xref: /openbmc/linux/net/rds/rdma_transport.c (revision a09d2831)
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 		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 
117 out:
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 
126 static 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 		goto out;
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;
166 out:
167 	if (cm_id)
168 		rdma_destroy_id(cm_id);
169 	return ret;
170 }
171 
172 static 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 
181 int __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 
199 err_ib_init:
200 	rds_iw_exit();
201 err_iw_init:
202 	rds_rdma_listen_stop();
203 out:
204 	return ret;
205 }
206 module_init(rds_rdma_init);
207 
208 void 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 }
215 module_exit(rds_rdma_exit);
216 
217 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
218 MODULE_DESCRIPTION("RDS: IB/iWARP transport");
219 MODULE_LICENSE("Dual BSD/GPL");
220 
221