xref: /openbmc/linux/net/rds/rdma_transport.c (revision e190bfe5)
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 int 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 		rdsdebug("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 "RDS: unknown event %u!\n", event->event);
113 		break;
114 	}
115 
116 out:
117 	if (conn)
118 		mutex_unlock(&conn->c_cm_lock);
119 
120 	rdsdebug("id %p event %u handling ret %d\n", cm_id, event->event, ret);
121 
122 	return ret;
123 }
124 
125 static int __init rds_rdma_listen_init(void)
126 {
127 	struct sockaddr_in sin;
128 	struct rdma_cm_id *cm_id;
129 	int ret;
130 
131 	cm_id = rdma_create_id(rds_rdma_cm_event_handler, NULL, RDMA_PS_TCP);
132 	if (IS_ERR(cm_id)) {
133 		ret = PTR_ERR(cm_id);
134 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
135 		       "rdma_create_id() returned %d\n", ret);
136 		return ret;
137 	}
138 
139 	sin.sin_family = AF_INET,
140 	sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
141 	sin.sin_port = (__force u16)htons(RDS_PORT);
142 
143 	/*
144 	 * XXX I bet this binds the cm_id to a device.  If we want to support
145 	 * fail-over we'll have to take this into consideration.
146 	 */
147 	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
148 	if (ret) {
149 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
150 		       "rdma_bind_addr() returned %d\n", ret);
151 		goto out;
152 	}
153 
154 	ret = rdma_listen(cm_id, 128);
155 	if (ret) {
156 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
157 		       "rdma_listen() returned %d\n", ret);
158 		goto out;
159 	}
160 
161 	rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
162 
163 	rds_rdma_listen_id = cm_id;
164 	cm_id = NULL;
165 out:
166 	if (cm_id)
167 		rdma_destroy_id(cm_id);
168 	return ret;
169 }
170 
171 static void rds_rdma_listen_stop(void)
172 {
173 	if (rds_rdma_listen_id) {
174 		rdsdebug("cm %p\n", rds_rdma_listen_id);
175 		rdma_destroy_id(rds_rdma_listen_id);
176 		rds_rdma_listen_id = NULL;
177 	}
178 }
179 
180 int __init rds_rdma_init(void)
181 {
182 	int ret;
183 
184 	ret = rds_rdma_listen_init();
185 	if (ret)
186 		goto out;
187 
188 	ret = rds_iw_init();
189 	if (ret)
190 		goto err_iw_init;
191 
192 	ret = rds_ib_init();
193 	if (ret)
194 		goto err_ib_init;
195 
196 	goto out;
197 
198 err_ib_init:
199 	rds_iw_exit();
200 err_iw_init:
201 	rds_rdma_listen_stop();
202 out:
203 	return ret;
204 }
205 module_init(rds_rdma_init);
206 
207 void rds_rdma_exit(void)
208 {
209 	/* stop listening first to ensure no new connections are attempted */
210 	rds_rdma_listen_stop();
211 	rds_ib_exit();
212 	rds_iw_exit();
213 }
214 module_exit(rds_rdma_exit);
215 
216 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
217 MODULE_DESCRIPTION("RDS: IB/iWARP transport");
218 MODULE_LICENSE("Dual BSD/GPL");
219 
220