LXR linux/net/rds/rdma

   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 */
  41static struct rdma_cm_id *rds_rdma_listen_id;
  42#if IS_ENABLED(CONFIG_IPV6)
  43static 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
  49static 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
 170out:
 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
 180int 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)
 187int 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
 194static 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;
 232out:
 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 */
 244static 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
 277static 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
 293static 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();
 304out:
 305        return ret;
 306}
 307module_init(rds_rdma_init);
 308
 309static 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}
 315module_exit(rds_rdma_exit);
 316
 317MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
 318MODULE_DESCRIPTION("RDS: IB transport");
 319MODULE_LICENSE("Dual BSD/GPL");
 320