Patchwork [RFC] ndisc: Fix skb allocation size for link layer options.

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Submitter Stephan Gatzka
Date Dec. 28, 2012, 1:46 p.m.
Message ID <1356702410-32293-1-git-send-email-stephan.gatzka@gmail.com>
Download mbox | patch
Permalink /patch/208484/
State RFC
Delegated to: David Miller
Headers show

Comments

Stephan Gatzka - Dec. 28, 2012, 1:46 p.m.
Signed-off-by: Stephan Gatzka <stephan.gatzka@gmail.com>
---
 net/ipv6/ndisc.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
YOSHIFUJI Hideaki / 吉藤英明 - Dec. 29, 2012, 3:29 p.m.
Stephan Gatzka wrote:
> Signed-off-by: Stephan Gatzka <stephan.gatzka@gmail.com>
> ---
>  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.

--yoshfuji
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YOSHIFUJI Hideaki / 吉藤英明 - Dec. 29, 2012, 3:32 p.m.
YOSHIFUJI Hideaki wrote:
> Stephan Gatzka wrote:
>> Signed-off-by: Stephan Gatzka <stephan.gatzka@gmail.com>
>> ---
>>  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
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Stephan Gatzka - Dec. 29, 2012, 4:37 p.m.
> 
> Disagree.  NDISC_OPT_SPACE() takes care size of nd option header.
Agree. I misunderstood this, my fault.

Maybe it's better to write:

#define NDISC_OPT_SPACE(len) (((len)+sizeof(nd_opt_hdr)+7)&~7)

Regards,

Stephan
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Patch

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);