u-boot/cmd/mbr.c
Simon Glass 362a79f3e8 mbr: Correct verification check
At present this command considers the partitions to be identical if the
start and size are smaller than expected. It should check that they are
the same. Fix this and tidy up the code style a little.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
2021-11-28 16:51:51 -07:00

315 lines
6.4 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* cmd_mbr.c -- MBR (Master Boot Record) handling command
*
* Copyright (C) 2020 Samsung Electronics
* author: Marek Szyprowski <m.szyprowski@samsung.com>
*
* based on the gpt command.
*/
#include <common.h>
#include <blk.h>
#include <command.h>
#include <malloc.h>
#include <part.h>
/**
* extract_val() - Extract a value from the key=value pair list
* @str: pointer to string with key=values pairs
* @key: pointer to the key to search for
*
* The list of parameters is come separated, only a value for
* the given key is returend.
*
* Function allocates memory for the value, remember to free!
*
* Return: Pointer to allocated string with the value.
*/
static char *extract_val(const char *str, const char *key)
{
char *v, *k;
char *s, *strcopy;
char *new = NULL;
strcopy = strdup(str);
if (strcopy == NULL)
return NULL;
s = strcopy;
while (s) {
v = strsep(&s, ",");
if (!v)
break;
k = strsep(&v, "=");
if (!k)
break;
if (strcmp(k, key) == 0) {
new = strdup(v);
break;
}
}
free(strcopy);
return new;
}
/**
* found_key() - Search for a key without a value in the parameter list
* @str: pointer to string with key
* @key: pointer to the key to search for
*
* The list of parameters is come separated.
*
* Return: True if key has been found.
*/
static bool found_key(const char *str, const char *key)
{
char *k;
char *s, *strcopy;
bool result = false;
strcopy = strdup(str);
if (!strcopy)
return NULL;
s = strcopy;
while (s) {
k = strsep(&s, ",");
if (!k)
break;
if (strcmp(k, key) == 0) {
result = true;
break;
}
}
free(strcopy);
return result;
}
static int str_to_partitions(const char *str_part, int blksz,
unsigned long *disk_uuid, struct disk_partition **partitions,
int *parts_count)
{
char *tok, *str, *s;
int i;
char *val, *p;
int p_count;
struct disk_partition *parts;
int errno = 0;
uint64_t size_ll, start_ll;
if (str_part == NULL)
return -1;
str = strdup(str_part);
if (str == NULL)
return -ENOMEM;
/* extract disk guid */
s = str;
val = extract_val(str, "uuid_disk");
if (val) {
val = strsep(&val, ";");
p = val;
*disk_uuid = ustrtoull(p, &p, 0);
free(val);
/* Move s to first partition */
strsep(&s, ";");
}
if (s == NULL) {
printf("Error: is the partitions string NULL-terminated?\n");
return -EINVAL;
}
/* remove the optional semicolon at the end of the string */
i = strlen(s) - 1;
if (s[i] == ';')
s[i] = '\0';
/* calculate expected number of partitions */
p_count = 1;
p = s;
while (*p) {
if (*p++ == ';')
p_count++;
}
/* allocate memory for partitions */
parts = calloc(sizeof(struct disk_partition), p_count);
if (parts == NULL)
return -ENOMEM;
/* retrieve partitions data from string */
for (i = 0; i < p_count; i++) {
tok = strsep(&s, ";");
if (tok == NULL)
break;
/* size */
val = extract_val(tok, "size");
if (!val) { /* 'size' is mandatory */
errno = -4;
goto err;
}
p = val;
if ((strcmp(p, "-") == 0)) {
/* auto extend the size */
parts[i].size = 0;
} else {
size_ll = ustrtoull(p, &p, 0);
parts[i].size = size_ll / blksz;
}
free(val);
/* start address */
val = extract_val(tok, "start");
if (val) { /* start address is optional */
p = val;
start_ll = ustrtoull(p, &p, 0);
parts[i].start = start_ll / blksz;
free(val);
}
/* system id */
val = extract_val(tok, "id");
if (!val) { /* '' is mandatory */
errno = -4;
goto err;
}
p = val;
parts[i].sys_ind = ustrtoul(p, &p, 0);
free(val);
/* bootable */
if (found_key(tok, "bootable"))
parts[i].bootable = PART_BOOTABLE;
}
*parts_count = p_count;
*partitions = parts;
free(str);
return 0;
err:
free(str);
free(parts);
return errno;
}
static int do_write_mbr(struct blk_desc *dev, const char *str)
{
unsigned long disk_uuid = 0;
struct disk_partition *partitions;
int blksz = dev->blksz;
int count;
if (str_to_partitions(str, blksz, &disk_uuid, &partitions, &count)) {
printf("MBR: failed to setup partitions from \"%s\"\n", str);
return -1;
}
if (layout_mbr_partitions(partitions, count, dev->lba)) {
printf("MBR: failed to layout partitions on the device\n");
free(partitions);
return -1;
}
if (write_mbr_partitions(dev, partitions, count, disk_uuid)) {
printf("MBR: failed to write partitions to the device\n");
free(partitions);
return -1;
}
return 0;
}
static int do_verify_mbr(struct blk_desc *dev, const char *str)
{
unsigned long disk_uuid = 0;
struct disk_partition *partitions;
int blksz = dev->blksz;
int count, i, ret = 1;
if (str_to_partitions(str, blksz, &disk_uuid, &partitions, &count)) {
printf("MBR: failed to setup partitions from \"%s\"\n", str);
return -1;
}
for (i = 0; i < count; i++) {
struct disk_partition p;
if (part_get_info(dev, i + 1, &p))
goto fail;
if ((partitions[i].size && p.size != partitions[i].size) ||
(partitions[i].start && p.start != partitions[i].start) ||
p.sys_ind != partitions[i].sys_ind)
goto fail;
}
ret = 0;
fail:
free(partitions);
return ret;
}
static int do_mbr(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
const char *parts = NULL;
int ret = CMD_RET_SUCCESS;
int dev = 0;
char *ep;
struct blk_desc *blk_dev_desc = NULL;
if (argc != 4 && argc != 5)
return CMD_RET_USAGE;
dev = (int)dectoul(argv[3], &ep);
if (!ep || ep[0] != '\0') {
printf("'%s' is not a number\n", argv[3]);
return CMD_RET_USAGE;
}
blk_dev_desc = blk_get_dev(argv[2], dev);
if (!blk_dev_desc) {
printf("%s: %s dev %d NOT available\n",
__func__, argv[2], dev);
return CMD_RET_FAILURE;
}
if ((strcmp(argv[1], "write") == 0)) {
parts = (argc == 5) ? argv[4] : env_get("mbr_parts");
printf("MBR: write ");
ret = do_write_mbr(blk_dev_desc, parts);
} else if ((strcmp(argv[1], "verify") == 0)) {
printf("MBR: verify ");
parts = (argc == 5) ? argv[4] : env_get("mbr_parts");
ret = do_verify_mbr(blk_dev_desc, parts);
} else {
return CMD_RET_USAGE;
}
if (ret) {
printf("error!\n");
return CMD_RET_FAILURE;
}
printf("success!\n");
return CMD_RET_SUCCESS;
}
U_BOOT_CMD(mbr, CONFIG_SYS_MAXARGS, 1, do_mbr,
"MBR (Master Boot Record)",
"<command> <interface> <dev> <partitions_list>\n"
" - MBR partition table restoration utility\n"
" Restore or check partition information on a device connected\n"
" to the given block interface\n"
" Example usage:\n"
" mbr write mmc 0 [\"${mbr_parts}\"]\n"
" mbr verify mmc 0 [\"${partitions}\"]\n"
);