Added Probe/ProbeTLS functions and demo command

cmd/dpi-protocol-probe/main.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"net"
+	"os"
+	"time"
+
+	"git.maze.io/go/dpi/protocol"
+)
+
+func main() {
+	networkFlag := flag.String("network", "tcp", "Network type to use for probing")
+	timeoutFlag := flag.Duration("timeout", 30*time.Second, "Timeout")
+	flag.Usage = func() {
+		fmt.Fprintf(os.Stderr, "Usage of %s [<flags>] <address>:\n\n", os.Args[0])
+		fmt.Fprintln(os.Stderr, "Available flags:")
+		flag.PrintDefaults()
+		fmt.Fprintln(os.Stderr, "\nRequired arguments:")
+		fmt.Fprintln(os.Stderr, "  address string")
+		fmt.Fprintln(os.Stderr, "\tNetwork address to connect to (ie localhost:22)")
+		os.Exit(0)
+	}
+	flag.Parse()
+
+	if flag.NArg() != 1 {
+		flag.Usage()
+	}
+
+	address := flag.Arg(0)
+	if _, _, err := net.SplitHostPort(address); err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(2)
+	}
+
+	protocol, confidence, err := protocol.ProbeTimeout(*networkFlag, address, *timeoutFlag)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Probing address %q failed: %v\n", address, err)
+		os.Exit(3)
+	}
+
+	fmt.Printf("Protocol at address %q is %s version %s (confidence %g%%)\n", address, protocol.Name, protocol.Version, confidence*100)
+}