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| author | Andreas Langer <an.langer@gmx.de> | 2010-09-05 01:58:25 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-09-05 00:29:45 -0700 |
| commit | e63760e59542ed872f7a5b1605a46e03b879d909 (patch) | |
| tree | e93a45f0ad5224fa2213a6d04e9806422dac7e7a /drivers/staging/batman-adv/types.h | |
| parent | 24c76fc07b7680536fa372905f16b57a45c0d514 (diff) | |
| download | op-kernel-dev-e63760e59542ed872f7a5b1605a46e03b879d909.zip op-kernel-dev-e63760e59542ed872f7a5b1605a46e03b879d909.tar.gz | |
Staging: batman-adv: layer2 unicast packet fragmentation
This patch implements a simple layer2 fragmentation to allow traffic
exchange over network interfaces with a MTU smaller than 1500 bytes. The
fragmentation splits the big packets into two parts and marks the frames
accordingly. The receiving end buffers the packets to reassemble the
orignal packet before passing it to the higher layers. This feature
makes it necessary to modify the batman-adv encapsulation for unicast
packets by adding a sequence number, flags and the originator address.
This modifcation is part of a seperate packet type for fragemented
packets to keep the original overhead as low as possible. This patch
enables the feature by default to ensure the data traffic can travel
through the network. But it also prints a warning to notify the user
about the performance implications.
Note: Fragmentation should be avoided at all costs since it has a
dramatic impact on the performance, especially when it comes wifi
networks. Instead of a single packet, 2 packets have to be sent! Not
only valuable airtime is wasted but also packetloss decreases the
throughput. A link with 50% packetloss and fragmentation enabled is
pretty much unusable.
Signed-off-by: Andreas Langer <an.langer@gmx.de>
[sven.eckelmann@gmx.de: Rework on top of current version]
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/staging/batman-adv/types.h')
| -rw-r--r-- | drivers/staging/batman-adv/types.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/staging/batman-adv/types.h b/drivers/staging/batman-adv/types.h index 67bf4db..ac16575 100644 --- a/drivers/staging/batman-adv/types.h +++ b/drivers/staging/batman-adv/types.h @@ -41,6 +41,7 @@ struct batman_if { char addr_str[ETH_STR_LEN]; struct net_device *net_dev; atomic_t seqno; + atomic_t frag_seqno; unsigned char *packet_buff; int packet_len; struct kobject *hardif_obj; @@ -81,6 +82,8 @@ struct orig_node { TYPE_OF_WORD bcast_bits[NUM_WORDS]; uint32_t last_bcast_seqno; struct list_head neigh_list; + struct list_head frag_list; + unsigned long last_frag_packet; struct { uint8_t candidates; struct neigh_node *selected; @@ -110,6 +113,7 @@ struct bat_priv { struct net_device_stats stats; atomic_t aggregation_enabled; atomic_t bonding_enabled; + atomic_t frag_enabled; atomic_t vis_mode; atomic_t orig_interval; atomic_t log_level; @@ -183,4 +187,10 @@ struct debug_log { wait_queue_head_t queue_wait; }; +struct frag_packet_list_entry { + struct list_head list; + uint16_t seqno; + struct sk_buff *skb; +}; + #endif /* _NET_BATMAN_ADV_TYPES_H_ */ |
