/*
 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*
 * This file contains code imported from the OFED rds source file
 * rdma_transport.c * Oracle elects to have and use the contents of
 * rdma_transport.c under and governed by the OpenIB.org BSD license
 * (see below for full license text). However, the following notice
 * accompanied the original version of this file:
 */

/*
 * Copyright (c) 2009 Oracle.  All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */
#include <sys/ib/clients/of/rdma/ib_verbs.h>
#include <sys/ib/clients/of/rdma/ib_addr.h>
#include <sys/ib/clients/of/rdma/rdma_cm.h>

#include <sys/ib/clients/rdsv3/ib.h>
#include <sys/ib/clients/rdsv3/rdma_transport.h>
#include <sys/ib/clients/rdsv3/rdsv3_debug.h>

kmutex_t rdsv3_rdma_listen_id_lock;
struct rdma_cm_id *rdsv3_rdma_listen_id = NULL;

int
rdsv3_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
    struct rdma_cm_event *event)
{
        /* this can be null in the listening path */
        struct rdsv3_connection *conn = cm_id->context;
        struct rdsv3_transport *trans;
        int ret = 0;

        RDSV3_DPRINTF2("rdsv3_rdma_cm_event_handler",
            "conn %p id %p handling event %u", conn, cm_id, event->event);

        trans = &rdsv3_ib_transport;

        /*
         * Prevent shutdown from tearing down the connection
         * while we're executing.
         */
        if (conn) {
                mutex_enter(&conn->c_cm_lock);

                /*
                 * If the connection is being shut down, bail out
                 * right away. We return 0 so cm_id doesn't get
                 * destroyed prematurely
                 */
                if (rdsv3_conn_state(conn) == RDSV3_CONN_DISCONNECTING) {
                        /*
                         * Reject incoming connections while we're tearing
                         * down an existing one.
                         */
                        if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
                                ret = 1;
                        RDSV3_DPRINTF2("rdsv3_rdma_cm_event_handler",
                            "conn %p id %p incoming event %u when "
                            "disconnecting", conn, cm_id, event->event);
                        goto out;
                }
        }

        switch (event->event) {
        case RDMA_CM_EVENT_CONNECT_REQUEST:
                ret = trans->cm_handle_connect(cm_id, event);
                break;

        case RDMA_CM_EVENT_ADDR_RESOLVED:
                /* XXX do we need to clean up if this fails? */
                ret = rdma_resolve_route(cm_id,
                    RDSV3_RDMA_RESOLVE_TIMEOUT_MS);
                break;

        case RDMA_CM_EVENT_ROUTE_RESOLVED:
                /* XXX worry about racing with listen acceptance */
                ret = trans->cm_initiate_connect(cm_id);
                break;

        case RDMA_CM_EVENT_ESTABLISHED:
                trans->cm_connect_complete(conn, event);
                break;

        case RDMA_CM_EVENT_ADDR_ERROR:
        case RDMA_CM_EVENT_ROUTE_ERROR:
        case RDMA_CM_EVENT_CONNECT_ERROR:
        case RDMA_CM_EVENT_UNREACHABLE:
        case RDMA_CM_EVENT_REJECTED:
        case RDMA_CM_EVENT_DEVICE_REMOVAL:
        case RDMA_CM_EVENT_ADDR_CHANGE:
                if (conn)
                        rdsv3_conn_drop(conn);
                break;

        case RDMA_CM_EVENT_DISCONNECTED:
                RDSV3_DPRINTF2("rdsv3_rdma_cm_event_handler",
                    "RDS/RDMA: DISCONNECT event - dropping connection "
                    "cm_id: %p", cm_id);
                if (conn) {
                        RDSV3_DPRINTF2("rdsv3_rdma_cm_event_handler",
                            "RDS/RDMA: DISCONNECT event - dropping connection "
                            "%u.%u.%u.%u->%u.%u.%u.%u", NIPQUAD(conn->c_laddr),
                            NIPQUAD(conn->c_faddr));
                        rdsv3_conn_drop(conn);
                }
                break;

        default:
                /* things like device disconnect? */
                RDSV3_DPRINTF2("rdsv3_rdma_cm_event_handler",
                    "unknown event %u!\n", event->event);
                RDSV3_PANIC();
                break;
        }

out:
        if (conn)
                mutex_exit(&conn->c_cm_lock);

        RDSV3_DPRINTF2("rdsv3_rdma_cm_event_handler",
            "id %p event %u handling ret %d", cm_id, event->event, ret);

        return (ret);
}

static int
rdsv3_rdma_listen_init(void)
{
        struct sockaddr_in sin;
        struct rdma_cm_id *cm_id;
        int ret;

        RDSV3_DPRINTF2("rdsv3_rdma_listen_init", "Enter");

        cm_id = rdma_create_id(rdsv3_rdma_cm_event_handler, NULL, RDMA_PS_TCP);
        if (IS_ERR(cm_id)) {
                ret = PTR_ERR(cm_id);
                RDSV3_DPRINTF2("rdsv3_rdma_listen_init",
                    "RDS/RDMA: failed to setup listener, "
                    "rdma_create_id() returned %d", ret);
                goto out;
        }

        sin.sin_family = PF_INET;
        sin.sin_addr.s_addr = (uint32_t)htonl(INADDR_ANY);
        sin.sin_port = (uint16_t)htons(RDSV3_PORT);

        /*
         * XXX I bet this binds the cm_id to a device.  If we want to support
         * fail-over we'll have to take this into consideration.
         */
        ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
        if (ret) {
                RDSV3_DPRINTF2("rdsv3_rdma_listen_init",
                    "RDS/RDMA: failed to setup listener, "
                    "rdma_bind_addr() returned %d", ret);
                goto out;
        }

        ret = rdma_listen(cm_id, 128);
        if (ret) {
                RDSV3_DPRINTF2("rdsv3_rdma_listen_init",
                    "RDS/RDMA: failed to setup listener, "
                    "rdma_listen() returned %d", ret);
                goto out;
        }

        RDSV3_DPRINTF5("rdsv3_rdma_listen_init",
            "cm %p listening on port %u", cm_id, RDSV3_PORT);

        rdsv3_rdma_listen_id = cm_id;
        cm_id = NULL;

        RDSV3_DPRINTF2("rdsv3_rdma_listen_init",
            "Return: rdsv3_rdma_listen_id: %p", rdsv3_rdma_listen_id);
out:
        if (cm_id)
                rdma_destroy_id(cm_id);
        return (ret);
}

static void rdsv3_rdma_listen_stop(void)
{
        RDSV3_DPRINTF2("rdsv3_rdma_listen_stop", "cm %p", rdsv3_rdma_listen_id);
        rdma_destroy_id(rdsv3_rdma_listen_id);
        RDSV3_DPRINTF2("rdsv3_rdma_listen_stop", "Return");
}

/*
 * This function can be called via two routes.
 *      1. During attach on a worker thread.
 *      2. From rdsv3_create() for 1st socket.
 */
void
rdsv3_rdma_init()
{
        int ret;

        RDSV3_DPRINTF2("rdsv3_rdma_init", "Enter");

        mutex_enter(&rdsv3_rdma_listen_id_lock);
        if (rdsv3_rdma_listen_id != NULL) {
                RDSV3_DPRINTF5("rdsv3_rdma_init",
                    "rdsv3_rdma_listen_id is already initialized: %p",
                    rdsv3_rdma_listen_id);
                mutex_exit(&rdsv3_rdma_listen_id_lock);
                return;
        }

        ret = rdsv3_rdma_listen_init();
        if (ret) {
                mutex_exit(&rdsv3_rdma_listen_id_lock);
                return;
        }

        ret = rdsv3_ib_init();
        if (ret) {
                rdsv3_rdma_listen_stop();
        }
        mutex_exit(&rdsv3_rdma_listen_id_lock);

        RDSV3_DPRINTF2("rdsv3_rdma_init", "Return");
}

/*ARGSUSED*/
void
rdsv3_rdma_exit(void *arg)
{
        RDSV3_DPRINTF2("rdsv3_rdma_exit", "Enter");

        /* stop listening first to ensure no new connections are attempted */
        if (rdsv3_rdma_listen_id) {
                rdsv3_rdma_listen_stop();
                rdsv3_ib_exit();
                rdsv3_rdma_listen_id = NULL;
        }

        RDSV3_DPRINTF2("rdsv3_rdma_exit", "Return");
}