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 #endif /* not lint */
  34 #include <sys/cdefs.h>
  35 #include <sys/param.h>
  36 #include <sys/capsicum.h>
  37 #include <sys/conf.h>
  38 #include <sys/ioctl.h>
  39 #include <sys/stat.h>
  40
  41 #include <capsicum_helpers.h>
  42 #include <ctype.h>
  43 #include <err.h>
  44 #include <errno.h>
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #include <unistd.h>
  49 #include "hexdump.h"
  50
  51 enum _vflag vflag = FIRST;
  52
  53 static off_t address;                   /* address/offset in stream */
  54 static off_t eaddress;                  /* end address */
  55
  56 static void print(PR *, u_char *);
  57 static void noseek(void);
  58
  59 void
  60 display(void)
  61 {
  62         FS *fs;
  63         FU *fu;
  64         PR *pr;
  65         int cnt;
  66         u_char *bp;
  67         off_t saveaddress;
  68         u_char savech, *savebp;
  69
  70         savech = 0;
  71         while ((bp = get()))
  72             for (fs = fshead, savebp = bp, saveaddress = address; fs;
  73                 fs = fs->nextfs, bp = savebp, address = saveaddress)
  74                     for (fu = fs->nextfu; fu; fu = fu->nextfu) {
  75                         if (fu->flags&F_IGNORE)
  76                                 break;
  77                         for (cnt = fu->reps; cnt; --cnt)
  78                             for (pr = fu->nextpr; pr; address += pr->bcnt,
  79                                 bp += pr->bcnt, pr = pr->nextpr) {
  80                                     if (eaddress && address >= eaddress &&
  81                                         !(pr->flags & (F_TEXT|F_BPAD)))
  82                                             bpad(pr);
  83                                     if (cnt == 1 && pr->nospace) {
  84                                         savech = *pr->nospace;
  85                                         *pr->nospace = '\0';
  86                                     }
  87                                     print(pr, bp);
  88                                     if (cnt == 1 && pr->nospace)
  89                                         *pr->nospace = savech;
  90                             }
  91                     }
  92         if (endfu) {
  93                 /*
  94                  * If eaddress not set, error or file size was multiple of
  95                  * blocksize, and no partial block ever found.
  96                  */
  97                 if (!eaddress) {
  98                         if (!address)
  99                                 return;
 100                         eaddress = address;
 101                 }
 102                 for (pr = endfu->nextpr; pr; pr = pr->nextpr)
 103                         switch(pr->flags) {
 104                         case F_ADDRESS:
 105                                 (void)printf(pr->fmt, (quad_t)eaddress);
 106                                 break;
 107                         case F_TEXT:
 108                                 (void)printf("%s", pr->fmt);
 109                                 break;
 110                         }
 111         }
 112 }
 113
 114 static void
 115 print(PR *pr, u_char *bp)
 116 {
 117         long double ldbl;
 118            double f8;
 119             float f4;
 120           int16_t s2;
 121           int32_t s4;
 122           int64_t s8;
 123         u_int16_t u2;
 124         u_int32_t u4;
 125         u_int64_t u8;
 126
 127         switch(pr->flags) {
 128         case F_ADDRESS:
 129                 (void)printf(pr->fmt, (quad_t)address);
 130                 break;
 131         case F_BPAD:
 132                 (void)printf(pr->fmt, "");
 133                 break;
 134         case F_C:
 135                 conv_c(pr, bp, eaddress ? eaddress - address :
 136                     blocksize - address % blocksize);
 137                 break;
 138         case F_CHAR:
 139                 (void)printf(pr->fmt, *bp);
 140                 break;
 141         case F_DBL:
 142                 switch(pr->bcnt) {
 143                 case 4:
 144                         bcopy(bp, &f4, sizeof(f4));
 145                         (void)printf(pr->fmt, f4);
 146                         break;
 147                 case 8:
 148                         bcopy(bp, &f8, sizeof(f8));
 149                         (void)printf(pr->fmt, f8);
 150                         break;
 151                 default:
 152                         if (pr->bcnt == sizeof(long double)) {
 153                                 bcopy(bp, &ldbl, sizeof(ldbl));
 154                                 (void)printf(pr->fmt, ldbl);
 155                         }
 156                         break;
 157                 }
 158                 break;
 159         case F_INT:
 160                 switch(pr->bcnt) {
 161                 case 1:
 162                         (void)printf(pr->fmt, (quad_t)(signed char)*bp);
 163                         break;
 164                 case 2:
 165                         bcopy(bp, &s2, sizeof(s2));
 166                         (void)printf(pr->fmt, (quad_t)s2);
 167                         break;
 168                 case 4:
 169                         bcopy(bp, &s4, sizeof(s4));
 170                         (void)printf(pr->fmt, (quad_t)s4);
 171                         break;
 172                 case 8:
 173                         bcopy(bp, &s8, sizeof(s8));
 174                         (void)printf(pr->fmt, s8);
 175                         break;
 176                 }
 177                 break;
 178         case F_P:
 179                 (void)printf(pr->fmt, isprint(*bp) ? *bp : '.');
 180                 break;
 181         case F_STR:
 182                 (void)printf(pr->fmt, (char *)bp);
 183                 break;
 184         case F_TEXT:
 185                 (void)printf("%s", pr->fmt);
 186                 break;
 187         case F_U:
 188                 conv_u(pr, bp);
 189                 break;
 190         case F_UINT:
 191                 switch(pr->bcnt) {
 192                 case 1:
 193                         (void)printf(pr->fmt, (u_quad_t)*bp);
 194                         break;
 195                 case 2:
 196                         bcopy(bp, &u2, sizeof(u2));
 197                         (void)printf(pr->fmt, (u_quad_t)u2);
 198                         break;
 199                 case 4:
 200                         bcopy(bp, &u4, sizeof(u4));
 201                         (void)printf(pr->fmt, (u_quad_t)u4);
 202                         break;
 203                 case 8:
 204                         bcopy(bp, &u8, sizeof(u8));
 205                         (void)printf(pr->fmt, u8);
 206                         break;
 207                 }
 208                 break;
 209         }
 210 }
 211
 212 void
 213 bpad(PR *pr)
 214 {
 215         static char const *spec = " -0+#";
 216         char *p1, *p2;
 217
 218         /*
 219          * Remove all conversion flags; '-' is the only one valid
 220          * with %s, and it's not useful here.
 221          */
 222         pr->flags = F_BPAD;
 223         pr->cchar[0] = 's';
 224         pr->cchar[1] = '\0';
 225         for (p1 = pr->fmt; *p1 != '%'; ++p1);
 226         for (p2 = ++p1; *p1 && strchr(spec, *p1); ++p1);
 227         while ((*p2++ = *p1++));
 228 }
 229
 230 static char **_argv;
 231
 232 u_char *
 233 get(void)
 234 {
 235         static int ateof = 1;
 236         static u_char *curp, *savp;
 237         int n;
 238         int need, nread;
 239         int valid_save = 0;
 240         u_char *tmpp;
 241
 242         if (!curp) {
 243                 if ((curp = calloc(1, blocksize)) == NULL)
 244                         err(1, NULL);
 245                 if ((savp = calloc(1, blocksize)) == NULL)
 246                         err(1, NULL);
 247         } else {
 248                 tmpp = curp;
 249                 curp = savp;
 250                 savp = tmpp;
 251                 address += blocksize;
 252                 valid_save = 1;
 253         }
 254         for (need = blocksize, nread = 0;;) {
 255                 /*
 256                  * if read the right number of bytes, or at EOF for one file,
 257                  * and no other files are available, zero-pad the rest of the
 258                  * block and set the end flag.
 259                  */
 260                 if (!length || (ateof && !next((char **)NULL))) {
 261                         if (odmode && skip > 0)
 262                                 errx(1, "cannot skip past end of input");
 263                         if (need == blocksize)
 264                                 return((u_char *)NULL);
 265                         /*
 266                          * XXX bcmp() is not quite right in the presence
 267                          * of multibyte characters.
 268                          */
 269                         if (need == 0 && vflag != ALL &&
 270                             valid_save &&
 271                             bcmp(curp, savp, nread) == 0) {
 272                                 if (vflag != DUP) {
 273                                         (void)printf("*\n");
 274                                         (void)fflush(stdout);
 275                                 }
 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                                 (void)fflush(stdout);
 308                         }
 309                         vflag = DUP;
 310                         address += blocksize;
 311                         need = blocksize;
 312                         nread = 0;
 313                 }
 314                 else
 315                         nread += n;
 316         }
 317 }
 318
 319 size_t
 320 peek(u_char *buf, size_t nbytes)
 321 {
 322         size_t n, nread;
 323         int c;
 324
 325         if (length != -1 && nbytes > (unsigned int)length)
 326                 nbytes = length;
 327         nread = 0;
 328         while (nread < nbytes && (c = getchar()) != EOF) {
 329                 *buf++ = c;
 330                 nread++;
 331         }
 332         n = nread;
 333         while (n-- > 0) {
 334                 c = *--buf;
 335                 ungetc(c, stdin);
 336         }
 337         return (nread);
 338 }
 339
 340 int
 341 next(char **argv)
 342 {
 343         static int done;
 344         int statok;
 345
 346         if (argv) {
 347                 _argv = argv;
 348                 return(1);
 349         }
 350         for (;;) {
 351                 if (*_argv) {
 352                         done = 1;
 353                         if (!(freopen(*_argv, "r", stdin))) {
 354                                 warn("%s", *_argv);
 355                                 exitval = 1;
 356                                 ++_argv;
 357                                 continue;
 358                         }
 359                         statok = 1;
 360                 } else {
 361                         if (done++)
 362                                 return(0);
 363                         statok = 0;
 364                 }
 365
 366                 if (caph_limit_stream(fileno(stdin), CAPH_READ) < 0)
 367                         err(1, "unable to restrict %s",
 368                             statok ? *_argv : "stdin");
 369
 370                 /*
 371                  * We've opened our last input file; enter capsicum sandbox.
 372                  */
 373                 if (statok == 0 || *(_argv + 1) == NULL) {
 374                         if (caph_enter() < 0)
 375                                 err(1, "unable to enter capability mode");
 376                 }
 377
 378                 if (skip)
 379                         doskip(statok ? *_argv : "stdin", statok);
 380                 if (*_argv)
 381                         ++_argv;
 382                 if (!skip)
 383                         return(1);
 384         }
 385         /* NOTREACHED */
 386 }
 387
 388 void
 389 doskip(const char *fname, int statok)
 390 {
 391         int type;
 392         struct stat sb;
 393
 394         if (statok) {
 395                 if (fstat(fileno(stdin), &sb))
 396                         err(1, "%s", fname);
 397                 if (S_ISREG(sb.st_mode) && skip > sb.st_size) {
 398                         address += sb.st_size;
 399                         skip -= sb.st_size;
 400                         return;
 401                 }
 402         }
 403         if (!statok || S_ISFIFO(sb.st_mode) || S_ISSOCK(sb.st_mode)) {
 404                 noseek();
 405                 return;
 406         }
 407         if (S_ISCHR(sb.st_mode) || S_ISBLK(sb.st_mode)) {
 408                 if (ioctl(fileno(stdin), FIODTYPE, &type))
 409                         err(1, "%s", fname);
 410                 /*
 411                  * Most tape drives don't support seeking,
 412                  * yet fseek() would succeed.
 413                  */
 414                 if (type & D_TAPE) {
 415                         noseek();
 416                         return;
 417                 }
 418         }
 419         if (fseeko(stdin, skip, SEEK_SET)) {
 420                 noseek();
 421                 return;
 422         }
 423         address += skip;
 424         skip = 0;
 425 }
 426
 427 static void
 428 noseek(void)
 429 {
 430         int count;
 431         for (count = 0; count < skip; ++count)
 432                 if (getchar() == EOF)
 433                         break;
 434         address += count;
 435         skip -= count;
 436 }