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 <linux/module.h>
  34 #include <rdma/rdma_cm.h>
  35
  36 #include "rdma_transport.h"
  37 #include "ib.h"
  38
  39 static struct rdma_cm_id *rds_rdma_listen_id;
  40
  41 int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
  42                               struct rdma_cm_event *event)
  43 {
  44         /* this can be null in the listening path */
  45         struct rds_connection *conn = cm_id->context;
  46         struct rds_transport *trans;
  47         int ret = 0;
  48
  49         rdsdebug("conn %p id %p handling event %u (%s)\n", conn, cm_id,
  50                  event->event, rdma_event_msg(event->event));
  51
  52         if (cm_id->device->node_type == RDMA_NODE_IB_CA)
  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                 /* Connection could have been dropped so make sure the
  85                  * cm_id is valid before proceeding
  86                  */
  87                 if (conn) {
  88                         struct rds_ib_connection *ibic;
  89
  90                         ibic = conn->c_transport_data;
  91                         if (ibic && ibic->i_cm_id == cm_id)
  92                                 ret = trans->cm_initiate_connect(cm_id);
  93                         else
  94                                 rds_conn_drop(conn);
  95                 }
  96                 break;
  97
  98         case RDMA_CM_EVENT_ESTABLISHED:
  99                 trans->cm_connect_complete(conn, event);
 100                 break;
 101
 102         case RDMA_CM_EVENT_ADDR_ERROR:
 103         case RDMA_CM_EVENT_ROUTE_ERROR:
 104         case RDMA_CM_EVENT_CONNECT_ERROR:
 105         case RDMA_CM_EVENT_UNREACHABLE:
 106         case RDMA_CM_EVENT_REJECTED:
 107         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 108         case RDMA_CM_EVENT_ADDR_CHANGE:
 109                 if (conn)
 110                         rds_conn_drop(conn);
 111                 break;
 112
 113         case RDMA_CM_EVENT_DISCONNECTED:
 114                 rdsdebug("DISCONNECT event - dropping connection "
 115                         "%pI4->%pI4\n", &conn->c_laddr,
 116                          &conn->c_faddr);
 117                 rds_conn_drop(conn);
 118                 break;
 119
 120         default:
 121                 /* things like device disconnect? */
 122                 printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
 123                        event->event, rdma_event_msg(event->event));
 124                 break;
 125         }
 126
 127 out:
 128         if (conn)
 129                 mutex_unlock(&conn->c_cm_lock);
 130
 131         rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
 132                  rdma_event_msg(event->event), ret);
 133
 134         return ret;
 135 }
 136
 137 static int rds_rdma_listen_init(void)
 138 {
 139         struct sockaddr_in sin;
 140         struct rdma_cm_id *cm_id;
 141         int ret;
 142
 143         cm_id = rdma_create_id(&init_net, rds_rdma_cm_event_handler, NULL,
 144                                RDMA_PS_TCP, IB_QPT_RC);
 145         if (IS_ERR(cm_id)) {
 146                 ret = PTR_ERR(cm_id);
 147                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 148                        "rdma_create_id() returned %d\n", ret);
 149                 return ret;
 150         }
 151
 152         sin.sin_family = AF_INET;
 153         sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
 154         sin.sin_port = (__force u16)htons(RDS_PORT);
 155
 156         /*
 157          * XXX I bet this binds the cm_id to a device.  If we want to support
 158          * fail-over we'll have to take this into consideration.
 159          */
 160         ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
 161         if (ret) {
 162                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 163                        "rdma_bind_addr() returned %d\n", ret);
 164                 goto out;
 165         }
 166
 167         ret = rdma_listen(cm_id, 128);
 168         if (ret) {
 169                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 170                        "rdma_listen() returned %d\n", ret);
 171                 goto out;
 172         }
 173
 174         rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
 175
 176         rds_rdma_listen_id = cm_id;
 177         cm_id = NULL;
 178 out:
 179         if (cm_id)
 180                 rdma_destroy_id(cm_id);
 181         return ret;
 182 }
 183
 184 static void rds_rdma_listen_stop(void)
 185 {
 186         if (rds_rdma_listen_id) {
 187                 rdsdebug("cm %p\n", rds_rdma_listen_id);
 188                 rdma_destroy_id(rds_rdma_listen_id);
 189                 rds_rdma_listen_id = NULL;
 190         }
 191 }
 192
 193 static int rds_rdma_init(void)
 194 {
 195         int ret;
 196
 197         ret = rds_rdma_listen_init();
 198         if (ret)
 199                 goto out;
 200
 201         ret = rds_ib_init();
 202         if (ret)
 203                 goto err_ib_init;
 204
 205         goto out;
 206
 207 err_ib_init:
 208         rds_rdma_listen_stop();
 209 out:
 210         return ret;
 211 }
 212 module_init(rds_rdma_init);
 213
 214 static void rds_rdma_exit(void)
 215 {
 216         /* stop listening first to ensure no new connections are attempted */
 217         rds_rdma_listen_stop();
 218         rds_ib_exit();
 219 }
 220 module_exit(rds_rdma_exit);
 221
 222 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
 223 MODULE_DESCRIPTION("RDS: IB transport");
 224 MODULE_LICENSE("Dual BSD/GPL");
 225