This is a note to let you know that I've just added the patch titled batman-adv: fix soft-interface MTU computation to the 3.13-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: batman-adv-fix-soft-interface-mtu-computation.patch and it can be found in the queue-3.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Thu Feb 27 20:11:26 PST 2014 From: Antonio Quartulli <antonio@xxxxxxxxxxxxxx> Date: Tue, 21 Jan 2014 11:22:05 +0100 Subject: batman-adv: fix soft-interface MTU computation From: Antonio Quartulli <antonio@xxxxxxxxxxxxxx> [ Upstream commit 930cd6e46eadce8b8ed2a232ee536e5fd286c152 ] The current MTU computation always returns a value smaller than 1500bytes even if the real interfaces have an MTU large enough to compensate the batman-adv overhead. Fix the computation by properly returning the highest admitted value. Introduced by a19d3d85e1b854e4a483a55d740a42458085560d ("batman-adv: limit local translation table max size") Reported-by: Russell Senior <russell@xxxxxxxxxxxxxxxxx> Signed-off-by: Antonio Quartulli <antonio@xxxxxxxxxxxxxx> Signed-off-by: Marek Lindner <mareklindner@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/batman-adv/hard-interface.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -244,7 +244,7 @@ int batadv_hardif_min_mtu(struct net_dev { struct batadv_priv *bat_priv = netdev_priv(soft_iface); const struct batadv_hard_iface *hard_iface; - int min_mtu = ETH_DATA_LEN; + int min_mtu = INT_MAX; rcu_read_lock(); list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { @@ -259,8 +259,6 @@ int batadv_hardif_min_mtu(struct net_dev } rcu_read_unlock(); - atomic_set(&bat_priv->packet_size_max, min_mtu); - if (atomic_read(&bat_priv->fragmentation) == 0) goto out; @@ -271,13 +269,21 @@ int batadv_hardif_min_mtu(struct net_dev min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE); min_mtu -= sizeof(struct batadv_frag_packet); min_mtu *= BATADV_FRAG_MAX_FRAGMENTS; - atomic_set(&bat_priv->packet_size_max, min_mtu); - - /* with fragmentation enabled we can fragment external packets easily */ - min_mtu = min_t(int, min_mtu, ETH_DATA_LEN); out: - return min_mtu - batadv_max_header_len(); + /* report to the other components the maximum amount of bytes that + * batman-adv can send over the wire (without considering the payload + * overhead). For example, this value is used by TT to compute the + * maximum local table table size + */ + atomic_set(&bat_priv->packet_size_max, min_mtu); + + /* the real soft-interface MTU is computed by removing the payload + * overhead from the maximum amount of bytes that was just computed. + * + * However batman-adv does not support MTUs bigger than ETH_DATA_LEN + */ + return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN); } /* adjusts the MTU if a new interface with a smaller MTU appeared. */ Patches currently in stable-queue which might be from antonio@xxxxxxxxxxxxxx are queue-3.13/batman-adv-fix-soft-interface-mtu-computation.patch queue-3.13/batman-adv-avoid-double-free-when-orig_node-initialization-fails.patch queue-3.13/batman-adv-fix-potential-orig_node-reference-leak.patch queue-3.13/batman-adv-release-vlan-object-after-checking-the-crc.patch queue-3.13/batman-adv-fix-potential-kernel-paging-error-for-unicast-transmissions.patch queue-3.13/batman-adv-properly-check-pskb_may_pull-return-value.patch queue-3.13/batman-adv-fix-tt-tvlv-parsing-on-ogm-reception.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html