[openib-general] [PATCH] [CM] add stale connection checks on passive side

[Sean Hefty]

This patch adds checks for a stale connection to the passive side of
the connection protocol.  Checks on the active side are still needed.

Signed-off-by: Sean Hefty <sean.hefty at intel.com>

Index: infiniband/core/cm.c
===================================================================
--- infiniband/core/cm.c	(revision 1817)
+++ infiniband/core/cm.c	(working copy)
@@ -108,10 +108,11 @@ struct cm_work {
 
 struct cm_timewait_info {
 	struct cm_work work;			/* Must be first. */
-	/* struct rb_node remote_qp_node; */
+	struct rb_node remote_qp_node;
 	struct rb_node remote_id_node;
 	u64 remote_ca_guid;
 	u32 remote_qpn;
+	u8 inserted_remote_qp;
 	u8 inserted_remote_id;
 };
 
@@ -424,80 +425,35 @@ static struct cm_id_private * cm_find_id
 }
 */
 
-static void cm_remove_remote_id(struct cm_timewait_info *timewait_info)
-{
-	unsigned long flags;
-
-	timewait_info->inserted_remote_id = 0;
-	spin_lock_irqsave(&cm.lock, flags);
-	rb_erase(&timewait_info->remote_id_node, &cm.remote_id_table);
-	spin_unlock_irqrestore(&cm.lock, flags);
-}
-
-/*
-todo: add test for stale connections
-static struct cm_id_private * cm_insert_remote_qpn(struct cm_id_private
-						   *cm_id_priv)
+static struct cm_timewait_info * cm_insert_remote_qpn(struct cm_timewait_info
+						      *timewait_info)
 {
 	struct rb_node **link = &cm.remote_qp_table.rb_node;
 	struct rb_node *parent = NULL;
-	struct cm_id_private *cur_cm_id_priv;
-	union ib_gid *port_gid = &cm_id_priv->dgid;
-	u32 remote_qpn = cm_id_priv->remote_qpn;
+	struct cm_timewait_info *cur_timewait_info;
+	u64 remote_ca_guid = timewait_info->remote_ca_guid;
+	u32 remote_qpn = timewait_info->remote_qpn;
 
 	while (*link) {
 		parent = *link;
-		cur_cm_id_priv = rb_entry(parent, struct cm_id_private,
-					  remote_qp_node);
-		if (remote_qpn < cur_cm_id_priv->remote_qpn)
+		cur_timewait_info = rb_entry(parent, struct cm_timewait_info,
+					     remote_qp_node);
+		if (remote_qpn < cur_timewait_info->remote_qpn)
 			link = &(*link)->rb_left;
-		else if (remote_qpn > cur_cm_id_priv->remote_qpn)
+		else if (remote_qpn > cur_timewait_info->remote_qpn)
 			link = &(*link)->rb_right;
-		else {
-			int cmp;
-			cmp = memcmp(port_gid, &cur_cm_id_priv->dgid,
-				     sizeof *port_gid);
-			if (cmp < 0)
-				link = &(*link)->rb_left;
-			else if (cmp > 0)
-				link = &(*link)->rb_right;
-			else
-				return cur_cm_id_priv;
-		}
-	}
-	rb_link_node(&cm_id_priv->remote_qp_node, parent, link);
-	rb_insert_color(&cm_id_priv->remote_qp_node, &cm.remote_qp_table);
-	return NULL;
-}
-
-static struct cm_id_private * cm_find_id_by_remote_qpn(union ib_gid *port_gid,
-						       u32 remote_qpn)
-{
-	struct rb_node *node = cm.remote_qp_table.rb_node;
-	struct cm_id_private *cm_id_priv;
-
-	while (node) {
-		cm_id_priv = rb_entry(node, struct cm_id_private, remote_qp_node);
-
-		if (remote_qpn < cm_id_priv->remote_qpn)
-			node = node->rb_left;
-		else if (remote_qpn > cm_id_priv->remote_qpn)
-			node = node->rb_right;
-		else {
-			int cmp;
-			cmp = memcmp(port_gid, &cm_id_priv->dgid,
-				     sizeof *port_gid);
-			if (cmp < 0)
-				node = node->rb_left;
-			else if (cmp > 0)
-				node = node->rb_right;
-			else
-				return cm_id_priv;
-		}
+		else if (remote_ca_guid < cur_timewait_info->remote_ca_guid)
+			link = &(*link)->rb_left;
+		else if (remote_ca_guid > cur_timewait_info->remote_ca_guid)
+			link = &(*link)->rb_right;
+		else
+			return cur_timewait_info;
 	}
+	timewait_info->inserted_remote_qp = 1;
+	rb_link_node(&timewait_info->remote_qp_node, parent, link);
+	rb_insert_color(&timewait_info->remote_qp_node, &cm.remote_qp_table);
 	return NULL;
 }
-*/
 
 static struct cm_id_private * cm_insert_remote_sidr(struct cm_id_private
 						    *cm_id_priv)
@@ -601,13 +557,23 @@ static inline int cm_convert_to_ms(int i
 
 static void cm_cleanup_timewait(struct cm_timewait_info *timewait_info)
 {
-	if (timewait_info->inserted_remote_id)
-		cm_remove_remote_id(timewait_info);
+	unsigned long flags;
 
-	/* todo: stale connection handling
-	if (timewait_info->inserted_remote_qpn)
-		cm_remove_remote_qpn(timewait_info);
-	*/
+	if (!timewait_info->inserted_remote_id &&
+	    !timewait_info->inserted_remote_qp)
+	    return;
+
+	spin_lock_irqsave(&cm.lock, flags);
+	if (timewait_info->inserted_remote_id) {
+		rb_erase(&timewait_info->remote_id_node, &cm.remote_id_table);
+		timewait_info->inserted_remote_id = 0;
+	}
+
+	if (timewait_info->inserted_remote_qp) {
+		rb_erase(&timewait_info->remote_qp_node, &cm.remote_qp_table);
+		timewait_info->inserted_remote_qp = 0;
+	}
+	spin_unlock_irqrestore(&cm.lock, flags);
 }
 
 static struct cm_timewait_info * cm_create_timewait_info(u32 local_id,
@@ -1088,14 +1054,13 @@ static int cm_req_handler(struct cm_work
 		ret = -EINVAL;
 		goto error2;
 	}
-	/* todo: Check for a stale connection.
+	/* Check for a stale connection. */
 	if (cm_insert_remote_qpn(cm_id_priv->timewait_info)) {
 		spin_unlock_irqrestore(&cm.lock, flags);
-		todo: reject as stale
+		/* todo: reject as stale */
 		ret = -EINVAL;
 		goto error2;
 	}
-	*/
 	/* Find matching listen request. */
 	listen_cm_id_priv = cm_find_listen(req_msg->service_id);
 	if (!listen_cm_id_priv) {