move automatic udp port selection into gortsplib

go.mod

@@ -5,7 +5,7 @@ go 1.12
 require (
 	github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751 // indirect
 	github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d // indirect
-	github.com/aler9/gortsplib v0.0.0-20200919120125-3cee9afbf0af
+	github.com/aler9/gortsplib v0.0.0-20200920093758-10469faa0777
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/stretchr/testify v1.6.1
 	gopkg.in/alecthomas/kingpin.v2 v2.2.6

go.sum

@@ -2,8 +2,8 @@ github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751 h1:JYp7IbQjafo
 github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d h1:UQZhZ2O0vMHr2cI+DC1Mbh0TJxzA3RcLoMsFw+aXw7E=
 github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d/go.mod h1:rBZYJk541a8SKzHPHnH3zbiI+7dagKZ0cgpgrD7Fyho=
-github.com/aler9/gortsplib v0.0.0-20200919120125-3cee9afbf0af h1:cC0wbPnVEzZn+quuMaHwrpdjo4loj2vD0T7NMypw6Kk=
-github.com/aler9/gortsplib v0.0.0-20200919120125-3cee9afbf0af/go.mod h1:IQy51zikcH4wQFNwYPHtC0+HTcPlahJcxcYiMqlCyiw=
+github.com/aler9/gortsplib v0.0.0-20200920093758-10469faa0777 h1:WpP46odBYEPXa1GLtGrf8W8gZGLohDJCJTYmlPJCo2w=
+github.com/aler9/gortsplib v0.0.0-20200920093758-10469faa0777/go.mod h1:IQy51zikcH4wQFNwYPHtC0+HTcPlahJcxcYiMqlCyiw=
 github.com/aler9/sdp-dirty/v3 v3.0.0-20200919115950-f1abc664f625 h1:A3upkpYzceQTuBPvVleu1zd6R8jInhg5ifimSO7ku/o=
 github.com/aler9/sdp-dirty/v3 v3.0.0-20200919115950-f1abc664f625/go.mod h1:5bO/aUQr9m3OasDatNNcVqKAgs7r5hgGXmszWHaC6mI=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=

proxy.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"math/rand"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -189,27 +188,15 @@ func (s *proxy) runUDP(conn *gortsplib.ConnClient) bool {
 	var rtcpReads []gortsplib.UDPReadFunc
 
 	for _, track := range s.tracks {
-		for {
-			// choose two consecutive ports in range 65535-10000
-			// rtp must be even and rtcp odd
-			rtpPort := (rand.Intn((65535-10000)/2) * 2) + 10000
-			rtcpPort := rtpPort + 1
-
-			rtpRead, rtcpRead, _, err := conn.SetupUDP(s.pathConf.sourceUrl, track, rtpPort, rtcpPort)
-			if err != nil {
-				if isBindError(err) {
-					continue // retry
-				}
-
-				conn.Close()
-				s.path.log("proxy ERR: %s", err)
-				return true
-			}
-
-			rtpReads = append(rtpReads, rtpRead)
-			rtcpReads = append(rtcpReads, rtcpRead)
-			break
+		rtpRead, rtcpRead, _, err := conn.SetupUDP(s.pathConf.sourceUrl, track, 0, 0)
+		if err != nil {
+			conn.Close()
+			s.path.log("proxy ERR: %s", err)
+			return true
 		}
+
+		rtpReads = append(rtpReads, rtpRead)
+		rtcpReads = append(rtcpReads, rtcpRead)
 	}
 
 	_, err := conn.Play(s.pathConf.sourceUrl)

utils.go

@@ -3,7 +3,6 @@ package main
 import (
 	"fmt"
 	"net"
-	"os"
 	"regexp"
 	"strings"
 	"sync"
@@ -135,17 +134,6 @@ func checkPathName(name string) error {
 	return nil
 }
 
-func isBindError(err error) bool {
-	if nerr, ok := err.(*net.OpError); ok {
-		if serr, ok := nerr.Err.(*os.SyscallError); ok {
-			if serr.Syscall == "bind" {
-				return true
-			}
-		}
-	}
-	return false
-}
-
 type udpPublisherAddr struct {
 	ip   [net.IPv6len]byte // use a fixed-size array to enable the equality operator
 	port int