[17/19] batman-adv: Add duplicate checks for multicast data
Commit Message
This commit adds duplicate checks to avoid endless rebroadcasts in the
case of forwarding multicast data packets via broadcasting.
Signed-off-by: Linus Lüssing <linus.luessing@saxnet.de>
---
originator.c | 2 ++
routing.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++----
types.h | 3 +++
3 files changed, 58 insertions(+), 4 deletions(-)
@@ -234,6 +234,8 @@ struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
orig_node->num_mca = 0;
orig_node->bcast_seqno_reset = jiffies - 1
- msecs_to_jiffies(RESET_PROTECTION_MS);
+ orig_node->mcast_seqno_reset = jiffies - 1
+ - msecs_to_jiffies(RESET_PROTECTION_MS);
orig_node->batman_seqno_reset = jiffies - 1
- msecs_to_jiffies(RESET_PROTECTION_MS);
@@ -1513,20 +1513,61 @@ out:
int recv_mcast_packet(struct sk_buff *skb, struct batman_if *recv_if)
{
struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface);
+ struct orig_node *orig_node = NULL;
+ struct mcast_packet *mcast_packet;
struct ethhdr *ethhdr;
MC_LIST *mc_entry;
- int ret = 1;
+ int32_t seq_diff;
+ int ret = NET_RX_DROP;
int hdr_size = sizeof(struct mcast_packet);
/* multicast data packets might be received via unicast or broadcast */
if (check_unicast_packet(skb, hdr_size) < 0 &&
check_broadcast_packet(skb, hdr_size) < 0)
- return NET_RX_DROP;
+ goto out;
+
+ mcast_packet = (struct mcast_packet *)skb->data;
+
+ /* ignore broadcasts originated by myself */
+ if (is_my_mac(mcast_packet->orig))
+ goto out;
+
+ if (mcast_packet->ttl < 2)
+ goto out;
+
+ rcu_read_lock();
+ orig_node = ((struct orig_node *)
+ hash_find(bat_priv->orig_hash, compare_orig, choose_orig,
+ mcast_packet->orig));
+
+ if (!orig_node)
+ goto unlock;
+
+ kref_get(&orig_node->refcount);
+ rcu_read_unlock();
+
+ /* check whether the packet is a duplicate */
+ if (get_bit_status(orig_node->mcast_bits,
+ orig_node->last_mcast_seqno,
+ ntohl(mcast_packet->seqno)))
+ goto out;
+
+ seq_diff = ntohl(mcast_packet->seqno) - orig_node->last_mcast_seqno;
+
+ /* check whether the packet is old and the host just restarted. */
+ if (window_protected(bat_priv, seq_diff,
+ &orig_node->mcast_seqno_reset))
+ goto out;
+
+ /* mark broadcast in flood history, update window position
+ * if required. */
+ if (bit_get_packet(bat_priv, orig_node->mcast_bits, seq_diff, 1))
+ orig_node->last_mcast_seqno = ntohl(mcast_packet->seqno);
/* forward multicast packet if necessary */
route_mcast_packet(skb, bat_priv);
- ethhdr = (struct ethhdr *)(skb->data + sizeof(struct mcast_packet));
+ ethhdr = (struct ethhdr *)(mcast_packet + 1);
/* multicast for me? */
netif_addr_lock_bh(recv_if->soft_iface);
@@ -1540,7 +1581,15 @@ int recv_mcast_packet(struct sk_buff *skb, struct batman_if *recv_if)
if (!ret)
interface_rx(recv_if->soft_iface, skb, recv_if, hdr_size);
- return NET_RX_SUCCESS;
+ ret = NET_RX_SUCCESS;
+ goto out;
+
+unlock:
+ rcu_read_unlock();
+out:
+ if (orig_node)
+ kref_put(&orig_node->refcount, orig_node_free_ref);
+ return ret;
}
int recv_mcast_tracker_packet(struct sk_buff *skb, struct batman_if *recv_if)
@@ -74,6 +74,7 @@ struct orig_node {
int tq_asym_penalty;
unsigned long last_valid;
unsigned long bcast_seqno_reset;
+ unsigned long mcast_seqno_reset;
unsigned long batman_seqno_reset;
uint8_t gw_flags;
uint8_t flags;
@@ -84,7 +85,9 @@ struct orig_node {
uint32_t last_real_seqno;
uint8_t last_ttl;
unsigned long bcast_bits[NUM_WORDS];
+ unsigned long mcast_bits[NUM_WORDS];
uint32_t last_bcast_seqno;
+ uint32_t last_mcast_seqno;
struct hlist_head neigh_list;
struct list_head frag_list;
spinlock_t neigh_list_lock; /* protects neighbor list */