From c3ffeab4345830aadfc78444933754330f1339e7 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 7 Mar 2013 20:54:29 +0100 Subject: [PATCH] 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 --- net/mac80211/ibss.c | 131 ++++++++++++++++++++++----------------------- net/mac80211/ieee80211_i.h | 3 +- net/mac80211/tx.c | 7 ++- 3 files changed, 70 insertions(+), 71 deletions(-) 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 @@ 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); @@ -1156,8 +1153,8 @@ 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, - 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 @@ 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); diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 55155e3..c7f8b8b 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -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; diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 2a6ae80..4a83d8d 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -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 | -- 2.7.4