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/* SPDX-License-Identifier: GPL-2.0-or-later */
#include "vs.h"
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "udk2017.h"
#include "utils.h"
static size_t get_var_hdr_size(bool auth_vars)
{
if (auth_vars)
return sizeof(AUTHENTICATED_VARIABLE_HEADER);
return sizeof(VARIABLE_HEADER);
}
struct var_store_t vs_load(struct mem_range_t vs_data, bool auth_vars)
{
uint8_t *var_hdr = vs_data.start;
struct var_store_t vs = {
.auth_vars = auth_vars,
.vars = NULL,
};
struct var_t *last_var = NULL;
const size_t var_hdr_size = get_var_hdr_size(auth_vars);
while (var_hdr + var_hdr_size < vs_data.start + vs_data.length) {
uint16_t start_id;
uint8_t state;
struct var_t var = {0};
uint8_t *var_data = var_hdr;
if (auth_vars) {
const AUTHENTICATED_VARIABLE_HEADER *auth_hdr =
(void *)var_data;
start_id = auth_hdr->StartId;
state = auth_hdr->State;
var.reserved = auth_hdr->Reserved;
var.attrs = auth_hdr->Attributes;
var.name_size = auth_hdr->NameSize;
var.data_size = auth_hdr->DataSize;
var.guid = auth_hdr->VendorGuid;
} else {
const VARIABLE_HEADER *no_auth_hdr = (void *)var_data;
start_id = no_auth_hdr->StartId;
state = no_auth_hdr->State;
var.reserved = no_auth_hdr->Reserved;
var.attrs = no_auth_hdr->Attributes;
var.name_size = no_auth_hdr->NameSize;
var.data_size = no_auth_hdr->DataSize;
var.guid = no_auth_hdr->VendorGuid;
}
var_hdr += HEADER_ALIGN(var_hdr_size +
var.name_size +
var.data_size);
if (start_id != VARIABLE_DATA)
break;
if (state != VAR_ADDED)
continue;
if (var.data_size == UINT32_MAX ||
var.name_size == UINT32_MAX ||
var.attrs == UINT32_MAX)
continue;
CHAR16 *name = (void *)(var_data + var_hdr_size);
var.name = xmalloc(var.name_size);
memcpy(var.name, name, var.name_size);
uint8_t *data =
(void *)(var_data + var_hdr_size + var.name_size);
var.data = xmalloc(var.data_size);
memcpy(var.data, data, var.data_size);
struct var_t *var_node = xmalloc(sizeof(*var_node));
*var_node = var;
if (last_var != NULL)
last_var->next = var_node;
else if (vs.vars == NULL)
vs.vars = var_node;
last_var = var_node;
}
return vs;
}
static void store_var(const struct var_t *var, bool auth_vars, uint8_t *data)
{
if (auth_vars) {
AUTHENTICATED_VARIABLE_HEADER hdr;
memset(&hdr, 0xff, sizeof(hdr));
hdr.StartId = VARIABLE_DATA;
hdr.State = VAR_ADDED;
hdr.Reserved = var->reserved;
hdr.Attributes = var->attrs;
hdr.VendorGuid = var->guid;
hdr.NameSize = var->name_size;
hdr.DataSize = var->data_size;
memcpy(data, &hdr, sizeof(hdr));
data += sizeof(hdr);
} else {
VARIABLE_HEADER hdr;
memset(&hdr, 0xff, sizeof(hdr));
hdr.StartId = VARIABLE_DATA;
hdr.State = VAR_ADDED;
hdr.Reserved = var->reserved;
hdr.Attributes = var->attrs;
hdr.VendorGuid = var->guid;
hdr.NameSize = var->name_size;
hdr.DataSize = var->data_size;
memcpy(data, &hdr, sizeof(hdr));
data += sizeof(hdr);
}
memcpy(data, var->name, var->name_size);
memcpy(data + var->name_size, var->data, var->data_size);
}
bool vs_store(struct var_store_t *vs, struct mem_range_t vs_data)
{
uint8_t *out_data = vs_data.start;
const size_t var_hdr_size = get_var_hdr_size(vs->auth_vars);
for (struct var_t *var = vs->vars; var != NULL; var = var->next) {
const size_t var_size =
var_hdr_size + var->name_size + var->data_size;
if (out_data + var_size > vs_data.start + vs_data.length) {
fprintf(stderr,
"Not enough space to serialize Variable Store.\n");
return false;
}
store_var(var, vs->auth_vars, out_data);
out_data += HEADER_ALIGN(var_size);
}
// The rest is "uninitialized".
memset(out_data, 0xff, vs_data.length - (out_data - vs_data.start));
return true;
}
struct var_t *vs_new_var(struct var_store_t *vs)
{
struct var_t *new_var = xmalloc(sizeof(*new_var));
memset(new_var, 0, sizeof(*new_var));
new_var->attrs = EFI_VARIABLE_NON_VOLATILE
| EFI_VARIABLE_BOOTSERVICE_ACCESS
| EFI_VARIABLE_RUNTIME_ACCESS;
struct var_t *var = vs->vars;
if (var == NULL) {
vs->vars = new_var;
} else {
while (var->next != NULL)
var = var->next;
var->next = new_var;
}
return new_var;
}
struct var_t *vs_find(struct var_store_t *vs,
const char name[],
const EFI_GUID *guid)
{
size_t name_size;
CHAR16 *uchar_name = to_uchars(name, &name_size);
struct var_t *var;
for (var = vs->vars; var != NULL; var = var->next) {
if (var->name_size != name_size)
continue;
if (memcmp(var->name, uchar_name, name_size) != 0)
continue;
if (memcmp(&var->guid, guid, sizeof(*guid)) != 0)
continue;
break;
}
free(uchar_name);
return var;
}
static void free_var(struct var_t *var)
{
free(var->name);
free(var->data);
free(var);
}
void vs_delete(struct var_store_t *vs, struct var_t *var)
{
if (vs->vars == var) {
vs->vars = var->next;
free_var(var);
return;
}
for (struct var_t *v = vs->vars; v != NULL; v = v->next) {
if (v->next == var) {
v->next = var->next;
free_var(var);
return;
}
}
}
void vs_free(struct var_store_t *vs)
{
for (struct var_t *next, *var = vs->vars; var != NULL; var = next) {
next = var->next;
free_var(var);
}
}
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