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Libbpf userspace function bpf_tc_attach

0.4.0

Attach a BPF_PROG_TYPE_SCHED_CLS program to a TC qdisc created with bpf_tc_hook_create.

Definition

int bpf_tc_attach(const struct bpf_tc_hook *hook, struct bpf_tc_opts *opts);

Parameters

  • hook: A pointer to a struct bpf_tc_hook that contains the hook information.
  • opts: A pointer to a struct bpf_tc_opts that contains the options for the TC qdisc.

Return

0 on success. A negative error code on failure.

struct bpf_tc_hook

struct bpf_tc_hook {
    size_t sz;
    int ifindex;
    enum bpf_tc_attach_point attach_point;
    __u32 parent;
    size_t :0;
};

ifindex

The interface index of the device to attach the TC qdisc to.

attach_point

The TC attach point. This can be one of the following values:

enum bpf_tc_attach_point {
    BPF_TC_INGRESS = 1 << 0,
    BPF_TC_EGRESS  = 1 << 1,
    BPF_TC_CUSTOM  = 1 << 2,
};

parent

The ID of the parent qdisc.

struct bpf_tc_opts

struct bpf_tc_opts {
    size_t sz;
    int prog_fd;
    __u32 flags;
    __u32 prog_id;
    __u32 handle;
    __u32 priority;
    size_t :0;
};

prog_fd

The file descriptor of the BPF program to attach.

flags

The flags for the TC qdisc. This can be one of the following values:

enum bpf_tc_flags {
    BPF_TC_F_REPLACE = 1 << 0, // Replace existing program, fail if no program is attached
};

prog_id

This field is unused for this operation. Must be set to 0.

handle

The handle of the TC classifier.

priority

The priority of the TC classifier. Must be a value between 0 and 65535.

Usage

Docs could be improved

This part of the docs is incomplete, contributions are very welcome

Example

Docs could be improved

This part of the docs is incomplete, contributions are very welcome