xref: /linux/net/rds/rdma_transport.c (revision 0ea5c948cb64bab5bc7a5516774eb8536f05aa0d)
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 /* Per IB specification 7.7.3, service level is a 4-bit field. */
47 #define TOS_TO_SL(tos)		((tos) & 0xF)
48 
rds_rdma_cm_event_handler_cmn(struct rdma_cm_id * cm_id,struct rdma_cm_event * event,bool isv6)49 static int rds_rdma_cm_event_handler_cmn(struct rdma_cm_id *cm_id,
50 					 struct rdma_cm_event *event,
51 					 bool isv6)
52 {
53 	/* this can be null in the listening path */
54 	struct rds_connection *conn = cm_id->context;
55 	struct rds_transport *trans;
56 	int ret = 0;
57 	int *err;
58 	u8 len;
59 
60 	rdsdebug("conn %p id %p handling event %u (%s)\n", conn, cm_id,
61 		 event->event, rdma_event_msg(event->event));
62 
63 	if (cm_id->device->node_type == RDMA_NODE_IB_CA)
64 		trans = &rds_ib_transport;
65 
66 	/* Prevent shutdown from tearing down the connection
67 	 * while we're executing. */
68 	if (conn) {
69 		mutex_lock(&conn->c_cm_lock);
70 
71 		/* If the connection is being shut down, bail out
72 		 * right away. We return 0 so cm_id doesn't get
73 		 * destroyed prematurely */
74 		if (rds_conn_state(conn) == RDS_CONN_DISCONNECTING) {
75 			/* Reject incoming connections while we're tearing
76 			 * down an existing one. */
77 			if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
78 				ret = 1;
79 			goto out;
80 		}
81 	}
82 
83 	switch (event->event) {
84 	case RDMA_CM_EVENT_CONNECT_REQUEST:
85 		ret = trans->cm_handle_connect(cm_id, event, isv6);
86 		break;
87 
88 	case RDMA_CM_EVENT_ADDR_RESOLVED:
89 		if (conn) {
90 			rdma_set_service_type(cm_id, conn->c_tos);
91 			rdma_set_min_rnr_timer(cm_id, IB_RNR_TIMER_000_32);
92 			/* XXX do we need to clean up if this fails? */
93 			ret = rdma_resolve_route(cm_id,
94 						 RDS_RDMA_RESOLVE_TIMEOUT_MS);
95 		}
96 		break;
97 
98 	case RDMA_CM_EVENT_ROUTE_RESOLVED:
99 		/* Connection could have been dropped so make sure the
100 		 * cm_id is valid before proceeding
101 		 */
102 		if (conn) {
103 			struct rds_ib_connection *ibic;
104 
105 			ibic = conn->c_transport_data;
106 			if (ibic && ibic->i_cm_id == cm_id) {
107 				cm_id->route.path_rec[0].sl =
108 					TOS_TO_SL(conn->c_tos);
109 				ret = trans->cm_initiate_connect(cm_id, isv6);
110 			} else {
111 				rds_conn_drop(conn);
112 			}
113 		}
114 		break;
115 
116 	case RDMA_CM_EVENT_ESTABLISHED:
117 		if (conn)
118 			trans->cm_connect_complete(conn, event);
119 		break;
120 
121 	case RDMA_CM_EVENT_REJECTED:
122 		if (!conn)
123 			break;
124 		err = (int *)rdma_consumer_reject_data(cm_id, event, &len);
125 		if (!err ||
126 		    (err && len >= sizeof(*err) &&
127 		     ((*err) <= RDS_RDMA_REJ_INCOMPAT))) {
128 			pr_warn("RDS/RDMA: conn <%pI6c, %pI6c> rejected, dropping connection\n",
129 				&conn->c_laddr, &conn->c_faddr);
130 
131 			if (!conn->c_tos)
132 				conn->c_proposed_version = RDS_PROTOCOL_COMPAT_VERSION;
133 
134 			rds_conn_drop(conn);
135 		}
136 		rdsdebug("Connection rejected: %s\n",
137 			 rdma_reject_msg(cm_id, event->status));
138 		break;
139 	case RDMA_CM_EVENT_ADDR_ERROR:
140 	case RDMA_CM_EVENT_ROUTE_ERROR:
141 	case RDMA_CM_EVENT_CONNECT_ERROR:
142 	case RDMA_CM_EVENT_UNREACHABLE:
143 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
144 	case RDMA_CM_EVENT_ADDR_CHANGE:
145 		if (conn)
146 			rds_conn_drop(conn);
147 		break;
148 
149 	case RDMA_CM_EVENT_DISCONNECTED:
150 		if (!conn)
151 			break;
152 		rdsdebug("DISCONNECT event - dropping connection "
153 			 "%pI6c->%pI6c\n", &conn->c_laddr,
154 			 &conn->c_faddr);
155 		rds_conn_drop(conn);
156 		break;
157 
158 	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
159 		if (conn) {
160 			pr_info("RDS: RDMA_CM_EVENT_TIMEWAIT_EXIT event: dropping connection %pI6c->%pI6c\n",
161 				&conn->c_laddr, &conn->c_faddr);
162 			rds_conn_drop(conn);
163 		}
164 		break;
165 
166 	default:
167 		/* things like device disconnect? */
168 		printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
169 		       event->event, rdma_event_msg(event->event));
170 		break;
171 	}
172 
173 out:
174 	if (conn)
175 		mutex_unlock(&conn->c_cm_lock);
176 
177 	rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
178 		 rdma_event_msg(event->event), ret);
179 
180 	return ret;
181 }
182 
rds_rdma_cm_event_handler(struct rdma_cm_id * cm_id,struct rdma_cm_event * event)183 int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
184 			      struct rdma_cm_event *event)
185 {
186 	return rds_rdma_cm_event_handler_cmn(cm_id, event, false);
187 }
188 
189 #if IS_ENABLED(CONFIG_IPV6)
rds6_rdma_cm_event_handler(struct rdma_cm_id * cm_id,struct rdma_cm_event * event)190 int rds6_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
191 			       struct rdma_cm_event *event)
192 {
193 	return rds_rdma_cm_event_handler_cmn(cm_id, event, true);
194 }
195 #endif
196 
rds_rdma_listen_init_common(rdma_cm_event_handler handler,struct sockaddr * sa,struct rdma_cm_id ** ret_cm_id)197 static int rds_rdma_listen_init_common(rdma_cm_event_handler handler,
198 				       struct sockaddr *sa,
199 				       struct rdma_cm_id **ret_cm_id)
200 {
201 	struct rdma_cm_id *cm_id;
202 	int ret;
203 
204 	cm_id = rdma_create_id(&init_net, handler, NULL,
205 			       RDMA_PS_TCP, IB_QPT_RC);
206 	if (IS_ERR(cm_id)) {
207 		ret = PTR_ERR(cm_id);
208 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
209 		       "rdma_create_id() returned %d\n", ret);
210 		return ret;
211 	}
212 
213 	/*
214 	 * XXX I bet this binds the cm_id to a device.  If we want to support
215 	 * fail-over we'll have to take this into consideration.
216 	 */
217 	ret = rdma_bind_addr(cm_id, sa);
218 	if (ret) {
219 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
220 		       "rdma_bind_addr() returned %d\n", ret);
221 		goto out;
222 	}
223 
224 	ret = rdma_listen(cm_id, 128);
225 	if (ret) {
226 		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
227 		       "rdma_listen() returned %d\n", ret);
228 		goto out;
229 	}
230 
231 	rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
232 
233 	*ret_cm_id = cm_id;
234 	cm_id = NULL;
235 out:
236 	if (cm_id)
237 		rdma_destroy_id(cm_id);
238 	return ret;
239 }
240 
241 /* Initialize the RDS RDMA listeners.  We create two listeners for
242  * compatibility reason.  The one on RDS_PORT is used for IPv4
243  * requests only.  The one on RDS_CM_PORT is used for IPv6 requests
244  * only.  So only IPv6 enabled RDS module will communicate using this
245  * port.
246  */
rds_rdma_listen_init(void)247 static int rds_rdma_listen_init(void)
248 {
249 	int ret;
250 #if IS_ENABLED(CONFIG_IPV6)
251 	struct sockaddr_in6 sin6;
252 #endif
253 	struct sockaddr_in sin;
254 
255 	sin.sin_family = PF_INET;
256 	sin.sin_addr.s_addr = htonl(INADDR_ANY);
257 	sin.sin_port = htons(RDS_PORT);
258 	ret = rds_rdma_listen_init_common(rds_rdma_cm_event_handler,
259 					  (struct sockaddr *)&sin,
260 					  &rds_rdma_listen_id);
261 	if (ret != 0)
262 		return ret;
263 
264 #if IS_ENABLED(CONFIG_IPV6)
265 	sin6.sin6_family = PF_INET6;
266 	sin6.sin6_addr = in6addr_any;
267 	sin6.sin6_port = htons(RDS_CM_PORT);
268 	sin6.sin6_scope_id = 0;
269 	sin6.sin6_flowinfo = 0;
270 	ret = rds_rdma_listen_init_common(rds6_rdma_cm_event_handler,
271 					  (struct sockaddr *)&sin6,
272 					  &rds6_rdma_listen_id);
273 	/* Keep going even when IPv6 is not enabled in the system. */
274 	if (ret != 0)
275 		rdsdebug("Cannot set up IPv6 RDMA listener\n");
276 #endif
277 	return 0;
278 }
279 
rds_rdma_listen_stop(void)280 static void rds_rdma_listen_stop(void)
281 {
282 	if (rds_rdma_listen_id) {
283 		rdsdebug("cm %p\n", rds_rdma_listen_id);
284 		rdma_destroy_id(rds_rdma_listen_id);
285 		rds_rdma_listen_id = NULL;
286 	}
287 #if IS_ENABLED(CONFIG_IPV6)
288 	if (rds6_rdma_listen_id) {
289 		rdsdebug("cm %p\n", rds6_rdma_listen_id);
290 		rdma_destroy_id(rds6_rdma_listen_id);
291 		rds6_rdma_listen_id = NULL;
292 	}
293 #endif
294 }
295 
rds_rdma_init(void)296 static int __init rds_rdma_init(void)
297 {
298 	int ret;
299 
300 	ret = rds_ib_init();
301 	if (ret)
302 		goto out;
303 
304 	ret = rds_rdma_listen_init();
305 	if (ret)
306 		rds_ib_exit();
307 out:
308 	return ret;
309 }
310 module_init(rds_rdma_init);
311 
rds_rdma_exit(void)312 static void __exit rds_rdma_exit(void)
313 {
314 	/* stop listening first to ensure no new connections are attempted */
315 	rds_rdma_listen_stop();
316 	rds_ib_exit();
317 }
318 module_exit(rds_rdma_exit);
319 
320 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
321 MODULE_DESCRIPTION("RDS: IB transport");
322 MODULE_LICENSE("Dual BSD/GPL");
323