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, struct team_gsetter_ctx *ctx)
  63 {
  64         if (ab_priv(team)->active_port)
  65                 ctx->data.u32_val = ab_priv(team)->active_port->dev->ifindex;
  66         else
  67                 ctx->data.u32_val = 0;
  68         return 0;
  69 }
  70
  71 static int ab_active_port_set(struct team *team, struct team_gsetter_ctx *ctx)
  72 {
  73         struct team_port *port;
  74
  75         list_for_each_entry(port, &team->port_list, list) {
  76                 if (port->dev->ifindex == ctx->data.u32_val) {
  77                         rcu_assign_pointer(ab_priv(team)->active_port, port);
  78                         return 0;
  79                 }
  80         }
  81         return -ENOENT;
  82 }
  83
  84 static const struct team_option ab_options[] = {
  85         {
  86                 .name = "activeport",
  87                 .type = TEAM_OPTION_TYPE_U32,
  88                 .getter = ab_active_port_get,
  89                 .setter = ab_active_port_set,
  90         },
  91 };
  92
  93 static int ab_init(struct team *team)
  94 {
  95         return team_options_register(team, ab_options, ARRAY_SIZE(ab_options));
  96 }
  97
  98 static void ab_exit(struct team *team)
  99 {
 100         team_options_unregister(team, ab_options, ARRAY_SIZE(ab_options));
 101 }
 102
 103 static const struct team_mode_ops ab_mode_ops = {
 104         .init                   = ab_init,
 105         .exit                   = ab_exit,
 106         .receive                = ab_receive,
 107         .transmit               = ab_transmit,
 108         .port_leave             = ab_port_leave,
 109 };
 110
 111 static struct team_mode ab_mode = {
 112         .kind           = "activebackup",
 113         .owner          = THIS_MODULE,
 114         .priv_size      = sizeof(struct ab_priv),
 115         .ops            = &ab_mode_ops,
 116 };
 117
 118 static int __init ab_init_module(void)
 119 {
 120         return team_mode_register(&ab_mode);
 121 }
 122
 123 static void __exit ab_cleanup_module(void)
 124 {
 125         team_mode_unregister(&ab_mode);
 126 }
 127
 128 module_init(ab_init_module);
 129 module_exit(ab_cleanup_module);
 130
 131 MODULE_LICENSE("GPL v2");
 132 MODULE_AUTHOR("Jiri Pirko <jpirko@redhat.com>");
 133 MODULE_DESCRIPTION("Active-backup mode for team");
 134 MODULE_ALIAS("team-mode-activebackup");