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() an 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 1.20 2022/07/30 17:04:18 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 #include <limits.h> 120 #include <stddef.h> 121 122 #define ALLOC_CHUNK 2048 123 #define ALLOC_SECURITY_MARGIN 1024 /* big value because some platforms have very big 'G' exponent */ 124 #if ALLOC_CHUNK < ALLOC_SECURITY_MARGIN 125 # error !!! ALLOC_CHUNK < ALLOC_SECURITY_MARGIN !!! 126 #endif 127 /* note: to have some interest, ALLOC_CHUNK should be much greater than ALLOC_SECURITY_MARGIN */ 128 129 /* 130 * To save a lot of push/pop, every variable are stored into this 131 * structure, which is passed among nearly every sub-functions. 132 */ 133 typedef struct { 134 const char * src_string; /* current position into input string */ 135 char * buffer_base; /* output buffer */ 136 char * dest_string; /* current position into output string */ 137 size_t buffer_len; /* length of output buffer */ 138 size_t real_len; /* real current length of output text */ 139 size_t pseudo_len; /* total length of output text if it were not limited in size */ 140 size_t maxlen; 141 va_list vargs; /* pointer to current position into vargs */ 142 char * sprintf_string; 143 FILE * fprintf_file; 144 } xprintf_struct; 145 146 /* 147 * Realloc buffer if needed 148 * Return value: 0 = ok 149 * EOF = not enough memory 150 */ 151 static int realloc_buff(xprintf_struct *s, size_t len) 152 { 153 char * ptr; 154 155 if (len + ALLOC_SECURITY_MARGIN + s->real_len > s->buffer_len) { 156 len += s->real_len + ALLOC_CHUNK; 157 ptr = (char *)realloc((void *)(s->buffer_base), len); 158 if (ptr == NULL) { 159 s->buffer_base = NULL; 160 return EOF; 161 } 162 163 s->dest_string = ptr + (size_t)(s->dest_string - s->buffer_base); 164 s->buffer_base = ptr; 165 s->buffer_len = len; 166 167 (s->buffer_base)[s->buffer_len - 1] = 1; /* overflow marker */ 168 } 169 170 return 0; 171 } 172 173 /* 174 * Prints 'usual' characters up to next '%' 175 * or up to end of text 176 */ 177 static int usual_char(xprintf_struct * s) 178 { 179 size_t len; 180 181 len = strcspn(s->src_string, "%"); /* reaches the next '%' or end of input string */ 182 /* note: 'len' is never 0 because the presence of '%' */ 183 /* or end-of-line is checked in the calling function */ 184 185 if (realloc_buff(s,len) == EOF) 186 return EOF; 187 188 memcpy(s->dest_string, s->src_string, len); 189 s->src_string += len; 190 s->dest_string += len; 191 s->real_len += len; 192 s->pseudo_len += len; 193 194 return 0; 195 } 196 197 /* 198 * Return value: 0 = ok 199 * EOF = error 200 */ 201 static int print_it(xprintf_struct *s, size_t approx_len, 202 const char *format_string, ...) 203 { 204 va_list varg; 205 int vsprintf_len; 206 size_t len; 207 208 if (realloc_buff(s,approx_len) == EOF) 209 return EOF; 210 211 va_start(varg, format_string); 212 vsprintf_len = vsprintf(s->dest_string, format_string, varg); 213 va_end(varg); 214 215 /* Check for overflow */ 216 assert((s->buffer_base)[s->buffer_len - 1] == 1); 217 218 if (vsprintf_len == EOF) /* must be done *after* overflow-check */ 219 return EOF; 220 221 s->pseudo_len += vsprintf_len; 222 len = strlen(s->dest_string); 223 s->real_len += len; 224 s->dest_string += len; 225 226 return 0; 227 } 228 229 /* 230 * Prints a string (%s) 231 * We need special handling because: 232 * a: the length of the string is unknown 233 * b: when .prec is used, we must not access any extra byte of the 234 * string (of course, if the original sprintf() does... what the 235 * hell, not my problem) 236 * 237 * Return value: 0 = ok 238 * EOF = error 239 */ 240 static int type_s(xprintf_struct *s, int width, int prec, 241 const char *format_string, const char *arg_string) 242 { 243 size_t string_len; 244 245 if (arg_string == NULL) 246 return print_it(s, (size_t)6, "(null)", 0); 247 248 /* hand-made strlen() which stops when 'prec' is reached. */ 249 /* if 'prec' is -1 then it is never reached. */ 250 string_len = 0; 251 while (arg_string[string_len] != 0 && (size_t)prec != string_len) 252 string_len++; 253 254 if (width != -1 && string_len < (size_t)width) 255 string_len = (size_t)width; 256 257 return print_it(s, string_len, format_string, arg_string); 258 } 259 260 /* 261 * Read a series of digits. Stop when non-digit is found. 262 * Return value: the value read (between 0 and 32767). 263 * Note: no checks are made against overflow. If the string contain a big 264 * number, then the return value won't be what we want (but, in this case, 265 * the programmer don't know whatr he wants, then no problem). 266 */ 267 static int getint(const char **string) 268 { 269 int i = 0; 270 271 while (isdigit((unsigned char)**string) != 0) { 272 i = i * 10 + (**string - '0'); 273 (*string)++; 274 } 275 276 if (i < 0 || i > 32767) 277 i = 32767; /* if we have i==-10 this is not because the number is */ 278 /* negative; this is because the number is big */ 279 return i; 280 } 281 282 /* 283 * Read a part of the format string. A part is 'usual characters' (ie "blabla") 284 * or '%%' escape sequence (to print a single '%') or any combination of 285 * format specifier (ie "%i" or "%10.2d"). 286 * After the current part is managed, the function returns to caller with 287 * everything ready to manage the following part. 288 * The caller must ensure than the string is not empty, i.e. the first byte 289 * is not zero. 290 * 291 * Return value: 0 = ok 292 * EOF = error 293 */ 294 static int dispatch(xprintf_struct *s) 295 { 296 const char *initial_ptr; 297 char format_string[24]; /* max length may be something like "% +-#032768.32768Ld" */ 298 char *format_ptr; 299 int flag_plus, flag_minus, flag_space, flag_sharp, flag_zero; 300 int width, prec, modifier, approx_width; 301 char type; 302 /* most of those variables are here to rewrite the format string */ 303 304 #define SRCTXT (s->src_string) 305 #define DESTTXT (s->dest_string) 306 307 /* incoherent format string. Characters after the '%' will be printed with the next call */ 308 #define INCOHERENT() do {SRCTXT=initial_ptr; return 0;} while (0) /* do/while to avoid */ 309 #define INCOHERENT_TEST() do {if(*SRCTXT==0) INCOHERENT();} while (0) /* a null statement */ 310 311 /* 'normal' text */ 312 if (*SRCTXT != '%') 313 return usual_char(s); 314 315 /* we then have a '%' */ 316 SRCTXT++; 317 /* don't check for end-of-string ; this is done later */ 318 319 /* '%%' escape sequence */ 320 if (*SRCTXT == '%') { 321 if (realloc_buff(s, (size_t)1) == EOF) /* because we can have "%%%%%%%%..." */ 322 return EOF; 323 *DESTTXT = '%'; 324 DESTTXT++; 325 SRCTXT++; 326 (s->real_len)++; 327 (s->pseudo_len)++; 328 return 0; 329 } 330 331 /* '%' managing */ 332 initial_ptr = SRCTXT; /* save current pointer in case of incorrect */ 333 /* 'decoding'. Points just after the '%' so the '%' */ 334 /* won't be printed in any case, as required. */ 335 336 /* flag */ 337 flag_plus = flag_minus = flag_space = flag_sharp = flag_zero = 0; 338 339 for (;; SRCTXT++) { 340 if (*SRCTXT == ' ') 341 flag_space = 1; 342 else if (*SRCTXT == '+') 343 flag_plus = 1; 344 else if (*SRCTXT == '-') 345 flag_minus = 1; 346 else if (*SRCTXT == '#') 347 flag_sharp = 1; 348 else if (*SRCTXT == '0') 349 flag_zero = 1; 350 else 351 break; 352 } 353 354 INCOHERENT_TEST(); /* here is the first test for end of string */ 355 356 /* width */ 357 if (*SRCTXT == '*') { /* width given by next argument */ 358 SRCTXT++; 359 width = va_arg(s->vargs, int); 360 if ((size_t)width > 0x3fffU) /* 'size_t' to check against negative values too */ 361 width = 0x3fff; 362 } else if (isdigit((unsigned char)*SRCTXT)) /* width given as ASCII number */ 363 width = getint(&SRCTXT); 364 else 365 width = -1; /* no width specified */ 366 367 INCOHERENT_TEST(); 368 369 /* .prec */ 370 if (*SRCTXT == '.') { 371 SRCTXT++; 372 if (*SRCTXT == '*') { /* .prec given by next argument */ 373 SRCTXT++; 374 prec = va_arg(s->vargs, int); 375 if ((size_t)prec >= 0x3fffU) /* 'size_t' to check against negative values too */ 376 prec = 0x3fff; 377 } else { /* .prec given as ASCII number */ 378 if (isdigit((unsigned char)*SRCTXT) == 0) 379 INCOHERENT(); 380 prec = getint(&SRCTXT); 381 } 382 INCOHERENT_TEST(); 383 } else 384 prec = -1; /* no .prec specified */ 385 386 /* modifier */ 387 switch (*SRCTXT) { 388 case 'L': 389 case 'h': 390 case 'l': 391 case 'z': 392 case 't': 393 modifier = *SRCTXT; 394 SRCTXT++; 395 if (modifier=='l' && *SRCTXT=='l') { 396 SRCTXT++; 397 modifier = 'L'; /* 'll' == 'L' long long == long double */ 398 } /* only for compatibility ; not portable */ 399 INCOHERENT_TEST(); 400 break; 401 default: 402 modifier = -1; /* no modifier specified */ 403 break; 404 } 405 406 /* type */ 407 type = *SRCTXT; 408 if (strchr("diouxXfegEGcspn",type) == NULL) 409 INCOHERENT(); /* unknown type */ 410 SRCTXT++; 411 412 /* rewrite format-string */ 413 format_string[0] = '%'; 414 format_ptr = &(format_string[1]); 415 416 if (flag_plus) { 417 *format_ptr = '+'; 418 format_ptr++; 419 } 420 if (flag_minus) { 421 *format_ptr = '-'; 422 format_ptr++; 423 } 424 if (flag_space) { 425 *format_ptr = ' '; 426 format_ptr++; 427 } 428 if (flag_sharp) { 429 *format_ptr = '#'; 430 format_ptr++; 431 } 432 if (flag_zero) { 433 *format_ptr = '0'; 434 format_ptr++; 435 } /* '0' *must* be the last one */ 436 437 if (width != -1) { 438 sprintf(format_ptr, "%i", width); 439 format_ptr += strlen(format_ptr); 440 } 441 442 if (prec != -1) { 443 *format_ptr = '.'; 444 format_ptr++; 445 sprintf(format_ptr, "%i", prec); 446 format_ptr += strlen(format_ptr); 447 } 448 449 if (modifier != -1) { 450 if (modifier == 'L' && strchr("diouxX",type) != NULL) { 451 *format_ptr = 'l'; 452 format_ptr++; 453 *format_ptr = 'l'; 454 format_ptr++; 455 } else { 456 *format_ptr = modifier; 457 format_ptr++; 458 } 459 } 460 461 *format_ptr = type; 462 format_ptr++; 463 *format_ptr = 0; 464 465 /* vague approximation of minimal length if width or prec are specified */ 466 approx_width = width + prec; 467 if (approx_width < 0) /* because width == -1 and/or prec == -1 */ 468 approx_width = 0; 469 470 switch (type) { 471 /* int */ 472 case 'd': 473 case 'i': 474 case 'o': 475 case 'u': 476 case 'x': 477 case 'X': 478 switch (modifier) { 479 case -1 : 480 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, int)); 481 case 'L': 482 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, long long int)); 483 case 'l': 484 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, long int)); 485 case 'h': 486 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, int)); 487 case 'z': 488 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, size_t)); 489 case 't': 490 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, ptrdiff_t)); 491 /* 'int' instead of 'short int' because default promotion is 'int' */ 492 default: 493 INCOHERENT(); 494 } 495 496 /* char */ 497 case 'c': 498 if (modifier != -1) 499 INCOHERENT(); 500 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, int)); 501 /* 'int' instead of 'char' because default promotion is 'int' */ 502 503 /* math */ 504 case 'e': 505 case 'f': 506 case 'g': 507 case 'E': 508 case 'G': 509 switch (modifier) { 510 case -1 : /* because of default promotion, no modifier means 'l' */ 511 case 'l': 512 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, double)); 513 case 'L': 514 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, long double)); 515 default: 516 INCOHERENT(); 517 } 518 519 /* string */ 520 case 's': 521 return type_s(s, width, prec, format_string, va_arg(s->vargs, const char*)); 522 523 /* pointer */ 524 case 'p': 525 if (modifier == -1) 526 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, void *)); 527 INCOHERENT(); 528 529 /* store */ 530 case 'n': 531 if (modifier == -1) { 532 int * p; 533 p = va_arg(s->vargs, int *); 534 if (p != NULL) { 535 *p = s->pseudo_len; 536 return 0; 537 } 538 return EOF; 539 } 540 INCOHERENT(); 541 542 } /* switch */ 543 544 INCOHERENT(); /* unknown type */ 545 546 #undef INCOHERENT 547 #undef INCOHERENT_TEST 548 #undef SRCTXT 549 #undef DESTTXT 550 } 551 552 /* 553 * Return value: number of *virtually* written characters 554 * EOF = error 555 */ 556 static int core(xprintf_struct *s) 557 { 558 size_t save_len; 559 char *dummy_base; 560 561 /* basic checks */ 562 if ((int)(s->maxlen) <= 0) /* 'int' to check against some conversion */ 563 return EOF; /* error for example if value is (int)-10 */ 564 s->maxlen--; /* because initial maxlen counts final 0 */ 565 /* note: now 'maxlen' _can_ be zero */ 566 567 if (s->src_string == NULL) 568 s->src_string = "(null)"; 569 570 /* struct init and memory allocation */ 571 s->buffer_base = NULL; 572 s->buffer_len = 0; 573 s->real_len = 0; 574 s->pseudo_len = 0; 575 if (realloc_buff(s, (size_t)0) == EOF) 576 return EOF; 577 s->dest_string = s->buffer_base; 578 579 /* process source string */ 580 for (;;) { 581 /* up to end of source string */ 582 if (*(s->src_string) == 0) { 583 *(s->dest_string) = '\0'; /* final NUL */ 584 break; 585 } 586 587 if (dispatch(s) == EOF) 588 goto free_EOF; 589 590 /* up to end of dest string */ 591 if (s->real_len >= s->maxlen) { 592 (s->buffer_base)[s->maxlen] = '\0'; /* final NUL */ 593 break; 594 } 595 } 596 597 /* for (v)asnprintf */ 598 dummy_base = s->buffer_base; 599 600 dummy_base = s->buffer_base + s->real_len; 601 save_len = s->real_len; 602 603 /* process the remaining of source string to compute 'pseudo_len'. We 604 * overwrite again and again, starting at 'dummy_base' because we don't 605 * need the text, only char count. */ 606 while(*(s->src_string) != 0) { /* up to end of source string */ 607 s->real_len = 0; 608 s->dest_string = dummy_base; 609 if (dispatch(s) == EOF) 610 goto free_EOF; 611 } 612 613 s->buffer_base = (char *)realloc((void *)(s->buffer_base), save_len + 1); 614 if (s->buffer_base == NULL) 615 return EOF; /* should rarely happen because we shrink the buffer */ 616 return s->pseudo_len; 617 618 free_EOF: 619 free(s->buffer_base); 620 return EOF; 621 } 622 623 int vasprintf(char **ptr, const char *format_string, va_list vargs) 624 { 625 xprintf_struct s; 626 int retval; 627 628 s.src_string = format_string; 629 #ifdef va_copy 630 va_copy (s.vargs, vargs); 631 #else 632 # ifdef __va_copy 633 __va_copy (s.vargs, vargs); 634 # else 635 # ifdef WIN32 636 s.vargs = vargs; 637 # else 638 memcpy (&s.vargs, &vargs, sizeof (s.vargs)); 639 # endif /* WIN32 */ 640 # endif /* __va_copy */ 641 #endif /* va_copy */ 642 s.maxlen = (size_t)INT_MAX; 643 644 retval = core(&s); 645 va_end(s.vargs); 646 if (retval == EOF) { 647 *ptr = NULL; 648 return EOF; 649 } 650 651 *ptr = s.buffer_base; 652 return retval; 653 } 654