Add support to unmarshall a CDB into a structure and update iscsi-dd

Add two new helper functions scsi_get_uint32() and scsi_get_uint16()

examples/iscsi-dd.c

@@ -85,6 +85,7 @@ void read10_cb(struct iscsi_context *iscsi _U_, int status, void *command_data,
 	struct client *client = (struct client *)private_data;
 	struct scsi_task *task = command_data;
 	struct write_task *wt;
+	struct scsi_read10_cdb *read10_cdb;
 
 	if (status == SCSI_STATUS_CHECK_CONDITION) {
 		printf("Read10 failed with sense key:%d ascq:%04x\n", task->sense.key, task->sense.ascq);
@@ -95,9 +96,14 @@ void read10_cb(struct iscsi_context *iscsi _U_, int status, void *command_data,
 	wt->rt = task;
 	wt->client = client;
 
+	read10_cdb = scsi_cdb_unmarshall(task);
+	if (read10_cdb == NULL) {
+		printf("Failed to unmarshall READ10 CDB.\n");
+		exit(10);
+	}
 	if (iscsi_write10_task(client->dst_iscsi,
 			client->dst_lun,
-			task->params.read10.lba,
+			read10_cdb->lba,
 			task->datain.data,
 			task->datain.size,
 			client->dst_blocksize,

include/scsi-lowlevel.h

@@ -657,8 +657,21 @@ struct scsi_report_supported_op_codes {
 	struct scsi_command_descriptor descriptors[0];
 };
 
+struct scsi_read10_cdb {
+	enum scsi_opcode opcode;
+	uint8_t  rdprotect;
+	uint8_t  dpo;
+	uint8_t  fua;
+	uint8_t  fua_nv;
+	uint32_t lba;
+	uint8_t  group;
+	uint16_t transfer_length;
+	uint8_t  control;
+};
+
 EXTERN int scsi_datain_getfullsize(struct scsi_task *task);
 EXTERN void *scsi_datain_unmarshall(struct scsi_task *task);
+EXTERN void *scsi_cdb_unmarshall(struct scsi_task *task);
 
 EXTERN struct scsi_task *scsi_cdb_read6(uint32_t lba, uint32_t xferlen, int blocksize);
 EXTERN struct scsi_task *scsi_cdb_read10(uint32_t lba, uint32_t xferlen, int blocksize, int rdprotect, int dpo, int fua, int fua_nv, int group_number);

lib/libiscsi.def

@@ -163,6 +163,7 @@ scsi_cdb_writesame16
 scsi_codeset_to_str
 scsi_datain_getfullsize
 scsi_datain_unmarshall
+scsi_cdb_unmarshall
 scsi_designator_type_to_str
 scsi_devqualifier_to_str
 scsi_devtype_to_str

lib/libiscsi.syms

@@ -161,6 +161,7 @@ scsi_cdb_writesame16
 scsi_codeset_to_str
 scsi_datain_getfullsize
 scsi_datain_unmarshall
+scsi_cdb_unmarshall
 scsi_designator_type_to_str
 scsi_devqualifier_to_str
 scsi_devtype_to_str

lib/scsi-lowlevel.c

@@ -15,8 +15,8 @@
    along with this program; if not, see <http://www.gnu.org/licenses/>.
 */
 /*
- * would be nice if this could grow into a full blown library for scsi to
- * 1, build a CDB
+ * would be nice if this could grow into a full blown library to
+ * 1, build and unmarshall a CDB
  * 2, check how big a complete data-in structure needs to be
  * 3, unmarshall data-in into a real structure
  * 4, marshall a real structure into a data-out blob
@@ -160,6 +160,18 @@ scsi_sense_ascq_str(int ascq)
 	return value_string_find(ascqs, ascq);
 }
 
+static uint32_t
+scsi_get_uint32(unsigned char *c)
+{
+	return ntohl(*(uint32_t *)c);
+}
+
+static uint16_t
+scsi_get_uint16(unsigned char *c)
+{
+	return ntohs(*(uint16_t *)c);
+}
+
 /*
  * TESTUNITREADY
  */
@@ -2298,6 +2310,39 @@ scsi_datain_unmarshall(struct scsi_task *task)
 }
 
 
+static struct scsi_read10_cdb *
+scsi_read10_cdb_unmarshall(struct scsi_task *task)
+{
+	struct scsi_read10_cdb *read10;
+
+	read10 = scsi_malloc(task, sizeof(struct scsi_read10_cdb));
+	if (read10 == NULL) {
+		return NULL;
+	}
+
+	read10->opcode          = SCSI_OPCODE_READ10;
+	read10->rdprotect       = (task->cdb[1] >> 5) & 0x7;
+	read10->dpo             = !!(task->cdb[1] & 0x10);
+	read10->fua             = !!(task->cdb[1] & 0x08);
+	read10->fua_nv          = !!(task->cdb[1] & 0x02);
+	read10->lba             = scsi_get_uint32(&task->cdb[2]);
+	read10->group           = task->cdb[6] & 0x1f;
+	read10->transfer_length = scsi_get_uint16(&task->cdb[7]);
+	read10->control         = task->cdb[9];
+
+        return read10;
+}
+
+void *
+scsi_cdb_unmarshall(struct scsi_task *task)
+{
+	switch (task->cdb[0]) {
+	case SCSI_OPCODE_READ10:
+		return scsi_read10_cdb_unmarshall(task);
+	}
+	return NULL;
+}
+
 const char *
 scsi_devtype_to_str(enum scsi_inquiry_peripheral_device_type type)
 {