/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2013 Nexenta Systems, Inc. All rights reserved.
 */

#include <sys/cpuvar.h>
#include <sys/types.h>
#include <sys/conf.h>
#include <sys/file.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/modctl.h>
#include <sys/sysmacros.h>

#include <sys/socket.h>
#include <sys/strsubr.h>
#include <sys/door.h>

#include <sys/stmf.h>
#include <sys/stmf_ioctl.h>
#include <sys/portif.h>

#include "pppt.h"

static void pppt_msg_tgt_register(stmf_ic_msg_t *reg_port);

static void pppt_msg_tgt_deregister(stmf_ic_msg_t *msg);

static void pppt_msg_session_destroy(stmf_ic_msg_t *msg);

static void pppt_msg_scsi_cmd(stmf_ic_msg_t *msg);

static void pppt_msg_data_xfer_done(stmf_ic_msg_t *msg);

static void pppt_msg_handle_status(stmf_ic_msg_t *msg);

void
pppt_msg_rx(stmf_ic_msg_t *msg)
{
        switch (msg->icm_msg_type) {
        case STMF_ICM_REGISTER_PROXY_PORT:
                pppt_msg_tgt_register(msg);
                break;
        case STMF_ICM_DEREGISTER_PROXY_PORT:
                pppt_msg_tgt_deregister(msg);
                break;
        case STMF_ICM_SESSION_CREATE:
                pppt_msg_tx_status(msg, STMF_NOT_SUPPORTED);
                stmf_ic_msg_free(msg);
                break;
        case STMF_ICM_SESSION_DESTROY:
                pppt_msg_session_destroy(msg);
                break;
        case STMF_ICM_SCSI_CMD:
                pppt_msg_scsi_cmd(msg);
                break;
        case STMF_ICM_SCSI_DATA_XFER_DONE:
                pppt_msg_data_xfer_done(msg);
                break;
        case STMF_ICM_SCSI_DATA:
                /* Ignore, all proxy data will be immediate for now */
                pppt_msg_tx_status(msg, STMF_NOT_SUPPORTED);
                stmf_ic_msg_free(msg);
                break;
        case STMF_ICM_STATUS:
                pppt_msg_handle_status(msg);
                break;
        default:
                /* Other message types are not allowed */
                ASSERT(0);
                break;
        }
}

void
pppt_msg_tx_status(stmf_ic_msg_t *orig_msg, stmf_status_t status)
{
        stmf_ic_msg_t   *msg;

        /*
         * If TX of status fails it should be treated the same as a loss of
         * connection.  We expect the remote node to handle it.
         */
        msg = stmf_ic_status_msg_alloc(status, orig_msg->icm_msg_type,
            orig_msg->icm_msgid);

        if (msg != NULL) {
                (void) stmf_ic_tx_msg(msg);
        }
}

static void
pppt_msg_tgt_register(stmf_ic_msg_t *msg)
{
        stmf_ic_reg_port_msg_t  *reg_port;
        pppt_tgt_t              *result;
        stmf_status_t           stmf_status;

        reg_port = msg->icm_msg;

        PPPT_GLOBAL_LOCK();
        if (pppt_global.global_svc_state != PSS_ENABLED) {
                stmf_status = STMF_FAILURE;
                PPPT_INC_STAT(es_tgt_reg_svc_disabled);
                goto pppt_register_tgt_done;
        }

        /*
         * For now we assume that the marshall/unmarshall code is responsible
         * for validating the message length and ensuring the resulting
         * request structure is self consistent.  Make sure this
         * target doesn't already exist.
         */
        if ((result = pppt_tgt_lookup_locked(reg_port->icrp_port_id)) != NULL) {
                stmf_status = STMF_ALREADY;
                PPPT_INC_STAT(es_tgt_reg_duplicate);
                goto pppt_register_tgt_done;
        }

        result = pppt_tgt_create(reg_port, &stmf_status);

        if (result == NULL) {
                stmf_status = STMF_TARGET_FAILURE;
                PPPT_INC_STAT(es_tgt_reg_create_fail);
                goto pppt_register_tgt_done;
        }

        avl_add(&pppt_global.global_target_list, result);

        stmf_status = STMF_SUCCESS;

pppt_register_tgt_done:
        PPPT_GLOBAL_UNLOCK();
        pppt_msg_tx_status(msg, stmf_status);
        stmf_ic_msg_free(msg);
}

static void
pppt_msg_tgt_deregister(stmf_ic_msg_t *msg)
{
        stmf_ic_dereg_port_msg_t        *dereg_port;
        stmf_status_t                   stmf_status;
        pppt_tgt_t                      *tgt;

        PPPT_GLOBAL_LOCK();
        if (pppt_global.global_svc_state != PSS_ENABLED) {
                PPPT_GLOBAL_UNLOCK();
                stmf_status = STMF_FAILURE;
                PPPT_INC_STAT(es_tgt_dereg_svc_disabled);
                goto pppt_deregister_tgt_done;
        }

        dereg_port = msg->icm_msg;

        /* Lookup target */
        if ((tgt = pppt_tgt_lookup_locked(dereg_port->icdp_port_id)) == NULL) {
                PPPT_GLOBAL_UNLOCK();
                stmf_status = STMF_NOT_FOUND;
                PPPT_INC_STAT(es_tgt_dereg_not_found);
                goto pppt_deregister_tgt_done;
        }
        avl_remove(&pppt_global.global_target_list, tgt);
        pppt_tgt_async_delete(tgt);

        PPPT_GLOBAL_UNLOCK();

        /* Wait for delete to complete */
        mutex_enter(&tgt->target_mutex);
        while ((tgt->target_refcount > 0) ||
            (tgt->target_state != TS_DELETING)) {
                cv_wait(&tgt->target_cv, &tgt->target_mutex);
        }
        mutex_exit(&tgt->target_mutex);

        pppt_tgt_destroy(tgt);
        stmf_status = STMF_SUCCESS;

pppt_deregister_tgt_done:
        pppt_msg_tx_status(msg, stmf_status);
        stmf_ic_msg_free(msg);
}

static void
pppt_msg_session_destroy(stmf_ic_msg_t *msg)
{
        stmf_ic_session_create_destroy_msg_t    *sess_destroy;
        pppt_tgt_t                              *tgt;
        pppt_sess_t                             *ps;

        sess_destroy = msg->icm_msg;

        PPPT_GLOBAL_LOCK();

        /*
         * Look for existing session for this ID
         */
        ps = pppt_sess_lookup_locked(sess_destroy->icscd_session_id,
            sess_destroy->icscd_tgt_devid, sess_destroy->icscd_rport);

        if (ps == NULL) {
                PPPT_GLOBAL_UNLOCK();
                stmf_ic_msg_free(msg);
                PPPT_INC_STAT(es_sess_destroy_no_session);
                return;
        }

        tgt = ps->ps_target;

        mutex_enter(&tgt->target_mutex);
        mutex_enter(&ps->ps_mutex);

        /* Release the reference from the lookup */
        pppt_sess_rele_locked(ps);

        /* Make sure another thread is not already closing the session */
        if (!ps->ps_closed) {
                /* Found matching open session, quiesce... */
                pppt_sess_close_locked(ps);
        }
        mutex_exit(&ps->ps_mutex);
        mutex_exit(&tgt->target_mutex);
        PPPT_GLOBAL_UNLOCK();

        stmf_ic_msg_free(msg);
}

static void
pppt_msg_scsi_cmd(stmf_ic_msg_t *msg)
{
        pppt_sess_t                     *pppt_sess;
        pppt_buf_t                      *pbuf;
        stmf_ic_scsi_cmd_msg_t          *scmd;
        pppt_task_t                     *ptask;
        scsi_task_t                     *task;
        pppt_status_t                   pppt_status;
        stmf_local_port_t               *lport;
        stmf_scsi_session_t             *stmf_sess;
        stmf_status_t                   stmf_status;

        /*
         * Get a task context
         */
        ptask = pppt_task_alloc();
        if (ptask == NULL) {
                /*
                 * We must be very low on memory.  Just free the message
                 * and let the command timeout.
                 */
                stmf_ic_msg_free(msg);
                PPPT_INC_STAT(es_scmd_ptask_alloc_fail);
                return;
        }

        scmd = msg->icm_msg;

        /*
         * Session are created implicitly on the first use of an
         * IT nexus
         */
        pppt_sess = pppt_sess_lookup_create(scmd->icsc_tgt_devid,
            scmd->icsc_ini_devid, scmd->icsc_rport,
            scmd->icsc_session_id, &stmf_status);
        if (pppt_sess == NULL) {
                pppt_task_free(ptask);
                pppt_msg_tx_status(msg, stmf_status);
                stmf_ic_msg_free(msg);
                PPPT_INC_STAT(es_scmd_sess_create_fail);
                return;
        }

        ptask->pt_sess = pppt_sess;
        ptask->pt_task_id = scmd->icsc_task_msgid;
        stmf_sess = pppt_sess->ps_stmf_sess;
        lport = stmf_sess->ss_lport;

        /*
         * Add task to our internal task set.
         */
        pppt_status = pppt_task_start(ptask);

        if (pppt_status != 0) {
                /* Release hold from pppt_sess_lookup_create() */
                PPPT_LOG(CE_WARN, "Duplicate taskid from remote node 0x%llx",
                    (longlong_t)scmd->icsc_task_msgid);
                pppt_task_free(ptask);
                pppt_sess_rele(pppt_sess);
                pppt_msg_tx_status(msg, STMF_ALREADY);
                stmf_ic_msg_free(msg);
                PPPT_INC_STAT(es_scmd_dup_task_count);
                return;
        }

        /*
         * Allocate STMF task context
         */
        ptask->pt_stmf_task = stmf_task_alloc(lport, stmf_sess,
            scmd->icsc_task_lun_no,
            scmd->icsc_task_cdb_length, 0);
        if (ptask->pt_stmf_task == NULL) {
                /* NOTE: pppt_task_done() will free ptask. */
                (void) pppt_task_done(ptask);
                pppt_sess_rele(pppt_sess);
                pppt_msg_tx_status(msg, STMF_ALLOC_FAILURE);
                stmf_ic_msg_free(msg);
                PPPT_INC_STAT(es_scmd_stask_alloc_fail);
                return;
        }

        task = ptask->pt_stmf_task;
        /* task_port_private reference is a real reference. */
        (void) pppt_task_hold(ptask);
        task->task_port_private = ptask;
        task->task_flags = scmd->icsc_task_flags;
        task->task_additional_flags = TASK_AF_PPPT_TASK;
        task->task_priority = 0;

        /*
         * Set task->task_mgmt_function to TM_NONE for a normal SCSI task
         * or one of these values for a task management command:
         *
         * TM_ABORT_TASK ***
         * TM_ABORT_TASK_SET
         * TM_CLEAR_ACA
         * TM_CLEAR_TASK_SET
         * TM_LUN_RESET
         * TM_TARGET_WARM_RESET
         * TM_TARGET_COLD_RESET
         *
         * *** Note that STMF does not currently support TM_ABORT_TASK so
         * port providers must implement this command on their own
         * (e.g. lookup the desired task and call stmf_abort).
         */
        task->task_mgmt_function = scmd->icsc_task_mgmt_function;

        task->task_max_nbufs = 1; /* Don't allow parallel xfers */
        task->task_cmd_seq_no = msg->icm_msgid;
        task->task_expected_xfer_length =
            scmd->icsc_task_expected_xfer_length;

        if (scmd->icsc_task_cdb_length) {
                bcopy(scmd->icsc_task_cdb, task->task_cdb,
                    scmd->icsc_task_cdb_length);
        }
        bcopy(scmd->icsc_lun_id, ptask->pt_lun_id, 16);

        if (scmd->icsc_immed_data_len) {
                pbuf = ptask->pt_immed_data;
                pbuf->pbuf_immed_msg = msg;
                pbuf->pbuf_stmf_buf->db_data_size = scmd->icsc_immed_data_len;
                pbuf->pbuf_stmf_buf->db_buf_size = scmd->icsc_immed_data_len;
                pbuf->pbuf_stmf_buf->db_relative_offset = 0;
                pbuf->pbuf_stmf_buf->db_sglist[0].seg_length =
                    scmd->icsc_immed_data_len;
                pbuf->pbuf_stmf_buf->db_sglist[0].seg_addr =
                    scmd->icsc_immed_data;

                stmf_post_task(task, pbuf->pbuf_stmf_buf);
        } else {
                stmf_post_task(task, NULL);
                stmf_ic_msg_free(msg);
        }
}

static void
pppt_msg_data_xfer_done(stmf_ic_msg_t *msg)
{
        pppt_task_t                             *pppt_task;
        stmf_ic_scsi_data_xfer_done_msg_t       *data_xfer_done;

        data_xfer_done = msg->icm_msg;

        /*
         * Find task
         */
        pppt_task = pppt_task_lookup(data_xfer_done->icsx_task_msgid);

        /* If we found one, complete the transfer */
        if (pppt_task != NULL) {
                pppt_xfer_read_complete(pppt_task, data_xfer_done->icsx_status);
        }

        stmf_ic_msg_free(msg);
}

static void
pppt_msg_handle_status(stmf_ic_msg_t *msg)
{
        /* Don't care for now */
        stmf_ic_msg_free(msg);
}