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 
19 struct rr_priv {
20 	unsigned int sent_packets;
21 };
22 
23 static struct rr_priv *rr_priv(struct team *team)
24 {
25 	return (struct rr_priv *) &team->mode_priv;
26 }
27 
28 static 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 
48 static 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 
63 drop:
64 	dev_kfree_skb_any(skb);
65 	return false;
66 }
67 
68 static int rr_port_enter(struct team *team, struct team_port *port)
69 {
70 	return team_port_set_team_mac(port);
71 }
72 
73 static void rr_port_change_mac(struct team *team, struct team_port *port)
74 {
75 	team_port_set_team_mac(port);
76 }
77 
78 static 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 
84 static 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 
91 static int __init rr_init_module(void)
92 {
93 	return team_mode_register(&rr_mode);
94 }
95 
96 static void __exit rr_cleanup_module(void)
97 {
98 	team_mode_unregister(&rr_mode);
99 }
100 
101 module_init(rr_init_module);
102 module_exit(rr_cleanup_module);
103 
104 MODULE_LICENSE("GPL v2");
105 MODULE_AUTHOR("Jiri Pirko <jpirko@redhat.com>");
106 MODULE_DESCRIPTION("Round-robin mode for team");
107 MODULE_ALIAS("team-mode-roundrobin");
108