Add support for UNMAP command and add a simple test for this opcode

lib/libiscsi.def

@@ -91,4 +91,5 @@ scsi_cdb_write10
 scsi_cdb_synchronizecache10
 scsi_cdb_readcapacity16
 scsi_cdb_serviceactionin16
+scsi_cdb_unmap
 

lib/scsi-command.c

@@ -794,6 +794,53 @@ iscsi_synchronizecache10_task(struct iscsi_context *iscsi, int lun, int lba,
 	return task;
 }
 
+struct scsi_task *
+iscsi_unmap_task(struct iscsi_context *iscsi, int lun, int anchor, int group,
+		 struct unmap_list *list, int list_len,
+		 iscsi_command_cb cb, void *private_data)
+{
+	struct scsi_task *task;
+	struct iscsi_data outdata;
+	unsigned char *data;
+	int xferlen;
+	int i;
+
+	xferlen = 8 + list_len * 16;
+
+	task = scsi_cdb_unmap(anchor, group, xferlen);
+	if (task == NULL) {
+		iscsi_set_error(iscsi, "Out-of-memory: Failed to create "
+				"unmap cdb.");
+		return NULL;
+	}
+
+	data = scsi_malloc(task, xferlen);
+	if (data == NULL) {
+		iscsi_set_error(iscsi, "Out-of-memory: Failed to create "
+				"unmap parameters.");
+		scsi_free_scsi_task(task);
+		return NULL;
+	}
+	*((uint16_t *)&data[0]) = htons(xferlen - 2);
+	*((uint16_t *)&data[2]) = htons(xferlen - 8);
+	for (i = 0; i < list_len; i++) {
+		*((uint32_t *)&data[8 + 16 * i])     = htonl(list[0].lba >> 32);
+		*((uint32_t *)&data[8 + 16 * i + 4]) = htonl(list[0].lba & 0xffffffff);
+		*((uint32_t *)&data[8 + 16 * i + 8]) = htonl(list[0].num);
+	}
+
+	outdata.data = data;
+	outdata.size = xferlen;
+
+	if (iscsi_scsi_command_async(iscsi, lun, task, cb, &outdata,
+				       private_data) != 0) {
+		scsi_free_scsi_task(task);
+		return NULL;
+	}
+
+	return task;
+}
+
 unsigned char *
 iscsi_get_user_in_buffer(struct iscsi_context *iscsi, struct iscsi_in_pdu *in, uint32_t pos, ssize_t *count)
 {

lib/scsi-lowlevel.c

@@ -55,7 +55,7 @@ scsi_free_scsi_task(struct scsi_task *task)
 	free(task);
 }
 
-static void *
+void *
 scsi_malloc(struct scsi_task *task, size_t size)
 {
 	struct scsi_allocated_memory *mem;
@@ -759,6 +759,36 @@ scsi_cdb_verify10(uint32_t lba, uint32_t xferlen, int vprotect, int dpo, int byt
 }
 
 
+/*
+ * UNMAP
+ */
+struct scsi_task *
+scsi_cdb_unmap(int anchor, int group, uint16_t xferlen)
+{
+	struct scsi_task *task;
+
+	task = malloc(sizeof(struct scsi_task));
+	if (task == NULL) {
+		return NULL;
+	}
+
+	memset(task, 0, sizeof(struct scsi_task));
+	task->cdb[0]   = SCSI_OPCODE_UNMAP;
+
+	if (anchor) {
+		task->cdb[1] |= 0x01;
+	}
+	task->cdb[6] |= group & 0x1f;
+
+	*(uint16_t *)&task->cdb[7] = htons(xferlen);
+
+	task->cdb_size = 10;
+	task->xfer_dir = SCSI_XFER_WRITE;
+	task->expxferlen = xferlen;
+
+	return task;
+}
+
 /*
  * MODESENSE6
  */

lib/sync.c

@@ -361,6 +361,26 @@ iscsi_verify10_sync(struct iscsi_context *iscsi, int lun, unsigned char *data, u
 	return state.task;
 }
 
+struct scsi_task *
+iscsi_unmap_sync(struct iscsi_context *iscsi, int lun, int anchor, int group,
+		 struct unmap_list *list, int list_len)
+{
+	struct iscsi_sync_state state;
+
+	memset(&state, 0, sizeof(state));
+
+	if (iscsi_unmap_task(iscsi, lun, anchor, group, list, list_len,
+				       scsi_sync_cb, &state) == NULL) {
+		iscsi_set_error(iscsi,
+				"Failed to send UNMAP command");
+		return NULL;
+	}
+
+	event_loop(iscsi, &state);
+
+	return state.task;
+}
+
 struct scsi_task *
 iscsi_scsi_command_sync(struct iscsi_context *iscsi, int lun,
 			struct scsi_task *task, struct iscsi_data *data)