Add per-file error identifiers

[people/oremanj/gpxe.git] / src / core / iobuf.c

diff --git a/src/core/iobuf.c b/src/core/iobuf.c
index d04ede5..cc4aede 100644 (file)
--- a/src/core/iobuf.c
+++ b/src/core/iobuf.c
@@ -17,6 +17,7 @@
  */
 
 #include <stdint.h>
+#include <errno.h>
 #include <gpxe/malloc.h>
 #include <gpxe/iobuf.h>
 
@@ -72,3 +73,22 @@ void free_iob ( struct io_buffer *iobuf ) {
                           ( iobuf->end - iobuf->head ) + sizeof ( *iobuf ) );
        }
 }
+
+/**
+ * Ensure I/O buffer has sufficient headroom
+ *
+ * @v iobuf    I/O buffer
+ * @v len      Required headroom
+ *
+ * This function currently only checks for the required headroom; it
+ * does not reallocate the I/O buffer if required.  If we ever have a
+ * code path that requires this functionality, it's a fairly trivial
+ * change to make.
+ */
+int iob_ensure_headroom ( struct io_buffer *iobuf, size_t len ) {
+
+       if ( iob_headroom ( iobuf ) >= len )
+               return 0;
+       return -ENOBUFS;
+}
+