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[mirror_ubuntu-zesty-kernel.git] / net / core / net-sysfs.c

/*
 * 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 <linux/nsproxy.h>
#include <net/sock.h>
#include <net/net_namespace.h>
#include <linux/rtnetlink.h>
#include <linux/wireless.h>
#include <linux/vmalloc.h>
#include <linux/export.h>
#include <linux/jiffies.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_udec[] = "%u\n";
static const char fmt_ulong[] = "%lu\n";
static const char fmt_u64[] = "%llu\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_assign_type, fmt_dec);
NETDEVICE_SHOW(addr_len, fmt_dec);
NETDEVICE_SHOW(iflink, fmt_dec);
NETDEVICE_SHOW(ifindex, fmt_dec);
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)) {
                struct ethtool_cmd cmd;
                if (!__ethtool_get_settings(netdev, &cmd))
                        ret = sprintf(buf, fmt_udec, 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)) {
                struct ethtool_cmd cmd;
                if (!__ethtool_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;
}

NETDEVICE_SHOW(group, fmt_dec);

static int change_group(struct net_device *net, unsigned long new_group)
{
        dev_set_group(net, (int) new_group);
        return 0;
}

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

static struct device_attribute net_class_attributes[] = {
        __ATTR(addr_assign_type, S_IRUGO, show_addr_assign_type, NULL),
        __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(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),
        __ATTR(netdev_group, S_IRUGO | S_IWUSR, show_group, store_group),
        {}
};

/* 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 rtnl_link_stats64) ||
                        offset % sizeof(u64) != 0);

        read_lock(&dev_base_lock);
        if (dev_isalive(dev)) {
                struct rtnl_link_stats64 temp;
                const struct rtnl_link_stats64 *stats = dev_get_stats(dev, &temp);

                ret = sprintf(buf, fmt_u64, *(u64 *)(((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 rtnl_link_stats64, 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_RPS
/*
 * RX queue sysfs structures and functions.
 */
struct rx_queue_attribute {
        struct attribute attr;
        ssize_t (*show)(struct netdev_rx_queue *queue,
            struct rx_queue_attribute *attr, char *buf);
        ssize_t (*store)(struct netdev_rx_queue *queue,
            struct rx_queue_attribute *attr, const char *buf, size_t len);
};
#define to_rx_queue_attr(_attr) container_of(_attr,             \
    struct rx_queue_attribute, attr)

#define to_rx_queue(obj) container_of(obj, struct netdev_rx_queue, kobj)

static ssize_t rx_queue_attr_show(struct kobject *kobj, struct attribute *attr,
                                  char *buf)
{
        struct rx_queue_attribute *attribute = to_rx_queue_attr(attr);
        struct netdev_rx_queue *queue = to_rx_queue(kobj);

        if (!attribute->show)
                return -EIO;

        return attribute->show(queue, attribute, buf);
}

static ssize_t rx_queue_attr_store(struct kobject *kobj, struct attribute *attr,
                                   const char *buf, size_t count)
{
        struct rx_queue_attribute *attribute = to_rx_queue_attr(attr);
        struct netdev_rx_queue *queue = to_rx_queue(kobj);

        if (!attribute->store)
                return -EIO;

        return attribute->store(queue, attribute, buf, count);
}

static const struct sysfs_ops rx_queue_sysfs_ops = {
        .show = rx_queue_attr_show,
        .store = rx_queue_attr_store,
};

static ssize_t show_rps_map(struct netdev_rx_queue *queue,
                            struct rx_queue_attribute *attribute, char *buf)
{
        struct rps_map *map;
        cpumask_var_t mask;
        size_t len = 0;
        int i;

        if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
                return -ENOMEM;

        rcu_read_lock();
        map = rcu_dereference(queue->rps_map);
        if (map)
                for (i = 0; i < map->len; i++)
                        cpumask_set_cpu(map->cpus[i], mask);

        len += cpumask_scnprintf(buf + len, PAGE_SIZE, mask);
        if (PAGE_SIZE - len < 3) {
                rcu_read_unlock();
                free_cpumask_var(mask);
                return -EINVAL;
        }
        rcu_read_unlock();

        free_cpumask_var(mask);
        len += sprintf(buf + len, "\n");
        return len;
}

static ssize_t store_rps_map(struct netdev_rx_queue *queue,
                      struct rx_queue_attribute *attribute,
                      const char *buf, size_t len)
{
        struct rps_map *old_map, *map;
        cpumask_var_t mask;
        int err, cpu, i;
        static DEFINE_SPINLOCK(rps_map_lock);

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

        if (!alloc_cpumask_var(&mask, GFP_KERNEL))
                return -ENOMEM;

        err = bitmap_parse(buf, len, cpumask_bits(mask), nr_cpumask_bits);
        if (err) {
                free_cpumask_var(mask);
                return err;
        }

        map = kzalloc(max_t(unsigned,
            RPS_MAP_SIZE(cpumask_weight(mask)), L1_CACHE_BYTES),
            GFP_KERNEL);
        if (!map) {
                free_cpumask_var(mask);
                return -ENOMEM;
        }

        i = 0;
        for_each_cpu_and(cpu, mask, cpu_online_mask)
                map->cpus[i++] = cpu;

        if (i)
                map->len = i;
        else {
                kfree(map);
                map = NULL;
        }

        spin_lock(&rps_map_lock);
        old_map = rcu_dereference_protected(queue->rps_map,
                                            lockdep_is_held(&rps_map_lock));
        rcu_assign_pointer(queue->rps_map, map);
        spin_unlock(&rps_map_lock);

        if (map)
                static_key_slow_inc(&rps_needed);
        if (old_map) {
                kfree_rcu(old_map, rcu);
                static_key_slow_dec(&rps_needed);
        }
        free_cpumask_var(mask);
        return len;
}

static ssize_t show_rps_dev_flow_table_cnt(struct netdev_rx_queue *queue,
                                           struct rx_queue_attribute *attr,
                                           char *buf)
{
        struct rps_dev_flow_table *flow_table;
        unsigned long val = 0;

        rcu_read_lock();
        flow_table = rcu_dereference(queue->rps_flow_table);
        if (flow_table)
                val = (unsigned long)flow_table->mask + 1;
        rcu_read_unlock();

        return sprintf(buf, "%lu\n", val);
}

static void rps_dev_flow_table_release_work(struct work_struct *work)
{
        struct rps_dev_flow_table *table = container_of(work,
            struct rps_dev_flow_table, free_work);

        vfree(table);
}

static void rps_dev_flow_table_release(struct rcu_head *rcu)
{
        struct rps_dev_flow_table *table = container_of(rcu,
            struct rps_dev_flow_table, rcu);

        INIT_WORK(&table->free_work, rps_dev_flow_table_release_work);
        schedule_work(&table->free_work);
}

static ssize_t store_rps_dev_flow_table_cnt(struct netdev_rx_queue *queue,
                                     struct rx_queue_attribute *attr,
                                     const char *buf, size_t len)
{
        unsigned long mask, count;
        struct rps_dev_flow_table *table, *old_table;
        static DEFINE_SPINLOCK(rps_dev_flow_lock);
        int rc;

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

        rc = kstrtoul(buf, 0, &count);
        if (rc < 0)
                return rc;

        if (count) {
                mask = count - 1;
                /* mask = roundup_pow_of_two(count) - 1;
                 * without overflows...
                 */
                while ((mask | (mask >> 1)) != mask)
                        mask |= (mask >> 1);
                /* On 64 bit arches, must check mask fits in table->mask (u32),
                 * and on 32bit arches, must check RPS_DEV_FLOW_TABLE_SIZE(mask + 1)
                 * doesnt overflow.
                 */
#if BITS_PER_LONG > 32
                if (mask > (unsigned long)(u32)mask)
                        return -EINVAL;
#else
                if (mask > (ULONG_MAX - RPS_DEV_FLOW_TABLE_SIZE(1))
                                / sizeof(struct rps_dev_flow)) {
                        /* Enforce a limit to prevent overflow */
                        return -EINVAL;
                }
#endif
                table = vmalloc(RPS_DEV_FLOW_TABLE_SIZE(mask + 1));
                if (!table)
                        return -ENOMEM;

                table->mask = mask;
                for (count = 0; count <= mask; count++)
                        table->flows[count].cpu = RPS_NO_CPU;
        } else
                table = NULL;

        spin_lock(&rps_dev_flow_lock);
        old_table = rcu_dereference_protected(queue->rps_flow_table,
                                              lockdep_is_held(&rps_dev_flow_lock));
        rcu_assign_pointer(queue->rps_flow_table, table);
        spin_unlock(&rps_dev_flow_lock);

        if (old_table)
                call_rcu(&old_table->rcu, rps_dev_flow_table_release);

        return len;
}

static struct rx_queue_attribute rps_cpus_attribute =
        __ATTR(rps_cpus, S_IRUGO | S_IWUSR, show_rps_map, store_rps_map);


static struct rx_queue_attribute rps_dev_flow_table_cnt_attribute =
        __ATTR(rps_flow_cnt, S_IRUGO | S_IWUSR,
            show_rps_dev_flow_table_cnt, store_rps_dev_flow_table_cnt);

static struct attribute *rx_queue_default_attrs[] = {
        &rps_cpus_attribute.attr,
        &rps_dev_flow_table_cnt_attribute.attr,
        NULL
};

static void rx_queue_release(struct kobject *kobj)
{
        struct netdev_rx_queue *queue = to_rx_queue(kobj);
        struct rps_map *map;
        struct rps_dev_flow_table *flow_table;


        map = rcu_dereference_protected(queue->rps_map, 1);
        if (map) {
                RCU_INIT_POINTER(queue->rps_map, NULL);
                kfree_rcu(map, rcu);
        }

        flow_table = rcu_dereference_protected(queue->rps_flow_table, 1);
        if (flow_table) {
                RCU_INIT_POINTER(queue->rps_flow_table, NULL);
                call_rcu(&flow_table->rcu, rps_dev_flow_table_release);
        }

        memset(kobj, 0, sizeof(*kobj));
        dev_put(queue->dev);
}

static struct kobj_type rx_queue_ktype = {
        .sysfs_ops = &rx_queue_sysfs_ops,
        .release = rx_queue_release,
        .default_attrs = rx_queue_default_attrs,
};

static int rx_queue_add_kobject(struct net_device *net, int index)
{
        struct netdev_rx_queue *queue = net->_rx + index;
        struct kobject *kobj = &queue->kobj;
        int error = 0;

        kobj->kset = net->queues_kset;
        error = kobject_init_and_add(kobj, &rx_queue_ktype, NULL,
            "rx-%u", index);
        if (error) {
                kobject_put(kobj);
                return error;
        }

        kobject_uevent(kobj, KOBJ_ADD);
        dev_hold(queue->dev);

        return error;
}
#endif /* CONFIG_RPS */

int
net_rx_queue_update_kobjects(struct net_device *net, int old_num, int new_num)
{
#ifdef CONFIG_RPS
        int i;
        int error = 0;

        for (i = old_num; i < new_num; i++) {
                error = rx_queue_add_kobject(net, i);
                if (error) {
                        new_num = old_num;
                        break;
                }
        }

        while (--i >= new_num)
                kobject_put(&net->_rx[i].kobj);

        return error;
#else
        return 0;
#endif
}

#ifdef CONFIG_SYSFS
/*
 * netdev_queue sysfs structures and functions.
 */
struct netdev_queue_attribute {
        struct attribute attr;
        ssize_t (*show)(struct netdev_queue *queue,
            struct netdev_queue_attribute *attr, char *buf);
        ssize_t (*store)(struct netdev_queue *queue,
            struct netdev_queue_attribute *attr, const char *buf, size_t len);
};
#define to_netdev_queue_attr(_attr) container_of(_attr,         \
    struct netdev_queue_attribute, attr)

#define to_netdev_queue(obj) container_of(obj, struct netdev_queue, kobj)

static ssize_t netdev_queue_attr_show(struct kobject *kobj,
                                      struct attribute *attr, char *buf)
{
        struct netdev_queue_attribute *attribute = to_netdev_queue_attr(attr);
        struct netdev_queue *queue = to_netdev_queue(kobj);

        if (!attribute->show)
                return -EIO;

        return attribute->show(queue, attribute, buf);
}

static ssize_t netdev_queue_attr_store(struct kobject *kobj,
                                       struct attribute *attr,
                                       const char *buf, size_t count)
{
        struct netdev_queue_attribute *attribute = to_netdev_queue_attr(attr);
        struct netdev_queue *queue = to_netdev_queue(kobj);

        if (!attribute->store)
                return -EIO;

        return attribute->store(queue, attribute, buf, count);
}

static const struct sysfs_ops netdev_queue_sysfs_ops = {
        .show = netdev_queue_attr_show,
        .store = netdev_queue_attr_store,
};

static ssize_t show_trans_timeout(struct netdev_queue *queue,
                                  struct netdev_queue_attribute *attribute,
                                  char *buf)
{
        unsigned long trans_timeout;

        spin_lock_irq(&queue->_xmit_lock);
        trans_timeout = queue->trans_timeout;
        spin_unlock_irq(&queue->_xmit_lock);

        return sprintf(buf, "%lu", trans_timeout);
}

static struct netdev_queue_attribute queue_trans_timeout =
        __ATTR(tx_timeout, S_IRUGO, show_trans_timeout, NULL);

#ifdef CONFIG_BQL
/*
 * Byte queue limits sysfs structures and functions.
 */
static ssize_t bql_show(char *buf, unsigned int value)
{
        return sprintf(buf, "%u\n", value);
}

static ssize_t bql_set(const char *buf, const size_t count,
                       unsigned int *pvalue)
{
        unsigned int value;
        int err;

        if (!strcmp(buf, "max") || !strcmp(buf, "max\n"))
                value = DQL_MAX_LIMIT;
        else {
                err = kstrtouint(buf, 10, &value);
                if (err < 0)
                        return err;
                if (value > DQL_MAX_LIMIT)
                        return -EINVAL;
        }

        *pvalue = value;

        return count;
}

static ssize_t bql_show_hold_time(struct netdev_queue *queue,
                                  struct netdev_queue_attribute *attr,
                                  char *buf)
{
        struct dql *dql = &queue->dql;

        return sprintf(buf, "%u\n", jiffies_to_msecs(dql->slack_hold_time));
}

static ssize_t bql_set_hold_time(struct netdev_queue *queue,
                                 struct netdev_queue_attribute *attribute,
                                 const char *buf, size_t len)
{
        struct dql *dql = &queue->dql;
        unsigned value;
        int err;

        err = kstrtouint(buf, 10, &value);
        if (err < 0)
                return err;

        dql->slack_hold_time = msecs_to_jiffies(value);

        return len;
}

static struct netdev_queue_attribute bql_hold_time_attribute =
        __ATTR(hold_time, S_IRUGO | S_IWUSR, bql_show_hold_time,
            bql_set_hold_time);

static ssize_t bql_show_inflight(struct netdev_queue *queue,
                                 struct netdev_queue_attribute *attr,
                                 char *buf)
{
        struct dql *dql = &queue->dql;

        return sprintf(buf, "%u\n", dql->num_queued - dql->num_completed);
}

static struct netdev_queue_attribute bql_inflight_attribute =
        __ATTR(inflight, S_IRUGO, bql_show_inflight, NULL);

#define BQL_ATTR(NAME, FIELD)                                           \
static ssize_t bql_show_ ## NAME(struct netdev_queue *queue,            \
                                 struct netdev_queue_attribute *attr,   \
                                 char *buf)                             \
{                                                                       \
        return bql_show(buf, queue->dql.FIELD);                         \
}                                                                       \
                                                                        \
static ssize_t bql_set_ ## NAME(struct netdev_queue *queue,             \
                                struct netdev_queue_attribute *attr,    \
                                const char *buf, size_t len)            \
{                                                                       \
        return bql_set(buf, len, &queue->dql.FIELD);                    \
}                                                                       \
                                                                        \
static struct netdev_queue_attribute bql_ ## NAME ## _attribute =       \
        __ATTR(NAME, S_IRUGO | S_IWUSR, bql_show_ ## NAME,              \
            bql_set_ ## NAME);

BQL_ATTR(limit, limit)
BQL_ATTR(limit_max, max_limit)
BQL_ATTR(limit_min, min_limit)

static struct attribute *dql_attrs[] = {
        &bql_limit_attribute.attr,
        &bql_limit_max_attribute.attr,
        &bql_limit_min_attribute.attr,
        &bql_hold_time_attribute.attr,
        &bql_inflight_attribute.attr,
        NULL
};

static struct attribute_group dql_group = {
        .name  = "byte_queue_limits",
        .attrs  = dql_attrs,
};
#endif /* CONFIG_BQL */

#ifdef CONFIG_XPS
static inline unsigned int get_netdev_queue_index(struct netdev_queue *queue)
{
        struct net_device *dev = queue->dev;
        int i;

        for (i = 0; i < dev->num_tx_queues; i++)
                if (queue == &dev->_tx[i])
                        break;

        BUG_ON(i >= dev->num_tx_queues);

        return i;
}


static ssize_t show_xps_map(struct netdev_queue *queue,
                            struct netdev_queue_attribute *attribute, char *buf)
{
        struct net_device *dev = queue->dev;
        struct xps_dev_maps *dev_maps;
        cpumask_var_t mask;
        unsigned long index;
        size_t len = 0;
        int i;

        if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
                return -ENOMEM;

        index = get_netdev_queue_index(queue);

        rcu_read_lock();
        dev_maps = rcu_dereference(dev->xps_maps);
        if (dev_maps) {
                for_each_possible_cpu(i) {
                        struct xps_map *map =
                            rcu_dereference(dev_maps->cpu_map[i]);
                        if (map) {
                                int j;
                                for (j = 0; j < map->len; j++) {
                                        if (map->queues[j] == index) {
                                                cpumask_set_cpu(i, mask);
                                                break;
                                        }
                                }
                        }
                }
        }
        rcu_read_unlock();

        len += cpumask_scnprintf(buf + len, PAGE_SIZE, mask);
        if (PAGE_SIZE - len < 3) {
                free_cpumask_var(mask);
                return -EINVAL;
        }

        free_cpumask_var(mask);
        len += sprintf(buf + len, "\n");
        return len;
}

static DEFINE_MUTEX(xps_map_mutex);
#define xmap_dereference(P)             \
        rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))

static void xps_queue_release(struct netdev_queue *queue)
{
        struct net_device *dev = queue->dev;
        struct xps_dev_maps *dev_maps;
        struct xps_map *map;
        unsigned long index;
        int i, pos, nonempty = 0;

        index = get_netdev_queue_index(queue);

        mutex_lock(&xps_map_mutex);
        dev_maps = xmap_dereference(dev->xps_maps);

        if (dev_maps) {
                for_each_possible_cpu(i) {
                        map = xmap_dereference(dev_maps->cpu_map[i]);
                        if (!map)
                                continue;

                        for (pos = 0; pos < map->len; pos++)
                                if (map->queues[pos] == index)
                                        break;

                        if (pos < map->len) {
                                if (map->len > 1)
                                        map->queues[pos] =
                                            map->queues[--map->len];
                                else {
                                        RCU_INIT_POINTER(dev_maps->cpu_map[i],
                                            NULL);
                                        kfree_rcu(map, rcu);
                                        map = NULL;
                                }
                        }
                        if (map)
                                nonempty = 1;
                }

                if (!nonempty) {
                        RCU_INIT_POINTER(dev->xps_maps, NULL);
                        kfree_rcu(dev_maps, rcu);
                }
        }
        mutex_unlock(&xps_map_mutex);
}

static ssize_t store_xps_map(struct netdev_queue *queue,
                      struct netdev_queue_attribute *attribute,
                      const char *buf, size_t len)
{
        struct net_device *dev = queue->dev;
        cpumask_var_t mask;
        int err, i, cpu, pos, map_len, alloc_len, need_set;
        unsigned long index;
        struct xps_map *map, *new_map;
        struct xps_dev_maps *dev_maps, *new_dev_maps;
        int nonempty = 0;
        int numa_node_id = -2;

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

        if (!alloc_cpumask_var(&mask, GFP_KERNEL))
                return -ENOMEM;

        index = get_netdev_queue_index(queue);

        err = bitmap_parse(buf, len, cpumask_bits(mask), nr_cpumask_bits);
        if (err) {
                free_cpumask_var(mask);
                return err;
        }

        new_dev_maps = kzalloc(max_t(unsigned,
            XPS_DEV_MAPS_SIZE, L1_CACHE_BYTES), GFP_KERNEL);
        if (!new_dev_maps) {
                free_cpumask_var(mask);
                return -ENOMEM;
        }

        mutex_lock(&xps_map_mutex);

        dev_maps = xmap_dereference(dev->xps_maps);

        for_each_possible_cpu(cpu) {
                map = dev_maps ?
                        xmap_dereference(dev_maps->cpu_map[cpu]) : NULL;
                new_map = map;
                if (map) {
                        for (pos = 0; pos < map->len; pos++)
                                if (map->queues[pos] == index)
                                        break;
                        map_len = map->len;
                        alloc_len = map->alloc_len;
                } else
                        pos = map_len = alloc_len = 0;

                need_set = cpumask_test_cpu(cpu, mask) && cpu_online(cpu);
#ifdef CONFIG_NUMA
                if (need_set) {
                        if (numa_node_id == -2)
                                numa_node_id = cpu_to_node(cpu);
                        else if (numa_node_id != cpu_to_node(cpu))
                                numa_node_id = -1;
                }
#endif
                if (need_set && pos >= map_len) {
                        /* Need to add queue to this CPU's map */
                        if (map_len >= alloc_len) {
                                alloc_len = alloc_len ?
                                    2 * alloc_len : XPS_MIN_MAP_ALLOC;
                                new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len),
                                                       GFP_KERNEL,
                                                       cpu_to_node(cpu));
                                if (!new_map)
                                        goto error;
                                new_map->alloc_len = alloc_len;
                                for (i = 0; i < map_len; i++)
                                        new_map->queues[i] = map->queues[i];
                                new_map->len = map_len;
                        }
                        new_map->queues[new_map->len++] = index;
                } else if (!need_set && pos < map_len) {
                        /* Need to remove queue from this CPU's map */
                        if (map_len > 1)
                                new_map->queues[pos] =
                                    new_map->queues[--new_map->len];
                        else
                                new_map = NULL;
                }
                RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], new_map);
        }

        /* Cleanup old maps */
        for_each_possible_cpu(cpu) {
                map = dev_maps ?
                        xmap_dereference(dev_maps->cpu_map[cpu]) : NULL;
                if (map && xmap_dereference(new_dev_maps->cpu_map[cpu]) != map)
                        kfree_rcu(map, rcu);
                if (new_dev_maps->cpu_map[cpu])
                        nonempty = 1;
        }

        if (nonempty) {
                rcu_assign_pointer(dev->xps_maps, new_dev_maps);
        } else {
                kfree(new_dev_maps);
                RCU_INIT_POINTER(dev->xps_maps, NULL);
        }

        if (dev_maps)
                kfree_rcu(dev_maps, rcu);

        netdev_queue_numa_node_write(queue, (numa_node_id >= 0) ? numa_node_id :
                                            NUMA_NO_NODE);

        mutex_unlock(&xps_map_mutex);

        free_cpumask_var(mask);
        return len;

error:
        mutex_unlock(&xps_map_mutex);

        if (new_dev_maps)
                for_each_possible_cpu(i)
                        kfree(rcu_dereference_protected(
                                new_dev_maps->cpu_map[i],
                                1));
        kfree(new_dev_maps);
        free_cpumask_var(mask);
        return -ENOMEM;
}

static struct netdev_queue_attribute xps_cpus_attribute =
    __ATTR(xps_cpus, S_IRUGO | S_IWUSR, show_xps_map, store_xps_map);
#endif /* CONFIG_XPS */

static struct attribute *netdev_queue_default_attrs[] = {
        &queue_trans_timeout.attr,
#ifdef CONFIG_XPS
        &xps_cpus_attribute.attr,
#endif
        NULL
};

static void netdev_queue_release(struct kobject *kobj)
{
        struct netdev_queue *queue = to_netdev_queue(kobj);

#ifdef CONFIG_XPS
        xps_queue_release(queue);
#endif

        memset(kobj, 0, sizeof(*kobj));
        dev_put(queue->dev);
}

static struct kobj_type netdev_queue_ktype = {
        .sysfs_ops = &netdev_queue_sysfs_ops,
        .release = netdev_queue_release,
        .default_attrs = netdev_queue_default_attrs,
};

static int netdev_queue_add_kobject(struct net_device *net, int index)
{
        struct netdev_queue *queue = net->_tx + index;
        struct kobject *kobj = &queue->kobj;
        int error = 0;

        kobj->kset = net->queues_kset;
        error = kobject_init_and_add(kobj, &netdev_queue_ktype, NULL,
            "tx-%u", index);
        if (error)
                goto exit;

#ifdef CONFIG_BQL
        error = sysfs_create_group(kobj, &dql_group);
        if (error)
                goto exit;
#endif

        kobject_uevent(kobj, KOBJ_ADD);
        dev_hold(queue->dev);

        return 0;
exit:
        kobject_put(kobj);
        return error;
}
#endif /* CONFIG_SYSFS */

int
netdev_queue_update_kobjects(struct net_device *net, int old_num, int new_num)
{
#ifdef CONFIG_SYSFS
        int i;
        int error = 0;

        for (i = old_num; i < new_num; i++) {
                error = netdev_queue_add_kobject(net, i);
                if (error) {
                        new_num = old_num;
                        break;
                }
        }

        while (--i >= new_num) {
                struct netdev_queue *queue = net->_tx + i;

#ifdef CONFIG_BQL
                sysfs_remove_group(&queue->kobj, &dql_group);
#endif
                kobject_put(&queue->kobj);
        }

        return error;
#else
        return 0;
#endif /* CONFIG_SYSFS */
}

static int register_queue_kobjects(struct net_device *net)
{
        int error = 0, txq = 0, rxq = 0, real_rx = 0, real_tx = 0;

#ifdef CONFIG_SYSFS
        net->queues_kset = kset_create_and_add("queues",
            NULL, &net->dev.kobj);
        if (!net->queues_kset)
                return -ENOMEM;
#endif

#ifdef CONFIG_RPS
        real_rx = net->real_num_rx_queues;
#endif
        real_tx = net->real_num_tx_queues;

        error = net_rx_queue_update_kobjects(net, 0, real_rx);
        if (error)
                goto error;
        rxq = real_rx;

        error = netdev_queue_update_kobjects(net, 0, real_tx);
        if (error)
                goto error;
        txq = real_tx;

        return 0;

error:
        netdev_queue_update_kobjects(net, txq, 0);
        net_rx_queue_update_kobjects(net, rxq, 0);
        return error;
}

static void remove_queue_kobjects(struct net_device *net)
{
        int real_rx = 0, real_tx = 0;

#ifdef CONFIG_RPS
        real_rx = net->real_num_rx_queues;
#endif
        real_tx = net->real_num_tx_queues;

        net_rx_queue_update_kobjects(net, real_rx, 0);
        netdev_queue_update_kobjects(net, real_tx, 0);
#ifdef CONFIG_SYSFS
        kset_unregister(net->queues_kset);
#endif
}

static void *net_grab_current_ns(void)
{
        struct net *ns = current->nsproxy->net_ns;
#ifdef CONFIG_NET_NS
        if (ns)
                atomic_inc(&ns->passive);
#endif
        return ns;
}

static const void *net_initial_ns(void)
{
        return &init_net;
}

static const void *net_netlink_ns(struct sock *sk)
{
        return sock_net(sk);
}

struct kobj_ns_type_operations net_ns_type_operations = {
        .type = KOBJ_NS_TYPE_NET,
        .grab_current_ns = net_grab_current_ns,
        .netlink_ns = net_netlink_ns,
        .initial_ns = net_initial_ns,
        .drop_ns = net_drop_ns,
};
EXPORT_SYMBOL_GPL(net_ns_type_operations);

#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;

        /* 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 const void *net_namespace(struct device *d)
{
        struct net_device *dev;
        dev = container_of(d, struct net_device, dev);
        return dev_net(dev);
}

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
        .ns_type = &net_ns_type_operations,
        .namespace = net_namespace,
};

/* 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);

        remove_queue_kobjects(net);

        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;
        int error = 0;

        device_initialize(dev);
        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 */

        error = device_add(dev);
        if (error)
                return error;

        error = register_queue_kobjects(net);
        if (error) {
                device_del(dev);
                return error;
        }

        return error;
}

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

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

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