target: split parsing of SPC commands into a separate helper

(nab: Add EXPORT_SYMBOL usage for spc_parse_cdb)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 169 insertions, 0 deletions

diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
new file mode 100644
index 000000000000..ec2108667d65
--- /dev/null
+++ b/drivers/target/target_core_spc.c
@@ -0,0 +1,169 @@
+/*
+ * SCSI Primary Commands (SPC) parsing and emulation.
+ *
+ * Copyright (c) 2002, 2003, 2004, 2005 PyX Technologies, Inc.
+ * Copyright (c) 2005, 2006, 2007 SBE, Inc.
+ * Copyright (c) 2007-2010 Rising Tide Systems
+ * Copyright (c) 2008-2010 Linux-iSCSI.org
+ *
+ * Nicholas A. Bellinger <nab@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <asm/unaligned.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_tcq.h>
+
+#include <target/target_core_base.h>
+#include <target/target_core_backend.h>
+#include <target/target_core_fabric.h>
+
+#include "target_core_internal.h"
+#include "target_core_pr.h"
+#include "target_core_ua.h"
+
+
+int spc_parse_cdb(struct se_cmd *cmd, unsigned int *size, bool passthrough)
+{
+	struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
+	unsigned char *cdb = cmd->t_task_cdb;
+
+	switch (cdb[0]) {
+	case MODE_SELECT:
+		*size = cdb[4];
+		break;
+	case MODE_SELECT_10:
+		*size = (cdb[7] << 8) + cdb[8];
+		break;
+	case MODE_SENSE:
+		*size = cdb[4];
+		if (!passthrough)
+			cmd->execute_cmd = target_emulate_modesense;
+		break;
+	case MODE_SENSE_10:
+		*size = (cdb[7] << 8) + cdb[8];
+		if (!passthrough)
+			cmd->execute_cmd = target_emulate_modesense;
+		break;
+	case LOG_SELECT:
+	case LOG_SENSE:
+		*size = (cdb[7] << 8) + cdb[8];
+		break;
+	case PERSISTENT_RESERVE_IN:
+		if (su_dev->t10_pr.res_type == SPC3_PERSISTENT_RESERVATIONS)
+			cmd->execute_cmd = target_scsi3_emulate_pr_in;
+		*size = (cdb[7] << 8) + cdb[8];
+		break;
+	case PERSISTENT_RESERVE_OUT:
+		if (su_dev->t10_pr.res_type == SPC3_PERSISTENT_RESERVATIONS)
+			cmd->execute_cmd = target_scsi3_emulate_pr_out;
+		*size = (cdb[7] << 8) + cdb[8];
+		break;
+	case RELEASE:
+	case RELEASE_10:
+		if (cdb[0] == RELEASE_10)
+			*size = (cdb[7] << 8) | cdb[8];
+		else
+			*size = cmd->data_length;
+
+		if (su_dev->t10_pr.res_type != SPC_PASSTHROUGH)
+			cmd->execute_cmd = target_scsi2_reservation_release;
+		break;
+	case RESERVE:
+	case RESERVE_10:
+		/*
+		 * The SPC-2 RESERVE does not contain a size in the SCSI CDB.
+		 * Assume the passthrough or $FABRIC_MOD will tell us about it.
+		 */
+		if (cdb[0] == RESERVE_10)
+			*size = (cdb[7] << 8) | cdb[8];
+		else
+			*size = cmd->data_length;
+
+		/*
+		 * Setup the legacy emulated handler for SPC-2 and
+		 * >= SPC-3 compatible reservation handling (CRH=1)
+		 * Otherwise, we assume the underlying SCSI logic is
+		 * is running in SPC_PASSTHROUGH, and wants reservations
+		 * emulation disabled.
+		 */
+		if (su_dev->t10_pr.res_type != SPC_PASSTHROUGH)
+			cmd->execute_cmd = target_scsi2_reservation_reserve;
+		break;
+	case REQUEST_SENSE:
+		*size = cdb[4];
+		if (!passthrough)
+			cmd->execute_cmd = target_emulate_request_sense;
+		break;
+	case INQUIRY:
+		*size = (cdb[3] << 8) + cdb[4];
+
+		/*
+		 * Do implict HEAD_OF_QUEUE processing for INQUIRY.
+		 * See spc4r17 section 5.3
+		 */
+		if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
+			cmd->sam_task_attr = MSG_HEAD_TAG;
+		if (!passthrough)
+			cmd->execute_cmd = target_emulate_inquiry;
+		break;
+	case SECURITY_PROTOCOL_IN:
+	case SECURITY_PROTOCOL_OUT:
+		*size = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
+		break;
+	case EXTENDED_COPY:
+	case READ_ATTRIBUTE:
+	case RECEIVE_COPY_RESULTS:
+	case WRITE_ATTRIBUTE:
+		*size = (cdb[10] << 24) | (cdb[11] << 16) |
+		       (cdb[12] << 8) | cdb[13];
+		break;
+	case RECEIVE_DIAGNOSTIC:
+	case SEND_DIAGNOSTIC:
+		*size = (cdb[3] << 8) | cdb[4];
+		break;
+	case WRITE_BUFFER:
+		*size = (cdb[6] << 16) + (cdb[7] << 8) + cdb[8];
+		break;
+	case REPORT_LUNS:
+		cmd->execute_cmd = target_report_luns;
+		*size = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
+		/*
+		 * Do implict HEAD_OF_QUEUE processing for REPORT_LUNS
+		 * See spc4r17 section 5.3
+		 */
+		if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
+			cmd->sam_task_attr = MSG_HEAD_TAG;
+		break;
+	case TEST_UNIT_READY:
+		if (!passthrough)
+			cmd->execute_cmd = target_emulate_noop;
+		break;
+	default:
+		pr_warn("TARGET_CORE[%s]: Unsupported SCSI Opcode"
+			" 0x%02x, sending CHECK_CONDITION.\n",
+			cmd->se_tfo->get_fabric_name(), cdb[0]);
+		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
+		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
+		return -EINVAL;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(spc_parse_cdb);