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![Gustavo A. R. Silva](/assets/img/avatar_default.png)
Fix the following out-of-bounds warning: net/wireless/wext-spy.c:178:2: warning: 'memcpy' offset [25, 28] from the object at 'threshold' is out of the bounds of referenced subobject 'low' with type 'struct iw_quality' at offset 20 [-Warray-bounds] The problem is that the original code is trying to copy data into a couple of struct members adjacent to each other in a single call to memcpy(). This causes a legitimate compiler warning because memcpy() overruns the length of &threshold.low and &spydata->spy_thr_low. As these are just a couple of struct members, fix this by using direct assignments, instead of memcpy(). This helps with the ongoing efforts to globally enable -Warray-bounds and get us closer to being able to tighten the FORTIFY_SOURCE routines on memcpy(). Link: https://github.com/KSPP/linux/issues/109 Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210422200032.GA168995@embeddedor Signed-off-by: Johannes Berg <johannes.berg@intel.com>
232 lines
6.5 KiB
C
232 lines
6.5 KiB
C
/*
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* This file implement the Wireless Extensions spy API.
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*
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* Authors : Jean Tourrilhes - HPL - <jt@hpl.hp.com>
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* Copyright (c) 1997-2007 Jean Tourrilhes, All Rights Reserved.
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*
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* (As all part of the Linux kernel, this file is GPL)
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*/
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#include <linux/wireless.h>
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#include <linux/netdevice.h>
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#include <linux/etherdevice.h>
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#include <linux/export.h>
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#include <net/iw_handler.h>
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#include <net/arp.h>
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#include <net/wext.h>
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static inline struct iw_spy_data *get_spydata(struct net_device *dev)
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{
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/* This is the new way */
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if (dev->wireless_data)
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return dev->wireless_data->spy_data;
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return NULL;
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}
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int iw_handler_set_spy(struct net_device * dev,
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struct iw_request_info * info,
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union iwreq_data * wrqu,
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char * extra)
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{
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struct iw_spy_data * spydata = get_spydata(dev);
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struct sockaddr * address = (struct sockaddr *) extra;
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/* Make sure driver is not buggy or using the old API */
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if (!spydata)
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return -EOPNOTSUPP;
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/* Disable spy collection while we copy the addresses.
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* While we copy addresses, any call to wireless_spy_update()
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* will NOP. This is OK, as anyway the addresses are changing. */
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spydata->spy_number = 0;
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/* We want to operate without locking, because wireless_spy_update()
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* most likely will happen in the interrupt handler, and therefore
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* have its own locking constraints and needs performance.
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* The rtnl_lock() make sure we don't race with the other iw_handlers.
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* This make sure wireless_spy_update() "see" that the spy list
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* is temporarily disabled. */
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smp_wmb();
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/* Are there are addresses to copy? */
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if (wrqu->data.length > 0) {
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int i;
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/* Copy addresses */
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for (i = 0; i < wrqu->data.length; i++)
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memcpy(spydata->spy_address[i], address[i].sa_data,
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ETH_ALEN);
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/* Reset stats */
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memset(spydata->spy_stat, 0,
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sizeof(struct iw_quality) * IW_MAX_SPY);
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}
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/* Make sure above is updated before re-enabling */
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smp_wmb();
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/* Enable addresses */
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spydata->spy_number = wrqu->data.length;
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return 0;
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}
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EXPORT_SYMBOL(iw_handler_set_spy);
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int iw_handler_get_spy(struct net_device * dev,
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struct iw_request_info * info,
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union iwreq_data * wrqu,
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char * extra)
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{
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struct iw_spy_data * spydata = get_spydata(dev);
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struct sockaddr * address = (struct sockaddr *) extra;
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int i;
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/* Make sure driver is not buggy or using the old API */
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if (!spydata)
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return -EOPNOTSUPP;
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wrqu->data.length = spydata->spy_number;
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/* Copy addresses. */
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for (i = 0; i < spydata->spy_number; i++) {
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memcpy(address[i].sa_data, spydata->spy_address[i], ETH_ALEN);
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address[i].sa_family = AF_UNIX;
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}
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/* Copy stats to the user buffer (just after). */
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if (spydata->spy_number > 0)
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memcpy(extra + (sizeof(struct sockaddr) *spydata->spy_number),
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spydata->spy_stat,
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sizeof(struct iw_quality) * spydata->spy_number);
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/* Reset updated flags. */
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for (i = 0; i < spydata->spy_number; i++)
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spydata->spy_stat[i].updated &= ~IW_QUAL_ALL_UPDATED;
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return 0;
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}
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EXPORT_SYMBOL(iw_handler_get_spy);
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/*------------------------------------------------------------------*/
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/*
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* Standard Wireless Handler : set spy threshold
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*/
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int iw_handler_set_thrspy(struct net_device * dev,
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struct iw_request_info *info,
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union iwreq_data * wrqu,
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char * extra)
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{
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struct iw_spy_data * spydata = get_spydata(dev);
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struct iw_thrspy * threshold = (struct iw_thrspy *) extra;
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/* Make sure driver is not buggy or using the old API */
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if (!spydata)
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return -EOPNOTSUPP;
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/* Just do it */
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spydata->spy_thr_low = threshold->low;
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spydata->spy_thr_high = threshold->high;
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/* Clear flag */
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memset(spydata->spy_thr_under, '\0', sizeof(spydata->spy_thr_under));
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return 0;
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}
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EXPORT_SYMBOL(iw_handler_set_thrspy);
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/*------------------------------------------------------------------*/
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/*
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* Standard Wireless Handler : get spy threshold
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*/
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int iw_handler_get_thrspy(struct net_device * dev,
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struct iw_request_info *info,
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union iwreq_data * wrqu,
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char * extra)
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{
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struct iw_spy_data * spydata = get_spydata(dev);
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struct iw_thrspy * threshold = (struct iw_thrspy *) extra;
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/* Make sure driver is not buggy or using the old API */
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if (!spydata)
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return -EOPNOTSUPP;
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/* Just do it */
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threshold->low = spydata->spy_thr_low;
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threshold->high = spydata->spy_thr_high;
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return 0;
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}
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EXPORT_SYMBOL(iw_handler_get_thrspy);
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/*------------------------------------------------------------------*/
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/*
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* Prepare and send a Spy Threshold event
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*/
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static void iw_send_thrspy_event(struct net_device * dev,
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struct iw_spy_data * spydata,
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unsigned char * address,
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struct iw_quality * wstats)
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{
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union iwreq_data wrqu;
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struct iw_thrspy threshold;
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/* Init */
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wrqu.data.length = 1;
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wrqu.data.flags = 0;
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/* Copy address */
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memcpy(threshold.addr.sa_data, address, ETH_ALEN);
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threshold.addr.sa_family = ARPHRD_ETHER;
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/* Copy stats */
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threshold.qual = *wstats;
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/* Copy also thresholds */
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threshold.low = spydata->spy_thr_low;
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threshold.high = spydata->spy_thr_high;
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/* Send event to user space */
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wireless_send_event(dev, SIOCGIWTHRSPY, &wrqu, (char *) &threshold);
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}
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/* ---------------------------------------------------------------- */
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/*
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* Call for the driver to update the spy data.
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* For now, the spy data is a simple array. As the size of the array is
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* small, this is good enough. If we wanted to support larger number of
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* spy addresses, we should use something more efficient...
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*/
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void wireless_spy_update(struct net_device * dev,
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unsigned char * address,
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struct iw_quality * wstats)
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{
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struct iw_spy_data * spydata = get_spydata(dev);
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int i;
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int match = -1;
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/* Make sure driver is not buggy or using the old API */
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if (!spydata)
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return;
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/* Update all records that match */
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for (i = 0; i < spydata->spy_number; i++)
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if (ether_addr_equal(address, spydata->spy_address[i])) {
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memcpy(&(spydata->spy_stat[i]), wstats,
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sizeof(struct iw_quality));
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match = i;
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}
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/* Generate an event if we cross the spy threshold.
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* To avoid event storms, we have a simple hysteresis : we generate
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* event only when we go under the low threshold or above the
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* high threshold. */
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if (match >= 0) {
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if (spydata->spy_thr_under[match]) {
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if (wstats->level > spydata->spy_thr_high.level) {
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spydata->spy_thr_under[match] = 0;
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iw_send_thrspy_event(dev, spydata,
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address, wstats);
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}
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} else {
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if (wstats->level < spydata->spy_thr_low.level) {
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spydata->spy_thr_under[match] = 1;
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iw_send_thrspy_event(dev, spydata,
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address, wstats);
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}
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}
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}
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}
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EXPORT_SYMBOL(wireless_spy_update);
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