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 static int dbg_session;
40 module_param_named(debug_session, dbg_session, int,
41 		   S_IRUGO | S_IWUSR);
42 MODULE_PARM_DESC(debug_session,
43 		 "Turn on debugging for sessions in scsi_transport_iscsi "
44 		 "module. Set to 1 to turn on, and zero to turn off. Default "
45 		 "is off.");
46 
47 static int dbg_conn;
48 module_param_named(debug_conn, dbg_conn, int,
49 		   S_IRUGO | S_IWUSR);
50 MODULE_PARM_DESC(debug_conn,
51 		 "Turn on debugging for connections in scsi_transport_iscsi "
52 		 "module. Set to 1 to turn on, and zero to turn off. Default "
53 		 "is off.");
54 
55 #define ISCSI_DBG_TRANS_SESSION(_session, dbg_fmt, arg...)		\
56 	do {								\
57 		if (dbg_session)					\
58 			iscsi_cls_session_printk(KERN_INFO, _session,	\
59 						 "%s: " dbg_fmt,	\
60 						 __func__, ##arg);	\
61 	} while (0);
62 
63 #define ISCSI_DBG_TRANS_CONN(_conn, dbg_fmt, arg...)			\
64 	do {								\
65 		if (dbg_conn)						\
66 			iscsi_cls_conn_printk(KERN_INFO, _conn,		\
67 					      "%s: " dbg_fmt,		\
68 					      __func__, ##arg);	\
69 	} while (0);
70 
71 struct iscsi_internal {
72 	struct scsi_transport_template t;
73 	struct iscsi_transport *iscsi_transport;
74 	struct list_head list;
75 	struct device dev;
76 
77 	struct device_attribute *host_attrs[ISCSI_HOST_ATTRS + 1];
78 	struct transport_container conn_cont;
79 	struct device_attribute *conn_attrs[ISCSI_CONN_ATTRS + 1];
80 	struct transport_container session_cont;
81 	struct device_attribute *session_attrs[ISCSI_SESSION_ATTRS + 1];
82 };
83 
84 static atomic_t iscsi_session_nr; /* sysfs session id for next new session */
85 static struct workqueue_struct *iscsi_eh_timer_workq;
86 
87 /*
88  * list of registered transports and lock that must
89  * be held while accessing list. The iscsi_transport_lock must
90  * be acquired after the rx_queue_mutex.
91  */
92 static LIST_HEAD(iscsi_transports);
93 static DEFINE_SPINLOCK(iscsi_transport_lock);
94 
95 #define to_iscsi_internal(tmpl) \
96 	container_of(tmpl, struct iscsi_internal, t)
97 
98 #define dev_to_iscsi_internal(_dev) \
99 	container_of(_dev, struct iscsi_internal, dev)
100 
101 static void iscsi_transport_release(struct device *dev)
102 {
103 	struct iscsi_internal *priv = dev_to_iscsi_internal(dev);
104 	kfree(priv);
105 }
106 
107 /*
108  * iscsi_transport_class represents the iscsi_transports that are
109  * registered.
110  */
111 static struct class iscsi_transport_class = {
112 	.name = "iscsi_transport",
113 	.dev_release = iscsi_transport_release,
114 };
115 
116 static ssize_t
117 show_transport_handle(struct device *dev, struct device_attribute *attr,
118 		      char *buf)
119 {
120 	struct iscsi_internal *priv = dev_to_iscsi_internal(dev);
121 	return sprintf(buf, "%llu\n", (unsigned long long)iscsi_handle(priv->iscsi_transport));
122 }
123 static DEVICE_ATTR(handle, S_IRUGO, show_transport_handle, NULL);
124 
125 #define show_transport_attr(name, format)				\
126 static ssize_t								\
127 show_transport_##name(struct device *dev, 				\
128 		      struct device_attribute *attr,char *buf)		\
129 {									\
130 	struct iscsi_internal *priv = dev_to_iscsi_internal(dev);	\
131 	return sprintf(buf, format"\n", priv->iscsi_transport->name);	\
132 }									\
133 static DEVICE_ATTR(name, S_IRUGO, show_transport_##name, NULL);
134 
135 show_transport_attr(caps, "0x%x");
136 
137 static struct attribute *iscsi_transport_attrs[] = {
138 	&dev_attr_handle.attr,
139 	&dev_attr_caps.attr,
140 	NULL,
141 };
142 
143 static struct attribute_group iscsi_transport_group = {
144 	.attrs = iscsi_transport_attrs,
145 };
146 
147 /*
148  * iSCSI endpoint attrs
149  */
150 #define iscsi_dev_to_endpoint(_dev) \
151 	container_of(_dev, struct iscsi_endpoint, dev)
152 
153 #define ISCSI_ATTR(_prefix,_name,_mode,_show,_store)	\
154 struct device_attribute dev_attr_##_prefix##_##_name =	\
155         __ATTR(_name,_mode,_show,_store)
156 
157 static void iscsi_endpoint_release(struct device *dev)
158 {
159 	struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
160 	kfree(ep);
161 }
162 
163 static struct class iscsi_endpoint_class = {
164 	.name = "iscsi_endpoint",
165 	.dev_release = iscsi_endpoint_release,
166 };
167 
168 static ssize_t
169 show_ep_handle(struct device *dev, struct device_attribute *attr, char *buf)
170 {
171 	struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
172 	return sprintf(buf, "%llu\n", (unsigned long long) ep->id);
173 }
174 static ISCSI_ATTR(ep, handle, S_IRUGO, show_ep_handle, NULL);
175 
176 static struct attribute *iscsi_endpoint_attrs[] = {
177 	&dev_attr_ep_handle.attr,
178 	NULL,
179 };
180 
181 static struct attribute_group iscsi_endpoint_group = {
182 	.attrs = iscsi_endpoint_attrs,
183 };
184 
185 #define ISCSI_MAX_EPID -1
186 
187 static int iscsi_match_epid(struct device *dev, void *data)
188 {
189 	struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
190 	uint64_t *epid = (uint64_t *) data;
191 
192 	return *epid == ep->id;
193 }
194 
195 struct iscsi_endpoint *
196 iscsi_create_endpoint(int dd_size)
197 {
198 	struct device *dev;
199 	struct iscsi_endpoint *ep;
200 	uint64_t id;
201 	int err;
202 
203 	for (id = 1; id < ISCSI_MAX_EPID; id++) {
204 		dev = class_find_device(&iscsi_endpoint_class, NULL, &id,
205 					iscsi_match_epid);
206 		if (!dev)
207 			break;
208 	}
209 	if (id == ISCSI_MAX_EPID) {
210 		printk(KERN_ERR "Too many connections. Max supported %u\n",
211 		       ISCSI_MAX_EPID - 1);
212 		return NULL;
213 	}
214 
215 	ep = kzalloc(sizeof(*ep) + dd_size, GFP_KERNEL);
216 	if (!ep)
217 		return NULL;
218 
219 	ep->id = id;
220 	ep->dev.class = &iscsi_endpoint_class;
221 	dev_set_name(&ep->dev, "ep-%llu", (unsigned long long) id);
222 	err = device_register(&ep->dev);
223         if (err)
224                 goto free_ep;
225 
226 	err = sysfs_create_group(&ep->dev.kobj, &iscsi_endpoint_group);
227 	if (err)
228 		goto unregister_dev;
229 
230 	if (dd_size)
231 		ep->dd_data = &ep[1];
232 	return ep;
233 
234 unregister_dev:
235 	device_unregister(&ep->dev);
236 	return NULL;
237 
238 free_ep:
239 	kfree(ep);
240 	return NULL;
241 }
242 EXPORT_SYMBOL_GPL(iscsi_create_endpoint);
243 
244 void iscsi_destroy_endpoint(struct iscsi_endpoint *ep)
245 {
246 	sysfs_remove_group(&ep->dev.kobj, &iscsi_endpoint_group);
247 	device_unregister(&ep->dev);
248 }
249 EXPORT_SYMBOL_GPL(iscsi_destroy_endpoint);
250 
251 struct iscsi_endpoint *iscsi_lookup_endpoint(u64 handle)
252 {
253 	struct iscsi_endpoint *ep;
254 	struct device *dev;
255 
256 	dev = class_find_device(&iscsi_endpoint_class, NULL, &handle,
257 				iscsi_match_epid);
258 	if (!dev)
259 		return NULL;
260 
261 	ep = iscsi_dev_to_endpoint(dev);
262 	/*
263 	 * we can drop this now because the interface will prevent
264 	 * removals and lookups from racing.
265 	 */
266 	put_device(dev);
267 	return ep;
268 }
269 EXPORT_SYMBOL_GPL(iscsi_lookup_endpoint);
270 
271 static int iscsi_setup_host(struct transport_container *tc, struct device *dev,
272 			    struct device *cdev)
273 {
274 	struct Scsi_Host *shost = dev_to_shost(dev);
275 	struct iscsi_cls_host *ihost = shost->shost_data;
276 
277 	memset(ihost, 0, sizeof(*ihost));
278 	atomic_set(&ihost->nr_scans, 0);
279 	mutex_init(&ihost->mutex);
280 	return 0;
281 }
282 
283 static DECLARE_TRANSPORT_CLASS(iscsi_host_class,
284 			       "iscsi_host",
285 			       iscsi_setup_host,
286 			       NULL,
287 			       NULL);
288 
289 static DECLARE_TRANSPORT_CLASS(iscsi_session_class,
290 			       "iscsi_session",
291 			       NULL,
292 			       NULL,
293 			       NULL);
294 
295 static DECLARE_TRANSPORT_CLASS(iscsi_connection_class,
296 			       "iscsi_connection",
297 			       NULL,
298 			       NULL,
299 			       NULL);
300 
301 static struct sock *nls;
302 static DEFINE_MUTEX(rx_queue_mutex);
303 
304 static LIST_HEAD(sesslist);
305 static DEFINE_SPINLOCK(sesslock);
306 static LIST_HEAD(connlist);
307 static DEFINE_SPINLOCK(connlock);
308 
309 static uint32_t iscsi_conn_get_sid(struct iscsi_cls_conn *conn)
310 {
311 	struct iscsi_cls_session *sess = iscsi_dev_to_session(conn->dev.parent);
312 	return sess->sid;
313 }
314 
315 /*
316  * Returns the matching session to a given sid
317  */
318 static struct iscsi_cls_session *iscsi_session_lookup(uint32_t sid)
319 {
320 	unsigned long flags;
321 	struct iscsi_cls_session *sess;
322 
323 	spin_lock_irqsave(&sesslock, flags);
324 	list_for_each_entry(sess, &sesslist, sess_list) {
325 		if (sess->sid == sid) {
326 			spin_unlock_irqrestore(&sesslock, flags);
327 			return sess;
328 		}
329 	}
330 	spin_unlock_irqrestore(&sesslock, flags);
331 	return NULL;
332 }
333 
334 /*
335  * Returns the matching connection to a given sid / cid tuple
336  */
337 static struct iscsi_cls_conn *iscsi_conn_lookup(uint32_t sid, uint32_t cid)
338 {
339 	unsigned long flags;
340 	struct iscsi_cls_conn *conn;
341 
342 	spin_lock_irqsave(&connlock, flags);
343 	list_for_each_entry(conn, &connlist, conn_list) {
344 		if ((conn->cid == cid) && (iscsi_conn_get_sid(conn) == sid)) {
345 			spin_unlock_irqrestore(&connlock, flags);
346 			return conn;
347 		}
348 	}
349 	spin_unlock_irqrestore(&connlock, flags);
350 	return NULL;
351 }
352 
353 /*
354  * The following functions can be used by LLDs that allocate
355  * their own scsi_hosts or by software iscsi LLDs
356  */
357 static struct {
358 	int value;
359 	char *name;
360 } iscsi_session_state_names[] = {
361 	{ ISCSI_SESSION_LOGGED_IN,	"LOGGED_IN" },
362 	{ ISCSI_SESSION_FAILED,		"FAILED" },
363 	{ ISCSI_SESSION_FREE,		"FREE" },
364 };
365 
366 static const char *iscsi_session_state_name(int state)
367 {
368 	int i;
369 	char *name = NULL;
370 
371 	for (i = 0; i < ARRAY_SIZE(iscsi_session_state_names); i++) {
372 		if (iscsi_session_state_names[i].value == state) {
373 			name = iscsi_session_state_names[i].name;
374 			break;
375 		}
376 	}
377 	return name;
378 }
379 
380 int iscsi_session_chkready(struct iscsi_cls_session *session)
381 {
382 	unsigned long flags;
383 	int err;
384 
385 	spin_lock_irqsave(&session->lock, flags);
386 	switch (session->state) {
387 	case ISCSI_SESSION_LOGGED_IN:
388 		err = 0;
389 		break;
390 	case ISCSI_SESSION_FAILED:
391 		err = DID_IMM_RETRY << 16;
392 		break;
393 	case ISCSI_SESSION_FREE:
394 		err = DID_TRANSPORT_FAILFAST << 16;
395 		break;
396 	default:
397 		err = DID_NO_CONNECT << 16;
398 		break;
399 	}
400 	spin_unlock_irqrestore(&session->lock, flags);
401 	return err;
402 }
403 EXPORT_SYMBOL_GPL(iscsi_session_chkready);
404 
405 static void iscsi_session_release(struct device *dev)
406 {
407 	struct iscsi_cls_session *session = iscsi_dev_to_session(dev);
408 	struct Scsi_Host *shost;
409 
410 	shost = iscsi_session_to_shost(session);
411 	scsi_host_put(shost);
412 	ISCSI_DBG_TRANS_SESSION(session, "Completing session release\n");
413 	kfree(session);
414 }
415 
416 static int iscsi_is_session_dev(const struct device *dev)
417 {
418 	return dev->release == iscsi_session_release;
419 }
420 
421 static int iscsi_iter_session_fn(struct device *dev, void *data)
422 {
423 	void (* fn) (struct iscsi_cls_session *) = data;
424 
425 	if (!iscsi_is_session_dev(dev))
426 		return 0;
427 	fn(iscsi_dev_to_session(dev));
428 	return 0;
429 }
430 
431 void iscsi_host_for_each_session(struct Scsi_Host *shost,
432 				 void (*fn)(struct iscsi_cls_session *))
433 {
434 	device_for_each_child(&shost->shost_gendev, fn,
435 			      iscsi_iter_session_fn);
436 }
437 EXPORT_SYMBOL_GPL(iscsi_host_for_each_session);
438 
439 /**
440  * iscsi_scan_finished - helper to report when running scans are done
441  * @shost: scsi host
442  * @time: scan run time
443  *
444  * This function can be used by drives like qla4xxx to report to the scsi
445  * layer when the scans it kicked off at module load time are done.
446  */
447 int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time)
448 {
449 	struct iscsi_cls_host *ihost = shost->shost_data;
450 	/*
451 	 * qla4xxx will have kicked off some session unblocks before calling
452 	 * scsi_scan_host, so just wait for them to complete.
453 	 */
454 	return !atomic_read(&ihost->nr_scans);
455 }
456 EXPORT_SYMBOL_GPL(iscsi_scan_finished);
457 
458 struct iscsi_scan_data {
459 	unsigned int channel;
460 	unsigned int id;
461 	unsigned int lun;
462 };
463 
464 static int iscsi_user_scan_session(struct device *dev, void *data)
465 {
466 	struct iscsi_scan_data *scan_data = data;
467 	struct iscsi_cls_session *session;
468 	struct Scsi_Host *shost;
469 	struct iscsi_cls_host *ihost;
470 	unsigned long flags;
471 	unsigned int id;
472 
473 	if (!iscsi_is_session_dev(dev))
474 		return 0;
475 
476 	session = iscsi_dev_to_session(dev);
477 
478 	ISCSI_DBG_TRANS_SESSION(session, "Scanning session\n");
479 
480 	shost = iscsi_session_to_shost(session);
481 	ihost = shost->shost_data;
482 
483 	mutex_lock(&ihost->mutex);
484 	spin_lock_irqsave(&session->lock, flags);
485 	if (session->state != ISCSI_SESSION_LOGGED_IN) {
486 		spin_unlock_irqrestore(&session->lock, flags);
487 		goto user_scan_exit;
488 	}
489 	id = session->target_id;
490 	spin_unlock_irqrestore(&session->lock, flags);
491 
492 	if (id != ISCSI_MAX_TARGET) {
493 		if ((scan_data->channel == SCAN_WILD_CARD ||
494 		     scan_data->channel == 0) &&
495 		    (scan_data->id == SCAN_WILD_CARD ||
496 		     scan_data->id == id))
497 			scsi_scan_target(&session->dev, 0, id,
498 					 scan_data->lun, 1);
499 	}
500 
501 user_scan_exit:
502 	mutex_unlock(&ihost->mutex);
503 	ISCSI_DBG_TRANS_SESSION(session, "Completed session scan\n");
504 	return 0;
505 }
506 
507 static int iscsi_user_scan(struct Scsi_Host *shost, uint channel,
508 			   uint id, uint lun)
509 {
510 	struct iscsi_scan_data scan_data;
511 
512 	scan_data.channel = channel;
513 	scan_data.id = id;
514 	scan_data.lun = lun;
515 
516 	return device_for_each_child(&shost->shost_gendev, &scan_data,
517 				     iscsi_user_scan_session);
518 }
519 
520 static void iscsi_scan_session(struct work_struct *work)
521 {
522 	struct iscsi_cls_session *session =
523 			container_of(work, struct iscsi_cls_session, scan_work);
524 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
525 	struct iscsi_cls_host *ihost = shost->shost_data;
526 	struct iscsi_scan_data scan_data;
527 
528 	scan_data.channel = 0;
529 	scan_data.id = SCAN_WILD_CARD;
530 	scan_data.lun = SCAN_WILD_CARD;
531 
532 	iscsi_user_scan_session(&session->dev, &scan_data);
533 	atomic_dec(&ihost->nr_scans);
534 }
535 
536 static void session_recovery_timedout(struct work_struct *work)
537 {
538 	struct iscsi_cls_session *session =
539 		container_of(work, struct iscsi_cls_session,
540 			     recovery_work.work);
541 	unsigned long flags;
542 
543 	iscsi_cls_session_printk(KERN_INFO, session,
544 				 "session recovery timed out after %d secs\n",
545 				 session->recovery_tmo);
546 
547 	spin_lock_irqsave(&session->lock, flags);
548 	switch (session->state) {
549 	case ISCSI_SESSION_FAILED:
550 		session->state = ISCSI_SESSION_FREE;
551 		break;
552 	case ISCSI_SESSION_LOGGED_IN:
553 	case ISCSI_SESSION_FREE:
554 		/* we raced with the unblock's flush */
555 		spin_unlock_irqrestore(&session->lock, flags);
556 		return;
557 	}
558 	spin_unlock_irqrestore(&session->lock, flags);
559 
560 	if (session->transport->session_recovery_timedout)
561 		session->transport->session_recovery_timedout(session);
562 
563 	ISCSI_DBG_TRANS_SESSION(session, "Unblocking SCSI target\n");
564 	scsi_target_unblock(&session->dev);
565 	ISCSI_DBG_TRANS_SESSION(session, "Completed unblocking SCSI target\n");
566 }
567 
568 static void __iscsi_unblock_session(struct work_struct *work)
569 {
570 	struct iscsi_cls_session *session =
571 			container_of(work, struct iscsi_cls_session,
572 				     unblock_work);
573 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
574 	struct iscsi_cls_host *ihost = shost->shost_data;
575 	unsigned long flags;
576 
577 	ISCSI_DBG_TRANS_SESSION(session, "Unblocking session\n");
578 	/*
579 	 * The recovery and unblock work get run from the same workqueue,
580 	 * so try to cancel it if it was going to run after this unblock.
581 	 */
582 	cancel_delayed_work(&session->recovery_work);
583 	spin_lock_irqsave(&session->lock, flags);
584 	session->state = ISCSI_SESSION_LOGGED_IN;
585 	spin_unlock_irqrestore(&session->lock, flags);
586 	/* start IO */
587 	scsi_target_unblock(&session->dev);
588 	/*
589 	 * Only do kernel scanning if the driver is properly hooked into
590 	 * the async scanning code (drivers like iscsi_tcp do login and
591 	 * scanning from userspace).
592 	 */
593 	if (shost->hostt->scan_finished) {
594 		if (scsi_queue_work(shost, &session->scan_work))
595 			atomic_inc(&ihost->nr_scans);
596 	}
597 	ISCSI_DBG_TRANS_SESSION(session, "Completed unblocking session\n");
598 }
599 
600 /**
601  * iscsi_unblock_session - set a session as logged in and start IO.
602  * @session: iscsi session
603  *
604  * Mark a session as ready to accept IO.
605  */
606 void iscsi_unblock_session(struct iscsi_cls_session *session)
607 {
608 	queue_work(iscsi_eh_timer_workq, &session->unblock_work);
609 	/*
610 	 * make sure all the events have completed before tell the driver
611 	 * it is safe
612 	 */
613 	flush_workqueue(iscsi_eh_timer_workq);
614 }
615 EXPORT_SYMBOL_GPL(iscsi_unblock_session);
616 
617 static void __iscsi_block_session(struct work_struct *work)
618 {
619 	struct iscsi_cls_session *session =
620 			container_of(work, struct iscsi_cls_session,
621 				     block_work);
622 	unsigned long flags;
623 
624 	ISCSI_DBG_TRANS_SESSION(session, "Blocking session\n");
625 	spin_lock_irqsave(&session->lock, flags);
626 	session->state = ISCSI_SESSION_FAILED;
627 	spin_unlock_irqrestore(&session->lock, flags);
628 	scsi_target_block(&session->dev);
629 	ISCSI_DBG_TRANS_SESSION(session, "Completed SCSI target blocking\n");
630 	queue_delayed_work(iscsi_eh_timer_workq, &session->recovery_work,
631 			   session->recovery_tmo * HZ);
632 }
633 
634 void iscsi_block_session(struct iscsi_cls_session *session)
635 {
636 	queue_work(iscsi_eh_timer_workq, &session->block_work);
637 }
638 EXPORT_SYMBOL_GPL(iscsi_block_session);
639 
640 static void __iscsi_unbind_session(struct work_struct *work)
641 {
642 	struct iscsi_cls_session *session =
643 			container_of(work, struct iscsi_cls_session,
644 				     unbind_work);
645 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
646 	struct iscsi_cls_host *ihost = shost->shost_data;
647 	unsigned long flags;
648 
649 	ISCSI_DBG_TRANS_SESSION(session, "Unbinding session\n");
650 
651 	/* Prevent new scans and make sure scanning is not in progress */
652 	mutex_lock(&ihost->mutex);
653 	spin_lock_irqsave(&session->lock, flags);
654 	if (session->target_id == ISCSI_MAX_TARGET) {
655 		spin_unlock_irqrestore(&session->lock, flags);
656 		mutex_unlock(&ihost->mutex);
657 		return;
658 	}
659 	session->target_id = ISCSI_MAX_TARGET;
660 	spin_unlock_irqrestore(&session->lock, flags);
661 	mutex_unlock(&ihost->mutex);
662 
663 	scsi_remove_target(&session->dev);
664 	iscsi_session_event(session, ISCSI_KEVENT_UNBIND_SESSION);
665 	ISCSI_DBG_TRANS_SESSION(session, "Completed target removal\n");
666 }
667 
668 struct iscsi_cls_session *
669 iscsi_alloc_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
670 		    int dd_size)
671 {
672 	struct iscsi_cls_session *session;
673 
674 	session = kzalloc(sizeof(*session) + dd_size,
675 			  GFP_KERNEL);
676 	if (!session)
677 		return NULL;
678 
679 	session->transport = transport;
680 	session->recovery_tmo = 120;
681 	session->state = ISCSI_SESSION_FREE;
682 	INIT_DELAYED_WORK(&session->recovery_work, session_recovery_timedout);
683 	INIT_LIST_HEAD(&session->sess_list);
684 	INIT_WORK(&session->unblock_work, __iscsi_unblock_session);
685 	INIT_WORK(&session->block_work, __iscsi_block_session);
686 	INIT_WORK(&session->unbind_work, __iscsi_unbind_session);
687 	INIT_WORK(&session->scan_work, iscsi_scan_session);
688 	spin_lock_init(&session->lock);
689 
690 	/* this is released in the dev's release function */
691 	scsi_host_get(shost);
692 	session->dev.parent = &shost->shost_gendev;
693 	session->dev.release = iscsi_session_release;
694 	device_initialize(&session->dev);
695 	if (dd_size)
696 		session->dd_data = &session[1];
697 
698 	ISCSI_DBG_TRANS_SESSION(session, "Completed session allocation\n");
699 	return session;
700 }
701 EXPORT_SYMBOL_GPL(iscsi_alloc_session);
702 
703 static int iscsi_get_next_target_id(struct device *dev, void *data)
704 {
705 	struct iscsi_cls_session *session;
706 	unsigned long flags;
707 	int err = 0;
708 
709 	if (!iscsi_is_session_dev(dev))
710 		return 0;
711 
712 	session = iscsi_dev_to_session(dev);
713 	spin_lock_irqsave(&session->lock, flags);
714 	if (*((unsigned int *) data) == session->target_id)
715 		err = -EEXIST;
716 	spin_unlock_irqrestore(&session->lock, flags);
717 	return err;
718 }
719 
720 int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
721 {
722 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
723 	struct iscsi_cls_host *ihost;
724 	unsigned long flags;
725 	unsigned int id = target_id;
726 	int err;
727 
728 	ihost = shost->shost_data;
729 	session->sid = atomic_add_return(1, &iscsi_session_nr);
730 
731 	if (id == ISCSI_MAX_TARGET) {
732 		for (id = 0; id < ISCSI_MAX_TARGET; id++) {
733 			err = device_for_each_child(&shost->shost_gendev, &id,
734 						    iscsi_get_next_target_id);
735 			if (!err)
736 				break;
737 		}
738 
739 		if (id == ISCSI_MAX_TARGET) {
740 			iscsi_cls_session_printk(KERN_ERR, session,
741 						 "Too many iscsi targets. Max "
742 						 "number of targets is %d.\n",
743 						 ISCSI_MAX_TARGET - 1);
744 			err = -EOVERFLOW;
745 			goto release_host;
746 		}
747 	}
748 	session->target_id = id;
749 
750 	dev_set_name(&session->dev, "session%u", session->sid);
751 	err = device_add(&session->dev);
752 	if (err) {
753 		iscsi_cls_session_printk(KERN_ERR, session,
754 					 "could not register session's dev\n");
755 		goto release_host;
756 	}
757 	transport_register_device(&session->dev);
758 
759 	spin_lock_irqsave(&sesslock, flags);
760 	list_add(&session->sess_list, &sesslist);
761 	spin_unlock_irqrestore(&sesslock, flags);
762 
763 	iscsi_session_event(session, ISCSI_KEVENT_CREATE_SESSION);
764 	ISCSI_DBG_TRANS_SESSION(session, "Completed session adding\n");
765 	return 0;
766 
767 release_host:
768 	scsi_host_put(shost);
769 	return err;
770 }
771 EXPORT_SYMBOL_GPL(iscsi_add_session);
772 
773 /**
774  * iscsi_create_session - create iscsi class session
775  * @shost: scsi host
776  * @transport: iscsi transport
777  * @dd_size: private driver data size
778  * @target_id: which target
779  *
780  * This can be called from a LLD or iscsi_transport.
781  */
782 struct iscsi_cls_session *
783 iscsi_create_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
784 		     int dd_size, unsigned int target_id)
785 {
786 	struct iscsi_cls_session *session;
787 
788 	session = iscsi_alloc_session(shost, transport, dd_size);
789 	if (!session)
790 		return NULL;
791 
792 	if (iscsi_add_session(session, target_id)) {
793 		iscsi_free_session(session);
794 		return NULL;
795 	}
796 	return session;
797 }
798 EXPORT_SYMBOL_GPL(iscsi_create_session);
799 
800 static void iscsi_conn_release(struct device *dev)
801 {
802 	struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev);
803 	struct device *parent = conn->dev.parent;
804 
805 	ISCSI_DBG_TRANS_CONN(conn, "Releasing conn\n");
806 	kfree(conn);
807 	put_device(parent);
808 }
809 
810 static int iscsi_is_conn_dev(const struct device *dev)
811 {
812 	return dev->release == iscsi_conn_release;
813 }
814 
815 static int iscsi_iter_destroy_conn_fn(struct device *dev, void *data)
816 {
817 	if (!iscsi_is_conn_dev(dev))
818 		return 0;
819 	return iscsi_destroy_conn(iscsi_dev_to_conn(dev));
820 }
821 
822 void iscsi_remove_session(struct iscsi_cls_session *session)
823 {
824 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
825 	unsigned long flags;
826 	int err;
827 
828 	ISCSI_DBG_TRANS_SESSION(session, "Removing session\n");
829 
830 	spin_lock_irqsave(&sesslock, flags);
831 	list_del(&session->sess_list);
832 	spin_unlock_irqrestore(&sesslock, flags);
833 
834 	/* make sure there are no blocks/unblocks queued */
835 	flush_workqueue(iscsi_eh_timer_workq);
836 	/* make sure the timedout callout is not running */
837 	if (!cancel_delayed_work(&session->recovery_work))
838 		flush_workqueue(iscsi_eh_timer_workq);
839 	/*
840 	 * If we are blocked let commands flow again. The lld or iscsi
841 	 * layer should set up the queuecommand to fail commands.
842 	 * We assume that LLD will not be calling block/unblock while
843 	 * removing the session.
844 	 */
845 	spin_lock_irqsave(&session->lock, flags);
846 	session->state = ISCSI_SESSION_FREE;
847 	spin_unlock_irqrestore(&session->lock, flags);
848 
849 	scsi_target_unblock(&session->dev);
850 	/* flush running scans then delete devices */
851 	scsi_flush_work(shost);
852 	__iscsi_unbind_session(&session->unbind_work);
853 
854 	/* hw iscsi may not have removed all connections from session */
855 	err = device_for_each_child(&session->dev, NULL,
856 				    iscsi_iter_destroy_conn_fn);
857 	if (err)
858 		iscsi_cls_session_printk(KERN_ERR, session,
859 					 "Could not delete all connections "
860 					 "for session. Error %d.\n", err);
861 
862 	transport_unregister_device(&session->dev);
863 
864 	ISCSI_DBG_TRANS_SESSION(session, "Completing session removal\n");
865 	device_del(&session->dev);
866 }
867 EXPORT_SYMBOL_GPL(iscsi_remove_session);
868 
869 void iscsi_free_session(struct iscsi_cls_session *session)
870 {
871 	ISCSI_DBG_TRANS_SESSION(session, "Freeing session\n");
872 	iscsi_session_event(session, ISCSI_KEVENT_DESTROY_SESSION);
873 	put_device(&session->dev);
874 }
875 EXPORT_SYMBOL_GPL(iscsi_free_session);
876 
877 /**
878  * iscsi_destroy_session - destroy iscsi session
879  * @session: iscsi_session
880  *
881  * Can be called by a LLD or iscsi_transport. There must not be
882  * any running connections.
883  */
884 int iscsi_destroy_session(struct iscsi_cls_session *session)
885 {
886 	iscsi_remove_session(session);
887 	ISCSI_DBG_TRANS_SESSION(session, "Completing session destruction\n");
888 	iscsi_free_session(session);
889 	return 0;
890 }
891 EXPORT_SYMBOL_GPL(iscsi_destroy_session);
892 
893 /**
894  * iscsi_create_conn - create iscsi class connection
895  * @session: iscsi cls session
896  * @dd_size: private driver data size
897  * @cid: connection id
898  *
899  * This can be called from a LLD or iscsi_transport. The connection
900  * is child of the session so cid must be unique for all connections
901  * on the session.
902  *
903  * Since we do not support MCS, cid will normally be zero. In some cases
904  * for software iscsi we could be trying to preallocate a connection struct
905  * in which case there could be two connection structs and cid would be
906  * non-zero.
907  */
908 struct iscsi_cls_conn *
909 iscsi_create_conn(struct iscsi_cls_session *session, int dd_size, uint32_t cid)
910 {
911 	struct iscsi_transport *transport = session->transport;
912 	struct iscsi_cls_conn *conn;
913 	unsigned long flags;
914 	int err;
915 
916 	conn = kzalloc(sizeof(*conn) + dd_size, GFP_KERNEL);
917 	if (!conn)
918 		return NULL;
919 	if (dd_size)
920 		conn->dd_data = &conn[1];
921 
922 	INIT_LIST_HEAD(&conn->conn_list);
923 	conn->transport = transport;
924 	conn->cid = cid;
925 
926 	/* this is released in the dev's release function */
927 	if (!get_device(&session->dev))
928 		goto free_conn;
929 
930 	dev_set_name(&conn->dev, "connection%d:%u", session->sid, cid);
931 	conn->dev.parent = &session->dev;
932 	conn->dev.release = iscsi_conn_release;
933 	err = device_register(&conn->dev);
934 	if (err) {
935 		iscsi_cls_session_printk(KERN_ERR, session, "could not "
936 					 "register connection's dev\n");
937 		goto release_parent_ref;
938 	}
939 	transport_register_device(&conn->dev);
940 
941 	spin_lock_irqsave(&connlock, flags);
942 	list_add(&conn->conn_list, &connlist);
943 	conn->active = 1;
944 	spin_unlock_irqrestore(&connlock, flags);
945 
946 	ISCSI_DBG_TRANS_CONN(conn, "Completed conn creation\n");
947 	return conn;
948 
949 release_parent_ref:
950 	put_device(&session->dev);
951 free_conn:
952 	kfree(conn);
953 	return NULL;
954 }
955 
956 EXPORT_SYMBOL_GPL(iscsi_create_conn);
957 
958 /**
959  * iscsi_destroy_conn - destroy iscsi class connection
960  * @conn: iscsi cls session
961  *
962  * This can be called from a LLD or iscsi_transport.
963  */
964 int iscsi_destroy_conn(struct iscsi_cls_conn *conn)
965 {
966 	unsigned long flags;
967 
968 	spin_lock_irqsave(&connlock, flags);
969 	conn->active = 0;
970 	list_del(&conn->conn_list);
971 	spin_unlock_irqrestore(&connlock, flags);
972 
973 	transport_unregister_device(&conn->dev);
974 	ISCSI_DBG_TRANS_CONN(conn, "Completing conn destruction\n");
975 	device_unregister(&conn->dev);
976 	return 0;
977 }
978 EXPORT_SYMBOL_GPL(iscsi_destroy_conn);
979 
980 /*
981  * iscsi interface functions
982  */
983 static struct iscsi_internal *
984 iscsi_if_transport_lookup(struct iscsi_transport *tt)
985 {
986 	struct iscsi_internal *priv;
987 	unsigned long flags;
988 
989 	spin_lock_irqsave(&iscsi_transport_lock, flags);
990 	list_for_each_entry(priv, &iscsi_transports, list) {
991 		if (tt == priv->iscsi_transport) {
992 			spin_unlock_irqrestore(&iscsi_transport_lock, flags);
993 			return priv;
994 		}
995 	}
996 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
997 	return NULL;
998 }
999 
1000 static int
1001 iscsi_multicast_skb(struct sk_buff *skb, uint32_t group, gfp_t gfp)
1002 {
1003 	return nlmsg_multicast(nls, skb, 0, group, gfp);
1004 }
1005 
1006 int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
1007 		   char *data, uint32_t data_size)
1008 {
1009 	struct nlmsghdr	*nlh;
1010 	struct sk_buff *skb;
1011 	struct iscsi_uevent *ev;
1012 	char *pdu;
1013 	struct iscsi_internal *priv;
1014 	int len = NLMSG_SPACE(sizeof(*ev) + sizeof(struct iscsi_hdr) +
1015 			      data_size);
1016 
1017 	priv = iscsi_if_transport_lookup(conn->transport);
1018 	if (!priv)
1019 		return -EINVAL;
1020 
1021 	skb = alloc_skb(len, GFP_ATOMIC);
1022 	if (!skb) {
1023 		iscsi_conn_error_event(conn, ISCSI_ERR_CONN_FAILED);
1024 		iscsi_cls_conn_printk(KERN_ERR, conn, "can not deliver "
1025 				      "control PDU: OOM\n");
1026 		return -ENOMEM;
1027 	}
1028 
1029 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1030 	ev = NLMSG_DATA(nlh);
1031 	memset(ev, 0, sizeof(*ev));
1032 	ev->transport_handle = iscsi_handle(conn->transport);
1033 	ev->type = ISCSI_KEVENT_RECV_PDU;
1034 	ev->r.recv_req.cid = conn->cid;
1035 	ev->r.recv_req.sid = iscsi_conn_get_sid(conn);
1036 	pdu = (char*)ev + sizeof(*ev);
1037 	memcpy(pdu, hdr, sizeof(struct iscsi_hdr));
1038 	memcpy(pdu + sizeof(struct iscsi_hdr), data, data_size);
1039 
1040 	return iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);
1041 }
1042 EXPORT_SYMBOL_GPL(iscsi_recv_pdu);
1043 
1044 int iscsi_offload_mesg(struct Scsi_Host *shost,
1045 		       struct iscsi_transport *transport, uint32_t type,
1046 		       char *data, uint16_t data_size)
1047 {
1048 	struct nlmsghdr	*nlh;
1049 	struct sk_buff *skb;
1050 	struct iscsi_uevent *ev;
1051 	int len = NLMSG_SPACE(sizeof(*ev) + data_size);
1052 
1053 	skb = alloc_skb(len, GFP_ATOMIC);
1054 	if (!skb) {
1055 		printk(KERN_ERR "can not deliver iscsi offload message:OOM\n");
1056 		return -ENOMEM;
1057 	}
1058 
1059 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1060 	ev = NLMSG_DATA(nlh);
1061 	memset(ev, 0, sizeof(*ev));
1062 	ev->type = type;
1063 	ev->transport_handle = iscsi_handle(transport);
1064 	switch (type) {
1065 	case ISCSI_KEVENT_PATH_REQ:
1066 		ev->r.req_path.host_no = shost->host_no;
1067 		break;
1068 	case ISCSI_KEVENT_IF_DOWN:
1069 		ev->r.notify_if_down.host_no = shost->host_no;
1070 		break;
1071 	}
1072 
1073 	memcpy((char *)ev + sizeof(*ev), data, data_size);
1074 
1075 	return iscsi_multicast_skb(skb, ISCSI_NL_GRP_UIP, GFP_ATOMIC);
1076 }
1077 EXPORT_SYMBOL_GPL(iscsi_offload_mesg);
1078 
1079 void iscsi_conn_error_event(struct iscsi_cls_conn *conn, enum iscsi_err error)
1080 {
1081 	struct nlmsghdr	*nlh;
1082 	struct sk_buff	*skb;
1083 	struct iscsi_uevent *ev;
1084 	struct iscsi_internal *priv;
1085 	int len = NLMSG_SPACE(sizeof(*ev));
1086 
1087 	priv = iscsi_if_transport_lookup(conn->transport);
1088 	if (!priv)
1089 		return;
1090 
1091 	skb = alloc_skb(len, GFP_ATOMIC);
1092 	if (!skb) {
1093 		iscsi_cls_conn_printk(KERN_ERR, conn, "gracefully ignored "
1094 				      "conn error (%d)\n", error);
1095 		return;
1096 	}
1097 
1098 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1099 	ev = NLMSG_DATA(nlh);
1100 	ev->transport_handle = iscsi_handle(conn->transport);
1101 	ev->type = ISCSI_KEVENT_CONN_ERROR;
1102 	ev->r.connerror.error = error;
1103 	ev->r.connerror.cid = conn->cid;
1104 	ev->r.connerror.sid = iscsi_conn_get_sid(conn);
1105 
1106 	iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);
1107 
1108 	iscsi_cls_conn_printk(KERN_INFO, conn, "detected conn error (%d)\n",
1109 			      error);
1110 }
1111 EXPORT_SYMBOL_GPL(iscsi_conn_error_event);
1112 
1113 static int
1114 iscsi_if_send_reply(uint32_t group, int seq, int type, int done, int multi,
1115 		    void *payload, int size)
1116 {
1117 	struct sk_buff	*skb;
1118 	struct nlmsghdr	*nlh;
1119 	int len = NLMSG_SPACE(size);
1120 	int flags = multi ? NLM_F_MULTI : 0;
1121 	int t = done ? NLMSG_DONE : type;
1122 
1123 	skb = alloc_skb(len, GFP_ATOMIC);
1124 	if (!skb) {
1125 		printk(KERN_ERR "Could not allocate skb to send reply.\n");
1126 		return -ENOMEM;
1127 	}
1128 
1129 	nlh = __nlmsg_put(skb, 0, 0, t, (len - sizeof(*nlh)), 0);
1130 	nlh->nlmsg_flags = flags;
1131 	memcpy(NLMSG_DATA(nlh), payload, size);
1132 	return iscsi_multicast_skb(skb, group, GFP_ATOMIC);
1133 }
1134 
1135 static int
1136 iscsi_if_get_stats(struct iscsi_transport *transport, struct nlmsghdr *nlh)
1137 {
1138 	struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1139 	struct iscsi_stats *stats;
1140 	struct sk_buff *skbstat;
1141 	struct iscsi_cls_conn *conn;
1142 	struct nlmsghdr	*nlhstat;
1143 	struct iscsi_uevent *evstat;
1144 	struct iscsi_internal *priv;
1145 	int len = NLMSG_SPACE(sizeof(*ev) +
1146 			      sizeof(struct iscsi_stats) +
1147 			      sizeof(struct iscsi_stats_custom) *
1148 			      ISCSI_STATS_CUSTOM_MAX);
1149 	int err = 0;
1150 
1151 	priv = iscsi_if_transport_lookup(transport);
1152 	if (!priv)
1153 		return -EINVAL;
1154 
1155 	conn = iscsi_conn_lookup(ev->u.get_stats.sid, ev->u.get_stats.cid);
1156 	if (!conn)
1157 		return -EEXIST;
1158 
1159 	do {
1160 		int actual_size;
1161 
1162 		skbstat = alloc_skb(len, GFP_ATOMIC);
1163 		if (!skbstat) {
1164 			iscsi_cls_conn_printk(KERN_ERR, conn, "can not "
1165 					      "deliver stats: OOM\n");
1166 			return -ENOMEM;
1167 		}
1168 
1169 		nlhstat = __nlmsg_put(skbstat, 0, 0, 0,
1170 				      (len - sizeof(*nlhstat)), 0);
1171 		evstat = NLMSG_DATA(nlhstat);
1172 		memset(evstat, 0, sizeof(*evstat));
1173 		evstat->transport_handle = iscsi_handle(conn->transport);
1174 		evstat->type = nlh->nlmsg_type;
1175 		evstat->u.get_stats.cid =
1176 			ev->u.get_stats.cid;
1177 		evstat->u.get_stats.sid =
1178 			ev->u.get_stats.sid;
1179 		stats = (struct iscsi_stats *)
1180 			((char*)evstat + sizeof(*evstat));
1181 		memset(stats, 0, sizeof(*stats));
1182 
1183 		transport->get_stats(conn, stats);
1184 		actual_size = NLMSG_SPACE(sizeof(struct iscsi_uevent) +
1185 					  sizeof(struct iscsi_stats) +
1186 					  sizeof(struct iscsi_stats_custom) *
1187 					  stats->custom_length);
1188 		actual_size -= sizeof(*nlhstat);
1189 		actual_size = NLMSG_LENGTH(actual_size);
1190 		skb_trim(skbstat, NLMSG_ALIGN(actual_size));
1191 		nlhstat->nlmsg_len = actual_size;
1192 
1193 		err = iscsi_multicast_skb(skbstat, ISCSI_NL_GRP_ISCSID,
1194 					  GFP_ATOMIC);
1195 	} while (err < 0 && err != -ECONNREFUSED);
1196 
1197 	return err;
1198 }
1199 
1200 /**
1201  * iscsi_session_event - send session destr. completion event
1202  * @session: iscsi class session
1203  * @event: type of event
1204  */
1205 int iscsi_session_event(struct iscsi_cls_session *session,
1206 			enum iscsi_uevent_e event)
1207 {
1208 	struct iscsi_internal *priv;
1209 	struct Scsi_Host *shost;
1210 	struct iscsi_uevent *ev;
1211 	struct sk_buff  *skb;
1212 	struct nlmsghdr *nlh;
1213 	int rc, len = NLMSG_SPACE(sizeof(*ev));
1214 
1215 	priv = iscsi_if_transport_lookup(session->transport);
1216 	if (!priv)
1217 		return -EINVAL;
1218 	shost = iscsi_session_to_shost(session);
1219 
1220 	skb = alloc_skb(len, GFP_KERNEL);
1221 	if (!skb) {
1222 		iscsi_cls_session_printk(KERN_ERR, session,
1223 					 "Cannot notify userspace of session "
1224 					 "event %u\n", event);
1225 		return -ENOMEM;
1226 	}
1227 
1228 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1229 	ev = NLMSG_DATA(nlh);
1230 	ev->transport_handle = iscsi_handle(session->transport);
1231 
1232 	ev->type = event;
1233 	switch (event) {
1234 	case ISCSI_KEVENT_DESTROY_SESSION:
1235 		ev->r.d_session.host_no = shost->host_no;
1236 		ev->r.d_session.sid = session->sid;
1237 		break;
1238 	case ISCSI_KEVENT_CREATE_SESSION:
1239 		ev->r.c_session_ret.host_no = shost->host_no;
1240 		ev->r.c_session_ret.sid = session->sid;
1241 		break;
1242 	case ISCSI_KEVENT_UNBIND_SESSION:
1243 		ev->r.unbind_session.host_no = shost->host_no;
1244 		ev->r.unbind_session.sid = session->sid;
1245 		break;
1246 	default:
1247 		iscsi_cls_session_printk(KERN_ERR, session, "Invalid event "
1248 					 "%u.\n", event);
1249 		kfree_skb(skb);
1250 		return -EINVAL;
1251 	}
1252 
1253 	/*
1254 	 * this will occur if the daemon is not up, so we just warn
1255 	 * the user and when the daemon is restarted it will handle it
1256 	 */
1257 	rc = iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_KERNEL);
1258 	if (rc == -ESRCH)
1259 		iscsi_cls_session_printk(KERN_ERR, session,
1260 					 "Cannot notify userspace of session "
1261 					 "event %u. Check iscsi daemon\n",
1262 					 event);
1263 
1264 	ISCSI_DBG_TRANS_SESSION(session, "Completed handling event %d rc %d\n",
1265 				event, rc);
1266 	return rc;
1267 }
1268 EXPORT_SYMBOL_GPL(iscsi_session_event);
1269 
1270 static int
1271 iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_endpoint *ep,
1272 			struct iscsi_uevent *ev, uint32_t initial_cmdsn,
1273 			uint16_t cmds_max, uint16_t queue_depth)
1274 {
1275 	struct iscsi_transport *transport = priv->iscsi_transport;
1276 	struct iscsi_cls_session *session;
1277 	struct Scsi_Host *shost;
1278 
1279 	session = transport->create_session(ep, cmds_max, queue_depth,
1280 					    initial_cmdsn);
1281 	if (!session)
1282 		return -ENOMEM;
1283 
1284 	shost = iscsi_session_to_shost(session);
1285 	ev->r.c_session_ret.host_no = shost->host_no;
1286 	ev->r.c_session_ret.sid = session->sid;
1287 	ISCSI_DBG_TRANS_SESSION(session,
1288 				"Completed creating transport session\n");
1289 	return 0;
1290 }
1291 
1292 static int
1293 iscsi_if_create_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1294 {
1295 	struct iscsi_cls_conn *conn;
1296 	struct iscsi_cls_session *session;
1297 
1298 	session = iscsi_session_lookup(ev->u.c_conn.sid);
1299 	if (!session) {
1300 		printk(KERN_ERR "iscsi: invalid session %d.\n",
1301 		       ev->u.c_conn.sid);
1302 		return -EINVAL;
1303 	}
1304 
1305 	conn = transport->create_conn(session, ev->u.c_conn.cid);
1306 	if (!conn) {
1307 		iscsi_cls_session_printk(KERN_ERR, session,
1308 					 "couldn't create a new connection.");
1309 		return -ENOMEM;
1310 	}
1311 
1312 	ev->r.c_conn_ret.sid = session->sid;
1313 	ev->r.c_conn_ret.cid = conn->cid;
1314 
1315 	ISCSI_DBG_TRANS_CONN(conn, "Completed creating transport conn\n");
1316 	return 0;
1317 }
1318 
1319 static int
1320 iscsi_if_destroy_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1321 {
1322 	struct iscsi_cls_conn *conn;
1323 
1324 	conn = iscsi_conn_lookup(ev->u.d_conn.sid, ev->u.d_conn.cid);
1325 	if (!conn)
1326 		return -EINVAL;
1327 
1328 	ISCSI_DBG_TRANS_CONN(conn, "Destroying transport conn\n");
1329 	if (transport->destroy_conn)
1330 		transport->destroy_conn(conn);
1331 
1332 	return 0;
1333 }
1334 
1335 static int
1336 iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1337 {
1338 	char *data = (char*)ev + sizeof(*ev);
1339 	struct iscsi_cls_conn *conn;
1340 	struct iscsi_cls_session *session;
1341 	int err = 0, value = 0;
1342 
1343 	session = iscsi_session_lookup(ev->u.set_param.sid);
1344 	conn = iscsi_conn_lookup(ev->u.set_param.sid, ev->u.set_param.cid);
1345 	if (!conn || !session)
1346 		return -EINVAL;
1347 
1348 	switch (ev->u.set_param.param) {
1349 	case ISCSI_PARAM_SESS_RECOVERY_TMO:
1350 		sscanf(data, "%d", &value);
1351 		if (value != 0)
1352 			session->recovery_tmo = value;
1353 		break;
1354 	default:
1355 		err = transport->set_param(conn, ev->u.set_param.param,
1356 					   data, ev->u.set_param.len);
1357 	}
1358 
1359 	return err;
1360 }
1361 
1362 static int iscsi_if_ep_connect(struct iscsi_transport *transport,
1363 			       struct iscsi_uevent *ev, int msg_type)
1364 {
1365 	struct iscsi_endpoint *ep;
1366 	struct sockaddr *dst_addr;
1367 	struct Scsi_Host *shost = NULL;
1368 	int non_blocking, err = 0;
1369 
1370 	if (!transport->ep_connect)
1371 		return -EINVAL;
1372 
1373 	if (msg_type == ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST) {
1374 		shost = scsi_host_lookup(ev->u.ep_connect_through_host.host_no);
1375 		if (!shost) {
1376 			printk(KERN_ERR "ep connect failed. Could not find "
1377 			       "host no %u\n",
1378 			       ev->u.ep_connect_through_host.host_no);
1379 			return -ENODEV;
1380 		}
1381 		non_blocking = ev->u.ep_connect_through_host.non_blocking;
1382 	} else
1383 		non_blocking = ev->u.ep_connect.non_blocking;
1384 
1385 	dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1386 	ep = transport->ep_connect(shost, dst_addr, non_blocking);
1387 	if (IS_ERR(ep)) {
1388 		err = PTR_ERR(ep);
1389 		goto release_host;
1390 	}
1391 
1392 	ev->r.ep_connect_ret.handle = ep->id;
1393 release_host:
1394 	if (shost)
1395 		scsi_host_put(shost);
1396 	return err;
1397 }
1398 
1399 static int
1400 iscsi_if_transport_ep(struct iscsi_transport *transport,
1401 		      struct iscsi_uevent *ev, int msg_type)
1402 {
1403 	struct iscsi_endpoint *ep;
1404 	int rc = 0;
1405 
1406 	switch (msg_type) {
1407 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST:
1408 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1409 		rc = iscsi_if_ep_connect(transport, ev, msg_type);
1410 		break;
1411 	case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1412 		if (!transport->ep_poll)
1413 			return -EINVAL;
1414 
1415 		ep = iscsi_lookup_endpoint(ev->u.ep_poll.ep_handle);
1416 		if (!ep)
1417 			return -EINVAL;
1418 
1419 		ev->r.retcode = transport->ep_poll(ep,
1420 						   ev->u.ep_poll.timeout_ms);
1421 		break;
1422 	case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1423 		if (!transport->ep_disconnect)
1424 			return -EINVAL;
1425 
1426 		ep = iscsi_lookup_endpoint(ev->u.ep_disconnect.ep_handle);
1427 		if (!ep)
1428 			return -EINVAL;
1429 
1430 		transport->ep_disconnect(ep);
1431 		break;
1432 	}
1433 	return rc;
1434 }
1435 
1436 static int
1437 iscsi_tgt_dscvr(struct iscsi_transport *transport,
1438 		struct iscsi_uevent *ev)
1439 {
1440 	struct Scsi_Host *shost;
1441 	struct sockaddr *dst_addr;
1442 	int err;
1443 
1444 	if (!transport->tgt_dscvr)
1445 		return -EINVAL;
1446 
1447 	shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);
1448 	if (!shost) {
1449 		printk(KERN_ERR "target discovery could not find host no %u\n",
1450 		       ev->u.tgt_dscvr.host_no);
1451 		return -ENODEV;
1452 	}
1453 
1454 
1455 	dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1456 	err = transport->tgt_dscvr(shost, ev->u.tgt_dscvr.type,
1457 				   ev->u.tgt_dscvr.enable, dst_addr);
1458 	scsi_host_put(shost);
1459 	return err;
1460 }
1461 
1462 static int
1463 iscsi_set_host_param(struct iscsi_transport *transport,
1464 		     struct iscsi_uevent *ev)
1465 {
1466 	char *data = (char*)ev + sizeof(*ev);
1467 	struct Scsi_Host *shost;
1468 	int err;
1469 
1470 	if (!transport->set_host_param)
1471 		return -ENOSYS;
1472 
1473 	shost = scsi_host_lookup(ev->u.set_host_param.host_no);
1474 	if (!shost) {
1475 		printk(KERN_ERR "set_host_param could not find host no %u\n",
1476 		       ev->u.set_host_param.host_no);
1477 		return -ENODEV;
1478 	}
1479 
1480 	err = transport->set_host_param(shost, ev->u.set_host_param.param,
1481 					data, ev->u.set_host_param.len);
1482 	scsi_host_put(shost);
1483 	return err;
1484 }
1485 
1486 static int
1487 iscsi_set_path(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1488 {
1489 	struct Scsi_Host *shost;
1490 	struct iscsi_path *params;
1491 	int err;
1492 
1493 	if (!transport->set_path)
1494 		return -ENOSYS;
1495 
1496 	shost = scsi_host_lookup(ev->u.set_path.host_no);
1497 	if (!shost) {
1498 		printk(KERN_ERR "set path could not find host no %u\n",
1499 		       ev->u.set_path.host_no);
1500 		return -ENODEV;
1501 	}
1502 
1503 	params = (struct iscsi_path *)((char *)ev + sizeof(*ev));
1504 	err = transport->set_path(shost, params);
1505 
1506 	scsi_host_put(shost);
1507 	return err;
1508 }
1509 
1510 static int
1511 iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
1512 {
1513 	int err = 0;
1514 	struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1515 	struct iscsi_transport *transport = NULL;
1516 	struct iscsi_internal *priv;
1517 	struct iscsi_cls_session *session;
1518 	struct iscsi_cls_conn *conn;
1519 	struct iscsi_endpoint *ep = NULL;
1520 
1521 	if (nlh->nlmsg_type == ISCSI_UEVENT_PATH_UPDATE)
1522 		*group = ISCSI_NL_GRP_UIP;
1523 	else
1524 		*group = ISCSI_NL_GRP_ISCSID;
1525 
1526 	priv = iscsi_if_transport_lookup(iscsi_ptr(ev->transport_handle));
1527 	if (!priv)
1528 		return -EINVAL;
1529 	transport = priv->iscsi_transport;
1530 
1531 	if (!try_module_get(transport->owner))
1532 		return -EINVAL;
1533 
1534 	switch (nlh->nlmsg_type) {
1535 	case ISCSI_UEVENT_CREATE_SESSION:
1536 		err = iscsi_if_create_session(priv, ep, ev,
1537 					      ev->u.c_session.initial_cmdsn,
1538 					      ev->u.c_session.cmds_max,
1539 					      ev->u.c_session.queue_depth);
1540 		break;
1541 	case ISCSI_UEVENT_CREATE_BOUND_SESSION:
1542 		ep = iscsi_lookup_endpoint(ev->u.c_bound_session.ep_handle);
1543 		if (!ep) {
1544 			err = -EINVAL;
1545 			break;
1546 		}
1547 
1548 		err = iscsi_if_create_session(priv, ep, ev,
1549 					ev->u.c_bound_session.initial_cmdsn,
1550 					ev->u.c_bound_session.cmds_max,
1551 					ev->u.c_bound_session.queue_depth);
1552 		break;
1553 	case ISCSI_UEVENT_DESTROY_SESSION:
1554 		session = iscsi_session_lookup(ev->u.d_session.sid);
1555 		if (session)
1556 			transport->destroy_session(session);
1557 		else
1558 			err = -EINVAL;
1559 		break;
1560 	case ISCSI_UEVENT_UNBIND_SESSION:
1561 		session = iscsi_session_lookup(ev->u.d_session.sid);
1562 		if (session)
1563 			scsi_queue_work(iscsi_session_to_shost(session),
1564 					&session->unbind_work);
1565 		else
1566 			err = -EINVAL;
1567 		break;
1568 	case ISCSI_UEVENT_CREATE_CONN:
1569 		err = iscsi_if_create_conn(transport, ev);
1570 		break;
1571 	case ISCSI_UEVENT_DESTROY_CONN:
1572 		err = iscsi_if_destroy_conn(transport, ev);
1573 		break;
1574 	case ISCSI_UEVENT_BIND_CONN:
1575 		session = iscsi_session_lookup(ev->u.b_conn.sid);
1576 		conn = iscsi_conn_lookup(ev->u.b_conn.sid, ev->u.b_conn.cid);
1577 
1578 		if (session && conn)
1579 			ev->r.retcode =	transport->bind_conn(session, conn,
1580 					ev->u.b_conn.transport_eph,
1581 					ev->u.b_conn.is_leading);
1582 		else
1583 			err = -EINVAL;
1584 		break;
1585 	case ISCSI_UEVENT_SET_PARAM:
1586 		err = iscsi_set_param(transport, ev);
1587 		break;
1588 	case ISCSI_UEVENT_START_CONN:
1589 		conn = iscsi_conn_lookup(ev->u.start_conn.sid, ev->u.start_conn.cid);
1590 		if (conn)
1591 			ev->r.retcode = transport->start_conn(conn);
1592 		else
1593 			err = -EINVAL;
1594 		break;
1595 	case ISCSI_UEVENT_STOP_CONN:
1596 		conn = iscsi_conn_lookup(ev->u.stop_conn.sid, ev->u.stop_conn.cid);
1597 		if (conn)
1598 			transport->stop_conn(conn, ev->u.stop_conn.flag);
1599 		else
1600 			err = -EINVAL;
1601 		break;
1602 	case ISCSI_UEVENT_SEND_PDU:
1603 		conn = iscsi_conn_lookup(ev->u.send_pdu.sid, ev->u.send_pdu.cid);
1604 		if (conn)
1605 			ev->r.retcode =	transport->send_pdu(conn,
1606 				(struct iscsi_hdr*)((char*)ev + sizeof(*ev)),
1607 				(char*)ev + sizeof(*ev) + ev->u.send_pdu.hdr_size,
1608 				ev->u.send_pdu.data_size);
1609 		else
1610 			err = -EINVAL;
1611 		break;
1612 	case ISCSI_UEVENT_GET_STATS:
1613 		err = iscsi_if_get_stats(transport, nlh);
1614 		break;
1615 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1616 	case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1617 	case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1618 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST:
1619 		err = iscsi_if_transport_ep(transport, ev, nlh->nlmsg_type);
1620 		break;
1621 	case ISCSI_UEVENT_TGT_DSCVR:
1622 		err = iscsi_tgt_dscvr(transport, ev);
1623 		break;
1624 	case ISCSI_UEVENT_SET_HOST_PARAM:
1625 		err = iscsi_set_host_param(transport, ev);
1626 		break;
1627 	case ISCSI_UEVENT_PATH_UPDATE:
1628 		err = iscsi_set_path(transport, ev);
1629 		break;
1630 	default:
1631 		err = -ENOSYS;
1632 		break;
1633 	}
1634 
1635 	module_put(transport->owner);
1636 	return err;
1637 }
1638 
1639 /*
1640  * Get message from skb.  Each message is processed by iscsi_if_recv_msg.
1641  * Malformed skbs with wrong lengths or invalid creds are not processed.
1642  */
1643 static void
1644 iscsi_if_rx(struct sk_buff *skb)
1645 {
1646 	mutex_lock(&rx_queue_mutex);
1647 	while (skb->len >= NLMSG_SPACE(0)) {
1648 		int err;
1649 		uint32_t rlen;
1650 		struct nlmsghdr	*nlh;
1651 		struct iscsi_uevent *ev;
1652 		uint32_t group;
1653 
1654 		nlh = nlmsg_hdr(skb);
1655 		if (nlh->nlmsg_len < sizeof(*nlh) ||
1656 		    skb->len < nlh->nlmsg_len) {
1657 			break;
1658 		}
1659 
1660 		ev = NLMSG_DATA(nlh);
1661 		rlen = NLMSG_ALIGN(nlh->nlmsg_len);
1662 		if (rlen > skb->len)
1663 			rlen = skb->len;
1664 
1665 		err = iscsi_if_recv_msg(skb, nlh, &group);
1666 		if (err) {
1667 			ev->type = ISCSI_KEVENT_IF_ERROR;
1668 			ev->iferror = err;
1669 		}
1670 		do {
1671 			/*
1672 			 * special case for GET_STATS:
1673 			 * on success - sending reply and stats from
1674 			 * inside of if_recv_msg(),
1675 			 * on error - fall through.
1676 			 */
1677 			if (ev->type == ISCSI_UEVENT_GET_STATS && !err)
1678 				break;
1679 			err = iscsi_if_send_reply(group, nlh->nlmsg_seq,
1680 				nlh->nlmsg_type, 0, 0, ev, sizeof(*ev));
1681 		} while (err < 0 && err != -ECONNREFUSED);
1682 		skb_pull(skb, rlen);
1683 	}
1684 	mutex_unlock(&rx_queue_mutex);
1685 }
1686 
1687 #define ISCSI_CLASS_ATTR(_prefix,_name,_mode,_show,_store)		\
1688 struct device_attribute dev_attr_##_prefix##_##_name =	\
1689 	__ATTR(_name,_mode,_show,_store)
1690 
1691 /*
1692  * iSCSI connection attrs
1693  */
1694 #define iscsi_conn_attr_show(param)					\
1695 static ssize_t								\
1696 show_conn_param_##param(struct device *dev, 				\
1697 			struct device_attribute *attr, char *buf)	\
1698 {									\
1699 	struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev->parent);	\
1700 	struct iscsi_transport *t = conn->transport;			\
1701 	return t->get_conn_param(conn, param, buf);			\
1702 }
1703 
1704 #define iscsi_conn_attr(field, param)					\
1705 	iscsi_conn_attr_show(param)					\
1706 static ISCSI_CLASS_ATTR(conn, field, S_IRUGO, show_conn_param_##param,	\
1707 			NULL);
1708 
1709 iscsi_conn_attr(max_recv_dlength, ISCSI_PARAM_MAX_RECV_DLENGTH);
1710 iscsi_conn_attr(max_xmit_dlength, ISCSI_PARAM_MAX_XMIT_DLENGTH);
1711 iscsi_conn_attr(header_digest, ISCSI_PARAM_HDRDGST_EN);
1712 iscsi_conn_attr(data_digest, ISCSI_PARAM_DATADGST_EN);
1713 iscsi_conn_attr(ifmarker, ISCSI_PARAM_IFMARKER_EN);
1714 iscsi_conn_attr(ofmarker, ISCSI_PARAM_OFMARKER_EN);
1715 iscsi_conn_attr(persistent_port, ISCSI_PARAM_PERSISTENT_PORT);
1716 iscsi_conn_attr(port, ISCSI_PARAM_CONN_PORT);
1717 iscsi_conn_attr(exp_statsn, ISCSI_PARAM_EXP_STATSN);
1718 iscsi_conn_attr(persistent_address, ISCSI_PARAM_PERSISTENT_ADDRESS);
1719 iscsi_conn_attr(address, ISCSI_PARAM_CONN_ADDRESS);
1720 iscsi_conn_attr(ping_tmo, ISCSI_PARAM_PING_TMO);
1721 iscsi_conn_attr(recv_tmo, ISCSI_PARAM_RECV_TMO);
1722 
1723 /*
1724  * iSCSI session attrs
1725  */
1726 #define iscsi_session_attr_show(param, perm)				\
1727 static ssize_t								\
1728 show_session_param_##param(struct device *dev,				\
1729 			   struct device_attribute *attr, char *buf)	\
1730 {									\
1731 	struct iscsi_cls_session *session = 				\
1732 		iscsi_dev_to_session(dev->parent);			\
1733 	struct iscsi_transport *t = session->transport;			\
1734 									\
1735 	if (perm && !capable(CAP_SYS_ADMIN))				\
1736 		return -EACCES;						\
1737 	return t->get_session_param(session, param, buf);		\
1738 }
1739 
1740 #define iscsi_session_attr(field, param, perm)				\
1741 	iscsi_session_attr_show(param, perm)				\
1742 static ISCSI_CLASS_ATTR(sess, field, S_IRUGO, show_session_param_##param, \
1743 			NULL);
1744 
1745 iscsi_session_attr(targetname, ISCSI_PARAM_TARGET_NAME, 0);
1746 iscsi_session_attr(initial_r2t, ISCSI_PARAM_INITIAL_R2T_EN, 0);
1747 iscsi_session_attr(max_outstanding_r2t, ISCSI_PARAM_MAX_R2T, 0);
1748 iscsi_session_attr(immediate_data, ISCSI_PARAM_IMM_DATA_EN, 0);
1749 iscsi_session_attr(first_burst_len, ISCSI_PARAM_FIRST_BURST, 0);
1750 iscsi_session_attr(max_burst_len, ISCSI_PARAM_MAX_BURST, 0);
1751 iscsi_session_attr(data_pdu_in_order, ISCSI_PARAM_PDU_INORDER_EN, 0);
1752 iscsi_session_attr(data_seq_in_order, ISCSI_PARAM_DATASEQ_INORDER_EN, 0);
1753 iscsi_session_attr(erl, ISCSI_PARAM_ERL, 0);
1754 iscsi_session_attr(tpgt, ISCSI_PARAM_TPGT, 0);
1755 iscsi_session_attr(username, ISCSI_PARAM_USERNAME, 1);
1756 iscsi_session_attr(username_in, ISCSI_PARAM_USERNAME_IN, 1);
1757 iscsi_session_attr(password, ISCSI_PARAM_PASSWORD, 1);
1758 iscsi_session_attr(password_in, ISCSI_PARAM_PASSWORD_IN, 1);
1759 iscsi_session_attr(fast_abort, ISCSI_PARAM_FAST_ABORT, 0);
1760 iscsi_session_attr(abort_tmo, ISCSI_PARAM_ABORT_TMO, 0);
1761 iscsi_session_attr(lu_reset_tmo, ISCSI_PARAM_LU_RESET_TMO, 0);
1762 iscsi_session_attr(ifacename, ISCSI_PARAM_IFACE_NAME, 0);
1763 iscsi_session_attr(initiatorname, ISCSI_PARAM_INITIATOR_NAME, 0)
1764 
1765 static ssize_t
1766 show_priv_session_state(struct device *dev, struct device_attribute *attr,
1767 			char *buf)
1768 {
1769 	struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
1770 	return sprintf(buf, "%s\n", iscsi_session_state_name(session->state));
1771 }
1772 static ISCSI_CLASS_ATTR(priv_sess, state, S_IRUGO, show_priv_session_state,
1773 			NULL);
1774 
1775 #define iscsi_priv_session_attr_show(field, format)			\
1776 static ssize_t								\
1777 show_priv_session_##field(struct device *dev, 				\
1778 			  struct device_attribute *attr, char *buf)	\
1779 {									\
1780 	struct iscsi_cls_session *session = 				\
1781 			iscsi_dev_to_session(dev->parent);		\
1782 	return sprintf(buf, format"\n", session->field);		\
1783 }
1784 
1785 #define iscsi_priv_session_attr(field, format)				\
1786 	iscsi_priv_session_attr_show(field, format)			\
1787 static ISCSI_CLASS_ATTR(priv_sess, field, S_IRUGO, show_priv_session_##field, \
1788 			NULL)
1789 iscsi_priv_session_attr(recovery_tmo, "%d");
1790 
1791 /*
1792  * iSCSI host attrs
1793  */
1794 #define iscsi_host_attr_show(param)					\
1795 static ssize_t								\
1796 show_host_param_##param(struct device *dev, 				\
1797 			struct device_attribute *attr, char *buf)	\
1798 {									\
1799 	struct Scsi_Host *shost = transport_class_to_shost(dev);	\
1800 	struct iscsi_internal *priv = to_iscsi_internal(shost->transportt); \
1801 	return priv->iscsi_transport->get_host_param(shost, param, buf); \
1802 }
1803 
1804 #define iscsi_host_attr(field, param)					\
1805 	iscsi_host_attr_show(param)					\
1806 static ISCSI_CLASS_ATTR(host, field, S_IRUGO, show_host_param_##param,	\
1807 			NULL);
1808 
1809 iscsi_host_attr(netdev, ISCSI_HOST_PARAM_NETDEV_NAME);
1810 iscsi_host_attr(hwaddress, ISCSI_HOST_PARAM_HWADDRESS);
1811 iscsi_host_attr(ipaddress, ISCSI_HOST_PARAM_IPADDRESS);
1812 iscsi_host_attr(initiatorname, ISCSI_HOST_PARAM_INITIATOR_NAME);
1813 
1814 #define SETUP_PRIV_SESSION_RD_ATTR(field)				\
1815 do {									\
1816 	priv->session_attrs[count] = &dev_attr_priv_sess_##field; \
1817 	count++;							\
1818 } while (0)
1819 
1820 
1821 #define SETUP_SESSION_RD_ATTR(field, param_flag)			\
1822 do {									\
1823 	if (tt->param_mask & param_flag) {				\
1824 		priv->session_attrs[count] = &dev_attr_sess_##field; \
1825 		count++;						\
1826 	}								\
1827 } while (0)
1828 
1829 #define SETUP_CONN_RD_ATTR(field, param_flag)				\
1830 do {									\
1831 	if (tt->param_mask & param_flag) {				\
1832 		priv->conn_attrs[count] = &dev_attr_conn_##field; \
1833 		count++;						\
1834 	}								\
1835 } while (0)
1836 
1837 #define SETUP_HOST_RD_ATTR(field, param_flag)				\
1838 do {									\
1839 	if (tt->host_param_mask & param_flag) {				\
1840 		priv->host_attrs[count] = &dev_attr_host_##field; \
1841 		count++;						\
1842 	}								\
1843 } while (0)
1844 
1845 static int iscsi_session_match(struct attribute_container *cont,
1846 			   struct device *dev)
1847 {
1848 	struct iscsi_cls_session *session;
1849 	struct Scsi_Host *shost;
1850 	struct iscsi_internal *priv;
1851 
1852 	if (!iscsi_is_session_dev(dev))
1853 		return 0;
1854 
1855 	session = iscsi_dev_to_session(dev);
1856 	shost = iscsi_session_to_shost(session);
1857 	if (!shost->transportt)
1858 		return 0;
1859 
1860 	priv = to_iscsi_internal(shost->transportt);
1861 	if (priv->session_cont.ac.class != &iscsi_session_class.class)
1862 		return 0;
1863 
1864 	return &priv->session_cont.ac == cont;
1865 }
1866 
1867 static int iscsi_conn_match(struct attribute_container *cont,
1868 			   struct device *dev)
1869 {
1870 	struct iscsi_cls_session *session;
1871 	struct iscsi_cls_conn *conn;
1872 	struct Scsi_Host *shost;
1873 	struct iscsi_internal *priv;
1874 
1875 	if (!iscsi_is_conn_dev(dev))
1876 		return 0;
1877 
1878 	conn = iscsi_dev_to_conn(dev);
1879 	session = iscsi_dev_to_session(conn->dev.parent);
1880 	shost = iscsi_session_to_shost(session);
1881 
1882 	if (!shost->transportt)
1883 		return 0;
1884 
1885 	priv = to_iscsi_internal(shost->transportt);
1886 	if (priv->conn_cont.ac.class != &iscsi_connection_class.class)
1887 		return 0;
1888 
1889 	return &priv->conn_cont.ac == cont;
1890 }
1891 
1892 static int iscsi_host_match(struct attribute_container *cont,
1893 			    struct device *dev)
1894 {
1895 	struct Scsi_Host *shost;
1896 	struct iscsi_internal *priv;
1897 
1898 	if (!scsi_is_host_device(dev))
1899 		return 0;
1900 
1901 	shost = dev_to_shost(dev);
1902 	if (!shost->transportt  ||
1903 	    shost->transportt->host_attrs.ac.class != &iscsi_host_class.class)
1904 		return 0;
1905 
1906         priv = to_iscsi_internal(shost->transportt);
1907         return &priv->t.host_attrs.ac == cont;
1908 }
1909 
1910 struct scsi_transport_template *
1911 iscsi_register_transport(struct iscsi_transport *tt)
1912 {
1913 	struct iscsi_internal *priv;
1914 	unsigned long flags;
1915 	int count = 0, err;
1916 
1917 	BUG_ON(!tt);
1918 
1919 	priv = iscsi_if_transport_lookup(tt);
1920 	if (priv)
1921 		return NULL;
1922 
1923 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1924 	if (!priv)
1925 		return NULL;
1926 	INIT_LIST_HEAD(&priv->list);
1927 	priv->iscsi_transport = tt;
1928 	priv->t.user_scan = iscsi_user_scan;
1929 	priv->t.create_work_queue = 1;
1930 
1931 	priv->dev.class = &iscsi_transport_class;
1932 	dev_set_name(&priv->dev, "%s", tt->name);
1933 	err = device_register(&priv->dev);
1934 	if (err)
1935 		goto free_priv;
1936 
1937 	err = sysfs_create_group(&priv->dev.kobj, &iscsi_transport_group);
1938 	if (err)
1939 		goto unregister_dev;
1940 
1941 	/* host parameters */
1942 	priv->t.host_attrs.ac.attrs = &priv->host_attrs[0];
1943 	priv->t.host_attrs.ac.class = &iscsi_host_class.class;
1944 	priv->t.host_attrs.ac.match = iscsi_host_match;
1945 	priv->t.host_size = sizeof(struct iscsi_cls_host);
1946 	transport_container_register(&priv->t.host_attrs);
1947 
1948 	SETUP_HOST_RD_ATTR(netdev, ISCSI_HOST_NETDEV_NAME);
1949 	SETUP_HOST_RD_ATTR(ipaddress, ISCSI_HOST_IPADDRESS);
1950 	SETUP_HOST_RD_ATTR(hwaddress, ISCSI_HOST_HWADDRESS);
1951 	SETUP_HOST_RD_ATTR(initiatorname, ISCSI_HOST_INITIATOR_NAME);
1952 	BUG_ON(count > ISCSI_HOST_ATTRS);
1953 	priv->host_attrs[count] = NULL;
1954 	count = 0;
1955 
1956 	/* connection parameters */
1957 	priv->conn_cont.ac.attrs = &priv->conn_attrs[0];
1958 	priv->conn_cont.ac.class = &iscsi_connection_class.class;
1959 	priv->conn_cont.ac.match = iscsi_conn_match;
1960 	transport_container_register(&priv->conn_cont);
1961 
1962 	SETUP_CONN_RD_ATTR(max_recv_dlength, ISCSI_MAX_RECV_DLENGTH);
1963 	SETUP_CONN_RD_ATTR(max_xmit_dlength, ISCSI_MAX_XMIT_DLENGTH);
1964 	SETUP_CONN_RD_ATTR(header_digest, ISCSI_HDRDGST_EN);
1965 	SETUP_CONN_RD_ATTR(data_digest, ISCSI_DATADGST_EN);
1966 	SETUP_CONN_RD_ATTR(ifmarker, ISCSI_IFMARKER_EN);
1967 	SETUP_CONN_RD_ATTR(ofmarker, ISCSI_OFMARKER_EN);
1968 	SETUP_CONN_RD_ATTR(address, ISCSI_CONN_ADDRESS);
1969 	SETUP_CONN_RD_ATTR(port, ISCSI_CONN_PORT);
1970 	SETUP_CONN_RD_ATTR(exp_statsn, ISCSI_EXP_STATSN);
1971 	SETUP_CONN_RD_ATTR(persistent_address, ISCSI_PERSISTENT_ADDRESS);
1972 	SETUP_CONN_RD_ATTR(persistent_port, ISCSI_PERSISTENT_PORT);
1973 	SETUP_CONN_RD_ATTR(ping_tmo, ISCSI_PING_TMO);
1974 	SETUP_CONN_RD_ATTR(recv_tmo, ISCSI_RECV_TMO);
1975 
1976 	BUG_ON(count > ISCSI_CONN_ATTRS);
1977 	priv->conn_attrs[count] = NULL;
1978 	count = 0;
1979 
1980 	/* session parameters */
1981 	priv->session_cont.ac.attrs = &priv->session_attrs[0];
1982 	priv->session_cont.ac.class = &iscsi_session_class.class;
1983 	priv->session_cont.ac.match = iscsi_session_match;
1984 	transport_container_register(&priv->session_cont);
1985 
1986 	SETUP_SESSION_RD_ATTR(initial_r2t, ISCSI_INITIAL_R2T_EN);
1987 	SETUP_SESSION_RD_ATTR(max_outstanding_r2t, ISCSI_MAX_R2T);
1988 	SETUP_SESSION_RD_ATTR(immediate_data, ISCSI_IMM_DATA_EN);
1989 	SETUP_SESSION_RD_ATTR(first_burst_len, ISCSI_FIRST_BURST);
1990 	SETUP_SESSION_RD_ATTR(max_burst_len, ISCSI_MAX_BURST);
1991 	SETUP_SESSION_RD_ATTR(data_pdu_in_order, ISCSI_PDU_INORDER_EN);
1992 	SETUP_SESSION_RD_ATTR(data_seq_in_order, ISCSI_DATASEQ_INORDER_EN);
1993 	SETUP_SESSION_RD_ATTR(erl, ISCSI_ERL);
1994 	SETUP_SESSION_RD_ATTR(targetname, ISCSI_TARGET_NAME);
1995 	SETUP_SESSION_RD_ATTR(tpgt, ISCSI_TPGT);
1996 	SETUP_SESSION_RD_ATTR(password, ISCSI_USERNAME);
1997 	SETUP_SESSION_RD_ATTR(password_in, ISCSI_USERNAME_IN);
1998 	SETUP_SESSION_RD_ATTR(username, ISCSI_PASSWORD);
1999 	SETUP_SESSION_RD_ATTR(username_in, ISCSI_PASSWORD_IN);
2000 	SETUP_SESSION_RD_ATTR(fast_abort, ISCSI_FAST_ABORT);
2001 	SETUP_SESSION_RD_ATTR(abort_tmo, ISCSI_ABORT_TMO);
2002 	SETUP_SESSION_RD_ATTR(lu_reset_tmo,ISCSI_LU_RESET_TMO);
2003 	SETUP_SESSION_RD_ATTR(ifacename, ISCSI_IFACE_NAME);
2004 	SETUP_SESSION_RD_ATTR(initiatorname, ISCSI_INITIATOR_NAME);
2005 	SETUP_PRIV_SESSION_RD_ATTR(recovery_tmo);
2006 	SETUP_PRIV_SESSION_RD_ATTR(state);
2007 
2008 	BUG_ON(count > ISCSI_SESSION_ATTRS);
2009 	priv->session_attrs[count] = NULL;
2010 
2011 	spin_lock_irqsave(&iscsi_transport_lock, flags);
2012 	list_add(&priv->list, &iscsi_transports);
2013 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
2014 
2015 	printk(KERN_NOTICE "iscsi: registered transport (%s)\n", tt->name);
2016 	return &priv->t;
2017 
2018 unregister_dev:
2019 	device_unregister(&priv->dev);
2020 	return NULL;
2021 free_priv:
2022 	kfree(priv);
2023 	return NULL;
2024 }
2025 EXPORT_SYMBOL_GPL(iscsi_register_transport);
2026 
2027 int iscsi_unregister_transport(struct iscsi_transport *tt)
2028 {
2029 	struct iscsi_internal *priv;
2030 	unsigned long flags;
2031 
2032 	BUG_ON(!tt);
2033 
2034 	mutex_lock(&rx_queue_mutex);
2035 
2036 	priv = iscsi_if_transport_lookup(tt);
2037 	BUG_ON (!priv);
2038 
2039 	spin_lock_irqsave(&iscsi_transport_lock, flags);
2040 	list_del(&priv->list);
2041 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
2042 
2043 	transport_container_unregister(&priv->conn_cont);
2044 	transport_container_unregister(&priv->session_cont);
2045 	transport_container_unregister(&priv->t.host_attrs);
2046 
2047 	sysfs_remove_group(&priv->dev.kobj, &iscsi_transport_group);
2048 	device_unregister(&priv->dev);
2049 	mutex_unlock(&rx_queue_mutex);
2050 
2051 	return 0;
2052 }
2053 EXPORT_SYMBOL_GPL(iscsi_unregister_transport);
2054 
2055 static __init int iscsi_transport_init(void)
2056 {
2057 	int err;
2058 
2059 	printk(KERN_INFO "Loading iSCSI transport class v%s.\n",
2060 		ISCSI_TRANSPORT_VERSION);
2061 
2062 	atomic_set(&iscsi_session_nr, 0);
2063 
2064 	err = class_register(&iscsi_transport_class);
2065 	if (err)
2066 		return err;
2067 
2068 	err = class_register(&iscsi_endpoint_class);
2069 	if (err)
2070 		goto unregister_transport_class;
2071 
2072 	err = transport_class_register(&iscsi_host_class);
2073 	if (err)
2074 		goto unregister_endpoint_class;
2075 
2076 	err = transport_class_register(&iscsi_connection_class);
2077 	if (err)
2078 		goto unregister_host_class;
2079 
2080 	err = transport_class_register(&iscsi_session_class);
2081 	if (err)
2082 		goto unregister_conn_class;
2083 
2084 	nls = netlink_kernel_create(&init_net, NETLINK_ISCSI, 1, iscsi_if_rx,
2085 				    NULL, THIS_MODULE);
2086 	if (!nls) {
2087 		err = -ENOBUFS;
2088 		goto unregister_session_class;
2089 	}
2090 
2091 	iscsi_eh_timer_workq = create_singlethread_workqueue("iscsi_eh");
2092 	if (!iscsi_eh_timer_workq)
2093 		goto release_nls;
2094 
2095 	return 0;
2096 
2097 release_nls:
2098 	netlink_kernel_release(nls);
2099 unregister_session_class:
2100 	transport_class_unregister(&iscsi_session_class);
2101 unregister_conn_class:
2102 	transport_class_unregister(&iscsi_connection_class);
2103 unregister_host_class:
2104 	transport_class_unregister(&iscsi_host_class);
2105 unregister_endpoint_class:
2106 	class_unregister(&iscsi_endpoint_class);
2107 unregister_transport_class:
2108 	class_unregister(&iscsi_transport_class);
2109 	return err;
2110 }
2111 
2112 static void __exit iscsi_transport_exit(void)
2113 {
2114 	destroy_workqueue(iscsi_eh_timer_workq);
2115 	netlink_kernel_release(nls);
2116 	transport_class_unregister(&iscsi_connection_class);
2117 	transport_class_unregister(&iscsi_session_class);
2118 	transport_class_unregister(&iscsi_host_class);
2119 	class_unregister(&iscsi_endpoint_class);
2120 	class_unregister(&iscsi_transport_class);
2121 }
2122 
2123 module_init(iscsi_transport_init);
2124 module_exit(iscsi_transport_exit);
2125 
2126 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
2127 	      "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
2128 	      "Alex Aizman <itn780@yahoo.com>");
2129 MODULE_DESCRIPTION("iSCSI Transport Interface");
2130 MODULE_LICENSE("GPL");
2131 MODULE_VERSION(ISCSI_TRANSPORT_VERSION);
2132