batman-adv: Merge bugfixes from 2019.5

[feed/routing.git] / batman-adv / patches / 0040-batman-adv-Fix-DAT-candidate-selection-on-little-end.patch

diff --git a/batman-adv/patches/0040-batman-adv-Fix-DAT-candidate-selection-on-little-end.patch b/batman-adv/patches/0040-batman-adv-Fix-DAT-candidate-selection-on-little-end.patch
new file mode 100644 (file)
index 0000000..05b0636
--- /dev/null
+++ b/batman-adv/patches/0040-batman-adv-Fix-DAT-candidate-selection-on-little-end.patch
@@ -0,0 +1,43 @@
+From: Sven Eckelmann <sven@narfation.org>
+Date: Thu, 28 Nov 2019 12:43:49 +0100
+Subject: 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>
+
+Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/728aea06f38e0e4d70f4f7d43698187f7f7055c5
+
+diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
+index a60bacf7120be88ba7626cf0a87dd34eef0a2eec..21783805a3afd974cebc7e640249402d637d731a 100644
+--- a/net/batman-adv/distributed-arp-table.c
++++ b/net/batman-adv/distributed-arp-table.c
+@@ -251,6 +251,7 @@ 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;
+@@ -260,7 +261,8 @@ 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);