freebsd-dev/lib/libefivar/efivar.c
Ed Maste 6decf2ccbb libefivar: use standard 2-Clause FreeBSD license
Approved by:	imp
Sponsored by:	The FreeBSD Foundation
2018-03-02 15:12:18 +00:00

401 lines
9.8 KiB
C

/*-
* Copyright (c) 2016 Netflix, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <efivar.h>
#include <sys/efiio.h>
#include <sys/param.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "efichar.h"
static int efi_fd = -2;
#define Z { 0, 0, 0, 0, 0, { 0 } }
const efi_guid_t efi_guid_empty = Z;
static struct uuid_table guid_tbl [] =
{
{ "00000000-0000-0000-0000-000000000000", "zero", Z },
{ "093e0fae-a6c4-4f50-9f1b-d41e2b89c19a", "sha512", Z },
{ "0abba7dc-e516-4167-bbf5-4d9d1c739416", "redhat", Z },
{ "0b6e5233-a65c-44c9-9407-d9ab83bfc8bd", "sha224", Z },
{ "126a762d-5758-4fca-8531-201a7f57f850", "lenovo_boot_menu", Z },
{ "3bd2a492-96c0-4079-b420-fcf98ef103ed", "x509_sha256", Z },
{ "3c5766e8-269c-4e34-aa14-ed776e85b3b6", "rsa2048", Z },
{ "3CC24E96-22C7-41D8-8863-8E39DCDCC2CF", "lenovo", Z },
{ "3f7e615b-0d45-4f80-88dc-26b234958560", "lenovo_diag", Z },
{ "446dbf63-2502-4cda-bcfa-2465d2b0fe9d", "x509_sha512", Z },
{ "4aafd29d-68df-49ee-8aa9-347d375665a7", "pkcs7_cert", Z },
{ "605dab50-e046-4300-abb6-3dd810dd8b23", "shim", Z },
{ "665d3f60-ad3e-4cad-8e26-db46eee9f1b5", "lenovo_rescue", Z },
{ "67f8444f-8743-48f1-a328-1eaab8736080", "rsa2048_sha1", Z },
{ "7076876e-80c2-4ee6-aad2-28b349a6865b", "x509_sha384", Z },
{ "721c8b66-426c-4e86-8e99-3457c46ab0b9", "lenovo_setup", Z },
{ "77fa9abd-0359-4d32-bd60-28f4e78f784b", "microsoft", Z },
{ "7FACC7B6-127F-4E9C-9C5D-080F98994345", "lenovo_2", Z },
{ "826ca512-cf10-4ac9-b187-be01496631bd", "sha1", Z },
{ "82988420-7467-4490-9059-feb448dd1963", "lenovo_me_config", Z },
{ "8be4df61-93ca-11d2-aa0d-00e098032b8c", "global", Z },
{ "a5c059a1-94e4-4aa7-87b5-ab155c2bf072", "x509_cert", Z },
{ "a7717414-c616-4977-9420-844712a735bf", "rsa2048_sha256_cert", Z },
{ "a7d8d9a6-6ab0-4aeb-ad9d-163e59a7a380", "lenovo_diag_splash", Z },
{ "ade9e48f-9cb8-98e6-31af-b4e6009e2fe3", "redhat_2", Z },
{ "bc7838d2-0f82-4d60-8316-c068ee79d25b", "lenovo_msg", Z },
{ "c1c41626-504c-4092-aca9-41f936934328", "sha256", Z },
{ "c57ad6b7-0515-40a8-9d21-551652854e37", "shell", Z },
{ "d719b2cb-3d3a-4596-a3bc-dad00e67656f", "security", Z },
{ "e2b36190-879b-4a3d-ad8d-f2e7bba32784", "rsa2048_sha256", Z },
{ "ff3e5307-9fd0-48c9-85f1-8ad56c701e01", "sha384", Z },
{ "f46ee6f4-4785-43a3-923d-7f786c3c8479", "lenovo_startup_interrupt", Z },
{ "ffffffff-ffff-ffff-ffff-ffffffffffff", "zzignore-this-guid", Z },
};
#undef Z
static void
efi_guid_tbl_compile(void)
{
size_t i;
uint32_t status;
static int done = 0;
if (done)
return;
for (i = 0; i < nitems(guid_tbl); i++) {
uuid_from_string(guid_tbl[i].uuid_str, &guid_tbl[i].guid,
&status);
/* all f's is a bad version, so ignore that error */
if (status != uuid_s_ok && status != uuid_s_bad_version)
fprintf(stderr, "Can't convert %s to a uuid for %s: %d\n",
guid_tbl[i].uuid_str, guid_tbl[i].name, (int)status);
}
done = 1;
}
int
efi_known_guid(struct uuid_table **tbl)
{
*tbl = guid_tbl;
return (nitems(guid_tbl));
}
static int
efi_open_dev(void)
{
if (efi_fd == -2)
efi_fd = open("/dev/efi", O_RDWR);
if (efi_fd < 0)
efi_fd = -1;
else
efi_guid_tbl_compile();
return (efi_fd);
}
static void
efi_var_reset(struct efi_var_ioc *var)
{
var->name = NULL;
var->namesize = 0;
memset(&var->vendor, 0, sizeof(var->vendor));
var->attrib = 0;
var->data = NULL;
var->datasize = 0;
}
static int
rv_to_linux_rv(int rv)
{
if (rv == 0)
rv = 1;
else
rv = -errno;
return (rv);
}
int
efi_append_variable(efi_guid_t guid, const char *name,
uint8_t *data, size_t data_size, uint32_t attributes)
{
return efi_set_variable(guid, name, data, data_size,
attributes | EFI_VARIABLE_APPEND_WRITE);
}
int
efi_del_variable(efi_guid_t guid, const char *name)
{
/* data_size of 0 deletes the variable */
return efi_set_variable(guid, name, NULL, 0, 0);
}
int
efi_get_variable(efi_guid_t guid, const char *name,
uint8_t **data, size_t *data_size, uint32_t *attributes)
{
struct efi_var_ioc var;
int rv;
static uint8_t buf[1024*32];
if (efi_open_dev() == -1)
return -1;
efi_var_reset(&var);
rv = utf8_to_ucs2(name, &var.name, &var.namesize);
if (rv != 0)
goto errout;
var.vendor = guid;
var.data = buf;
var.datasize = sizeof(buf);
rv = ioctl(efi_fd, EFIIOC_VAR_GET, &var);
if (data_size != NULL)
*data_size = var.datasize;
if (data != NULL)
*data = buf;
if (attributes != NULL)
*attributes = var.attrib;
errout:
free(var.name);
return rv_to_linux_rv(rv);
}
int
efi_get_variable_attributes(efi_guid_t guid, const char *name,
uint32_t *attributes)
{
/* Make sure this construct works -- I think it will fail */
return efi_get_variable(guid, name, NULL, NULL, attributes);
}
int
efi_get_variable_size(efi_guid_t guid, const char *name,
size_t *size)
{
/* XXX check to make sure this matches the linux value */
*size = 0;
return efi_get_variable(guid, name, NULL, size, NULL);
}
int
efi_get_next_variable_name(efi_guid_t **guid, char **name)
{
struct efi_var_ioc var;
int rv;
static efi_char *buf;
static size_t buflen = 256 * sizeof(efi_char);
static efi_guid_t retguid;
size_t size;
if (efi_open_dev() == -1)
return -1;
/*
* Always allocate enough for an extra NUL on the end, but don't tell
* the IOCTL about it so we can NUL terminate the name before converting
* it to UTF8.
*/
if (buf == NULL)
buf = malloc(buflen + sizeof(efi_char));
again:
efi_var_reset(&var);
var.name = buf;
var.namesize = buflen;
if (*name == NULL) {
*buf = 0;
/* GUID zeroed in var_reset */
} else {
rv = utf8_to_ucs2(*name, &var.name, &size);
if (rv != 0)
goto errout;
var.vendor = **guid;
}
rv = ioctl(efi_fd, EFIIOC_VAR_NEXT, &var);
if (rv == 0 && var.name == NULL) {
/*
* Variable name not long enough, so allocate more space for the
* name and try again. As above, mind the NUL we add.
*/
void *new = realloc(buf, var.namesize + sizeof(efi_char));
if (new == NULL) {
rv = -1;
errno = ENOMEM;
goto done;
}
buflen = var.namesize;
buf = new;
goto again;
}
if (rv == 0) {
free(*name); /* Free last name, to avoid leaking */
*name = NULL; /* Force ucs2_to_utf8 to malloc new space */
var.name[var.namesize / sizeof(efi_char)] = 0; /* EFI doesn't NUL terminate */
rv = ucs2_to_utf8(var.name, name);
if (rv != 0)
goto errout;
retguid = var.vendor;
*guid = &retguid;
}
errout:
/* XXX The linux interface expects name to be a static buffer -- fix or leak memory? */
/* XXX for the moment, we free just before we'd leak, but still leak last one */
done:
if (rv != 0 && errno == ENOENT) {
errno = 0;
free(*name); /* Free last name, to avoid leaking */
return 0;
}
return (rv_to_linux_rv(rv));
}
int
efi_guid_cmp(const efi_guid_t *guid1, const efi_guid_t *guid2)
{
uint32_t status;
return uuid_compare(guid1, guid2, &status);
}
int
efi_guid_is_zero(const efi_guid_t *guid)
{
uint32_t status;
return uuid_is_nil(guid, &status);
}
int
efi_guid_to_name(efi_guid_t *guid, char **name)
{
size_t i;
uint32_t status;
efi_guid_tbl_compile();
for (i = 0; i < nitems(guid_tbl); i++) {
if (uuid_equal(guid, &guid_tbl[i].guid, &status)) {
*name = strdup(guid_tbl[i].name);
return (0);
}
}
return (efi_guid_to_str(guid, name));
}
int
efi_guid_to_symbol(efi_guid_t *guid __unused, char **symbol __unused)
{
/*
* Unsure what this is used for, efibootmgr doesn't use it.
* Leave unimplemented for now.
*/
return -1;
}
int
efi_guid_to_str(const efi_guid_t *guid, char **sp)
{
uint32_t status;
/* knows efi_guid_t is a typedef of uuid_t */
uuid_to_string(guid, sp, &status);
return (status == uuid_s_ok ? 0 : -1);
}
int
efi_name_to_guid(const char *name, efi_guid_t *guid)
{
size_t i;
efi_guid_tbl_compile();
for (i = 0; i < nitems(guid_tbl); i++) {
if (strcmp(name, guid_tbl[i].name) == 0) {
*guid = guid_tbl[i].guid;
return (0);
}
}
return (efi_str_to_guid(name, guid));
}
int
efi_set_variable(efi_guid_t guid, const char *name,
uint8_t *data, size_t data_size, uint32_t attributes)
{
struct efi_var_ioc var;
int rv;
if (efi_open_dev() == -1)
return -1;
efi_var_reset(&var);
rv = utf8_to_ucs2(name, &var.name, &var.namesize);
if (rv != 0)
goto errout;
var.vendor = guid;
var.data = data;
var.datasize = data_size;
var.attrib = attributes;
rv = ioctl(efi_fd, EFIIOC_VAR_SET, &var);
errout:
free(var.name);
return rv;
}
int
efi_str_to_guid(const char *s, efi_guid_t *guid)
{
uint32_t status;
/* knows efi_guid_t is a typedef of uuid_t */
uuid_from_string(s, guid, &status);
return (status == uuid_s_ok ? 0 : -1);
}
int
efi_variables_supported(void)
{
return efi_open_dev() != -1;
}