freebsd-dev/usr.sbin/boot0cfg/boot0cfg.c
Baptiste Daroussin 5b990a9463 Revert r362466
Such change should not have happen without prior discussion and review.

With hat:	transitioning core
2020-06-22 07:46:24 +00:00

603 lines
16 KiB
C

/*
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2008 Luigi Rizzo
* 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("$FreeBSD$");
#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 <libgeom.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, only boot0version */
#define OFF_SERIAL 0x1b8 /* offset: volume serial number */
#define OFF_PTBL 0x1be /* offset: partition table */
#define OFF_MAGIC 0x1fe /* offset: magic number */
/*
* Offsets to the parameters of the 512-byte boot block.
* For historical reasons they are set as macros
*/
struct opt_offsets {
int opt;
int drive;
int flags;
int ticks;
};
static struct opt_offsets b0_ofs[] = {
{ 0x0, 0x0, 0x0, 0x0 }, /* no boot block */
{ 0x1b9, 0x1ba, 0x1bb, 0x1bc }, /* original block */
{ 0x1b5, 0x1b6, 0x1b7, 0x1bc }, /* NT_SERIAL block */
};
static int b0_ver; /* boot block version set by boot0bs */
#define OFF_OPT (b0_ofs[b0_ver].opt) /* default boot option */
#define OFF_DRIVE (b0_ofs[b0_ver].drive) /* setdrv drive */
#define OFF_FLAGS (b0_ofs[b0_ver].flags) /* option flags */
#define OFF_TICKS (b0_ofs[b0_ver].ticks) /* clock ticks */
#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 = nitems(opttbl);
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 geom_class_available(const char *);
static int read_mbr(const char *, u_int8_t **, int);
static void write_mbr(const char *, int, u_int8_t *, int, 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 int argtoi(const char *, int, int, int);
static int set_bell(u_int8_t *, int, int);
static void usage(void);
static unsigned vol_id[5]; /* 4 plus 1 for flag */
static int v_flag;
/*
* 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, o_flag;
int d_arg, m_arg, s_arg, t_arg;
int o_and, o_or, o_e = -1;
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:e:f:i: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 'e':
if (optarg[0] == '0' && optarg[1] == 'x')
sscanf(optarg, "0x%02x", &o_e);
else
o_e = optarg[0];
break;
case 'f':
fpath = optarg;
break;
case 'i':
if (sscanf(optarg, "%02x%02x-%02x%02x",
vol_id, vol_id+1, vol_id+2, vol_id+3) == 4)
vol_id[4] = 1;
else
errx(1, "bad argument %s", 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':
if (strcasecmp(optarg, "pxe") == 0)
s_arg = 6;
else
s_arg = argtoi(optarg, 1, 6, 's');
break;
case 't':
t_arg = argtoi(optarg, 1, 0xffff, 't');
break;
default:
usage();
}
argc -= optind;
argv += optind;
if (argc != 1)
usage();
disk = g_device_path(*argv);
if (disk == NULL)
errx(1, "Unable to get providername for %s\n", *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. Either here or
* when reading the block from disk, we do check for the version
* and abort if a suitable block is not found.
*/
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, 0);
/*
* 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);
if (b0_ver == 2) /* volume serial number support */
memcpy(boot0 + OFF_SERIAL, mbr + OFF_SERIAL, 4);
} 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);
/* set the bell char */
if (o_e != -1 && set_bell(boot0, o_e, 0) != -1)
up = 1;
if (vol_id[4]) {
if (b0_ver != 2)
errx(1, "incompatible boot block, cannot set volume ID");
boot0[OFF_SERIAL] = vol_id[0];
boot0[OFF_SERIAL+1] = vol_id[1];
boot0[OFF_SERIAL+2] = vol_id[2];
boot0[OFF_SERIAL+3] = vol_id[3];
up = 1; /* force update */
}
/* write the MBR back to disk */
if (up)
write_mbr(disk, 0, boot0, boot0_size, vol_id[4] || b0_ver == 1);
/* display the MBR */
if (v_flag)
display_mbr(boot0);
/* clean up */
if (mbr != boot0)
free(boot0);
free(mbr);
free(disk);
return 0;
}
/* get or set the 'bell' character to be used in case of errors.
* Lookup for a certain code sequence, return -1 if not found.
*/
static int
set_bell(u_int8_t *mbr, int new_bell, int report)
{
/* lookup sequence: 0x100 means skip, 0x200 means done */
static unsigned seq[] =
{ 0xb0, 0x100, 0xe8, 0x100, 0x100, 0x30, 0xe4, 0x200 };
int ofs, i, c;
for (ofs = 0x60; ofs < 0x180; ofs++) { /* search range */
if (mbr[ofs] != seq[0]) /* search initial pattern */
continue;
for (i=0;; i++) {
if (seq[i] == 0x200) { /* found */
c = mbr[ofs+1];
if (!report)
mbr[ofs+1] = c = new_bell;
else
printf(" bell=%c (0x%x)",
(c >= ' ' && c < 0x7f) ? c : ' ', c);
return c;
}
if (seq[i] != 0x100 && seq[i] != mbr[ofs+i])
break;
}
}
warn("bell not found");
return -1;
}
/*
* 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;
int ver;
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 (! (ver = 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);
close(fd);
return (mbr_size);
}
if ((*mbr = malloc(sizeof(buf))) == NULL)
errx(1, "%s: unable to allocate MBR buffer", disk);
memcpy(*mbr, buf, sizeof(buf));
close(fd);
return sizeof(buf);
}
static int
geom_class_available(const char *name)
{
struct gclass *class;
struct gmesh mesh;
int error;
error = geom_gettree(&mesh);
if (error != 0)
errc(1, error, "Cannot get GEOM tree");
LIST_FOREACH(class, &mesh.lg_class, lg_class) {
if (strcmp(class->lg_name, name) == 0) {
geom_deletetree(&mesh);
return (1);
}
}
geom_deletetree(&mesh);
return (0);
}
/*
* 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 disable_dsn)
{
struct gctl_req *grq;
const char *errmsg;
char *pname;
ssize_t n;
int fd;
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 we're called to write to a backup file, don't try to
* write through GEOM.
*/
if (flags != 0)
err(1, "can't open file %s to write backup", fname);
/* Try open it read only. */
fd = open(fname, O_RDONLY);
if (fd == -1) {
warn("error opening %s", fname);
return;
}
pname = g_providername(fd);
if (pname == NULL) {
warn("error getting providername for %s", fname);
return;
}
/* First check that GEOM_PART is available */
if (geom_class_available("PART") != 0) {
grq = gctl_get_handle();
gctl_ro_param(grq, "class", -1, "PART");
gctl_ro_param(grq, "arg0", -1, pname);
gctl_ro_param(grq, "verb", -1, "bootcode");
gctl_ro_param(grq, "bootcode", mbr_size, mbr);
gctl_ro_param(grq, "flags", -1, "C");
if (disable_dsn)
gctl_ro_param(grq, "skip_dsn", sizeof(int),
&disable_dsn);
errmsg = gctl_issue(grq);
if (errmsg != NULL && errmsg[0] != '\0')
errx(1, "GEOM_PART: write bootcode to %s failed: %s",
fname, errmsg);
gctl_free(grq);
} else
errx(1, "can't write MBR to %s", fname);
free(pname);
}
/*
* 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",
version >> 8, version & 0xff, mbr[OFF_DRIVE],
mbr[OFF_FLAGS] & 0xf, cv2(mbr + OFF_TICKS));
set_bell(mbr, 0, 1);
printf("\noptions=");
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");
if (b0_ver == 2)
printf("volume serial ID %02x%02x-%02x%02x\n",
mbr[OFF_SERIAL], mbr[OFF_SERIAL+1],
mbr[OFF_SERIAL+2], mbr[OFF_SERIAL+3]);
printf("default_selection=F%d (", mbr[OFF_OPT] + 1);
if (mbr[OFF_OPT] < 4)
printf("Slice %d", mbr[OFF_OPT] + 1);
else if (mbr[OFF_OPT] == 4)
printf("Drive 1");
else
printf("PXE");
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)
{
/* Check for old version, and return 0x100 if found. */
int v = boot0bs(bs);
if (v != 0)
return v << 8;
/* We have a newer boot0, so extract the version number and return it. */
return *(const int *)(bs + OFF_VERSION) & 0xffff;
}
/* descriptor of a pattern to match.
* Start from the first entry trying to match the chunk of bytes,
* if you hit an entry with len=0 terminate the search and report
* off as the version. Otherwise skip to the next block after len=0
* An entry with len=0, off=0 is the end marker.
*/
struct byte_pattern {
unsigned off;
unsigned len;
u_int8_t *key;
};
/*
* 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)
{
/* the initial code sequence */
static u_int8_t id0[] = {0xfc, 0x31, 0xc0, 0x8e, 0xc0, 0x8e, 0xd8,
0x8e, 0xd0, 0xbc, 0x00, 0x7c };
/* the drive id */
static u_int8_t id1[] = {'D', 'r', 'i', 'v', 'e', ' '};
static struct byte_pattern patterns[] = {
{0x0, sizeof(id0), id0},
{0x1b2, sizeof(id1), id1},
{1, 0, NULL},
{0x0, sizeof(id0), id0}, /* version with NT support */
{0x1ae, sizeof(id1), id1},
{2, 0, NULL},
{0, 0, NULL},
};
struct byte_pattern *p = patterns;
for (; p->off || p->len; p++) {
if (p->len == 0)
break;
if (!memcmp(bs + p->off, p->key, p->len)) /* match */
continue;
while (p->len) /* skip to next block */
p++;
}
b0_ver = p->off; /* XXX ugly side effect */
return p->off;
}
/*
* 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);
}
/*
* 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);
}