With this patch a multicast packet is not always simply flooded anymore, the bevahiour for the following cases is changed to reduce unnecessary overhead:
If all nodes within the horizon of a certain node have signalized multicast listener announcement capability (BATADV_MCAST_LISTENER_ANNOUNCEMENT) then an IPv6 multicast packet with a destination of IPv6 link-local scope coming from the upstream of this node... * ...is dropped if there is no according multicast listener in the translation table, * ...is forwarded via unicast if there is a single node with interested multicast listeners * ...and otherwise still gets flooded. Signed-off-by: Linus Lüssing <[email protected]> --- multicast.c | 49 ++++++++++++++++++++++++++++++++++++++ multicast.h | 23 ++++++++++++++++++ soft-interface.c | 11 +++++++++ translation-table.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++ translation-table.h | 1 + 5 files changed, 150 insertions(+) diff --git a/multicast.c b/multicast.c index 6375347..e4bcdb2 100644 --- a/multicast.c +++ b/multicast.c @@ -21,6 +21,7 @@ #include "originator.h" #include "hard-interface.h" #include "translation-table.h" +#include "multicast.h" struct batadv_hw_addr { struct list_head list; @@ -209,6 +210,54 @@ out: } /** + * batadv_mcast_forw_mode - check on how to forward a multicast packet + * @skb: The multicast packet to check + * @bat_priv: the bat priv with all the soft interface information + * + * Return the forwarding mode as enum batadv_forw_mode. + */ +enum batadv_forw_mode +batadv_mcast_forw_mode(struct sk_buff *skb, struct batadv_priv *bat_priv) +{ + struct ethhdr *ethhdr = (struct ethhdr *)(skb->data); + struct ipv6hdr *ip6hdr; + int count; + + if (!atomic_read(&bat_priv->mcast_group_awareness)) + return BATADV_FORW_ALL; + + if (atomic_read(&bat_priv->mcast.num_no_mla)) + return BATADV_FORW_ALL; + + if (ntohs(ethhdr->h_proto) != ETH_P_IPV6) + return BATADV_FORW_ALL; + + /* We might fail due to out-of-memory -> drop it */ + if (!pskb_may_pull(skb, sizeof(*ethhdr) + sizeof(*ip6hdr))) + return BATADV_FORW_NONE; + + ip6hdr = ipv6_hdr(skb); + + /* TODO: Implement Multicast Router Discovery, then add + * scope >= IPV6_ADDR_SCOPE_LINKLOCAL, too + */ + if (IPV6_ADDR_MC_SCOPE(&ip6hdr->daddr) != + IPV6_ADDR_SCOPE_LINKLOCAL) + return BATADV_FORW_ALL; + + count = batadv_tt_global_hash_count(bat_priv, ethhdr->h_dest); + + switch (count) { + case 0: + return BATADV_FORW_NONE; + case 1: + return BATADV_FORW_SINGLE; + default: + return BATADV_FORW_ALL; + } +} + +/** * batadv_mcast_tvlv_ogm_handler_v1 - process incoming multicast tvlv container * @bat_priv: the bat priv with all the soft interface information * @orig: the orig_node of the ogm diff --git a/multicast.h b/multicast.h index aa58e4b..6388793 100644 --- a/multicast.h +++ b/multicast.h @@ -20,10 +20,27 @@ #ifndef _NET_BATMAN_ADV_MULTICAST_H_ #define _NET_BATMAN_ADV_MULTICAST_H_ +/** + * batadv_forw_mode - the way a packet should be forwarded as + * @BATADV_FORW_ALL: forward the packet to all nodes + * (currently via classic flooding) + * @BATADV_FORW_SINGLE: forward the packet to a single node + * (currently via the BATMAN_IV unicast routing protocol) + * @BATADV_FORW_NONE: don't forward, drop it + */ +enum batadv_forw_mode { + BATADV_FORW_ALL, + BATADV_FORW_SINGLE, + BATADV_FORW_NONE, +}; + #ifdef CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS void batadv_mcast_mla_tt_update(struct batadv_priv *bat_priv); +enum batadv_forw_mode +batadv_mcast_forw_mode(struct sk_buff *skb, struct batadv_priv *bat_priv); + int batadv_mcast_init(struct batadv_priv *bat_priv); void batadv_mcast_free(struct batadv_priv *bat_priv); @@ -37,6 +54,12 @@ static inline void batadv_mcast_mla_tt_update(struct batadv_priv *bat_priv) return; } +static inline batadv_forw_mode +batadv_mcast_forw_mode(struct sk_buff *skb, struct batadv_priv *bat_priv) +{ + return BATADV_FORW_ALL; +} + static inline int batadv_mcast_init(struct batadv_priv *bat_priv) { return 0; diff --git a/soft-interface.c b/soft-interface.c index bc0cc35..7ff5a02 100644 --- a/soft-interface.c +++ b/soft-interface.c @@ -34,6 +34,7 @@ #include <linux/ethtool.h> #include <linux/etherdevice.h> #include <linux/if_vlan.h> +#include "multicast.h" #include "bridge_loop_avoidance.h" #include "network-coding.h" @@ -156,6 +157,7 @@ static int batadv_interface_tx(struct sk_buff *skb, bool do_bcast = false; uint32_t seqno; unsigned long brd_delay = 1; + enum batadv_forw_mode mode; if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) goto dropped; @@ -218,6 +220,15 @@ static int batadv_interface_tx(struct sk_buff *skb, default: break; } + + if (do_bcast && !is_broadcast_ether_addr(ethhdr->h_dest)) { + mode = batadv_mcast_forw_mode(skb, bat_priv); + if (mode == BATADV_FORW_NONE) + goto dropped; + + if (mode == BATADV_FORW_SINGLE) + do_bcast = false; + } } /* ethernet packet should be broadcasted */ diff --git a/translation-table.c b/translation-table.c index 0be7b15..d14ee64 100644 --- a/translation-table.c +++ b/translation-table.c @@ -83,6 +83,72 @@ batadv_tt_hash_find(struct batadv_hashtable *hash, const void *data) return tt_common_entry_tmp; } +/** + * batadv_tt_orig_entries_count - count the number of originators + * @head: a list of originators + * + * Return the number of originator entries in the given list. + * + * The caller needs to hold the rcu_read_lock(). + */ +static int batadv_tt_orig_entries_count(struct hlist_head *head) +{ + struct batadv_tt_orig_list_entry *orig_entry; + int count = 0; + + hlist_for_each_entry_rcu(orig_entry, head, list) { + if (!atomic_read(&orig_entry->refcount)) + continue; + + count++; + } + + return count; +} + +/** + * batadv_tt_global_hash_count - count the number of orig entries + * @hash: hash table containing the tt entries + * @data: the data to count entries for + * + * Return the number of originators advertising the given address/data + * (excluding ourself). + */ +int batadv_tt_global_hash_count(struct batadv_priv *bat_priv, const void *data) +{ + struct hlist_head *head, *orig_list; + struct batadv_tt_common_entry *tt_common_entry; + struct batadv_tt_global_entry *tt_global_entry; + uint32_t index; + int count = 0; + + if (!bat_priv->tt.global_hash) + goto out; + + index = batadv_choose_orig(data, bat_priv->tt.global_hash->size); + head = &bat_priv->tt.global_hash->table[index]; + + rcu_read_lock(); + hlist_for_each_entry_rcu(tt_common_entry, head, hash_entry) { + if (!batadv_compare_eth(tt_common_entry, data)) + continue; + + if (!atomic_read(&tt_common_entry->refcount)) + continue; + + tt_global_entry = container_of(tt_common_entry, + struct batadv_tt_global_entry, + common); + orig_list = &tt_global_entry->orig_list; + count = batadv_tt_orig_entries_count(orig_list); + break; + } + rcu_read_unlock(); + +out: + return count; +} + static struct batadv_tt_local_entry * batadv_tt_local_hash_find(struct batadv_priv *bat_priv, const void *data) { diff --git a/translation-table.h b/translation-table.h index 015d8b9..5986c57 100644 --- a/translation-table.h +++ b/translation-table.h @@ -31,6 +31,7 @@ int batadv_tt_global_seq_print_text(struct seq_file *seq, void *offset); void batadv_tt_global_del_orig(struct batadv_priv *bat_priv, struct batadv_orig_node *orig_node, const char *message); +int batadv_tt_global_hash_count(struct batadv_priv *bat_priv, const void *data); struct batadv_orig_node *batadv_transtable_search(struct batadv_priv *bat_priv, const uint8_t *src, const uint8_t *addr); -- 1.7.10.4
