usr.bin/hexdump/display.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 1989, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, 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  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #ifndef lint
  33 #if 0
  34 static char sccsid[] = "@(#)display.c   8.1 (Berkeley) 6/6/93";
  35 #endif
  36 #endif /* not lint */
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD$");
  39
  40 #include <sys/param.h>
  41 #include <sys/capsicum.h>
  42 #include <sys/stat.h>
  43
  44 #include <capsicum_helpers.h>
  45 #include <ctype.h>
  46 #include <err.h>
  47 #include <errno.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <unistd.h>
  52 #include "hexdump.h"
  53
  54 enum _vflag vflag = FIRST;
  55
  56 static off_t address;                   /* address/offset in stream */
  57 static off_t eaddress;                  /* end address */
  58
  59 static void print(PR *, u_char *);
  60
  61 void
  62 display(void)
  63 {
  64         FS *fs;
  65         FU *fu;
  66         PR *pr;
  67         int cnt;
  68         u_char *bp;
  69         off_t saveaddress;
  70         u_char savech, *savebp;
  71
  72         savech = 0;
  73         while ((bp = get()))
  74             for (fs = fshead, savebp = bp, saveaddress = address; fs;
  75                 fs = fs->nextfs, bp = savebp, address = saveaddress)
  76                     for (fu = fs->nextfu; fu; fu = fu->nextfu) {
  77                         if (fu->flags&F_IGNORE)
  78                                 break;
  79                         for (cnt = fu->reps; cnt; --cnt)
  80                             for (pr = fu->nextpr; pr; address += pr->bcnt,
  81                                 bp += pr->bcnt, pr = pr->nextpr) {
  82                                     if (eaddress && address >= eaddress &&
  83                                         !(pr->flags & (F_TEXT|F_BPAD)))
  84                                             bpad(pr);
  85                                     if (cnt == 1 && pr->nospace) {
  86                                         savech = *pr->nospace;
  87                                         *pr->nospace = '\0';
  88                                     }
  89                                     print(pr, bp);
  90                                     if (cnt == 1 && pr->nospace)
  91                                         *pr->nospace = savech;
  92                             }
  93                     }
  94         if (endfu) {
  95                 /*
  96                  * If eaddress not set, error or file size was multiple of
  97                  * blocksize, and no partial block ever found.
  98                  */
  99                 if (!eaddress) {
 100                         if (!address)
 101                                 return;
 102                         eaddress = address;
 103                 }
 104                 for (pr = endfu->nextpr; pr; pr = pr->nextpr)
 105                         switch(pr->flags) {
 106                         case F_ADDRESS:
 107                                 (void)printf(pr->fmt, (quad_t)eaddress);
 108                                 break;
 109                         case F_TEXT:
 110                                 (void)printf("%s", pr->fmt);
 111                                 break;
 112                         }
 113         }
 114 }
 115
 116 static void
 117 print(PR *pr, u_char *bp)
 118 {
 119         long double ldbl;
 120            double f8;
 121             float f4;
 122           int16_t s2;
 123            int8_t s8;
 124           int32_t s4;
 125         u_int16_t u2;
 126         u_int32_t u4;
 127         u_int64_t u8;
 128
 129         switch(pr->flags) {
 130         case F_ADDRESS:
 131                 (void)printf(pr->fmt, (quad_t)address);
 132                 break;
 133         case F_BPAD:
 134                 (void)printf(pr->fmt, "");
 135                 break;
 136         case F_C:
 137                 conv_c(pr, bp, eaddress ? eaddress - address :
 138                     blocksize - address % blocksize);
 139                 break;
 140         case F_CHAR:
 141                 (void)printf(pr->fmt, *bp);
 142                 break;
 143         case F_DBL:
 144                 switch(pr->bcnt) {
 145                 case 4:
 146                         bcopy(bp, &f4, sizeof(f4));
 147                         (void)printf(pr->fmt, f4);
 148                         break;
 149                 case 8:
 150                         bcopy(bp, &f8, sizeof(f8));
 151                         (void)printf(pr->fmt, f8);
 152                         break;
 153                 default:
 154                         if (pr->bcnt == sizeof(long double)) {
 155                                 bcopy(bp, &ldbl, sizeof(ldbl));
 156                                 (void)printf(pr->fmt, ldbl);
 157                         }
 158                         break;
 159                 }
 160                 break;
 161         case F_INT:
 162                 switch(pr->bcnt) {
 163                 case 1:
 164                         (void)printf(pr->fmt, (quad_t)(signed char)*bp);
 165                         break;
 166                 case 2:
 167                         bcopy(bp, &s2, sizeof(s2));
 168                         (void)printf(pr->fmt, (quad_t)s2);
 169                         break;
 170                 case 4:
 171                         bcopy(bp, &s4, sizeof(s4));
 172                         (void)printf(pr->fmt, (quad_t)s4);
 173                         break;
 174                 case 8:
 175                         bcopy(bp, &s8, sizeof(s8));
 176                         (void)printf(pr->fmt, s8);
 177                         break;
 178                 }
 179                 break;
 180         case F_P:
 181                 (void)printf(pr->fmt, isprint(*bp) ? *bp : '.');
 182                 break;
 183         case F_STR:
 184                 (void)printf(pr->fmt, (char *)bp);
 185                 break;
 186         case F_TEXT:
 187                 (void)printf("%s", pr->fmt);
 188                 break;
 189         case F_U:
 190                 conv_u(pr, bp);
 191                 break;
 192         case F_UINT:
 193                 switch(pr->bcnt) {
 194                 case 1:
 195                         (void)printf(pr->fmt, (u_quad_t)*bp);
 196                         break;
 197                 case 2:
 198                         bcopy(bp, &u2, sizeof(u2));
 199                         (void)printf(pr->fmt, (u_quad_t)u2);
 200                         break;
 201                 case 4:
 202                         bcopy(bp, &u4, sizeof(u4));
 203                         (void)printf(pr->fmt, (u_quad_t)u4);
 204                         break;
 205                 case 8:
 206                         bcopy(bp, &u8, sizeof(u8));
 207                         (void)printf(pr->fmt, u8);
 208                         break;
 209                 }
 210                 break;
 211         }
 212 }
 213
 214 void
 215 bpad(PR *pr)
 216 {
 217         static char const *spec = " -0+#";
 218         char *p1, *p2;
 219
 220         /*
 221          * Remove all conversion flags; '-' is the only one valid
 222          * with %s, and it's not useful here.
 223          */
 224         pr->flags = F_BPAD;
 225         pr->cchar[0] = 's';
 226         pr->cchar[1] = '\0';
 227         for (p1 = pr->fmt; *p1 != '%'; ++p1);
 228         for (p2 = ++p1; *p1 && strchr(spec, *p1); ++p1);
 229         while ((*p2++ = *p1++));
 230 }
 231
 232 static char **_argv;
 233
 234 u_char *
 235 get(void)
 236 {
 237         static int ateof = 1;
 238         static u_char *curp, *savp;
 239         int n;
 240         int need, nread;
 241         int valid_save = 0;
 242         u_char *tmpp;
 243
 244         if (!curp) {
 245                 if ((curp = calloc(1, blocksize)) == NULL)
 246                         err(1, NULL);
 247                 if ((savp = calloc(1, blocksize)) == NULL)
 248                         err(1, NULL);
 249         } else {
 250                 tmpp = curp;
 251                 curp = savp;
 252                 savp = tmpp;
 253                 address += blocksize;
 254                 valid_save = 1;
 255         }
 256         for (need = blocksize, nread = 0;;) {
 257                 /*
 258                  * if read the right number of bytes, or at EOF for one file,
 259                  * and no other files are available, zero-pad the rest of the
 260                  * block and set the end flag.
 261                  */
 262                 if (!length || (ateof && !next((char **)NULL))) {
 263                         if (odmode && address < skip)
 264                                 errx(1, "cannot skip past end of input");
 265                         if (need == blocksize)
 266                                 return((u_char *)NULL);
 267                         /*
 268                          * XXX bcmp() is not quite right in the presence
 269                          * of multibyte characters.
 270                          */
 271                         if (vflag != ALL &&
 272                             valid_save &&
 273                             bcmp(curp, savp, nread) == 0) {
 274                                 if (vflag != DUP)
 275                                         (void)printf("*\n");
 276                                 return((u_char *)NULL);
 277                         }
 278                         bzero((char *)curp + nread, need);
 279                         eaddress = address + nread;
 280                         return(curp);
 281                 }
 282                 n = fread((char *)curp + nread, sizeof(u_char),
 283                     length == -1 ? need : MIN(length, need), stdin);
 284                 if (!n) {
 285                         if (ferror(stdin))
 286                                 warn("%s", _argv[-1]);
 287                         ateof = 1;
 288                         continue;
 289                 }
 290                 ateof = 0;
 291                 if (length != -1)
 292                         length -= n;
 293                 if (!(need -= n)) {
 294                         /*
 295                          * XXX bcmp() is not quite right in the presence
 296                          * of multibyte characters.
 297                          */
 298                         if (vflag == ALL || vflag == FIRST ||
 299                             valid_save == 0 ||
 300                             bcmp(curp, savp, blocksize) != 0) {
 301                                 if (vflag == DUP || vflag == FIRST)
 302                                         vflag = WAIT;
 303                                 return(curp);
 304                         }
 305                         if (vflag == WAIT)
 306                                 (void)printf("*\n");
 307                         vflag = DUP;
 308                         address += blocksize;
 309                         need = blocksize;
 310                         nread = 0;
 311                 }
 312                 else
 313                         nread += n;
 314         }
 315 }
 316
 317 size_t
 318 peek(u_char *buf, size_t nbytes)
 319 {
 320         size_t n, nread;
 321         int c;
 322
 323         if (length != -1 && nbytes > (unsigned int)length)
 324                 nbytes = length;
 325         nread = 0;
 326         while (nread < nbytes && (c = getchar()) != EOF) {
 327                 *buf++ = c;
 328                 nread++;
 329         }
 330         n = nread;
 331         while (n-- > 0) {
 332                 c = *--buf;
 333                 ungetc(c, stdin);
 334         }
 335         return (nread);
 336 }
 337
 338 int
 339 next(char **argv)
 340 {
 341         static int done;
 342         int statok;
 343
 344         if (argv) {
 345                 _argv = argv;
 346                 return(1);
 347         }
 348         for (;;) {
 349                 if (*_argv) {
 350                         done = 1;
 351                         if (!(freopen(*_argv, "r", stdin))) {
 352                                 warn("%s", *_argv);
 353                                 exitval = 1;
 354                                 ++_argv;
 355                                 continue;
 356                         }
 357                         statok = 1;
 358                 } else {
 359                         if (done++)
 360                                 return(0);
 361                         statok = 0;
 362                 }
 363
 364                 if (caph_limit_stream(fileno(stdin), CAPH_READ) < 0)
 365                         err(1, "unable to restrict %s",
 366                             statok ? *_argv : "stdin");
 367
 368                 /*
 369                  * We've opened our last input file; enter capsicum sandbox.
 370                  */
 371                 if (statok == 0 || *(_argv + 1) == NULL) {
 372                         if (cap_enter() < 0 && errno != ENOSYS)
 373                                 err(1, "unable to enter capability mode");
 374                 }
 375
 376                 if (skip)
 377                         doskip(statok ? *_argv : "stdin", statok);
 378                 if (*_argv)
 379                         ++_argv;
 380                 if (!skip)
 381                         return(1);
 382         }
 383         /* NOTREACHED */
 384 }
 385
 386 void
 387 doskip(const char *fname, int statok)
 388 {
 389         int cnt;
 390         struct stat sb;
 391
 392         if (statok) {
 393                 if (fstat(fileno(stdin), &sb))
 394                         err(1, "%s", fname);
 395                 if (S_ISREG(sb.st_mode) && skip > sb.st_size) {
 396                         address += sb.st_size;
 397                         skip -= sb.st_size;
 398                         return;
 399                 }
 400         }
 401         if (statok && S_ISREG(sb.st_mode)) {
 402                 if (fseeko(stdin, skip, SEEK_SET))
 403                         err(1, "%s", fname);
 404                 address += skip;
 405                 skip = 0;
 406         } else {
 407                 for (cnt = 0; cnt < skip; ++cnt)
 408                         if (getchar() == EOF)
 409                                 break;
 410                 address += cnt;
 411                 skip -= cnt;
 412         }
 413 }