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 #include <sys/types.h>
33 #include <sys/stat.h>
34
35 #include <capsicum_helpers.h>
36 #include <err.h>
37 #include <errno.h>
38 #include <fcntl.h>
39 #include <getopt.h>
40 #include <nl_types.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45
46 #include <libutil.h>
47
48 #include "extern.h"
49
50 bool bflag, lflag, sflag, xflag, zflag;
51
52 static const struct option long_opts[] =
53 {
54 {"print-bytes", no_argument, NULL, 'b'},
55 {"ignore-initial", required_argument, NULL, 'i'},
56 {"verbose", no_argument, NULL, 'l'},
57 {"bytes", required_argument, NULL, 'n'},
58 {"silent", no_argument, NULL, 's'},
59 {"quiet", no_argument, NULL, 's'},
60 {NULL, no_argument, NULL, 0}
61 };
62
63 #ifdef SIGINFO
64 volatile sig_atomic_t info;
65
66 static void
siginfo(int signo)67 siginfo(int signo)
68 {
69
70 info = signo;
71 }
72 #endif
73
74 static void usage(void) __dead2;
75
76 static bool
parse_iskipspec(char * spec,off_t * skip1,off_t * skip2)77 parse_iskipspec(char *spec, off_t *skip1, off_t *skip2)
78 {
79 char *colon;
80
81 colon = strchr(spec, ':');
82 if (colon != NULL)
83 *colon++ = '\0';
84
85 if (expand_number(spec, skip1) < 0)
86 return (false);
87
88 if (colon != NULL)
89 return (expand_number(colon, skip2) == 0);
90
91 *skip2 = *skip1;
92 return (true);
93 }
94
95 int
main(int argc,char * argv[])96 main(int argc, char *argv[])
97 {
98 struct stat sb1, sb2;
99 off_t skip1, skip2, limit;
100 int ch, fd1, fd2, oflag;
101 bool special;
102 const char *file1, *file2;
103
104 limit = skip1 = skip2 = 0;
105 oflag = O_RDONLY;
106 while ((ch = getopt_long(argc, argv, "+bhi:ln:sxz", long_opts, NULL)) != -1)
107 switch (ch) {
108 case 'b': /* Print bytes */
109 bflag = true;
110 break;
111 case 'h': /* Don't follow symlinks */
112 oflag |= O_NOFOLLOW;
113 break;
114 case 'i':
115 if (!parse_iskipspec(optarg, &skip1, &skip2)) {
116 fprintf(stderr,
117 "Invalid --ignore-initial: %s\n",
118 optarg);
119 usage();
120 }
121 break;
122 case 'l': /* print all differences */
123 lflag = true;
124 break;
125 case 'n': /* Limit */
126 if (expand_number(optarg, &limit) < 0 || limit < 0) {
127 fprintf(stderr, "Invalid --bytes: %s\n",
128 optarg);
129 usage();
130 }
131 break;
132 case 's': /* silent run */
133 sflag = true;
134 break;
135 case 'x': /* hex output */
136 lflag = true;
137 xflag = true;
138 break;
139 case 'z': /* compare size first */
140 zflag = true;
141 break;
142 case '?':
143 default:
144 usage();
145 }
146 argv += optind;
147 argc -= optind;
148
149 if (lflag && sflag)
150 errx(ERR_EXIT, "specifying -s with -l or -x is not permitted");
151
152 if (argc < 2 || argc > 4)
153 usage();
154
155 /* Don't limit rights on stdin since it may be one of the inputs. */
156 if (caph_limit_stream(STDOUT_FILENO, CAPH_WRITE | CAPH_IGNORE_EBADF))
157 err(ERR_EXIT, "unable to limit rights on stdout");
158 if (caph_limit_stream(STDERR_FILENO, CAPH_WRITE | CAPH_IGNORE_EBADF))
159 err(ERR_EXIT, "unable to limit rights on stderr");
160
161 /* Backward compatibility -- handle "-" meaning stdin. */
162 special = false;
163 if (strcmp(file1 = argv[0], "-") == 0) {
164 special = true;
165 fd1 = STDIN_FILENO;
166 file1 = "stdin";
167 } else if ((fd1 = open(file1, oflag, 0)) < 0 && errno != EMLINK) {
168 if (!sflag)
169 err(ERR_EXIT, "%s", file1);
170 else
171 exit(ERR_EXIT);
172 }
173 if (strcmp(file2 = argv[1], "-") == 0) {
174 if (special)
175 errx(ERR_EXIT,
176 "standard input may only be specified once");
177 special = true;
178 fd2 = STDIN_FILENO;
179 file2 = "stdin";
180 } else if ((fd2 = open(file2, oflag, 0)) < 0 && errno != EMLINK) {
181 if (!sflag)
182 err(ERR_EXIT, "%s", file2);
183 else
184 exit(ERR_EXIT);
185 }
186
187 if (argc > 2 && expand_number(argv[2], &skip1) < 0) {
188 fprintf(stderr, "Invalid skip1: %s\n", argv[2]);
189 usage();
190 }
191
192 if (argc == 4 && expand_number(argv[3], &skip2) < 0) {
193 fprintf(stderr, "Invalid skip2: %s\n", argv[3]);
194 usage();
195 }
196
197 if (sflag && skip1 == 0 && skip2 == 0)
198 zflag = true;
199
200 if (fd1 == -1) {
201 if (fd2 == -1) {
202 c_link(file1, skip1, file2, skip2, limit);
203 exit(0);
204 } else if (!sflag)
205 errx(ERR_EXIT, "%s: Not a symbolic link", file2);
206 else
207 exit(ERR_EXIT);
208 } else if (fd2 == -1) {
209 if (!sflag)
210 errx(ERR_EXIT, "%s: Not a symbolic link", file1);
211 else
212 exit(ERR_EXIT);
213 }
214
215 /* FD rights are limited in c_special() and c_regular(). */
216 caph_cache_catpages();
217
218 if (!special) {
219 if (fstat(fd1, &sb1)) {
220 if (!sflag)
221 err(ERR_EXIT, "%s", file1);
222 else
223 exit(ERR_EXIT);
224 }
225 if (!S_ISREG(sb1.st_mode))
226 special = true;
227 else {
228 if (fstat(fd2, &sb2)) {
229 if (!sflag)
230 err(ERR_EXIT, "%s", file2);
231 else
232 exit(ERR_EXIT);
233 }
234 if (!S_ISREG(sb2.st_mode))
235 special = true;
236 }
237 }
238
239 #ifdef SIGINFO
240 (void)signal(SIGINFO, siginfo);
241 #endif
242 if (special)
243 c_special(fd1, file1, skip1, fd2, file2, skip2, limit);
244 else {
245 if (zflag && sb1.st_size != sb2.st_size) {
246 if (!sflag)
247 (void) printf("%s %s differ: size\n",
248 file1, file2);
249 exit(DIFF_EXIT);
250 }
251 c_regular(fd1, file1, skip1, sb1.st_size,
252 fd2, file2, skip2, sb2.st_size, limit);
253 }
254 exit(0);
255 }
256
257 static void
usage(void)258 usage(void)
259 {
260
261 (void)fprintf(stderr,
262 "usage: cmp [-l | -s | -x] [-hz] file1 file2 [skip1 [skip2]]\n");
263 exit(ERR_EXIT);
264 }
265