1 /* 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1987, 1990, 1993, 1994 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 static const char copyright[] = 34 "@(#) Copyright (c) 1987, 1990, 1993, 1994\n\ 35 The Regents of the University of California. All rights reserved.\n"; 36 #endif 37 38 #if 0 39 #ifndef lint 40 static char sccsid[] = "@(#)cmp.c 8.3 (Berkeley) 4/2/94"; 41 #endif 42 #endif 43 44 #include <sys/cdefs.h> 45 __FBSDID("$FreeBSD$"); 46 47 #include <sys/types.h> 48 #include <sys/capsicum.h> 49 #include <sys/stat.h> 50 51 #include <capsicum_helpers.h> 52 #include <err.h> 53 #include <errno.h> 54 #include <fcntl.h> 55 #include <getopt.h> 56 #include <nl_types.h> 57 #include <stdio.h> 58 #include <stdlib.h> 59 #include <string.h> 60 #include <unistd.h> 61 62 #include "extern.h" 63 64 int lflag, sflag, xflag, zflag; 65 66 static const struct option long_opts[] = 67 { 68 {"verbose", no_argument, NULL, 'l'}, 69 {"silent", no_argument, NULL, 's'}, 70 {"quiet", no_argument, NULL, 's'}, 71 {NULL, no_argument, NULL, 0} 72 }; 73 74 static void usage(void); 75 76 int 77 main(int argc, char *argv[]) 78 { 79 struct stat sb1, sb2; 80 off_t skip1, skip2; 81 int ch, fd1, fd2, oflag, special; 82 const char *file1, *file2; 83 cap_rights_t rights; 84 uint32_t fcntls; 85 86 oflag = O_RDONLY; 87 while ((ch = getopt_long(argc, argv, "+hlsxz", long_opts, NULL)) != -1) 88 switch (ch) { 89 case 'h': /* Don't follow symlinks */ 90 oflag |= O_NOFOLLOW; 91 break; 92 case 'l': /* print all differences */ 93 lflag = 1; 94 break; 95 case 's': /* silent run */ 96 sflag = 1; 97 zflag = 1; 98 break; 99 case 'x': /* hex output */ 100 lflag = 1; 101 xflag = 1; 102 break; 103 case 'z': /* compare size first */ 104 zflag = 1; 105 break; 106 case '?': 107 default: 108 usage(); 109 } 110 argv += optind; 111 argc -= optind; 112 113 if (lflag && sflag) 114 errx(ERR_EXIT, "specifying -s with -l or -x is not permitted"); 115 116 if (argc < 2 || argc > 4) 117 usage(); 118 119 /* Backward compatibility -- handle "-" meaning stdin. */ 120 special = 0; 121 if (strcmp(file1 = argv[0], "-") == 0) { 122 special = 1; 123 fd1 = 0; 124 file1 = "stdin"; 125 } 126 else if ((fd1 = open(file1, oflag, 0)) < 0 && errno != EMLINK) { 127 if (!sflag) 128 err(ERR_EXIT, "%s", file1); 129 else 130 exit(ERR_EXIT); 131 } 132 if (strcmp(file2 = argv[1], "-") == 0) { 133 if (special) 134 errx(ERR_EXIT, 135 "standard input may only be specified once"); 136 special = 1; 137 fd2 = 0; 138 file2 = "stdin"; 139 } 140 else if ((fd2 = open(file2, oflag, 0)) < 0 && errno != EMLINK) { 141 if (!sflag) 142 err(ERR_EXIT, "%s", file2); 143 else 144 exit(ERR_EXIT); 145 } 146 147 skip1 = argc > 2 ? strtol(argv[2], NULL, 0) : 0; 148 skip2 = argc == 4 ? strtol(argv[3], NULL, 0) : 0; 149 150 if (fd1 == -1) { 151 if (fd2 == -1) { 152 c_link(file1, skip1, file2, skip2); 153 exit(0); 154 } else if (!sflag) 155 errx(ERR_EXIT, "%s: Not a symbolic link", file2); 156 else 157 exit(ERR_EXIT); 158 } else if (fd2 == -1) { 159 if (!sflag) 160 errx(ERR_EXIT, "%s: Not a symbolic link", file1); 161 else 162 exit(ERR_EXIT); 163 } 164 165 cap_rights_init(&rights, CAP_FCNTL, CAP_FSTAT, CAP_MMAP_R); 166 if (caph_rights_limit(fd1, &rights) < 0) 167 err(ERR_EXIT, "unable to limit rights for %s", file1); 168 if (caph_rights_limit(fd2, &rights) < 0) 169 err(ERR_EXIT, "unable to limit rights for %s", file2); 170 171 /* Required for fdopen(3). */ 172 fcntls = CAP_FCNTL_GETFL; 173 if (caph_fcntls_limit(fd1, fcntls) < 0) 174 err(ERR_EXIT, "unable to limit fcntls for %s", file1); 175 if (caph_fcntls_limit(fd2, fcntls) < 0) 176 err(ERR_EXIT, "unable to limit fcntls for %s", file2); 177 178 if (!special) { 179 cap_rights_init(&rights); 180 if (caph_rights_limit(STDIN_FILENO, &rights) < 0) { 181 err(ERR_EXIT, "unable to limit stdio"); 182 } 183 } 184 185 if (caph_limit_stdout() == -1 || caph_limit_stderr() == -1) 186 err(ERR_EXIT, "unable to limit stdio"); 187 188 caph_cache_catpages(); 189 190 if (caph_enter() < 0) 191 err(ERR_EXIT, "unable to enter capability mode"); 192 193 if (!special) { 194 if (fstat(fd1, &sb1)) { 195 if (!sflag) 196 err(ERR_EXIT, "%s", file1); 197 else 198 exit(ERR_EXIT); 199 } 200 if (!S_ISREG(sb1.st_mode)) 201 special = 1; 202 else { 203 if (fstat(fd2, &sb2)) { 204 if (!sflag) 205 err(ERR_EXIT, "%s", file2); 206 else 207 exit(ERR_EXIT); 208 } 209 if (!S_ISREG(sb2.st_mode)) 210 special = 1; 211 } 212 } 213 214 if (special) 215 c_special(fd1, file1, skip1, fd2, file2, skip2); 216 else { 217 if (zflag && sb1.st_size != sb2.st_size) { 218 if (!sflag) 219 (void) printf("%s %s differ: size\n", 220 file1, file2); 221 exit(DIFF_EXIT); 222 } 223 c_regular(fd1, file1, skip1, sb1.st_size, 224 fd2, file2, skip2, sb2.st_size); 225 } 226 exit(0); 227 } 228 229 static void 230 usage(void) 231 { 232 233 (void)fprintf(stderr, 234 "usage: cmp [-l | -s | -x] [-hz] file1 file2 [skip1 [skip2]]\n"); 235 exit(ERR_EXIT); 236 } 237