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