diff options
| -rw-r--r-- | src/core/iobuf.c | 30 | ||||
| -rw-r--r-- | src/include/ipxe/iobuf.h | 1 |
2 files changed, 31 insertions, 0 deletions
diff --git a/src/core/iobuf.c b/src/core/iobuf.c index afc91d1..6dae0c1 100644 --- a/src/core/iobuf.c +++ b/src/core/iobuf.c @@ -200,3 +200,33 @@ struct io_buffer * iob_concatenate ( struct list_head *list ) { return concatenated; } + +/** + * Split I/O buffer + * + * @v iobuf I/O buffer + * @v len Length to split into a new I/O buffer + * @ret split New I/O buffer, or NULL on allocation failure + * + * Split the first @c len bytes of the existing I/O buffer into a + * separate I/O buffer. The resulting buffers are likely to have no + * headroom or tailroom. + * + * If this call fails, then the original buffer will be unmodified. + */ +struct io_buffer * iob_split ( struct io_buffer *iobuf, size_t len ) { + struct io_buffer *split; + + /* Sanity checks */ + assert ( len <= iob_len ( iobuf ) ); + + /* Allocate new I/O buffer */ + split = alloc_iob ( len ); + if ( ! split ) + return NULL; + + /* Copy in data */ + memcpy ( iob_put ( split, len ), iobuf->data, len ); + iob_pull ( iobuf, len ); + return split; +} diff --git a/src/include/ipxe/iobuf.h b/src/include/ipxe/iobuf.h index b2b0cb4..d7c10ab 100644 --- a/src/include/ipxe/iobuf.h +++ b/src/include/ipxe/iobuf.h @@ -217,5 +217,6 @@ extern void free_iob ( struct io_buffer *iobuf ); extern void iob_pad ( struct io_buffer *iobuf, size_t min_len ); extern int iob_ensure_headroom ( struct io_buffer *iobuf, size_t len ); extern struct io_buffer * iob_concatenate ( struct list_head *list ); +extern struct io_buffer * iob_split ( struct io_buffer *iobuf, size_t len ); #endif /* _IPXE_IOBUF_H */ |