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authorSean Hefty <sean.hefty@intel.com>2006-08-28 15:15:18 -0700
committerRoland Dreier <rolandd@cisco.com>2006-09-22 15:22:45 -0700
commitf06d26537559113207e4b73af6a22eaa5c5e9dc3 (patch)
treed5d33db61adc4070a4b4b0d4f903d3223299db7b
parent2b3e258e5dd1938e2708eb5354ad8ba056fe8154 (diff)
IB/cm: Randomize starting comm ID
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 <sean.hefty@intel.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
-rw-r--r--drivers/infiniband/core/cm.c24
1 files changed, 16 insertions, 8 deletions
diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index 1aad33e0352..c8982b02d9b 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -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;
@@ -299,15 +301,17 @@ static int cm_init_av_by_path(struct ib_sa_path_rec *path, struct cm_av *av)
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;
}
@@ -316,7 +320,8 @@ 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);
}
@@ -324,7 +329,8 @@ static struct cm_id_private * cm_get_id(__be32 local_id, __be32 remote_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);
@@ -2082,8 +2088,9 @@ static struct cm_id_private * cm_acquire_rejected_id(struct cm_rej_msg *rej_msg)
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);
@@ -3360,6 +3367,7 @@ 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");