From f06d26537559113207e4b73af6a22eaa5c5e9dc3 Mon Sep 17 00:00:00 2001 From: Sean Hefty Date: Mon, 28 Aug 2006 15:15:18 -0700 Subject: [PATCH] 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 Signed-off-by: Roland Dreier --- drivers/infiniband/core/cm.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c index 1aad33e035..c8982b02d9 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 #include #include +#include #include #include #include @@ -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"); -- 2.39.5