xref: /openbsd-src/usr.sbin/installboot/util.c (revision cb39b41371628601fbe4c618205356d538b9d08a)
1 /*	$OpenBSD: util.c,v 1.5 2015/01/16 00:05:12 deraadt 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/stat.h>
20 #include <err.h>
21 #include <fcntl.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <unistd.h>
26 #include <limits.h>
27 
28 #include "installboot.h"
29 
30 #define MINIMUM(a, b)	(((a) < (b)) ? (a) : (b))
31 
32 #define BUFSIZE 512
33 
34 void
35 filecopy(const char *srcfile, const char *dstfile)
36 {
37 	struct stat sb;
38 	ssize_t sz, n;
39 	int sfd, dfd;
40 	char *buf;
41 
42 	if ((buf = malloc(BUFSIZE)) == NULL)
43 		err(1, "malloc");
44 
45 	sfd = open(srcfile, O_RDONLY);
46 	if (sfd == -1)
47 		err(1, "open %s", srcfile);
48 	if (fstat(sfd, &sb) == -1)
49 		err(1, "fstat");
50 	sz = sb.st_size;
51 
52 	dfd = open(dstfile, O_WRONLY|O_CREAT);
53 	if (dfd == -1)
54 		err(1, "open %s", dstfile);
55 	if (fchown(dfd, 0, 0) == -1)
56 		err(1, "chown");
57 	if (fchmod(dfd, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH) == -1)
58 		err(1, "chmod");
59 
60 	while (sz > 0) {
61 		n = MINIMUM(sz, BUFSIZE);
62 		if ((n = read(sfd, buf, n)) == -1)
63 			err(1, "read");
64 		sz -= n;
65 		if (write(dfd, buf, n) != n)
66 			err(1, "write");
67 	}
68 
69 	ftruncate(dfd, sb.st_size);
70 
71 	close(dfd);
72 	close(sfd);
73 	free(buf);
74 }
75 
76 char *
77 fileprefix(const char *base, const char *path)
78 {
79 	char *r, *s;
80 	int n;
81 
82 	if ((s = malloc(PATH_MAX)) == NULL)
83 		err(1, "malloc");
84 	n = snprintf(s, PATH_MAX, "%s/%s", base, path);
85 	if (n < 1 || n >= PATH_MAX)
86 		err(1, "snprintf");
87 	if ((r = realpath(s, NULL)) == NULL)
88 		err(1, "realpath");
89 	free(s);
90 
91 	return r;
92 }
93