net/rds/rdma_transport.c

   1 /*
   2  * Copyright (c) 2009, 2018 Oracle and/or its affiliates. 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 /* Global IPv4 and IPv6 RDS RDMA listener cm_id */
  41 static struct rdma_cm_id *rds_rdma_listen_id;
  42 #if IS_ENABLED(CONFIG_IPV6)
  43 static struct rdma_cm_id *rds6_rdma_listen_id;
  44 #endif
  45
  46 /* Per IB specification 7.7.3, service level is a 4-bit field. */
  47 #define TOS_TO_SL(tos)          ((tos) & 0xF)
  48
  49 static int rds_rdma_cm_event_handler_cmn(struct rdma_cm_id *cm_id,
  50                                          struct rdma_cm_event *event,
  51                                          bool isv6)
  52 {
  53         /* this can be null in the listening path */
  54         struct rds_connection *conn = cm_id->context;
  55         struct rds_transport *trans;
  56         int ret = 0;
  57         int *err;
  58         u8 len;
  59
  60         rdsdebug("conn %p id %p handling event %u (%s)\n", conn, cm_id,
  61                  event->event, rdma_event_msg(event->event));
  62
  63         if (cm_id->device->node_type == RDMA_NODE_IB_CA)
  64                 trans = &rds_ib_transport;
  65
  66         /* Prevent shutdown from tearing down the connection
  67          * while we're executing. */
  68         if (conn) {
  69                 mutex_lock(&conn->c_cm_lock);
  70
  71                 /* If the connection is being shut down, bail out
  72                  * right away. We return 0 so cm_id doesn't get
  73                  * destroyed prematurely */
  74                 if (rds_conn_state(conn) == RDS_CONN_DISCONNECTING) {
  75                         /* Reject incoming connections while we're tearing
  76                          * down an existing one. */
  77                         if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
  78                                 ret = 1;
  79                         goto out;
  80                 }
  81         }
  82
  83         switch (event->event) {
  84         case RDMA_CM_EVENT_CONNECT_REQUEST:
  85                 ret = trans->cm_handle_connect(cm_id, event, isv6);
  86                 break;
  87
  88         case RDMA_CM_EVENT_ADDR_RESOLVED:
  89                 rdma_set_service_type(cm_id, conn->c_tos);
  90                 /* XXX do we need to clean up if this fails? */
  91                 ret = rdma_resolve_route(cm_id,
  92                                          RDS_RDMA_RESOLVE_TIMEOUT_MS);
  93                 break;
  94
  95         case RDMA_CM_EVENT_ROUTE_RESOLVED:
  96                 /* Connection could have been dropped so make sure the
  97                  * cm_id is valid before proceeding
  98                  */
  99                 if (conn) {
 100                         struct rds_ib_connection *ibic;
 101
 102                         ibic = conn->c_transport_data;
 103                         if (ibic && ibic->i_cm_id == cm_id) {
 104                                 cm_id->route.path_rec[0].sl =
 105                                         TOS_TO_SL(conn->c_tos);
 106                                 ret = trans->cm_initiate_connect(cm_id, isv6);
 107                         } else {
 108                                 rds_conn_drop(conn);
 109                         }
 110                 }
 111                 break;
 112
 113         case RDMA_CM_EVENT_ESTABLISHED:
 114                 if (conn)
 115                         trans->cm_connect_complete(conn, event);
 116                 break;
 117
 118         case RDMA_CM_EVENT_REJECTED:
 119                 if (!conn)
 120                         break;
 121                 err = (int *)rdma_consumer_reject_data(cm_id, event, &len);
 122                 if (!err ||
 123                     (err && len >= sizeof(*err) &&
 124                      ((*err) <= RDS_RDMA_REJ_INCOMPAT))) {
 125                         pr_warn("RDS/RDMA: conn <%pI6c, %pI6c> rejected, dropping connection\n",
 126                                 &conn->c_laddr, &conn->c_faddr);
 127
 128                         if (!conn->c_tos)
 129                                 conn->c_proposed_version = RDS_PROTOCOL_COMPAT_VERSION;
 130
 131                         rds_conn_drop(conn);
 132                 }
 133                 rdsdebug("Connection rejected: %s\n",
 134                          rdma_reject_msg(cm_id, event->status));
 135                 break;
 136         case RDMA_CM_EVENT_ADDR_ERROR:
 137         case RDMA_CM_EVENT_ROUTE_ERROR:
 138         case RDMA_CM_EVENT_CONNECT_ERROR:
 139         case RDMA_CM_EVENT_UNREACHABLE:
 140         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 141         case RDMA_CM_EVENT_ADDR_CHANGE:
 142                 if (conn)
 143                         rds_conn_drop(conn);
 144                 break;
 145
 146         case RDMA_CM_EVENT_DISCONNECTED:
 147                 if (!conn)
 148                         break;
 149                 rdsdebug("DISCONNECT event - dropping connection "
 150                          "%pI6c->%pI6c\n", &conn->c_laddr,
 151                          &conn->c_faddr);
 152                 rds_conn_drop(conn);
 153                 break;
 154
 155         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 156                 if (conn) {
 157                         pr_info("RDS: RDMA_CM_EVENT_TIMEWAIT_EXIT event: dropping connection %pI6c->%pI6c\n",
 158                                 &conn->c_laddr, &conn->c_faddr);
 159                         rds_conn_drop(conn);
 160                 }
 161                 break;
 162
 163         default:
 164                 /* things like device disconnect? */
 165                 printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
 166                        event->event, rdma_event_msg(event->event));
 167                 break;
 168         }
 169
 170 out:
 171         if (conn)
 172                 mutex_unlock(&conn->c_cm_lock);
 173
 174         rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
 175                  rdma_event_msg(event->event), ret);
 176
 177         return ret;
 178 }
 179
 180 int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
 181                               struct rdma_cm_event *event)
 182 {
 183         return rds_rdma_cm_event_handler_cmn(cm_id, event, false);
 184 }
 185
 186 #if IS_ENABLED(CONFIG_IPV6)
 187 int rds6_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
 188                                struct rdma_cm_event *event)
 189 {
 190         return rds_rdma_cm_event_handler_cmn(cm_id, event, true);
 191 }
 192 #endif
 193
 194 static int rds_rdma_listen_init_common(rdma_cm_event_handler handler,
 195                                        struct sockaddr *sa,
 196                                        struct rdma_cm_id **ret_cm_id)
 197 {
 198         struct rdma_cm_id *cm_id;
 199         int ret;
 200
 201         cm_id = rdma_create_id(&init_net, handler, NULL,
 202                                RDMA_PS_TCP, IB_QPT_RC);
 203         if (IS_ERR(cm_id)) {
 204                 ret = PTR_ERR(cm_id);
 205                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 206                        "rdma_create_id() returned %d\n", ret);
 207                 return ret;
 208         }
 209
 210         /*
 211          * XXX I bet this binds the cm_id to a device.  If we want to support
 212          * fail-over we'll have to take this into consideration.
 213          */
 214         ret = rdma_bind_addr(cm_id, sa);
 215         if (ret) {
 216                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 217                        "rdma_bind_addr() returned %d\n", ret);
 218                 goto out;
 219         }
 220
 221         ret = rdma_listen(cm_id, 128);
 222         if (ret) {
 223                 printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 224                        "rdma_listen() returned %d\n", ret);
 225                 goto out;
 226         }
 227
 228         rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
 229
 230         *ret_cm_id = cm_id;
 231         cm_id = NULL;
 232 out:
 233         if (cm_id)
 234                 rdma_destroy_id(cm_id);
 235         return ret;
 236 }
 237
 238 /* Initialize the RDS RDMA listeners.  We create two listeners for
 239  * compatibility reason.  The one on RDS_PORT is used for IPv4
 240  * requests only.  The one on RDS_CM_PORT is used for IPv6 requests
 241  * only.  So only IPv6 enabled RDS module will communicate using this
 242  * port.
 243  */
 244 static int rds_rdma_listen_init(void)
 245 {
 246         int ret;
 247 #if IS_ENABLED(CONFIG_IPV6)
 248         struct sockaddr_in6 sin6;
 249 #endif
 250         struct sockaddr_in sin;
 251
 252         sin.sin_family = PF_INET;
 253         sin.sin_addr.s_addr = htonl(INADDR_ANY);
 254         sin.sin_port = htons(RDS_PORT);
 255         ret = rds_rdma_listen_init_common(rds_rdma_cm_event_handler,
 256                                           (struct sockaddr *)&sin,
 257                                           &rds_rdma_listen_id);
 258         if (ret != 0)
 259                 return ret;
 260
 261 #if IS_ENABLED(CONFIG_IPV6)
 262         sin6.sin6_family = PF_INET6;
 263         sin6.sin6_addr = in6addr_any;
 264         sin6.sin6_port = htons(RDS_CM_PORT);
 265         sin6.sin6_scope_id = 0;
 266         sin6.sin6_flowinfo = 0;
 267         ret = rds_rdma_listen_init_common(rds6_rdma_cm_event_handler,
 268                                           (struct sockaddr *)&sin6,
 269                                           &rds6_rdma_listen_id);
 270         /* Keep going even when IPv6 is not enabled in the system. */
 271         if (ret != 0)
 272                 rdsdebug("Cannot set up IPv6 RDMA listener\n");
 273 #endif
 274         return 0;
 275 }
 276
 277 static void rds_rdma_listen_stop(void)
 278 {
 279         if (rds_rdma_listen_id) {
 280                 rdsdebug("cm %p\n", rds_rdma_listen_id);
 281                 rdma_destroy_id(rds_rdma_listen_id);
 282                 rds_rdma_listen_id = NULL;
 283         }
 284 #if IS_ENABLED(CONFIG_IPV6)
 285         if (rds6_rdma_listen_id) {
 286                 rdsdebug("cm %p\n", rds6_rdma_listen_id);
 287                 rdma_destroy_id(rds6_rdma_listen_id);
 288                 rds6_rdma_listen_id = NULL;
 289         }
 290 #endif
 291 }
 292
 293 static int rds_rdma_init(void)
 294 {
 295         int ret;
 296
 297         ret = rds_ib_init();
 298         if (ret)
 299                 goto out;
 300
 301         ret = rds_rdma_listen_init();
 302         if (ret)
 303                 rds_ib_exit();
 304 out:
 305         return ret;
 306 }
 307 module_init(rds_rdma_init);
 308
 309 static void rds_rdma_exit(void)
 310 {
 311         /* stop listening first to ensure no new connections are attempted */
 312         rds_rdma_listen_stop();
 313         rds_ib_exit();
 314 }
 315 module_exit(rds_rdma_exit);
 316
 317 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
 318 MODULE_DESCRIPTION("RDS: IB transport");
 319 MODULE_LICENSE("Dual BSD/GPL");