+static bool check_node(const struct exfat_node* node, uint16_t actual_checksum,
+ uint16_t reference_checksum, uint64_t valid_size, int cluster_size)
+{
+ char buffer[EXFAT_UTF8_NAME_BUFFER_MAX];
+ bool ret = true;
+
+ /*
+ Validate checksum first. If it's invalid all other fields probably
+ contain just garbage.
+ */
+ if (actual_checksum != reference_checksum)
+ {
+ exfat_get_name(node, buffer);
+ exfat_error("'%s' has invalid checksum (%#hx != %#hx)", buffer,
+ actual_checksum, reference_checksum);
+ ret = false;
+ }
+
+ /*
+ exFAT does not support sparse files but allows files with uninitialized
+ clusters. For such files valid_size means initialized data size and
+ cannot be greater than file size. See SetFileValidData() function
+ description in MSDN.
+ */
+ if (valid_size > node->size)
+ {
+ exfat_get_name(node, buffer);
+ exfat_error("'%s' has valid size (%"PRIu64") greater than size "
+ "(%"PRIu64")", buffer, valid_size, node->size);
+ ret = false;
+ }
+
+ /*
+ 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);
+ 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);
+ 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->is_contiguous)
+ {
+ exfat_get_name(node, buffer);
+ exfat_error("'%s' is empty but marked as contiguous (%#hx)", buffer,
+ node->attrib);
+ ret = false;
+ }
+
+ /* Directory size must be aligned on at cluster boundary. */
+ if ((node->attrib & EXFAT_ATTRIB_DIR) && node->size % cluster_size != 0)
+ {
+ exfat_get_name(node, buffer);
+ 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,
+ size_t size)
+{
+ size_t si;
+ size_t oi;
+
+ for (oi = 0; oi < EXFAT_UPCASE_CHARS; oi++)
+ output[oi] = oi;
+
+ for (si = 0, oi = 0; si < size && oi < EXFAT_UPCASE_CHARS; si++)
+ {
+ uint16_t ch = le16_to_cpu(source[si]);
+
+ if (ch == 0xffff && si + 1 < size) /* indicates a run */
+ oi += le16_to_cpu(source[++si]);
+ else
+ output[oi++] = ch;
+ }
+}
+
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