Add Version Output Support to Snowflake

From now on, there will be a file at common/version/version.go that includes current version number.

client/snowflake.go

@@ -3,6 +3,7 @@ package main
 
 import (
 	"flag"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"log"
@@ -19,6 +20,7 @@ import (
 	sf "git.torproject.org/pluggable-transports/snowflake.git/v2/client/lib"
 	"git.torproject.org/pluggable-transports/snowflake.git/v2/common/event"
 	"git.torproject.org/pluggable-transports/snowflake.git/v2/common/safelog"
+	"git.torproject.org/pluggable-transports/snowflake.git/v2/common/version"
 )
 
 const (
@@ -157,6 +159,7 @@ func main() {
 	unsafeLogging := flag.Bool("unsafe-logging", false, "prevent logs from being scrubbed")
 	max := flag.Int("max", DefaultSnowflakeCapacity,
 		"capacity for number of multiplexed WebRTC peers")
+	versionFlag := flag.Bool("version", false, "display version info to stderr and quit")
 
 	// Deprecated
 	oldLogToStateDir := flag.Bool("logToStateDir", false, "use -log-to-state-dir instead")
@@ -164,6 +167,11 @@ func main() {
 
 	flag.Parse()
 
+	if *versionFlag {
+		fmt.Fprintf(os.Stderr, "snowflake-client %s", version.ConstructResult())
+		os.Exit(0)
+	}
+
 	log.SetFlags(log.LstdFlags | log.LUTC)
 
 	// Don't write to stderr; versions of tor earlier than about 0.3.5.6 do

common/utls/client_hello_id.go

@@ -36,3 +36,11 @@ func NameToUTLSID(name string) (utls.ClientHelloID, error) {
 	}
 	return utls.ClientHelloID{}, errNameNotFound
 }
+
+func ListAllNames() []string {
+	var names []string
+	for k, _ := range clientHelloIDMap {
+		names = append(names, k)
+	}
+	return names
+}

common/utls/client_hello_id_version.go

@@ -0,0 +1,24 @@
+package utls
+
+import (
+	"git.torproject.org/pluggable-transports/snowflake.git/v2/common/version"
+	"strings"
+)
+
+func generateVersionOutput() string {
+	var versionOutputBuilder strings.Builder
+
+	versionOutputBuilder.WriteString(`Known utls-imitate values:
+(empty)
+`)
+
+	for _, name := range ListAllNames() {
+		versionOutputBuilder.WriteString(name)
+		versionOutputBuilder.WriteRune('\n')
+	}
+	return versionOutputBuilder.String()
+}
+
+func init() {
+	version.AddVersionDetail(generateVersionOutput())
+}

common/version/combined.go

@@ -0,0 +1,5 @@
+package version
+
+func ConstructResult() string {
+	return GetVersion() + "\n" + GetVersionDetail()
+}

common/version/detail.go

@@ -0,0 +1,13 @@
+package version
+
+import "strings"
+
+var detailBuilder strings.Builder
+
+func AddVersionDetail(detail string) {
+	detailBuilder.WriteString(detail)
+}
+
+func GetVersionDetail() string {
+	return detailBuilder.String()
+}

common/version/version.go

@@ -0,0 +1,7 @@
+package version
+
+func GetVersion() string {
+	return version
+}
+
+var version = "2.3.1"

proxy/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"flag"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"log"
@@ -12,6 +13,7 @@ import (
 
 	"git.torproject.org/pluggable-transports/snowflake.git/v2/common/event"
 	"git.torproject.org/pluggable-transports/snowflake.git/v2/common/safelog"
+	"git.torproject.org/pluggable-transports/snowflake.git/v2/common/version"
 	sf "git.torproject.org/pluggable-transports/snowflake.git/v2/proxy/lib"
 )
 
@@ -31,11 +33,17 @@ func main() {
 		"the time interval to output summary, 0s disables summaries. Valid time units are \"s\", \"m\", \"h\". ")
 	verboseLogging := flag.Bool("verbose", false, "increase log verbosity")
 	ephemeralPortsRangeFlag := flag.String("ephemeral-ports-range", "", "ICE UDP ephemeral ports range (format:\"<min>:<max>\")")
+	versionFlag := flag.Bool("version", false, "display version info to stderr and quit")
 
 	var ephemeralPortsRange []uint16 = []uint16{0, 0}
 
 	flag.Parse()
 
+	if *versionFlag {
+		fmt.Fprintf(os.Stderr, "snowflake-proxy %s", version.ConstructResult())
+		os.Exit(0)
+	}
+
 	eventLogger := event.NewSnowflakeEventDispatcher()
 
 	if *ephemeralPortsRangeFlag != "" {

server/server.go

@@ -19,6 +19,7 @@ import (
 	"syscall"
 
 	"git.torproject.org/pluggable-transports/snowflake.git/v2/common/safelog"
+	"git.torproject.org/pluggable-transports/snowflake.git/v2/common/version"
 	"golang.org/x/crypto/acme/autocert"
 
 	pt "git.torproject.org/pluggable-transports/goptlib.git"
@@ -130,6 +131,7 @@ func main() {
 	var disableTLS bool
 	var logFilename string
 	var unsafeLogging bool
+	var versionFlag bool
 
 	flag.Usage = usage
 	flag.StringVar(&acmeEmail, "acme-email", "", "optional contact email for Let's Encrypt notifications")
@@ -137,8 +139,14 @@ func main() {
 	flag.BoolVar(&disableTLS, "disable-tls", false, "don't use HTTPS")
 	flag.StringVar(&logFilename, "log", "", "log file to write to")
 	flag.BoolVar(&unsafeLogging, "unsafe-logging", false, "prevent logs from being scrubbed")
+	flag.BoolVar(&versionFlag, "unsafe-logging", false, "display version info to stderr and quit")
 	flag.Parse()
 
+	if versionFlag {
+		fmt.Fprintf(os.Stderr, "snowflake-server %s", version.ConstructResult())
+		os.Exit(0)
+	}
+
 	log.SetFlags(log.LstdFlags | log.LUTC)
 
 	var logOutput io.Writer = os.Stderr