batman-adv is receiving and sending the packets of its own ether type on a very early/low level. Therefore we need to add explicit hooks to give netfilter/ebtables a chance to filter them.

//git revert 660d20261343e0b2ff57e51e50d7eb0e557d5e5b

//Signed-off-by: Linus Lüssing linus.luessing@web.de //Reported-by: Antonio Quartulli ordex@ritirata.org --- hard-interface.c | 70 ++++++++++++++++++++++++++++++------------------------ send.c | 8 ++++- 2 files changed, 45 insertions(+), 33 deletions(-)

diff --git a/hard-interface.c b/hard-interface.c index ef95680..9153b19 100644 --- a/hard-interface.c +++ b/hard-interface.c @@ -30,6 +30,7 @@ #include "hash.h"

#include <linux/if_arp.h> +#include <linux/netfilter_bridge.h>

#include "compat.h"

@@ -539,46 +540,29 @@ out: return NOTIFY_DONE; }

-/* receive a packet with the batman ethertype coming on a hard - * interface */ -int batman_skb_recv(struct sk_buff *skb, struct net_device *dev, - struct packet_type *ptype, struct net_device *orig_dev) +static int batman_skb_recv_finish(struct sk_buff *skb) { - struct bat_priv *bat_priv; struct batman_packet *batman_packet; struct batman_if *batman_if; + struct bat_priv *bat_priv; int ret;

- batman_if = container_of(ptype, struct batman_if, batman_adv_ptype); - skb = skb_share_check(skb, GFP_ATOMIC); - - /* skb was released by skb_share_check() */ - if (!skb) - goto err_out; - - /* packet should hold at least type and version */ - if (unlikely(!pskb_may_pull(skb, 2))) + batman_if = get_batman_if_by_netdev(skb->dev); + if (!batman_if) goto err_free;

- /* expect a valid ethernet header here. */ - if (unlikely(skb->mac_len != sizeof(struct ethhdr) - || !skb_mac_header(skb))) + if (!batman_if->soft_iface) goto err_free;

- if (!batman_if->soft_iface) + /* discard frames on not active interfaces */ + if (batman_if->if_status != IF_ACTIVE) goto err_free;

bat_priv = netdev_priv(batman_if->soft_iface); - if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE) goto err_free;

- /* discard frames on not active interfaces */ - if (batman_if->if_status != IF_ACTIVE) - goto err_free; - batman_packet = (struct batman_packet *)skb->data; - if (batman_packet->version != COMPAT_VERSION) { bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: incompatible batman version (%i)\n", @@ -624,18 +608,42 @@ int batman_skb_recv(struct sk_buff *skb, struct net_device *dev, }

if (ret == NET_RX_DROP) - kfree_skb(skb); + goto err_free; + + return 0;

- /* return NET_RX_SUCCESS in any case as we - * most probably dropped the packet for - * routing-logical reasons. */ +err_free: + kfree_skb(skb); + return 0; +}

- return NET_RX_SUCCESS; +/* receive a packet with the batman ethertype coming on a hard + * interface */ +int batman_skb_recv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *ptype, struct net_device *orig_dev) +{ + skb = skb_share_check(skb, GFP_ATOMIC);

+ /* skb was released by skb_share_check() */ + if (!skb) + return 0; + + /* packet should hold at least type and version */ + if (unlikely(!pskb_may_pull(skb, 2))) + goto err_free; + + /* expect a valid ethernet header here. */ + if (unlikely(skb->mac_len != sizeof(struct ethhdr) || + !skb_mac_header(skb))) + goto err_free; + + /* if netfilter/ebtables wants to block incoming batman + * packets then give them a chance to do so here */ + return NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, dev, + NULL, batman_skb_recv_finish); err_free: kfree_skb(skb); -err_out: - return NET_RX_DROP; + return 0; }

struct notifier_block hard_if_notifier = { diff --git a/send.c b/send.c index a96a786..11a009f 100644 --- a/send.c +++ b/send.c @@ -30,6 +30,7 @@ #include "aggregation.h" #include "gateway_common.h" #include "originator.h" +#include <linux/netfilter_bridge.h>

#include "compat.h"

@@ -95,9 +96,12 @@ int send_skb_packet(struct sk_buff *skb,

/* dev_queue_xmit() returns a negative result on error. However on * congestion and traffic shaping, it drops and returns NET_XMIT_DROP - * (which is > 0). This will not be treated as an error. */ + * (which is > 0). This will not be treated as an error. + * Also, if netfilter/ebtables wants to block outgoing batman + * packets then giving them a chance to do so here */

- return dev_queue_xmit(skb); + return NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev, + dev_queue_xmit); send_skb_err: kfree_skb(skb); return NET_XMIT_DROP;