+
+#if !HAVE_DECL_KEY_SERIAL_T
+typedef int32_t key_serial_t;
+#endif
+
+#if !HAVE_DECL_KEYCTL
+static inline long keyctl(int cmd, unsigned long arg2, unsigned long arg3, unsigned long arg4,unsigned long arg5) {
+#if defined(__NR_keyctl)
+ return syscall(__NR_keyctl, cmd, arg2, arg3, arg4, arg5);
+#else
+ errno = ENOSYS;
+ return -1;
+#endif
+}
+
+static inline key_serial_t add_key(const char *type, const char *description, const void *payload, size_t plen, key_serial_t ringid) {
+#if defined (__NR_add_key)
+ return syscall(__NR_add_key, type, description, payload, plen, ringid);
+#else
+ errno = ENOSYS;
+ return -1;
+#endif
+}
+
+static inline key_serial_t request_key(const char *type, const char *description, const char * callout_info, key_serial_t destringid) {
+#if defined (__NR_request_key)
+ return syscall(__NR_request_key, type, description, callout_info, destringid);
+#else
+ errno = ENOSYS;
+ return -1;
+#endif
+}
+#endif
+
+#ifndef KEYCTL_READ
+#define KEYCTL_READ 11
+#endif
+
+#ifndef KEYCTL_SET_TIMEOUT
+#define KEYCTL_SET_TIMEOUT 15
+#endif
+
+#ifndef KEY_SPEC_USER_KEYRING
+#define KEY_SPEC_USER_KEYRING -4
+#endif
+#endif // 0
+
+#ifndef PR_CAP_AMBIENT
+#define PR_CAP_AMBIENT 47
+#endif
+
+#ifndef PR_CAP_AMBIENT_IS_SET
+#define PR_CAP_AMBIENT_IS_SET 1
+#endif
+
+#ifndef PR_CAP_AMBIENT_RAISE
+#define PR_CAP_AMBIENT_RAISE 2
+#endif
+
+#ifndef PR_CAP_AMBIENT_CLEAR_ALL
+#define PR_CAP_AMBIENT_CLEAR_ALL 4
+#endif
+
+/* The following two defines are actually available in the kernel headers for longer, but we define them here anyway,
+ * since that makes it easier to use them in conjunction with the glibc net/if.h header which conflicts with
+ * linux/if.h. */
+#ifndef IF_OPER_UNKNOWN
+#define IF_OPER_UNKNOWN 0
+#endif
+
+#ifndef IF_OPER_UP
+#define IF_OPER_UP 6
+
+#ifndef HAVE_DECL_CHAR32_T
+#define char32_t uint32_t
+#endif
+
+#ifndef HAVE_DECL_CHAR16_T
+#define char16_t uint16_t
+#endif
+
+#endif