ChangeLog

+== v1.5.0
+
+Added the ReportVersion function that lets a client or server report its
+implementation version using the new STATUS TYPE=version feature.
+
+https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/goptlib/-/issues/1
+
 == v1.4.0
 
 Moved the repository URL from git.torproject.org/pluggable-transports/goptlib.git

examples/dummy-client/dummy-client.go

@@ -80,6 +80,8 @@ func main() {
 		os.Exit(1)
 	}
 
+	pt.ReportVersion("dummy-client", "0.1")
+
 	if ptInfo.ProxyURL != nil {
 		pt.ProxyError("proxy is not supported")
 		os.Exit(1)

examples/dummy-server/dummy-server.go

@@ -77,6 +77,8 @@ func main() {
 		os.Exit(1)
 	}
 
+	pt.ReportVersion("dummy-server", "0.1")
+
 	listeners := make([]net.Listener, 0)
 	for _, bindaddr := range ptInfo.Bindaddrs {
 		switch bindaddr.MethodName {

pt.go

@@ -36,6 +36,7 @@
 // 	...
 // 	func main() {
 // 		var err error
+// 		pt.ReportVersion("program", "v1.0")
 // 		ptInfo, err = pt.ClientSetup(nil)
 // 		if err != nil {
 // 			os.Exit(1)
@@ -94,6 +95,7 @@
 // 	...
 // 	func main() {
 // 		var err error
+// 		pt.ReportVersion("program", "v1.0")
 // 		ptInfo, err = pt.ServerSetup(nil)
 // 		if err != nil {
 // 			os.Exit(1)
@@ -343,6 +345,15 @@ func ProxyDone() {
 	fmt.Fprintf(Stdout, "PROXY DONE\n")
 }
 
+// Report this program's name and version number using a STATUS TYPE=version
+// line. Can be called any time before calling CmethodsDone or SmethodsDone.
+//
+// When called in a pluggable transport server, the implementation name and
+// version number will appear in the relay's bridge-extra-info descriptor.
+func ReportVersion(implementation string, version string) {
+	line("STATUS", "TYPE=version", "IMPLEMENTATION="+encodeCString(implementation), "VERSION="+encodeCString(version))
+}
+
 // Unexported type to represent log severities, preventing external callers from
 // inventing new severity strings that may violate quoting rules.
 //