drivers/net/team/team_mode_activebackup.c

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