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biosboot.c revision 1.26 
      1 /*	$NetBSD: biosboot.c,v 1.26 2016/06/09 19:04:43 christos Exp $ */
      2 
      3 /*
      4  * Copyright (c) 2009 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to the NetBSD Foundation
      8  * by Mike M. Volokhov. Development of this software was supported by the
      9  * Google Summer of Code program.
     10  * The GSoC project was mentored by Allen Briggs and Joerg Sonnenberger.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions and the following disclaimer.
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notice, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     31  * POSSIBILITY OF SUCH DAMAGE.
     32  */
     33 
     34 #if HAVE_NBTOOL_CONFIG_H
     35 #include "nbtool_config.h"
     36 #endif
     37 
     38 #include <sys/cdefs.h>
     39 #ifdef __RCSID
     40 __RCSID("$NetBSD: biosboot.c,v 1.26 2016/06/09 19:04:43 christos Exp $");
     41 #endif
     42 
     43 #include <sys/stat.h>
     44 #include <sys/types.h>
     45 #include <sys/ioctl.h>
     46 #ifdef DIOCGWEDGEINFO
     47 #include <sys/disk.h>
     48 #endif
     49 #include <sys/param.h>
     50 #include <sys/bootblock.h>
     51 
     52 #include <err.h>
     53 #include <fcntl.h>
     54 #include <paths.h>
     55 #include <stddef.h>
     56 #include <stdio.h>
     57 #include <stdlib.h>
     58 #include <string.h>
     59 #include <unistd.h>
     60 
     61 #include "map.h"
     62 #include "gpt.h"
     63 #include "gpt_private.h"
     64 
     65 #define DEFAULT_BOOTDIR		"/usr/mdec"
     66 #define DEFAULT_BOOTCODE	"gptmbr.bin"
     67 
     68 static int cmd_biosboot(gpt_t, int, char *[]);
     69 
     70 static const char *biosboothelp[] = {
     71 	"[-A] [-c bootcode] [-i index] [-L label]",
     72 #if notyet
     73 	"[-a alignment] [-b blocknr] [-i index] [-l label]",
     74 	"[-s size] [-t type]",
     75 #endif
     76 };
     77 
     78 struct gpt_cmd c_biosboot = {
     79 	"biosboot",
     80 	cmd_biosboot,
     81 	biosboothelp, __arraycount(biosboothelp),
     82 	0,
     83 };
     84 
     85 #define usage() gpt_usage(NULL, &c_biosboot)
     86 
     87 static struct mbr*
     88 read_boot(gpt_t gpt, const char *bootpath)
     89 {
     90 	int bfd, ret = -1;
     91 	struct mbr *buf;
     92 	struct stat st;
     93 	char *bp;
     94 
     95 	buf = NULL;
     96 	bfd = -1;
     97 
     98 	if (bootpath == NULL)
     99 		bp = strdup(DEFAULT_BOOTDIR "/" DEFAULT_BOOTCODE);
    100 	else if (*bootpath == '/')
    101 		bp = strdup(bootpath);
    102 	else {
    103 		if (asprintf(&bp, "%s/%s", DEFAULT_BOOTDIR, bootpath) < 0)
    104 			bp = NULL;
    105 	}
    106 
    107 	if (bp == NULL) {
    108 		gpt_warn(gpt, "Can't allocate memory for bootpath");
    109 		goto fail;
    110 	}
    111 
    112 	if ((buf = malloc((size_t)gpt->secsz)) == NULL) {
    113 		gpt_warn(gpt, "Can't allocate memory for sector");
    114 		goto fail;
    115 	}
    116 
    117 
    118 	if ((bfd = open(bp, O_RDONLY)) < 0 || fstat(bfd, &st) == -1) {
    119 		gpt_warn(gpt, "Can't open `%s'", bp);
    120 		goto fail;
    121 	}
    122 
    123 	if (st.st_size != MBR_DSN_OFFSET) {
    124 		gpt_warnx(gpt, "The bootcode in `%s' does not match the"
    125 		    " expected size %u", bp, MBR_DSN_OFFSET);
    126 		goto fail;
    127 	}
    128 
    129 	if (read(bfd, buf, (size_t)st.st_size) != (ssize_t)st.st_size) {
    130 		gpt_warn(gpt, "Error reading from `%s'", bp);
    131 		goto fail;
    132 	}
    133 
    134 	ret = 0;
    135 fail:
    136 	if (bfd != -1)
    137 		close(bfd);
    138 	if (ret == -1) {
    139 		free(buf);
    140 		buf = NULL;
    141 	}
    142 	free(bp);
    143 	return buf;
    144 }
    145 
    146 static int
    147 set_bootable(gpt_t gpt, map_t map, map_t tbl, unsigned int i)
    148 {
    149 	unsigned int j;
    150 	struct gpt_hdr *hdr = map->map_data;
    151 	struct gpt_ent *ent;
    152 	unsigned int ne = le32toh(hdr->hdr_entries);
    153 
    154 	for (j = 0; j < ne; j++) {
    155 		ent = gpt_ent(map, tbl, j);
    156 		ent->ent_attr &= ~GPT_ENT_ATTR_LEGACY_BIOS_BOOTABLE;
    157 	}
    158 
    159 	ent = gpt_ent(map, tbl, i);
    160 	ent->ent_attr |= GPT_ENT_ATTR_LEGACY_BIOS_BOOTABLE;
    161 
    162 	return gpt_write_crc(gpt, map, tbl);
    163 }
    164 
    165 static int
    166 biosboot(gpt_t gpt, daddr_t start, uint64_t size, u_int entry, uint8_t *label,
    167     const char *bootpath, int active)
    168 {
    169 	map_t mbrmap, m;
    170 	struct mbr *mbr, *bootcode;
    171 	unsigned int i;
    172 	struct gpt_ent *ent;
    173 	uint8_t utfbuf[__arraycount(ent->ent_name) * 3 + 1];
    174 
    175 	/*
    176 	 * Parse and validate partition maps
    177 	 */
    178 	if (gpt_hdr(gpt) == NULL)
    179 		return -1;
    180 
    181 	mbrmap = map_find(gpt, MAP_TYPE_PMBR);
    182 	if (mbrmap == NULL || mbrmap->map_start != 0) {
    183 		gpt_warnx(gpt, "No valid Protective MBR found");
    184 		return -1;
    185 	}
    186 
    187 	mbr = mbrmap->map_data;
    188 
    189 	/*
    190 	 * Update the boot code
    191 	 */
    192 	if ((bootcode = read_boot(gpt, bootpath)) == NULL) {
    193 		gpt_warnx(gpt, "Error reading bootcode");
    194 		return -1;
    195 	}
    196 	(void)memcpy(&mbr->mbr_code, &bootcode->mbr_code,
    197 		sizeof(mbr->mbr_code));
    198 	free(bootcode);
    199 
    200 	for (i = 0; i < __arraycount(mbr->mbr_part); i++)
    201 		if (mbr->mbr_part[i].part_typ == MBR_PTYPE_PMBR)
    202 			mbr->mbr_part[i].part_flag = active ? 0x80 : 0;
    203 
    204 	/*
    205 	 * Walk through the GPT and see where we can boot from
    206 	 */
    207 	for (m = map_first(gpt); m != NULL; m = m->map_next) {
    208 		if (m->map_type != MAP_TYPE_GPT_PART || m->map_index < 1)
    209 			continue;
    210 
    211 		ent = m->map_data;
    212 
    213 		/* first, prefer user selection */
    214 		if (entry > 0 && m->map_index == entry)
    215 			break;
    216 
    217 		if (label != NULL) {
    218 			utf16_to_utf8(ent->ent_name, utfbuf, sizeof(utfbuf));
    219 			if (strcmp((char *)label, (char *)utfbuf) == 0)
    220 				break;
    221 		}
    222 
    223 		/* next, partition as could be specified by wedge */
    224 		if (entry < 1 && label == NULL && size > 0 &&
    225 		    m->map_start == start && m->map_size == (off_t)size)
    226 			break;
    227 	}
    228 
    229 	if (m == NULL) {
    230 		gpt_warnx(gpt, "No bootable partition");
    231 		return -1;
    232 	}
    233 
    234 	i = m->map_index - 1;
    235 
    236 
    237 	if (set_bootable(gpt, gpt->gpt, gpt->tbl, i) == -1)
    238 		return -1;
    239 
    240 	if (set_bootable(gpt, gpt->tpg, gpt->lbt, i) == -1)
    241 		return -1;
    242 
    243 	if (gpt_write(gpt, mbrmap) == -1) {
    244 		gpt_warnx(gpt, "Cannot update Protective MBR");
    245 		return -1;
    246 	}
    247 
    248 	gpt_msg(gpt, "Partition %d marked as bootable", i + 1);
    249 	return 0;
    250 }
    251 
    252 static int
    253 cmd_biosboot(gpt_t gpt, int argc, char *argv[])
    254 {
    255 #ifdef DIOCGWEDGEINFO
    256 	struct dkwedge_info dkw;
    257 #endif
    258 	int ch;
    259 	gpt_t ngpt = gpt;
    260 	daddr_t start = 0;
    261 	uint64_t size = 0;
    262 	int active = 0;
    263 	unsigned int entry = 0;
    264 	uint8_t *label = NULL;
    265 	char *bootpath = NULL;
    266 
    267 	while ((ch = getopt(argc, argv, "Ac:i:L:")) != -1) {
    268 		switch(ch) {
    269 		case 'A':
    270 			active = 1;
    271 			break;
    272 		case 'c':
    273 			if (gpt_name_get(gpt, &bootpath) == -1)
    274 				goto usage;
    275 			break;
    276 		case 'i':
    277 			if (gpt_uint_get(gpt, &entry) == -1)
    278 				goto usage;
    279 			break;
    280 		case 'L':
    281 			if (gpt_name_get(gpt, &label) == -1)
    282 				goto usage;
    283 			break;
    284 		default:
    285 			goto usage;
    286 		}
    287 	}
    288 
    289 	if (argc != optind)
    290 		return usage();
    291 
    292 #ifdef DIOCGWEDGEINFO
    293 	if ((gpt->sb.st_mode & S_IFMT) != S_IFREG &&
    294 	    ioctl(gpt->fd, DIOCGWEDGEINFO, &dkw) != -1) {
    295 		if (entry > 0)
    296 			/* wedges and indexes are mutually exclusive */
    297 			goto usage;
    298 		start = dkw.dkw_offset;
    299 		size = dkw.dkw_size;
    300 		ngpt = gpt_open(dkw.dkw_parent, gpt->flags, gpt->verbose,
    301 		    gpt->mediasz, gpt->secsz);
    302 		if (ngpt == NULL)
    303 			goto cleanup;
    304 	}
    305 #endif
    306 	if (biosboot(ngpt, start, size, entry, label, bootpath, active) == -1)
    307 		goto cleanup;
    308 	if (ngpt != gpt)
    309 		gpt_close(ngpt);
    310 	return 0;
    311 usage:
    312 	usage();
    313 cleanup:
    314 	if (ngpt != gpt)
    315 		gpt_close(ngpt);
    316 	free(bootpath);
    317 	free(label);
    318 	return -1;
    319 }
    320