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pgevent.c
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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 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  */
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)
57  return S_OK;
58 }
59 
60 /*
61  * DllRegisterServer --- Instructs DLL to create its registry entries
62  */
63 
64 STDAPI
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
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 }
STDAPI DllUnregisterServer(void)
Definition: pgevent.c:127
HANDLE g_module
Definition: pgevent.c:18
STDAPI DllRegisterServer(void)
Definition: pgevent.c:65
HRESULT DllInstall(BOOL bInstall, LPCWSTR pszCmdLine)
Definition: pgevent.c:38
BOOL WINAPI DllMain(HANDLE hModule, DWORD ul_reason_for_call, LPVOID lpReserved)
Definition: pgevent.c:152
#define DEFAULT_EVENT_SOURCE
#define NULL
Definition: c.h:229
char event_source[256]
Definition: pgevent.c:25
#define TRUE
Definition: c.h:217
typedef BOOL(WINAPI *MINIDUMPWRITEDUMP)(HANDLE hProcess