mirror of
https://github.com/xdp-project/bpf-examples.git
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fb84a226b0
Yocto build have a problem with loading this via tc # tc filter replace dev eth1 egress prio 0xC000 handle 1 bpf da obj tc_txq_policy_kern.o Continuing without mounted eBPF fs. Too old kernel? mkdir (null)/globals failed: No such file or directory Unable to load program It can be worked around via mounting BPF file-system manually: # mount -t bpf bpf /sys/fs/bpf/ Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
48 lines
1.3 KiB
C
48 lines
1.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/* Copyright 2022 Jesper Dangaard Brouer */
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/compiler.h>
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#include <linux/pkt_sched.h>
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#include <linux/pkt_cls.h>
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//#include <stdbool.h>
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//#include "../include/xdp/parsing_helpers.h"
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/* Manuel setup:
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export DEV=eth1
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tc qdisc add dev "$DEV" clsact
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tc filter add dev "$DEV" egress bpf da obj tc_txq_policy_kern.o
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tc filter list dev "$DEV" egress
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* Quick test reloading with tc:
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tc filter replace dev "$DEV" egress prio 0xC000 handle 1 bpf da obj tc_txq_policy_kern.o
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* Delete by teardown of clsact
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tc qdisc delete dev "$DEV" clsact
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*/
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SEC("classifier")
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int queue_map_4 (struct __sk_buff *skb)
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{
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__u16 txq_root_handle;
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/* The skb->queue_mapping is 1-indexed (zero means not set). The
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* underlying MQ leaf's are also 1-indexed, which makes it easier to
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* reason about.
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*/
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txq_root_handle = 4;
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skb->queue_mapping = txq_root_handle;
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/* Details: Kernel double protect against setting a too high
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* queue_mapping. In skb_tx_hash() it will reduce number to be
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* less-than (or equal) dev->real_num_tx_queues. And netdev_pick_tx()
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* cap via netdev_cap_txqueue().
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*/
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// FIXME: Do we need to set TC_H_MAJOR(skb->priority) for this to work?
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return TC_ACT_OK;
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}
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