1 /*
2  * drivers/net/team/team_mode_activebackup.c - Active-backup 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 <net/rtnetlink.h>
18 #include <linux/if_team.h>
19 
20 struct ab_priv {
21 	struct team_port __rcu *active_port;
22 };
23 
24 static struct ab_priv *ab_priv(struct team *team)
25 {
26 	return (struct ab_priv *) &team->mode_priv;
27 }
28 
29 static rx_handler_result_t ab_receive(struct team *team, struct team_port *port,
30 				      struct sk_buff *skb) {
31 	struct team_port *active_port;
32 
33 	active_port = rcu_dereference(ab_priv(team)->active_port);
34 	if (active_port != port)
35 		return RX_HANDLER_EXACT;
36 	return RX_HANDLER_ANOTHER;
37 }
38 
39 static bool ab_transmit(struct team *team, struct sk_buff *skb)
40 {
41 	struct team_port *active_port;
42 
43 	active_port = rcu_dereference_bh(ab_priv(team)->active_port);
44 	if (unlikely(!active_port))
45 		goto drop;
46 	if (team_dev_queue_xmit(team, active_port, skb))
47 		return false;
48 	return true;
49 
50 drop:
51 	dev_kfree_skb_any(skb);
52 	return false;
53 }
54 
55 static void ab_port_leave(struct team *team, struct team_port *port)
56 {
57 	if (ab_priv(team)->active_port == port)
58 		RCU_INIT_POINTER(ab_priv(team)->active_port, NULL);
59 }
60 
61 static int ab_active_port_get(struct team *team, struct team_gsetter_ctx *ctx)
62 {
63 	struct team_port *active_port;
64 
65 	active_port = rcu_dereference_protected(ab_priv(team)->active_port,
66 						lockdep_is_held(&team->lock));
67 	if (active_port)
68 		ctx->data.u32_val = active_port->dev->ifindex;
69 	else
70 		ctx->data.u32_val = 0;
71 	return 0;
72 }
73 
74 static int ab_active_port_set(struct team *team, struct team_gsetter_ctx *ctx)
75 {
76 	struct team_port *port;
77 
78 	list_for_each_entry(port, &team->port_list, list) {
79 		if (port->dev->ifindex == ctx->data.u32_val) {
80 			rcu_assign_pointer(ab_priv(team)->active_port, port);
81 			return 0;
82 		}
83 	}
84 	return -ENOENT;
85 }
86 
87 static const struct team_option ab_options[] = {
88 	{
89 		.name = "activeport",
90 		.type = TEAM_OPTION_TYPE_U32,
91 		.getter = ab_active_port_get,
92 		.setter = ab_active_port_set,
93 	},
94 };
95 
96 static int ab_init(struct team *team)
97 {
98 	return team_options_register(team, ab_options, ARRAY_SIZE(ab_options));
99 }
100 
101 static void ab_exit(struct team *team)
102 {
103 	team_options_unregister(team, ab_options, ARRAY_SIZE(ab_options));
104 }
105 
106 static const struct team_mode_ops ab_mode_ops = {
107 	.init			= ab_init,
108 	.exit			= ab_exit,
109 	.receive		= ab_receive,
110 	.transmit		= ab_transmit,
111 	.port_leave		= ab_port_leave,
112 };
113 
114 static const struct team_mode ab_mode = {
115 	.kind		= "activebackup",
116 	.owner		= THIS_MODULE,
117 	.priv_size	= sizeof(struct ab_priv),
118 	.ops		= &ab_mode_ops,
119 };
120 
121 static int __init ab_init_module(void)
122 {
123 	return team_mode_register(&ab_mode);
124 }
125 
126 static void __exit ab_cleanup_module(void)
127 {
128 	team_mode_unregister(&ab_mode);
129 }
130 
131 module_init(ab_init_module);
132 module_exit(ab_cleanup_module);
133 
134 MODULE_LICENSE("GPL v2");
135 MODULE_AUTHOR("Jiri Pirko <jpirko@redhat.com>");
136 MODULE_DESCRIPTION("Active-backup mode for team");
137 MODULE_ALIAS("team-mode-activebackup");
138