feat(forwarder): split forwarder to different file

core/peer_status.go

@@ -0,0 +1,82 @@
+package core
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/netip"
+	"sync"
+	"time"
+
+	"tailscale.com/ipn/ipnstate"
+	"tailscale.com/tsnet"
+)
+
+var statusCache struct {
+	mu      sync.Mutex
+	status  *ipnstate.Status
+	expires time.Time
+}
+
+const statusCacheTTL = 5 * time.Second
+
+func getCachedStatus(ctx context.Context, srv *tsnet.Server) (*ipnstate.Status, error) {
+	statusCache.mu.Lock()
+	if statusCache.status != nil && time.Now().Before(statusCache.expires) {
+		st := statusCache.status
+		statusCache.mu.Unlock()
+		return st, nil
+	}
+	statusCache.mu.Unlock()
+
+	lc, err := srv.LocalClient()
+	if err != nil {
+		return nil, err
+	}
+	st, err := lc.Status(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	statusCache.mu.Lock()
+	statusCache.status = st
+	statusCache.expires = time.Now().Add(statusCacheTTL)
+	statusCache.mu.Unlock()
+	return st, nil
+}
+
+func isTsnetTarget(host string) bool {
+	if ip, err := netip.ParseAddr(host); err == nil {
+		tsnetV4 := netip.MustParsePrefix("100.64.0.0/10")
+		tsnetV6 := netip.MustParsePrefix("fd7a:115c:a1e0::/48")
+		return tsnetV4.Contains(ip) || tsnetV6.Contains(ip)
+	}
+	return true
+}
+
+func getConnType(ctx context.Context, srv *tsnet.Server, remoteAddrStr string) string {
+	st, err := getCachedStatus(ctx, srv)
+	if err != nil {
+		return "unknown"
+	}
+
+	remoteHost, _, err := net.SplitHostPort(remoteAddrStr)
+	if err != nil {
+		return "unknown"
+	}
+
+	for _, peer := range st.Peer {
+		for _, addr := range peer.TailscaleIPs {
+			if addr.String() == remoteHost {
+				if peer.CurAddr != "" {
+					return "direct"
+				}
+				if peer.Relay != "" {
+					return fmt.Sprintf("derp(%s)", peer.Relay)
+				}
+				return "direct"
+			}
+		}
+	}
+	return "unknown"
+}