xref: /openbmc/linux/net/rds/rdma_transport.c (revision 565d76cb)
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 
37 static struct rdma_cm_id *rds_rdma_listen_id;
38 
39 static char *rds_cm_event_strings[] = {
40 #define RDS_CM_EVENT_STRING(foo) \
41 		[RDMA_CM_EVENT_##foo] = __stringify(RDMA_CM_EVENT_##foo)
42 	RDS_CM_EVENT_STRING(ADDR_RESOLVED),
43 	RDS_CM_EVENT_STRING(ADDR_ERROR),
44 	RDS_CM_EVENT_STRING(ROUTE_RESOLVED),
45 	RDS_CM_EVENT_STRING(ROUTE_ERROR),
46 	RDS_CM_EVENT_STRING(CONNECT_REQUEST),
47 	RDS_CM_EVENT_STRING(CONNECT_RESPONSE),
48 	RDS_CM_EVENT_STRING(CONNECT_ERROR),
49 	RDS_CM_EVENT_STRING(UNREACHABLE),
50 	RDS_CM_EVENT_STRING(REJECTED),
51 	RDS_CM_EVENT_STRING(ESTABLISHED),
52 	RDS_CM_EVENT_STRING(DISCONNECTED),
53 	RDS_CM_EVENT_STRING(DEVICE_REMOVAL),
54 	RDS_CM_EVENT_STRING(MULTICAST_JOIN),
55 	RDS_CM_EVENT_STRING(MULTICAST_ERROR),
56 	RDS_CM_EVENT_STRING(ADDR_CHANGE),
57 	RDS_CM_EVENT_STRING(TIMEWAIT_EXIT),
58 #undef RDS_CM_EVENT_STRING
59 };
60 
61 static char *rds_cm_event_str(enum rdma_cm_event_type type)
62 {
63 	return rds_str_array(rds_cm_event_strings,
64 			     ARRAY_SIZE(rds_cm_event_strings), type);
65 };
66 
67 int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
68 			      struct rdma_cm_event *event)
69 {
70 	/* this can be null in the listening path */
71 	struct rds_connection *conn = cm_id->context;
72 	struct rds_transport *trans;
73 	int ret = 0;
74 
75 	rdsdebug("conn %p id %p handling event %u (%s)\n", conn, cm_id,
76 		 event->event, rds_cm_event_str(event->event));
77 
78 	if (cm_id->device->node_type == RDMA_NODE_RNIC)
79 		trans = &rds_iw_transport;
80 	else
81 		trans = &rds_ib_transport;
82 
83 	/* Prevent shutdown from tearing down the connection
84 	 * while we're executing. */
85 	if (conn) {
86 		mutex_lock(&conn->c_cm_lock);
87 
88 		/* If the connection is being shut down, bail out
89 		 * right away. We return 0 so cm_id doesn't get
90 		 * destroyed prematurely */
91 		if (rds_conn_state(conn) == RDS_CONN_DISCONNECTING) {
92 			/* Reject incoming connections while we're tearing
93 			 * down an existing one. */
94 			if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
95 				ret = 1;
96 			goto out;
97 		}
98 	}
99 
100 	switch (event->event) {
101 	case RDMA_CM_EVENT_CONNECT_REQUEST:
102 		ret = trans->cm_handle_connect(cm_id, event);
103 		break;
104 
105 	case RDMA_CM_EVENT_ADDR_RESOLVED:
106 		/* XXX do we need to clean up if this fails? */
107 		ret = rdma_resolve_route(cm_id,
108 					 RDS_RDMA_RESOLVE_TIMEOUT_MS);
109 		break;
110 
111 	case RDMA_CM_EVENT_ROUTE_RESOLVED:
112 		/* XXX worry about racing with listen acceptance */
113 		ret = trans->cm_initiate_connect(cm_id);
114 		break;
115 
116 	case RDMA_CM_EVENT_ESTABLISHED:
117 		trans->cm_connect_complete(conn, event);
118 		break;
119 
120 	case RDMA_CM_EVENT_ADDR_ERROR:
121 	case RDMA_CM_EVENT_ROUTE_ERROR:
122 	case RDMA_CM_EVENT_CONNECT_ERROR:
123 	case RDMA_CM_EVENT_UNREACHABLE:
124 	case RDMA_CM_EVENT_REJECTED:
125 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
126 	case RDMA_CM_EVENT_ADDR_CHANGE:
127 		if (conn)
128 			rds_conn_drop(conn);
129 		break;
130 
131 	case RDMA_CM_EVENT_DISCONNECTED:
132 		rdsdebug("DISCONNECT event - dropping connection "
133 			"%pI4->%pI4\n", &conn->c_laddr,
134 			 &conn->c_faddr);
135 		rds_conn_drop(conn);
136 		break;
137 
138 	default:
139 		/* things like device disconnect? */
140 		printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
141 		       event->event, rds_cm_event_str(event->event));
142 		break;
143 	}
144 
145 out:
146 	if (conn)
147 		mutex_unlock(&conn->c_cm_lock);
148 
149 	rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
150 		 rds_cm_event_str(event->event), ret);
151 
152 	return ret;
153 }
154 
155 static int rds_rdma_listen_init(void)
156 {
157 	struct sockaddr_in sin;
158 	struct rdma_cm_id *cm_id;
159 	int ret;
160 
161 	cm_id = rdma_create_id(rds_rdma_cm_event_handler, NULL, RDMA_PS_TCP);
162 	if (IS_ERR(cm_id)) {
163 		ret = PTR_ERR(cm_id);
164 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
165 		       "rdma_create_id() returned %d\n", ret);
166 		return ret;
167 	}
168 
169 	sin.sin_family = AF_INET,
170 	sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
171 	sin.sin_port = (__force u16)htons(RDS_PORT);
172 
173 	/*
174 	 * XXX I bet this binds the cm_id to a device.  If we want to support
175 	 * fail-over we'll have to take this into consideration.
176 	 */
177 	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
178 	if (ret) {
179 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
180 		       "rdma_bind_addr() returned %d\n", ret);
181 		goto out;
182 	}
183 
184 	ret = rdma_listen(cm_id, 128);
185 	if (ret) {
186 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
187 		       "rdma_listen() returned %d\n", ret);
188 		goto out;
189 	}
190 
191 	rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
192 
193 	rds_rdma_listen_id = cm_id;
194 	cm_id = NULL;
195 out:
196 	if (cm_id)
197 		rdma_destroy_id(cm_id);
198 	return ret;
199 }
200 
201 static void rds_rdma_listen_stop(void)
202 {
203 	if (rds_rdma_listen_id) {
204 		rdsdebug("cm %p\n", rds_rdma_listen_id);
205 		rdma_destroy_id(rds_rdma_listen_id);
206 		rds_rdma_listen_id = NULL;
207 	}
208 }
209 
210 static int rds_rdma_init(void)
211 {
212 	int ret;
213 
214 	ret = rds_rdma_listen_init();
215 	if (ret)
216 		goto out;
217 
218 	ret = rds_iw_init();
219 	if (ret)
220 		goto err_iw_init;
221 
222 	ret = rds_ib_init();
223 	if (ret)
224 		goto err_ib_init;
225 
226 	goto out;
227 
228 err_ib_init:
229 	rds_iw_exit();
230 err_iw_init:
231 	rds_rdma_listen_stop();
232 out:
233 	return ret;
234 }
235 module_init(rds_rdma_init);
236 
237 static void rds_rdma_exit(void)
238 {
239 	/* stop listening first to ensure no new connections are attempted */
240 	rds_rdma_listen_stop();
241 	rds_ib_exit();
242 	rds_iw_exit();
243 }
244 module_exit(rds_rdma_exit);
245 
246 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
247 MODULE_DESCRIPTION("RDS: IB/iWARP transport");
248 MODULE_LICENSE("Dual BSD/GPL");
249 
250