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- // SPDX-License-Identifier: GPL-2.0+
- /*
- * EFI utils
- *
- * Copyright (c) 2017 Rob Clark
- */
- #include <common.h>
- #include <efi_loader.h>
- #include <env_internal.h>
- #include <hexdump.h>
- #include <malloc.h>
- #include <search.h>
- #include <u-boot/crc.h>
- #define READ_ONLY BIT(31)
- /*
- * Mapping between EFI variables and u-boot variables:
- *
- * efi_$guid_$varname = {attributes}(type)value
- *
- * For example:
- *
- * efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_OsIndicationsSupported=
- * "{ro,boot,run}(blob)0000000000000000"
- * efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_BootOrder=
- * "(blob)00010000"
- *
- * The attributes are a comma separated list of these possible
- * attributes:
- *
- * + ro - read-only
- * + boot - boot-services access
- * + run - runtime access
- *
- * NOTE: with current implementation, no variables are available after
- * ExitBootServices, and all are persisted (if possible).
- *
- * If not specified, the attributes default to "{boot}".
- *
- * The required type is one of:
- *
- * + utf8 - raw utf8 string
- * + blob - arbitrary length hex string
- *
- * Maybe a utf16 type would be useful to for a string value to be auto
- * converted to utf16?
- */
- #define PREFIX_LEN (strlen("efi_xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx_"))
- /**
- * 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 = PREFIX_LEN + utf16_utf8_strlen(variable_name) + 1;
- *native = malloc(len);
- if (!*native)
- return EFI_OUT_OF_RESOURCES;
- 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);
- if (!strncmp(prefix, str, n))
- return str + n;
- return NULL;
- }
- /**
- * 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;
- char sep = '{';
- if (*str != '{') {
- *attrp = EFI_VARIABLE_BOOTSERVICE_ACCESS;
- return str;
- }
- while (*str == sep) {
- const char *s;
- str++;
- if ((s = prefix(str, "ro"))) {
- attr |= READ_ONLY;
- } else if ((s = prefix(str, "nv"))) {
- attr |= EFI_VARIABLE_NON_VOLATILE;
- } else if ((s = prefix(str, "boot"))) {
- attr |= EFI_VARIABLE_BOOTSERVICE_ACCESS;
- } else if ((s = prefix(str, "run"))) {
- attr |= EFI_VARIABLE_RUNTIME_ACCESS;
- } else {
- printf("invalid attribute: %s\n", str);
- break;
- }
- str = s;
- sep = ',';
- }
- str++;
- *attrp = attr;
- return str;
- }
- /**
- * 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;
- efi_status_t ret;
- unsigned long in_size;
- const char *val, *s;
- u32 attr;
- EFI_ENTRY("\"%ls\" %pUl %p %p %p", variable_name, vendor, attributes,
- data_size, data);
- if (!variable_name || !vendor || !data_size)
- return EFI_EXIT(EFI_INVALID_PARAMETER);
- ret = efi_to_native(&native_name, variable_name, vendor);
- if (ret)
- return EFI_EXIT(ret);
- EFI_PRINT("get '%s'\n", native_name);
- val = env_get(native_name);
- free(native_name);
- if (!val)
- return EFI_EXIT(EFI_NOT_FOUND);
- val = parse_attr(val, &attr);
- in_size = *data_size;
- if ((s = prefix(val, "(blob)"))) {
- 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 /= 2;
- *data_size = len;
- if (in_size < len) {
- ret = EFI_BUFFER_TOO_SMALL;
- goto out;
- }
- if (!data)
- return EFI_EXIT(EFI_INVALID_PARAMETER);
- if (hex2bin(data, s, len))
- return EFI_EXIT(EFI_DEVICE_ERROR);
- EFI_PRINT("got value: \"%s\"\n", s);
- } else if ((s = prefix(val, "(utf8)"))) {
- unsigned len = strlen(s) + 1;
- *data_size = len;
- if (in_size < len) {
- ret = EFI_BUFFER_TOO_SMALL;
- goto out;
- }
- if (!data)
- return EFI_EXIT(EFI_INVALID_PARAMETER);
- memcpy(data, s, len);
- ((char *)data)[len] = '\0';
- EFI_PRINT("got value: \"%s\"\n", (char *)data);
- } else {
- EFI_PRINT("invalid value: '%s'\n", val);
- return EFI_EXIT(EFI_DEVICE_ERROR);
- }
- out:
- if (attributes)
- *attributes = attr & EFI_VARIABLE_MASK;
- return EFI_EXIT(ret);
- }
- 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.
- *
- * 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);
- 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);
- }
- /**
- * 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 = NULL, *val = NULL, *s;
- const char *old_val;
- size_t old_size;
- efi_status_t ret = EFI_SUCCESS;
- u32 attr;
- EFI_ENTRY("\"%ls\" %pUl %x %zu %p", variable_name, vendor, attributes,
- data_size, data);
- if (!variable_name || !*variable_name || !vendor ||
- ((attributes & EFI_VARIABLE_RUNTIME_ACCESS) &&
- !(attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS))) {
- ret = EFI_INVALID_PARAMETER;
- goto out;
- }
- ret = efi_to_native(&native_name, variable_name, vendor);
- if (ret)
- goto out;
- old_val = env_get(native_name);
- if (old_val) {
- old_val = parse_attr(old_val, &attr);
- /* check read-only first */
- if (attr & READ_ONLY) {
- ret = EFI_WRITE_PROTECTED;
- goto out;
- }
- if ((data_size == 0 &&
- !(attributes & EFI_VARIABLE_APPEND_WRITE)) ||
- !attributes) {
- /* delete the variable: */
- env_set(native_name, NULL);
- ret = EFI_SUCCESS;
- goto out;
- }
- /* attributes won't be changed */
- if (attr != (attributes & ~EFI_VARIABLE_APPEND_WRITE)) {
- ret = EFI_INVALID_PARAMETER;
- goto out;
- }
- if (attributes & EFI_VARIABLE_APPEND_WRITE) {
- if (!prefix(old_val, "(blob)")) {
- ret = EFI_DEVICE_ERROR;
- goto out;
- }
- old_size = strlen(old_val);
- } else {
- old_size = 0;
- }
- } else {
- if (data_size == 0 || !attributes ||
- (attributes & EFI_VARIABLE_APPEND_WRITE)) {
- /*
- * Trying to delete or to update a non-existent
- * variable.
- */
- ret = EFI_NOT_FOUND;
- goto out;
- }
- old_size = 0;
- }
- val = malloc(old_size + 2 * data_size
- + strlen("{ro,run,boot,nv}(blob)") + 1);
- if (!val) {
- ret = EFI_OUT_OF_RESOURCES;
- goto out;
- }
- s = val;
- /* store attributes */
- attributes &= (EFI_VARIABLE_NON_VOLATILE |
- EFI_VARIABLE_BOOTSERVICE_ACCESS |
- EFI_VARIABLE_RUNTIME_ACCESS);
- s += sprintf(s, "{");
- while (attributes) {
- u32 attr = 1 << (ffs(attributes) - 1);
- if (attr == EFI_VARIABLE_NON_VOLATILE)
- s += sprintf(s, "nv");
- else if (attr == EFI_VARIABLE_BOOTSERVICE_ACCESS)
- s += sprintf(s, "boot");
- else if (attr == EFI_VARIABLE_RUNTIME_ACCESS)
- s += sprintf(s, "run");
- attributes &= ~attr;
- if (attributes)
- s += sprintf(s, ",");
- }
- s += sprintf(s, "}");
- if (old_size)
- /* APPEND_WRITE */
- s += sprintf(s, old_val);
- else
- s += sprintf(s, "(blob)");
- /* store payload: */
- s = bin2hex(s, data, data_size);
- *s = '\0';
- EFI_PRINT("setting: %s=%s\n", native_name, val);
- if (env_set(native_name, val))
- ret = EFI_DEVICE_ERROR;
- out:
- free(native_name);
- free(val);
- return EFI_EXIT(ret);
- }
- /**
- * efi_query_variable_info() - get information about EFI variables
- *
- * This function implements the QueryVariableInfo() runtime service.
- *
- * See the Unified Extensible Firmware Interface (UEFI) specification for
- * details.
- *
- * @attributes: bitmask to select variables to be
- * queried
- * @maximum_variable_storage_size: maximum size of storage area for the
- * selected variable types
- * @remaining_variable_storage_size: remaining size of storage are for the
- * selected variable types
- * @maximum_variable_size: maximum size of a variable of the
- * selected type
- * Returns: status code
- */
- efi_status_t __efi_runtime EFIAPI efi_query_variable_info(
- u32 attributes,
- u64 *maximum_variable_storage_size,
- u64 *remaining_variable_storage_size,
- u64 *maximum_variable_size)
- {
- return EFI_UNSUPPORTED;
- }
- /**
- * efi_get_variable_runtime() - runtime implementation of GetVariable()
- *
- * @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
- */
- static efi_status_t __efi_runtime EFIAPI
- efi_get_variable_runtime(u16 *variable_name, const efi_guid_t *vendor,
- u32 *attributes, efi_uintn_t *data_size, void *data)
- {
- return EFI_UNSUPPORTED;
- }
- /**
- * efi_get_next_variable_name_runtime() - runtime implementation of
- * GetNextVariable()
- *
- * @variable_name_size: size of variable_name buffer in byte
- * @variable_name: name of uefi variable's name in u16
- * @vendor: vendor's guid
- * Return: status code
- */
- static efi_status_t __efi_runtime EFIAPI
- efi_get_next_variable_name_runtime(efi_uintn_t *variable_name_size,
- u16 *variable_name, const efi_guid_t *vendor)
- {
- return EFI_UNSUPPORTED;
- }
- /**
- * efi_set_variable_runtime() - runtime implementation of SetVariable()
- *
- * @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
- */
- static efi_status_t __efi_runtime EFIAPI
- efi_set_variable_runtime(u16 *variable_name, const efi_guid_t *vendor,
- u32 attributes, efi_uintn_t data_size,
- const void *data)
- {
- return EFI_UNSUPPORTED;
- }
- /**
- * efi_variables_boot_exit_notify() - notify ExitBootServices() is called
- */
- void efi_variables_boot_exit_notify(void)
- {
- efi_runtime_services.get_variable = efi_get_variable_runtime;
- efi_runtime_services.get_next_variable_name =
- efi_get_next_variable_name_runtime;
- efi_runtime_services.set_variable = efi_set_variable_runtime;
- efi_update_table_header_crc32(&efi_runtime_services.hdr);
- }
- /**
- * efi_init_variables() - initialize variable services
- *
- * Return: status code
- */
- efi_status_t efi_init_variables(void)
- {
- return EFI_SUCCESS;
- }
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