Added a method to bio_writer_t that allows to skip a number of bytes

A chunk pointing to the skipped bytes is returned, allowing users of
bio_writer_t to write/copy data to the skipped bytes themselves.

diff --git a/src/libstrongswan/bio/bio_writer.c b/src/libstrongswan/bio/bio_writer.c
index 16a16f4bd8c3a1fb9108cddf3b452c9394ac2247..8576843ee6cf7a21245981c40ba152a84014b555 100644 (file)
--- a/src/libstrongswan/bio/bio_writer.c
+++ b/src/libstrongswan/bio/bio_writer.c
@@ -202,6 +202,20 @@ METHOD(bio_writer_t, wrap32, void,
        this->used += 4;
 }
 
+METHOD(bio_writer_t, skip, chunk_t,
+       private_bio_writer_t *this, size_t len)
+{
+       chunk_t skipped;
+
+       while (this->used + len > this->buf.len)
+       {
+               increase(this);
+       }
+       skipped = chunk_create(this->buf.ptr + this->used, len);
+       this->used += len;
+       return skipped;
+}
+
 METHOD(bio_writer_t, get_buf, chunk_t,
        private_bio_writer_t *this)
 {
@@ -247,6 +261,7 @@ bio_writer_t *bio_writer_create(u_int32_t bufsize)
                        .wrap16 = _wrap16,
                        .wrap24 = _wrap24,
                        .wrap32 = _wrap32,
+                       .skip = _skip,
                        .get_buf = _get_buf,
                        .extract_buf = _extract_buf,
                        .destroy = _destroy,

diff --git a/src/libstrongswan/bio/bio_writer.h b/src/libstrongswan/bio/bio_writer.h
index 8f84d050024eadbf8009d3ac173cfc0a09f06ec2..57a5c3d384f8c7f28c09039b4c82e5f8ea5fc841 100644 (file)
--- a/src/libstrongswan/bio/bio_writer.h
+++ b/src/libstrongswan/bio/bio_writer.h
@@ -125,6 +125,15 @@ struct bio_writer_t {
         */
        void (*wrap32)(bio_writer_t *this);
 
+       /**
+        * Skips len bytes in the buffer before the next data is written, returns
+        * a chunk covering the skipped bytes.
+        *
+        * @param len           number of bytes to skip
+        * @return                      chunk pointing to skipped bytes in the internal buffer
+        */
+       chunk_t (*skip)(bio_writer_t *this, size_t len);
+
        /**
         * Get the encoded data buffer.
         *