1 files changed, 69 insertions, 0 deletions
diff --git a/host/lib/cbfstool.c b/host/lib/cbfstool.c
new file mode 100644
index 00000000..ff70f3d2
--- /dev/null
+++ b/host/lib/cbfstool.c
@@ -0,0 +1,69 @@
+/* Copyright 2022 The ChromiumOS Authors.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "2common.h"
+#include "2return_codes.h"
+#include "subprocess.h"
+#include "cbfstool.h"
+
+static const char *get_cbfstool_path(void)
+{
+	static const char *cbfstool = NULL;
+
+	if (cbfstool)
+		return cbfstool;
+
+	const char *env_cbfstool = getenv(ENV_CBFSTOOL);
+	if (env_cbfstool && env_cbfstool[0] != '\0') {
+		cbfstool = strdup(env_cbfstool);
+		return cbfstool;
+	}
+
+	cbfstool = DEFAULT_CBFSTOOL;
+	return cbfstool;
+}
+
+vb2_error_t cbfstool_truncate(const char *file, const char *region,
+			      size_t *new_size)
+{
+	int status;
+	char output_buffer[128];
+	const char *cbfstool = get_cbfstool_path();
+
+	struct subprocess_target output = {
+		.type = TARGET_BUFFER_NULL_TERMINATED,
+		.buffer = {
+			.buf = output_buffer,
+			.size = sizeof(output_buffer),
+		},
+	};
+	const char *const argv[] = {
+		cbfstool, file, "truncate", "-r", region, NULL,
+	};
+
+	VB2_DEBUG("Calling: %s '%s' truncate -r '%s'\n", cbfstool, file,
+		  region);
+	status = subprocess_run(argv, &subprocess_null, &output,
+				&subprocess_null);
+
+	if (status < 0)
+		return VB2_ERROR_CBFSTOOL;
+
+	/* Positive exit code means something is wrong with image. Return zero
+	   as new size, because it might be problem with missing CBFS.*/
+	if (status > 0) {
+		*new_size = 0;
+		return VB2_ERROR_CBFSTOOL;
+	}
+
+	if (sscanf(output_buffer, "%zi", new_size) != 1) {
+		VB2_DEBUG("Failed to parse command output. Unexpected "
+			  "output.\n");
+		*new_size = 0;
+		return VB2_ERROR_CBFSTOOL;
+	}
+
+	return VB2_SUCCESS;
+}