tap: Completely de-serialise input message batches

Until now, messages would be passed to protocol handlers in a single
batch only if they happened to be dequeued in a row. Packets
interleaved between different connections would result in multiple
calls to the same protocol handler for a single connection.

Instead, keep track of incoming packet descriptors, arrange them in
sequences, and call protocol handlers only as we completely sorted
input messages in batches.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 12 insertions, 6 deletions

diff --git a/passt.h b/passt.h
index bb41e90..57b5c09 100644
--- a/passt.h
+++ b/passt.h
@@ -3,15 +3,21 @@
 
 /**
  * struct tap_msg - Generic message descriptor for arrays of messages
- * @start:	Pointer to message start
- * @l4_start:	Pointer to L4 header
- * @len:	Message length, with L2 headers
- * @l4_len:	Message length, with L4 headers
+ * @pkt_buf_offset:	Offset from @pkt_buf
+ * @len:		Message length, with L2 headers
  */
 struct tap_msg {
-	char *start;
-	char *l4h;
+	uint32_t pkt_buf_offset;
 	uint16_t len;
+};
+
+/**
+ * struct tap_l4_msg - Layer-4 message descriptor for protocol handlers
+ * @pkt_buf_offset:	Offset of message from @pkt_buf
+ * @l4_len:		Length of Layer-4 payload, host order
+ */
+struct tap_l4_msg {
+	uint32_t pkt_buf_offset;
 	uint16_t l4_len;
 };