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

   1 /*
   2  * winmisc.c: miscellaneous Windows-specific things.
   3  */
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include "putty.h"
   8
   9 OSVERSIONINFO osVersion;
  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 char *get_username(void)
  41 {
  42     DWORD namelen;
  43     char *user;
  44
  45     namelen = 0;
  46     if (GetUserName(NULL, &namelen) == FALSE)
  47         return NULL;
  48
  49     user = snewn(namelen, char);
  50     GetUserName(user, &namelen);
  51
  52     return user;
  53 }
  54
  55 int SaneDialogBox(HINSTANCE hinst,
  56                   LPCTSTR tmpl,
  57                   HWND hwndparent,
  58                   DLGPROC lpDialogFunc)
  59 {
  60     WNDCLASS wc;
  61     HWND hwnd;
  62     MSG msg;
  63     int flags;
  64     int ret;
  65     int gm;
  66
  67     wc.style = CS_DBLCLKS | CS_SAVEBITS | CS_BYTEALIGNWINDOW;
  68     wc.lpfnWndProc = DefDlgProc;
  69     wc.cbClsExtra = 0;
  70     wc.cbWndExtra = DLGWINDOWEXTRA + 8;
  71     wc.hInstance = hinst;
  72     wc.hIcon = NULL;
  73     wc.hCursor = LoadCursor(NULL, IDC_ARROW);
  74     wc.hbrBackground = (HBRUSH) (COLOR_BACKGROUND +1);
  75     wc.lpszMenuName = NULL;
  76     wc.lpszClassName = "PuTTYConfigBox";
  77     RegisterClass(&wc);
  78
  79     hwnd = CreateDialog(hinst, tmpl, hwndparent, lpDialogFunc);
  80
  81     SetWindowLong(hwnd, BOXFLAGS, 0); /* flags */
  82     SetWindowLong(hwnd, BOXRESULT, 0); /* result from SaneEndDialog */
  83
  84     while ((gm=GetMessage(&msg, NULL, 0, 0)) > 0) {
  85         flags=GetWindowLong(hwnd, BOXFLAGS);
  86         if (!(flags & DF_END) && !IsDialogMessage(hwnd, &msg))
  87             DispatchMessage(&msg);
  88         if (flags & DF_END)
  89             break;
  90     }
  91
  92     if (gm == 0)
  93         PostQuitMessage(msg.wParam); /* We got a WM_QUIT, pass it on */
  94
  95     ret=GetWindowLong(hwnd, BOXRESULT);
  96     DestroyWindow(hwnd);
  97     return ret;
  98 }
  99
 100 void SaneEndDialog(HWND hwnd, int ret)
 101 {
 102     SetWindowLong(hwnd, BOXRESULT, ret);
 103     SetWindowLong(hwnd, BOXFLAGS, DF_END);
 104 }
 105
 106 BOOL init_winver(void)
 107 {
 108     ZeroMemory(&osVersion, sizeof(osVersion));
 109     osVersion.dwOSVersionInfoSize = sizeof (OSVERSIONINFO);
 110     return GetVersionEx ( (OSVERSIONINFO *) &osVersion);
 111 }
 112
 113 #ifdef DEBUG
 114 static FILE *debug_fp = NULL;
 115 static HANDLE debug_hdl = INVALID_HANDLE_VALUE;
 116 static int debug_got_console = 0;
 117
 118 void dputs(char *buf)
 119 {
 120     DWORD dw;
 121
 122     if (!debug_got_console) {
 123         if (AllocConsole()) {
 124             debug_got_console = 1;
 125             debug_hdl = GetStdHandle(STD_OUTPUT_HANDLE);
 126         }
 127     }
 128     if (!debug_fp) {
 129         debug_fp = fopen("debug.log", "w");
 130     }
 131
 132     if (debug_hdl != INVALID_HANDLE_VALUE) {
 133         WriteFile(debug_hdl, buf, strlen(buf), &dw, NULL);
 134     }
 135     fputs(buf, debug_fp);
 136     fflush(debug_fp);
 137 }
 138 #endif
 139
 140 #ifdef MINEFIELD
 141 /*
 142  * Minefield - a Windows equivalent for Electric Fence
 143  */
 144
 145 #define PAGESIZE 4096
 146
 147 /*
 148  * Design:
 149  *
 150  * We start by reserving as much virtual address space as Windows
 151  * will sensibly (or not sensibly) let us have. We flag it all as
 152  * invalid memory.
 153  *
 154  * Any allocation attempt is satisfied by committing one or more
 155  * pages, with an uncommitted page on either side. The returned
 156  * memory region is jammed up against the _end_ of the pages.
 157  *
 158  * Freeing anything causes instantaneous decommitment of the pages
 159  * involved, so stale pointers are caught as soon as possible.
 160  */
 161
 162 static int minefield_initialised = 0;
 163 static void *minefield_region = NULL;
 164 static long minefield_size = 0;
 165 static long minefield_npages = 0;
 166 static long minefield_curpos = 0;
 167 static unsigned short *minefield_admin = NULL;
 168 static void *minefield_pages = NULL;
 169
 170 static void minefield_admin_hide(int hide)
 171 {
 172     int access = hide ? PAGE_NOACCESS : PAGE_READWRITE;
 173     VirtualProtect(minefield_admin, minefield_npages * 2, access, NULL);
 174 }
 175
 176 static void minefield_init(void)
 177 {
 178     int size;
 179     int admin_size;
 180     int i;
 181
 182     for (size = 0x40000000; size > 0; size = ((size >> 3) * 7) & ~0xFFF) {
 183         minefield_region = VirtualAlloc(NULL, size,
 184                                         MEM_RESERVE, PAGE_NOACCESS);
 185         if (minefield_region)
 186             break;
 187     }
 188     minefield_size = size;
 189
 190     /*
 191      * Firstly, allocate a section of that to be the admin block.
 192      * We'll need a two-byte field for each page.
 193      */
 194     minefield_admin = minefield_region;
 195     minefield_npages = minefield_size / PAGESIZE;
 196     admin_size = (minefield_npages * 2 + PAGESIZE - 1) & ~(PAGESIZE - 1);
 197     minefield_npages = (minefield_size - admin_size) / PAGESIZE;
 198     minefield_pages = (char *) minefield_region + admin_size;
 199
 200     /*
 201      * Commit the admin region.
 202      */
 203     VirtualAlloc(minefield_admin, minefield_npages * 2,
 204                  MEM_COMMIT, PAGE_READWRITE);
 205
 206     /*
 207      * Mark all pages as unused (0xFFFF).
 208      */
 209     for (i = 0; i < minefield_npages; i++)
 210         minefield_admin[i] = 0xFFFF;
 211
 212     /*
 213      * Hide the admin region.
 214      */
 215     minefield_admin_hide(1);
 216
 217     minefield_initialised = 1;
 218 }
 219
 220 static void minefield_bomb(void)
 221 {
 222     div(1, *(int *) minefield_pages);
 223 }
 224
 225 static void *minefield_alloc(int size)
 226 {
 227     int npages;
 228     int pos, lim, region_end, region_start;
 229     int start;
 230     int i;
 231
 232     npages = (size + PAGESIZE - 1) / PAGESIZE;
 233
 234     minefield_admin_hide(0);
 235
 236     /*
 237      * Search from current position until we find a contiguous
 238      * bunch of npages+2 unused pages.
 239      */
 240     pos = minefield_curpos;
 241     lim = minefield_npages;
 242     while (1) {
 243         /* Skip over used pages. */
 244         while (pos < lim && minefield_admin[pos] != 0xFFFF)
 245             pos++;
 246         /* Count unused pages. */
 247         start = pos;
 248         while (pos < lim && pos - start < npages + 2 &&
 249                minefield_admin[pos] == 0xFFFF)
 250             pos++;
 251         if (pos - start == npages + 2)
 252             break;
 253         /* If we've reached the limit, reset the limit or stop. */
 254         if (pos >= lim) {
 255             if (lim == minefield_npages) {
 256                 /* go round and start again at zero */
 257                 lim = minefield_curpos;
 258                 pos = 0;
 259             } else {
 260                 minefield_admin_hide(1);
 261                 return NULL;
 262             }
 263         }
 264     }
 265
 266     minefield_curpos = pos - 1;
 267
 268     /*
 269      * We have npages+2 unused pages starting at start. We leave
 270      * the first and last of these alone and use the rest.
 271      */
 272     region_end = (start + npages + 1) * PAGESIZE;
 273     region_start = region_end - size;
 274     /* FIXME: could align here if we wanted */
 275
 276     /*
 277      * Update the admin region.
 278      */
 279     for (i = start + 2; i < start + npages + 1; i++)
 280         minefield_admin[i] = 0xFFFE;   /* used but no region starts here */
 281     minefield_admin[start + 1] = region_start % PAGESIZE;
 282
 283     minefield_admin_hide(1);
 284
 285     VirtualAlloc((char *) minefield_pages + region_start, size,
 286                  MEM_COMMIT, PAGE_READWRITE);
 287     return (char *) minefield_pages + region_start;
 288 }
 289
 290 static void minefield_free(void *ptr)
 291 {
 292     int region_start, i, j;
 293
 294     minefield_admin_hide(0);
 295
 296     region_start = (char *) ptr - (char *) minefield_pages;
 297     i = region_start / PAGESIZE;
 298     if (i < 0 || i >= minefield_npages ||
 299         minefield_admin[i] != region_start % PAGESIZE)
 300         minefield_bomb();
 301     for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++) {
 302         minefield_admin[j] = 0xFFFF;
 303     }
 304
 305     VirtualFree(ptr, j * PAGESIZE - region_start, MEM_DECOMMIT);
 306
 307     minefield_admin_hide(1);
 308 }
 309
 310 static int minefield_get_size(void *ptr)
 311 {
 312     int region_start, i, j;
 313
 314     minefield_admin_hide(0);
 315
 316     region_start = (char *) ptr - (char *) minefield_pages;
 317     i = region_start / PAGESIZE;
 318     if (i < 0 || i >= minefield_npages ||
 319         minefield_admin[i] != region_start % PAGESIZE)
 320         minefield_bomb();
 321     for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++);
 322
 323     minefield_admin_hide(1);
 324
 325     return j * PAGESIZE - region_start;
 326 }
 327
 328 void *minefield_c_malloc(size_t size)
 329 {
 330     if (!minefield_initialised)
 331         minefield_init();
 332     return minefield_alloc(size);
 333 }
 334
 335 void minefield_c_free(void *p)
 336 {
 337     if (!minefield_initialised)
 338         minefield_init();
 339     minefield_free(p);
 340 }
 341
 342 /*
 343  * realloc _always_ moves the chunk, for rapid detection of code
 344  * that assumes it won't.
 345  */
 346 void *minefield_c_realloc(void *p, size_t size)
 347 {
 348     size_t oldsize;
 349     void *q;
 350     if (!minefield_initialised)
 351         minefield_init();
 352     q = minefield_alloc(size);
 353     oldsize = minefield_get_size(p);
 354     memcpy(q, p, (oldsize < size ? oldsize : size));
 355     minefield_free(p);
 356     return q;
 357 }
 358
 359 #endif                          /* MINEFIELD */