u-boot/lib/smbios-parser.c
Masahisa Kojima 3d49ee8510 efi_loader: add SMBIOS table measurement
TCG PC Client Platform Firmware Profile Specification
requires to measure the SMBIOS table that contains static
configuration information (e.g. Platform Manufacturer
Enterprise Number assigned by IANA, platform model number,
Vendor and Device IDs for each SMBIOS table).

The device- and environment-dependent information such as
serial number is cleared to zero or space character for
the measurement.

Existing smbios_string() function returns pointer to the string
with const qualifier, but exisintg use case is updating version
string and const qualifier must be removed.
This commit removes const qualifier from smbios_string()
return value and reuses to clear the strings for the measurement.

This commit also fixes the following compiler warning:

lib/smbios-parser.c:59:39: warning: cast to pointer from integer of
different size [-Wint-to-pointer-cast]
  const struct smbios_header *header = (struct smbios_header *)entry->struct_table_address;

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
2021-10-26 17:58:14 +02:00

266 lines
6.8 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2020, Bachmann electronic GmbH
*/
#define LOG_CATEGORY LOGC_BOOT
#include <common.h>
#include <smbios.h>
static inline int verify_checksum(const struct smbios_entry *e)
{
/*
* Checksums for SMBIOS tables are calculated to have a value, so that
* the sum over all bytes yields zero (using unsigned 8 bit arithmetic).
*/
u8 *byte = (u8 *)e;
u8 sum = 0;
for (int i = 0; i < e->length; i++)
sum += byte[i];
return sum;
}
const struct smbios_entry *smbios_entry(u64 address, u32 size)
{
const struct smbios_entry *entry = (struct smbios_entry *)(uintptr_t)address;
if (!address | !size)
return NULL;
if (memcmp(entry->anchor, "_SM_", 4))
return NULL;
if (verify_checksum(entry))
return NULL;
return entry;
}
static u8 *find_next_header(u8 *pos)
{
/* search for _double_ NULL bytes */
while (!((*pos == 0) && (*(pos + 1) == 0)))
pos++;
/* step behind the double NULL bytes */
pos += 2;
return pos;
}
static struct smbios_header *get_next_header(struct smbios_header *curr)
{
u8 *pos = ((u8 *)curr) + curr->length;
return (struct smbios_header *)find_next_header(pos);
}
static const struct smbios_header *next_header(const struct smbios_header *curr)
{
u8 *pos = ((u8 *)curr) + curr->length;
return (struct smbios_header *)find_next_header(pos);
}
const struct smbios_header *smbios_header(const struct smbios_entry *entry, int type)
{
const unsigned int num_header = entry->struct_count;
const struct smbios_header *header = (struct smbios_header *)((uintptr_t)entry->struct_table_address);
for (unsigned int i = 0; i < num_header; i++) {
if (header->type == type)
return header;
header = next_header(header);
}
return NULL;
}
static char *string_from_smbios_table(const struct smbios_header *header,
int idx)
{
unsigned int i = 1;
u8 *pos;
if (!header)
return NULL;
pos = ((u8 *)header) + header->length;
while (i < idx) {
if (*pos == 0x0)
i++;
pos++;
}
return (char *)pos;
}
char *smbios_string(const struct smbios_header *header, int index)
{
if (!header)
return NULL;
return string_from_smbios_table(header, index);
}
int smbios_update_version_full(void *smbios_tab, const char *version)
{
const struct smbios_header *hdr;
struct smbios_type0 *bios;
uint old_len, len;
char *ptr;
log_info("Updating SMBIOS table at %p\n", smbios_tab);
hdr = smbios_header(smbios_tab, SMBIOS_BIOS_INFORMATION);
if (!hdr)
return log_msg_ret("tab", -ENOENT);
bios = (struct smbios_type0 *)hdr;
ptr = smbios_string(hdr, bios->bios_ver);
if (!ptr)
return log_msg_ret("str", -ENOMEDIUM);
/*
* This string is supposed to have at least enough bytes and is
* padded with spaces. Update it, taking care not to move the
* \0 terminator, so that other strings in the string table
* are not disturbed. See smbios_add_string()
*/
old_len = strnlen(ptr, SMBIOS_STR_MAX);
len = strnlen(version, SMBIOS_STR_MAX);
if (len > old_len)
return log_ret(-ENOSPC);
log_debug("Replacing SMBIOS type 0 version string '%s'\n", ptr);
memcpy(ptr, version, len);
#ifdef LOG_DEBUG
print_buffer((ulong)ptr, ptr, 1, old_len + 1, 0);
#endif
return 0;
}
struct smbios_filter_param {
u32 offset;
u32 size;
bool is_string;
};
struct smbios_filter_table {
int type;
struct smbios_filter_param *params;
u32 count;
};
struct smbios_filter_param smbios_type1_filter_params[] = {
{offsetof(struct smbios_type1, serial_number),
FIELD_SIZEOF(struct smbios_type1, serial_number), true},
{offsetof(struct smbios_type1, uuid),
FIELD_SIZEOF(struct smbios_type1, uuid), false},
{offsetof(struct smbios_type1, wakeup_type),
FIELD_SIZEOF(struct smbios_type1, wakeup_type), false},
};
struct smbios_filter_param smbios_type2_filter_params[] = {
{offsetof(struct smbios_type2, serial_number),
FIELD_SIZEOF(struct smbios_type2, serial_number), true},
{offsetof(struct smbios_type2, chassis_location),
FIELD_SIZEOF(struct smbios_type2, chassis_location), false},
};
struct smbios_filter_param smbios_type3_filter_params[] = {
{offsetof(struct smbios_type3, serial_number),
FIELD_SIZEOF(struct smbios_type3, serial_number), true},
{offsetof(struct smbios_type3, asset_tag_number),
FIELD_SIZEOF(struct smbios_type3, asset_tag_number), true},
};
struct smbios_filter_param smbios_type4_filter_params[] = {
{offsetof(struct smbios_type4, serial_number),
FIELD_SIZEOF(struct smbios_type4, serial_number), true},
{offsetof(struct smbios_type4, asset_tag),
FIELD_SIZEOF(struct smbios_type4, asset_tag), true},
{offsetof(struct smbios_type4, part_number),
FIELD_SIZEOF(struct smbios_type4, part_number), true},
{offsetof(struct smbios_type4, core_count),
FIELD_SIZEOF(struct smbios_type4, core_count), false},
{offsetof(struct smbios_type4, core_enabled),
FIELD_SIZEOF(struct smbios_type4, core_enabled), false},
{offsetof(struct smbios_type4, thread_count),
FIELD_SIZEOF(struct smbios_type4, thread_count), false},
{offsetof(struct smbios_type4, core_count2),
FIELD_SIZEOF(struct smbios_type4, core_count2), false},
{offsetof(struct smbios_type4, core_enabled2),
FIELD_SIZEOF(struct smbios_type4, core_enabled2), false},
{offsetof(struct smbios_type4, thread_count2),
FIELD_SIZEOF(struct smbios_type4, thread_count2), false},
{offsetof(struct smbios_type4, voltage),
FIELD_SIZEOF(struct smbios_type4, voltage), false},
};
struct smbios_filter_table smbios_filter_tables[] = {
{SMBIOS_SYSTEM_INFORMATION, smbios_type1_filter_params,
ARRAY_SIZE(smbios_type1_filter_params)},
{SMBIOS_BOARD_INFORMATION, smbios_type2_filter_params,
ARRAY_SIZE(smbios_type2_filter_params)},
{SMBIOS_SYSTEM_ENCLOSURE, smbios_type3_filter_params,
ARRAY_SIZE(smbios_type3_filter_params)},
{SMBIOS_PROCESSOR_INFORMATION, smbios_type4_filter_params,
ARRAY_SIZE(smbios_type4_filter_params)},
};
static void clear_smbios_table(struct smbios_header *header,
struct smbios_filter_param *filter,
u32 count)
{
u32 i;
char *str;
u8 string_id;
for (i = 0; i < count; i++) {
if (filter[i].is_string) {
string_id = *((u8 *)header + filter[i].offset);
if (string_id == 0) /* string is empty */
continue;
str = smbios_string(header, string_id);
if (!str)
continue;
/* string is cleared to space, keep '\0' terminator */
memset(str, ' ', strlen(str));
} else {
memset((void *)((u8 *)header + filter[i].offset),
0, filter[i].size);
}
}
}
void smbios_prepare_measurement(const struct smbios_entry *entry,
struct smbios_header *smbios_copy)
{
u32 i, j;
struct smbios_header *header;
for (i = 0; i < ARRAY_SIZE(smbios_filter_tables); i++) {
header = smbios_copy;
for (j = 0; j < entry->struct_count; j++) {
if (header->type == smbios_filter_tables[i].type)
break;
header = get_next_header(header);
}
if (j >= entry->struct_count)
continue;
clear_smbios_table(header,
smbios_filter_tables[i].params,
smbios_filter_tables[i].count);
}
}