xref: /openbmc/linux/net/rds/rdma_transport.c (revision 32981ea5)
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_IB_CA)
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 		/* Connection could have been dropped so make sure the
85 		 * cm_id is valid before proceeding
86 		 */
87 		if (conn) {
88 			struct rds_ib_connection *ibic;
89 
90 			ibic = conn->c_transport_data;
91 			if (ibic && ibic->i_cm_id == cm_id)
92 				ret = trans->cm_initiate_connect(cm_id);
93 			else
94 				rds_conn_drop(conn);
95 		}
96 		break;
97 
98 	case RDMA_CM_EVENT_ESTABLISHED:
99 		trans->cm_connect_complete(conn, event);
100 		break;
101 
102 	case RDMA_CM_EVENT_ADDR_ERROR:
103 	case RDMA_CM_EVENT_ROUTE_ERROR:
104 	case RDMA_CM_EVENT_CONNECT_ERROR:
105 	case RDMA_CM_EVENT_UNREACHABLE:
106 	case RDMA_CM_EVENT_REJECTED:
107 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
108 	case RDMA_CM_EVENT_ADDR_CHANGE:
109 		if (conn)
110 			rds_conn_drop(conn);
111 		break;
112 
113 	case RDMA_CM_EVENT_DISCONNECTED:
114 		rdsdebug("DISCONNECT event - dropping connection "
115 			"%pI4->%pI4\n", &conn->c_laddr,
116 			 &conn->c_faddr);
117 		rds_conn_drop(conn);
118 		break;
119 
120 	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
121 		if (conn) {
122 			pr_info("RDS: RDMA_CM_EVENT_TIMEWAIT_EXIT event: dropping connection %pI4->%pI4\n",
123 				&conn->c_laddr, &conn->c_faddr);
124 			rds_conn_drop(conn);
125 		}
126 		break;
127 
128 	default:
129 		/* things like device disconnect? */
130 		printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
131 		       event->event, rdma_event_msg(event->event));
132 		break;
133 	}
134 
135 out:
136 	if (conn)
137 		mutex_unlock(&conn->c_cm_lock);
138 
139 	rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
140 		 rdma_event_msg(event->event), ret);
141 
142 	return ret;
143 }
144 
145 static int rds_rdma_listen_init(void)
146 {
147 	struct sockaddr_in sin;
148 	struct rdma_cm_id *cm_id;
149 	int ret;
150 
151 	cm_id = rdma_create_id(&init_net, rds_rdma_cm_event_handler, NULL,
152 			       RDMA_PS_TCP, IB_QPT_RC);
153 	if (IS_ERR(cm_id)) {
154 		ret = PTR_ERR(cm_id);
155 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
156 		       "rdma_create_id() returned %d\n", ret);
157 		return ret;
158 	}
159 
160 	sin.sin_family = AF_INET;
161 	sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
162 	sin.sin_port = (__force u16)htons(RDS_PORT);
163 
164 	/*
165 	 * XXX I bet this binds the cm_id to a device.  If we want to support
166 	 * fail-over we'll have to take this into consideration.
167 	 */
168 	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
169 	if (ret) {
170 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
171 		       "rdma_bind_addr() returned %d\n", ret);
172 		goto out;
173 	}
174 
175 	ret = rdma_listen(cm_id, 128);
176 	if (ret) {
177 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
178 		       "rdma_listen() returned %d\n", ret);
179 		goto out;
180 	}
181 
182 	rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
183 
184 	rds_rdma_listen_id = cm_id;
185 	cm_id = NULL;
186 out:
187 	if (cm_id)
188 		rdma_destroy_id(cm_id);
189 	return ret;
190 }
191 
192 static void rds_rdma_listen_stop(void)
193 {
194 	if (rds_rdma_listen_id) {
195 		rdsdebug("cm %p\n", rds_rdma_listen_id);
196 		rdma_destroy_id(rds_rdma_listen_id);
197 		rds_rdma_listen_id = NULL;
198 	}
199 }
200 
201 static int rds_rdma_init(void)
202 {
203 	int ret;
204 
205 	ret = rds_rdma_listen_init();
206 	if (ret)
207 		goto out;
208 
209 	ret = rds_ib_init();
210 	if (ret)
211 		goto err_ib_init;
212 
213 	goto out;
214 
215 err_ib_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 }
228 module_exit(rds_rdma_exit);
229 
230 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
231 MODULE_DESCRIPTION("RDS: IB transport");
232 MODULE_LICENSE("Dual BSD/GPL");
233 
234