vendor/golang.org/x/sys/windows/svc/mgr/config.go

   1 // Copyright 2012 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 // +build windows
   6
   7 package mgr
   8
   9 import (
  10         "syscall"
  11         "unicode/utf16"
  12         "unsafe"
  13
  14         "golang.org/x/sys/windows"
  15 )
  16
  17 const (
  18         // Service start types.
  19         StartManual    = windows.SERVICE_DEMAND_START // the service must be started manually
  20         StartAutomatic = windows.SERVICE_AUTO_START   // the service will start by itself whenever the computer reboots
  21         StartDisabled  = windows.SERVICE_DISABLED     // the service cannot be started
  22
  23         // The severity of the error, and action taken,
  24         // if this service fails to start.
  25         ErrorCritical = windows.SERVICE_ERROR_CRITICAL
  26         ErrorIgnore   = windows.SERVICE_ERROR_IGNORE
  27         ErrorNormal   = windows.SERVICE_ERROR_NORMAL
  28         ErrorSevere   = windows.SERVICE_ERROR_SEVERE
  29 )
  30
  31 // TODO(brainman): Password is not returned by windows.QueryServiceConfig, not sure how to get it.
  32
  33 type Config struct {
  34         ServiceType      uint32
  35         StartType        uint32
  36         ErrorControl     uint32
  37         BinaryPathName   string // fully qualified path to the service binary file, can also include arguments for an auto-start service
  38         LoadOrderGroup   string
  39         TagId            uint32
  40         Dependencies     []string
  41         ServiceStartName string // name of the account under which the service should run
  42         DisplayName      string
  43         Password         string
  44         Description      string
  45 }
  46
  47 func toString(p *uint16) string {
  48         if p == nil {
  49                 return ""
  50         }
  51         return syscall.UTF16ToString((*[4096]uint16)(unsafe.Pointer(p))[:])
  52 }
  53
  54 func toStringSlice(ps *uint16) []string {
  55         if ps == nil {
  56                 return nil
  57         }
  58         r := make([]string, 0)
  59         for from, i, p := 0, 0, (*[1 << 24]uint16)(unsafe.Pointer(ps)); true; i++ {
  60                 if p[i] == 0 {
  61                         // empty string marks the end
  62                         if i <= from {
  63                                 break
  64                         }
  65                         r = append(r, string(utf16.Decode(p[from:i])))
  66                         from = i + 1
  67                 }
  68         }
  69         return r
  70 }
  71
  72 // Config retrieves service s configuration paramteres.
  73 func (s *Service) Config() (Config, error) {
  74         var p *windows.QUERY_SERVICE_CONFIG
  75         n := uint32(1024)
  76         for {
  77                 b := make([]byte, n)
  78                 p = (*windows.QUERY_SERVICE_CONFIG)(unsafe.Pointer(&b[0]))
  79                 err := windows.QueryServiceConfig(s.Handle, p, n, &n)
  80                 if err == nil {
  81                         break
  82                 }
  83                 if err.(syscall.Errno) != syscall.ERROR_INSUFFICIENT_BUFFER {
  84                         return Config{}, err
  85                 }
  86                 if n <= uint32(len(b)) {
  87                         return Config{}, err
  88                 }
  89         }
  90
  91         var p2 *windows.SERVICE_DESCRIPTION
  92         n = uint32(1024)
  93         for {
  94                 b := make([]byte, n)
  95                 p2 = (*windows.SERVICE_DESCRIPTION)(unsafe.Pointer(&b[0]))
  96                 err := windows.QueryServiceConfig2(s.Handle,
  97                         windows.SERVICE_CONFIG_DESCRIPTION, &b[0], n, &n)
  98                 if err == nil {
  99                         break
 100                 }
 101                 if err.(syscall.Errno) != syscall.ERROR_INSUFFICIENT_BUFFER {
 102                         return Config{}, err
 103                 }
 104                 if n <= uint32(len(b)) {
 105                         return Config{}, err
 106                 }
 107         }
 108
 109         return Config{
 110                 ServiceType:      p.ServiceType,
 111                 StartType:        p.StartType,
 112                 ErrorControl:     p.ErrorControl,
 113                 BinaryPathName:   toString(p.BinaryPathName),
 114                 LoadOrderGroup:   toString(p.LoadOrderGroup),
 115                 TagId:            p.TagId,
 116                 Dependencies:     toStringSlice(p.Dependencies),
 117                 ServiceStartName: toString(p.ServiceStartName),
 118                 DisplayName:      toString(p.DisplayName),
 119                 Description:      toString(p2.Description),
 120         }, nil
 121 }
 122
 123 func updateDescription(handle windows.Handle, desc string) error {
 124         d := windows.SERVICE_DESCRIPTION{toPtr(desc)}
 125         return windows.ChangeServiceConfig2(handle,
 126                 windows.SERVICE_CONFIG_DESCRIPTION, (*byte)(unsafe.Pointer(&d)))
 127 }
 128
 129 // UpdateConfig updates service s configuration parameters.
 130 func (s *Service) UpdateConfig(c Config) error {
 131         err := windows.ChangeServiceConfig(s.Handle, c.ServiceType, c.StartType,
 132                 c.ErrorControl, toPtr(c.BinaryPathName), toPtr(c.LoadOrderGroup),
 133                 nil, toStringBlock(c.Dependencies), toPtr(c.ServiceStartName),
 134                 toPtr(c.Password), toPtr(c.DisplayName))
 135         if err != nil {
 136                 return err
 137         }
 138         return updateDescription(s.Handle, c.Description)
 139 }