[U-Boot] [PATCH v3] cmd: env: extend "env [set|print] -e" to manage UEFI variables

[AKASHI Takahiro <takahiro.akashi@linaro.org>]

On Sat, Oct 05, 2019 at 08:53:39AM +0200, Heinrich Schuchardt wrote:
> On 10/4/19 3:20 AM, AKASHI Takahiro wrote:
> >With this patch, when setting UEFI variable with "env set -e" command,
> >we will be able to
> >- specify vendor guid with "-guid guid",
> >- specify variable attributes,  BOOTSERVICE_ACCESS, RUNTIME_ACCESS,
> >   respectively with "-bs" and "-rt",
> >- append a value instead of overwriting with "-a",
> >- use memory as variable's value instead of explicit values given
> >   at the command line with "-i address,size"
> >
> >If guid is not explicitly given, default value will be used.
> >
> >When "-at" is given, a variable should be authenticated with
> >appropriate signature database before setting or modifying its value.
> >(Authentication is not supported yet though.)
> 
> Didn't you remove this in v2?

It was an editorial error, which also existed in v2 commit message.

> >
> >Meanwhile, "env print -e," will be modified so that it will dump
> >a variable's value only if '-v' (verbose) is specified.
> >
> >Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> 
> This does not work as expected:
> 
> => setenv -e -guid 0123456789abcdef0123456789abcdef -bs ARGONAUT hello world
> => printenv -e
> OsIndicationsSupported:
>     EFI_GLOBAL_VARIABLE_GUID: BS|RT, DataSize = 0x8
> PlatformLang:
>     EFI_GLOBAL_VARIABLE_GUID: NV|BS|RT, DataSize = 0x6
> PlatformLangCodes:
>     EFI_GLOBAL_VARIABLE_GUID: BS|RT, DataSize = 0x6
> RuntimeServicesSupported:
>     EFI_GLOBAL_VARIABLE_GUID: BS|RT, DataSize = 0x2
> 
> Neither do I see an error nor is the variable set.

You have an incorrect guid format, so env_set_efi() should
return CMD_RET_USAGE, but mistakenly returns CMD_RET_FAILURE.

> The patch increases the size of u-boot.bin by 2216 bytes for qemu-arm64.
> Tom is always asking me how we can stop the size increase in the UEFI
> sub-system.
> 
> Why do we need this patch? This functionality is already available via
> the UEFI shell.

Such a question should have been made before initially "-e" option
has been introduced a long time ago.

* As far as we have "-e" option, this new patch is a natural extension.
* Why do we have to reply on external apps? We should have a minimum
  self-contained command set to manage UEFI as part of U-Boot.
* "-i" is used in secure boot pytest.

Thanks,
-Takahiro Akashi

> Just open the UEFI shell and run
> 
> Shell> setvar ARGONAUT -guid 01234567-89ab-cdef-0123-456789abcdef -rt
> =L"Hello world"
> Shell> exit
> 
> Best regards
> 
> Heinrich
> 
> 
> >---
> >Changes in v3 (Oct 4, 2019)
> >* add verbose messages when SetVariable() fails
> >
> >Changes in v2 (Sept 6, 2019)
> >* remove "-at" option
> >
> >---
> >  cmd/nvedit.c     |  19 +++--
> >  cmd/nvedit_efi.c | 212 +++++++++++++++++++++++++++++++++++++++--------
> >  2 files changed, 190 insertions(+), 41 deletions(-)
> >
> >diff --git a/cmd/nvedit.c b/cmd/nvedit.c
> >index 1cb0bc1460b9..1e542972db30 100644
> >--- a/cmd/nvedit.c
> >+++ b/cmd/nvedit.c
> >@@ -1387,7 +1387,7 @@ static char env_help_text[] =
> >  #endif
> >  	"env print [-a | name ...] - print environment\n"
> >  #if defined(CONFIG_CMD_NVEDIT_EFI)
> >-	"env print -e [name ...] - print UEFI environment\n"
> >+	"env print -e [-v] [name ...] - print UEFI environment\n"
> >  #endif
> >  #if defined(CONFIG_CMD_RUN)
> >  	"env run var [...] - run commands in an environment variable\n"
> >@@ -1399,7 +1399,8 @@ static char env_help_text[] =
> >  #endif
> >  #endif
> >  #if defined(CONFIG_CMD_NVEDIT_EFI)
> >-	"env set -e name [arg ...] - set UEFI variable; unset if 'arg' not specified\n"
> >+	"env set -e [-nv][-bs][-rt][-a][-i addr,size][-v] name [arg ...]\n"
> >+	"    - set UEFI variable; unset if '-i' or 'arg' not specified\n"
> >  #endif
> >  	"env set [-f] name [arg ...]\n";
> >  #endif
> >@@ -1428,8 +1429,9 @@ U_BOOT_CMD_COMPLETE(
> >  	"print environment variables",
> >  	"[-a]\n    - print [all] values of all environment variables\n"
> >  #if defined(CONFIG_CMD_NVEDIT_EFI)
> >-	"printenv -e [name ...]\n"
> >+	"printenv -e [-v] [name ...]\n"
> >  	"    - print UEFI variable 'name' or all the variables\n"
> >+	"      \"-v\": verbose for signature database\n"
> >  #endif
> >  	"printenv name ...\n"
> >  	"    - print value of environment variable 'name'",
> >@@ -1459,9 +1461,16 @@ U_BOOT_CMD_COMPLETE(
> >  	setenv, CONFIG_SYS_MAXARGS, 0,	do_env_set,
> >  	"set environment variables",
> >  #if defined(CONFIG_CMD_NVEDIT_EFI)
> >-	"-e [-nv] name [value ...]\n"
> >+	"-e [-guid guid][-nv][-bs][-rt][-a][-v]\n"
> >+	"        [-i addr,size name], or [name [value ...]]\n"
> >  	"    - set UEFI variable 'name' to 'value' ...'\n"
> >-	"      'nv' option makes the variable non-volatile\n"
> >+	"      \"-guid\": set vendor guid\n"
> >+	"      \"-nv\": set non-volatile attribute\n"
> >+	"      \"-bs\": set boot-service attribute\n"
> >+	"      \"-rt\": set runtime attribute\n"
> >+	"      \"-a\": append-write\n"
> >+	"      \"-i addr,size\": use <addr,size> as variable's value\n"
> >+	"      \"-v\": verbose print\n"
> >  	"    - delete UEFI variable 'name' if 'value' not specified\n"
> >  #endif
> >  	"setenv [-f] name value ...\n"
> >diff --git a/cmd/nvedit_efi.c b/cmd/nvedit_efi.c
> >index ed6d09a53046..795c95be0ef7 100644
> >--- a/cmd/nvedit_efi.c
> >+++ b/cmd/nvedit_efi.c
> >@@ -13,6 +13,7 @@
> >  #include <exports.h>
> >  #include <hexdump.h>
> >  #include <malloc.h>
> >+#include <mapmem.h>
> >  #include <linux/kernel.h>
> >
> >  /*
> >@@ -34,15 +35,48 @@ static const struct {
> >  	{EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS, "AT"},
> >  };
> >
> >+static const struct {
> >+	efi_guid_t guid;
> >+	char *text;
> >+} efi_guid_text[] = {
> >+	/* signature database */
> >+	{EFI_GLOBAL_VARIABLE_GUID, "EFI_GLOBAL_VARIABLE_GUID"},
> >+};
> >+
> >+/* "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" */
> >+static char unknown_guid[37];
> >+
> >+/**
> >+ * efi_guid_to_str() - convert guid to readable name
> >+ *
> >+ * @guid:	GUID
> >+ * Return:	string for GUID
> >+ *
> >+ * convert guid to readable name
> >+ */
> >+static const char *efi_guid_to_str(efi_guid_t *guid)
> >+{
> >+	int i;
> >+
> >+	for (i = 0; i < ARRAY_SIZE(efi_guid_text); i++)
> >+		if (!guidcmp(guid, &efi_guid_text[i].guid))
> >+			return efi_guid_text[i].text;
> >+
> >+	uuid_bin_to_str(guid->b, unknown_guid, UUID_STR_FORMAT_GUID);
> >+
> >+	return unknown_guid;
> >+}
> >+
> >  /**
> >   * efi_dump_single_var() - show information about a UEFI variable
> >   *
> >   * @name:	Name of the variable
> >   * @guid:	Vendor GUID
> >+ * @verbose:	if true, dump data
> >   *
> >   * Show information encoded in one UEFI variable
> >   */
> >-static void efi_dump_single_var(u16 *name, efi_guid_t *guid)
> >+static void efi_dump_single_var(u16 *name, efi_guid_t *guid, bool verbose)
> >  {
> >  	u32 attributes;
> >  	u8 *data;
> >@@ -68,7 +102,7 @@ static void efi_dump_single_var(u16 *name, efi_guid_t *guid)
> >  	if (ret != EFI_SUCCESS)
> >  		goto out;
> >
> >-	printf("%ls:", name);
> >+	printf("%ls:\n    %s:", name, efi_guid_to_str(guid));
> >  	for (count = 0, i = 0; i < ARRAY_SIZE(efi_var_attrs); i++)
> >  		if (attributes & efi_var_attrs[i].mask) {
> >  			if (count)
> >@@ -79,7 +113,9 @@ static void efi_dump_single_var(u16 *name, efi_guid_t *guid)
> >  			puts(efi_var_attrs[i].text);
> >  		}
> >  	printf(", DataSize = 0x%zx\n", size);
> >-	print_hex_dump("    ", DUMP_PREFIX_OFFSET, 16, 1, data, size, true);
> >+	if (verbose)
> >+		print_hex_dump("    ", DUMP_PREFIX_OFFSET, 16, 1,
> >+			       data, size, true);
> >
> >  out:
> >  	free(data);
> >@@ -90,11 +126,12 @@ out:
> >   *
> >   * @argc:	Number of arguments (variables)
> >   * @argv:	Argument (variable name) array
> >+ * @verbose:	if true, dump data
> >   * 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[])
> >+static int efi_dump_vars(int argc,  char * const argv[], bool verbose)
> >  {
> >  	u16 *var_name16, *p;
> >  	efi_uintn_t buf_size, size;
> >@@ -120,7 +157,8 @@ static int efi_dump_vars(int argc,  char * const argv[])
> >  		utf8_utf16_strcpy(&p, argv[0]);
> >
> >  		efi_dump_single_var(var_name16,
> >-				    (efi_guid_t *)&efi_global_variable_guid);
> >+				    (efi_guid_t *)&efi_global_variable_guid,
> >+				    verbose);
> >  	}
> >
> >  	free(var_name16);
> >@@ -131,11 +169,12 @@ static int efi_dump_vars(int argc,  char * const argv[])
> >  /**
> >   * efi_dump_vars() - show information about all the UEFI variables
> >   *
> >+ * @verbose:	if true, dump data
> >   * 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)
> >+static int efi_dump_var_all(bool verbose)
> >  {
> >  	u16 *var_name16, *p;
> >  	efi_uintn_t buf_size, size;
> >@@ -171,7 +210,7 @@ static int efi_dump_var_all(void)
> >  			return CMD_RET_FAILURE;
> >  		}
> >
> >-		efi_dump_single_var(var_name16, &guid);
> >+		efi_dump_single_var(var_name16, &guid, verbose);
> >  	}
> >
> >  	free(var_name16);
> >@@ -189,12 +228,13 @@ static int efi_dump_var_all(void)
> >   * 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 [...]]
> >+ *   => env print -e [-v] [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[])
> >  {
> >+	bool verbose;
> >  	efi_status_t ret;
> >
> >  	/* Initialize EFI drivers */
> >@@ -205,12 +245,23 @@ int do_env_print_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> >  		return CMD_RET_FAILURE;
> >  	}
> >
> >-	if (argc > 1)
> >+	verbose = false;
> >+	for (argc--, argv++; argc > 0 && argv[0][0] == '-'; argc--, argv++) {
> >+		switch (argv[0][1]) {
> >+		case 'v':
> >+			verbose = true;
> >+			break;
> >+		default:
> >+			return CMD_RET_USAGE;
> >+		}
> >+	}
> >+
> >+	if (argc)
> >  		/* show specified UEFI variables */
> >-		return efi_dump_vars(--argc, ++argv);
> >+		return efi_dump_vars(argc, argv, verbose);
> >
> >  	/* enumerate and show all UEFI variables */
> >-	return efi_dump_var_all();
> >+	return efi_dump_var_all(verbose);
> >  }
> >
> >  /**
> >@@ -339,18 +390,22 @@ out:
> >   * 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 ...]]
> >+ *   => env set -e [-guid guid][-nv][-bs][-rt][-a][-v]
> >+ *		   [-i address,size] var, or
> >+ *                 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;
> >+	char *var_name, *value, *ep;
> >+	ulong addr;
> >+	efi_uintn_t size;
> >  	efi_guid_t guid;
> >  	u32 attributes;
> >+	bool default_guid, verbose, value_on_memory;
> >+	u16 *var_name16 = NULL, *p;
> >+	size_t len;
> >  	efi_status_t ret;
> >
> >  	if (argc == 1)
> >@@ -364,32 +419,92 @@ int do_env_set_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> >  		return CMD_RET_FAILURE;
> >  	}
> >
> >-	attributes = EFI_VARIABLE_BOOTSERVICE_ACCESS |
> >-		     EFI_VARIABLE_RUNTIME_ACCESS;
> >-	if (!strcmp(argv[1], "-nv")) {
> >-		attributes |= EFI_VARIABLE_NON_VOLATILE;
> >-		argc--;
> >-		argv++;
> >-		if (argc == 1)
> >-			return CMD_RET_SUCCESS;
> >+	/*
> >+	 * attributes = EFI_VARIABLE_BOOTSERVICE_ACCESS |
> >+	 *	     EFI_VARIABLE_RUNTIME_ACCESS;
> >+	 */
> >+	value = NULL;
> >+	size = 0;
> >+	attributes = 0;
> >+	guid = efi_global_variable_guid;
> >+	default_guid = true;
> >+	verbose = false;
> >+	value_on_memory = false;
> >+	for (argc--, argv++; argc > 0 && argv[0][0] == '-'; argc--, argv++) {
> >+		if (!strcmp(argv[0], "-guid")) {
> >+			if (argc == 1)
> >+				return CMD_RET_USAGE;
> >+
> >+			argc--;
> >+			argv++;
> >+			if (uuid_str_to_bin(argv[0], guid.b,
> >+					    UUID_STR_FORMAT_GUID))
> >+				return CMD_RET_FAILURE;
> >+			default_guid = false;
> >+		} else if (!strcmp(argv[0], "-bs")) {
> >+			attributes |= EFI_VARIABLE_BOOTSERVICE_ACCESS;
> >+		} else if (!strcmp(argv[0], "-rt")) {
> >+			attributes |= EFI_VARIABLE_RUNTIME_ACCESS;
> >+		} else if (!strcmp(argv[0], "-nv")) {
> >+			attributes |= EFI_VARIABLE_NON_VOLATILE;
> >+		} else if (!strcmp(argv[0], "-a")) {
> >+			attributes |= EFI_VARIABLE_APPEND_WRITE;
> >+		} else if (!strcmp(argv[0], "-i")) {
> >+			/* data comes from memory */
> >+			if (argc == 1)
> >+				return CMD_RET_USAGE;
> >+
> >+			argc--;
> >+			argv++;
> >+			addr = simple_strtoul(argv[0], &ep, 16);
> >+			if (*ep != ',')
> >+				return CMD_RET_USAGE;
> >+
> >+			size = simple_strtoul(++ep, NULL, 16);
> >+			if (!size)
> >+				return CMD_RET_FAILURE;
> >+			value_on_memory = true;
> >+		} else if (!strcmp(argv[0], "-v")) {
> >+			verbose = true;
> >+		} else {
> >+			return CMD_RET_USAGE;
> >+		}
> >  	}
> >+	if (!argc)
> >+		return CMD_RET_USAGE;
> >+
> >+	var_name = argv[0];
> >+	if (default_guid)
> >+		guid = efi_global_variable_guid;
> >
> >-	var_name = argv[1];
> >-	if (argc == 2) {
> >-		/* delete */
> >-		value = NULL;
> >-		size = 0;
> >-	} else { /* set */
> >-		argc -= 2;
> >-		argv += 2;
> >+	if (verbose) {
> >+		printf("GUID: %s\n", efi_guid_to_str(&guid));
> >+		printf("Attributes: 0x%x\n", attributes);
> >+	}
> >
> >-		for ( ; argc > 0; argc--, argv++)
> >+	/* for value */
> >+	if (value_on_memory)
> >+		value = map_sysmem(addr, 0);
> >+	else if (argc > 1)
> >+		for (argc--, argv++; argc > 0; argc--, argv++)
> >  			if (append_value(&value, &size, argv[0]) < 0) {
> >  				printf("## Failed to process an argument, %s\n",
> >  				       argv[0]);
> >  				ret = CMD_RET_FAILURE;
> >  				goto out;
> >  			}
> >+
> >+	if (size && !(attributes & (EFI_VARIABLE_BOOTSERVICE_ACCESS |
> >+				    EFI_VARIABLE_RUNTIME_ACCESS))) {
> >+		printf("## Attributes (-bs or -rt) must be specified\n");
> >+		ret = CMD_RET_FAILURE;
> >+		goto out;
> >+	}
> >+
> >+	if (size && verbose) {
> >+		printf("Value:\n");
> >+		print_hex_dump("    ", DUMP_PREFIX_OFFSET,
> >+			       16, 1, value, size, true);
> >  	}
> >
> >  	len = utf8_utf16_strnlen(var_name, strlen(var_name));
> >@@ -402,17 +517,42 @@ int do_env_set_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> >  	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, attributes,
> >  					size, value));
> >+	unmap_sysmem(value);
> >  	if (ret == EFI_SUCCESS) {
> >  		ret = CMD_RET_SUCCESS;
> >  	} else {
> >-		printf("## Failed to set EFI variable\n");
> >+		const char *msg;
> >+
> >+		switch (ret) {
> >+		case EFI_NOT_FOUND:
> >+			msg = " (not found)";
> >+			break;
> >+		case EFI_WRITE_PROTECTED:
> >+			msg = " (read only)";
> >+			break;
> >+		case EFI_INVALID_PARAMETER:
> >+			msg = " (invalid parameter)";
> >+			break;
> >+		case EFI_SECURITY_VIOLATION:
> >+			msg = " (validation failed)";
> >+			break;
> >+		case EFI_OUT_OF_RESOURCES:
> >+			msg = " (out of memory)";
> >+			break;
> >+		default:
> >+			msg = "";
> >+			break;
> >+		}
> >+		printf("## Failed to set EFI variable%s\n", msg);
> >  		ret = CMD_RET_FAILURE;
> >  	}
> >  out:
> >-	free(value);
> >+	if (value_on_memory)
> >+		unmap_sysmem(value);
> >+	else
> >+		free(value);
> >  	free(var_name16);
> >
> >  	return ret;
> >
>