUint32(b, magicLittleEndian)
+ buf := bytes.NewBuffer(b)
+ if err := binary.Write(buf, binary.LittleEndian, &file.Header); err != nil {
+ return nil, fmt.Errorf("global header: %v", err)
+ }
+
+ for i, p := range file.Packets {
+ sec, nsec := timestamp(p.Header.Time)
+ h := header{
+ Seconds: sec,
+ SubSeconds: nsec / 1000,
+ InclLen: uint32(len(p.Data)),
+ OrigLen: p.Header.OrigLen,
+ }
+ if err := binary.Write(buf, binary.LittleEndian, h); err != nil {
+ return nil, fmt.Errorf("packet %d: header: %v", i, err)
+ }
+ if _, err := buf.Write(p.Data); err != nil {
+ return nil, fmt.Errorf("packet %d: data: %v", i, err)
+ }
+ }
+
+ return buf.Bytes(), nil
+}
+
+func timestamp(t time.Time) (seconds, nanoSeconds uint32) {
+ seconds = uint32(t.Unix())
+ nanoSeconds = uint32(t.UnixNano() - t.Unix()*1e9)
+ return
+}
diff --git a/pcap/parser_test.go b/pcap/pcap_test.go
