1 /* $OpenBSD: file.c,v 1.13 2003/07/02 21:04:09 deraadt Exp $ */ 2 3 /* 4 * file - find type of a file or files - main program. 5 * 6 * Copyright (c) Ian F. Darwin 1986-1995. 7 * Software written by Ian F. Darwin and others; 8 * maintained 1995-present by Christos Zoulas and others. 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 immediately at the beginning of the file, without modification, 15 * this list of conditions, and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 24 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #ifndef lint 34 static char *moduleid = "$OpenBSD: file.c,v 1.13 2003/07/02 21:04:09 deraadt Exp $"; 35 #endif /* lint */ 36 37 #include <stdio.h> 38 #include <stdlib.h> 39 #include <string.h> 40 #include <sys/types.h> 41 #include <sys/param.h> /* for MAXPATHLEN */ 42 #include <sys/stat.h> 43 #include <fcntl.h> /* for open() */ 44 #if (__COHERENT__ >= 0x420) 45 # include <sys/utime.h> 46 #else 47 # ifdef USE_UTIMES 48 # include <sys/time.h> 49 # else 50 # include <utime.h> 51 # endif 52 #endif 53 #include <unistd.h> /* for read() */ 54 #include <err.h> 55 56 #include <netinet/in.h> /* for byte swapping */ 57 58 #include "patchlevel.h" 59 #include "file.h" 60 61 #ifdef S_IFLNK 62 # define USAGE "Usage: %s [-vbczL] [-f namefile] [-m magicfiles] file...\n" 63 #else 64 # define USAGE "Usage: %s [-vbcz] [-f namefile] [-m magicfiles] file...\n" 65 #endif 66 67 #ifndef MAGIC 68 # define MAGIC "/etc/magic" 69 #endif 70 71 int /* Global command-line options */ 72 debug = 0, /* debugging */ 73 bflag = 0, /* Don't print filename */ 74 lflag = 0, /* follow Symlinks (BSD only) */ 75 zflag = 0; /* follow (uncompress) compressed files */ 76 77 int /* Misc globals */ 78 nmagic = 0; /* number of valid magic[]s */ 79 80 struct magic *magic; /* array of magic entries */ 81 82 char *magicfile; /* where magic be found */ 83 84 int lineno; /* line number in the magic file */ 85 86 87 static void unwrap(char *fn); 88 #if 0 89 static int byteconv4(int, int, int); 90 static short byteconv2(int, int, int); 91 #endif 92 93 /* 94 * main - parse arguments and handle options 95 */ 96 int 97 main(int argc, char *argv[]) 98 { 99 int c; 100 int check = 0, didsomefiles = 0, errflg = 0, ret = 0, app = 0; 101 extern char *__progname; 102 103 if (!(magicfile = getenv("MAGIC"))) 104 magicfile = MAGIC; 105 106 while ((c = getopt(argc, argv, "bvcdf:Lm:z")) != -1) 107 switch (c) { 108 case 'v': 109 (void) printf("%s-%d.%d\n", __progname, 110 FILE_VERSION_MAJOR, patchlevel); 111 return 1; 112 case 'b': 113 ++bflag; 114 break; 115 case 'c': 116 ++check; 117 break; 118 case 'd': 119 ++debug; 120 break; 121 case 'f': 122 if (!app) { 123 ret = apprentice(magicfile, check); 124 if (check) 125 exit(ret); 126 app = 1; 127 } 128 unwrap(optarg); 129 ++didsomefiles; 130 break; 131 #ifdef S_IFLNK 132 case 'L': 133 ++lflag; 134 break; 135 #endif 136 case 'm': 137 magicfile = optarg; 138 break; 139 case 'z': 140 zflag++; 141 break; 142 case '?': 143 default: 144 errflg++; 145 break; 146 } 147 148 if (errflg) { 149 (void) fprintf(stderr, USAGE, __progname); 150 exit(2); 151 } 152 153 if (!app) { 154 ret = apprentice(magicfile, check); 155 if (check) 156 exit(ret); 157 app = 1; 158 } 159 160 if (optind == argc) { 161 if (!didsomefiles) { 162 fprintf(stderr, USAGE, __progname); 163 exit(2); 164 } 165 } else { 166 int i, wid, nw; 167 for (wid = 0, i = optind; i < argc; i++) { 168 nw = strlen(argv[i]); 169 if (nw > wid) 170 wid = nw; 171 } 172 for (; optind < argc; optind++) 173 process(argv[optind], wid); 174 } 175 176 return 0; 177 } 178 179 180 /* 181 * unwrap -- read a file of filenames, do each one. 182 */ 183 static void 184 unwrap(fn) 185 char *fn; 186 { 187 char buf[MAXPATHLEN]; 188 FILE *f; 189 int wid = 0, cwid; 190 191 if (strcmp("-", fn) == 0) { 192 f = stdin; 193 wid = 1; 194 } else { 195 if ((f = fopen(fn, "r")) == NULL) { 196 err(1, "Cannot open `%s'", fn); 197 /*NOTREACHED*/ 198 } 199 200 while (fgets(buf, sizeof(buf), f) != NULL) { 201 cwid = strlen(buf) - 1; 202 if (cwid > wid) 203 wid = cwid; 204 } 205 206 rewind(f); 207 } 208 209 while (fgets(buf, sizeof(buf), f) != NULL) { 210 buf[strlen(buf)-1] = '\0'; 211 process(buf, wid); 212 } 213 214 (void) fclose(f); 215 } 216 217 218 #if 0 219 /* 220 * byteconv4 221 * Input: 222 * from 4 byte quantity to convert 223 * same whether to perform byte swapping 224 * big_endian whether we are a big endian host 225 */ 226 static int 227 byteconv4(from, same, big_endian) 228 int from; 229 int same; 230 int big_endian; 231 { 232 if (same) 233 return from; 234 else if (big_endian) /* lsb -> msb conversion on msb */ 235 { 236 union { 237 int i; 238 char c[4]; 239 } retval, tmpval; 240 241 tmpval.i = from; 242 retval.c[0] = tmpval.c[3]; 243 retval.c[1] = tmpval.c[2]; 244 retval.c[2] = tmpval.c[1]; 245 retval.c[3] = tmpval.c[0]; 246 247 return retval.i; 248 } 249 else 250 return ntohl(from); /* msb -> lsb conversion on lsb */ 251 } 252 253 /* 254 * byteconv2 255 * Same as byteconv4, but for shorts 256 */ 257 static short 258 byteconv2(from, same, big_endian) 259 int from; 260 int same; 261 int big_endian; 262 { 263 if (same) 264 return from; 265 else if (big_endian) /* lsb -> msb conversion on msb */ 266 { 267 union { 268 short s; 269 char c[2]; 270 } retval, tmpval; 271 272 tmpval.s = (short) from; 273 retval.c[0] = tmpval.c[1]; 274 retval.c[1] = tmpval.c[0]; 275 276 return retval.s; 277 } 278 else 279 return ntohs(from); /* msb -> lsb conversion on lsb */ 280 } 281 #endif 282 283 /* 284 * process - process input file 285 */ 286 void 287 process(inname, wid) 288 const char *inname; 289 int wid; 290 { 291 int fd = 0; 292 static const char stdname[] = "standard input"; 293 unsigned char buf[HOWMANY+1]; /* one extra for terminating '\0' */ 294 struct stat sb; 295 int nbytes = 0; /* number of bytes read from a datafile */ 296 char match = '\0'; 297 298 if (strcmp("-", inname) == 0) { 299 if (fstat(0, &sb)<0) { 300 err(1, "cannot fstat `%s'", stdname); 301 /*NOTREACHED*/ 302 } 303 inname = stdname; 304 } 305 306 if (wid > 0 && !bflag) 307 (void) printf("%s:%*s ", inname, 308 (int) (wid - strlen(inname)), ""); 309 310 if (inname != stdname) { 311 /* 312 * first try judging the file based on its filesystem status 313 */ 314 if (fsmagic(inname, &sb) != 0) { 315 putchar('\n'); 316 return; 317 } 318 319 if ((fd = open(inname, O_RDONLY)) < 0) { 320 /* We can't open it, but we were able to stat it. */ 321 if (sb.st_mode & 0002) ckfputs("writable, ", stdout); 322 if (sb.st_mode & 0111) ckfputs("executable, ", stdout); 323 ckfprintf(stdout, "can't read `%s' (%s).\n", 324 inname, strerror(errno)); 325 return; 326 } 327 } 328 329 330 /* 331 * try looking at the first HOWMANY bytes 332 */ 333 if ((nbytes = read(fd, (char *)buf, HOWMANY)) == -1) { 334 err(1, "read failed"); 335 /*NOTREACHED*/ 336 } 337 338 if (nbytes == 0) 339 ckfputs("empty", stdout); 340 else { 341 buf[nbytes++] = '\0'; /* null-terminate it */ 342 match = tryit(buf, nbytes, zflag); 343 } 344 345 #ifdef BUILTIN_ELF 346 if (match == 's' && nbytes > 5) 347 tryelf(fd, buf, nbytes); 348 #endif 349 350 if (inname != stdname) { 351 #ifdef RESTORE_TIME 352 /* 353 * Try to restore access, modification times if read it. 354 */ 355 # ifdef USE_UTIMES 356 struct timeval utsbuf[2]; 357 utsbuf[0].tv_sec = sb.st_atime; 358 utsbuf[1].tv_sec = sb.st_mtime; 359 360 (void) utimes(inname, utsbuf); /* don't care if loses */ 361 # else 362 struct utimbuf utbuf; 363 364 utbuf.actime = sb.st_atime; 365 utbuf.modtime = sb.st_mtime; 366 (void) utime(inname, &utbuf); /* don't care if loses */ 367 # endif 368 #endif 369 (void) close(fd); 370 } 371 (void) putchar('\n'); 372 } 373 374 375 int 376 tryit(buf, nb, zflag) 377 unsigned char *buf; 378 int nb, zflag; 379 { 380 /* try compression stuff */ 381 if (zflag && zmagic(buf, nb)) 382 return 'z'; 383 384 /* try tests in /etc/magic (or surrogate magic file) */ 385 if (softmagic(buf, nb)) 386 return 's'; 387 388 /* try known keywords, check whether it is ASCII */ 389 if (ascmagic(buf, nb)) 390 return 'a'; 391 392 /* see if it's international language text */ 393 if (internatmagic(buf, nb)) 394 return 'i'; 395 396 /* abandon hope, all ye who remain here */ 397 ckfputs("data", stdout); 398 return '\0'; 399 } 400