blob: ff9163dc159614fe76ca7c476ff80b64de9c4e54 [file] [log] [blame]
Tom Tucker922a8e92006-08-03 16:02:40 -05001/*
2 * Copyright (c) 2004, 2005 Intel Corporation. All rights reserved.
3 * Copyright (c) 2004 Topspin Corporation. All rights reserved.
4 * Copyright (c) 2004, 2005 Voltaire Corporation. All rights reserved.
5 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
6 * Copyright (c) 2005 Open Grid Computing, Inc. All rights reserved.
7 * Copyright (c) 2005 Network Appliance, Inc. All rights reserved.
8 *
9 * This software is available to you under a choice of one of two
10 * licenses. You may choose to be licensed under the terms of the GNU
11 * General Public License (GPL) Version 2, available from the file
12 * COPYING in the main directory of this source tree, or the
13 * OpenIB.org BSD license below:
14 *
15 * Redistribution and use in source and binary forms, with or
16 * without modification, are permitted provided that the following
17 * conditions are met:
18 *
19 * - Redistributions of source code must retain the above
20 * copyright notice, this list of conditions and the following
21 * disclaimer.
22 *
23 * - Redistributions in binary form must reproduce the above
24 * copyright notice, this list of conditions and the following
25 * disclaimer in the documentation and/or other materials
26 * provided with the distribution.
27 *
28 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
29 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
30 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
31 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
32 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
33 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
34 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
35 * SOFTWARE.
36 *
37 */
38#include <linux/dma-mapping.h>
39#include <linux/err.h>
40#include <linux/idr.h>
41#include <linux/interrupt.h>
Tom Tucker922a8e92006-08-03 16:02:40 -050042#include <linux/rbtree.h>
Alexey Dobriyand43c36d2009-10-07 17:09:06 +040043#include <linux/sched.h>
Tom Tucker922a8e92006-08-03 16:02:40 -050044#include <linux/spinlock.h>
45#include <linux/workqueue.h>
46#include <linux/completion.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090047#include <linux/slab.h>
Paul Gortmakere4dd23d2011-05-27 15:35:46 -040048#include <linux/module.h>
Steve Wise2f0304d2014-07-25 09:11:33 -050049#include <linux/sysctl.h>
Tom Tucker922a8e92006-08-03 16:02:40 -050050
51#include <rdma/iw_cm.h>
52#include <rdma/ib_addr.h>
53
54#include "iwcm.h"
55
56MODULE_AUTHOR("Tom Tucker");
57MODULE_DESCRIPTION("iWARP CM");
58MODULE_LICENSE("Dual BSD/GPL");
59
60static struct workqueue_struct *iwcm_wq;
61struct iwcm_work {
62 struct work_struct work;
63 struct iwcm_id_private *cm_id;
64 struct list_head list;
65 struct iw_cm_event event;
66 struct list_head free_list;
67};
68
Steve Wise2f0304d2014-07-25 09:11:33 -050069static unsigned int default_backlog = 256;
70
71static struct ctl_table_header *iwcm_ctl_table_hdr;
72static struct ctl_table iwcm_ctl_table[] = {
73 {
74 .procname = "default_backlog",
75 .data = &default_backlog,
76 .maxlen = sizeof(default_backlog),
77 .mode = 0644,
78 .proc_handler = proc_dointvec,
79 },
80 { }
81};
82
Tom Tucker922a8e92006-08-03 16:02:40 -050083/*
84 * The following services provide a mechanism for pre-allocating iwcm_work
85 * elements. The design pre-allocates them based on the cm_id type:
86 * LISTENING IDS: Get enough elements preallocated to handle the
87 * listen backlog.
88 * ACTIVE IDS: 4: CONNECT_REPLY, ESTABLISHED, DISCONNECT, CLOSE
89 * PASSIVE IDS: 3: ESTABLISHED, DISCONNECT, CLOSE
90 *
91 * Allocating them in connect and listen avoids having to deal
92 * with allocation failures on the event upcall from the provider (which
93 * is called in the interrupt context).
94 *
95 * One exception is when creating the cm_id for incoming connection requests.
96 * There are two cases:
97 * 1) in the event upcall, cm_event_handler(), for a listening cm_id. If
98 * the backlog is exceeded, then no more connection request events will
99 * be processed. cm_event_handler() returns -ENOMEM in this case. Its up
Krishna Kumar715a5882006-11-09 09:30:45 +0530100 * to the provider to reject the connection request.
Tom Tucker922a8e92006-08-03 16:02:40 -0500101 * 2) in the connection request workqueue handler, cm_conn_req_handler().
102 * If work elements cannot be allocated for the new connect request cm_id,
103 * then IWCM will call the provider reject method. This is ok since
104 * cm_conn_req_handler() runs in the workqueue thread context.
105 */
106
107static struct iwcm_work *get_work(struct iwcm_id_private *cm_id_priv)
108{
109 struct iwcm_work *work;
110
111 if (list_empty(&cm_id_priv->work_free_list))
112 return NULL;
113 work = list_entry(cm_id_priv->work_free_list.next, struct iwcm_work,
114 free_list);
115 list_del_init(&work->free_list);
116 return work;
117}
118
119static void put_work(struct iwcm_work *work)
120{
121 list_add(&work->free_list, &work->cm_id->work_free_list);
122}
123
124static void dealloc_work_entries(struct iwcm_id_private *cm_id_priv)
125{
126 struct list_head *e, *tmp;
127
128 list_for_each_safe(e, tmp, &cm_id_priv->work_free_list)
129 kfree(list_entry(e, struct iwcm_work, free_list));
130}
131
132static int alloc_work_entries(struct iwcm_id_private *cm_id_priv, int count)
133{
134 struct iwcm_work *work;
135
136 BUG_ON(!list_empty(&cm_id_priv->work_free_list));
137 while (count--) {
138 work = kmalloc(sizeof(struct iwcm_work), GFP_KERNEL);
139 if (!work) {
140 dealloc_work_entries(cm_id_priv);
141 return -ENOMEM;
142 }
143 work->cm_id = cm_id_priv;
144 INIT_LIST_HEAD(&work->list);
145 put_work(work);
146 }
147 return 0;
148}
149
150/*
Krishna Kumar715a5882006-11-09 09:30:45 +0530151 * Save private data from incoming connection requests to
152 * iw_cm_event, so the low level driver doesn't have to. Adjust
Tom Tucker922a8e92006-08-03 16:02:40 -0500153 * the event ptr to point to the local copy.
154 */
Krishna Kumar715a5882006-11-09 09:30:45 +0530155static int copy_private_data(struct iw_cm_event *event)
Tom Tucker922a8e92006-08-03 16:02:40 -0500156{
157 void *p;
158
Eric Sesterhennbed8bdf2006-10-23 22:17:21 +0200159 p = kmemdup(event->private_data, event->private_data_len, GFP_ATOMIC);
Tom Tucker922a8e92006-08-03 16:02:40 -0500160 if (!p)
161 return -ENOMEM;
Tom Tucker922a8e92006-08-03 16:02:40 -0500162 event->private_data = p;
163 return 0;
164}
165
Steve Wiseebb90982007-02-15 08:09:36 -0600166static void free_cm_id(struct iwcm_id_private *cm_id_priv)
167{
168 dealloc_work_entries(cm_id_priv);
169 kfree(cm_id_priv);
170}
171
Tom Tucker922a8e92006-08-03 16:02:40 -0500172/*
Krishna Kumar9ab1ffa2006-11-09 09:30:48 +0530173 * Release a reference on cm_id. If the last reference is being
174 * released, enable the waiting thread (in iw_destroy_cm_id) to
175 * get woken up, and return 1 if a thread is already waiting.
Tom Tucker922a8e92006-08-03 16:02:40 -0500176 */
177static int iwcm_deref_id(struct iwcm_id_private *cm_id_priv)
178{
Tom Tucker922a8e92006-08-03 16:02:40 -0500179 BUG_ON(atomic_read(&cm_id_priv->refcount)==0);
180 if (atomic_dec_and_test(&cm_id_priv->refcount)) {
181 BUG_ON(!list_empty(&cm_id_priv->work_list));
Tom Tucker922a8e92006-08-03 16:02:40 -0500182 complete(&cm_id_priv->destroy_comp);
Steve Wiseebb90982007-02-15 08:09:36 -0600183 return 1;
Tom Tucker922a8e92006-08-03 16:02:40 -0500184 }
185
Steve Wiseebb90982007-02-15 08:09:36 -0600186 return 0;
Tom Tucker922a8e92006-08-03 16:02:40 -0500187}
188
189static void add_ref(struct iw_cm_id *cm_id)
190{
191 struct iwcm_id_private *cm_id_priv;
192 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
193 atomic_inc(&cm_id_priv->refcount);
194}
195
196static void rem_ref(struct iw_cm_id *cm_id)
197{
198 struct iwcm_id_private *cm_id_priv;
Steve Wise6b59ba62013-11-21 15:40:14 -0600199 int cb_destroy;
200
Tom Tucker922a8e92006-08-03 16:02:40 -0500201 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
Steve Wise6b59ba62013-11-21 15:40:14 -0600202
203 /*
204 * Test bit before deref in case the cm_id gets freed on another
205 * thread.
206 */
207 cb_destroy = test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
208 if (iwcm_deref_id(cm_id_priv) && cb_destroy) {
Steve Wiseebb90982007-02-15 08:09:36 -0600209 BUG_ON(!list_empty(&cm_id_priv->work_list));
210 free_cm_id(cm_id_priv);
211 }
Tom Tucker922a8e92006-08-03 16:02:40 -0500212}
213
214static int cm_event_handler(struct iw_cm_id *cm_id, struct iw_cm_event *event);
215
216struct iw_cm_id *iw_create_cm_id(struct ib_device *device,
217 iw_cm_handler cm_handler,
218 void *context)
219{
220 struct iwcm_id_private *cm_id_priv;
221
222 cm_id_priv = kzalloc(sizeof(*cm_id_priv), GFP_KERNEL);
223 if (!cm_id_priv)
224 return ERR_PTR(-ENOMEM);
225
226 cm_id_priv->state = IW_CM_STATE_IDLE;
227 cm_id_priv->id.device = device;
228 cm_id_priv->id.cm_handler = cm_handler;
229 cm_id_priv->id.context = context;
230 cm_id_priv->id.event_handler = cm_event_handler;
231 cm_id_priv->id.add_ref = add_ref;
232 cm_id_priv->id.rem_ref = rem_ref;
233 spin_lock_init(&cm_id_priv->lock);
234 atomic_set(&cm_id_priv->refcount, 1);
235 init_waitqueue_head(&cm_id_priv->connect_wait);
236 init_completion(&cm_id_priv->destroy_comp);
237 INIT_LIST_HEAD(&cm_id_priv->work_list);
238 INIT_LIST_HEAD(&cm_id_priv->work_free_list);
239
240 return &cm_id_priv->id;
241}
242EXPORT_SYMBOL(iw_create_cm_id);
243
244
245static int iwcm_modify_qp_err(struct ib_qp *qp)
246{
247 struct ib_qp_attr qp_attr;
248
249 if (!qp)
250 return -EINVAL;
251
252 qp_attr.qp_state = IB_QPS_ERR;
253 return ib_modify_qp(qp, &qp_attr, IB_QP_STATE);
254}
255
256/*
257 * This is really the RDMAC CLOSING state. It is most similar to the
258 * IB SQD QP state.
259 */
260static int iwcm_modify_qp_sqd(struct ib_qp *qp)
261{
262 struct ib_qp_attr qp_attr;
263
264 BUG_ON(qp == NULL);
265 qp_attr.qp_state = IB_QPS_SQD;
266 return ib_modify_qp(qp, &qp_attr, IB_QP_STATE);
267}
268
269/*
270 * CM_ID <-- CLOSING
271 *
Krishna Kumar715a5882006-11-09 09:30:45 +0530272 * Block if a passive or active connection is currently being processed. Then
Tom Tucker922a8e92006-08-03 16:02:40 -0500273 * process the event as follows:
274 * - If we are ESTABLISHED, move to CLOSING and modify the QP state
275 * based on the abrupt flag
276 * - If the connection is already in the CLOSING or IDLE state, the peer is
277 * disconnecting concurrently with us and we've already seen the
278 * DISCONNECT event -- ignore the request and return 0
279 * - Disconnect on a listening endpoint returns -EINVAL
280 */
281int iw_cm_disconnect(struct iw_cm_id *cm_id, int abrupt)
282{
283 struct iwcm_id_private *cm_id_priv;
284 unsigned long flags;
285 int ret = 0;
286 struct ib_qp *qp = NULL;
287
288 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
289 /* Wait if we're currently in a connect or accept downcall */
290 wait_event(cm_id_priv->connect_wait,
291 !test_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags));
292
293 spin_lock_irqsave(&cm_id_priv->lock, flags);
294 switch (cm_id_priv->state) {
295 case IW_CM_STATE_ESTABLISHED:
296 cm_id_priv->state = IW_CM_STATE_CLOSING;
297
298 /* QP could be <nul> for user-mode client */
299 if (cm_id_priv->qp)
300 qp = cm_id_priv->qp;
301 else
302 ret = -EINVAL;
303 break;
304 case IW_CM_STATE_LISTEN:
305 ret = -EINVAL;
306 break;
307 case IW_CM_STATE_CLOSING:
308 /* remote peer closed first */
309 case IW_CM_STATE_IDLE:
310 /* accept or connect returned !0 */
311 break;
312 case IW_CM_STATE_CONN_RECV:
313 /*
314 * App called disconnect before/without calling accept after
315 * connect_request event delivered.
316 */
317 break;
318 case IW_CM_STATE_CONN_SENT:
319 /* Can only get here if wait above fails */
320 default:
321 BUG();
322 }
323 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
324
325 if (qp) {
326 if (abrupt)
327 ret = iwcm_modify_qp_err(qp);
328 else
329 ret = iwcm_modify_qp_sqd(qp);
330
331 /*
332 * If both sides are disconnecting the QP could
333 * already be in ERR or SQD states
334 */
335 ret = 0;
336 }
337
338 return ret;
339}
340EXPORT_SYMBOL(iw_cm_disconnect);
341
342/*
343 * CM_ID <-- DESTROYING
344 *
345 * Clean up all resources associated with the connection and release
346 * the initial reference taken by iw_create_cm_id.
347 */
348static void destroy_cm_id(struct iw_cm_id *cm_id)
349{
350 struct iwcm_id_private *cm_id_priv;
351 unsigned long flags;
Tom Tucker922a8e92006-08-03 16:02:40 -0500352
353 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
354 /*
355 * Wait if we're currently in a connect or accept downcall. A
356 * listening endpoint should never block here.
357 */
358 wait_event(cm_id_priv->connect_wait,
359 !test_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags));
360
361 spin_lock_irqsave(&cm_id_priv->lock, flags);
362 switch (cm_id_priv->state) {
363 case IW_CM_STATE_LISTEN:
364 cm_id_priv->state = IW_CM_STATE_DESTROYING;
365 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
366 /* destroy the listening endpoint */
Or Gerlitz05633102013-11-03 10:20:43 +0200367 cm_id->device->iwcm->destroy_listen(cm_id);
Tom Tucker922a8e92006-08-03 16:02:40 -0500368 spin_lock_irqsave(&cm_id_priv->lock, flags);
369 break;
370 case IW_CM_STATE_ESTABLISHED:
371 cm_id_priv->state = IW_CM_STATE_DESTROYING;
372 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
373 /* Abrupt close of the connection */
374 (void)iwcm_modify_qp_err(cm_id_priv->qp);
375 spin_lock_irqsave(&cm_id_priv->lock, flags);
376 break;
377 case IW_CM_STATE_IDLE:
378 case IW_CM_STATE_CLOSING:
379 cm_id_priv->state = IW_CM_STATE_DESTROYING;
380 break;
381 case IW_CM_STATE_CONN_RECV:
382 /*
383 * App called destroy before/without calling accept after
Steve Wiseebb90982007-02-15 08:09:36 -0600384 * receiving connection request event notification or
385 * returned non zero from the event callback function.
386 * In either case, must tell the provider to reject.
Tom Tucker922a8e92006-08-03 16:02:40 -0500387 */
388 cm_id_priv->state = IW_CM_STATE_DESTROYING;
Steve Wise54e05f12009-10-07 15:38:12 -0700389 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
Steve Wisecb581602009-09-09 11:37:38 -0700390 cm_id->device->iwcm->reject(cm_id, NULL, 0);
Steve Wise54e05f12009-10-07 15:38:12 -0700391 spin_lock_irqsave(&cm_id_priv->lock, flags);
Tom Tucker922a8e92006-08-03 16:02:40 -0500392 break;
393 case IW_CM_STATE_CONN_SENT:
394 case IW_CM_STATE_DESTROYING:
395 default:
396 BUG();
397 break;
398 }
399 if (cm_id_priv->qp) {
400 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
401 cm_id_priv->qp = NULL;
402 }
403 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
404
405 (void)iwcm_deref_id(cm_id_priv);
406}
407
408/*
409 * This function is only called by the application thread and cannot
410 * be called by the event thread. The function will wait for all
411 * references to be released on the cm_id and then kfree the cm_id
412 * object.
413 */
414void iw_destroy_cm_id(struct iw_cm_id *cm_id)
415{
416 struct iwcm_id_private *cm_id_priv;
417
418 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
419 BUG_ON(test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags));
420
421 destroy_cm_id(cm_id);
422
423 wait_for_completion(&cm_id_priv->destroy_comp);
424
Steve Wiseebb90982007-02-15 08:09:36 -0600425 free_cm_id(cm_id_priv);
Tom Tucker922a8e92006-08-03 16:02:40 -0500426}
427EXPORT_SYMBOL(iw_destroy_cm_id);
428
429/*
430 * CM_ID <-- LISTEN
431 *
432 * Start listening for connect requests. Generates one CONNECT_REQUEST
433 * event for each inbound connect request.
434 */
435int iw_cm_listen(struct iw_cm_id *cm_id, int backlog)
436{
437 struct iwcm_id_private *cm_id_priv;
438 unsigned long flags;
Krishna Kumar13fccdb2006-11-09 09:30:43 +0530439 int ret;
Tom Tucker922a8e92006-08-03 16:02:40 -0500440
441 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
442
Steve Wise2f0304d2014-07-25 09:11:33 -0500443 if (!backlog)
444 backlog = default_backlog;
445
Tom Tucker922a8e92006-08-03 16:02:40 -0500446 ret = alloc_work_entries(cm_id_priv, backlog);
447 if (ret)
448 return ret;
449
450 spin_lock_irqsave(&cm_id_priv->lock, flags);
451 switch (cm_id_priv->state) {
452 case IW_CM_STATE_IDLE:
453 cm_id_priv->state = IW_CM_STATE_LISTEN;
454 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
455 ret = cm_id->device->iwcm->create_listen(cm_id, backlog);
456 if (ret)
457 cm_id_priv->state = IW_CM_STATE_IDLE;
458 spin_lock_irqsave(&cm_id_priv->lock, flags);
459 break;
460 default:
461 ret = -EINVAL;
462 }
463 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
464
465 return ret;
466}
467EXPORT_SYMBOL(iw_cm_listen);
468
469/*
470 * CM_ID <-- IDLE
471 *
472 * Rejects an inbound connection request. No events are generated.
473 */
474int iw_cm_reject(struct iw_cm_id *cm_id,
475 const void *private_data,
476 u8 private_data_len)
477{
478 struct iwcm_id_private *cm_id_priv;
479 unsigned long flags;
480 int ret;
481
482 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
483 set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
484
485 spin_lock_irqsave(&cm_id_priv->lock, flags);
486 if (cm_id_priv->state != IW_CM_STATE_CONN_RECV) {
487 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
488 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
489 wake_up_all(&cm_id_priv->connect_wait);
490 return -EINVAL;
491 }
492 cm_id_priv->state = IW_CM_STATE_IDLE;
493 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
494
495 ret = cm_id->device->iwcm->reject(cm_id, private_data,
496 private_data_len);
497
498 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
499 wake_up_all(&cm_id_priv->connect_wait);
500
501 return ret;
502}
503EXPORT_SYMBOL(iw_cm_reject);
504
505/*
506 * CM_ID <-- ESTABLISHED
507 *
508 * Accepts an inbound connection request and generates an ESTABLISHED
509 * event. Callers of iw_cm_disconnect and iw_destroy_cm_id will block
510 * until the ESTABLISHED event is received from the provider.
511 */
512int iw_cm_accept(struct iw_cm_id *cm_id,
513 struct iw_cm_conn_param *iw_param)
514{
515 struct iwcm_id_private *cm_id_priv;
516 struct ib_qp *qp;
517 unsigned long flags;
518 int ret;
519
520 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
521 set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
522
523 spin_lock_irqsave(&cm_id_priv->lock, flags);
524 if (cm_id_priv->state != IW_CM_STATE_CONN_RECV) {
525 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
526 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
527 wake_up_all(&cm_id_priv->connect_wait);
528 return -EINVAL;
529 }
530 /* Get the ib_qp given the QPN */
531 qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn);
532 if (!qp) {
533 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
Animesh K Trivedi26012f02010-09-28 14:44:02 +0000534 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
535 wake_up_all(&cm_id_priv->connect_wait);
Tom Tucker922a8e92006-08-03 16:02:40 -0500536 return -EINVAL;
537 }
538 cm_id->device->iwcm->add_ref(qp);
539 cm_id_priv->qp = qp;
540 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
541
542 ret = cm_id->device->iwcm->accept(cm_id, iw_param);
543 if (ret) {
544 /* An error on accept precludes provider events */
545 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_RECV);
546 cm_id_priv->state = IW_CM_STATE_IDLE;
547 spin_lock_irqsave(&cm_id_priv->lock, flags);
548 if (cm_id_priv->qp) {
549 cm_id->device->iwcm->rem_ref(qp);
550 cm_id_priv->qp = NULL;
551 }
552 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
553 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
554 wake_up_all(&cm_id_priv->connect_wait);
555 }
556
557 return ret;
558}
559EXPORT_SYMBOL(iw_cm_accept);
560
561/*
562 * Active Side: CM_ID <-- CONN_SENT
563 *
564 * If successful, results in the generation of a CONNECT_REPLY
565 * event. iw_cm_disconnect and iw_cm_destroy will block until the
566 * CONNECT_REPLY event is received from the provider.
567 */
568int iw_cm_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *iw_param)
569{
570 struct iwcm_id_private *cm_id_priv;
Krishna Kumar13fccdb2006-11-09 09:30:43 +0530571 int ret;
Tom Tucker922a8e92006-08-03 16:02:40 -0500572 unsigned long flags;
573 struct ib_qp *qp;
574
575 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
576
577 ret = alloc_work_entries(cm_id_priv, 4);
578 if (ret)
579 return ret;
580
581 set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
582 spin_lock_irqsave(&cm_id_priv->lock, flags);
583
584 if (cm_id_priv->state != IW_CM_STATE_IDLE) {
585 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
586 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
587 wake_up_all(&cm_id_priv->connect_wait);
588 return -EINVAL;
589 }
590
591 /* Get the ib_qp given the QPN */
592 qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn);
593 if (!qp) {
594 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
Animesh K Trivedi26012f02010-09-28 14:44:02 +0000595 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
596 wake_up_all(&cm_id_priv->connect_wait);
Tom Tucker922a8e92006-08-03 16:02:40 -0500597 return -EINVAL;
598 }
599 cm_id->device->iwcm->add_ref(qp);
600 cm_id_priv->qp = qp;
601 cm_id_priv->state = IW_CM_STATE_CONN_SENT;
602 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
603
604 ret = cm_id->device->iwcm->connect(cm_id, iw_param);
605 if (ret) {
606 spin_lock_irqsave(&cm_id_priv->lock, flags);
607 if (cm_id_priv->qp) {
608 cm_id->device->iwcm->rem_ref(qp);
609 cm_id_priv->qp = NULL;
610 }
611 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
612 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_SENT);
613 cm_id_priv->state = IW_CM_STATE_IDLE;
614 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
615 wake_up_all(&cm_id_priv->connect_wait);
616 }
617
618 return ret;
619}
620EXPORT_SYMBOL(iw_cm_connect);
621
622/*
623 * Passive Side: new CM_ID <-- CONN_RECV
624 *
625 * Handles an inbound connect request. The function creates a new
626 * iw_cm_id to represent the new connection and inherits the client
627 * callback function and other attributes from the listening parent.
628 *
629 * The work item contains a pointer to the listen_cm_id and the event. The
630 * listen_cm_id contains the client cm_handler, context and
631 * device. These are copied when the device is cloned. The event
632 * contains the new four tuple.
633 *
634 * An error on the child should not affect the parent, so this
635 * function does not return a value.
636 */
637static void cm_conn_req_handler(struct iwcm_id_private *listen_id_priv,
638 struct iw_cm_event *iw_event)
639{
640 unsigned long flags;
641 struct iw_cm_id *cm_id;
642 struct iwcm_id_private *cm_id_priv;
643 int ret;
644
645 /*
646 * The provider should never generate a connection request
647 * event with a bad status.
648 */
649 BUG_ON(iw_event->status);
650
Tom Tucker922a8e92006-08-03 16:02:40 -0500651 cm_id = iw_create_cm_id(listen_id_priv->id.device,
652 listen_id_priv->id.cm_handler,
653 listen_id_priv->id.context);
654 /* If the cm_id could not be created, ignore the request */
655 if (IS_ERR(cm_id))
Krishna Kumar83b96582006-11-09 09:30:41 +0530656 goto out;
Tom Tucker922a8e92006-08-03 16:02:40 -0500657
658 cm_id->provider_data = iw_event->provider_data;
659 cm_id->local_addr = iw_event->local_addr;
660 cm_id->remote_addr = iw_event->remote_addr;
661
662 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
663 cm_id_priv->state = IW_CM_STATE_CONN_RECV;
664
Steve Wise3eae7c92012-03-07 16:48:11 -0600665 /*
666 * We could be destroying the listening id. If so, ignore this
667 * upcall.
668 */
669 spin_lock_irqsave(&listen_id_priv->lock, flags);
670 if (listen_id_priv->state != IW_CM_STATE_LISTEN) {
671 spin_unlock_irqrestore(&listen_id_priv->lock, flags);
672 iw_cm_reject(cm_id, NULL, 0);
673 iw_destroy_cm_id(cm_id);
674 goto out;
675 }
676 spin_unlock_irqrestore(&listen_id_priv->lock, flags);
677
Tom Tucker922a8e92006-08-03 16:02:40 -0500678 ret = alloc_work_entries(cm_id_priv, 3);
679 if (ret) {
680 iw_cm_reject(cm_id, NULL, 0);
681 iw_destroy_cm_id(cm_id);
Krishna Kumar83b96582006-11-09 09:30:41 +0530682 goto out;
Tom Tucker922a8e92006-08-03 16:02:40 -0500683 }
684
685 /* Call the client CM handler */
686 ret = cm_id->cm_handler(cm_id, iw_event);
687 if (ret) {
Steve Wiseebb90982007-02-15 08:09:36 -0600688 iw_cm_reject(cm_id, NULL, 0);
Tom Tucker922a8e92006-08-03 16:02:40 -0500689 set_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
690 destroy_cm_id(cm_id);
691 if (atomic_read(&cm_id_priv->refcount)==0)
Steve Wiseebb90982007-02-15 08:09:36 -0600692 free_cm_id(cm_id_priv);
Tom Tucker922a8e92006-08-03 16:02:40 -0500693 }
694
Krishna Kumar83b96582006-11-09 09:30:41 +0530695out:
Tom Tucker922a8e92006-08-03 16:02:40 -0500696 if (iw_event->private_data_len)
697 kfree(iw_event->private_data);
698}
699
700/*
701 * Passive Side: CM_ID <-- ESTABLISHED
702 *
703 * The provider generated an ESTABLISHED event which means that
704 * the MPA negotion has completed successfully and we are now in MPA
705 * FPDU mode.
706 *
707 * This event can only be received in the CONN_RECV state. If the
708 * remote peer closed, the ESTABLISHED event would be received followed
709 * by the CLOSE event. If the app closes, it will block until we wake
710 * it up after processing this event.
711 */
712static int cm_conn_est_handler(struct iwcm_id_private *cm_id_priv,
713 struct iw_cm_event *iw_event)
714{
715 unsigned long flags;
Krishna Kumar13fccdb2006-11-09 09:30:43 +0530716 int ret;
Tom Tucker922a8e92006-08-03 16:02:40 -0500717
718 spin_lock_irqsave(&cm_id_priv->lock, flags);
719
720 /*
721 * We clear the CONNECT_WAIT bit here to allow the callback
722 * function to call iw_cm_disconnect. Calling iw_destroy_cm_id
723 * from a callback handler is not allowed.
724 */
725 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
726 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_RECV);
727 cm_id_priv->state = IW_CM_STATE_ESTABLISHED;
728 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
729 ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
730 wake_up_all(&cm_id_priv->connect_wait);
731
732 return ret;
733}
734
735/*
736 * Active Side: CM_ID <-- ESTABLISHED
737 *
738 * The app has called connect and is waiting for the established event to
739 * post it's requests to the server. This event will wake up anyone
740 * blocked in iw_cm_disconnect or iw_destroy_id.
741 */
742static int cm_conn_rep_handler(struct iwcm_id_private *cm_id_priv,
743 struct iw_cm_event *iw_event)
744{
745 unsigned long flags;
Krishna Kumar13fccdb2006-11-09 09:30:43 +0530746 int ret;
Tom Tucker922a8e92006-08-03 16:02:40 -0500747
748 spin_lock_irqsave(&cm_id_priv->lock, flags);
749 /*
750 * Clear the connect wait bit so a callback function calling
751 * iw_cm_disconnect will not wait and deadlock this thread
752 */
753 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
754 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_SENT);
Roland Dreierd0c49bf2011-05-09 22:23:57 -0700755 if (iw_event->status == 0) {
Tom Tucker922a8e92006-08-03 16:02:40 -0500756 cm_id_priv->id.local_addr = iw_event->local_addr;
757 cm_id_priv->id.remote_addr = iw_event->remote_addr;
758 cm_id_priv->state = IW_CM_STATE_ESTABLISHED;
759 } else {
760 /* REJECTED or RESET */
761 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
762 cm_id_priv->qp = NULL;
763 cm_id_priv->state = IW_CM_STATE_IDLE;
764 }
765 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
766 ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
767
768 if (iw_event->private_data_len)
769 kfree(iw_event->private_data);
770
771 /* Wake up waiters on connect complete */
772 wake_up_all(&cm_id_priv->connect_wait);
773
774 return ret;
775}
776
777/*
778 * CM_ID <-- CLOSING
779 *
780 * If in the ESTABLISHED state, move to CLOSING.
781 */
782static void cm_disconnect_handler(struct iwcm_id_private *cm_id_priv,
783 struct iw_cm_event *iw_event)
784{
785 unsigned long flags;
786
787 spin_lock_irqsave(&cm_id_priv->lock, flags);
788 if (cm_id_priv->state == IW_CM_STATE_ESTABLISHED)
789 cm_id_priv->state = IW_CM_STATE_CLOSING;
790 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
791}
792
793/*
794 * CM_ID <-- IDLE
795 *
796 * If in the ESTBLISHED or CLOSING states, the QP will have have been
797 * moved by the provider to the ERR state. Disassociate the CM_ID from
798 * the QP, move to IDLE, and remove the 'connected' reference.
799 *
800 * If in some other state, the cm_id was destroyed asynchronously.
801 * This is the last reference that will result in waking up
802 * the app thread blocked in iw_destroy_cm_id.
803 */
804static int cm_close_handler(struct iwcm_id_private *cm_id_priv,
805 struct iw_cm_event *iw_event)
806{
807 unsigned long flags;
808 int ret = 0;
809 spin_lock_irqsave(&cm_id_priv->lock, flags);
810
811 if (cm_id_priv->qp) {
812 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
813 cm_id_priv->qp = NULL;
814 }
815 switch (cm_id_priv->state) {
816 case IW_CM_STATE_ESTABLISHED:
817 case IW_CM_STATE_CLOSING:
818 cm_id_priv->state = IW_CM_STATE_IDLE;
819 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
820 ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
821 spin_lock_irqsave(&cm_id_priv->lock, flags);
822 break;
823 case IW_CM_STATE_DESTROYING:
824 break;
825 default:
826 BUG();
827 }
828 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
829
830 return ret;
831}
832
833static int process_event(struct iwcm_id_private *cm_id_priv,
834 struct iw_cm_event *iw_event)
835{
836 int ret = 0;
837
838 switch (iw_event->event) {
839 case IW_CM_EVENT_CONNECT_REQUEST:
840 cm_conn_req_handler(cm_id_priv, iw_event);
841 break;
842 case IW_CM_EVENT_CONNECT_REPLY:
843 ret = cm_conn_rep_handler(cm_id_priv, iw_event);
844 break;
845 case IW_CM_EVENT_ESTABLISHED:
846 ret = cm_conn_est_handler(cm_id_priv, iw_event);
847 break;
848 case IW_CM_EVENT_DISCONNECT:
849 cm_disconnect_handler(cm_id_priv, iw_event);
850 break;
851 case IW_CM_EVENT_CLOSE:
852 ret = cm_close_handler(cm_id_priv, iw_event);
853 break;
854 default:
855 BUG();
856 }
857
858 return ret;
859}
860
861/*
862 * Process events on the work_list for the cm_id. If the callback
863 * function requests that the cm_id be deleted, a flag is set in the
864 * cm_id flags to indicate that when the last reference is
865 * removed, the cm_id is to be destroyed. This is necessary to
866 * distinguish between an object that will be destroyed by the app
867 * thread asleep on the destroy_comp list vs. an object destroyed
868 * here synchronously when the last reference is removed.
869 */
David Howellsc4028952006-11-22 14:57:56 +0000870static void cm_work_handler(struct work_struct *_work)
Tom Tucker922a8e92006-08-03 16:02:40 -0500871{
David Howells4c1ac1b2006-12-05 14:37:56 +0000872 struct iwcm_work *work = container_of(_work, struct iwcm_work, work);
Krishna Kumar33ba0fa2006-11-09 09:30:34 +0530873 struct iw_cm_event levent;
Tom Tucker922a8e92006-08-03 16:02:40 -0500874 struct iwcm_id_private *cm_id_priv = work->cm_id;
875 unsigned long flags;
876 int empty;
877 int ret = 0;
Steve Wised7c1fbd2008-03-04 16:44:52 -0600878 int destroy_id;
Tom Tucker922a8e92006-08-03 16:02:40 -0500879
880 spin_lock_irqsave(&cm_id_priv->lock, flags);
881 empty = list_empty(&cm_id_priv->work_list);
882 while (!empty) {
883 work = list_entry(cm_id_priv->work_list.next,
884 struct iwcm_work, list);
885 list_del_init(&work->list);
886 empty = list_empty(&cm_id_priv->work_list);
Krishna Kumar33ba0fa2006-11-09 09:30:34 +0530887 levent = work->event;
Tom Tucker922a8e92006-08-03 16:02:40 -0500888 put_work(work);
889 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
890
Krishna Kumar33ba0fa2006-11-09 09:30:34 +0530891 ret = process_event(cm_id_priv, &levent);
Tom Tucker922a8e92006-08-03 16:02:40 -0500892 if (ret) {
893 set_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
894 destroy_cm_id(&cm_id_priv->id);
895 }
896 BUG_ON(atomic_read(&cm_id_priv->refcount)==0);
Steve Wised7c1fbd2008-03-04 16:44:52 -0600897 destroy_id = test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
Steve Wiseebb90982007-02-15 08:09:36 -0600898 if (iwcm_deref_id(cm_id_priv)) {
Steve Wised7c1fbd2008-03-04 16:44:52 -0600899 if (destroy_id) {
Steve Wiseebb90982007-02-15 08:09:36 -0600900 BUG_ON(!list_empty(&cm_id_priv->work_list));
901 free_cm_id(cm_id_priv);
902 }
Tom Tucker922a8e92006-08-03 16:02:40 -0500903 return;
904 }
Steve Wisee413a8232013-04-23 16:17:14 +0000905 if (empty)
906 return;
Tom Tucker922a8e92006-08-03 16:02:40 -0500907 spin_lock_irqsave(&cm_id_priv->lock, flags);
908 }
909 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
910}
911
912/*
913 * This function is called on interrupt context. Schedule events on
914 * the iwcm_wq thread to allow callback functions to downcall into
915 * the CM and/or block. Events are queued to a per-CM_ID
916 * work_list. If this is the first event on the work_list, the work
917 * element is also queued on the iwcm_wq thread.
918 *
919 * Each event holds a reference on the cm_id. Until the last posted
920 * event has been delivered and processed, the cm_id cannot be
921 * deleted.
922 *
923 * Returns:
924 * 0 - the event was handled.
925 * -ENOMEM - the event was not handled due to lack of resources.
926 */
927static int cm_event_handler(struct iw_cm_id *cm_id,
928 struct iw_cm_event *iw_event)
929{
930 struct iwcm_work *work;
931 struct iwcm_id_private *cm_id_priv;
932 unsigned long flags;
933 int ret = 0;
934
935 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
936
937 spin_lock_irqsave(&cm_id_priv->lock, flags);
938 work = get_work(cm_id_priv);
939 if (!work) {
940 ret = -ENOMEM;
941 goto out;
942 }
943
David Howellsc4028952006-11-22 14:57:56 +0000944 INIT_WORK(&work->work, cm_work_handler);
Tom Tucker922a8e92006-08-03 16:02:40 -0500945 work->cm_id = cm_id_priv;
946 work->event = *iw_event;
947
948 if ((work->event.event == IW_CM_EVENT_CONNECT_REQUEST ||
949 work->event.event == IW_CM_EVENT_CONNECT_REPLY) &&
950 work->event.private_data_len) {
Krishna Kumar715a5882006-11-09 09:30:45 +0530951 ret = copy_private_data(&work->event);
Tom Tucker922a8e92006-08-03 16:02:40 -0500952 if (ret) {
953 put_work(work);
954 goto out;
955 }
956 }
957
958 atomic_inc(&cm_id_priv->refcount);
959 if (list_empty(&cm_id_priv->work_list)) {
960 list_add_tail(&work->list, &cm_id_priv->work_list);
961 queue_work(iwcm_wq, &work->work);
962 } else
963 list_add_tail(&work->list, &cm_id_priv->work_list);
964out:
965 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
966 return ret;
967}
968
969static int iwcm_init_qp_init_attr(struct iwcm_id_private *cm_id_priv,
970 struct ib_qp_attr *qp_attr,
971 int *qp_attr_mask)
972{
973 unsigned long flags;
974 int ret;
975
976 spin_lock_irqsave(&cm_id_priv->lock, flags);
977 switch (cm_id_priv->state) {
978 case IW_CM_STATE_IDLE:
979 case IW_CM_STATE_CONN_SENT:
980 case IW_CM_STATE_CONN_RECV:
981 case IW_CM_STATE_ESTABLISHED:
982 *qp_attr_mask = IB_QP_STATE | IB_QP_ACCESS_FLAGS;
Dotan Barak1ca8d152008-07-22 14:18:34 -0700983 qp_attr->qp_access_flags = IB_ACCESS_REMOTE_WRITE|
Tom Tucker922a8e92006-08-03 16:02:40 -0500984 IB_ACCESS_REMOTE_READ;
985 ret = 0;
986 break;
987 default:
988 ret = -EINVAL;
989 break;
990 }
991 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
992 return ret;
993}
994
995static int iwcm_init_qp_rts_attr(struct iwcm_id_private *cm_id_priv,
996 struct ib_qp_attr *qp_attr,
997 int *qp_attr_mask)
998{
999 unsigned long flags;
1000 int ret;
1001
1002 spin_lock_irqsave(&cm_id_priv->lock, flags);
1003 switch (cm_id_priv->state) {
1004 case IW_CM_STATE_IDLE:
1005 case IW_CM_STATE_CONN_SENT:
1006 case IW_CM_STATE_CONN_RECV:
1007 case IW_CM_STATE_ESTABLISHED:
1008 *qp_attr_mask = 0;
1009 ret = 0;
1010 break;
1011 default:
1012 ret = -EINVAL;
1013 break;
1014 }
1015 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
1016 return ret;
1017}
1018
1019int iw_cm_init_qp_attr(struct iw_cm_id *cm_id,
1020 struct ib_qp_attr *qp_attr,
1021 int *qp_attr_mask)
1022{
1023 struct iwcm_id_private *cm_id_priv;
1024 int ret;
1025
1026 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
1027 switch (qp_attr->qp_state) {
1028 case IB_QPS_INIT:
1029 case IB_QPS_RTR:
1030 ret = iwcm_init_qp_init_attr(cm_id_priv,
1031 qp_attr, qp_attr_mask);
1032 break;
1033 case IB_QPS_RTS:
1034 ret = iwcm_init_qp_rts_attr(cm_id_priv,
1035 qp_attr, qp_attr_mask);
1036 break;
1037 default:
1038 ret = -EINVAL;
1039 break;
1040 }
1041 return ret;
1042}
1043EXPORT_SYMBOL(iw_cm_init_qp_attr);
1044
1045static int __init iw_cm_init(void)
1046{
1047 iwcm_wq = create_singlethread_workqueue("iw_cm_wq");
1048 if (!iwcm_wq)
1049 return -ENOMEM;
1050
Steve Wise2f0304d2014-07-25 09:11:33 -05001051 iwcm_ctl_table_hdr = register_net_sysctl(&init_net, "net/iw_cm",
1052 iwcm_ctl_table);
1053 if (!iwcm_ctl_table_hdr) {
1054 pr_err("iw_cm: couldn't register sysctl paths\n");
1055 destroy_workqueue(iwcm_wq);
1056 return -ENOMEM;
1057 }
1058
Tom Tucker922a8e92006-08-03 16:02:40 -05001059 return 0;
1060}
1061
1062static void __exit iw_cm_cleanup(void)
1063{
Steve Wise2f0304d2014-07-25 09:11:33 -05001064 unregister_net_sysctl_table(iwcm_ctl_table_hdr);
Tom Tucker922a8e92006-08-03 16:02:40 -05001065 destroy_workqueue(iwcm_wq);
1066}
1067
1068module_init(iw_cm_init);
1069module_exit(iw_cm_cleanup);