X-Git-Url: https://git.librecmc.org/?p=oweals%2Fu-boot.git;a=blobdiff_plain;f=lib%2Fefi_loader%2Fefi_variable.c;h=699f4184d932c1b3870951dd7d06e43ceb659d32;hp=6c177da3a6054339ae77296a4d6dab2fd0fc523d;hb=66c433ed4342e5761ee9b048c85fe47d31130b2e;hpb=2ee87b0c1a5439e4ad6467cb8d5e8fb58922ca4b

diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index 6c177da3a6..699f4184d9 100644
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -1,14 +1,17 @@
+// 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)
 
@@ -45,91 +48,48 @@
  * 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);
@@ -138,7 +98,16 @@ static const char *prefix(const char *str, const char *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;
@@ -176,12 +145,26 @@ static const char *parse_attr(const char *str, u32 *attrp)
 	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;
@@ -193,13 +176,14 @@ efi_status_t EFIAPI efi_get_variable(s16 *variable_name,
 	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);
 
@@ -208,10 +192,14 @@ efi_status_t EFIAPI efi_get_variable(s16 *variable_name,
 	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)
@@ -220,7 +208,7 @@ efi_status_t EFIAPI efi_get_variable(s16 *variable_name,
 		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);
@@ -250,59 +238,232 @@ efi_status_t EFIAPI efi_get_variable(s16 *variable_name,
 	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) {
@@ -321,7 +482,7 @@ efi_status_t EFIAPI efi_set_variable(s16 *variable_name,
 
 	/* 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);
@@ -329,6 +490,8 @@ efi_status_t EFIAPI efi_set_variable(s16 *variable_name,
 	if (env_set(native_name, val))
 		ret = EFI_DEVICE_ERROR;
 
+out:
+	free(native_name);
 	free(val);
 
 	return EFI_EXIT(ret);