Vendor dependencies

Signed-off-by: Alexander Morozov <lk4d4@docker.com>

vendor/src/github.com/opencontainers/runc/libcontainer/capabilities_linux.go

@@ -0,0 +1,69 @@
+// +build linux
+
+package libcontainer
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/syndtr/gocapability/capability"
+)
+
+const allCapabilityTypes = capability.CAPS | capability.BOUNDS
+
+var capabilityMap map[string]capability.Cap
+
+func init() {
+	capabilityMap = make(map[string]capability.Cap)
+	last := capability.CAP_LAST_CAP
+	// workaround for RHEL6 which has no /proc/sys/kernel/cap_last_cap
+	if last == capability.Cap(63) {
+		last = capability.CAP_BLOCK_SUSPEND
+	}
+	for _, cap := range capability.List() {
+		if cap > last {
+			continue
+		}
+		capKey := fmt.Sprintf("CAP_%s", strings.ToUpper(cap.String()))
+		capabilityMap[capKey] = cap
+	}
+}
+
+func newCapWhitelist(caps []string) (*whitelist, error) {
+	l := []capability.Cap{}
+	for _, c := range caps {
+		v, ok := capabilityMap[c]
+		if !ok {
+			return nil, fmt.Errorf("unknown capability %q", c)
+		}
+		l = append(l, v)
+	}
+	pid, err := capability.NewPid(os.Getpid())
+	if err != nil {
+		return nil, err
+	}
+	return &whitelist{
+		keep: l,
+		pid:  pid,
+	}, nil
+}
+
+type whitelist struct {
+	pid  capability.Capabilities
+	keep []capability.Cap
+}
+
+// dropBoundingSet drops the capability bounding set to those specified in the whitelist.
+func (w *whitelist) dropBoundingSet() error {
+	w.pid.Clear(capability.BOUNDS)
+	w.pid.Set(capability.BOUNDS, w.keep...)
+	return w.pid.Apply(capability.BOUNDS)
+}
+
+// drop drops all capabilities for the current process except those specified in the whitelist.
+func (w *whitelist) drop() error {
+	w.pid.Clear(allCapabilityTypes)
+	w.pid.Set(allCapabilityTypes, w.keep...)
+	return w.pid.Apply(allCapabilityTypes)
+}