1 files changed, 96 insertions, 0 deletions
diff --git a/vendor/github.com/cilium/ebpf/internal/sys/fd.go b/vendor/github.com/cilium/ebpf/internal/sys/fd.go
new file mode 100644
index 000000000..65517d45e
--- /dev/null
+++ b/vendor/github.com/cilium/ebpf/internal/sys/fd.go
@@ -0,0 +1,96 @@
+package sys
+
+import (
+	"fmt"
+	"math"
+	"os"
+	"runtime"
+	"strconv"
+
+	"github.com/cilium/ebpf/internal/unix"
+)
+
+var ErrClosedFd = unix.EBADF
+
+type FD struct {
+	raw int
+}
+
+func newFD(value int) *FD {
+	fd := &FD{value}
+	runtime.SetFinalizer(fd, (*FD).Close)
+	return fd
+}
+
+// NewFD wraps a raw fd with a finalizer.
+//
+// You must not use the raw fd after calling this function, since the underlying
+// file descriptor number may change. This is because the BPF UAPI assumes that
+// zero is not a valid fd value.
+func NewFD(value int) (*FD, error) {
+	if value < 0 {
+		return nil, fmt.Errorf("invalid fd %d", value)
+	}
+
+	fd := newFD(value)
+	if value != 0 {
+		return fd, nil
+	}
+
+	dup, err := fd.Dup()
+	_ = fd.Close()
+	return dup, err
+}
+
+func (fd *FD) String() string {
+	return strconv.FormatInt(int64(fd.raw), 10)
+}
+
+func (fd *FD) Int() int {
+	return fd.raw
+}
+
+func (fd *FD) Uint() uint32 {
+	if fd.raw < 0 || int64(fd.raw) > math.MaxUint32 {
+		// Best effort: this is the number most likely to be an invalid file
+		// descriptor. It is equal to -1 (on two's complement arches).
+		return math.MaxUint32
+	}
+	return uint32(fd.raw)
+}
+
+func (fd *FD) Close() error {
+	if fd.raw < 0 {
+		return nil
+	}
+
+	value := int(fd.raw)
+	fd.raw = -1
+
+	fd.Forget()
+	return unix.Close(value)
+}
+
+func (fd *FD) Forget() {
+	runtime.SetFinalizer(fd, nil)
+}
+
+func (fd *FD) Dup() (*FD, error) {
+	if fd.raw < 0 {
+		return nil, ErrClosedFd
+	}
+
+	// Always require the fd to be larger than zero: the BPF API treats the value
+	// as "no argument provided".
+	dup, err := unix.FcntlInt(uintptr(fd.raw), unix.F_DUPFD_CLOEXEC, 1)
+	if err != nil {
+		return nil, fmt.Errorf("can't dup fd: %v", err)
+	}
+
+	return newFD(dup), nil
+}
+
+func (fd *FD) File(name string) *os.File {
+	fd.Forget()
+	return os.NewFile(uintptr(fd.raw), name)
+}