cmd: support logging reads & writes from sshbytestream to a file.

util/io.go

@@ -2,8 +2,48 @@ package util
 
 import (
 	"io"
+	"os"
 )
 
+type ReadWriteCloserLogger struct {
+	RWC       io.ReadWriteCloser
+	ReadFile  *os.File
+	WriteFile *os.File
+}
+
+func NewReadWriteCloserLogger(rwc io.ReadWriteCloser, readlog, writelog string) (l *ReadWriteCloserLogger, err error) {
+	l = &ReadWriteCloserLogger{
+		RWC: rwc,
+	}
+	flags := os.O_CREATE | os.O_WRONLY
+	if l.ReadFile, err = os.OpenFile(readlog, flags, 0600); err != nil {
+		return
+	}
+	if l.WriteFile, err = os.OpenFile(writelog, flags, 0600); err != nil {
+		return
+	}
+	return
+}
+
+func (c *ReadWriteCloserLogger) Read(buf []byte) (n int, err error) {
+	n, err = c.RWC.Read(buf)
+	if _, writeErr := c.ReadFile.Write(buf[0:n]); writeErr != nil {
+		panic(writeErr)
+	}
+	return
+}
+
+func (c *ReadWriteCloserLogger) Write(buf []byte) (n int, err error) {
+	n, err = c.RWC.Write(buf)
+	if _, writeErr := c.WriteFile.Write(buf[0:n]); writeErr != nil {
+		panic(writeErr)
+	}
+	return
+}
+func (c *ReadWriteCloserLogger) Close() error {
+	return c.RWC.Close()
+}
+
 type ChainedReader struct {
 	Readers   []io.Reader
 	curReader int