xref: /netbsd-src/usr.sbin/mdsetimage/mdsetimage.c (revision 3b01aba77a7a698587faaae455bbfe740923c1f5)
1 /* $NetBSD: mdsetimage.c,v 1.15 2001/03/21 23:46:48 cgd Exp $ */
2 
3 /*
4  * Copyright (c) 1996 Christopher G. Demetriou
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *          This product includes software developed for the
18  *          NetBSD Project.  See http://www.netbsd.org/ for
19  *          information about NetBSD.
20  * 4. The name of the author may not be used to endorse or promote products
21  *    derived from this software without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  *
34  * <<Id: LICENSE,v 1.2 2000/06/14 15:57:33 cgd Exp>>
35  */
36 
37 #include <sys/cdefs.h>
38 #ifndef lint
39 __COPYRIGHT(
40     "@(#) Copyright (c) 1996 Christopher G. Demetriou.\
41   All rights reserved.\n");
42 #endif /* not lint */
43 
44 #ifndef lint
45 __RCSID("$NetBSD: mdsetimage.c,v 1.15 2001/03/21 23:46:48 cgd Exp $");
46 #endif /* not lint */
47 
48 #include <sys/types.h>
49 #include <sys/mman.h>
50 #include <sys/stat.h>
51 
52 #include <err.h>
53 #include <fcntl.h>
54 #include <limits.h>
55 #include <nlist.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <unistd.h>
59 
60 #include "extern.h"
61 
62 int		main __P((int, char *[]));
63 static void	usage __P((void)) __attribute__((noreturn));
64 static int	find_md_root __P((const char *, const char *, size_t,
65 		    const struct nlist *, size_t *, u_int32_t *));
66 
67 static struct nlist md_root_nlist[] = {
68 #define	X_MD_ROOT_IMAGE		0
69 	{ "_md_root_image" },
70 #define	X_MD_ROOT_SIZE		1
71 	{ "_md_root_size" },
72 	{ NULL }
73 };
74 
75 int	verbose;
76 #ifdef NLIST_AOUT
77 /*
78  * Since we can't get the text address from an a.out executable, we
79  * need to be able to specify it.  Note: there's no way to test to
80  * see if the user entered a valid address!
81  */
82 int	T_flag_specified;	/* the -T flag was specified */
83 u_long	text_start;		/* Start of kernel text */
84 #endif /* NLIST_AOUT */
85 
86 int
87 main(argc, argv)
88 	int argc;
89 	char *argv[];
90 {
91 	struct stat ksb, fssb;
92 	size_t md_root_offset;
93 	u_int32_t md_root_size;
94 	const char *kfile, *fsfile;
95 	char *mappedkfile;
96 	int ch, kfd, fsfd, rv;
97 
98 	setprogname(argv[0]);
99 
100 	while ((ch = getopt(argc, argv, "T:v")) != -1)
101 		switch (ch) {
102 		case 'v':
103 			verbose = 1;
104 			break;
105 		case 'T':
106 #ifdef NLIST_AOUT
107 			T_flag_specified = 1;
108 			text_start = strtoul(optarg, NULL, 0);
109 			break;
110 #endif /* NLIST_AOUT */
111 			/* FALLTHROUGH */
112 		case '?':
113 		default:
114 			usage();
115 	}
116 	argc -= optind;
117 	argv += optind;
118 
119 	if (argc != 2)
120 		usage();
121 	kfile = argv[0];
122 	fsfile = argv[1];
123 
124 	if ((kfd = open(kfile, O_RDWR, 0))  == -1)
125 		err(1, "open %s", kfile);
126 
127 	if ((rv = __fdnlist(kfd, md_root_nlist)) != 0)
128 		errx(1, "could not find symbols in %s", kfile);
129 	if (verbose)
130 		fprintf(stderr, "got symbols from %s\n", kfile);
131 
132 	if (fstat(kfd, &ksb) == -1)
133 		err(1, "fstat %s", kfile);
134 	if (ksb.st_size != (size_t)ksb.st_size)
135 		errx(1, "%s too big to map", kfile);
136 
137 	if ((mappedkfile = mmap(NULL, ksb.st_size, PROT_READ | PROT_WRITE,
138 	    MAP_FILE | MAP_SHARED, kfd, 0)) == (caddr_t)-1)
139 		err(1, "mmap %s", kfile);
140 	if (verbose)
141 		fprintf(stderr, "mapped %s\n", kfile);
142 
143 	if (find_md_root(kfile, mappedkfile, ksb.st_size, md_root_nlist,
144 	    &md_root_offset, &md_root_size) != 0)
145 		errx(1, "could not find md root buffer in %s", kfile);
146 
147 	if ((fsfd = open(fsfile, O_RDONLY, 0)) == -1)
148 		err(1, "open %s", fsfile);
149 	if (fstat(fsfd, &fssb) == -1)
150 		err(1, "fstat %s", fsfile);
151 	if (fssb.st_size != (size_t)fssb.st_size)
152 		errx(1, "fs image is too big");
153 	if (fssb.st_size > md_root_size)
154 		errx(1, "fs image (%lld bytes) too big for buffer (%lu bytes)",
155 		    (long long)fssb.st_size, (unsigned long)md_root_size);
156 
157 	if (verbose)
158 		fprintf(stderr, "copying image from %s into %s\n", fsfile,
159 		    kfile);
160 	if ((rv = read(fsfd, mappedkfile + md_root_offset,
161 	    fssb.st_size)) != fssb.st_size) {
162 		if (rv == -1)
163 			err(1, "read %s", fsfile);
164 		else
165 			errx(1, "unexpected EOF reading %s", fsfile);
166 	}
167 	if (verbose)
168 		fprintf(stderr, "done copying image\n");
169 
170 	close(fsfd);
171 
172 	munmap(mappedkfile, ksb.st_size);
173 	close(kfd);
174 
175 	if (verbose)
176 		fprintf(stderr, "exiting\n");
177 	exit(0);
178 }
179 
180 static void
181 usage()
182 {
183 
184 	fprintf(stderr,
185 	    "usage: %s kernel_file fsimage_file\n",
186 	    getprogname());
187 	exit(1);
188 }
189 
190 
191 struct {
192 	const char *name;
193 	int	(*check) __P((const char *, size_t));
194 	int	(*findoff) __P((const char *, size_t, u_long, size_t *));
195 } exec_formats[] = {
196 #ifdef NLIST_AOUT
197 	{	"a.out",	check_aout,	findoff_aout,	},
198 #endif
199 #ifdef NLIST_ECOFF
200 	{	"ECOFF",	check_ecoff,	findoff_ecoff,	},
201 #endif
202 #ifdef NLIST_ELF32
203 	{	"ELF32",	check_elf32,	findoff_elf32,	},
204 #endif
205 #ifdef NLIST_ELF64
206 	{	"ELF64",	check_elf64,	findoff_elf64,	},
207 #endif
208 #ifdef NLIST_COFF
209 	{	"COFF",		check_coff,	findoff_coff,	},
210 #endif
211 };
212 
213 static int
214 find_md_root(fname, mappedfile, mappedsize, nl, rootoffp, rootsizep)
215 	const char *fname, *mappedfile;
216 	size_t mappedsize;
217 	const struct nlist *nl;
218 	size_t *rootoffp;
219 	u_int32_t *rootsizep;
220 {
221 	int i, n;
222 	size_t rootsizeoff;
223 
224 	n = sizeof exec_formats / sizeof exec_formats[0];
225 	for (i = 0; i < n; i++) {
226 		if ((*exec_formats[i].check)(mappedfile, mappedsize) == 0)
227 			break;
228 	}
229 	if (i == n) {
230 		warnx("%s: unknown executable format", fname);
231 		return (1);
232 	}
233 
234 	if (verbose) {
235 		fprintf(stderr, "%s is an %s binary\n", fname,
236 		    exec_formats[i].name);
237 #ifdef NLIST_AOUT
238 		if (T_flag_specified)
239 			fprintf(stderr, "kernel text loads at 0x%lx\n",
240 			    text_start);
241 #endif
242 	}
243 
244 	if ((*exec_formats[i].findoff)(mappedfile, mappedsize,
245 	    nl[X_MD_ROOT_SIZE].n_value, &rootsizeoff) != 0) {
246 		warnx("couldn't find offset for %s in %s",
247 		    nl[X_MD_ROOT_SIZE].n_name, fname);
248 		return (1);
249 	}
250 	if (verbose)
251 		fprintf(stderr, "%s is at offset %#lx in %s\n",
252 			nl[X_MD_ROOT_SIZE].n_name,
253 			(unsigned long)rootsizeoff, fname);
254 	*rootsizep = *(u_int32_t *)&mappedfile[rootsizeoff];
255 	if (verbose)
256 		fprintf(stderr, "%s has value %#x\n",
257 		    nl[X_MD_ROOT_SIZE].n_name, *rootsizep);
258 
259 	if ((*exec_formats[i].findoff)(mappedfile, mappedsize,
260 	    nl[X_MD_ROOT_IMAGE].n_value, rootoffp) != 0) {
261 		warnx("couldn't find offset for %s in %s",
262 		    nl[X_MD_ROOT_IMAGE].n_name, fname);
263 		return (1);
264 	}
265 	if (verbose)
266 		fprintf(stderr, "%s is at offset %#lx in %s\n",
267 			nl[X_MD_ROOT_IMAGE].n_name,
268 			(unsigned long)(*rootoffp), fname);
269 
270 	return (0);
271 }
272