1 files changed, 32 insertions, 0 deletions
diff --git a/security/selinux/ss/context.c b/security/selinux/ss/context.c
new file mode 100644
index 000000000..38bc0aa52
--- /dev/null
+++ b/security/selinux/ss/context.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Implementations of the security context functions.
+ *
+ * Author: Ondrej Mosnacek <omosnacek@gmail.com>
+ * Copyright (C) 2020 Red Hat, Inc.
+ */
+
+#include <linux/jhash.h>
+
+#include "context.h"
+#include "mls.h"
+
+u32 context_compute_hash(const struct context *c)
+{
+	u32 hash = 0;
+
+	/*
+	 * If a context is invalid, it will always be represented by a
+	 * context struct with only the len & str set (and vice versa)
+	 * under a given policy. Since context structs from different
+	 * policies should never meet, it is safe to hash valid and
+	 * invalid contexts differently. The context_cmp() function
+	 * already operates under the same assumption.
+	 */
+	if (c->len)
+		return full_name_hash(NULL, c->str, c->len);
+
+	hash = jhash_3words(c->user, c->role, c->type, hash);
+	hash = mls_range_hash(&c->range, hash);
+	return hash;
+}