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 1.23 2022/09/24 20:30:13 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 } xprintf_struct; 143 144 /* 145 * Realloc buffer if needed 146 * Return value: 0 = ok 147 * EOF = not enough memory 148 */ 149 static int realloc_buff(xprintf_struct *s, size_t len) 150 { 151 char * ptr; 152 153 if (len + ALLOC_SECURITY_MARGIN + s->real_len > s->buffer_len) { 154 len += s->real_len + ALLOC_CHUNK; 155 ptr = (char *)realloc((void *)(s->buffer_base), len); 156 if (ptr == NULL) { 157 s->buffer_base = NULL; 158 return EOF; 159 } 160 161 s->dest_string = ptr + (size_t)(s->dest_string - s->buffer_base); 162 s->buffer_base = ptr; 163 s->buffer_len = len; 164 165 (s->buffer_base)[s->buffer_len - 1] = 1; /* overflow marker */ 166 } 167 168 return 0; 169 } 170 171 /* 172 * Prints 'usual' characters up to next '%' 173 * or up to end of text 174 */ 175 static int usual_char(xprintf_struct * s) 176 { 177 size_t len; 178 179 len = strcspn(s->src_string, "%"); /* reaches the next '%' or end of input string */ 180 /* note: 'len' is never 0 because the presence of '%' */ 181 /* or end-of-line is checked in the calling function */ 182 183 if (realloc_buff(s,len) == EOF) 184 return EOF; 185 186 memcpy(s->dest_string, s->src_string, len); 187 s->src_string += len; 188 s->dest_string += len; 189 s->real_len += len; 190 s->pseudo_len += len; 191 192 return 0; 193 } 194 195 /* 196 * Return value: 0 = ok 197 * EOF = error 198 */ 199 static int print_it(xprintf_struct *s, size_t approx_len, 200 const char *format_string, ...) 201 { 202 va_list varg; 203 int vsprintf_len; 204 size_t len; 205 206 if (realloc_buff(s,approx_len) == EOF) 207 return EOF; 208 209 va_start(varg, format_string); 210 vsprintf_len = vsprintf(s->dest_string, format_string, varg); 211 va_end(varg); 212 213 /* Check for overflow */ 214 assert((s->buffer_base)[s->buffer_len - 1] == 1); 215 216 if (vsprintf_len == EOF) /* must be done *after* overflow-check */ 217 return EOF; 218 219 s->pseudo_len += vsprintf_len; 220 len = strlen(s->dest_string); 221 s->real_len += len; 222 s->dest_string += len; 223 224 return 0; 225 } 226 227 /* 228 * Prints a string (%s) 229 * We need special handling because: 230 * a: the length of the string is unknown 231 * b: when .prec is used, we must not access any extra byte of the 232 * string (of course, if the original sprintf() does... what the 233 * hell, not my problem) 234 * 235 * Return value: 0 = ok 236 * EOF = error 237 */ 238 static int type_s(xprintf_struct *s, int width, int prec, 239 const char *format_string, const char *arg_string) 240 { 241 size_t string_len; 242 243 if (arg_string == NULL) 244 return print_it(s, (size_t)6, "(null)", 0); 245 246 /* hand-made strlen() which stops when 'prec' is reached. */ 247 /* if 'prec' is -1 then it is never reached. */ 248 string_len = 0; 249 while (arg_string[string_len] != 0 && (size_t)prec != string_len) 250 string_len++; 251 252 if (width != -1 && string_len < (size_t)width) 253 string_len = (size_t)width; 254 255 return print_it(s, string_len, format_string, arg_string); 256 } 257 258 /* 259 * Read a series of digits. Stop when non-digit is found. 260 * Return value: the value read (between 0 and 32767). 261 * Note: no checks are made against overflow. If the string contain a big 262 * number, then the return value won't be what we want (but, in this case, 263 * the programmer don't know whatr he wants, then no problem). 264 */ 265 static int getint(const char **string) 266 { 267 int i = 0; 268 269 while (isdigit((unsigned char)**string) != 0) { 270 i = i * 10 + (**string - '0'); 271 (*string)++; 272 } 273 274 if (i < 0 || i > 32767) 275 i = 32767; /* if we have i==-10 this is not because the number is */ 276 /* negative; this is because the number is big */ 277 return i; 278 } 279 280 /* 281 * Read a part of the format string. A part is 'usual characters' (ie "blabla") 282 * or '%%' escape sequence (to print a single '%') or any combination of 283 * format specifier (ie "%i" or "%10.2d"). 284 * After the current part is managed, the function returns to caller with 285 * everything ready to manage the following part. 286 * The caller must ensure than the string is not empty, i.e. the first byte 287 * is not zero. 288 * 289 * Return value: 0 = ok 290 * EOF = error 291 */ 292 static int dispatch(xprintf_struct *s) 293 { 294 const char *initial_ptr; 295 char format_string[24]; /* max length may be something like "% +-#032768.32768Ld" */ 296 char *format_ptr; 297 int flag_plus, flag_minus, flag_space, flag_sharp, flag_zero; 298 int width, prec, modifier, approx_width; 299 char type; 300 /* most of those variables are here to rewrite the format string */ 301 302 #define SRCTXT (s->src_string) 303 #define DESTTXT (s->dest_string) 304 305 /* incoherent format string. Characters after the '%' will be printed with the next call */ 306 #define INCOHERENT() do {SRCTXT=initial_ptr; return 0;} while (0) /* do/while to avoid */ 307 #define INCOHERENT_TEST() do {if(*SRCTXT==0) INCOHERENT();} while (0) /* a null statement */ 308 309 /* 'normal' text */ 310 if (*SRCTXT != '%') 311 return usual_char(s); 312 313 /* we then have a '%' */ 314 SRCTXT++; 315 /* don't check for end-of-string ; this is done later */ 316 317 /* '%%' escape sequence */ 318 if (*SRCTXT == '%') { 319 if (realloc_buff(s, (size_t)1) == EOF) /* because we can have "%%%%%%%%..." */ 320 return EOF; 321 *DESTTXT = '%'; 322 DESTTXT++; 323 SRCTXT++; 324 (s->real_len)++; 325 (s->pseudo_len)++; 326 return 0; 327 } 328 329 /* '%' managing */ 330 initial_ptr = SRCTXT; /* save current pointer in case of incorrect */ 331 /* 'decoding'. Points just after the '%' so the '%' */ 332 /* won't be printed in any case, as required. */ 333 334 /* flag */ 335 flag_plus = flag_minus = flag_space = flag_sharp = flag_zero = 0; 336 337 for (;; SRCTXT++) { 338 if (*SRCTXT == ' ') 339 flag_space = 1; 340 else if (*SRCTXT == '+') 341 flag_plus = 1; 342 else if (*SRCTXT == '-') 343 flag_minus = 1; 344 else if (*SRCTXT == '#') 345 flag_sharp = 1; 346 else if (*SRCTXT == '0') 347 flag_zero = 1; 348 else 349 break; 350 } 351 352 INCOHERENT_TEST(); /* here is the first test for end of string */ 353 354 /* width */ 355 if (*SRCTXT == '*') { /* width given by next argument */ 356 SRCTXT++; 357 width = va_arg(s->vargs, int); 358 if ((size_t)width > 0x3fffU) /* 'size_t' to check against negative values too */ 359 width = 0x3fff; 360 } else if (isdigit((unsigned char)*SRCTXT)) /* width given as ASCII number */ 361 width = getint(&SRCTXT); 362 else 363 width = -1; /* no width specified */ 364 365 INCOHERENT_TEST(); 366 367 /* .prec */ 368 if (*SRCTXT == '.') { 369 SRCTXT++; 370 if (*SRCTXT == '*') { /* .prec given by next argument */ 371 SRCTXT++; 372 prec = va_arg(s->vargs, int); 373 if ((size_t)prec >= 0x3fffU) /* 'size_t' to check against negative values too */ 374 prec = 0x3fff; 375 } else { /* .prec given as ASCII number */ 376 if (isdigit((unsigned char)*SRCTXT) == 0) 377 INCOHERENT(); 378 prec = getint(&SRCTXT); 379 } 380 INCOHERENT_TEST(); 381 } else 382 prec = -1; /* no .prec specified */ 383 384 /* modifier */ 385 switch (*SRCTXT) { 386 case 'L': 387 case 'h': 388 case 'l': 389 case 'z': 390 case 't': 391 modifier = *SRCTXT; 392 SRCTXT++; 393 if (modifier=='l' && *SRCTXT=='l') { 394 SRCTXT++; 395 modifier = 'L'; /* 'll' == 'L' long long == long double */ 396 } /* only for compatibility ; not portable */ 397 INCOHERENT_TEST(); 398 break; 399 default: 400 modifier = -1; /* no modifier specified */ 401 break; 402 } 403 404 /* type */ 405 type = *SRCTXT; 406 if (strchr("diouxXfegEGcspn",type) == NULL) 407 INCOHERENT(); /* unknown type */ 408 SRCTXT++; 409 410 /* rewrite format-string */ 411 format_string[0] = '%'; 412 format_ptr = &(format_string[1]); 413 414 if (flag_plus) { 415 *format_ptr = '+'; 416 format_ptr++; 417 } 418 if (flag_minus) { 419 *format_ptr = '-'; 420 format_ptr++; 421 } 422 if (flag_space) { 423 *format_ptr = ' '; 424 format_ptr++; 425 } 426 if (flag_sharp) { 427 *format_ptr = '#'; 428 format_ptr++; 429 } 430 if (flag_zero) { 431 *format_ptr = '0'; 432 format_ptr++; 433 } /* '0' *must* be the last one */ 434 435 if (width != -1) { 436 sprintf(format_ptr, "%i", width); 437 format_ptr += strlen(format_ptr); 438 } 439 440 if (prec != -1) { 441 *format_ptr = '.'; 442 format_ptr++; 443 sprintf(format_ptr, "%i", prec); 444 format_ptr += strlen(format_ptr); 445 } 446 447 if (modifier != -1) { 448 if (modifier == 'L' && strchr("diouxX",type) != NULL) { 449 *format_ptr = 'l'; 450 format_ptr++; 451 *format_ptr = 'l'; 452 format_ptr++; 453 } else { 454 *format_ptr = modifier; 455 format_ptr++; 456 } 457 } 458 459 *format_ptr = type; 460 format_ptr++; 461 *format_ptr = 0; 462 463 /* vague approximation of minimal length if width or prec are specified */ 464 approx_width = width + prec; 465 if (approx_width < 0) /* because width == -1 and/or prec == -1 */ 466 approx_width = 0; 467 468 switch (type) { 469 /* int */ 470 case 'd': 471 case 'i': 472 case 'o': 473 case 'u': 474 case 'x': 475 case 'X': 476 switch (modifier) { 477 case -1 : 478 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, int)); 479 case 'L': 480 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, long long int)); 481 case 'l': 482 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, long int)); 483 case 'h': 484 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, int)); 485 case 'z': 486 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, size_t)); 487 case 't': 488 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, ptrdiff_t)); 489 /* 'int' instead of 'short int' because default promotion is 'int' */ 490 default: 491 INCOHERENT(); 492 } 493 494 /* char */ 495 case 'c': 496 if (modifier != -1) 497 INCOHERENT(); 498 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, int)); 499 /* 'int' instead of 'char' because default promotion is 'int' */ 500 501 /* math */ 502 case 'e': 503 case 'f': 504 case 'g': 505 case 'E': 506 case 'G': 507 switch (modifier) { 508 case -1 : /* because of default promotion, no modifier means 'l' */ 509 case 'l': 510 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, double)); 511 case 'L': 512 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, long double)); 513 default: 514 INCOHERENT(); 515 } 516 517 /* string */ 518 case 's': 519 return type_s(s, width, prec, format_string, va_arg(s->vargs, const char*)); 520 521 /* pointer */ 522 case 'p': 523 if (modifier == -1) 524 return print_it(s, (size_t)approx_width, format_string, va_arg(s->vargs, void *)); 525 INCOHERENT(); 526 527 /* store */ 528 case 'n': 529 if (modifier == -1) { 530 int * p; 531 p = va_arg(s->vargs, int *); 532 if (p != NULL) { 533 *p = s->pseudo_len; 534 return 0; 535 } 536 return EOF; 537 } 538 INCOHERENT(); 539 540 } /* switch */ 541 542 INCOHERENT(); /* unknown type */ 543 544 #undef INCOHERENT 545 #undef INCOHERENT_TEST 546 #undef SRCTXT 547 #undef DESTTXT 548 } 549 550 /* 551 * Return value: number of *virtually* written characters 552 * EOF = error 553 */ 554 static int core(xprintf_struct *s) 555 { 556 size_t save_len; 557 char *dummy_base; 558 559 /* basic checks */ 560 if ((int)(s->maxlen) <= 0) /* 'int' to check against some conversion */ 561 return EOF; /* error for example if value is (int)-10 */ 562 s->maxlen--; /* because initial maxlen counts final 0 */ 563 /* note: now 'maxlen' _can_ be zero */ 564 565 if (s->src_string == NULL) 566 s->src_string = "(null)"; 567 568 /* struct init and memory allocation */ 569 s->buffer_base = NULL; 570 s->buffer_len = 0; 571 s->real_len = 0; 572 s->pseudo_len = 0; 573 if (realloc_buff(s, (size_t)0) == EOF) 574 return EOF; 575 s->dest_string = s->buffer_base; 576 577 /* process source string */ 578 for (;;) { 579 /* up to end of source string */ 580 if (*(s->src_string) == 0) { 581 *(s->dest_string) = '\0'; /* final NUL */ 582 break; 583 } 584 585 if (dispatch(s) == EOF) 586 goto free_EOF; 587 588 /* up to end of dest string */ 589 if (s->real_len >= s->maxlen) { 590 (s->buffer_base)[s->maxlen] = '\0'; /* final NUL */ 591 break; 592 } 593 } 594 595 /* for (v)asnprintf */ 596 dummy_base = s->buffer_base + s->real_len; 597 save_len = s->real_len; 598 599 /* process the remaining of source string to compute 'pseudo_len'. We 600 * overwrite again and again, starting at 'dummy_base' because we don't 601 * need the text, only char count. */ 602 while(*(s->src_string) != 0) { /* up to end of source string */ 603 s->real_len = 0; 604 s->dest_string = dummy_base; 605 if (dispatch(s) == EOF) 606 goto free_EOF; 607 } 608 609 s->buffer_base = (char *)realloc((void *)(s->buffer_base), save_len + 1); 610 if (s->buffer_base == NULL) 611 return EOF; /* should rarely happen because we shrink the buffer */ 612 return s->pseudo_len; 613 614 free_EOF: 615 free(s->buffer_base); 616 return EOF; 617 } 618 619 int vasprintf(char **ptr, const char *format_string, va_list vargs) 620 { 621 xprintf_struct s; 622 int retval; 623 624 memset(&s, 0, sizeof(s)); 625 s.src_string = format_string; 626 #ifdef va_copy 627 va_copy (s.vargs, vargs); 628 #else 629 # ifdef __va_copy 630 __va_copy (s.vargs, vargs); 631 # else 632 # ifdef WIN32 633 s.vargs = vargs; 634 # else 635 memcpy (&s.vargs, &vargs, sizeof (s.vargs)); 636 # endif /* WIN32 */ 637 # endif /* __va_copy */ 638 #endif /* va_copy */ 639 s.maxlen = (size_t)INT_MAX; 640 641 retval = core(&s); 642 va_end(s.vargs); 643 if (retval == EOF) { 644 *ptr = NULL; 645 return EOF; 646 } 647 648 *ptr = s.buffer_base; 649 return retval; 650 } 651