This commit adds duplicate checks to avoid endless rebroadcasts in the case of forwarding multicast data packets via broadcasting.
Signed-off-by: Linus Lüssing <[email protected]> --- originator.c | 3 ++ routing.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--- types.h | 5 ++++ 3 files changed, 68 insertions(+), 4 deletions(-) diff --git a/batman-adv/originator.c b/batman-adv/originator.c index 81b4865..977e75c 100644 --- a/batman-adv/originator.c +++ b/batman-adv/originator.c @@ -224,6 +224,7 @@ struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr) INIT_LIST_HEAD(&orig_node->bond_list); spin_lock_init(&orig_node->ogm_cnt_lock); spin_lock_init(&orig_node->bcast_seqno_lock); + spin_lock_init(&orig_node->mcast_seqno_lock); spin_lock_init(&orig_node->neigh_list_lock); kref_init(&orig_node->refcount); @@ -235,6 +236,8 @@ 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); diff --git a/batman-adv/routing.c b/batman-adv/routing.c index 05482d4..64bff51 100644 --- a/batman-adv/routing.c +++ b/batman-adv/routing.c @@ -1509,20 +1509,65 @@ 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; struct netdev_hw_addr *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 rcu_unlock; + + kref_get(&orig_node->refcount); + rcu_read_unlock(); + + spin_lock_bh(&orig_node->mcast_seqno_lock); + + /* 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 spin_unlock; + + 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 spin_unlock; + + /* 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); + + spin_unlock_bh(&orig_node->mcast_seqno_lock); /* 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); @@ -1536,7 +1581,18 @@ 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; + +rcu_unlock: + rcu_read_unlock(); + goto out; +spin_unlock: + spin_unlock_bh(&orig_node->mcast_seqno_lock); +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) diff --git a/batman-adv/types.h b/batman-adv/types.h index c3dde7c..1af391e 100644 --- a/batman-adv/types.h +++ b/batman-adv/types.h @@ -72,6 +72,7 @@ struct orig_node { uint8_t *bcast_own_sum; 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; @@ -82,7 +83,9 @@ 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 */ @@ -94,6 +97,8 @@ struct orig_node { * neigh_node->real_packet_count */ spinlock_t bcast_seqno_lock; /* protects bcast_bits, * last_bcast_seqno */ + spinlock_t mcast_seqno_lock; /* protects mcast_bits, + * last_mcast_seqno */ atomic_t bond_candidates; struct list_head bond_list; }; -- 1.7.2.3
