Initial checkin from CRI-O repo

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>

vendor/github.com/opencontainers/runc/libcontainer/utils/utils_unix.go

@@ -0,0 +1,44 @@
+// +build !windows
+
+package utils
+
+import (
+	"io/ioutil"
+	"os"
+	"strconv"
+
+	"golang.org/x/sys/unix"
+)
+
+func CloseExecFrom(minFd int) error {
+	fdList, err := ioutil.ReadDir("/proc/self/fd")
+	if err != nil {
+		return err
+	}
+	for _, fi := range fdList {
+		fd, err := strconv.Atoi(fi.Name())
+		if err != nil {
+			// ignore non-numeric file names
+			continue
+		}
+
+		if fd < minFd {
+			// ignore descriptors lower than our specified minimum
+			continue
+		}
+
+		// intentionally ignore errors from unix.CloseOnExec
+		unix.CloseOnExec(fd)
+		// the cases where this might fail are basically file descriptors that have already been closed (including and especially the one that was created when ioutil.ReadDir did the "opendir" syscall)
+	}
+	return nil
+}
+
+// NewSockPair returns a new unix socket pair
+func NewSockPair(name string) (parent *os.File, child *os.File, err error) {
+	fds, err := unix.Socketpair(unix.AF_LOCAL, unix.SOCK_STREAM|unix.SOCK_CLOEXEC, 0)
+	if err != nil {
+		return nil, nil, err
+	}
+	return os.NewFile(uintptr(fds[1]), name+"-p"), os.NewFile(uintptr(fds[0]), name+"-c"), nil
+}