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biosboot.c revision 1.32 
      1 /*	$NetBSD: biosboot.c,v 1.32 2019/06/20 10:56:38 martin 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 1.32 2019/06/20 10:56:38 martin Exp $");
     41 #endif
     42 
     43 #include <sys/stat.h>
     44 #include <sys/types.h>
     45 #include <sys/ioctl.h>
     46 #include <sys/param.h>
     47 #include <sys/bootblock.h>
     48 
     49 #if defined(DIOCGWEDGEINFO) && !defined(HAVE_NBTOOL_CONFIG_H)
     50 #define USE_WEDGES
     51 #endif
     52 #ifdef USE_WEDGES
     53 #include <sys/disk.h>
     54 #endif
     55 
     56 #include <err.h>
     57 #include <fcntl.h>
     58 #include <paths.h>
     59 #include <stddef.h>
     60 #include <stdio.h>
     61 #include <stdlib.h>
     62 #include <string.h>
     63 #include <unistd.h>
     64 
     65 #include "map.h"
     66 #include "gpt.h"
     67 #include "gpt_private.h"
     68 
     69 #define DEFAULT_BOOTDIR		"/usr/mdec"
     70 #define DEFAULT_BOOTCODE	"gptmbr.bin"
     71 
     72 static int cmd_biosboot(gpt_t, int, char *[]);
     73 
     74 static const char *biosboothelp[] = {
     75 	"[-A] [-c bootcode] [-i index] [-L label] [-b startsec]",
     76 #if notyet
     77 	"[-a alignment] [-b blocknr] [-i index] [-l label]",
     78 	"[-s size] [-t type]",
     79 #endif
     80 };
     81 
     82 struct gpt_cmd c_biosboot = {
     83 	"biosboot",
     84 	cmd_biosboot,
     85 	biosboothelp, __arraycount(biosboothelp),
     86 	0,
     87 };
     88 
     89 #define usage() gpt_usage(NULL, &c_biosboot)
     90 
     91 static struct mbr*
     92 read_boot(gpt_t gpt, const char *bootpath)
     93 {
     94 	int bfd, ret = -1;
     95 	struct mbr *buf;
     96 	struct stat st;
     97 	char *bp;
     98 
     99 	buf = NULL;
    100 	bfd = -1;
    101 
    102 	if (bootpath == NULL)
    103 		bp = strdup(DEFAULT_BOOTDIR "/" DEFAULT_BOOTCODE);
    104 	else if (*bootpath == '/')
    105 		bp = strdup(bootpath);
    106 	else {
    107 		if (asprintf(&bp, "%s/%s", DEFAULT_BOOTDIR, bootpath) < 0)
    108 			bp = NULL;
    109 	}
    110 
    111 	if (bp == NULL) {
    112 		gpt_warn(gpt, "Can't allocate memory for bootpath");
    113 		goto fail;
    114 	}
    115 
    116 	if ((buf = malloc((size_t)gpt->secsz)) == NULL) {
    117 		gpt_warn(gpt, "Can't allocate memory for sector");
    118 		goto fail;
    119 	}
    120 
    121 
    122 	if ((bfd = open(bp, O_RDONLY)) < 0 || fstat(bfd, &st) == -1) {
    123 		gpt_warn(gpt, "Can't open `%s'", bp);
    124 		goto fail;
    125 	}
    126 
    127 	if (st.st_size != MBR_DSN_OFFSET) {
    128 		gpt_warnx(gpt, "The bootcode in `%s' does not match the"
    129 		    " expected size %u", bp, MBR_DSN_OFFSET);
    130 		goto fail;
    131 	}
    132 
    133 	if (read(bfd, buf, (size_t)st.st_size) != (ssize_t)st.st_size) {
    134 		gpt_warn(gpt, "Error reading from `%s'", bp);
    135 		goto fail;
    136 	}
    137 
    138 	ret = 0;
    139 fail:
    140 	if (bfd != -1)
    141 		close(bfd);
    142 	if (ret == -1) {
    143 		free(buf);
    144 		buf = NULL;
    145 	}
    146 	free(bp);
    147 	return buf;
    148 }
    149 
    150 static int
    151 set_bootable(gpt_t gpt, map_t map, map_t tbl, unsigned int i)
    152 {
    153 	unsigned int j;
    154 	struct gpt_hdr *hdr = map->map_data;
    155 	struct gpt_ent *ent;
    156 	unsigned int ne = le32toh(hdr->hdr_entries);
    157 
    158 	for (j = 0; j < ne; j++) {
    159 		ent = gpt_ent(map, tbl, j);
    160 		ent->ent_attr &= ~GPT_ENT_ATTR_LEGACY_BIOS_BOOTABLE;
    161 	}
    162 
    163 	ent = gpt_ent(map, tbl, i);
    164 	ent->ent_attr |= GPT_ENT_ATTR_LEGACY_BIOS_BOOTABLE;
    165 
    166 	return gpt_write_crc(gpt, map, tbl);
    167 }
    168 
    169 static int
    170 biosboot(gpt_t gpt, daddr_t start, uint64_t size, u_int entry, uint8_t *label,
    171     const char *bootpath, int active)
    172 {
    173 	map_t mbrmap, m;
    174 	struct mbr *mbr, *bootcode;
    175 	unsigned int i;
    176 	struct gpt_ent *ent;
    177 	uint8_t utfbuf[__arraycount(ent->ent_name) * 3 + 1];
    178 
    179 	/*
    180 	 * Parse and validate partition maps
    181 	 */
    182 	if (gpt_hdr(gpt) == NULL)
    183 		return -1;
    184 
    185 	mbrmap = map_find(gpt, MAP_TYPE_PMBR);
    186 	if (mbrmap == NULL || mbrmap->map_start != 0) {
    187 		gpt_warnx(gpt, "No valid Protective MBR found");
    188 		return -1;
    189 	}
    190 
    191 	mbr = mbrmap->map_data;
    192 
    193 	/*
    194 	 * Update the boot code
    195 	 */
    196 	if ((bootcode = read_boot(gpt, bootpath)) == NULL) {
    197 		gpt_warnx(gpt, "Error reading bootcode");
    198 		return -1;
    199 	}
    200 	(void)memcpy(&mbr->mbr_code, &bootcode->mbr_code,
    201 		sizeof(mbr->mbr_code));
    202 	free(bootcode);
    203 
    204 	for (i = 0; i < __arraycount(mbr->mbr_part); i++)
    205 		if (mbr->mbr_part[i].part_typ == MBR_PTYPE_PMBR)
    206 			mbr->mbr_part[i].part_flag = active ? 0x80 : 0;
    207 
    208 	/*
    209 	 * Walk through the GPT and see where we can boot from
    210 	 */
    211 	for (m = map_first(gpt); m != NULL; m = m->map_next) {
    212 		if (m->map_type != MAP_TYPE_GPT_PART || m->map_index < 1)
    213 			continue;
    214 
    215 		ent = m->map_data;
    216 
    217 		/* first, prefer user selection */
    218 		if (entry > 0 && m->map_index == entry)
    219 			break;
    220 
    221 		if (label != NULL) {
    222 			utf16_to_utf8(ent->ent_name,
    223 			    __arraycount(ent->ent_name), utfbuf,
    224 			    __arraycount(utfbuf));
    225 			if (strcmp((char *)label, (char *)utfbuf) == 0)
    226 				break;
    227 		}
    228 
    229 		/* next, partition as could be specified by wedge */
    230 		if (entry < 1 && label == NULL && size > 0 &&
    231 		    m->map_start == start && m->map_size == (off_t)size)
    232 			break;
    233 		/* next could be start sector specified by -b option */
    234 		if (entry < 1 && label == NULL && size == 0 &&
    235 		    m->map_start == start)
    236 			break;
    237 	}
    238 
    239 	if (m == NULL) {
    240 		gpt_warnx(gpt, "No bootable partition");
    241 		return -1;
    242 	}
    243 
    244 	i = m->map_index - 1;
    245 
    246 
    247 	if (set_bootable(gpt, gpt->gpt, gpt->tbl, i) == -1)
    248 		return -1;
    249 
    250 	if (set_bootable(gpt, gpt->tpg, gpt->lbt, i) == -1)
    251 		return -1;
    252 
    253 	if (gpt_write(gpt, mbrmap) == -1) {
    254 		gpt_warnx(gpt, "Cannot update Protective MBR");
    255 		return -1;
    256 	}
    257 
    258 	gpt_msg(gpt, "Partition %d marked as bootable", i + 1);
    259 	return 0;
    260 }
    261 
    262 static int
    263 cmd_biosboot(gpt_t gpt, int argc, char *argv[])
    264 {
    265 #ifdef USE_WEDGES
    266 	struct dkwedge_info dkw;
    267 #endif
    268 	int ch;
    269 	gpt_t ngpt = gpt;
    270 	daddr_t start = 0;
    271 	uint64_t size = 0;
    272 	int active = 0;
    273 	unsigned int entry = 0;
    274 	uint8_t *label = NULL;
    275 	char *bootpath = NULL;
    276 
    277 	while ((ch = getopt(argc, argv, "Ac:i:L:b:")) != -1) {
    278 		switch(ch) {
    279 		case 'A':
    280 			active = 1;
    281 			break;
    282 		case 'c':
    283 			if (gpt_name_get(gpt, &bootpath) == -1)
    284 				goto usage;
    285 			break;
    286 		case 'i':
    287 			if (gpt_uint_get(gpt, &entry) == -1)
    288 				goto usage;
    289 			break;
    290 		case 'L':
    291 			if (gpt_name_get(gpt, &label) == -1)
    292 				goto usage;
    293 			break;
    294 		case 'b':
    295 			if (gpt_human_get(gpt, &start) == -1)
    296 				goto usage;
    297 			break;
    298 		default:
    299 			goto usage;
    300 		}
    301 	}
    302 
    303 	if (argc != optind)
    304 		return usage();
    305 
    306 #ifdef USE_WEDGES
    307 	if ((gpt->sb.st_mode & S_IFMT) != S_IFREG &&
    308 	    ioctl(gpt->fd, DIOCGWEDGEINFO, &dkw) != -1) {
    309 		if (entry > 0)
    310 			/* wedges and indexes are mutually exclusive */
    311 			goto usage;
    312 		start = dkw.dkw_offset;
    313 		size = dkw.dkw_size;
    314 		ngpt = gpt_open(dkw.dkw_parent, gpt->flags, gpt->verbose,
    315 		    0, 0, 0);
    316 		if (ngpt == NULL)
    317 			goto cleanup;
    318 	}
    319 #endif
    320 	if (biosboot(ngpt, start, size, entry, label, bootpath, active) == -1)
    321 		goto cleanup;
    322 	if (ngpt != gpt)
    323 		gpt_close(ngpt);
    324 	return 0;
    325 usage:
    326 	usage();
    327 cleanup:
    328 	if (ngpt != gpt)
    329 		gpt_close(ngpt);
    330 	free(bootpath);
    331 	free(label);
    332 	return -1;
    333 }
    334