xref: /linux/net/rds/rdma_transport.c (revision 7aacf86b75bc5523d20fd9127104384fce51ce9c)
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_REJECTED:
104 		rdsdebug("Connection rejected: %s\n",
105 			 rdma_reject_msg(cm_id, event->status));
106 		/* FALLTHROUGH */
107 	case RDMA_CM_EVENT_ADDR_ERROR:
108 	case RDMA_CM_EVENT_ROUTE_ERROR:
109 	case RDMA_CM_EVENT_CONNECT_ERROR:
110 	case RDMA_CM_EVENT_UNREACHABLE:
111 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
112 	case RDMA_CM_EVENT_ADDR_CHANGE:
113 		if (conn)
114 			rds_conn_drop(conn);
115 		break;
116 
117 	case RDMA_CM_EVENT_DISCONNECTED:
118 		rdsdebug("DISCONNECT event - dropping connection "
119 			"%pI4->%pI4\n", &conn->c_laddr,
120 			 &conn->c_faddr);
121 		rds_conn_drop(conn);
122 		break;
123 
124 	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
125 		if (conn) {
126 			pr_info("RDS: RDMA_CM_EVENT_TIMEWAIT_EXIT event: dropping connection %pI4->%pI4\n",
127 				&conn->c_laddr, &conn->c_faddr);
128 			rds_conn_drop(conn);
129 		}
130 		break;
131 
132 	default:
133 		/* things like device disconnect? */
134 		printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
135 		       event->event, rdma_event_msg(event->event));
136 		break;
137 	}
138 
139 out:
140 	if (conn)
141 		mutex_unlock(&conn->c_cm_lock);
142 
143 	rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
144 		 rdma_event_msg(event->event), ret);
145 
146 	return ret;
147 }
148 
149 static int rds_rdma_listen_init(void)
150 {
151 	struct sockaddr_in sin;
152 	struct rdma_cm_id *cm_id;
153 	int ret;
154 
155 	cm_id = rdma_create_id(&init_net, rds_rdma_cm_event_handler, NULL,
156 			       RDMA_PS_TCP, IB_QPT_RC);
157 	if (IS_ERR(cm_id)) {
158 		ret = PTR_ERR(cm_id);
159 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
160 		       "rdma_create_id() returned %d\n", ret);
161 		return ret;
162 	}
163 
164 	sin.sin_family = AF_INET;
165 	sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
166 	sin.sin_port = (__force u16)htons(RDS_PORT);
167 
168 	/*
169 	 * XXX I bet this binds the cm_id to a device.  If we want to support
170 	 * fail-over we'll have to take this into consideration.
171 	 */
172 	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
173 	if (ret) {
174 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
175 		       "rdma_bind_addr() returned %d\n", ret);
176 		goto out;
177 	}
178 
179 	ret = rdma_listen(cm_id, 128);
180 	if (ret) {
181 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
182 		       "rdma_listen() returned %d\n", ret);
183 		goto out;
184 	}
185 
186 	rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
187 
188 	rds_rdma_listen_id = cm_id;
189 	cm_id = NULL;
190 out:
191 	if (cm_id)
192 		rdma_destroy_id(cm_id);
193 	return ret;
194 }
195 
196 static void rds_rdma_listen_stop(void)
197 {
198 	if (rds_rdma_listen_id) {
199 		rdsdebug("cm %p\n", rds_rdma_listen_id);
200 		rdma_destroy_id(rds_rdma_listen_id);
201 		rds_rdma_listen_id = NULL;
202 	}
203 }
204 
205 static int rds_rdma_init(void)
206 {
207 	int ret;
208 
209 	ret = rds_ib_init();
210 	if (ret)
211 		goto out;
212 
213 	ret = rds_rdma_listen_init();
214 	if (ret)
215 		rds_ib_exit();
216 out:
217 	return ret;
218 }
219 module_init(rds_rdma_init);
220 
221 static void rds_rdma_exit(void)
222 {
223 	/* stop listening first to ensure no new connections are attempted */
224 	rds_rdma_listen_stop();
225 	rds_ib_exit();
226 }
227 module_exit(rds_rdma_exit);
228 
229 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
230 MODULE_DESCRIPTION("RDS: IB transport");
231 MODULE_LICENSE("Dual BSD/GPL");
232 
233