Introduce file for luks2 segments handling.

lib/luks2/luks2_segment.c

@@ -0,0 +1,183 @@
+/*
+ * LUKS - Linux Unified Key Setup v2, internal segment handling
+ *
+ * Copyright (C) 2018-2019, Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2018-2019, Ondrej Kozina
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "luks2_internal.h"
+
+json_object *json_get_segments_jobj(json_object *hdr_jobj)
+{
+	json_object *jobj_segments;
+
+	if (!hdr_jobj || !json_object_object_get_ex(hdr_jobj, "segments", &jobj_segments))
+		return NULL;
+
+	return jobj_segments;
+}
+
+uint64_t json_segment_get_offset(json_object *jobj_segment, unsigned blockwise)
+{
+	json_object *jobj;
+
+	if (!jobj_segment ||
+	    !json_object_object_get_ex(jobj_segment, "offset", &jobj))
+		return 0;
+
+	return blockwise ? json_object_get_uint64(jobj) >> SECTOR_SHIFT : json_object_get_uint64(jobj);
+}
+
+const char *json_segment_type(json_object *jobj_segment)
+{
+	json_object *jobj;
+
+	if (!jobj_segment ||
+	    !json_object_object_get_ex(jobj_segment, "type", &jobj))
+		return NULL;
+
+	return json_object_get_string(jobj);
+}
+
+uint64_t json_segment_get_iv_offset(json_object *jobj_segment)
+{
+	json_object *jobj;
+
+	if (!jobj_segment ||
+	    !json_object_object_get_ex(jobj_segment, "iv_tweak", &jobj))
+		return 0;
+
+	return json_object_get_uint64(jobj);
+}
+
+uint64_t json_segment_get_size(json_object *jobj_segment, unsigned blockwise)
+{
+	json_object *jobj;
+
+	if (!jobj_segment ||
+	    !json_object_object_get_ex(jobj_segment, "size", &jobj))
+		return 0;
+
+	return blockwise ? json_object_get_uint64(jobj) >> SECTOR_SHIFT : json_object_get_uint64(jobj);
+}
+
+const char *json_segment_get_cipher(json_object *jobj_segment)
+{
+	json_object *jobj;
+
+	/* FIXME: Pseudo "null" cipher should be handled elsewhere */
+	if (!jobj_segment ||
+	    !json_object_object_get_ex(jobj_segment, "encryption", &jobj))
+		return "null";
+
+	return json_object_get_string(jobj);
+}
+
+int json_segment_get_sector_size(json_object *jobj_segment)
+{
+	json_object *jobj;
+
+	if (!jobj_segment ||
+            !json_object_object_get_ex(jobj_segment, "sector_size", &jobj))
+		return -1;
+
+	return json_object_get_int(jobj);
+}
+
+json_object *json_segment_get_flags(json_object *jobj_segment)
+{
+	json_object *jobj;
+
+	if (!jobj_segment || !(json_object_object_get_ex(jobj_segment, "flags", &jobj)))
+		return NULL;
+	return jobj;
+}
+
+json_object *json_segments_get_segment(json_object *jobj_segments, int segment)
+{
+	json_object *jobj;
+	char segment_name[16];
+
+	if (snprintf(segment_name, sizeof(segment_name), "%u", segment) < 1)
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj_segments, segment_name, &jobj))
+		return NULL;
+
+	return jobj;
+}
+
+int json_segments_count(json_object *jobj_segments)
+{
+	if (!jobj_segments)
+		return -EINVAL;
+
+	return json_object_object_length(jobj_segments);
+}
+
+static void _get_segment_or_id_by_flag(json_object *jobj_segments, const char *flag, unsigned id, void *retval)
+{
+	json_object *jobj_flags, **jobj_ret = (json_object **)retval;
+	int *ret = (int *)retval;
+
+	if (!flag)
+		return;
+
+	json_object_object_foreach(jobj_segments, key, value) {
+		if (!json_object_object_get_ex(value, "flags", &jobj_flags))
+			continue;
+		if (LUKS2_array_jobj(jobj_flags, flag)) {
+			if (id)
+				*ret = atoi(key);
+			else
+				*jobj_ret = value;
+			return;
+		}
+	}
+}
+
+json_object *json_segments_get_segment_by_flag(json_object *jobj_segments, const char *flag)
+{
+	json_object *jobj_segment = NULL;
+
+	if (jobj_segments)
+		_get_segment_or_id_by_flag(jobj_segments, flag, 0, &jobj_segment);
+
+	return jobj_segment;
+}
+
+void json_segment_remove_flag(json_object *jobj_segment, const char *flag)
+{
+	json_object *jobj_flags, *jobj_flags_new;
+
+	if (!jobj_segment)
+		return;
+
+	jobj_flags = json_segment_get_flags(jobj_segment);
+	if (!jobj_flags)
+		return;
+
+	jobj_flags_new = LUKS2_array_remove(jobj_flags, flag);
+	if (!jobj_flags_new)
+		return;
+
+	if (json_object_array_length(jobj_flags_new) <= 0) {
+		json_object_put(jobj_flags_new);
+		json_object_object_del(jobj_segment, "flags");
+	} else
+		json_object_object_add(jobj_segment, "flags", jobj_flags_new);
+}