97 lines
2.3 KiB
C
97 lines
2.3 KiB
C
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/* SPDX-License-Identifier: GPL-2.0
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* Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
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*
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* Example howto extract XDP RX-queue info
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*/
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#include <uapi/linux/bpf.h>
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#include "bpf_helpers.h"
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/* Config setup from with userspace
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*
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* User-side setup ifindex in config_map, to verify that
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* ctx->ingress_ifindex is correct (against configured ifindex)
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*/
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struct config {
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__u32 action;
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int ifindex;
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};
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struct bpf_map_def SEC("maps") config_map = {
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.type = BPF_MAP_TYPE_ARRAY,
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.key_size = sizeof(int),
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.value_size = sizeof(struct config),
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.max_entries = 1,
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};
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/* Common stats data record (shared with userspace) */
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struct datarec {
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__u64 processed;
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__u64 issue;
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};
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struct bpf_map_def SEC("maps") stats_global_map = {
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.type = BPF_MAP_TYPE_PERCPU_ARRAY,
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.key_size = sizeof(u32),
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.value_size = sizeof(struct datarec),
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.max_entries = 1,
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};
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#define MAX_RXQs 64
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/* Stats per rx_queue_index (per CPU) */
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struct bpf_map_def SEC("maps") rx_queue_index_map = {
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.type = BPF_MAP_TYPE_PERCPU_ARRAY,
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.key_size = sizeof(u32),
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.value_size = sizeof(struct datarec),
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.max_entries = MAX_RXQs + 1,
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};
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SEC("xdp_prog0")
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int xdp_prognum0(struct xdp_md *ctx)
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{
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void *data_end = (void *)(long)ctx->data_end;
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void *data = (void *)(long)ctx->data;
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struct datarec *rec, *rxq_rec;
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int ingress_ifindex;
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struct config *config;
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u32 key = 0;
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/* Global stats record */
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rec = bpf_map_lookup_elem(&stats_global_map, &key);
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if (!rec)
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return XDP_ABORTED;
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rec->processed++;
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/* Accessing ctx->ingress_ifindex, cause BPF to rewrite BPF
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* instructions inside kernel to access xdp_rxq->dev->ifindex
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*/
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ingress_ifindex = ctx->ingress_ifindex;
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config = bpf_map_lookup_elem(&config_map, &key);
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if (!config)
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return XDP_ABORTED;
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/* Simple test: check ctx provided ifindex is as expected */
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if (ingress_ifindex != config->ifindex) {
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/* count this error case */
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rec->issue++;
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return XDP_ABORTED;
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}
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/* Update stats per rx_queue_index. Handle if rx_queue_index
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* is larger than stats map can contain info for.
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*/
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key = ctx->rx_queue_index;
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if (key >= MAX_RXQs)
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key = MAX_RXQs;
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rxq_rec = bpf_map_lookup_elem(&rx_queue_index_map, &key);
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if (!rxq_rec)
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return XDP_ABORTED;
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rxq_rec->processed++;
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if (key == MAX_RXQs)
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rxq_rec->issue++;
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return config->action;
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}
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char _license[] SEC("license") = "GPL";
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