1package main
 2
 3import (
 4	"errors"
 5	"fmt"
 6	"io"
 7	"log/slog"
 8	"net"
 9	"time"
10
11	"github.com/dustin/go-humanize"
12)
13
14func (c connection) Proxy() error {
15	c.proxyData(send)
16	c.proxyData(recv)
17	return c.errgroup.Wait()
18}
19
20func (c connection) proxyData(d direction) {
21
22	c.errgroup.Go(func() error {
23
24		// send/recv direction
25		id := c.Id()
26		name := d.String()
27		src, dst := c.sConn, c.dConn
28		if d == recv {
29			src, dst = c.dConn, c.sConn
30		}
31
32		start := time.Now()
33		lastByte := time.Now()
34		bytes := uint64(0)
35
36		defer func() {
37			c.cancel()
38			speed := uint64(0)
39			elapsed := time.Since(start).Round(time.Second)
40			if elapsed > 0 {
41				speed = bytes / uint64(elapsed.Seconds())
42			}
43			elapsedLB := time.Since(lastByte).Round(time.Second)
44			if elapsedLB > 0 {
45				speed = bytes / uint64(elapsedLB.Seconds())
46			}
47			human_speed := humanize.Bytes(speed)
48			slog.Info("complete",
49				slog.String("conn", d.String()),
50				slog.String("speed", human_speed+"/s"),
51				slog.Uint64("bytes", bytes),
52				slog.Duration("duration", elapsed),
53				slog.Duration("durationLB", elapsedLB))
54		}()
55
56		buf := make([]byte, bufSize)
57		for {
58			select {
59			case <-c.ctx.Done():
60				err := src.Close()
61				if err != nil {
62					return fmt.Errorf("proxy: %s failed to close id=%q: %w",
63						name, id, err)
64				}
65				return nil
66			default:
67				src.SetReadDeadline(time.Now().Add(timeout))
68				n, err := src.Read(buf)
69				if err != nil {
70					if errors.Is(err, io.EOF) {
71						return nil
72					}
73					opErr, ok := err.(*net.OpError)
74					if ok && opErr.Timeout() {
75						return fmt.Errorf("proxy: %s timeout id=%q: %w",
76							name, id, err)
77					}
78					return fmt.Errorf("proxy: %s failed to read id=%q: %w",
79						name, id, err)
80				}
81				lastByte = time.Now()
82				bytes += uint64(n)
83				dst.SetWriteDeadline(time.Now().Add(timeout))
84				_, err = dst.Write(buf[:n])
85				if err != nil {
86					return fmt.Errorf("proxy: %s failed to write id=%q: %w",
87						name, id, err)
88				}
89			}
90		}
91	})
92}