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authorNeale Ranns <nranns@cisco.com>2016-11-22 08:29:51 +0000
committerDave Barach <openvpp@barachs.net>2016-11-22 18:22:41 +0000
commit8817061c7337c936da2553a4881098e1646d05dc (patch)
tree6e167b33db7005c35782671ab1c7718782ecbcad
parentfba8a9510283a1b7d8e047fe93a47612c4c1b7cd (diff)
Prevent a frame leak when a pending node dispatches packets to itself.
this patch recognises the case where the pending frame has packets dispatched to the same to-node, i.e. when restoring the frame there now exists a new to-node frame, and then frees the frame in hand. Change-Id: If166bf56970b7b3412fa6097cd90bf22f72abe4d Signed-off-by: Neale Ranns <nranns@cisco.com>
-rw-r--r--vlib/vlib/main.c36
1 files changed, 30 insertions, 6 deletions
diff --git a/vlib/vlib/main.c b/vlib/vlib/main.c
index eba2d4535e8..fc294a72621 100644
--- a/vlib/vlib/main.c
+++ b/vlib/vlib/main.c
@@ -1141,18 +1141,42 @@ dispatch_pending_node (vlib_main_t * vm,
/* Frame is ready to be used again, so restore it. */
if (restore_frame_index != ~0)
{
+ /* we musn't restore a frame that is flagged to be freed. This shouldn't
+ happen since frames to be freed post dispatch are those used
+ when the to-node frame becomes full i.e. they form a sort of queue of
+ frames to a single node. If we get here then the to-node frame and the
+ pending frame *were* the same, and so we removed the to-node frame.
+ Therefore this frame is no longer part of the queue for that node
+ and hence it cannot be it's overspill.
+ */
+ ASSERT (!(f->flags & VLIB_FRAME_FREE_AFTER_DISPATCH));
+
/* p->next_frame_index can change during node dispatch if node
function decides to change graph hook up. */
nf = vec_elt_at_index (nm->next_frames, p->next_frame_index);
- nf->frame_index = restore_frame_index;
nf->flags |= VLIB_FRAME_IS_ALLOCATED;
- f->n_vectors = 0;
- }
- if (f->flags & VLIB_FRAME_FREE_AFTER_DISPATCH)
+ if (~0 == nf->frame_index)
+ {
+ /* no new frame has been assigned to this node, use the saved one */
+ nf->frame_index = restore_frame_index;
+ f->n_vectors = 0;
+ }
+ else
+ {
+ /* The node has gained a frame, implying packets from the current frame
+ were re-queued to this same node. we don't need the saved one
+ anymore */
+ vlib_frame_free (vm, n, f);
+ }
+ }
+ else
{
- ASSERT (!(n->flags & VLIB_NODE_FLAG_FRAME_NO_FREE_AFTER_DISPATCH));
- vlib_frame_free (vm, n, f);
+ if (f->flags & VLIB_FRAME_FREE_AFTER_DISPATCH)
+ {
+ ASSERT (!(n->flags & VLIB_NODE_FLAG_FRAME_NO_FREE_AFTER_DISPATCH));
+ vlib_frame_free (vm, n, f);
+ }
}
return last_time_stamp;