staging: batman-adv: Use linux/etherdevice.h address helper functions
Commit Message
Replace custom ethernet address check functions by calls to the helpers
in linux/etherdevice.h
In one case where the address was tested for broadcast and multicast
address, the broadcast address check can be omitted as broadcast is also
a multicast address.
The patch is only compile-tested.
Cc: Marek Lindner <lindner_marek@yahoo.de>
Cc: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Cc: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
---
drivers/staging/batman-adv/main.c | 12 +-----------
drivers/staging/batman-adv/main.h | 3 +--
drivers/staging/batman-adv/routing.c | 16 ++++++++--------
drivers/staging/batman-adv/soft-interface.c | 2 +-
drivers/staging/batman-adv/vis.c | 4 ++--
5 files changed, 13 insertions(+), 24 deletions(-)
Comments
On Wednesday 03 November 2010 10:59:02 you wrote:
> Replace custom ethernet address check functions by calls to the helpers
> in linux/etherdevice.h
Have you proven that the addresses are always two bytes aligned in memory?
Afaik this function needs it.
> In one case where the address was tested for broadcast and multicast
> address, the broadcast address check can be omitted as broadcast is also
> a multicast address.
We need to distinguish between these two types for different optimizations
(research is currently done for multicast over mesh - but currently not part
of batman-adv).
Best regards,
Sven
On 2010-11-03 at 11:12:12 +0100, Sven Eckelmann <sven.eckelmann@gmx.de> wrote:
> On Wednesday 03 November 2010 10:59:02 you wrote:
> > Replace custom ethernet address check functions by calls to the helpers
> > in linux/etherdevice.h
>
> Have you proven that the addresses are always two bytes aligned in memory?
> Afaik this function needs it.
I don't think they need to be two bytes aligned, but I might be wrong.
> > In one case where the address was tested for broadcast and multicast
> > address, the broadcast address check can be omitted as broadcast is also
> > a multicast address.
>
> We need to distinguish between these two types for different optimizations
> (research is currently done for multicast over mesh - but currently not part
> of batman-adv).
I was refering to the following part of the patch:
- if (is_bcast(ethhdr->h_dest) || is_mcast(ethhdr->h_dest)) {
+ if (is_multicast_ether_addr(ethhdr->h_dest)) {
I think this change should be legitimate as the same branch is done for
multicast and broadcast addresses.
Thanks
Tobias
On Wednesday 03 November 2010 11:25:12 Tobias Klauser wrote:
> On 2010-11-03 at 11:12:12 +0100, Sven Eckelmann <sven.eckelmann@gmx.de>
wrote:
> > On Wednesday 03 November 2010 10:59:02 you wrote:
> > > Replace custom ethernet address check functions by calls to the helpers
> > > in linux/etherdevice.h
> >
> > Have you proven that the addresses are always two bytes aligned in
> > memory? Afaik this function needs it.
>
> I don't think they need to be two bytes aligned, but I might be wrong.
compare_ether_addr uses a two byte pointer to access 3x two bytes. This makes
it necessary to have all those 3 bytes aligned to 2 byte boundaries. Otherwise
the compiler has to generate special instructions on architectures which don't
support loads on non-aligned addresses. Usually he doesn't do it unless he has
some indications that it is necessary (__attribute__ ((packed)) for example).
There is also documentation available on that topic in
Documentation/unaligned-memory-access.txt
And maybe it is good to use is_broadcast_ether_addr, but leave
compare_ether_addr part open (or prove that we always have those two operands
correctly aligned).
> > > In one case where the address was tested for broadcast and multicast
> > > address, the broadcast address check can be omitted as broadcast is
> > > also a multicast address.
> >
> > We need to distinguish between these two types for different
> > optimizations (research is currently done for multicast over mesh - but
> > currently not part of batman-adv).
>
> I was refering to the following part of the patch:
>
> - if (is_bcast(ethhdr->h_dest) || is_mcast(ethhdr->h_dest)) {
> + if (is_multicast_ether_addr(ethhdr->h_dest)) {
>
> I think this change should be legitimate as the same branch is done for
> multicast and broadcast addresses.
Yes, in that situation it is correct. I was talking more about the complete
bcast vs. multicast in batman-adv and didn't look at your patch.
Best regards,
Sven
On Wednesday 03 November 2010 11:56:19 Sven Eckelmann wrote:
> On Wednesday 03 November 2010 11:25:12 Tobias Klauser wrote:
> > On 2010-11-03 at 11:12:12 +0100, Sven Eckelmann <sven.eckelmann@gmx.de>
>
> wrote:
> > > On Wednesday 03 November 2010 10:59:02 you wrote:
> > > > Replace custom ethernet address check functions by calls to the
> > > > helpers in linux/etherdevice.h
> > >
> > > Have you proven that the addresses are always two bytes aligned in
> > > memory? Afaik this function needs it.
> >
> > I don't think they need to be two bytes aligned, but I might be wrong.
>
> compare_ether_addr uses a two byte pointer to access 3x two bytes. This
> makes it necessary to have all those 3 bytes aligned to 2 byte boundaries.
3x two bytes for each ethernet address == 6x two bytes and not 3 bytes... I
don't know why I wrote that.
Best regards,
Sven
On Wednesday 03 November 2010 11:25:12 Tobias Klauser wrote:
> I was refering to the following part of the patch:
>
> - if (is_bcast(ethhdr->h_dest) || is_mcast(ethhdr->h_dest)) {
> + if (is_multicast_ether_addr(ethhdr->h_dest)) {
>
> I think this change should be legitimate as the same branch is done for
> multicast and broadcast addresses.
Soon we will have different code paths for broadcast and multicast right at
this spot as multicast can be optimized further. But I think we can merge the
change for the time being.
Regards,
Marek
@@ -149,7 +149,7 @@ void dec_module_count(void)
int compare_orig(void *data1, void *data2)
{
- return (memcmp(data1, data2, ETH_ALEN) == 0 ? 1 : 0);
+ return (compare_ether_addr(data1, data2) == 0 ? 1 : 0);
}
/* hashfunction to choose an entry in a hash table of given size */
@@ -192,16 +192,6 @@ 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);
@@ -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>
#include <linux/if_ether.h> /* ethernet header */
#include <linux/poll.h> /* poll_table */
#include <linux/kthread.h> /* kernel threads */
@@ -138,8 +139,6 @@ void dec_module_count(void);
int compare_orig(void *data1, void *data2);
int choose_orig(void *data, int32_t size);
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, ...);
@@ -756,11 +756,11 @@ 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. */
@@ -933,11 +933,11 @@ 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 */
@@ -1107,11 +1107,11 @@ 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 */
@@ -1283,11 +1283,11 @@ 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 */
@@ -140,7 +140,7 @@ int interface_tx(struct sk_buff *skb, struct net_device *soft_iface)
hna_local_add(soft_iface, ethhdr->h_source);
/* ethernet packet should be broadcasted */
- if (is_bcast(ethhdr->h_dest) || is_mcast(ethhdr->h_dest)) {
+ if (is_multicast_ether_addr(ethhdr->h_dest)) {
if (!bat_priv->primary_if)
goto dropped;
@@ -470,7 +470,7 @@ 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? */
@@ -747,7 +747,7 @@ 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);