Mult Port + TCP Calibration (SSH DEAD)

core/cmd/dragontcp-server/internal_targets.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+	"net"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+type internalTargetRegistry struct {
+	sync.RWMutex
+	m map[string]string
+}
+
+var dragonTCPInternalTargets = internalTargetRegistry{m: make(map[string]string)}
+var sshOnlyInternalTargets = internalTargetRegistry{m: make(map[string]string)}
+
+func internalTargetKey(host string, port int) string {
+	return strings.ToLower(strings.TrimSpace(host)) + ":" + strconv.Itoa(port)
+}
+
+func registerInternalTarget(host string, port int, dialAddr string) {
+	registerTarget(&dragonTCPInternalTargets, host, port, dialAddr)
+}
+
+func lookupInternalTarget(host string, port int) (string, bool) {
+	return lookupTarget(&dragonTCPInternalTargets, host, port)
+}
+
+// registerSSHOnlyInternalTarget creates a destination that is reachable only
+// after SSH authentication. It is deliberately not exposed to raw DragonTCP
+// clients, which prevents direct access to services such as the UDP gateway.
+func registerSSHOnlyInternalTarget(host string, port int, dialAddr string) {
+	registerTarget(&sshOnlyInternalTargets, host, port, dialAddr)
+}
+
+func lookupSSHOnlyInternalTarget(host string, port int) (string, bool) {
+	return lookupTarget(&sshOnlyInternalTargets, host, port)
+}
+
+func registerTarget(registry *internalTargetRegistry, host string, port int, dialAddr string) {
+	if strings.TrimSpace(host) == "" || port < 1 || port > 65535 || strings.TrimSpace(dialAddr) == "" {
+		return
+	}
+	registry.Lock()
+	registry.m[internalTargetKey(host, port)] = dialAddr
+	registry.Unlock()
+}
+
+func lookupTarget(registry *internalTargetRegistry, host string, port int) (string, bool) {
+	registry.RLock()
+	addr, ok := registry.m[internalTargetKey(host, port)]
+	registry.RUnlock()
+	return addr, ok
+}
+
+func dialInternalTarget(dialer *net.Dialer, network, addr string) (net.Conn, error) {
+	return dialer.Dial(network, addr)
+}