Logo Search packages:      
Sourcecode: linux version File versions  Download package

wext.c

/*
 * This file implement the Wireless Extensions APIs.
 *
 * Authors :      Jean Tourrilhes - HPL - <jt@hpl.hp.com>
 * Copyright (c) 1997-2007 Jean Tourrilhes, All Rights Reserved.
 *
 * (As all part of the Linux kernel, this file is GPL)
 */

/************************** DOCUMENTATION **************************/
/*
 * API definition :
 * --------------
 * See <linux/wireless.h> for details of the APIs and the rest.
 *
 * History :
 * -------
 *
 * v1 - 5.12.01 - Jean II
 *    o Created this file.
 *
 * v2 - 13.12.01 - Jean II
 *    o Move /proc/net/wireless stuff from net/core/dev.c to here
 *    o Make Wireless Extension IOCTLs go through here
 *    o Added iw_handler handling ;-)
 *    o Added standard ioctl description
 *    o Initial dumb commit strategy based on orinoco.c
 *
 * v3 - 19.12.01 - Jean II
 *    o Make sure we don't go out of standard_ioctl[] in ioctl_standard_call
 *    o Add event dispatcher function
 *    o Add event description
 *    o Propagate events as rtnetlink IFLA_WIRELESS option
 *    o Generate event on selected SET requests
 *
 * v4 - 18.04.02 - Jean II
 *    o Fix stupid off by one in iw_ioctl_description : IW_ESSID_MAX_SIZE + 1
 *
 * v5 - 21.06.02 - Jean II
 *    o Add IW_PRIV_TYPE_ADDR in priv_type_size (+cleanup)
 *    o Reshuffle IW_HEADER_TYPE_XXX to map IW_PRIV_TYPE_XXX changes
 *    o Add IWEVCUSTOM for driver specific event/scanning token
 *    o Turn on WE_STRICT_WRITE by default + kernel warning
 *    o Fix WE_STRICT_WRITE in ioctl_export_private() (32 => iw_num)
 *    o Fix off-by-one in test (extra_size <= IFNAMSIZ)
 *
 * v6 - 9.01.03 - Jean II
 *    o Add common spy support : iw_handler_set_spy(), wireless_spy_update()
 *    o Add enhanced spy support : iw_handler_set_thrspy() and event.
 *    o Add WIRELESS_EXT version display in /proc/net/wireless
 *
 * v6 - 18.06.04 - Jean II
 *    o Change get_spydata() method for added safety
 *    o Remove spy #ifdef, they are always on -> cleaner code
 *    o Allow any size GET request if user specifies length > max
 *          and if request has IW_DESCR_FLAG_NOMAX flag or is SIOCGIWPRIV
 *    o Start migrating get_wireless_stats to struct iw_handler_def
 *    o Add wmb() in iw_handler_set_spy() for non-coherent archs/cpus
 * Based on patch from Pavel Roskin <proski@gnu.org> :
 *    o Fix kernel data leak to user space in private handler handling
 *
 * v7 - 18.3.05 - Jean II
 *    o Remove (struct iw_point *)->pointer from events and streams
 *    o Remove spy_offset from struct iw_handler_def
 *    o Start deprecating dev->get_wireless_stats, output a warning
 *    o If IW_QUAL_DBM is set, show dBm values in /proc/net/wireless
 *    o Don't loose INVALID/DBM flags when clearing UPDATED flags (iwstats)
 *
 * v8 - 17.02.06 - Jean II
 *    o RtNetlink requests support (SET/GET)
 *
 * v8b - 03.08.06 - Herbert Xu
 *    o Fix Wireless Event locking issues.
 *
 * v9 - 14.3.06 - Jean II
 *    o Change length in ESSID and NICK to strlen() instead of strlen()+1
 *    o Make standard_ioctl_num and standard_event_num unsigned
 *    o Remove (struct net_device *)->get_wireless_stats()
 *
 * v10 - 16.3.07 - Jean II
 *    o Prevent leaking of kernel space in stream on 64 bits.
 */

/***************************** INCLUDES *****************************/

#include <linux/module.h>
#include <linux/types.h>            /* off_t */
#include <linux/netdevice.h>        /* struct ifreq, dev_get_by_name() */
#include <linux/proc_fs.h>
#include <linux/rtnetlink.h>        /* rtnetlink stuff */
#include <linux/seq_file.h>
#include <linux/init.h>             /* for __init */
#include <linux/if_arp.h>           /* ARPHRD_ETHER */
#include <linux/etherdevice.h>            /* compare_ether_addr */
#include <linux/interrupt.h>
#include <net/net_namespace.h>

#include <linux/wireless.h>         /* Pretty obvious */
#include <net/iw_handler.h>         /* New driver API */
#include <net/netlink.h>
#include <net/wext.h>

#include <asm/uaccess.h>            /* copy_to_user() */

/************************* GLOBAL VARIABLES *************************/
/*
 * You should not use global variables, because of re-entrancy.
 * On our case, it's only const, so it's OK...
 */
/*
 * Meta-data about all the standard Wireless Extension request we
 * know about.
 */
static const struct iw_ioctl_description standard_ioctl[] = {
      [SIOCSIWCOMMIT    - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_NULL,
      },
      [SIOCGIWNAME      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_CHAR,
            .flags            = IW_DESCR_FLAG_DUMP,
      },
      [SIOCSIWNWID      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
            .flags            = IW_DESCR_FLAG_EVENT,
      },
      [SIOCGIWNWID      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
            .flags            = IW_DESCR_FLAG_DUMP,
      },
      [SIOCSIWFREQ      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_FREQ,
            .flags            = IW_DESCR_FLAG_EVENT,
      },
      [SIOCGIWFREQ      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_FREQ,
            .flags            = IW_DESCR_FLAG_DUMP,
      },
      [SIOCSIWMODE      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_UINT,
            .flags            = IW_DESCR_FLAG_EVENT,
      },
      [SIOCGIWMODE      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_UINT,
            .flags            = IW_DESCR_FLAG_DUMP,
      },
      [SIOCSIWSENS      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
      },
      [SIOCGIWSENS      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
      },
      [SIOCSIWRANGE     - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_NULL,
      },
      [SIOCGIWRANGE     - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = sizeof(struct iw_range),
            .flags            = IW_DESCR_FLAG_DUMP,
      },
      [SIOCSIWPRIV      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_NULL,
      },
      [SIOCGIWPRIV      - SIOCIWFIRST] = { /* (handled directly by us) */
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = sizeof(struct iw_priv_args),
            .max_tokens = 16,
            .flags            = IW_DESCR_FLAG_NOMAX,
      },
      [SIOCSIWSTATS     - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_NULL,
      },
      [SIOCGIWSTATS     - SIOCIWFIRST] = { /* (handled directly by us) */
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = sizeof(struct iw_statistics),
            .flags            = IW_DESCR_FLAG_DUMP,
      },
      [SIOCSIWSPY - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = sizeof(struct sockaddr),
            .max_tokens = IW_MAX_SPY,
      },
      [SIOCGIWSPY - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = sizeof(struct sockaddr) +
                          sizeof(struct iw_quality),
            .max_tokens = IW_MAX_SPY,
      },
      [SIOCSIWTHRSPY    - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = sizeof(struct iw_thrspy),
            .min_tokens = 1,
            .max_tokens = 1,
      },
      [SIOCGIWTHRSPY    - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = sizeof(struct iw_thrspy),
            .min_tokens = 1,
            .max_tokens = 1,
      },
      [SIOCSIWAP  - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_ADDR,
      },
      [SIOCGIWAP  - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_ADDR,
            .flags            = IW_DESCR_FLAG_DUMP,
      },
      [SIOCSIWMLME      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .min_tokens = sizeof(struct iw_mlme),
            .max_tokens = sizeof(struct iw_mlme),
      },
      [SIOCGIWAPLIST    - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = sizeof(struct sockaddr) +
                          sizeof(struct iw_quality),
            .max_tokens = IW_MAX_AP,
            .flags            = IW_DESCR_FLAG_NOMAX,
      },
      [SIOCSIWSCAN      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .min_tokens = 0,
            .max_tokens = sizeof(struct iw_scan_req),
      },
      [SIOCGIWSCAN      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = IW_SCAN_MAX_DATA,
            .flags            = IW_DESCR_FLAG_NOMAX,
      },
      [SIOCSIWESSID     - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = IW_ESSID_MAX_SIZE,
            .flags            = IW_DESCR_FLAG_EVENT,
      },
      [SIOCGIWESSID     - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = IW_ESSID_MAX_SIZE,
            .flags            = IW_DESCR_FLAG_DUMP,
      },
      [SIOCSIWNICKN     - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = IW_ESSID_MAX_SIZE,
      },
      [SIOCGIWNICKN     - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = IW_ESSID_MAX_SIZE,
      },
      [SIOCSIWRATE      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
      },
      [SIOCGIWRATE      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
      },
      [SIOCSIWRTS - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
      },
      [SIOCGIWRTS - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
      },
      [SIOCSIWFRAG      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
      },
      [SIOCGIWFRAG      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
      },
      [SIOCSIWTXPOW     - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
      },
      [SIOCGIWTXPOW     - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
      },
      [SIOCSIWRETRY     - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
      },
      [SIOCGIWRETRY     - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
      },
      [SIOCSIWENCODE    - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = IW_ENCODING_TOKEN_MAX,
            .flags            = IW_DESCR_FLAG_EVENT | IW_DESCR_FLAG_RESTRICT,
      },
      [SIOCGIWENCODE    - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = IW_ENCODING_TOKEN_MAX,
            .flags            = IW_DESCR_FLAG_DUMP | IW_DESCR_FLAG_RESTRICT,
      },
      [SIOCSIWPOWER     - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
      },
      [SIOCGIWPOWER     - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
      },
      [SIOCSIWGENIE     - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = IW_GENERIC_IE_MAX,
      },
      [SIOCGIWGENIE     - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = IW_GENERIC_IE_MAX,
      },
      [SIOCSIWAUTH      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
      },
      [SIOCGIWAUTH      - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_PARAM,
      },
      [SIOCSIWENCODEEXT - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .min_tokens = sizeof(struct iw_encode_ext),
            .max_tokens = sizeof(struct iw_encode_ext) +
                          IW_ENCODING_TOKEN_MAX,
      },
      [SIOCGIWENCODEEXT - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .min_tokens = sizeof(struct iw_encode_ext),
            .max_tokens = sizeof(struct iw_encode_ext) +
                          IW_ENCODING_TOKEN_MAX,
      },
      [SIOCSIWPMKSA - SIOCIWFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .min_tokens = sizeof(struct iw_pmksa),
            .max_tokens = sizeof(struct iw_pmksa),
      },
};
static const unsigned standard_ioctl_num = ARRAY_SIZE(standard_ioctl);

/*
 * Meta-data about all the additional standard Wireless Extension events
 * we know about.
 */
static const struct iw_ioctl_description standard_event[] = {
      [IWEVTXDROP - IWEVFIRST] = {
            .header_type      = IW_HEADER_TYPE_ADDR,
      },
      [IWEVQUAL   - IWEVFIRST] = {
            .header_type      = IW_HEADER_TYPE_QUAL,
      },
      [IWEVCUSTOM - IWEVFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = IW_CUSTOM_MAX,
      },
      [IWEVREGISTERED   - IWEVFIRST] = {
            .header_type      = IW_HEADER_TYPE_ADDR,
      },
      [IWEVEXPIRED      - IWEVFIRST] = {
            .header_type      = IW_HEADER_TYPE_ADDR,
      },
      [IWEVGENIE  - IWEVFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = IW_GENERIC_IE_MAX,
      },
      [IWEVMICHAELMICFAILURE  - IWEVFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = sizeof(struct iw_michaelmicfailure),
      },
      [IWEVASSOCREQIE   - IWEVFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = IW_GENERIC_IE_MAX,
      },
      [IWEVASSOCRESPIE  - IWEVFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = IW_GENERIC_IE_MAX,
      },
      [IWEVPMKIDCAND    - IWEVFIRST] = {
            .header_type      = IW_HEADER_TYPE_POINT,
            .token_size = 1,
            .max_tokens = sizeof(struct iw_pmkid_cand),
      },
};
static const unsigned standard_event_num = ARRAY_SIZE(standard_event);

/* Size (in bytes) of the various private data types */
static const char iw_priv_type_size[] = {
      0,                      /* IW_PRIV_TYPE_NONE */
      1,                      /* IW_PRIV_TYPE_BYTE */
      1,                      /* IW_PRIV_TYPE_CHAR */
      0,                      /* Not defined */
      sizeof(__u32),                /* IW_PRIV_TYPE_INT */
      sizeof(struct iw_freq),       /* IW_PRIV_TYPE_FLOAT */
      sizeof(struct sockaddr),      /* IW_PRIV_TYPE_ADDR */
      0,                      /* Not defined */
};

/* Size (in bytes) of various events */
static const int event_type_size[] = {
      IW_EV_LCP_LEN,                /* IW_HEADER_TYPE_NULL */
      0,
      IW_EV_CHAR_LEN,               /* IW_HEADER_TYPE_CHAR */
      0,
      IW_EV_UINT_LEN,               /* IW_HEADER_TYPE_UINT */
      IW_EV_FREQ_LEN,               /* IW_HEADER_TYPE_FREQ */
      IW_EV_ADDR_LEN,               /* IW_HEADER_TYPE_ADDR */
      0,
      IW_EV_POINT_LEN,        /* Without variable payload */
      IW_EV_PARAM_LEN,        /* IW_HEADER_TYPE_PARAM */
      IW_EV_QUAL_LEN,               /* IW_HEADER_TYPE_QUAL */
};

/* Size (in bytes) of various events, as packed */
static const int event_type_pk_size[] = {
      IW_EV_LCP_PK_LEN,       /* IW_HEADER_TYPE_NULL */
      0,
      IW_EV_CHAR_PK_LEN,            /* IW_HEADER_TYPE_CHAR */
      0,
      IW_EV_UINT_PK_LEN,            /* IW_HEADER_TYPE_UINT */
      IW_EV_FREQ_PK_LEN,            /* IW_HEADER_TYPE_FREQ */
      IW_EV_ADDR_PK_LEN,            /* IW_HEADER_TYPE_ADDR */
      0,
      IW_EV_POINT_PK_LEN,           /* Without variable payload */
      IW_EV_PARAM_PK_LEN,           /* IW_HEADER_TYPE_PARAM */
      IW_EV_QUAL_PK_LEN,            /* IW_HEADER_TYPE_QUAL */
};

/************************ COMMON SUBROUTINES ************************/
/*
 * Stuff that may be used in various place or doesn't fit in one
 * of the section below.
 */

/* ---------------------------------------------------------------- */
/*
 * Return the driver handler associated with a specific Wireless Extension.
 */
static iw_handler get_handler(struct net_device *dev, unsigned int cmd)
{
      /* Don't "optimise" the following variable, it will crash */
      unsigned int      index;            /* *MUST* be unsigned */

      /* Check if we have some wireless handlers defined */
      if (dev->wireless_handlers == NULL)
            return NULL;

      /* Try as a standard command */
      index = cmd - SIOCIWFIRST;
      if (index < dev->wireless_handlers->num_standard)
            return dev->wireless_handlers->standard[index];

      /* Try as a private command */
      index = cmd - SIOCIWFIRSTPRIV;
      if (index < dev->wireless_handlers->num_private)
            return dev->wireless_handlers->private[index];

      /* Not found */
      return NULL;
}

/* ---------------------------------------------------------------- */
/*
 * Get statistics out of the driver
 */
static struct iw_statistics *get_wireless_stats(struct net_device *dev)
{
      /* New location */
      if ((dev->wireless_handlers != NULL) &&
         (dev->wireless_handlers->get_wireless_stats != NULL))
            return dev->wireless_handlers->get_wireless_stats(dev);

      /* Not found */
      return NULL;
}

/* ---------------------------------------------------------------- */
/*
 * Call the commit handler in the driver
 * (if exist and if conditions are right)
 *
 * Note : our current commit strategy is currently pretty dumb,
 * but we will be able to improve on that...
 * The goal is to try to agreagate as many changes as possible
 * before doing the commit. Drivers that will define a commit handler
 * are usually those that need a reset after changing parameters, so
 * we want to minimise the number of reset.
 * A cool idea is to use a timer : at each "set" command, we re-set the
 * timer, when the timer eventually fires, we call the driver.
 * Hopefully, more on that later.
 *
 * Also, I'm waiting to see how many people will complain about the
 * netif_running(dev) test. I'm open on that one...
 * Hopefully, the driver will remember to do a commit in "open()" ;-)
 */
static int call_commit_handler(struct net_device *dev)
{
      if ((netif_running(dev)) &&
         (dev->wireless_handlers->standard[0] != NULL))
            /* Call the commit handler on the driver */
            return dev->wireless_handlers->standard[0](dev, NULL,
                                             NULL, NULL);
      else
            return 0;         /* Command completed successfully */
}

/* ---------------------------------------------------------------- */
/*
 * Calculate size of private arguments
 */
static inline int get_priv_size(__u16     args)
{
      int   num = args & IW_PRIV_SIZE_MASK;
      int   type = (args & IW_PRIV_TYPE_MASK) >> 12;

      return num * iw_priv_type_size[type];
}

/* ---------------------------------------------------------------- */
/*
 * Re-calculate the size of private arguments
 */
static inline int adjust_priv_size(__u16        args,
                           union iwreq_data *   wrqu)
{
      int   num = wrqu->data.length;
      int   max = args & IW_PRIV_SIZE_MASK;
      int   type = (args & IW_PRIV_TYPE_MASK) >> 12;

      /* Make sure the driver doesn't goof up */
      if (max < num)
            num = max;

      return num * iw_priv_type_size[type];
}

/* ---------------------------------------------------------------- */
/*
 * Standard Wireless Handler : get wireless stats
 *    Allow programatic access to /proc/net/wireless even if /proc
 *    doesn't exist... Also more efficient...
 */
static int iw_handler_get_iwstats(struct net_device *       dev,
                          struct iw_request_info *    info,
                          union iwreq_data *          wrqu,
                          char *                extra)
{
      /* Get stats from the driver */
      struct iw_statistics *stats;

      stats = get_wireless_stats(dev);
      if (stats) {
            /* Copy statistics to extra */
            memcpy(extra, stats, sizeof(struct iw_statistics));
            wrqu->data.length = sizeof(struct iw_statistics);

            /* Check if we need to clear the updated flag */
            if (wrqu->data.flags != 0)
                  stats->qual.updated &= ~IW_QUAL_ALL_UPDATED;
            return 0;
      } else
            return -EOPNOTSUPP;
}

/* ---------------------------------------------------------------- */
/*
 * Standard Wireless Handler : get iwpriv definitions
 * Export the driver private handler definition
 * They will be picked up by tools like iwpriv...
 */
static int iw_handler_get_private(struct net_device *       dev,
                          struct iw_request_info *    info,
                          union iwreq_data *          wrqu,
                          char *                extra)
{
      /* Check if the driver has something to export */
      if ((dev->wireless_handlers->num_private_args == 0) ||
         (dev->wireless_handlers->private_args == NULL))
            return -EOPNOTSUPP;

      /* Check if there is enough buffer up there */
      if (wrqu->data.length < dev->wireless_handlers->num_private_args) {
            /* User space can't know in advance how large the buffer
             * needs to be. Give it a hint, so that we can support
             * any size buffer we want somewhat efficiently... */
            wrqu->data.length = dev->wireless_handlers->num_private_args;
            return -E2BIG;
      }

      /* Set the number of available ioctls. */
      wrqu->data.length = dev->wireless_handlers->num_private_args;

      /* Copy structure to the user buffer. */
      memcpy(extra, dev->wireless_handlers->private_args,
             sizeof(struct iw_priv_args) * wrqu->data.length);

      return 0;
}


/******************** /proc/net/wireless SUPPORT ********************/
/*
 * 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".
 */

#ifdef CONFIG_PROC_FS

/* ---------------------------------------------------------------- */
/*
 * Print one entry (line) of /proc/net/wireless
 */
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);

      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);
            stats->qual.updated &= ~IW_QUAL_ALL_UPDATED;
      }
}

/* ---------------------------------------------------------------- */
/*
 * Print info for /proc/net/wireless (print all entries)
 */
static int wireless_seq_show(struct seq_file *seq, void *v)
{
      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 const struct seq_operations wireless_seq_ops = {
      .start = dev_seq_start,
      .next  = dev_seq_next,
      .stop  = dev_seq_stop,
      .show  = wireless_seq_show,
};

static int wireless_seq_open(struct inode *inode, struct file *file)
{
      struct seq_file *seq;
      int res;
      res = seq_open(file, &wireless_seq_ops);
      if (!res) {
            seq = file->private_data;
            seq->private = get_proc_net(inode);
            if (!seq->private) {
                  seq_release(inode, file);
                  res = -ENXIO;
            }
      }
      return res;
}

static int wireless_seq_release(struct inode *inode, struct file *file)
{
      struct seq_file *seq = file->private_data;
      struct net *net = seq->private;
      put_net(net);
      return seq_release(inode, file);
}

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

int 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 wext_proc_exit(struct net *net)
{
      proc_net_remove(net, "wireless");
}
#endif      /* CONFIG_PROC_FS */

/************************** IOCTL SUPPORT **************************/
/*
 * The original user space API to configure all those Wireless Extensions
 * is through IOCTLs.
 * In there, we check if we need to call the new driver API (iw_handler)
 * or just call the driver ioctl handler.
 */

/* ---------------------------------------------------------------- */
/*
 * Wrapper to call a standard Wireless Extension handler.
 * We do various checks and also take care of moving data between
 * user space and kernel space.
 */
static int ioctl_standard_call(struct net_device *    dev,
                         struct ifreq *         ifr,
                         unsigned int           cmd,
                         iw_handler       handler)
{
      struct iwreq *                      iwr = (struct iwreq *) ifr;
      const struct iw_ioctl_description * descr;
      struct iw_request_info              info;
      int                           ret = -EINVAL;

      /* Get the description of the IOCTL */
      if ((cmd - SIOCIWFIRST) >= standard_ioctl_num)
            return -EOPNOTSUPP;
      descr = &(standard_ioctl[cmd - SIOCIWFIRST]);

      /* Prepare the call */
      info.cmd = cmd;
      info.flags = 0;

      /* Check if we have a pointer to user space data or not */
      if (descr->header_type != IW_HEADER_TYPE_POINT) {

            /* No extra arguments. Trivial to handle */
            ret = handler(dev, &info, &(iwr->u), NULL);

            /* Generate an event to notify listeners of the change */
            if ((descr->flags & IW_DESCR_FLAG_EVENT) &&
               ((ret == 0) || (ret == -EIWCOMMIT)))
                  wireless_send_event(dev, cmd, &(iwr->u), NULL);
      } else {
            char *      extra;
            int   extra_size;
            int   user_length = 0;
            int   err;
            int   essid_compat = 0;

            /* Calculate space needed by arguments. Always allocate
             * for max space. Easier, and won't last long... */
            extra_size = descr->max_tokens * descr->token_size;

            /* Check need for ESSID compatibility for WE < 21 */
            switch (cmd) {
            case SIOCSIWESSID:
            case SIOCGIWESSID:
            case SIOCSIWNICKN:
            case SIOCGIWNICKN:
                  if (iwr->u.data.length == descr->max_tokens + 1)
                        essid_compat = 1;
                  else if (IW_IS_SET(cmd) && (iwr->u.data.length != 0)) {
                        char essid[IW_ESSID_MAX_SIZE + 1];

                        err = copy_from_user(essid, iwr->u.data.pointer,
                                         iwr->u.data.length *
                                         descr->token_size);
                        if (err)
                              return -EFAULT;

                        if (essid[iwr->u.data.length - 1] == '\0')
                              essid_compat = 1;
                  }
                  break;
            default:
                  break;
            }

            iwr->u.data.length -= essid_compat;

            /* Check what user space is giving us */
            if (IW_IS_SET(cmd)) {
                  /* Check NULL pointer */
                  if ((iwr->u.data.pointer == NULL) &&
                     (iwr->u.data.length != 0))
                        return -EFAULT;
                  /* Check if number of token fits within bounds */
                  if (iwr->u.data.length > descr->max_tokens)
                        return -E2BIG;
                  if (iwr->u.data.length < descr->min_tokens)
                        return -EINVAL;
            } else {
                  /* Check NULL pointer */
                  if (iwr->u.data.pointer == NULL)
                        return -EFAULT;
                  /* Save user space buffer size for checking */
                  user_length = iwr->u.data.length;

                  /* Don't check if user_length > max to allow forward
                   * compatibility. The test user_length < min is
                   * implied by the test at the end. */

                  /* Support for very large requests */
                  if ((descr->flags & IW_DESCR_FLAG_NOMAX) &&
                     (user_length > descr->max_tokens)) {
                        /* Allow userspace to GET more than max so
                         * we can support any size GET requests.
                         * There is still a limit : -ENOMEM. */
                        extra_size = user_length * descr->token_size;
                        /* Note : user_length is originally a __u16,
                         * and token_size is controlled by us,
                         * so extra_size won't get negative and
                         * won't overflow... */
                  }
            }

            /* Create the kernel buffer */
            /*    kzalloc ensures NULL-termination for essid_compat */
            extra = kzalloc(extra_size, GFP_KERNEL);
            if (extra == NULL)
                  return -ENOMEM;

            /* If it is a SET, get all the extra data in here */
            if (IW_IS_SET(cmd) && (iwr->u.data.length != 0)) {
                  err = copy_from_user(extra, iwr->u.data.pointer,
                                   iwr->u.data.length *
                                   descr->token_size);
                  if (err) {
                        kfree(extra);
                        return -EFAULT;
                  }
            }

            /* Call the handler */
            ret = handler(dev, &info, &(iwr->u), extra);

            iwr->u.data.length += essid_compat;

            /* If we have something to return to the user */
            if (!ret && IW_IS_GET(cmd)) {
                  /* Check if there is enough buffer up there */
                  if (user_length < iwr->u.data.length) {
                        kfree(extra);
                        return -E2BIG;
                  }

                  err = copy_to_user(iwr->u.data.pointer, extra,
                                 iwr->u.data.length *
                                 descr->token_size);
                  if (err)
                        ret =  -EFAULT;
            }

            /* Generate an event to notify listeners of the change */
            if ((descr->flags & IW_DESCR_FLAG_EVENT) &&
               ((ret == 0) || (ret == -EIWCOMMIT))) {
                  if (descr->flags & IW_DESCR_FLAG_RESTRICT)
                        /* If the event is restricted, don't
                         * export the payload */
                        wireless_send_event(dev, cmd, &(iwr->u), NULL);
                  else
                        wireless_send_event(dev, cmd, &(iwr->u),
                                        extra);
            }

            /* Cleanup - I told you it wasn't that long ;-) */
            kfree(extra);
      }

      /* Call commit handler if needed and defined */
      if (ret == -EIWCOMMIT)
            ret = call_commit_handler(dev);

      /* Here, we will generate the appropriate event if needed */

      return ret;
}

/* ---------------------------------------------------------------- */
/*
 * Wrapper to call a private Wireless Extension handler.
 * We do various checks and also take care of moving data between
 * user space and kernel space.
 * It's not as nice and slimline as the standard wrapper. The cause
 * is struct iw_priv_args, which was not really designed for the
 * job we are going here.
 *
 * IMPORTANT : This function prevent to set and get data on the same
 * IOCTL and enforce the SET/GET convention. Not doing it would be
 * far too hairy...
 * If you need to set and get data at the same time, please don't use
 * a iw_handler but process it in your ioctl handler (i.e. use the
 * old driver API).
 */
static int ioctl_private_call(struct net_device *dev, struct ifreq *ifr,
                        unsigned int cmd, iw_handler handler)
{
      struct iwreq *                iwr = (struct iwreq *) ifr;
      const struct iw_priv_args *   descr = NULL;
      struct iw_request_info        info;
      int                     extra_size = 0;
      int                     i;
      int                     ret = -EINVAL;

      /* Get the description of the IOCTL */
      for (i = 0; i < dev->wireless_handlers->num_private_args; i++)
            if (cmd == dev->wireless_handlers->private_args[i].cmd) {
                  descr = &(dev->wireless_handlers->private_args[i]);
                  break;
            }

      /* Compute the size of the set/get arguments */
      if (descr != NULL) {
            if (IW_IS_SET(cmd)) {
                  int   offset = 0; /* For sub-ioctls */
                  /* Check for sub-ioctl handler */
                  if (descr->name[0] == '\0')
                        /* Reserve one int for sub-ioctl index */
                        offset = sizeof(__u32);

                  /* Size of set arguments */
                  extra_size = get_priv_size(descr->set_args);

                  /* Does it fits in iwr ? */
                  if ((descr->set_args & IW_PRIV_SIZE_FIXED) &&
                     ((extra_size + offset) <= IFNAMSIZ))
                        extra_size = 0;
            } else {
                  /* Size of get arguments */
                  extra_size = get_priv_size(descr->get_args);

                  /* Does it fits in iwr ? */
                  if ((descr->get_args & IW_PRIV_SIZE_FIXED) &&
                     (extra_size <= IFNAMSIZ))
                        extra_size = 0;
            }
      }

      /* Prepare the call */
      info.cmd = cmd;
      info.flags = 0;

      /* Check if we have a pointer to user space data or not. */
      if (extra_size == 0) {
            /* No extra arguments. Trivial to handle */
            ret = handler(dev, &info, &(iwr->u), (char *) &(iwr->u));
      } else {
            char *      extra;
            int   err;

            /* Check what user space is giving us */
            if (IW_IS_SET(cmd)) {
                  /* Check NULL pointer */
                  if ((iwr->u.data.pointer == NULL) &&
                     (iwr->u.data.length != 0))
                        return -EFAULT;

                  /* Does it fits within bounds ? */
                  if (iwr->u.data.length > (descr->set_args &
                                     IW_PRIV_SIZE_MASK))
                        return -E2BIG;
            } else if (iwr->u.data.pointer == NULL)
                  return -EFAULT;

            /* Always allocate for max space. Easier, and won't last
             * long... */
            extra = kmalloc(extra_size, GFP_KERNEL);
            if (extra == NULL)
                  return -ENOMEM;

            /* If it is a SET, get all the extra data in here */
            if (IW_IS_SET(cmd) && (iwr->u.data.length != 0)) {
                  err = copy_from_user(extra, iwr->u.data.pointer,
                                   extra_size);
                  if (err) {
                        kfree(extra);
                        return -EFAULT;
                  }
            }

            /* Call the handler */
            ret = handler(dev, &info, &(iwr->u), extra);

            /* If we have something to return to the user */
            if (!ret && IW_IS_GET(cmd)) {

                  /* Adjust for the actual length if it's variable,
                   * avoid leaking kernel bits outside. */
                  if (!(descr->get_args & IW_PRIV_SIZE_FIXED)) {
                        extra_size = adjust_priv_size(descr->get_args,
                                                &(iwr->u));
                  }

                  err = copy_to_user(iwr->u.data.pointer, extra,
                                 extra_size);
                  if (err)
                        ret =  -EFAULT;
            }

            /* Cleanup - I told you it wasn't that long ;-) */
            kfree(extra);
      }


      /* Call commit handler if needed and defined */
      if (ret == -EIWCOMMIT)
            ret = call_commit_handler(dev);

      return ret;
}

/* ---------------------------------------------------------------- */
/*
 * Main IOCTl dispatcher.
 * Check the type of IOCTL and call the appropriate wrapper...
 */
static int wireless_process_ioctl(struct net *net, struct ifreq *ifr, unsigned int cmd)
{
      struct net_device *dev;
      iw_handler  handler;

      /* Permissions are already checked in dev_ioctl() before calling us.
       * The copy_to/from_user() of ifr is also dealt with in there */

      /* Make sure the device exist */
      if ((dev = __dev_get_by_name(net, ifr->ifr_name)) == NULL)
            return -ENODEV;

      /* A bunch of special cases, then the generic case...
       * Note that 'cmd' is already filtered in dev_ioctl() with
       * (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) */
      if (cmd == SIOCGIWSTATS)
            return ioctl_standard_call(dev, ifr, cmd,
                                 &iw_handler_get_iwstats);

      if (cmd == SIOCGIWPRIV && dev->wireless_handlers)
            return ioctl_standard_call(dev, ifr, cmd,
                                 &iw_handler_get_private);

      /* Basic check */
      if (!netif_device_present(dev))
            return -ENODEV;

      /* New driver API : try to find the handler */
      handler = get_handler(dev, cmd);
      if (handler) {
            /* Standard and private are not the same */
            if (cmd < SIOCIWFIRSTPRIV)
                  return ioctl_standard_call(dev, ifr, cmd, handler);
            else
                  return ioctl_private_call(dev, ifr, cmd, handler);
      }
      /* Old driver API : call driver ioctl handler */
      if (dev->do_ioctl)
            return dev->do_ioctl(dev, ifr, cmd);
      return -EOPNOTSUPP;
}

/* entry point from dev ioctl */
int wext_handle_ioctl(struct net *net, struct ifreq *ifr, unsigned int cmd,
                  void __user *arg)
{
      int ret;

      /* If command is `set a parameter', or
       * `get the encoding parameters', check if
       * the user has the right to do it */
      if ((IW_IS_SET(cmd) || cmd == SIOCGIWENCODE || cmd == SIOCGIWENCODEEXT)
          && !capable(CAP_NET_ADMIN))
            return -EPERM;

      dev_load(net, ifr->ifr_name);
      rtnl_lock();
      ret = wireless_process_ioctl(net, ifr, cmd);
      rtnl_unlock();
      if (IW_IS_GET(cmd) && copy_to_user(arg, ifr, sizeof(struct iwreq)))
            return -EFAULT;
      return ret;
}

/************************* EVENT PROCESSING *************************/
/*
 * Process events generated by the wireless layer or the driver.
 * Most often, the event will be propagated through rtnetlink
 */

/* ---------------------------------------------------------------- */
/*
 * Locking...
 * ----------
 *
 * Thanks to Herbert Xu <herbert@gondor.apana.org.au> for fixing
 * the locking issue in here and implementing this code !
 *
 * The issue : wireless_send_event() is often called in interrupt context,
 * while the Netlink layer can never be called in interrupt context.
 * The fully formed RtNetlink events are queued, and then a tasklet is run
 * to feed those to Netlink.
 * The skb_queue is interrupt safe, and its lock is not held while calling
 * Netlink, so there is no possibility of dealock.
 * Jean II
 */

static struct sk_buff_head wireless_nlevent_queue;

static int __init wireless_nlevent_init(void)
{
      skb_queue_head_init(&wireless_nlevent_queue);
      return 0;
}

subsys_initcall(wireless_nlevent_init);

static void wireless_nlevent_process(unsigned long data)
{
      struct sk_buff *skb;

      while ((skb = skb_dequeue(&wireless_nlevent_queue)))
            rtnl_notify(skb, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC);
}

static DECLARE_TASKLET(wireless_nlevent_tasklet, wireless_nlevent_process, 0);

/* ---------------------------------------------------------------- */
/*
 * Fill a rtnetlink message with our event data.
 * Note that we propage only the specified event and don't dump the
 * current wireless config. Dumping the wireless config is far too
 * expensive (for each parameter, the driver need to query the hardware).
 */
static int rtnetlink_fill_iwinfo(struct sk_buff *skb, struct net_device *dev,
                         int type, char *event, int event_len)
{
      struct ifinfomsg *r;
      struct nlmsghdr  *nlh;

      nlh = nlmsg_put(skb, 0, 0, type, sizeof(*r), 0);
      if (nlh == NULL)
            return -EMSGSIZE;

      r = nlmsg_data(nlh);
      r->ifi_family = AF_UNSPEC;
      r->__ifi_pad = 0;
      r->ifi_type = dev->type;
      r->ifi_index = dev->ifindex;
      r->ifi_flags = dev_get_flags(dev);
      r->ifi_change = 0;      /* Wireless changes don't affect those flags */

      /* Add the wireless events in the netlink packet */
      NLA_PUT(skb, IFLA_WIRELESS, event_len, event);

      return nlmsg_end(skb, nlh);

nla_put_failure:
      nlmsg_cancel(skb, nlh);
      return -EMSGSIZE;
}

/* ---------------------------------------------------------------- */
/*
 * Create and broadcast and send it on the standard rtnetlink socket
 * This is a pure clone rtmsg_ifinfo() in net/core/rtnetlink.c
 * Andrzej Krzysztofowicz mandated that I used a IFLA_XXX field
 * within a RTM_NEWLINK event.
 */
static void rtmsg_iwinfo(struct net_device *dev, char *event, int event_len)
{
      struct sk_buff *skb;
      int err;

      skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
      if (!skb)
            return;

      err = rtnetlink_fill_iwinfo(skb, dev, RTM_NEWLINK, event, event_len);
      if (err < 0) {
            WARN_ON(err == -EMSGSIZE);
            kfree_skb(skb);
            return;
      }

      NETLINK_CB(skb).dst_group = RTNLGRP_LINK;
      skb_queue_tail(&wireless_nlevent_queue, skb);
      tasklet_schedule(&wireless_nlevent_tasklet);
}

/* ---------------------------------------------------------------- */
/*
 * Main event dispatcher. Called from other parts and drivers.
 * Send the event on the appropriate channels.
 * May be called from interrupt context.
 */
void wireless_send_event(struct net_device *    dev,
                   unsigned int           cmd,
                   union iwreq_data *     wrqu,
                   char *                 extra)
{
      const struct iw_ioctl_description * descr = NULL;
      int extra_len = 0;
      struct iw_event  *event;            /* Mallocated whole event */
      int event_len;                      /* Its size */
      int hdr_len;                        /* Size of the event header */
      int wrqu_off = 0;             /* Offset in wrqu */
      /* Don't "optimise" the following variable, it will crash */
      unsigned    cmd_index;        /* *MUST* be unsigned */

      /* Get the description of the Event */
      if (cmd <= SIOCIWLAST) {
            cmd_index = cmd - SIOCIWFIRST;
            if (cmd_index < standard_ioctl_num)
                  descr = &(standard_ioctl[cmd_index]);
      } else {
            cmd_index = cmd - IWEVFIRST;
            if (cmd_index < standard_event_num)
                  descr = &(standard_event[cmd_index]);
      }
      /* Don't accept unknown events */
      if (descr == NULL) {
            /* Note : we don't return an error to the driver, because
             * the driver would not know what to do about it. It can't
             * return an error to the user, because the event is not
             * initiated by a user request.
             * The best the driver could do is to log an error message.
             * We will do it ourselves instead...
             */
            printk(KERN_ERR "%s (WE) : Invalid/Unknown Wireless Event (0x%04X)\n",
                   dev->name, cmd);
            return;
      }

      /* Check extra parameters and set extra_len */
      if (descr->header_type == IW_HEADER_TYPE_POINT) {
            /* Check if number of token fits within bounds */
            if (wrqu->data.length > descr->max_tokens) {
                  printk(KERN_ERR "%s (WE) : Wireless Event too big (%d)\n", dev->name, wrqu->data.length);
                  return;
            }
            if (wrqu->data.length < descr->min_tokens) {
                  printk(KERN_ERR "%s (WE) : Wireless Event too small (%d)\n", dev->name, wrqu->data.length);
                  return;
            }
            /* Calculate extra_len - extra is NULL for restricted events */
            if (extra != NULL)
                  extra_len = wrqu->data.length * descr->token_size;
            /* Always at an offset in wrqu */
            wrqu_off = IW_EV_POINT_OFF;
      }

      /* Total length of the event */
      hdr_len = event_type_size[descr->header_type];
      event_len = hdr_len + extra_len;

      /* Create temporary buffer to hold the event */
      event = kmalloc(event_len, GFP_ATOMIC);
      if (event == NULL)
            return;

      /* Fill event */
      event->len = event_len;
      event->cmd = cmd;
      memcpy(&event->u, ((char *) wrqu) + wrqu_off, hdr_len - IW_EV_LCP_LEN);
      if (extra)
            memcpy(((char *) event) + hdr_len, extra, extra_len);

      /* Send via the RtNetlink event channel */
      rtmsg_iwinfo(dev, (char *) event, event_len);

      /* Cleanup */
      kfree(event);

      return;           /* Always success, I guess ;-) */
}
EXPORT_SYMBOL(wireless_send_event);

/********************** ENHANCED IWSPY SUPPORT **********************/
/*
 * In the old days, the driver was handling spy support all by itself.
 * Now, the driver can delegate this task to Wireless Extensions.
 * It needs to use those standard spy iw_handler in struct iw_handler_def,
 * push data to us via wireless_spy_update() and include struct iw_spy_data
 * in its private part (and export it in net_device->wireless_data->spy_data).
 * One of the main advantage of centralising spy support here is that
 * it becomes much easier to improve and extend it without having to touch
 * the drivers. One example is the addition of the Spy-Threshold events.
 */

/* ---------------------------------------------------------------- */
/*
 * Return the pointer to the spy data in the driver.
 * Because this is called on the Rx path via wireless_spy_update(),
 * we want it to be efficient...
 */
static inline struct iw_spy_data *get_spydata(struct net_device *dev)
{
      /* This is the new way */
      if (dev->wireless_data)
            return dev->wireless_data->spy_data;
      return NULL;
}

/*------------------------------------------------------------------*/
/*
 * Standard Wireless Handler : set Spy List
 */
int iw_handler_set_spy(struct net_device *      dev,
                   struct iw_request_info *     info,
                   union iwreq_data *     wrqu,
                   char *                 extra)
{
      struct iw_spy_data *    spydata = get_spydata(dev);
      struct sockaddr * address = (struct sockaddr *) extra;

      /* Make sure driver is not buggy or using the old API */
      if (!spydata)
            return -EOPNOTSUPP;

      /* Disable spy collection while we copy the addresses.
       * While we copy addresses, any call to wireless_spy_update()
       * will NOP. This is OK, as anyway the addresses are changing. */
      spydata->spy_number = 0;

      /* We want to operate without locking, because wireless_spy_update()
       * most likely will happen in the interrupt handler, and therefore
       * have its own locking constraints and needs performance.
       * The rtnl_lock() make sure we don't race with the other iw_handlers.
       * This make sure wireless_spy_update() "see" that the spy list
       * is temporarily disabled. */
      smp_wmb();

      /* Are there are addresses to copy? */
      if (wrqu->data.length > 0) {
            int i;

            /* Copy addresses */
            for (i = 0; i < wrqu->data.length; i++)
                  memcpy(spydata->spy_address[i], address[i].sa_data,
                         ETH_ALEN);
            /* Reset stats */
            memset(spydata->spy_stat, 0,
                   sizeof(struct iw_quality) * IW_MAX_SPY);
      }

      /* Make sure above is updated before re-enabling */
      smp_wmb();

      /* Enable addresses */
      spydata->spy_number = wrqu->data.length;

      return 0;
}
EXPORT_SYMBOL(iw_handler_set_spy);

/*------------------------------------------------------------------*/
/*
 * Standard Wireless Handler : get Spy List
 */
int iw_handler_get_spy(struct net_device *      dev,
                   struct iw_request_info *     info,
                   union iwreq_data *     wrqu,
                   char *                 extra)
{
      struct iw_spy_data *    spydata = get_spydata(dev);
      struct sockaddr * address = (struct sockaddr *) extra;
      int               i;

      /* Make sure driver is not buggy or using the old API */
      if (!spydata)
            return -EOPNOTSUPP;

      wrqu->data.length = spydata->spy_number;

      /* Copy addresses. */
      for (i = 0; i < spydata->spy_number; i++)       {
            memcpy(address[i].sa_data, spydata->spy_address[i], ETH_ALEN);
            address[i].sa_family = AF_UNIX;
      }
      /* Copy stats to the user buffer (just after). */
      if (spydata->spy_number > 0)
            memcpy(extra  + (sizeof(struct sockaddr) *spydata->spy_number),
                   spydata->spy_stat,
                   sizeof(struct iw_quality) * spydata->spy_number);
      /* Reset updated flags. */
      for (i = 0; i < spydata->spy_number; i++)
            spydata->spy_stat[i].updated &= ~IW_QUAL_ALL_UPDATED;
      return 0;
}
EXPORT_SYMBOL(iw_handler_get_spy);

/*------------------------------------------------------------------*/
/*
 * Standard Wireless Handler : set spy threshold
 */
int iw_handler_set_thrspy(struct net_device *   dev,
                    struct iw_request_info *info,
                    union iwreq_data *    wrqu,
                    char *          extra)
{
      struct iw_spy_data *    spydata = get_spydata(dev);
      struct iw_thrspy *      threshold = (struct iw_thrspy *) extra;

      /* Make sure driver is not buggy or using the old API */
      if (!spydata)
            return -EOPNOTSUPP;

      /* Just do it */
      memcpy(&(spydata->spy_thr_low), &(threshold->low),
             2 * sizeof(struct iw_quality));

      /* Clear flag */
      memset(spydata->spy_thr_under, '\0', sizeof(spydata->spy_thr_under));

      return 0;
}
EXPORT_SYMBOL(iw_handler_set_thrspy);

/*------------------------------------------------------------------*/
/*
 * Standard Wireless Handler : get spy threshold
 */
int iw_handler_get_thrspy(struct net_device *   dev,
                    struct iw_request_info *info,
                    union iwreq_data *    wrqu,
                    char *          extra)
{
      struct iw_spy_data *    spydata = get_spydata(dev);
      struct iw_thrspy *      threshold = (struct iw_thrspy *) extra;

      /* Make sure driver is not buggy or using the old API */
      if (!spydata)
            return -EOPNOTSUPP;

      /* Just do it */
      memcpy(&(threshold->low), &(spydata->spy_thr_low),
             2 * sizeof(struct iw_quality));

      return 0;
}
EXPORT_SYMBOL(iw_handler_get_thrspy);

/*------------------------------------------------------------------*/
/*
 * Prepare and send a Spy Threshold event
 */
static void iw_send_thrspy_event(struct net_device *  dev,
                         struct iw_spy_data *   spydata,
                         unsigned char *  address,
                         struct iw_quality *    wstats)
{
      union iwreq_data  wrqu;
      struct iw_thrspy  threshold;

      /* Init */
      wrqu.data.length = 1;
      wrqu.data.flags = 0;
      /* Copy address */
      memcpy(threshold.addr.sa_data, address, ETH_ALEN);
      threshold.addr.sa_family = ARPHRD_ETHER;
      /* Copy stats */
      memcpy(&(threshold.qual), wstats, sizeof(struct iw_quality));
      /* Copy also thresholds */
      memcpy(&(threshold.low), &(spydata->spy_thr_low),
             2 * sizeof(struct iw_quality));

      /* Send event to user space */
      wireless_send_event(dev, SIOCGIWTHRSPY, &wrqu, (char *) &threshold);
}

/* ---------------------------------------------------------------- */
/*
 * Call for the driver to update the spy data.
 * For now, the spy data is a simple array. As the size of the array is
 * small, this is good enough. If we wanted to support larger number of
 * spy addresses, we should use something more efficient...
 */
void wireless_spy_update(struct net_device *    dev,
                   unsigned char *  address,
                   struct iw_quality *    wstats)
{
      struct iw_spy_data *    spydata = get_spydata(dev);
      int               i;
      int               match = -1;

      /* Make sure driver is not buggy or using the old API */
      if (!spydata)
            return;

      /* Update all records that match */
      for (i = 0; i < spydata->spy_number; i++)
            if (!compare_ether_addr(address, spydata->spy_address[i])) {
                  memcpy(&(spydata->spy_stat[i]), wstats,
                         sizeof(struct iw_quality));
                  match = i;
            }

      /* Generate an event if we cross the spy threshold.
       * To avoid event storms, we have a simple hysteresis : we generate
       * event only when we go under the low threshold or above the
       * high threshold. */
      if (match >= 0) {
            if (spydata->spy_thr_under[match]) {
                  if (wstats->level > spydata->spy_thr_high.level) {
                        spydata->spy_thr_under[match] = 0;
                        iw_send_thrspy_event(dev, spydata,
                                         address, wstats);
                  }
            } else {
                  if (wstats->level < spydata->spy_thr_low.level) {
                        spydata->spy_thr_under[match] = 1;
                        iw_send_thrspy_event(dev, spydata,
                                         address, wstats);
                  }
            }
      }
}
EXPORT_SYMBOL(wireless_spy_update);

Generated by  Doxygen 1.6.0   Back to index