[tor-commits] [flashproxy/master] Add server pluggable transports functions.

[dcf at torproject.org]

commit 1854f66a59942347b5d3c66bbe2d6260d37bb075
Author: David Fifield <david at bamsoftware.com>
Date:   Sun Nov 25 19:04:01 2012 -0800

    Add server pluggable transports functions.
---
 websocket-transport/pt.go |  116 +++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 116 insertions(+), 0 deletions(-)

diff --git a/websocket-transport/pt.go b/websocket-transport/pt.go
index 686cc76..e63dd6a 100644
--- a/websocket-transport/pt.go
+++ b/websocket-transport/pt.go
@@ -110,3 +110,119 @@ func ptClientSetup(methodNames []string) []string {
 
 	return methods
 }
+
+func ptSmethodError(methodName, msg string) {
+	ptLine("SMETHOD-ERROR", methodName, msg)
+	os.Exit(1)
+}
+
+func ptSmethod(name string, addr net.Addr) {
+	ptLine("SMETHOD", name, addr.String())
+}
+
+func ptSmethodsDone() {
+	ptLine("SMETHODS", "DONE")
+}
+
+func resolveBindAddr(bindAddr string) (*net.TCPAddr, error) {
+	addr, err := net.ResolveTCPAddr("tcp", bindAddr)
+	if err == nil {
+		return addr, nil
+	}
+	// Before the fixing of bug #7011, tor doesn't put brackets around IPv6
+	// addresses. Split after the last colon, assuming it is a port
+	// separator, and try adding the brackets.
+	parts := strings.Split(bindAddr, ":")
+	if len(parts) <= 2 {
+		return nil, err
+	}
+	bindAddr = "[" + strings.Join(parts[:len(parts)-1], ":") + "]:" + parts[len(parts)-1]
+	return net.ResolveTCPAddr("tcp", bindAddr)
+}
+
+type ptBindAddr struct {
+	MethodName string
+	Addr       *net.TCPAddr
+}
+
+func filterBindAddrs(addrs []ptBindAddr, supported []string) []ptBindAddr {
+	var result []ptBindAddr
+
+	for _, ba := range addrs {
+		for _, methodName := range supported {
+			if ba.MethodName == methodName {
+				result = append(result, ba)
+				break
+			}
+		}
+	}
+
+	return result
+}
+
+// Return a map from method names to bind addresses. The map is the contents of
+// TOR_PT_SERVER_BINDADDR, with keys filtered by TOR_PT_SERVER_TRANSPORTS, and
+// further filtered by methods that we know.
+func ptGetServerBindAddrs(supported []string) []ptBindAddr {
+	var result []ptBindAddr
+
+	// Get the list of all requested bindaddrs.
+	var serverBindAddr = getenvRequired("TOR_PT_SERVER_BINDADDR")
+	for _, spec := range strings.Split(serverBindAddr, ",") {
+		var bindAddr ptBindAddr
+
+		parts := strings.SplitN(spec, "-", 2)
+		if len(parts) != 2 {
+			ptEnvError(fmt.Sprintf("TOR_PT_SERVER_BINDADDR: %q: doesn't contain \"-\"", spec))
+		}
+		bindAddr.MethodName = parts[0]
+		addr, err := resolveBindAddr(parts[1])
+		if err != nil {
+			ptEnvError(fmt.Sprintf("TOR_PT_SERVER_BINDADDR: %q: %s", spec, err.Error()))
+		}
+		bindAddr.Addr = addr
+		result = append(result, bindAddr)
+	}
+
+	// Filter by TOR_PT_SERVER_TRANSPORTS.
+	serverTransports := getenvRequired("TOR_PT_SERVER_TRANSPORTS")
+	if serverTransports != "*" {
+		result = filterBindAddrs(result, strings.Split(serverTransports, ","))
+	}
+
+	// Finally filter by what we understand.
+	result = filterBindAddrs(result, supported)
+
+	return result
+}
+
+type ptServerInfo struct {
+	BindAddrs []ptBindAddr
+	OrAddr    *net.TCPAddr
+}
+
+func ptServerSetup(methodNames []string) ptServerInfo {
+	var info ptServerInfo
+	var err error
+
+	ver := ptGetManagedTransportVer()
+	if ver == "" {
+		ptVersionError("no-version")
+	} else {
+		ptLine("VERSION", ver)
+	}
+
+	var orPort = getenvRequired("TOR_PT_ORPORT")
+	info.OrAddr, err = net.ResolveTCPAddr("tcp", orPort)
+	if err != nil {
+		ptEnvError(fmt.Sprintf("cannot resolve TOR_PT_ORPORT %q: %s", orPort, err.Error()))
+	}
+
+	info.BindAddrs = ptGetServerBindAddrs(methodNames)
+	if len(info.BindAddrs) == 0 {
+		ptSmethodsDone()
+		os.Exit(1)
+	}
+
+	return info
+}