forked from luck/tmp_suning_uos_patched
f337db64af
Many functions have open coded a function that returns a random number in range [0,N-1]. Under the assumption that we have a PRNG such as taus113 with being well distributed in [0, ~0U] space, we can implement such a function as uword t = (n*m')>>32, where m' is a random number obtained from PRNG, n the right open interval border and t our resulting random number, with n,m',t in u32 universe. Lets go with Joe and simply call it prandom_u32_max(), although technically we have an right open interval endpoint, but that we have documented. Other users can further be migrated to the new prandom_u32_max() function later on; for now, we need to make sure to migrate reciprocal_divide() users for the reciprocal_divide() follow-up fixup since their function signatures are going to change. Joint work with Hannes Frederic Sowa. Cc: Jakub Zawadzki <darkjames-ws@darkjames.pl> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
68 lines
1.6 KiB
C
68 lines
1.6 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/if_team.h>
|
|
|
|
static bool rnd_transmit(struct team *team, struct sk_buff *skb)
|
|
{
|
|
struct team_port *port;
|
|
int port_index;
|
|
|
|
port_index = prandom_u32_max(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");
|