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#if (defined(_WIN64) || defined(_WIN32_WCE)) && !defined(UNICODE)
# define UNICODE
#endif
#if defined(UNICODE) && !defined(_UNICODE)
# define _UNICODE
#endif
#if defined(_UNICODE) && !defined(UNICODE)
# define UNICODE
#endif
#include <windows.h>
#include <tchar.h>
#include <stdio.h>
#include "uplink.h"
void OPENSSL_showfatal(const char *, ...);
static TCHAR msg[128];
static void unimplemented(void)
{
OPENSSL_showfatal(sizeof(TCHAR) == sizeof(char) ? "%s\n" : "%S\n", msg);
ExitProcess(1);
}
void OPENSSL_Uplink(volatile void **table, int index)
{
static HMODULE volatile apphandle = NULL;
static void **volatile applinktable = NULL;
int len;
void (*func) (void) = unimplemented;
HANDLE h;
void **p;
/*
* Note that the below code is not MT-safe in respect to msg buffer, but
* what's the worst thing that can happen? Error message might be
* misleading or corrupted. As error condition is fatal and should never
* be risen, I accept the risk...
*/
/*
* One can argue that I should have used InterlockedExchangePointer or
* something to update static variables and table[]. Well, store
* instructions are as atomic as they can get and assigned values are
* effectively constant... So that volatile qualifier should be
* sufficient [it prohibits compiler to reorder memory access
* instructions].
*/
do {
len = _sntprintf(msg, sizeof(msg) / sizeof(TCHAR),
_T("OPENSSL_Uplink(%p,%02X): "), table, index);
_tcscpy(msg + len, _T("unimplemented function"));
if ((h = apphandle) == NULL) {
if ((h = GetModuleHandle(NULL)) == NULL) {
apphandle = (HMODULE) - 1;
_tcscpy(msg + len, _T("no host application"));
break;
}
apphandle = h;
}
if ((h = apphandle) == (HMODULE) - 1) /* revalidate */
break;
if (applinktable == NULL) {
void **(*applink) ();
applink = (void **(*)())GetProcAddress(h, "OPENSSL_Applink");
if (applink == NULL) {
apphandle = (HMODULE) - 1;
_tcscpy(msg + len, _T("no OPENSSL_Applink"));
break;
}
p = (*applink) ();
if (p == NULL) {
apphandle = (HMODULE) - 1;
_tcscpy(msg + len, _T("no ApplinkTable"));
break;
}
applinktable = p;
} else
p = applinktable;
if (index > (int)p[0])
break;
if (p[index])
func = p[index];
} while (0);
table[index] = func;
}
#ifdef SELFTEST
main()
{
UP_fprintf(UP_stdout, "hello, world!\n");
}
#endif
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