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 * 4. 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 <err.h> 50 #include <errno.h> 51 #include <fcntl.h> 52 #include <nl_types.h> 53 #include <stdio.h> 54 #include <stdlib.h> 55 #include <string.h> 56 #include <termios.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 unsigned long cmd; 74 uint32_t fcntls; 75 76 oflag = O_RDONLY; 77 while ((ch = getopt(argc, argv, "hlsxz")) != -1) 78 switch (ch) { 79 case 'h': /* Don't follow symlinks */ 80 oflag |= O_NOFOLLOW; 81 break; 82 case 'l': /* print all differences */ 83 lflag = 1; 84 break; 85 case 's': /* silent run */ 86 sflag = 1; 87 zflag = 1; 88 break; 89 case 'x': /* hex output */ 90 lflag = 1; 91 xflag = 1; 92 break; 93 case 'z': /* compare size first */ 94 zflag = 1; 95 break; 96 case '?': 97 default: 98 usage(); 99 } 100 argv += optind; 101 argc -= optind; 102 103 if (lflag && sflag) 104 errx(ERR_EXIT, "specifying -s with -l or -x is not permitted"); 105 106 if (argc < 2 || argc > 4) 107 usage(); 108 109 /* Backward compatibility -- handle "-" meaning stdin. */ 110 special = 0; 111 if (strcmp(file1 = argv[0], "-") == 0) { 112 special = 1; 113 fd1 = 0; 114 file1 = "stdin"; 115 } 116 else if ((fd1 = open(file1, oflag, 0)) < 0 && errno != EMLINK) { 117 if (!sflag) 118 err(ERR_EXIT, "%s", file1); 119 else 120 exit(ERR_EXIT); 121 } 122 if (strcmp(file2 = argv[1], "-") == 0) { 123 if (special) 124 errx(ERR_EXIT, 125 "standard input may only be specified once"); 126 special = 1; 127 fd2 = 0; 128 file2 = "stdin"; 129 } 130 else if ((fd2 = open(file2, oflag, 0)) < 0 && errno != EMLINK) { 131 if (!sflag) 132 err(ERR_EXIT, "%s", file2); 133 else 134 exit(ERR_EXIT); 135 } 136 137 skip1 = argc > 2 ? strtol(argv[2], NULL, 0) : 0; 138 skip2 = argc == 4 ? strtol(argv[3], NULL, 0) : 0; 139 140 if (fd1 == -1) { 141 if (fd2 == -1) { 142 c_link(file1, skip1, file2, skip2); 143 exit(0); 144 } else if (!sflag) 145 errx(ERR_EXIT, "%s: Not a symbolic link", file2); 146 else 147 exit(ERR_EXIT); 148 } else if (fd2 == -1) { 149 if (!sflag) 150 errx(ERR_EXIT, "%s: Not a symbolic link", file1); 151 else 152 exit(ERR_EXIT); 153 } 154 155 cap_rights_init(&rights, CAP_FCNTL, CAP_FSTAT, CAP_MMAP_R); 156 if (cap_rights_limit(fd1, &rights) < 0 && errno != ENOSYS) 157 err(ERR_EXIT, "unable to limit rights for %s", file1); 158 if (cap_rights_limit(fd2, &rights) < 0 && errno != ENOSYS) 159 err(ERR_EXIT, "unable to limit rights for %s", file2); 160 161 /* Required for fdopen(3). */ 162 fcntls = CAP_FCNTL_GETFL; 163 if (cap_fcntls_limit(fd1, fcntls) < 0 && errno != ENOSYS) 164 err(ERR_EXIT, "unable to limit fcntls for %s", file1); 165 if (cap_fcntls_limit(fd2, fcntls) < 0 && errno != ENOSYS) 166 err(ERR_EXIT, "unable to limit fcntls for %s", file2); 167 168 cap_rights_init(&rights, CAP_FSTAT, CAP_WRITE, CAP_IOCTL); 169 if (cap_rights_limit(STDOUT_FILENO, &rights) < 0 && errno != ENOSYS) 170 err(ERR_EXIT, "unable to limit rights for stdout"); 171 172 /* Required for printf(3) via isatty(3). */ 173 cmd = TIOCGETA; 174 if (cap_ioctls_limit(STDOUT_FILENO, &cmd, 1) < 0 && errno != ENOSYS) 175 err(ERR_EXIT, "unable to limit ioctls for stdout"); 176 177 /* 178 * Cache NLS data, for strerror, for err(3), before entering capability 179 * mode. 180 */ 181 (void)catopen("libc", NL_CAT_LOCALE); 182 183 if (cap_enter() < 0 && errno != ENOSYS) 184 err(ERR_EXIT, "unable to enter capability mode"); 185 186 if (!special) { 187 if (fstat(fd1, &sb1)) { 188 if (!sflag) 189 err(ERR_EXIT, "%s", file1); 190 else 191 exit(ERR_EXIT); 192 } 193 if (!S_ISREG(sb1.st_mode)) 194 special = 1; 195 else { 196 if (fstat(fd2, &sb2)) { 197 if (!sflag) 198 err(ERR_EXIT, "%s", file2); 199 else 200 exit(ERR_EXIT); 201 } 202 if (!S_ISREG(sb2.st_mode)) 203 special = 1; 204 } 205 } 206 207 if (special) 208 c_special(fd1, file1, skip1, fd2, file2, skip2); 209 else { 210 if (zflag && sb1.st_size != sb2.st_size) { 211 if (!sflag) 212 (void) printf("%s %s differ: size\n", 213 file1, file2); 214 exit(DIFF_EXIT); 215 } 216 c_regular(fd1, file1, skip1, sb1.st_size, 217 fd2, file2, skip2, sb2.st_size); 218 } 219 exit(0); 220 } 221 222 static void 223 usage(void) 224 { 225 226 (void)fprintf(stderr, 227 "usage: cmp [-l | -s | -x] [-hz] file1 file2 [skip1 [skip2]]\n"); 228 exit(ERR_EXIT); 229 } 230