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 "rds_single_path.h"
  37 #include "rdma_transport.h"
  38 #include "ib.h"
  39
  40 static struct rdma_cm_id *rds_rdma_listen_id;
  41
  42 int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
  43                               struct rdma_cm_event *event)
  44 {
  45         /* this can be null in the listening path */
  46         struct rds_connection *conn = cm_id->context;
  47         struct rds_transport *trans;
  48         int ret = 0;
  49
  50         rdsdebug("conn %p id %p handling event %u (%s)\n", conn, cm_id,
  51                  event->event, rdma_event_msg(event->event));
  52
  53         if (cm_id->device->node_type == RDMA_NODE_IB_CA)
  54                 trans = &rds_ib_transport;
  55
  56         /* Prevent shutdown from tearing down the connection
  57          * while we're executing. */
  58         if (conn) {
  59                 mutex_lock(&conn->c_cm_lock);
  60
  61                 /* If the connection is being shut down, bail out
  62                  * right away. We return 0 so cm_id doesn't get
  63                  * destroyed prematurely */
  64                 if (rds_conn_state(conn) == RDS_CONN_DISCONNECTING) {
  65                         /* Reject incoming connections while we're tearing
  66                          * down an existing one. */
  67                         if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
  68                                 ret = 1;
  69                         goto out;
  70                 }
  71         }
  72
  73         switch (event->event) {
  74         case RDMA_CM_EVENT_CONNECT_REQUEST:
  75                 ret = trans->cm_handle_connect(cm_id, event);
  76                 break;
  77
  78         case RDMA_CM_EVENT_ADDR_RESOLVED:
  79                 /* XXX do we need to clean up if this fails? */
  80                 ret = rdma_resolve_route(cm_id,
  81                                          RDS_RDMA_RESOLVE_TIMEOUT_MS);
  82                 break;
  83
  84         case RDMA_CM_EVENT_ROUTE_RESOLVED:
  85                 /* Connection could have been dropped so make sure the
  86                  * cm_id is valid before proceeding
  87                  */
  88                 if (conn) {
  89                         struct rds_ib_connection *ibic;
  90
  91                         ibic = conn->c_transport_data;
  92                         if (ibic && ibic->i_cm_id == cm_id)
  93                                 ret = trans->cm_initiate_connect(cm_id);
  94                         else
  95                                 rds_conn_drop(conn);
  96                 }
  97                 break;
  98
  99         case RDMA_CM_EVENT_ESTABLISHED:
 100                 trans->cm_connect_complete(conn, event);
 101                 break;
 102
 103         case RDMA_CM_EVENT_REJECTED:
 104                 rdsdebug("Connection rejected: %s\n",
 105                          rdma_reject_msg(cm_id, event->status));
 106                 /* FALLTHROUGH */
 107         case RDMA_CM_EVENT_ADDR_ERROR:
 108         case RDMA_CM_EVENT_ROUTE_ERROR:
 109         case RDMA_CM_EVENT_CONNECT_ERROR:
 110         case RDMA_CM_EVENT_UNREACHABLE:
 111         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 112         case RDMA_CM_EVENT_ADDR_CHANGE:
 113                 if (conn)
 114                         rds_conn_drop(conn);
 115                 break;
 116
 117         case RDMA_CM_EVENT_DISCONNECTED:
 118                 rdsdebug("DISCONNECT event - dropping connection "
 119                         "%pI4->%pI4\n", &conn->c_laddr,
 120                          &conn->c_faddr);
 121                 rds_conn_drop(conn);
 122                 break;
 123
 124         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 125                 if (conn) {
 126                         pr_info("RDS: RDMA_CM_EVENT_TIMEWAIT_EXIT event: dropping connection %pI4->%pI4\n",
 127                                 &conn->c_laddr, &conn->c_faddr);
 128                         rds_conn_drop(conn);
 129                 }
 130                 break;
 131
 132         default:
 133                 /* things like device disconnect? */
 134                 printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
 135                        event->event, rdma_event_msg(event->event));
 136                 break;
 137         }
 138
 139 out:
 140         if (conn)
 141                 mutex_unlock(&conn->c_cm_lock);
 142
 143         rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
 144                  rdma_event_msg(event->event), ret);
 145
 146         return ret;
 147 }
 148
 149 static int rds_rdma_listen_init(void)
 150 {
 151         struct sockaddr_in sin;
 152         struct rdma_cm_id *cm_id;
 153         int ret;
 154
 155         cm_id = rdma_create_id(&init_net, rds_rdma_cm_event_handler, NULL,
 156                                RDMA_PS_TCP, IB_QPT_RC);
 157         if (IS_ERR(cm_id)) {
 158                 ret = PTR_ERR(cm_id);
 159                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 160                        "rdma_create_id() returned %d\n", ret);
 161                 return ret;
 162         }
 163
 164         sin.sin_family = AF_INET;
 165         sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
 166         sin.sin_port = (__force u16)htons(RDS_PORT);
 167
 168         /*
 169          * XXX I bet this binds the cm_id to a device.  If we want to support
 170          * fail-over we'll have to take this into consideration.
 171          */
 172         ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
 173         if (ret) {
 174                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 175                        "rdma_bind_addr() returned %d\n", ret);
 176                 goto out;
 177         }
 178
 179         ret = rdma_listen(cm_id, 128);
 180         if (ret) {
 181                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 182                        "rdma_listen() returned %d\n", ret);
 183                 goto out;
 184         }
 185
 186         rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
 187
 188         rds_rdma_listen_id = cm_id;
 189         cm_id = NULL;
 190 out:
 191         if (cm_id)
 192                 rdma_destroy_id(cm_id);
 193         return ret;
 194 }
 195
 196 static void rds_rdma_listen_stop(void)
 197 {
 198         if (rds_rdma_listen_id) {
 199                 rdsdebug("cm %p\n", rds_rdma_listen_id);
 200                 rdma_destroy_id(rds_rdma_listen_id);
 201                 rds_rdma_listen_id = NULL;
 202         }
 203 }
 204
 205 static int rds_rdma_init(void)
 206 {
 207         int ret;
 208
 209         ret = rds_ib_init();
 210         if (ret)
 211                 goto out;
 212
 213         ret = rds_rdma_listen_init();
 214         if (ret)
 215                 rds_ib_exit();
 216 out:
 217         return ret;
 218 }
 219 module_init(rds_rdma_init);
 220
 221 static void rds_rdma_exit(void)
 222 {
 223         /* stop listening first to ensure no new connections are attempted */
 224         rds_rdma_listen_stop();
 225         rds_ib_exit();
 226 }
 227 module_exit(rds_rdma_exit);
 228
 229 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
 230 MODULE_DESCRIPTION("RDS: IB transport");
 231 MODULE_LICENSE("Dual BSD/GPL");
 232