/*
 * net-sysfs.c - network device class and attributes
 *
 * Copyright (c) 2003 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_arp.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <linux/rtnetlink.h>
#include <linux/wireless.h>
#include <net/wext.h>

#include "net-sysfs.h"

#ifdef CONFIG_SYSFS
static const char fmt_hex[] = "%#x\n";
static const char fmt_long_hex[] = "%#lx\n";
static const char fmt_dec[] = "%d\n";
static const char fmt_ulong[] = "%lu\n";

static inline int dev_isalive(const struct net_device *dev)
{
        return dev->reg_state <= NETREG_REGISTERED;
}

/* use same locking rules as GIF* ioctl's */
static ssize_t netdev_show(const struct device *dev,
                           struct device_attribute *attr, char *buf,
                           ssize_t (*format)(const struct net_device *, char *))
{
        struct net_device *net = to_net_dev(dev);
        ssize_t ret = -EINVAL;

        read_lock(&dev_base_lock);
        if (dev_isalive(net))
                ret = (*format)(net, buf);
        read_unlock(&dev_base_lock);

        return ret;
}

/* generate a show function for simple field */
#define NETDEVICE_SHOW(field, format_string)                            \
static ssize_t format_##field(const struct net_device *net, char *buf)  \
{                                                                       \
        return sprintf(buf, format_string, net->field);                 \
}                                                                       \
static ssize_t show_##field(struct device *dev,                         \
                            struct device_attribute *attr, char *buf)   \
{                                                                       \
        return netdev_show(dev, attr, buf, format_##field);             \
}


/* use same locking and permission rules as SIF* ioctl's */
static ssize_t netdev_store(struct device *dev, struct device_attribute *attr,
                            const char *buf, size_t len,
                            int (*set)(struct net_device *, unsigned long))
{
        struct net_device *net = to_net_dev(dev);
        char *endp;
        unsigned long new;
        int ret = -EINVAL;

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

        new = simple_strtoul(buf, &endp, 0);
        if (endp == buf)
                goto err;

        if (!rtnl_trylock())
                return restart_syscall();

        if (dev_isalive(net)) {
                if ((ret = (*set)(net, new)) == 0)
                        ret = len;
        }
        rtnl_unlock();
 err:
        return ret;
}

NETDEVICE_SHOW(dev_id, fmt_hex);
NETDEVICE_SHOW(addr_len, fmt_dec);
NETDEVICE_SHOW(iflink, fmt_dec);
NETDEVICE_SHOW(ifindex, fmt_dec);
NETDEVICE_SHOW(features, fmt_long_hex);
NETDEVICE_SHOW(type, fmt_dec);
NETDEVICE_SHOW(link_mode, fmt_dec);

/* use same locking rules as GIFHWADDR ioctl's */
static ssize_t show_address(struct device *dev, struct device_attribute *attr,
                            char *buf)
{
        struct net_device *net = to_net_dev(dev);
        ssize_t ret = -EINVAL;

        read_lock(&dev_base_lock);
        if (dev_isalive(net))
                ret = sysfs_format_mac(buf, net->dev_addr, net->addr_len);
        read_unlock(&dev_base_lock);
        return ret;
}

static ssize_t show_broadcast(struct device *dev,
                            struct device_attribute *attr, char *buf)
{
        struct net_device *net = to_net_dev(dev);
        if (dev_isalive(net))
                return sysfs_format_mac(buf, net->broadcast, net->addr_len);
        return -EINVAL;
}

static ssize_t show_carrier(struct device *dev,
                            struct device_attribute *attr, char *buf)
{
        struct net_device *netdev = to_net_dev(dev);
        if (netif_running(netdev)) {
                return sprintf(buf, fmt_dec, !!netif_carrier_ok(netdev));
        }
        return -EINVAL;
}

static ssize_t show_speed(struct device *dev,
                          struct device_attribute *attr, char *buf)
{
        struct net_device *netdev = to_net_dev(dev);
        int ret = -EINVAL;

        if (!rtnl_trylock())
                return restart_syscall();

        if (netif_running(netdev) &&
            netdev->ethtool_ops &&
            netdev->ethtool_ops->get_settings) {
                struct ethtool_cmd cmd = { ETHTOOL_GSET };

                if (!netdev->ethtool_ops->get_settings(netdev, &cmd))
                        ret = sprintf(buf, fmt_dec, ethtool_cmd_speed(&cmd));
        }
        rtnl_unlock();
        return ret;
}

static ssize_t show_duplex(struct device *dev,
                           struct device_attribute *attr, char *buf)
{
        struct net_device *netdev = to_net_dev(dev);
        int ret = -EINVAL;

        if (!rtnl_trylock())
                return restart_syscall();

        if (netif_running(netdev) &&
            netdev->ethtool_ops &&
            netdev->ethtool_ops->get_settings) {
                struct ethtool_cmd cmd = { ETHTOOL_GSET };

                if (!netdev->ethtool_ops->get_settings(netdev, &cmd))
                        ret = sprintf(buf, "%s\n", cmd.duplex ? "full" : "half");
        }
        rtnl_unlock();
        return ret;
}

static ssize_t show_dormant(struct device *dev,
                            struct device_attribute *attr, char *buf)
{
        struct net_device *netdev = to_net_dev(dev);

        if (netif_running(netdev))
                return sprintf(buf, fmt_dec, !!netif_dormant(netdev));

        return -EINVAL;
}

static const char *const operstates[] = {
        "unknown",
        "notpresent", /* currently unused */
        "down",
        "lowerlayerdown",
        "testing", /* currently unused */
        "dormant",
        "up"
};

static ssize_t show_operstate(struct device *dev,
                              struct device_attribute *attr, char *buf)
{
        const struct net_device *netdev = to_net_dev(dev);
        unsigned char operstate;

        read_lock(&dev_base_lock);
        operstate = netdev->operstate;
        if (!netif_running(netdev))
                operstate = IF_OPER_DOWN;
        read_unlock(&dev_base_lock);

        if (operstate >= ARRAY_SIZE(operstates))
                return -EINVAL; /* should not happen */

        return sprintf(buf, "%s\n", operstates[operstate]);
}

/* read-write attributes */
NETDEVICE_SHOW(mtu, fmt_dec);

static int change_mtu(struct net_device *net, unsigned long new_mtu)
{
        return dev_set_mtu(net, (int) new_mtu);
}

static ssize_t store_mtu(struct device *dev, struct device_attribute *attr,
                         const char *buf, size_t len)
{
        return netdev_store(dev, attr, buf, len, change_mtu);
}

NETDEVICE_SHOW(flags, fmt_hex);

static int change_flags(struct net_device *net, unsigned long new_flags)
{
        return dev_change_flags(net, (unsigned) new_flags);
}

static ssize_t store_flags(struct device *dev, struct device_attribute *attr,
                           const char *buf, size_t len)
{
        return netdev_store(dev, attr, buf, len, change_flags);
}

NETDEVICE_SHOW(tx_queue_len, fmt_ulong);

static int change_tx_queue_len(struct net_device *net, unsigned long new_len)
{
        net->tx_queue_len = new_len;
        return 0;
}

static ssize_t store_tx_queue_len(struct device *dev,
                                  struct device_attribute *attr,
                                  const char *buf, size_t len)
{
        return netdev_store(dev, attr, buf, len, change_tx_queue_len);
}

static ssize_t store_ifalias(struct device *dev, struct device_attribute *attr,
                             const char *buf, size_t len)
{
        struct net_device *netdev = to_net_dev(dev);
        size_t count = len;
        ssize_t ret;

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

        /* ignore trailing newline */
        if (len >  0 && buf[len - 1] == '\n')
                --count;

        if (!rtnl_trylock())
                return restart_syscall();
        ret = dev_set_alias(netdev, buf, count);
        rtnl_unlock();

        return ret < 0 ? ret : len;
}

static ssize_t show_ifalias(struct device *dev,
                            struct device_attribute *attr, char *buf)
{
        const struct net_device *netdev = to_net_dev(dev);
        ssize_t ret = 0;

        if (!rtnl_trylock())
                return restart_syscall();
        if (netdev->ifalias)
                ret = sprintf(buf, "%s\n", netdev->ifalias);
        rtnl_unlock();
        return ret;
}

static struct device_attribute net_class_attributes[] = {
        __ATTR(addr_len, S_IRUGO, show_addr_len, NULL),
        __ATTR(dev_id, S_IRUGO, show_dev_id, NULL),
        __ATTR(ifalias, S_IRUGO | S_IWUSR, show_ifalias, store_ifalias),
        __ATTR(iflink, S_IRUGO, show_iflink, NULL),
        __ATTR(ifindex, S_IRUGO, show_ifindex, NULL),
        __ATTR(features, S_IRUGO, show_features, NULL),
        __ATTR(type, S_IRUGO, show_type, NULL),
        __ATTR(link_mode, S_IRUGO, show_link_mode, NULL),
        __ATTR(address, S_IRUGO, show_address, NULL),
        __ATTR(broadcast, S_IRUGO, show_broadcast, NULL),
        __ATTR(carrier, S_IRUGO, show_carrier, NULL),
        __ATTR(speed, S_IRUGO, show_speed, NULL),
        __ATTR(duplex, S_IRUGO, show_duplex, NULL),
        __ATTR(dormant, S_IRUGO, show_dormant, NULL),
        __ATTR(operstate, S_IRUGO, show_operstate, NULL),
        __ATTR(mtu, S_IRUGO | S_IWUSR, show_mtu, store_mtu),
        __ATTR(flags, S_IRUGO | S_IWUSR, show_flags, store_flags),
        __ATTR(tx_queue_len, S_IRUGO | S_IWUSR, show_tx_queue_len,
               store_tx_queue_len),
        {}
};

/* Show a given an attribute in the statistics group */
static ssize_t netstat_show(const struct device *d,
                            struct device_attribute *attr, char *buf,
                            unsigned long offset)
{
        struct net_device *dev = to_net_dev(d);
        ssize_t ret = -EINVAL;

        WARN_ON(offset > sizeof(struct net_device_stats) ||
                        offset % sizeof(unsigned long) != 0);

        read_lock(&dev_base_lock);
        if (dev_isalive(dev)) {
                const struct net_device_stats *stats = dev_get_stats(dev);
                ret = sprintf(buf, fmt_ulong,
                              *(unsigned long *)(((u8 *) stats) + offset));
        }
        read_unlock(&dev_base_lock);
        return ret;
}

/* generate a read-only statistics attribute */
#define NETSTAT_ENTRY(name)                                             \
static ssize_t show_##name(struct device *d,                            \
                           struct device_attribute *attr, char *buf)    \
{                                                                       \
        return netstat_show(d, attr, buf,                               \
                            offsetof(struct net_device_stats, name));   \
}                                                                       \
static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)

NETSTAT_ENTRY(rx_packets);
NETSTAT_ENTRY(tx_packets);
NETSTAT_ENTRY(rx_bytes);
NETSTAT_ENTRY(tx_bytes);
NETSTAT_ENTRY(rx_errors);
NETSTAT_ENTRY(tx_errors);
NETSTAT_ENTRY(rx_dropped);
NETSTAT_ENTRY(tx_dropped);
NETSTAT_ENTRY(multicast);
NETSTAT_ENTRY(collisions);
NETSTAT_ENTRY(rx_length_errors);
NETSTAT_ENTRY(rx_over_errors);
NETSTAT_ENTRY(rx_crc_errors);
NETSTAT_ENTRY(rx_frame_errors);
NETSTAT_ENTRY(rx_fifo_errors);
NETSTAT_ENTRY(rx_missed_errors);
NETSTAT_ENTRY(tx_aborted_errors);
NETSTAT_ENTRY(tx_carrier_errors);
NETSTAT_ENTRY(tx_fifo_errors);
NETSTAT_ENTRY(tx_heartbeat_errors);
NETSTAT_ENTRY(tx_window_errors);
NETSTAT_ENTRY(rx_compressed);
NETSTAT_ENTRY(tx_compressed);

static struct attribute *netstat_attrs[] = {
        &dev_attr_rx_packets.attr,
        &dev_attr_tx_packets.attr,
        &dev_attr_rx_bytes.attr,
        &dev_attr_tx_bytes.attr,
        &dev_attr_rx_errors.attr,
        &dev_attr_tx_errors.attr,
        &dev_attr_rx_dropped.attr,
        &dev_attr_tx_dropped.attr,
        &dev_attr_multicast.attr,
        &dev_attr_collisions.attr,
        &dev_attr_rx_length_errors.attr,
        &dev_attr_rx_over_errors.attr,
        &dev_attr_rx_crc_errors.attr,
        &dev_attr_rx_frame_errors.attr,
        &dev_attr_rx_fifo_errors.attr,
        &dev_attr_rx_missed_errors.attr,
        &dev_attr_tx_aborted_errors.attr,
        &dev_attr_tx_carrier_errors.attr,
        &dev_attr_tx_fifo_errors.attr,
        &dev_attr_tx_heartbeat_errors.attr,
        &dev_attr_tx_window_errors.attr,
        &dev_attr_rx_compressed.attr,
        &dev_attr_tx_compressed.attr,
        NULL
};


static struct attribute_group netstat_group = {
        .name  = "statistics",
        .attrs  = netstat_attrs,
};

#ifdef CONFIG_WIRELESS_EXT_SYSFS
/* helper function that does all the locking etc for wireless stats */
static ssize_t wireless_show(struct device *d, char *buf,
                             ssize_t (*format)(const struct iw_statistics *,
                                               char *))
{
        struct net_device *dev = to_net_dev(d);
        const struct iw_statistics *iw;
        ssize_t ret = -EINVAL;

        if (!rtnl_trylock())
                return restart_syscall();
        if (dev_isalive(dev)) {
                iw = get_wireless_stats(dev);
                if (iw)
                        ret = (*format)(iw, buf);
        }
        rtnl_unlock();

        return ret;
}

/* show function template for wireless fields */
#define WIRELESS_SHOW(name, field, format_string)                       \
static ssize_t format_iw_##name(const struct iw_statistics *iw, char *buf) \
{                                                                       \
        return sprintf(buf, format_string, iw->field);                  \
}                                                                       \
static ssize_t show_iw_##name(struct device *d,                         \
                              struct device_attribute *attr, char *buf) \
{                                                                       \
        return wireless_show(d, buf, format_iw_##name);                 \
}                                                                       \
static DEVICE_ATTR(name, S_IRUGO, show_iw_##name, NULL)

WIRELESS_SHOW(status, status, fmt_hex);
WIRELESS_SHOW(link, qual.qual, fmt_dec);
WIRELESS_SHOW(level, qual.level, fmt_dec);
WIRELESS_SHOW(noise, qual.noise, fmt_dec);
WIRELESS_SHOW(nwid, discard.nwid, fmt_dec);
WIRELESS_SHOW(crypt, discard.code, fmt_dec);
WIRELESS_SHOW(fragment, discard.fragment, fmt_dec);
WIRELESS_SHOW(misc, discard.misc, fmt_dec);
WIRELESS_SHOW(retries, discard.retries, fmt_dec);
WIRELESS_SHOW(beacon, miss.beacon, fmt_dec);

static struct attribute *wireless_attrs[] = {
        &dev_attr_status.attr,
        &dev_attr_link.attr,
        &dev_attr_level.attr,
        &dev_attr_noise.attr,
        &dev_attr_nwid.attr,
        &dev_attr_crypt.attr,
        &dev_attr_fragment.attr,
        &dev_attr_retries.attr,
        &dev_attr_misc.attr,
        &dev_attr_beacon.attr,
        NULL
};

static struct attribute_group wireless_group = {
        .name = "wireless",
        .attrs = wireless_attrs,
};
#endif

#endif /* CONFIG_SYSFS */

#ifdef CONFIG_HOTPLUG
static int netdev_uevent(struct device *d, struct kobj_uevent_env *env)
{
        struct net_device *dev = to_net_dev(d);
        int retval;

        if (!net_eq(dev_net(dev), &init_net))
                return 0;

        /* pass interface to uevent. */
        retval = add_uevent_var(env, "INTERFACE=%s", dev->name);
        if (retval)
                goto exit;

        /* pass ifindex to uevent.
         * ifindex is useful as it won't change (interface name may change)
         * and is what RtNetlink uses natively. */
        retval = add_uevent_var(env, "IFINDEX=%d", dev->ifindex);

exit:
        return retval;
}
#endif

/*
 *      netdev_release -- destroy and free a dead device.
 *      Called when last reference to device kobject is gone.
 */
static void netdev_release(struct device *d)
{
        struct net_device *dev = to_net_dev(d);

        BUG_ON(dev->reg_state != NETREG_RELEASED);

        kfree(dev->ifalias);
        kfree((char *)dev - dev->padded);
}

static struct class net_class = {
        .name = "net",
        .dev_release = netdev_release,
#ifdef CONFIG_SYSFS
        .dev_attrs = net_class_attributes,
#endif /* CONFIG_SYSFS */
#ifdef CONFIG_HOTPLUG
        .dev_uevent = netdev_uevent,
#endif
};

/* Delete sysfs entries but hold kobject reference until after all
 * netdev references are gone.
 */
void netdev_unregister_kobject(struct net_device * net)
{
        struct device *dev = &(net->dev);

        kobject_get(&dev->kobj);

        if (!net_eq(dev_net(net), &init_net))
                return;

        device_del(dev);
}

/* Create sysfs entries for network device. */
int netdev_register_kobject(struct net_device *net)
{
        struct device *dev = &(net->dev);
        const struct attribute_group **groups = net->sysfs_groups;

        dev->class = &net_class;
        dev->platform_data = net;
        dev->groups = groups;

        dev_set_name(dev, "%s", net->name);

#ifdef CONFIG_SYSFS
        /* Allow for a device specific group */
        if (*groups)
                groups++;

        *groups++ = &netstat_group;
#ifdef CONFIG_WIRELESS_EXT_SYSFS
        if (net->ieee80211_ptr)
                *groups++ = &wireless_group;
#ifdef CONFIG_WIRELESS_EXT
        else if (net->wireless_handlers)
                *groups++ = &wireless_group;
#endif
#endif
#endif /* CONFIG_SYSFS */

        if (!net_eq(dev_net(net), &init_net))
                return 0;

        return device_add(dev);
}

int netdev_class_create_file(struct class_attribute *class_attr)
{
        return class_create_file(&net_class, class_attr);
}

void netdev_class_remove_file(struct class_attribute *class_attr)
{
        class_remove_file(&net_class, class_attr);
}

EXPORT_SYMBOL(netdev_class_create_file);
EXPORT_SYMBOL(netdev_class_remove_file);

void netdev_initialize_kobject(struct net_device *net)
{
        struct device *device = &(net->dev);
        device_initialize(device);
}

int netdev_kobject_init(void)
{
        return class_register(&net_class);
}