+ /* the descriptor offset = 0x200 */
+ if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
+ return 0;
+
+ if (parent) {
+ cid_str = "parentCID";
+ cid_str_size = sizeof("parentCID");
+ } else {
+ cid_str = "CID";
+ cid_str_size = sizeof("CID");
+ }
+
+ if ((p_name = strstr(desc,cid_str)) != NULL) {
+ p_name += cid_str_size;
+ sscanf(p_name,"%x",&cid);
+ }
+
+ return cid;
+}
+
+static int vmdk_write_cid(BlockDriverState *bs, uint32_t cid)
+{
+ BDRVVmdkState *s = bs->opaque;
+ char desc[DESC_SIZE], tmp_desc[DESC_SIZE];
+ char *p_name, *tmp_str;
+
+ /* the descriptor offset = 0x200 */
+ if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
+ return -1;
+
+ tmp_str = strstr(desc,"parentCID");
+ pstrcpy(tmp_desc, sizeof(tmp_desc), tmp_str);
+ if ((p_name = strstr(desc,"CID")) != NULL) {
+ p_name += sizeof("CID");
+ snprintf(p_name, sizeof(desc) - (p_name - desc), "%x\n", cid);
+ pstrcat(desc, sizeof(desc), tmp_desc);
+ }
+
+ if (bdrv_pwrite(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)
+ return -1;
+ return 0;
+}
+
+static int vmdk_is_cid_valid(BlockDriverState *bs)
+{
+#ifdef CHECK_CID
+ BDRVVmdkState *s = bs->opaque;
+ BlockDriverState *p_bs = s->hd->backing_hd;
+ uint32_t cur_pcid;
+
+ if (p_bs) {
+ cur_pcid = vmdk_read_cid(p_bs,0);
+ if (s->parent_cid != cur_pcid)
+ // CID not valid
+ return 0;
+ }
+#endif
+ // CID valid
+ return 1;
+}
+
+static int vmdk_snapshot_create(const char *filename, const char *backing_file)
+{
+ int snp_fd, p_fd;
+ uint32_t p_cid;
+ char *p_name, *gd_buf, *rgd_buf;
+ const char *real_filename, *temp_str;
+ VMDK4Header header;
+ uint32_t gde_entries, gd_size;
+ int64_t gd_offset, rgd_offset, capacity, gt_size;
+ char p_desc[DESC_SIZE], s_desc[DESC_SIZE], hdr[HEADER_SIZE];
+ static const char desc_template[] =
+ "# Disk DescriptorFile\n"
+ "version=1\n"
+ "CID=%x\n"
+ "parentCID=%x\n"
+ "createType=\"monolithicSparse\"\n"
+ "parentFileNameHint=\"%s\"\n"
+ "\n"
+ "# Extent description\n"
+ "RW %u SPARSE \"%s\"\n"
+ "\n"
+ "# The Disk Data Base \n"
+ "#DDB\n"
+ "\n";
+
+ snp_fd = open(filename, O_RDWR | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, 0644);
+ if (snp_fd < 0)
+ return -1;
+ p_fd = open(backing_file, O_RDONLY | O_BINARY | O_LARGEFILE);
+ if (p_fd < 0) {
+ close(snp_fd);
+ return -1;
+ }
+
+ /* read the header */
+ if (lseek(p_fd, 0x0, SEEK_SET) == -1)
+ goto fail;
+ if (read(p_fd, hdr, HEADER_SIZE) != HEADER_SIZE)
+ goto fail;
+
+ /* write the header */
+ if (lseek(snp_fd, 0x0, SEEK_SET) == -1)
+ goto fail;
+ if (write(snp_fd, hdr, HEADER_SIZE) == -1)
+ goto fail;
+
+ memset(&header, 0, sizeof(header));
+ memcpy(&header,&hdr[4], sizeof(header)); // skip the VMDK4_MAGIC
+
+ ftruncate(snp_fd, header.grain_offset << 9);
+ /* the descriptor offset = 0x200 */
+ if (lseek(p_fd, 0x200, SEEK_SET) == -1)
+ goto fail;
+ if (read(p_fd, p_desc, DESC_SIZE) != DESC_SIZE)
+ goto fail;
+
+ if ((p_name = strstr(p_desc,"CID")) != NULL) {
+ p_name += sizeof("CID");
+ sscanf(p_name,"%x",&p_cid);
+ }
+
+ real_filename = filename;
+ if ((temp_str = strrchr(real_filename, '\\')) != NULL)
+ real_filename = temp_str + 1;
+ if ((temp_str = strrchr(real_filename, '/')) != NULL)
+ real_filename = temp_str + 1;
+ if ((temp_str = strrchr(real_filename, ':')) != NULL)
+ real_filename = temp_str + 1;
+
+ snprintf(s_desc, sizeof(s_desc), desc_template, p_cid, p_cid, backing_file,
+ (uint32_t)header.capacity, real_filename);
+
+ /* write the descriptor */
+ if (lseek(snp_fd, 0x200, SEEK_SET) == -1)
+ goto fail;
+ if (write(snp_fd, s_desc, strlen(s_desc)) == -1)
+ goto fail;
+
+ gd_offset = header.gd_offset * SECTOR_SIZE; // offset of GD table
+ rgd_offset = header.rgd_offset * SECTOR_SIZE; // offset of RGD table
+ capacity = header.capacity * SECTOR_SIZE; // Extent size
+ /*
+ * Each GDE span 32M disk, means:
+ * 512 GTE per GT, each GTE points to grain
+ */
+ gt_size = (int64_t)header.num_gtes_per_gte * header.granularity * SECTOR_SIZE;
+ if (!gt_size)
+ goto fail;
+ gde_entries = (uint32_t)(capacity / gt_size); // number of gde/rgde
+ gd_size = gde_entries * sizeof(uint32_t);
+
+ /* write RGD */
+ rgd_buf = qemu_malloc(gd_size);
+ if (lseek(p_fd, rgd_offset, SEEK_SET) == -1)
+ goto fail_rgd;
+ if (read(p_fd, rgd_buf, gd_size) != gd_size)
+ goto fail_rgd;
+ if (lseek(snp_fd, rgd_offset, SEEK_SET) == -1)
+ goto fail_rgd;
+ if (write(snp_fd, rgd_buf, gd_size) == -1)
+ goto fail_rgd;
+ qemu_free(rgd_buf);
+
+ /* write GD */
+ gd_buf = qemu_malloc(gd_size);
+ if (lseek(p_fd, gd_offset, SEEK_SET) == -1)
+ goto fail_gd;
+ if (read(p_fd, gd_buf, gd_size) != gd_size)
+ goto fail_gd;
+ if (lseek(snp_fd, gd_offset, SEEK_SET) == -1)
+ goto fail_gd;
+ if (write(snp_fd, gd_buf, gd_size) == -1)
+ goto fail_gd;
+ qemu_free(gd_buf);
+
+ close(p_fd);
+ close(snp_fd);
+ return 0;
+
+ fail_gd:
+ qemu_free(gd_buf);
+ fail_rgd:
+ qemu_free(rgd_buf);
+ fail:
+ close(p_fd);
+ close(snp_fd);
+ return -1;
+}
+
+static void vmdk_parent_close(BlockDriverState *bs)
+{
+ if (bs->backing_hd)
+ bdrv_close(bs->backing_hd);
+}
+
+static int parent_open = 0;
+static int vmdk_parent_open(BlockDriverState *bs, const char * filename)
+{
+ BDRVVmdkState *s = bs->opaque;
+ char *p_name;
+ char desc[DESC_SIZE];
+ char parent_img_name[1024];
+
+ /* the descriptor offset = 0x200 */
+ if (bdrv_pread(s->hd, 0x200, desc, DESC_SIZE) != DESC_SIZE)