Re: [B.A.T.M.A.N.] [PATCH 8/8] batman-adv: add gateway IPv6 support by filtering DHCPv6 messages

["Linus Lüssing" <linus.luessing@web.de>]

Acked-by: Linus Lüssing <linus.luessing@web.de>

Just gave it a go on a basic dhcpv6 setup and works fine. Though
some additional checks will be needed in case of extension headers
like the fragmentation or hop-by-hop (for jumbo frames for example)
headers or ipsec stuff. But this patch should do for most people
for now, the rest can be added with a later one.

Cheers, Linus

On Sun, Oct 24, 2010 at 03:14:23AM +0200, Marek Lindner wrote:
> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
> ---
>  batman-adv/gateway_client.c |   40 +++++++++++++++++++++++++++++++---------
>  1 files changed, 31 insertions(+), 9 deletions(-)
> 
> diff --git a/batman-adv/gateway_client.c b/batman-adv/gateway_client.c
> index e6cd9ac..128f851 100644
> --- a/batman-adv/gateway_client.c
> +++ b/batman-adv/gateway_client.c
> @@ -25,6 +25,7 @@
>  #include "hard-interface.h"
>  #include "compat.h"
>  #include <linux/ip.h>
> +#include <linux/ipv6.h>
>  #include <linux/udp.h>
>  #include <linux/if_vlan.h>
>  
> @@ -404,6 +405,7 @@ int gw_is_target(struct bat_priv *bat_priv, struct sk_buff *skb)
>  {
>  	struct ethhdr *ethhdr;
>  	struct iphdr *iphdr;
> +	struct ipv6hdr *ipv6hdr;
>  	struct udphdr *udphdr;
>  	unsigned int header_len = 0;
>  
> @@ -425,17 +427,32 @@ int gw_is_target(struct bat_priv *bat_priv, struct sk_buff *skb)
>  	}
>  
>  	/* check for ip header */
> -	if (ntohs(ethhdr->h_proto) != ETH_P_IP)
> -		return 0;
> +	switch (ntohs(ethhdr->h_proto)) {
> +	case ETH_P_IP:
> +		if (!pskb_may_pull(skb, header_len + sizeof(struct iphdr)))
> +			return 0;
> +		iphdr = (struct iphdr *)(skb->data + header_len);
> +		header_len += iphdr->ihl * 4;
>  
> -	if (!pskb_may_pull(skb, header_len + sizeof(struct iphdr)))
> -		return 0;
> -	iphdr = (struct iphdr *)(skb->data + header_len);
> -	header_len += iphdr->ihl * 4;
> +		/* check for udp header */
> +		if (iphdr->protocol != IPPROTO_UDP)
> +			return 0;
> +
> +		break;
> +	case ETH_P_IPV6:
> +		if (!pskb_may_pull(skb, header_len + sizeof(struct ipv6hdr)))
> +			return 0;
> +		ipv6hdr = (struct ipv6hdr *)(skb->data + header_len);
> +		header_len += sizeof(struct ipv6hdr);
>  
> -	/* check for udp header */
> -	if (iphdr->protocol != IPPROTO_UDP)
> +		/* check for udp header */
> +		if (ipv6hdr->nexthdr != IPPROTO_UDP)
> +			return 0;
> +
> +		break;
> +	default:
>  		return 0;
> +	}
>  
>  	if (!pskb_may_pull(skb, header_len + sizeof(struct udphdr)))
>  		return 0;
> @@ -443,7 +460,12 @@ int gw_is_target(struct bat_priv *bat_priv, struct sk_buff *skb)
>  	header_len += sizeof(struct udphdr);
>  
>  	/* check for bootp port */
> -	if (ntohs(udphdr->dest) != 67)
> +	if ((ntohs(ethhdr->h_proto) == ETH_P_IP) &&
> +	     (ntohs(udphdr->dest) != 67))
> +		return 0;
> +
> +	if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) &&
> +	    (ntohs(udphdr->dest) != 547))
>  		return 0;
>  
>  	if (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER)
> -- 
> 1.7.1
>