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 | 48 +++++++++++++++++++++++++++++++++++++++++++++++- types.h | 3 +++ 3 files changed, 52 insertions(+), 1 deletions(-)
diff --git a/originator.c b/originator.c index 39ce8d5..f882292 100644 --- a/originator.c +++ b/originator.c @@ -154,6 +154,8 @@ 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/routing.c b/routing.c index f9582be..19f045a 100644 --- a/routing.c +++ b/routing.c @@ -1391,8 +1391,11 @@ int recv_bcast_packet(struct sk_buff *skb, struct batman_if *recv_if) 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; + struct mcast_packet *mcast_packet; struct ethhdr *ethhdr; MC_LIST *mc_entry; + int32_t seq_diff; unsigned long flags; int ret = 1; int hdr_size = sizeof(struct mcast_packet); @@ -1402,10 +1405,53 @@ int recv_mcast_packet(struct sk_buff *skb, struct batman_if *recv_if) check_broadcast_packet(skb, hdr_size) < 0) return NET_RX_DROP;
+ mcast_packet = (struct mcast_packet *)skb->data; + + /* ignore broadcasts originated by myself */ + if (is_my_mac(mcast_packet->orig)) + return NET_RX_DROP; + + if (mcast_packet->ttl < 2) + return NET_RX_DROP; + + spin_lock_irqsave(&bat_priv->orig_hash_lock, flags); + orig_node = ((struct orig_node *) + hash_find(bat_priv->orig_hash, compare_orig, choose_orig, + mcast_packet->orig)); + + if (orig_node == NULL) { + spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags); + return NET_RX_DROP; + } + + /* check whether the packet is a duplicate */ + if (get_bit_status(orig_node->mcast_bits, + orig_node->last_mcast_seqno, + ntohl(mcast_packet->seqno))) { + spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags); + return NET_RX_DROP; + } + + 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)) { + spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags); + return NET_RX_DROP; + } + + /* 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_irqrestore(&bat_priv->orig_hash_lock, flags); + /* 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? */ MC_LIST_LOCK(recv_if->soft_iface, flags); diff --git a/types.h b/types.h index c12fd2c..890822f 100644 --- a/types.h +++ b/types.h @@ -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; TYPE_OF_WORD bcast_bits[NUM_WORDS]; + TYPE_OF_WORD mcast_bits[NUM_WORDS]; uint32_t last_bcast_seqno; + uint32_t last_mcast_seqno; struct list_head neigh_list; struct list_head frag_list; unsigned long last_frag_packet;