1 files changed, 173 insertions, 0 deletions
diff --git a/vendor/github.com/cilium/ebpf/link/syscalls.go b/vendor/github.com/cilium/ebpf/link/syscalls.go
new file mode 100644
index 000000000..19326c8af
--- /dev/null
+++ b/vendor/github.com/cilium/ebpf/link/syscalls.go
@@ -0,0 +1,173 @@
+package link
+
+import (
+	"errors"
+	"unsafe"
+
+	"github.com/cilium/ebpf"
+	"github.com/cilium/ebpf/asm"
+	"github.com/cilium/ebpf/internal"
+	"github.com/cilium/ebpf/internal/unix"
+)
+
+// Type is the kind of link.
+type Type uint32
+
+// Valid link types.
+//
+// Equivalent to enum bpf_link_type.
+const (
+	UnspecifiedType Type = iota
+	RawTracepointType
+	TracingType
+	CgroupType
+	IterType
+	NetNsType
+	XDPType
+)
+
+var haveProgAttach = internal.FeatureTest("BPF_PROG_ATTACH", "4.10", func() error {
+	prog, err := ebpf.NewProgram(&ebpf.ProgramSpec{
+		Type:       ebpf.CGroupSKB,
+		AttachType: ebpf.AttachCGroupInetIngress,
+		License:    "MIT",
+		Instructions: asm.Instructions{
+			asm.Mov.Imm(asm.R0, 0),
+			asm.Return(),
+		},
+	})
+	if err != nil {
+		return internal.ErrNotSupported
+	}
+
+	// BPF_PROG_ATTACH was introduced at the same time as CGgroupSKB,
+	// so being able to load the program is enough to infer that we
+	// have the syscall.
+	prog.Close()
+	return nil
+})
+
+var haveProgAttachReplace = internal.FeatureTest("BPF_PROG_ATTACH atomic replacement", "5.5", func() error {
+	if err := haveProgAttach(); err != nil {
+		return err
+	}
+
+	prog, err := ebpf.NewProgram(&ebpf.ProgramSpec{
+		Type:       ebpf.CGroupSKB,
+		AttachType: ebpf.AttachCGroupInetIngress,
+		License:    "MIT",
+		Instructions: asm.Instructions{
+			asm.Mov.Imm(asm.R0, 0),
+			asm.Return(),
+		},
+	})
+	if err != nil {
+		return internal.ErrNotSupported
+	}
+	defer prog.Close()
+
+	// We know that we have BPF_PROG_ATTACH since we can load CGroupSKB programs.
+	// If passing BPF_F_REPLACE gives us EINVAL we know that the feature isn't
+	// present.
+	attr := internal.BPFProgAttachAttr{
+		// We rely on this being checked after attachFlags.
+		TargetFd:    ^uint32(0),
+		AttachBpfFd: uint32(prog.FD()),
+		AttachType:  uint32(ebpf.AttachCGroupInetIngress),
+		AttachFlags: uint32(flagReplace),
+	}
+
+	err = internal.BPFProgAttach(&attr)
+	if errors.Is(err, unix.EINVAL) {
+		return internal.ErrNotSupported
+	}
+	if errors.Is(err, unix.EBADF) {
+		return nil
+	}
+	return err
+})
+
+type bpfLinkCreateAttr struct {
+	progFd     uint32
+	targetFd   uint32
+	attachType ebpf.AttachType
+	flags      uint32
+}
+
+func bpfLinkCreate(attr *bpfLinkCreateAttr) (*internal.FD, error) {
+	ptr, err := internal.BPF(internal.BPF_LINK_CREATE, unsafe.Pointer(attr), unsafe.Sizeof(*attr))
+	if err != nil {
+		return nil, err
+	}
+	return internal.NewFD(uint32(ptr)), nil
+}
+
+type bpfLinkUpdateAttr struct {
+	linkFd    uint32
+	newProgFd uint32
+	flags     uint32
+	oldProgFd uint32
+}
+
+func bpfLinkUpdate(attr *bpfLinkUpdateAttr) error {
+	_, err := internal.BPF(internal.BPF_LINK_UPDATE, unsafe.Pointer(attr), unsafe.Sizeof(*attr))
+	return err
+}
+
+var haveBPFLink = internal.FeatureTest("bpf_link", "5.7", func() error {
+	prog, err := ebpf.NewProgram(&ebpf.ProgramSpec{
+		Type:       ebpf.CGroupSKB,
+		AttachType: ebpf.AttachCGroupInetIngress,
+		License:    "MIT",
+		Instructions: asm.Instructions{
+			asm.Mov.Imm(asm.R0, 0),
+			asm.Return(),
+		},
+	})
+	if err != nil {
+		return internal.ErrNotSupported
+	}
+	defer prog.Close()
+
+	attr := bpfLinkCreateAttr{
+		// This is a hopefully invalid file descriptor, which triggers EBADF.
+		targetFd:   ^uint32(0),
+		progFd:     uint32(prog.FD()),
+		attachType: ebpf.AttachCGroupInetIngress,
+	}
+	_, err = bpfLinkCreate(&attr)
+	if errors.Is(err, unix.EINVAL) {
+		return internal.ErrNotSupported
+	}
+	if errors.Is(err, unix.EBADF) {
+		return nil
+	}
+	return err
+})
+
+type bpfIterCreateAttr struct {
+	linkFd uint32
+	flags  uint32
+}
+
+func bpfIterCreate(attr *bpfIterCreateAttr) (*internal.FD, error) {
+	ptr, err := internal.BPF(internal.BPF_ITER_CREATE, unsafe.Pointer(attr), unsafe.Sizeof(*attr))
+	if err == nil {
+		return internal.NewFD(uint32(ptr)), nil
+	}
+	return nil, err
+}
+
+type bpfRawTracepointOpenAttr struct {
+	name internal.Pointer
+	fd   uint32
+	_    uint32
+}
+
+func bpfRawTracepointOpen(attr *bpfRawTracepointOpenAttr) (*internal.FD, error) {
+	ptr, err := internal.BPF(internal.BPF_RAW_TRACEPOINT_OPEN, unsafe.Pointer(attr), unsafe.Sizeof(*attr))
+	if err == nil {
+		return internal.NewFD(uint32(ptr)), nil
+	}
+	return nil, err
+}