new feature plugin and unix domian socket plugin

models/config/proxy.go

@@ -239,6 +239,7 @@ func (cfg *DomainConf) check() (err error) {
 	return nil
 }
 
+// Local service info
 type LocalSvrConf struct {
 	LocalIp   string `json:"-"`
 	LocalPort int    `json:"-"`
@@ -259,12 +260,34 @@ func (cfg *LocalSvrConf) LoadFromFile(name string, section ini.Section) (err err
 	return nil
 }
 
+type PluginConf struct {
+	Plugin       string            `json:"-"`
+	PluginParams map[string]string `json:"-"`
+}
+
+func (cfg *PluginConf) LoadFromFile(name string, section ini.Section) (err error) {
+	cfg.Plugin = section["plugin"]
+	cfg.PluginParams = make(map[string]string)
+	if cfg.Plugin != "" {
+		// get params begin with "plugin_"
+		for k, v := range section {
+			if strings.HasPrefix(k, "plugin_") {
+				cfg.PluginParams[k] = v
+			}
+		}
+	} else {
+		return fmt.Errorf("Parse conf error: proxy [%s] no plugin info found", name)
+	}
+	return
+}
+
 // TCP
 type TcpProxyConf struct {
 	BaseProxyConf
 	BindInfoConf
 
 	LocalSvrConf
+	PluginConf
 }
 
 func (cfg *TcpProxyConf) LoadFromMsg(pMsg *msg.NewProxy) {
@@ -279,8 +302,11 @@ func (cfg *TcpProxyConf) LoadFromFile(name string, section ini.Section) (err err
 	if err = cfg.BindInfoConf.LoadFromFile(name, section); err != nil {
 		return
 	}
-	if err = cfg.LocalSvrConf.LoadFromFile(name, section); err != nil {
-		return
+
+	if err = cfg.PluginConf.LoadFromFile(name, section); err != nil {
+		if err = cfg.LocalSvrConf.LoadFromFile(name, section); err != nil {
+			return
+		}
 	}
 	return
 }
@@ -337,6 +363,7 @@ type HttpProxyConf struct {
 	DomainConf
 
 	LocalSvrConf
+	PluginConf
 
 	Locations         []string `json:"locations"`
 	HostHeaderRewrite string   `json:"host_header_rewrite"`
@@ -405,6 +432,7 @@ type HttpsProxyConf struct {
 	DomainConf
 
 	LocalSvrConf
+	PluginConf
 }
 
 func (cfg *HttpsProxyConf) LoadFromMsg(pMsg *msg.NewProxy) {

models/plugin/plugin.go

@@ -0,0 +1,45 @@
+// Copyright 2017 fatedier, fatedier@gmail.com
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package plugin
+
+import (
+	"fmt"
+	"io"
+)
+
+// Creators is used for create plugins to handle connections.
+var creators = make(map[string]CreatorFn)
+
+// params has prefix "plugin_"
+type CreatorFn func(params map[string]string) (Plugin, error)
+
+func Register(name string, fn CreatorFn) {
+	creators[name] = fn
+}
+
+func Create(name string, params map[string]string) (p Plugin, err error) {
+	if fn, ok := creators[name]; ok {
+		p, err = fn(params)
+	} else {
+		err = fmt.Errorf("plugin [%s] is not registered", name)
+	}
+	return
+}
+
+type Plugin interface {
+	Name() string
+	Handle(conn io.ReadWriteCloser)
+	Close() error
+}

models/plugin/unix_domain_socket.go

@@ -0,0 +1,69 @@
+// Copyright 2017 fatedier, fatedier@gmail.com
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package plugin
+
+import (
+	"fmt"
+	"io"
+	"net"
+
+	"github.com/fatedier/frp/models/proto/tcp"
+)
+
+const PluginUnixDomainSocket = "unix_domain_socket"
+
+func init() {
+	Register(PluginUnixDomainSocket, NewUnixDomainSocketPlugin)
+}
+
+type UnixDomainSocketPlugin struct {
+	UnixAddr *net.UnixAddr
+}
+
+func NewUnixDomainSocketPlugin(params map[string]string) (p Plugin, err error) {
+	unixPath, ok := params["plugin_unix_path"]
+	if !ok {
+		err = fmt.Errorf("plugin_unix_path not found")
+		return
+	}
+
+	unixAddr, errRet := net.ResolveUnixAddr("unix", unixPath)
+	if errRet != nil {
+		err = errRet
+		return
+	}
+
+	p = &UnixDomainSocketPlugin{
+		UnixAddr: unixAddr,
+	}
+	return
+}
+
+func (uds *UnixDomainSocketPlugin) Handle(conn io.ReadWriteCloser) {
+	localConn, err := net.DialUnix("unix", nil, uds.UnixAddr)
+	if err != nil {
+		return
+	}
+
+	tcp.Join(localConn, conn)
+}
+
+func (uds *UnixDomainSocketPlugin) Name() string {
+	return PluginUnixDomainSocket
+}
+
+func (uds *UnixDomainSocketPlugin) Close() error {
+	return nil
+}