76c455decb
team_get_port_by_index_rcu() might return NULL due to race between port removal and skb tx path. Panic is easily triggeable when txing packets and adding/removing port in a loop. introduced by commit3d249d4ca"net: introduce ethernet teaming device" and commit753f993911"team: introduce random mode" (for random mode) Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net>
73 lines
1.7 KiB
C
73 lines
1.7 KiB
C
/*
|
|
* drivers/net/team/team_mode_random.c - Random mode for team
|
|
* Copyright (c) 2013 Jiri Pirko <jiri@resnulli.us>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/types.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/reciprocal_div.h>
|
|
#include <linux/if_team.h>
|
|
|
|
static u32 random_N(unsigned int N)
|
|
{
|
|
return reciprocal_divide(prandom_u32(), N);
|
|
}
|
|
|
|
static bool rnd_transmit(struct team *team, struct sk_buff *skb)
|
|
{
|
|
struct team_port *port;
|
|
int port_index;
|
|
|
|
port_index = random_N(team->en_port_count);
|
|
port = team_get_port_by_index_rcu(team, port_index);
|
|
if (unlikely(!port))
|
|
goto drop;
|
|
port = team_get_first_port_txable_rcu(team, port);
|
|
if (unlikely(!port))
|
|
goto drop;
|
|
if (team_dev_queue_xmit(team, port, skb))
|
|
return false;
|
|
return true;
|
|
|
|
drop:
|
|
dev_kfree_skb_any(skb);
|
|
return false;
|
|
}
|
|
|
|
static const struct team_mode_ops rnd_mode_ops = {
|
|
.transmit = rnd_transmit,
|
|
.port_enter = team_modeop_port_enter,
|
|
.port_change_dev_addr = team_modeop_port_change_dev_addr,
|
|
};
|
|
|
|
static const struct team_mode rnd_mode = {
|
|
.kind = "random",
|
|
.owner = THIS_MODULE,
|
|
.ops = &rnd_mode_ops,
|
|
};
|
|
|
|
static int __init rnd_init_module(void)
|
|
{
|
|
return team_mode_register(&rnd_mode);
|
|
}
|
|
|
|
static void __exit rnd_cleanup_module(void)
|
|
{
|
|
team_mode_unregister(&rnd_mode);
|
|
}
|
|
|
|
module_init(rnd_init_module);
|
|
module_exit(rnd_cleanup_module);
|
|
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
|
|
MODULE_DESCRIPTION("Random mode for team");
|
|
MODULE_ALIAS("team-mode-random");
|