+/*
+ * verify_swm_set: - Sanity checks to make sure a set of WIMs correctly
+ * correspond to a spanned set.
+ *
+ * @wim:
+ * Part 1 of the set.
+ *
+ * @additional_swms:
+ * All parts of the set other than part 1.
+ *
+ * @num_additional_swms:
+ * Number of WIMStructs in @additional_swms. Or, the total number of parts
+ * in the set minus 1.
+ *
+ * @return:
+ * 0 on success; WIMLIB_ERR_SPLIT_INVALID if the set is not valid.
+ */
+static int
+verify_swm_set(WIMStruct *wim, WIMStruct **additional_swms,
+ unsigned num_additional_swms)
+{
+ unsigned total_parts = wim->hdr.total_parts;
+ int ctype;
+ u32 chunk_size;
+ const u8 *guid;
+
+ if (total_parts != num_additional_swms + 1) {
+ ERROR("`%"TS"' says there are %u parts in the spanned set, "
+ "but %"TS"%u part%"TS" provided",
+ wim->filename, total_parts,
+ (num_additional_swms + 1 < total_parts) ? T("only ") : T(""),
+ num_additional_swms + 1,
+ (num_additional_swms) ? T("s were") : T(" was"));
+ return WIMLIB_ERR_SPLIT_INVALID;
+ }
+ if (wim->hdr.part_number != 1) {
+ ERROR("WIM `%"TS"' is not the first part of the split WIM.",
+ wim->filename);
+ return WIMLIB_ERR_SPLIT_INVALID;
+ }
+ for (unsigned i = 0; i < num_additional_swms; i++) {
+ if (additional_swms[i]->hdr.total_parts != total_parts) {
+ ERROR("WIM `%"TS"' says there are %u parts in the "
+ "spanned set, but %u parts were provided",
+ additional_swms[i]->filename,
+ additional_swms[i]->hdr.total_parts,
+ total_parts);
+ return WIMLIB_ERR_SPLIT_INVALID;
+ }
+ }
+
+ /* Keep track of the compression type, chunk size, and GUID to make sure
+ * they are the same for all the WIMs. */
+ ctype = wim->compression_type;
+ chunk_size = wim->chunk_size;
+ guid = wim->hdr.guid;
+
+ {
+ /* parts_to_swms is not allocated at function scope because it
+ * should only be allocated after num_additional_swms was
+ * checked to be the same as wim->hdr.total_parts. Otherwise, it
+ * could be unexpectedly high and cause a stack overflow. */
+ WIMStruct *parts_to_swms[num_additional_swms];
+ memset(parts_to_swms, 0, sizeof(parts_to_swms));
+ for (unsigned i = 0; i < num_additional_swms; i++) {
+
+ WIMStruct *swm = additional_swms[i];
+
+ if (swm->compression_type != ctype) {
+ ERROR("The split WIMs do not all have the same "
+ "compression type");
+ return WIMLIB_ERR_SPLIT_INVALID;
+ }
+ if (swm->chunk_size != chunk_size &&
+ ctype != WIMLIB_COMPRESSION_TYPE_NONE) {
+ ERROR("The split WIMs do not all have the same "
+ "chunk size");
+ return WIMLIB_ERR_SPLIT_INVALID;
+ }
+ if (!guids_equal(guid, swm->hdr.guid)) {
+ ERROR("The split WIMs do not all have the same "
+ "GUID");
+ return WIMLIB_ERR_SPLIT_INVALID;
+ }
+ if (swm->hdr.part_number == 1) {
+ ERROR("WIMs `%"TS"' and `%"TS"' both are marked "
+ "as the first WIM in the spanned set",
+ wim->filename, swm->filename);
+ return WIMLIB_ERR_SPLIT_INVALID;
+ }
+ if (swm->hdr.part_number == 0 ||
+ swm->hdr.part_number > total_parts)
+ {
+ ERROR("WIM `%"TS"' says it is part %u in the "
+ "spanned set, but the part number must "
+ "be in the range [1, %u]",
+ swm->filename, swm->hdr.part_number, total_parts);
+ return WIMLIB_ERR_SPLIT_INVALID;
+ }
+ if (parts_to_swms[swm->hdr.part_number - 2])
+ {
+ ERROR("`%"TS"' and `%"TS"' are both marked as "
+ "part %u of %u in the spanned set",
+ parts_to_swms[swm->hdr.part_number - 2]->filename,
+ swm->filename,
+ swm->hdr.part_number,
+ total_parts);
+ return WIMLIB_ERR_SPLIT_INVALID;
+ } else {
+ parts_to_swms[swm->hdr.part_number - 2] = swm;
+ }
+ }
+ }
+ return 0;
+}
+