rdma_transport.c

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/*
 * 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 <linux/module.h>
#include <rdma/rdma_cm.h>

#include "rdma_transport.h"

static struct rdma_cm_id *rds_rdma_listen_id;

static char *rds_cm_event_strings[] = {
#define RDS_CM_EVENT_STRING(foo) \
        [RDMA_CM_EVENT_##foo] = __stringify(RDMA_CM_EVENT_##foo)
    RDS_CM_EVENT_STRING(ADDR_RESOLVED),
    RDS_CM_EVENT_STRING(ADDR_ERROR),
    RDS_CM_EVENT_STRING(ROUTE_RESOLVED),
    RDS_CM_EVENT_STRING(ROUTE_ERROR),
    RDS_CM_EVENT_STRING(CONNECT_REQUEST),
    RDS_CM_EVENT_STRING(CONNECT_RESPONSE),
    RDS_CM_EVENT_STRING(CONNECT_ERROR),
    RDS_CM_EVENT_STRING(UNREACHABLE),
    RDS_CM_EVENT_STRING(REJECTED),
    RDS_CM_EVENT_STRING(ESTABLISHED),
    RDS_CM_EVENT_STRING(DISCONNECTED),
    RDS_CM_EVENT_STRING(DEVICE_REMOVAL),
    RDS_CM_EVENT_STRING(MULTICAST_JOIN),
    RDS_CM_EVENT_STRING(MULTICAST_ERROR),
    RDS_CM_EVENT_STRING(ADDR_CHANGE),
    RDS_CM_EVENT_STRING(TIMEWAIT_EXIT),
#undef RDS_CM_EVENT_STRING
};

static char *rds_cm_event_str(enum rdma_cm_event_type type)
{
    return rds_str_array(rds_cm_event_strings,
                 ARRAY_SIZE(rds_cm_event_strings), type);
};

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

    rdsdebug("conn %p id %p handling event %u (%s)\n", conn, cm_id,
         event->event, rds_cm_event_str(event->event));

    if (cm_id->device->node_type == RDMA_NODE_RNIC)
        trans = &rds_iw_transport;
    else
        trans = &rds_ib_transport;

    /* Prevent shutdown from tearing down the connection
     * while we're executing. */
    if (conn) {
        mutex_lock(&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 (rds_conn_state(conn) == RDS_CONN_DISCONNECTING) {
            /* Reject incoming connections while we're tearing
             * down an existing one. */
            if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
                ret = 1;
            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,
                     RDS_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)
            rds_conn_drop(conn);
        break;

    case RDMA_CM_EVENT_DISCONNECTED:
        rdsdebug("DISCONNECT event - dropping connection "
            "%pI4->%pI4\n", &conn->c_laddr,
             &conn->c_faddr);
        rds_conn_drop(conn);
        break;

    default:
        /* things like device disconnect? */
        printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
               event->event, rds_cm_event_str(event->event));
        break;
    }

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

    rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
         rds_cm_event_str(event->event), ret);

    return ret;
}

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

    cm_id = rdma_create_id(rds_rdma_cm_event_handler, NULL, RDMA_PS_TCP,
                   IB_QPT_RC);
    if (IS_ERR(cm_id)) {
        ret = PTR_ERR(cm_id);
        printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
               "rdma_create_id() returned %d\n", ret);
        return ret;
    }

    sin.sin_family = AF_INET,
    sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
    sin.sin_port = (__force u16)htons(RDS_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) {
        printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
               "rdma_bind_addr() returned %d\n", ret);
        goto out;
    }

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

    rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);

    rds_rdma_listen_id = cm_id;
    cm_id = NULL;
out:
    if (cm_id)
        rdma_destroy_id(cm_id);
    return ret;
}

static void rds_rdma_listen_stop(void)
{
    if (rds_rdma_listen_id) {
        rdsdebug("cm %p\n", rds_rdma_listen_id);
        rdma_destroy_id(rds_rdma_listen_id);
        rds_rdma_listen_id = NULL;
    }
}

static int rds_rdma_init(void)
{
    int ret;

    ret = rds_rdma_listen_init();
    if (ret)
        goto out;

    ret = rds_iw_init();
    if (ret)
        goto err_iw_init;

    ret = rds_ib_init();
    if (ret)
        goto err_ib_init;

    goto out;

err_ib_init:
    rds_iw_exit();
err_iw_init:
    rds_rdma_listen_stop();
out:
    return ret;
}
module_init(rds_rdma_init);

static void rds_rdma_exit(void)
{
    /* stop listening first to ensure no new connections are attempted */
    rds_rdma_listen_stop();
    rds_ib_exit();
    rds_iw_exit();
}
module_exit(rds_rdma_exit);

MODULE_AUTHOR("Oracle Corporation <[email protected]>");
MODULE_DESCRIPTION("RDS: IB/iWARP transport");
MODULE_LICENSE("Dual BSD/GPL");