// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * drivers/net/team/team_mode_activebackup.c - Active-backup mode for team
 * Copyright (c) 2011 Jiri Pirko <jpirko@redhat.com>
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <net/rtnetlink.h>
#include <linux/if_team.h>

struct ab_priv {
        struct team_port __rcu *active_port;
        struct team_option_inst_info *ap_opt_inst_info;
};

static struct ab_priv *ab_priv(struct team *team)
{
        return (struct ab_priv *) &team->mode_priv;
}

static rx_handler_result_t ab_receive(struct team *team, struct team_port *port,
                                      struct sk_buff *skb) {
        struct team_port *active_port;

        active_port = rcu_dereference(ab_priv(team)->active_port);
        if (active_port != port)
                return RX_HANDLER_EXACT;
        return RX_HANDLER_ANOTHER;
}

static bool ab_transmit(struct team *team, struct sk_buff *skb)
{
        struct team_port *active_port;

        active_port = rcu_dereference_bh(ab_priv(team)->active_port);
        if (unlikely(!active_port))
                goto drop;
        if (team_dev_queue_xmit(team, active_port, skb))
                return false;
        return true;

drop:
        dev_kfree_skb_any(skb);
        return false;
}

static void ab_port_leave(struct team *team, struct team_port *port)
{
        if (ab_priv(team)->active_port == port) {
                RCU_INIT_POINTER(ab_priv(team)->active_port, NULL);
                team_option_inst_set_change(ab_priv(team)->ap_opt_inst_info);
        }
}

static void ab_active_port_init(struct team *team,
                                struct team_option_inst_info *info)
{
        ab_priv(team)->ap_opt_inst_info = info;
}

static void ab_active_port_get(struct team *team, struct team_gsetter_ctx *ctx)
{
        struct team_port *active_port;

        active_port = rtnl_dereference(ab_priv(team)->active_port);
        if (active_port)
                ctx->data.u32_val = active_port->dev->ifindex;
        else
                ctx->data.u32_val = 0;
}

static int ab_active_port_set(struct team *team, struct team_gsetter_ctx *ctx)
{
        struct team_port *port;

        list_for_each_entry(port, &team->port_list, list) {
                if (port->dev->ifindex == ctx->data.u32_val) {
                        rcu_assign_pointer(ab_priv(team)->active_port, port);
                        return 0;
                }
        }
        return -ENOENT;
}

static const struct team_option ab_options[] = {
        {
                .name = "activeport",
                .type = TEAM_OPTION_TYPE_U32,
                .init = ab_active_port_init,
                .getter = ab_active_port_get,
                .setter = ab_active_port_set,
        },
};

static int ab_init(struct team *team)
{
        return team_options_register(team, ab_options, ARRAY_SIZE(ab_options));
}

static void ab_exit(struct team *team)
{
        team_options_unregister(team, ab_options, ARRAY_SIZE(ab_options));
}

static const struct team_mode_ops ab_mode_ops = {
        .init                   = ab_init,
        .exit                   = ab_exit,
        .receive                = ab_receive,
        .transmit               = ab_transmit,
        .port_leave             = ab_port_leave,
};

static const struct team_mode ab_mode = {
        .kind           = "activebackup",
        .owner          = THIS_MODULE,
        .priv_size      = sizeof(struct ab_priv),
        .ops            = &ab_mode_ops,
        .lag_tx_type    = NETDEV_LAG_TX_TYPE_ACTIVEBACKUP,
};

static int __init ab_init_module(void)
{
        return team_mode_register(&ab_mode);
}

static void __exit ab_cleanup_module(void)
{
        team_mode_unregister(&ab_mode);
}

module_init(ab_init_module);
module_exit(ab_cleanup_module);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Jiri Pirko <jpirko@redhat.com>");
MODULE_DESCRIPTION("Active-backup mode for team");
MODULE_ALIAS_TEAM_MODE("activebackup");