1/*
2 * net/drivers/team/team_mode_roundrobin.c - Round-robin mode for team
3 * Copyright (c) 2011 Jiri Pirko <jpirko@redhat.com>
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/errno.h>
16#include <linux/netdevice.h>
17#include <linux/if_team.h>
18
19struct rr_priv {
20	unsigned int sent_packets;
21};
22
23static struct rr_priv *rr_priv(struct team *team)
24{
25	return (struct rr_priv *) &team->mode_priv;
26}
27
28static struct team_port *__get_first_port_up(struct team *team,
29					     struct team_port *port)
30{
31	struct team_port *cur;
32
33	if (port->linkup)
34		return port;
35	cur = port;
36	list_for_each_entry_continue_rcu(cur, &team->port_list, list)
37		if (cur->linkup)
38			return cur;
39	list_for_each_entry_rcu(cur, &team->port_list, list) {
40		if (cur == port)
41			break;
42		if (cur->linkup)
43			return cur;
44	}
45	return NULL;
46}
47
48static bool rr_transmit(struct team *team, struct sk_buff *skb)
49{
50	struct team_port *port;
51	int port_index;
52
53	port_index = rr_priv(team)->sent_packets++ % team->port_count;
54	port = team_get_port_by_index_rcu(team, port_index);
55	port = __get_first_port_up(team, port);
56	if (unlikely(!port))
57		goto drop;
58	skb->dev = port->dev;
59	if (dev_queue_xmit(skb))
60		return false;
61	return true;
62
63drop:
64	dev_kfree_skb_any(skb);
65	return false;
66}
67
68static int rr_port_enter(struct team *team, struct team_port *port)
69{
70	return team_port_set_team_mac(port);
71}
72
73static void rr_port_change_mac(struct team *team, struct team_port *port)
74{
75	team_port_set_team_mac(port);
76}
77
78static const struct team_mode_ops rr_mode_ops = {
79	.transmit		= rr_transmit,
80	.port_enter		= rr_port_enter,
81	.port_change_mac	= rr_port_change_mac,
82};
83
84static struct team_mode rr_mode = {
85	.kind		= "roundrobin",
86	.owner		= THIS_MODULE,
87	.priv_size	= sizeof(struct rr_priv),
88	.ops		= &rr_mode_ops,
89};
90
91static int __init rr_init_module(void)
92{
93	return team_mode_register(&rr_mode);
94}
95
96static void __exit rr_cleanup_module(void)
97{
98	team_mode_unregister(&rr_mode);
99}
100
101module_init(rr_init_module);
102module_exit(rr_cleanup_module);
103
104MODULE_LICENSE("GPL v2");
105MODULE_AUTHOR("Jiri Pirko <jpirko@redhat.com>");
106MODULE_DESCRIPTION("Round-robin mode for team");
107MODULE_ALIAS("team-mode-roundrobin");
108