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mac80211: rcu-ify scan and scheduled scan request pointers

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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>
This commit is contained in:
Johannes Berg 2014-11-19 11:55:49 +01:00
parent ad2b26abc1
commit 6ea0a69ca2
3 changed files with 56 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
net/mac80211/ieee80211_i.h
View File

@ -1238,7 +1238,7 @@ struct ieee80211_local {
unsigned long scanning;
struct cfg80211_ssid scan_ssid;
struct cfg80211_scan_request *int_scan_req;
struct cfg80211_scan_request *scan_req;
struct cfg80211_scan_request __rcu *scan_req;
struct ieee80211_scan_request *hw_scan_req;
struct cfg80211_chan_def scan_chandef;
enum ieee80211_band hw_scan_band;
@ -1248,7 +1248,7 @@ struct ieee80211_local {
struct work_struct sched_scan_stopped_work;
struct ieee80211_sub_if_data __rcu *sched_scan_sdata;
struct cfg80211_sched_scan_request *sched_scan_req;
struct cfg80211_sched_scan_request __rcu *sched_scan_req;
unsigned long leave_oper_channel_time;
enum mac80211_scan_state next_scan_state;

79
net/mac80211/scan.c
View File

@ -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);

7
net/mac80211/util.c
View File

@ -1721,6 +1721,7 @@ int ieee80211_reconfig(struct ieee80211_local *local)
int res, i;
bool reconfig_due_to_wowlan = false;
struct ieee80211_sub_if_data *sched_scan_sdata;
struct cfg80211_sched_scan_request *sched_scan_req;
bool sched_scan_stopped = false;
#ifdef CONFIG_PM
@ -2011,13 +2012,15 @@ int ieee80211_reconfig(struct ieee80211_local *local)
mutex_lock(&local->mtx);
sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
lockdep_is_held(&local->mtx));
if (sched_scan_sdata && local->sched_scan_req)
sched_scan_req = rcu_dereference_protected(local->sched_scan_req,
lockdep_is_held(&local->mtx));
if (sched_scan_sdata && sched_scan_req)
/*
* Sched scan stopped, but we don't want to report it. Instead,
* we're trying to reschedule.
*/
if (__ieee80211_request_sched_scan_start(sched_scan_sdata,
local->sched_scan_req))
sched_scan_req))
sched_scan_stopped = true;
mutex_unlock(&local->mtx);