Supports webrtc interface filtering on server (#2460)

* Supports webrtc interface filtering on server

* test(#2707): Fixed testing for build

* lint(#2707): Fixed lint issues for build

* normalize setting name

* move instructions in the configuration file

---------

Co-authored-by: Pieter Fabry <pieterfabry@observe.tech>
Co-authored-by: aler9 <46489434+aler9@users.noreply.github.com>

apidocs/openapi.yaml

@@ -162,6 +162,10 @@ components:
                 type: string
               password:
                 type: string
+        webrtcICEInterfaces:
+          type: array
+          items:
+            type: string
         webrtcICEHostNAT1To1IPs:
           type: array
           items:

internal/conf/conf.go

@@ -164,6 +164,7 @@ type Conf struct {
 	WebRTCTrustedProxies    IPsOrCIDRs        `json:"webrtcTrustedProxies"`
 	WebRTCICEServers        []string          `json:"webrtcICEServers"` // deprecated
 	WebRTCICEServers2       []WebRTCICEServer `json:"webrtcICEServers2"`
+	WebRTCICEInterfaces     []string          `json:"webrtcICEInterfaces"`
 	WebRTCICEHostNAT1To1IPs []string          `json:"webrtcICEHostNAT1To1IPs"`
 	WebRTCICEUDPMuxAddress  string            `json:"webrtcICEUDPMuxAddress"`
 	WebRTCICETCPMuxAddress  string            `json:"webrtcICETCPMuxAddress"`
@@ -395,6 +396,7 @@ func (conf *Conf) UnmarshalJSON(b []byte) error {
 	conf.WebRTCServerCert = "server.crt"
 	conf.WebRTCAllowOrigin = "*"
 	conf.WebRTCICEServers2 = []WebRTCICEServer{{URL: "stun:stun.l.google.com:19302"}}
+	conf.WebRTCICEInterfaces = []string{}
 	conf.WebRTCICEHostNAT1To1IPs = []string{}
 
 	// SRT

internal/core/core.go

@@ -454,6 +454,7 @@ func (p *Core) createResources(initial bool) error {
 			p.conf.WebRTCICEServers2,
 			p.conf.ReadTimeout,
 			p.conf.WriteQueueSize,
+			p.conf.WebRTCICEInterfaces,
 			p.conf.WebRTCICEHostNAT1To1IPs,
 			p.conf.WebRTCICEUDPMuxAddress,
 			p.conf.WebRTCICETCPMuxAddress,
@@ -667,6 +668,7 @@ func (p *Core) closeResources(newConf *conf.Conf, calledByAPI bool) {
 		!reflect.DeepEqual(newConf.WebRTCICEServers2, p.conf.WebRTCICEServers2) ||
 		newConf.ReadTimeout != p.conf.ReadTimeout ||
 		newConf.WriteQueueSize != p.conf.WriteQueueSize ||
+		!reflect.DeepEqual(newConf.WebRTCICEInterfaces, p.conf.WebRTCICEInterfaces) ||
 		!reflect.DeepEqual(newConf.WebRTCICEHostNAT1To1IPs, p.conf.WebRTCICEHostNAT1To1IPs) ||
 		newConf.WebRTCICEUDPMuxAddress != p.conf.WebRTCICEUDPMuxAddress ||
 		newConf.WebRTCICETCPMuxAddress != p.conf.WebRTCICETCPMuxAddress ||

internal/core/webrtc_manager.go

@@ -168,13 +168,29 @@ func randomTurnUser() (string, error) {
 	return string(b), nil
 }
 
+func stringInSlice(a string, list []string) bool {
+	for _, b := range list {
+		if b == a {
+			return true
+		}
+	}
+	return false
+}
+
 func webrtcNewAPI(
+	iceInterfaces []string,
 	iceHostNAT1To1IPs []string,
 	iceUDPMux ice.UDPMux,
 	iceTCPMux ice.TCPMux,
 ) (*webrtc.API, error) {
 	settingsEngine := webrtc.SettingEngine{}
 
+	if len(iceInterfaces) != 0 {
+		settingsEngine.SetInterfaceFilter(func(iface string) bool {
+			return stringInSlice(iface, iceInterfaces)
+		})
+	}
+
 	if len(iceHostNAT1To1IPs) != 0 {
 		settingsEngine.SetNAT1To1IPs(iceHostNAT1To1IPs, webrtc.ICECandidateTypeHost)
 	}
@@ -317,6 +333,7 @@ func newWebRTCManager(
 	iceServers []conf.WebRTCICEServer,
 	readTimeout conf.StringDuration,
 	writeQueueSize int,
+	iceInterfaces []string,
 	iceHostNAT1To1IPs []string,
 	iceUDPMuxAddress string,
 	iceTCPMuxAddress string,
@@ -391,7 +408,7 @@ func newWebRTCManager(
 		iceTCPMux = webrtc.NewICETCPMux(nil, m.tcpMuxLn, 8)
 	}
 
-	m.api, err = webrtcNewAPI(iceHostNAT1To1IPs, iceUDPMux, iceTCPMux)
+	m.api, err = webrtcNewAPI(iceInterfaces, iceHostNAT1To1IPs, iceUDPMux, iceTCPMux)
 	if err != nil {
 		m.udpMuxLn.Close()
 		m.tcpMuxLn.Close()

internal/core/webrtc_manager_test.go

@@ -43,7 +43,7 @@ func newWebRTCTestClient(
 
 	c := &webRTCTestClient{}
 
-	api, err := webrtcNewAPI(nil, nil, nil)
+	api, err := webrtcNewAPI(nil, nil, nil, nil)
 	require.NoError(t, err)
 
 	pc, err := webrtcpc.New(iceServers, api, nilLogger{})

internal/core/webrtc_source.go

@@ -67,7 +67,7 @@ func (s *webRTCSource) run(ctx context.Context, cnf *conf.PathConf, _ chan *conf
 		return err
 	}
 
-	api, err := webrtcNewAPI(nil, nil, nil)
+	api, err := webrtcNewAPI(nil, nil, nil, nil)
 	if err != nil {
 		return err
 	}

internal/core/webrtc_source_test.go

@@ -20,7 +20,7 @@ import (
 func TestWebRTCSource(t *testing.T) {
 	state := 0
 
-	api, err := webrtcNewAPI(nil, nil, nil)
+	api, err := webrtcNewAPI(nil, nil, nil, nil)
 	require.NoError(t, err)
 
 	pc, err := webrtcpc.New(nil, api, nilLogger{})

mediamtx.yml

@@ -215,6 +215,9 @@ webrtcICEServers2:
   # the secret must be inserted into the password field.
   username: ''
   password: ''
+# List of interfaces that will be used to gather IPs to send
+# to the counterpart to establish a connection.
+webrtcICEInterfaces: []
 # List of public IP addresses that are to be used as a host.
 # This is used typically for servers that are behind 1:1 D-NAT.
 webrtcICEHostNAT1To1IPs: []