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         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 121                 if (conn) {
 122                         pr_info("RDS: RDMA_CM_EVENT_TIMEWAIT_EXIT event: dropping connection %pI4->%pI4\n",
 123                                 &conn->c_laddr, &conn->c_faddr);
 124                         rds_conn_drop(conn);
 125                 }
 126                 break;
 127
 128         default:
 129                 /* things like device disconnect? */
 130                 printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
 131                        event->event, rdma_event_msg(event->event));
 132                 break;
 133         }
 134
 135 out:
 136         if (conn)
 137                 mutex_unlock(&conn->c_cm_lock);
 138
 139         rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
 140                  rdma_event_msg(event->event), ret);
 141
 142         return ret;
 143 }
 144
 145 static int rds_rdma_listen_init(void)
 146 {
 147         struct sockaddr_in sin;
 148         struct rdma_cm_id *cm_id;
 149         int ret;
 150
 151         cm_id = rdma_create_id(&init_net, rds_rdma_cm_event_handler, NULL,
 152                                RDMA_PS_TCP, IB_QPT_RC);
 153         if (IS_ERR(cm_id)) {
 154                 ret = PTR_ERR(cm_id);
 155                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 156                        "rdma_create_id() returned %d\n", ret);
 157                 return ret;
 158         }
 159
 160         sin.sin_family = AF_INET;
 161         sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
 162         sin.sin_port = (__force u16)htons(RDS_PORT);
 163
 164         /*
 165          * XXX I bet this binds the cm_id to a device.  If we want to support
 166          * fail-over we'll have to take this into consideration.
 167          */
 168         ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
 169         if (ret) {
 170                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 171                        "rdma_bind_addr() returned %d\n", ret);
 172                 goto out;
 173         }
 174
 175         ret = rdma_listen(cm_id, 128);
 176         if (ret) {
 177                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 178                        "rdma_listen() returned %d\n", ret);
 179                 goto out;
 180         }
 181
 182         rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
 183
 184         rds_rdma_listen_id = cm_id;
 185         cm_id = NULL;
 186 out:
 187         if (cm_id)
 188                 rdma_destroy_id(cm_id);
 189         return ret;
 190 }
 191
 192 static void rds_rdma_listen_stop(void)
 193 {
 194         if (rds_rdma_listen_id) {
 195                 rdsdebug("cm %p\n", rds_rdma_listen_id);
 196                 rdma_destroy_id(rds_rdma_listen_id);
 197                 rds_rdma_listen_id = NULL;
 198         }
 199 }
 200
 201 static int rds_rdma_init(void)
 202 {
 203         int ret;
 204
 205         ret = rds_rdma_listen_init();
 206         if (ret)
 207                 goto out;
 208
 209         ret = rds_ib_init();
 210         if (ret)
 211                 goto err_ib_init;
 212
 213         goto out;
 214
 215 err_ib_init:
 216         rds_rdma_listen_stop();
 217 out:
 218         return ret;
 219 }
 220 module_init(rds_rdma_init);
 221
 222 static void rds_rdma_exit(void)
 223 {
 224         /* stop listening first to ensure no new connections are attempted */
 225         rds_rdma_listen_stop();
 226         rds_ib_exit();
 227 }
 228 module_exit(rds_rdma_exit);
 229
 230 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
 231 MODULE_DESCRIPTION("RDS: IB transport");
 232 MODULE_LICENSE("Dual BSD/GPL");
 233