1 files changed, 108 insertions, 0 deletions
diff --git a/host/lib/chromeos_config.c b/host/lib/chromeos_config.c
new file mode 100644
index 00000000..6307318c
--- /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;
+}