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
main(int argc,char * argv[])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 (cap_rights_limit(fd1, &rights) < 0 && errno != ENOSYS)
167 err(ERR_EXIT, "unable to limit rights for %s", file1);
168 if (cap_rights_limit(fd2, &rights) < 0 && errno != ENOSYS)
169 err(ERR_EXIT, "unable to limit rights for %s", file2);
170
171 /* Required for fdopen(3). */
172 fcntls = CAP_FCNTL_GETFL;
173 if (cap_fcntls_limit(fd1, fcntls) < 0 && errno != ENOSYS)
174 err(ERR_EXIT, "unable to limit fcntls for %s", file1);
175 if (cap_fcntls_limit(fd2, fcntls) < 0 && errno != ENOSYS)
176 err(ERR_EXIT, "unable to limit fcntls for %s", file2);
177
178 if (!special) {
179 cap_rights_init(&rights);
180 if (cap_rights_limit(STDIN_FILENO, &rights) < 0 &&
181 errno != ENOSYS) {
182 err(ERR_EXIT, "unable to limit stdio");
183 }
184 }
185
186 if (caph_limit_stdout() == -1 || caph_limit_stderr() == -1)
187 err(ERR_EXIT, "unable to limit stdio");
188
189 caph_cache_catpages();
190
191 if (caph_enter() < 0)
192 err(ERR_EXIT, "unable to enter capability mode");
193
194 if (!special) {
195 if (fstat(fd1, &sb1)) {
196 if (!sflag)
197 err(ERR_EXIT, "%s", file1);
198 else
199 exit(ERR_EXIT);
200 }
201 if (!S_ISREG(sb1.st_mode))
202 special = 1;
203 else {
204 if (fstat(fd2, &sb2)) {
205 if (!sflag)
206 err(ERR_EXIT, "%s", file2);
207 else
208 exit(ERR_EXIT);
209 }
210 if (!S_ISREG(sb2.st_mode))
211 special = 1;
212 }
213 }
214
215 if (special)
216 c_special(fd1, file1, skip1, fd2, file2, skip2);
217 else {
218 if (zflag && sb1.st_size != sb2.st_size) {
219 if (!sflag)
220 (void) printf("%s %s differ: size\n",
221 file1, file2);
222 exit(DIFF_EXIT);
223 }
224 c_regular(fd1, file1, skip1, sb1.st_size,
225 fd2, file2, skip2, sb2.st_size);
226 }
227 exit(0);
228 }
229
230 static void
usage(void)231 usage(void)
232 {
233
234 (void)fprintf(stderr,
235 "usage: cmp [-l | -s | -x] [-hz] file1 file2 [skip1 [skip2]]\n");
236 exit(ERR_EXIT);
237 }
238