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authorSven Eckelmann <sven@narfation.org>2019-11-28 12:25:45 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-01-23 08:18:40 +0100
commit5dd3cd576f5e4418823a514b8dfce3c617537382 (patch)
tree880dd6ca859c8240f0fd71704876c81106abd3f7
parent629ae6077258ed01dc5ee66b242cb0c87593c0cb (diff)
batman-adv: Fix DAT candidate selection on little endian systems
commit 4cc4a1708903f404d2ca0dfde30e71e052c6cbc9 upstream. 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, this 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: be1db4f6615b ("batman-adv: make the Distributed ARP Table vlan aware") Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/batman-adv/distributed-arp-table.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
index c2dff7c6e960..76808c5e8183 100644
--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.c
@@ -226,6 +226,7 @@ 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;
@@ -235,7 +236,8 @@ 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);