Added a method to bio_writer_t that allows to extract the internal buffer

src/libstrongswan/bio/bio_writer.h

@@ -1,4 +1,7 @@
 /*
+ * Copyright (C) 2012 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
  * Copyright (C) 2010 Martin Willi
  * Copyright (C) 2010 revosec AG
  *
@@ -27,6 +30,8 @@ typedef struct bio_writer_t bio_writer_t;
 
 /**
  * Buffered output generator.
+ *
+ * @note Integers are converted to network byte order before writing.
  */
 struct bio_writer_t {
 
@@ -127,6 +132,14 @@ struct bio_writer_t {
 	 */
 	chunk_t (*get_buf)(bio_writer_t *this);
 
+	/**
+	 * Return the encoded data buffer and detach it from the writer (resets
+	 * the internal buffer).
+	 *
+	 * @return			chunk to internal buffer (has to be freed)
+	 */
+	chunk_t (*extract_buf)(bio_writer_t *this);
+
 	/**
 	 * Destroy a bio_writer_t.
 	 */
@@ -136,6 +149,9 @@ struct bio_writer_t {
 /**
  * Create a bio_writer instance.
  *
+ * The size of the internal buffer is increased automatically by bufsize (or a
+ * default if not given) if the initial size does not suffice.
+ *
  * @param bufsize		initially allocated buffer size
  */
 bio_writer_t *bio_writer_create(u_int32_t bufsize);