host: add host library for accessing chromeos-config
Host side library for accessing chromeos-config. Initially, this will
be used by futility to access the /firmware:image-name property during
a firmware update.
More background: go/mosys-firmware-name
(note: despite the name "mosys" in the design doc, this is an effort
to *not* rely on mosys during the firmware update)
BUG=chromium:1061192
BRANCH=none
TEST=provided unit tests
Signed-off-by: Jack Rosenthal <jrosenth@chromium.org>
Change-Id: Ib8e5f8f836a93695e3b30731ae227501f37c4633
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2099449
Reviewed-by: Julius Werner <jwerner@chromium.org>
diff --git a/Makefile b/Makefile
index 58f930a..6a610c8 100644
--- a/Makefile
+++ b/Makefile
@@ -442,6 +442,7 @@
cgpt/cgpt_show.c \
futility/dump_kernel_config_lib.c \
host/arch/${ARCH}/lib/crossystem_arch.c \
+ host/lib/chromeos_config.c \
host/lib/crossystem.c \
host/lib/file_keys.c \
host/lib/fmap.c \
@@ -498,6 +499,7 @@
firmware/stub/vboot_api_stub_init.c \
futility/dump_kernel_config_lib.c \
host/arch/${ARCH}/lib/crossystem_arch.c \
+ host/lib/chromeos_config.c \
host/lib/crossystem.c \
host/lib/extract_vmlinuz.c \
host/lib/fmap.c \
@@ -661,6 +663,7 @@
# And some compiled tests.
TEST_NAMES = \
+ tests/chromeos_config_tests \
tests/cgptlib_test \
tests/sha_benchmark \
tests/subprocess_tests \
diff --git a/host/lib/chromeos_config.c b/host/lib/chromeos_config.c
new file mode 100644
index 0000000..6307318
--- /dev/null
+++ b/host/lib/chromeos_config.c
@@ -0,0 +1,108 @@
+/* Copyright 2020 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <errno.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "2common.h"
+#include "2return_codes.h"
+#include "chromeos_config.h"
+#include "host_misc.h"
+
+#define CHROMEOS_CONFIG_BASE "/run/chromeos-config/v1"
+
+vb2_error_t chromeos_config_get_string(const char *path, const char *property,
+ char **val_out)
+{
+ vb2_error_t rv;
+ uint32_t size;
+ char filepath[PATH_MAX];
+
+ *val_out = NULL;
+
+ if (!path || path[0] != '/') {
+ VB2_DEBUG("Path parameter must begin with /");
+ return VB2_ERROR_INVALID_PARAMETER;
+ }
+
+ if (strstr(path, "//")) {
+ VB2_DEBUG("Path cannot contain //");
+ return VB2_ERROR_INVALID_PARAMETER;
+ }
+
+ if (strchr(property, '/')) {
+ VB2_DEBUG("Property cannot contain /");
+ return VB2_ERROR_INVALID_PARAMETER;
+ }
+
+ snprintf(filepath, sizeof(filepath), CHROMEOS_CONFIG_BASE "%s/%s", path,
+ property);
+ rv = vb2_read_file(filepath, (uint8_t **)val_out, &size);
+
+ if (rv == VB2_SUCCESS) {
+ *val_out = realloc(*val_out, size + 1);
+ (*val_out)[size] = '\0';
+ }
+
+ return rv;
+}
+
+vb2_error_t chromeos_config_get_boolean(const char *path, const char *property,
+ bool *val_out)
+{
+ char *val_string;
+ vb2_error_t rv;
+
+ *val_out = false;
+ if ((rv = chromeos_config_get_string(path, property, &val_string)) !=
+ VB2_SUCCESS)
+ return rv;
+
+ if (!strcmp(val_string, "false"))
+ goto exit;
+
+ if (!strcmp(val_string, "true")) {
+ *val_out = true;
+ goto exit;
+ }
+
+ VB2_DEBUG("Config entry is not a boolean: %s:%s", path, property);
+ rv = VB2_ERROR_INVALID_PARAMETER;
+
+ exit:
+ free(val_string);
+ return rv;
+}
+
+vb2_error_t chromeos_config_get_integer(const char *path, const char *property,
+ int *val_out)
+{
+ char *endptr;
+ char *val_string;
+ vb2_error_t rv;
+
+ *val_out = -1;
+ if ((rv = chromeos_config_get_string(path, property, &val_string)) !=
+ VB2_SUCCESS)
+ goto exit;
+
+ errno = 0;
+ *val_out = strtol(val_string, &endptr, 10);
+ if (errno || endptr) {
+ VB2_DEBUG("Config entry is not an integer: %s:%s", path,
+ property);
+ rv = VB2_ERROR_INVALID_PARAMETER;
+ goto exit;
+ }
+
+ exit:
+ free(val_string);
+ return rv;
+}
diff --git a/host/lib/include/chromeos_config.h b/host/lib/include/chromeos_config.h
new file mode 100644
index 0000000..e83570e
--- /dev/null
+++ b/host/lib/include/chromeos_config.h
@@ -0,0 +1,56 @@
+/* Copyright 2020 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef VBOOT_REFERENCE_CHROMEOS_CONFIG_H_
+#define VBOOT_REFERENCE_CHROMEOS_CONFIG_H_
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "2common.h"
+#include "2return_codes.h"
+
+/**
+ * Get a value from the model configuration on the device as a string.
+ *
+ * Note: this function allocates memory by its use of vb2_read_file, and relies
+ * on the caller to free the allocated memory. The output parameter will be set
+ * to NULL upon failure, so free can be safely called on this parameter.
+ *
+ * @param path The path in the config schema to the object containing
+ * the requested property.
+ * @param property The name of the requested property.
+ * @param val_out Output parameter which gets assigned to a
+ * null-terminated string.
+ * @return VB2_SUCCESS on success, or a relevant error upon error.
+ */
+vb2_error_t chromeos_config_get_string(const char *path, const char *property,
+ char **val_out);
+
+/**
+ * Get a value from the model configuration on the device as a boolean.
+ *
+ * @param path The path in the config schema to the object containing
+ * the requested property.
+ * @param property The name of the requested property.
+ * @param val_out Output parameter which gets assigned to a boolean.
+ * @return VB2_SUCCESS on success, or a relevant error upon error.
+ */
+vb2_error_t chromeos_config_get_boolean(const char *path, const char *property,
+ bool *val_out);
+
+/**
+ * Get a value from the model configuration on the device as an integer.
+ *
+ * @param path The path in the config schema to the object containing
+ * the requested property.
+ * @param property The name of the requested property.
+ * @param val_out Output parameter which gets assigned to an integer.
+ * @return VB2_SUCCESS on success, or a relevant error upon error.
+ */
+vb2_error_t chromeos_config_get_integer(const char *path, const char *property,
+ int *val_out);
+
+#endif /* VBOOT_REFERENCE_CHROMEOS_CONFIG_H_ */
diff --git a/tests/chromeos_config_tests.c b/tests/chromeos_config_tests.c
new file mode 100644
index 0000000..2408d8c
--- /dev/null
+++ b/tests/chromeos_config_tests.c
@@ -0,0 +1,158 @@
+/* Copyright 2020 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "2common.h"
+#include "2return_codes.h"
+#include "chromeos_config.h"
+#include "host_misc.h"
+#include "test_common.h"
+
+static struct {
+ const char *path;
+ const char *data;
+} fakefs[] = {
+ {"/run/chromeos-config/v1/name", "bleh_model"},
+ {"/run/chromeos-config/v1/brand-code", "ZZCR"},
+ {"/run/chromeos-config/v1/identity/sku-id", "7"},
+ {"/run/chromeos-config/v1/firmware/image-name", "bloop"},
+ {"/run/chromeos-config/v1/auto-night-light", "true"},
+ {"/run/chromeos-config/v1/hardware-properties/is-lid-convertible",
+ "false"},
+};
+
+vb2_error_t vb2_read_file(const char *filepath, uint8_t **data_ptr,
+ uint32_t *size_ptr)
+{
+ *data_ptr = NULL;
+ *size_ptr = 0;
+
+ for (size_t i = 0; i < ARRAY_SIZE(fakefs); i++) {
+ if (!strcmp(fakefs[i].path, filepath)) {
+ *size_ptr = strlen(fakefs[i].data);
+ *data_ptr = malloc(*size_ptr);
+
+ if (!*data_ptr)
+ return VB2_ERROR_READ_FILE_ALLOC;
+
+ memcpy(*data_ptr, fakefs[i].data, *size_ptr);
+ return VB2_SUCCESS;
+ }
+ }
+
+ return VB2_ERROR_READ_FILE_OPEN;
+}
+
+static void test_get_string(void)
+{
+ char *val_out;
+
+ TEST_EQ(chromeos_config_get_string("/firmware", "image-name", &val_out),
+ VB2_SUCCESS, "Reading a string is successful");
+ TEST_STR_EQ(val_out, "bloop", "The string is the correct value");
+ free(val_out);
+}
+
+static void test_get_boolean_true(void)
+{
+ bool val_out;
+
+ TEST_EQ(chromeos_config_get_boolean("/", "auto-night-light", &val_out),
+ VB2_SUCCESS, "Reading a true boolean is successful");
+ TEST_EQ(val_out, true, "The resulting boolean is true");
+}
+
+static void test_get_boolean_false(void)
+{
+ bool val_out;
+
+ TEST_EQ(chromeos_config_get_boolean("/hardware-properties",
+ "is-lid-convertible", &val_out),
+ VB2_SUCCESS, "Reading a false boolean is successful");
+ TEST_EQ(val_out, false, "The resulting boolean is false");
+}
+
+static void test_get_integer(void)
+{
+ int val_out;
+
+ TEST_EQ(chromeos_config_get_integer("/identity", "sku-id", &val_out),
+ VB2_SUCCESS, "Reading an integer is successful");
+ TEST_EQ(val_out, 7, "The resulting integer is correct");
+}
+
+static void test_get_no_exist(void)
+{
+ char *val_out;
+
+ TEST_NEQ(
+ chromeos_config_get_string("/this/does", "not-exist", &val_out),
+ VB2_SUCCESS, "Reading non-existent property fails");
+ free(val_out);
+}
+
+static void test_get_bad_path(void)
+{
+ char *val_out;
+
+ TEST_NEQ(chromeos_config_get_string("name", "name", &val_out),
+ VB2_SUCCESS, "Reading bad path fails");
+ free(val_out);
+}
+
+static void test_get_bad_path2(void)
+{
+ char *val_out;
+
+ TEST_NEQ(chromeos_config_get_string("//name", "name", &val_out),
+ VB2_SUCCESS, "Reading bad path fails");
+ free(val_out);
+}
+
+static void test_get_bad_property(void)
+{
+ char *val_out;
+
+ TEST_NEQ(chromeos_config_get_string("/firmware", "/image-name",
+ &val_out),
+ VB2_SUCCESS, "Reading bad property fails");
+ free(val_out);
+}
+
+static void test_get_not_boolean(void)
+{
+ bool val_out;
+
+ TEST_NEQ(chromeos_config_get_boolean("/identity", "sku-id", &val_out),
+ VB2_SUCCESS, "Reading integer as boolean fails");
+}
+
+static void test_get_not_integer(void)
+{
+ int val_out;
+
+ TEST_NEQ(chromeos_config_get_integer("/", "brand-code", &val_out),
+ VB2_SUCCESS, "Reading string as integer fails");
+}
+
+int main(int argc, char *argv[])
+{
+ test_get_string();
+ test_get_boolean_true();
+ test_get_boolean_false();
+ test_get_integer();
+ test_get_no_exist();
+ test_get_bad_path();
+ test_get_bad_path2();
+ test_get_bad_property();
+ test_get_not_boolean();
+ test_get_not_integer();
+
+ return gTestSuccess ? 0 : 255;
+}
