1 files changed, 64 insertions, 5 deletions

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index e8f849f6b5b7..cc53f78e448c 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -1079,8 +1079,9 @@ out:
 	return skb;
 }
 
-int send_tt_request(struct bat_priv *bat_priv, struct orig_node *dst_orig_node,
-		    uint8_t ttvn, uint16_t tt_crc, bool full_table)
+static int send_tt_request(struct bat_priv *bat_priv,
+			   struct orig_node *dst_orig_node,
+			   uint8_t ttvn, uint16_t tt_crc, bool full_table)
 {
 	struct sk_buff *skb = NULL;
 	struct tt_query_packet *tt_request;
@@ -1455,9 +1456,10 @@ out:
 		orig_node_free_ref(orig_node);
 }
 
-void tt_update_changes(struct bat_priv *bat_priv, struct orig_node *orig_node,
-		       uint16_t tt_num_changes, uint8_t ttvn,
-		       struct tt_change *tt_change)
+static void tt_update_changes(struct bat_priv *bat_priv,
+			      struct orig_node *orig_node,
+			      uint16_t tt_num_changes, uint8_t ttvn,
+			      struct tt_change *tt_change)
 {
 	_tt_update_changes(bat_priv, orig_node, tt_change, tt_num_changes,
 			   ttvn);
@@ -1802,3 +1804,60 @@ out:
 		tt_local_entry_free_ref(tt_local_entry);
 	return ret;
 }
+
+void tt_update_orig(struct bat_priv *bat_priv, struct orig_node *orig_node,
+		    const unsigned char *tt_buff, uint8_t tt_num_changes,
+		    uint8_t ttvn, uint16_t tt_crc)
+{
+	uint8_t orig_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
+	bool full_table = true;
+
+	/* the ttvn increased by one -> we can apply the attached changes */
+	if (ttvn - orig_ttvn == 1) {
+		/* the OGM could not contain the changes due to their size or
+		 * because they have already been sent TT_OGM_APPEND_MAX times.
+		 * In this case send a tt request */
+		if (!tt_num_changes) {
+			full_table = false;
+			goto request_table;
+		}
+
+		tt_update_changes(bat_priv, orig_node, tt_num_changes, ttvn,
+				  (struct tt_change *)tt_buff);
+
+		/* Even if we received the precomputed crc with the OGM, we
+		 * prefer to recompute it to spot any possible inconsistency
+		 * in the global table */
+		orig_node->tt_crc = tt_global_crc(bat_priv, orig_node);
+
+		/* The ttvn alone is not enough to guarantee consistency
+		 * because a single value could represent different states
+		 * (due to the wrap around). Thus a node has to check whether
+		 * the resulting table (after applying the changes) is still
+		 * consistent or not. E.g. a node could disconnect while its
+		 * ttvn is X and reconnect on ttvn = X + TTVN_MAX: in this case
+		 * checking the CRC value is mandatory to detect the
+		 * inconsistency */
+		if (orig_node->tt_crc != tt_crc)
+			goto request_table;
+
+		/* Roaming phase is over: tables are in sync again. I can
+		 * unset the flag */
+		orig_node->tt_poss_change = false;
+	} else {
+		/* if we missed more than one change or our tables are not
+		 * in sync anymore -> request fresh tt data */
+		if (ttvn != orig_ttvn || orig_node->tt_crc != tt_crc) {
+request_table:
+			bat_dbg(DBG_TT, bat_priv, "TT inconsistency for %pM. "
+				"Need to retrieve the correct information "
+				"(ttvn: %u last_ttvn: %u crc: %u last_crc: "
+				"%u num_changes: %u)\n", orig_node->orig, ttvn,
+				orig_ttvn, tt_crc, orig_node->tt_crc,
+				tt_num_changes);
+			send_tt_request(bat_priv, orig_node, ttvn, tt_crc,
+					full_table);
+			return;
+		}
+	}
+}