Re: [B.A.T.M.A.N.] [PATCHv2 2/7] batman-adv: speed up dat by snooping received ip traffic

On Friday 26 February 2016 14:18:17 Andreas Pape wrote:

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 apape@phoenixcontact.com

[...]

switch (ntohs(ethhdr->h_proto)) {

• case ETH_P_IP:

• iphdr = (struct iphdr *)(skb->data + ETH_HLEN);
  

• /* snoop incoming traffic for dat update using the source mac
  

•  * and source ip to speed up dat.
  

•  */
  

• batadv_dat_entry_check(bat_priv, iphdr->saddr,
  

• 		       ethhdr->h_source, vid);
  

• break;
  

  case ETH_P_8021Q: vhdr = (struct vlan_ethhdr *)skb->data;

• if (vhdr->h_vlan_encapsulated_proto != ethertype)
  

• if (vhdr->h_vlan_encapsulated_proto != ethertype) {
  

• 	/* snoop incoming traffic for dat update also for vlan
  

• 	 * tagged frames.
  

• 	 */
  

• 	if (vhdr->h_vlan_encapsulated_proto == ETH_P_IP) {
  

• 		iphdr = (struct iphdr *)(vhdr +
  

• 				sizeof(struct vlan_ethhdr));
  

• 		batadv_dat_entry_check(bat_priv, iphdr->saddr,
  

• 				       vhdr->h_source, vid);
  

• 	}
  

Where is the code to check that there is enough data for the iphdr (pskb_may_pull)? Same question goes to Marek for his initial change in 48628bb9419f ("batman-adv: softif bridge loop avoidance") that introduced the vhdr->vlan_ethhdr check

Kind regards, Sven