diff options
| -rw-r--r-- | tests/image-fuzzer/qcow2/layout.py | 138 |
1 files changed, 137 insertions, 1 deletions
diff --git a/tests/image-fuzzer/qcow2/layout.py b/tests/image-fuzzer/qcow2/layout.py index 730c771d3c..63e801f4e8 100644 --- a/tests/image-fuzzer/qcow2/layout.py +++ b/tests/image-fuzzer/qcow2/layout.py @@ -102,6 +102,8 @@ class Image(object): self.end_of_extension_area = FieldsList() self.l2_tables = FieldsList() self.l1_table = FieldsList() + self.refcount_table = FieldsList() + self.refcount_blocks = FieldsList() self.ext_offset = 0 self.create_header(cluster_bits, backing_file_name) self.set_backing_file_name(backing_file_name) @@ -113,7 +115,8 @@ class Image(object): def __iter__(self): return chain(self.header, self.backing_file_format, self.feature_name_table, self.end_of_extension_area, - self.backing_file_name, self.l1_table, self.l2_tables) + self.backing_file_name, self.l1_table, self.l2_tables, + self.refcount_table, self.refcount_blocks) def create_header(self, cluster_bits, backing_file_name=None): """Generate a random valid header.""" @@ -330,6 +333,138 @@ class Image(object): float(self.cluster_size**2))) self.header['l1_table_offset'][0].value = l1_offset + def create_refcount_structures(self): + """Generate random refcount blocks and refcount table.""" + def allocate_rfc_blocks(data, size): + """Return indices of clusters allocated for refcount blocks.""" + cluster_ids = set() + diff = block_ids = set([x / size for x in data]) + while len(diff) != 0: + # Allocate all yet not allocated clusters + new = self._get_available_clusters(data | cluster_ids, + len(diff)) + # Indices of new refcount blocks necessary to cover clusters + # in 'new' + diff = set([x / size for x in new]) - block_ids + cluster_ids |= new + block_ids |= diff + return cluster_ids, block_ids + + def allocate_rfc_table(data, init_blocks, block_size): + """Return indices of clusters allocated for the refcount table + and updated indices of clusters allocated for blocks and indices + of blocks. + """ + blocks = set(init_blocks) + clusters = set() + # Number of entries in one cluster of the refcount table + size = self.cluster_size / UINT64_S + # Number of clusters necessary for the refcount table based on + # the current number of refcount blocks + table_size = int(ceil((max(blocks) + 1) / float(size))) + # Index of the first cluster of the refcount table + table_start = self._get_adjacent_clusters(data, table_size + 1) + # Clusters allocated for the current length of the refcount table + table_clusters = set(range(table_start, table_start + table_size)) + # Clusters allocated for the refcount table including + # last optional one for potential l1 growth + table_clusters_allocated = set(range(table_start, table_start + + table_size + 1)) + # New refcount blocks necessary for clusters occupied by the + # refcount table + diff = set([c / block_size for c in table_clusters]) - blocks + blocks |= diff + while len(diff) != 0: + # Allocate clusters for new refcount blocks + new = self._get_available_clusters((data | clusters) | + table_clusters_allocated, + len(diff)) + # Indices of new refcount blocks necessary to cover + # clusters in 'new' + diff = set([x / block_size for x in new]) - blocks + clusters |= new + blocks |= diff + # Check if the refcount table needs one more cluster + if int(ceil((max(blocks) + 1) / float(size))) > table_size: + new_block_id = (table_start + table_size) / block_size + # Check if the additional table cluster needs + # one more refcount block + if new_block_id not in blocks: + diff.add(new_block_id) + table_clusters.add(table_start + table_size) + table_size += 1 + return table_clusters, blocks, clusters + + def create_table_entry(table_offset, block_cluster, block_size, + cluster): + """Generate a refcount table entry.""" + offset = table_offset + UINT64_S * (cluster / block_size) + return ['>Q', offset, block_cluster * self.cluster_size, + 'refcount_table_entry'] + + def create_block_entry(block_cluster, block_size, cluster): + """Generate a list of entries for the current block.""" + entry_size = self.cluster_size / block_size + offset = block_cluster * self.cluster_size + entry_offset = offset + entry_size * (cluster % block_size) + # While snapshots are not supported all refcounts are set to 1 + return ['>H', entry_offset, 1, 'refcount_block_entry'] + # Size of a block entry in bits + refcount_bits = 1 << self.header['refcount_order'][0].value + # Number of refcount entries per refcount block + # Convert self.cluster_size from bytes to bits to have the same + # base for the numerator and denominator + block_size = self.cluster_size * 8 / refcount_bits + meta_data = self._get_metadata() + if len(self.data_clusters) == 0: + # All metadata for an empty guest image needs 4 clusters: + # header, rfc table, rfc block, L1 table. + # Header takes cluster #0, other clusters ##1-3 can be used + block_clusters = set([random.choice(list(set(range(1, 4)) - + meta_data))]) + block_ids = set([0]) + table_clusters = set([random.choice(list(set(range(1, 4)) - + meta_data - + block_clusters))]) + else: + block_clusters, block_ids = \ + allocate_rfc_blocks(self.data_clusters | + meta_data, block_size) + table_clusters, block_ids, new_clusters = \ + allocate_rfc_table(self.data_clusters | + meta_data | + block_clusters, + block_ids, + block_size) + block_clusters |= new_clusters + + meta_data |= block_clusters | table_clusters + table_offset = min(table_clusters) * self.cluster_size + block_id = None + # Clusters allocated for refcount blocks + block_clusters = list(block_clusters) + # Indices of refcount blocks + block_ids = list(block_ids) + # Refcount table entries + rfc_table = [] + # Refcount entries + rfc_blocks = [] + + for cluster in sorted(self.data_clusters | meta_data): + if cluster / block_size != block_id: + block_id = cluster / block_size + block_cluster = block_clusters[block_ids.index(block_id)] + rfc_table.append(create_table_entry(table_offset, + block_cluster, + block_size, cluster)) + rfc_blocks.append(create_block_entry(block_cluster, block_size, + cluster)) + self.refcount_table = FieldsList(rfc_table) + self.refcount_blocks = FieldsList(rfc_blocks) + + self.header['refcount_table_offset'][0].value = table_offset + self.header['refcount_table_clusters'][0].value = len(table_clusters) + def fuzz(self, fields_to_fuzz=None): """Fuzz an image by corrupting values of a random subset of its fields. @@ -471,6 +606,7 @@ def create_image(test_img_path, backing_file_name=None, backing_file_fmt=None, image.create_feature_name_table() image.set_end_of_extension_area() image.create_l_structures() + image.create_refcount_structures() image.fuzz(fields_to_fuzz) image.write(test_img_path) return image.image_size |