cmd: env: add "-e" option for handling UEFI variables

"env [print|set] -e" allows for handling uefi variables without
knowing details about mapping to corresponding u-boot variables.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

4 files changed, 437 insertions, 1 deletions

diff --git a/cmd/Kconfig b/cmd/Kconfig
index ed8d85bfa6..af2bfb4e58 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -420,6 +420,16 @@ config CMD_ENV_FLAGS
 	  be deleted. This command shows the variables that have special
 	  flags.
 
+config CMD_NVEDIT_EFI
+	bool "env [set|print] -e - set/print UEFI variables"
+	depends on EFI_LOADER
+	default y
+	imply HEXDUMP
+	help
+	  UEFI variables are encoded as some form of U-Boot variables.
+	  If enabled, we are allowed to set/print UEFI variables using
+	  "env" command with "-e" option without knowing details.
+
 endmenu
 
 menu "Memory commands"
diff --git a/cmd/Makefile b/cmd/Makefile
index a127a99539..b9ee51869d 100644
--- a/cmd/Makefile
+++ b/cmd/Makefile
@@ -98,6 +98,7 @@ obj-$(CONFIG_CMD_MTD) += mtd.o
 obj-$(CONFIG_CMD_MTDPARTS) += mtdparts.o
 obj-$(CONFIG_CMD_NAND) += nand.o
 obj-$(CONFIG_CMD_NET) += net.o
+obj-$(CONFIG_CMD_NVEDIT_EFI) += nvedit_efi.o
 obj-$(CONFIG_CMD_ONENAND) += onenand.o
 obj-$(CONFIG_CMD_OSD) += osd.o
 obj-$(CONFIG_CMD_PART) += part.o
diff --git a/cmd/nvedit.c b/cmd/nvedit.c
index ebaa16b754..24a6cf7824 100644
--- a/cmd/nvedit.c
+++ b/cmd/nvedit.c
@@ -119,6 +119,11 @@ static int do_env_print(cmd_tbl_t *cmdtp, int flag, int argc,
 	int rcode = 0;
 	int env_flag = H_HIDE_DOT;
 
+#if defined(CONFIG_CMD_NVEDIT_EFI)
+	if (argc > 1 && argv[1][0] == '-' && argv[1][1] == 'e')
+		return do_env_print_efi(cmdtp, flag, --argc, ++argv);
+#endif
+
 	if (argc > 1 && argv[1][0] == '-' && argv[1][1] == 'a') {
 		argc--;
 		argv++;
@@ -216,6 +221,12 @@ static int _do_env_set(int flag, int argc, char * const argv[], int env_flag)
 	ENTRY e, *ep;
 
 	debug("Initial value for argc=%d\n", argc);
+
+#if CONFIG_IS_ENABLED(CMD_NVEDIT_EFI)
+	if (argc > 1 && argv[1][0] == '-' && argv[1][1] == 'e')
+		return do_env_set_efi(NULL, flag, --argc, ++argv);
+#endif
+
 	while (argc > 1 && **(argv + 1) == '-') {
 		char *arg = *++argv;
 
@@ -1263,12 +1274,18 @@ static char env_help_text[] =
 	"env import [-d] [-t [-r] | -b | -c] addr [size] [var ...] - import environment\n"
 #endif
 	"env print [-a | name ...] - print environment\n"
+#if defined(CONFIG_CMD_NVEDIT_EFI)
+	"env print -e [name ...] - print UEFI environment\n"
+#endif
 #if defined(CONFIG_CMD_RUN)
 	"env run var [...] - run commands in an environment variable\n"
 #endif
 #if defined(CONFIG_CMD_SAVEENV) && !defined(CONFIG_ENV_IS_NOWHERE)
 	"env save - save environment\n"
 #endif
+#if defined(CONFIG_CMD_NVEDIT_EFI)
+	"env set -e name [arg ...] - set UEFI variable; unset if 'arg' not specified\n"
+#endif
 	"env set [-f] name [arg ...]\n";
 #endif
 
@@ -1295,6 +1312,10 @@ U_BOOT_CMD_COMPLETE(
 	printenv, CONFIG_SYS_MAXARGS, 1,	do_env_print,
 	"print environment variables",
 	"[-a]\n    - print [all] values of all environment variables\n"
+#if defined(CONFIG_CMD_NVEDIT_EFI)
+	"printenv -e [name ...]\n"
+	"    - print UEFI variable 'name' or all the variables\n"
+#endif
 	"printenv name ...\n"
 	"    - print value of environment variable 'name'",
 	var_complete
@@ -1322,7 +1343,12 @@ U_BOOT_CMD_COMPLETE(
 U_BOOT_CMD_COMPLETE(
 	setenv, CONFIG_SYS_MAXARGS, 0,	do_env_set,
 	"set environment variables",
-	"[-f] name value ...\n"
+#if defined(CONFIG_CMD_NVEDIT_EFI)
+	"-e name [value ...]\n"
+	"    - set UEFI variable 'name' to 'value' ...'\n"
+	"    - delete UEFI variable 'name' if 'value' not specified\n"
+#endif
+	"setenv [-f] name value ...\n"
 	"    - [forcibly] set environment variable 'name' to 'value ...'\n"
 	"setenv [-f] name\n"
 	"    - [forcibly] delete environment variable 'name'",
diff --git a/cmd/nvedit_efi.c b/cmd/nvedit_efi.c
new file mode 100644
index 0000000000..ca32566a61
--- /dev/null
+++ b/cmd/nvedit_efi.c
@@ -0,0 +1,399 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Integrate UEFI variables to u-boot env interface
+ *
+ *  Copyright (c) 2018 AKASHI Takahiro, Linaro Limited
+ */
+
+#include <charset.h>
+#include <common.h>
+#include <command.h>
+#include <efi_loader.h>
+#include <exports.h>
+#include <hexdump.h>
+#include <malloc.h>
+#include <linux/kernel.h>
+
+/*
+ * From efi_variable.c,
+ *
+ * Mapping between UEFI variables and u-boot variables:
+ *
+ *   efi_$guid_$varname = {attributes}(type)value
+ */
+
+static const struct {
+	u32 mask;
+	char *text;
+} efi_var_attrs[] = {
+	{EFI_VARIABLE_NON_VOLATILE, "NV"},
+	{EFI_VARIABLE_BOOTSERVICE_ACCESS, "BS"},
+	{EFI_VARIABLE_RUNTIME_ACCESS, "RT"},
+	{EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS, "AW"},
+	{EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS, "AT"},
+};
+
+/**
+ * efi_dump_single_var() - show information about a UEFI variable
+ *
+ * @name:	Name of the variable
+ * @guid:	Vendor GUID
+ *
+ * Show information encoded in one UEFI variable
+ */
+static void efi_dump_single_var(u16 *name, efi_guid_t *guid)
+{
+	u32 attributes;
+	u8 *data;
+	efi_uintn_t size;
+	int count, i;
+	efi_status_t ret;
+
+	data = NULL;
+	size = 0;
+	ret = EFI_CALL(efi_get_variable(name, guid, &attributes, &size, data));
+	if (ret == EFI_BUFFER_TOO_SMALL) {
+		data = malloc(size);
+		if (!data)
+			goto out;
+
+		ret = EFI_CALL(efi_get_variable(name, guid, &attributes, &size,
+						data));
+	}
+	if (ret == EFI_NOT_FOUND) {
+		printf("Error: \"%ls\" not defined\n", name);
+		goto out;
+	}
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	printf("%ls:", name);
+	for (count = 0, i = 0; i < ARRAY_SIZE(efi_var_attrs); i++)
+		if (attributes & efi_var_attrs[i].mask) {
+			if (count)
+				putc('|');
+			else
+				putc(' ');
+			count++;
+			puts(efi_var_attrs[i].text);
+		}
+	printf(", DataSize = 0x%zx\n", size);
+	print_hex_dump("    ", DUMP_PREFIX_OFFSET, 16, 1, data, size, true);
+
+	return;
+out:
+	free(data);
+}
+
+/**
+ * efi_dump_vars() - show information about named UEFI variables
+ *
+ * @argc:	Number of arguments (variables)
+ * @argv:	Argument (variable name) array
+ * Return:	CMD_RET_SUCCESS on success, or CMD_RET_RET_FAILURE
+ *
+ * Show information encoded in named UEFI variables
+ */
+static int efi_dump_vars(int argc,  char * const argv[])
+{
+	u16 *var_name16, *p;
+	efi_uintn_t buf_size, size;
+
+	buf_size = 128;
+	var_name16 = malloc(buf_size);
+	if (!var_name16)
+		return CMD_RET_FAILURE;
+
+	for (; argc > 0; argc--, argv++) {
+		size = (utf8_utf16_strlen(argv[0]) + 1) * sizeof(u16);
+		if (buf_size < size) {
+			buf_size = size;
+			p = realloc(var_name16, buf_size);
+			if (!p) {
+				free(var_name16);
+				return CMD_RET_FAILURE;
+			}
+			var_name16 = p;
+		}
+
+		p = var_name16;
+		utf8_utf16_strcpy(&p, argv[0]);
+
+		efi_dump_single_var(var_name16,
+				    (efi_guid_t *)&efi_global_variable_guid);
+	}
+
+	free(var_name16);
+
+	return CMD_RET_SUCCESS;
+}
+
+/**
+ * efi_dump_vars() - show information about all the UEFI variables
+ *
+ * Return:	CMD_RET_SUCCESS on success, or CMD_RET_RET_FAILURE
+ *
+ * Show information encoded in all the UEFI variables
+ */
+static int efi_dump_var_all(void)
+{
+	u16 *var_name16, *p;
+	efi_uintn_t buf_size, size;
+	efi_guid_t guid;
+	efi_status_t ret;
+
+	buf_size = 128;
+	var_name16 = malloc(buf_size);
+	if (!var_name16)
+		return CMD_RET_FAILURE;
+
+	var_name16[0] = 0;
+	for (;;) {
+		size = buf_size;
+		ret = EFI_CALL(efi_get_next_variable_name(&size, var_name16,
+							  &guid));
+		if (ret == EFI_NOT_FOUND)
+			break;
+		if (ret == EFI_BUFFER_TOO_SMALL) {
+			buf_size = size;
+			p = realloc(var_name16, buf_size);
+			if (!p) {
+				free(var_name16);
+				return CMD_RET_FAILURE;
+			}
+			var_name16 = p;
+			ret = EFI_CALL(efi_get_next_variable_name(&size,
+								  var_name16,
+								  &guid));
+		}
+		if (ret != EFI_SUCCESS) {
+			free(var_name16);
+			return CMD_RET_FAILURE;
+		}
+
+		efi_dump_single_var(var_name16, &guid);
+	}
+
+	free(var_name16);
+
+	return CMD_RET_SUCCESS;
+}
+
+/**
+ * do_env_print_efi() - show information about UEFI variables
+ *
+ * @cmdtp:	Command table
+ * @flag:	Command flag
+ * @argc:	Number of arguments
+ * @argv:	Argument array
+ * Return:	CMD_RET_SUCCESS on success, or CMD_RET_RET_FAILURE
+ *
+ * This function is for "env print -e" or "printenv -e" command:
+ *   => env print -e [var [...]]
+ * If one or more variable names are specified, show information
+ * named UEFI variables, otherwise show all the UEFI variables.
+ */
+int do_env_print_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	efi_status_t ret;
+
+	/* Initialize EFI drivers */
+	ret = efi_init_obj_list();
+	if (ret != EFI_SUCCESS) {
+		printf("Error: Cannot initialize UEFI sub-system, r = %lu\n",
+		       ret & ~EFI_ERROR_MASK);
+		return CMD_RET_FAILURE;
+	}
+
+	if (argc > 1)
+		/* show specified UEFI variables */
+		return efi_dump_vars(--argc, ++argv);
+
+	/* enumerate and show all UEFI variables */
+	return efi_dump_var_all();
+}
+
+/**
+ * append_value() - encode UEFI variable's value
+ * @bufp:	Buffer of encoded UEFI variable's value
+ * @sizep:	Size of buffer
+ * @data:	data to be encoded into the value
+ * Return:	0 on success, -1 otherwise
+ *
+ * Interpret a given data string and append it to buffer.
+ * Buffer will be realloc'ed if necessary.
+ *
+ * Currently supported formats are:
+ *   =0x0123...:		Hexadecimal number
+ *   =H0123...:			Hexadecimal-byte array
+ *   ="...", =S"..." or <string>:
+ *				String
+ */
+static int append_value(char **bufp, size_t *sizep, char *data)
+{
+	char *tmp_buf = NULL, *new_buf = NULL, *value;
+	unsigned long len = 0;
+
+	if (!strncmp(data, "=0x", 2)) { /* hexadecimal number */
+		union {
+			u8 u8;
+			u16 u16;
+			u32 u32;
+			u64 u64;
+		} tmp_data;
+		unsigned long hex_value;
+		void *hex_ptr;
+
+		data += 3;
+		len = strlen(data);
+		if ((len & 0x1)) /* not multiple of two */
+			return -1;
+
+		len /= 2;
+		if (len > 8)
+			return -1;
+		else if (len > 4)
+			len = 8;
+		else if (len > 2)
+			len = 4;
+
+		/* convert hex hexadecimal number */
+		if (strict_strtoul(data, 16, &hex_value) < 0)
+			return -1;
+
+		tmp_buf = malloc(len);
+		if (!tmp_buf)
+			return -1;
+
+		if (len == 1) {
+			tmp_data.u8 = hex_value;
+			hex_ptr = &tmp_data.u8;
+		} else if (len == 2) {
+			tmp_data.u16 = hex_value;
+			hex_ptr = &tmp_data.u16;
+		} else if (len == 4) {
+			tmp_data.u32 = hex_value;
+			hex_ptr = &tmp_data.u32;
+		} else {
+			tmp_data.u64 = hex_value;
+			hex_ptr = &tmp_data.u64;
+		}
+		memcpy(tmp_buf, hex_ptr, len);
+		value = tmp_buf;
+
+	} else if (!strncmp(data, "=H", 2)) { /* hexadecimal-byte array */
+		data += 2;
+		len = strlen(data);
+		if (len & 0x1) /* not multiple of two */
+			return -1;
+
+		len /= 2;
+		tmp_buf = malloc(len);
+		if (!tmp_buf)
+			return -1;
+
+		if (hex2bin((u8 *)tmp_buf, data, len) < 0)
+			return -1;
+
+		value = tmp_buf;
+	} else { /* string */
+		if (!strncmp(data, "=\"", 2) || !strncmp(data, "=S\"", 3)) {
+			if (data[1] == '"')
+				data += 2;
+			else
+				data += 3;
+			value = data;
+			len = strlen(data) - 1;
+			if (data[len] != '"')
+				return -1;
+		} else {
+			value = data;
+			len = strlen(data);
+		}
+	}
+
+	new_buf = realloc(*bufp, *sizep + len);
+	if (!new_buf)
+		goto out;
+
+	memcpy(new_buf + *sizep, value, len);
+	*bufp = new_buf;
+	*sizep += len;
+
+out:
+	free(tmp_buf);
+
+	return 0;
+}
+
+/**
+ * do_env_print_efi() - set UEFI variable
+ *
+ * @cmdtp:	Command table
+ * @flag:	Command flag
+ * @argc:	Number of arguments
+ * @argv:	Argument array
+ * Return:	CMD_RET_SUCCESS on success, or CMD_RET_RET_FAILURE
+ *
+ * This function is for "env set -e" or "setenv -e" command:
+ *   => env set -e var [value ...]]
+ * Encode values specified and set given UEFI variable.
+ * If no value is specified, delete the variable.
+ */
+int do_env_set_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	char *var_name, *value = NULL;
+	efi_uintn_t size = 0;
+	u16 *var_name16 = NULL, *p;
+	size_t len;
+	efi_guid_t guid;
+	efi_status_t ret;
+
+	if (argc == 1)
+		return CMD_RET_USAGE;
+
+	/* Initialize EFI drivers */
+	ret = efi_init_obj_list();
+	if (ret != EFI_SUCCESS) {
+		printf("Error: Cannot initialize UEFI sub-system, r = %lu\n",
+		       ret & ~EFI_ERROR_MASK);
+		return CMD_RET_FAILURE;
+	}
+
+	var_name = argv[1];
+	if (argc == 2) {
+		/* delete */
+		value = NULL;
+		size = 0;
+	} else { /* set */
+		argc -= 2;
+		argv += 2;
+
+		for ( ; argc > 0; argc--, argv++)
+			if (append_value(&value, &size, argv[0]) < 0) {
+				ret = CMD_RET_FAILURE;
+				goto out;
+			}
+	}
+
+	len = utf8_utf16_strnlen(var_name, strlen(var_name));
+	var_name16 = malloc((len + 1) * 2);
+	if (!var_name16) {
+		ret = CMD_RET_FAILURE;
+		goto out;
+	}
+	p = var_name16;
+	utf8_utf16_strncpy(&p, var_name, len + 1);
+
+	guid = efi_global_variable_guid;
+	ret = EFI_CALL(efi_set_variable(var_name16, &guid,
+					EFI_VARIABLE_BOOTSERVICE_ACCESS |
+					EFI_VARIABLE_RUNTIME_ACCESS,
+					size, value));
+	ret = (ret == EFI_SUCCESS ? CMD_RET_SUCCESS : CMD_RET_FAILURE);
+out:
+	free(value);
+	free(var_name16);
+
+	return ret;
+}