xref: /linux/net/rds/rdma_transport.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
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 "rds_single_path.h"
37 #include "rdma_transport.h"
38 #include "ib.h"
39 
40 static struct rdma_cm_id *rds_rdma_listen_id;
41 
42 int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
43 			      struct rdma_cm_event *event)
44 {
45 	/* this can be null in the listening path */
46 	struct rds_connection *conn = cm_id->context;
47 	struct rds_transport *trans;
48 	int ret = 0;
49 
50 	rdsdebug("conn %p id %p handling event %u (%s)\n", conn, cm_id,
51 		 event->event, rdma_event_msg(event->event));
52 
53 	if (cm_id->device->node_type == RDMA_NODE_IB_CA)
54 		trans = &rds_ib_transport;
55 
56 	/* Prevent shutdown from tearing down the connection
57 	 * while we're executing. */
58 	if (conn) {
59 		mutex_lock(&conn->c_cm_lock);
60 
61 		/* If the connection is being shut down, bail out
62 		 * right away. We return 0 so cm_id doesn't get
63 		 * destroyed prematurely */
64 		if (rds_conn_state(conn) == RDS_CONN_DISCONNECTING) {
65 			/* Reject incoming connections while we're tearing
66 			 * down an existing one. */
67 			if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
68 				ret = 1;
69 			goto out;
70 		}
71 	}
72 
73 	switch (event->event) {
74 	case RDMA_CM_EVENT_CONNECT_REQUEST:
75 		ret = trans->cm_handle_connect(cm_id, event);
76 		break;
77 
78 	case RDMA_CM_EVENT_ADDR_RESOLVED:
79 		/* XXX do we need to clean up if this fails? */
80 		ret = rdma_resolve_route(cm_id,
81 					 RDS_RDMA_RESOLVE_TIMEOUT_MS);
82 		break;
83 
84 	case RDMA_CM_EVENT_ROUTE_RESOLVED:
85 		/* Connection could have been dropped so make sure the
86 		 * cm_id is valid before proceeding
87 		 */
88 		if (conn) {
89 			struct rds_ib_connection *ibic;
90 
91 			ibic = conn->c_transport_data;
92 			if (ibic && ibic->i_cm_id == cm_id)
93 				ret = trans->cm_initiate_connect(cm_id);
94 			else
95 				rds_conn_drop(conn);
96 		}
97 		break;
98 
99 	case RDMA_CM_EVENT_ESTABLISHED:
100 		trans->cm_connect_complete(conn, event);
101 		break;
102 
103 	case RDMA_CM_EVENT_ADDR_ERROR:
104 	case RDMA_CM_EVENT_ROUTE_ERROR:
105 	case RDMA_CM_EVENT_CONNECT_ERROR:
106 	case RDMA_CM_EVENT_UNREACHABLE:
107 	case RDMA_CM_EVENT_REJECTED:
108 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
109 	case RDMA_CM_EVENT_ADDR_CHANGE:
110 		if (conn)
111 			rds_conn_drop(conn);
112 		break;
113 
114 	case RDMA_CM_EVENT_DISCONNECTED:
115 		rdsdebug("DISCONNECT event - dropping connection "
116 			"%pI4->%pI4\n", &conn->c_laddr,
117 			 &conn->c_faddr);
118 		rds_conn_drop(conn);
119 		break;
120 
121 	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
122 		if (conn) {
123 			pr_info("RDS: RDMA_CM_EVENT_TIMEWAIT_EXIT event: dropping connection %pI4->%pI4\n",
124 				&conn->c_laddr, &conn->c_faddr);
125 			rds_conn_drop(conn);
126 		}
127 		break;
128 
129 	default:
130 		/* things like device disconnect? */
131 		printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
132 		       event->event, rdma_event_msg(event->event));
133 		break;
134 	}
135 
136 out:
137 	if (conn)
138 		mutex_unlock(&conn->c_cm_lock);
139 
140 	rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
141 		 rdma_event_msg(event->event), ret);
142 
143 	return ret;
144 }
145 
146 static int rds_rdma_listen_init(void)
147 {
148 	struct sockaddr_in sin;
149 	struct rdma_cm_id *cm_id;
150 	int ret;
151 
152 	cm_id = rdma_create_id(&init_net, rds_rdma_cm_event_handler, NULL,
153 			       RDMA_PS_TCP, IB_QPT_RC);
154 	if (IS_ERR(cm_id)) {
155 		ret = PTR_ERR(cm_id);
156 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
157 		       "rdma_create_id() returned %d\n", ret);
158 		return ret;
159 	}
160 
161 	sin.sin_family = AF_INET;
162 	sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
163 	sin.sin_port = (__force u16)htons(RDS_PORT);
164 
165 	/*
166 	 * XXX I bet this binds the cm_id to a device.  If we want to support
167 	 * fail-over we'll have to take this into consideration.
168 	 */
169 	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
170 	if (ret) {
171 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
172 		       "rdma_bind_addr() returned %d\n", ret);
173 		goto out;
174 	}
175 
176 	ret = rdma_listen(cm_id, 128);
177 	if (ret) {
178 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
179 		       "rdma_listen() returned %d\n", ret);
180 		goto out;
181 	}
182 
183 	rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
184 
185 	rds_rdma_listen_id = cm_id;
186 	cm_id = NULL;
187 out:
188 	if (cm_id)
189 		rdma_destroy_id(cm_id);
190 	return ret;
191 }
192 
193 static void rds_rdma_listen_stop(void)
194 {
195 	if (rds_rdma_listen_id) {
196 		rdsdebug("cm %p\n", rds_rdma_listen_id);
197 		rdma_destroy_id(rds_rdma_listen_id);
198 		rds_rdma_listen_id = NULL;
199 	}
200 }
201 
202 static int rds_rdma_init(void)
203 {
204 	int ret;
205 
206 	ret = rds_rdma_listen_init();
207 	if (ret)
208 		goto out;
209 
210 	ret = rds_ib_init();
211 	if (ret)
212 		goto err_ib_init;
213 
214 	goto out;
215 
216 err_ib_init:
217 	rds_rdma_listen_stop();
218 out:
219 	return ret;
220 }
221 module_init(rds_rdma_init);
222 
223 static void rds_rdma_exit(void)
224 {
225 	/* stop listening first to ensure no new connections are attempted */
226 	rds_rdma_listen_stop();
227 	rds_ib_exit();
228 }
229 module_exit(rds_rdma_exit);
230 
231 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
232 MODULE_DESCRIPTION("RDS: IB transport");
233 MODULE_LICENSE("Dual BSD/GPL");
234 
235