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mdsetimage.c revision 1.6
      1 /*	$NetBSD: mdsetimage.c,v 1.6 1997/10/17 10:28:44 lukem Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1996 Christopher G. Demetriou.  All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. All advertising materials mentioning features or use of this software
     15  *    must display the following acknowledgement:
     16  *      This product includes software developed by Christopher G. Demetriou
     17  *	for the NetBSD Project.
     18  * 4. The name of the author may not be used to endorse or promote products
     19  *    derived from this software without specific prior written permission
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #include <sys/cdefs.h>
     34 #ifndef lint
     35 __COPYRIGHT(
     36     "@(#) Copyright (c) 1996 Christopher G. Demetriou.\
     37   All rights reserved.\n");
     38 #endif /* not lint */
     39 
     40 #ifndef lint
     41 __RCSID("$NetBSD: mdsetimage.c,v 1.6 1997/10/17 10:28:44 lukem Exp $");
     42 #endif /* not lint */
     43 
     44 #include <sys/types.h>
     45 #include <sys/mman.h>
     46 #include <sys/stat.h>
     47 
     48 #include <err.h>
     49 #include <fcntl.h>
     50 #include <limits.h>
     51 #include <nlist.h>
     52 #include <stdio.h>
     53 #include <stdlib.h>
     54 #include <unistd.h>
     55 
     56 #include "extern.h"
     57 
     58 int		main __P((int, char *[]));
     59 static void	usage __P((void)) __attribute__((noreturn));
     60 static int	find_md_root __P((const char *, const char *, size_t,
     61 		    const struct nlist *, size_t *, u_int32_t *));
     62 
     63 static struct nlist md_root_nlist[] = {
     64 #define	X_MD_ROOT_IMAGE		0
     65 	{ "_md_root_image" },
     66 #define	X_MD_ROOT_SIZE		1
     67 	{ "_md_root_size" },
     68 	{ NULL }
     69 };
     70 
     71 int	verbose;
     72 #ifdef NLIST_AOUT
     73 /*
     74  * Since we can't get the text address from an a.out executable, we
     75  * need to be able to specify it.  Note: there's no way to test to
     76  * see if the user entered a valid address!
     77  */
     78 int	T_flag_specified;	/* the -T flag was specified */
     79 u_long	text_start;		/* Start of kernel text */
     80 #endif /* NLIST_AOUT */
     81 
     82 int
     83 main(argc, argv)
     84 	int argc;
     85 	char *argv[];
     86 {
     87 	struct stat ksb, fssb;
     88 	size_t md_root_offset;
     89 	u_int32_t md_root_size;
     90 	const char *kfile, *fsfile;
     91 	char *mappedkfile;
     92 	int ch, kfd, fsfd, rv;
     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_MAX)
    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_MAX)
    146 		errx(1, "fs image is too big");
    147 	if (fssb.st_size > md_root_size)
    148 		errx(1, "fs image (%qd bytes) too big for buffer (%ld 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 	if (verbose)
    161 		fprintf(stderr, "done copying image\n");
    162 
    163 	close(fsfd);
    164 
    165 	munmap(mappedkfile, ksb.st_size);
    166 	close(kfd);
    167 
    168 	if (verbose)
    169 		fprintf(stderr, "exiting\n");
    170 	exit(0);
    171 }
    172 
    173 static void
    174 usage()
    175 {
    176 	extern const char *__progname;
    177 
    178 	fprintf(stderr, "usage: %s kernel_file fsimage_file\n", __progname);
    179 	exit(1);
    180 }
    181 
    182 
    183 struct {
    184 	const char *name;
    185 	int	(*check) __P((const char *, size_t));
    186 	int	(*findoff) __P((const char *, size_t, u_long, size_t *));
    187 } exec_formats[] = {
    188 #ifdef NLIST_AOUT
    189 	{	"a.out",	check_aout,	findoff_aout,	},
    190 #endif
    191 #ifdef NLIST_ECOFF
    192 	{	"ECOFF",	check_ecoff,	findoff_ecoff,	},
    193 #endif
    194 #ifdef NLIST_ELF32
    195 	{	"ELF32",	check_elf32,	findoff_elf32,	},
    196 #endif
    197 #ifdef NLIST_ELF64
    198 	{	"ELF64",	check_elf64,	findoff_elf64,	},
    199 #endif
    200 };
    201 
    202 static int
    203 find_md_root(fname, mappedfile, mappedsize, nl, rootoffp, rootsizep)
    204 	const char *fname, *mappedfile;
    205 	size_t mappedsize;
    206 	const struct nlist *nl;
    207 	size_t *rootoffp;
    208 	u_int32_t *rootsizep;
    209 {
    210 	int i, n;
    211 	size_t rootsizeoff;
    212 
    213 	n = sizeof exec_formats / sizeof exec_formats[0];
    214 	for (i = 0; i < n; i++) {
    215 		if ((*exec_formats[i].check)(mappedfile, mappedsize) == 0)
    216 			break;
    217 	}
    218 	if (i == n) {
    219 		warnx("%s: unknown executable format", fname);
    220 		return (1);
    221 	}
    222 
    223 	if (verbose) {
    224 		fprintf(stderr, "%s is an %s binary\n", fname,
    225 		    exec_formats[i].name);
    226 #ifdef NLIST_AOUT
    227 		if (T_flag_specified)
    228 			fprintf(stderr, "kernel text loads at 0x%lx\n",
    229 			    text_start);
    230 #endif
    231 	}
    232 
    233 	if ((*exec_formats[i].findoff)(mappedfile, mappedsize,
    234 	    nl[X_MD_ROOT_SIZE].n_value, &rootsizeoff) != 0) {
    235 		warnx("couldn't find offset for %s in %s",
    236 		    nl[X_MD_ROOT_SIZE].n_name, fname);
    237 		return (1);
    238 	}
    239 	if (verbose)
    240 		fprintf(stderr, "%s is at offset %#lx in %s\n",
    241 			nl[X_MD_ROOT_SIZE].n_name,
    242 			(unsigned long)rootsizeoff, fname);
    243 	*rootsizep = *(u_int32_t *)&mappedfile[rootsizeoff];
    244 	if (verbose)
    245 		fprintf(stderr, "%s has value %#x\n",
    246 		    nl[X_MD_ROOT_SIZE].n_name, *rootsizep);
    247 
    248 	if ((*exec_formats[i].findoff)(mappedfile, mappedsize,
    249 	    nl[X_MD_ROOT_IMAGE].n_value, rootoffp) != 0) {
    250 		warnx("couldn't find offset for %s in %s",
    251 		    nl[X_MD_ROOT_IMAGE].n_name, fname);
    252 		return (1);
    253 	}
    254 	if (verbose)
    255 		fprintf(stderr, "%s is at offset %#lx in %s\n",
    256 			nl[X_MD_ROOT_IMAGE].n_name,
    257 			(unsigned long)(*rootoffp), fname);
    258 
    259 	return (0);
    260 }
    261