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 linus.luessing@web.de --- distributed-arp-table.c | 2 +- multicast.c | 56 +++++++++++++++++++++++++++++++++++++ multicast.h | 23 +++++++++++++++ send.c | 5 ++-- send.h | 9 +++--- soft-interface.c | 18 ++++++++++-- translation-table.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++ translation-table.h | 2 ++ 8 files changed, 177 insertions(+), 9 deletions(-)
diff --git a/distributed-arp-table.c b/distributed-arp-table.c index f2543c2..87248bb 100644 --- a/distributed-arp-table.c +++ b/distributed-arp-table.c @@ -1030,7 +1030,7 @@ bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv, BATADV_P_DAT_CACHE_REPLY, vid); else - err = batadv_send_skb_unicast(bat_priv, skb_new, vid); + err = batadv_send_skb_unicast(bat_priv, skb_new, vid, false);
if (!err) { batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX); diff --git a/multicast.c b/multicast.c index 74fb19e..7a52a63 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; @@ -210,6 +211,61 @@ 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; + + /* We cannot snoop and therefore cannot optimize the + * all-nodes-multicast address + */ + if (ipv6_addr_is_ll_all_nodes(&ip6hdr->daddr)) + return BATADV_FORW_ALL; + + count = batadv_tt_global_hash_count(bat_priv, ethhdr->h_dest, + BATADV_NO_FLAGS); + + 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..7b291d5 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 enum 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/send.c b/send.c index b631355..68f65f1 100644 --- a/send.c +++ b/send.c @@ -242,13 +242,14 @@ out: * @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast * 4addr packets) * @vid: the vid to be used to search the translation table + * @forw_to_gw: whether to forward to a gateway (or via TT otherwise) * * Returns 1 in case of error or 0 otherwise. */ int batadv_send_skb_generic_unicast(struct batadv_priv *bat_priv, struct sk_buff *skb, int packet_type, int packet_subtype, - unsigned short vid) + unsigned short vid, bool forw_to_gw) { struct ethhdr *ethhdr = (struct ethhdr *)skb->data; struct batadv_unicast_packet *unicast_packet; @@ -256,7 +257,7 @@ int batadv_send_skb_generic_unicast(struct batadv_priv *bat_priv, int ret = NET_RX_DROP;
/* get routing information */ - if (is_multicast_ether_addr(ethhdr->h_dest)) + if (forw_to_gw) orig_node = batadv_gw_get_selected_orig(bat_priv); else /* check for tt host - increases orig_node refcount. diff --git a/send.h b/send.h index c030cb7..642f9fc 100644 --- a/send.h +++ b/send.h @@ -41,22 +41,23 @@ bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv, int batadv_send_skb_generic_unicast(struct batadv_priv *bat_priv, struct sk_buff *skb, int packet_type, int packet_subtype, - unsigned short vid); + unsigned short vid, bool forw_to_gw);
/** * batadv_send_unicast_skb - send the skb encapsulated in a unicast packet * @bat_priv: the bat priv with all the soft interface information * @skb: the payload to send * @vid: the vid to be used to search the translation table + * @forw_to_gw: whether to forward to a gateway (or via TT otherwise) * * Returns 1 in case of error or 0 otherwise. */ static inline int batadv_send_skb_unicast(struct batadv_priv *bat_priv, struct sk_buff *skb, - unsigned short vid) + unsigned short vid, bool forw_to_gw) { return batadv_send_skb_generic_unicast(bat_priv, skb, BATADV_UNICAST, - 0, vid); + 0, vid, forw_to_gw); }
/** @@ -76,7 +77,7 @@ static inline int batadv_send_skb_unicast_4addr(struct batadv_priv *bat_priv, { return batadv_send_skb_generic_unicast(bat_priv, skb, BATADV_UNICAST_4ADDR, - packet_subtype, vid); + packet_subtype, vid, false); }
#endif /* _NET_BATMAN_ADV_SEND_H_ */ diff --git a/soft-interface.c b/soft-interface.c index 90d06c5..d91526f 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"
@@ -169,6 +170,8 @@ static int batadv_interface_tx(struct sk_buff *skb, bool do_bcast = false; unsigned short vid; uint32_t seqno; + enum batadv_forw_mode mode; + bool forw_to_gw = false;
if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) goto dropped; @@ -226,13 +229,24 @@ static int batadv_interface_tx(struct sk_buff *skb, * via unicast to their gateway */ ret = batadv_gw_is_dhcp_target(skb, &header_len); - if (ret) + if (ret) { do_bcast = false; + forw_to_gw = true; + } break; case BATADV_GW_MODE_OFF: 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 */ @@ -289,7 +303,7 @@ static int batadv_interface_tx(struct sk_buff *skb,
batadv_dat_snoop_outgoing_arp_reply(bat_priv, skb);
- ret = batadv_send_skb_unicast(bat_priv, skb, vid); + ret = batadv_send_skb_unicast(bat_priv, skb, vid, forw_to_gw); if (ret != 0) goto dropped_freed; } diff --git a/translation-table.c b/translation-table.c index 18a2051..87287c7 100644 --- a/translation-table.c +++ b/translation-table.c @@ -125,6 +125,77 @@ batadv_tt_hash_find(struct batadv_hashtable *hash, const uint8_t *addr, }
/** + * 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 + * @addr: the mac address of the client to count entries for + * @vid: VLAN identifier + * + * Return the number of originators advertising the given address/data + * (excluding ourself). + */ +int batadv_tt_global_hash_count(struct batadv_priv *bat_priv, + const uint8_t *addr, unsigned short vid) +{ + struct hlist_head *head, *orig_list; + struct batadv_tt_common_entry to_search, *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; + + memcpy(to_search.addr, addr, ETH_ALEN); + to_search.vid = vid; + + index = batadv_choose_tt(&to_search, 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, addr)) + 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; +} + +/** * batadv_tt_local_hash_find - search the local table for a given client * @bat_priv: the bat priv with all the soft interface information * @addr: the mac address of the client to look for diff --git a/translation-table.h b/translation-table.h index 1d9506d..3916ca8 100644 --- a/translation-table.h +++ b/translation-table.h @@ -31,6 +31,8 @@ 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 uint8_t *addr, unsigned short vid); struct batadv_orig_node *batadv_transtable_search(struct batadv_priv *bat_priv, const uint8_t *src, const uint8_t *addr,