From ec94670fcb3bdeaf3baaa8d86f54e90a5557f53b Mon Sep 17 00:00:00 2001 From: Zvi Effron Date: Wed, 7 Jul 2021 22:16:56 +0000 Subject: 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: Cody Haas Co-developed-by: Lisa Watanabe Signed-off-by: Cody Haas Signed-off-by: Lisa Watanabe Signed-off-by: Zvi Effron Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20210707221657.3985075-4-zeffron@riotgames.com --- net/bpf/test_run.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 49 insertions(+), 7 deletions(-) (limited to 'net/bpf/test_run.c') diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index 229c5deb813c..cda8375bbbaf 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -690,18 +690,60 @@ out: 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) -- cgit v1.2.3