xref: /netbsd-src/lib/libutil/getbootfile.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /*	$NetBSD: getbootfile.c,v 1.4 2003/10/21 00:47:46 fvdl Exp $	*/
2 
3 /*-
4  * Copyright (c) 2000 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Thomas Klausner.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #if defined(LIBC_SCCS) && !defined(lint)
41 __RCSID("$NetBSD: getbootfile.c,v 1.4 2003/10/21 00:47:46 fvdl Exp $");
42 #endif
43 
44 #include <sys/param.h>
45 #include <sys/sysctl.h>
46 #include <machine/cpu.h>
47 #include <string.h>
48 #include <paths.h>
49 #include <util.h>
50 
51 #ifdef CPU_BOOTED_KERNEL
52 static char name[MAXPATHLEN];
53 #endif
54 
55 const char *
56 getbootfile(void)
57 {
58 #ifdef CPU_BOOTED_KERNEL
59 	int mib[2];
60 	size_t size;
61 #endif
62 	const char *kernel;
63 
64 	kernel = _PATH_UNIX;
65 #ifdef CPU_BOOTED_KERNEL
66 	/* find real boot-kernel name */
67 	mib[0] = CTL_MACHDEP;
68 	mib[1] = CPU_BOOTED_KERNEL;
69 	size = sizeof(name) - 1;
70 	if (sysctl(mib, 2, name + 1, &size, NULL, 0) == 0) {
71 		/*
72 		 * traditionally, this sysctl returns the relative
73 		 * path of the kernel with the leading slash stripped
74 		 * -- could be empty, though (e.g. when netbooting).
75 		 */
76 		if (name[1] != '\0') {
77 			name[0] = '/';
78 			kernel = name;
79 		}
80 
81 		/* check if we got a valid and 'secure' filename */
82 		if (strcmp(kernel, _PATH_UNIX) != 0 &&
83 		    secure_path(kernel) != 0) {
84 			/* doesn't seems so, fall back to default */
85 			kernel = _PATH_UNIX;
86 		}
87 	}
88 #endif
89 
90 	return (kernel);
91 }
92