kernel/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         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");