service: keep track of proper errors

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 89 insertions, 14 deletions

diff --git a/service/errors.go b/service/errors.go
index 04cedb45..ea6147a9 100644
--- a/service/errors.go
+++ b/service/errors.go
@@ -5,19 +5,94 @@
 
 package service
 
+import (
+	"fmt"
+	"golang.org/x/sys/windows"
+	"syscall"
+)
+
+type Error uint32
+
+const (
+	ErrorSuccess Error = iota
+	ErrorEventlogOpen
+	ErrorLoadConfiguration
+	ErrorCreateWintun
+	ErrorDetermineWintunName
+	ErrorUAPIListen
+	ErrorUAPISerialization
+	ErrorDeviceSetConfig
+	ErrorBindSocketsToDefaultRoutes
+	ErrorSetNetConfig
+	ErrorDetermineExecutablePath
+	ErrorFindAdministratorsSID
+	ErrorOpenNULFile
+	ErrorTrackTunnels
+	ErrorEnumerateSessions
+	ErrorWin32
+)
+
+func (e Error) Error() string {
+	switch e {
+	case ErrorSuccess:
+		return "No error."
+	case ErrorEventlogOpen:
+		return "Unable to open Windows event log."
+	case ErrorDetermineExecutablePath:
+		return "Unable to determine path of running executable."
+	case ErrorLoadConfiguration:
+		return "Unable to load configuration from path."
+	case ErrorCreateWintun:
+		return "Unable to create Wintun device."
+	case ErrorDetermineWintunName:
+		return "Unable to determine Wintun name."
+	case ErrorUAPIListen:
+		return "Unable to listen on named pipe."
+	case ErrorUAPISerialization:
+		return "Unable to serialize configuration into uapi form."
+	case ErrorDeviceSetConfig:
+		return "Unable to set device configuration."
+	case ErrorBindSocketsToDefaultRoutes:
+		return "Unable to bind sockets to default route."
+	case ErrorSetNetConfig:
+		return "Unable to set interface addresses, routes, dns, and/or adapter settings."
+	case ErrorFindAdministratorsSID:
+		return "Unable to find Administrators SID."
+	case ErrorOpenNULFile:
+		return "Unable to open NUL file."
+	case ErrorTrackTunnels:
+		return "Unable to track existing tunnels."
+	case ErrorEnumerateSessions:
+		return "Unable to enumerate current sessions."
+	case ErrorWin32:
+		return "An internal Windows error has occurred."
+	default:
+		return "An unknown error has occurred."
+	}
+}
+
+func determineErrorCode(err error, serviceError Error) (bool, uint32) {
+	if syserr, ok := err.(syscall.Errno); ok {
+		return false, uint32(syserr)
+	} else if serviceError != ErrorSuccess {
+		return true, uint32(serviceError)
+	} else {
+		return false, windows.NO_ERROR
+	}
+}
+
+func combineErrors(err error, serviceError Error) error {
+	if serviceError != ErrorSuccess {
+		if err != nil {
+			return fmt.Errorf("%v: %v", serviceError, err)
+		} else {
+			return serviceError
+		}
+	}
+	return err
+}
+
 const (
-	ERROR_LOG_CONTAINER_OPEN_FAILED uint32 = 0x000019F1
-	ERROR_INVALID_PARAMETER         uint32 = 0x00000057
-	ERROR_OPEN_FAILED               uint32 = 0x0000006E
-	ERROR_ADAP_HDW_ERR              uint32 = 0x00000039
-	ERROR_PIPE_LISTENING            uint32 = 0x00000218
-	ERROR_BAD_LOGON_SESSION_STATE   uint32 = 0x00000555
-	ERROR_BAD_PATHNAME              uint32 = 0x000000A1
-	ERROR_FILE_NOT_FOUND            uint32 = 0x00000002
-	ERROR_SERVER_SID_MISMATCH       uint32 = 0x00000274
-	ERROR_NETWORK_BUSY              uint32 = 0x00000036
-	ERROR_NO_TRACKING_SERVICE       uint32 = 0x00000494
-	ERROR_OBJECT_ALREADY_EXISTS     uint32 = 0x00001392
-	ERROR_SERVICE_DOES_NOT_EXIST    uint32 = 0x00000424
-	ERROR_SERVICE_MARKED_FOR_DELETE uint32 = 0x00000430
+	serviceDOES_NOT_EXIST    uint32 = 0x00000424
+	serviceMARKED_FOR_DELETE uint32 = 0x00000430
 )