Subject: Re: [Patch RFC] ndisc: Fix skb allocation size for link layer options.

From: YOSHIFUJI Hideaki <[email-masked]>
Date: Sun, 30 Dec 2012 00:32:19 +0900

YOSHIFUJI Hideaki wrote:
> Stephan Gatzka wrote:
>> Signed-off-by: Stephan Gatzka <[email-masked]>
>> ---
>>  net/ipv6/ndisc.c |    5 +++--
>>  1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
>> index 6574175..b12b94c 100644
>> --- a/net/ipv6/ndisc.c
>> +++ b/net/ipv6/ndisc.c
>> @@ -392,7 +392,7 @@ static struct sk_buff *ndisc_build_skb(struct net_device *dev,
>>  
>>  	len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0);
>>  	if (llinfo)
>> -		len += ndisc_opt_addr_space(dev);
>> +		len += sizeof(struct nd_opt_hdr) + ndisc_opt_addr_space(dev);
>>  
>>  	skb = sock_alloc_send_skb(sk,
>>  				  (MAX_HEADER + sizeof(struct ipv6hdr) +
>> @@ -1424,7 +1424,8 @@ void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
>>  			memcpy(ha_buf, neigh->ha, dev->addr_len);
>>  			read_unlock_bh(&neigh->lock);
>>  			ha = ha_buf;
>> -			len += ndisc_opt_addr_space(dev);
>> +			len += sizeof(struct nd_opt_hdr) +
>> +				ndisc_opt_addr_space(dev);
>>  		} else
>>  			read_unlock_bh(&neigh->lock);
>>  
>>
> 
> Disagree.  NDISC_OPT_SPACE() takes care size of nd option header.

Please note:

static inline int ndisc_opt_addr_space(struct net_device *dev)
{
        return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type));
}

--yoshfuji