FreeBSD-5.3/usr.sbin/boot0cfg/boot0cfg.c
/*
* Copyright (c) 1999 Robert Nordier
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
* OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/usr.sbin/boot0cfg/boot0cfg.c,v 1.17.2.1 2004/10/15 15:59:26 kensmith Exp $");
#include <sys/param.h>
#include <sys/disklabel.h>
#include <sys/diskmbr.h>
#include <sys/stat.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#define MBRSIZE 512 /* master boot record size */
#define OFF_VERSION 0x1b0 /* offset: version number */
#define OFF_OPT 0x1b9 /* offset: default boot option */
#define OFF_DRIVE 0x1ba /* offset: setdrv drive */
#define OFF_FLAGS 0x1bb /* offset: option flags */
#define OFF_TICKS 0x1bc /* offset: clock ticks */
#define OFF_PTBL 0x1be /* offset: partition table */
#define OFF_MAGIC 0x1fe /* offset: magic number */
#define cv2(p) ((p)[0] | (p)[1] << 010)
#define mk2(p, x) \
(p)[0] = (u_int8_t)(x), \
(p)[1] = (u_int8_t)((x) >> 010)
static const struct {
const char *tok;
int def;
} opttbl[] = {
{"packet", 0},
{"update", 1},
{"setdrv", 0}
};
static const int nopt = sizeof(opttbl) / sizeof(opttbl[0]);
static const char fmt0[] = "# flag start chs type"
" end chs offset size\n";
static const char fmt1[] = "%d 0x%02x %4u:%3u:%2u 0x%02x"
" %4u:%3u:%2u %10u %10u\n";
static int read_mbr(const char *, u_int8_t **, int);
static void write_mbr(const char *, int, u_int8_t *, int);
static void display_mbr(u_int8_t *);
static int boot0version(const u_int8_t *);
static int boot0bs(const u_int8_t *);
static void stropt(const char *, int *, int *);
static char *mkrdev(const char *);
static int argtoi(const char *, int, int, int);
static void usage(void);
/*
* Boot manager installation/configuration utility.
*/
int
main(int argc, char *argv[])
{
u_int8_t *mbr, *boot0;
int boot0_size, mbr_size;
const char *bpath, *fpath;
char *disk;
int B_flag, v_flag, o_flag;
int d_arg, m_arg, s_arg, t_arg;
int o_and, o_or;
int up, c;
bpath = "/boot/boot0";
fpath = NULL;
B_flag = v_flag = o_flag = 0;
d_arg = m_arg = s_arg = t_arg = -1;
o_and = 0xff;
o_or = 0;
while ((c = getopt(argc, argv, "Bvb:d:f:m:o:s:t:")) != -1)
switch (c) {
case 'B':
B_flag = 1;
break;
case 'v':
v_flag = 1;
break;
case 'b':
bpath = optarg;
break;
case 'd':
d_arg = argtoi(optarg, 0, 0xff, 'd');
break;
case 'f':
fpath = optarg;
break;
case 'm':
m_arg = argtoi(optarg, 0, 0xf, 'm');
break;
case 'o':
stropt(optarg, &o_and, &o_or);
o_flag = 1;
break;
case 's':
s_arg = argtoi(optarg, 1, 5, 's');
break;
case 't':
t_arg = argtoi(optarg, 1, 0xffff, 't');
break;
default:
usage();
}
argc -= optind;
argv += optind;
if (argc != 1)
usage();
disk = mkrdev(*argv);
up = B_flag || d_arg != -1 || m_arg != -1 || o_flag || s_arg != -1
|| t_arg != -1;
/* open the disk and read in the existing mbr */
mbr_size = read_mbr(disk, &mbr, !B_flag);
/* save the existing MBR if we are asked to do so */
if (fpath)
write_mbr(fpath, O_CREAT | O_TRUNC, mbr, mbr_size);
/*
* If we are installing the boot loader, read it from disk and copy the
* slice table over from the existing MBR. If not, then point boot0
* back at the MBR we just read in. After this, boot0 is the data to
* write back to disk if we are going to do a write.
*/
if (B_flag) {
boot0_size = read_mbr(bpath, &boot0, 1);
memcpy(boot0 + OFF_PTBL, mbr + OFF_PTBL,
sizeof(struct dos_partition) * NDOSPART);
} else {
boot0 = mbr;
boot0_size = mbr_size;
}
/* set the drive */
if (d_arg != -1)
boot0[OFF_DRIVE] = d_arg;
/* set various flags */
if (m_arg != -1) {
boot0[OFF_FLAGS] &= 0xf0;
boot0[OFF_FLAGS] |= m_arg;
}
if (o_flag) {
boot0[OFF_FLAGS] &= o_and;
boot0[OFF_FLAGS] |= o_or;
}
/* set the default boot selection */
if (s_arg != -1)
boot0[OFF_OPT] = s_arg - 1;
/* set the timeout */
if (t_arg != -1)
mk2(boot0 + OFF_TICKS, t_arg);
/* write the MBR back to disk */
if (up)
write_mbr(disk, 0, boot0, boot0_size);
/* display the MBR */
if (v_flag)
display_mbr(boot0);
/* clean up */
if (mbr != boot0)
free(boot0);
free(mbr);
free(disk);
return 0;
}
/*
* Read in the MBR of the disk. If it is boot0, then use the version to
* read in all of it if necessary. Use pointers to return a malloc'd
* buffer containing the MBR and then return its size.
*/
static int
read_mbr(const char *disk, u_int8_t **mbr, int check_version)
{
u_int8_t buf[MBRSIZE];
int mbr_size, fd;
ssize_t n;
if ((fd = open(disk, O_RDONLY)) == -1)
err(1, "open %s", disk);
if ((n = read(fd, buf, MBRSIZE)) == -1)
err(1, "read %s", disk);
if (n != MBRSIZE)
errx(1, "%s: short read", disk);
if (cv2(buf + OFF_MAGIC) != 0xaa55)
errx(1, "%s: bad magic", disk);
if (!boot0bs(buf)) {
if (check_version)
errx(1, "%s: unknown or incompatible boot code", disk);
} else if (boot0version(buf) == 0x101) {
mbr_size = 1024;
if ((*mbr = malloc(mbr_size)) == NULL)
errx(1, "%s: unable to allocate read buffer", disk);
if (lseek(fd, 0, SEEK_SET) == -1 ||
(n = read(fd, *mbr, mbr_size)) == -1)
err(1, "%s", disk);
if (n != mbr_size)
errx(1, "%s: short read", disk);
return (mbr_size);
}
*mbr = malloc(sizeof(buf));
memcpy(*mbr, buf, sizeof(buf));
return sizeof(buf);
}
/*
* Write out the mbr to the specified file.
*/
static void
write_mbr(const char *fname, int flags, u_int8_t *mbr, int mbr_size)
{
int fd, p;
ssize_t n;
char *s;
fd = open(fname, O_WRONLY | flags, 0666);
if (fd != -1) {
n = write(fd, mbr, mbr_size);
close(fd);
if (n != mbr_size)
errx(1, "%s: short write", fname);
return;
}
if (flags != 0)
err(1, "%s", fname);
#ifdef DIOCSMBR
for (p = 1; p < 5; p++) {
asprintf(&s, "%ss%d", fname, p);
fd = open(s, O_RDONLY);
if (fd < 0) {
free(s);
continue;
}
n = ioctl(fd, DIOCSMBR, (mbr));
if (n != 0)
err(1, "%s: ioctl DIOCSMBR", fname);
close(fd);
free(s);
return;
}
#endif
err(1, "write_mbr: %s", fname);
}
/*
* Outputs an informative dump of the data in the MBR to stdout.
*/
static void
display_mbr(u_int8_t *mbr)
{
struct dos_partition *part;
int i, version;
part = (struct dos_partition *)(mbr + DOSPARTOFF);
printf(fmt0);
for (i = 0; i < NDOSPART; i++)
if (part[i].dp_typ)
printf(fmt1, 1 + i, part[i].dp_flag,
part[i].dp_scyl + ((part[i].dp_ssect & 0xc0) << 2),
part[i].dp_shd, part[i].dp_ssect & 0x3f, part[i].dp_typ,
part[i].dp_ecyl + ((part[i].dp_esect & 0xc0) << 2),
part[i].dp_ehd, part[i].dp_esect & 0x3f, part[i].dp_start,
part[i].dp_size);
printf("\n");
version = boot0version(mbr);
printf("version=%d.%d drive=0x%x mask=0x%x ticks=%u\noptions=",
version >> 8, version & 0xff, mbr[OFF_DRIVE],
mbr[OFF_FLAGS] & 0xf, cv2(mbr + OFF_TICKS));
for (i = 0; i < nopt; i++) {
if (i)
printf(",");
if (!(mbr[OFF_FLAGS] & 1 << (7 - i)) ^ opttbl[i].def)
printf("no");
printf("%s", opttbl[i].tok);
}
printf("\n");
printf("default_selection=F%d (", mbr[OFF_OPT] + 1);
if (mbr[OFF_OPT] < 4)
printf("Slice %d", mbr[OFF_OPT] + 1);
else
printf("Drive 1");
printf(")\n");
}
/*
* Return the boot0 version with the minor revision in the low byte, and
* the major revision in the next higher byte.
*/
static int
boot0version(const u_int8_t *bs)
{
static u_int8_t idold[] = {0xfe, 0x45, 0xf2, 0xe9, 0x00, 0x8a};
/* Check for old version, and return 0x100 if found. */
if (memcmp(bs + 0x1c, idold, sizeof(idold)) == 0)
return 0x100;
/* We have a newer boot0, so extract the version number and return it. */
return *(const int *)(bs + OFF_VERSION) & 0xffff;
}
/*
* Decide if we have valid boot0 boot code by looking for
* characteristic byte sequences at fixed offsets.
*/
static int
boot0bs(const u_int8_t *bs)
{
static u_int8_t id0[] = {0xfc, 0x31, 0xc0, 0x8e, 0xc0, 0x8e, 0xd8,
0x8e, 0xd0, 0xbc, 0x00, 0x7c };
static u_int8_t id1[] = {'D', 'r', 'i', 'v', 'e', ' '};
static struct {
unsigned off;
unsigned len;
u_int8_t *key;
} ident[2] = {
{0x0, sizeof(id0), id0},
{0x1b2, sizeof(id1), id1}
};
unsigned int i;
for (i = 0; i < sizeof(ident) / sizeof(ident[0]); i++)
if (memcmp(bs + ident[i].off, ident[i].key, ident[i].len))
return 0;
return 1;
}
/*
* Adjust "and" and "or" masks for a -o option argument.
*/
static void
stropt(const char *arg, int *xa, int *xo)
{
const char *q;
char *s, *s1;
int inv, i, x;
if (!(s = strdup(arg)))
err(1, NULL);
for (s1 = s; (q = strtok(s1, ",")); s1 = NULL) {
if ((inv = !strncmp(q, "no", 2)))
q += 2;
for (i = 0; i < nopt; i++)
if (!strcmp(q, opttbl[i].tok))
break;
if (i == nopt)
errx(1, "%s: Unknown -o option", q);
if (opttbl[i].def)
inv ^= 1;
x = 1 << (7 - i);
if (inv)
*xa &= ~x;
else
*xo |= x;
}
free(s);
}
/*
* Produce a device path for a "canonical" name, where appropriate.
*/
static char *
mkrdev(const char *fname)
{
char buf[MAXPATHLEN];
char *s;
if (!strchr(fname, '/')) {
snprintf(buf, sizeof(buf), "%s%s", _PATH_DEV, fname);
s = strdup(buf);
} else
s = strdup(fname);
if (s == NULL)
errx(1, "No more memory");
return s;
}
/*
* Convert and check an option argument.
*/
static int
argtoi(const char *arg, int lo, int hi, int opt)
{
char *s;
long x;
errno = 0;
x = strtol(arg, &s, 0);
if (errno || !*arg || *s || x < lo || x > hi)
errx(1, "%s: Bad argument to -%c option", arg, opt);
return x;
}
/*
* Display usage information.
*/
static void
usage(void)
{
fprintf(stderr, "%s\n%s\n",
"usage: boot0cfg [-Bv] [-b boot0] [-d drive] [-f file] [-m mask]",
" [-o options] [-s slice] [-t ticks] disk");
exit(1);
}