Repository : ssh://git@open-mesh.org/batman-adv

On branch : master

commit 728aea06f38e0e4d70f4f7d43698187f7f7055c5 Author: Sven Eckelmann sven@narfation.org Date: Thu Nov 28 12:43:49 2019 +0100

batman-adv: Fix DAT candidate selection on little endian systems

The distributed arp table is using a DHT to store and retrieve MAC address information for an IP address. This is done using unicast messages to selected peers. The potential peers are looked up using the IP address and the VID.

While the IP address is always stored in big endian byte order, it is not the case of the VID. It can (depending on the host system) either be big endian or little endian. The host must therefore always convert it to big endian to ensure that all devices calculate the same peers for the same lookup data.

Fixes: 3e26722bc9f2 ("batman-adv: make the Distributed ARP Table vlan aware") Signed-off-by: Sven Eckelmann sven@narfation.org Acked-by: Antonio Quartulli a@unstable.cc

728aea06f38e0e4d70f4f7d43698187f7f7055c5 net/batman-adv/distributed-arp-table.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index b0af3a11..ec7bf5a4 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -285,6 +285,7 @@ static u32 batadv_hash_dat(const void *data, u32 size) u32 hash = 0; const struct batadv_dat_entry *dat = data; const unsigned char *key; + __be16 vid; u32 i;

key = (const unsigned char *)&dat->ip; @@ -294,7 +295,8 @@ static u32 batadv_hash_dat(const void *data, u32 size) hash ^= (hash >> 6); }

- key = (const unsigned char *)&dat->vid; + vid = htons(dat->vid); + key = (__force const unsigned char *)&vid; for (i = 0; i < sizeof(dat->vid); i++) { hash += key[i]; hash += (hash << 10);