src/bin/pgevent/pgevent.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * pgevent.c
   4  *              Defines the entry point for pgevent dll.
   5  *              The DLL defines event source for backend
   6  *
   7  *
   8  * IDENTIFICATION
   9  *        src/bin/pgevent/pgevent.c
  10  *
  11  *-------------------------------------------------------------------------
  12  */
  13 #include "postgres_fe.h"
  14
  15 #include <olectl.h>
  16
  17 /* Global variables */
  18 static HANDLE g_module = NULL;  /* hModule of DLL */
  19
  20 /*
  21  * The event source is stored as a registry key.
  22  * The maximum length of a registry key is 255 characters.
  23  * http://msdn.microsoft.com/en-us/library/ms724872(v=vs.85).aspx
  24  */
  25 static char event_source[256] = DEFAULT_EVENT_SOURCE;
  26
  27 /* Prototypes */
  28 HRESULT         DllInstall(BOOL bInstall, LPCWSTR pszCmdLine);
  29 STDAPI          DllRegisterServer(void);
  30 STDAPI          DllUnregisterServer(void);
  31 BOOL            WINAPI DllMain(HANDLE hModule, DWORD ul_reason_for_call, LPVOID lpReserved);
  32
  33 /*
  34  * DllInstall --- Passes the command line argument to DLL
  35  */
  36
  37 HRESULT
  38 DllInstall(BOOL bInstall,
  39                    LPCWSTR pszCmdLine)
  40 {
  41         if (pszCmdLine && *pszCmdLine != '\0')
  42                 wcstombs(event_source, pszCmdLine, sizeof(event_source));
  43
  44         /*
  45          * This is an ugly hack due to the strange behavior of "regsvr32 /i".
  46          *
  47          * When installing, regsvr32 calls DllRegisterServer before DllInstall.
  48          * When uninstalling (i.e. "regsvr32 /u /i"), on the other hand, regsvr32
  49          * calls DllInstall and then DllUnregisterServer as expected.
  50          *
  51          * This strange behavior forces us to specify -n (i.e. "regsvr32 /n /i").
  52          * Without -n, DllRegisterServer called before DllInstall would mistakenly
  53          * overwrite the default "PostgreSQL" event source registration.
  54          */
  55         if (bInstall)
  56                 DllRegisterServer();
  57         return S_OK;
  58 }
  59
  60 /*
  61  * DllRegisterServer --- Instructs DLL to create its registry entries
  62  */
  63
  64 STDAPI
  65 DllRegisterServer(void)
  66 {
  67         HKEY            key;
  68         DWORD           data;
  69         char            buffer[_MAX_PATH];
  70         char            key_name[400];
  71
  72         /* Set the name of DLL full path name. */
  73         if (!GetModuleFileName((HMODULE) g_module, buffer, sizeof(buffer)))
  74         {
  75                 MessageBox(NULL, "Could not retrieve DLL filename", "PostgreSQL error", MB_OK | MB_ICONSTOP);
  76                 return SELFREG_E_TYPELIB;
  77         }
  78
  79         /*
  80          * Add PostgreSQL source name as a subkey under the Application key in the
  81          * EventLog registry key.
  82          */
  83         _snprintf(key_name, sizeof(key_name),
  84                           "SYSTEM\\CurrentControlSet\\Services\\EventLog\\Application\\%s",
  85                           event_source);
  86         if (RegCreateKey(HKEY_LOCAL_MACHINE, key_name, &key))
  87         {
  88                 MessageBox(NULL, "Could not create the registry key.", "PostgreSQL error", MB_OK | MB_ICONSTOP);
  89                 return SELFREG_E_TYPELIB;
  90         }
  91
  92         /* Add the name to the EventMessageFile subkey. */
  93         if (RegSetValueEx(key,
  94                                           "EventMessageFile",
  95                                           0,
  96                                           REG_EXPAND_SZ,
  97                                           (LPBYTE) buffer,
  98                                           strlen(buffer) + 1))
  99         {
 100                 MessageBox(NULL, "Could not set the event message file.", "PostgreSQL error", MB_OK | MB_ICONSTOP);
 101                 return SELFREG_E_TYPELIB;
 102         }
 103
 104         /* Set the supported event types in the TypesSupported subkey. */
 105         data = EVENTLOG_ERROR_TYPE | EVENTLOG_WARNING_TYPE | EVENTLOG_INFORMATION_TYPE;
 106
 107         if (RegSetValueEx(key,
 108                                           "TypesSupported",
 109                                           0,
 110                                           REG_DWORD,
 111                                           (LPBYTE) &data,
 112                                           sizeof(DWORD)))
 113         {
 114                 MessageBox(NULL, "Could not set the supported types.", "PostgreSQL error", MB_OK | MB_ICONSTOP);
 115                 return SELFREG_E_TYPELIB;
 116         }
 117
 118         RegCloseKey(key);
 119         return S_OK;
 120 }
 121
 122 /*
 123  * DllUnregisterServer --- Instructs DLL to remove only those entries created through DllRegisterServer
 124  */
 125
 126 STDAPI
 127 DllUnregisterServer(void)
 128 {
 129         char            key_name[400];
 130
 131         /*
 132          * Remove PostgreSQL source name as a subkey under the Application key in
 133          * the EventLog registry key.
 134          */
 135
 136         _snprintf(key_name, sizeof(key_name),
 137                           "SYSTEM\\CurrentControlSet\\Services\\EventLog\\Application\\%s",
 138                           event_source);
 139         if (RegDeleteKey(HKEY_LOCAL_MACHINE, key_name))
 140         {
 141                 MessageBox(NULL, "Could not delete the registry key.", "PostgreSQL error", MB_OK | MB_ICONSTOP);
 142                 return SELFREG_E_TYPELIB;
 143         }
 144         return S_OK;
 145 }
 146
 147 /*
 148  * DllMain --- is an optional entry point into a DLL.
 149  */
 150
 151 BOOL            WINAPI
 152 DllMain(HANDLE hModule,
 153                 DWORD ul_reason_for_call,
 154                 LPVOID lpReserved
 155 )
 156 {
 157         if (ul_reason_for_call == DLL_PROCESS_ATTACH)
 158                 g_module = hModule;
 159         return TRUE;
 160 }