Randomize the starting local comm ID to avoid getting a rejected connection
due to a stale connection after a system reboot or reloading of the ib_cm.
Signed-off-by: Sean Hefty <[EMAIL PROTECTED]>
---
Index: cm.c
===================================================================
--- cm.c (revision 8928)
+++ cm.c (working copy)
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2004, 2005 Intel Corporation. All rights reserved.
+ * Copyright (c) 2004-2006 Intel Corporation. All rights reserved.
* Copyright (c) 2004 Topspin Corporation. All rights reserved.
* Copyright (c) 2004, 2005 Voltaire Corporation. All rights reserved.
* Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
@@ -41,6 +41,7 @@
#include <linux/idr.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
+#include <linux/random.h>
#include <linux/rbtree.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
@@ -73,6 +74,7 @@ static struct ib_cm {
struct rb_root remote_id_table;
struct rb_root remote_sidr_table;
struct idr local_id_table;
+ __be32 random_id_operand;
struct workqueue_struct *wq;
} cm;
@@ -300,15 +302,17 @@ static int cm_init_av_by_path(struct ib_
static int cm_alloc_id(struct cm_id_private *cm_id_priv)
{
unsigned long flags;
- int ret;
+ int ret, id;
static int next_id;
do {
spin_lock_irqsave(&cm.lock, flags);
- ret = idr_get_new_above(&cm.local_id_table, cm_id_priv,
next_id++,
- (__force int *)
&cm_id_priv->id.local_id);
+ ret = idr_get_new_above(&cm.local_id_table, cm_id_priv,
+ next_id++, &id);
spin_unlock_irqrestore(&cm.lock, flags);
} while( (ret == -EAGAIN) && idr_pre_get(&cm.local_id_table,
GFP_KERNEL) );
+
+ cm_id_priv->id.local_id = (__force __be32) (id ^ cm.random_id_operand);
return ret;
}
@@ -317,7 +321,8 @@ static void cm_free_id(__be32 local_id)
unsigned long flags;
spin_lock_irqsave(&cm.lock, flags);
- idr_remove(&cm.local_id_table, (__force int) local_id);
+ idr_remove(&cm.local_id_table,
+ (__force int) (local_id ^ cm.random_id_operand));
spin_unlock_irqrestore(&cm.lock, flags);
}
@@ -325,7 +330,8 @@ static struct cm_id_private * cm_get_id(
{
struct cm_id_private *cm_id_priv;
- cm_id_priv = idr_find(&cm.local_id_table, (__force int) local_id);
+ cm_id_priv = idr_find(&cm.local_id_table,
+ (__force int) (local_id ^ cm.random_id_operand));
if (cm_id_priv) {
if (cm_id_priv->id.remote_id == remote_id)
atomic_inc(&cm_id_priv->refcount);
@@ -2083,8 +2089,9 @@ static struct cm_id_private * cm_acquire
spin_unlock_irqrestore(&cm.lock, flags);
return NULL;
}
- cm_id_priv = idr_find(&cm.local_id_table,
- (__force int)
timewait_info->work.local_id);
+ cm_id_priv = idr_find(&cm.local_id_table, (__force int)
+ (timewait_info->work.local_id ^
+ cm.random_id_operand));
if (cm_id_priv) {
if (cm_id_priv->id.remote_id == remote_id)
atomic_inc(&cm_id_priv->refcount);
@@ -3391,6 +3398,7 @@ static int __init ib_cm_init(void)
cm.remote_qp_table = RB_ROOT;
cm.remote_sidr_table = RB_ROOT;
idr_init(&cm.local_id_table);
+ get_random_bytes(&cm.random_id_operand, sizeof cm.random_id_operand);
idr_pre_get(&cm.local_id_table, GFP_KERNEL);
cm.wq = create_workqueue("ib_cm");
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