Root/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
37static struct rdma_cm_id *rds_rdma_listen_id;
38
39int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
40                  struct rdma_cm_event *event)
41{
42    /* this can be null in the listening path */
43    struct rds_connection *conn = cm_id->context;
44    struct rds_transport *trans;
45    int ret = 0;
46
47    rdsdebug("conn %p id %p handling event %u\n", conn, cm_id,
48         event->event);
49
50    if (cm_id->device->node_type == RDMA_NODE_RNIC)
51        trans = &rds_iw_transport;
52    else
53        trans = &rds_ib_transport;
54
55    /* Prevent shutdown from tearing down the connection
56     * while we're executing. */
57    if (conn) {
58        mutex_lock(&conn->c_cm_lock);
59
60        /* If the connection is being shut down, bail out
61         * right away. We return 0 so cm_id doesn't get
62         * destroyed prematurely */
63        if (rds_conn_state(conn) == RDS_CONN_DISCONNECTING) {
64            /* Reject incoming connections while we're tearing
65             * down an existing one. */
66            if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
67                ret = 1;
68            goto out;
69        }
70    }
71
72    switch (event->event) {
73    case RDMA_CM_EVENT_CONNECT_REQUEST:
74        ret = trans->cm_handle_connect(cm_id, event);
75        break;
76
77    case RDMA_CM_EVENT_ADDR_RESOLVED:
78        /* XXX do we need to clean up if this fails? */
79        ret = rdma_resolve_route(cm_id,
80                     RDS_RDMA_RESOLVE_TIMEOUT_MS);
81        break;
82
83    case RDMA_CM_EVENT_ROUTE_RESOLVED:
84        /* XXX worry about racing with listen acceptance */
85        ret = trans->cm_initiate_connect(cm_id);
86        break;
87
88    case RDMA_CM_EVENT_ESTABLISHED:
89        trans->cm_connect_complete(conn, event);
90        break;
91
92    case RDMA_CM_EVENT_ADDR_ERROR:
93    case RDMA_CM_EVENT_ROUTE_ERROR:
94    case RDMA_CM_EVENT_CONNECT_ERROR:
95    case RDMA_CM_EVENT_UNREACHABLE:
96    case RDMA_CM_EVENT_REJECTED:
97    case RDMA_CM_EVENT_DEVICE_REMOVAL:
98    case RDMA_CM_EVENT_ADDR_CHANGE:
99        if (conn)
100            rds_conn_drop(conn);
101        break;
102
103    case RDMA_CM_EVENT_DISCONNECTED:
104        printk(KERN_WARNING "RDS/RDMA: DISCONNECT event - dropping connection "
105            "%pI4->%pI4\n", &conn->c_laddr,
106             &conn->c_faddr);
107        rds_conn_drop(conn);
108        break;
109
110    default:
111        /* things like device disconnect? */
112        printk(KERN_ERR "unknown event %u\n", event->event);
113        BUG();
114        break;
115    }
116
117out:
118    if (conn)
119        mutex_unlock(&conn->c_cm_lock);
120
121    rdsdebug("id %p event %u handling ret %d\n", cm_id, event->event, ret);
122
123    return ret;
124}
125
126static int __init rds_rdma_listen_init(void)
127{
128    struct sockaddr_in sin;
129    struct rdma_cm_id *cm_id;
130    int ret;
131
132    cm_id = rdma_create_id(rds_rdma_cm_event_handler, NULL, RDMA_PS_TCP);
133    if (IS_ERR(cm_id)) {
134        ret = PTR_ERR(cm_id);
135        printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
136               "rdma_create_id() returned %d\n", ret);
137        return ret;
138    }
139
140    sin.sin_family = AF_INET,
141    sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
142    sin.sin_port = (__force u16)htons(RDS_PORT);
143
144    /*
145     * XXX I bet this binds the cm_id to a device. If we want to support
146     * fail-over we'll have to take this into consideration.
147     */
148    ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
149    if (ret) {
150        printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
151               "rdma_bind_addr() returned %d\n", ret);
152        goto out;
153    }
154
155    ret = rdma_listen(cm_id, 128);
156    if (ret) {
157        printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
158               "rdma_listen() returned %d\n", ret);
159        goto out;
160    }
161
162    rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
163
164    rds_rdma_listen_id = cm_id;
165    cm_id = NULL;
166out:
167    if (cm_id)
168        rdma_destroy_id(cm_id);
169    return ret;
170}
171
172static void rds_rdma_listen_stop(void)
173{
174    if (rds_rdma_listen_id) {
175        rdsdebug("cm %p\n", rds_rdma_listen_id);
176        rdma_destroy_id(rds_rdma_listen_id);
177        rds_rdma_listen_id = NULL;
178    }
179}
180
181int __init rds_rdma_init(void)
182{
183    int ret;
184
185    ret = rds_rdma_listen_init();
186    if (ret)
187        goto out;
188
189    ret = rds_iw_init();
190    if (ret)
191        goto err_iw_init;
192
193    ret = rds_ib_init();
194    if (ret)
195        goto err_ib_init;
196
197    goto out;
198
199err_ib_init:
200    rds_iw_exit();
201err_iw_init:
202    rds_rdma_listen_stop();
203out:
204    return ret;
205}
206module_init(rds_rdma_init);
207
208void rds_rdma_exit(void)
209{
210    /* stop listening first to ensure no new connections are attempted */
211    rds_rdma_listen_stop();
212    rds_ib_exit();
213    rds_iw_exit();
214}
215module_exit(rds_rdma_exit);
216
217MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
218MODULE_DESCRIPTION("RDS: IB/iWARP transport");
219MODULE_LICENSE("Dual BSD/GPL");
220
221

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