X-Git-Url: http://git.cascardo.eti.br/?a=blobdiff_plain;f=lib%2Fdpif-provider.h;h=90a02b43600f9797fb11305d4d54a26aa401c0e5;hb=18b063cdbf3e59c1922ffd34fd03f2dc5b0c6db6;hp=1afac99e4a7c42c71077f0a84c2d61c446a13941;hpb=1dd16b9a274afbde46c9d9a4052d720d4cf3c3e2;p=cascardo%2Fovs.git

diff --git a/lib/dpif-provider.h b/lib/dpif-provider.h
index 1afac99e4..90a02b436 100644
--- a/lib/dpif-provider.h
+++ b/lib/dpif-provider.h
@@ -341,11 +341,17 @@ struct dpif_class {
      * '*upcall', using 'buf' for storage.  Should only be called if 'recv_set'
      * has been used to enable receiving packets from 'dpif'.
      *
-     * The implementation should point 'upcall->packet' and 'upcall->key' into
-     * data in the caller-provided 'buf'.  If necessary to make room, the
-     * implementation may expand the data in 'buf'.  (This is hardly a great
-     * way to do things but it works out OK for the dpif providers that exist
-     * so far.)
+     * The implementation should point 'upcall->key' and 'upcall->userdata'
+     * (if any) into data in the caller-provided 'buf'.  The implementation may
+     * also use 'buf' for storing the data of 'upcall->packet'.  If necessary
+     * to make room, the implementation may reallocate the data in 'buf'.
+     *
+     * The caller owns the data of 'upcall->packet' and may modify it.  If
+     * packet's headroom is exhausted as it is manipulated, 'upcall->packet'
+     * will be reallocated.  This requires the data of 'upcall->packet' to be
+     * released with ofpbuf_uninit() before 'upcall' is destroyed.  However,
+     * when an error is returned, the 'upcall->packet' may be uninitialized
+     * and should not be released.
      *
      * This function must not block.  If no upcall is pending when it is
      * called, it should return EAGAIN without blocking. */