Commit c3ffeab4 authored by Johannes Berg's avatar Johannes Berg
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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: default avatarJohannes Berg <johannes.berg@intel.com>
parent 1852d40e
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+64 −67
Original line number Diff line number Diff line
@@ -44,7 +44,6 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
	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 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
	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 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
						 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 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,

	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 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
	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 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
	*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 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
	}

	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 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
		*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 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
		  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 @@ static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
	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 @@ static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
	}

	/* 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 @@ void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
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 @@ int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
			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_join(struct ieee80211_sub_if_data *sdata,

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);

@@ -1156,7 +1153,7 @@ int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)

	/* remove beacon */
	kfree(sdata->u.ibss.ie);
	skb = rcu_dereference_protected(sdata->u.ibss.presp,
	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;
@@ -1166,7 +1163,7 @@ int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
	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);

+1 −2
Original line number Diff line number Diff line
@@ -508,8 +508,7 @@ struct ieee80211_if_ibss {

	unsigned long ibss_join_req;
	/* probe response/beacon for IBSS */
	struct sk_buff __rcu *presp;
	struct sk_buff *skb;
	struct beacon_data __rcu *presp;

	spinlock_t incomplete_lock;
	struct list_head incomplete_stations;
+5 −2
Original line number Diff line number Diff line
@@ -2442,14 +2442,17 @@ struct sk_buff *ieee80211_beacon_get_tim(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 sk_buff *presp = rcu_dereference(ifibss->presp);
		struct beacon_data *presp = rcu_dereference(ifibss->presp);

		if (!presp)
			goto out;

		skb = skb_copy(presp, GFP_ATOMIC);
		skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
		if (!skb)
			goto out;
		skb_reserve(skb, local->tx_headroom);
		memcpy(skb_put(skb, presp->head_len), presp->head,
		       presp->head_len);

		hdr = (struct ieee80211_hdr *) skb->data;
		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |