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                rdma_set_min_rnr_timer(cm_id, IB_RNR_TIMER_000_32);
  91                /* XXX do we need to clean up if this fails? */
  92                ret = rdma_resolve_route(cm_id,
  93                                         RDS_RDMA_RESOLVE_TIMEOUT_MS);
  94                break;
  95
  96        case RDMA_CM_EVENT_ROUTE_RESOLVED:
  97                /* Connection could have been dropped so make sure the
  98                 * cm_id is valid before proceeding
  99                 */
 100                if (conn) {
 101                        struct rds_ib_connection *ibic;
 102
 103                        ibic = conn->c_transport_data;
 104                        if (ibic && ibic->i_cm_id == cm_id) {
 105                                cm_id->route.path_rec[0].sl =
 106                                        TOS_TO_SL(conn->c_tos);
 107                                ret = trans->cm_initiate_connect(cm_id, isv6);
 108                        } else {
 109                                rds_conn_drop(conn);
 110                        }
 111                }
 112                break;
 113
 114        case RDMA_CM_EVENT_ESTABLISHED:
 115                if (conn)
 116                        trans->cm_connect_complete(conn, event);
 117                break;
 118
 119        case RDMA_CM_EVENT_REJECTED:
 120                if (!conn)
 121                        break;
 122                err = (int *)rdma_consumer_reject_data(cm_id, event, &len);
 123                if (!err ||
 124                    (err && len >= sizeof(*err) &&
 125                     ((*err) <= RDS_RDMA_REJ_INCOMPAT))) {
 126                        pr_warn("RDS/RDMA: conn <%pI6c, %pI6c> rejected, dropping connection\n",
 127                                &conn->c_laddr, &conn->c_faddr);
 128
 129                        if (!conn->c_tos)
 130                                conn->c_proposed_version = RDS_PROTOCOL_COMPAT_VERSION;
 131
 132                        rds_conn_drop(conn);
 133                }
 134                rdsdebug("Connection rejected: %s\n",
 135                         rdma_reject_msg(cm_id, event->status));
 136                break;
 137        case RDMA_CM_EVENT_ADDR_ERROR:
 138        case RDMA_CM_EVENT_ROUTE_ERROR:
 139        case RDMA_CM_EVENT_CONNECT_ERROR:
 140        case RDMA_CM_EVENT_UNREACHABLE:
 141        case RDMA_CM_EVENT_DEVICE_REMOVAL:
 142        case RDMA_CM_EVENT_ADDR_CHANGE:
 143                if (conn)
 144                        rds_conn_drop(conn);
 145                break;
 146
 147        case RDMA_CM_EVENT_DISCONNECTED:
 148                if (!conn)
 149                        break;
 150                rdsdebug("DISCONNECT event - dropping connection "
 151                         "%pI6c->%pI6c\n", &conn->c_laddr,
 152                         &conn->c_faddr);
 153                rds_conn_drop(conn);
 154                break;
 155
 156        case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 157                if (conn) {
 158                        pr_info("RDS: RDMA_CM_EVENT_TIMEWAIT_EXIT event: dropping connection %pI6c->%pI6c\n",
 159                                &conn->c_laddr, &conn->c_faddr);
 160                        rds_conn_drop(conn);
 161                }
 162                break;
 163
 164        default:
 165                /* things like device disconnect? */
 166                printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
 167                       event->event, rdma_event_msg(event->event));
 168                break;
 169        }
 170
 171out:
 172        if (conn)
 173                mutex_unlock(&conn->c_cm_lock);
 174
 175        rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
 176                 rdma_event_msg(event->event), ret);
 177
 178        return ret;
 179}
 180
 181int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
 182                              struct rdma_cm_event *event)
 183{
 184        return rds_rdma_cm_event_handler_cmn(cm_id, event, false);
 185}
 186
 187#if IS_ENABLED(CONFIG_IPV6)
 188int rds6_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
 189                               struct rdma_cm_event *event)
 190{
 191        return rds_rdma_cm_event_handler_cmn(cm_id, event, true);
 192}
 193#endif
 194
 195static int rds_rdma_listen_init_common(rdma_cm_event_handler handler,
 196                                       struct sockaddr *sa,
 197                                       struct rdma_cm_id **ret_cm_id)
 198{
 199        struct rdma_cm_id *cm_id;
 200        int ret;
 201
 202        cm_id = rdma_create_id(&init_net, handler, NULL,
 203                               RDMA_PS_TCP, IB_QPT_RC);
 204        if (IS_ERR(cm_id)) {
 205                ret = PTR_ERR(cm_id);
 206                printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 207                       "rdma_create_id() returned %d\n", ret);
 208                return ret;
 209        }
 210
 211        /*
 212         * XXX I bet this binds the cm_id to a device.  If we want to support
 213         * fail-over we'll have to take this into consideration.
 214         */
 215        ret = rdma_bind_addr(cm_id, sa);
 216        if (ret) {
 217                printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 218                       "rdma_bind_addr() returned %d\n", ret);
 219                goto out;
 220        }
 221
 222        ret = rdma_listen(cm_id, 128);
 223        if (ret) {
 224                printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 225                       "rdma_listen() returned %d\n", ret);
 226                goto out;
 227        }
 228
 229        rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
 230
 231        *ret_cm_id = cm_id;
 232        cm_id = NULL;
 233out:
 234        if (cm_id)
 235                rdma_destroy_id(cm_id);
 236        return ret;
 237}
 238
 239/* Initialize the RDS RDMA listeners.  We create two listeners for
 240 * compatibility reason.  The one on RDS_PORT is used for IPv4
 241 * requests only.  The one on RDS_CM_PORT is used for IPv6 requests
 242 * only.  So only IPv6 enabled RDS module will communicate using this
 243 * port.
 244 */
 245static int rds_rdma_listen_init(void)
 246{
 247        int ret;
 248#if IS_ENABLED(CONFIG_IPV6)
 249        struct sockaddr_in6 sin6;
 250#endif
 251        struct sockaddr_in sin;
 252
 253        sin.sin_family = PF_INET;
 254        sin.sin_addr.s_addr = htonl(INADDR_ANY);
 255        sin.sin_port = htons(RDS_PORT);
 256        ret = rds_rdma_listen_init_common(rds_rdma_cm_event_handler,
 257                                          (struct sockaddr *)&sin,
 258                                          &rds_rdma_listen_id);
 259        if (ret != 0)
 260                return ret;
 261
 262#if IS_ENABLED(CONFIG_IPV6)
 263        sin6.sin6_family = PF_INET6;
 264        sin6.sin6_addr = in6addr_any;
 265        sin6.sin6_port = htons(RDS_CM_PORT);
 266        sin6.sin6_scope_id = 0;
 267        sin6.sin6_flowinfo = 0;
 268        ret = rds_rdma_listen_init_common(rds6_rdma_cm_event_handler,
 269                                          (struct sockaddr *)&sin6,
 270                                          &rds6_rdma_listen_id);
 271        /* Keep going even when IPv6 is not enabled in the system. */
 272        if (ret != 0)
 273                rdsdebug("Cannot set up IPv6 RDMA listener\n");
 274#endif
 275        return 0;
 276}
 277
 278static void rds_rdma_listen_stop(void)
 279{
 280        if (rds_rdma_listen_id) {
 281                rdsdebug("cm %p\n", rds_rdma_listen_id);
 282                rdma_destroy_id(rds_rdma_listen_id);
 283                rds_rdma_listen_id = NULL;
 284        }
 285#if IS_ENABLED(CONFIG_IPV6)
 286        if (rds6_rdma_listen_id) {
 287                rdsdebug("cm %p\n", rds6_rdma_listen_id);
 288                rdma_destroy_id(rds6_rdma_listen_id);
 289                rds6_rdma_listen_id = NULL;
 290        }
 291#endif
 292}
 293
 294static int rds_rdma_init(void)
 295{
 296        int ret;
 297
 298        ret = rds_ib_init();
 299        if (ret)
 300                goto out;
 301
 302        ret = rds_rdma_listen_init();
 303        if (ret)
 304                rds_ib_exit();
 305out:
 306        return ret;
 307}
 308module_init(rds_rdma_init);
 309
 310static void rds_rdma_exit(void)
 311{
 312        /* stop listening first to ensure no new connections are attempted */
 313        rds_rdma_listen_stop();
 314        rds_ib_exit();
 315}
 316module_exit(rds_rdma_exit);
 317
 318MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
 319MODULE_DESCRIPTION("RDS: IB transport");
 320MODULE_LICENSE("Dual BSD/GPL");
 321