Fernando Fernandez Mancera <ffmanc...@riseup.net> wrote:
> This is a WIP patch version. I still having some issues in userspace but I
> would like to get feedback about the kernel-side patch. Thanks!
>
> Signed-off-by: Fernando Fernandez Mancera <ffmanc...@riseup.net>
> ---
> include/net/netfilter/nf_tables.h | 6 +++
> net/netfilter/nf_tables_api.c | 73 ++++++++++++++++++++++++++++---
> 2 files changed, 72 insertions(+), 7 deletions(-)
>
> diff --git a/include/net/netfilter/nf_tables.h
> b/include/net/netfilter/nf_tables.h
> index dc301e3d6739..dc4e32040ea9 100644
> --- a/include/net/netfilter/nf_tables.h
> +++ b/include/net/netfilter/nf_tables.h
> @@ -1123,6 +1123,9 @@ struct nft_object_ops {
> int (*dump)(struct sk_buff *skb,
> struct nft_object *obj,
> bool reset);
> + int (*update)(const struct nft_ctx *ctx,
> + const struct nlattr *const
> tb[],
> + struct nft_object *obj);
> const struct nft_object_type *type;
> };
>
> @@ -1405,10 +1408,13 @@ struct nft_trans_elem {
>
> struct nft_trans_obj {
> struct nft_object *obj;
> + bool update;
> };
>
> #define nft_trans_obj(trans) \
> (((struct nft_trans_obj *)trans->data)->obj)
> +#define nft_trans_obj_update(trans) \
> + (((struct nft_trans_obj *)trans->data)->update)
>
> struct nft_trans_flowtable {
> struct nft_flowtable *flowtable;
> diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
> index fe3b7b0c6c66..d7b94904599c 100644
> --- a/net/netfilter/nf_tables_api.c
> +++ b/net/netfilter/nf_tables_api.c
> @@ -5122,6 +5122,48 @@ nft_obj_type_get(struct net *net, u32 objtype)
> return ERR_PTR(-ENOENT);
> }
>
> +static int nf_tables_updobj(const struct nft_ctx *ctx,
> + const struct nft_object_type *type,
> + const struct nlattr *attr,
> + struct nft_object *obj)
> +{
> + struct nft_trans *trans;
> + struct nlattr **tb;
> + int err = -ENOMEM;
> +
> + trans = nft_trans_alloc(ctx, NFT_MSG_NEWOBJ,
> + sizeof(struct nft_trans_obj));
> + if (!trans)
> + return -ENOMEM;
> +
> + tb = kmalloc_array(type->maxattr + 1, sizeof(*tb), GFP_KERNEL);
You can use kcalloc here and then remove the memset().
> + err = obj->ops->update(ctx, (const struct nlattr * const *)tb, obj);
> + if (err < 0)
> + goto err;
This looks wrong, see below.
> @@ -5161,7 +5203,13 @@ static int nf_tables_newobj(struct net *net, struct
> sock *nlsk,
> NL_SET_BAD_ATTR(extack, nla[NFTA_OBJ_NAME]);
> return -EEXIST;
> }
> - return 0;
> + if (nlh->nlmsg_flags & NLM_F_REPLACE)
> + return -EOPNOTSUPP;
> +
> + type = nft_obj_type_get(net, objtype);
> + nft_ctx_init(&ctx, net, skb, nlh, family, table, NULL, nla);
> +
> + return nf_tables_updobj(&ctx, type, nla[NFTA_OBJ_DATA], obj);
> }
>
> case NFT_MSG_NEWOBJ:
> - nft_clear(net, nft_trans_obj(trans));
> - nf_tables_obj_notify(&trans->ctx, nft_trans_obj(trans),
> - NFT_MSG_NEWOBJ);
> - nft_trans_destroy(trans);
> + if (nft_trans_obj_update(trans)) {
> + nf_tables_obj_notify(&trans->ctx,
> + nft_trans_obj(trans),
> + NFT_MSG_NEWOBJ);
I would have expected the ->update() here, when committing the batch.
Under what conditions can an update() fail?
