1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3 * CDDL HEADER START
4 *
5 * The contents of this file are subject to the terms of the
6 * Common Development and Distribution License (the "License").
7 * You may not use this file except in compliance with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or https://opensource.org/licenses/CDDL-1.0.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22
23 /*
24 * Copyright (c) 2024 by Pawel Jakub Dawidek
25 */
26
27 #include <sys/mman.h>
28 #include <sys/stat.h>
29
30 #include <assert.h>
31 #include <errno.h>
32 #include <fcntl.h>
33 #include <stdbool.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <unistd.h>
38
39 #ifdef __FreeBSD__
40 #define loff_t off_t
41 #endif
42
43 ssize_t
44 copy_file_range(int, loff_t *, int, loff_t *, size_t, unsigned int)
45 __attribute__((weak));
46
47 static void *
mmap_file(int fd,size_t size)48 mmap_file(int fd, size_t size)
49 {
50 void *p;
51
52 p = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0);
53 if (p == MAP_FAILED) {
54 (void) fprintf(stderr, "mmap failed: %s\n", strerror(errno));
55 exit(2);
56 }
57
58 return (p);
59 }
60
61 static void
usage(const char * progname)62 usage(const char *progname)
63 {
64
65 /*
66 * -i cache input before copy_file_range(2).
67 * -o cache input before copy_file_range(2).
68 */
69 (void) fprintf(stderr, "usage: %s [-io] <input> <output>\n", progname);
70 exit(3);
71 }
72
73 int
main(int argc,char * argv[])74 main(int argc, char *argv[])
75 {
76 int dfd, sfd;
77 size_t dsize, ssize;
78 void *dmem, *smem, *ptr;
79 off_t doff, soff;
80 struct stat sb;
81 bool cache_input, cache_output;
82 const char *progname;
83 int c;
84
85 progname = argv[0];
86 cache_input = cache_output = false;
87
88 while ((c = getopt(argc, argv, "io")) != -1) {
89 switch (c) {
90 case 'i':
91 cache_input = true;
92 break;
93 case 'o':
94 cache_output = true;
95 break;
96 default:
97 usage(progname);
98 }
99 }
100 argc -= optind;
101 argv += optind;
102
103 if (argc != 2) {
104 usage(progname);
105 }
106
107 sfd = open(argv[0], O_RDONLY);
108 if (fstat(sfd, &sb) == -1) {
109 (void) fprintf(stderr, "fstat failed: %s\n", strerror(errno));
110 exit(2);
111 }
112 ssize = sb.st_size;
113 smem = mmap_file(sfd, ssize);
114
115 dfd = open(argv[1], O_RDWR);
116 if (fstat(dfd, &sb) == -1) {
117 (void) fprintf(stderr, "fstat failed: %s\n", strerror(errno));
118 exit(2);
119 }
120 dsize = sb.st_size;
121 dmem = mmap_file(dfd, dsize);
122
123 /*
124 * Hopefully it won't be compiled out.
125 */
126 if (cache_input) {
127 ptr = malloc(ssize);
128 assert(ptr != NULL);
129 memcpy(ptr, smem, ssize);
130 free(ptr);
131 }
132 if (cache_output) {
133 ptr = malloc(ssize);
134 assert(ptr != NULL);
135 memcpy(ptr, dmem, dsize);
136 free(ptr);
137 }
138
139 soff = doff = 0;
140 if (copy_file_range(sfd, &soff, dfd, &doff, ssize, 0) < 0) {
141 (void) fprintf(stderr, "copy_file_range failed: %s\n",
142 strerror(errno));
143 exit(2);
144 }
145
146 exit(memcmp(smem, dmem, ssize) == 0 ? 0 : 1);
147 }
148