Re: [B.A.T.M.A.N.] [PATCH v2 2/2] batman-adv: filter ARP packets with invalid MAC addresses in DAT

Matthias Schiffer
2013-01-24T17:33:04Z

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On 01/24/2013 06:18 PM, Matthias Schiffer wrote:
> We never want multicast MAC addresses in the Distributed ARP Table, so it's
> best to completely ignore ARP packets containing them where we expect unicast
> addresses.
>
> Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
> ---
> distributed-arp-table.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/distributed-arp-table.c b/distributed-arp-table.c
> index a35466a..c89a01e 100644
> --- a/distributed-arp-table.c
> +++ b/distributed-arp-table.c
> @@ -738,6 +738,7 @@ static uint16_t batadv_arp_get_type(struct batadv_priv *bat_priv,
> struct arphdr *arphdr;
> struct ethhdr *ethhdr;
> __be32 ip_src, ip_dst;
> + uint8_t *hw_src, *hw_dst;
> uint16_t type = 0;
>
> /* pull the ethernet header */
> @@ -782,6 +783,18 @@ static uint16_t batadv_arp_get_type(struct batadv_priv *bat_priv,
> ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst))
> goto out;
>
> + hw_src = batadv_arp_hw_src(skb, hdr_size);
> + if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src))
> + goto out;
> +
> + /* we don't care for the destination MAC address in ARP requests */
Oops, this comment should be "care about" ... if the patch is okay apart
from this, should I make a v3, or can you just fix it when applying the
patch?

> + if (arphdr->ar_op != htons(ARPOP_REQUEST)) {
> + hw_dst = batadv_arp_hw_dst(skb, hdr_size);
> + if (is_zero_ether_addr(hw_dst) ||
> + is_multicast_ether_addr(hw_dst))
> + goto out;
> + }
> +
> type = ntohs(arphdr->ar_op);
> out:
> return type;
>

Matthias

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