1 /* 2 * Copyright (c) Ian F. Darwin 1986-1995. 3 * Software written by Ian F. Darwin and others; 4 * maintained 1995-present by Christos Zoulas and others. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice immediately at the beginning of the file, without modification, 11 * this list of conditions, and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 /*########################################################################### 29 # # 30 # vasprintf # 31 # # 32 # Copyright (c) 2002-2005 David TAILLANDIER # 33 # # 34 ###########################################################################*/ 35 36 /* 37 38 This software is distributed under the "modified BSD licence". 39 40 This software is also released with GNU license (GPL) in another file (same 41 source-code, only license differ). 42 43 44 45 Redistribution and use in source and binary forms, with or without 46 modification, are permitted provided that the following conditions are met: 47 48 Redistributions of source code must retain the above copyright notice, this 49 list of conditions and the following disclaimer. Redistributions in binary 50 form must reproduce the above copyright notice, this list of conditions and 51 the following disclaimer in the documentation and/or other materials 52 provided with the distribution. The name of the author may not be used to 53 endorse or promote products derived from this software without specific 54 prior written permission. 55 56 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 57 WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 58 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 59 EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 60 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 61 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 62 OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 63 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 64 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 65 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 66 67 ==================== 68 69 Hacked from xnprintf version of 26th February 2005 to provide only 70 vasprintf by Reuben Thomas <rrt@sc3d.org>. 71 72 ==================== 73 74 75 'printf' function family use the following format string: 76 77 %[flag][width][.prec][modifier]type 78 79 %% is the escape sequence to print a '%' 80 % followed by an unknown format will print the characters without 81 trying to do any interpretation 82 83 flag: none + - # (blank) 84 width: n 0n * 85 prec: none .0 .n .* 86 modifier: F N L h l ll z t ('F' and 'N' are ms-dos/16-bit specific) 87 type: d i o u x X f e g E G c s p n 88 89 90 The function needs to allocate memory to store the full text before to 91 actually writing it. i.e if you want to fnprintf() 1000 characters, the 92 functions will allocate 1000 bytes. 93 This behaviour can be modified: you have to customise the code to flush the 94 internal buffer (writing to screen or file) when it reach a given size. Then 95 the buffer can have a shorter length. But what? If you really need to write 96 HUGE string, don't use printf! 97 During the process, some other memory is allocated (1024 bytes minimum) 98 to handle the output of partial sprintf() calls. If you have only 10000 bytes 99 free in memory, you *may* not be able to nprintf() a 8000 bytes-long text. 100 101 note: if a buffer overflow occurs, exit() is called. This situation should 102 never appear ... but if you want to be *really* sure, you have to modify the 103 code to handle those situations (only one place to modify). 104 A buffer overflow can only occur if your sprintf() do strange things or when 105 you use strange formats. 106 107 */ 108 #include "file.h" 109 110 #ifndef lint 111 FILE_RCSID("@(#)$File: vasprintf.c,v 1.14 2017/08/13 00:21:47 christos Exp $") 112 #endif /* lint */ 113 114 #include <assert.h> 115 #include <string.h> 116 #include <stdlib.h> 117 #include <stdarg.h> 118 #include <ctype.h> 119 #ifdef HAVE_LIMITS_H 120 #include <limits.h> 121 #endif 122 #ifdef HAVE_STDDEF_H 123 #include <stddef.h> 124 #endif 125 126 #define ALLOC_CHUNK 2048 127 #define ALLOC_SECURITY_MARGIN 1024 /* big value because some platforms have very big 'G' exponent */ 128 #if ALLOC_CHUNK < ALLOC_SECURITY_MARGIN 129 # error !!! ALLOC_CHUNK < ALLOC_SECURITY_MARGIN !!! 130 #endif 131 /* note: to have some interest, ALLOC_CHUNK should be much greater than ALLOC_SECURITY_MARGIN */ 132 133 /* 134 * To save a lot of push/pop, every variable are stored into this 135 * structure, which is passed among nearly every sub-functions. 136 */ 137 typedef struct { 138 const char * src_string; /* current position into intput string */ 139 char * buffer_base; /* output buffer */ 140 char * dest_string; /* current position into output string */ 141 size_t buffer_len; /* length of output buffer */ 142 size_t real_len; /* real current length of output text */ 143 size_t pseudo_len; /* total length of output text if it were not limited in size */ 144 size_t maxlen; 145 va_list vargs; /* pointer to current position into vargs */ 146 char * sprintf_string; 147 FILE * fprintf_file; 148 } xprintf_struct; 149 150 /* 151 * Realloc buffer if needed 152 * Return value: 0 = ok 153 * EOF = not enought memory 154 */ 155 static int realloc_buff(xprintf_struct *s, size_t len) 156 { 157 char * ptr; 158 159 if (len + ALLOC_SECURITY_MARGIN + s->real_len > s->buffer_len) { 160 len += s->real_len + ALLOC_CHUNK; 161 ptr = (char *)realloc((void *)(s->buffer_base), len); 162 if (ptr == NULL) { 163 s->buffer_base = NULL; 164 return EOF; 165 } 166 167 s->dest_string = ptr + (size_t)(s->dest_string - s->buffer_base); 168 s->buffer_base = ptr; 169 s->buffer_len = len; 170 171 (s->buffer_base)[s->buffer_len - 1] = 1; /* overflow marker */ 172 } 173 174 return 0; 175 } 176 177 /* 178 * Prints 'usual' characters up to next '%' 179 * or up to end of text 180 */ 181 static int usual_char(xprintf_struct * s) 182 { 183 size_t len; 184 185 len = strcspn(s->src_string, "%"); /* reachs the next '%' or end of input string */ 186 /* note: 'len' is never 0 because the presence of '%' */ 187 /* or end-of-line is checked in the calling function */ 188 189 if (realloc_buff(s,len) == EOF) 190 return EOF; 191 192 memcpy(s->dest_string, s->src_string, len); 193 s->src_string += len; 194 s->dest_string += len; 195 s->real_len += len; 196 s->pseudo_len += len; 197 198 return 0; 199 } 200 201 /* 202 * Return value: 0 = ok 203 * EOF = error 204 */ 205 static int print_it(xprintf_struct *s, size_t approx_len, 206 const char *format_string, ...) 207 { 208 va_list varg; 209 int vsprintf_len; 210 size_t len; 211 212 if (realloc_buff(s,approx_len) == EOF) 213 return EOF; 214 215 va_start(varg, format_string); 216 vsprintf_len = vsprintf(s->dest_string, format_string, varg); 217 va_end(varg); 218 219 /* Check for overflow */ 220 assert((s->buffer_base)[s->buffer_len - 1] == 1); 221 222 if (vsprintf_len == EOF) /* must be done *after* overflow-check */ 223 return EOF; 224 225 s->pseudo_len += vsprintf_len; 226 len = strlen(s->dest_string); 227 s->real_len += len; 228 s->dest_string += len; 229 230 return 0; 231 } 232 233 /* 234 * Prints a string (%s) 235 * We need special handling because: 236 * a: the length of the string is unknown 237 * b: when .prec is used, we must not access any extra byte of the 238 * string (of course, if the original sprintf() does... what the 239 * hell, not my problem) 240 * 241 * Return value: 0 = ok 242 * EOF = error 243 */ 244 static int type_s(xprintf_struct *s, int width, int prec, 245 const char *format_string, const char *arg_string) 246 { 247 size_t string_len; 248 249 if (arg_string == NULL) 250 return print_it(s, (size_t)6, "(null)", 0); 251 252 /* hand-made strlen() whitch stops when 'prec' is reached. */ 253 /* if 'prec' is -1 then it is never reached. */ 254 string_len = 0; 255 while (arg_string[string_len] != 0 && (size_t)prec != string_len) 256 string_len++; 257 258 if (width != -1 && string_len < (size_t)width) 259 string_len = (size_t)width; 260 261 return print_it(s, string_len, format_string, arg_string); 262 } 263 264 /* 265 * Read a serie of digits. Stop when non-digit is found. 266 * Return value: the value read (between 0 and 32767). 267 * Note: no checks are made against overflow. If the string contain a big 268 * number, then the return value won't be what we want (but, in this case, 269 * the programmer don't know whatr he wants, then no problem). 270 */ 271 static int getint(const char **string) 272 { 273 int i = 0; 274 275 while (isdigit((unsigned char)**string) != 0) { 276 i = i * 10 + (**string - '0'); 277 (*string)++; 278 } 279 280 if (i < 0 || i > 32767) 281 i = 32767; /* if we have i==-10 this is not because the number is */ 282 /* negative; this is because the number is big */ 283 return i; 284 } 285 286 /* 287 * Read a part of the format string. A part is 'usual characters' (ie "blabla") 288 * or '%%' escape sequence (to print a single '%') or any combination of 289 * format specifier (ie "%i" or "%10.2d"). 290 * After the current part is managed, the function returns to caller with 291 * everything ready to manage the following part. 292 * The caller must ensure than the string is not empty, i.e. the first byte 293 * is not zero. 294 * 295 * Return value: 0 = ok 296 * EOF = error 297 */ 298 static int dispatch(xprintf_struct *s) 299 { 300 const char *initial_ptr; 301 char format_string[24]; /* max length may be something like "% +-#032768.32768Ld" */ 302 char *format_ptr; 303 int flag_plus, flag_minus, flag_space, flag_sharp, flag_zero; 304 int width, prec, modifier, approx_width; 305 char type; 306 /* most of those variables are here to rewrite the format string */ 307 308 #define SRCTXT (s->src_string) 309 #define DESTTXT (s->dest_string) 310 311 /* incoherent format string. Characters after the '%' will be printed with the next call */ 312 #define INCOHERENT() do {SRCTXT=initial_ptr; return 0;} while (0) /* do/while to avoid */ 313 #define INCOHERENT_TEST() do {if(*SRCTXT==0) INCOHERENT();} while (0) /* a null statement */ 314 315 /* 'normal' text */ 316 if (*SRCTXT != '%') 317 return usual_char(s); 318 319 /* we then have a '%' */ 320 SRCTXT++; 321 /* don't check for end-of-string ; this is done later */ 322 323 /* '%%' escape sequence */ 324 if (*SRCTXT == '%') { 325 if (realloc_buff(s, (size_t)1) == EOF) /* because we can have "%%%%%%%%..." */ 326 return EOF; 327 *DESTTXT = '%'; 328 DESTTXT++; 329 SRCTXT++; 330 (s->real_len)++; 331 (s->pseudo_len)++; 332 return 0; 333 } 334 335 /* '%' managing */ 336 initial_ptr = SRCTXT; /* save current pointer in case of incorrect */ 337 /* 'decoding'. Points just after the '%' so the '%' */ 338 /* won't be printed in any case, as required. */ 339 340 /* flag */ 341 flag_plus = flag_minus = flag_space = flag_sharp = flag_zero = 0; 342 343 for (;; SRCTXT++) { 344 if (*SRCTXT == ' ') 345 flag_space = 1; 346 else if (*SRCTXT == '+') 347 flag_plus = 1; 348 else if (*SRCTXT == '-') 349 flag_minus = 1; 350 else if (*SRCTXT == '#') 351 flag_sharp = 1; 352 else if (*SRCTXT == '0') 353 flag_zero = 1; 354 else 355 break; 356 } 357 358 INCOHERENT_TEST(); /* here is the first test for end of string */ 359 360 /* width */ 361 if (*SRCTXT == '*') { /* width given by next argument */ 362 SRCTXT++; 363 width = va_arg(s->vargs, int); 364 if ((size_t)width > 0x3fffU) /* 'size_t' to check against negative values too */ 365 width = 0x3fff; 366 } else if (isdigit((unsigned char)*SRCTXT)) /* width given as ASCII number */ 367 width = getint(&SRCTXT); 368 else 369 width = -1; /* no width specified */ 370 371 INCOHERENT_TEST(); 372 373 /* .prec */ 374 if (*SRCTXT == '.') { 375 SRCTXT++; 376 if (*SRCTXT == '*') { /* .prec given by next argument */ 377 SRCTXT++; 378 prec = va_arg(s->vargs, int); 379 if ((size_t)prec >= 0x3fffU) /* 'size_t' to check against negative values too */ 380 prec = 0x3fff; 381 } else { /* .prec given as ASCII number */ 382 if (isdigit((unsigned char)*SRCTXT) == 0) 383 INCOHERENT(); 384 prec = getint(&SRCTXT); 385 } 386 INCOHERENT_TEST(); 387 } else 388 prec = -1; /* no .prec specified */ 389 390 /* modifier */ 391 switch (*SRCTXT) { 392 case 'L': 393 case 'h': 394 case 'l': 395 case 'z': 396 case 't': 397 modifier = *SRCTXT; 398 SRCTXT++; 399 if (modifier=='l' && *SRCTXT=='l') { 400 SRCTXT++; 401 modifier = 'L'; /* 'll' == 'L' long long == long double */ 402 } /* only for compatibility ; not portable */ 403 INCOHERENT_TEST(); 404 break; 405 default: 406 modifier = -1; /* no modifier specified */ 407 break; 408 } 409 410 /* type */ 411 type = *SRCTXT; 412 if (strchr("diouxXfegEGcspn",type) == NULL) 413 INCOHERENT(); /* unknown type */ 414 SRCTXT++; 415 416 /* rewrite format-string */ 417 format_string[0] = '%'; 418 format_ptr = &(format_string[1]); 419 420 if (flag_plus) { 421 *format_ptr = '+'; 422 format_ptr++; 423 } 424 if (flag_minus) { 425 *format_ptr = '-'; 426 format_ptr++; 427 } 428 if (flag_space) { 429 *format_ptr = ' '; 430 format_ptr++; 431 } 432 if (flag_sharp) { 433 *format_ptr = '#'; 434 format_ptr++; 435 } 436 if (flag_zero) { 437 *format_ptr = '0'; 438 format_ptr++; 439 } /* '0' *must* be the last one */ 440 441 if (width != -1) { 442 sprintf(format_ptr, "%i", width); 443 format_ptr += strlen(format_ptr); 444 } 445 446 if (prec != -1) { 447 *format_ptr = '.'; 448 format_ptr++; 449 sprintf(format_ptr, "%i", prec); 450 format_ptr += strlen(format_ptr); 451 } 452 453 if (modifier != -1) { 454 if (modifier == 'L' && strchr("diouxX",type) != NULL) { 455 *format_ptr = 'l'; 456 format_ptr++; 457 *format_ptr = 'l'; 458 format_ptr++; 459 } else { 460 *format_ptr = modifier; 461 format_ptr++; 462 } 463 } 464 465 *format_ptr = type; 466 format_ptr++; 467 *format_ptr = 0; 468 469 /* vague approximation of minimal length if width or prec are specified */ 470 approx_width = width + prec; 471 if (approx_width < 0) /* because width == -1 and/or prec == -1 */ 472 approx_width = 0; 473 474 switch (type) { 475 /* int */ 476 case 'd': 477 case 'i': 478 case 'o': 479 case 'u': 480 case 'x': 481 case 'X': 482 switch (modifier) { 483 case -1 : 484 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, int)); 485 case 'L': 486 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, long long int)); 487 case 'l': 488 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, long int)); 489 case 'h': 490 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, int)); 491 case 'z': 492 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, size_t)); 493 case 't': 494 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, ptrdiff_t)); 495 /* 'int' instead of 'short int' because default promotion is 'int' */ 496 default: 497 INCOHERENT(); 498 } 499 500 /* char */ 501 case 'c': 502 if (modifier != -1) 503 INCOHERENT(); 504 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, int)); 505 /* 'int' instead of 'char' because default promotion is 'int' */ 506 507 /* math */ 508 case 'e': 509 case 'f': 510 case 'g': 511 case 'E': 512 case 'G': 513 switch (modifier) { 514 case -1 : /* because of default promotion, no modifier means 'l' */ 515 case 'l': 516 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, double)); 517 case 'L': 518 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, long double)); 519 default: 520 INCOHERENT(); 521 } 522 523 /* string */ 524 case 's': 525 return type_s(s, width, prec, format_string, va_arg(s->vargs, const char*)); 526 527 /* pointer */ 528 case 'p': 529 if (modifier == -1) 530 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, void *)); 531 INCOHERENT(); 532 533 /* store */ 534 case 'n': 535 if (modifier == -1) { 536 int * p; 537 p = va_arg(s->vargs, int *); 538 if (p != NULL) { 539 *p = s->pseudo_len; 540 return 0; 541 } 542 return EOF; 543 } 544 INCOHERENT(); 545 546 } /* switch */ 547 548 INCOHERENT(); /* unknown type */ 549 550 #undef INCOHERENT 551 #undef INCOHERENT_TEST 552 #undef SRCTXT 553 #undef DESTTXT 554 } 555 556 /* 557 * Return value: number of *virtually* written characters 558 * EOF = error 559 */ 560 static int core(xprintf_struct *s) 561 { 562 size_t save_len; 563 char *dummy_base; 564 565 /* basic checks */ 566 if ((int)(s->maxlen) <= 0) /* 'int' to check against some conversion */ 567 return EOF; /* error for example if value is (int)-10 */ 568 s->maxlen--; /* because initial maxlen counts final 0 */ 569 /* note: now 'maxlen' _can_ be zero */ 570 571 if (s->src_string == NULL) 572 s->src_string = "(null)"; 573 574 /* struct init and memory allocation */ 575 s->buffer_base = NULL; 576 s->buffer_len = 0; 577 s->real_len = 0; 578 s->pseudo_len = 0; 579 if (realloc_buff(s, (size_t)0) == EOF) 580 return EOF; 581 s->dest_string = s->buffer_base; 582 583 /* process source string */ 584 for (;;) { 585 /* up to end of source string */ 586 if (*(s->src_string) == 0) { 587 *(s->dest_string) = '\0'; /* final NUL */ 588 break; 589 } 590 591 if (dispatch(s) == EOF) 592 goto free_EOF; 593 594 /* up to end of dest string */ 595 if (s->real_len >= s->maxlen) { 596 (s->buffer_base)[s->maxlen] = '\0'; /* final NUL */ 597 break; 598 } 599 } 600 601 /* for (v)asnprintf */ 602 dummy_base = s->buffer_base; 603 604 dummy_base = s->buffer_base + s->real_len; 605 save_len = s->real_len; 606 607 /* process the remaining of source string to compute 'pseudo_len'. We 608 * overwrite again and again, starting at 'dummy_base' because we don't 609 * need the text, only char count. */ 610 while(*(s->src_string) != 0) { /* up to end of source string */ 611 s->real_len = 0; 612 s->dest_string = dummy_base; 613 if (dispatch(s) == EOF) 614 goto free_EOF; 615 } 616 617 s->buffer_base = (char *)realloc((void *)(s->buffer_base), save_len + 1); 618 if (s->buffer_base == NULL) 619 return EOF; /* should rarely happen because we shrink the buffer */ 620 return s->pseudo_len; 621 622 free_EOF: 623 free(s->buffer_base); 624 return EOF; 625 } 626 627 int vasprintf(char **ptr, const char *format_string, va_list vargs) 628 { 629 xprintf_struct s; 630 int retval; 631 632 s.src_string = format_string; 633 #ifdef va_copy 634 va_copy (s.vargs, vargs); 635 #else 636 # ifdef __va_copy 637 __va_copy (s.vargs, vargs); 638 # else 639 # ifdef WIN32 640 s.vargs = vargs; 641 # else 642 memcpy (&s.vargs, &vargs, sizeof (s.va_args)); 643 # endif /* WIN32 */ 644 # endif /* __va_copy */ 645 #endif /* va_copy */ 646 s.maxlen = (size_t)INT_MAX; 647 648 retval = core(&s); 649 va_end(s.vargs); 650 if (retval == EOF) { 651 *ptr = NULL; 652 return EOF; 653 } 654 655 *ptr = s.buffer_base; 656 return retval; 657 } 658