X-Git-Url: https://git.sven.stormbind.net/?p=sven%2Fexfat-utils.git;a=blobdiff_plain;f=libexfat%2Fnode.c;fp=libexfat%2Fnode.c;h=90002eb9a03f2b0d59a1a44eed3f339d55656a83;hp=fa04e257709eb8d5e949c74ab22d19c8738fd000;hb=0e295d91bb7f18afee1a0b0d587e5a0cf58bf2fb;hpb=62ddc92d38808bea3aba8fe70e3a417197e9d42f

diff --git a/libexfat/node.c b/libexfat/node.c
index fa04e25..90002eb 100644
--- a/libexfat/node.c
+++ b/libexfat/node.c
@@ -30,7 +30,6 @@ struct iterator
 {
 	cluster_t cluster;
 	off_t offset;
-	int contiguous;
 	char* chunk;
 };
 
@@ -95,21 +94,35 @@ static off_t co2o(struct exfat* ef, cluster_t cluster, off_t offset)
 static int opendir(struct exfat* ef, const struct exfat_node* dir,
 		struct iterator* it)
 {
+	char buffer[UTF8_BYTES(EXFAT_NAME_MAX) + 1];
+
 	if (!(dir->flags & EXFAT_ATTRIB_DIR))
-		exfat_bug("not a directory");
+	{
+		exfat_get_name(dir, buffer, sizeof(buffer) - 1);
+		exfat_bug("'%s' is not a directory", buffer);
+	}
+	if (CLUSTER_INVALID(dir->start_cluster))
+	{
+		exfat_get_name(dir, buffer, sizeof(buffer) - 1);
+		exfat_error("'%s' directory starts with invalid cluster %#x", buffer,
+				dir->start_cluster);
+		return -EIO;
+	}
 	it->cluster = dir->start_cluster;
 	it->offset = 0;
-	it->contiguous = IS_CONTIGUOUS(*dir);
 	it->chunk = malloc(CLUSTER_SIZE(*ef->sb));
 	if (it->chunk == NULL)
 	{
-		exfat_error("out of memory");
+		exfat_error("failed to allocate memory for directory cluster");
 		return -ENOMEM;
 	}
 	if (exfat_pread(ef->dev, it->chunk, CLUSTER_SIZE(*ef->sb),
 			exfat_c2o(ef, it->cluster)) < 0)
 	{
-		exfat_error("failed to read directory cluster %#x", it->cluster);
+		free(it->chunk);
+		exfat_get_name(dir, buffer, sizeof(buffer) - 1);
+		exfat_error("failed to read '%s' directory cluster %#x", buffer,
+				it->cluster);
 		return -EIO;
 	}
 	return 0;
@@ -119,7 +132,6 @@ static void closedir(struct iterator* it)
 {
 	it->cluster = 0;
 	it->offset = 0;
-	it->contiguous = 0;
 	free(it->chunk);
 	it->chunk = NULL;
 }
@@ -194,9 +206,10 @@ static const struct exfat_entry* get_entry_ptr(const struct exfat* ef,
 }
 
 static bool check_node(const struct exfat_node* node, uint16_t actual_checksum,
-		uint16_t reference_checksum, uint64_t valid_size)
+		uint16_t reference_checksum, uint64_t valid_size, int cluster_size)
 {
 	char buffer[UTF8_BYTES(EXFAT_NAME_MAX) + 1];
+	bool ret = true;
 
 	/*
 	   Validate checksum first. If it's invalid all other fields probably
@@ -207,7 +220,7 @@ static bool check_node(const struct exfat_node* node, uint16_t actual_checksum,
 		exfat_get_name(node, buffer, sizeof(buffer) - 1);
 		exfat_error("'%s' has invalid checksum (%#hx != %#hx)", buffer,
 				actual_checksum, reference_checksum);
-		return false;
+		ret = false;
 	}
 
 	/*
@@ -221,10 +234,49 @@ static bool check_node(const struct exfat_node* node, uint16_t actual_checksum,
 		exfat_get_name(node, buffer, sizeof(buffer) - 1);
 		exfat_error("'%s' has valid size (%"PRIu64") greater than size "
 				"(%"PRIu64")", buffer, valid_size, node->size);
-		return false;
+		ret = false;
 	}
 
-	return true;
+	/*
+	   Empty file must have zero start cluster. Non-empty file must start
+	   with a valid cluster. Directories cannot be empty (i.e. must always
+	   have a valid start cluster), but we will check this later in opendir()
+	   to give user a chance to read current directory.
+	*/
+	if (node->size == 0 && node->start_cluster != EXFAT_CLUSTER_FREE)
+	{
+		exfat_get_name(node, buffer, sizeof(buffer) - 1);
+		exfat_error("'%s' is empty but start cluster is %#x", buffer,
+				node->start_cluster);
+		ret = false;
+	}
+	if (node->size > 0 && CLUSTER_INVALID(node->start_cluster))
+	{
+		exfat_get_name(node, buffer, sizeof(buffer) - 1);
+		exfat_error("'%s' points to invalid cluster %#x", buffer,
+				node->start_cluster);
+		ret = false;
+	}
+
+	/* Empty file or directory must be marked as non-contiguous. */
+	if (node->size == 0 && (node->flags & EXFAT_ATTRIB_CONTIGUOUS))
+	{
+		exfat_get_name(node, buffer, sizeof(buffer) - 1);
+		exfat_error("'%s' is empty but marked as contiguous (%#x)", buffer,
+				node->flags);
+		ret = false;
+	}
+
+	/* Directory size must be aligned on at cluster boundary. */
+	if ((node->flags & EXFAT_ATTRIB_DIR) && node->size % cluster_size != 0)
+	{
+		exfat_get_name(node, buffer, sizeof(buffer) - 1);
+		exfat_error("'%s' directory size %"PRIu64" is not divisible by %d", buffer,
+				node->size, cluster_size);
+		ret = false;
+	}
+
+	return ret;
 }
 
 static void decompress_upcase(uint16_t* output, const le16_t* source,
@@ -340,21 +392,6 @@ static int readdir(struct exfat* ef, const struct exfat_node* parent,
 			init_node_meta2(*node, meta2);
 			actual_checksum = exfat_add_checksum(entry, actual_checksum);
 			valid_size = le64_to_cpu(meta2->valid_size);
-			/* empty files must be marked as non-contiguous */
-			if ((*node)->size == 0 && (meta2->flags & EXFAT_FLAG_CONTIGUOUS))
-			{
-				exfat_error("empty file marked as contiguous (0x%hhx)",
-						meta2->flags);
-				goto error;
-			}
-			/* directories must be aligned on at cluster boundary */
-			if (((*node)->flags & EXFAT_ATTRIB_DIR) &&
-				(*node)->size % CLUSTER_SIZE(*ef->sb) != 0)
-			{
-				exfat_error("directory has invalid size %"PRIu64" bytes",
-						(*node)->size);
-				goto error;
-			}
 			--continuations;
 			break;
 
@@ -375,7 +412,7 @@ static int readdir(struct exfat* ef, const struct exfat_node* parent,
 			if (--continuations == 0)
 			{
 				if (!check_node(*node, actual_checksum, reference_checksum,
-						valid_size))
+						valid_size, CLUSTER_SIZE(*ef->sb)))
 					goto error;
 				if (!fetch_next_entry(ef, parent, it))
 					goto error;