bin/cat/cat.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  * This code is derived from software contributed to Berkeley by
   8  * Kevin Fall.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #if 0
  36 #ifndef lint
  37 static char const copyright[] =
  38 "@(#) Copyright (c) 1989, 1993\n\
  39         The Regents of the University of California.  All rights reserved.\n";
  40 #endif /* not lint */
  41 #endif
  42
  43 #ifndef lint
  44 #if 0
  45 static char sccsid[] = "@(#)cat.c       8.2 (Berkeley) 4/27/95";
  46 #endif
  47 #endif /* not lint */
  48 #include <sys/cdefs.h>
  49 __FBSDID("$FreeBSD$");
  50
  51 #include <sys/capsicum.h>
  52 #include <sys/param.h>
  53 #include <sys/stat.h>
  54 #ifndef NO_UDOM_SUPPORT
  55 #include <sys/socket.h>
  56 #include <sys/un.h>
  57 #include <netdb.h>
  58 #endif
  59
  60 #include <capsicum_helpers.h>
  61 #include <ctype.h>
  62 #include <err.h>
  63 #include <errno.h>
  64 #include <fcntl.h>
  65 #include <locale.h>
  66 #include <stdio.h>
  67 #include <stdlib.h>
  68 #include <string.h>
  69 #include <unistd.h>
  70 #include <wchar.h>
  71 #include <wctype.h>
  72
  73 #include <libcasper.h>
  74 #include <casper/cap_fileargs.h>
  75 #include <casper/cap_net.h>
  76
  77 static int bflag, eflag, lflag, nflag, sflag, tflag, vflag;
  78 static int rval;
  79 static const char *filename;
  80 static fileargs_t *fa;
  81
  82 static void usage(void) __dead2;
  83 static void scanfiles(char *argv[], int cooked);
  84 #ifndef BOOTSTRAP_CAT
  85 static void cook_cat(FILE *);
  86 #endif
  87 static void raw_cat(int);
  88
  89 #ifndef NO_UDOM_SUPPORT
  90 static cap_channel_t *capnet;
  91
  92 static int udom_open(const char *path, int flags);
  93 #endif
  94
  95 /*
  96  * Memory strategy threshold, in pages: if physmem is larger than this,
  97  * use a large buffer.
  98  */
  99 #define PHYSPAGES_THRESHOLD (32 * 1024)
 100
 101 /* Maximum buffer size in bytes - do not allow it to grow larger than this. */
 102 #define BUFSIZE_MAX (2 * 1024 * 1024)
 103
 104 /*
 105  * Small (default) buffer size in bytes. It's inefficient for this to be
 106  * smaller than MAXPHYS.
 107  */
 108 #define BUFSIZE_SMALL (MAXPHYS)
 109
 110
 111 /*
 112  * For the bootstrapped cat binary (needed for locked appending to METALOG), we
 113  * disable all flags except -l and -u to avoid non-portable function calls.
 114  * In the future we may instead want to write a small portable bootstrap tool
 115  * that locks the output file before writing to it. However, for now
 116  * bootstrapping cat without multibyte support is the simpler solution.
 117  */
 118 #ifdef BOOTSTRAP_CAT
 119 #define SUPPORTED_FLAGS "lu"
 120 #else
 121 #define SUPPORTED_FLAGS "belnstuv"
 122 #endif
 123
 124 #ifndef NO_UDOM_SUPPORT
 125 static void
 126 init_casper_net(cap_channel_t *casper)
 127 {
 128         cap_net_limit_t *limit;
 129         int familylimit;
 130
 131         capnet = cap_service_open(casper, "system.net");
 132         if (capnet == NULL)
 133                 err(EXIT_FAILURE, "unable to create network service");
 134
 135         limit = cap_net_limit_init(capnet, CAPNET_NAME2ADDR |
 136             CAPNET_CONNECTDNS);
 137         if (limit == NULL)
 138                 err(EXIT_FAILURE, "unable to create limits");
 139
 140         familylimit = AF_LOCAL;
 141         cap_net_limit_name2addr_family(limit, &familylimit, 1);
 142
 143         if (cap_net_limit(limit) < 0)
 144                 err(EXIT_FAILURE, "unable to apply limits");
 145 }
 146 #endif
 147
 148 static void
 149 init_casper(int argc, char *argv[])
 150 {
 151         cap_channel_t *casper;
 152         cap_rights_t rights;
 153
 154         casper = cap_init();
 155         if (casper == NULL)
 156                 err(EXIT_FAILURE, "unable to create Casper");
 157
 158         fa = fileargs_cinit(casper, argc, argv, O_RDONLY, 0,
 159             cap_rights_init(&rights, CAP_READ | CAP_FSTAT | CAP_FCNTL),
 160             FA_OPEN | FA_REALPATH);
 161         if (fa == NULL)
 162                 err(EXIT_FAILURE, "unable to create fileargs");
 163
 164 #ifndef NO_UDOM_SUPPORT
 165         init_casper_net(casper);
 166 #endif
 167
 168         cap_close(casper);
 169 }
 170
 171 int
 172 main(int argc, char *argv[])
 173 {
 174         int ch;
 175         struct flock stdout_lock;
 176
 177         setlocale(LC_CTYPE, "");
 178
 179         while ((ch = getopt(argc, argv, SUPPORTED_FLAGS)) != -1)
 180                 switch (ch) {
 181                 case 'b':
 182                         bflag = nflag = 1;      /* -b implies -n */
 183                         break;
 184                 case 'e':
 185                         eflag = vflag = 1;      /* -e implies -v */
 186                         break;
 187                 case 'l':
 188                         lflag = 1;
 189                         break;
 190                 case 'n':
 191                         nflag = 1;
 192                         break;
 193                 case 's':
 194                         sflag = 1;
 195                         break;
 196                 case 't':
 197                         tflag = vflag = 1;      /* -t implies -v */
 198                         break;
 199                 case 'u':
 200                         setbuf(stdout, NULL);
 201                         break;
 202                 case 'v':
 203                         vflag = 1;
 204                         break;
 205                 default:
 206                         usage();
 207                 }
 208         argv += optind;
 209         argc -= optind;
 210
 211         if (lflag) {
 212                 stdout_lock.l_len = 0;
 213                 stdout_lock.l_start = 0;
 214                 stdout_lock.l_type = F_WRLCK;
 215                 stdout_lock.l_whence = SEEK_SET;
 216                 if (fcntl(STDOUT_FILENO, F_SETLKW, &stdout_lock) == -1)
 217                         err(EXIT_FAILURE, "stdout");
 218         }
 219
 220         init_casper(argc, argv);
 221
 222         caph_cache_catpages();
 223
 224         if (caph_enter_casper() < 0)
 225                 err(EXIT_FAILURE, "capsicum");
 226
 227         if (bflag || eflag || nflag || sflag || tflag || vflag)
 228                 scanfiles(argv, 1);
 229         else
 230                 scanfiles(argv, 0);
 231         if (fclose(stdout))
 232                 err(1, "stdout");
 233         exit(rval);
 234         /* NOTREACHED */
 235 }
 236
 237 static void
 238 usage(void)
 239 {
 240
 241         fprintf(stderr, "usage: cat [-" SUPPORTED_FLAGS "] [file ...]\n");
 242         exit(1);
 243         /* NOTREACHED */
 244 }
 245
 246 static void
 247 scanfiles(char *argv[], int cooked __unused)
 248 {
 249         int fd, i;
 250         char *path;
 251 #ifndef BOOTSTRAP_CAT
 252         FILE *fp;
 253 #endif
 254
 255         i = 0;
 256         fd = -1;
 257         while ((path = argv[i]) != NULL || i == 0) {
 258                 if (path == NULL || strcmp(path, "-") == 0) {
 259                         filename = "stdin";
 260                         fd = STDIN_FILENO;
 261                 } else {
 262                         filename = path;
 263                         fd = fileargs_open(fa, path);
 264 #ifndef NO_UDOM_SUPPORT
 265                         if (fd < 0 && errno == EOPNOTSUPP)
 266                                 fd = udom_open(path, O_RDONLY);
 267 #endif
 268                 }
 269                 if (fd < 0) {
 270                         warn("%s", path);
 271                         rval = 1;
 272 #ifndef BOOTSTRAP_CAT
 273                 } else if (cooked) {
 274                         if (fd == STDIN_FILENO)
 275                                 cook_cat(stdin);
 276                         else {
 277                                 fp = fdopen(fd, "r");
 278                                 cook_cat(fp);
 279                                 fclose(fp);
 280                         }
 281 #endif
 282                 } else {
 283                         raw_cat(fd);
 284                         if (fd != STDIN_FILENO)
 285                                 close(fd);
 286                 }
 287                 if (path == NULL)
 288                         break;
 289                 ++i;
 290         }
 291 }
 292
 293 #ifndef BOOTSTRAP_CAT
 294 static void
 295 cook_cat(FILE *fp)
 296 {
 297         int ch, gobble, line, prev;
 298         wint_t wch;
 299
 300         /* Reset EOF condition on stdin. */
 301         if (fp == stdin && feof(stdin))
 302                 clearerr(stdin);
 303
 304         line = gobble = 0;
 305         for (prev = '\n'; (ch = getc(fp)) != EOF; prev = ch) {
 306                 if (prev == '\n') {
 307                         if (sflag) {
 308                                 if (ch == '\n') {
 309                                         if (gobble)
 310                                                 continue;
 311                                         gobble = 1;
 312                                 } else
 313                                         gobble = 0;
 314                         }
 315                         if (nflag) {
 316                                 if (!bflag || ch != '\n') {
 317                                         (void)fprintf(stdout, "%6d\t", ++line);
 318                                         if (ferror(stdout))
 319                                                 break;
 320                                 } else if (eflag) {
 321                                         (void)fprintf(stdout, "%6s\t", "");
 322                                         if (ferror(stdout))
 323                                                 break;
 324                                 }
 325                         }
 326                 }
 327                 if (ch == '\n') {
 328                         if (eflag && putchar('$') == EOF)
 329                                 break;
 330                 } else if (ch == '\t') {
 331                         if (tflag) {
 332                                 if (putchar('^') == EOF || putchar('I') == EOF)
 333                                         break;
 334                                 continue;
 335                         }
 336                 } else if (vflag) {
 337                         (void)ungetc(ch, fp);
 338                         /*
 339                          * Our getwc(3) doesn't change file position
 340                          * on error.
 341                          */
 342                         if ((wch = getwc(fp)) == WEOF) {
 343                                 if (ferror(fp) && errno == EILSEQ) {
 344                                         clearerr(fp);
 345                                         /* Resync attempt. */
 346                                         memset(&fp->_mbstate, 0, sizeof(mbstate_t));
 347                                         if ((ch = getc(fp)) == EOF)
 348                                                 break;
 349                                         wch = ch;
 350                                         goto ilseq;
 351                                 } else
 352                                         break;
 353                         }
 354                         if (!iswascii(wch) && !iswprint(wch)) {
 355 ilseq:
 356                                 if (putchar('M') == EOF || putchar('-') == EOF)
 357                                         break;
 358                                 wch = toascii(wch);
 359                         }
 360                         if (iswcntrl(wch)) {
 361                                 ch = toascii(wch);
 362                                 ch = (ch == '\177') ? '?' : (ch | 0100);
 363                                 if (putchar('^') == EOF || putchar(ch) == EOF)
 364                                         break;
 365                                 continue;
 366                         }
 367                         if (putwchar(wch) == WEOF)
 368                                 break;
 369                         ch = -1;
 370                         continue;
 371                 }
 372                 if (putchar(ch) == EOF)
 373                         break;
 374         }
 375         if (ferror(fp)) {
 376                 warn("%s", filename);
 377                 rval = 1;
 378                 clearerr(fp);
 379         }
 380         if (ferror(stdout))
 381                 err(1, "stdout");
 382 }
 383 #endif /* BOOTSTRAP_CAT */
 384
 385 static void
 386 raw_cat(int rfd)
 387 {
 388         long pagesize;
 389         int off, wfd;
 390         ssize_t nr, nw;
 391         static size_t bsize;
 392         static char *buf = NULL;
 393         struct stat sbuf;
 394
 395         wfd = fileno(stdout);
 396         if (buf == NULL) {
 397                 if (fstat(wfd, &sbuf))
 398                         err(1, "stdout");
 399                 if (S_ISREG(sbuf.st_mode)) {
 400                         /* If there's plenty of RAM, use a large copy buffer */
 401                         if (sysconf(_SC_PHYS_PAGES) > PHYSPAGES_THRESHOLD)
 402                                 bsize = MIN(BUFSIZE_MAX, MAXPHYS * 8);
 403                         else
 404                                 bsize = BUFSIZE_SMALL;
 405                 } else {
 406                         bsize = sbuf.st_blksize;
 407                         pagesize = sysconf(_SC_PAGESIZE);
 408                         if (pagesize > 0)
 409                                 bsize = MAX(bsize, (size_t)pagesize);
 410                 }
 411                 if ((buf = malloc(bsize)) == NULL)
 412                         err(1, "malloc() failure of IO buffer");
 413         }
 414         while ((nr = read(rfd, buf, bsize)) > 0)
 415                 for (off = 0; nr; nr -= nw, off += nw)
 416                         if ((nw = write(wfd, buf + off, (size_t)nr)) < 0)
 417                                 err(1, "stdout");
 418         if (nr < 0) {
 419                 warn("%s", filename);
 420                 rval = 1;
 421         }
 422 }
 423
 424 #ifndef NO_UDOM_SUPPORT
 425
 426 static int
 427 udom_open(const char *path, int flags)
 428 {
 429         struct addrinfo hints, *res, *res0;
 430         char rpath[PATH_MAX];
 431         int error, fd, serrno;
 432         cap_rights_t rights;
 433
 434         /*
 435          * Construct the unix domain socket address and attempt to connect.
 436          */
 437         bzero(&hints, sizeof(hints));
 438         hints.ai_family = AF_LOCAL;
 439         fd = -1;
 440
 441         if (fileargs_realpath(fa, path, rpath) == NULL)
 442                 return (-1);
 443
 444         error = cap_getaddrinfo(capnet, rpath, NULL, &hints, &res0);
 445         if (error) {
 446                 warn("%s", gai_strerror(error));
 447                 errno = EINVAL;
 448                 return (-1);
 449         }
 450         cap_rights_init(&rights, CAP_CONNECT, CAP_READ, CAP_WRITE,
 451             CAP_SHUTDOWN, CAP_FSTAT, CAP_FCNTL);
 452         for (res = res0; res != NULL; res = res->ai_next) {
 453                 fd = socket(res->ai_family, res->ai_socktype,
 454                     res->ai_protocol);
 455                 if (fd < 0) {
 456                         serrno = errno;
 457                         freeaddrinfo(res0);
 458                         errno = serrno;
 459                         return (-1);
 460                 }
 461                 if (caph_rights_limit(fd, &rights) < 0) {
 462                         serrno = errno;
 463                         close(fd);
 464                         freeaddrinfo(res0);
 465                         errno = serrno;
 466                         return (-1);
 467                 }
 468                 error = cap_connect(capnet, fd, res->ai_addr, res->ai_addrlen);
 469                 if (error == 0)
 470                         break;
 471                 else {
 472                         serrno = errno;
 473                         close(fd);
 474                         fd = -1;
 475                 }
 476         }
 477         freeaddrinfo(res0);
 478
 479         /*
 480          * handle the open flags by shutting down appropriate directions
 481          */
 482         if (fd >= 0) {
 483                 switch(flags & O_ACCMODE) {
 484                 case O_RDONLY:
 485                         cap_rights_clear(&rights, CAP_WRITE);
 486                         if (shutdown(fd, SHUT_WR) == -1)
 487                                 warn(NULL);
 488                         break;
 489                 case O_WRONLY:
 490                         cap_rights_clear(&rights, CAP_READ);
 491                         if (shutdown(fd, SHUT_RD) == -1)
 492                                 warn(NULL);
 493                         break;
 494                 default:
 495                         break;
 496                 }
 497
 498                 cap_rights_clear(&rights, CAP_CONNECT, CAP_SHUTDOWN);
 499                 if (caph_rights_limit(fd, &rights) < 0) {
 500                         serrno = errno;
 501                         close(fd);
 502                         errno = serrno;
 503                         return (-1);
 504                 }
 505         } else {
 506                 errno = serrno;
 507         }
 508         return (fd);
 509 }
 510
 511 #endif