Fix: macOS udp find process should use unspecified fallback

https://github.com/Dreamacro/clash/commit/be8d63ba8f70a6f4e7b240899cd2903a77243c24

common/process/searcher_darwin.go

@@ -76,6 +76,8 @@ func findProcessName(network string, ip netip.Addr, port int) (string, error) {
 		// rup8(sizeof(xtcpcb_n))
 		itemSize += 208
 	}
+
+	var fallbackUDPProcess string
 	// skip the first xinpgen(24 bytes) block
 	for i := 24; i+itemSize <= len(buf); i += itemSize {
 		// offset of xinpcb_n and xsocket_n
@@ -90,10 +92,12 @@ func findProcessName(network string, ip netip.Addr, port int) (string, error) {
 		flag := buf[inp+44]
 
 		var srcIP netip.Addr
+		srcIsIPv4 := false
 		switch {
 		case flag&0x1 > 0 && isIPv4:
 			// ipv4
 			srcIP = netip.AddrFrom4(*(*[4]byte)(buf[inp+76 : inp+80]))
+			srcIsIPv4 = true
 		case flag&0x2 > 0 && !isIPv4:
 			// ipv6
 			srcIP = netip.AddrFrom16(*(*[16]byte)(buf[inp+64 : inp+80]))
@@ -101,13 +105,21 @@ func findProcessName(network string, ip netip.Addr, port int) (string, error) {
 			continue
 		}
 
-		if ip != srcIP {
-			continue
+		if ip == srcIP {
+			// xsocket_n.so_last_pid
+			pid := readNativeUint32(buf[so+68 : so+72])
+			return getExecPathFromPID(pid)
 		}
 
-		// xsocket_n.so_last_pid
-		pid := readNativeUint32(buf[so+68 : so+72])
-		return getExecPathFromPID(pid)
+		// udp packet connection may be not equal with srcIP
+		if network == N.NetworkUDP && srcIP.IsUnspecified() && isIPv4 == srcIsIPv4 {
+			pid := readNativeUint32(buf[so+68 : so+72])
+			fallbackUDPProcess, _ = getExecPathFromPID(pid)
+		}
+	}
+
+	if network == N.NetworkUDP && len(fallbackUDPProcess) > 0 {
+		return fallbackUDPProcess, nil
 	}
 
 	return "", ErrNotFound