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 */
41static struct rdma_cm_id *rds_rdma_listen_id;
42#if IS_ENABLED(CONFIG_IPV6)
43static 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
49static 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			/* XXX do we need to clean up if this fails? */
92			ret = rdma_resolve_route(cm_id,
93					 RDS_RDMA_RESOLVE_TIMEOUT_MS);
94		}
95		break;
96
97	case RDMA_CM_EVENT_ROUTE_RESOLVED:
98		/* Connection could have been dropped so make sure the
99		 * cm_id is valid before proceeding
100		 */
101		if (conn) {
102			struct rds_ib_connection *ibic;
103
104			ibic = conn->c_transport_data;
105			if (ibic && ibic->i_cm_id == cm_id) {
106				cm_id->route.path_rec[0].sl =
107					TOS_TO_SL(conn->c_tos);
108				ret = trans->cm_initiate_connect(cm_id, isv6);
109			} else {
110				rds_conn_drop(conn);
111			}
112		}
113		break;
114
115	case RDMA_CM_EVENT_ESTABLISHED:
116		if (conn)
117			trans->cm_connect_complete(conn, event);
118		break;
119
120	case RDMA_CM_EVENT_REJECTED:
121		if (!conn)
122			break;
123		err = (int *)rdma_consumer_reject_data(cm_id, event, &len);
124		if (!err ||
125		    (err && len >= sizeof(*err) &&
126		     ((*err) <= RDS_RDMA_REJ_INCOMPAT))) {
127			pr_warn("RDS/RDMA: conn <%pI6c, %pI6c> rejected, dropping connection\n",
128				&conn->c_laddr, &conn->c_faddr);
129
130			if (!conn->c_tos)
131				conn->c_proposed_version = RDS_PROTOCOL_COMPAT_VERSION;
132
133			rds_conn_drop(conn);
134		}
135		rdsdebug("Connection rejected: %s\n",
136			 rdma_reject_msg(cm_id, event->status));
137		break;
138	case RDMA_CM_EVENT_ADDR_ERROR:
139	case RDMA_CM_EVENT_ROUTE_ERROR:
140	case RDMA_CM_EVENT_CONNECT_ERROR:
141	case RDMA_CM_EVENT_UNREACHABLE:
142	case RDMA_CM_EVENT_DEVICE_REMOVAL:
143	case RDMA_CM_EVENT_ADDR_CHANGE:
144		if (conn)
145			rds_conn_drop(conn);
146		break;
147
148	case RDMA_CM_EVENT_DISCONNECTED:
149		if (!conn)
150			break;
151		rdsdebug("DISCONNECT event - dropping connection "
152			 "%pI6c->%pI6c\n", &conn->c_laddr,
153			 &conn->c_faddr);
154		rds_conn_drop(conn);
155		break;
156
157	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
158		if (conn) {
159			pr_info("RDS: RDMA_CM_EVENT_TIMEWAIT_EXIT event: dropping connection %pI6c->%pI6c\n",
160				&conn->c_laddr, &conn->c_faddr);
161			rds_conn_drop(conn);
162		}
163		break;
164
165	default:
166		/* things like device disconnect? */
167		printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
168		       event->event, rdma_event_msg(event->event));
169		break;
170	}
171
172out:
173	if (conn)
174		mutex_unlock(&conn->c_cm_lock);
175
176	rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
177		 rdma_event_msg(event->event), ret);
178
179	return ret;
180}
181
182int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
183			      struct rdma_cm_event *event)
184{
185	return rds_rdma_cm_event_handler_cmn(cm_id, event, false);
186}
187
188#if IS_ENABLED(CONFIG_IPV6)
189int rds6_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
190			       struct rdma_cm_event *event)
191{
192	return rds_rdma_cm_event_handler_cmn(cm_id, event, true);
193}
194#endif
195
196static int rds_rdma_listen_init_common(rdma_cm_event_handler handler,
197				       struct sockaddr *sa,
198				       struct rdma_cm_id **ret_cm_id)
199{
200	struct rdma_cm_id *cm_id;
201	int ret;
202
203	cm_id = rdma_create_id(&init_net, handler, NULL,
204			       RDMA_PS_TCP, IB_QPT_RC);
205	if (IS_ERR(cm_id)) {
206		ret = PTR_ERR(cm_id);
207		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
208		       "rdma_create_id() returned %d\n", ret);
209		return ret;
210	}
211
212	/*
213	 * XXX I bet this binds the cm_id to a device.  If we want to support
214	 * fail-over we'll have to take this into consideration.
215	 */
216	ret = rdma_bind_addr(cm_id, sa);
217	if (ret) {
218		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
219		       "rdma_bind_addr() returned %d\n", ret);
220		goto out;
221	}
222
223	ret = rdma_listen(cm_id, 128);
224	if (ret) {
225		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
226		       "rdma_listen() returned %d\n", ret);
227		goto out;
228	}
229
230	rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
231
232	*ret_cm_id = cm_id;
233	cm_id = NULL;
234out:
235	if (cm_id)
236		rdma_destroy_id(cm_id);
237	return ret;
238}
239
240/* Initialize the RDS RDMA listeners.  We create two listeners for
241 * compatibility reason.  The one on RDS_PORT is used for IPv4
242 * requests only.  The one on RDS_CM_PORT is used for IPv6 requests
243 * only.  So only IPv6 enabled RDS module will communicate using this
244 * port.
245 */
246static int rds_rdma_listen_init(void)
247{
248	int ret;
249#if IS_ENABLED(CONFIG_IPV6)
250	struct sockaddr_in6 sin6;
251#endif
252	struct sockaddr_in sin;
253
254	sin.sin_family = PF_INET;
255	sin.sin_addr.s_addr = htonl(INADDR_ANY);
256	sin.sin_port = htons(RDS_PORT);
257	ret = rds_rdma_listen_init_common(rds_rdma_cm_event_handler,
258					  (struct sockaddr *)&sin,
259					  &rds_rdma_listen_id);
260	if (ret != 0)
261		return ret;
262
263#if IS_ENABLED(CONFIG_IPV6)
264	sin6.sin6_family = PF_INET6;
265	sin6.sin6_addr = in6addr_any;
266	sin6.sin6_port = htons(RDS_CM_PORT);
267	sin6.sin6_scope_id = 0;
268	sin6.sin6_flowinfo = 0;
269	ret = rds_rdma_listen_init_common(rds6_rdma_cm_event_handler,
270					  (struct sockaddr *)&sin6,
271					  &rds6_rdma_listen_id);
272	/* Keep going even when IPv6 is not enabled in the system. */
273	if (ret != 0)
274		rdsdebug("Cannot set up IPv6 RDMA listener\n");
275#endif
276	return 0;
277}
278
279static void rds_rdma_listen_stop(void)
280{
281	if (rds_rdma_listen_id) {
282		rdsdebug("cm %p\n", rds_rdma_listen_id);
283		rdma_destroy_id(rds_rdma_listen_id);
284		rds_rdma_listen_id = NULL;
285	}
286#if IS_ENABLED(CONFIG_IPV6)
287	if (rds6_rdma_listen_id) {
288		rdsdebug("cm %p\n", rds6_rdma_listen_id);
289		rdma_destroy_id(rds6_rdma_listen_id);
290		rds6_rdma_listen_id = NULL;
291	}
292#endif
293}
294
295static int rds_rdma_init(void)
296{
297	int ret;
298
299	ret = rds_ib_init();
300	if (ret)
301		goto out;
302
303	ret = rds_rdma_listen_init();
304	if (ret)
305		rds_ib_exit();
306out:
307	return ret;
308}
309module_init(rds_rdma_init);
310
311static void rds_rdma_exit(void)
312{
313	/* stop listening first to ensure no new connections are attempted */
314	rds_rdma_listen_stop();
315	rds_ib_exit();
316}
317module_exit(rds_rdma_exit);
318
319MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
320MODULE_DESCRIPTION("RDS: IB transport");
321MODULE_LICENSE("Dual BSD/GPL");
322