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