Commit ec94670f authored by Zvi Effron's avatar Zvi Effron Committed by Alexei Starovoitov
Browse files

bpf: Support specifying ingress via xdp_md context in BPF_PROG_TEST_RUN 



Support specifying the ingress_ifindex and rx_queue_index of xdp_md
contexts for BPF_PROG_TEST_RUN.

The intended use case is to allow testing XDP programs that make decisions
based on the ingress interface or RX queue.

If ingress_ifindex is specified, look up the device by the provided index
in the current namespace and use its xdp_rxq for the xdp_buff. If the
rx_queue_index is out of range, or is non-zero when the ingress_ifindex is
0, return -EINVAL.

Co-developed-by: default avatarCody Haas <chaas@riotgames.com>
Co-developed-by: default avatarLisa Watanabe <lwatanabe@riotgames.com>
Signed-off-by: default avatarCody Haas <chaas@riotgames.com>
Signed-off-by: default avatarLisa Watanabe <lwatanabe@riotgames.com>
Signed-off-by: default avatarZvi Effron <zeffron@riotgames.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210707221657.3985075-4-zeffron@riotgames.com
parent 47316f4a

net/bpf/test_run.c

+49 −7
Original line number Diff line number Diff line
@@ -690,18 +690,60 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr, 


static int xdp_convert_md_to_buff(struct xdp_md *xdp_md, struct xdp_buff *xdp)

{

	unsigned int ingress_ifindex, rx_queue_index;

	struct netdev_rx_queue *rxqueue;

	struct net_device *device;



	if (!xdp_md)

		return 0;



	if (xdp_md->egress_ifindex != 0)

		return -EINVAL;



	if (xdp_md->ingress_ifindex != 0 || xdp_md->rx_queue_index != 0)

	ingress_ifindex = xdp_md->ingress_ifindex;

	rx_queue_index = xdp_md->rx_queue_index;



	if (!ingress_ifindex && rx_queue_index)

		return -EINVAL;



	xdp->data = xdp->data_meta + xdp_md->data;

	if (ingress_ifindex) {

		device = dev_get_by_index(current->nsproxy->net_ns,

					  ingress_ifindex);

		if (!device)

			return -ENODEV;



		if (rx_queue_index >= device->real_num_rx_queues)

			goto free_dev;



		rxqueue = __netif_get_rx_queue(device, rx_queue_index);



		if (!xdp_rxq_info_is_reg(&rxqueue->xdp_rxq))

			goto free_dev;



		xdp->rxq = &rxqueue->xdp_rxq;

		/* The device is now tracked in the xdp->rxq for later

		 * dev_put()

		 */

	}



	xdp->data = xdp->data_meta + xdp_md->data;

	return 0;



free_dev:

	dev_put(device);

	return -EINVAL;

}



static void xdp_convert_buff_to_md(struct xdp_buff *xdp, struct xdp_md *xdp_md)

{

	if (!xdp_md)

		return;



	xdp_md->data = xdp->data - xdp->data_meta;

	xdp_md->data_end = xdp->data_end - xdp->data_meta;



	if (xdp_md->ingress_ifindex)

		dev_put(xdp->rxq->dev);

}



int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
@@ -753,6 +795,11 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr, 


	bpf_prog_change_xdp(NULL, prog);

	ret = bpf_test_run(prog, &xdp, repeat, &retval, &duration, true);

	/* We convert the xdp_buff back to an xdp_md before checking the return

	 * code so the reference count of any held netdevice will be decremented

	 * even if the test run failed.

	 */

	xdp_convert_buff_to_md(&xdp, ctx);

	if (ret)

		goto out;
@@ -760,11 +807,6 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr, 
	    xdp.data_end != xdp.data_meta + size)

		size = xdp.data_end - xdp.data_meta;



	if (ctx) {

		ctx->data = xdp.data - xdp.data_meta;

		ctx->data_end = xdp.data_end - xdp.data_meta;

	}



	ret = bpf_test_finish(kattr, uattr, xdp.data_meta, size, retval,

			      duration);

	if (!ret)