xref: /netbsd-src/usr.sbin/mdsetimage/mdsetimage.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /* $NetBSD: mdsetimage.c,v 1.19 2009/07/30 15:16:38 tsutsui 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. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  * <<Id: LICENSE_GC,v 1.1 2001/10/01 23:24:05 cgd Exp>>
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1996\
35  Christopher G. Demetriou.  All rights reserved.");
36 #endif /* not lint */
37 
38 #ifndef lint
39 __RCSID("$NetBSD: mdsetimage.c,v 1.19 2009/07/30 15:16:38 tsutsui Exp $");
40 #endif /* not lint */
41 
42 #include <sys/types.h>
43 #include <sys/mman.h>
44 #include <sys/stat.h>
45 
46 #include <err.h>
47 #include <fcntl.h>
48 #include <limits.h>
49 #include <nlist.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <unistd.h>
53 
54 #include "extern.h"
55 
56 int		main __P((int, char *[]));
57 static void	usage __P((void)) __dead;
58 static int	find_md_root __P((const char *, const char *, size_t,
59 		    const struct nlist *, size_t *, u_int32_t *));
60 
61 static struct nlist md_root_nlist[] = {
62 #define	X_MD_ROOT_IMAGE		0
63 	{ "_md_root_image", 0, 0, 0, 0 },
64 #define	X_MD_ROOT_SIZE		1
65 	{ "_md_root_size", 0, 0, 0, 0 },
66 	{ NULL, 0, 0, 0, 0 }
67 };
68 
69 int	verbose;
70 #ifdef NLIST_AOUT
71 /*
72  * Since we can't get the text address from an a.out executable, we
73  * need to be able to specify it.  Note: there's no way to test to
74  * see if the user entered a valid address!
75  */
76 int	T_flag_specified;	/* the -T flag was specified */
77 u_long	text_start;		/* Start of kernel text */
78 #endif /* NLIST_AOUT */
79 
80 int
81 main(argc, argv)
82 	int argc;
83 	char *argv[];
84 {
85 	struct stat ksb, fssb;
86 	size_t md_root_offset;
87 	u_int32_t md_root_size;
88 	const char *kfile, *fsfile;
89 	char *mappedkfile;
90 	int ch, kfd, fsfd, rv;
91 
92 	setprogname(argv[0]);
93 
94 	while ((ch = getopt(argc, argv, "T:v")) != -1)
95 		switch (ch) {
96 		case 'v':
97 			verbose = 1;
98 			break;
99 		case 'T':
100 #ifdef NLIST_AOUT
101 			T_flag_specified = 1;
102 			text_start = strtoul(optarg, NULL, 0);
103 			break;
104 #endif /* NLIST_AOUT */
105 			/* FALLTHROUGH */
106 		case '?':
107 		default:
108 			usage();
109 	}
110 	argc -= optind;
111 	argv += optind;
112 
113 	if (argc != 2)
114 		usage();
115 	kfile = argv[0];
116 	fsfile = argv[1];
117 
118 	if ((kfd = open(kfile, O_RDWR, 0))  == -1)
119 		err(1, "open %s", kfile);
120 
121 	if ((rv = __fdnlist(kfd, md_root_nlist)) != 0)
122 		errx(1, "could not find symbols in %s", kfile);
123 	if (verbose)
124 		fprintf(stderr, "got symbols from %s\n", kfile);
125 
126 	if (fstat(kfd, &ksb) == -1)
127 		err(1, "fstat %s", kfile);
128 	if (ksb.st_size != (size_t)ksb.st_size)
129 		errx(1, "%s too big to map", kfile);
130 
131 	if ((mappedkfile = mmap(NULL, ksb.st_size, PROT_READ | PROT_WRITE,
132 	    MAP_FILE | MAP_SHARED, kfd, 0)) == (caddr_t)-1)
133 		err(1, "mmap %s", kfile);
134 	if (verbose)
135 		fprintf(stderr, "mapped %s\n", kfile);
136 
137 	if (find_md_root(kfile, mappedkfile, ksb.st_size, md_root_nlist,
138 	    &md_root_offset, &md_root_size) != 0)
139 		errx(1, "could not find md root buffer in %s", kfile);
140 
141 	if ((fsfd = open(fsfile, O_RDONLY, 0)) == -1)
142 		err(1, "open %s", fsfile);
143 	if (fstat(fsfd, &fssb) == -1)
144 		err(1, "fstat %s", fsfile);
145 	if (fssb.st_size != (size_t)fssb.st_size)
146 		errx(1, "fs image is too big");
147 	if (fssb.st_size > md_root_size)
148 		errx(1, "fs image (%lld bytes) too big for buffer (%lu bytes)",
149 		    (long long)fssb.st_size, (unsigned long)md_root_size);
150 
151 	if (verbose)
152 		fprintf(stderr, "copying image from %s into %s\n", fsfile,
153 		    kfile);
154 	if ((rv = read(fsfd, mappedkfile + md_root_offset,
155 	    fssb.st_size)) != fssb.st_size) {
156 		if (rv == -1)
157 			err(1, "read %s", fsfile);
158 		else
159 			errx(1, "unexpected EOF reading %s", fsfile);
160 	}
161 	if (verbose)
162 		fprintf(stderr, "done copying image\n");
163 
164 	close(fsfd);
165 
166 	munmap(mappedkfile, ksb.st_size);
167 	close(kfd);
168 
169 	if (verbose)
170 		fprintf(stderr, "exiting\n");
171 	exit(0);
172 }
173 
174 static void
175 usage()
176 {
177 
178 	fprintf(stderr,
179 	    "usage: %s kernel_file fsimage_file\n",
180 	    getprogname());
181 	exit(1);
182 }
183 
184 
185 struct {
186 	const char *name;
187 	int	(*check) __P((const char *, size_t));
188 	int	(*findoff) __P((const char *, size_t, u_long, size_t *));
189 } exec_formats[] = {
190 #ifdef NLIST_AOUT
191 	{	"a.out",	check_aout,	findoff_aout,	},
192 #endif
193 #ifdef NLIST_ECOFF
194 	{	"ECOFF",	check_ecoff,	findoff_ecoff,	},
195 #endif
196 #ifdef NLIST_ELF32
197 	{	"ELF32",	check_elf32,	findoff_elf32,	},
198 #endif
199 #ifdef NLIST_ELF64
200 	{	"ELF64",	check_elf64,	findoff_elf64,	},
201 #endif
202 #ifdef NLIST_COFF
203 	{	"COFF",		check_coff,	findoff_coff,	},
204 #endif
205 };
206 
207 static int
208 find_md_root(fname, mappedfile, mappedsize, nl, rootoffp, rootsizep)
209 	const char *fname, *mappedfile;
210 	size_t mappedsize;
211 	const struct nlist *nl;
212 	size_t *rootoffp;
213 	u_int32_t *rootsizep;
214 {
215 	int i, n;
216 	size_t rootsizeoff;
217 
218 	n = sizeof exec_formats / sizeof exec_formats[0];
219 	for (i = 0; i < n; i++) {
220 		if ((*exec_formats[i].check)(mappedfile, mappedsize) == 0)
221 			break;
222 	}
223 	if (i == n) {
224 		warnx("%s: unknown executable format", fname);
225 		return (1);
226 	}
227 
228 	if (verbose) {
229 		fprintf(stderr, "%s is an %s binary\n", fname,
230 		    exec_formats[i].name);
231 #ifdef NLIST_AOUT
232 		if (T_flag_specified)
233 			fprintf(stderr, "kernel text loads at 0x%lx\n",
234 			    text_start);
235 #endif
236 	}
237 
238 	if ((*exec_formats[i].findoff)(mappedfile, mappedsize,
239 	    nl[X_MD_ROOT_SIZE].n_value, &rootsizeoff) != 0) {
240 		warnx("couldn't find offset for %s in %s",
241 		    nl[X_MD_ROOT_SIZE].n_name, fname);
242 		return (1);
243 	}
244 	if (verbose)
245 		fprintf(stderr, "%s is at offset %#lx in %s\n",
246 			nl[X_MD_ROOT_SIZE].n_name,
247 			(unsigned long)rootsizeoff, fname);
248 	*rootsizep = *(const u_int32_t *)&mappedfile[rootsizeoff];
249 	if (verbose)
250 		fprintf(stderr, "%s has value %#x\n",
251 		    nl[X_MD_ROOT_SIZE].n_name, *rootsizep);
252 
253 	if ((*exec_formats[i].findoff)(mappedfile, mappedsize,
254 	    nl[X_MD_ROOT_IMAGE].n_value, rootoffp) != 0) {
255 		warnx("couldn't find offset for %s in %s",
256 		    nl[X_MD_ROOT_IMAGE].n_name, fname);
257 		return (1);
258 	}
259 	if (verbose)
260 		fprintf(stderr, "%s is at offset %#lx in %s\n",
261 			nl[X_MD_ROOT_IMAGE].n_name,
262 			(unsigned long)(*rootoffp), fname);
263 
264 	return (0);
265 }
266