92 lines
1.8 KiB
Go
92 lines
1.8 KiB
Go
package link
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import (
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"fmt"
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"io"
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"github.com/cilium/ebpf"
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)
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type IterOptions struct {
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// Program must be of type Tracing with attach type
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// AttachTraceIter. The kind of iterator to attach to is
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// determined at load time via the AttachTo field.
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//
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// AttachTo requires the kernel to include BTF of itself,
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// and it to be compiled with a recent pahole (>= 1.16).
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Program *ebpf.Program
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}
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// AttachIter attaches a BPF seq_file iterator.
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func AttachIter(opts IterOptions) (*Iter, error) {
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link, err := AttachRawLink(RawLinkOptions{
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Program: opts.Program,
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Attach: ebpf.AttachTraceIter,
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})
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if err != nil {
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return nil, fmt.Errorf("can't link iterator: %w", err)
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}
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return &Iter{link}, err
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}
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// LoadPinnedIter loads a pinned iterator from a bpffs.
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func LoadPinnedIter(fileName string) (*Iter, error) {
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link, err := LoadPinnedRawLink(fileName)
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if err != nil {
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return nil, err
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}
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return &Iter{link}, err
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}
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// Iter represents an attached bpf_iter.
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type Iter struct {
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link *RawLink
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}
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var _ Link = (*Iter)(nil)
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func (it *Iter) isLink() {}
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// FD returns the underlying file descriptor.
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func (it *Iter) FD() int {
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return it.link.FD()
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}
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// Close implements Link.
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func (it *Iter) Close() error {
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return it.link.Close()
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}
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// Pin implements Link.
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func (it *Iter) Pin(fileName string) error {
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return it.link.Pin(fileName)
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}
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// Update implements Link.
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func (it *Iter) Update(new *ebpf.Program) error {
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return it.link.Update(new)
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}
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// Open creates a new instance of the iterator.
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//
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// Reading from the returned reader triggers the BPF program.
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func (it *Iter) Open() (io.ReadCloser, error) {
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linkFd, err := it.link.fd.Value()
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if err != nil {
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return nil, err
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}
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attr := &bpfIterCreateAttr{
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linkFd: linkFd,
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}
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fd, err := bpfIterCreate(attr)
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if err != nil {
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return nil, fmt.Errorf("can't create iterator: %w", err)
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}
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return fd.File("bpf_iter"), nil
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}
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