wext-proc.c

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/*
 * This file implement the Wireless Extensions proc API.
 *
 * Authors :    Jean Tourrilhes - HPL - <[email protected]>
 * Copyright (c) 1997-2007 Jean Tourrilhes, All Rights Reserved.
 *
 * (As all part of the Linux kernel, this file is GPL)
 */

/*
 * The /proc/net/wireless file is a human readable user-space interface
 * exporting various wireless specific statistics from the wireless devices.
 * This is the most popular part of the Wireless Extensions ;-)
 *
 * This interface is a pure clone of /proc/net/dev (in net/core/dev.c).
 * The content of the file is basically the content of "struct iw_statistics".
 */

#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/wireless.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <net/iw_handler.h>
#include <net/wext.h>


static void wireless_seq_printf_stats(struct seq_file *seq,
                      struct net_device *dev)
{
    /* Get stats from the driver */
    struct iw_statistics *stats = get_wireless_stats(dev);
    static struct iw_statistics nullstats = {};

    /* show device if it's wireless regardless of current stats */
    if (!stats) {
#ifdef CONFIG_WIRELESS_EXT
        if (dev->wireless_handlers)
            stats = &nullstats;
#endif
#ifdef CONFIG_CFG80211
        if (dev->ieee80211_ptr)
            stats = &nullstats;
#endif
    }

    if (stats) {
        seq_printf(seq, "%6s: %04x  %3d%c  %3d%c  %3d%c  %6d %6d %6d "
                "%6d %6d   %6d\n",
               dev->name, stats->status, stats->qual.qual,
               stats->qual.updated & IW_QUAL_QUAL_UPDATED
               ? '.' : ' ',
               ((__s32) stats->qual.level) -
               ((stats->qual.updated & IW_QUAL_DBM) ? 0x100 : 0),
               stats->qual.updated & IW_QUAL_LEVEL_UPDATED
               ? '.' : ' ',
               ((__s32) stats->qual.noise) -
               ((stats->qual.updated & IW_QUAL_DBM) ? 0x100 : 0),
               stats->qual.updated & IW_QUAL_NOISE_UPDATED
               ? '.' : ' ',
               stats->discard.nwid, stats->discard.code,
               stats->discard.fragment, stats->discard.retries,
               stats->discard.misc, stats->miss.beacon);

        if (stats != &nullstats)
            stats->qual.updated &= ~IW_QUAL_ALL_UPDATED;
    }
}

/* ---------------------------------------------------------------- */
/*
 * Print info for /proc/net/wireless (print all entries)
 */
static int wireless_dev_seq_show(struct seq_file *seq, void *v)
{
    might_sleep();

    if (v == SEQ_START_TOKEN)
        seq_printf(seq, "Inter-| sta-|   Quality        |   Discarded "
                "packets               | Missed | WE\n"
                " face | tus | link level noise |  nwid  "
                "crypt   frag  retry   misc | beacon | %d\n",
               WIRELESS_EXT);
    else
        wireless_seq_printf_stats(seq, v);
    return 0;
}

static void *wireless_dev_seq_start(struct seq_file *seq, loff_t *pos)
{
    struct net *net = seq_file_net(seq);
    loff_t off;
    struct net_device *dev;

    rtnl_lock();
    if (!*pos)
        return SEQ_START_TOKEN;

    off = 1;
    for_each_netdev(net, dev)
        if (off++ == *pos)
            return dev;
    return NULL;
}

static void *wireless_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
    struct net *net = seq_file_net(seq);

    ++*pos;

    return v == SEQ_START_TOKEN ?
        first_net_device(net) : next_net_device(v);
}

static void wireless_dev_seq_stop(struct seq_file *seq, void *v)
{
    rtnl_unlock();
}

static const struct seq_operations wireless_seq_ops = {
    .start = wireless_dev_seq_start,
    .next  = wireless_dev_seq_next,
    .stop  = wireless_dev_seq_stop,
    .show  = wireless_dev_seq_show,
};

static int seq_open_wireless(struct inode *inode, struct file *file)
{
    return seq_open_net(inode, file, &wireless_seq_ops,
                sizeof(struct seq_net_private));
}

static const struct file_operations wireless_seq_fops = {
    .owner   = THIS_MODULE,
    .open    = seq_open_wireless,
    .read    = seq_read,
    .llseek  = seq_lseek,
    .release = seq_release_net,
};

int __net_init wext_proc_init(struct net *net)
{
    /* Create /proc/net/wireless entry */
    if (!proc_net_fops_create(net, "wireless", S_IRUGO, &wireless_seq_fops))
        return -ENOMEM;

    return 0;
}

void __net_exit wext_proc_exit(struct net *net)
{
    proc_net_remove(net, "wireless");
}