1 /*
2  * iSCSI transport class definitions
3  *
4  * Copyright (C) IBM Corporation, 2004
5  * Copyright (C) Mike Christie, 2004 - 2005
6  * Copyright (C) Dmitry Yusupov, 2004 - 2005
7  * Copyright (C) Alex Aizman, 2004 - 2005
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22  */
23 #include <linux/module.h>
24 #include <linux/mutex.h>
25 #include <net/tcp.h>
26 #include <scsi/scsi.h>
27 #include <scsi/scsi_host.h>
28 #include <scsi/scsi_device.h>
29 #include <scsi/scsi_transport.h>
30 #include <scsi/scsi_transport_iscsi.h>
31 #include <scsi/iscsi_if.h>
32 
33 #define ISCSI_SESSION_ATTRS 21
34 #define ISCSI_CONN_ATTRS 13
35 #define ISCSI_HOST_ATTRS 4
36 
37 #define ISCSI_TRANSPORT_VERSION "2.0-870"
38 
39 struct iscsi_internal {
40 	int daemon_pid;
41 	struct scsi_transport_template t;
42 	struct iscsi_transport *iscsi_transport;
43 	struct list_head list;
44 	struct device dev;
45 
46 	struct device_attribute *host_attrs[ISCSI_HOST_ATTRS + 1];
47 	struct transport_container conn_cont;
48 	struct device_attribute *conn_attrs[ISCSI_CONN_ATTRS + 1];
49 	struct transport_container session_cont;
50 	struct device_attribute *session_attrs[ISCSI_SESSION_ATTRS + 1];
51 };
52 
53 static atomic_t iscsi_session_nr; /* sysfs session id for next new session */
54 static struct workqueue_struct *iscsi_eh_timer_workq;
55 
56 /*
57  * list of registered transports and lock that must
58  * be held while accessing list. The iscsi_transport_lock must
59  * be acquired after the rx_queue_mutex.
60  */
61 static LIST_HEAD(iscsi_transports);
62 static DEFINE_SPINLOCK(iscsi_transport_lock);
63 
64 #define to_iscsi_internal(tmpl) \
65 	container_of(tmpl, struct iscsi_internal, t)
66 
67 #define dev_to_iscsi_internal(_dev) \
68 	container_of(_dev, struct iscsi_internal, dev)
69 
70 static void iscsi_transport_release(struct device *dev)
71 {
72 	struct iscsi_internal *priv = dev_to_iscsi_internal(dev);
73 	kfree(priv);
74 }
75 
76 /*
77  * iscsi_transport_class represents the iscsi_transports that are
78  * registered.
79  */
80 static struct class iscsi_transport_class = {
81 	.name = "iscsi_transport",
82 	.dev_release = iscsi_transport_release,
83 };
84 
85 static ssize_t
86 show_transport_handle(struct device *dev, struct device_attribute *attr,
87 		      char *buf)
88 {
89 	struct iscsi_internal *priv = dev_to_iscsi_internal(dev);
90 	return sprintf(buf, "%llu\n", (unsigned long long)iscsi_handle(priv->iscsi_transport));
91 }
92 static DEVICE_ATTR(handle, S_IRUGO, show_transport_handle, NULL);
93 
94 #define show_transport_attr(name, format)				\
95 static ssize_t								\
96 show_transport_##name(struct device *dev, 				\
97 		      struct device_attribute *attr,char *buf)		\
98 {									\
99 	struct iscsi_internal *priv = dev_to_iscsi_internal(dev);	\
100 	return sprintf(buf, format"\n", priv->iscsi_transport->name);	\
101 }									\
102 static DEVICE_ATTR(name, S_IRUGO, show_transport_##name, NULL);
103 
104 show_transport_attr(caps, "0x%x");
105 
106 static struct attribute *iscsi_transport_attrs[] = {
107 	&dev_attr_handle.attr,
108 	&dev_attr_caps.attr,
109 	NULL,
110 };
111 
112 static struct attribute_group iscsi_transport_group = {
113 	.attrs = iscsi_transport_attrs,
114 };
115 
116 /*
117  * iSCSI endpoint attrs
118  */
119 #define iscsi_dev_to_endpoint(_dev) \
120 	container_of(_dev, struct iscsi_endpoint, dev)
121 
122 #define ISCSI_ATTR(_prefix,_name,_mode,_show,_store)	\
123 struct device_attribute dev_attr_##_prefix##_##_name =	\
124         __ATTR(_name,_mode,_show,_store)
125 
126 static void iscsi_endpoint_release(struct device *dev)
127 {
128 	struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
129 	kfree(ep);
130 }
131 
132 static struct class iscsi_endpoint_class = {
133 	.name = "iscsi_endpoint",
134 	.dev_release = iscsi_endpoint_release,
135 };
136 
137 static ssize_t
138 show_ep_handle(struct device *dev, struct device_attribute *attr, char *buf)
139 {
140 	struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
141 	return sprintf(buf, "%llu\n", (unsigned long long) ep->id);
142 }
143 static ISCSI_ATTR(ep, handle, S_IRUGO, show_ep_handle, NULL);
144 
145 static struct attribute *iscsi_endpoint_attrs[] = {
146 	&dev_attr_ep_handle.attr,
147 	NULL,
148 };
149 
150 static struct attribute_group iscsi_endpoint_group = {
151 	.attrs = iscsi_endpoint_attrs,
152 };
153 
154 #define ISCSI_MAX_EPID -1
155 
156 static int iscsi_match_epid(struct device *dev, void *data)
157 {
158 	struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
159 	uint64_t *epid = (uint64_t *) data;
160 
161 	return *epid == ep->id;
162 }
163 
164 struct iscsi_endpoint *
165 iscsi_create_endpoint(int dd_size)
166 {
167 	struct device *dev;
168 	struct iscsi_endpoint *ep;
169 	uint64_t id;
170 	int err;
171 
172 	for (id = 1; id < ISCSI_MAX_EPID; id++) {
173 		dev = class_find_device(&iscsi_endpoint_class, NULL, &id,
174 					iscsi_match_epid);
175 		if (!dev)
176 			break;
177 	}
178 	if (id == ISCSI_MAX_EPID) {
179 		printk(KERN_ERR "Too many connections. Max supported %u\n",
180 		       ISCSI_MAX_EPID - 1);
181 		return NULL;
182 	}
183 
184 	ep = kzalloc(sizeof(*ep) + dd_size, GFP_KERNEL);
185 	if (!ep)
186 		return NULL;
187 
188 	ep->id = id;
189 	ep->dev.class = &iscsi_endpoint_class;
190 	snprintf(ep->dev.bus_id, BUS_ID_SIZE, "ep-%llu",
191 		 (unsigned long long) id);
192 	err = device_register(&ep->dev);
193         if (err)
194                 goto free_ep;
195 
196 	err = sysfs_create_group(&ep->dev.kobj, &iscsi_endpoint_group);
197 	if (err)
198 		goto unregister_dev;
199 
200 	if (dd_size)
201 		ep->dd_data = &ep[1];
202 	return ep;
203 
204 unregister_dev:
205 	device_unregister(&ep->dev);
206 	return NULL;
207 
208 free_ep:
209 	kfree(ep);
210 	return NULL;
211 }
212 EXPORT_SYMBOL_GPL(iscsi_create_endpoint);
213 
214 void iscsi_destroy_endpoint(struct iscsi_endpoint *ep)
215 {
216 	sysfs_remove_group(&ep->dev.kobj, &iscsi_endpoint_group);
217 	device_unregister(&ep->dev);
218 }
219 EXPORT_SYMBOL_GPL(iscsi_destroy_endpoint);
220 
221 struct iscsi_endpoint *iscsi_lookup_endpoint(u64 handle)
222 {
223 	struct iscsi_endpoint *ep;
224 	struct device *dev;
225 
226 	dev = class_find_device(&iscsi_endpoint_class, NULL, &handle,
227 				iscsi_match_epid);
228 	if (!dev)
229 		return NULL;
230 
231 	ep = iscsi_dev_to_endpoint(dev);
232 	/*
233 	 * we can drop this now because the interface will prevent
234 	 * removals and lookups from racing.
235 	 */
236 	put_device(dev);
237 	return ep;
238 }
239 EXPORT_SYMBOL_GPL(iscsi_lookup_endpoint);
240 
241 static int iscsi_setup_host(struct transport_container *tc, struct device *dev,
242 			    struct device *cdev)
243 {
244 	struct Scsi_Host *shost = dev_to_shost(dev);
245 	struct iscsi_cls_host *ihost = shost->shost_data;
246 
247 	memset(ihost, 0, sizeof(*ihost));
248 	atomic_set(&ihost->nr_scans, 0);
249 	mutex_init(&ihost->mutex);
250 
251 	snprintf(ihost->scan_workq_name, sizeof(ihost->scan_workq_name),
252 		 "iscsi_scan_%d", shost->host_no);
253 	ihost->scan_workq = create_singlethread_workqueue(
254 						ihost->scan_workq_name);
255 	if (!ihost->scan_workq)
256 		return -ENOMEM;
257 	return 0;
258 }
259 
260 static int iscsi_remove_host(struct transport_container *tc, struct device *dev,
261 			     struct device *cdev)
262 {
263 	struct Scsi_Host *shost = dev_to_shost(dev);
264 	struct iscsi_cls_host *ihost = shost->shost_data;
265 
266 	destroy_workqueue(ihost->scan_workq);
267 	return 0;
268 }
269 
270 static DECLARE_TRANSPORT_CLASS(iscsi_host_class,
271 			       "iscsi_host",
272 			       iscsi_setup_host,
273 			       iscsi_remove_host,
274 			       NULL);
275 
276 static DECLARE_TRANSPORT_CLASS(iscsi_session_class,
277 			       "iscsi_session",
278 			       NULL,
279 			       NULL,
280 			       NULL);
281 
282 static DECLARE_TRANSPORT_CLASS(iscsi_connection_class,
283 			       "iscsi_connection",
284 			       NULL,
285 			       NULL,
286 			       NULL);
287 
288 static struct sock *nls;
289 static DEFINE_MUTEX(rx_queue_mutex);
290 
291 static LIST_HEAD(sesslist);
292 static DEFINE_SPINLOCK(sesslock);
293 static LIST_HEAD(connlist);
294 static DEFINE_SPINLOCK(connlock);
295 
296 static uint32_t iscsi_conn_get_sid(struct iscsi_cls_conn *conn)
297 {
298 	struct iscsi_cls_session *sess = iscsi_dev_to_session(conn->dev.parent);
299 	return sess->sid;
300 }
301 
302 /*
303  * Returns the matching session to a given sid
304  */
305 static struct iscsi_cls_session *iscsi_session_lookup(uint32_t sid)
306 {
307 	unsigned long flags;
308 	struct iscsi_cls_session *sess;
309 
310 	spin_lock_irqsave(&sesslock, flags);
311 	list_for_each_entry(sess, &sesslist, sess_list) {
312 		if (sess->sid == sid) {
313 			spin_unlock_irqrestore(&sesslock, flags);
314 			return sess;
315 		}
316 	}
317 	spin_unlock_irqrestore(&sesslock, flags);
318 	return NULL;
319 }
320 
321 /*
322  * Returns the matching connection to a given sid / cid tuple
323  */
324 static struct iscsi_cls_conn *iscsi_conn_lookup(uint32_t sid, uint32_t cid)
325 {
326 	unsigned long flags;
327 	struct iscsi_cls_conn *conn;
328 
329 	spin_lock_irqsave(&connlock, flags);
330 	list_for_each_entry(conn, &connlist, conn_list) {
331 		if ((conn->cid == cid) && (iscsi_conn_get_sid(conn) == sid)) {
332 			spin_unlock_irqrestore(&connlock, flags);
333 			return conn;
334 		}
335 	}
336 	spin_unlock_irqrestore(&connlock, flags);
337 	return NULL;
338 }
339 
340 /*
341  * The following functions can be used by LLDs that allocate
342  * their own scsi_hosts or by software iscsi LLDs
343  */
344 static struct {
345 	int value;
346 	char *name;
347 } iscsi_session_state_names[] = {
348 	{ ISCSI_SESSION_LOGGED_IN,	"LOGGED_IN" },
349 	{ ISCSI_SESSION_FAILED,		"FAILED" },
350 	{ ISCSI_SESSION_FREE,		"FREE" },
351 };
352 
353 static const char *iscsi_session_state_name(int state)
354 {
355 	int i;
356 	char *name = NULL;
357 
358 	for (i = 0; i < ARRAY_SIZE(iscsi_session_state_names); i++) {
359 		if (iscsi_session_state_names[i].value == state) {
360 			name = iscsi_session_state_names[i].name;
361 			break;
362 		}
363 	}
364 	return name;
365 }
366 
367 int iscsi_session_chkready(struct iscsi_cls_session *session)
368 {
369 	unsigned long flags;
370 	int err;
371 
372 	spin_lock_irqsave(&session->lock, flags);
373 	switch (session->state) {
374 	case ISCSI_SESSION_LOGGED_IN:
375 		err = 0;
376 		break;
377 	case ISCSI_SESSION_FAILED:
378 		err = DID_TRANSPORT_DISRUPTED << 16;
379 		break;
380 	case ISCSI_SESSION_FREE:
381 		err = DID_TRANSPORT_FAILFAST << 16;
382 		break;
383 	default:
384 		err = DID_NO_CONNECT << 16;
385 		break;
386 	}
387 	spin_unlock_irqrestore(&session->lock, flags);
388 	return err;
389 }
390 EXPORT_SYMBOL_GPL(iscsi_session_chkready);
391 
392 static void iscsi_session_release(struct device *dev)
393 {
394 	struct iscsi_cls_session *session = iscsi_dev_to_session(dev);
395 	struct Scsi_Host *shost;
396 
397 	shost = iscsi_session_to_shost(session);
398 	scsi_host_put(shost);
399 	kfree(session);
400 }
401 
402 static int iscsi_is_session_dev(const struct device *dev)
403 {
404 	return dev->release == iscsi_session_release;
405 }
406 
407 static int iscsi_iter_session_fn(struct device *dev, void *data)
408 {
409 	void (* fn) (struct iscsi_cls_session *) = data;
410 
411 	if (!iscsi_is_session_dev(dev))
412 		return 0;
413 	fn(iscsi_dev_to_session(dev));
414 	return 0;
415 }
416 
417 void iscsi_host_for_each_session(struct Scsi_Host *shost,
418 				 void (*fn)(struct iscsi_cls_session *))
419 {
420 	device_for_each_child(&shost->shost_gendev, fn,
421 			      iscsi_iter_session_fn);
422 }
423 EXPORT_SYMBOL_GPL(iscsi_host_for_each_session);
424 
425 /**
426  * iscsi_scan_finished - helper to report when running scans are done
427  * @shost: scsi host
428  * @time: scan run time
429  *
430  * This function can be used by drives like qla4xxx to report to the scsi
431  * layer when the scans it kicked off at module load time are done.
432  */
433 int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time)
434 {
435 	struct iscsi_cls_host *ihost = shost->shost_data;
436 	/*
437 	 * qla4xxx will have kicked off some session unblocks before calling
438 	 * scsi_scan_host, so just wait for them to complete.
439 	 */
440 	return !atomic_read(&ihost->nr_scans);
441 }
442 EXPORT_SYMBOL_GPL(iscsi_scan_finished);
443 
444 struct iscsi_scan_data {
445 	unsigned int channel;
446 	unsigned int id;
447 	unsigned int lun;
448 };
449 
450 static int iscsi_user_scan_session(struct device *dev, void *data)
451 {
452 	struct iscsi_scan_data *scan_data = data;
453 	struct iscsi_cls_session *session;
454 	struct Scsi_Host *shost;
455 	struct iscsi_cls_host *ihost;
456 	unsigned long flags;
457 	unsigned int id;
458 
459 	if (!iscsi_is_session_dev(dev))
460 		return 0;
461 
462 	session = iscsi_dev_to_session(dev);
463 	shost = iscsi_session_to_shost(session);
464 	ihost = shost->shost_data;
465 
466 	mutex_lock(&ihost->mutex);
467 	spin_lock_irqsave(&session->lock, flags);
468 	if (session->state != ISCSI_SESSION_LOGGED_IN) {
469 		spin_unlock_irqrestore(&session->lock, flags);
470 		mutex_unlock(&ihost->mutex);
471 		return 0;
472 	}
473 	id = session->target_id;
474 	spin_unlock_irqrestore(&session->lock, flags);
475 
476 	if (id != ISCSI_MAX_TARGET) {
477 		if ((scan_data->channel == SCAN_WILD_CARD ||
478 		     scan_data->channel == 0) &&
479 		    (scan_data->id == SCAN_WILD_CARD ||
480 		     scan_data->id == id))
481 			scsi_scan_target(&session->dev, 0, id,
482 					 scan_data->lun, 1);
483 	}
484 	mutex_unlock(&ihost->mutex);
485 	return 0;
486 }
487 
488 static int iscsi_user_scan(struct Scsi_Host *shost, uint channel,
489 			   uint id, uint lun)
490 {
491 	struct iscsi_scan_data scan_data;
492 
493 	scan_data.channel = channel;
494 	scan_data.id = id;
495 	scan_data.lun = lun;
496 
497 	return device_for_each_child(&shost->shost_gendev, &scan_data,
498 				     iscsi_user_scan_session);
499 }
500 
501 static void iscsi_scan_session(struct work_struct *work)
502 {
503 	struct iscsi_cls_session *session =
504 			container_of(work, struct iscsi_cls_session, scan_work);
505 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
506 	struct iscsi_cls_host *ihost = shost->shost_data;
507 	struct iscsi_scan_data scan_data;
508 
509 	scan_data.channel = 0;
510 	scan_data.id = SCAN_WILD_CARD;
511 	scan_data.lun = SCAN_WILD_CARD;
512 
513 	iscsi_user_scan_session(&session->dev, &scan_data);
514 	atomic_dec(&ihost->nr_scans);
515 }
516 
517 static void session_recovery_timedout(struct work_struct *work)
518 {
519 	struct iscsi_cls_session *session =
520 		container_of(work, struct iscsi_cls_session,
521 			     recovery_work.work);
522 	unsigned long flags;
523 
524 	iscsi_cls_session_printk(KERN_INFO, session,
525 				 "session recovery timed out after %d secs\n",
526 				 session->recovery_tmo);
527 
528 	spin_lock_irqsave(&session->lock, flags);
529 	switch (session->state) {
530 	case ISCSI_SESSION_FAILED:
531 		session->state = ISCSI_SESSION_FREE;
532 		break;
533 	case ISCSI_SESSION_LOGGED_IN:
534 	case ISCSI_SESSION_FREE:
535 		/* we raced with the unblock's flush */
536 		spin_unlock_irqrestore(&session->lock, flags);
537 		return;
538 	}
539 	spin_unlock_irqrestore(&session->lock, flags);
540 
541 	if (session->transport->session_recovery_timedout)
542 		session->transport->session_recovery_timedout(session);
543 
544 	scsi_target_unblock(&session->dev);
545 }
546 
547 static void __iscsi_unblock_session(struct work_struct *work)
548 {
549 	struct iscsi_cls_session *session =
550 			container_of(work, struct iscsi_cls_session,
551 				     unblock_work);
552 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
553 	struct iscsi_cls_host *ihost = shost->shost_data;
554 	unsigned long flags;
555 
556 	/*
557 	 * The recovery and unblock work get run from the same workqueue,
558 	 * so try to cancel it if it was going to run after this unblock.
559 	 */
560 	cancel_delayed_work(&session->recovery_work);
561 	spin_lock_irqsave(&session->lock, flags);
562 	session->state = ISCSI_SESSION_LOGGED_IN;
563 	spin_unlock_irqrestore(&session->lock, flags);
564 	/* start IO */
565 	scsi_target_unblock(&session->dev);
566 	/*
567 	 * Only do kernel scanning if the driver is properly hooked into
568 	 * the async scanning code (drivers like iscsi_tcp do login and
569 	 * scanning from userspace).
570 	 */
571 	if (shost->hostt->scan_finished) {
572 		if (queue_work(ihost->scan_workq, &session->scan_work))
573 			atomic_inc(&ihost->nr_scans);
574 	}
575 }
576 
577 /**
578  * iscsi_unblock_session - set a session as logged in and start IO.
579  * @session: iscsi session
580  *
581  * Mark a session as ready to accept IO.
582  */
583 void iscsi_unblock_session(struct iscsi_cls_session *session)
584 {
585 	queue_work(iscsi_eh_timer_workq, &session->unblock_work);
586 	/*
587 	 * make sure all the events have completed before tell the driver
588 	 * it is safe
589 	 */
590 	flush_workqueue(iscsi_eh_timer_workq);
591 }
592 EXPORT_SYMBOL_GPL(iscsi_unblock_session);
593 
594 static void __iscsi_block_session(struct work_struct *work)
595 {
596 	struct iscsi_cls_session *session =
597 			container_of(work, struct iscsi_cls_session,
598 				     block_work);
599 	unsigned long flags;
600 
601 	spin_lock_irqsave(&session->lock, flags);
602 	session->state = ISCSI_SESSION_FAILED;
603 	spin_unlock_irqrestore(&session->lock, flags);
604 	scsi_target_block(&session->dev);
605 	queue_delayed_work(iscsi_eh_timer_workq, &session->recovery_work,
606 			   session->recovery_tmo * HZ);
607 }
608 
609 void iscsi_block_session(struct iscsi_cls_session *session)
610 {
611 	queue_work(iscsi_eh_timer_workq, &session->block_work);
612 }
613 EXPORT_SYMBOL_GPL(iscsi_block_session);
614 
615 static void __iscsi_unbind_session(struct work_struct *work)
616 {
617 	struct iscsi_cls_session *session =
618 			container_of(work, struct iscsi_cls_session,
619 				     unbind_work);
620 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
621 	struct iscsi_cls_host *ihost = shost->shost_data;
622 	unsigned long flags;
623 
624 	/* Prevent new scans and make sure scanning is not in progress */
625 	mutex_lock(&ihost->mutex);
626 	spin_lock_irqsave(&session->lock, flags);
627 	if (session->target_id == ISCSI_MAX_TARGET) {
628 		spin_unlock_irqrestore(&session->lock, flags);
629 		mutex_unlock(&ihost->mutex);
630 		return;
631 	}
632 	session->target_id = ISCSI_MAX_TARGET;
633 	spin_unlock_irqrestore(&session->lock, flags);
634 	mutex_unlock(&ihost->mutex);
635 
636 	scsi_remove_target(&session->dev);
637 	iscsi_session_event(session, ISCSI_KEVENT_UNBIND_SESSION);
638 }
639 
640 static int iscsi_unbind_session(struct iscsi_cls_session *session)
641 {
642 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
643 	struct iscsi_cls_host *ihost = shost->shost_data;
644 
645 	return queue_work(ihost->scan_workq, &session->unbind_work);
646 }
647 
648 struct iscsi_cls_session *
649 iscsi_alloc_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
650 		    int dd_size)
651 {
652 	struct iscsi_cls_session *session;
653 
654 	session = kzalloc(sizeof(*session) + dd_size,
655 			  GFP_KERNEL);
656 	if (!session)
657 		return NULL;
658 
659 	session->transport = transport;
660 	session->recovery_tmo = 120;
661 	session->state = ISCSI_SESSION_FREE;
662 	INIT_DELAYED_WORK(&session->recovery_work, session_recovery_timedout);
663 	INIT_LIST_HEAD(&session->sess_list);
664 	INIT_WORK(&session->unblock_work, __iscsi_unblock_session);
665 	INIT_WORK(&session->block_work, __iscsi_block_session);
666 	INIT_WORK(&session->unbind_work, __iscsi_unbind_session);
667 	INIT_WORK(&session->scan_work, iscsi_scan_session);
668 	spin_lock_init(&session->lock);
669 
670 	/* this is released in the dev's release function */
671 	scsi_host_get(shost);
672 	session->dev.parent = &shost->shost_gendev;
673 	session->dev.release = iscsi_session_release;
674 	device_initialize(&session->dev);
675 	if (dd_size)
676 		session->dd_data = &session[1];
677 	return session;
678 }
679 EXPORT_SYMBOL_GPL(iscsi_alloc_session);
680 
681 static int iscsi_get_next_target_id(struct device *dev, void *data)
682 {
683 	struct iscsi_cls_session *session;
684 	unsigned long flags;
685 	int err = 0;
686 
687 	if (!iscsi_is_session_dev(dev))
688 		return 0;
689 
690 	session = iscsi_dev_to_session(dev);
691 	spin_lock_irqsave(&session->lock, flags);
692 	if (*((unsigned int *) data) == session->target_id)
693 		err = -EEXIST;
694 	spin_unlock_irqrestore(&session->lock, flags);
695 	return err;
696 }
697 
698 int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
699 {
700 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
701 	struct iscsi_cls_host *ihost;
702 	unsigned long flags;
703 	unsigned int id = target_id;
704 	int err;
705 
706 	ihost = shost->shost_data;
707 	session->sid = atomic_add_return(1, &iscsi_session_nr);
708 
709 	if (id == ISCSI_MAX_TARGET) {
710 		for (id = 0; id < ISCSI_MAX_TARGET; id++) {
711 			err = device_for_each_child(&shost->shost_gendev, &id,
712 						    iscsi_get_next_target_id);
713 			if (!err)
714 				break;
715 		}
716 
717 		if (id == ISCSI_MAX_TARGET) {
718 			iscsi_cls_session_printk(KERN_ERR, session,
719 						 "Too many iscsi targets. Max "
720 						 "number of targets is %d.\n",
721 						 ISCSI_MAX_TARGET - 1);
722 			goto release_host;
723 		}
724 	}
725 	session->target_id = id;
726 
727 	snprintf(session->dev.bus_id, BUS_ID_SIZE, "session%u",
728 		 session->sid);
729 	err = device_add(&session->dev);
730 	if (err) {
731 		iscsi_cls_session_printk(KERN_ERR, session,
732 					 "could not register session's dev\n");
733 		goto release_host;
734 	}
735 	transport_register_device(&session->dev);
736 
737 	spin_lock_irqsave(&sesslock, flags);
738 	list_add(&session->sess_list, &sesslist);
739 	spin_unlock_irqrestore(&sesslock, flags);
740 
741 	iscsi_session_event(session, ISCSI_KEVENT_CREATE_SESSION);
742 	return 0;
743 
744 release_host:
745 	scsi_host_put(shost);
746 	return err;
747 }
748 EXPORT_SYMBOL_GPL(iscsi_add_session);
749 
750 /**
751  * iscsi_create_session - create iscsi class session
752  * @shost: scsi host
753  * @transport: iscsi transport
754  * @dd_size: private driver data size
755  * @target_id: which target
756  *
757  * This can be called from a LLD or iscsi_transport.
758  */
759 struct iscsi_cls_session *
760 iscsi_create_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
761 		     int dd_size, unsigned int target_id)
762 {
763 	struct iscsi_cls_session *session;
764 
765 	session = iscsi_alloc_session(shost, transport, dd_size);
766 	if (!session)
767 		return NULL;
768 
769 	if (iscsi_add_session(session, target_id)) {
770 		iscsi_free_session(session);
771 		return NULL;
772 	}
773 	return session;
774 }
775 EXPORT_SYMBOL_GPL(iscsi_create_session);
776 
777 static void iscsi_conn_release(struct device *dev)
778 {
779 	struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev);
780 	struct device *parent = conn->dev.parent;
781 
782 	kfree(conn);
783 	put_device(parent);
784 }
785 
786 static int iscsi_is_conn_dev(const struct device *dev)
787 {
788 	return dev->release == iscsi_conn_release;
789 }
790 
791 static int iscsi_iter_destroy_conn_fn(struct device *dev, void *data)
792 {
793 	if (!iscsi_is_conn_dev(dev))
794 		return 0;
795 	return iscsi_destroy_conn(iscsi_dev_to_conn(dev));
796 }
797 
798 void iscsi_remove_session(struct iscsi_cls_session *session)
799 {
800 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
801 	struct iscsi_cls_host *ihost = shost->shost_data;
802 	unsigned long flags;
803 	int err;
804 
805 	spin_lock_irqsave(&sesslock, flags);
806 	list_del(&session->sess_list);
807 	spin_unlock_irqrestore(&sesslock, flags);
808 
809 	/* make sure there are no blocks/unblocks queued */
810 	flush_workqueue(iscsi_eh_timer_workq);
811 	/* make sure the timedout callout is not running */
812 	if (!cancel_delayed_work(&session->recovery_work))
813 		flush_workqueue(iscsi_eh_timer_workq);
814 	/*
815 	 * If we are blocked let commands flow again. The lld or iscsi
816 	 * layer should set up the queuecommand to fail commands.
817 	 * We assume that LLD will not be calling block/unblock while
818 	 * removing the session.
819 	 */
820 	spin_lock_irqsave(&session->lock, flags);
821 	session->state = ISCSI_SESSION_FREE;
822 	spin_unlock_irqrestore(&session->lock, flags);
823 
824 	scsi_target_unblock(&session->dev);
825 	/* flush running scans then delete devices */
826 	flush_workqueue(ihost->scan_workq);
827 	__iscsi_unbind_session(&session->unbind_work);
828 
829 	/* hw iscsi may not have removed all connections from session */
830 	err = device_for_each_child(&session->dev, NULL,
831 				    iscsi_iter_destroy_conn_fn);
832 	if (err)
833 		iscsi_cls_session_printk(KERN_ERR, session,
834 					 "Could not delete all connections "
835 					 "for session. Error %d.\n", err);
836 
837 	transport_unregister_device(&session->dev);
838 	device_del(&session->dev);
839 }
840 EXPORT_SYMBOL_GPL(iscsi_remove_session);
841 
842 void iscsi_free_session(struct iscsi_cls_session *session)
843 {
844 	iscsi_session_event(session, ISCSI_KEVENT_DESTROY_SESSION);
845 	put_device(&session->dev);
846 }
847 EXPORT_SYMBOL_GPL(iscsi_free_session);
848 
849 /**
850  * iscsi_destroy_session - destroy iscsi session
851  * @session: iscsi_session
852  *
853  * Can be called by a LLD or iscsi_transport. There must not be
854  * any running connections.
855  */
856 int iscsi_destroy_session(struct iscsi_cls_session *session)
857 {
858 	iscsi_remove_session(session);
859 	iscsi_free_session(session);
860 	return 0;
861 }
862 EXPORT_SYMBOL_GPL(iscsi_destroy_session);
863 
864 /**
865  * iscsi_create_conn - create iscsi class connection
866  * @session: iscsi cls session
867  * @dd_size: private driver data size
868  * @cid: connection id
869  *
870  * This can be called from a LLD or iscsi_transport. The connection
871  * is child of the session so cid must be unique for all connections
872  * on the session.
873  *
874  * Since we do not support MCS, cid will normally be zero. In some cases
875  * for software iscsi we could be trying to preallocate a connection struct
876  * in which case there could be two connection structs and cid would be
877  * non-zero.
878  */
879 struct iscsi_cls_conn *
880 iscsi_create_conn(struct iscsi_cls_session *session, int dd_size, uint32_t cid)
881 {
882 	struct iscsi_transport *transport = session->transport;
883 	struct iscsi_cls_conn *conn;
884 	unsigned long flags;
885 	int err;
886 
887 	conn = kzalloc(sizeof(*conn) + dd_size, GFP_KERNEL);
888 	if (!conn)
889 		return NULL;
890 	if (dd_size)
891 		conn->dd_data = &conn[1];
892 
893 	INIT_LIST_HEAD(&conn->conn_list);
894 	conn->transport = transport;
895 	conn->cid = cid;
896 
897 	/* this is released in the dev's release function */
898 	if (!get_device(&session->dev))
899 		goto free_conn;
900 
901 	snprintf(conn->dev.bus_id, BUS_ID_SIZE, "connection%d:%u",
902 		 session->sid, cid);
903 	conn->dev.parent = &session->dev;
904 	conn->dev.release = iscsi_conn_release;
905 	err = device_register(&conn->dev);
906 	if (err) {
907 		iscsi_cls_session_printk(KERN_ERR, session, "could not "
908 					 "register connection's dev\n");
909 		goto release_parent_ref;
910 	}
911 	transport_register_device(&conn->dev);
912 
913 	spin_lock_irqsave(&connlock, flags);
914 	list_add(&conn->conn_list, &connlist);
915 	conn->active = 1;
916 	spin_unlock_irqrestore(&connlock, flags);
917 	return conn;
918 
919 release_parent_ref:
920 	put_device(&session->dev);
921 free_conn:
922 	kfree(conn);
923 	return NULL;
924 }
925 
926 EXPORT_SYMBOL_GPL(iscsi_create_conn);
927 
928 /**
929  * iscsi_destroy_conn - destroy iscsi class connection
930  * @conn: iscsi cls session
931  *
932  * This can be called from a LLD or iscsi_transport.
933  */
934 int iscsi_destroy_conn(struct iscsi_cls_conn *conn)
935 {
936 	unsigned long flags;
937 
938 	spin_lock_irqsave(&connlock, flags);
939 	conn->active = 0;
940 	list_del(&conn->conn_list);
941 	spin_unlock_irqrestore(&connlock, flags);
942 
943 	transport_unregister_device(&conn->dev);
944 	device_unregister(&conn->dev);
945 	return 0;
946 }
947 EXPORT_SYMBOL_GPL(iscsi_destroy_conn);
948 
949 /*
950  * iscsi interface functions
951  */
952 static struct iscsi_internal *
953 iscsi_if_transport_lookup(struct iscsi_transport *tt)
954 {
955 	struct iscsi_internal *priv;
956 	unsigned long flags;
957 
958 	spin_lock_irqsave(&iscsi_transport_lock, flags);
959 	list_for_each_entry(priv, &iscsi_transports, list) {
960 		if (tt == priv->iscsi_transport) {
961 			spin_unlock_irqrestore(&iscsi_transport_lock, flags);
962 			return priv;
963 		}
964 	}
965 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
966 	return NULL;
967 }
968 
969 static int
970 iscsi_broadcast_skb(struct sk_buff *skb, gfp_t gfp)
971 {
972 	int rc;
973 
974 	rc = netlink_broadcast(nls, skb, 0, 1, gfp);
975 	if (rc < 0) {
976 		printk(KERN_ERR "iscsi: can not broadcast skb (%d)\n", rc);
977 		return rc;
978 	}
979 
980 	return 0;
981 }
982 
983 static int
984 iscsi_unicast_skb(struct sk_buff *skb, int pid)
985 {
986 	int rc;
987 
988 	rc = netlink_unicast(nls, skb, pid, MSG_DONTWAIT);
989 	if (rc < 0) {
990 		printk(KERN_ERR "iscsi: can not unicast skb (%d)\n", rc);
991 		return rc;
992 	}
993 
994 	return 0;
995 }
996 
997 int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
998 		   char *data, uint32_t data_size)
999 {
1000 	struct nlmsghdr	*nlh;
1001 	struct sk_buff *skb;
1002 	struct iscsi_uevent *ev;
1003 	char *pdu;
1004 	struct iscsi_internal *priv;
1005 	int len = NLMSG_SPACE(sizeof(*ev) + sizeof(struct iscsi_hdr) +
1006 			      data_size);
1007 
1008 	priv = iscsi_if_transport_lookup(conn->transport);
1009 	if (!priv)
1010 		return -EINVAL;
1011 
1012 	skb = alloc_skb(len, GFP_ATOMIC);
1013 	if (!skb) {
1014 		iscsi_conn_error_event(conn, ISCSI_ERR_CONN_FAILED);
1015 		iscsi_cls_conn_printk(KERN_ERR, conn, "can not deliver "
1016 				      "control PDU: OOM\n");
1017 		return -ENOMEM;
1018 	}
1019 
1020 	nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
1021 	ev = NLMSG_DATA(nlh);
1022 	memset(ev, 0, sizeof(*ev));
1023 	ev->transport_handle = iscsi_handle(conn->transport);
1024 	ev->type = ISCSI_KEVENT_RECV_PDU;
1025 	ev->r.recv_req.cid = conn->cid;
1026 	ev->r.recv_req.sid = iscsi_conn_get_sid(conn);
1027 	pdu = (char*)ev + sizeof(*ev);
1028 	memcpy(pdu, hdr, sizeof(struct iscsi_hdr));
1029 	memcpy(pdu + sizeof(struct iscsi_hdr), data, data_size);
1030 
1031 	return iscsi_unicast_skb(skb, priv->daemon_pid);
1032 }
1033 EXPORT_SYMBOL_GPL(iscsi_recv_pdu);
1034 
1035 void iscsi_conn_error_event(struct iscsi_cls_conn *conn, enum iscsi_err error)
1036 {
1037 	struct nlmsghdr	*nlh;
1038 	struct sk_buff	*skb;
1039 	struct iscsi_uevent *ev;
1040 	struct iscsi_internal *priv;
1041 	int len = NLMSG_SPACE(sizeof(*ev));
1042 
1043 	priv = iscsi_if_transport_lookup(conn->transport);
1044 	if (!priv)
1045 		return;
1046 
1047 	skb = alloc_skb(len, GFP_ATOMIC);
1048 	if (!skb) {
1049 		iscsi_cls_conn_printk(KERN_ERR, conn, "gracefully ignored "
1050 				      "conn error (%d)\n", error);
1051 		return;
1052 	}
1053 
1054 	nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
1055 	ev = NLMSG_DATA(nlh);
1056 	ev->transport_handle = iscsi_handle(conn->transport);
1057 	ev->type = ISCSI_KEVENT_CONN_ERROR;
1058 	ev->r.connerror.error = error;
1059 	ev->r.connerror.cid = conn->cid;
1060 	ev->r.connerror.sid = iscsi_conn_get_sid(conn);
1061 
1062 	iscsi_broadcast_skb(skb, GFP_ATOMIC);
1063 
1064 	iscsi_cls_conn_printk(KERN_INFO, conn, "detected conn error (%d)\n",
1065 			      error);
1066 }
1067 EXPORT_SYMBOL_GPL(iscsi_conn_error_event);
1068 
1069 static int
1070 iscsi_if_send_reply(int pid, int seq, int type, int done, int multi,
1071 		      void *payload, int size)
1072 {
1073 	struct sk_buff	*skb;
1074 	struct nlmsghdr	*nlh;
1075 	int len = NLMSG_SPACE(size);
1076 	int flags = multi ? NLM_F_MULTI : 0;
1077 	int t = done ? NLMSG_DONE : type;
1078 
1079 	skb = alloc_skb(len, GFP_ATOMIC);
1080 	if (!skb) {
1081 		printk(KERN_ERR "Could not allocate skb to send reply.\n");
1082 		return -ENOMEM;
1083 	}
1084 
1085 	nlh = __nlmsg_put(skb, pid, seq, t, (len - sizeof(*nlh)), 0);
1086 	nlh->nlmsg_flags = flags;
1087 	memcpy(NLMSG_DATA(nlh), payload, size);
1088 	return iscsi_unicast_skb(skb, pid);
1089 }
1090 
1091 static int
1092 iscsi_if_get_stats(struct iscsi_transport *transport, struct nlmsghdr *nlh)
1093 {
1094 	struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1095 	struct iscsi_stats *stats;
1096 	struct sk_buff *skbstat;
1097 	struct iscsi_cls_conn *conn;
1098 	struct nlmsghdr	*nlhstat;
1099 	struct iscsi_uevent *evstat;
1100 	struct iscsi_internal *priv;
1101 	int len = NLMSG_SPACE(sizeof(*ev) +
1102 			      sizeof(struct iscsi_stats) +
1103 			      sizeof(struct iscsi_stats_custom) *
1104 			      ISCSI_STATS_CUSTOM_MAX);
1105 	int err = 0;
1106 
1107 	priv = iscsi_if_transport_lookup(transport);
1108 	if (!priv)
1109 		return -EINVAL;
1110 
1111 	conn = iscsi_conn_lookup(ev->u.get_stats.sid, ev->u.get_stats.cid);
1112 	if (!conn)
1113 		return -EEXIST;
1114 
1115 	do {
1116 		int actual_size;
1117 
1118 		skbstat = alloc_skb(len, GFP_ATOMIC);
1119 		if (!skbstat) {
1120 			iscsi_cls_conn_printk(KERN_ERR, conn, "can not "
1121 					      "deliver stats: OOM\n");
1122 			return -ENOMEM;
1123 		}
1124 
1125 		nlhstat = __nlmsg_put(skbstat, priv->daemon_pid, 0, 0,
1126 				      (len - sizeof(*nlhstat)), 0);
1127 		evstat = NLMSG_DATA(nlhstat);
1128 		memset(evstat, 0, sizeof(*evstat));
1129 		evstat->transport_handle = iscsi_handle(conn->transport);
1130 		evstat->type = nlh->nlmsg_type;
1131 		evstat->u.get_stats.cid =
1132 			ev->u.get_stats.cid;
1133 		evstat->u.get_stats.sid =
1134 			ev->u.get_stats.sid;
1135 		stats = (struct iscsi_stats *)
1136 			((char*)evstat + sizeof(*evstat));
1137 		memset(stats, 0, sizeof(*stats));
1138 
1139 		transport->get_stats(conn, stats);
1140 		actual_size = NLMSG_SPACE(sizeof(struct iscsi_uevent) +
1141 					  sizeof(struct iscsi_stats) +
1142 					  sizeof(struct iscsi_stats_custom) *
1143 					  stats->custom_length);
1144 		actual_size -= sizeof(*nlhstat);
1145 		actual_size = NLMSG_LENGTH(actual_size);
1146 		skb_trim(skbstat, NLMSG_ALIGN(actual_size));
1147 		nlhstat->nlmsg_len = actual_size;
1148 
1149 		err = iscsi_unicast_skb(skbstat, priv->daemon_pid);
1150 	} while (err < 0 && err != -ECONNREFUSED);
1151 
1152 	return err;
1153 }
1154 
1155 /**
1156  * iscsi_session_event - send session destr. completion event
1157  * @session: iscsi class session
1158  * @event: type of event
1159  */
1160 int iscsi_session_event(struct iscsi_cls_session *session,
1161 			enum iscsi_uevent_e event)
1162 {
1163 	struct iscsi_internal *priv;
1164 	struct Scsi_Host *shost;
1165 	struct iscsi_uevent *ev;
1166 	struct sk_buff  *skb;
1167 	struct nlmsghdr *nlh;
1168 	int rc, len = NLMSG_SPACE(sizeof(*ev));
1169 
1170 	priv = iscsi_if_transport_lookup(session->transport);
1171 	if (!priv)
1172 		return -EINVAL;
1173 	shost = iscsi_session_to_shost(session);
1174 
1175 	skb = alloc_skb(len, GFP_KERNEL);
1176 	if (!skb) {
1177 		iscsi_cls_session_printk(KERN_ERR, session,
1178 					 "Cannot notify userspace of session "
1179 					 "event %u\n", event);
1180 		return -ENOMEM;
1181 	}
1182 
1183 	nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
1184 	ev = NLMSG_DATA(nlh);
1185 	ev->transport_handle = iscsi_handle(session->transport);
1186 
1187 	ev->type = event;
1188 	switch (event) {
1189 	case ISCSI_KEVENT_DESTROY_SESSION:
1190 		ev->r.d_session.host_no = shost->host_no;
1191 		ev->r.d_session.sid = session->sid;
1192 		break;
1193 	case ISCSI_KEVENT_CREATE_SESSION:
1194 		ev->r.c_session_ret.host_no = shost->host_no;
1195 		ev->r.c_session_ret.sid = session->sid;
1196 		break;
1197 	case ISCSI_KEVENT_UNBIND_SESSION:
1198 		ev->r.unbind_session.host_no = shost->host_no;
1199 		ev->r.unbind_session.sid = session->sid;
1200 		break;
1201 	default:
1202 		iscsi_cls_session_printk(KERN_ERR, session, "Invalid event "
1203 					 "%u.\n", event);
1204 		kfree_skb(skb);
1205 		return -EINVAL;
1206 	}
1207 
1208 	/*
1209 	 * this will occur if the daemon is not up, so we just warn
1210 	 * the user and when the daemon is restarted it will handle it
1211 	 */
1212 	rc = iscsi_broadcast_skb(skb, GFP_KERNEL);
1213 	if (rc < 0)
1214 		iscsi_cls_session_printk(KERN_ERR, session,
1215 					 "Cannot notify userspace of session "
1216 					 "event %u. Check iscsi daemon\n",
1217 					 event);
1218 	return rc;
1219 }
1220 EXPORT_SYMBOL_GPL(iscsi_session_event);
1221 
1222 static int
1223 iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_endpoint *ep,
1224 			struct iscsi_uevent *ev, uint32_t initial_cmdsn,
1225 			uint16_t cmds_max, uint16_t queue_depth)
1226 {
1227 	struct iscsi_transport *transport = priv->iscsi_transport;
1228 	struct iscsi_cls_session *session;
1229 	uint32_t host_no;
1230 
1231 	session = transport->create_session(ep, cmds_max, queue_depth,
1232 					    initial_cmdsn, &host_no);
1233 	if (!session)
1234 		return -ENOMEM;
1235 
1236 	ev->r.c_session_ret.host_no = host_no;
1237 	ev->r.c_session_ret.sid = session->sid;
1238 	return 0;
1239 }
1240 
1241 static int
1242 iscsi_if_create_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1243 {
1244 	struct iscsi_cls_conn *conn;
1245 	struct iscsi_cls_session *session;
1246 
1247 	session = iscsi_session_lookup(ev->u.c_conn.sid);
1248 	if (!session) {
1249 		printk(KERN_ERR "iscsi: invalid session %d.\n",
1250 		       ev->u.c_conn.sid);
1251 		return -EINVAL;
1252 	}
1253 
1254 	conn = transport->create_conn(session, ev->u.c_conn.cid);
1255 	if (!conn) {
1256 		iscsi_cls_session_printk(KERN_ERR, session,
1257 					 "couldn't create a new connection.");
1258 		return -ENOMEM;
1259 	}
1260 
1261 	ev->r.c_conn_ret.sid = session->sid;
1262 	ev->r.c_conn_ret.cid = conn->cid;
1263 	return 0;
1264 }
1265 
1266 static int
1267 iscsi_if_destroy_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1268 {
1269 	struct iscsi_cls_conn *conn;
1270 
1271 	conn = iscsi_conn_lookup(ev->u.d_conn.sid, ev->u.d_conn.cid);
1272 	if (!conn)
1273 		return -EINVAL;
1274 
1275 	if (transport->destroy_conn)
1276 		transport->destroy_conn(conn);
1277 	return 0;
1278 }
1279 
1280 static int
1281 iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1282 {
1283 	char *data = (char*)ev + sizeof(*ev);
1284 	struct iscsi_cls_conn *conn;
1285 	struct iscsi_cls_session *session;
1286 	int err = 0, value = 0;
1287 
1288 	session = iscsi_session_lookup(ev->u.set_param.sid);
1289 	conn = iscsi_conn_lookup(ev->u.set_param.sid, ev->u.set_param.cid);
1290 	if (!conn || !session)
1291 		return -EINVAL;
1292 
1293 	switch (ev->u.set_param.param) {
1294 	case ISCSI_PARAM_SESS_RECOVERY_TMO:
1295 		sscanf(data, "%d", &value);
1296 		if (value != 0)
1297 			session->recovery_tmo = value;
1298 		break;
1299 	default:
1300 		err = transport->set_param(conn, ev->u.set_param.param,
1301 					   data, ev->u.set_param.len);
1302 	}
1303 
1304 	return err;
1305 }
1306 
1307 static int
1308 iscsi_if_transport_ep(struct iscsi_transport *transport,
1309 		      struct iscsi_uevent *ev, int msg_type)
1310 {
1311 	struct iscsi_endpoint *ep;
1312 	struct sockaddr *dst_addr;
1313 	int rc = 0;
1314 
1315 	switch (msg_type) {
1316 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1317 		if (!transport->ep_connect)
1318 			return -EINVAL;
1319 
1320 		dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1321 		ep = transport->ep_connect(dst_addr,
1322 					   ev->u.ep_connect.non_blocking);
1323 		if (IS_ERR(ep))
1324 			return PTR_ERR(ep);
1325 
1326 		ev->r.ep_connect_ret.handle = ep->id;
1327 		break;
1328 	case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1329 		if (!transport->ep_poll)
1330 			return -EINVAL;
1331 
1332 		ep = iscsi_lookup_endpoint(ev->u.ep_poll.ep_handle);
1333 		if (!ep)
1334 			return -EINVAL;
1335 
1336 		ev->r.retcode = transport->ep_poll(ep,
1337 						   ev->u.ep_poll.timeout_ms);
1338 		break;
1339 	case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1340 		if (!transport->ep_disconnect)
1341 			return -EINVAL;
1342 
1343 		ep = iscsi_lookup_endpoint(ev->u.ep_disconnect.ep_handle);
1344 		if (!ep)
1345 			return -EINVAL;
1346 
1347 		transport->ep_disconnect(ep);
1348 		break;
1349 	}
1350 	return rc;
1351 }
1352 
1353 static int
1354 iscsi_tgt_dscvr(struct iscsi_transport *transport,
1355 		struct iscsi_uevent *ev)
1356 {
1357 	struct Scsi_Host *shost;
1358 	struct sockaddr *dst_addr;
1359 	int err;
1360 
1361 	if (!transport->tgt_dscvr)
1362 		return -EINVAL;
1363 
1364 	shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);
1365 	if (!shost) {
1366 		printk(KERN_ERR "target discovery could not find host no %u\n",
1367 		       ev->u.tgt_dscvr.host_no);
1368 		return -ENODEV;
1369 	}
1370 
1371 
1372 	dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1373 	err = transport->tgt_dscvr(shost, ev->u.tgt_dscvr.type,
1374 				   ev->u.tgt_dscvr.enable, dst_addr);
1375 	scsi_host_put(shost);
1376 	return err;
1377 }
1378 
1379 static int
1380 iscsi_set_host_param(struct iscsi_transport *transport,
1381 		     struct iscsi_uevent *ev)
1382 {
1383 	char *data = (char*)ev + sizeof(*ev);
1384 	struct Scsi_Host *shost;
1385 	int err;
1386 
1387 	if (!transport->set_host_param)
1388 		return -ENOSYS;
1389 
1390 	shost = scsi_host_lookup(ev->u.set_host_param.host_no);
1391 	if (!shost) {
1392 		printk(KERN_ERR "set_host_param could not find host no %u\n",
1393 		       ev->u.set_host_param.host_no);
1394 		return -ENODEV;
1395 	}
1396 
1397 	err = transport->set_host_param(shost, ev->u.set_host_param.param,
1398 					data, ev->u.set_host_param.len);
1399 	scsi_host_put(shost);
1400 	return err;
1401 }
1402 
1403 static int
1404 iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
1405 {
1406 	int err = 0;
1407 	struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1408 	struct iscsi_transport *transport = NULL;
1409 	struct iscsi_internal *priv;
1410 	struct iscsi_cls_session *session;
1411 	struct iscsi_cls_conn *conn;
1412 	struct iscsi_endpoint *ep = NULL;
1413 
1414 	priv = iscsi_if_transport_lookup(iscsi_ptr(ev->transport_handle));
1415 	if (!priv)
1416 		return -EINVAL;
1417 	transport = priv->iscsi_transport;
1418 
1419 	if (!try_module_get(transport->owner))
1420 		return -EINVAL;
1421 
1422 	priv->daemon_pid = NETLINK_CREDS(skb)->pid;
1423 
1424 	switch (nlh->nlmsg_type) {
1425 	case ISCSI_UEVENT_CREATE_SESSION:
1426 		err = iscsi_if_create_session(priv, ep, ev,
1427 					      ev->u.c_session.initial_cmdsn,
1428 					      ev->u.c_session.cmds_max,
1429 					      ev->u.c_session.queue_depth);
1430 		break;
1431 	case ISCSI_UEVENT_CREATE_BOUND_SESSION:
1432 		ep = iscsi_lookup_endpoint(ev->u.c_bound_session.ep_handle);
1433 		if (!ep) {
1434 			err = -EINVAL;
1435 			break;
1436 		}
1437 
1438 		err = iscsi_if_create_session(priv, ep, ev,
1439 					ev->u.c_bound_session.initial_cmdsn,
1440 					ev->u.c_bound_session.cmds_max,
1441 					ev->u.c_bound_session.queue_depth);
1442 		break;
1443 	case ISCSI_UEVENT_DESTROY_SESSION:
1444 		session = iscsi_session_lookup(ev->u.d_session.sid);
1445 		if (session)
1446 			transport->destroy_session(session);
1447 		else
1448 			err = -EINVAL;
1449 		break;
1450 	case ISCSI_UEVENT_UNBIND_SESSION:
1451 		session = iscsi_session_lookup(ev->u.d_session.sid);
1452 		if (session)
1453 			iscsi_unbind_session(session);
1454 		else
1455 			err = -EINVAL;
1456 		break;
1457 	case ISCSI_UEVENT_CREATE_CONN:
1458 		err = iscsi_if_create_conn(transport, ev);
1459 		break;
1460 	case ISCSI_UEVENT_DESTROY_CONN:
1461 		err = iscsi_if_destroy_conn(transport, ev);
1462 		break;
1463 	case ISCSI_UEVENT_BIND_CONN:
1464 		session = iscsi_session_lookup(ev->u.b_conn.sid);
1465 		conn = iscsi_conn_lookup(ev->u.b_conn.sid, ev->u.b_conn.cid);
1466 
1467 		if (session && conn)
1468 			ev->r.retcode =	transport->bind_conn(session, conn,
1469 					ev->u.b_conn.transport_eph,
1470 					ev->u.b_conn.is_leading);
1471 		else
1472 			err = -EINVAL;
1473 		break;
1474 	case ISCSI_UEVENT_SET_PARAM:
1475 		err = iscsi_set_param(transport, ev);
1476 		break;
1477 	case ISCSI_UEVENT_START_CONN:
1478 		conn = iscsi_conn_lookup(ev->u.start_conn.sid, ev->u.start_conn.cid);
1479 		if (conn)
1480 			ev->r.retcode = transport->start_conn(conn);
1481 		else
1482 			err = -EINVAL;
1483 		break;
1484 	case ISCSI_UEVENT_STOP_CONN:
1485 		conn = iscsi_conn_lookup(ev->u.stop_conn.sid, ev->u.stop_conn.cid);
1486 		if (conn)
1487 			transport->stop_conn(conn, ev->u.stop_conn.flag);
1488 		else
1489 			err = -EINVAL;
1490 		break;
1491 	case ISCSI_UEVENT_SEND_PDU:
1492 		conn = iscsi_conn_lookup(ev->u.send_pdu.sid, ev->u.send_pdu.cid);
1493 		if (conn)
1494 			ev->r.retcode =	transport->send_pdu(conn,
1495 				(struct iscsi_hdr*)((char*)ev + sizeof(*ev)),
1496 				(char*)ev + sizeof(*ev) + ev->u.send_pdu.hdr_size,
1497 				ev->u.send_pdu.data_size);
1498 		else
1499 			err = -EINVAL;
1500 		break;
1501 	case ISCSI_UEVENT_GET_STATS:
1502 		err = iscsi_if_get_stats(transport, nlh);
1503 		break;
1504 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1505 	case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1506 	case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1507 		err = iscsi_if_transport_ep(transport, ev, nlh->nlmsg_type);
1508 		break;
1509 	case ISCSI_UEVENT_TGT_DSCVR:
1510 		err = iscsi_tgt_dscvr(transport, ev);
1511 		break;
1512 	case ISCSI_UEVENT_SET_HOST_PARAM:
1513 		err = iscsi_set_host_param(transport, ev);
1514 		break;
1515 	default:
1516 		err = -ENOSYS;
1517 		break;
1518 	}
1519 
1520 	module_put(transport->owner);
1521 	return err;
1522 }
1523 
1524 /*
1525  * Get message from skb.  Each message is processed by iscsi_if_recv_msg.
1526  * Malformed skbs with wrong lengths or invalid creds are not processed.
1527  */
1528 static void
1529 iscsi_if_rx(struct sk_buff *skb)
1530 {
1531 	mutex_lock(&rx_queue_mutex);
1532 	while (skb->len >= NLMSG_SPACE(0)) {
1533 		int err;
1534 		uint32_t rlen;
1535 		struct nlmsghdr	*nlh;
1536 		struct iscsi_uevent *ev;
1537 
1538 		nlh = nlmsg_hdr(skb);
1539 		if (nlh->nlmsg_len < sizeof(*nlh) ||
1540 		    skb->len < nlh->nlmsg_len) {
1541 			break;
1542 		}
1543 
1544 		ev = NLMSG_DATA(nlh);
1545 		rlen = NLMSG_ALIGN(nlh->nlmsg_len);
1546 		if (rlen > skb->len)
1547 			rlen = skb->len;
1548 
1549 		err = iscsi_if_recv_msg(skb, nlh);
1550 		if (err) {
1551 			ev->type = ISCSI_KEVENT_IF_ERROR;
1552 			ev->iferror = err;
1553 		}
1554 		do {
1555 			/*
1556 			 * special case for GET_STATS:
1557 			 * on success - sending reply and stats from
1558 			 * inside of if_recv_msg(),
1559 			 * on error - fall through.
1560 			 */
1561 			if (ev->type == ISCSI_UEVENT_GET_STATS && !err)
1562 				break;
1563 			err = iscsi_if_send_reply(
1564 				NETLINK_CREDS(skb)->pid, nlh->nlmsg_seq,
1565 				nlh->nlmsg_type, 0, 0, ev, sizeof(*ev));
1566 		} while (err < 0 && err != -ECONNREFUSED);
1567 		skb_pull(skb, rlen);
1568 	}
1569 	mutex_unlock(&rx_queue_mutex);
1570 }
1571 
1572 #define ISCSI_CLASS_ATTR(_prefix,_name,_mode,_show,_store)		\
1573 struct device_attribute dev_attr_##_prefix##_##_name =	\
1574 	__ATTR(_name,_mode,_show,_store)
1575 
1576 /*
1577  * iSCSI connection attrs
1578  */
1579 #define iscsi_conn_attr_show(param)					\
1580 static ssize_t								\
1581 show_conn_param_##param(struct device *dev, 				\
1582 			struct device_attribute *attr, char *buf)	\
1583 {									\
1584 	struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev->parent);	\
1585 	struct iscsi_transport *t = conn->transport;			\
1586 	return t->get_conn_param(conn, param, buf);			\
1587 }
1588 
1589 #define iscsi_conn_attr(field, param)					\
1590 	iscsi_conn_attr_show(param)					\
1591 static ISCSI_CLASS_ATTR(conn, field, S_IRUGO, show_conn_param_##param,	\
1592 			NULL);
1593 
1594 iscsi_conn_attr(max_recv_dlength, ISCSI_PARAM_MAX_RECV_DLENGTH);
1595 iscsi_conn_attr(max_xmit_dlength, ISCSI_PARAM_MAX_XMIT_DLENGTH);
1596 iscsi_conn_attr(header_digest, ISCSI_PARAM_HDRDGST_EN);
1597 iscsi_conn_attr(data_digest, ISCSI_PARAM_DATADGST_EN);
1598 iscsi_conn_attr(ifmarker, ISCSI_PARAM_IFMARKER_EN);
1599 iscsi_conn_attr(ofmarker, ISCSI_PARAM_OFMARKER_EN);
1600 iscsi_conn_attr(persistent_port, ISCSI_PARAM_PERSISTENT_PORT);
1601 iscsi_conn_attr(port, ISCSI_PARAM_CONN_PORT);
1602 iscsi_conn_attr(exp_statsn, ISCSI_PARAM_EXP_STATSN);
1603 iscsi_conn_attr(persistent_address, ISCSI_PARAM_PERSISTENT_ADDRESS);
1604 iscsi_conn_attr(address, ISCSI_PARAM_CONN_ADDRESS);
1605 iscsi_conn_attr(ping_tmo, ISCSI_PARAM_PING_TMO);
1606 iscsi_conn_attr(recv_tmo, ISCSI_PARAM_RECV_TMO);
1607 
1608 /*
1609  * iSCSI session attrs
1610  */
1611 #define iscsi_session_attr_show(param, perm)				\
1612 static ssize_t								\
1613 show_session_param_##param(struct device *dev,				\
1614 			   struct device_attribute *attr, char *buf)	\
1615 {									\
1616 	struct iscsi_cls_session *session = 				\
1617 		iscsi_dev_to_session(dev->parent);			\
1618 	struct iscsi_transport *t = session->transport;			\
1619 									\
1620 	if (perm && !capable(CAP_SYS_ADMIN))				\
1621 		return -EACCES;						\
1622 	return t->get_session_param(session, param, buf);		\
1623 }
1624 
1625 #define iscsi_session_attr(field, param, perm)				\
1626 	iscsi_session_attr_show(param, perm)				\
1627 static ISCSI_CLASS_ATTR(sess, field, S_IRUGO, show_session_param_##param, \
1628 			NULL);
1629 
1630 iscsi_session_attr(targetname, ISCSI_PARAM_TARGET_NAME, 0);
1631 iscsi_session_attr(initial_r2t, ISCSI_PARAM_INITIAL_R2T_EN, 0);
1632 iscsi_session_attr(max_outstanding_r2t, ISCSI_PARAM_MAX_R2T, 0);
1633 iscsi_session_attr(immediate_data, ISCSI_PARAM_IMM_DATA_EN, 0);
1634 iscsi_session_attr(first_burst_len, ISCSI_PARAM_FIRST_BURST, 0);
1635 iscsi_session_attr(max_burst_len, ISCSI_PARAM_MAX_BURST, 0);
1636 iscsi_session_attr(data_pdu_in_order, ISCSI_PARAM_PDU_INORDER_EN, 0);
1637 iscsi_session_attr(data_seq_in_order, ISCSI_PARAM_DATASEQ_INORDER_EN, 0);
1638 iscsi_session_attr(erl, ISCSI_PARAM_ERL, 0);
1639 iscsi_session_attr(tpgt, ISCSI_PARAM_TPGT, 0);
1640 iscsi_session_attr(username, ISCSI_PARAM_USERNAME, 1);
1641 iscsi_session_attr(username_in, ISCSI_PARAM_USERNAME_IN, 1);
1642 iscsi_session_attr(password, ISCSI_PARAM_PASSWORD, 1);
1643 iscsi_session_attr(password_in, ISCSI_PARAM_PASSWORD_IN, 1);
1644 iscsi_session_attr(fast_abort, ISCSI_PARAM_FAST_ABORT, 0);
1645 iscsi_session_attr(abort_tmo, ISCSI_PARAM_ABORT_TMO, 0);
1646 iscsi_session_attr(lu_reset_tmo, ISCSI_PARAM_LU_RESET_TMO, 0);
1647 iscsi_session_attr(ifacename, ISCSI_PARAM_IFACE_NAME, 0);
1648 iscsi_session_attr(initiatorname, ISCSI_PARAM_INITIATOR_NAME, 0)
1649 
1650 static ssize_t
1651 show_priv_session_state(struct device *dev, struct device_attribute *attr,
1652 			char *buf)
1653 {
1654 	struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
1655 	return sprintf(buf, "%s\n", iscsi_session_state_name(session->state));
1656 }
1657 static ISCSI_CLASS_ATTR(priv_sess, state, S_IRUGO, show_priv_session_state,
1658 			NULL);
1659 
1660 #define iscsi_priv_session_attr_show(field, format)			\
1661 static ssize_t								\
1662 show_priv_session_##field(struct device *dev, 				\
1663 			  struct device_attribute *attr, char *buf)	\
1664 {									\
1665 	struct iscsi_cls_session *session = 				\
1666 			iscsi_dev_to_session(dev->parent);		\
1667 	return sprintf(buf, format"\n", session->field);		\
1668 }
1669 
1670 #define iscsi_priv_session_attr(field, format)				\
1671 	iscsi_priv_session_attr_show(field, format)			\
1672 static ISCSI_CLASS_ATTR(priv_sess, field, S_IRUGO, show_priv_session_##field, \
1673 			NULL)
1674 iscsi_priv_session_attr(recovery_tmo, "%d");
1675 
1676 /*
1677  * iSCSI host attrs
1678  */
1679 #define iscsi_host_attr_show(param)					\
1680 static ssize_t								\
1681 show_host_param_##param(struct device *dev, 				\
1682 			struct device_attribute *attr, char *buf)	\
1683 {									\
1684 	struct Scsi_Host *shost = transport_class_to_shost(dev);	\
1685 	struct iscsi_internal *priv = to_iscsi_internal(shost->transportt); \
1686 	return priv->iscsi_transport->get_host_param(shost, param, buf); \
1687 }
1688 
1689 #define iscsi_host_attr(field, param)					\
1690 	iscsi_host_attr_show(param)					\
1691 static ISCSI_CLASS_ATTR(host, field, S_IRUGO, show_host_param_##param,	\
1692 			NULL);
1693 
1694 iscsi_host_attr(netdev, ISCSI_HOST_PARAM_NETDEV_NAME);
1695 iscsi_host_attr(hwaddress, ISCSI_HOST_PARAM_HWADDRESS);
1696 iscsi_host_attr(ipaddress, ISCSI_HOST_PARAM_IPADDRESS);
1697 iscsi_host_attr(initiatorname, ISCSI_HOST_PARAM_INITIATOR_NAME);
1698 
1699 #define SETUP_PRIV_SESSION_RD_ATTR(field)				\
1700 do {									\
1701 	priv->session_attrs[count] = &dev_attr_priv_sess_##field; \
1702 	count++;							\
1703 } while (0)
1704 
1705 
1706 #define SETUP_SESSION_RD_ATTR(field, param_flag)			\
1707 do {									\
1708 	if (tt->param_mask & param_flag) {				\
1709 		priv->session_attrs[count] = &dev_attr_sess_##field; \
1710 		count++;						\
1711 	}								\
1712 } while (0)
1713 
1714 #define SETUP_CONN_RD_ATTR(field, param_flag)				\
1715 do {									\
1716 	if (tt->param_mask & param_flag) {				\
1717 		priv->conn_attrs[count] = &dev_attr_conn_##field; \
1718 		count++;						\
1719 	}								\
1720 } while (0)
1721 
1722 #define SETUP_HOST_RD_ATTR(field, param_flag)				\
1723 do {									\
1724 	if (tt->host_param_mask & param_flag) {				\
1725 		priv->host_attrs[count] = &dev_attr_host_##field; \
1726 		count++;						\
1727 	}								\
1728 } while (0)
1729 
1730 static int iscsi_session_match(struct attribute_container *cont,
1731 			   struct device *dev)
1732 {
1733 	struct iscsi_cls_session *session;
1734 	struct Scsi_Host *shost;
1735 	struct iscsi_internal *priv;
1736 
1737 	if (!iscsi_is_session_dev(dev))
1738 		return 0;
1739 
1740 	session = iscsi_dev_to_session(dev);
1741 	shost = iscsi_session_to_shost(session);
1742 	if (!shost->transportt)
1743 		return 0;
1744 
1745 	priv = to_iscsi_internal(shost->transportt);
1746 	if (priv->session_cont.ac.class != &iscsi_session_class.class)
1747 		return 0;
1748 
1749 	return &priv->session_cont.ac == cont;
1750 }
1751 
1752 static int iscsi_conn_match(struct attribute_container *cont,
1753 			   struct device *dev)
1754 {
1755 	struct iscsi_cls_session *session;
1756 	struct iscsi_cls_conn *conn;
1757 	struct Scsi_Host *shost;
1758 	struct iscsi_internal *priv;
1759 
1760 	if (!iscsi_is_conn_dev(dev))
1761 		return 0;
1762 
1763 	conn = iscsi_dev_to_conn(dev);
1764 	session = iscsi_dev_to_session(conn->dev.parent);
1765 	shost = iscsi_session_to_shost(session);
1766 
1767 	if (!shost->transportt)
1768 		return 0;
1769 
1770 	priv = to_iscsi_internal(shost->transportt);
1771 	if (priv->conn_cont.ac.class != &iscsi_connection_class.class)
1772 		return 0;
1773 
1774 	return &priv->conn_cont.ac == cont;
1775 }
1776 
1777 static int iscsi_host_match(struct attribute_container *cont,
1778 			    struct device *dev)
1779 {
1780 	struct Scsi_Host *shost;
1781 	struct iscsi_internal *priv;
1782 
1783 	if (!scsi_is_host_device(dev))
1784 		return 0;
1785 
1786 	shost = dev_to_shost(dev);
1787 	if (!shost->transportt  ||
1788 	    shost->transportt->host_attrs.ac.class != &iscsi_host_class.class)
1789 		return 0;
1790 
1791         priv = to_iscsi_internal(shost->transportt);
1792         return &priv->t.host_attrs.ac == cont;
1793 }
1794 
1795 struct scsi_transport_template *
1796 iscsi_register_transport(struct iscsi_transport *tt)
1797 {
1798 	struct iscsi_internal *priv;
1799 	unsigned long flags;
1800 	int count = 0, err;
1801 
1802 	BUG_ON(!tt);
1803 
1804 	priv = iscsi_if_transport_lookup(tt);
1805 	if (priv)
1806 		return NULL;
1807 
1808 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1809 	if (!priv)
1810 		return NULL;
1811 	INIT_LIST_HEAD(&priv->list);
1812 	priv->daemon_pid = -1;
1813 	priv->iscsi_transport = tt;
1814 	priv->t.user_scan = iscsi_user_scan;
1815 	if (!(tt->caps & CAP_DATA_PATH_OFFLOAD))
1816 		priv->t.create_work_queue = 1;
1817 
1818 	priv->dev.class = &iscsi_transport_class;
1819 	snprintf(priv->dev.bus_id, BUS_ID_SIZE, "%s", tt->name);
1820 	err = device_register(&priv->dev);
1821 	if (err)
1822 		goto free_priv;
1823 
1824 	err = sysfs_create_group(&priv->dev.kobj, &iscsi_transport_group);
1825 	if (err)
1826 		goto unregister_dev;
1827 
1828 	/* host parameters */
1829 	priv->t.host_attrs.ac.attrs = &priv->host_attrs[0];
1830 	priv->t.host_attrs.ac.class = &iscsi_host_class.class;
1831 	priv->t.host_attrs.ac.match = iscsi_host_match;
1832 	priv->t.host_size = sizeof(struct iscsi_cls_host);
1833 	transport_container_register(&priv->t.host_attrs);
1834 
1835 	SETUP_HOST_RD_ATTR(netdev, ISCSI_HOST_NETDEV_NAME);
1836 	SETUP_HOST_RD_ATTR(ipaddress, ISCSI_HOST_IPADDRESS);
1837 	SETUP_HOST_RD_ATTR(hwaddress, ISCSI_HOST_HWADDRESS);
1838 	SETUP_HOST_RD_ATTR(initiatorname, ISCSI_HOST_INITIATOR_NAME);
1839 	BUG_ON(count > ISCSI_HOST_ATTRS);
1840 	priv->host_attrs[count] = NULL;
1841 	count = 0;
1842 
1843 	/* connection parameters */
1844 	priv->conn_cont.ac.attrs = &priv->conn_attrs[0];
1845 	priv->conn_cont.ac.class = &iscsi_connection_class.class;
1846 	priv->conn_cont.ac.match = iscsi_conn_match;
1847 	transport_container_register(&priv->conn_cont);
1848 
1849 	SETUP_CONN_RD_ATTR(max_recv_dlength, ISCSI_MAX_RECV_DLENGTH);
1850 	SETUP_CONN_RD_ATTR(max_xmit_dlength, ISCSI_MAX_XMIT_DLENGTH);
1851 	SETUP_CONN_RD_ATTR(header_digest, ISCSI_HDRDGST_EN);
1852 	SETUP_CONN_RD_ATTR(data_digest, ISCSI_DATADGST_EN);
1853 	SETUP_CONN_RD_ATTR(ifmarker, ISCSI_IFMARKER_EN);
1854 	SETUP_CONN_RD_ATTR(ofmarker, ISCSI_OFMARKER_EN);
1855 	SETUP_CONN_RD_ATTR(address, ISCSI_CONN_ADDRESS);
1856 	SETUP_CONN_RD_ATTR(port, ISCSI_CONN_PORT);
1857 	SETUP_CONN_RD_ATTR(exp_statsn, ISCSI_EXP_STATSN);
1858 	SETUP_CONN_RD_ATTR(persistent_address, ISCSI_PERSISTENT_ADDRESS);
1859 	SETUP_CONN_RD_ATTR(persistent_port, ISCSI_PERSISTENT_PORT);
1860 	SETUP_CONN_RD_ATTR(ping_tmo, ISCSI_PING_TMO);
1861 	SETUP_CONN_RD_ATTR(recv_tmo, ISCSI_RECV_TMO);
1862 
1863 	BUG_ON(count > ISCSI_CONN_ATTRS);
1864 	priv->conn_attrs[count] = NULL;
1865 	count = 0;
1866 
1867 	/* session parameters */
1868 	priv->session_cont.ac.attrs = &priv->session_attrs[0];
1869 	priv->session_cont.ac.class = &iscsi_session_class.class;
1870 	priv->session_cont.ac.match = iscsi_session_match;
1871 	transport_container_register(&priv->session_cont);
1872 
1873 	SETUP_SESSION_RD_ATTR(initial_r2t, ISCSI_INITIAL_R2T_EN);
1874 	SETUP_SESSION_RD_ATTR(max_outstanding_r2t, ISCSI_MAX_R2T);
1875 	SETUP_SESSION_RD_ATTR(immediate_data, ISCSI_IMM_DATA_EN);
1876 	SETUP_SESSION_RD_ATTR(first_burst_len, ISCSI_FIRST_BURST);
1877 	SETUP_SESSION_RD_ATTR(max_burst_len, ISCSI_MAX_BURST);
1878 	SETUP_SESSION_RD_ATTR(data_pdu_in_order, ISCSI_PDU_INORDER_EN);
1879 	SETUP_SESSION_RD_ATTR(data_seq_in_order, ISCSI_DATASEQ_INORDER_EN);
1880 	SETUP_SESSION_RD_ATTR(erl, ISCSI_ERL);
1881 	SETUP_SESSION_RD_ATTR(targetname, ISCSI_TARGET_NAME);
1882 	SETUP_SESSION_RD_ATTR(tpgt, ISCSI_TPGT);
1883 	SETUP_SESSION_RD_ATTR(password, ISCSI_USERNAME);
1884 	SETUP_SESSION_RD_ATTR(password_in, ISCSI_USERNAME_IN);
1885 	SETUP_SESSION_RD_ATTR(username, ISCSI_PASSWORD);
1886 	SETUP_SESSION_RD_ATTR(username_in, ISCSI_PASSWORD_IN);
1887 	SETUP_SESSION_RD_ATTR(fast_abort, ISCSI_FAST_ABORT);
1888 	SETUP_SESSION_RD_ATTR(abort_tmo, ISCSI_ABORT_TMO);
1889 	SETUP_SESSION_RD_ATTR(lu_reset_tmo,ISCSI_LU_RESET_TMO);
1890 	SETUP_SESSION_RD_ATTR(ifacename, ISCSI_IFACE_NAME);
1891 	SETUP_SESSION_RD_ATTR(initiatorname, ISCSI_INITIATOR_NAME);
1892 	SETUP_PRIV_SESSION_RD_ATTR(recovery_tmo);
1893 	SETUP_PRIV_SESSION_RD_ATTR(state);
1894 
1895 	BUG_ON(count > ISCSI_SESSION_ATTRS);
1896 	priv->session_attrs[count] = NULL;
1897 
1898 	spin_lock_irqsave(&iscsi_transport_lock, flags);
1899 	list_add(&priv->list, &iscsi_transports);
1900 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1901 
1902 	printk(KERN_NOTICE "iscsi: registered transport (%s)\n", tt->name);
1903 	return &priv->t;
1904 
1905 unregister_dev:
1906 	device_unregister(&priv->dev);
1907 	return NULL;
1908 free_priv:
1909 	kfree(priv);
1910 	return NULL;
1911 }
1912 EXPORT_SYMBOL_GPL(iscsi_register_transport);
1913 
1914 int iscsi_unregister_transport(struct iscsi_transport *tt)
1915 {
1916 	struct iscsi_internal *priv;
1917 	unsigned long flags;
1918 
1919 	BUG_ON(!tt);
1920 
1921 	mutex_lock(&rx_queue_mutex);
1922 
1923 	priv = iscsi_if_transport_lookup(tt);
1924 	BUG_ON (!priv);
1925 
1926 	spin_lock_irqsave(&iscsi_transport_lock, flags);
1927 	list_del(&priv->list);
1928 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1929 
1930 	transport_container_unregister(&priv->conn_cont);
1931 	transport_container_unregister(&priv->session_cont);
1932 	transport_container_unregister(&priv->t.host_attrs);
1933 
1934 	sysfs_remove_group(&priv->dev.kobj, &iscsi_transport_group);
1935 	device_unregister(&priv->dev);
1936 	mutex_unlock(&rx_queue_mutex);
1937 
1938 	return 0;
1939 }
1940 EXPORT_SYMBOL_GPL(iscsi_unregister_transport);
1941 
1942 static __init int iscsi_transport_init(void)
1943 {
1944 	int err;
1945 
1946 	printk(KERN_INFO "Loading iSCSI transport class v%s.\n",
1947 		ISCSI_TRANSPORT_VERSION);
1948 
1949 	atomic_set(&iscsi_session_nr, 0);
1950 
1951 	err = class_register(&iscsi_transport_class);
1952 	if (err)
1953 		return err;
1954 
1955 	err = class_register(&iscsi_endpoint_class);
1956 	if (err)
1957 		goto unregister_transport_class;
1958 
1959 	err = transport_class_register(&iscsi_host_class);
1960 	if (err)
1961 		goto unregister_endpoint_class;
1962 
1963 	err = transport_class_register(&iscsi_connection_class);
1964 	if (err)
1965 		goto unregister_host_class;
1966 
1967 	err = transport_class_register(&iscsi_session_class);
1968 	if (err)
1969 		goto unregister_conn_class;
1970 
1971 	nls = netlink_kernel_create(&init_net, NETLINK_ISCSI, 1, iscsi_if_rx,
1972 				    NULL, THIS_MODULE);
1973 	if (!nls) {
1974 		err = -ENOBUFS;
1975 		goto unregister_session_class;
1976 	}
1977 
1978 	iscsi_eh_timer_workq = create_singlethread_workqueue("iscsi_eh");
1979 	if (!iscsi_eh_timer_workq)
1980 		goto release_nls;
1981 
1982 	return 0;
1983 
1984 release_nls:
1985 	netlink_kernel_release(nls);
1986 unregister_session_class:
1987 	transport_class_unregister(&iscsi_session_class);
1988 unregister_conn_class:
1989 	transport_class_unregister(&iscsi_connection_class);
1990 unregister_host_class:
1991 	transport_class_unregister(&iscsi_host_class);
1992 unregister_endpoint_class:
1993 	class_unregister(&iscsi_endpoint_class);
1994 unregister_transport_class:
1995 	class_unregister(&iscsi_transport_class);
1996 	return err;
1997 }
1998 
1999 static void __exit iscsi_transport_exit(void)
2000 {
2001 	destroy_workqueue(iscsi_eh_timer_workq);
2002 	netlink_kernel_release(nls);
2003 	transport_class_unregister(&iscsi_connection_class);
2004 	transport_class_unregister(&iscsi_session_class);
2005 	transport_class_unregister(&iscsi_host_class);
2006 	class_unregister(&iscsi_endpoint_class);
2007 	class_unregister(&iscsi_transport_class);
2008 }
2009 
2010 module_init(iscsi_transport_init);
2011 module_exit(iscsi_transport_exit);
2012 
2013 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
2014 	      "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
2015 	      "Alex Aizman <itn780@yahoo.com>");
2016 MODULE_DESCRIPTION("iSCSI Transport Interface");
2017 MODULE_LICENSE("GPL");
2018 MODULE_VERSION(ISCSI_TRANSPORT_VERSION);
2019