xref: /linux/net/rds/rdma_transport.c (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
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 #include "ib.h"
38 
39 static struct rdma_cm_id *rds_rdma_listen_id;
40 
41 int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
42 			      struct rdma_cm_event *event)
43 {
44 	/* this can be null in the listening path */
45 	struct rds_connection *conn = cm_id->context;
46 	struct rds_transport *trans;
47 	int ret = 0;
48 
49 	rdsdebug("conn %p id %p handling event %u (%s)\n", conn, cm_id,
50 		 event->event, rdma_event_msg(event->event));
51 
52 	if (cm_id->device->node_type == RDMA_NODE_RNIC)
53 		trans = &rds_iw_transport;
54 	else
55 		trans = &rds_ib_transport;
56 
57 	/* Prevent shutdown from tearing down the connection
58 	 * while we're executing. */
59 	if (conn) {
60 		mutex_lock(&conn->c_cm_lock);
61 
62 		/* If the connection is being shut down, bail out
63 		 * right away. We return 0 so cm_id doesn't get
64 		 * destroyed prematurely */
65 		if (rds_conn_state(conn) == RDS_CONN_DISCONNECTING) {
66 			/* Reject incoming connections while we're tearing
67 			 * down an existing one. */
68 			if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
69 				ret = 1;
70 			goto out;
71 		}
72 	}
73 
74 	switch (event->event) {
75 	case RDMA_CM_EVENT_CONNECT_REQUEST:
76 		ret = trans->cm_handle_connect(cm_id, event);
77 		break;
78 
79 	case RDMA_CM_EVENT_ADDR_RESOLVED:
80 		/* XXX do we need to clean up if this fails? */
81 		ret = rdma_resolve_route(cm_id,
82 					 RDS_RDMA_RESOLVE_TIMEOUT_MS);
83 		break;
84 
85 	case RDMA_CM_EVENT_ROUTE_RESOLVED:
86 		/* Connection could have been dropped so make sure the
87 		 * cm_id is valid before proceeding
88 		 */
89 		if (conn) {
90 			struct rds_ib_connection *ibic;
91 
92 			ibic = conn->c_transport_data;
93 			if (ibic && ibic->i_cm_id == cm_id)
94 				ret = trans->cm_initiate_connect(cm_id);
95 			else
96 				rds_conn_drop(conn);
97 		}
98 		break;
99 
100 	case RDMA_CM_EVENT_ESTABLISHED:
101 		trans->cm_connect_complete(conn, event);
102 		break;
103 
104 	case RDMA_CM_EVENT_ADDR_ERROR:
105 	case RDMA_CM_EVENT_ROUTE_ERROR:
106 	case RDMA_CM_EVENT_CONNECT_ERROR:
107 	case RDMA_CM_EVENT_UNREACHABLE:
108 	case RDMA_CM_EVENT_REJECTED:
109 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
110 	case RDMA_CM_EVENT_ADDR_CHANGE:
111 		if (conn)
112 			rds_conn_drop(conn);
113 		break;
114 
115 	case RDMA_CM_EVENT_DISCONNECTED:
116 		rdsdebug("DISCONNECT event - dropping connection "
117 			"%pI4->%pI4\n", &conn->c_laddr,
118 			 &conn->c_faddr);
119 		rds_conn_drop(conn);
120 		break;
121 
122 	default:
123 		/* things like device disconnect? */
124 		printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
125 		       event->event, rdma_event_msg(event->event));
126 		break;
127 	}
128 
129 out:
130 	if (conn)
131 		mutex_unlock(&conn->c_cm_lock);
132 
133 	rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
134 		 rdma_event_msg(event->event), ret);
135 
136 	return ret;
137 }
138 
139 static int rds_rdma_listen_init(void)
140 {
141 	struct sockaddr_in sin;
142 	struct rdma_cm_id *cm_id;
143 	int ret;
144 
145 	cm_id = rdma_create_id(rds_rdma_cm_event_handler, NULL, RDMA_PS_TCP,
146 			       IB_QPT_RC);
147 	if (IS_ERR(cm_id)) {
148 		ret = PTR_ERR(cm_id);
149 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
150 		       "rdma_create_id() returned %d\n", ret);
151 		return ret;
152 	}
153 
154 	sin.sin_family = AF_INET;
155 	sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
156 	sin.sin_port = (__force u16)htons(RDS_PORT);
157 
158 	/*
159 	 * XXX I bet this binds the cm_id to a device.  If we want to support
160 	 * fail-over we'll have to take this into consideration.
161 	 */
162 	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
163 	if (ret) {
164 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
165 		       "rdma_bind_addr() returned %d\n", ret);
166 		goto out;
167 	}
168 
169 	ret = rdma_listen(cm_id, 128);
170 	if (ret) {
171 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
172 		       "rdma_listen() returned %d\n", ret);
173 		goto out;
174 	}
175 
176 	rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
177 
178 	rds_rdma_listen_id = cm_id;
179 	cm_id = NULL;
180 out:
181 	if (cm_id)
182 		rdma_destroy_id(cm_id);
183 	return ret;
184 }
185 
186 static void rds_rdma_listen_stop(void)
187 {
188 	if (rds_rdma_listen_id) {
189 		rdsdebug("cm %p\n", rds_rdma_listen_id);
190 		rdma_destroy_id(rds_rdma_listen_id);
191 		rds_rdma_listen_id = NULL;
192 	}
193 }
194 
195 static int rds_rdma_init(void)
196 {
197 	int ret;
198 
199 	ret = rds_rdma_listen_init();
200 	if (ret)
201 		goto out;
202 
203 	ret = rds_iw_init();
204 	if (ret)
205 		goto err_iw_init;
206 
207 	ret = rds_ib_init();
208 	if (ret)
209 		goto err_ib_init;
210 
211 	goto out;
212 
213 err_ib_init:
214 	rds_iw_exit();
215 err_iw_init:
216 	rds_rdma_listen_stop();
217 out:
218 	return ret;
219 }
220 module_init(rds_rdma_init);
221 
222 static void rds_rdma_exit(void)
223 {
224 	/* stop listening first to ensure no new connections are attempted */
225 	rds_rdma_listen_stop();
226 	rds_ib_exit();
227 	rds_iw_exit();
228 }
229 module_exit(rds_rdma_exit);
230 
231 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
232 MODULE_DESCRIPTION("RDS: IB/iWARP transport");
233 MODULE_LICENSE("Dual BSD/GPL");
234 
235