mac80211: ibss: use beacon_data struct for beacon and probe response
Instead of having an SKB all the time, use a beacon_data struct
with just the information required. This also allows removing a
synchronize_rcu() and using kfree_rcu() instead.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index bd02fac..5ab32e2 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -44,7 +44,6 @@
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
int rates, i;
- struct sk_buff *skb;
struct ieee80211_mgmt *mgmt;
u8 *pos;
struct ieee80211_supported_band *sband;
@@ -52,6 +51,8 @@
u32 bss_change;
u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
struct cfg80211_chan_def chandef;
+ struct beacon_data *presp;
+ int frame_len;
lockdep_assert_held(&ifibss->mtx);
@@ -72,13 +73,11 @@
BSS_CHANGED_BEACON_ENABLED);
}
- skb = ifibss->skb;
- RCU_INIT_POINTER(ifibss->presp, NULL);
- synchronize_rcu();
- skb->data = skb->head;
- skb->len = 0;
- skb_reset_tail_pointer(skb);
- skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
+ presp = rcu_dereference_protected(ifibss->presp,
+ lockdep_is_held(&ifibss->mtx));
+ rcu_assign_pointer(ifibss->presp, NULL);
+ if (presp)
+ kfree_rcu(presp, rcu_head);
sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
@@ -101,19 +100,24 @@
sband = local->hw.wiphy->bands[chan->band];
- /* build supported rates array */
- pos = supp_rates;
- for (i = 0; i < sband->n_bitrates; i++) {
- int rate = sband->bitrates[i].bitrate;
- u8 basic = 0;
- if (basic_rates & BIT(i))
- basic = 0x80;
- *pos++ = basic | (u8) (rate / 5);
- }
-
/* Build IBSS probe response */
- mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
- memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
+ frame_len = sizeof(struct ieee80211_hdr_3addr) +
+ 12 /* struct ieee80211_mgmt.u.beacon */ +
+ 2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
+ 2 + 8 /* max Supported Rates */ +
+ 3 /* max DS params */ +
+ 4 /* IBSS params */ +
+ 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
+ 2 + sizeof(struct ieee80211_ht_cap) +
+ 2 + sizeof(struct ieee80211_ht_operation) +
+ ifibss->ie_len;
+ presp = kzalloc(sizeof(*presp) + frame_len, GFP_KERNEL);
+ if (!presp)
+ return;
+
+ presp->head = (void *)(presp + 1);
+
+ mgmt = (void *) presp->head;
mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
IEEE80211_STYPE_PROBE_RESP);
eth_broadcast_addr(mgmt->da);
@@ -123,27 +127,30 @@
mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
mgmt->u.beacon.capab_info = cpu_to_le16(capability);
- pos = skb_put(skb, 2 + ifibss->ssid_len);
+ pos = (u8 *)mgmt + offsetof(struct ieee80211_mgmt, u.beacon.variable);
+
*pos++ = WLAN_EID_SSID;
*pos++ = ifibss->ssid_len;
memcpy(pos, ifibss->ssid, ifibss->ssid_len);
+ pos += ifibss->ssid_len;
- rates = sband->n_bitrates;
- if (rates > 8)
- rates = 8;
- pos = skb_put(skb, 2 + rates);
+ rates = min_t(int, 8, sband->n_bitrates);
*pos++ = WLAN_EID_SUPP_RATES;
*pos++ = rates;
- memcpy(pos, supp_rates, rates);
+ for (i = 0; i < rates; i++) {
+ int rate = sband->bitrates[i].bitrate;
+ u8 basic = 0;
+ if (basic_rates & BIT(i))
+ basic = 0x80;
+ *pos++ = basic | (u8) (rate / 5);
+ }
if (sband->band == IEEE80211_BAND_2GHZ) {
- pos = skb_put(skb, 2 + 1);
*pos++ = WLAN_EID_DS_PARAMS;
*pos++ = 1;
*pos++ = ieee80211_frequency_to_channel(chan->center_freq);
}
- pos = skb_put(skb, 2 + 2);
*pos++ = WLAN_EID_IBSS_PARAMS;
*pos++ = 2;
/* FIX: set ATIM window based on scan results */
@@ -151,23 +158,25 @@
*pos++ = 0;
if (sband->n_bitrates > 8) {
- rates = sband->n_bitrates - 8;
- pos = skb_put(skb, 2 + rates);
*pos++ = WLAN_EID_EXT_SUPP_RATES;
- *pos++ = rates;
- memcpy(pos, &supp_rates[8], rates);
+ *pos++ = sband->n_bitrates - 8;
+ for (i = 8; i < sband->n_bitrates; i++) {
+ int rate = sband->bitrates[i].bitrate;
+ u8 basic = 0;
+ if (basic_rates & BIT(i))
+ basic = 0x80;
+ *pos++ = basic | (u8) (rate / 5);
+ }
}
- if (ifibss->ie_len)
- memcpy(skb_put(skb, ifibss->ie_len),
- ifibss->ie, ifibss->ie_len);
+ if (ifibss->ie_len) {
+ memcpy(pos, ifibss->ie, ifibss->ie_len);
+ pos += ifibss->ie_len;
+ }
/* add HT capability and information IEs */
if (chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
sband->ht_cap.ht_supported) {
- pos = skb_put(skb, 4 +
- sizeof(struct ieee80211_ht_cap) +
- sizeof(struct ieee80211_ht_operation));
pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap,
sband->ht_cap.cap);
/*
@@ -180,7 +189,6 @@
}
if (local->hw.queues >= IEEE80211_NUM_ACS) {
- pos = skb_put(skb, 9);
*pos++ = WLAN_EID_VENDOR_SPECIFIC;
*pos++ = 7; /* len */
*pos++ = 0x00; /* Microsoft OUI 00:50:F2 */
@@ -192,7 +200,11 @@
*pos++ = 0; /* U-APSD no in use */
}
- rcu_assign_pointer(ifibss->presp, skb);
+ presp->head_len = pos - presp->head;
+ if (WARN_ON(presp->head_len > frame_len))
+ return;
+
+ rcu_assign_pointer(ifibss->presp, presp);
sdata->vif.bss_conf.enable_beacon = true;
sdata->vif.bss_conf.beacon_int = beacon_int;
@@ -230,7 +242,7 @@
round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
bss = cfg80211_inform_bss_frame(local->hw.wiphy, chan,
- mgmt, skb->len, 0, GFP_KERNEL);
+ mgmt, presp->head_len, 0, GFP_KERNEL);
cfg80211_put_bss(local->hw.wiphy, bss);
netif_carrier_on(sdata->dev);
cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
@@ -825,8 +837,7 @@
struct ieee80211_local *local = sdata->local;
int tx_last_beacon, len = req->len;
struct sk_buff *skb;
- struct ieee80211_mgmt *resp;
- struct sk_buff *presp;
+ struct beacon_data *presp;
u8 *pos, *end;
lockdep_assert_held(&ifibss->mtx);
@@ -867,13 +878,15 @@
}
/* Reply with ProbeResp */
- skb = skb_copy(presp, GFP_KERNEL);
+ skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
if (!skb)
return;
- resp = (struct ieee80211_mgmt *) skb->data;
- memcpy(resp->da, mgmt->sa, ETH_ALEN);
- ibss_dbg(sdata, "Sending ProbeResp to %pM\n", resp->da);
+ skb_reserve(skb, local->tx_headroom);
+ memcpy(skb_put(skb, presp->head_len), presp->head, presp->head_len);
+
+ memcpy(((struct ieee80211_mgmt *) skb->data)->da, mgmt->sa, ETH_ALEN);
+ ibss_dbg(sdata, "Sending ProbeResp to %pM\n", mgmt->sa);
IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
ieee80211_tx_skb(sdata, skb);
}
@@ -1023,23 +1036,8 @@
int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
struct cfg80211_ibss_params *params)
{
- struct sk_buff *skb;
u32 changed = 0;
- skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
- sizeof(struct ieee80211_hdr_3addr) +
- 12 /* struct ieee80211_mgmt.u.beacon */ +
- 2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
- 2 + 8 /* max Supported Rates */ +
- 3 /* max DS params */ +
- 4 /* IBSS params */ +
- 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
- 2 + sizeof(struct ieee80211_ht_cap) +
- 2 + sizeof(struct ieee80211_ht_operation) +
- params->ie_len);
- if (!skb)
- return -ENOMEM;
-
mutex_lock(&sdata->u.ibss.mtx);
if (params->bssid) {
@@ -1068,7 +1066,6 @@
sdata->u.ibss.ie_len = params->ie_len;
}
- sdata->u.ibss.skb = skb;
sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
sdata->u.ibss.ibss_join_req = jiffies;
@@ -1104,13 +1101,13 @@
int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
{
- struct sk_buff *skb;
struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
struct ieee80211_local *local = sdata->local;
struct cfg80211_bss *cbss;
u16 capability;
int active_ibss;
struct sta_info *sta;
+ struct beacon_data *presp;
mutex_lock(&sdata->u.ibss.mtx);
@@ -1156,8 +1153,8 @@
/* remove beacon */
kfree(sdata->u.ibss.ie);
- skb = rcu_dereference_protected(sdata->u.ibss.presp,
- lockdep_is_held(&sdata->u.ibss.mtx));
+ presp = rcu_dereference_protected(ifibss->presp,
+ lockdep_is_held(&sdata->u.ibss.mtx));
RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
sdata->vif.bss_conf.ibss_joined = false;
sdata->vif.bss_conf.ibss_creator = false;
@@ -1166,7 +1163,7 @@
ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
BSS_CHANGED_IBSS);
synchronize_rcu();
- kfree_skb(skb);
+ kfree(presp);
skb_queue_purge(&sdata->skb_queue);