Refactor WebRTC candidates processing

pkg/webrtc/helpers.go

@@ -7,6 +7,7 @@ import (
 	"github.com/pion/ice/v2"
 	"github.com/pion/stun"
 	"github.com/pion/webrtc/v3"
+	"hash/crc32"
 	"net"
 	"strconv"
 	"strings"
@@ -157,3 +158,35 @@ func MimeType(codec *streamer.Codec) string {
 	}
 	panic("not implemented")
 }
+
+const PriorityHost = (1 << 24) * uint32(126)
+const PriorityLocalUDP = (1 << 8) * uint32(65535)
+const PriorityLocalTCPPassive = (1 << 8) * uint32((1<<13)*4+8191)
+const PriorityComponentRTP = uint32(256 - ice.ComponentRTP)
+
+func CandidateHostUDP(host string, port int) string {
+	foundation := crc32.ChecksumIEEE([]byte("host" + host + "udp4"))
+	priority := PriorityHost + PriorityLocalUDP + PriorityComponentRTP
+
+	// 1. Foundation
+	// 2. Component, always 1 because RTP
+	// 3. udp or tcp
+	// 4. Priority
+	// 5. Host - IP4 or IP6 or domain name
+	// 6. Port
+	// 7. typ host
+	return fmt.Sprintf(
+		"candidate:%d 1 udp %d %s %d typ host",
+		foundation, priority, host, port,
+	)
+}
+
+func CandidateHostTCPPassive(address string, port int) string {
+	foundation := crc32.ChecksumIEEE([]byte("host" + address + "tcp4"))
+	priority := PriorityHost + PriorityLocalTCPPassive + PriorityComponentRTP
+
+	return fmt.Sprintf(
+		"candidate:%d 1 tcp %d %s %d typ host tcptype passive",
+		foundation, priority, address, port,
+	)
+}

pkg/webrtc/webrtc_test.go

@@ -5,19 +5,31 @@ import (
 	"github.com/pion/sdp/v3"
 	"github.com/pion/webrtc/v3"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"testing"
 )
 
-func TestName(t *testing.T) {
-	i, _ := ice.NewCandidateHost(&ice.CandidateHostConfig{
+func TestCandidates(t *testing.T) {
+	conf := &ice.CandidateHostConfig{
+		Network:   "udp",
+		Address:   "192.168.1.123",
+		Port:      8555,
+		Component: ice.ComponentRTP,
+	}
+	cand, err := ice.NewCandidateHost(conf)
+	require.Nil(t, err)
+	assert.Equal(t, "candidate:"+cand.Marshal(), CandidateHostUDP(conf.Address, conf.Port))
+
+	conf = &ice.CandidateHostConfig{
 		Network:   "tcp",
 		Address:   "192.168.1.123",
 		Port:      8555,
 		Component: ice.ComponentRTP,
 		TCPType:   ice.TCPTypePassive,
-	})
-	a := i.Marshal()
-	println(a)
+	}
+	cand, err = ice.NewCandidateHost(conf)
+	require.Nil(t, err)
+	assert.Equal(t, "candidate:"+cand.Marshal(), CandidateHostTCPPassive(conf.Address, conf.Port))
 }
 
 func TestPublicIP(t *testing.T) {