| 1 | package portal |
| 2 | |
| 3 | import ( |
| 4 | "errors" |
| 5 | "io" |
| 6 | "net" |
| 7 | "sync" |
| 8 | "sync/atomic" |
| 9 | "time" |
| 10 | |
| 11 | "golang.org/x/sync/errgroup" |
| 12 | |
| 13 | "github.com/gosuda/portal-tunnel/v2/portal/policy" |
| 14 | ) |
| 15 | |
| 16 | type proxy struct { |
| 17 | activeConns atomic.Int64 |
| 18 | tcpBytes atomic.Int64 |
| 19 | tcpLoadMu sync.Mutex |
| 20 | tcpLoadAt time.Time |
| 21 | tcpLoadBytes int64 |
| 22 | } |
| 23 | |
| 24 | func (p *proxy) bridge(left, right net.Conn, identityKey string, bpsManager *policy.BPSManager) { |
| 25 | p.activeConns.Add(1) |
| 26 | defer p.activeConns.Add(-1) |
| 27 | |
| 28 | defer left.Close() |
| 29 | defer right.Close() |
| 30 | |
| 31 | throttled := bpsManager != nil && bpsManager.IdentityBPS(identityKey) > 0 |
| 32 | var group errgroup.Group |
| 33 | group.Go(func() error { |
| 34 | err := p.copy(right, left, identityKey, bpsManager, throttled) |
| 35 | closeWrite(right) |
| 36 | return err |
| 37 | }) |
| 38 | group.Go(func() error { |
| 39 | err := p.copy(left, right, identityKey, bpsManager, throttled) |
| 40 | closeWrite(left) |
| 41 | return err |
| 42 | }) |
| 43 | _ = group.Wait() |
| 44 | } |
| 45 | |
| 46 | func (p *proxy) activeConnectionCount() int64 { |
| 47 | return p.activeConns.Load() |
| 48 | } |
| 49 | |
| 50 | func (p *proxy) currentTCPBPS(now time.Time) float64 { |
| 51 | totalTCPBytes := p.tcpBytes.Load() |
| 52 | |
| 53 | p.tcpLoadMu.Lock() |
| 54 | defer p.tcpLoadMu.Unlock() |
| 55 | |
| 56 | if p.tcpLoadAt.IsZero() { |
| 57 | p.tcpLoadAt = now |
| 58 | p.tcpLoadBytes = totalTCPBytes |
| 59 | return 0 |
| 60 | } |
| 61 | |
| 62 | if elapsed := now.Sub(p.tcpLoadAt); elapsed > 0 { |
| 63 | tcpTrafficBPS := float64(totalTCPBytes-p.tcpLoadBytes) / elapsed.Seconds() |
| 64 | p.tcpLoadAt = now |
| 65 | p.tcpLoadBytes = totalTCPBytes |
| 66 | return tcpTrafficBPS |
| 67 | } |
| 68 | |
| 69 | return 0 |
| 70 | } |
| 71 | |
| 72 | func (p *proxy) copy(dst, src net.Conn, identityKey string, bpsManager *policy.BPSManager, throttled bool) error { |
| 73 | // fast path |
| 74 | if !throttled { |
| 75 | _, err := io.Copy(&countingConn{Conn: dst, bytes: &p.tcpBytes}, src) |
| 76 | return err |
| 77 | } |
| 78 | |
| 79 | buf := make([]byte, 32*1024) |
| 80 | for { |
| 81 | nr, readErr := src.Read(buf) |
| 82 | if nr > 0 { |
| 83 | data := buf[:nr] |
| 84 | for len(data) > 0 { |
| 85 | chunkSize := len(data) |
| 86 | if bpsManager != nil { |
| 87 | chunkSize = bpsManager.ThrottleIdentityBPS(identityKey, chunkSize) |
| 88 | } |
| 89 | |
| 90 | n, err := dst.Write(data[:chunkSize]) |
| 91 | if n > 0 { |
| 92 | p.tcpBytes.Add(int64(n)) |
| 93 | data = data[n:] |
| 94 | } |
| 95 | if err != nil { |
| 96 | return err |
| 97 | } |
| 98 | if n == 0 { |
| 99 | return io.ErrShortWrite |
| 100 | } |
| 101 | } |
| 102 | } |
| 103 | if readErr != nil { |
| 104 | if errors.Is(readErr, io.EOF) { |
| 105 | return nil |
| 106 | } |
| 107 | return readErr |
| 108 | } |
| 109 | } |
| 110 | } |
| 111 | |
| 112 | type countingConn struct { |
| 113 | net.Conn |
| 114 | bytes *atomic.Int64 |
| 115 | } |
| 116 | |
| 117 | func (c *countingConn) Write(p []byte) (int, error) { |
| 118 | n, err := c.Conn.Write(p) |
| 119 | if n > 0 { |
| 120 | c.bytes.Add(int64(n)) |
| 121 | } |
| 122 | return n, err |
| 123 | } |
| 124 | |
| 125 | func (c *countingConn) ReadFrom(r io.Reader) (int64, error) { |
| 126 | readerFrom, ok := c.Conn.(io.ReaderFrom) |
| 127 | if !ok { |
| 128 | return io.Copy(struct{ io.Writer }{Writer: c}, r) |
| 129 | } |
| 130 | |
| 131 | n, err := readerFrom.ReadFrom(r) |
| 132 | if n > 0 { |
| 133 | c.bytes.Add(n) |
| 134 | } |
| 135 | return n, err |
| 136 | } |
| 137 | |
| 138 | func closeWrite(conn net.Conn) { |
| 139 | type closeWriter interface { |
| 140 | CloseWrite() error |
| 141 | } |
| 142 | if cw, ok := conn.(closeWriter); ok { |
| 143 | _ = cw.CloseWrite() |
| 144 | } |
| 145 | } |