batman-adv: simplify bat_ogm_receive API call

Most of the values in that call are derived from the skb, so we can hand
over the skb instead.
Reported-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

net/batman-adv/bat_iv_ogm.c

@@ -1140,13 +1140,16 @@ static void bat_ogm_process(const struct ethhdr *ethhdr,
 	orig_node_free_ref(orig_node);
 }
 
-void bat_ogm_receive(const struct ethhdr *ethhdr, unsigned char *packet_buff,
-		     int packet_len, struct hard_iface *if_incoming)
+void bat_ogm_receive(struct hard_iface *if_incoming, struct sk_buff *skb)
 {
 	struct batman_ogm_packet *batman_ogm_packet;
-	int buff_pos = 0;
-	unsigned char *tt_buff;
+	struct ethhdr *ethhdr;
+	int buff_pos = 0, packet_len;
+	unsigned char *tt_buff, *packet_buff;
 
+	packet_len = skb_headlen(skb);
+	ethhdr = (struct ethhdr *)skb_mac_header(skb);
+	packet_buff = skb->data;
 	batman_ogm_packet = (struct batman_ogm_packet *)packet_buff;
 
 	/* unpack the aggregated packets and process them one by one */

net/batman-adv/bat_ogm.h

@@ -29,7 +29,6 @@ void bat_ogm_init_primary(struct hard_iface *hard_iface);
 void bat_ogm_update_mac(struct hard_iface *hard_iface);
 void bat_ogm_schedule(struct hard_iface *hard_iface, int tt_num_changes);
 void bat_ogm_emit(struct forw_packet *forw_packet);
-void bat_ogm_receive(const struct ethhdr *ethhdr, unsigned char *packet_buff,
-		     int packet_len, struct hard_iface *if_incoming);
+void bat_ogm_receive(struct hard_iface *if_incoming, struct sk_buff *skb);
 
 #endif /* _NET_BATMAN_ADV_OGM_H_ */

net/batman-adv/routing.c

@@ -272,9 +272,7 @@ int recv_bat_ogm_packet(struct sk_buff *skb, struct hard_iface *hard_iface)
 	if (skb_linearize(skb) < 0)
 		return NET_RX_DROP;
 
-	ethhdr = (struct ethhdr *)skb_mac_header(skb);
-
-	bat_ogm_receive(ethhdr, skb->data, skb_headlen(skb), hard_iface);
+	bat_ogm_receive(hard_iface, skb);
 
 	kfree_skb(skb);
 	return NET_RX_SUCCESS;