drivers/net/team/team_mode_random.c

   1 /*
   2  * drivers/net/team/team_mode_random.c - Random mode for team
   3  * Copyright (c) 2013 Jiri Pirko <jiri@resnulli.us>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/types.h>
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/skbuff.h>
  16 #include <linux/reciprocal_div.h>
  17 #include <linux/if_team.h>
  18
  19 static u32 random_N(unsigned int N)
  20 {
  21         return reciprocal_divide(prandom_u32(), N);
  22 }
  23
  24 static bool rnd_transmit(struct team *team, struct sk_buff *skb)
  25 {
  26         struct team_port *port;
  27         int port_index;
  28
  29         port_index = random_N(team->en_port_count);
  30         port = team_get_port_by_index_rcu(team, port_index);
  31         if (unlikely(!port))
  32                 goto drop;
  33         port = team_get_first_port_txable_rcu(team, port);
  34         if (unlikely(!port))
  35                 goto drop;
  36         if (team_dev_queue_xmit(team, port, skb))
  37                 return false;
  38         return true;
  39
  40 drop:
  41         dev_kfree_skb_any(skb);
  42         return false;
  43 }
  44
  45 static const struct team_mode_ops rnd_mode_ops = {
  46         .transmit               = rnd_transmit,
  47         .port_enter             = team_modeop_port_enter,
  48         .port_change_dev_addr   = team_modeop_port_change_dev_addr,
  49 };
  50
  51 static const struct team_mode rnd_mode = {
  52         .kind           = "random",
  53         .owner          = THIS_MODULE,
  54         .ops            = &rnd_mode_ops,
  55 };
  56
  57 static int __init rnd_init_module(void)
  58 {
  59         return team_mode_register(&rnd_mode);
  60 }
  61
  62 static void __exit rnd_cleanup_module(void)
  63 {
  64         team_mode_unregister(&rnd_mode);
  65 }
  66
  67 module_init(rnd_init_module);
  68 module_exit(rnd_cleanup_module);
  69
  70 MODULE_LICENSE("GPL v2");
  71 MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
  72 MODULE_DESCRIPTION("Random mode for team");
  73 MODULE_ALIAS("team-mode-random");