diff mbox

[3/3] extra: fix wrong implementation in nfq_udp_get_payload_len

Message ID 1403260021-8732-3-git-send-email-lantw44@gmail.com
State Changes Requested
Headers show

Commit Message

lantw44@gmail.com June 20, 2014, 10:27 a.m. UTC 
From: Ting-Wei Lan <lantw44@gmail.com>

---
 src/extra/udp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Pablo Neira Ayuso June 30, 2014, 10:11 a.m. UTC | #1 
On Fri, Jun 20, 2014 at 06:27:01PM +0800, lantw44@gmail.com wrote:
> From: Ting-Wei Lan <lantw44@gmail.com>
> 
> ---
>  src/extra/udp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/extra/udp.c b/src/extra/udp.c
> index 2a17a2f..64d3db4 100644
> --- a/src/extra/udp.c
> +++ b/src/extra/udp.c
> @@ -76,7 +76,7 @@ EXPORT_SYMBOL(nfq_udp_get_payload);
>   */
>  unsigned int nfq_udp_get_payload_len(struct udphdr *udph, struct pkt_buff *pktb)
>  {
> -	return pktb->tail - pktb->transport_header;
> +	return pktb->tail - pktb->transport_header - sizeof(struct udphdr);

I agree that this should substract the UDP header size, but:

1) This underflows the unsigned int if the UDP header is truncated.
2) This breaks the current behaviour, but we don't have any client in
   the tree for this code yet though.

Let's do it well, deprecate this interface and introduce a new one:

int nfq_udp_get_payload_length(struct udphdr *udph, struct pkt_buff *pktb)

Same thing for the tcp variant.

The deprecation can be achieved through this:

in __attribute__((deprecated) nfq_udp_get_payload_len(...)

in the header file.

Would you send me a patch for that, please?

BTW, please Signed-off-by your userspace patches too. Thanks.
--
To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/src/extra/udp.c b/src/extra/udp.c
index 2a17a2f..64d3db4 100644
--- a/src/extra/udp.c
+++ b/src/extra/udp.c
@@ -76,7 +76,7 @@  EXPORT_SYMBOL(nfq_udp_get_payload);
  */
 unsigned int nfq_udp_get_payload_len(struct udphdr *udph, struct pkt_buff *pktb)
 {
-	return pktb->tail - pktb->transport_header;
+	return pktb->tail - pktb->transport_header - sizeof(struct udphdr);
 }
 EXPORT_SYMBOL(nfq_udp_get_payload_len);