On Wed, Aug 26, 2020 at 11:20 AM Casey Schaufler <casey@xxxxxxxxxxxxxxxx> wrote:
>
> Change netlink netfilter interfaces to use lsmcontext
> pointers, and remove scaffolding.
>
> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
> Reviewed-by: John Johansen <john.johansen@xxxxxxxxxxxxx>
> Acked-by: Stephen Smalley <sds@xxxxxxxxxxxxx>
> Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
> cc: netdev@xxxxxxxxxxxxxxx
> ---
> net/netfilter/nfnetlink_queue.c | 31 ++++++++++++-------------------
> 1 file changed, 12 insertions(+), 19 deletions(-)
...
> diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
> index d3f8e808c5d3..c830401f7792 100644
> --- a/net/netfilter/nfnetlink_queue.c
> +++ b/net/netfilter/nfnetlink_queue.c
> @@ -401,8 +399,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
> enum ip_conntrack_info ctinfo;
> struct nfnl_ct_hook *nfnl_ct;
> bool csum_verify;
> - struct lsmcontext scaff; /* scaffolding */
> - char *secdata = NULL;
> + struct lsmcontext context = { };
> u32 seclen = 0;
>
> size = nlmsg_total_size(sizeof(struct nfgenmsg))
> @@ -469,7 +466,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
> }
>
> if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) {
> - seclen = nfqnl_get_sk_secctx(entskb, &secdata);
> + seclen = nfqnl_get_sk_secctx(entskb, &context);
> if (seclen)
> size += nla_total_size(seclen);
> }
I think we can get rid of the local "seclen" variable, right? We can
embed the nfqnl_get_sk_secctx() in the conditional and then simply
reference "context.len" everywhere else, yes? For example:
if (nfqnl_get_sk_secctx(..., &context))
size += nla_total_size(context.len);
--
paul moore
www.paul-moore.com
