xref: /openbmc/linux/net/rds/rdma_transport.c (revision 0c874100)
1 /*
2  * Copyright (c) 2009, 2018 Oracle and/or its affiliates. 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 /* Global IPv4 and IPv6 RDS RDMA listener cm_id */
41 static struct rdma_cm_id *rds_rdma_listen_id;
42 #if IS_ENABLED(CONFIG_IPV6)
43 static struct rdma_cm_id *rds6_rdma_listen_id;
44 #endif
45 
46 static int rds_rdma_cm_event_handler_cmn(struct rdma_cm_id *cm_id,
47 					 struct rdma_cm_event *event,
48 					 bool isv6)
49 {
50 	/* this can be null in the listening path */
51 	struct rds_connection *conn = cm_id->context;
52 	struct rds_transport *trans;
53 	int ret = 0;
54 
55 	rdsdebug("conn %p id %p handling event %u (%s)\n", conn, cm_id,
56 		 event->event, rdma_event_msg(event->event));
57 
58 	if (cm_id->device->node_type == RDMA_NODE_IB_CA)
59 		trans = &rds_ib_transport;
60 
61 	/* Prevent shutdown from tearing down the connection
62 	 * while we're executing. */
63 	if (conn) {
64 		mutex_lock(&conn->c_cm_lock);
65 
66 		/* If the connection is being shut down, bail out
67 		 * right away. We return 0 so cm_id doesn't get
68 		 * destroyed prematurely */
69 		if (rds_conn_state(conn) == RDS_CONN_DISCONNECTING) {
70 			/* Reject incoming connections while we're tearing
71 			 * down an existing one. */
72 			if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
73 				ret = 1;
74 			goto out;
75 		}
76 	}
77 
78 	switch (event->event) {
79 	case RDMA_CM_EVENT_CONNECT_REQUEST:
80 		ret = trans->cm_handle_connect(cm_id, event, isv6);
81 		break;
82 
83 	case RDMA_CM_EVENT_ADDR_RESOLVED:
84 		/* XXX do we need to clean up if this fails? */
85 		ret = rdma_resolve_route(cm_id,
86 					 RDS_RDMA_RESOLVE_TIMEOUT_MS);
87 		break;
88 
89 	case RDMA_CM_EVENT_ROUTE_RESOLVED:
90 		/* Connection could have been dropped so make sure the
91 		 * cm_id is valid before proceeding
92 		 */
93 		if (conn) {
94 			struct rds_ib_connection *ibic;
95 
96 			ibic = conn->c_transport_data;
97 			if (ibic && ibic->i_cm_id == cm_id)
98 				ret = trans->cm_initiate_connect(cm_id, isv6);
99 			else
100 				rds_conn_drop(conn);
101 		}
102 		break;
103 
104 	case RDMA_CM_EVENT_ESTABLISHED:
105 		trans->cm_connect_complete(conn, event);
106 		break;
107 
108 	case RDMA_CM_EVENT_REJECTED:
109 		rdsdebug("Connection rejected: %s\n",
110 			 rdma_reject_msg(cm_id, event->status));
111 		/* FALLTHROUGH */
112 	case RDMA_CM_EVENT_ADDR_ERROR:
113 	case RDMA_CM_EVENT_ROUTE_ERROR:
114 	case RDMA_CM_EVENT_CONNECT_ERROR:
115 	case RDMA_CM_EVENT_UNREACHABLE:
116 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
117 	case RDMA_CM_EVENT_ADDR_CHANGE:
118 		if (conn)
119 			rds_conn_drop(conn);
120 		break;
121 
122 	case RDMA_CM_EVENT_DISCONNECTED:
123 		rdsdebug("DISCONNECT event - dropping connection "
124 			 "%pI6c->%pI6c\n", &conn->c_laddr,
125 			 &conn->c_faddr);
126 		rds_conn_drop(conn);
127 		break;
128 
129 	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
130 		if (conn) {
131 			pr_info("RDS: RDMA_CM_EVENT_TIMEWAIT_EXIT event: dropping connection %pI6c->%pI6c\n",
132 				&conn->c_laddr, &conn->c_faddr);
133 			rds_conn_drop(conn);
134 		}
135 		break;
136 
137 	default:
138 		/* things like device disconnect? */
139 		printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
140 		       event->event, rdma_event_msg(event->event));
141 		break;
142 	}
143 
144 out:
145 	if (conn)
146 		mutex_unlock(&conn->c_cm_lock);
147 
148 	rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
149 		 rdma_event_msg(event->event), ret);
150 
151 	return ret;
152 }
153 
154 int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
155 			      struct rdma_cm_event *event)
156 {
157 	return rds_rdma_cm_event_handler_cmn(cm_id, event, false);
158 }
159 
160 #if IS_ENABLED(CONFIG_IPV6)
161 int rds6_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
162 			       struct rdma_cm_event *event)
163 {
164 	return rds_rdma_cm_event_handler_cmn(cm_id, event, true);
165 }
166 #endif
167 
168 static int rds_rdma_listen_init_common(rdma_cm_event_handler handler,
169 				       struct sockaddr *sa,
170 				       struct rdma_cm_id **ret_cm_id)
171 {
172 	struct rdma_cm_id *cm_id;
173 	int ret;
174 
175 	cm_id = rdma_create_id(&init_net, handler, NULL,
176 			       RDMA_PS_TCP, IB_QPT_RC);
177 	if (IS_ERR(cm_id)) {
178 		ret = PTR_ERR(cm_id);
179 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
180 		       "rdma_create_id() returned %d\n", ret);
181 		return ret;
182 	}
183 
184 	/*
185 	 * XXX I bet this binds the cm_id to a device.  If we want to support
186 	 * fail-over we'll have to take this into consideration.
187 	 */
188 	ret = rdma_bind_addr(cm_id, sa);
189 	if (ret) {
190 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
191 		       "rdma_bind_addr() returned %d\n", ret);
192 		goto out;
193 	}
194 
195 	ret = rdma_listen(cm_id, 128);
196 	if (ret) {
197 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
198 		       "rdma_listen() returned %d\n", ret);
199 		goto out;
200 	}
201 
202 	rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
203 
204 	*ret_cm_id = cm_id;
205 	cm_id = NULL;
206 out:
207 	if (cm_id)
208 		rdma_destroy_id(cm_id);
209 	return ret;
210 }
211 
212 /* Initialize the RDS RDMA listeners.  We create two listeners for
213  * compatibility reason.  The one on RDS_PORT is used for IPv4
214  * requests only.  The one on RDS_CM_PORT is used for IPv6 requests
215  * only.  So only IPv6 enabled RDS module will communicate using this
216  * port.
217  */
218 static int rds_rdma_listen_init(void)
219 {
220 	int ret;
221 #if IS_ENABLED(CONFIG_IPV6)
222 	struct sockaddr_in6 sin6;
223 #endif
224 	struct sockaddr_in sin;
225 
226 	sin.sin_family = PF_INET;
227 	sin.sin_addr.s_addr = htonl(INADDR_ANY);
228 	sin.sin_port = htons(RDS_PORT);
229 	ret = rds_rdma_listen_init_common(rds_rdma_cm_event_handler,
230 					  (struct sockaddr *)&sin,
231 					  &rds_rdma_listen_id);
232 	if (ret != 0)
233 		return ret;
234 
235 #if IS_ENABLED(CONFIG_IPV6)
236 	sin6.sin6_family = PF_INET6;
237 	sin6.sin6_addr = in6addr_any;
238 	sin6.sin6_port = htons(RDS_CM_PORT);
239 	sin6.sin6_scope_id = 0;
240 	sin6.sin6_flowinfo = 0;
241 	ret = rds_rdma_listen_init_common(rds6_rdma_cm_event_handler,
242 					  (struct sockaddr *)&sin6,
243 					  &rds6_rdma_listen_id);
244 	/* Keep going even when IPv6 is not enabled in the system. */
245 	if (ret != 0)
246 		rdsdebug("Cannot set up IPv6 RDMA listener\n");
247 #endif
248 	return 0;
249 }
250 
251 static void rds_rdma_listen_stop(void)
252 {
253 	if (rds_rdma_listen_id) {
254 		rdsdebug("cm %p\n", rds_rdma_listen_id);
255 		rdma_destroy_id(rds_rdma_listen_id);
256 		rds_rdma_listen_id = NULL;
257 	}
258 #if IS_ENABLED(CONFIG_IPV6)
259 	if (rds6_rdma_listen_id) {
260 		rdsdebug("cm %p\n", rds6_rdma_listen_id);
261 		rdma_destroy_id(rds6_rdma_listen_id);
262 		rds6_rdma_listen_id = NULL;
263 	}
264 #endif
265 }
266 
267 static int rds_rdma_init(void)
268 {
269 	int ret;
270 
271 	ret = rds_ib_init();
272 	if (ret)
273 		goto out;
274 
275 	ret = rds_rdma_listen_init();
276 	if (ret)
277 		rds_ib_exit();
278 out:
279 	return ret;
280 }
281 module_init(rds_rdma_init);
282 
283 static void rds_rdma_exit(void)
284 {
285 	/* stop listening first to ensure no new connections are attempted */
286 	rds_rdma_listen_stop();
287 	rds_ib_exit();
288 }
289 module_exit(rds_rdma_exit);
290 
291 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
292 MODULE_DESCRIPTION("RDS: IB transport");
293 MODULE_LICENSE("Dual BSD/GPL");
294