xref: /openbmc/linux/net/rds/rdma_transport.c (revision 89e33ea7)
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 	int *err;
55 	u8 len;
56 
57 	rdsdebug("conn %p id %p handling event %u (%s)\n", conn, cm_id,
58 		 event->event, rdma_event_msg(event->event));
59 
60 	if (cm_id->device->node_type == RDMA_NODE_IB_CA)
61 		trans = &rds_ib_transport;
62 
63 	/* Prevent shutdown from tearing down the connection
64 	 * while we're executing. */
65 	if (conn) {
66 		mutex_lock(&conn->c_cm_lock);
67 
68 		/* If the connection is being shut down, bail out
69 		 * right away. We return 0 so cm_id doesn't get
70 		 * destroyed prematurely */
71 		if (rds_conn_state(conn) == RDS_CONN_DISCONNECTING) {
72 			/* Reject incoming connections while we're tearing
73 			 * down an existing one. */
74 			if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
75 				ret = 1;
76 			goto out;
77 		}
78 	}
79 
80 	switch (event->event) {
81 	case RDMA_CM_EVENT_CONNECT_REQUEST:
82 		ret = trans->cm_handle_connect(cm_id, event, isv6);
83 		break;
84 
85 	case RDMA_CM_EVENT_ADDR_RESOLVED:
86 		rdma_set_service_type(cm_id, conn->c_tos);
87 		/* XXX do we need to clean up if this fails? */
88 		ret = rdma_resolve_route(cm_id,
89 					 RDS_RDMA_RESOLVE_TIMEOUT_MS);
90 		break;
91 
92 	case RDMA_CM_EVENT_ROUTE_RESOLVED:
93 		/* Connection could have been dropped so make sure the
94 		 * cm_id is valid before proceeding
95 		 */
96 		if (conn) {
97 			struct rds_ib_connection *ibic;
98 
99 			ibic = conn->c_transport_data;
100 			if (ibic && ibic->i_cm_id == cm_id)
101 				ret = trans->cm_initiate_connect(cm_id, isv6);
102 			else
103 				rds_conn_drop(conn);
104 		}
105 		break;
106 
107 	case RDMA_CM_EVENT_ESTABLISHED:
108 		trans->cm_connect_complete(conn, event);
109 		break;
110 
111 	case RDMA_CM_EVENT_REJECTED:
112 		if (!conn)
113 			break;
114 		err = (int *)rdma_consumer_reject_data(cm_id, event, &len);
115 		if (!err || (err && ((*err) == RDS_RDMA_REJ_INCOMPAT))) {
116 			pr_warn("RDS/RDMA: conn <%pI6c, %pI6c> rejected, dropping connection\n",
117 				&conn->c_laddr, &conn->c_faddr);
118 			conn->c_proposed_version = RDS_PROTOCOL_COMPAT_VERSION;
119 			conn->c_tos = 0;
120 			rds_conn_drop(conn);
121 		}
122 		rdsdebug("Connection rejected: %s\n",
123 			 rdma_reject_msg(cm_id, event->status));
124 		break;
125 		/* FALLTHROUGH */
126 	case RDMA_CM_EVENT_ADDR_ERROR:
127 	case RDMA_CM_EVENT_ROUTE_ERROR:
128 	case RDMA_CM_EVENT_CONNECT_ERROR:
129 	case RDMA_CM_EVENT_UNREACHABLE:
130 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
131 	case RDMA_CM_EVENT_ADDR_CHANGE:
132 		if (conn)
133 			rds_conn_drop(conn);
134 		break;
135 
136 	case RDMA_CM_EVENT_DISCONNECTED:
137 		rdsdebug("DISCONNECT event - dropping connection "
138 			 "%pI6c->%pI6c\n", &conn->c_laddr,
139 			 &conn->c_faddr);
140 		rds_conn_drop(conn);
141 		break;
142 
143 	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
144 		if (conn) {
145 			pr_info("RDS: RDMA_CM_EVENT_TIMEWAIT_EXIT event: dropping connection %pI6c->%pI6c\n",
146 				&conn->c_laddr, &conn->c_faddr);
147 			rds_conn_drop(conn);
148 		}
149 		break;
150 
151 	default:
152 		/* things like device disconnect? */
153 		printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
154 		       event->event, rdma_event_msg(event->event));
155 		break;
156 	}
157 
158 out:
159 	if (conn)
160 		mutex_unlock(&conn->c_cm_lock);
161 
162 	rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
163 		 rdma_event_msg(event->event), ret);
164 
165 	return ret;
166 }
167 
168 int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
169 			      struct rdma_cm_event *event)
170 {
171 	return rds_rdma_cm_event_handler_cmn(cm_id, event, false);
172 }
173 
174 #if IS_ENABLED(CONFIG_IPV6)
175 int rds6_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
176 			       struct rdma_cm_event *event)
177 {
178 	return rds_rdma_cm_event_handler_cmn(cm_id, event, true);
179 }
180 #endif
181 
182 static int rds_rdma_listen_init_common(rdma_cm_event_handler handler,
183 				       struct sockaddr *sa,
184 				       struct rdma_cm_id **ret_cm_id)
185 {
186 	struct rdma_cm_id *cm_id;
187 	int ret;
188 
189 	cm_id = rdma_create_id(&init_net, handler, NULL,
190 			       RDMA_PS_TCP, IB_QPT_RC);
191 	if (IS_ERR(cm_id)) {
192 		ret = PTR_ERR(cm_id);
193 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
194 		       "rdma_create_id() returned %d\n", ret);
195 		return ret;
196 	}
197 
198 	/*
199 	 * XXX I bet this binds the cm_id to a device.  If we want to support
200 	 * fail-over we'll have to take this into consideration.
201 	 */
202 	ret = rdma_bind_addr(cm_id, sa);
203 	if (ret) {
204 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
205 		       "rdma_bind_addr() returned %d\n", ret);
206 		goto out;
207 	}
208 
209 	ret = rdma_listen(cm_id, 128);
210 	if (ret) {
211 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
212 		       "rdma_listen() returned %d\n", ret);
213 		goto out;
214 	}
215 
216 	rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
217 
218 	*ret_cm_id = cm_id;
219 	cm_id = NULL;
220 out:
221 	if (cm_id)
222 		rdma_destroy_id(cm_id);
223 	return ret;
224 }
225 
226 /* Initialize the RDS RDMA listeners.  We create two listeners for
227  * compatibility reason.  The one on RDS_PORT is used for IPv4
228  * requests only.  The one on RDS_CM_PORT is used for IPv6 requests
229  * only.  So only IPv6 enabled RDS module will communicate using this
230  * port.
231  */
232 static int rds_rdma_listen_init(void)
233 {
234 	int ret;
235 #if IS_ENABLED(CONFIG_IPV6)
236 	struct sockaddr_in6 sin6;
237 #endif
238 	struct sockaddr_in sin;
239 
240 	sin.sin_family = PF_INET;
241 	sin.sin_addr.s_addr = htonl(INADDR_ANY);
242 	sin.sin_port = htons(RDS_PORT);
243 	ret = rds_rdma_listen_init_common(rds_rdma_cm_event_handler,
244 					  (struct sockaddr *)&sin,
245 					  &rds_rdma_listen_id);
246 	if (ret != 0)
247 		return ret;
248 
249 #if IS_ENABLED(CONFIG_IPV6)
250 	sin6.sin6_family = PF_INET6;
251 	sin6.sin6_addr = in6addr_any;
252 	sin6.sin6_port = htons(RDS_CM_PORT);
253 	sin6.sin6_scope_id = 0;
254 	sin6.sin6_flowinfo = 0;
255 	ret = rds_rdma_listen_init_common(rds6_rdma_cm_event_handler,
256 					  (struct sockaddr *)&sin6,
257 					  &rds6_rdma_listen_id);
258 	/* Keep going even when IPv6 is not enabled in the system. */
259 	if (ret != 0)
260 		rdsdebug("Cannot set up IPv6 RDMA listener\n");
261 #endif
262 	return 0;
263 }
264 
265 static void rds_rdma_listen_stop(void)
266 {
267 	if (rds_rdma_listen_id) {
268 		rdsdebug("cm %p\n", rds_rdma_listen_id);
269 		rdma_destroy_id(rds_rdma_listen_id);
270 		rds_rdma_listen_id = NULL;
271 	}
272 #if IS_ENABLED(CONFIG_IPV6)
273 	if (rds6_rdma_listen_id) {
274 		rdsdebug("cm %p\n", rds6_rdma_listen_id);
275 		rdma_destroy_id(rds6_rdma_listen_id);
276 		rds6_rdma_listen_id = NULL;
277 	}
278 #endif
279 }
280 
281 static int rds_rdma_init(void)
282 {
283 	int ret;
284 
285 	ret = rds_ib_init();
286 	if (ret)
287 		goto out;
288 
289 	ret = rds_rdma_listen_init();
290 	if (ret)
291 		rds_ib_exit();
292 out:
293 	return ret;
294 }
295 module_init(rds_rdma_init);
296 
297 static void rds_rdma_exit(void)
298 {
299 	/* stop listening first to ensure no new connections are attempted */
300 	rds_rdma_listen_stop();
301 	rds_ib_exit();
302 }
303 module_exit(rds_rdma_exit);
304 
305 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
306 MODULE_DESCRIPTION("RDS: IB transport");
307 MODULE_LICENSE("Dual BSD/GPL");
308