xref: /openbsd-src/usr.sbin/installboot/util.c (revision 7762a34bea7c67d99ecb6c2d3cae4fbd5adf1134)
1 /*	$OpenBSD: util.c,v 1.2 2014/01/18 03:07:05 jsing Exp $	*/
2 
3 /*
4  * Copyright (c) 2014 Joel Sing <jsing@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/param.h>
20 #include <sys/stat.h>
21 #include <err.h>
22 #include <fcntl.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27 
28 #include "installboot.h"
29 
30 #define BUFSIZE 2048
31 
32 void
33 filecopy(const char *srcfile, const char *dstfile)
34 {
35 	char *buf, tempfile[MAXPATHLEN];
36 	struct stat sb;
37 	ssize_t sz, n;
38 	int sfd, dfd;
39 
40 	if ((buf = malloc(BUFSIZE)) == NULL)
41 		err(1, "malloc");
42 
43 	sfd = open(srcfile, O_RDONLY);
44 	if (sfd == -1)
45 		err(1, "open");
46 	if (fstat(sfd, &sb) == -1)
47 		err(1, "fstat");
48 	sz = sb.st_size;
49 
50 	snprintf(tempfile, sizeof(tempfile), "%s.XXXXXXXX", dstfile);
51 	dfd = mkstemp(tempfile);
52 	if (dfd == -1)
53 		err(1, "mkstemp");
54 
55 	if (chown(tempfile, 0, 0) == -1)
56 		err(1, "chown");
57 	if (chmod(tempfile, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH) == -1)
58 		err(1, "chmod");
59 
60 	if (verbose)
61 		fprintf(stderr, "Copying %s to %s\n", srcfile, tempfile);
62 
63 	while (sz > 0) {
64 		n = MIN(sz, BUFSIZE);
65 		if ((n = read(sfd, buf, n)) == -1)
66 			err(1, "read");
67 		sz -= n;
68 		if (write(dfd, buf, n) != n)
69 			err(1, "write");
70 	}
71 
72 	close(dfd);
73 	close(sfd);
74 	free(buf);
75 
76 	if (verbose)
77 		fprintf(stderr, "Renaming %s to %s\n", tempfile, dstfile);
78 
79 	if (rename(tempfile, dstfile) == -1)
80 		err(1, "rename");
81 }
82 
83 char *
84 fileprefix(const char *base, const char *path)
85 {
86 	char *r, *s;
87 	int n;
88 
89 	if ((s = malloc(PATH_MAX)) == NULL)
90 		err(1, "malloc");
91 	n = snprintf(s, PATH_MAX, "%s/%s", base, path);
92 	if (n < 1 || n >= PATH_MAX)
93 		err(1, "snprintf");
94 	if ((r = realpath(s, NULL)) == NULL)
95 		err(1, "realpath");
96 	free(s);
97 
98 	return r;
99 }
100