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