[U-Boot] [PATCH] cmd: env: extend "env [set|print] -e" to manage UEFI variables
Heinrich Schuchardt
xypron.glpk at gmx.de
Thu Sep 5 12:05:24 UTC 2019
On 9/5/19 11:20 AM, AKASHI Takahiro wrote:
> On Tue, Sep 03, 2019 at 10:46:04PM +0200, Heinrich Schuchardt wrote:
>> On 9/3/19 7:41 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,
>>> TIME_BASED_AUTHENTICATED_WRITE_ACCESS respectively with
>>
>> Doesn't TIME_BASED_AUTHENTICATED_WRITE_ACCESS mandate changes in
>> SetVariable() too?
>>
>> I could not find the EFI_VARIABLE_AUTHENTICATION_2 descriptor in the patch.
>
> As you might image, this patch was part of my patch set for
> UEFI secure boot implementation.
>
>> I think we should not provide "-at" as a parameter of this command if it
>> is not supported.
>
> I believed that efi_set_variable() always checks for unsupported attributes
> first, but it does so only under my local repository :)
> Okay, I will remove it for now.
>
>> So there should be first a patch to change
>> SetVariable(). Then a patch implementing efidebug -at may follow.
>>
>> In a case of an error, please, provide a meaningful error message. (A
>> variable might be READ_ONLY or NOT_FOUND. -rt might be specified without
>> -bs.)
>
> in which printf?
> I didn't change anything in efi_variable.c.
Shouldn't sentenv -e check the parameters before calling SetVariable()
and provide a message?
Regards
Heinrich
>>> "-bs", "-rt" and "-at",
>>> - 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 at linaro.org>
>>> ---
>>> cmd/nvedit.c | 20 +++--
>>> cmd/nvedit_efi.c | 192 ++++++++++++++++++++++++++++++++++++++---------
>>> 2 files changed, 172 insertions(+), 40 deletions(-)
>>>
>>> diff --git a/cmd/nvedit.c b/cmd/nvedit.c
>>> index 1cb0bc1460b9..2d2adc8529db 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][-at][-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 +1461,17 @@ 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][-at][-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"
>>> + " \"-at\": set time-based authentication 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..a9ecb3ee4dc3 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][-at][-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 +419,96 @@ 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], "-at")) {
>>> + attributes |=
>>> + EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
>>> + } 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[1];
>>> - if (argc == 2) {
>>> - /* delete */
>>> - value = NULL;
>>> - size = 0;
>>> - } else { /* set */
>>> - argc -= 2;
>>> - argv += 2;
>>> + var_name = argv[0];
>>> + if (default_guid)
>>> + guid = efi_global_variable_guid;
>>>
>>> - for ( ; argc > 0; argc--, argv++)
>>> + if (verbose) {
>>> + printf("GUID: %s\n", efi_guid_to_str(&guid));
>>> + printf("Attributes: 0x%x\n", attributes);
>>> + }
>>> +
>>> + /* for value */
>>> + if (value_on_memory)
>>> + value = map_sysmem(addr, 0);
>>> + else if (argc > 1)
>>> + for (argc--, argv++; argc > 0; argc--, argv++)
>>> + /* FIXME: signness of value */
>>> 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 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));
>>> @@ -402,9 +521,9 @@ 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 {
>>> @@ -412,7 +531,10 @@ int do_env_set_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>>> ret = CMD_RET_FAILURE;
>>> }
>>> out:
>>> - free(value);
>>> + if (value_on_memory)
>>> + unmap_sysmem(value);
>>> + else
>>> + free(value);
>>> free(var_name16);
>>>
>>> return ret;
>>>
>>
>
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