net/rds/rdma_transport.c

   1 /*
   2  * Copyright (c) 2009 Oracle.  All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  *
  32  */
  33 #include <rdma/rdma_cm.h>
  34
  35 #include "rdma_transport.h"
  36
  37 static struct rdma_cm_id *rds_rdma_listen_id;
  38
  39 int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
  40                               struct rdma_cm_event *event)
  41 {
  42         /* this can be null in the listening path */
  43         struct rds_connection *conn = cm_id->context;
  44         struct rds_transport *trans;
  45         int ret = 0;
  46
  47         rdsdebug("conn %p id %p handling event %u\n", conn, cm_id,
  48                  event->event);
  49
  50         if (cm_id->device->node_type == RDMA_NODE_RNIC)
  51                 trans = &rds_iw_transport;
  52         else
  53                 trans = &rds_ib_transport;
  54
  55         /* Prevent shutdown from tearing down the connection
  56          * while we're executing. */
  57         if (conn) {
  58                 mutex_lock(&conn->c_cm_lock);
  59
  60                 /* If the connection is being shut down, bail out
  61                  * right away. We return 0 so cm_id doesn't get
  62                  * destroyed prematurely */
  63                 if (rds_conn_state(conn) == RDS_CONN_DISCONNECTING) {
  64                         /* Reject incoming connections while we're tearing
  65                          * down an existing one. */
  66                         if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
  67                                 ret = 1;
  68                         goto out;
  69                 }
  70         }
  71
  72         switch (event->event) {
  73         case RDMA_CM_EVENT_CONNECT_REQUEST:
  74                 ret = trans->cm_handle_connect(cm_id, event);
  75                 break;
  76
  77         case RDMA_CM_EVENT_ADDR_RESOLVED:
  78                 /* XXX do we need to clean up if this fails? */
  79                 ret = rdma_resolve_route(cm_id,
  80                                          RDS_RDMA_RESOLVE_TIMEOUT_MS);
  81                 break;
  82
  83         case RDMA_CM_EVENT_ROUTE_RESOLVED:
  84                 /* XXX worry about racing with listen acceptance */
  85                 ret = trans->cm_initiate_connect(cm_id);
  86                 break;
  87
  88         case RDMA_CM_EVENT_ESTABLISHED:
  89                 trans->cm_connect_complete(conn, event);
  90                 break;
  91
  92         case RDMA_CM_EVENT_ADDR_ERROR:
  93         case RDMA_CM_EVENT_ROUTE_ERROR:
  94         case RDMA_CM_EVENT_CONNECT_ERROR:
  95         case RDMA_CM_EVENT_UNREACHABLE:
  96         case RDMA_CM_EVENT_REJECTED:
  97         case RDMA_CM_EVENT_DEVICE_REMOVAL:
  98         case RDMA_CM_EVENT_ADDR_CHANGE:
  99                 if (conn)
 100                         rds_conn_drop(conn);
 101                 break;
 102
 103         case RDMA_CM_EVENT_DISCONNECTED:
 104                 printk(KERN_WARNING "RDS/IW: DISCONNECT event - dropping connection "
 105                         "%pI4->%pI4\n", &conn->c_laddr,
 106                          &conn->c_faddr);
 107                 rds_conn_drop(conn);
 108                 break;
 109
 110         default:
 111                 /* things like device disconnect? */
 112                 printk(KERN_ERR "unknown event %u\n", event->event);
 113                 BUG();
 114                 break;
 115         }
 116
 117 out:
 118         if (conn)
 119                 mutex_unlock(&conn->c_cm_lock);
 120
 121         rdsdebug("id %p event %u handling ret %d\n", cm_id, event->event, ret);
 122
 123         return ret;
 124 }
 125
 126 static int __init rds_rdma_listen_init(void)
 127 {
 128         struct sockaddr_in sin;
 129         struct rdma_cm_id *cm_id;
 130         int ret;
 131
 132         cm_id = rdma_create_id(rds_rdma_cm_event_handler, NULL, RDMA_PS_TCP);
 133         if (IS_ERR(cm_id)) {
 134                 ret = PTR_ERR(cm_id);
 135                 printk(KERN_ERR "RDS/IW: failed to setup listener, "
 136                        "rdma_create_id() returned %d\n", ret);
 137                 goto out;
 138         }
 139
 140         sin.sin_family = PF_INET,
 141         sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
 142         sin.sin_port = (__force u16)htons(RDS_PORT);
 143
 144         /*
 145          * XXX I bet this binds the cm_id to a device.  If we want to support
 146          * fail-over we'll have to take this into consideration.
 147          */
 148         ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
 149         if (ret) {
 150                 printk(KERN_ERR "RDS/IW: failed to setup listener, "
 151                        "rdma_bind_addr() returned %d\n", ret);
 152                 goto out;
 153         }
 154
 155         ret = rdma_listen(cm_id, 128);
 156         if (ret) {
 157                 printk(KERN_ERR "RDS/IW: failed to setup listener, "
 158                        "rdma_listen() returned %d\n", ret);
 159                 goto out;
 160         }
 161
 162         rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
 163
 164         rds_rdma_listen_id = cm_id;
 165         cm_id = NULL;
 166 out:
 167         if (cm_id)
 168                 rdma_destroy_id(cm_id);
 169         return ret;
 170 }
 171
 172 static void rds_rdma_listen_stop(void)
 173 {
 174         if (rds_rdma_listen_id) {
 175                 rdsdebug("cm %p\n", rds_rdma_listen_id);
 176                 rdma_destroy_id(rds_rdma_listen_id);
 177                 rds_rdma_listen_id = NULL;
 178         }
 179 }
 180
 181 int __init rds_rdma_init(void)
 182 {
 183         int ret;
 184
 185         ret = rds_rdma_listen_init();
 186         if (ret)
 187                 goto out;
 188
 189         ret = rds_iw_init();
 190         if (ret)
 191                 goto err_iw_init;
 192
 193         ret = rds_ib_init();
 194         if (ret)
 195                 goto err_ib_init;
 196
 197         goto out;
 198
 199 err_ib_init:
 200         rds_iw_exit();
 201 err_iw_init:
 202         rds_rdma_listen_stop();
 203 out:
 204         return ret;
 205 }
 206
 207 void rds_rdma_exit(void)
 208 {
 209         /* stop listening first to ensure no new connections are attempted */
 210         rds_rdma_listen_stop();
 211         rds_ib_exit();
 212         rds_iw_exit();
 213 }
 214