On Fri, Mar 03, 2023 at 07:12:39PM -0500, Xin Long wrote:
> br_nf_check_hbh_len() is a function to check the Hop-by-hop option
> header, and shouldn't do pskb_trim_rcsum() there. This patch is to
> pass pkt_len out to br_validate_ipv6() and do pskb_trim_rcsum()
> after calling br_validate_ipv6() instead.
>
> Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
> ---
> net/bridge/br_netfilter_ipv6.c | 33 ++++++++++++++-------------------
> 1 file changed, 14 insertions(+), 19 deletions(-)
>
> diff --git a/net/bridge/br_netfilter_ipv6.c b/net/bridge/br_netfilter_ipv6.c
> index 50f564c33551..07289e4f3213 100644
> --- a/net/bridge/br_netfilter_ipv6.c
> +++ b/net/bridge/br_netfilter_ipv6.c
> @@ -43,11 +43,11 @@
> /* We only check the length. A bridge shouldn't do any hop-by-hop stuff
> * anyway
> */
> -static int br_nf_check_hbh_len(struct sk_buff *skb)
> +static int br_nf_check_hbh_len(struct sk_buff *skb, u32 *plen)
> {
> int len, off = sizeof(struct ipv6hdr);
> unsigned char *nh;
> - u32 pkt_len;
> + u32 pkt_len = 0;
>
> if (!pskb_may_pull(skb, off + 8))
> return -1;
> @@ -83,10 +83,6 @@ static int br_nf_check_hbh_len(struct sk_buff *skb)
> return -1;
> if (pkt_len > skb->len - sizeof(struct ipv6hdr))
> return -1;
> - if (pskb_trim_rcsum(skb,
> - pkt_len + sizeof(struct ipv6hdr)))
> - return -1;
> - nh = skb_network_header(skb);
nit: Something you may want to consider if you spin a v2.
It seems that pkt_len is only set here.
So *plen could also be set here, simplifying the return path slightly.
Also, if so, then a not entirely related clean-up would
be to reduce the scope of pkt_len to this block.
> }
> off += optlen;
> len -= optlen;
> @@ -94,6 +90,8 @@ static int br_nf_check_hbh_len(struct sk_buff *skb)
> if (len)
> return -1;
>
> + if (pkt_len)
> + *plen = pkt_len;
> return 0;
> }
>
...
