Add support for multiple defined forwards in SSH config

go.mod

@@ -9,7 +9,7 @@ require (
 	github.com/gofrs/uuid v3.2.0+incompatible
 	github.com/hpcloud/tail v1.0.0
 	github.com/kardianos/osext v0.0.0-20190222173326-2bc1f35cddc0 // indirect
-	github.com/kevinburke/ssh_config v0.0.0-20190630040420-2e50c441276c
+	github.com/kevinburke/ssh_config v1.1.0
 	github.com/mitchellh/go-ps v1.0.0 // indirect
 	github.com/mitchellh/mapstructure v1.4.1
 	github.com/pelletier/go-buffruneio v0.2.0 // indirect

go.sum

@@ -27,6 +27,8 @@ github.com/kardianos/osext v0.0.0-20190222173326-2bc1f35cddc0 h1:iQTw/8FWTuc7uia
 github.com/kardianos/osext v0.0.0-20190222173326-2bc1f35cddc0/go.mod h1:1NbS8ALrpOvjt0rHPNLyCIeMtbizbir8U//inJ+zuB8=
 github.com/kevinburke/ssh_config v0.0.0-20190630040420-2e50c441276c h1:VAx3LRNjVNvjtgO7KFRuT/3aye/0zJvwn01rHSfoolo=
 github.com/kevinburke/ssh_config v0.0.0-20190630040420-2e50c441276c/go.mod h1:CT57kijsi8u/K/BOFA39wgDQJ9CxiF4nAY/ojJ6r6mM=
+github.com/kevinburke/ssh_config v1.1.0 h1:pH/t1WS9NzT8go394IqZeJTMHVm6Cr6ZJ6AQ+mdNo/o=
+github.com/kevinburke/ssh_config v1.1.0/go.mod h1:CT57kijsi8u/K/BOFA39wgDQJ9CxiF4nAY/ojJ6r6mM=
 github.com/konsorten/go-windows-terminal-sequences v1.0.3 h1:CE8S1cTafDpPvMhIxNJKvHsGVBgn1xWYf1NbHQhywc8=
 github.com/konsorten/go-windows-terminal-sequences v1.0.3/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=

tunnel/config.go

@@ -66,12 +66,12 @@ func (r SSHConfigFile) Get(host string) *SSHHost {
 		user = ""
 	}
 
-	localForward, err := r.getForward("LocalForward", host)
+	localForwards, err := r.getForwards("LocalForward", host)
 	if err != nil {
 		log.Warningf("error reading local forwarding configuration from ssh config file: %v", err)
 	}
 
-	remoteForward, err := r.getForward("RemoteForward", host)
+	remoteForwards, err := r.getForwards("RemoteForward", host)
 	if err != nil {
 		log.Warningf("error reading remote configuration from ssh config file: %v", err)
 	}
@@ -84,13 +84,13 @@ func (r SSHConfigFile) Get(host string) *SSHHost {
 	}
 
 	return &SSHHost{
-		Hostname:      hostname,
-		Port:          port,
-		User:          user,
-		Key:           key,
-		IdentityAgent: identityAgent,
-		LocalForward:  localForward,
-		RemoteForward: remoteForward,
+		Hostname:       hostname,
+		Port:           port,
+		User:           user,
+		Key:            key,
+		IdentityAgent:  identityAgent,
+		LocalForwards:  localForwards,
+		RemoteForwards: remoteForwards,
 	}
 }
 
@@ -103,34 +103,44 @@ func (r SSHConfigFile) getHostname(host string) string {
 	return hostname
 }
 
-func (r SSHConfigFile) getForward(forwardType, host string) (*ForwardConfig, error) {
-	c, err := r.sshConfig.Get(host, forwardType)
+func (r SSHConfigFile) getForwards(forwardType, host string) ([]*ForwardConfig, error) {
+	fwds, err := r.sshConfig.GetAll(host, forwardType)
 	if err != nil {
 		return nil, err
 	}
 
-	if c == "" {
-		return nil, nil
-	}
+	forwards := []*ForwardConfig{}
+
+	for _, c := range fwds {
+		if c == "" {
+			continue
+		}
 
-	l := strings.Fields(c)
+		l := strings.Fields(c)
 
-	if len(l) < 2 {
-		return nil, fmt.Errorf("malformed forwarding configuration on ssh config file: %s", l)
-	}
+		if len(l) < 2 {
+			return nil, fmt.Errorf("malformed forwarding configuration on ssh config file: %s", l)
+		}
 
-	source := l[0]
-	destination := l[1]
+		source := l[0]
+		destination := l[1]
 
-	if strings.HasPrefix(source, ":") {
-		source = fmt.Sprintf("127.0.0.1%s", source)
+		if strings.HasPrefix(source, ":") {
+			source = fmt.Sprintf("127.0.0.1%s", source)
+		}
+
+		if source != "" && !strings.Contains(source, ":") {
+			source = fmt.Sprintf("127.0.0.1:%s", source)
+		}
+
+		forwards = append(forwards, &ForwardConfig{Source: source, Destination: destination})
 	}
 
-	if source != "" && !strings.Contains(source, ":") {
-		source = fmt.Sprintf("127.0.0.1:%s", source)
+	if len(forwards) == 0 {
+		return nil, nil
 	}
 
-	return &ForwardConfig{Source: source, Destination: destination}, nil
+	return forwards, nil
 
 }
 
@@ -154,18 +164,18 @@ func (r SSHConfigFile) getKey(host string) string {
 
 // SSHHost represents a host configuration extracted from a ssh config file.
 type SSHHost struct {
-	Hostname      string
-	Port          string
-	User          string
-	Key           string
-	IdentityAgent string
-	LocalForward  *ForwardConfig
-	RemoteForward *ForwardConfig
+	Hostname       string
+	Port           string
+	User           string
+	Key            string
+	IdentityAgent  string
+	LocalForwards  []*ForwardConfig
+	RemoteForwards []*ForwardConfig
 }
 
 // String returns a string representation of a SSHHost.
 func (h SSHHost) String() string {
-	return fmt.Sprintf("[hostname=%s, port=%s, user=%s, key=%s, identity_agent=%s, local_forward=%s, remote_forward=%s]", h.Hostname, h.Port, h.User, h.Key, h.IdentityAgent, h.LocalForward, h.RemoteForward)
+	return fmt.Sprintf("[hostname=%s, port=%s, user=%s, key=%s, identity_agent=%s, local_forward=%v, remote_forward=%v]", h.Hostname, h.Port, h.User, h.Key, h.IdentityAgent, h.LocalForwards, h.RemoteForwards)
 }
 
 // ForwardConfig represents either a LocalForward or a RemoteForward configuration

tunnel/config_test.go

@@ -20,11 +20,11 @@ Host example2
 	LocalForward 8080 127.0.0.1:8080
 Host example3
 	LocalForward 9090 127.0.0.1:9090
+	LocalForward 9091 127.0.0.1:9091
 Host example4
 	RemoteForward 80 127.0.0.1:8080
 Host example5
 	RemoteForward 192.168.1.100:80 my-server:8080
-
 `
 
 	c, _ := ssh_config.Decode(strings.NewReader(config))
@@ -37,51 +37,54 @@ Host example5
 		{
 			"example1",
 			&SSHHost{
-				Hostname:     "172.17.0.1",
-				Port:         "3306",
-				User:         "john",
-				Key:          "/path/.ssh/id_rsa",
-				LocalForward: nil,
+				Hostname:      "172.17.0.1",
+				Port:          "3306",
+				User:          "john",
+				Key:           "/path/.ssh/id_rsa",
+				LocalForwards: nil,
 			},
 		},
 		{
 			"example2",
 			&SSHHost{
-				Hostname:     "",
-				Port:         "",
-				User:         "",
-				Key:          "",
-				LocalForward: &ForwardConfig{Source: "127.0.0.1:8080", Destination: "127.0.0.1:8080"},
+				Hostname:      "",
+				Port:          "",
+				User:          "",
+				Key:           "",
+				LocalForwards: []*ForwardConfig{&ForwardConfig{Source: "127.0.0.1:8080", Destination: "127.0.0.1:8080"}},
 			},
 		},
 		{
 			"example3",
 			&SSHHost{
-				Hostname:     "",
-				Port:         "",
-				User:         "",
-				Key:          "",
-				LocalForward: &ForwardConfig{Source: "127.0.0.1:9090", Destination: "127.0.0.1:9090"},
+				Hostname: "",
+				Port:     "",
+				User:     "",
+				Key:      "",
+				LocalForwards: []*ForwardConfig{
+					&ForwardConfig{Source: "127.0.0.1:9090", Destination: "127.0.0.1:9090"},
+					&ForwardConfig{Source: "127.0.0.1:9091", Destination: "127.0.0.1:9091"},
+				},
 			},
 		},
 		{
 			"example4",
 			&SSHHost{
-				Hostname:      "",
-				Port:          "",
-				User:          "",
-				Key:           "",
-				RemoteForward: &ForwardConfig{Source: "127.0.0.1:80", Destination: "127.0.0.1:8080"},
+				Hostname:       "",
+				Port:           "",
+				User:           "",
+				Key:            "",
+				RemoteForwards: []*ForwardConfig{&ForwardConfig{Source: "127.0.0.1:80", Destination: "127.0.0.1:8080"}},
 			},
 		},
 		{
 			"example5",
 			&SSHHost{
-				Hostname:      "",
-				Port:          "",
-				User:          "",
-				Key:           "",
-				RemoteForward: &ForwardConfig{Source: "192.168.1.100:80", Destination: "my-server:8080"},
+				Hostname:       "",
+				Port:           "",
+				User:           "",
+				Key:            "",
+				RemoteForwards: []*ForwardConfig{&ForwardConfig{Source: "192.168.1.100:80", Destination: "my-server:8080"}},
 			},
 		},
 	}

tunnel/testdata/dotssh/config

@@ -17,3 +17,10 @@ Host hostWithLocalForward
     User mole_test
     IdentityFile ~/.ssh/id_rsa
 
+Host hostWithTwoLocalForwards
+    Hostname 127.0.0.1
+    Port 2222
+    LocalForward 8080 172.17.0.1:8080
+    LocalForward 9090 172.17.0.1:9090
+    User mole_test
+    IdentityFile ~/.ssh/id_rsa

tunnel/tunnel.go

@@ -583,13 +583,17 @@ func buildSSHChannels(serverName, channelType string, source, destination []stri
 	// if source and destination were not given, try to find the addresses from the
 	// SSH configuration file.
 	if len(source) == 0 && len(destination) == 0 {
-		f, err := getForward(channelType, serverName, cfgPath)
+		fwds, err := getForwards(channelType, serverName, cfgPath)
 		if err != nil {
 			return nil, err
 		}
 
-		source = []string{f.Source}
-		destination = []string{f.Destination}
+		source = []string{}
+		destination = []string{}
+		for _, f := range fwds {
+			source = append(source, f.Source)
+			destination = append(destination, f.Destination)
+		}
 	} else {
 
 		lSize := len(source)
@@ -640,8 +644,8 @@ func buildSSHChannels(serverName, channelType string, source, destination []stri
 	return channels, nil
 }
 
-func getForward(channelType, serverName string, cfgPath string) (*ForwardConfig, error) {
-	var f *ForwardConfig
+func getForwards(channelType, serverName string, cfgPath string) ([]*ForwardConfig, error) {
+	var fwds []*ForwardConfig
 
 	cfg, err := NewSSHConfigFile(cfgPath)
 	if err != nil {
@@ -651,16 +655,16 @@ func getForward(channelType, serverName string, cfgPath string) (*ForwardConfig,
 	sh := cfg.Get(serverName)
 
 	if channelType == "local" {
-		f = sh.LocalForward
+		fwds = sh.LocalForwards
 	} else if channelType == "remote" {
-		f = sh.RemoteForward
+		fwds = sh.RemoteForwards
 	} else {
 		return nil, fmt.Errorf("could not retrieve forwarding information from ssh configuration file: unsupported channel type %s", channelType)
 	}
 
-	if f == nil {
+	if fwds == nil {
 		return nil, fmt.Errorf("forward config could not be found or has invalid syntax for host %s", serverName)
 	}
 
-	return f, nil
+	return fwds, nil
 }

tunnel/tunnel_test.go

@@ -337,6 +337,14 @@ func TestBuildSSHChannels(t *testing.T) {
 			expected:      1,
 			expectedError: nil,
 		},
+		{
+			serverName:    "hostWithTwoLocalForwards",
+			source:        []string{},
+			destination:   []string{},
+			config:        "testdata/.ssh/config",
+			expected:      2,
+			expectedError: nil,
+		},
 		{
 			serverName:    "test",
 			source:        []string{":3360", ":8080"},