autoload.c

   1 /*
   2  * Copyright (c) 2000, Red Hat, Inc.
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     A copy of the GNU General Public License can be found at
  10  *     http://www.gnu.org/
  11  *
  12  * Written by DJ Delorie <dj@cygnus.com>
  13  *
  14  */
  15
  16 static char *cvsid = "\n%%% $Id$\n";
  17
  18 #include "win32.h"
  19
  20 typedef struct {
  21   char *name;
  22   HINSTANCE handle;
  23 } DllInfo;
  24
  25 #define DLL(n) static DllInfo n ## _info __asm__ (#n "_info") = { #n, 0}
  26
  27 #define Auto(dll, func, size) \
  28         __asm__ ("\t.data"); \
  29         __asm__ ("\t.global\t_" #func "@" #size); \
  30         __asm__ ("_" #func "@" #size ":"); \
  31         __asm__ ("\tcall\tautoload_common"); \
  32         __asm__ ("\t.long\t" #dll "_info"); \
  33         __asm__ ("\t.ascii\t\"" #func "\\0\"")
  34
  35 DLL (wininet);
  36
  37 Auto (wininet, InternetAttemptConnect, 4);
  38 Auto (wininet, InternetCloseHandle, 4);
  39 Auto (wininet, InternetGetLastResponseInfoA, 12);
  40 Auto (wininet, InternetOpenA, 20);
  41 Auto (wininet, InternetOpenUrlA, 24);
  42 Auto (wininet, InternetReadFile, 16);
  43 Auto (wininet, InternetSetOptionA, 16);
  44 Auto (wininet, InternetQueryOptionA, 16);
  45 Auto (wininet, HttpQueryInfoA, 20);
  46 Auto (wininet, HttpSendRequestA, 20);
  47
  48 typedef struct {
  49   DllInfo *dll;
  50   char name[100];
  51 } AutoEntry;
  52
  53 static void autoload_common () __asm__ ("autoload_common");
  54
  55 static void
  56 autoload_common (int x)
  57 {
  58   int fp, rel;
  59   unsigned char *proc;
  60   HINSTANCE h;
  61   AutoEntry *a;
  62
  63   a = *(AutoEntry **)(&x - 1);
  64   if (a->dll->handle == 0)
  65     {
  66       h = LoadLibrary (a->dll->name);
  67       a->dll->handle = h;
  68     }
  69   fp = (int) GetProcAddress (a->dll->handle, a->name);
  70   proc = ((unsigned char *)a) - 5;
  71   rel = fp - (int)(a); /* now it's a relative call */
  72   *proc++ = 0xe9; /* jump near 32-bit relative */
  73   *proc++ = rel;
  74   *proc++ = rel>>8;
  75   *proc++ = rel>>16;
  76   *proc++ = rel>>24;
  77
  78   *(int *)(&x-1) = (int)proc-5;
  79 }