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

AKASHI Takahiro
2019-10-04T01:20:33Z

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.)

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>
---
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;
--
2.21.0