+// SPDX-License-Identifier: GPL-2.0+
/*
* EFI utils
*
* Copyright (c) 2017 Rob Clark
- *
- * SPDX-License-Identifier: GPL-2.0+
*/
#include <malloc.h>
#include <charset.h>
#include <efi_loader.h>
+#include <hexdump.h>
+#include <environment.h>
+#include <search.h>
+#include <uuid.h>
#define READ_ONLY BIT(31)
* converted to utf16?
*/
-#define MAX_VAR_NAME 31
-#define MAX_NATIVE_VAR_NAME \
- (strlen("efi_xxxxxxxx-xxxx-xxxx-xxxxxxxxxxxxxxxx_") + \
- (MAX_VAR_NAME * MAX_UTF8_PER_UTF16))
-
-static int hex(unsigned char ch)
-{
- if (ch >= 'a' && ch <= 'f')
- return ch-'a'+10;
- if (ch >= '0' && ch <= '9')
- return ch-'0';
- if (ch >= 'A' && ch <= 'F')
- return ch-'A'+10;
- return -1;
-}
-
-static const char *hex2mem(u8 *mem, const char *hexstr, int count)
-{
- memset(mem, 0, count/2);
-
- do {
- int nibble;
-
- *mem = 0;
-
- if (!count || !*hexstr)
- break;
-
- nibble = hex(*hexstr);
- if (nibble < 0)
- break;
-
- *mem = nibble;
- count--;
- hexstr++;
-
- if (!count || !*hexstr)
- break;
-
- nibble = hex(*hexstr);
- if (nibble < 0)
- break;
-
- *mem = (*mem << 4) | nibble;
- count--;
- hexstr++;
- mem++;
-
- } while (1);
-
- if (*hexstr)
- return hexstr;
-
- return NULL;
-}
-
-static char *mem2hex(char *hexstr, const u8 *mem, int count)
-{
- static const char hexchars[] = "0123456789abcdef";
-
- while (count-- > 0) {
- u8 ch = *mem++;
- *hexstr++ = hexchars[ch >> 4];
- *hexstr++ = hexchars[ch & 0xf];
- }
+#define PREFIX_LEN (strlen("efi_xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx_"))
- return hexstr;
-}
-
-static efi_status_t efi_to_native(char *native, s16 *variable_name,
- efi_guid_t *vendor)
+/**
+ * efi_to_native() - convert the UEFI variable name and vendor GUID to U-Boot
+ * variable name
+ *
+ * The U-Boot variable name is a concatenation of prefix 'efi', the hexstring
+ * encoded vendor GUID, and the UTF-8 encoded UEFI variable name separated by
+ * underscores, e.g. 'efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_BootOrder'.
+ *
+ * @native: pointer to pointer to U-Boot variable name
+ * @variable_name: UEFI variable name
+ * @vendor: vendor GUID
+ * Return: status code
+ */
+static efi_status_t efi_to_native(char **native, const u16 *variable_name,
+ const efi_guid_t *vendor)
{
size_t len;
+ char *pos;
- len = utf16_strlen((u16 *)variable_name);
- if (len >= MAX_VAR_NAME)
- return EFI_DEVICE_ERROR;
+ len = PREFIX_LEN + utf16_utf8_strlen(variable_name) + 1;
+ *native = malloc(len);
+ if (!*native)
+ return EFI_OUT_OF_RESOURCES;
- native += sprintf(native, "efi_%pUl_", vendor);
- native = (char *)utf16_to_utf8((u8 *)native, (u16 *)variable_name, len);
- *native = '\0';
+ pos = *native;
+ pos += sprintf(pos, "efi_%pUl_", vendor);
+ utf16_utf8_strcpy(&pos, variable_name);
return EFI_SUCCESS;
}
+/**
+ * prefix() - skip over prefix
+ *
+ * Skip over a prefix string.
+ *
+ * @str: string with prefix
+ * @prefix: prefix string
+ * Return: string without prefix, or NULL if prefix not found
+ */
static const char *prefix(const char *str, const char *prefix)
{
size_t n = strlen(prefix);
return NULL;
}
-/* parse attributes part of variable value, if present: */
+/**
+ * parse_attr() - decode attributes part of variable value
+ *
+ * Convert the string encoded attributes of a UEFI variable to a bit mask.
+ * TODO: Several attributes are not supported.
+ *
+ * @str: value of U-Boot variable
+ * @attrp: pointer to UEFI attributes
+ * Return: pointer to remainder of U-Boot variable value
+ */
static const char *parse_attr(const char *str, u32 *attrp)
{
u32 attr = 0;
return str;
}
-/* http://wiki.phoenix.com/wiki/index.php/EFI_RUNTIME_SERVICES#GetVariable.28.29 */
-efi_status_t EFIAPI efi_get_variable(s16 *variable_name,
- efi_guid_t *vendor, u32 *attributes,
- unsigned long *data_size, void *data)
+/**
+ * efi_efi_get_variable() - retrieve value of a UEFI variable
+ *
+ * This function implements the GetVariable runtime service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * @variable_name: name of the variable
+ * @vendor: vendor GUID
+ * @attributes: attributes of the variable
+ * @data_size: size of the buffer to which the variable value is copied
+ * @data: buffer to which the variable value is copied
+ * Return: status code
+ */
+efi_status_t EFIAPI efi_get_variable(u16 *variable_name,
+ const efi_guid_t *vendor, u32 *attributes,
+ efi_uintn_t *data_size, void *data)
{
- char native_name[MAX_NATIVE_VAR_NAME + 1];
+ char *native_name;
efi_status_t ret;
unsigned long in_size;
const char *val, *s;
if (!variable_name || !vendor || !data_size)
return EFI_EXIT(EFI_INVALID_PARAMETER);
- ret = efi_to_native(native_name, variable_name, vendor);
+ ret = efi_to_native(&native_name, variable_name, vendor);
if (ret)
return EFI_EXIT(ret);
debug("%s: get '%s'\n", __func__, native_name);
val = env_get(native_name);
+ free(native_name);
if (!val)
return EFI_EXIT(EFI_NOT_FOUND);
in_size = *data_size;
if ((s = prefix(val, "(blob)"))) {
- unsigned len = strlen(s);
+ size_t len = strlen(s);
+
+ /* number of hexadecimal digits must be even */
+ if (len & 1)
+ return EFI_EXIT(EFI_DEVICE_ERROR);
/* two characters per byte: */
- len = DIV_ROUND_UP(len, 2);
+ len /= 2;
*data_size = len;
if (in_size < len)
if (!data)
return EFI_EXIT(EFI_INVALID_PARAMETER);
- if (hex2mem(data, s, len * 2))
+ if (hex2bin(data, s, len))
return EFI_EXIT(EFI_DEVICE_ERROR);
debug("%s: got value: \"%s\"\n", __func__, s);
return EFI_EXIT(EFI_SUCCESS);
}
-/* http://wiki.phoenix.com/wiki/index.php/EFI_RUNTIME_SERVICES#GetNextVariableName.28.29 */
-efi_status_t EFIAPI efi_get_next_variable(
- unsigned long *variable_name_size,
- s16 *variable_name, efi_guid_t *vendor)
+static char *efi_variables_list;
+static char *efi_cur_variable;
+
+/**
+ * parse_uboot_variable() - parse a u-boot variable and get uefi-related
+ * information
+ * @variable: whole data of u-boot variable (ie. name=value)
+ * @variable_name_size: size of variable_name buffer in byte
+ * @variable_name: name of uefi variable in u16, null-terminated
+ * @vendor: vendor's guid
+ * @attributes: attributes
+ *
+ * A uefi variable is encoded into a u-boot variable as described above.
+ * This function parses such a u-boot variable and retrieve uefi-related
+ * information into respective parameters. In return, variable_name_size
+ * is the size of variable name including NULL.
+ *
+ * Return: EFI_SUCCESS if parsing is OK, EFI_NOT_FOUND when
+ the entire variable list has been returned,
+ otherwise non-zero status code
+ */
+static efi_status_t parse_uboot_variable(char *variable,
+ efi_uintn_t *variable_name_size,
+ u16 *variable_name,
+ const efi_guid_t *vendor,
+ u32 *attributes)
+{
+ char *guid, *name, *end, c;
+ unsigned long name_len;
+ u16 *p;
+
+ guid = strchr(variable, '_');
+ if (!guid)
+ return EFI_INVALID_PARAMETER;
+ guid++;
+ name = strchr(guid, '_');
+ if (!name)
+ return EFI_INVALID_PARAMETER;
+ name++;
+ end = strchr(name, '=');
+ if (!end)
+ return EFI_INVALID_PARAMETER;
+
+ name_len = end - name;
+ if (*variable_name_size < (name_len + 1)) {
+ *variable_name_size = name_len + 1;
+ return EFI_BUFFER_TOO_SMALL;
+ }
+ end++; /* point to value */
+
+ /* variable name */
+ p = variable_name;
+ utf8_utf16_strncpy(&p, name, name_len);
+ variable_name[name_len] = 0;
+ *variable_name_size = name_len + 1;
+
+ /* guid */
+ c = *(name - 1);
+ *(name - 1) = '\0'; /* guid need be null-terminated here */
+ uuid_str_to_bin(guid, (unsigned char *)vendor, UUID_STR_FORMAT_GUID);
+ *(name - 1) = c;
+
+ /* attributes */
+ parse_attr(end, attributes);
+
+ return EFI_SUCCESS;
+}
+
+/**
+ * efi_get_next_variable_name() - enumerate the current variable names
+ * @variable_name_size: size of variable_name buffer in byte
+ * @variable_name: name of uefi variable's name in u16
+ * @vendor: vendor's guid
+ *
+ * This function implements the GetNextVariableName service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details: http://wiki.phoenix.com/wiki/index.php/
+ * EFI_RUNTIME_SERVICES#GetNextVariableName.28.29
+ *
+ * Return: status code
+ */
+efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size,
+ u16 *variable_name,
+ const efi_guid_t *vendor)
{
+ char *native_name, *variable;
+ ssize_t name_len, list_len;
+ char regex[256];
+ char * const regexlist[] = {regex};
+ u32 attributes;
+ int i;
+ efi_status_t ret;
+
EFI_ENTRY("%p \"%ls\" %pUl", variable_name_size, variable_name, vendor);
- return EFI_EXIT(EFI_DEVICE_ERROR);
+ if (!variable_name_size || !variable_name || !vendor)
+ return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+ if (variable_name[0]) {
+ /* check null-terminated string */
+ for (i = 0; i < *variable_name_size; i++)
+ if (!variable_name[i])
+ break;
+ if (i >= *variable_name_size)
+ return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+ /* search for the last-returned variable */
+ ret = efi_to_native(&native_name, variable_name, vendor);
+ if (ret)
+ return EFI_EXIT(ret);
+
+ name_len = strlen(native_name);
+ for (variable = efi_variables_list; variable && *variable;) {
+ if (!strncmp(variable, native_name, name_len) &&
+ variable[name_len] == '=')
+ break;
+
+ variable = strchr(variable, '\n');
+ if (variable)
+ variable++;
+ }
+
+ free(native_name);
+ if (!(variable && *variable))
+ return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+ /* next variable */
+ variable = strchr(variable, '\n');
+ if (variable)
+ variable++;
+ if (!(variable && *variable))
+ return EFI_EXIT(EFI_NOT_FOUND);
+ } else {
+ /*
+ *new search: free a list used in the previous search
+ */
+ free(efi_variables_list);
+ efi_variables_list = NULL;
+ efi_cur_variable = NULL;
+
+ snprintf(regex, 256, "efi_.*-.*-.*-.*-.*_.*");
+ list_len = hexport_r(&env_htab, '\n',
+ H_MATCH_REGEX | H_MATCH_KEY,
+ &efi_variables_list, 0, 1, regexlist);
+ /* 1 indicates that no match was found */
+ if (list_len <= 1)
+ return EFI_EXIT(EFI_NOT_FOUND);
+
+ variable = efi_variables_list;
+ }
+
+ ret = parse_uboot_variable(variable, variable_name_size, variable_name,
+ vendor, &attributes);
+
+ return EFI_EXIT(ret);
}
-/* http://wiki.phoenix.com/wiki/index.php/EFI_RUNTIME_SERVICES#SetVariable.28.29 */
-efi_status_t EFIAPI efi_set_variable(s16 *variable_name,
- efi_guid_t *vendor, u32 attributes,
- unsigned long data_size, void *data)
+/**
+ * efi_efi_set_variable() - set value of a UEFI variable
+ *
+ * This function implements the SetVariable runtime service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * @variable_name: name of the variable
+ * @vendor: vendor GUID
+ * @attributes: attributes of the variable
+ * @data_size: size of the buffer with the variable value
+ * @data: buffer with the variable value
+ * Return: status code
+ */
+efi_status_t EFIAPI efi_set_variable(u16 *variable_name,
+ const efi_guid_t *vendor, u32 attributes,
+ efi_uintn_t data_size, const void *data)
{
- char native_name[MAX_NATIVE_VAR_NAME + 1];
+ char *native_name = NULL, *val = NULL, *s;
efi_status_t ret = EFI_SUCCESS;
- char *val, *s;
u32 attr;
- EFI_ENTRY("\"%ls\" %pUl %x %lu %p", variable_name, vendor, attributes,
+ EFI_ENTRY("\"%ls\" %pUl %x %zu %p", variable_name, vendor, attributes,
data_size, data);
- if (!variable_name || !vendor)
- return EFI_EXIT(EFI_INVALID_PARAMETER);
+ if (!variable_name || !vendor) {
+ ret = EFI_INVALID_PARAMETER;
+ goto out;
+ }
- ret = efi_to_native(native_name, variable_name, vendor);
+ ret = efi_to_native(&native_name, variable_name, vendor);
if (ret)
- return EFI_EXIT(ret);
+ goto out;
#define ACCESS_ATTR (EFI_VARIABLE_RUNTIME_ACCESS | EFI_VARIABLE_BOOTSERVICE_ACCESS)
if ((data_size == 0) || !(attributes & ACCESS_ATTR)) {
/* delete the variable: */
env_set(native_name, NULL);
- return EFI_EXIT(EFI_SUCCESS);
+ ret = EFI_SUCCESS;
+ goto out;
}
val = env_get(native_name);
if (val) {
parse_attr(val, &attr);
- if (attr & READ_ONLY)
- return EFI_EXIT(EFI_WRITE_PROTECTED);
+ if (attr & READ_ONLY) {
+ /* We should not free val */
+ val = NULL;
+ ret = EFI_WRITE_PROTECTED;
+ goto out;
+ }
}
val = malloc(2 * data_size + strlen("{ro,run,boot}(blob)") + 1);
- if (!val)
- return EFI_EXIT(EFI_OUT_OF_RESOURCES);
+ if (!val) {
+ ret = EFI_OUT_OF_RESOURCES;
+ goto out;
+ }
s = val;
- /* store attributes: */
+ /*
+ * store attributes
+ * TODO: several attributes are not supported
+ */
attributes &= (EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS);
s += sprintf(s, "{");
while (attributes) {
/* store payload: */
s += sprintf(s, "(blob)");
- s = mem2hex(s, data, data_size);
+ s = bin2hex(s, data, data_size);
*s = '\0';
debug("%s: setting: %s=%s\n", __func__, native_name, val);
if (env_set(native_name, val))
ret = EFI_DEVICE_ERROR;
+out:
+ free(native_name);
free(val);
return EFI_EXIT(ret);