xref: /openbmc/linux/net/rds/rdma_transport.c (revision 8fdff1dc)
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 
38 static struct rdma_cm_id *rds_rdma_listen_id;
39 
40 static char *rds_cm_event_strings[] = {
41 #define RDS_CM_EVENT_STRING(foo) \
42 		[RDMA_CM_EVENT_##foo] = __stringify(RDMA_CM_EVENT_##foo)
43 	RDS_CM_EVENT_STRING(ADDR_RESOLVED),
44 	RDS_CM_EVENT_STRING(ADDR_ERROR),
45 	RDS_CM_EVENT_STRING(ROUTE_RESOLVED),
46 	RDS_CM_EVENT_STRING(ROUTE_ERROR),
47 	RDS_CM_EVENT_STRING(CONNECT_REQUEST),
48 	RDS_CM_EVENT_STRING(CONNECT_RESPONSE),
49 	RDS_CM_EVENT_STRING(CONNECT_ERROR),
50 	RDS_CM_EVENT_STRING(UNREACHABLE),
51 	RDS_CM_EVENT_STRING(REJECTED),
52 	RDS_CM_EVENT_STRING(ESTABLISHED),
53 	RDS_CM_EVENT_STRING(DISCONNECTED),
54 	RDS_CM_EVENT_STRING(DEVICE_REMOVAL),
55 	RDS_CM_EVENT_STRING(MULTICAST_JOIN),
56 	RDS_CM_EVENT_STRING(MULTICAST_ERROR),
57 	RDS_CM_EVENT_STRING(ADDR_CHANGE),
58 	RDS_CM_EVENT_STRING(TIMEWAIT_EXIT),
59 #undef RDS_CM_EVENT_STRING
60 };
61 
62 static char *rds_cm_event_str(enum rdma_cm_event_type type)
63 {
64 	return rds_str_array(rds_cm_event_strings,
65 			     ARRAY_SIZE(rds_cm_event_strings), type);
66 };
67 
68 int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
69 			      struct rdma_cm_event *event)
70 {
71 	/* this can be null in the listening path */
72 	struct rds_connection *conn = cm_id->context;
73 	struct rds_transport *trans;
74 	int ret = 0;
75 
76 	rdsdebug("conn %p id %p handling event %u (%s)\n", conn, cm_id,
77 		 event->event, rds_cm_event_str(event->event));
78 
79 	if (cm_id->device->node_type == RDMA_NODE_RNIC)
80 		trans = &rds_iw_transport;
81 	else
82 		trans = &rds_ib_transport;
83 
84 	/* Prevent shutdown from tearing down the connection
85 	 * while we're executing. */
86 	if (conn) {
87 		mutex_lock(&conn->c_cm_lock);
88 
89 		/* If the connection is being shut down, bail out
90 		 * right away. We return 0 so cm_id doesn't get
91 		 * destroyed prematurely */
92 		if (rds_conn_state(conn) == RDS_CONN_DISCONNECTING) {
93 			/* Reject incoming connections while we're tearing
94 			 * down an existing one. */
95 			if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
96 				ret = 1;
97 			goto out;
98 		}
99 	}
100 
101 	switch (event->event) {
102 	case RDMA_CM_EVENT_CONNECT_REQUEST:
103 		ret = trans->cm_handle_connect(cm_id, event);
104 		break;
105 
106 	case RDMA_CM_EVENT_ADDR_RESOLVED:
107 		/* XXX do we need to clean up if this fails? */
108 		ret = rdma_resolve_route(cm_id,
109 					 RDS_RDMA_RESOLVE_TIMEOUT_MS);
110 		break;
111 
112 	case RDMA_CM_EVENT_ROUTE_RESOLVED:
113 		/* XXX worry about racing with listen acceptance */
114 		ret = trans->cm_initiate_connect(cm_id);
115 		break;
116 
117 	case RDMA_CM_EVENT_ESTABLISHED:
118 		trans->cm_connect_complete(conn, event);
119 		break;
120 
121 	case RDMA_CM_EVENT_ADDR_ERROR:
122 	case RDMA_CM_EVENT_ROUTE_ERROR:
123 	case RDMA_CM_EVENT_CONNECT_ERROR:
124 	case RDMA_CM_EVENT_UNREACHABLE:
125 	case RDMA_CM_EVENT_REJECTED:
126 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
127 	case RDMA_CM_EVENT_ADDR_CHANGE:
128 		if (conn)
129 			rds_conn_drop(conn);
130 		break;
131 
132 	case RDMA_CM_EVENT_DISCONNECTED:
133 		rdsdebug("DISCONNECT event - dropping connection "
134 			"%pI4->%pI4\n", &conn->c_laddr,
135 			 &conn->c_faddr);
136 		rds_conn_drop(conn);
137 		break;
138 
139 	default:
140 		/* things like device disconnect? */
141 		printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
142 		       event->event, rds_cm_event_str(event->event));
143 		break;
144 	}
145 
146 out:
147 	if (conn)
148 		mutex_unlock(&conn->c_cm_lock);
149 
150 	rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
151 		 rds_cm_event_str(event->event), ret);
152 
153 	return ret;
154 }
155 
156 static int rds_rdma_listen_init(void)
157 {
158 	struct sockaddr_in sin;
159 	struct rdma_cm_id *cm_id;
160 	int ret;
161 
162 	cm_id = rdma_create_id(rds_rdma_cm_event_handler, NULL, RDMA_PS_TCP,
163 			       IB_QPT_RC);
164 	if (IS_ERR(cm_id)) {
165 		ret = PTR_ERR(cm_id);
166 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
167 		       "rdma_create_id() returned %d\n", ret);
168 		return ret;
169 	}
170 
171 	sin.sin_family = AF_INET,
172 	sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
173 	sin.sin_port = (__force u16)htons(RDS_PORT);
174 
175 	/*
176 	 * XXX I bet this binds the cm_id to a device.  If we want to support
177 	 * fail-over we'll have to take this into consideration.
178 	 */
179 	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
180 	if (ret) {
181 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
182 		       "rdma_bind_addr() returned %d\n", ret);
183 		goto out;
184 	}
185 
186 	ret = rdma_listen(cm_id, 128);
187 	if (ret) {
188 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
189 		       "rdma_listen() returned %d\n", ret);
190 		goto out;
191 	}
192 
193 	rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
194 
195 	rds_rdma_listen_id = cm_id;
196 	cm_id = NULL;
197 out:
198 	if (cm_id)
199 		rdma_destroy_id(cm_id);
200 	return ret;
201 }
202 
203 static void rds_rdma_listen_stop(void)
204 {
205 	if (rds_rdma_listen_id) {
206 		rdsdebug("cm %p\n", rds_rdma_listen_id);
207 		rdma_destroy_id(rds_rdma_listen_id);
208 		rds_rdma_listen_id = NULL;
209 	}
210 }
211 
212 static int rds_rdma_init(void)
213 {
214 	int ret;
215 
216 	ret = rds_rdma_listen_init();
217 	if (ret)
218 		goto out;
219 
220 	ret = rds_iw_init();
221 	if (ret)
222 		goto err_iw_init;
223 
224 	ret = rds_ib_init();
225 	if (ret)
226 		goto err_ib_init;
227 
228 	goto out;
229 
230 err_ib_init:
231 	rds_iw_exit();
232 err_iw_init:
233 	rds_rdma_listen_stop();
234 out:
235 	return ret;
236 }
237 module_init(rds_rdma_init);
238 
239 static void rds_rdma_exit(void)
240 {
241 	/* stop listening first to ensure no new connections are attempted */
242 	rds_rdma_listen_stop();
243 	rds_ib_exit();
244 	rds_iw_exit();
245 }
246 module_exit(rds_rdma_exit);
247 
248 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
249 MODULE_DESCRIPTION("RDS: IB/iWARP transport");
250 MODULE_LICENSE("Dual BSD/GPL");
251 
252