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			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
173out:
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
183int 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)
190int 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
197static 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;
235out:
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 */
247static 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
280static 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
296static 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();
307out:
308	return ret;
309}
310module_init(rds_rdma_init);
311
312static 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}
318module_exit(rds_rdma_exit);
319
320MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
321MODULE_DESCRIPTION("RDS: IB transport");
322MODULE_LICENSE("Dual BSD/GPL");
323