mdw@git.distorted.org.uk Git - sgt/putty/blob - winmisc.c

   1 /*
   2  * winmisc.c: miscellaneous Windows-specific things.
   3  */
   4
   5 #include <windows.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include "putty.h"
   9 #include "winstuff.h"
  10
  11 void platform_get_x11_auth(char *display, int *proto,
  12                            unsigned char *data, int *datalen)
  13 {
  14     /* We don't support this at all under Windows. */
  15 }
  16
  17 Filename filename_from_str(const char *str)
  18 {
  19     Filename ret;
  20     strncpy(ret.path, str, sizeof(ret.path));
  21     ret.path[sizeof(ret.path)-1] = '\0';
  22     return ret;
  23 }
  24
  25 const char *filename_to_str(const Filename *fn)
  26 {
  27     return fn->path;
  28 }
  29
  30 int filename_equal(Filename f1, Filename f2)
  31 {
  32     return !strcmp(f1.path, f2.path);
  33 }
  34
  35 int filename_is_null(Filename fn)
  36 {
  37     return !*fn.path;
  38 }
  39
  40 int SaneDialogBox(HINSTANCE hinst,
  41                   LPCTSTR tmpl,
  42                   HWND hwndparent,
  43                   DLGPROC lpDialogFunc)
  44 {
  45     WNDCLASS wc;
  46     HWND hwnd;
  47     MSG msg;
  48     int flags;
  49     int ret;
  50     int gm;
  51
  52     wc.style = CS_DBLCLKS | CS_SAVEBITS | CS_BYTEALIGNWINDOW;
  53     wc.lpfnWndProc = DefDlgProc;
  54     wc.cbClsExtra = 0;
  55     wc.cbWndExtra = DLGWINDOWEXTRA + 8;
  56     wc.hInstance = hinst;
  57     wc.hIcon = NULL;
  58     wc.hCursor = LoadCursor(NULL, IDC_ARROW);
  59     wc.hbrBackground = (HBRUSH) (COLOR_BACKGROUND +1);
  60     wc.lpszMenuName = NULL;
  61     wc.lpszClassName = "PuTTYConfigBox";
  62     RegisterClass(&wc);
  63
  64     hwnd = CreateDialog(hinst, tmpl, hwndparent, lpDialogFunc);
  65
  66     SetWindowLong(hwnd, BOXFLAGS, 0); /* flags */
  67     SetWindowLong(hwnd, BOXRESULT, 0); /* result from SaneEndDialog */
  68
  69     while ((gm=GetMessage(&msg, NULL, 0, 0)) > 0) {
  70         flags=GetWindowLong(hwnd, BOXFLAGS);
  71         if (!(flags & DF_END) && !IsDialogMessage(hwnd, &msg))
  72             DispatchMessage(&msg);
  73         if (flags & DF_END)
  74             break;
  75     }
  76
  77     if (gm == 0)
  78         PostQuitMessage(msg.wParam); /* We got a WM_QUIT, pass it on */
  79
  80     ret=GetWindowLong(hwnd, BOXRESULT);
  81     DestroyWindow(hwnd);
  82     return ret;
  83 }
  84
  85 void SaneEndDialog(HWND hwnd, int ret)
  86 {
  87     SetWindowLong(hwnd, BOXRESULT, ret);
  88     SetWindowLong(hwnd, BOXFLAGS, DF_END);
  89 }
  90
  91 #ifdef DEBUG
  92 static FILE *debug_fp = NULL;
  93 static HANDLE debug_hdl = INVALID_HANDLE_VALUE;
  94 static int debug_got_console = 0;
  95
  96 void dputs(char *buf)
  97 {
  98     DWORD dw;
  99
 100     if (!debug_got_console) {
 101         if (AllocConsole()) {
 102             debug_got_console = 1;
 103             debug_hdl = GetStdHandle(STD_OUTPUT_HANDLE);
 104         }
 105     }
 106     if (!debug_fp) {
 107         debug_fp = fopen("debug.log", "w");
 108     }
 109
 110     if (debug_hdl != INVALID_HANDLE_VALUE) {
 111         WriteFile(debug_hdl, buf, strlen(buf), &dw, NULL);
 112     }
 113     fputs(buf, debug_fp);
 114     fflush(debug_fp);
 115 }
 116 #endif
 117
 118 #ifdef MINEFIELD
 119 /*
 120  * Minefield - a Windows equivalent for Electric Fence
 121  */
 122
 123 #define PAGESIZE 4096
 124
 125 /*
 126  * Design:
 127  *
 128  * We start by reserving as much virtual address space as Windows
 129  * will sensibly (or not sensibly) let us have. We flag it all as
 130  * invalid memory.
 131  *
 132  * Any allocation attempt is satisfied by committing one or more
 133  * pages, with an uncommitted page on either side. The returned
 134  * memory region is jammed up against the _end_ of the pages.
 135  *
 136  * Freeing anything causes instantaneous decommitment of the pages
 137  * involved, so stale pointers are caught as soon as possible.
 138  */
 139
 140 static int minefield_initialised = 0;
 141 static void *minefield_region = NULL;
 142 static long minefield_size = 0;
 143 static long minefield_npages = 0;
 144 static long minefield_curpos = 0;
 145 static unsigned short *minefield_admin = NULL;
 146 static void *minefield_pages = NULL;
 147
 148 static void minefield_admin_hide(int hide)
 149 {
 150     int access = hide ? PAGE_NOACCESS : PAGE_READWRITE;
 151     VirtualProtect(minefield_admin, minefield_npages * 2, access, NULL);
 152 }
 153
 154 static void minefield_init(void)
 155 {
 156     int size;
 157     int admin_size;
 158     int i;
 159
 160     for (size = 0x40000000; size > 0; size = ((size >> 3) * 7) & ~0xFFF) {
 161         minefield_region = VirtualAlloc(NULL, size,
 162                                         MEM_RESERVE, PAGE_NOACCESS);
 163         if (minefield_region)
 164             break;
 165     }
 166     minefield_size = size;
 167
 168     /*
 169      * Firstly, allocate a section of that to be the admin block.
 170      * We'll need a two-byte field for each page.
 171      */
 172     minefield_admin = minefield_region;
 173     minefield_npages = minefield_size / PAGESIZE;
 174     admin_size = (minefield_npages * 2 + PAGESIZE - 1) & ~(PAGESIZE - 1);
 175     minefield_npages = (minefield_size - admin_size) / PAGESIZE;
 176     minefield_pages = (char *) minefield_region + admin_size;
 177
 178     /*
 179      * Commit the admin region.
 180      */
 181     VirtualAlloc(minefield_admin, minefield_npages * 2,
 182                  MEM_COMMIT, PAGE_READWRITE);
 183
 184     /*
 185      * Mark all pages as unused (0xFFFF).
 186      */
 187     for (i = 0; i < minefield_npages; i++)
 188         minefield_admin[i] = 0xFFFF;
 189
 190     /*
 191      * Hide the admin region.
 192      */
 193     minefield_admin_hide(1);
 194
 195     minefield_initialised = 1;
 196 }
 197
 198 static void minefield_bomb(void)
 199 {
 200     div(1, *(int *) minefield_pages);
 201 }
 202
 203 static void *minefield_alloc(int size)
 204 {
 205     int npages;
 206     int pos, lim, region_end, region_start;
 207     int start;
 208     int i;
 209
 210     npages = (size + PAGESIZE - 1) / PAGESIZE;
 211
 212     minefield_admin_hide(0);
 213
 214     /*
 215      * Search from current position until we find a contiguous
 216      * bunch of npages+2 unused pages.
 217      */
 218     pos = minefield_curpos;
 219     lim = minefield_npages;
 220     while (1) {
 221         /* Skip over used pages. */
 222         while (pos < lim && minefield_admin[pos] != 0xFFFF)
 223             pos++;
 224         /* Count unused pages. */
 225         start = pos;
 226         while (pos < lim && pos - start < npages + 2 &&
 227                minefield_admin[pos] == 0xFFFF)
 228             pos++;
 229         if (pos - start == npages + 2)
 230             break;
 231         /* If we've reached the limit, reset the limit or stop. */
 232         if (pos >= lim) {
 233             if (lim == minefield_npages) {
 234                 /* go round and start again at zero */
 235                 lim = minefield_curpos;
 236                 pos = 0;
 237             } else {
 238                 minefield_admin_hide(1);
 239                 return NULL;
 240             }
 241         }
 242     }
 243
 244     minefield_curpos = pos - 1;
 245
 246     /*
 247      * We have npages+2 unused pages starting at start. We leave
 248      * the first and last of these alone and use the rest.
 249      */
 250     region_end = (start + npages + 1) * PAGESIZE;
 251     region_start = region_end - size;
 252     /* FIXME: could align here if we wanted */
 253
 254     /*
 255      * Update the admin region.
 256      */
 257     for (i = start + 2; i < start + npages + 1; i++)
 258         minefield_admin[i] = 0xFFFE;   /* used but no region starts here */
 259     minefield_admin[start + 1] = region_start % PAGESIZE;
 260
 261     minefield_admin_hide(1);
 262
 263     VirtualAlloc((char *) minefield_pages + region_start, size,
 264                  MEM_COMMIT, PAGE_READWRITE);
 265     return (char *) minefield_pages + region_start;
 266 }
 267
 268 static void minefield_free(void *ptr)
 269 {
 270     int region_start, i, j;
 271
 272     minefield_admin_hide(0);
 273
 274     region_start = (char *) ptr - (char *) minefield_pages;
 275     i = region_start / PAGESIZE;
 276     if (i < 0 || i >= minefield_npages ||
 277         minefield_admin[i] != region_start % PAGESIZE)
 278         minefield_bomb();
 279     for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++) {
 280         minefield_admin[j] = 0xFFFF;
 281     }
 282
 283     VirtualFree(ptr, j * PAGESIZE - region_start, MEM_DECOMMIT);
 284
 285     minefield_admin_hide(1);
 286 }
 287
 288 static int minefield_get_size(void *ptr)
 289 {
 290     int region_start, i, j;
 291
 292     minefield_admin_hide(0);
 293
 294     region_start = (char *) ptr - (char *) minefield_pages;
 295     i = region_start / PAGESIZE;
 296     if (i < 0 || i >= minefield_npages ||
 297         minefield_admin[i] != region_start % PAGESIZE)
 298         minefield_bomb();
 299     for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++);
 300
 301     minefield_admin_hide(1);
 302
 303     return j * PAGESIZE - region_start;
 304 }
 305
 306 void *minefield_c_malloc(size_t size)
 307 {
 308     if (!minefield_initialised)
 309         minefield_init();
 310     return minefield_alloc(size);
 311 }
 312
 313 void minefield_c_free(void *p)
 314 {
 315     if (!minefield_initialised)
 316         minefield_init();
 317     minefield_free(p);
 318 }
 319
 320 /*
 321  * realloc _always_ moves the chunk, for rapid detection of code
 322  * that assumes it won't.
 323  */
 324 void *minefield_c_realloc(void *p, size_t size)
 325 {
 326     size_t oldsize;
 327     void *q;
 328     if (!minefield_initialised)
 329         minefield_init();
 330     q = minefield_alloc(size);
 331     oldsize = minefield_get_size(p);
 332     memcpy(q, p, (oldsize < size ? oldsize : size));
 333     minefield_free(p);
 334     return q;
 335 }
 336
 337 #endif                          /* MINEFIELD */