ofpbuf: New function ofpbuf_push_zeros().

diff --git a/lib/ofpbuf.c b/lib/ofpbuf.c
index 9cb2ceb80f7adc0d03b906d3b6552a78a65138d3..1621bcc198128e9140323a32891ab9d99e9cef82 100644 (file)
--- a/lib/ofpbuf.c
+++ b/lib/ofpbuf.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -219,6 +219,17 @@ ofpbuf_push_uninit(struct ofpbuf *b, size_t size)
     return b->data;
 }
 
+/* Prefixes 'size' zeroed bytes to the head end of 'b'.  'b' must have at least
+ * 'size' bytes of headroom.  Returns a pointer to the first byte of the data's
+ * location in the ofpbuf. */
+void *
+ofpbuf_push_zeros(struct ofpbuf *b, size_t size)
+{
+    void *dst = ofpbuf_push_uninit(b, size);
+    memset(dst, 0, size);
+    return dst;
+}
+
 void *
 ofpbuf_push(struct ofpbuf *b, const void *p, size_t size) 
 {

diff --git a/lib/ofpbuf.h b/lib/ofpbuf.h
index 9072cc47407398358affe62b2fb076b89a176f41..736b8f5e5ee35156f381e5390c7b2e33fd97a406 100644 (file)
--- a/lib/ofpbuf.h
+++ b/lib/ofpbuf.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -62,6 +62,7 @@ void *ofpbuf_put_zeros(struct ofpbuf *, size_t);
 void *ofpbuf_put(struct ofpbuf *, const void *, size_t);
 void ofpbuf_reserve(struct ofpbuf *, size_t);
 void *ofpbuf_push_uninit(struct ofpbuf *b, size_t);
+void *ofpbuf_push_zeros(struct ofpbuf *, size_t);
 void *ofpbuf_push(struct ofpbuf *b, const void *, size_t);
 
 size_t ofpbuf_headroom(const struct ofpbuf *);