[PATCH v5 05/19] flow: Common data structures for tracking flow addresses

[David Gibson <david@gibson.dropbear.id.au>]

Handling of each protocol needs some degree of tracking of the
addresses and ports at the end of each connection or flow.  Sometimes
that's explicit (as in the guest visible addresses for TCP
connections), sometimes implicit (the bound and connected addresses of
sockets).

To allow more consistent handling across protocols we want to
uniformly track the address and port at each end of the connection.
Furthermore, because we allow port remapping, and we sometimes need to
apply NAT, the addresses and ports can be different as seen by the
guest/namespace and as by the host.

Introduce 'struct flowside' to keep track of address and port
information related to one side of a flow. Store two of these in the
common fields of a flow to track that information for both sides.  For
now we just introduce the structure itself, later patches will
actually populate and use it.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 flow.h  | 16 ++++++++++++++++
 passt.h |  3 +++
 2 files changed, 19 insertions(+)

diff --git a/flow.h b/flow.h
index 9871e3b..437579b 100644
--- a/flow.h
+++ b/flow.h
@@ -133,8 +133,23 @@ extern const uint8_t flow_proto[];
 #define INISIDE			0	/* Initiating side */
 #define FWDSIDE			1	/* Forwarded side */
 
+/**
+ * struct flowside - Address information for one side of a flow
+ * @eaddr:	Endpoint address (remote address from passt's PoV)
+ * @faddr:	Forwarding address (local address from passt's PoV)
+ * @eport:	Endpoint port
+ * @fport:	Forwarding port
+ */
+struct flowside {
+	union inany_addr	faddr;
+	union inany_addr	eaddr;
+	in_port_t		fport;
+	in_port_t		eport;
+};
+
 /**
  * struct flow_common - Common fields for packet flows
+ * @side[]:	Information for each side of the flow
  * @state:	State of the flow table entry
  * @type:	Type of packet flow
  * @pif[]:	Interface for each side of the flow
@@ -143,6 +158,7 @@ struct flow_common {
 	uint8_t		state;
 	uint8_t		type;
 	uint8_t		pif[SIDES];
+	struct flowside	side[SIDES];
 };
 
 #define FLOW_INDEX_BITS		17	/* 128k - 1 */
diff --git a/passt.h b/passt.h
index bc58d64..3db0b8e 100644
--- a/passt.h
+++ b/passt.h
@@ -17,6 +17,9 @@ union epoll_ref;
 
 #include "pif.h"
 #include "packet.h"
+#include "siphash.h"
+#include "ip.h"
+#include "inany.h"
 #include "flow.h"
 #include "icmp.h"
 #include "fwd.h"
-- 
@@ -17,6 +17,9 @@ union epoll_ref;
 
 #include "pif.h"
 #include "packet.h"
+#include "siphash.h"
+#include "ip.h"
+#include "inany.h"
 #include "flow.h"
 #include "icmp.h"
 #include "fwd.h"
-- 
2.45.0