mac80211: refactor and move scan RX code

This patch refactors some code and moves the scan RX function
to scan.c. More importantly, however, it changes it so that the
MLME's beacon/probe_resp functions aren't invoked when scanning
so that we can remove a "if (scanning)" conditions from two
places.

There's a very slight behavioural change in this patch: now,
when scanning, IBSS and mesh aren't updated even on the same
channel.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 194 insertions, 136 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 25dccd5cb2ff..4753ed3f3f10 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -937,6 +937,15 @@ void ieee802_11_parse_elems(u8 *start, size_t len,
 void ieee80211_mlme_notify_scan_completed(struct ieee80211_local *local);
 int ieee80211_sta_start_scan(struct ieee80211_sub_if_data *scan_sdata,
                              u8 *ssid, size_t ssid_len);
+struct ieee80211_sta_bss *
+ieee80211_bss_info_update(struct ieee80211_local *local,
+                          struct ieee80211_rx_status *rx_status,
+                          struct ieee80211_mgmt *mgmt,
+                          size_t len,
+                          struct ieee802_11_elems *elems,
+                          int freq, bool beacon);
+void ieee80211_rx_bss_put(struct ieee80211_local *local,
+                          struct ieee80211_sta_bss *bss);
 
 #ifdef CONFIG_MAC80211_MESH
 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 2caea9759b7e..1708a3d1cd38 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -128,10 +128,9 @@ static void __ieee80211_rx_bss_hash_del(struct ieee80211_local *local,
 }
 
 static struct ieee80211_sta_bss *
-ieee80211_rx_bss_add(struct ieee80211_sub_if_data *sdata, u8 *bssid, int freq,
+ieee80211_rx_bss_add(struct ieee80211_local *local, u8 *bssid, int freq,
                      u8 *ssid, u8 ssid_len)
 {
-        struct ieee80211_local *local = sdata->local;
         struct ieee80211_sta_bss *bss;
 
         bss = kzalloc(sizeof(*bss), GFP_ATOMIC);
@@ -230,8 +229,8 @@ static void ieee80211_rx_bss_free(struct ieee80211_sta_bss *bss)
         kfree(bss);
 }
 
-static void ieee80211_rx_bss_put(struct ieee80211_local *local,
-                                 struct ieee80211_sta_bss *bss)
+void ieee80211_rx_bss_put(struct ieee80211_local *local,
+                          struct ieee80211_sta_bss *bss)
 {
         local_bh_disable();
         if (!atomic_dec_and_lock(&bss->users, &local->sta_bss_lock)) {
@@ -2443,74 +2442,16 @@ static u64 ieee80211_sta_get_mandatory_rates(struct ieee80211_local *local,
         return mandatory_rates;
 }
 
-static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
-                                  struct ieee80211_mgmt *mgmt,
-                                  size_t len,
-                                  struct ieee80211_rx_status *rx_status,
-                                  struct ieee802_11_elems *elems)
+struct ieee80211_sta_bss *
+ieee80211_bss_info_update(struct ieee80211_local *local,
+                          struct ieee80211_rx_status *rx_status,
+                          struct ieee80211_mgmt *mgmt,
+                          size_t len,
+                          struct ieee802_11_elems *elems,
+                          int freq, bool beacon)
 {
-        struct ieee80211_local *local = sdata->local;
-        int freq, clen;
         struct ieee80211_sta_bss *bss;
-        struct sta_info *sta;
-        struct ieee80211_channel *channel;
-        u64 beacon_timestamp, rx_timestamp;
-        u64 supp_rates = 0;
-        bool beacon = ieee80211_is_beacon(mgmt->frame_control);
-        enum ieee80211_band band = rx_status->band;
-        DECLARE_MAC_BUF(mac);
-        DECLARE_MAC_BUF(mac2);
-
-        if (elems->ds_params && elems->ds_params_len == 1)
-                freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
-        else
-                freq = rx_status->freq;
-
-        channel = ieee80211_get_channel(local->hw.wiphy, freq);
-
-        if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
-                return;
-
-        if (ieee80211_vif_is_mesh(&sdata->vif) && elems->mesh_id &&
-            elems->mesh_config && mesh_matches_local(elems, sdata)) {
-                supp_rates = ieee80211_sta_get_rates(local, elems, band);
-
-                mesh_neighbour_update(mgmt->sa, supp_rates, sdata,
-                                      mesh_peer_accepts_plinks(elems));
-        }
-
-        if (sdata->vif.type == IEEE80211_IF_TYPE_IBSS && elems->supp_rates &&
-            memcmp(mgmt->bssid, sdata->u.sta.bssid, ETH_ALEN) == 0) {
-                supp_rates = ieee80211_sta_get_rates(local, elems, band);
-
-                rcu_read_lock();
-
-                sta = sta_info_get(local, mgmt->sa);
-                if (sta) {
-                        u64 prev_rates;
-
-                        prev_rates = sta->supp_rates[band];
-                        /* make sure mandatory rates are always added */
-                        sta->supp_rates[band] = supp_rates |
-                                ieee80211_sta_get_mandatory_rates(local, band);
-
-#ifdef CONFIG_MAC80211_IBSS_DEBUG
-                        if (sta->supp_rates[band] != prev_rates)
-                                printk(KERN_DEBUG "%s: updated supp_rates set "
-                                    "for %s based on beacon info (0x%llx | "
-                                    "0x%llx -> 0x%llx)\n",
-                                    sdata->dev->name, print_mac(mac, sta->addr),
-                                    (unsigned long long) prev_rates,
-                                    (unsigned long long) supp_rates,
-                                    (unsigned long long) sta->supp_rates[band]);
-#endif
-                } else {
-                        ieee80211_ibss_add_sta(sdata, NULL, mgmt->bssid,
-                                               mgmt->sa, supp_rates);
-                }
-
-                rcu_read_unlock();
-        }
+        int clen;
 
 #ifdef CONFIG_MAC80211_MESH
         if (elems->mesh_config)
@@ -2528,10 +2469,10 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
                                 elems->mesh_config_len, freq);
                 else
 #endif
-                        bss = ieee80211_rx_bss_add(sdata, mgmt->bssid, freq,
+                        bss = ieee80211_rx_bss_add(local, mgmt->bssid, freq,
                                                   elems->ssid, elems->ssid_len);
                 if (!bss)
-                        return;
+                        return NULL;
         } else {
 #if 0
                 /* TODO: order by RSSI? */
@@ -2578,17 +2519,114 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
                 bss->supp_rates_len += clen;
         }
 
-        bss->band = band;
+        bss->band = rx_status->band;
 
-        beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
-
-        bss->timestamp = beacon_timestamp;
+        bss->timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
         bss->last_update = jiffies;
         bss->signal = rx_status->signal;
         bss->noise = rx_status->noise;
         bss->qual = rx_status->qual;
+        bss->wmm_used = elems->wmm_param || elems->wmm_info;
+
         if (!beacon)
                 bss->last_probe_resp = jiffies;
+
+        /*
+         * For probe responses, or if we don't have any information yet,
+         * use the IEs from the beacon.
+         */
+        if (!bss->ies || !beacon) {
+                if (bss->ies == NULL || bss->ies_len < elems->total_len) {
+                        kfree(bss->ies);
+                        bss->ies = kmalloc(elems->total_len, GFP_ATOMIC);
+                }
+                if (bss->ies) {
+                        memcpy(bss->ies, elems->ie_start, elems->total_len);
+                        bss->ies_len = elems->total_len;
+                } else
+                        bss->ies_len = 0;
+        }
+
+        return bss;
+}
+
+static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
+                                  struct ieee80211_mgmt *mgmt,
+                                  size_t len,
+                                  struct ieee80211_rx_status *rx_status,
+                                  struct ieee802_11_elems *elems,
+                                  bool beacon)
+{
+        struct ieee80211_local *local = sdata->local;
+        int freq;
+        struct ieee80211_sta_bss *bss;
+        struct sta_info *sta;
+        struct ieee80211_channel *channel;
+        u64 beacon_timestamp, rx_timestamp;
+        u64 supp_rates = 0;
+        enum ieee80211_band band = rx_status->band;
+        DECLARE_MAC_BUF(mac);
+        DECLARE_MAC_BUF(mac2);
+
+        if (elems->ds_params && elems->ds_params_len == 1)
+                freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
+        else
+                freq = rx_status->freq;
+
+        channel = ieee80211_get_channel(local->hw.wiphy, freq);
+
+        if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
+                return;
+
+        if (ieee80211_vif_is_mesh(&sdata->vif) && elems->mesh_id &&
+            elems->mesh_config && mesh_matches_local(elems, sdata)) {
+                supp_rates = ieee80211_sta_get_rates(local, elems, band);
+
+                mesh_neighbour_update(mgmt->sa, supp_rates, sdata,
+                                      mesh_peer_accepts_plinks(elems));
+        }
+
+        if (sdata->vif.type == IEEE80211_IF_TYPE_IBSS && elems->supp_rates &&
+            memcmp(mgmt->bssid, sdata->u.sta.bssid, ETH_ALEN) == 0) {
+                supp_rates = ieee80211_sta_get_rates(local, elems, band);
+
+                rcu_read_lock();
+
+                sta = sta_info_get(local, mgmt->sa);
+                if (sta) {
+                        u64 prev_rates;
+
+                        prev_rates = sta->supp_rates[band];
+                        /* make sure mandatory rates are always added */
+                        sta->supp_rates[band] = supp_rates |
+                                ieee80211_sta_get_mandatory_rates(local, band);
+
+#ifdef CONFIG_MAC80211_IBSS_DEBUG
+                        if (sta->supp_rates[band] != prev_rates)
+                                printk(KERN_DEBUG "%s: updated supp_rates set "
+                                    "for %s based on beacon info (0x%llx | "
+                                    "0x%llx -> 0x%llx)\n",
+                                    sdata->dev->name, print_mac(mac, sta->addr),
+                                    (unsigned long long) prev_rates,
+                                    (unsigned long long) supp_rates,
+                                    (unsigned long long) sta->supp_rates[band]);
+#endif
+                } else {
+                        ieee80211_ibss_add_sta(sdata, NULL, mgmt->bssid,
+                                               mgmt->sa, supp_rates);
+                }
+
+                rcu_read_unlock();
+        }
+
+        bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
+                                        freq, beacon);
+        if (!bss)
+                return;
+
+        /* was just updated in ieee80211_bss_info_update */
+        beacon_timestamp = bss->timestamp;
+
         /*
          * In STA mode, the remaining parameters should not be overridden
          * by beacons because they're not necessarily accurate there.
@@ -2599,21 +2637,8 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
                 return;
         }
 
-        if (bss->ies == NULL || bss->ies_len < elems->total_len) {
-                kfree(bss->ies);
-                bss->ies = kmalloc(elems->total_len, GFP_ATOMIC);
-        }
-        if (bss->ies) {
-                memcpy(bss->ies, elems->ie_start, elems->total_len);
-                bss->ies_len = elems->total_len;
-        } else
-                bss->ies_len = 0;
-
-        bss->wmm_used = elems->wmm_param || elems->wmm_info;
-
         /* check if we need to merge IBSS */
         if (sdata->vif.type == IEEE80211_IF_TYPE_IBSS && beacon &&
-            !local->sta_sw_scanning && !local->sta_hw_scanning &&
             bss->capability & WLAN_CAPABILITY_IBSS &&
             bss->freq == local->oper_channel->center_freq &&
             elems->ssid_len == sdata->u.sta.ssid_len &&
@@ -2690,7 +2715,7 @@ static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
                                 &elems);
 
-        ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems);
+        ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
 
         /* direct probe may be part of the association flow */
         if (test_and_clear_bit(IEEE80211_STA_REQ_DIRECT_PROBE,
@@ -2721,7 +2746,7 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
 
         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
 
-        ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems);
+        ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
 
         if (sdata->vif.type != IEEE80211_IF_TYPE_STA)
                 return;
@@ -2731,15 +2756,6 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
             memcmp(ifsta->bssid, mgmt->bssid, ETH_ALEN) != 0)
                 return;
 
-        /* Do not send changes to driver if we are scanning. This removes
-         * requirement that a driver's bss_info_changed/conf_tx functions
-         * need to be atomic.
-         * This is really ugly code, we should rewrite scanning and make
-         * all this more understandable for humans.
-         */
-        if (local->sta_sw_scanning || local->sta_hw_scanning)
-                return;
-
         ieee80211_sta_wmm_params(local, ifsta, elems.wmm_param,
                                  elems.wmm_param_len);
 
@@ -2982,41 +2998,6 @@ static void ieee80211_sta_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 }
 
 
-ieee80211_rx_result
-ieee80211_sta_rx_scan(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
-                      struct ieee80211_rx_status *rx_status)
-{
-        struct ieee80211_mgmt *mgmt;
-        __le16 fc;
-
-        if (skb->len < 2)
-                return RX_DROP_UNUSABLE;
-
-        mgmt = (struct ieee80211_mgmt *) skb->data;
-        fc = mgmt->frame_control;
-
-        if (ieee80211_is_ctl(fc))
-                return RX_CONTINUE;
-
-        if (skb->len < 24)
-                return RX_DROP_MONITOR;
-
-        if (ieee80211_is_probe_resp(fc)) {
-                ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, rx_status);
-                dev_kfree_skb(skb);
-                return RX_QUEUED;
-        }
-
-        if (ieee80211_is_beacon(fc)) {
-                ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, rx_status);
-                dev_kfree_skb(skb);
-                return RX_QUEUED;
-        }
-
-        return RX_CONTINUE;
-}
-
-
 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
 {
         struct ieee80211_local *local = sdata->local;
@@ -3233,7 +3214,7 @@ static int ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata,
         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %s\n",
                sdata->dev->name, print_mac(mac, bssid));
 
-        bss = ieee80211_rx_bss_add(sdata, bssid,
+        bss = ieee80211_rx_bss_add(local, bssid,
                                    local->hw.conf.channel->center_freq,
                                    sdata->u.sta.ssid, sdata->u.sta.ssid_len);
         if (!bss)
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 68fa782acd75..2848ba3a08e3 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -23,6 +23,74 @@
 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 5)
 
 
+ieee80211_rx_result
+ieee80211_sta_rx_scan(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
+                      struct ieee80211_rx_status *rx_status)
+{
+        struct ieee80211_mgmt *mgmt;
+        struct ieee80211_sta_bss *bss;
+        u8 *elements;
+        struct ieee80211_channel *channel;
+        size_t baselen;
+        int freq;
+        __le16 fc;
+        bool presp, beacon = false;
+        struct ieee802_11_elems elems;
+
+        if (skb->len < 2)
+                return RX_DROP_UNUSABLE;
+
+        mgmt = (struct ieee80211_mgmt *) skb->data;
+        fc = mgmt->frame_control;
+
+        if (ieee80211_is_ctl(fc))
+                return RX_CONTINUE;
+
+        if (skb->len < 24)
+                return RX_DROP_MONITOR;
+
+        presp = ieee80211_is_probe_resp(fc);
+        if (presp) {
+                /* ignore ProbeResp to foreign address */
+                if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN))
+                        return RX_DROP_MONITOR;
+
+                presp = true;
+                elements = mgmt->u.probe_resp.variable;
+                baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
+        } else {
+                beacon = ieee80211_is_beacon(fc);
+                baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
+                elements = mgmt->u.beacon.variable;
+        }
+
+        if (!presp && !beacon)
+                return RX_CONTINUE;
+
+        if (baselen > skb->len)
+                return RX_DROP_MONITOR;
+
+        ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
+
+        if (elems.ds_params && elems.ds_params_len == 1)
+                freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
+        else
+                freq = rx_status->freq;
+
+        channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq);
+
+        if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
+                return RX_DROP_MONITOR;
+
+        bss = ieee80211_bss_info_update(sdata->local, rx_status,
+                                        mgmt, skb->len, &elems,
+                                        freq, beacon);
+        ieee80211_rx_bss_put(sdata->local, bss);
+
+        dev_kfree_skb(skb);
+        return RX_QUEUED;
+}
+
 static void ieee80211_send_nullfunc(struct ieee80211_local *local,
                                     struct ieee80211_sub_if_data *sdata,
                                     int powersave)