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mac80211: move csa counters from sdata to beacon/presp

Browse source 
Having csa counters part of beacon and probe_resp
structures makes it easier to get rid of possible
races between setting a beacon and updating
counters on SMP systems by guaranteeing counters
are always consistent against given beacon struct.

While at it relax WARN_ON into WARN_ON_ONCE to
prevent spamming logs and racing.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
[remove pointless array check]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Michal Kazior 2014-06-05 14:21:36 +02:00 committed by Johannes Berg
parent b49328361b
commit af296bdb8d
5 changed files with 115 additions and 75 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

67
net/mac80211/cfg.c
View file

@ -554,7 +554,8 @@ static int ieee80211_set_monitor_channel(struct wiphy *wiphy,
}
static int ieee80211_set_probe_resp(struct ieee80211_sub_if_data *sdata,
const u8 *resp, size_t resp_len)
const u8 *resp, size_t resp_len,
const struct ieee80211_csa_settings *csa)
{
struct probe_resp *new, *old;
@ -570,6 +571,11 @@ static int ieee80211_set_probe_resp(struct ieee80211_sub_if_data *sdata,
new->len = resp_len;
memcpy(new->data, resp, resp_len);
if (csa)
memcpy(new->csa_counter_offsets, csa->counter_offsets_presp,
csa->n_counter_offsets_presp *
sizeof(new->csa_counter_offsets[0]));
rcu_assign_pointer(sdata->u.ap.probe_resp, new);
if (old)
kfree_rcu(old, rcu_head);
@ -578,7 +584,8 @@ static int ieee80211_set_probe_resp(struct ieee80211_sub_if_data *sdata,
}
static int ieee80211_assign_beacon(struct ieee80211_sub_if_data *sdata,
struct cfg80211_beacon_data *params)
struct cfg80211_beacon_data *params,
const struct ieee80211_csa_settings *csa)
{
struct beacon_data *new, *old;
int new_head_len, new_tail_len;
@ -622,6 +629,13 @@ static int ieee80211_assign_beacon(struct ieee80211_sub_if_data *sdata,
new->head_len = new_head_len;
new->tail_len = new_tail_len;
if (csa) {
new->csa_current_counter = csa->count;
memcpy(new->csa_counter_offsets, csa->counter_offsets_beacon,
csa->n_counter_offsets_beacon *
sizeof(new->csa_counter_offsets[0]));
}
/* copy in head */
if (params->head)
memcpy(new->head, params->head, new_head_len);
@ -636,7 +650,7 @@ static int ieee80211_assign_beacon(struct ieee80211_sub_if_data *sdata,
memcpy(new->tail, old->tail, new_tail_len);
err = ieee80211_set_probe_resp(sdata, params->probe_resp,
params->probe_resp_len);
params->probe_resp_len, csa);
if (err < 0)
return err;
if (err == 0)
@ -721,7 +735,7 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev,
sdata->vif.bss_conf.p2p_noa_attr.oppps_ctwindow |=
IEEE80211_P2P_OPPPS_ENABLE_BIT;
err = ieee80211_assign_beacon(sdata, &params->beacon);
err = ieee80211_assign_beacon(sdata, &params->beacon, NULL);
if (err < 0) {
ieee80211_vif_release_channel(sdata);
return err;
@ -769,7 +783,7 @@ static int ieee80211_change_beacon(struct wiphy *wiphy, struct net_device *dev,
if (!old)
return -ENOENT;
err = ieee80211_assign_beacon(sdata, params);
err = ieee80211_assign_beacon(sdata, params, NULL);
if (err < 0)
return err;
ieee80211_bss_info_change_notify(sdata, err);
@ -2752,7 +2766,8 @@ static int ieee80211_set_after_csa_beacon(struct ieee80211_sub_if_data *sdata,
switch (sdata->vif.type) {
case NL80211_IFTYPE_AP:
err = ieee80211_assign_beacon(sdata, sdata->u.ap.next_beacon);
err = ieee80211_assign_beacon(sdata, sdata->u.ap.next_beacon,
NULL);
kfree(sdata->u.ap.next_beacon);
sdata->u.ap.next_beacon = NULL;
@ -2855,6 +2870,7 @@ static int ieee80211_set_csa_beacon(struct ieee80211_sub_if_data *sdata,
struct cfg80211_csa_settings *params,
u32 *changed)
{
struct ieee80211_csa_settings csa = {};
int err;
switch (sdata->vif.type) {
@ -2889,20 +2905,13 @@ static int ieee80211_set_csa_beacon(struct ieee80211_sub_if_data *sdata,
IEEE80211_MAX_CSA_COUNTERS_NUM))
return -EINVAL;
/* make sure we don't have garbage in other counters */
memset(sdata->csa_counter_offset_beacon, 0,
sizeof(sdata->csa_counter_offset_beacon));
memset(sdata->csa_counter_offset_presp, 0,
sizeof(sdata->csa_counter_offset_presp));
csa.counter_offsets_beacon = params->counter_offsets_beacon;
csa.counter_offsets_presp = params->counter_offsets_presp;
csa.n_counter_offsets_beacon = params->n_counter_offsets_beacon;
csa.n_counter_offsets_presp = params->n_counter_offsets_presp;
csa.count = params->count;
memcpy(sdata->csa_counter_offset_beacon,
params->counter_offsets_beacon,
params->n_counter_offsets_beacon * sizeof(u16));
memcpy(sdata->csa_counter_offset_presp,
params->counter_offsets_presp,
params->n_counter_offsets_presp * sizeof(u16));
err = ieee80211_assign_beacon(sdata, &params->beacon_csa);
err = ieee80211_assign_beacon(sdata, &params->beacon_csa, &csa);
if (err < 0) {
kfree(sdata->u.ap.next_beacon);
return err;
@ -3046,7 +3055,6 @@ __ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
sdata->csa_radar_required = params->radar_required;
sdata->csa_chandef = params->chandef;
sdata->csa_block_tx = params->block_tx;
sdata->csa_current_counter = params->count;
sdata->vif.csa_active = true;
if (sdata->csa_block_tx)
@ -3194,10 +3202,23 @@ static int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
sdata->vif.type == NL80211_IFTYPE_ADHOC) &&
params->n_csa_offsets) {
int i;
u8 c = sdata->csa_current_counter;
struct beacon_data *beacon = NULL;
for (i = 0; i < params->n_csa_offsets; i++)
data[params->csa_offsets[i]] = c;
rcu_read_lock();
if (sdata->vif.type == NL80211_IFTYPE_AP)
beacon = rcu_dereference(sdata->u.ap.beacon);
else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
beacon = rcu_dereference(sdata->u.ibss.presp);
else if (ieee80211_vif_is_mesh(&sdata->vif))
beacon = rcu_dereference(sdata->u.mesh.beacon);
if (beacon)
for (i = 0; i < params->n_csa_offsets; i++)
data[params->csa_offsets[i]] =
beacon->csa_current_counter;
rcu_read_unlock();
}
IEEE80211_SKB_CB(skb)->flags = flags;

2
net/mac80211/ibss.c
View file

@ -143,7 +143,7 @@ ieee80211_ibss_build_presp(struct ieee80211_sub_if_data *sdata,
*pos++ = csa_settings->block_tx ? 1 : 0;
*pos++ = ieee80211_frequency_to_channel(
csa_settings->chandef.chan->center_freq);
sdata->csa_counter_offset_beacon[0] = (pos - presp->head);
presp->csa_counter_offsets[0] = (pos - presp->head);
*pos++ = csa_settings->count;
}

16
net/mac80211/ieee80211_i.h
View file

@ -229,16 +229,29 @@ struct ieee80211_rx_data {
u16 tkip_iv16;
};
struct ieee80211_csa_settings {
const u16 *counter_offsets_beacon;
const u16 *counter_offsets_presp;
int n_counter_offsets_beacon;
int n_counter_offsets_presp;
u8 count;
};
struct beacon_data {
u8 *head, *tail;
int head_len, tail_len;
struct ieee80211_meshconf_ie *meshconf;
u16 csa_counter_offsets[IEEE80211_MAX_CSA_COUNTERS_NUM];
u8 csa_current_counter;
struct rcu_head rcu_head;
};
struct probe_resp {
struct rcu_head rcu_head;
int len;
u16 csa_counter_offsets[IEEE80211_MAX_CSA_COUNTERS_NUM];
u8 data[0];
};
@ -754,8 +767,6 @@ struct ieee80211_sub_if_data {
struct mac80211_qos_map __rcu *qos_map;
struct work_struct csa_finalize_work;
u16 csa_counter_offset_beacon[IEEE80211_MAX_CSA_COUNTERS_NUM];
u16 csa_counter_offset_presp[IEEE80211_MAX_CSA_COUNTERS_NUM];
bool csa_radar_required;
bool csa_block_tx; /* write-protected by sdata_lock and local->mtx */
struct cfg80211_chan_def csa_chandef;
@ -767,7 +778,6 @@ struct ieee80211_sub_if_data {
struct ieee80211_chanctx *reserved_chanctx;
struct cfg80211_chan_def reserved_chandef;
bool reserved_radar_required;
u8 csa_current_counter;
/* used to reconfigure hardware SM PS */
struct work_struct recalc_smps;

2
net/mac80211/mesh.c
View file

@ -679,7 +679,7 @@ ieee80211_mesh_build_beacon(struct ieee80211_if_mesh *ifmsh)
*pos++ = 0x0;
*pos++ = ieee80211_frequency_to_channel(
csa->settings.chandef.chan->center_freq);
sdata->csa_counter_offset_beacon[0] = hdr_len + 6;
bcn->csa_counter_offsets[0] = hdr_len + 6;
*pos++ = csa->settings.count;
*pos++ = WLAN_EID_CHAN_SWITCH_PARAM;
*pos++ = 6;

103
net/mac80211/tx.c
View file

@ -2426,7 +2426,7 @@ static void ieee80211_set_csa(struct ieee80211_sub_if_data *sdata,
u8 *beacon_data;
size_t beacon_data_len;
int i;
u8 count = sdata->csa_current_counter;
u8 count = beacon->csa_current_counter;
switch (sdata->vif.type) {
case NL80211_IFTYPE_AP:
@ -2445,46 +2445,53 @@ static void ieee80211_set_csa(struct ieee80211_sub_if_data *sdata,
return;
}
rcu_read_lock();
for (i = 0; i < IEEE80211_MAX_CSA_COUNTERS_NUM; ++i) {
u16 counter_offset_beacon =
sdata->csa_counter_offset_beacon[i];
u16 counter_offset_presp = sdata->csa_counter_offset_presp[i];
resp = rcu_dereference(sdata->u.ap.probe_resp);
if (counter_offset_beacon) {
if (WARN_ON(counter_offset_beacon >= beacon_data_len))
return;
beacon_data[counter_offset_beacon] = count;
}
if (sdata->vif.type == NL80211_IFTYPE_AP &&
counter_offset_presp) {
rcu_read_lock();
resp = rcu_dereference(sdata->u.ap.probe_resp);
/* If nl80211 accepted the offset, this should
* not happen.
*/
if (WARN_ON(!resp)) {
if (beacon->csa_counter_offsets[i]) {
if (WARN_ON_ONCE(beacon->csa_counter_offsets[i] >=
beacon_data_len)) {
rcu_read_unlock();
return;
}
resp->data[counter_offset_presp] = count;
rcu_read_unlock();
beacon_data[beacon->csa_counter_offsets[i]] = count;
}
if (sdata->vif.type == NL80211_IFTYPE_AP && resp)
resp->data[resp->csa_counter_offsets[i]] = count;
}
rcu_read_unlock();
}
u8 ieee80211_csa_update_counter(struct ieee80211_vif *vif)
{
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
struct beacon_data *beacon = NULL;
u8 count = 0;
sdata->csa_current_counter--;
rcu_read_lock();
if (sdata->vif.type == NL80211_IFTYPE_AP)
beacon = rcu_dereference(sdata->u.ap.beacon);
else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
beacon = rcu_dereference(sdata->u.ibss.presp);
else if (ieee80211_vif_is_mesh(&sdata->vif))
beacon = rcu_dereference(sdata->u.mesh.beacon);
if (!beacon)
goto unlock;
beacon->csa_current_counter--;
/* the counter should never reach 0 */
WARN_ON(!sdata->csa_current_counter);
WARN_ON_ONCE(!beacon->csa_current_counter);
count = beacon->csa_current_counter;
return sdata->csa_current_counter;
unlock:
rcu_read_unlock();
return count;
}
EXPORT_SYMBOL(ieee80211_csa_update_counter);
@ -2494,7 +2501,6 @@ bool ieee80211_csa_is_complete(struct ieee80211_vif *vif)
struct beacon_data *beacon = NULL;
u8 *beacon_data;
size_t beacon_data_len;
int counter_beacon = sdata->csa_counter_offset_beacon[0];
int ret = false;
if (!ieee80211_sdata_running(sdata))
@ -2532,10 +2538,10 @@ bool ieee80211_csa_is_complete(struct ieee80211_vif *vif)
goto out;
}
if (WARN_ON(counter_beacon > beacon_data_len))
if (WARN_ON_ONCE(beacon->csa_counter_offsets[0] > beacon_data_len))
goto out;
if (beacon_data[counter_beacon] == 1)
if (beacon_data[beacon->csa_counter_offsets[0]] == 1)
ret = true;
out:
rcu_read_unlock();
@ -2551,6 +2557,7 @@ __ieee80211_beacon_get(struct ieee80211_hw *hw,
bool is_template)
{
struct ieee80211_local *local = hw_to_local(hw);
struct beacon_data *beacon = NULL;
struct sk_buff *skb = NULL;
struct ieee80211_tx_info *info;
struct ieee80211_sub_if_data *sdata = NULL;
@ -2572,8 +2579,8 @@ __ieee80211_beacon_get(struct ieee80211_hw *hw,
if (sdata->vif.type == NL80211_IFTYPE_AP) {
struct ieee80211_if_ap *ap = &sdata->u.ap;
struct beacon_data *beacon = rcu_dereference(ap->beacon);
beacon = rcu_dereference(ap->beacon);
if (beacon) {
if (sdata->vif.csa_active) {
if (!is_template)
@ -2616,34 +2623,34 @@ __ieee80211_beacon_get(struct ieee80211_hw *hw,
} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_hdr *hdr;
struct beacon_data *presp = rcu_dereference(ifibss->presp);
if (!presp)
beacon = rcu_dereference(ifibss->presp);
if (!beacon)
goto out;
if (sdata->vif.csa_active) {
if (!is_template)
ieee80211_csa_update_counter(vif);
ieee80211_set_csa(sdata, presp);
ieee80211_set_csa(sdata, beacon);
}
skb = dev_alloc_skb(local->tx_headroom + presp->head_len +
skb = dev_alloc_skb(local->tx_headroom + beacon->head_len +
local->hw.extra_beacon_tailroom);
if (!skb)
goto out;
skb_reserve(skb, local->tx_headroom);
memcpy(skb_put(skb, presp->head_len), presp->head,
presp->head_len);
memcpy(skb_put(skb, beacon->head_len), beacon->head,
beacon->head_len);
hdr = (struct ieee80211_hdr *) skb->data;
hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
IEEE80211_STYPE_BEACON);
} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct beacon_data *bcn = rcu_dereference(ifmsh->beacon);
if (!bcn)
beacon = rcu_dereference(ifmsh->beacon);
if (!beacon)
goto out;
if (sdata->vif.csa_active) {
@ -2655,40 +2662,42 @@ __ieee80211_beacon_get(struct ieee80211_hw *hw,
*/
ieee80211_csa_update_counter(vif);
ieee80211_set_csa(sdata, bcn);
ieee80211_set_csa(sdata, beacon);
}
if (ifmsh->sync_ops)
ifmsh->sync_ops->adjust_tbtt(sdata, bcn);
ifmsh->sync_ops->adjust_tbtt(sdata, beacon);
skb = dev_alloc_skb(local->tx_headroom +
bcn->head_len +
beacon->head_len +
256 + /* TIM IE */
bcn->tail_len +
beacon->tail_len +
local->hw.extra_beacon_tailroom);
if (!skb)
goto out;
skb_reserve(skb, local->tx_headroom);
memcpy(skb_put(skb, bcn->head_len), bcn->head, bcn->head_len);
memcpy(skb_put(skb, beacon->head_len), beacon->head,
beacon->head_len);
ieee80211_beacon_add_tim(sdata, &ifmsh->ps, skb, is_template);
if (offs) {
offs->tim_offset = bcn->head_len;
offs->tim_length = skb->len - bcn->head_len;
offs->tim_offset = beacon->head_len;
offs->tim_length = skb->len - beacon->head_len;
}
memcpy(skb_put(skb, bcn->tail_len), bcn->tail, bcn->tail_len);
memcpy(skb_put(skb, beacon->tail_len), beacon->tail,
beacon->tail_len);
} else {
WARN_ON(1);
goto out;
}
/* CSA offsets */
if (offs) {
if (offs && beacon) {
int i;
for (i = 0; i < IEEE80211_MAX_CSA_COUNTERS_NUM; i++) {
u16 csa_off = sdata->csa_counter_offset_beacon[i];
u16 csa_off = beacon->csa_counter_offsets[i];
if (!csa_off)
continue;