Enhancement of "redirect" function, adding support for MacOS

Added the function of "MacOS" FreeBSD firewall traffic forwarding and resolving destination address
example:
"inbounds": [
{
"listen": "127.0.0.1",
"port": 1122,
"protocol": "dokodemo-door",
"tag": "dokodemo",
"settings": {
"network": "tcp",
"followRedirect": true,
"userLevel": 0
},
"streamSettings": {
"sockopt": {
"tproxy": "Redirect"
}
}
}
]

还原#1189 提交

transport/internet/tcp/sockopt_darwin.go

@@ -0,0 +1,25 @@
+//go:build darwin
+// +build darwin
+
+package tcp
+
+import (
+	"github.com/xtls/xray-core/common/net"
+	"github.com/xtls/xray-core/transport/internet"
+	"github.com/xtls/xray-core/transport/internet/stat"
+)
+
+// GetOriginalDestination from tcp conn
+func GetOriginalDestination(conn stat.Connection) (net.Destination, error) {
+	la := conn.LocalAddr()
+	ra := conn.RemoteAddr()
+	ip, port, err := internet.OriginalDst(la, ra)
+	if err != nil {
+		return net.Destination{}, newError("failed to get destination").Base(err)
+	}
+	dest := net.TCPDestination(net.IPAddress(ip), net.Port(port))
+	if !dest.IsValid() {
+		return net.Destination{}, newError("failed to parse destination.")
+	}
+	return dest, nil
+}