Prep v235: Apply pending upstream updates in src/basic [1/4]

1 files changed, 15 insertions, 0 deletions

diff --git a/src/basic/capability-util.c b/src/basic/capability-util.c
index 952bcc2d7..294dcc8d4 100644
--- a/src/basic/capability-util.c
+++ b/src/basic/capability-util.c
@@ -372,4 +372,19 @@ int drop_capability(cap_value_t cv) {
 
         return 0;
 }
+
+bool ambient_capabilities_supported(void) {
+        static int cache = -1;
+
+        if (cache >= 0)
+                return cache;
+
+        /* If PR_CAP_AMBIENT returns something valid, or an unexpected error code we assume that ambient caps are
+         * available. */
+
+        cache = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET, CAP_KILL, 0, 0) >= 0 ||
+                !IN_SET(errno, EINVAL, EOPNOTSUPP, ENOSYS);
+
+        return cache;
+}
 #endif // 0