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
  38 static struct rdma_cm_id *rds_rdma_listen_id;
  39
  40 static char *rds_cm_event_strings[] = {
  41 #define RDS_CM_EVENT_STRING(foo) \
  42                 [RDMA_CM_EVENT_##foo] = __stringify(RDMA_CM_EVENT_##foo)
  43         RDS_CM_EVENT_STRING(ADDR_RESOLVED),
  44         RDS_CM_EVENT_STRING(ADDR_ERROR),
  45         RDS_CM_EVENT_STRING(ROUTE_RESOLVED),
  46         RDS_CM_EVENT_STRING(ROUTE_ERROR),
  47         RDS_CM_EVENT_STRING(CONNECT_REQUEST),
  48         RDS_CM_EVENT_STRING(CONNECT_RESPONSE),
  49         RDS_CM_EVENT_STRING(CONNECT_ERROR),
  50         RDS_CM_EVENT_STRING(UNREACHABLE),
  51         RDS_CM_EVENT_STRING(REJECTED),
  52         RDS_CM_EVENT_STRING(ESTABLISHED),
  53         RDS_CM_EVENT_STRING(DISCONNECTED),
  54         RDS_CM_EVENT_STRING(DEVICE_REMOVAL),
  55         RDS_CM_EVENT_STRING(MULTICAST_JOIN),
  56         RDS_CM_EVENT_STRING(MULTICAST_ERROR),
  57         RDS_CM_EVENT_STRING(ADDR_CHANGE),
  58         RDS_CM_EVENT_STRING(TIMEWAIT_EXIT),
  59 #undef RDS_CM_EVENT_STRING
  60 };
  61
  62 static char *rds_cm_event_str(enum rdma_cm_event_type type)
  63 {
  64         return rds_str_array(rds_cm_event_strings,
  65                              ARRAY_SIZE(rds_cm_event_strings), type);
  66 };
  67
  68 int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
  69                               struct rdma_cm_event *event)
  70 {
  71         /* this can be null in the listening path */
  72         struct rds_connection *conn = cm_id->context;
  73         struct rds_transport *trans;
  74         int ret = 0;
  75
  76         rdsdebug("conn %p id %p handling event %u (%s)\n", conn, cm_id,
  77                  event->event, rds_cm_event_str(event->event));
  78
  79         if (cm_id->device->node_type == RDMA_NODE_RNIC)
  80                 trans = &rds_iw_transport;
  81         else
  82                 trans = &rds_ib_transport;
  83
  84         /* Prevent shutdown from tearing down the connection
  85          * while we're executing. */
  86         if (conn) {
  87                 mutex_lock(&conn->c_cm_lock);
  88
  89                 /* If the connection is being shut down, bail out
  90                  * right away. We return 0 so cm_id doesn't get
  91                  * destroyed prematurely */
  92                 if (rds_conn_state(conn) == RDS_CONN_DISCONNECTING) {
  93                         /* Reject incoming connections while we're tearing
  94                          * down an existing one. */
  95                         if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
  96                                 ret = 1;
  97                         goto out;
  98                 }
  99         }
 100
 101         switch (event->event) {
 102         case RDMA_CM_EVENT_CONNECT_REQUEST:
 103                 ret = trans->cm_handle_connect(cm_id, event);
 104                 break;
 105
 106         case RDMA_CM_EVENT_ADDR_RESOLVED:
 107                 /* XXX do we need to clean up if this fails? */
 108                 ret = rdma_resolve_route(cm_id,
 109                                          RDS_RDMA_RESOLVE_TIMEOUT_MS);
 110                 break;
 111
 112         case RDMA_CM_EVENT_ROUTE_RESOLVED:
 113                 /* XXX worry about racing with listen acceptance */
 114                 ret = trans->cm_initiate_connect(cm_id);
 115                 break;
 116
 117         case RDMA_CM_EVENT_ESTABLISHED:
 118                 trans->cm_connect_complete(conn, event);
 119                 break;
 120
 121         case RDMA_CM_EVENT_ADDR_ERROR:
 122         case RDMA_CM_EVENT_ROUTE_ERROR:
 123         case RDMA_CM_EVENT_CONNECT_ERROR:
 124         case RDMA_CM_EVENT_UNREACHABLE:
 125         case RDMA_CM_EVENT_REJECTED:
 126         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 127         case RDMA_CM_EVENT_ADDR_CHANGE:
 128                 if (conn)
 129                         rds_conn_drop(conn);
 130                 break;
 131
 132         case RDMA_CM_EVENT_DISCONNECTED:
 133                 rdsdebug("DISCONNECT event - dropping connection "
 134                         "%pI4->%pI4\n", &conn->c_laddr,
 135                          &conn->c_faddr);
 136                 rds_conn_drop(conn);
 137                 break;
 138
 139         default:
 140                 /* things like device disconnect? */
 141                 printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
 142                        event->event, rds_cm_event_str(event->event));
 143                 break;
 144         }
 145
 146 out:
 147         if (conn)
 148                 mutex_unlock(&conn->c_cm_lock);
 149
 150         rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
 151                  rds_cm_event_str(event->event), ret);
 152
 153         return ret;
 154 }
 155
 156 static int rds_rdma_listen_init(void)
 157 {
 158         struct sockaddr_in sin;
 159         struct rdma_cm_id *cm_id;
 160         int ret;
 161
 162         cm_id = rdma_create_id(rds_rdma_cm_event_handler, NULL, RDMA_PS_TCP,
 163                                IB_QPT_RC);
 164         if (IS_ERR(cm_id)) {
 165                 ret = PTR_ERR(cm_id);
 166                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 167                        "rdma_create_id() returned %d\n", ret);
 168                 return ret;
 169         }
 170
 171         sin.sin_family = AF_INET;
 172         sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
 173         sin.sin_port = (__force u16)htons(RDS_PORT);
 174
 175         /*
 176          * XXX I bet this binds the cm_id to a device.  If we want to support
 177          * fail-over we'll have to take this into consideration.
 178          */
 179         ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
 180         if (ret) {
 181                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 182                        "rdma_bind_addr() returned %d\n", ret);
 183                 goto out;
 184         }
 185
 186         ret = rdma_listen(cm_id, 128);
 187         if (ret) {
 188                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 189                        "rdma_listen() returned %d\n", ret);
 190                 goto out;
 191         }
 192
 193         rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
 194
 195         rds_rdma_listen_id = cm_id;
 196         cm_id = NULL;
 197 out:
 198         if (cm_id)
 199                 rdma_destroy_id(cm_id);
 200         return ret;
 201 }
 202
 203 static void rds_rdma_listen_stop(void)
 204 {
 205         if (rds_rdma_listen_id) {
 206                 rdsdebug("cm %p\n", rds_rdma_listen_id);
 207                 rdma_destroy_id(rds_rdma_listen_id);
 208                 rds_rdma_listen_id = NULL;
 209         }
 210 }
 211
 212 static int rds_rdma_init(void)
 213 {
 214         int ret;
 215
 216         ret = rds_rdma_listen_init();
 217         if (ret)
 218                 goto out;
 219
 220         ret = rds_iw_init();
 221         if (ret)
 222                 goto err_iw_init;
 223
 224         ret = rds_ib_init();
 225         if (ret)
 226                 goto err_ib_init;
 227
 228         goto out;
 229
 230 err_ib_init:
 231         rds_iw_exit();
 232 err_iw_init:
 233         rds_rdma_listen_stop();
 234 out:
 235         return ret;
 236 }
 237 module_init(rds_rdma_init);
 238
 239 static void rds_rdma_exit(void)
 240 {
 241         /* stop listening first to ensure no new connections are attempted */
 242         rds_rdma_listen_stop();
 243         rds_ib_exit();
 244         rds_iw_exit();
 245 }
 246 module_exit(rds_rdma_exit);
 247
 248 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
 249 MODULE_DESCRIPTION("RDS: IB/iWARP transport");
 250 MODULE_LICENSE("Dual BSD/GPL");
 251