The Tcpdump Group git mirrors - tcpdump/blob - missing/snprintf.c

   1 /*
   2  * Copyright (c) 1995-1999 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   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  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /* $Id: snprintf.c,v 1.2 2000-01-09 21:35:46 fenner Exp $ */
  35
  36 #ifdef HAVE_CONFIG_H
  37 #include <config.h>
  38 #endif
  39
  40 #ifndef lint
  41 static const char rcsid[] =
  42      "@(#) $Header: /tcpdump/master/tcpdump/missing/snprintf.c,v 1.2 2000-01-09 21:35:46 fenner Exp $";
  43 #endif
  44
  45 #include <stdio.h>
  46 #include <stdarg.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <ctype.h>
  50
  51 #include <interface.h>
  52
  53 enum format_flags {
  54     minus_flag     =  1,
  55     plus_flag      =  2,
  56     space_flag     =  4,
  57     alternate_flag =  8,
  58     zero_flag      = 16
  59 };
  60
  61 /*
  62  * Common state
  63  */
  64
  65 struct state {
  66   unsigned char *str;
  67   unsigned char *s;
  68   unsigned char *theend;
  69   size_t sz;
  70   size_t max_sz;
  71   int (*append_char)(struct state *, unsigned char);
  72   int (*reserve)(struct state *, size_t);
  73   /* XXX - methods */
  74 };
  75
  76 #ifndef HAVE_VSNPRINTF
  77 static int
  78 sn_reserve (struct state *state, size_t n)
  79 {
  80   return state->s + n > state->theend;
  81 }
  82
  83 static int
  84 sn_append_char (struct state *state, unsigned char c)
  85 {
  86   if (sn_reserve (state, 1)) {
  87     return 1;
  88   } else {
  89     *state->s++ = c;
  90     return 0;
  91   }
  92 }
  93 #endif
  94
  95 static int
  96 as_reserve (struct state *state, size_t n)
  97 {
  98   if (state->s + n > state->theend) {
  99     int off = state->s - state->str;
 100     unsigned char *tmp;
 101
 102     if (state->max_sz && state->sz >= state->max_sz)
 103       return 1;
 104
 105     state->sz = max(state->sz * 2, state->sz + n);
 106     if (state->max_sz)
 107       state->sz = min(state->sz, state->max_sz);
 108     tmp = realloc (state->str, state->sz);
 109     if (tmp == NULL)
 110       return 1;
 111     state->str = tmp;
 112     state->s = state->str + off;
 113     state->theend = state->str + state->sz - 1;
 114   }
 115   return 0;
 116 }
 117
 118 static int
 119 as_append_char (struct state *state, unsigned char c)
 120 {
 121   if(as_reserve (state, 1))
 122     return 1;
 123   else {
 124     *state->s++ = c;
 125     return 0;
 126   }
 127 }
 128
 129 static int
 130 append_number(struct state *state,
 131               unsigned long num, unsigned base, char *rep,
 132               int width, int prec, int flags, int minusp)
 133 {
 134   int len = 0;
 135   int i;
 136
 137   /* given precision, ignore zero flag */
 138   if(prec != -1)
 139     flags &= ~zero_flag;
 140   else
 141     prec = 1;
 142   /* zero value with zero precision -> "" */
 143   if(prec == 0 && num == 0)
 144     return 0;
 145   do{
 146     if((*state->append_char)(state, rep[num % base]))
 147       return 1;
 148     len++;
 149     num /= base;
 150   }while(num);
 151   prec -= len;
 152   /* pad with prec zeros */
 153   while(prec-- > 0){
 154     if((*state->append_char)(state, '0'))
 155       return 1;
 156     len++;
 157   }
 158   /* add length of alternate prefix (added later) to len */
 159   if(flags & alternate_flag && (base == 16 || base == 8))
 160     len += base / 8;
 161   /* pad with zeros */
 162   if(flags & zero_flag){
 163     width -= len;
 164     if(minusp || (flags & space_flag) || (flags & plus_flag))
 165       width--;
 166     while(width-- > 0){
 167       if((*state->append_char)(state, '0'))
 168         return 1;
 169       len++;
 170     }
 171   }
 172   /* add alternate prefix */
 173   if(flags & alternate_flag && (base == 16 || base == 8)){
 174     if(base == 16)
 175       if((*state->append_char)(state, rep[10] + 23)) /* XXX */
 176         return 1;
 177     if((*state->append_char)(state, '0'))
 178       return 1;
 179   }
 180   /* add sign */
 181   if(minusp){
 182     if((*state->append_char)(state, '-'))
 183       return 1;
 184     len++;
 185   } else if(flags & plus_flag) {
 186     if((*state->append_char)(state, '+'))
 187       return 1;
 188     len++;
 189   } else if(flags & space_flag) {
 190     if((*state->append_char)(state, ' '))
 191       return 1;
 192     len++;
 193   }
 194   if(flags & minus_flag)
 195     /* swap before padding with spaces */
 196     for(i = 0; i < len / 2; i++){
 197       char c = state->s[-i-1];
 198       state->s[-i-1] = state->s[-len+i];
 199       state->s[-len+i] = c;
 200     }
 201   width -= len;
 202   while(width-- > 0){
 203     if((*state->append_char)(state,  ' '))
 204       return 1;
 205     len++;
 206   }
 207   if(!(flags & minus_flag))
 208     /* swap after padding with spaces */
 209     for(i = 0; i < len / 2; i++){
 210       char c = state->s[-i-1];
 211       state->s[-i-1] = state->s[-len+i];
 212       state->s[-len+i] = c;
 213     }
 214
 215   return 0;
 216 }
 217
 218 static int
 219 append_string (struct state *state,
 220                unsigned char *arg,
 221                int width,
 222                int prec,
 223                int flags)
 224 {
 225   if(prec != -1)
 226     width -= prec;
 227   else
 228     width -= strlen((char *)arg);
 229   if(!(flags & minus_flag))
 230     while(width-- > 0)
 231       if((*state->append_char) (state, ' '))
 232         return 1;
 233   if (prec != -1) {
 234     while (*arg && prec--)
 235       if ((*state->append_char) (state, *arg++))
 236         return 1;
 237   } else {
 238     while (*arg)
 239       if ((*state->append_char) (state, *arg++))
 240         return 1;
 241   }
 242   if(flags & minus_flag)
 243     while(width-- > 0)
 244       if((*state->append_char) (state, ' '))
 245         return 1;
 246   return 0;
 247 }
 248
 249 static int
 250 append_char(struct state *state,
 251             unsigned char arg,
 252             int width,
 253             int flags)
 254 {
 255   while(!(flags & minus_flag) && --width > 0)
 256     if((*state->append_char) (state, ' '))
 257       return 1;
 258
 259   if((*state->append_char) (state, arg))
 260     return 1;
 261   while((flags & minus_flag) && --width > 0)
 262     if((*state->append_char) (state, ' '))
 263       return 1;
 264
 265   return 0;
 266 }
 267
 268 /*
 269  * This can't be made into a function...
 270  */
 271
 272 #define PARSE_INT_FORMAT(res, arg, unsig) \
 273 if (long_flag) \
 274      res = (unsig long)va_arg(arg, unsig long); \
 275 else if (short_flag) \
 276      res = (unsig short)va_arg(arg, unsig short); \
 277 else \
 278      res = (unsig int)va_arg(arg, unsig int)
 279
 280 /*
 281  * zyxprintf - return 0 or -1
 282  */
 283
 284 static int
 285 xyzprintf (struct state *state, const char *char_format, va_list ap)
 286 {
 287   const unsigned char *format = (const unsigned char *)char_format;
 288   unsigned char c;
 289
 290   while((c = *format++)) {
 291     if (c == '%') {
 292       int flags      = 0;
 293       int width      = 0;
 294       int prec       = -1;
 295       int long_flag  = 0;
 296       int short_flag = 0;
 297
 298       /* flags */
 299       while((c = *format++)){
 300         if(c == '-')
 301           flags |= minus_flag;
 302         else if(c == '+')
 303           flags |= plus_flag;
 304         else if(c == ' ')
 305           flags |= space_flag;
 306         else if(c == '#')
 307           flags |= alternate_flag;
 308         else if(c == '0')
 309           flags |= zero_flag;
 310         else
 311           break;
 312       }
 313
 314       if((flags & space_flag) && (flags & plus_flag))
 315         flags ^= space_flag;
 316
 317       if((flags & minus_flag) && (flags & zero_flag))
 318         flags ^= zero_flag;
 319
 320       /* width */
 321       if (isdigit(c))
 322         do {
 323           width = width * 10 + c - '0';
 324           c = *format++;
 325         } while(isdigit(c));
 326       else if(c == '*') {
 327         width = va_arg(ap, int);
 328         c = *format++;
 329       }
 330
 331       /* precision */
 332       if (c == '.') {
 333         prec = 0;
 334         c = *format++;
 335         if (isdigit(c))
 336           do {
 337             prec = prec * 10 + c - '0';
 338             c = *format++;
 339           } while(isdigit(c));
 340         else if (c == '*') {
 341           prec = va_arg(ap, int);
 342           c = *format++;
 343         }
 344       }
 345
 346       /* size */
 347
 348       if (c == 'h') {
 349         short_flag = 1;
 350         c = *format++;
 351       } else if (c == 'l') {
 352         long_flag = 1;
 353         c = *format++;
 354       }
 355
 356       switch (c) {
 357       case 'c' :
 358         if(append_char(state, va_arg(ap, int), width, flags))
 359           return -1;
 360         break;
 361       case 's' :
 362         if (append_string(state,
 363                           va_arg(ap, unsigned char*),
 364                           width,
 365                           prec,
 366                           flags))
 367           return -1;
 368         break;
 369       case 'd' :
 370       case 'i' : {
 371         long arg;
 372         unsigned long num;
 373         int minusp = 0;
 374
 375         PARSE_INT_FORMAT(arg, ap, signed);
 376
 377         if (arg < 0) {
 378           minusp = 1;
 379           num = -arg;
 380         } else
 381           num = arg;
 382
 383         if (append_number (state, num, 10, "0123456789",
 384                            width, prec, flags, minusp))
 385           return -1;
 386         break;
 387       }
 388       case 'u' : {
 389         unsigned long arg;
 390
 391         PARSE_INT_FORMAT(arg, ap, unsigned);
 392
 393         if (append_number (state, arg, 10, "0123456789",
 394                            width, prec, flags, 0))
 395           return -1;
 396         break;
 397       }
 398       case 'o' : {
 399         unsigned long arg;
 400
 401         PARSE_INT_FORMAT(arg, ap, unsigned);
 402
 403         if (append_number (state, arg, 010, "01234567",
 404                            width, prec, flags, 0))
 405           return -1;
 406         break;
 407       }
 408       case 'x' : {
 409         unsigned long arg;
 410
 411         PARSE_INT_FORMAT(arg, ap, unsigned);
 412
 413         if (append_number (state, arg, 0x10, "0123456789abcdef",
 414                            width, prec, flags, 0))
 415           return -1;
 416         break;
 417       }
 418       case 'X' :{
 419         unsigned long arg;
 420
 421         PARSE_INT_FORMAT(arg, ap, unsigned);
 422
 423         if (append_number (state, arg, 0x10, "0123456789ABCDEF",
 424                            width, prec, flags, 0))
 425           return -1;
 426         break;
 427       }
 428       case 'p' : {
 429         unsigned long arg = (unsigned long)va_arg(ap, void*);
 430
 431         if (append_number (state, arg, 0x10, "0123456789ABCDEF",
 432                            width, prec, flags, 0))
 433           return -1;
 434         break;
 435       }
 436       case 'n' : {
 437         int *arg = va_arg(ap, int*);
 438         *arg = state->s - state->str;
 439         break;
 440       }
 441       case '\0' :
 442           --format;
 443           /* FALLTHROUGH */
 444       case '%' :
 445         if ((*state->append_char)(state, c))
 446           return -1;
 447         break;
 448       default :
 449         if (   (*state->append_char)(state, '%')
 450             || (*state->append_char)(state, c))
 451           return -1;
 452         break;
 453       }
 454     } else
 455       if ((*state->append_char) (state, c))
 456         return -1;
 457   }
 458   return 0;
 459 }
 460
 461 #ifndef HAVE_SNPRINTF
 462 int
 463 snprintf (char *str, size_t sz, const char *format, ...)
 464 {
 465   va_list args;
 466   int ret;
 467
 468   va_start(args, format);
 469   ret = vsnprintf (str, sz, format, args);
 470
 471 #ifdef PARANOIA
 472   {
 473     int ret2;
 474     char *tmp;
 475
 476     tmp = malloc (sz);
 477     if (tmp == NULL)
 478       abort ();
 479
 480     ret2 = vsprintf (tmp, format, args);
 481     if (ret != ret2 || strcmp(str, tmp))
 482       abort ();
 483     free (tmp);
 484   }
 485 #endif
 486
 487   va_end(args);
 488   return ret;
 489 }
 490 #endif
 491
 492 #ifndef HAVE_ASPRINTF
 493 int
 494 asprintf (char **ret, const char *format, ...)
 495 {
 496   va_list args;
 497   int val;
 498
 499   va_start(args, format);
 500   val = vasprintf (ret, format, args);
 501
 502 #ifdef PARANOIA
 503   {
 504     int ret2;
 505     char *tmp;
 506     tmp = malloc (val + 1);
 507     if (tmp == NULL)
 508       abort ();
 509
 510     ret2 = vsprintf (tmp, format, args);
 511     if (val != ret2 || strcmp(*ret, tmp))
 512       abort ();
 513     free (tmp);
 514   }
 515 #endif
 516
 517   va_end(args);
 518   return val;
 519 }
 520 #endif
 521
 522 #ifndef HAVE_ASNPRINTF
 523 int
 524 asnprintf (char **ret, size_t max_sz, const char *format, ...)
 525 {
 526   va_list args;
 527   int val;
 528
 529   va_start(args, format);
 530   val = vasnprintf (ret, max_sz, format, args);
 531
 532 #ifdef PARANOIA
 533   {
 534     int ret2;
 535     char *tmp;
 536     tmp = malloc (val + 1);
 537     if (tmp == NULL)
 538       abort ();
 539
 540     ret2 = vsprintf (tmp, format, args);
 541     if (val != ret2 || strcmp(*ret, tmp))
 542       abort ();
 543     free (tmp);
 544   }
 545 #endif
 546
 547   va_end(args);
 548   return val;
 549 }
 550 #endif
 551
 552 #ifndef HAVE_VASPRINTF
 553 int
 554 vasprintf (char **ret, const char *format, va_list args)
 555 {
 556   return vasnprintf (ret, 0, format, args);
 557 }
 558 #endif
 559
 560
 561 #ifndef HAVE_VASNPRINTF
 562 int
 563 vasnprintf (char **ret, size_t max_sz, const char *format, va_list args)
 564 {
 565   int st;
 566   size_t len;
 567   struct state state;
 568
 569   state.max_sz = max_sz;
 570   state.sz     = 1;
 571   state.str    = malloc(state.sz);
 572   if (state.str == NULL) {
 573     *ret = NULL;
 574     return -1;
 575   }
 576   state.s = state.str;
 577   state.theend = state.s + state.sz - 1;
 578   state.append_char = as_append_char;
 579   state.reserve     = as_reserve;
 580
 581   st = xyzprintf (&state, format, args);
 582   if (st) {
 583     free (state.str);
 584     *ret = NULL;
 585     return -1;
 586   } else {
 587     char *tmp;
 588
 589     *state.s = '\0';
 590     len = state.s - state.str;
 591     tmp = realloc (state.str, len+1);
 592     if (tmp == NULL) {
 593       free (state.str);
 594       *ret = NULL;
 595       return -1;
 596     }
 597     *ret = tmp;
 598     return len;
 599   }
 600 }
 601 #endif
 602
 603 #ifndef HAVE_VSNPRINTF
 604 int
 605 vsnprintf (char *str, size_t sz, const char *format, va_list args)
 606 {
 607   struct state state;
 608   int ret;
 609   unsigned char *ustr = (unsigned char *)str;
 610
 611   state.max_sz = 0;
 612   state.sz     = sz;
 613   state.str    = ustr;
 614   state.s      = ustr;
 615   state.theend = ustr + sz - 1;
 616   state.append_char = sn_append_char;
 617   state.reserve     = sn_reserve;
 618
 619   ret = xyzprintf (&state, format, args);
 620   *state.s = '\0';
 621   if (ret)
 622     return sz;
 623   else
 624     return state.s - state.str;
 625 }
 626 #endif
 627