Sorry, pasted wrong file. Here is the correct one: diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def index 0cc40bb..aa7b927 100644 --- a/grub-core/Makefile.core.def +++ b/grub-core/Makefile.core.def @@ -735,6 +735,12 @@ module = { };
module = { + name = efivar; + efi = commands/efi/efivar.c; + enable = efi; +}; + +module = { name = blocklist; common = commands/blocklist.c; }; diff --git a/grub-core/commands/efi/efivar.c b/grub-core/commands/efi/efivar.c new file mode 100644 index 0000000..7fe7bda --- /dev/null +++ b/grub-core/commands/efi/efivar.c @@ -0,0 +1,236 @@ +/* efivar.c - Read EFI global variables. */ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2015 Free Software Foundation, Inc. + * Copyright (C) 2015 CloudFlare, Inc. + * + * GRUB is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * GRUB is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GRUB. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <grub/types.h> +#include <grub/mm.h> +#include <grub/misc.h> +#include <grub/efi/api.h> +#include <grub/efi/efi.h> +#include <grub/extcmd.h> +#include <grub/env.h> +#include <grub/lib/hexdump.h> + +GRUB_MOD_LICENSE ("GPLv3+"); + +static const struct grub_arg_option options[] = { + {"format", 'f', GRUB_ARG_OPTION_OPTIONAL, N_("Parse EFI_VAR in specific format (hex, uint8, ascii, dump). Default: hex."), N_("FORMAT"), ARG_TYPE_STRING}, + {"set", 's', GRUB_ARG_OPTION_OPTIONAL, N_("Save parsed result to environment variable (does not work with dump)."), N_("ENV_VAR"), ARG_TYPE_STRING}, + {0, 0, 0, 0, 0, 0} +}; + +enum efi_var_type + { + EFI_VAR_ASCII = 0, + EFI_VAR_UINT8, + EFI_VAR_HEX, + EFI_VAR_DUMP, + EFI_VAR_INVALID = -1 + }; + +static enum efi_var_type +parse_efi_var_type (const char *type) +{ + if (!grub_strcmp (type, "ascii")) + return EFI_VAR_ASCII; + + if (!grub_strcmp (type, "uint8")) + return EFI_VAR_UINT8; + + if (!grub_strcmp (type, "hex")) + return EFI_VAR_HEX; + + if (!grub_strcmp (type, "dump")) + return EFI_VAR_DUMP; + + return EFI_VAR_INVALID; +} + +static int +grub_print_ascii (char *str, char c) +{ + if (grub_iscntrl (c)) + { + switch (c) + { + case '\0': + str[0] = '\\'; + str[1] = '0'; + return 2; + + case '\a': + str[0] = '\\'; + str[1] = 'a'; + return 2; + + case '\b': + str[0] = '\\'; + str[1] = 'b'; + return 2; + + case '\f': + str[0] = '\\'; + str[1] = 'f'; + return 2; + + case '\n': + str[0] = '\\'; + str[1] = 'n'; + return 2; + + case '\r': + str[0] = '\\'; + str[1] = 'r'; + return 2; + + case '\t': + str[0] = '\\'; + str[1] = 't'; + return 2; + + case '\v': + str[0] = '\\'; + str[1] = 'v'; + return 2; + + default: + str[0] = '.'; /* as in hexdump -C */ + return 1; + } + } + + str[0] = c; + return 1; +} + +static grub_err_t +grub_cmd_get_efi_var (struct grub_extcmd_context *ctxt, + int argc, char **args) +{ + struct grub_arg_list *state = ctxt->state; + grub_err_t status; + void *efi_var = NULL; + grub_size_t efi_var_size = 0; + enum efi_var_type efi_type = EFI_VAR_HEX; + grub_efi_guid_t global = GRUB_EFI_GLOBAL_VARIABLE_GUID; + char *env_var = NULL; + grub_size_t i; + char *ptr; + + if (1 != argc) + return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("one argument expected")); + + if (state[0].set) + efi_type = parse_efi_var_type (state[0].arg); + + if (EFI_VAR_INVALID == efi_type) + return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("invalid format specifier")); + + efi_var = grub_efi_get_variable (args[0], &global, &efi_var_size); + if (!efi_var || !efi_var_size) + { + status = grub_error (GRUB_ERR_READ_ERROR, N_("cannot read variable")); + goto err; + } + + switch (efi_type) + { + case EFI_VAR_ASCII: + env_var = grub_malloc (efi_var_size * 2 + 1); + if (!env_var) + { + status = grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory")); + goto err; + } + + ptr = env_var; + + for (i = 0; i < efi_var_size; i++) + ptr += grub_print_ascii (ptr, ((const char *)efi_var)[i]); + *ptr = '\0'; + break; + + case EFI_VAR_UINT8: + env_var = grub_malloc (4); + if (!env_var) + { + status = grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory")); + goto err; + } + grub_snprintf (env_var, 4, "%u", *((grub_uint8_t *)efi_var)); + break; + + case EFI_VAR_HEX: + env_var = grub_malloc (efi_var_size * 2 + 1); + if (!env_var) + { + status = grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory")); + goto err; + } + for (i = 0; i < efi_var_size; i++) + grub_snprintf (env_var + (i * 2), 3, "%02x", ((grub_uint8_t *)efi_var)[i]); + break; + + case EFI_VAR_DUMP: + if (state[1].set) + status = grub_error (GRUB_ERR_BAD_ARGUMENT, N_("cannot set variable with dump format specifier")); + else + { + hexdump (0, (char *)efi_var, efi_var_size); + status = GRUB_ERR_NONE; + } + break; + + default: + status = grub_error (GRUB_ERR_BUG, N_("should not happen (bug in module?)")); + goto err; + } + + if (efi_type != EFI_VAR_DUMP) + { + if (state[1].set) + status = grub_env_set (state[1].arg, env_var); + else + { + grub_printf ("%s\n", (const char *)env_var); + status = GRUB_ERR_NONE; + } + } + +err: + + grub_free (env_var); + grub_free (efi_var); + + return status; +} + +static grub_extcmd_t cmd = NULL; + +GRUB_MOD_INIT (efivar) +{ + cmd = grub_register_extcmd ("get_efivar", grub_cmd_get_efi_var, 0, N_("[-f FORMAT] [-s ENV_VAR] EFI_VAR"), + N_("Read EFI variable and print it or save its contents to environment variable."), options); +} + +GRUB_MOD_FINI (efivar) +{ + if (cmd) + grub_unregister_extcmd (cmd); +} On Mon, Dec 14, 2015 at 11:08 AM, Ignat Korchagin <ig...@cloudflare.com> wrote: >> Assuming uint8 remains - should not you check that variable size is exactly >> 1 byte in this case? > There are reports of a buggy firmware returning 4 bytes size for uint8 > variables, however did not encounter them myself. > >> Do we really need unit8 at all? "hex" already provides exactly the same >> functionality, not? Do you think there are cases when uint8 is really >> required? > Well, when checking for SecureBoot variable in grub configuration file > hex mode makes it look weird and creates a point of confusion. For > example to check if SecureBoot (suppose the result of the our command > is stored in secure_boot env variable in hex mode) is enabled one > should write: > if [ secure_boot = "01" ] > ... > uint8 just allows to do a more straightforward config > if [ secure_boot = 1] - this case would be false for hex mode - > possible security breach > ... > > Added goto err in the module as pointed, see patch below. I will do a > follow-up patch for documentation once we get this confirmed. > > diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def > index 0cc40bb..aa7b927 100644 > --- a/grub-core/Makefile.core.def > +++ b/grub-core/Makefile.core.def > @@ -735,6 +735,12 @@ module = { > }; > > module = { > + name = efivar; > + efi = commands/efi/efivar.c; > + enable = efi; > +}; > + > +module = { > name = blocklist; > common = commands/blocklist.c; > }; > diff --git a/grub-core/commands/efi/efivar.c b/grub-core/commands/efi/efivar.c > new file mode 100644 > index 0000000..7f5a957 > --- /dev/null > +++ b/grub-core/commands/efi/efivar.c > @@ -0,0 +1,251 @@ > +/* efivar.c - Read EFI global variables. */ > +/* > + * GRUB -- GRand Unified Bootloader > + * Copyright (C) 2015 Free Software Foundation, Inc. > + * Copyright (C) 2015 CloudFlare, Inc. > + * > + * GRUB is free software: you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation, either version 3 of the License, or > + * (at your option) any later version. > + * > + * GRUB is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with GRUB. If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#include <grub/types.h> > +#include <grub/mm.h> > +#include <grub/misc.h> > +#include <grub/efi/api.h> > +#include <grub/efi/efi.h> > +#include <grub/extcmd.h> > +#include <grub/env.h> > +#include <grub/lib/hexdump.h> > + > +GRUB_MOD_LICENSE ("GPLv3+"); > + > +static const struct grub_arg_option options[] = { > + {"format", 'f', GRUB_ARG_OPTION_OPTIONAL, N_("Parse EFI_VAR in > specific format (hex, uint8, ascii, raw, dump). Default: hex."), > N_("FORMAT"), ARG_TYPE_STRING}, > + {"set", 's', GRUB_ARG_OPTION_OPTIONAL, N_("Save parsed result to > environment variable (does not work with dump)."), N_("ENV_VAR"), > ARG_TYPE_STRING}, > + {0, 0, 0, 0, 0, 0} > +}; > + > +enum efi_var_type > + { > + EFI_VAR_ASCII = 0, > + EFI_VAR_RAW, > + EFI_VAR_UINT8, > + EFI_VAR_HEX, > + EFI_VAR_DUMP, > + EFI_VAR_INVALID = -1 > + }; > + > +static enum efi_var_type > +parse_efi_var_type (const char *type) > +{ > + if (!grub_strncmp (type, "ascii", sizeof("ascii"))) > + return EFI_VAR_ASCII; > + > + if (!grub_strncmp (type, "raw", sizeof("raw"))) > + return EFI_VAR_ASCII; > + > + if (!grub_strncmp (type, "uint8", sizeof("uint8"))) > + return EFI_VAR_UINT8; > + > + if (!grub_strncmp (type, "hex", sizeof("hex"))) > + return EFI_VAR_HEX; > + > + if (!grub_strncmp (type, "dump", sizeof("dump"))) > + return EFI_VAR_DUMP; > + > + return EFI_VAR_INVALID; > +} > + > +static int > +grub_print_ascii (char *str, char c) > +{ > + if (grub_iscntrl (c)) > + { > + switch (c) > + { > + case '\0': > + str[0] = '\\'; > + str[1] = '0'; > + return 2; > + > + case '\a': > + str[0] = '\\'; > + str[1] = 'a'; > + return 2; > + > + case '\b': > + str[0] = '\\'; > + str[1] = 'b'; > + return 2; > + > + case '\f': > + str[0] = '\\'; > + str[1] = 'f'; > + return 2; > + > + case '\n': > + str[0] = '\\'; > + str[1] = 'n'; > + return 2; > + > + case '\r': > + str[0] = '\\'; > + str[1] = 'r'; > + return 2; > + > + case '\t': > + str[0] = '\\'; > + str[1] = 't'; > + return 2; > + > + case '\v': > + str[0] = '\\'; > + str[1] = 'v'; > + return 2; > + > + default: > + str[0] = '.'; /* as in hexdump -C */ > + return 1; > + } > + } > + > + str[0] = c; > + return 1; > +} > + > +static grub_err_t > +grub_cmd_get_efi_var (struct grub_extcmd_context *ctxt, > + int argc, char **args) > +{ > + struct grub_arg_list *state = ctxt->state; > + grub_err_t status; > + void *efi_var = NULL; > + grub_size_t efi_var_size = 0; > + enum efi_var_type efi_type = EFI_VAR_HEX; > + grub_efi_guid_t global = GRUB_EFI_GLOBAL_VARIABLE_GUID; > + char *env_var = NULL; > + grub_size_t i; > + char *ptr; > + > + if (1 != argc) > + return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("one argument expected")); > + > + if (state[0].set) > + efi_type = parse_efi_var_type (state[0].arg); > + > + if (EFI_VAR_INVALID == efi_type) > + return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("invalid format > specifier")); > + > + efi_var = grub_efi_get_variable (args[0], &global, &efi_var_size); > + if (!efi_var || !efi_var_size) > + { > + status = grub_error (GRUB_ERR_READ_ERROR, N_("cannot read variable")); > + goto err; > + } > + > + switch (efi_type) > + { > + case EFI_VAR_ASCII: > + env_var = grub_malloc (efi_var_size * 2 + 1); > + if (!env_var) > + { > + status = grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory")); > + goto err; > + } > + > + ptr = env_var; > + > + for (i = 0; i < efi_var_size; i++) > + ptr += grub_print_ascii (ptr, ((const char *)efi_var)[i]); > + *ptr = '\0'; > + break; > + > + case EFI_VAR_RAW: > + env_var = grub_malloc (efi_var_size + 1); > + if (!env_var) > + { > + status = grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory")); > + goto err; > + } > + grub_memcpy (env_var, efi_var, efi_var_size); > + env_var[efi_var_size] = '\0'; > + break; > + > + case EFI_VAR_UINT8: > + env_var = grub_malloc (4); > + if (!env_var) > + { > + status = grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory")); > + goto err; > + } > + grub_snprintf (env_var, 4, "%u", *((grub_uint8_t *)efi_var)); > + break; > + > + case EFI_VAR_HEX: > + env_var = grub_malloc (efi_var_size * 2 + 1); > + if (!env_var) > + { > + status = grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory")); > + goto err; > + } > + for (i = 0; i < efi_var_size; i++) > + grub_snprintf (env_var + (i * 2), 3, "%02x", ((grub_uint8_t > *)efi_var)[i]); > + break; > + > + case EFI_VAR_DUMP: > + if (state[1].set) > + status = grub_error (GRUB_ERR_BAD_ARGUMENT, N_("cannot set > variable with dump format specifier")); > + else > + { > + hexdump (0, (char *)efi_var, efi_var_size); > + status = GRUB_ERR_NONE; > + } > + break; > + > + default: > + status = grub_error (GRUB_ERR_BUG, N_("should not happen (bug > in module?)")); > + goto err; > + } > + > + if (efi_type != EFI_VAR_DUMP) > + { > + if (state[1].set) > + status = grub_env_set (state[1].arg, env_var); > + else > + { > + grub_printf ("%s\n", (const char *)env_var); > + status = GRUB_ERR_NONE; > + } > + } > + > +err: > + > + grub_free (env_var); > + grub_free (efi_var); > + > + return status; > +} > + > +static grub_extcmd_t cmd = NULL; > + > +GRUB_MOD_INIT (efivar) > +{ > + cmd = grub_register_extcmd ("get_efivar", grub_cmd_get_efi_var, 0, > N_("[-f FORMAT] [-s ENV_VAR] EFI_VAR"), > + N_("Read EFI variable and print it or save its contents to > environment variable."), options); > +} > + > +GRUB_MOD_FINI (efivar) > +{ > + if (cmd) > + grub_unregister_extcmd (cmd); > +} _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel