Staging: batman-adv: Use kernel functions to identify broadcasts

linux/etherdevice.h already provides functions to classify different
ethernet addresses. These inlineable functions should be used instead of
custom functions.

The check for multicast together with multicast can also be replaced
with a single test for multicast because for every ethernet address x
following is always true:

is_broadcast_ether_addr(x) => is_multicast_ether_addr(x)

or when looking more at the implementation:

(FF:FF:FF:FF:FF:FF == x) => [(01:00:00:00:00:00 & x) != 00:00:00:00:00:00]

Reported-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/batman-adv/main.c

@@ -172,16 +172,6 @@ int is_my_mac(uint8_t *addr)
 
 }
 
-int is_bcast(uint8_t *addr)
-{
-	return (addr[0] == (uint8_t)0xff) && (addr[1] == (uint8_t)0xff);
-}
-
-int is_mcast(uint8_t *addr)
-{
-	return *addr & 0x01;
-}
-
 module_init(batman_init);
 module_exit(batman_exit);
 

drivers/staging/batman-adv/main.h

@@ -109,6 +109,7 @@
 #include <linux/mutex.h>	/* mutex */
 #include <linux/module.h>	/* needed by all modules */
 #include <linux/netdevice.h>	/* netdevice */
+#include <linux/etherdevice.h>  /* ethernet address classifaction */
 #include <linux/if_ether.h>	/* ethernet header */
 #include <linux/poll.h>		/* poll_table */
 #include <linux/kthread.h>	/* kernel threads */
@@ -136,8 +137,6 @@ void mesh_free(struct net_device *soft_iface);
 void inc_module_count(void);
 void dec_module_count(void);
 int is_my_mac(uint8_t *addr);
-int is_bcast(uint8_t *addr);
-int is_mcast(uint8_t *addr);
 
 #ifdef CONFIG_BATMAN_ADV_DEBUG
 int debug_log(struct bat_priv *bat_priv, char *fmt, ...);

drivers/staging/batman-adv/routing.c

@@ -770,11 +770,11 @@ int recv_bat_packet(struct sk_buff *skb, struct batman_if *batman_if)
 	ethhdr = (struct ethhdr *)skb_mac_header(skb);
 
 	/* packet with broadcast indication but unicast recipient */
-	if (!is_bcast(ethhdr->h_dest))
+	if (!is_broadcast_ether_addr(ethhdr->h_dest))
 		return NET_RX_DROP;
 
 	/* packet with broadcast sender address */
-	if (is_bcast(ethhdr->h_source))
+	if (is_broadcast_ether_addr(ethhdr->h_source))
 		return NET_RX_DROP;
 
 	/* create a copy of the skb, if needed, to modify it. */
@@ -946,11 +946,11 @@ int recv_icmp_packet(struct sk_buff *skb, struct batman_if *recv_if)
 	ethhdr = (struct ethhdr *)skb_mac_header(skb);
 
 	/* packet with unicast indication but broadcast recipient */
-	if (is_bcast(ethhdr->h_dest))
+	if (is_broadcast_ether_addr(ethhdr->h_dest))
 		return NET_RX_DROP;
 
 	/* packet with broadcast sender address */
-	if (is_bcast(ethhdr->h_source))
+	if (is_broadcast_ether_addr(ethhdr->h_source))
 		return NET_RX_DROP;
 
 	/* not for me */
@@ -1118,11 +1118,11 @@ static int check_unicast_packet(struct sk_buff *skb, int hdr_size)
 	ethhdr = (struct ethhdr *)skb_mac_header(skb);
 
 	/* packet with unicast indication but broadcast recipient */
-	if (is_bcast(ethhdr->h_dest))
+	if (is_broadcast_ether_addr(ethhdr->h_dest))
 		return -1;
 
 	/* packet with broadcast sender address */
-	if (is_bcast(ethhdr->h_source))
+	if (is_broadcast_ether_addr(ethhdr->h_source))
 		return -1;
 
 	/* not for me */
@@ -1282,11 +1282,11 @@ int recv_bcast_packet(struct sk_buff *skb, struct batman_if *recv_if)
 	ethhdr = (struct ethhdr *)skb_mac_header(skb);
 
 	/* packet with broadcast indication but unicast recipient */
-	if (!is_bcast(ethhdr->h_dest))
+	if (!is_broadcast_ether_addr(ethhdr->h_dest))
 		return NET_RX_DROP;
 
 	/* packet with broadcast sender address */
-	if (is_bcast(ethhdr->h_source))
+	if (is_broadcast_ether_addr(ethhdr->h_source))
 		return NET_RX_DROP;
 
 	/* ignore broadcasts sent by myself */

drivers/staging/batman-adv/soft-interface.c

@@ -378,7 +378,7 @@ int interface_tx(struct sk_buff *skb, struct net_device *soft_iface)
 	/* TODO: check this for locks */
 	hna_local_add(soft_iface, ethhdr->h_source);
 
-	if (is_bcast(ethhdr->h_dest) || is_mcast(ethhdr->h_dest)) {
+	if (is_multicast_ether_addr(ethhdr->h_dest)) {
 		ret = gw_is_target(bat_priv, skb);
 
 		if (ret < 0)

drivers/staging/batman-adv/unicast.c

@@ -283,7 +283,7 @@ int unicast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv)
 	spin_lock_bh(&bat_priv->orig_hash_lock);
 
 	/* get routing information */
-	if (is_bcast(ethhdr->h_dest) || is_mcast(ethhdr->h_dest))
+	if (is_multicast_ether_addr(ethhdr->h_dest))
 		orig_node = (struct orig_node *)gw_get_selected(bat_priv);
 	else
 		orig_node = ((struct orig_node *)hash_find(bat_priv->orig_hash,

drivers/staging/batman-adv/vis.c

@@ -472,7 +472,7 @@ void receive_client_update_packet(struct bat_priv *bat_priv,
 	int are_target = 0;
 
 	/* clients shall not broadcast. */
-	if (is_bcast(vis_packet->target_orig))
+	if (is_broadcast_ether_addr(vis_packet->target_orig))
 		return;
 
 	/* Are we the target for this VIS packet? */
@@ -755,7 +755,7 @@ static void send_vis_packet(struct bat_priv *bat_priv, struct vis_info *info)
 	       ETH_ALEN);
 	packet->ttl--;
 
-	if (is_bcast(packet->target_orig))
+	if (is_broadcast_ether_addr(packet->target_orig))
 		broadcast_vis_packet(bat_priv, info);
 	else
 		unicast_vis_packet(bat_priv, info);