u-boot/cmd/bcb.c
Eugeniu Rosca bafdf4caac cmd: bcb: Add support for processing const string literals in bcb_set()
On request/suggestion from Simon Glass back in May 22 2019 [1], the
'strsep' mechanism implemented in bcb_set() was set to work directly
with user-provided argv strings, to avoid duplicating memory and for
the sake of simpler implementation.

However, since we recently exposed bcb_write_reboot_reason() API to be
called by U-Boot fastboot, the idea is to be able to pass const string
literals to this new BCB API, carrying the reboot reason.

Since 'strsep' (just like its older/superseded sibling 'strtok')
modifies the input string passed as parameter, BCB command in its
current state would attempt to perform in-place modifications in a
readonly string, which might lead to unexpected results.

Fix the above with the cost of one dynamic memory allocation ('strdup').
This will also ensure no compiler warnings when passing string literals
to bcb_write_reboot_reason().

[1] http://u-boot.10912.n7.nabble.com/PATCH-v2-0-2-Add-bcb-command-to-read-modify-write-Android-BCB-td369934i20.html#a370456

Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Roman Kovalivskyi <roman.kovalivskyi@globallogic.com>
2021-01-31 14:08:56 +01:00

392 lines
8.6 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2019 Eugeniu Rosca <rosca.eugeniu@gmail.com>
*
* Command to read/modify/write Android BCB fields
*/
#include <android_bootloader_message.h>
#include <bcb.h>
#include <command.h>
#include <common.h>
#include <log.h>
#include <part.h>
#include <malloc.h>
enum bcb_cmd {
BCB_CMD_LOAD,
BCB_CMD_FIELD_SET,
BCB_CMD_FIELD_CLEAR,
BCB_CMD_FIELD_TEST,
BCB_CMD_FIELD_DUMP,
BCB_CMD_STORE,
};
static int bcb_dev = -1;
static int bcb_part = -1;
static struct bootloader_message bcb = { { 0 } };
static int bcb_cmd_get(char *cmd)
{
if (!strcmp(cmd, "load"))
return BCB_CMD_LOAD;
if (!strcmp(cmd, "set"))
return BCB_CMD_FIELD_SET;
if (!strcmp(cmd, "clear"))
return BCB_CMD_FIELD_CLEAR;
if (!strcmp(cmd, "test"))
return BCB_CMD_FIELD_TEST;
if (!strcmp(cmd, "store"))
return BCB_CMD_STORE;
if (!strcmp(cmd, "dump"))
return BCB_CMD_FIELD_DUMP;
else
return -1;
}
static int bcb_is_misused(int argc, char *const argv[])
{
int cmd = bcb_cmd_get(argv[0]);
switch (cmd) {
case BCB_CMD_LOAD:
case BCB_CMD_FIELD_SET:
if (argc != 3)
goto err;
break;
case BCB_CMD_FIELD_TEST:
if (argc != 4)
goto err;
break;
case BCB_CMD_FIELD_CLEAR:
if (argc != 1 && argc != 2)
goto err;
break;
case BCB_CMD_STORE:
if (argc != 1)
goto err;
break;
case BCB_CMD_FIELD_DUMP:
if (argc != 2)
goto err;
break;
default:
printf("Error: 'bcb %s' not supported\n", argv[0]);
return -1;
}
if (cmd != BCB_CMD_LOAD && (bcb_dev < 0 || bcb_part < 0)) {
printf("Error: Please, load BCB first!\n");
return -1;
}
return 0;
err:
printf("Error: Bad usage of 'bcb %s'\n", argv[0]);
return -1;
}
static int bcb_field_get(char *name, char **fieldp, int *sizep)
{
if (!strcmp(name, "command")) {
*fieldp = bcb.command;
*sizep = sizeof(bcb.command);
} else if (!strcmp(name, "status")) {
*fieldp = bcb.status;
*sizep = sizeof(bcb.status);
} else if (!strcmp(name, "recovery")) {
*fieldp = bcb.recovery;
*sizep = sizeof(bcb.recovery);
} else if (!strcmp(name, "stage")) {
*fieldp = bcb.stage;
*sizep = sizeof(bcb.stage);
} else if (!strcmp(name, "reserved")) {
*fieldp = bcb.reserved;
*sizep = sizeof(bcb.reserved);
} else {
printf("Error: Unknown bcb field '%s'\n", name);
return -1;
}
return 0;
}
static int __bcb_load(int devnum, const char *partp)
{
struct blk_desc *desc;
struct disk_partition info;
u64 cnt;
char *endp;
int part, ret;
desc = blk_get_devnum_by_type(IF_TYPE_MMC, devnum);
if (!desc) {
ret = -ENODEV;
goto err_read_fail;
}
part = simple_strtoul(partp, &endp, 0);
if (*endp == '\0') {
ret = part_get_info(desc, part, &info);
if (ret)
goto err_read_fail;
} else {
part = part_get_info_by_name(desc, partp, &info);
if (part < 0) {
ret = part;
goto err_read_fail;
}
}
cnt = DIV_ROUND_UP(sizeof(struct bootloader_message), info.blksz);
if (cnt > info.size)
goto err_too_small;
if (blk_dread(desc, info.start, cnt, &bcb) != cnt) {
ret = -EIO;
goto err_read_fail;
}
bcb_dev = desc->devnum;
bcb_part = part;
debug("%s: Loaded from mmc %d:%d\n", __func__, bcb_dev, bcb_part);
return CMD_RET_SUCCESS;
err_read_fail:
printf("Error: mmc %d:%s read failed (%d)\n", devnum, partp, ret);
goto err;
err_too_small:
printf("Error: mmc %d:%s too small!", devnum, partp);
goto err;
err:
bcb_dev = -1;
bcb_part = -1;
return CMD_RET_FAILURE;
}
static int do_bcb_load(struct cmd_tbl *cmdtp, int flag, int argc,
char * const argv[])
{
char *endp;
int devnum = simple_strtoul(argv[1], &endp, 0);
if (*endp != '\0') {
printf("Error: Device id '%s' not a number\n", argv[1]);
return CMD_RET_FAILURE;
}
return __bcb_load(devnum, argv[2]);
}
static int __bcb_set(char *fieldp, const char *valp)
{
int size, len;
char *field, *str, *found, *tmp;
if (bcb_field_get(fieldp, &field, &size))
return CMD_RET_FAILURE;
len = strlen(valp);
if (len >= size) {
printf("Error: sizeof('%s') = %d >= %d = sizeof(bcb.%s)\n",
valp, len, size, fieldp);
return CMD_RET_FAILURE;
}
str = strdup(valp);
if (!str) {
printf("Error: Out of memory while strdup\n");
return CMD_RET_FAILURE;
}
tmp = str;
field[0] = '\0';
while ((found = strsep(&tmp, ":"))) {
if (field[0] != '\0')
strcat(field, "\n");
strcat(field, found);
}
free(str);
return CMD_RET_SUCCESS;
}
static int do_bcb_set(struct cmd_tbl *cmdtp, int flag, int argc,
char * const argv[])
{
return __bcb_set(argv[1], argv[2]);
}
static int do_bcb_clear(struct cmd_tbl *cmdtp, int flag, int argc,
char *const argv[])
{
int size;
char *field;
if (argc == 1) {
memset(&bcb, 0, sizeof(bcb));
return CMD_RET_SUCCESS;
}
if (bcb_field_get(argv[1], &field, &size))
return CMD_RET_FAILURE;
memset(field, 0, size);
return CMD_RET_SUCCESS;
}
static int do_bcb_test(struct cmd_tbl *cmdtp, int flag, int argc,
char *const argv[])
{
int size;
char *field;
char *op = argv[2];
if (bcb_field_get(argv[1], &field, &size))
return CMD_RET_FAILURE;
if (*op == '=' && *(op + 1) == '\0') {
if (!strncmp(argv[3], field, size))
return CMD_RET_SUCCESS;
else
return CMD_RET_FAILURE;
} else if (*op == '~' && *(op + 1) == '\0') {
if (!strstr(field, argv[3]))
return CMD_RET_FAILURE;
else
return CMD_RET_SUCCESS;
} else {
printf("Error: Unknown operator '%s'\n", op);
}
return CMD_RET_FAILURE;
}
static int do_bcb_dump(struct cmd_tbl *cmdtp, int flag, int argc,
char *const argv[])
{
int size;
char *field;
if (bcb_field_get(argv[1], &field, &size))
return CMD_RET_FAILURE;
print_buffer((ulong)field - (ulong)&bcb, (void *)field, 1, size, 16);
return CMD_RET_SUCCESS;
}
static int __bcb_store(void)
{
struct blk_desc *desc;
struct disk_partition info;
u64 cnt;
int ret;
desc = blk_get_devnum_by_type(IF_TYPE_MMC, bcb_dev);
if (!desc) {
ret = -ENODEV;
goto err;
}
ret = part_get_info(desc, bcb_part, &info);
if (ret)
goto err;
cnt = DIV_ROUND_UP(sizeof(struct bootloader_message), info.blksz);
if (blk_dwrite(desc, info.start, cnt, &bcb) != cnt) {
ret = -EIO;
goto err;
}
return CMD_RET_SUCCESS;
err:
printf("Error: mmc %d:%d write failed (%d)\n", bcb_dev, bcb_part, ret);
return CMD_RET_FAILURE;
}
static int do_bcb_store(struct cmd_tbl *cmdtp, int flag, int argc,
char * const argv[])
{
return __bcb_store();
}
int bcb_write_reboot_reason(int devnum, char *partp, const char *reasonp)
{
int ret;
ret = __bcb_load(devnum, partp);
if (ret != CMD_RET_SUCCESS)
return ret;
ret = __bcb_set("command", reasonp);
if (ret != CMD_RET_SUCCESS)
return ret;
ret = __bcb_store();
if (ret != CMD_RET_SUCCESS)
return ret;
return 0;
}
static struct cmd_tbl cmd_bcb_sub[] = {
U_BOOT_CMD_MKENT(load, CONFIG_SYS_MAXARGS, 1, do_bcb_load, "", ""),
U_BOOT_CMD_MKENT(set, CONFIG_SYS_MAXARGS, 1, do_bcb_set, "", ""),
U_BOOT_CMD_MKENT(clear, CONFIG_SYS_MAXARGS, 1, do_bcb_clear, "", ""),
U_BOOT_CMD_MKENT(test, CONFIG_SYS_MAXARGS, 1, do_bcb_test, "", ""),
U_BOOT_CMD_MKENT(dump, CONFIG_SYS_MAXARGS, 1, do_bcb_dump, "", ""),
U_BOOT_CMD_MKENT(store, CONFIG_SYS_MAXARGS, 1, do_bcb_store, "", ""),
};
static int do_bcb(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
struct cmd_tbl *c;
if (argc < 2)
return CMD_RET_USAGE;
argc--;
argv++;
c = find_cmd_tbl(argv[0], cmd_bcb_sub, ARRAY_SIZE(cmd_bcb_sub));
if (!c)
return CMD_RET_USAGE;
if (bcb_is_misused(argc, argv)) {
/*
* We try to improve the user experience by reporting the
* root-cause of misusage, so don't return CMD_RET_USAGE,
* since the latter prints out the full-blown help text
*/
return CMD_RET_FAILURE;
}
return c->cmd(cmdtp, flag, argc, argv);
}
U_BOOT_CMD(
bcb, CONFIG_SYS_MAXARGS, 1, do_bcb,
"Load/set/clear/test/dump/store Android BCB fields",
"load <dev> <part> - load BCB from mmc <dev>:<part>\n"
"bcb set <field> <val> - set BCB <field> to <val>\n"
"bcb clear [<field>] - clear BCB <field> or all fields\n"
"bcb test <field> <op> <val> - test BCB <field> against <val>\n"
"bcb dump <field> - dump BCB <field>\n"
"bcb store - store BCB back to mmc\n"
"\n"
"Legend:\n"
"<dev> - MMC device index containing the BCB partition\n"
"<part> - MMC partition index or name containing the BCB\n"
"<field> - one of {command,status,recovery,stage,reserved}\n"
"<op> - the binary operator used in 'bcb test':\n"
" '=' returns true if <val> matches the string stored in <field>\n"
" '~' returns true if <val> matches a subset of <field>'s string\n"
"<val> - string/text provided as input to bcb {set,test}\n"
" NOTE: any ':' character in <val> will be replaced by line feed\n"
" during 'bcb set' and used as separator by upper layers\n"
);