Libbpf userspace function `bpf_link_get_fd_by_id_opts`

1.1.0

Low level wrapper around the BPF_LINK_GET_FD_BY_ID syscall command.

Definition

int bpf_link_get_fd_by_id_opts(__u32 id, const struct bpf_get_fd_by_id_opts *opts);

Parameters

id: BPF link ID
opts: options for configuring the file descriptor retrieval

Return

>0, a file descriptor for the BPF link; negative error code, otherwise

`struct bpf_get_fd_by_id_opts`

struct bpf_get_fd_by_id_opts {
    size_t sz; /* size of this struct for forward/backward compatibility */
    __u32 open_flags; /* permissions requested for the operation on fd */
    size_t :0;
};

`open_flags`

1.1.0

Usage

This function returns the file descriptor of the BPF link with the given id. This causes the current process to hold a reference to the link, preventing the kernel from unloading it. The file descriptor should be closed with close when it is no longer needed.

Example

Docs could be improved

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

Libbpf userspace function bpf_link_get_fd_by_id_opts