/*
 *      Sysfs attributes of bridge ports
 *      Linux ethernet bridge
 *
 *      Authors:
 *      Stephen Hemminger               <shemminger@osdl.org>
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <linux/capability.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/if_bridge.h>
#include <linux/rtnetlink.h>
#include <linux/spinlock.h>

#include "br_private.h"

struct brport_attribute {
        struct attribute        attr;
        ssize_t (*show)(struct net_bridge_port *, char *);
        ssize_t (*store)(struct net_bridge_port *, unsigned long);
};

#define BRPORT_ATTR(_name,_mode,_show,_store)                   \
struct brport_attribute brport_attr_##_name = {                 \
        .attr = {.name = __stringify(_name),                    \
                 .mode = _mode },                               \
        .show   = _show,                                        \
        .store  = _store,                                       \
};

static ssize_t show_path_cost(struct net_bridge_port *p, char *buf)
{
        return sprintf(buf, "%d\n", p->path_cost);
}
static ssize_t store_path_cost(struct net_bridge_port *p, unsigned long v)
{
        br_stp_set_path_cost(p, v);
        return 0;
}
static BRPORT_ATTR(path_cost, S_IRUGO | S_IWUSR,
                   show_path_cost, store_path_cost);

static ssize_t show_priority(struct net_bridge_port *p, char *buf)
{
        return sprintf(buf, "%d\n", p->priority);
}
static ssize_t store_priority(struct net_bridge_port *p, unsigned long v)
{
        if (v >= (1<<(16-BR_PORT_BITS)))
                return -ERANGE;
        br_stp_set_port_priority(p, v);
        return 0;
}
static BRPORT_ATTR(priority, S_IRUGO | S_IWUSR,
                         show_priority, store_priority);

static ssize_t show_designated_root(struct net_bridge_port *p, char *buf)
{
        return br_show_bridge_id(buf, &p->designated_root);
}
static BRPORT_ATTR(designated_root, S_IRUGO, show_designated_root, NULL);

static ssize_t show_designated_bridge(struct net_bridge_port *p, char *buf)
{
        return br_show_bridge_id(buf, &p->designated_bridge);
}
static BRPORT_ATTR(designated_bridge, S_IRUGO, show_designated_bridge, NULL);

static ssize_t show_designated_port(struct net_bridge_port *p, char *buf)
{
        return sprintf(buf, "%d\n", p->designated_port);
}
static BRPORT_ATTR(designated_port, S_IRUGO, show_designated_port, NULL);

static ssize_t show_designated_cost(struct net_bridge_port *p, char *buf)
{
        return sprintf(buf, "%d\n", p->designated_cost);
}
static BRPORT_ATTR(designated_cost, S_IRUGO, show_designated_cost, NULL);

static ssize_t show_port_id(struct net_bridge_port *p, char *buf)
{
        return sprintf(buf, "0x%x\n", p->port_id);
}
static BRPORT_ATTR(port_id, S_IRUGO, show_port_id, NULL);

static ssize_t show_port_no(struct net_bridge_port *p, char *buf)
{
        return sprintf(buf, "0x%x\n", p->port_no);
}

static BRPORT_ATTR(port_no, S_IRUGO, show_port_no, NULL);

static ssize_t show_change_ack(struct net_bridge_port *p, char *buf)
{
        return sprintf(buf, "%d\n", p->topology_change_ack);
}
static BRPORT_ATTR(change_ack, S_IRUGO, show_change_ack, NULL);

static ssize_t show_config_pending(struct net_bridge_port *p, char *buf)
{
        return sprintf(buf, "%d\n", p->config_pending);
}
static BRPORT_ATTR(config_pending, S_IRUGO, show_config_pending, NULL);

static ssize_t show_port_state(struct net_bridge_port *p, char *buf)
{
        return sprintf(buf, "%d\n", p->state);
}
static BRPORT_ATTR(state, S_IRUGO, show_port_state, NULL);

static ssize_t show_message_age_timer(struct net_bridge_port *p,
                                            char *buf)
{
        return sprintf(buf, "%ld\n", br_timer_value(&p->message_age_timer));
}
static BRPORT_ATTR(message_age_timer, S_IRUGO, show_message_age_timer, NULL);

static ssize_t show_forward_delay_timer(struct net_bridge_port *p,
                                            char *buf)
{
        return sprintf(buf, "%ld\n", br_timer_value(&p->forward_delay_timer));
}
static BRPORT_ATTR(forward_delay_timer, S_IRUGO, show_forward_delay_timer, NULL);

static ssize_t show_hold_timer(struct net_bridge_port *p,
                                            char *buf)
{
        return sprintf(buf, "%ld\n", br_timer_value(&p->hold_timer));
}
static BRPORT_ATTR(hold_timer, S_IRUGO, show_hold_timer, NULL);

static ssize_t store_flush(struct net_bridge_port *p, unsigned long v)
{
        br_fdb_delete_by_port(p->br, p, 0); // Don't delete local entry
        return 0;
}
static BRPORT_ATTR(flush, S_IWUSR, NULL, store_flush);

static struct brport_attribute *brport_attrs[] = {
        &brport_attr_path_cost,
        &brport_attr_priority,
        &brport_attr_port_id,
        &brport_attr_port_no,
        &brport_attr_designated_root,
        &brport_attr_designated_bridge,
        &brport_attr_designated_port,
        &brport_attr_designated_cost,
        &brport_attr_state,
        &brport_attr_change_ack,
        &brport_attr_config_pending,
        &brport_attr_message_age_timer,
        &brport_attr_forward_delay_timer,
        &brport_attr_hold_timer,
        &brport_attr_flush,
        NULL
};

#define to_brport_attr(_at) container_of(_at, struct brport_attribute, attr)
#define to_brport(obj)  container_of(obj, struct net_bridge_port, kobj)

static ssize_t brport_show(struct kobject * kobj,
                           struct attribute * attr, char * buf)
{
        struct brport_attribute * brport_attr = to_brport_attr(attr);
        struct net_bridge_port * p = to_brport(kobj);

        return brport_attr->show(p, buf);
}

static ssize_t brport_store(struct kobject * kobj,
                            struct attribute * attr,
                            const char * buf, size_t count)
{
        struct brport_attribute * brport_attr = to_brport_attr(attr);
        struct net_bridge_port * p = to_brport(kobj);
        ssize_t ret = -EINVAL;
        char *endp;
        unsigned long val;

        if (!capable(CAP_NET_ADMIN))
                return -EPERM;

        val = simple_strtoul(buf, &endp, 0);
        if (endp != buf) {
                rtnl_lock();
                if (p->dev && p->br && brport_attr->store) {
                        spin_lock_bh(&p->br->lock);
                        ret = brport_attr->store(p, val);
                        spin_unlock_bh(&p->br->lock);
                        if (ret == 0)
                                ret = count;
                }
                rtnl_unlock();
        }
        return ret;
}

struct sysfs_ops brport_sysfs_ops = {
        .show = brport_show,
        .store = brport_store,
};

/*
 * Add sysfs entries to ethernet device added to a bridge.
 * Creates a brport subdirectory with bridge attributes.
 * Puts symlink in bridge's brport subdirectory
 */
int br_sysfs_addif(struct net_bridge_port *p)
{
        struct net_bridge *br = p->br;
        struct brport_attribute **a;
        int err;

        err = sysfs_create_link(&p->kobj, &br->dev->dev.kobj,
                                SYSFS_BRIDGE_PORT_LINK);
        if (err)
                goto out2;

        for (a = brport_attrs; *a; ++a) {
                err = sysfs_create_file(&p->kobj, &((*a)->attr));
                if (err)
                        goto out2;
        }

        err= sysfs_create_link(&br->ifobj, &p->kobj, p->dev->name);
out2:
        return err;
}