1 /* 2 * Copyright (c) 1987, 1990, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #ifndef lint 31 static const char copyright[] = 32 "@(#) Copyright (c) 1987, 1990, 1993, 1994\n\ 33 The Regents of the University of California. All rights reserved.\n"; 34 #endif 35 36 #if 0 37 #ifndef lint 38 static char sccsid[] = "@(#)cmp.c 8.3 (Berkeley) 4/2/94"; 39 #endif 40 #endif 41 42 #include <sys/cdefs.h> 43 __FBSDID("$FreeBSD$"); 44 45 #include <sys/types.h> 46 #include <sys/capsicum.h> 47 #include <sys/stat.h> 48 49 #include <capsicum_helpers.h> 50 #include <err.h> 51 #include <errno.h> 52 #include <fcntl.h> 53 #include <nl_types.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <unistd.h> 58 59 #include "extern.h" 60 61 int lflag, sflag, xflag, zflag; 62 63 static void usage(void); 64 65 int 66 main(int argc, char *argv[]) 67 { 68 struct stat sb1, sb2; 69 off_t skip1, skip2; 70 int ch, fd1, fd2, oflag, special; 71 const char *file1, *file2; 72 cap_rights_t rights; 73 uint32_t fcntls; 74 75 oflag = O_RDONLY; 76 while ((ch = getopt(argc, argv, "hlsxz")) != -1) 77 switch (ch) { 78 case 'h': /* Don't follow symlinks */ 79 oflag |= O_NOFOLLOW; 80 break; 81 case 'l': /* print all differences */ 82 lflag = 1; 83 break; 84 case 's': /* silent run */ 85 sflag = 1; 86 zflag = 1; 87 break; 88 case 'x': /* hex output */ 89 lflag = 1; 90 xflag = 1; 91 break; 92 case 'z': /* compare size first */ 93 zflag = 1; 94 break; 95 case '?': 96 default: 97 usage(); 98 } 99 argv += optind; 100 argc -= optind; 101 102 if (lflag && sflag) 103 errx(ERR_EXIT, "specifying -s with -l or -x is not permitted"); 104 105 if (argc < 2 || argc > 4) 106 usage(); 107 108 /* Backward compatibility -- handle "-" meaning stdin. */ 109 special = 0; 110 if (strcmp(file1 = argv[0], "-") == 0) { 111 special = 1; 112 fd1 = 0; 113 file1 = "stdin"; 114 } 115 else if ((fd1 = open(file1, oflag, 0)) < 0 && errno != EMLINK) { 116 if (!sflag) 117 err(ERR_EXIT, "%s", file1); 118 else 119 exit(ERR_EXIT); 120 } 121 if (strcmp(file2 = argv[1], "-") == 0) { 122 if (special) 123 errx(ERR_EXIT, 124 "standard input may only be specified once"); 125 special = 1; 126 fd2 = 0; 127 file2 = "stdin"; 128 } 129 else if ((fd2 = open(file2, oflag, 0)) < 0 && errno != EMLINK) { 130 if (!sflag) 131 err(ERR_EXIT, "%s", file2); 132 else 133 exit(ERR_EXIT); 134 } 135 136 skip1 = argc > 2 ? strtol(argv[2], NULL, 0) : 0; 137 skip2 = argc == 4 ? strtol(argv[3], NULL, 0) : 0; 138 139 if (fd1 == -1) { 140 if (fd2 == -1) { 141 c_link(file1, skip1, file2, skip2); 142 exit(0); 143 } else if (!sflag) 144 errx(ERR_EXIT, "%s: Not a symbolic link", file2); 145 else 146 exit(ERR_EXIT); 147 } else if (fd2 == -1) { 148 if (!sflag) 149 errx(ERR_EXIT, "%s: Not a symbolic link", file1); 150 else 151 exit(ERR_EXIT); 152 } 153 154 cap_rights_init(&rights, CAP_FCNTL, CAP_FSTAT, CAP_MMAP_R); 155 if (cap_rights_limit(fd1, &rights) < 0 && errno != ENOSYS) 156 err(ERR_EXIT, "unable to limit rights for %s", file1); 157 if (cap_rights_limit(fd2, &rights) < 0 && errno != ENOSYS) 158 err(ERR_EXIT, "unable to limit rights for %s", file2); 159 160 /* Required for fdopen(3). */ 161 fcntls = CAP_FCNTL_GETFL; 162 if (cap_fcntls_limit(fd1, fcntls) < 0 && errno != ENOSYS) 163 err(ERR_EXIT, "unable to limit fcntls for %s", file1); 164 if (cap_fcntls_limit(fd2, fcntls) < 0 && errno != ENOSYS) 165 err(ERR_EXIT, "unable to limit fcntls for %s", file2); 166 167 if (!special) { 168 cap_rights_init(&rights); 169 if (cap_rights_limit(STDIN_FILENO, &rights) < 0 && 170 errno != ENOSYS) { 171 err(ERR_EXIT, "unable to limit stdio"); 172 } 173 } 174 175 if (caph_limit_stdout() == -1 || caph_limit_stderr() == -1) 176 err(ERR_EXIT, "unable to limit stdio"); 177 178 caph_cache_catpages(); 179 180 if (cap_enter() < 0 && errno != ENOSYS) 181 err(ERR_EXIT, "unable to enter capability mode"); 182 183 if (!special) { 184 if (fstat(fd1, &sb1)) { 185 if (!sflag) 186 err(ERR_EXIT, "%s", file1); 187 else 188 exit(ERR_EXIT); 189 } 190 if (!S_ISREG(sb1.st_mode)) 191 special = 1; 192 else { 193 if (fstat(fd2, &sb2)) { 194 if (!sflag) 195 err(ERR_EXIT, "%s", file2); 196 else 197 exit(ERR_EXIT); 198 } 199 if (!S_ISREG(sb2.st_mode)) 200 special = 1; 201 } 202 } 203 204 if (special) 205 c_special(fd1, file1, skip1, fd2, file2, skip2); 206 else { 207 if (zflag && sb1.st_size != sb2.st_size) { 208 if (!sflag) 209 (void) printf("%s %s differ: size\n", 210 file1, file2); 211 exit(DIFF_EXIT); 212 } 213 c_regular(fd1, file1, skip1, sb1.st_size, 214 fd2, file2, skip2, sb2.st_size); 215 } 216 exit(0); 217 } 218 219 static void 220 usage(void) 221 { 222 223 (void)fprintf(stderr, 224 "usage: cmp [-l | -s | -x] [-hz] file1 file2 [skip1 [skip2]]\n"); 225 exit(ERR_EXIT); 226 } 227