fix close by interrupt read, do not close multiple times

[govpn.git] / src / cypherpunks.ru / govpn / tap.go

diff --git a/src/cypherpunks.ru/govpn/tap.go b/src/cypherpunks.ru/govpn/tap.go
index 5a71f1f1acb23346c35f5ecb97dcfb2508eb5b2a..dd3c7e9dd678606997c88ec2991430988aff9f1f 100644 (file)
--- a/src/cypherpunks.ru/govpn/tap.go
+++ b/src/cypherpunks.ru/govpn/tap.go
@@ -20,24 +20,35 @@ package govpn
 
 import (
        "io"
+
+       "github.com/Sirupsen/logrus"
+       "github.com/pkg/errors"
+)
+
+const (
+       interfaceTap = "tap"
+       interfaceTun = "tun"
 )
 
 // TAP is a TUN or a TAP interface.
+// TODO: rename to something more... generic?
 type TAP struct {
        Name string
        Sink chan []byte
-       dev  io.ReadWriter
+       dev  io.ReadWriteCloser
+       closed bool
 }
 
 var (
-       taps = make(map[string]*TAP)
+       taps                    = make(map[string]*TAP)
+       errUnsupportedInterface = errors.New("Unsupported interface")
 )
 
-// NewTAP create a new TUN/TAP virtual interface
+// NewTAP creates a new TUN/TAP virtual interface
 func NewTAP(ifaceName string, mtu int) (*TAP, error) {
-       tapRaw, err := newTAPer(ifaceName)
+       tapRaw, err := newTAPer(&ifaceName)
        if err != nil {
-               return nil, err
+               return nil, errors.Wrap(err, "newTAPer")
        }
        tap := TAP{
                Name: ifaceName,
@@ -60,7 +71,18 @@ func NewTAP(ifaceName string, mtu int) (*TAP, error) {
                        bufZ = !bufZ
                        n, err = tap.dev.Read(buf)
                        if err != nil {
-                               panic("Reading TUN/TAP:" + err.Error())
+                               if tap.closed {
+                                       return
+                               }
+                               logger.WithError(err).WithFields(logrus.Fields{
+                                       "func": logFuncPrefix + "TAP read sink loop",
+                                       "name": tap.Name,
+                                       "mtu":  mtu,
+                               }).Error("Can not read interface")
+                               return
+                               // TODO: need a way to warn consumer that something is wrong
+                               // TODO: to force peer to just disconnect
+                               // TODO: use the client/server error channel?
                        }
                        tap.Sink <- buf[:n]
                }
@@ -68,11 +90,25 @@ func NewTAP(ifaceName string, mtu int) (*TAP, error) {
        return &tap, nil
 }
 
-func (t *TAP) Write(data []byte) (n int, err error) {
-       return t.dev.Write(data)
+func (t *TAP) Write(data []byte) (int, error) {
+       n, err := t.dev.Write(data)
+       return n, errors.Wrapf(err, "t.dev.Write %d", len(data))
+}
+
+// Close close TAP/TUN virtual network interface
+func (t *TAP) Close() error {
+       if t.closed {
+               return nil
+       }
+       err := t.dev.Close()
+       if err != nil {
+               return errors.Wrap(err, "water.Interface.Close")
+       }
+       t.closed = true
+       return nil
 }
 
-// TAPListen open an existing TAP, if none exists, open one
+// TAPListen opens an existing TAP (creates if none exists)
 func TAPListen(ifaceName string, mtu int) (*TAP, error) {
        tap, exists := taps[ifaceName]
        if exists {
@@ -80,7 +116,7 @@ func TAPListen(ifaceName string, mtu int) (*TAP, error) {
        }
        tap, err := NewTAP(ifaceName, mtu)
        if err != nil {
-               return nil, err
+               return nil, errors.Wrap(err, "NewTAP")
        }
        taps[ifaceName] = tap
        return tap, nil