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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 | |
10 | void platform_get_x11_auth(char *display, int *proto, |
11 | unsigned char *data, int *datalen) |
12 | { |
13 | /* We don't support this at all under Windows. */ |
14 | } |
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15 | |
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16 | Filename filename_from_str(const char *str) |
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17 | { |
18 | Filename ret; |
19 | strncpy(ret.path, str, sizeof(ret.path)); |
20 | ret.path[sizeof(ret.path)-1] = '\0'; |
21 | return ret; |
22 | } |
23 | |
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24 | const char *filename_to_str(const Filename *fn) |
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25 | { |
9fab77dc |
26 | return fn->path; |
9a30e26b |
27 | } |
28 | |
29 | int filename_equal(Filename f1, Filename f2) |
30 | { |
31 | return !strcmp(f1.path, f2.path); |
32 | } |
33 | |
34 | int filename_is_null(Filename fn) |
35 | { |
36 | return !*fn.path; |
37 | } |
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38 | |
39 | #ifdef DEBUG |
40 | static FILE *debug_fp = NULL; |
41 | static HANDLE debug_hdl = INVALID_HANDLE_VALUE; |
42 | static int debug_got_console = 0; |
43 | |
44 | void dputs(char *buf) |
45 | { |
46 | DWORD dw; |
47 | |
48 | if (!debug_got_console) { |
49 | if (AllocConsole()) { |
50 | debug_got_console = 1; |
51 | debug_hdl = GetStdHandle(STD_OUTPUT_HANDLE); |
52 | } |
53 | } |
54 | if (!debug_fp) { |
55 | debug_fp = fopen("debug.log", "w"); |
56 | } |
57 | |
58 | if (debug_hdl != INVALID_HANDLE_VALUE) { |
59 | WriteFile(debug_hdl, buf, strlen(buf), &dw, NULL); |
60 | } |
61 | fputs(buf, debug_fp); |
62 | fflush(debug_fp); |
63 | } |
64 | #endif |
65 | |
66 | #ifdef MINEFIELD |
67 | /* |
68 | * Minefield - a Windows equivalent for Electric Fence |
69 | */ |
70 | |
71 | #define PAGESIZE 4096 |
72 | |
73 | /* |
74 | * Design: |
75 | * |
76 | * We start by reserving as much virtual address space as Windows |
77 | * will sensibly (or not sensibly) let us have. We flag it all as |
78 | * invalid memory. |
79 | * |
80 | * Any allocation attempt is satisfied by committing one or more |
81 | * pages, with an uncommitted page on either side. The returned |
82 | * memory region is jammed up against the _end_ of the pages. |
83 | * |
84 | * Freeing anything causes instantaneous decommitment of the pages |
85 | * involved, so stale pointers are caught as soon as possible. |
86 | */ |
87 | |
88 | static int minefield_initialised = 0; |
89 | static void *minefield_region = NULL; |
90 | static long minefield_size = 0; |
91 | static long minefield_npages = 0; |
92 | static long minefield_curpos = 0; |
93 | static unsigned short *minefield_admin = NULL; |
94 | static void *minefield_pages = NULL; |
95 | |
96 | static void minefield_admin_hide(int hide) |
97 | { |
98 | int access = hide ? PAGE_NOACCESS : PAGE_READWRITE; |
99 | VirtualProtect(minefield_admin, minefield_npages * 2, access, NULL); |
100 | } |
101 | |
102 | static void minefield_init(void) |
103 | { |
104 | int size; |
105 | int admin_size; |
106 | int i; |
107 | |
108 | for (size = 0x40000000; size > 0; size = ((size >> 3) * 7) & ~0xFFF) { |
109 | minefield_region = VirtualAlloc(NULL, size, |
110 | MEM_RESERVE, PAGE_NOACCESS); |
111 | if (minefield_region) |
112 | break; |
113 | } |
114 | minefield_size = size; |
115 | |
116 | /* |
117 | * Firstly, allocate a section of that to be the admin block. |
118 | * We'll need a two-byte field for each page. |
119 | */ |
120 | minefield_admin = minefield_region; |
121 | minefield_npages = minefield_size / PAGESIZE; |
122 | admin_size = (minefield_npages * 2 + PAGESIZE - 1) & ~(PAGESIZE - 1); |
123 | minefield_npages = (minefield_size - admin_size) / PAGESIZE; |
124 | minefield_pages = (char *) minefield_region + admin_size; |
125 | |
126 | /* |
127 | * Commit the admin region. |
128 | */ |
129 | VirtualAlloc(minefield_admin, minefield_npages * 2, |
130 | MEM_COMMIT, PAGE_READWRITE); |
131 | |
132 | /* |
133 | * Mark all pages as unused (0xFFFF). |
134 | */ |
135 | for (i = 0; i < minefield_npages; i++) |
136 | minefield_admin[i] = 0xFFFF; |
137 | |
138 | /* |
139 | * Hide the admin region. |
140 | */ |
141 | minefield_admin_hide(1); |
142 | |
143 | minefield_initialised = 1; |
144 | } |
145 | |
146 | static void minefield_bomb(void) |
147 | { |
148 | div(1, *(int *) minefield_pages); |
149 | } |
150 | |
151 | static void *minefield_alloc(int size) |
152 | { |
153 | int npages; |
154 | int pos, lim, region_end, region_start; |
155 | int start; |
156 | int i; |
157 | |
158 | npages = (size + PAGESIZE - 1) / PAGESIZE; |
159 | |
160 | minefield_admin_hide(0); |
161 | |
162 | /* |
163 | * Search from current position until we find a contiguous |
164 | * bunch of npages+2 unused pages. |
165 | */ |
166 | pos = minefield_curpos; |
167 | lim = minefield_npages; |
168 | while (1) { |
169 | /* Skip over used pages. */ |
170 | while (pos < lim && minefield_admin[pos] != 0xFFFF) |
171 | pos++; |
172 | /* Count unused pages. */ |
173 | start = pos; |
174 | while (pos < lim && pos - start < npages + 2 && |
175 | minefield_admin[pos] == 0xFFFF) |
176 | pos++; |
177 | if (pos - start == npages + 2) |
178 | break; |
179 | /* If we've reached the limit, reset the limit or stop. */ |
180 | if (pos >= lim) { |
181 | if (lim == minefield_npages) { |
182 | /* go round and start again at zero */ |
183 | lim = minefield_curpos; |
184 | pos = 0; |
185 | } else { |
186 | minefield_admin_hide(1); |
187 | return NULL; |
188 | } |
189 | } |
190 | } |
191 | |
192 | minefield_curpos = pos - 1; |
193 | |
194 | /* |
195 | * We have npages+2 unused pages starting at start. We leave |
196 | * the first and last of these alone and use the rest. |
197 | */ |
198 | region_end = (start + npages + 1) * PAGESIZE; |
199 | region_start = region_end - size; |
200 | /* FIXME: could align here if we wanted */ |
201 | |
202 | /* |
203 | * Update the admin region. |
204 | */ |
205 | for (i = start + 2; i < start + npages + 1; i++) |
206 | minefield_admin[i] = 0xFFFE; /* used but no region starts here */ |
207 | minefield_admin[start + 1] = region_start % PAGESIZE; |
208 | |
209 | minefield_admin_hide(1); |
210 | |
211 | VirtualAlloc((char *) minefield_pages + region_start, size, |
212 | MEM_COMMIT, PAGE_READWRITE); |
213 | return (char *) minefield_pages + region_start; |
214 | } |
215 | |
216 | static void minefield_free(void *ptr) |
217 | { |
218 | int region_start, i, j; |
219 | |
220 | minefield_admin_hide(0); |
221 | |
222 | region_start = (char *) ptr - (char *) minefield_pages; |
223 | i = region_start / PAGESIZE; |
224 | if (i < 0 || i >= minefield_npages || |
225 | minefield_admin[i] != region_start % PAGESIZE) |
226 | minefield_bomb(); |
227 | for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++) { |
228 | minefield_admin[j] = 0xFFFF; |
229 | } |
230 | |
231 | VirtualFree(ptr, j * PAGESIZE - region_start, MEM_DECOMMIT); |
232 | |
233 | minefield_admin_hide(1); |
234 | } |
235 | |
236 | static int minefield_get_size(void *ptr) |
237 | { |
238 | int region_start, i, j; |
239 | |
240 | minefield_admin_hide(0); |
241 | |
242 | region_start = (char *) ptr - (char *) minefield_pages; |
243 | i = region_start / PAGESIZE; |
244 | if (i < 0 || i >= minefield_npages || |
245 | minefield_admin[i] != region_start % PAGESIZE) |
246 | minefield_bomb(); |
247 | for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++); |
248 | |
249 | minefield_admin_hide(1); |
250 | |
251 | return j * PAGESIZE - region_start; |
252 | } |
253 | |
254 | void *minefield_c_malloc(size_t size) |
255 | { |
256 | if (!minefield_initialised) |
257 | minefield_init(); |
258 | return minefield_alloc(size); |
259 | } |
260 | |
261 | void minefield_c_free(void *p) |
262 | { |
263 | if (!minefield_initialised) |
264 | minefield_init(); |
265 | minefield_free(p); |
266 | } |
267 | |
268 | /* |
269 | * realloc _always_ moves the chunk, for rapid detection of code |
270 | * that assumes it won't. |
271 | */ |
272 | void *minefield_c_realloc(void *p, size_t size) |
273 | { |
274 | size_t oldsize; |
275 | void *q; |
276 | if (!minefield_initialised) |
277 | minefield_init(); |
278 | q = minefield_alloc(size); |
279 | oldsize = minefield_get_size(p); |
280 | memcpy(q, p, (oldsize < size ? oldsize : size)); |
281 | minefield_free(p); |
282 | return q; |
283 | } |
284 | |
285 | #endif /* MINEFIELD */ |