mac80211: factor out plink event gathering

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mesh_plink.c

@@ -844,110 +844,69 @@ static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
 	return changed;
 }
 
-static void
-mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
-			 struct ieee80211_mgmt *mgmt,
-			 struct ieee802_11_elems *elems)
+/*
+ * mesh_plink_get_event - get correct MPM event
+ *
+ * @sdata: interface
+ * @sta: peer, leave NULL if processing a frame from a new suitable peer
+ * @elems: peering management IEs
+ * @ftype: frame type
+ * @llid: peer's peer link ID
+ * @plid: peer's local link ID
+ *
+ * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
+ * an error.
+ */
+static enum plink_event
+mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
+		     struct sta_info *sta,
+		     struct ieee802_11_elems *elems,
+		     enum ieee80211_self_protected_actioncode ftype,
+		     __le16 llid, __le16 plid)
 {
-
-	struct sta_info *sta;
-	enum plink_event event;
-	enum ieee80211_self_protected_actioncode ftype;
+	enum plink_event event = PLINK_UNDEFINED;
+	u8 ie_len = elems->peering_len;
 	bool matches_local;
-	u32 changed = 0;
-	u8 ie_len;
-	__le16 plid, llid = 0;
-
-	if (!elems->peering) {
-		mpl_dbg(sdata,
-			"Mesh plink: missing necessary peer link ie\n");
-		return;
-	}
-
-	if (elems->rsn_len &&
-	    sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
-		mpl_dbg(sdata,
-			"Mesh plink: can't establish link with secure peer\n");
-		return;
-	}
-
-	ftype = mgmt->u.action.u.self_prot.action_code;
-	ie_len = elems->peering_len;
-	if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
-	    (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
-	    (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
-							&& ie_len != 8)) {
-		mpl_dbg(sdata,
-			"Mesh plink: incorrect plink ie length %d %d\n",
-			ftype, ie_len);
-		return;
-	}
-
-	if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
-	    (!elems->mesh_id || !elems->mesh_config)) {
-		mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
-		return;
-	}
-	/* Note the lines below are correct, the llid in the frame is the plid
-	 * from the point of view of this host.
-	 */
-	memcpy(&plid, PLINK_GET_LLID(elems->peering), 2);
-	if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
-	    (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
-		memcpy(&llid, PLINK_GET_PLID(elems->peering), 2);
-
-	/* WARNING: Only for sta pointer, is dropped & re-acquired */
-	rcu_read_lock();
-
-	sta = sta_info_get(sdata, mgmt->sa);
 
 	matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
 			 mesh_matches_local(sdata, elems));
 
-	if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
-	    !rssi_threshold_check(sdata, sta)) {
-		mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
-			mgmt->sa);
-		goto unlock_rcu;
+	/* deny open request from non-matching peer */
+	if (!matches_local && !sta) {
+		event = OPN_RJCT;
+		goto out;
 	}
 
 	if (!sta) {
 		if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
 			mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
-			goto unlock_rcu;
+			goto out;
 		}
 		/* ftype == WLAN_SP_MESH_PEERING_OPEN */
 		if (!mesh_plink_free_count(sdata)) {
 			mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
-			goto unlock_rcu;
-		}
-		/* deny open request from non-matching peer */
-		if (!matches_local) {
-			mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
-					    mgmt->sa, 0, plid,
-					    cpu_to_le16(WLAN_REASON_MESH_CONFIG));
-			goto unlock_rcu;
+			goto out;
 		}
 	} else {
 		if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
 			mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
-			goto unlock_rcu;
+			goto out;
 		}
 		if (sta->plink_state == NL80211_PLINK_BLOCKED)
-			goto unlock_rcu;
+			goto out;
 	}
 
-	/* Now we will figure out the appropriate event... */
-	event = PLINK_UNDEFINED;
-
-	if (!sta)
+	/* new matching peer */
+	if (!sta) {
 		event = OPN_ACPT;
-	else {
+		goto out;
+	}
+
 	switch (ftype) {
 	case WLAN_SP_MESH_PEERING_OPEN:
 		if (!matches_local)
 			event = OPN_RJCT;
-			else if (!mesh_plink_free_count(sdata) ||
+		if (!mesh_plink_free_count(sdata) ||
 		    (sta->plid && sta->plid != plid))
 			event = OPN_IGNR;
 		else
@@ -956,7 +915,7 @@ mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
 	case WLAN_SP_MESH_PEERING_CONFIRM:
 		if (!matches_local)
 			event = CNF_RJCT;
-			else if (!mesh_plink_free_count(sdata) ||
+		if (!mesh_plink_free_count(sdata) ||
 		    (sta->llid != llid || sta->plid != plid))
 			event = CNF_IGNR;
 		else
@@ -983,10 +942,78 @@ mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
 		break;
 	default:
 		mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
-			goto unlock_rcu;
+		break;
+	}
+
+out:
+	return event;
+}
+
+static void
+mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
+			 struct ieee80211_mgmt *mgmt,
+			 struct ieee802_11_elems *elems)
+{
+
+	struct sta_info *sta;
+	enum plink_event event;
+	enum ieee80211_self_protected_actioncode ftype;
+	u32 changed = 0;
+	u8 ie_len = elems->peering_len;
+	__le16 plid, llid = 0;
+
+	if (!elems->peering) {
+		mpl_dbg(sdata,
+			"Mesh plink: missing necessary peer link ie\n");
+		return;
 	}
+
+	if (elems->rsn_len &&
+	    sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
+		mpl_dbg(sdata,
+			"Mesh plink: can't establish link with secure peer\n");
+		return;
 	}
 
+	ftype = mgmt->u.action.u.self_prot.action_code;
+	if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
+	    (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
+	    (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
+							&& ie_len != 8)) {
+		mpl_dbg(sdata,
+			"Mesh plink: incorrect plink ie length %d %d\n",
+			ftype, ie_len);
+		return;
+	}
+
+	if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
+	    (!elems->mesh_id || !elems->mesh_config)) {
+		mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
+		return;
+	}
+	/* Note the lines below are correct, the llid in the frame is the plid
+	 * from the point of view of this host.
+	 */
+	memcpy(&plid, PLINK_GET_LLID(elems->peering), 2);
+	if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
+	    (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
+		memcpy(&llid, PLINK_GET_PLID(elems->peering), 2);
+
+	/* WARNING: Only for sta pointer, is dropped & re-acquired */
+	rcu_read_lock();
+
+	sta = sta_info_get(sdata, mgmt->sa);
+
+	if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
+	    !rssi_threshold_check(sdata, sta)) {
+		mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
+			mgmt->sa);
+		goto unlock_rcu;
+	}
+
+	/* Now we will figure out the appropriate event... */
+	event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
+
 	if (event == OPN_ACPT) {
 		rcu_read_unlock();
 		/* allocate sta entry if necessary and update info */
@@ -996,6 +1023,14 @@ mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
 			goto unlock_rcu;
 		}
 		sta->plid = plid;
+	} else if (!sta && event == OPN_RJCT) {
+		mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
+				    mgmt->sa, 0, plid,
+				    cpu_to_le16(WLAN_REASON_MESH_CONFIG));
+		goto unlock_rcu;
+	} else if (!sta || event == PLINK_UNDEFINED) {
+		/* something went wrong */
+		goto unlock_rcu;
 	}
 
 	changed |= mesh_plink_fsm(sdata, sta, event);