mac80211: cache mesh beacon
Previously, the entire mesh beacon would be generated each
time the beacon timer fired. Instead generate a beacon
head and tail (so the TIM can easily be inserted when mesh
power save is on) when starting a mesh or the MBSS
parameters change.
Also add a mutex for protecting beacon updates and
preventing leaks.
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index 0adec3d..6ff8ee9 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -171,7 +171,7 @@
}
if (changed)
- ieee80211_bss_info_change_notify(sdata, changed);
+ ieee80211_mbss_info_change_notify(sdata, changed);
}
int mesh_rmc_init(struct ieee80211_sub_if_data *sdata)
@@ -593,7 +593,7 @@
mesh_path_expire(sdata);
changed = mesh_accept_plinks_update(sdata);
- ieee80211_bss_info_change_notify(sdata, changed);
+ ieee80211_mbss_info_change_notify(sdata, changed);
mod_timer(&ifmsh->housekeeping_timer,
round_jiffies(jiffies + IEEE80211_MESH_HOUSEKEEPING_INTERVAL));
@@ -644,7 +644,140 @@
}
#endif
-void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
+static int
+ieee80211_mesh_build_beacon(struct ieee80211_if_mesh *ifmsh)
+{
+ struct beacon_data *bcn;
+ int head_len, tail_len;
+ struct sk_buff *skb;
+ struct ieee80211_mgmt *mgmt;
+ struct ieee80211_chanctx_conf *chanctx_conf;
+ enum ieee80211_band band;
+ u8 *pos;
+ struct ieee80211_sub_if_data *sdata;
+ int hdr_len = offsetof(struct ieee80211_mgmt, u.beacon) +
+ sizeof(mgmt->u.beacon);
+
+ sdata = container_of(ifmsh, struct ieee80211_sub_if_data, u.mesh);
+ rcu_read_lock();
+ chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
+ band = chanctx_conf->def.chan->band;
+ rcu_read_unlock();
+
+ head_len = hdr_len +
+ 2 + /* NULL SSID */
+ 2 + 8 + /* supported rates */
+ 2 + 3; /* DS params */
+ tail_len = 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
+ 2 + sizeof(struct ieee80211_ht_cap) +
+ 2 + sizeof(struct ieee80211_ht_operation) +
+ 2 + ifmsh->mesh_id_len +
+ 2 + sizeof(struct ieee80211_meshconf_ie) +
+ 2 + sizeof(__le16) + /* awake window */
+ ifmsh->ie_len;
+
+ bcn = kzalloc(sizeof(*bcn) + head_len + tail_len, GFP_KERNEL);
+ /* need an skb for IE builders to operate on */
+ skb = dev_alloc_skb(max(head_len, tail_len));
+
+ if (!bcn || !skb)
+ goto out_free;
+
+ /*
+ * pointers go into the block we allocated,
+ * memory is | beacon_data | head | tail |
+ */
+ bcn->head = ((u8 *) bcn) + sizeof(*bcn);
+
+ /* fill in the head */
+ mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
+ memset(mgmt, 0, hdr_len);
+ mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
+ IEEE80211_STYPE_BEACON);
+ eth_broadcast_addr(mgmt->da);
+ memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
+ memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
+ ieee80211_mps_set_frame_flags(sdata, NULL, (void *) mgmt);
+ mgmt->u.beacon.beacon_int =
+ cpu_to_le16(sdata->vif.bss_conf.beacon_int);
+ mgmt->u.beacon.capab_info |= cpu_to_le16(
+ sdata->u.mesh.security ? WLAN_CAPABILITY_PRIVACY : 0);
+
+ pos = skb_put(skb, 2);
+ *pos++ = WLAN_EID_SSID;
+ *pos++ = 0x0;
+
+ if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
+ mesh_add_ds_params_ie(skb, sdata))
+ goto out_free;
+
+ bcn->head_len = skb->len;
+ memcpy(bcn->head, skb->data, bcn->head_len);
+
+ /* now the tail */
+ skb_trim(skb, 0);
+ bcn->tail = bcn->head + bcn->head_len;
+
+ if (ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
+ mesh_add_rsn_ie(skb, sdata) ||
+ mesh_add_ht_cap_ie(skb, sdata) ||
+ mesh_add_ht_oper_ie(skb, sdata) ||
+ mesh_add_meshid_ie(skb, sdata) ||
+ mesh_add_meshconf_ie(skb, sdata) ||
+ mesh_add_awake_window_ie(skb, sdata) ||
+ mesh_add_vendor_ies(skb, sdata))
+ goto out_free;
+
+ bcn->tail_len = skb->len;
+ memcpy(bcn->tail, skb->data, bcn->tail_len);
+
+ dev_kfree_skb(skb);
+ rcu_assign_pointer(ifmsh->beacon, bcn);
+ return 0;
+out_free:
+ kfree(bcn);
+ dev_kfree_skb(skb);
+ return -ENOMEM;
+}
+
+static int
+ieee80211_mesh_rebuild_beacon(struct ieee80211_if_mesh *ifmsh)
+{
+ struct ieee80211_sub_if_data *sdata;
+ struct beacon_data *old_bcn;
+ int ret;
+ sdata = container_of(ifmsh, struct ieee80211_sub_if_data, u.mesh);
+
+ mutex_lock(&ifmsh->mtx);
+
+ old_bcn = rcu_dereference_protected(ifmsh->beacon,
+ lockdep_is_held(&ifmsh->mtx));
+ ret = ieee80211_mesh_build_beacon(ifmsh);
+ if (ret)
+ /* just reuse old beacon */
+ goto out;
+
+ if (old_bcn)
+ kfree_rcu(old_bcn, rcu_head);
+out:
+ mutex_unlock(&ifmsh->mtx);
+ return ret;
+}
+
+void ieee80211_mbss_info_change_notify(struct ieee80211_sub_if_data *sdata,
+ u32 changed)
+{
+ if (sdata->vif.bss_conf.enable_beacon &&
+ (changed & (BSS_CHANGED_BEACON |
+ BSS_CHANGED_HT |
+ BSS_CHANGED_BASIC_RATES |
+ BSS_CHANGED_BEACON_INT)))
+ if (ieee80211_mesh_rebuild_beacon(&sdata->u.mesh))
+ return;
+ ieee80211_bss_info_change_notify(sdata, changed);
+}
+
+int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct ieee80211_local *local = sdata->local;
@@ -677,15 +810,22 @@
changed |= ieee80211_mps_local_status_update(sdata);
+ if (ieee80211_mesh_build_beacon(ifmsh)) {
+ ieee80211_stop_mesh(sdata);
+ return -ENOMEM;
+ }
+
ieee80211_bss_info_change_notify(sdata, changed);
netif_carrier_on(sdata->dev);
+ return 0;
}
void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
+ struct beacon_data *bcn;
netif_carrier_off(sdata->dev);
@@ -694,6 +834,12 @@
sdata->vif.bss_conf.enable_beacon = false;
clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
+ mutex_lock(&ifmsh->mtx);
+ bcn = rcu_dereference_protected(ifmsh->beacon,
+ lockdep_is_held(&ifmsh->mtx));
+ rcu_assign_pointer(ifmsh->beacon, NULL);
+ kfree_rcu(bcn, rcu_head);
+ mutex_unlock(&ifmsh->mtx);
/* flush STAs and mpaths on this iface */
sta_info_flush(sdata);
@@ -883,6 +1029,8 @@
skb_queue_head_init(&ifmsh->ps.bc_buf);
spin_lock_init(&ifmsh->mesh_preq_queue_lock);
spin_lock_init(&ifmsh->sync_offset_lock);
+ RCU_INIT_POINTER(ifmsh->beacon, NULL);
+ mutex_init(&ifmsh->mtx);
sdata->vif.bss_conf.bssid = zero_addr;
}