On Sun, Oct 07, 2018 at 08:16:42PM -0700, David Ahern wrote:
> From: David Ahern <dsah...@gmail.com>
>
> Update br_mdb_dump for strict data checking. If the flag is set,
> the dump request is expected to have a br_port_msg struct as the
> header. All elements of the struct are expected to be 0 and no
> attributes can be appended.
>
> Signed-off-by: David Ahern <dsah...@gmail.com>
Acked-by: Christian Brauner <christ...@brauner.io>
> ---
> net/bridge/br_mdb.c | 30 ++++++++++++++++++++++++++++++
> 1 file changed, 30 insertions(+)
>
> diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c
> index a4a848bf827b..a7ea2d431714 100644
> --- a/net/bridge/br_mdb.c
> +++ b/net/bridge/br_mdb.c
> @@ -162,6 +162,29 @@ static int br_mdb_fill_info(struct sk_buff *skb, struct
> netlink_callback *cb,
> return err;
> }
>
> +static int br_mdb_valid_dump_req(const struct nlmsghdr *nlh,
> + struct netlink_ext_ack *extack)
> +{
> + struct br_port_msg *bpm;
> +
> + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*bpm))) {
> + NL_SET_ERR_MSG_MOD(extack, "Invalid header for mdb dump
> request");
> + return -EINVAL;
> + }
> +
> + bpm = nlmsg_data(nlh);
> + if (bpm->ifindex) {
> + NL_SET_ERR_MSG_MOD(extack, "Filtering by device index is not
> supported for mdb dump request");
> + return -EINVAL;
> + }
> + if (nlmsg_attrlen(nlh, sizeof(*bpm))) {
> + NL_SET_ERR_MSG(extack, "Invalid data after header in mdb dump
> request");
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
> {
> struct net_device *dev;
> @@ -169,6 +192,13 @@ static int br_mdb_dump(struct sk_buff *skb, struct
> netlink_callback *cb)
> struct nlmsghdr *nlh = NULL;
> int idx = 0, s_idx;
>
> + if (cb->strict_check) {
> + int err = br_mdb_valid_dump_req(cb->nlh, cb->extack);
> +
> + if (err < 0)
> + return err;
> + }
> +
> s_idx = cb->args[0];
>
> rcu_read_lock();
> --
> 2.11.0
>
