add tee module

5 files changed, 128 insertions, 9 deletions

diff --git a/pkg/server/env/env.go b/pkg/server/env/env.go
index 237c0c5..118f853 100644
--- a/pkg/server/env/env.go
+++ b/pkg/server/env/env.go
@@ -22,6 +22,7 @@ var isNamePattern = regexp.MustCompile("^" + namePattern + "$").MatchString
 var namePatternRe = regexp.MustCompile("@(" + namePattern + "|{" + namePattern + "})")
 
 var errBadVariable = errors.New("bad variable name")
+var errEmptyVariable = errors.New("empty variable")
 
 func New() Env {
 	return Env{new(env)}
@@ -66,6 +67,10 @@ func (e *env) Set(key string, value string) error {
 		return errBadVariable
 	}
 
+	if value == "" {
+		return errEmptyVariable
+	}
+
 	e.Lock()
 	defer e.Unlock()
 
diff --git a/pkg/server/module/auth.go b/pkg/server/module/auth.go
index de58e82..5e5caeb 100644
--- a/pkg/server/module/auth.go
+++ b/pkg/server/module/auth.go
@@ -4,7 +4,6 @@ import (
 	"crypto/md5"
 	"crypto/rand"
 	"errors"
-	"fmt"
 	"io"
 	"tunnel/pkg/netstring"
 	"tunnel/pkg/server/env"
@@ -124,12 +123,8 @@ func (a *auth) Recv(rq, wq queue.Q) (err error) {
 }
 
 func getAuthSecret(env env.Env) string {
-	if id, ok := env.Find("tunnel"); ok {
-		k := fmt.Sprintf("tunnel.%s.secret", id)
-
-		if v, ok := env.Find(k); ok {
-			return v
-		}
+	if v := env.Eval("@{tunnel.@{tunnel}.secret}"); v != "" {
+		return v
 	}
 
 	return env.Get("secret")
diff --git a/pkg/server/module/hex.go b/pkg/server/module/hex.go
index e71688c..ef4ff37 100644
--- a/pkg/server/module/hex.go
+++ b/pkg/server/module/hex.go
@@ -24,7 +24,7 @@ func (m hexModule) Recv(rq, wq queue.Q) error {
 	return queue.IoCopy(r, wq.Writer())
 }
 
-func (m hexModule) Open(env env.Env) (interface{}, error) {
+func (m hexModule) Open(env.Env) (interface{}, error) {
 	return m, nil
 }
 
diff --git a/pkg/server/module/tee.go b/pkg/server/module/tee.go
new file mode 100644
index 0000000..7953247
--- /dev/null
+++ b/pkg/server/module/tee.go
@@ -0,0 +1,112 @@
+package module
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"encoding/hex"
+	"sync"
+	"tunnel/pkg/server/env"
+	"tunnel/pkg/server/opts"
+	"tunnel/pkg/server/queue"
+)
+
+const teeDefaultPath = "/tmp/tunnel.dump"
+
+type tee struct {
+	f *os.File
+	mu sync.Mutex
+	wg sync.WaitGroup
+}
+
+type teeModule struct {
+	path string
+}
+
+func (t *tee) dump(s string, p []byte) error {
+	var out bytes.Buffer
+
+	fmt.Fprintln(&out, s, len(p))
+
+	w := hex.Dumper(&out)
+	w.Write(p)
+	w.Close()
+
+	if _, err := t.f.Write(out.Bytes()); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (t *tee) Send(rq, wq queue.Q) error {
+	defer t.wg.Done()
+
+	for b := range rq {
+		t.dump(">", b)
+		wq <- b
+	}
+
+	return nil
+}
+
+func (t *tee) Recv(rq, wq queue.Q) error {
+	defer t.wg.Done()
+
+	for b := range rq {
+		t.dump("<", b)
+		wq <- b
+	}
+
+	return nil
+}
+
+func (m *teeModule) where(env env.Env) string {
+	if m.path != "" {
+		return m.path
+	}
+
+	if v := env.Eval("@{tunnel.@{tunnel}.tee.path}"); v != "" {
+		return v
+	}
+
+	if v, ok := env.Find("module.tee.path"); ok {
+		return v
+	}
+
+	return teeDefaultPath
+}
+
+func (m *teeModule) Open(env env.Env) (interface{}, error) {
+	tid, sid := env.Get("tunnel"), env.Get("stream")
+	name := fmt.Sprintf("%s.%s.%s", m.where(env), tid, sid)
+
+	var t tee
+
+	if f, err := os.Create(name); err != nil {
+		return nil, err
+	} else {
+		t.f = f
+	}
+
+	t.wg.Add(2)
+
+	go func() {
+		t.wg.Wait()
+		t.f.Close()
+	}()
+
+	return &t, nil
+}
+
+func newTeeModule(opts opts.Opts, env env.Env) (module, error) {
+	m := &teeModule{}
+	if path, ok := opts["path"]; ok {
+		m.path = path
+	}
+	return m, nil
+}
+
+func init() {
+	register("tee", newTeeModule)
+}
diff --git a/pkg/server/tunnel.go b/pkg/server/tunnel.go
index 189703d..91d7533 100644
--- a/pkg/server/tunnel.go
+++ b/pkg/server/tunnel.go
@@ -6,6 +6,7 @@ import (
 	"io"
 	"log"
 	"sort"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -140,6 +141,7 @@ func (t *tunnel) newStream(in, out socket.Channel) *stream {
 	}
 
 	s.env.Set("tunnel", t.id)
+	s.env.Set("stream", strconv.Itoa(s.id))
 
 	s.run()
 
@@ -208,7 +210,12 @@ func (s *stream) run() {
 	s.channel(s.in, rq, wq)
 
 	for _, m := range s.t.m {
-		send, recv, _ := module.Open(m, s.env)
+		send, recv, err := module.Open(m, s.env)
+		if err != nil {
+			// FIXME: abort stream on error
+			log.Println(s.t, s, m, err)
+			continue
+		}
 
 		if send != nil {
 			q := queue.New()