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 	struct team_option_inst_info *ap_opt_inst_info;
23 };
24 
25 static struct ab_priv *ab_priv(struct team *team)
26 {
27 	return (struct ab_priv *) &team->mode_priv;
28 }
29 
30 static rx_handler_result_t ab_receive(struct team *team, struct team_port *port,
31 				      struct sk_buff *skb) {
32 	struct team_port *active_port;
33 
34 	active_port = rcu_dereference(ab_priv(team)->active_port);
35 	if (active_port != port)
36 		return RX_HANDLER_EXACT;
37 	return RX_HANDLER_ANOTHER;
38 }
39 
40 static bool ab_transmit(struct team *team, struct sk_buff *skb)
41 {
42 	struct team_port *active_port;
43 
44 	active_port = rcu_dereference_bh(ab_priv(team)->active_port);
45 	if (unlikely(!active_port))
46 		goto drop;
47 	if (team_dev_queue_xmit(team, active_port, skb))
48 		return false;
49 	return true;
50 
51 drop:
52 	dev_kfree_skb_any(skb);
53 	return false;
54 }
55 
56 static void ab_port_leave(struct team *team, struct team_port *port)
57 {
58 	if (ab_priv(team)->active_port == port) {
59 		RCU_INIT_POINTER(ab_priv(team)->active_port, NULL);
60 		team_option_inst_set_change(ab_priv(team)->ap_opt_inst_info);
61 	}
62 }
63 
64 static int ab_active_port_init(struct team *team,
65 			       struct team_option_inst_info *info)
66 {
67 	ab_priv(team)->ap_opt_inst_info = info;
68 	return 0;
69 }
70 
71 static int ab_active_port_get(struct team *team, struct team_gsetter_ctx *ctx)
72 {
73 	struct team_port *active_port;
74 
75 	active_port = rcu_dereference_protected(ab_priv(team)->active_port,
76 						lockdep_is_held(&team->lock));
77 	if (active_port)
78 		ctx->data.u32_val = active_port->dev->ifindex;
79 	else
80 		ctx->data.u32_val = 0;
81 	return 0;
82 }
83 
84 static int ab_active_port_set(struct team *team, struct team_gsetter_ctx *ctx)
85 {
86 	struct team_port *port;
87 
88 	list_for_each_entry(port, &team->port_list, list) {
89 		if (port->dev->ifindex == ctx->data.u32_val) {
90 			rcu_assign_pointer(ab_priv(team)->active_port, port);
91 			return 0;
92 		}
93 	}
94 	return -ENOENT;
95 }
96 
97 static const struct team_option ab_options[] = {
98 	{
99 		.name = "activeport",
100 		.type = TEAM_OPTION_TYPE_U32,
101 		.init = ab_active_port_init,
102 		.getter = ab_active_port_get,
103 		.setter = ab_active_port_set,
104 	},
105 };
106 
107 static int ab_init(struct team *team)
108 {
109 	return team_options_register(team, ab_options, ARRAY_SIZE(ab_options));
110 }
111 
112 static void ab_exit(struct team *team)
113 {
114 	team_options_unregister(team, ab_options, ARRAY_SIZE(ab_options));
115 }
116 
117 static const struct team_mode_ops ab_mode_ops = {
118 	.init			= ab_init,
119 	.exit			= ab_exit,
120 	.receive		= ab_receive,
121 	.transmit		= ab_transmit,
122 	.port_leave		= ab_port_leave,
123 };
124 
125 static const struct team_mode ab_mode = {
126 	.kind		= "activebackup",
127 	.owner		= THIS_MODULE,
128 	.priv_size	= sizeof(struct ab_priv),
129 	.ops		= &ab_mode_ops,
130 };
131 
132 static int __init ab_init_module(void)
133 {
134 	return team_mode_register(&ab_mode);
135 }
136 
137 static void __exit ab_cleanup_module(void)
138 {
139 	team_mode_unregister(&ab_mode);
140 }
141 
142 module_init(ab_init_module);
143 module_exit(ab_cleanup_module);
144 
145 MODULE_LICENSE("GPL v2");
146 MODULE_AUTHOR("Jiri Pirko <jpirko@redhat.com>");
147 MODULE_DESCRIPTION("Active-backup mode for team");
148 MODULE_ALIAS("team-mode-activebackup");
149