On 6/21/19 11:52 AM, Casey Schaufler wrote:
> Change netlink netfilter interfaces to use lsmcontext
> pointers, and remove scaffolding.
>
> Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
Reviewed-by: John Johansen <john.johansen@xxxxxxxxxxxxx>
> ---
> net/netfilter/nfnetlink_queue.c | 32 +++++++++++++-------------------
> 1 file changed, 13 insertions(+), 19 deletions(-)
>
> diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
> index 6da00c7add5b..69efb688383f 100644
> --- a/net/netfilter/nfnetlink_queue.c
> +++ b/net/netfilter/nfnetlink_queue.c
> @@ -305,12 +305,10 @@ static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk)
> return -1;
> }
>
> -static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
> +static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsmcontext *context)
> {
> - u32 seclen = 0;
> #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
> struct lsmblob blob;
> - struct lsmcontext context;
>
> if (!skb || !sk_fullsock(skb->sk))
> return 0;
> @@ -318,15 +316,16 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
> read_lock_bh(&skb->sk->sk_callback_lock);
>
> if (skb->secmark) {
> + /* Any LSM might be looking for the secmark */
> lsmblob_init(&blob, skb->secmark);
> - security_secid_to_secctx(&blob, &context);
> - *secdata = context.context;
> + security_secid_to_secctx(&blob, context);
> }
>
> read_unlock_bh(&skb->sk->sk_callback_lock);
> - seclen = context.len;
> + return context->len;
> +#else
> + return 0;
> #endif
> - return seclen;
> }
>
> static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
> @@ -402,8 +401,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
> enum ip_conntrack_info uninitialized_var(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))
> @@ -470,7 +468,7 @@ 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);
> }
> @@ -605,7 +603,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
> nfqnl_put_sk_uidgid(skb, entskb->sk) < 0)
> goto nla_put_failure;
>
> - if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata))
> + if (seclen && nla_put(skb, NFQA_SECCTX, context.len, context.context))
> goto nla_put_failure;
>
> if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0)
> @@ -633,10 +631,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
> }
>
> nlh->nlmsg_len = skb->len;
> - if (seclen) {
> - lsmcontext_init(&scaff, secdata, seclen, 0);
> - security_release_secctx(&scaff);
> - }
> + if (seclen)
> + security_release_secctx(&context);
> return skb;
>
> nla_put_failure:
> @@ -644,10 +640,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
> kfree_skb(skb);
> net_err_ratelimited("nf_queue: error creating packet message\n");
> nlmsg_failure:
> - if (seclen) {
> - lsmcontext_init(&scaff, secdata, seclen, 0);
> - security_release_secctx(&scaff);
> - }
> + if (seclen)
> + security_release_secctx(&context);
> return NULL;
> }
>
>
