Staging: batman-adv: 32bit sequence number and TTL for broadcasts

This patch changes the sequence number range from 8 or 16 bit to 32 bit.
This should avoid problems with the sequence number sliding window algorithm
which we had seen in the past for broadcast floods or malicious packet
injections. We can not assure 100% security with this patch, but it is quite
an improvement over the old 16 bit sequence numbers:

 * expected window size can be increased (4096 -> 65536)
 * 64k packets in the right order would now be needed to cause a loop,
   which seems practically impossible.

Furthermore, a TTL field has been added to the broadcast packet type, just to
make sure.

These changes required to increase the compatibility level once again.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
[sven.eckelmann@gmx.de: Change atomic64_* back to atomic_*, Rework on
top of current version]
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/staging/batman-adv/types.h b/drivers/staging/batman-adv/types.h
index 751cd63..d0af489 100644
--- a/drivers/staging/batman-adv/types.h
+++ b/drivers/staging/batman-adv/types.h
@@ -72,11 +72,11 @@ struct orig_node {
 	unsigned long batman_seqno_reset;
 	uint8_t  flags;
 	unsigned char *hna_buff;
-	int16_t  hna_buff_len;
-	uint16_t last_real_seqno;
+	int16_t hna_buff_len;
+	uint32_t last_real_seqno;
 	uint8_t last_ttl;
 	TYPE_OF_WORD bcast_bits[NUM_WORDS];
-	uint16_t last_bcast_seqno;
+	uint32_t last_bcast_seqno;
 	struct list_head neigh_list;
 };