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     HWND boxhwnd;
  46     MSG msg;
  47
  48     boxhwnd = CreateDialog(hinst, tmpl, hwndparent, lpDialogFunc);
  49     while (GetMessage(&msg, NULL, 0, 0)) {
  50         if (!(boxinfo.flags & DF_END) && !IsDialogMessage(boxhwnd, &msg))
  51             DispatchMessage(&msg);
  52         if (boxinfo.flags & DF_END) break;
  53     }
  54     boxinfo.flags=0;
  55     return boxinfo.result;
  56 }
  57
  58 void SaneEndDialog(HWND hwnd, int ret)
  59 {
  60     boxinfo.result = ret;
  61     boxinfo.flags |= DF_END;
  62     DestroyWindow(hwnd);
  63 }
  64
  65 #ifdef DEBUG
  66 static FILE *debug_fp = NULL;
  67 static HANDLE debug_hdl = INVALID_HANDLE_VALUE;
  68 static int debug_got_console = 0;
  69
  70 void dputs(char *buf)
  71 {
  72     DWORD dw;
  73
  74     if (!debug_got_console) {
  75         if (AllocConsole()) {
  76             debug_got_console = 1;
  77             debug_hdl = GetStdHandle(STD_OUTPUT_HANDLE);
  78         }
  79     }
  80     if (!debug_fp) {
  81         debug_fp = fopen("debug.log", "w");
  82     }
  83
  84     if (debug_hdl != INVALID_HANDLE_VALUE) {
  85         WriteFile(debug_hdl, buf, strlen(buf), &dw, NULL);
  86     }
  87     fputs(buf, debug_fp);
  88     fflush(debug_fp);
  89 }
  90 #endif
  91
  92 #ifdef MINEFIELD
  93 /*
  94  * Minefield - a Windows equivalent for Electric Fence
  95  */
  96
  97 #define PAGESIZE 4096
  98
  99 /*
 100  * Design:
 101  *
 102  * We start by reserving as much virtual address space as Windows
 103  * will sensibly (or not sensibly) let us have. We flag it all as
 104  * invalid memory.
 105  *
 106  * Any allocation attempt is satisfied by committing one or more
 107  * pages, with an uncommitted page on either side. The returned
 108  * memory region is jammed up against the _end_ of the pages.
 109  *
 110  * Freeing anything causes instantaneous decommitment of the pages
 111  * involved, so stale pointers are caught as soon as possible.
 112  */
 113
 114 static int minefield_initialised = 0;
 115 static void *minefield_region = NULL;
 116 static long minefield_size = 0;
 117 static long minefield_npages = 0;
 118 static long minefield_curpos = 0;
 119 static unsigned short *minefield_admin = NULL;
 120 static void *minefield_pages = NULL;
 121
 122 static void minefield_admin_hide(int hide)
 123 {
 124     int access = hide ? PAGE_NOACCESS : PAGE_READWRITE;
 125     VirtualProtect(minefield_admin, minefield_npages * 2, access, NULL);
 126 }
 127
 128 static void minefield_init(void)
 129 {
 130     int size;
 131     int admin_size;
 132     int i;
 133
 134     for (size = 0x40000000; size > 0; size = ((size >> 3) * 7) & ~0xFFF) {
 135         minefield_region = VirtualAlloc(NULL, size,
 136                                         MEM_RESERVE, PAGE_NOACCESS);
 137         if (minefield_region)
 138             break;
 139     }
 140     minefield_size = size;
 141
 142     /*
 143      * Firstly, allocate a section of that to be the admin block.
 144      * We'll need a two-byte field for each page.
 145      */
 146     minefield_admin = minefield_region;
 147     minefield_npages = minefield_size / PAGESIZE;
 148     admin_size = (minefield_npages * 2 + PAGESIZE - 1) & ~(PAGESIZE - 1);
 149     minefield_npages = (minefield_size - admin_size) / PAGESIZE;
 150     minefield_pages = (char *) minefield_region + admin_size;
 151
 152     /*
 153      * Commit the admin region.
 154      */
 155     VirtualAlloc(minefield_admin, minefield_npages * 2,
 156                  MEM_COMMIT, PAGE_READWRITE);
 157
 158     /*
 159      * Mark all pages as unused (0xFFFF).
 160      */
 161     for (i = 0; i < minefield_npages; i++)
 162         minefield_admin[i] = 0xFFFF;
 163
 164     /*
 165      * Hide the admin region.
 166      */
 167     minefield_admin_hide(1);
 168
 169     minefield_initialised = 1;
 170 }
 171
 172 static void minefield_bomb(void)
 173 {
 174     div(1, *(int *) minefield_pages);
 175 }
 176
 177 static void *minefield_alloc(int size)
 178 {
 179     int npages;
 180     int pos, lim, region_end, region_start;
 181     int start;
 182     int i;
 183
 184     npages = (size + PAGESIZE - 1) / PAGESIZE;
 185
 186     minefield_admin_hide(0);
 187
 188     /*
 189      * Search from current position until we find a contiguous
 190      * bunch of npages+2 unused pages.
 191      */
 192     pos = minefield_curpos;
 193     lim = minefield_npages;
 194     while (1) {
 195         /* Skip over used pages. */
 196         while (pos < lim && minefield_admin[pos] != 0xFFFF)
 197             pos++;
 198         /* Count unused pages. */
 199         start = pos;
 200         while (pos < lim && pos - start < npages + 2 &&
 201                minefield_admin[pos] == 0xFFFF)
 202             pos++;
 203         if (pos - start == npages + 2)
 204             break;
 205         /* If we've reached the limit, reset the limit or stop. */
 206         if (pos >= lim) {
 207             if (lim == minefield_npages) {
 208                 /* go round and start again at zero */
 209                 lim = minefield_curpos;
 210                 pos = 0;
 211             } else {
 212                 minefield_admin_hide(1);
 213                 return NULL;
 214             }
 215         }
 216     }
 217
 218     minefield_curpos = pos - 1;
 219
 220     /*
 221      * We have npages+2 unused pages starting at start. We leave
 222      * the first and last of these alone and use the rest.
 223      */
 224     region_end = (start + npages + 1) * PAGESIZE;
 225     region_start = region_end - size;
 226     /* FIXME: could align here if we wanted */
 227
 228     /*
 229      * Update the admin region.
 230      */
 231     for (i = start + 2; i < start + npages + 1; i++)
 232         minefield_admin[i] = 0xFFFE;   /* used but no region starts here */
 233     minefield_admin[start + 1] = region_start % PAGESIZE;
 234
 235     minefield_admin_hide(1);
 236
 237     VirtualAlloc((char *) minefield_pages + region_start, size,
 238                  MEM_COMMIT, PAGE_READWRITE);
 239     return (char *) minefield_pages + region_start;
 240 }
 241
 242 static void minefield_free(void *ptr)
 243 {
 244     int region_start, i, j;
 245
 246     minefield_admin_hide(0);
 247
 248     region_start = (char *) ptr - (char *) minefield_pages;
 249     i = region_start / PAGESIZE;
 250     if (i < 0 || i >= minefield_npages ||
 251         minefield_admin[i] != region_start % PAGESIZE)
 252         minefield_bomb();
 253     for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++) {
 254         minefield_admin[j] = 0xFFFF;
 255     }
 256
 257     VirtualFree(ptr, j * PAGESIZE - region_start, MEM_DECOMMIT);
 258
 259     minefield_admin_hide(1);
 260 }
 261
 262 static int minefield_get_size(void *ptr)
 263 {
 264     int region_start, i, j;
 265
 266     minefield_admin_hide(0);
 267
 268     region_start = (char *) ptr - (char *) minefield_pages;
 269     i = region_start / PAGESIZE;
 270     if (i < 0 || i >= minefield_npages ||
 271         minefield_admin[i] != region_start % PAGESIZE)
 272         minefield_bomb();
 273     for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++);
 274
 275     minefield_admin_hide(1);
 276
 277     return j * PAGESIZE - region_start;
 278 }
 279
 280 void *minefield_c_malloc(size_t size)
 281 {
 282     if (!minefield_initialised)
 283         minefield_init();
 284     return minefield_alloc(size);
 285 }
 286
 287 void minefield_c_free(void *p)
 288 {
 289     if (!minefield_initialised)
 290         minefield_init();
 291     minefield_free(p);
 292 }
 293
 294 /*
 295  * realloc _always_ moves the chunk, for rapid detection of code
 296  * that assumes it won't.
 297  */
 298 void *minefield_c_realloc(void *p, size_t size)
 299 {
 300     size_t oldsize;
 301     void *q;
 302     if (!minefield_initialised)
 303         minefield_init();
 304     q = minefield_alloc(size);
 305     oldsize = minefield_get_size(p);
 306     memcpy(q, p, (oldsize < size ? oldsize : size));
 307     minefield_free(p);
 308     return q;
 309 }
 310
 311 #endif                          /* MINEFIELD */