diff options
Diffstat (limited to 'grub-core/commands/smbios.c')
| -rw-r--r-- | grub-core/commands/smbios.c | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/grub-core/commands/smbios.c b/grub-core/commands/smbios.c new file mode 100644 index 0000000..1a9086d --- /dev/null +++ b/grub-core/commands/smbios.c @@ -0,0 +1,398 @@ +/* smbios.c - retrieve smbios information. */ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2019 Free Software Foundation, 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/dl.h> +#include <grub/env.h> +#include <grub/extcmd.h> +#include <grub/i18n.h> +#include <grub/misc.h> +#include <grub/mm.h> +#include <grub/smbios.h> + +GRUB_MOD_LICENSE ("GPLv3+"); + +/* Abstract useful values found in either the SMBIOS3 or SMBIOS EPS. */ +static struct { + grub_addr_t start; + grub_addr_t end; + grub_uint16_t structures; +} table_desc; + +static grub_extcmd_t cmd; + +/* Locate the SMBIOS entry point structure depending on the hardware. */ +struct grub_smbios_eps * +grub_smbios_get_eps (void) +{ + static struct grub_smbios_eps *eps = NULL; + + if (eps != NULL) + return eps; + + eps = grub_machine_smbios_get_eps (); + + return eps; +} + +/* Locate the SMBIOS3 entry point structure depending on the hardware. */ +static struct grub_smbios_eps3 * +grub_smbios_get_eps3 (void) +{ + static struct grub_smbios_eps3 *eps = NULL; + + if (eps != NULL) + return eps; + + eps = grub_machine_smbios_get_eps3 (); + + return eps; +} + +static char * +linux_string (const char *value) +{ + char *out = grub_malloc( grub_strlen (value) + 1); + const char *src = value; + char *dst = out; + + for (; *src; src++) + if (*src > ' ' && *src < 127 && *src != ':') + *dst++ = *src; + + *dst = 0; + return out; +} + +/* + * These functions convert values from the various SMBIOS structure field types + * into a string formatted to be returned to the user. They expect that the + * structure and offset were already validated. When the requested data is + * successfully retrieved and formatted, the pointer to the string is returned; + * otherwise, NULL is returned on failure. Don't free the result. + */ + +static const char * +grub_smbios_format_byte (const grub_uint8_t *structure, grub_uint8_t offset) +{ + static char buffer[sizeof ("255")]; + + grub_snprintf (buffer, sizeof (buffer), "%u", structure[offset]); + + return (const char *)buffer; +} + +static const char * +grub_smbios_format_word (const grub_uint8_t *structure, grub_uint8_t offset) +{ + static char buffer[sizeof ("65535")]; + + grub_uint16_t value = grub_get_unaligned16 (structure + offset); + grub_snprintf (buffer, sizeof (buffer), "%u", value); + + return (const char *)buffer; +} + +static const char * +grub_smbios_format_dword (const grub_uint8_t *structure, grub_uint8_t offset) +{ + static char buffer[sizeof ("4294967295")]; + + grub_uint32_t value = grub_get_unaligned32 (structure + offset); + grub_snprintf (buffer, sizeof (buffer), "%" PRIuGRUB_UINT32_T, value); + + return (const char *)buffer; +} + +static const char * +grub_smbios_format_qword (const grub_uint8_t *structure, grub_uint8_t offset) +{ + static char buffer[sizeof ("18446744073709551615")]; + + grub_uint64_t value = grub_get_unaligned64 (structure + offset); + grub_snprintf (buffer, sizeof (buffer), "%" PRIuGRUB_UINT64_T, value); + + return (const char *)buffer; +} + +static const char * +grub_smbios_get_string (const grub_uint8_t *structure, grub_uint8_t offset) +{ + const grub_uint8_t *ptr = structure + structure[1]; + const grub_uint8_t *table_end = (const grub_uint8_t *)table_desc.end; + const grub_uint8_t referenced_string_number = structure[offset]; + grub_uint8_t i; + + /* A string referenced with zero is interpreted as unset. */ + if (referenced_string_number == 0) + return NULL; + + /* Search the string set. */ + for (i = 1; *ptr != 0 && ptr < table_end; i++) + if (i == referenced_string_number) + { + const char *str = (const char *)ptr; + while (*ptr++ != 0) + if (ptr >= table_end) + return NULL; /* The string isn't terminated. */ + return str; + } + else + while (*ptr++ != 0 && ptr < table_end); + + /* The string number is greater than the number of strings in the set. */ + return NULL; +} + +static const char * +grub_smbios_format_uuid (const grub_uint8_t *structure, grub_uint8_t offset) +{ + static char buffer[sizeof ("ffffffff-ffff-ffff-ffff-ffffffffffff")]; + const grub_uint8_t *f = structure + offset; /* little-endian fields */ + const grub_uint8_t *g = f + 8; /* byte-by-byte fields */ + + grub_snprintf (buffer, sizeof (buffer), + "%02x%02x%02x%02x-%02x%02x-%02x%02x-" + "%02x%02x-%02x%02x%02x%02x%02x%02x", + f[3], f[2], f[1], f[0], f[5], f[4], f[7], f[6], + g[0], g[1], g[2], g[3], g[4], g[5], g[6], g[7]); + + return (const char *)buffer; +} + +/* List the field formatting functions and the number of bytes they need. */ +static const struct { + const char *(*format) (const grub_uint8_t *structure, grub_uint8_t offset); + grub_uint8_t field_length; +} field_extractors[] = { + {grub_smbios_format_byte, 1}, + {grub_smbios_format_word, 2}, + {grub_smbios_format_dword, 4}, + {grub_smbios_format_qword, 8}, + {grub_smbios_get_string, 1}, + {grub_smbios_format_uuid, 16} +}; + +/* List command options, with structure field getters ordered as above. */ +#define FIRST_GETTER_OPT (3) +#define SETTER_OPT (FIRST_GETTER_OPT + ARRAY_SIZE(field_extractors)) +#define LINUX_OPT (FIRST_GETTER_OPT + ARRAY_SIZE(field_extractors) + 1) + +static const struct grub_arg_option options[] = { + {"type", 't', 0, N_("Match structures with the given type."), + N_("type"), ARG_TYPE_INT}, + {"handle", 'h', 0, N_("Match structures with the given handle."), + N_("handle"), ARG_TYPE_INT}, + {"match", 'm', 0, N_("Select a structure when several match."), + N_("match"), ARG_TYPE_INT}, + {"get-byte", 'b', 0, N_("Get the byte's value at the given offset."), + N_("offset"), ARG_TYPE_INT}, + {"get-word", 'w', 0, N_("Get two bytes' value at the given offset."), + N_("offset"), ARG_TYPE_INT}, + {"get-dword", 'd', 0, N_("Get four bytes' value at the given offset."), + N_("offset"), ARG_TYPE_INT}, + {"get-qword", 'q', 0, N_("Get eight bytes' value at the given offset."), + N_("offset"), ARG_TYPE_INT}, + {"get-string", 's', 0, N_("Get the string specified at the given offset."), + N_("offset"), ARG_TYPE_INT}, + {"get-uuid", 'u', 0, N_("Get the UUID's value at the given offset."), + N_("offset"), ARG_TYPE_INT}, + {"set", '\0', 0, N_("Store the value in the given variable name."), + N_("variable"), ARG_TYPE_STRING}, + {"linux", '\0', 0, N_("Filter the result like linux does."), + N_("variable"), ARG_TYPE_NONE}, + {0, 0, 0, 0, 0, 0} +}; + +/* + * Return a matching SMBIOS structure. + * + * This method can use up to three criteria for selecting a structure: + * - The "type" field (use -1 to ignore) + * - The "handle" field (use -1 to ignore) + * - Which to return if several match (use 0 to ignore) + * + * The return value is a pointer to the first matching structure. If no + * structures match the given parameters, NULL is returned. + */ +static const grub_uint8_t * +grub_smbios_match_structure (const grub_int16_t type, + const grub_int32_t handle, + const grub_uint16_t match) +{ + const grub_uint8_t *ptr = (const grub_uint8_t *)table_desc.start; + const grub_uint8_t *table_end = (const grub_uint8_t *)table_desc.end; + grub_uint16_t structures = table_desc.structures; + grub_uint16_t structure_count = 0; + grub_uint16_t matches = 0; + + while (ptr < table_end + && ptr[1] >= 4 /* Valid structures include the 4-byte header. */ + && (structure_count++ < structures || structures == 0)) + { + grub_uint16_t structure_handle = grub_get_unaligned16 (ptr + 2); + grub_uint8_t structure_type = ptr[0]; + + if ((handle < 0 || handle == structure_handle) + && (type < 0 || type == structure_type) + && (match == 0 || match == ++matches)) + return ptr; + else + { + ptr += ptr[1]; + while ((*ptr++ != 0 || *ptr++ != 0) && ptr < table_end); + } + + if (structure_type == GRUB_SMBIOS_TYPE_END_OF_TABLE) + break; + } + + return NULL; +} + +static grub_err_t +grub_cmd_smbios (grub_extcmd_context_t ctxt, + int argc __attribute__ ((unused)), + char **argv __attribute__ ((unused))) +{ + struct grub_arg_list *state = ctxt->state; + + grub_int16_t type = -1; + grub_int32_t handle = -1; + grub_uint16_t match = 0; + grub_uint8_t offset = 0; + + const grub_uint8_t *structure; + const char *value; + char *modified_value = NULL; + grub_int32_t option; + grub_int8_t field_type = -1; + grub_uint8_t i; + + if (table_desc.start == 0) + return grub_error (GRUB_ERR_IO, + N_("the SMBIOS entry point structure was not found")); + + /* Read the given filtering options. */ + if (state[0].set) + { + option = grub_strtol (state[0].arg, NULL, 0); + if (option < 0 || option > 255) + return grub_error (GRUB_ERR_BAD_ARGUMENT, + N_("the type must be between 0 and 255")); + type = (grub_int16_t)option; + } + if (state[1].set) + { + option = grub_strtol (state[1].arg, NULL, 0); + if (option < 0 || option > 65535) + return grub_error (GRUB_ERR_BAD_ARGUMENT, + N_("the handle must be between 0 and 65535")); + handle = (grub_int32_t)option; + } + if (state[2].set) + { + option = grub_strtol (state[2].arg, NULL, 0); + if (option <= 0 || option > 65535) + return grub_error (GRUB_ERR_BAD_ARGUMENT, + N_("the match must be a positive integer")); + match = (grub_uint16_t)option; + } + + /* Determine the data type of the structure field to retrieve. */ + for (i = 0; i < ARRAY_SIZE(field_extractors); i++) + if (state[FIRST_GETTER_OPT + i].set) + { + if (field_type >= 0) + return grub_error (GRUB_ERR_BAD_ARGUMENT, + N_("only one --get option is usable at a time")); + field_type = i; + } + + /* Require a choice of a structure field to return. */ + if (field_type < 0) + return grub_error (GRUB_ERR_BAD_ARGUMENT, + N_("one of the --get options is required")); + + /* Locate a matching SMBIOS structure. */ + structure = grub_smbios_match_structure (type, handle, match); + if (structure == NULL) + return grub_error (GRUB_ERR_IO, + N_("no structure matched the given options")); + + /* Ensure the requested byte offset is inside the structure. */ + option = grub_strtol (state[FIRST_GETTER_OPT + field_type].arg, NULL, 0); + if (option < 0 || option >= structure[1]) + return grub_error (GRUB_ERR_OUT_OF_RANGE, + N_("the given offset is outside the structure")); + + /* Ensure the requested data type at the offset is inside the structure. */ + offset = (grub_uint8_t)option; + if (offset + field_extractors[field_type].field_length > structure[1]) + return grub_error (GRUB_ERR_OUT_OF_RANGE, + N_("the field ends outside the structure")); + + /* Format the requested structure field into a readable string. */ + value = field_extractors[field_type].format (structure, offset); + if (value == NULL) + return grub_error (GRUB_ERR_IO, + N_("failed to retrieve the structure field")); + + if (state[LINUX_OPT].set) + value = modified_value = linux_string (value); + + /* Store or print the formatted value. */ + if (state[SETTER_OPT].set) + grub_env_set (state[SETTER_OPT].arg, value); + else + grub_printf ("%s\n", value); + + grub_free(modified_value); + + return GRUB_ERR_NONE; +} + +GRUB_MOD_INIT(smbios) +{ + struct grub_smbios_eps3 *eps3; + struct grub_smbios_eps *eps; + + if ((eps3 = grub_smbios_get_eps3 ())) + { + table_desc.start = (grub_addr_t)eps3->table_address; + table_desc.end = table_desc.start + eps3->maximum_table_length; + table_desc.structures = 0; /* SMBIOS3 drops the structure count. */ + } + else if ((eps = grub_smbios_get_eps ())) + { + table_desc.start = (grub_addr_t)eps->intermediate.table_address; + table_desc.end = table_desc.start + eps->intermediate.table_length; + table_desc.structures = eps->intermediate.structures; + } + + cmd = grub_register_extcmd ("smbios", grub_cmd_smbios, 0, + N_("[-t type] [-h handle] [-m match] " + "(-b|-w|-d|-q|-s|-u) offset " + "[--set variable]"), + N_("Retrieve SMBIOS information."), options); +} + +GRUB_MOD_FINI(smbios) +{ + grub_unregister_extcmd (cmd); +} |