Files
x/handler/serial/conn.go
T
ginuerzh c6d3238b15 docs(handler/serial): add comprehensive English comments to all files
Add package-level architecture documentation describing two modes
(hop-based forwarding and direct proxy), two-tier dialing strategy
in forwardSerial, recorderConn per-packet logging with direction
convention, and metadata parsing details. No code changes.
2026-06-05 20:46:00 +08:00

88 lines
2.7 KiB
Go

package serial
import (
"bytes"
"context"
"encoding/hex"
"net"
"time"
"github.com/go-gost/core/recorder"
)
// recorderConn wraps a net.Conn to record raw traffic flowing through it.
// Each successful Read or Write that transfers data is logged via the
// configured Recorder, optionally annotated with direction markers,
// timestamps, and hex dumps.
//
// The direction convention is:
// - Read: '>' (data entering GOST from the serial port / client side)
// - Write: '<' (data leaving GOST toward the serial port / client side)
//
// This provides a per-packet-level traffic log, as opposed to the
// aggregate stats approach used by handlers like redirect/tcp (which
// accumulate total byte counts and record once at the end).
type recorderConn struct {
net.Conn
recorder recorder.RecorderObject
}
// Read reads from the underlying connection and records the received data.
// Recording happens only when bytes were actually read (n > 0) AND a
// Recorder is configured. If Read returns an error alongside data
// (e.g. io.EOF after the last chunk), the data is still recorded —
// partial reads before an error are meaningful traffic.
func (c *recorderConn) Read(b []byte) (n int, err error) {
n, err = c.Conn.Read(b)
if n > 0 && c.recorder.Recorder != nil {
var buf bytes.Buffer
if c.recorder.Options != nil && c.recorder.Options.Direction {
buf.WriteByte('>')
}
if c.recorder.Options != nil && c.recorder.Options.TimestampFormat != "" {
buf.WriteString(time.Now().Format(c.recorder.Options.TimestampFormat))
}
if buf.Len() > 0 {
buf.WriteByte('\n')
}
if c.recorder.Options != nil && c.recorder.Options.Hexdump {
buf.WriteString(hex.Dump(b[:n]))
} else {
buf.Write(b[:n])
}
c.recorder.Recorder.Record(context.Background(), buf.Bytes())
}
return
}
// Write writes to the underlying connection and records the sent data.
// Recording follows the same rules as Read: only when n > 0 and a
// Recorder is configured. The direction marker is '<' to indicate
// outbound traffic (data leaving GOST toward the target).
func (c *recorderConn) Write(b []byte) (n int, err error) {
n, err = c.Conn.Write(b)
if n > 0 && c.recorder.Recorder != nil {
var buf bytes.Buffer
if c.recorder.Options != nil && c.recorder.Options.Direction {
buf.WriteByte('<')
}
if c.recorder.Options != nil && c.recorder.Options.TimestampFormat != "" {
buf.WriteString(time.Now().Format(c.recorder.Options.TimestampFormat))
}
if buf.Len() > 0 {
buf.WriteByte('\n')
}
if c.recorder.Options != nil && c.recorder.Options.Hexdump {
buf.WriteString(hex.Dump(b[:n]))
} else {
buf.Write(b[:n])
}
c.recorder.Recorder.Record(context.Background(), buf.Bytes())
}
return
}