Function structOpsFindTarget

struct_ops.go:97–116

structOpsFindTarget resolves the kernel-side "value struct" for a struct_ops map.

(userType *btf.Struct, cache *btf.Cache)

// structOpsFindTarget resolves the kernel-side "value struct" for a struct_ops map.
func structOpsFindTarget(userType *btf.Struct, cache *btf.Cache) (vType *btf.Struct, id btf.TypeID, module *btf.Handle, err error) {
	// the kernel value type name, e.g. "bpf_struct_ops_<name>"
	vTypeName := structOpsValuePrefix + userType.Name

	target := btf.Type((*btf.Struct)(nil))
	spec, module, err := findTargetInKernel(vTypeName, &target, cache)
	if errors.Is(err, btf.ErrNotFound) {
		return nil, 0, nil, fmt.Errorf("%q doesn't exist in kernel: %w", vTypeName, ErrNotSupported)
	}
	if err != nil {
		return nil, 0, nil, fmt.Errorf("lookup value type %q: %w", vTypeName, err)
	}

	id, err = spec.TypeID(target)
	if err != nil {
		return nil, 0, nil, err
	}

	return target.(*btf.Struct), id, module, nil
}

// structOpsPopulateValue writes a `prog FD` which references to `p` into the
// struct_ops value buffer `kernVData` at byte offset `dstOff` corresponding to