drivers/net/team/team_mode_activebackup.c

   1 /*
   2  * net/drivers/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(ab_priv(team)->active_port);
  44         if (unlikely(!active_port))
  45                 goto drop;
  46         skb->dev = active_port->dev;
  47         if (dev_queue_xmit(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 }
  61
  62 static int ab_active_port_get(struct team *team, void *arg)
  63 {
  64         u32 *ifindex = arg;
  65
  66         *ifindex = 0;
  67         if (ab_priv(team)->active_port)
  68                 *ifindex = ab_priv(team)->active_port->dev->ifindex;
  69         return 0;
  70 }
  71
  72 static int ab_active_port_set(struct team *team, void *arg)
  73 {
  74         u32 *ifindex = arg;
  75         struct team_port *port;
  76
  77         list_for_each_entry_rcu(port, &team->port_list, list) {
  78                 if (port->dev->ifindex == *ifindex) {
  79                         rcu_assign_pointer(ab_priv(team)->active_port, port);
  80                         return 0;
  81                 }
  82         }
  83         return -ENOENT;
  84 }
  85
  86 static const struct team_option ab_options[] = {
  87         {
  88                 .name = "activeport",
  89                 .type = TEAM_OPTION_TYPE_U32,
  90                 .getter = ab_active_port_get,
  91                 .setter = ab_active_port_set,
  92         },
  93 };
  94
  95 int ab_init(struct team *team)
  96 {
  97         return team_options_register(team, ab_options, ARRAY_SIZE(ab_options));
  98 }
  99
 100 void ab_exit(struct team *team)
 101 {
 102         team_options_unregister(team, ab_options, ARRAY_SIZE(ab_options));
 103 }
 104
 105 static const struct team_mode_ops ab_mode_ops = {
 106         .init                   = ab_init,
 107         .exit                   = ab_exit,
 108         .receive                = ab_receive,
 109         .transmit               = ab_transmit,
 110         .port_leave             = ab_port_leave,
 111 };
 112
 113 static struct team_mode ab_mode = {
 114         .kind           = "activebackup",
 115         .owner          = THIS_MODULE,
 116         .priv_size      = sizeof(struct ab_priv),
 117         .ops            = &ab_mode_ops,
 118 };
 119
 120 static int __init ab_init_module(void)
 121 {
 122         return team_mode_register(&ab_mode);
 123 }
 124
 125 static void __exit ab_cleanup_module(void)
 126 {
 127         team_mode_unregister(&ab_mode);
 128 }
 129
 130 module_init(ab_init_module);
 131 module_exit(ab_cleanup_module);
 132
 133 MODULE_LICENSE("GPL v2");
 134 MODULE_AUTHOR("Jiri Pirko <jpirko@redhat.com>");
 135 MODULE_DESCRIPTION("Active-backup mode for team");
 136 MODULE_ALIAS("team-mode-activebackup");