1 files changed, 94 insertions, 21 deletions

diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index d8a2f33e60e5..e470410abb44 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -359,6 +359,7 @@ int batadv_recv_icmp_packet(struct sk_buff *skb,
 		if (skb_cow(skb, ETH_HLEN) < 0)
 			goto out;
 
+		ethhdr = eth_hdr(skb);
 		icmph = (struct batadv_icmp_header *)skb->data;
 		icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmph;
 		if (icmp_packet_rr->rr_cur >= BATADV_RR_LEN)
@@ -439,6 +440,52 @@ static int batadv_check_unicast_packet(struct batadv_priv *bat_priv,
 }
 
 /**
+ * batadv_last_bonding_get - Get last_bonding_candidate of orig_node
+ * @orig_node: originator node whose last bonding candidate should be retrieved
+ *
+ * Return: last bonding candidate of router or NULL if not found
+ *
+ * The object is returned with refcounter increased by 1.
+ */
+static struct batadv_orig_ifinfo *
+batadv_last_bonding_get(struct batadv_orig_node *orig_node)
+{
+	struct batadv_orig_ifinfo *last_bonding_candidate;
+
+	spin_lock_bh(&orig_node->neigh_list_lock);
+	last_bonding_candidate = orig_node->last_bonding_candidate;
+
+	if (last_bonding_candidate)
+		atomic_inc(&last_bonding_candidate->refcount);
+	spin_unlock_bh(&orig_node->neigh_list_lock);
+
+	return last_bonding_candidate;
+}
+
+/**
+ * batadv_last_bonding_replace - Replace last_bonding_candidate of orig_node
+ * @orig_node: originator node whose bonding candidates should be replaced
+ * @new_candidate: new bonding candidate or NULL
+ */
+static void
+batadv_last_bonding_replace(struct batadv_orig_node *orig_node,
+			    struct batadv_orig_ifinfo *new_candidate)
+{
+	struct batadv_orig_ifinfo *old_candidate;
+
+	spin_lock_bh(&orig_node->neigh_list_lock);
+	old_candidate = orig_node->last_bonding_candidate;
+
+	if (new_candidate)
+		atomic_inc(&new_candidate->refcount);
+	orig_node->last_bonding_candidate = new_candidate;
+	spin_unlock_bh(&orig_node->neigh_list_lock);
+
+	if (old_candidate)
+		batadv_orig_ifinfo_free_ref(old_candidate);
+}
+
+/**
  * batadv_find_router - find a suitable router for this originator
  * @bat_priv: the bat priv with all the soft interface information
  * @orig_node: the destination node
@@ -485,7 +532,7 @@ batadv_find_router(struct batadv_priv *bat_priv,
 	 * router - obviously there are no other candidates.
 	 */
 	rcu_read_lock();
-	last_candidate = orig_node->last_bonding_candidate;
+	last_candidate = batadv_last_bonding_get(orig_node);
 	if (last_candidate)
 		last_cand_router = rcu_dereference(last_candidate->router);
 
@@ -545,10 +592,6 @@ next:
 	}
 	rcu_read_unlock();
 
-	/* last_bonding_candidate is reset below, remove the old reference. */
-	if (orig_node->last_bonding_candidate)
-		batadv_orig_ifinfo_free_ref(orig_node->last_bonding_candidate);
-
 	/* After finding candidates, handle the three cases:
 	 * 1) there is a next candidate, use that
 	 * 2) there is no next candidate, use the first of the list
@@ -557,23 +600,33 @@ next:
 	if (next_candidate) {
 		batadv_neigh_node_free_ref(router);
 
-		/* remove references to first candidate, we don't need it. */
-		if (first_candidate) {
-			batadv_neigh_node_free_ref(first_candidate_router);
-			batadv_orig_ifinfo_free_ref(first_candidate);
-		}
+		atomic_inc(&next_candidate_router->refcount);
 		router = next_candidate_router;
-		orig_node->last_bonding_candidate = next_candidate;
+		batadv_last_bonding_replace(orig_node, next_candidate);
 	} else if (first_candidate) {
 		batadv_neigh_node_free_ref(router);
 
-		/* refcounting has already been done in the loop above. */
+		atomic_inc(&first_candidate_router->refcount);
 		router = first_candidate_router;
-		orig_node->last_bonding_candidate = first_candidate;
+		batadv_last_bonding_replace(orig_node, first_candidate);
 	} else {
-		orig_node->last_bonding_candidate = NULL;
+		batadv_last_bonding_replace(orig_node, NULL);
+	}
+
+	/* cleanup of candidates */
+	if (first_candidate) {
+		batadv_neigh_node_free_ref(first_candidate_router);
+		batadv_orig_ifinfo_free_ref(first_candidate);
 	}
 
+	if (next_candidate) {
+		batadv_neigh_node_free_ref(next_candidate_router);
+		batadv_orig_ifinfo_free_ref(next_candidate);
+	}
+
+	if (last_candidate)
+		batadv_orig_ifinfo_free_ref(last_candidate);
+
 	return router;
 }
 
@@ -585,6 +638,7 @@ static int batadv_route_unicast_packet(struct sk_buff *skb,
 	struct batadv_unicast_packet *unicast_packet;
 	struct ethhdr *ethhdr = eth_hdr(skb);
 	int res, hdr_len, ret = NET_RX_DROP;
+	unsigned int len;
 
 	unicast_packet = (struct batadv_unicast_packet *)skb->data;
 
@@ -625,6 +679,7 @@ static int batadv_route_unicast_packet(struct sk_buff *skb,
 	if (hdr_len > 0)
 		batadv_skb_set_priority(skb, hdr_len);
 
+	len = skb->len;
 	res = batadv_send_skb_to_orig(skb, orig_node, recv_if);
 
 	/* translate transmit result into receive result */
@@ -632,7 +687,7 @@ static int batadv_route_unicast_packet(struct sk_buff *skb,
 		/* skb was transmitted and consumed */
 		batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD);
 		batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES,
-				   skb->len + ETH_HLEN);
+				   len + ETH_HLEN);
 
 		ret = NET_RX_SUCCESS;
 	} else if (res == NET_XMIT_POLICED) {
@@ -649,6 +704,7 @@ out:
 /**
  * batadv_reroute_unicast_packet - update the unicast header for re-routing
  * @bat_priv: the bat priv with all the soft interface information
+ * @skb: unicast packet to process
  * @unicast_packet: the unicast header to be updated
  * @dst_addr: the payload destination
  * @vid: VLAN identifier
@@ -660,7 +716,7 @@ out:
  * Returns true if the packet header has been updated, false otherwise
  */
 static bool
-batadv_reroute_unicast_packet(struct batadv_priv *bat_priv,
+batadv_reroute_unicast_packet(struct batadv_priv *bat_priv, struct sk_buff *skb,
 			      struct batadv_unicast_packet *unicast_packet,
 			      u8 *dst_addr, unsigned short vid)
 {
@@ -689,8 +745,10 @@ batadv_reroute_unicast_packet(struct batadv_priv *bat_priv,
 	}
 
 	/* update the packet header */
+	skb_postpull_rcsum(skb, unicast_packet, sizeof(*unicast_packet));
 	ether_addr_copy(unicast_packet->dest, orig_addr);
 	unicast_packet->ttvn = orig_ttvn;
+	skb_postpush_rcsum(skb, unicast_packet, sizeof(*unicast_packet));
 
 	ret = true;
 out:
@@ -724,13 +782,17 @@ static int batadv_check_unicast_ttvn(struct batadv_priv *bat_priv,
 	vid = batadv_get_vid(skb, hdr_len);
 	ethhdr = (struct ethhdr *)(skb->data + hdr_len);
 
+	/* do not reroute multicast frames in a unicast header */
+	if (is_multicast_ether_addr(ethhdr->h_dest))
+		return true;
+
 	/* check if the destination client was served by this node and it is now
 	 * roaming. In this case, it means that the node has got a ROAM_ADV
 	 * message and that it knows the new destination in the mesh to re-route
 	 * the packet to
 	 */
 	if (batadv_tt_local_client_is_roaming(bat_priv, ethhdr->h_dest, vid)) {
-		if (batadv_reroute_unicast_packet(bat_priv, unicast_packet,
+		if (batadv_reroute_unicast_packet(bat_priv, skb, unicast_packet,
 						  ethhdr->h_dest, vid))
 			batadv_dbg_ratelimited(BATADV_DBG_TT,
 					       bat_priv,
@@ -776,7 +838,7 @@ static int batadv_check_unicast_ttvn(struct batadv_priv *bat_priv,
 	 * destination can possibly be updated and forwarded towards the new
 	 * target host
 	 */
-	if (batadv_reroute_unicast_packet(bat_priv, unicast_packet,
+	if (batadv_reroute_unicast_packet(bat_priv, skb, unicast_packet,
 					  ethhdr->h_dest, vid)) {
 		batadv_dbg_ratelimited(BATADV_DBG_TT, bat_priv,
 				       "Rerouting unicast packet to %pM (dst=%pM): TTVN mismatch old_ttvn=%u new_ttvn=%u\n",
@@ -799,12 +861,14 @@ static int batadv_check_unicast_ttvn(struct batadv_priv *bat_priv,
 	if (!primary_if)
 		return 0;
 
+	/* update the packet header */
+	skb_postpull_rcsum(skb, unicast_packet, sizeof(*unicast_packet));
 	ether_addr_copy(unicast_packet->dest, primary_if->net_dev->dev_addr);
+	unicast_packet->ttvn = curr_ttvn;
+	skb_postpush_rcsum(skb, unicast_packet, sizeof(*unicast_packet));
 
 	batadv_hardif_free_ref(primary_if);
 
-	unicast_packet->ttvn = curr_ttvn;
-
 	return 1;
 }
 
@@ -849,7 +913,6 @@ int batadv_recv_unicast_packet(struct sk_buff *skb,
 	bool is4addr;
 
 	unicast_packet = (struct batadv_unicast_packet *)skb->data;
-	unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
 
 	is4addr = unicast_packet->packet_type == BATADV_UNICAST_4ADDR;
 	/* the caller function should have already pulled 2 bytes */
@@ -870,9 +933,13 @@ int batadv_recv_unicast_packet(struct sk_buff *skb,
 	if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size))
 		return NET_RX_DROP;
 
+	unicast_packet = (struct batadv_unicast_packet *)skb->data;
+
 	/* packet for me */
 	if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) {
 		if (is4addr) {
+			unicast_4addr_packet =
+				(struct batadv_unicast_4addr_packet *)skb->data;
 			subtype = unicast_4addr_packet->subtype;
 			batadv_dat_inc_counter(bat_priv, subtype);
 
@@ -998,6 +1065,12 @@ int batadv_recv_frag_packet(struct sk_buff *skb,
 	batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_RX);
 	batadv_add_counter(bat_priv, BATADV_CNT_FRAG_RX_BYTES, skb->len);
 
+	/* batadv_frag_skb_buffer will always consume the skb and
+	 * the caller should therefore never try to free the
+	 * skb after this point
+	 */
+	ret = NET_RX_SUCCESS;
+
 	/* Add fragment to buffer and merge if possible. */
 	if (!batadv_frag_skb_buffer(&skb, orig_node_src))
 		goto out;