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 <stdbool.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46
47 #include <libutil.h>
48
49 #include "extern.h"
50
51 bool bflag, lflag, sflag, xflag, zflag;
52
53 static const struct option long_opts[] =
54 {
55 {"print-bytes", no_argument, NULL, 'b'},
56 {"ignore-initial", required_argument, NULL, 'i'},
57 {"verbose", no_argument, NULL, 'l'},
58 {"bytes", required_argument, NULL, 'n'},
59 {"silent", no_argument, NULL, 's'},
60 {"quiet", no_argument, NULL, 's'},
61 {NULL, no_argument, NULL, 0}
62 };
63
64 #ifdef SIGINFO
65 volatile sig_atomic_t info;
66
67 static void
siginfo(int signo)68 siginfo(int signo)
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 int ret;
104
105 limit = skip1 = skip2 = ret = 0;
106 oflag = O_RDONLY;
107 while ((ch = getopt_long(argc, argv, "+bhi:ln:sxz", long_opts, NULL)) != -1)
108 switch (ch) {
109 case 'b': /* Print bytes */
110 bflag = true;
111 break;
112 case 'h': /* Don't follow symlinks */
113 oflag |= O_NOFOLLOW;
114 break;
115 case 'i':
116 if (!parse_iskipspec(optarg, &skip1, &skip2)) {
117 fprintf(stderr,
118 "Invalid --ignore-initial: %s\n",
119 optarg);
120 usage();
121 }
122 break;
123 case 'l': /* print all differences */
124 lflag = true;
125 break;
126 case 'n': /* Limit */
127 if (expand_number(optarg, &limit) < 0 || limit < 0) {
128 fprintf(stderr, "Invalid --bytes: %s\n",
129 optarg);
130 usage();
131 }
132 break;
133 case 's': /* silent run */
134 sflag = true;
135 break;
136 case 'x': /* hex output */
137 lflag = true;
138 xflag = true;
139 break;
140 case 'z': /* compare size first */
141 zflag = true;
142 break;
143 case '?':
144 default:
145 usage();
146 }
147 argv += optind;
148 argc -= optind;
149
150 if (lflag && sflag)
151 errx(ERR_EXIT, "specifying -s with -l or -x is not permitted");
152
153 if (argc < 2 || argc > 4)
154 usage();
155
156 /* Don't limit rights on stdin since it may be one of the inputs. */
157 if (caph_limit_stream(STDOUT_FILENO, CAPH_WRITE | CAPH_IGNORE_EBADF))
158 err(ERR_EXIT, "unable to limit rights on stdout");
159 if (caph_limit_stream(STDERR_FILENO, CAPH_WRITE | CAPH_IGNORE_EBADF))
160 err(ERR_EXIT, "unable to limit rights on stderr");
161
162 /* Backward compatibility -- handle "-" meaning stdin. */
163 special = false;
164 if (strcmp(file1 = argv[0], "-") == 0) {
165 special = true;
166 fd1 = STDIN_FILENO;
167 file1 = "stdin";
168 } else if ((fd1 = open(file1, oflag, 0)) < 0 && errno != EMLINK) {
169 if (!sflag)
170 err(ERR_EXIT, "%s", file1);
171 else
172 exit(ERR_EXIT);
173 }
174 if (strcmp(file2 = argv[1], "-") == 0) {
175 if (special)
176 errx(ERR_EXIT,
177 "standard input may only be specified once");
178 special = true;
179 fd2 = STDIN_FILENO;
180 file2 = "stdin";
181 } else if ((fd2 = open(file2, oflag, 0)) < 0 && errno != EMLINK) {
182 if (!sflag)
183 err(ERR_EXIT, "%s", file2);
184 else
185 exit(ERR_EXIT);
186 }
187
188 if (argc > 2 && expand_number(argv[2], &skip1) < 0) {
189 fprintf(stderr, "Invalid skip1: %s\n", argv[2]);
190 usage();
191 }
192
193 if (argc == 4 && expand_number(argv[3], &skip2) < 0) {
194 fprintf(stderr, "Invalid skip2: %s\n", argv[3]);
195 usage();
196 }
197
198 if (sflag && skip1 == 0 && skip2 == 0)
199 zflag = true;
200
201 if (fd1 == -1) {
202 if (fd2 == -1) {
203 ret = c_link(file1, skip1, file2, skip2, limit);
204 goto end;
205 } else if (!sflag)
206 errx(ERR_EXIT, "%s: Not a symbolic link", file2);
207 else
208 exit(ERR_EXIT);
209 } else if (fd2 == -1) {
210 if (!sflag)
211 errx(ERR_EXIT, "%s: Not a symbolic link", file1);
212 else
213 exit(ERR_EXIT);
214 }
215
216 /* FD rights are limited in c_special() and c_regular(). */
217 caph_cache_catpages();
218
219 if (!special) {
220 if (fstat(fd1, &sb1)) {
221 if (!sflag)
222 err(ERR_EXIT, "%s", file1);
223 else
224 exit(ERR_EXIT);
225 }
226 if (!S_ISREG(sb1.st_mode))
227 special = true;
228 else {
229 if (fstat(fd2, &sb2)) {
230 if (!sflag)
231 err(ERR_EXIT, "%s", file2);
232 else
233 exit(ERR_EXIT);
234 }
235 if (!S_ISREG(sb2.st_mode))
236 special = true;
237 }
238 }
239
240 #ifdef SIGINFO
241 (void)signal(SIGINFO, siginfo);
242 #endif
243 if (special) {
244 ret = c_special(fd1, file1, skip1, fd2, file2, skip2, limit);
245 } else {
246 if (zflag && sb1.st_size != sb2.st_size) {
247 if (!sflag)
248 (void)printf("%s %s differ: size\n",
249 file1, file2);
250 ret = DIFF_EXIT;
251 } else {
252 ret = c_regular(fd1, file1, skip1, sb1.st_size,
253 fd2, file2, skip2, sb2.st_size, limit);
254 }
255 }
256 end:
257 if (!sflag && fflush(stdout) != 0)
258 err(ERR_EXIT, "stdout");
259 exit(ret);
260 }
261
262 static void
usage(void)263 usage(void)
264 {
265
266 (void)fprintf(stderr,
267 "usage: cmp [-l | -s | -x] [-hz] file1 file2 [skip1 [skip2]]\n");
268 exit(ERR_EXIT);
269 }
270