Move get_first_data_offset to luks2_segment.c

lib/luks2/luks2.h

@@ -277,6 +277,7 @@ json_object *json_segments_get_segment(json_object *jobj_segments, int segment);
 int json_segments_count(json_object *jobj_segments);
 json_object *json_segments_get_segment_by_flag(json_object *jobj_segments, const char *flag);
 void json_segment_remove_flag(json_object *jobj_segment, const char *flag);
+uint64_t json_segments_get_minimal_offset(json_object *jobj_segments, unsigned blockwise);
 
 /*
  * Generic LUKS2 digest

lib/luks2/luks2_internal.h

@@ -54,6 +54,7 @@ json_object *LUKS2_get_token_jobj(struct luks2_hdr *hdr, int token);
 json_object *LUKS2_get_digest_jobj(struct luks2_hdr *hdr, int digest);
 json_object *LUKS2_get_segment_jobj(struct luks2_hdr *hdr, int segment);
 json_object *LUKS2_get_tokens_jobj(struct luks2_hdr *hdr);
+json_object *LUKS2_get_segments_jobj(struct luks2_hdr *hdr);
 
 void hexprint_base64(struct crypt_device *cd, json_object *jobj,
 		     const char *sep, const char *line_sep);

lib/luks2/luks2_json_metadata.c

@@ -174,6 +174,11 @@ json_object *LUKS2_get_segment_jobj(struct luks2_hdr *hdr, int segment)
 	return hdr ? json_segments_get_segment(json_get_segments_jobj(hdr->jobj), segment) : NULL;
 }
 
+json_object *LUKS2_get_segments_jobj(struct luks2_hdr *hdr)
+{
+	return hdr ? json_get_segments_jobj(hdr->jobj) : NULL;
+}
+
 /*
  * json_type_int needs to be validated first.
  * See validate_json_uint32()
@@ -251,34 +256,6 @@ json_object *json_contains(struct crypt_device *cd, json_object *jobj, const cha
 	return sobj;
 }
 
-/* use only on already validated 'segments' object */
-static uint64_t get_first_data_offset(json_object *jobj_segs, const char *type)
-{
-	json_object *jobj_offset, *jobj_type;
-	uint64_t tmp, min = UINT64_MAX;
-
-	json_object_object_foreach(jobj_segs, key, val) {
-		UNUSED(key);
-
-		if (type) {
-			json_object_object_get_ex(val, "type", &jobj_type);
-			if (strcmp(type, json_object_get_string(jobj_type)))
-				continue;
-		}
-
-		json_object_object_get_ex(val, "offset", &jobj_offset);
-		tmp = json_object_get_uint64(jobj_offset);
-
-		if (!tmp)
-			return tmp;
-
-		if (tmp < min)
-			min = tmp;
-	}
-
-	return min;
-}
-
 static json_bool validate_json_uint32(json_object *jobj)
 {
 	int64_t tmp;
@@ -770,8 +747,7 @@ static int hdr_validate_config(struct crypt_device *cd, json_object *hdr_jobj)
 	 * validate keyslots_size fits in between (2 * metadata_size) and first
 	 * segment_offset (except detached header)
 	 */
-	json_object_object_get_ex(hdr_jobj, "segments", &jobj);
+	segment_offset = json_segments_get_minimal_offset(json_get_segments_jobj(hdr_jobj), 0);
-	segment_offset = get_first_data_offset(jobj, "crypt");
 	if (segment_offset &&
 	    (segment_offset < keyslots_size ||
 	     (segment_offset - keyslots_size) < (2 * metadata_size))) {
@@ -1618,12 +1594,7 @@ int LUKS2_hdr_dump(struct crypt_device *cd, struct luks2_hdr *hdr)
 
 uint64_t LUKS2_get_data_offset(struct luks2_hdr *hdr)
 {
-	json_object *jobj1;
+	return json_segments_get_minimal_offset(LUKS2_get_segments_jobj(hdr), 1);
-
-	if (!json_object_object_get_ex(hdr->jobj, "segments", &jobj1))
-		return 0;
-
-	return get_first_data_offset(jobj1, "crypt") / SECTOR_SIZE;
 }
 
 const char *LUKS2_get_cipher(struct luks2_hdr *hdr, int segment)

lib/luks2/luks2_segment.c

@@ -21,6 +21,34 @@
 
 #include "luks2_internal.h"
 
+/* use only on already validated 'segments' object */
+static uint64_t get_first_data_offset(json_object *jobj_segs, const char *type)
+{
+	json_object *jobj_offset, *jobj_type;
+	uint64_t tmp, min = UINT64_MAX;
+
+	json_object_object_foreach(jobj_segs, key, val) {
+		UNUSED(key);
+
+		if (type) {
+			json_object_object_get_ex(val, "type", &jobj_type);
+			if (strcmp(type, json_object_get_string(jobj_type)))
+				continue;
+		}
+
+		json_object_object_get_ex(val, "offset", &jobj_offset);
+		tmp = json_object_get_uint64(jobj_offset);
+
+		if (!tmp)
+			return tmp;
+
+		if (tmp < min)
+			min = tmp;
+	}
+
+	return min;
+}
+
 json_object *json_get_segments_jobj(json_object *hdr_jobj)
 {
 	json_object *jobj_segments;
@@ -31,6 +59,13 @@ json_object *json_get_segments_jobj(json_object *hdr_jobj)
 	return jobj_segments;
 }
 
+uint64_t json_segments_get_minimal_offset(json_object *jobj_segments, unsigned blockwise)
+{
+	if (!jobj_segments)
+		return 0;
+	return blockwise ? get_first_data_offset(jobj_segments, NULL) >> SECTOR_SHIFT : get_first_data_offset(jobj_segments, NULL);
+}
+
 uint64_t json_segment_get_offset(json_object *jobj_segment, unsigned blockwise)
 {
 	json_object *jobj;