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 static char *rds_cm_event_strings[] = {
  40 #define RDS_CM_EVENT_STRING(foo) \
  41                 [RDMA_CM_EVENT_##foo] = __stringify(RDMA_CM_EVENT_##foo)
  42         RDS_CM_EVENT_STRING(ADDR_RESOLVED),
  43         RDS_CM_EVENT_STRING(ADDR_ERROR),
  44         RDS_CM_EVENT_STRING(ROUTE_RESOLVED),
  45         RDS_CM_EVENT_STRING(ROUTE_ERROR),
  46         RDS_CM_EVENT_STRING(CONNECT_REQUEST),
  47         RDS_CM_EVENT_STRING(CONNECT_RESPONSE),
  48         RDS_CM_EVENT_STRING(CONNECT_ERROR),
  49         RDS_CM_EVENT_STRING(UNREACHABLE),
  50         RDS_CM_EVENT_STRING(REJECTED),
  51         RDS_CM_EVENT_STRING(ESTABLISHED),
  52         RDS_CM_EVENT_STRING(DISCONNECTED),
  53         RDS_CM_EVENT_STRING(DEVICE_REMOVAL),
  54         RDS_CM_EVENT_STRING(MULTICAST_JOIN),
  55         RDS_CM_EVENT_STRING(MULTICAST_ERROR),
  56         RDS_CM_EVENT_STRING(ADDR_CHANGE),
  57         RDS_CM_EVENT_STRING(TIMEWAIT_EXIT),
  58 #undef RDS_CM_EVENT_STRING
  59 };
  60
  61 static char *rds_cm_event_str(enum rdma_cm_event_type type)
  62 {
  63         return rds_str_array(rds_cm_event_strings,
  64                              ARRAY_SIZE(rds_cm_event_strings), type);
  65 };
  66
  67 int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
  68                               struct rdma_cm_event *event)
  69 {
  70         /* this can be null in the listening path */
  71         struct rds_connection *conn = cm_id->context;
  72         struct rds_transport *trans;
  73         int ret = 0;
  74
  75         rdsdebug("conn %p id %p handling event %u (%s)\n", conn, cm_id,
  76                  event->event, rds_cm_event_str(event->event));
  77
  78         if (cm_id->device->node_type == RDMA_NODE_RNIC)
  79                 trans = &rds_iw_transport;
  80         else
  81                 trans = &rds_ib_transport;
  82
  83         /* Prevent shutdown from tearing down the connection
  84          * while we're executing. */
  85         if (conn) {
  86                 mutex_lock(&conn->c_cm_lock);
  87
  88                 /* If the connection is being shut down, bail out
  89                  * right away. We return 0 so cm_id doesn't get
  90                  * destroyed prematurely */
  91                 if (rds_conn_state(conn) == RDS_CONN_DISCONNECTING) {
  92                         /* Reject incoming connections while we're tearing
  93                          * down an existing one. */
  94                         if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
  95                                 ret = 1;
  96                         goto out;
  97                 }
  98         }
  99
 100         switch (event->event) {
 101         case RDMA_CM_EVENT_CONNECT_REQUEST:
 102                 ret = trans->cm_handle_connect(cm_id, event);
 103                 break;
 104
 105         case RDMA_CM_EVENT_ADDR_RESOLVED:
 106                 /* XXX do we need to clean up if this fails? */
 107                 ret = rdma_resolve_route(cm_id,
 108                                          RDS_RDMA_RESOLVE_TIMEOUT_MS);
 109                 break;
 110
 111         case RDMA_CM_EVENT_ROUTE_RESOLVED:
 112                 /* XXX worry about racing with listen acceptance */
 113                 ret = trans->cm_initiate_connect(cm_id);
 114                 break;
 115
 116         case RDMA_CM_EVENT_ESTABLISHED:
 117                 trans->cm_connect_complete(conn, event);
 118                 break;
 119
 120         case RDMA_CM_EVENT_ADDR_ERROR:
 121         case RDMA_CM_EVENT_ROUTE_ERROR:
 122         case RDMA_CM_EVENT_CONNECT_ERROR:
 123         case RDMA_CM_EVENT_UNREACHABLE:
 124         case RDMA_CM_EVENT_REJECTED:
 125         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 126         case RDMA_CM_EVENT_ADDR_CHANGE:
 127                 if (conn)
 128                         rds_conn_drop(conn);
 129                 break;
 130
 131         case RDMA_CM_EVENT_DISCONNECTED:
 132                 rdsdebug("DISCONNECT event - dropping connection "
 133                         "%pI4->%pI4\n", &conn->c_laddr,
 134                          &conn->c_faddr);
 135                 rds_conn_drop(conn);
 136                 break;
 137
 138         default:
 139                 /* things like device disconnect? */
 140                 printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
 141                        event->event, rds_cm_event_str(event->event));
 142                 break;
 143         }
 144
 145 out:
 146         if (conn)
 147                 mutex_unlock(&conn->c_cm_lock);
 148
 149         rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
 150                  rds_cm_event_str(event->event), ret);
 151
 152         return ret;
 153 }
 154
 155 static int rds_rdma_listen_init(void)
 156 {
 157         struct sockaddr_in sin;
 158         struct rdma_cm_id *cm_id;
 159         int ret;
 160
 161         cm_id = rdma_create_id(rds_rdma_cm_event_handler, NULL, RDMA_PS_TCP,
 162                                IB_QPT_RC);
 163         if (IS_ERR(cm_id)) {
 164                 ret = PTR_ERR(cm_id);
 165                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 166                        "rdma_create_id() returned %d\n", ret);
 167                 return ret;
 168         }
 169
 170         sin.sin_family = AF_INET,
 171         sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
 172         sin.sin_port = (__force u16)htons(RDS_PORT);
 173
 174         /*
 175          * XXX I bet this binds the cm_id to a device.  If we want to support
 176          * fail-over we'll have to take this into consideration.
 177          */
 178         ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
 179         if (ret) {
 180                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 181                        "rdma_bind_addr() returned %d\n", ret);
 182                 goto out;
 183         }
 184
 185         ret = rdma_listen(cm_id, 128);
 186         if (ret) {
 187                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 188                        "rdma_listen() returned %d\n", ret);
 189                 goto out;
 190         }
 191
 192         rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
 193
 194         rds_rdma_listen_id = cm_id;
 195         cm_id = NULL;
 196 out:
 197         if (cm_id)
 198                 rdma_destroy_id(cm_id);
 199         return ret;
 200 }
 201
 202 static void rds_rdma_listen_stop(void)
 203 {
 204         if (rds_rdma_listen_id) {
 205                 rdsdebug("cm %p\n", rds_rdma_listen_id);
 206                 rdma_destroy_id(rds_rdma_listen_id);
 207                 rds_rdma_listen_id = NULL;
 208         }
 209 }
 210
 211 static int rds_rdma_init(void)
 212 {
 213         int ret;
 214
 215         ret = rds_rdma_listen_init();
 216         if (ret)
 217                 goto out;
 218
 219         ret = rds_iw_init();
 220         if (ret)
 221                 goto err_iw_init;
 222
 223         ret = rds_ib_init();
 224         if (ret)
 225                 goto err_ib_init;
 226
 227         goto out;
 228
 229 err_ib_init:
 230         rds_iw_exit();
 231 err_iw_init:
 232         rds_rdma_listen_stop();
 233 out:
 234         return ret;
 235 }
 236 module_init(rds_rdma_init);
 237
 238 static void rds_rdma_exit(void)
 239 {
 240         /* stop listening first to ensure no new connections are attempted */
 241         rds_rdma_listen_stop();
 242         rds_ib_exit();
 243         rds_iw_exit();
 244 }
 245 module_exit(rds_rdma_exit);
 246
 247 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
 248 MODULE_DESCRIPTION("RDS: IB/iWARP transport");
 249 MODULE_LICENSE("Dual BSD/GPL");
 250