flow: Make unified version of flow table compaction

tcp_table_compact() will move entries in the connection/flow table to keep
it compact when other entries are removed.  The moved entries need not have
the same type as the flow removed, so it needs to be able to handle moving
any type of flow.  Therefore, move it to flow.c rather than being
purportedly TCP specific.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

5 files changed, 48 insertions, 44 deletions

diff --git a/flow.c b/flow.c
index 5bb7173..534638b 100644
--- a/flow.c
+++ b/flow.c
@@ -27,3 +27,42 @@ static_assert(ARRAY_SIZE(flow_type_str) == FLOW_NUM_TYPES,
 
 /* Global Flow Table */
 union flow flowtab[FLOW_MAX];
+
+/**
+ * flow_table_compact() - Perform compaction on flow table
+ * @c:		Execution context
+ * @hole:	Pointer to recently closed flow
+ */
+void flow_table_compact(struct ctx *c, union flow *hole)
+{
+	union flow *from;
+
+	if (FLOW_IDX(hole) == --c->flow_count) {
+		debug("flow: table compaction: maximum index was %u (%p)",
+		      FLOW_IDX(hole), (void *)hole);
+		memset(hole, 0, sizeof(*hole));
+		return;
+	}
+
+	from = flowtab + c->flow_count;
+	memcpy(hole, from, sizeof(*hole));
+
+	switch (from->f.type) {
+	case FLOW_TCP:
+		tcp_tap_conn_update(c, &from->tcp, &hole->tcp);
+		break;
+	case FLOW_TCP_SPLICE:
+		tcp_splice_conn_update(c, &hole->tcp_splice);
+		break;
+	default:
+		die("Unexpected %s in tcp_table_compact()",
+		    FLOW_TYPE(&from->f));
+	}
+
+	debug("flow: table compaction (%s): old index %u, new index %u, "
+	      "from: %p, to: %p",
+	      FLOW_TYPE(&from->f), FLOW_IDX(from), FLOW_IDX(hole),
+	      (void *)from, (void *)hole);
+
+	memset(from, 0, sizeof(*from));
+}
diff --git a/flow.h b/flow.h
index 3bf1f51..f3dad53 100644
--- a/flow.h
+++ b/flow.h
@@ -41,4 +41,6 @@ struct flow_common {
 
 union flow;
 
+void flow_table_compact(struct ctx *c, union flow *hole);
+
 #endif /* FLOW_H */
diff --git a/tcp.c b/tcp.c
index 33a7366..0fca342 100644
--- a/tcp.c
+++ b/tcp.c
@@ -1244,8 +1244,9 @@ static void tcp_hash_remove(const struct ctx *c,
  * @old:	Old location of tcp_tap_conn
  * @new:	New location of tcp_tap_conn
  */
-static void tcp_tap_conn_update(const struct ctx *c, struct tcp_tap_conn *old,
-				struct tcp_tap_conn *new)
+void tcp_tap_conn_update(const struct ctx *c, struct tcp_tap_conn *old,
+			 struct tcp_tap_conn *new)
+
 {
 	struct tcp_tap_conn *entry, *prev = NULL;
 	int b = tcp_conn_hash(c, old);
@@ -1298,45 +1299,6 @@ static struct tcp_tap_conn *tcp_hash_lookup(const struct ctx *c,
 }
 
 /**
- * tcp_table_compact() - Perform compaction on connection table
- * @c:		Execution context
- * @hole:	Pointer to recently closed connection
- */
-void tcp_table_compact(struct ctx *c, union flow *hole)
-{
-	union flow *from;
-
-	if (FLOW_IDX(hole) == --c->flow_count) {
-		debug("TCP: table compaction: maximum index was %u (%p)",
-		      FLOW_IDX(hole), (void *)hole);
-		memset(hole, 0, sizeof(*hole));
-		return;
-	}
-
-	from = flowtab + c->flow_count;
-	memcpy(hole, from, sizeof(*hole));
-
-	switch (from->f.type) {
-	case FLOW_TCP:
-		tcp_tap_conn_update(c, &from->tcp, &hole->tcp);
-		break;
-	case FLOW_TCP_SPLICE:
-		tcp_splice_conn_update(c, &hole->tcp_splice);
-		break;
-	default:
-		die("Unexpected %s in tcp_table_compact()",
-		    FLOW_TYPE(&from->f));
-	}
-
-	debug("TCP: table compaction (%s): old index %u, new index %u, "
-	      "from: %p, to: %p",
-	      FLOW_TYPE(&from->f), FLOW_IDX(from), FLOW_IDX(hole),
-	      (void *)from, (void *)hole);
-
-	memset(from, 0, sizeof(*from));
-}
-
-/**
  * tcp_conn_destroy() - Close sockets, trigger hash table removal and compaction
  * @c:		Execution context
  * @flow:	Flow table entry for this connection
@@ -1350,7 +1312,7 @@ static void tcp_conn_destroy(struct ctx *c, union flow *flow)
 		close(conn->timer);
 
 	tcp_hash_remove(c, conn);
-	tcp_table_compact(c, flow);
+	flow_table_compact(c, flow);
 }
 
 static void tcp_rst_do(struct ctx *c, struct tcp_tap_conn *conn);
diff --git a/tcp_conn.h b/tcp_conn.h
index 5a9376e..3900305 100644
--- a/tcp_conn.h
+++ b/tcp_conn.h
@@ -157,8 +157,9 @@ struct tcp_splice_conn {
 extern int init_sock_pool4	[TCP_SOCK_POOL_SIZE];
 extern int init_sock_pool6	[TCP_SOCK_POOL_SIZE];
 
+void tcp_tap_conn_update(const struct ctx *c, struct tcp_tap_conn *old,
+			 struct tcp_tap_conn *new);
 void tcp_splice_conn_update(const struct ctx *c, struct tcp_splice_conn *new);
-void tcp_table_compact(struct ctx *c, union flow *hole);
 void tcp_splice_destroy(struct ctx *c, union flow *flow);
 void tcp_splice_timer(struct ctx *c, union flow *flow);
 int tcp_conn_pool_sock(int pool[]);
diff --git a/tcp_splice.c b/tcp_splice.c
index 4b5c81a..a1c32a0 100644
--- a/tcp_splice.c
+++ b/tcp_splice.c
@@ -283,7 +283,7 @@ void tcp_splice_destroy(struct ctx *c, union flow *flow)
 	conn->flags = 0;
 	debug("TCP (spliced): index %u, CLOSED", FLOW_IDX(conn));
 
-	tcp_table_compact(c, flow);
+	flow_table_compact(c, flow);
 }
 
 /**