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authorJohannes Berg <johannes.berg@intel.com>2014-11-19 13:55:49 +0300
committerJohannes Berg <johannes.berg@intel.com>2014-11-19 20:45:58 +0300
commit6ea0a69ca21bbddab5b3979c2190013b0263e749 (patch)
tree27fe05578c960fa946d68ce8db3dfead88b47b49 /net/mac80211/scan.c
parentad2b26abc157460ca6fac1a53a2bfeade283adfa (diff)
downloadlinux-6ea0a69ca21bbddab5b3979c2190013b0263e749.tar.xz
mac80211: rcu-ify scan and scheduled scan request pointers
In order to use the scan and scheduled scan request pointers during RX to check for randomisation, make them accessible using RCU. Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/mac80211/scan.c')
-rw-r--r--net/mac80211/scan.c79
1 files changed, 49 insertions, 30 deletions
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index d23c8d90c3b4..e75e64b8042c 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -234,11 +234,14 @@ ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
/* return false if no more work */
static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
{
- struct cfg80211_scan_request *req = local->scan_req;
+ struct cfg80211_scan_request *req;
struct cfg80211_chan_def chandef;
u8 bands_used = 0;
int i, ielen, n_chans;
+ req = rcu_dereference_protected(local->scan_req,
+ lockdep_is_held(&local->mtx));
+
if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
return false;
@@ -290,6 +293,7 @@ static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
struct ieee80211_local *local = hw_to_local(hw);
bool hw_scan = local->ops->hw_scan;
bool was_scanning = local->scanning;
+ struct cfg80211_scan_request *scan_req;
lockdep_assert_held(&local->mtx);
@@ -322,9 +326,12 @@ static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
kfree(local->hw_scan_req);
local->hw_scan_req = NULL;
- if (local->scan_req != local->int_scan_req)
- cfg80211_scan_done(local->scan_req, aborted);
- local->scan_req = NULL;
+ scan_req = rcu_dereference_protected(local->scan_req,
+ lockdep_is_held(&local->mtx));
+
+ if (scan_req != local->int_scan_req)
+ cfg80211_scan_done(scan_req, aborted);
+ RCU_INIT_POINTER(local->scan_req, NULL);
RCU_INIT_POINTER(local->scan_sdata, NULL);
local->scanning = 0;
@@ -440,23 +447,26 @@ static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
{
int i;
struct ieee80211_sub_if_data *sdata;
+ struct cfg80211_scan_request *scan_req;
enum ieee80211_band band = local->hw.conf.chandef.chan->band;
u32 tx_flags;
+ scan_req = rcu_dereference_protected(local->scan_req,
+ lockdep_is_held(&local->mtx));
+
tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
- if (local->scan_req->no_cck)
+ if (scan_req->no_cck)
tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
sdata = rcu_dereference_protected(local->scan_sdata,
lockdep_is_held(&local->mtx));
- for (i = 0; i < local->scan_req->n_ssids; i++)
+ for (i = 0; i < scan_req->n_ssids; i++)
ieee80211_send_probe_req(
sdata, NULL,
- local->scan_req->ssids[i].ssid,
- local->scan_req->ssids[i].ssid_len,
- local->scan_req->ie, local->scan_req->ie_len,
- local->scan_req->rates[band], false,
+ scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
+ scan_req->ie, scan_req->ie_len,
+ scan_req->rates[band], false,
tx_flags, local->hw.conf.chandef.chan, true);
/*
@@ -480,7 +490,7 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
if (!ieee80211_can_scan(local, sdata)) {
/* wait for the work to finish/time out */
- local->scan_req = req;
+ rcu_assign_pointer(local->scan_req, req);
rcu_assign_pointer(local->scan_sdata, sdata);
return 0;
}
@@ -530,7 +540,7 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
*/
}
- local->scan_req = req;
+ rcu_assign_pointer(local->scan_req, req);
rcu_assign_pointer(local->scan_sdata, sdata);
if (local->ops->hw_scan) {
@@ -558,7 +568,7 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
if ((req->channels[0]->flags &
IEEE80211_CHAN_NO_IR) ||
- !local->scan_req->n_ssids) {
+ !req->n_ssids) {
next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
} else {
ieee80211_scan_state_send_probe(local, &next_delay);
@@ -617,6 +627,7 @@ static void ieee80211_scan_state_decision(struct ieee80211_local *local,
struct ieee80211_sub_if_data *sdata;
struct ieee80211_channel *next_chan;
enum mac80211_scan_state next_scan_state;
+ struct cfg80211_scan_request *scan_req;
/*
* check if at least one STA interface is associated,
@@ -641,7 +652,10 @@ static void ieee80211_scan_state_decision(struct ieee80211_local *local,
}
mutex_unlock(&local->iflist_mtx);
- next_chan = local->scan_req->channels[local->scan_channel_idx];
+ scan_req = rcu_dereference_protected(local->scan_req,
+ lockdep_is_held(&local->mtx));
+
+ next_chan = scan_req->channels[local->scan_channel_idx];
/*
* we're currently scanning a different channel, let's
@@ -656,7 +670,7 @@ static void ieee80211_scan_state_decision(struct ieee80211_local *local,
local->leave_oper_channel_time + HZ / 8);
if (associated && !tx_empty) {
- if (local->scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
+ if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
next_scan_state = SCAN_ABORT;
else
next_scan_state = SCAN_SUSPEND;
@@ -677,14 +691,18 @@ static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
int skip;
struct ieee80211_channel *chan;
enum nl80211_bss_scan_width oper_scan_width;
+ struct cfg80211_scan_request *scan_req;
+
+ scan_req = rcu_dereference_protected(local->scan_req,
+ lockdep_is_held(&local->mtx));
skip = 0;
- chan = local->scan_req->channels[local->scan_channel_idx];
+ chan = scan_req->channels[local->scan_channel_idx];
local->scan_chandef.chan = chan;
local->scan_chandef.center_freq1 = chan->center_freq;
local->scan_chandef.center_freq2 = 0;
- switch (local->scan_req->scan_width) {
+ switch (scan_req->scan_width) {
case NL80211_BSS_CHAN_WIDTH_5:
local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
break;
@@ -698,7 +716,7 @@ static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
oper_scan_width = cfg80211_chandef_to_scan_width(
&local->_oper_chandef);
if (chan == local->_oper_chandef.chan &&
- oper_scan_width == local->scan_req->scan_width)
+ oper_scan_width == scan_req->scan_width)
local->scan_chandef = local->_oper_chandef;
else
local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
@@ -727,8 +745,7 @@ static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
*
* In any case, it is not necessary for a passive scan.
*/
- if (chan->flags & IEEE80211_CHAN_NO_IR ||
- !local->scan_req->n_ssids) {
+ if (chan->flags & IEEE80211_CHAN_NO_IR || !scan_req->n_ssids) {
*next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
local->next_scan_state = SCAN_DECISION;
return;
@@ -777,6 +794,7 @@ void ieee80211_scan_work(struct work_struct *work)
struct ieee80211_local *local =
container_of(work, struct ieee80211_local, scan_work.work);
struct ieee80211_sub_if_data *sdata;
+ struct cfg80211_scan_request *scan_req;
unsigned long next_delay = 0;
bool aborted;
@@ -784,6 +802,8 @@ void ieee80211_scan_work(struct work_struct *work)
sdata = rcu_dereference_protected(local->scan_sdata,
lockdep_is_held(&local->mtx));
+ scan_req = rcu_dereference_protected(local->scan_req,
+ lockdep_is_held(&local->mtx));
/* When scanning on-channel, the first-callback means completed. */
if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
@@ -796,20 +816,19 @@ void ieee80211_scan_work(struct work_struct *work)
goto out_complete;
}
- if (!sdata || !local->scan_req)
+ if (!sdata || !scan_req)
goto out;
if (!local->scanning) {
- struct cfg80211_scan_request *req = local->scan_req;
int rc;
- local->scan_req = NULL;
+ RCU_INIT_POINTER(local->scan_req, NULL);
RCU_INIT_POINTER(local->scan_sdata, NULL);
- rc = __ieee80211_start_scan(sdata, req);
+ rc = __ieee80211_start_scan(sdata, scan_req);
if (rc) {
/* need to complete scan in cfg80211 */
- local->scan_req = req;
+ rcu_assign_pointer(local->scan_req, scan_req);
aborted = true;
goto out_complete;
} else
@@ -829,7 +848,7 @@ void ieee80211_scan_work(struct work_struct *work)
switch (local->next_scan_state) {
case SCAN_DECISION:
/* if no more bands/channels left, complete scan */
- if (local->scan_channel_idx >= local->scan_req->n_channels) {
+ if (local->scan_channel_idx >= scan_req->n_channels) {
aborted = false;
goto out_complete;
}
@@ -1043,7 +1062,7 @@ int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
if (ret == 0) {
rcu_assign_pointer(local->sched_scan_sdata, sdata);
- local->sched_scan_req = req;
+ rcu_assign_pointer(local->sched_scan_req, req);
}
kfree(ie);
@@ -1052,7 +1071,7 @@ out:
if (ret) {
/* Clean in case of failure after HW restart or upon resume. */
RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
- local->sched_scan_req = NULL;
+ RCU_INIT_POINTER(local->sched_scan_req, NULL);
}
return ret;
@@ -1090,7 +1109,7 @@ int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
}
/* We don't want to restart sched scan anymore. */
- local->sched_scan_req = NULL;
+ RCU_INIT_POINTER(local->sched_scan_req, NULL);
if (rcu_access_pointer(local->sched_scan_sdata)) {
ret = drv_sched_scan_stop(local, sdata);
@@ -1125,7 +1144,7 @@ void ieee80211_sched_scan_end(struct ieee80211_local *local)
RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
/* If sched scan was aborted by the driver. */
- local->sched_scan_req = NULL;
+ RCU_INIT_POINTER(local->sched_scan_req, NULL);
mutex_unlock(&local->mtx);