| 1 | /* |
| 2 | * Platform-independent routines shared between all PuTTY programs. |
| 3 | */ |
| 4 | |
| 5 | #include <stdio.h> |
| 6 | #include <stdlib.h> |
| 7 | #include <stdarg.h> |
| 8 | #include <ctype.h> |
| 9 | #include <assert.h> |
| 10 | #include "putty.h" |
| 11 | |
| 12 | /* ---------------------------------------------------------------------- |
| 13 | * String handling routines. |
| 14 | */ |
| 15 | |
| 16 | char *dupstr(const char *s) |
| 17 | { |
| 18 | char *p = NULL; |
| 19 | if (s) { |
| 20 | int len = strlen(s); |
| 21 | p = snewn(len + 1, char); |
| 22 | strcpy(p, s); |
| 23 | } |
| 24 | return p; |
| 25 | } |
| 26 | |
| 27 | /* Allocate the concatenation of N strings. Terminate arg list with NULL. */ |
| 28 | char *dupcat(const char *s1, ...) |
| 29 | { |
| 30 | int len; |
| 31 | char *p, *q, *sn; |
| 32 | va_list ap; |
| 33 | |
| 34 | len = strlen(s1); |
| 35 | va_start(ap, s1); |
| 36 | while (1) { |
| 37 | sn = va_arg(ap, char *); |
| 38 | if (!sn) |
| 39 | break; |
| 40 | len += strlen(sn); |
| 41 | } |
| 42 | va_end(ap); |
| 43 | |
| 44 | p = snewn(len + 1, char); |
| 45 | strcpy(p, s1); |
| 46 | q = p + strlen(p); |
| 47 | |
| 48 | va_start(ap, s1); |
| 49 | while (1) { |
| 50 | sn = va_arg(ap, char *); |
| 51 | if (!sn) |
| 52 | break; |
| 53 | strcpy(q, sn); |
| 54 | q += strlen(q); |
| 55 | } |
| 56 | va_end(ap); |
| 57 | |
| 58 | return p; |
| 59 | } |
| 60 | |
| 61 | /* |
| 62 | * Do an sprintf(), but into a custom-allocated buffer. |
| 63 | * |
| 64 | * Currently I'm doing this via vsnprintf. This has worked so far, |
| 65 | * but it's not good, because: |
| 66 | * |
| 67 | * - vsnprintf is not available on all platforms. There's an ifdef |
| 68 | * to use `_vsnprintf', which seems to be the local name for it |
| 69 | * on Windows. Other platforms may lack it completely, in which |
| 70 | * case it'll be time to rewrite this function in a totally |
| 71 | * different way. |
| 72 | * |
| 73 | * - technically you can't reuse a va_list like this: it is left |
| 74 | * unspecified whether advancing a va_list pointer modifies its |
| 75 | * value or something it points to, so on some platforms calling |
| 76 | * vsnprintf twice on the same va_list might fail hideously. It |
| 77 | * would be better to use the `va_copy' macro mandated by C99, |
| 78 | * but that too is not yet ubiquitous. |
| 79 | * |
| 80 | * The only `properly' portable solution I can think of is to |
| 81 | * implement my own format string scanner, which figures out an |
| 82 | * upper bound for the length of each formatting directive, |
| 83 | * allocates the buffer as it goes along, and calls sprintf() to |
| 84 | * actually process each directive. If I ever need to actually do |
| 85 | * this, some caveats: |
| 86 | * |
| 87 | * - It's very hard to find a reliable upper bound for |
| 88 | * floating-point values. %f, in particular, when supplied with |
| 89 | * a number near to the upper or lower limit of representable |
| 90 | * numbers, could easily take several hundred characters. It's |
| 91 | * probably feasible to predict this statically using the |
| 92 | * constants in <float.h>, or even to predict it dynamically by |
| 93 | * looking at the exponent of the specific float provided, but |
| 94 | * it won't be fun. |
| 95 | * |
| 96 | * - Don't forget to _check_, after calling sprintf, that it's |
| 97 | * used at most the amount of space we had available. |
| 98 | * |
| 99 | * - Fault any formatting directive we don't fully understand. The |
| 100 | * aim here is to _guarantee_ that we never overflow the buffer, |
| 101 | * because this is a security-critical function. If we see a |
| 102 | * directive we don't know about, we should panic and die rather |
| 103 | * than run any risk. |
| 104 | */ |
| 105 | char *dupprintf(const char *fmt, ...) |
| 106 | { |
| 107 | char *ret; |
| 108 | va_list ap; |
| 109 | va_start(ap, fmt); |
| 110 | ret = dupvprintf(fmt, ap); |
| 111 | va_end(ap); |
| 112 | return ret; |
| 113 | } |
| 114 | char *dupvprintf(const char *fmt, va_list ap) |
| 115 | { |
| 116 | char *buf; |
| 117 | int len, size; |
| 118 | |
| 119 | buf = snewn(512, char); |
| 120 | size = 512; |
| 121 | |
| 122 | while (1) { |
| 123 | #ifdef _WINDOWS |
| 124 | #define vsnprintf _vsnprintf |
| 125 | #endif |
| 126 | len = vsnprintf(buf, size, fmt, ap); |
| 127 | if (len >= 0 && len < size) { |
| 128 | /* This is the C99-specified criterion for snprintf to have |
| 129 | * been completely successful. */ |
| 130 | return buf; |
| 131 | } else if (len > 0) { |
| 132 | /* This is the C99 error condition: the returned length is |
| 133 | * the required buffer size not counting the NUL. */ |
| 134 | size = len + 1; |
| 135 | } else { |
| 136 | /* This is the pre-C99 glibc error condition: <0 means the |
| 137 | * buffer wasn't big enough, so we enlarge it a bit and hope. */ |
| 138 | size += 512; |
| 139 | } |
| 140 | buf = sresize(buf, size, char); |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | /* |
| 145 | * Read an entire line of text from a file. Return a buffer |
| 146 | * malloced to be as big as necessary (caller must free). |
| 147 | */ |
| 148 | char *fgetline(FILE *fp) |
| 149 | { |
| 150 | char *ret = snewn(512, char); |
| 151 | int size = 512, len = 0; |
| 152 | while (fgets(ret + len, size - len, fp)) { |
| 153 | len += strlen(ret + len); |
| 154 | if (ret[len-1] == '\n') |
| 155 | break; /* got a newline, we're done */ |
| 156 | size = len + 512; |
| 157 | ret = sresize(ret, size, char); |
| 158 | } |
| 159 | if (len == 0) { /* first fgets returned NULL */ |
| 160 | sfree(ret); |
| 161 | return NULL; |
| 162 | } |
| 163 | ret[len] = '\0'; |
| 164 | return ret; |
| 165 | } |
| 166 | |
| 167 | /* ---------------------------------------------------------------------- |
| 168 | * Base64 encoding routine. This is required in public-key writing |
| 169 | * but also in HTTP proxy handling, so it's centralised here. |
| 170 | */ |
| 171 | |
| 172 | void base64_encode_atom(unsigned char *data, int n, char *out) |
| 173 | { |
| 174 | static const char base64_chars[] = |
| 175 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
| 176 | |
| 177 | unsigned word; |
| 178 | |
| 179 | word = data[0] << 16; |
| 180 | if (n > 1) |
| 181 | word |= data[1] << 8; |
| 182 | if (n > 2) |
| 183 | word |= data[2]; |
| 184 | out[0] = base64_chars[(word >> 18) & 0x3F]; |
| 185 | out[1] = base64_chars[(word >> 12) & 0x3F]; |
| 186 | if (n > 1) |
| 187 | out[2] = base64_chars[(word >> 6) & 0x3F]; |
| 188 | else |
| 189 | out[2] = '='; |
| 190 | if (n > 2) |
| 191 | out[3] = base64_chars[word & 0x3F]; |
| 192 | else |
| 193 | out[3] = '='; |
| 194 | } |
| 195 | |
| 196 | /* ---------------------------------------------------------------------- |
| 197 | * Generic routines to deal with send buffers: a linked list of |
| 198 | * smallish blocks, with the operations |
| 199 | * |
| 200 | * - add an arbitrary amount of data to the end of the list |
| 201 | * - remove the first N bytes from the list |
| 202 | * - return a (pointer,length) pair giving some initial data in |
| 203 | * the list, suitable for passing to a send or write system |
| 204 | * call |
| 205 | * - retrieve a larger amount of initial data from the list |
| 206 | * - return the current size of the buffer chain in bytes |
| 207 | */ |
| 208 | |
| 209 | #define BUFFER_GRANULE 512 |
| 210 | |
| 211 | struct bufchain_granule { |
| 212 | struct bufchain_granule *next; |
| 213 | int buflen, bufpos; |
| 214 | char buf[BUFFER_GRANULE]; |
| 215 | }; |
| 216 | |
| 217 | void bufchain_init(bufchain *ch) |
| 218 | { |
| 219 | ch->head = ch->tail = NULL; |
| 220 | ch->buffersize = 0; |
| 221 | } |
| 222 | |
| 223 | void bufchain_clear(bufchain *ch) |
| 224 | { |
| 225 | struct bufchain_granule *b; |
| 226 | while (ch->head) { |
| 227 | b = ch->head; |
| 228 | ch->head = ch->head->next; |
| 229 | sfree(b); |
| 230 | } |
| 231 | ch->tail = NULL; |
| 232 | ch->buffersize = 0; |
| 233 | } |
| 234 | |
| 235 | int bufchain_size(bufchain *ch) |
| 236 | { |
| 237 | return ch->buffersize; |
| 238 | } |
| 239 | |
| 240 | void bufchain_add(bufchain *ch, const void *data, int len) |
| 241 | { |
| 242 | const char *buf = (const char *)data; |
| 243 | |
| 244 | if (len == 0) return; |
| 245 | |
| 246 | ch->buffersize += len; |
| 247 | |
| 248 | if (ch->tail && ch->tail->buflen < BUFFER_GRANULE) { |
| 249 | int copylen = min(len, BUFFER_GRANULE - ch->tail->buflen); |
| 250 | memcpy(ch->tail->buf + ch->tail->buflen, buf, copylen); |
| 251 | buf += copylen; |
| 252 | len -= copylen; |
| 253 | ch->tail->buflen += copylen; |
| 254 | } |
| 255 | while (len > 0) { |
| 256 | int grainlen = min(len, BUFFER_GRANULE); |
| 257 | struct bufchain_granule *newbuf; |
| 258 | newbuf = snew(struct bufchain_granule); |
| 259 | newbuf->bufpos = 0; |
| 260 | newbuf->buflen = grainlen; |
| 261 | memcpy(newbuf->buf, buf, grainlen); |
| 262 | buf += grainlen; |
| 263 | len -= grainlen; |
| 264 | if (ch->tail) |
| 265 | ch->tail->next = newbuf; |
| 266 | else |
| 267 | ch->head = ch->tail = newbuf; |
| 268 | newbuf->next = NULL; |
| 269 | ch->tail = newbuf; |
| 270 | } |
| 271 | } |
| 272 | |
| 273 | void bufchain_consume(bufchain *ch, int len) |
| 274 | { |
| 275 | struct bufchain_granule *tmp; |
| 276 | |
| 277 | assert(ch->buffersize >= len); |
| 278 | while (len > 0) { |
| 279 | int remlen = len; |
| 280 | assert(ch->head != NULL); |
| 281 | if (remlen >= ch->head->buflen - ch->head->bufpos) { |
| 282 | remlen = ch->head->buflen - ch->head->bufpos; |
| 283 | tmp = ch->head; |
| 284 | ch->head = tmp->next; |
| 285 | sfree(tmp); |
| 286 | if (!ch->head) |
| 287 | ch->tail = NULL; |
| 288 | } else |
| 289 | ch->head->bufpos += remlen; |
| 290 | ch->buffersize -= remlen; |
| 291 | len -= remlen; |
| 292 | } |
| 293 | } |
| 294 | |
| 295 | void bufchain_prefix(bufchain *ch, void **data, int *len) |
| 296 | { |
| 297 | *len = ch->head->buflen - ch->head->bufpos; |
| 298 | *data = ch->head->buf + ch->head->bufpos; |
| 299 | } |
| 300 | |
| 301 | void bufchain_fetch(bufchain *ch, void *data, int len) |
| 302 | { |
| 303 | struct bufchain_granule *tmp; |
| 304 | char *data_c = (char *)data; |
| 305 | |
| 306 | tmp = ch->head; |
| 307 | |
| 308 | assert(ch->buffersize >= len); |
| 309 | while (len > 0) { |
| 310 | int remlen = len; |
| 311 | |
| 312 | assert(tmp != NULL); |
| 313 | if (remlen >= tmp->buflen - tmp->bufpos) |
| 314 | remlen = tmp->buflen - tmp->bufpos; |
| 315 | memcpy(data_c, tmp->buf + tmp->bufpos, remlen); |
| 316 | |
| 317 | tmp = tmp->next; |
| 318 | len -= remlen; |
| 319 | data_c += remlen; |
| 320 | } |
| 321 | } |
| 322 | |
| 323 | /* ---------------------------------------------------------------------- |
| 324 | * My own versions of malloc, realloc and free. Because I want |
| 325 | * malloc and realloc to bomb out and exit the program if they run |
| 326 | * out of memory, realloc to reliably call malloc if passed a NULL |
| 327 | * pointer, and free to reliably do nothing if passed a NULL |
| 328 | * pointer. We can also put trace printouts in, if we need to; and |
| 329 | * we can also replace the allocator with an ElectricFence-like |
| 330 | * one. |
| 331 | */ |
| 332 | |
| 333 | #ifdef MINEFIELD |
| 334 | void *minefield_c_malloc(size_t size); |
| 335 | void minefield_c_free(void *p); |
| 336 | void *minefield_c_realloc(void *p, size_t size); |
| 337 | #endif |
| 338 | |
| 339 | #ifdef MALLOC_LOG |
| 340 | static FILE *fp = NULL; |
| 341 | |
| 342 | static char *mlog_file = NULL; |
| 343 | static int mlog_line = 0; |
| 344 | |
| 345 | void mlog(char *file, int line) |
| 346 | { |
| 347 | mlog_file = file; |
| 348 | mlog_line = line; |
| 349 | if (!fp) { |
| 350 | fp = fopen("putty_mem.log", "w"); |
| 351 | setvbuf(fp, NULL, _IONBF, BUFSIZ); |
| 352 | } |
| 353 | if (fp) |
| 354 | fprintf(fp, "%s:%d: ", file, line); |
| 355 | } |
| 356 | #endif |
| 357 | |
| 358 | void *safemalloc(size_t size) |
| 359 | { |
| 360 | void *p; |
| 361 | #ifdef MINEFIELD |
| 362 | p = minefield_c_malloc(size); |
| 363 | #else |
| 364 | p = malloc(size); |
| 365 | #endif |
| 366 | if (!p) { |
| 367 | char str[200]; |
| 368 | #ifdef MALLOC_LOG |
| 369 | sprintf(str, "Out of memory! (%s:%d, size=%d)", |
| 370 | mlog_file, mlog_line, size); |
| 371 | fprintf(fp, "*** %s\n", str); |
| 372 | fclose(fp); |
| 373 | #else |
| 374 | strcpy(str, "Out of memory!"); |
| 375 | #endif |
| 376 | modalfatalbox(str); |
| 377 | } |
| 378 | #ifdef MALLOC_LOG |
| 379 | if (fp) |
| 380 | fprintf(fp, "malloc(%d) returns %p\n", size, p); |
| 381 | #endif |
| 382 | return p; |
| 383 | } |
| 384 | |
| 385 | void *saferealloc(void *ptr, size_t size) |
| 386 | { |
| 387 | void *p; |
| 388 | if (!ptr) { |
| 389 | #ifdef MINEFIELD |
| 390 | p = minefield_c_malloc(size); |
| 391 | #else |
| 392 | p = malloc(size); |
| 393 | #endif |
| 394 | } else { |
| 395 | #ifdef MINEFIELD |
| 396 | p = minefield_c_realloc(ptr, size); |
| 397 | #else |
| 398 | p = realloc(ptr, size); |
| 399 | #endif |
| 400 | } |
| 401 | if (!p) { |
| 402 | char str[200]; |
| 403 | #ifdef MALLOC_LOG |
| 404 | sprintf(str, "Out of memory! (%s:%d, size=%d)", |
| 405 | mlog_file, mlog_line, size); |
| 406 | fprintf(fp, "*** %s\n", str); |
| 407 | fclose(fp); |
| 408 | #else |
| 409 | strcpy(str, "Out of memory!"); |
| 410 | #endif |
| 411 | modalfatalbox(str); |
| 412 | } |
| 413 | #ifdef MALLOC_LOG |
| 414 | if (fp) |
| 415 | fprintf(fp, "realloc(%p,%d) returns %p\n", ptr, size, p); |
| 416 | #endif |
| 417 | return p; |
| 418 | } |
| 419 | |
| 420 | void safefree(void *ptr) |
| 421 | { |
| 422 | if (ptr) { |
| 423 | #ifdef MALLOC_LOG |
| 424 | if (fp) |
| 425 | fprintf(fp, "free(%p)\n", ptr); |
| 426 | #endif |
| 427 | #ifdef MINEFIELD |
| 428 | minefield_c_free(ptr); |
| 429 | #else |
| 430 | free(ptr); |
| 431 | #endif |
| 432 | } |
| 433 | #ifdef MALLOC_LOG |
| 434 | else if (fp) |
| 435 | fprintf(fp, "freeing null pointer - no action taken\n"); |
| 436 | #endif |
| 437 | } |
| 438 | |
| 439 | /* ---------------------------------------------------------------------- |
| 440 | * Debugging routines. |
| 441 | */ |
| 442 | |
| 443 | #ifdef DEBUG |
| 444 | extern void dputs(char *); /* defined in per-platform *misc.c */ |
| 445 | |
| 446 | void debug_printf(char *fmt, ...) |
| 447 | { |
| 448 | char *buf; |
| 449 | va_list ap; |
| 450 | |
| 451 | va_start(ap, fmt); |
| 452 | buf = dupvprintf(fmt, ap); |
| 453 | dputs(buf); |
| 454 | sfree(buf); |
| 455 | va_end(ap); |
| 456 | } |
| 457 | |
| 458 | |
| 459 | void debug_memdump(void *buf, int len, int L) |
| 460 | { |
| 461 | int i; |
| 462 | unsigned char *p = buf; |
| 463 | char foo[17]; |
| 464 | if (L) { |
| 465 | int delta; |
| 466 | debug_printf("\t%d (0x%x) bytes:\n", len, len); |
| 467 | delta = 15 & (int) p; |
| 468 | p -= delta; |
| 469 | len += delta; |
| 470 | } |
| 471 | for (; 0 < len; p += 16, len -= 16) { |
| 472 | dputs(" "); |
| 473 | if (L) |
| 474 | debug_printf("%p: ", p); |
| 475 | strcpy(foo, "................"); /* sixteen dots */ |
| 476 | for (i = 0; i < 16 && i < len; ++i) { |
| 477 | if (&p[i] < (unsigned char *) buf) { |
| 478 | dputs(" "); /* 3 spaces */ |
| 479 | foo[i] = ' '; |
| 480 | } else { |
| 481 | debug_printf("%c%02.2x", |
| 482 | &p[i] != (unsigned char *) buf |
| 483 | && i % 4 ? '.' : ' ', p[i] |
| 484 | ); |
| 485 | if (p[i] >= ' ' && p[i] <= '~') |
| 486 | foo[i] = (char) p[i]; |
| 487 | } |
| 488 | } |
| 489 | foo[i] = '\0'; |
| 490 | debug_printf("%*s%s\n", (16 - i) * 3 + 2, "", foo); |
| 491 | } |
| 492 | } |
| 493 | |
| 494 | #endif /* def DEBUG */ |