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cfg80211: validate scan channels

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Currently it is possible to request a scan on only
disabled channels, which could be problematic for
some drivers. Reject such scans, and also ignore
disabled channels that are given. This resuls in
the scan begin/end event only including channels
that are actually used.

This makes the mac80211 check for disabled channels
superfluous. At the same time, remove the no-IBSS
check from mac80211 -- nothing says that we should
not find any networks on channels that cannot be
used for an IBSS, even when operating in IBSS mode.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Berg 2009-11-02 13:32:03 +01:00 committed by John W. Linville
parent 6c085227bd
commit 584991dccf
3 changed files with 35 additions and 18 deletions
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13
net/mac80211/scan.c
View File

@ -614,23 +614,14 @@ static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
{
int skip;
struct ieee80211_channel *chan;
struct ieee80211_sub_if_data *sdata = local->scan_sdata;
skip = 0;
chan = local->scan_req->channels[local->scan_channel_idx];
if (chan->flags & IEEE80211_CHAN_DISABLED ||
(sdata->vif.type == NL80211_IFTYPE_ADHOC &&
chan->flags & IEEE80211_CHAN_NO_IBSS))
local->scan_channel = chan;
if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
skip = 1;
if (!skip) {
local->scan_channel = chan;
if (ieee80211_hw_config(local,
IEEE80211_CONF_CHANGE_CHANNEL))
skip = 1;
}
/* advance state machine to next channel/band */
local->scan_channel_idx++;

34
net/wireless/nl80211.c
View File

@ -2988,7 +2988,6 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
goto out;
}
request->n_channels = n_channels;
if (n_ssids)
request->ssids = (void *)&request->channels[n_channels];
request->n_ssids = n_ssids;
@ -2999,32 +2998,53 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
request->ie = (void *)(request->channels + n_channels);
}
i = 0;
if (info->attrs[NL80211_ATTR_SCAN_FREQUENCIES]) {
/* user specified, bail out if channel not found */
request->n_channels = n_channels;
i = 0;
nla_for_each_nested(attr, info->attrs[NL80211_ATTR_SCAN_FREQUENCIES], tmp) {
request->channels[i] = ieee80211_get_channel(wiphy, nla_get_u32(attr));
if (!request->channels[i]) {
struct ieee80211_channel *chan;
chan = ieee80211_get_channel(wiphy, nla_get_u32(attr));
if (!chan) {
err = -EINVAL;
goto out_free;
}
/* ignore disabled channels */
if (chan->flags & IEEE80211_CHAN_DISABLED)
continue;
request->channels[i] = chan;
i++;
}
} else {
/* all channels */
i = 0;
for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
int j;
if (!wiphy->bands[band])
continue;
for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
request->channels[i] = &wiphy->bands[band]->channels[j];
struct ieee80211_channel *chan;
chan = &wiphy->bands[band]->channels[j];
if (chan->flags & IEEE80211_CHAN_DISABLED)
continue;
request->channels[i] = chan;
i++;
}
}
}
if (!i) {
err = -EINVAL;
goto out_free;
}
request->n_channels = i;
i = 0;
if (info->attrs[NL80211_ATTR_SCAN_SSIDS]) {
nla_for_each_nested(attr, info->attrs[NL80211_ATTR_SCAN_SSIDS], tmp) {

6
net/wireless/scan.c
View File

@ -650,9 +650,15 @@ int cfg80211_wext_siwscan(struct net_device *dev,
i = 0;
for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
int j;
if (!wiphy->bands[band])
continue;
for (j = 0; j < wiphy->bands[band]->n_channels; j++) {
/* ignore disabled channels */
if (wiphy->bands[band]->channels[j].flags &
IEEE80211_CHAN_DISABLED)
continue;
/* If we have a wireless request structure and the
* wireless request specifies frequencies, then search