[B.A.T.M.A.N.] [PATCHv3 2/6] batman-adv: speed up dat by snooping received ip traffic

Speeding up dat address lookup is achieved by snooping all incoming ip traffic. This especially increases the propability in bla setups that a gateway into a common backbone network already has a fitting dat entry to answer incoming ARP requests directly coming from the backbone network thus further reducing ARP traffic in the mesh. Signed-off-by: Andreas Pape &lt;apape(a)phoenixcontact.com&gt; --- net/batman-adv/distributed-arp-table.c | 50 ++++++++++++++++++++++++++++++++ net/batman-adv/distributed-arp-table.h | 9 +++++- net/batman-adv/soft-interface.c | 4 ++ 3 files changed, 62 insertions(+), 1 deletions(-) diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index c11f035..58cb488 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -27,6 +27,7 @@ #include <linux/if_arp.h> #include <linux/if_ether.h> #include <linux/if_vlan.h> +#include <linux/ip.h> #include <linux/in.h> #include <linux/jiffies.h> #include <linux/kernel.h> @@ -362,6 +363,55 @@ out: batadv_dat_entry_put(dat_entry); } +/** + * batadv_dat_entry_check - check and update a dat entry + * @bat_priv: the bat priv with all the soft interface information + * @skb: socket buffer + * @vid: VLAN identifier + * + * snoops incoming socket buffer for dat cache updates, if dat is enabled. + * Can be called from other modules. + */ +void batadv_dat_entry_check(struct batadv_priv *bat_priv, struct sk_buff *skb, + unsigned short vid) +{ + struct vlan_ethhdr *vhdr = NULL, tmp_vhdr; + struct ethhdr *ethhdr = NULL; + struct iphdr *iphdr = NULL, tmp_iphdr; + + if (!atomic_read(&bat_priv->distributed_arp_table)) + return; + + ethhdr = eth_hdr(skb); + + switch (ntohs(ethhdr->h_proto)) { + case ETH_P_IP: + iphdr = skb_header_pointer(skb, ETH_HLEN, sizeof(tmp_iphdr), + &tmp_iphdr); + break; + case ETH_P_8021Q: + vhdr = skb_header_pointer(skb, 0, sizeof(tmp_vhdr), + &tmp_vhdr); + if (!vhdr) + break; + if (ntohs(vhdr->h_vlan_encapsulated_proto) == ETH_P_IP) { + iphdr = skb_header_pointer(skb, sizeof(tmp_vhdr), + sizeof(tmp_iphdr), + &tmp_iphdr); + } + break; + } + + if (iphdr) { + batadv_dbg(BATADV_DBG_DAT, bat_priv, + "Snooped IP address: %pI4 %pM (vid: %d)\n", + &iphdr->saddr, ethhdr->h_source, + BATADV_PRINT_VID(vid)); + batadv_dat_entry_add(bat_priv, iphdr->saddr, + ethhdr->h_source, vid); + } +} + #ifdef CONFIG_BATMAN_ADV_DEBUG /** diff --git a/net/batman-adv/distributed-arp-table.h b/net/batman-adv/distributed-arp-table.h index 813ecea..cf1b93c 100644 --- a/net/batman-adv/distributed-arp-table.h +++ b/net/batman-adv/distributed-arp-table.h @@ -80,7 +80,8 @@ batadv_dat_init_own_addr(struct batadv_priv *bat_priv, int batadv_dat_init(struct batadv_priv *bat_priv); void batadv_dat_free(struct batadv_priv *bat_priv); int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset); - +void batadv_dat_entry_check(struct batadv_priv *bat_priv, struct sk_buff *skb, + unsigned short vid); /** * batadv_dat_inc_counter - increment the correct DAT packet counter * @bat_priv: the bat priv with all the soft interface information @@ -173,6 +174,12 @@ static inline void batadv_dat_inc_counter(struct batadv_priv *bat_priv, { } +static inline +void batadv_dat_entry_check(struct batadv_priv *bat_priv, struct sk_buff *skb, + unsigned short vid) +{ +} + #endif /* CONFIG_BATMAN_ADV_DAT */ #endif /* _NET_BATMAN_ADV_DISTRIBUTED_ARP_TABLE_H_ */ diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 81665b1..1f1742a 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -28,6 +28,7 @@ #include <linux/fs.h> #include <linux/if_ether.h> #include <linux/if_vlan.h> +#include <linux/ip.h> #include <linux/jiffies.h> #include <linux/kernel.h> #include <linux/kref.h> @@ -442,6 +443,9 @@ void batadv_interface_rx(struct net_device *soft_iface, goto dropped; } + /* Snoop incoming traffic for dat update */ + batadv_dat_entry_check(bat_priv, skb, vid); + /* skb->dev & skb->pkt_type are set here */ skb->protocol = eth_type_trans(skb, soft_iface); -- 1.7.0.4 .................................................................. 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