xref: /openbsd-src/usr.sbin/installboot/util.c (revision 5b859c19fe53bbea08f5c342e0a4470e99f883e1)
1 /*	$OpenBSD: util.c,v 1.4 2014/06/09 15:50:08 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 512
31 
32 void
33 filecopy(const char *srcfile, const char *dstfile)
34 {
35 	struct stat sb;
36 	ssize_t sz, n;
37 	int sfd, dfd;
38 	char *buf;
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 %s", srcfile);
46 	if (fstat(sfd, &sb) == -1)
47 		err(1, "fstat");
48 	sz = sb.st_size;
49 
50 	dfd = open(dstfile, O_WRONLY|O_CREAT);
51 	if (dfd == -1)
52 		err(1, "open %s", dstfile);
53 	if (fchown(dfd, 0, 0) == -1)
54 		err(1, "chown");
55 	if (fchmod(dfd, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH) == -1)
56 		err(1, "chmod");
57 
58 	while (sz > 0) {
59 		n = MIN(sz, BUFSIZE);
60 		if ((n = read(sfd, buf, n)) == -1)
61 			err(1, "read");
62 		sz -= n;
63 		if (write(dfd, buf, n) != n)
64 			err(1, "write");
65 	}
66 
67 	ftruncate(dfd, sb.st_size);
68 
69 	close(dfd);
70 	close(sfd);
71 	free(buf);
72 }
73 
74 char *
75 fileprefix(const char *base, const char *path)
76 {
77 	char *r, *s;
78 	int n;
79 
80 	if ((s = malloc(PATH_MAX)) == NULL)
81 		err(1, "malloc");
82 	n = snprintf(s, PATH_MAX, "%s/%s", base, path);
83 	if (n < 1 || n >= PATH_MAX)
84 		err(1, "snprintf");
85 	if ((r = realpath(s, NULL)) == NULL)
86 		err(1, "realpath");
87 	free(s);
88 
89 	return r;
90 }
91