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 22
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 	if (session->recovery_tmo >= 0)
631 		queue_delayed_work(iscsi_eh_timer_workq,
632 				   &session->recovery_work,
633 				   session->recovery_tmo * HZ);
634 }
635 
636 void iscsi_block_session(struct iscsi_cls_session *session)
637 {
638 	queue_work(iscsi_eh_timer_workq, &session->block_work);
639 }
640 EXPORT_SYMBOL_GPL(iscsi_block_session);
641 
642 static void __iscsi_unbind_session(struct work_struct *work)
643 {
644 	struct iscsi_cls_session *session =
645 			container_of(work, struct iscsi_cls_session,
646 				     unbind_work);
647 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
648 	struct iscsi_cls_host *ihost = shost->shost_data;
649 	unsigned long flags;
650 
651 	ISCSI_DBG_TRANS_SESSION(session, "Unbinding session\n");
652 
653 	/* Prevent new scans and make sure scanning is not in progress */
654 	mutex_lock(&ihost->mutex);
655 	spin_lock_irqsave(&session->lock, flags);
656 	if (session->target_id == ISCSI_MAX_TARGET) {
657 		spin_unlock_irqrestore(&session->lock, flags);
658 		mutex_unlock(&ihost->mutex);
659 		return;
660 	}
661 	session->target_id = ISCSI_MAX_TARGET;
662 	spin_unlock_irqrestore(&session->lock, flags);
663 	mutex_unlock(&ihost->mutex);
664 
665 	scsi_remove_target(&session->dev);
666 	iscsi_session_event(session, ISCSI_KEVENT_UNBIND_SESSION);
667 	ISCSI_DBG_TRANS_SESSION(session, "Completed target removal\n");
668 }
669 
670 struct iscsi_cls_session *
671 iscsi_alloc_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
672 		    int dd_size)
673 {
674 	struct iscsi_cls_session *session;
675 
676 	session = kzalloc(sizeof(*session) + dd_size,
677 			  GFP_KERNEL);
678 	if (!session)
679 		return NULL;
680 
681 	session->transport = transport;
682 	session->recovery_tmo = 120;
683 	session->state = ISCSI_SESSION_FREE;
684 	INIT_DELAYED_WORK(&session->recovery_work, session_recovery_timedout);
685 	INIT_LIST_HEAD(&session->sess_list);
686 	INIT_WORK(&session->unblock_work, __iscsi_unblock_session);
687 	INIT_WORK(&session->block_work, __iscsi_block_session);
688 	INIT_WORK(&session->unbind_work, __iscsi_unbind_session);
689 	INIT_WORK(&session->scan_work, iscsi_scan_session);
690 	spin_lock_init(&session->lock);
691 
692 	/* this is released in the dev's release function */
693 	scsi_host_get(shost);
694 	session->dev.parent = &shost->shost_gendev;
695 	session->dev.release = iscsi_session_release;
696 	device_initialize(&session->dev);
697 	if (dd_size)
698 		session->dd_data = &session[1];
699 
700 	ISCSI_DBG_TRANS_SESSION(session, "Completed session allocation\n");
701 	return session;
702 }
703 EXPORT_SYMBOL_GPL(iscsi_alloc_session);
704 
705 static int iscsi_get_next_target_id(struct device *dev, void *data)
706 {
707 	struct iscsi_cls_session *session;
708 	unsigned long flags;
709 	int err = 0;
710 
711 	if (!iscsi_is_session_dev(dev))
712 		return 0;
713 
714 	session = iscsi_dev_to_session(dev);
715 	spin_lock_irqsave(&session->lock, flags);
716 	if (*((unsigned int *) data) == session->target_id)
717 		err = -EEXIST;
718 	spin_unlock_irqrestore(&session->lock, flags);
719 	return err;
720 }
721 
722 int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
723 {
724 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
725 	struct iscsi_cls_host *ihost;
726 	unsigned long flags;
727 	unsigned int id = target_id;
728 	int err;
729 
730 	ihost = shost->shost_data;
731 	session->sid = atomic_add_return(1, &iscsi_session_nr);
732 
733 	if (id == ISCSI_MAX_TARGET) {
734 		for (id = 0; id < ISCSI_MAX_TARGET; id++) {
735 			err = device_for_each_child(&shost->shost_gendev, &id,
736 						    iscsi_get_next_target_id);
737 			if (!err)
738 				break;
739 		}
740 
741 		if (id == ISCSI_MAX_TARGET) {
742 			iscsi_cls_session_printk(KERN_ERR, session,
743 						 "Too many iscsi targets. Max "
744 						 "number of targets is %d.\n",
745 						 ISCSI_MAX_TARGET - 1);
746 			err = -EOVERFLOW;
747 			goto release_host;
748 		}
749 	}
750 	session->target_id = id;
751 
752 	dev_set_name(&session->dev, "session%u", session->sid);
753 	err = device_add(&session->dev);
754 	if (err) {
755 		iscsi_cls_session_printk(KERN_ERR, session,
756 					 "could not register session's dev\n");
757 		goto release_host;
758 	}
759 	transport_register_device(&session->dev);
760 
761 	spin_lock_irqsave(&sesslock, flags);
762 	list_add(&session->sess_list, &sesslist);
763 	spin_unlock_irqrestore(&sesslock, flags);
764 
765 	iscsi_session_event(session, ISCSI_KEVENT_CREATE_SESSION);
766 	ISCSI_DBG_TRANS_SESSION(session, "Completed session adding\n");
767 	return 0;
768 
769 release_host:
770 	scsi_host_put(shost);
771 	return err;
772 }
773 EXPORT_SYMBOL_GPL(iscsi_add_session);
774 
775 /**
776  * iscsi_create_session - create iscsi class session
777  * @shost: scsi host
778  * @transport: iscsi transport
779  * @dd_size: private driver data size
780  * @target_id: which target
781  *
782  * This can be called from a LLD or iscsi_transport.
783  */
784 struct iscsi_cls_session *
785 iscsi_create_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
786 		     int dd_size, unsigned int target_id)
787 {
788 	struct iscsi_cls_session *session;
789 
790 	session = iscsi_alloc_session(shost, transport, dd_size);
791 	if (!session)
792 		return NULL;
793 
794 	if (iscsi_add_session(session, target_id)) {
795 		iscsi_free_session(session);
796 		return NULL;
797 	}
798 	return session;
799 }
800 EXPORT_SYMBOL_GPL(iscsi_create_session);
801 
802 static void iscsi_conn_release(struct device *dev)
803 {
804 	struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev);
805 	struct device *parent = conn->dev.parent;
806 
807 	ISCSI_DBG_TRANS_CONN(conn, "Releasing conn\n");
808 	kfree(conn);
809 	put_device(parent);
810 }
811 
812 static int iscsi_is_conn_dev(const struct device *dev)
813 {
814 	return dev->release == iscsi_conn_release;
815 }
816 
817 static int iscsi_iter_destroy_conn_fn(struct device *dev, void *data)
818 {
819 	if (!iscsi_is_conn_dev(dev))
820 		return 0;
821 	return iscsi_destroy_conn(iscsi_dev_to_conn(dev));
822 }
823 
824 void iscsi_remove_session(struct iscsi_cls_session *session)
825 {
826 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
827 	unsigned long flags;
828 	int err;
829 
830 	ISCSI_DBG_TRANS_SESSION(session, "Removing session\n");
831 
832 	spin_lock_irqsave(&sesslock, flags);
833 	list_del(&session->sess_list);
834 	spin_unlock_irqrestore(&sesslock, flags);
835 
836 	/* make sure there are no blocks/unblocks queued */
837 	flush_workqueue(iscsi_eh_timer_workq);
838 	/* make sure the timedout callout is not running */
839 	if (!cancel_delayed_work(&session->recovery_work))
840 		flush_workqueue(iscsi_eh_timer_workq);
841 	/*
842 	 * If we are blocked let commands flow again. The lld or iscsi
843 	 * layer should set up the queuecommand to fail commands.
844 	 * We assume that LLD will not be calling block/unblock while
845 	 * removing the session.
846 	 */
847 	spin_lock_irqsave(&session->lock, flags);
848 	session->state = ISCSI_SESSION_FREE;
849 	spin_unlock_irqrestore(&session->lock, flags);
850 
851 	scsi_target_unblock(&session->dev);
852 	/* flush running scans then delete devices */
853 	scsi_flush_work(shost);
854 	__iscsi_unbind_session(&session->unbind_work);
855 
856 	/* hw iscsi may not have removed all connections from session */
857 	err = device_for_each_child(&session->dev, NULL,
858 				    iscsi_iter_destroy_conn_fn);
859 	if (err)
860 		iscsi_cls_session_printk(KERN_ERR, session,
861 					 "Could not delete all connections "
862 					 "for session. Error %d.\n", err);
863 
864 	transport_unregister_device(&session->dev);
865 
866 	ISCSI_DBG_TRANS_SESSION(session, "Completing session removal\n");
867 	device_del(&session->dev);
868 }
869 EXPORT_SYMBOL_GPL(iscsi_remove_session);
870 
871 void iscsi_free_session(struct iscsi_cls_session *session)
872 {
873 	ISCSI_DBG_TRANS_SESSION(session, "Freeing session\n");
874 	iscsi_session_event(session, ISCSI_KEVENT_DESTROY_SESSION);
875 	put_device(&session->dev);
876 }
877 EXPORT_SYMBOL_GPL(iscsi_free_session);
878 
879 /**
880  * iscsi_destroy_session - destroy iscsi session
881  * @session: iscsi_session
882  *
883  * Can be called by a LLD or iscsi_transport. There must not be
884  * any running connections.
885  */
886 int iscsi_destroy_session(struct iscsi_cls_session *session)
887 {
888 	iscsi_remove_session(session);
889 	ISCSI_DBG_TRANS_SESSION(session, "Completing session destruction\n");
890 	iscsi_free_session(session);
891 	return 0;
892 }
893 EXPORT_SYMBOL_GPL(iscsi_destroy_session);
894 
895 /**
896  * iscsi_create_conn - create iscsi class connection
897  * @session: iscsi cls session
898  * @dd_size: private driver data size
899  * @cid: connection id
900  *
901  * This can be called from a LLD or iscsi_transport. The connection
902  * is child of the session so cid must be unique for all connections
903  * on the session.
904  *
905  * Since we do not support MCS, cid will normally be zero. In some cases
906  * for software iscsi we could be trying to preallocate a connection struct
907  * in which case there could be two connection structs and cid would be
908  * non-zero.
909  */
910 struct iscsi_cls_conn *
911 iscsi_create_conn(struct iscsi_cls_session *session, int dd_size, uint32_t cid)
912 {
913 	struct iscsi_transport *transport = session->transport;
914 	struct iscsi_cls_conn *conn;
915 	unsigned long flags;
916 	int err;
917 
918 	conn = kzalloc(sizeof(*conn) + dd_size, GFP_KERNEL);
919 	if (!conn)
920 		return NULL;
921 	if (dd_size)
922 		conn->dd_data = &conn[1];
923 
924 	INIT_LIST_HEAD(&conn->conn_list);
925 	conn->transport = transport;
926 	conn->cid = cid;
927 
928 	/* this is released in the dev's release function */
929 	if (!get_device(&session->dev))
930 		goto free_conn;
931 
932 	dev_set_name(&conn->dev, "connection%d:%u", session->sid, cid);
933 	conn->dev.parent = &session->dev;
934 	conn->dev.release = iscsi_conn_release;
935 	err = device_register(&conn->dev);
936 	if (err) {
937 		iscsi_cls_session_printk(KERN_ERR, session, "could not "
938 					 "register connection's dev\n");
939 		goto release_parent_ref;
940 	}
941 	transport_register_device(&conn->dev);
942 
943 	spin_lock_irqsave(&connlock, flags);
944 	list_add(&conn->conn_list, &connlist);
945 	conn->active = 1;
946 	spin_unlock_irqrestore(&connlock, flags);
947 
948 	ISCSI_DBG_TRANS_CONN(conn, "Completed conn creation\n");
949 	return conn;
950 
951 release_parent_ref:
952 	put_device(&session->dev);
953 free_conn:
954 	kfree(conn);
955 	return NULL;
956 }
957 
958 EXPORT_SYMBOL_GPL(iscsi_create_conn);
959 
960 /**
961  * iscsi_destroy_conn - destroy iscsi class connection
962  * @conn: iscsi cls session
963  *
964  * This can be called from a LLD or iscsi_transport.
965  */
966 int iscsi_destroy_conn(struct iscsi_cls_conn *conn)
967 {
968 	unsigned long flags;
969 
970 	spin_lock_irqsave(&connlock, flags);
971 	conn->active = 0;
972 	list_del(&conn->conn_list);
973 	spin_unlock_irqrestore(&connlock, flags);
974 
975 	transport_unregister_device(&conn->dev);
976 	ISCSI_DBG_TRANS_CONN(conn, "Completing conn destruction\n");
977 	device_unregister(&conn->dev);
978 	return 0;
979 }
980 EXPORT_SYMBOL_GPL(iscsi_destroy_conn);
981 
982 /*
983  * iscsi interface functions
984  */
985 static struct iscsi_internal *
986 iscsi_if_transport_lookup(struct iscsi_transport *tt)
987 {
988 	struct iscsi_internal *priv;
989 	unsigned long flags;
990 
991 	spin_lock_irqsave(&iscsi_transport_lock, flags);
992 	list_for_each_entry(priv, &iscsi_transports, list) {
993 		if (tt == priv->iscsi_transport) {
994 			spin_unlock_irqrestore(&iscsi_transport_lock, flags);
995 			return priv;
996 		}
997 	}
998 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
999 	return NULL;
1000 }
1001 
1002 static int
1003 iscsi_multicast_skb(struct sk_buff *skb, uint32_t group, gfp_t gfp)
1004 {
1005 	return nlmsg_multicast(nls, skb, 0, group, gfp);
1006 }
1007 
1008 int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
1009 		   char *data, uint32_t data_size)
1010 {
1011 	struct nlmsghdr	*nlh;
1012 	struct sk_buff *skb;
1013 	struct iscsi_uevent *ev;
1014 	char *pdu;
1015 	struct iscsi_internal *priv;
1016 	int len = NLMSG_SPACE(sizeof(*ev) + sizeof(struct iscsi_hdr) +
1017 			      data_size);
1018 
1019 	priv = iscsi_if_transport_lookup(conn->transport);
1020 	if (!priv)
1021 		return -EINVAL;
1022 
1023 	skb = alloc_skb(len, GFP_ATOMIC);
1024 	if (!skb) {
1025 		iscsi_conn_error_event(conn, ISCSI_ERR_CONN_FAILED);
1026 		iscsi_cls_conn_printk(KERN_ERR, conn, "can not deliver "
1027 				      "control PDU: OOM\n");
1028 		return -ENOMEM;
1029 	}
1030 
1031 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1032 	ev = NLMSG_DATA(nlh);
1033 	memset(ev, 0, sizeof(*ev));
1034 	ev->transport_handle = iscsi_handle(conn->transport);
1035 	ev->type = ISCSI_KEVENT_RECV_PDU;
1036 	ev->r.recv_req.cid = conn->cid;
1037 	ev->r.recv_req.sid = iscsi_conn_get_sid(conn);
1038 	pdu = (char*)ev + sizeof(*ev);
1039 	memcpy(pdu, hdr, sizeof(struct iscsi_hdr));
1040 	memcpy(pdu + sizeof(struct iscsi_hdr), data, data_size);
1041 
1042 	return iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);
1043 }
1044 EXPORT_SYMBOL_GPL(iscsi_recv_pdu);
1045 
1046 int iscsi_offload_mesg(struct Scsi_Host *shost,
1047 		       struct iscsi_transport *transport, uint32_t type,
1048 		       char *data, uint16_t data_size)
1049 {
1050 	struct nlmsghdr	*nlh;
1051 	struct sk_buff *skb;
1052 	struct iscsi_uevent *ev;
1053 	int len = NLMSG_SPACE(sizeof(*ev) + data_size);
1054 
1055 	skb = alloc_skb(len, GFP_ATOMIC);
1056 	if (!skb) {
1057 		printk(KERN_ERR "can not deliver iscsi offload message:OOM\n");
1058 		return -ENOMEM;
1059 	}
1060 
1061 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1062 	ev = NLMSG_DATA(nlh);
1063 	memset(ev, 0, sizeof(*ev));
1064 	ev->type = type;
1065 	ev->transport_handle = iscsi_handle(transport);
1066 	switch (type) {
1067 	case ISCSI_KEVENT_PATH_REQ:
1068 		ev->r.req_path.host_no = shost->host_no;
1069 		break;
1070 	case ISCSI_KEVENT_IF_DOWN:
1071 		ev->r.notify_if_down.host_no = shost->host_no;
1072 		break;
1073 	}
1074 
1075 	memcpy((char *)ev + sizeof(*ev), data, data_size);
1076 
1077 	return iscsi_multicast_skb(skb, ISCSI_NL_GRP_UIP, GFP_ATOMIC);
1078 }
1079 EXPORT_SYMBOL_GPL(iscsi_offload_mesg);
1080 
1081 void iscsi_conn_error_event(struct iscsi_cls_conn *conn, enum iscsi_err error)
1082 {
1083 	struct nlmsghdr	*nlh;
1084 	struct sk_buff	*skb;
1085 	struct iscsi_uevent *ev;
1086 	struct iscsi_internal *priv;
1087 	int len = NLMSG_SPACE(sizeof(*ev));
1088 
1089 	priv = iscsi_if_transport_lookup(conn->transport);
1090 	if (!priv)
1091 		return;
1092 
1093 	skb = alloc_skb(len, GFP_ATOMIC);
1094 	if (!skb) {
1095 		iscsi_cls_conn_printk(KERN_ERR, conn, "gracefully ignored "
1096 				      "conn error (%d)\n", error);
1097 		return;
1098 	}
1099 
1100 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1101 	ev = NLMSG_DATA(nlh);
1102 	ev->transport_handle = iscsi_handle(conn->transport);
1103 	ev->type = ISCSI_KEVENT_CONN_ERROR;
1104 	ev->r.connerror.error = error;
1105 	ev->r.connerror.cid = conn->cid;
1106 	ev->r.connerror.sid = iscsi_conn_get_sid(conn);
1107 
1108 	iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);
1109 
1110 	iscsi_cls_conn_printk(KERN_INFO, conn, "detected conn error (%d)\n",
1111 			      error);
1112 }
1113 EXPORT_SYMBOL_GPL(iscsi_conn_error_event);
1114 
1115 static int
1116 iscsi_if_send_reply(uint32_t group, int seq, int type, int done, int multi,
1117 		    void *payload, int size)
1118 {
1119 	struct sk_buff	*skb;
1120 	struct nlmsghdr	*nlh;
1121 	int len = NLMSG_SPACE(size);
1122 	int flags = multi ? NLM_F_MULTI : 0;
1123 	int t = done ? NLMSG_DONE : type;
1124 
1125 	skb = alloc_skb(len, GFP_ATOMIC);
1126 	if (!skb) {
1127 		printk(KERN_ERR "Could not allocate skb to send reply.\n");
1128 		return -ENOMEM;
1129 	}
1130 
1131 	nlh = __nlmsg_put(skb, 0, 0, t, (len - sizeof(*nlh)), 0);
1132 	nlh->nlmsg_flags = flags;
1133 	memcpy(NLMSG_DATA(nlh), payload, size);
1134 	return iscsi_multicast_skb(skb, group, GFP_ATOMIC);
1135 }
1136 
1137 static int
1138 iscsi_if_get_stats(struct iscsi_transport *transport, struct nlmsghdr *nlh)
1139 {
1140 	struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1141 	struct iscsi_stats *stats;
1142 	struct sk_buff *skbstat;
1143 	struct iscsi_cls_conn *conn;
1144 	struct nlmsghdr	*nlhstat;
1145 	struct iscsi_uevent *evstat;
1146 	struct iscsi_internal *priv;
1147 	int len = NLMSG_SPACE(sizeof(*ev) +
1148 			      sizeof(struct iscsi_stats) +
1149 			      sizeof(struct iscsi_stats_custom) *
1150 			      ISCSI_STATS_CUSTOM_MAX);
1151 	int err = 0;
1152 
1153 	priv = iscsi_if_transport_lookup(transport);
1154 	if (!priv)
1155 		return -EINVAL;
1156 
1157 	conn = iscsi_conn_lookup(ev->u.get_stats.sid, ev->u.get_stats.cid);
1158 	if (!conn)
1159 		return -EEXIST;
1160 
1161 	do {
1162 		int actual_size;
1163 
1164 		skbstat = alloc_skb(len, GFP_ATOMIC);
1165 		if (!skbstat) {
1166 			iscsi_cls_conn_printk(KERN_ERR, conn, "can not "
1167 					      "deliver stats: OOM\n");
1168 			return -ENOMEM;
1169 		}
1170 
1171 		nlhstat = __nlmsg_put(skbstat, 0, 0, 0,
1172 				      (len - sizeof(*nlhstat)), 0);
1173 		evstat = NLMSG_DATA(nlhstat);
1174 		memset(evstat, 0, sizeof(*evstat));
1175 		evstat->transport_handle = iscsi_handle(conn->transport);
1176 		evstat->type = nlh->nlmsg_type;
1177 		evstat->u.get_stats.cid =
1178 			ev->u.get_stats.cid;
1179 		evstat->u.get_stats.sid =
1180 			ev->u.get_stats.sid;
1181 		stats = (struct iscsi_stats *)
1182 			((char*)evstat + sizeof(*evstat));
1183 		memset(stats, 0, sizeof(*stats));
1184 
1185 		transport->get_stats(conn, stats);
1186 		actual_size = NLMSG_SPACE(sizeof(struct iscsi_uevent) +
1187 					  sizeof(struct iscsi_stats) +
1188 					  sizeof(struct iscsi_stats_custom) *
1189 					  stats->custom_length);
1190 		actual_size -= sizeof(*nlhstat);
1191 		actual_size = NLMSG_LENGTH(actual_size);
1192 		skb_trim(skbstat, NLMSG_ALIGN(actual_size));
1193 		nlhstat->nlmsg_len = actual_size;
1194 
1195 		err = iscsi_multicast_skb(skbstat, ISCSI_NL_GRP_ISCSID,
1196 					  GFP_ATOMIC);
1197 	} while (err < 0 && err != -ECONNREFUSED);
1198 
1199 	return err;
1200 }
1201 
1202 /**
1203  * iscsi_session_event - send session destr. completion event
1204  * @session: iscsi class session
1205  * @event: type of event
1206  */
1207 int iscsi_session_event(struct iscsi_cls_session *session,
1208 			enum iscsi_uevent_e event)
1209 {
1210 	struct iscsi_internal *priv;
1211 	struct Scsi_Host *shost;
1212 	struct iscsi_uevent *ev;
1213 	struct sk_buff  *skb;
1214 	struct nlmsghdr *nlh;
1215 	int rc, len = NLMSG_SPACE(sizeof(*ev));
1216 
1217 	priv = iscsi_if_transport_lookup(session->transport);
1218 	if (!priv)
1219 		return -EINVAL;
1220 	shost = iscsi_session_to_shost(session);
1221 
1222 	skb = alloc_skb(len, GFP_KERNEL);
1223 	if (!skb) {
1224 		iscsi_cls_session_printk(KERN_ERR, session,
1225 					 "Cannot notify userspace of session "
1226 					 "event %u\n", event);
1227 		return -ENOMEM;
1228 	}
1229 
1230 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1231 	ev = NLMSG_DATA(nlh);
1232 	ev->transport_handle = iscsi_handle(session->transport);
1233 
1234 	ev->type = event;
1235 	switch (event) {
1236 	case ISCSI_KEVENT_DESTROY_SESSION:
1237 		ev->r.d_session.host_no = shost->host_no;
1238 		ev->r.d_session.sid = session->sid;
1239 		break;
1240 	case ISCSI_KEVENT_CREATE_SESSION:
1241 		ev->r.c_session_ret.host_no = shost->host_no;
1242 		ev->r.c_session_ret.sid = session->sid;
1243 		break;
1244 	case ISCSI_KEVENT_UNBIND_SESSION:
1245 		ev->r.unbind_session.host_no = shost->host_no;
1246 		ev->r.unbind_session.sid = session->sid;
1247 		break;
1248 	default:
1249 		iscsi_cls_session_printk(KERN_ERR, session, "Invalid event "
1250 					 "%u.\n", event);
1251 		kfree_skb(skb);
1252 		return -EINVAL;
1253 	}
1254 
1255 	/*
1256 	 * this will occur if the daemon is not up, so we just warn
1257 	 * the user and when the daemon is restarted it will handle it
1258 	 */
1259 	rc = iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_KERNEL);
1260 	if (rc == -ESRCH)
1261 		iscsi_cls_session_printk(KERN_ERR, session,
1262 					 "Cannot notify userspace of session "
1263 					 "event %u. Check iscsi daemon\n",
1264 					 event);
1265 
1266 	ISCSI_DBG_TRANS_SESSION(session, "Completed handling event %d rc %d\n",
1267 				event, rc);
1268 	return rc;
1269 }
1270 EXPORT_SYMBOL_GPL(iscsi_session_event);
1271 
1272 static int
1273 iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_endpoint *ep,
1274 			struct iscsi_uevent *ev, uint32_t initial_cmdsn,
1275 			uint16_t cmds_max, uint16_t queue_depth)
1276 {
1277 	struct iscsi_transport *transport = priv->iscsi_transport;
1278 	struct iscsi_cls_session *session;
1279 	struct Scsi_Host *shost;
1280 
1281 	session = transport->create_session(ep, cmds_max, queue_depth,
1282 					    initial_cmdsn);
1283 	if (!session)
1284 		return -ENOMEM;
1285 
1286 	shost = iscsi_session_to_shost(session);
1287 	ev->r.c_session_ret.host_no = shost->host_no;
1288 	ev->r.c_session_ret.sid = session->sid;
1289 	ISCSI_DBG_TRANS_SESSION(session,
1290 				"Completed creating transport session\n");
1291 	return 0;
1292 }
1293 
1294 static int
1295 iscsi_if_create_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1296 {
1297 	struct iscsi_cls_conn *conn;
1298 	struct iscsi_cls_session *session;
1299 
1300 	session = iscsi_session_lookup(ev->u.c_conn.sid);
1301 	if (!session) {
1302 		printk(KERN_ERR "iscsi: invalid session %d.\n",
1303 		       ev->u.c_conn.sid);
1304 		return -EINVAL;
1305 	}
1306 
1307 	conn = transport->create_conn(session, ev->u.c_conn.cid);
1308 	if (!conn) {
1309 		iscsi_cls_session_printk(KERN_ERR, session,
1310 					 "couldn't create a new connection.");
1311 		return -ENOMEM;
1312 	}
1313 
1314 	ev->r.c_conn_ret.sid = session->sid;
1315 	ev->r.c_conn_ret.cid = conn->cid;
1316 
1317 	ISCSI_DBG_TRANS_CONN(conn, "Completed creating transport conn\n");
1318 	return 0;
1319 }
1320 
1321 static int
1322 iscsi_if_destroy_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1323 {
1324 	struct iscsi_cls_conn *conn;
1325 
1326 	conn = iscsi_conn_lookup(ev->u.d_conn.sid, ev->u.d_conn.cid);
1327 	if (!conn)
1328 		return -EINVAL;
1329 
1330 	ISCSI_DBG_TRANS_CONN(conn, "Destroying transport conn\n");
1331 	if (transport->destroy_conn)
1332 		transport->destroy_conn(conn);
1333 
1334 	return 0;
1335 }
1336 
1337 static int
1338 iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1339 {
1340 	char *data = (char*)ev + sizeof(*ev);
1341 	struct iscsi_cls_conn *conn;
1342 	struct iscsi_cls_session *session;
1343 	int err = 0, value = 0;
1344 
1345 	session = iscsi_session_lookup(ev->u.set_param.sid);
1346 	conn = iscsi_conn_lookup(ev->u.set_param.sid, ev->u.set_param.cid);
1347 	if (!conn || !session)
1348 		return -EINVAL;
1349 
1350 	switch (ev->u.set_param.param) {
1351 	case ISCSI_PARAM_SESS_RECOVERY_TMO:
1352 		sscanf(data, "%d", &value);
1353 		session->recovery_tmo = value;
1354 		break;
1355 	default:
1356 		err = transport->set_param(conn, ev->u.set_param.param,
1357 					   data, ev->u.set_param.len);
1358 	}
1359 
1360 	return err;
1361 }
1362 
1363 static int iscsi_if_ep_connect(struct iscsi_transport *transport,
1364 			       struct iscsi_uevent *ev, int msg_type)
1365 {
1366 	struct iscsi_endpoint *ep;
1367 	struct sockaddr *dst_addr;
1368 	struct Scsi_Host *shost = NULL;
1369 	int non_blocking, err = 0;
1370 
1371 	if (!transport->ep_connect)
1372 		return -EINVAL;
1373 
1374 	if (msg_type == ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST) {
1375 		shost = scsi_host_lookup(ev->u.ep_connect_through_host.host_no);
1376 		if (!shost) {
1377 			printk(KERN_ERR "ep connect failed. Could not find "
1378 			       "host no %u\n",
1379 			       ev->u.ep_connect_through_host.host_no);
1380 			return -ENODEV;
1381 		}
1382 		non_blocking = ev->u.ep_connect_through_host.non_blocking;
1383 	} else
1384 		non_blocking = ev->u.ep_connect.non_blocking;
1385 
1386 	dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1387 	ep = transport->ep_connect(shost, dst_addr, non_blocking);
1388 	if (IS_ERR(ep)) {
1389 		err = PTR_ERR(ep);
1390 		goto release_host;
1391 	}
1392 
1393 	ev->r.ep_connect_ret.handle = ep->id;
1394 release_host:
1395 	if (shost)
1396 		scsi_host_put(shost);
1397 	return err;
1398 }
1399 
1400 static int
1401 iscsi_if_transport_ep(struct iscsi_transport *transport,
1402 		      struct iscsi_uevent *ev, int msg_type)
1403 {
1404 	struct iscsi_endpoint *ep;
1405 	int rc = 0;
1406 
1407 	switch (msg_type) {
1408 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST:
1409 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1410 		rc = iscsi_if_ep_connect(transport, ev, msg_type);
1411 		break;
1412 	case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1413 		if (!transport->ep_poll)
1414 			return -EINVAL;
1415 
1416 		ep = iscsi_lookup_endpoint(ev->u.ep_poll.ep_handle);
1417 		if (!ep)
1418 			return -EINVAL;
1419 
1420 		ev->r.retcode = transport->ep_poll(ep,
1421 						   ev->u.ep_poll.timeout_ms);
1422 		break;
1423 	case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1424 		if (!transport->ep_disconnect)
1425 			return -EINVAL;
1426 
1427 		ep = iscsi_lookup_endpoint(ev->u.ep_disconnect.ep_handle);
1428 		if (!ep)
1429 			return -EINVAL;
1430 
1431 		transport->ep_disconnect(ep);
1432 		break;
1433 	}
1434 	return rc;
1435 }
1436 
1437 static int
1438 iscsi_tgt_dscvr(struct iscsi_transport *transport,
1439 		struct iscsi_uevent *ev)
1440 {
1441 	struct Scsi_Host *shost;
1442 	struct sockaddr *dst_addr;
1443 	int err;
1444 
1445 	if (!transport->tgt_dscvr)
1446 		return -EINVAL;
1447 
1448 	shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);
1449 	if (!shost) {
1450 		printk(KERN_ERR "target discovery could not find host no %u\n",
1451 		       ev->u.tgt_dscvr.host_no);
1452 		return -ENODEV;
1453 	}
1454 
1455 
1456 	dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1457 	err = transport->tgt_dscvr(shost, ev->u.tgt_dscvr.type,
1458 				   ev->u.tgt_dscvr.enable, dst_addr);
1459 	scsi_host_put(shost);
1460 	return err;
1461 }
1462 
1463 static int
1464 iscsi_set_host_param(struct iscsi_transport *transport,
1465 		     struct iscsi_uevent *ev)
1466 {
1467 	char *data = (char*)ev + sizeof(*ev);
1468 	struct Scsi_Host *shost;
1469 	int err;
1470 
1471 	if (!transport->set_host_param)
1472 		return -ENOSYS;
1473 
1474 	shost = scsi_host_lookup(ev->u.set_host_param.host_no);
1475 	if (!shost) {
1476 		printk(KERN_ERR "set_host_param could not find host no %u\n",
1477 		       ev->u.set_host_param.host_no);
1478 		return -ENODEV;
1479 	}
1480 
1481 	err = transport->set_host_param(shost, ev->u.set_host_param.param,
1482 					data, ev->u.set_host_param.len);
1483 	scsi_host_put(shost);
1484 	return err;
1485 }
1486 
1487 static int
1488 iscsi_set_path(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1489 {
1490 	struct Scsi_Host *shost;
1491 	struct iscsi_path *params;
1492 	int err;
1493 
1494 	if (!transport->set_path)
1495 		return -ENOSYS;
1496 
1497 	shost = scsi_host_lookup(ev->u.set_path.host_no);
1498 	if (!shost) {
1499 		printk(KERN_ERR "set path could not find host no %u\n",
1500 		       ev->u.set_path.host_no);
1501 		return -ENODEV;
1502 	}
1503 
1504 	params = (struct iscsi_path *)((char *)ev + sizeof(*ev));
1505 	err = transport->set_path(shost, params);
1506 
1507 	scsi_host_put(shost);
1508 	return err;
1509 }
1510 
1511 static int
1512 iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
1513 {
1514 	int err = 0;
1515 	struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1516 	struct iscsi_transport *transport = NULL;
1517 	struct iscsi_internal *priv;
1518 	struct iscsi_cls_session *session;
1519 	struct iscsi_cls_conn *conn;
1520 	struct iscsi_endpoint *ep = NULL;
1521 
1522 	if (nlh->nlmsg_type == ISCSI_UEVENT_PATH_UPDATE)
1523 		*group = ISCSI_NL_GRP_UIP;
1524 	else
1525 		*group = ISCSI_NL_GRP_ISCSID;
1526 
1527 	priv = iscsi_if_transport_lookup(iscsi_ptr(ev->transport_handle));
1528 	if (!priv)
1529 		return -EINVAL;
1530 	transport = priv->iscsi_transport;
1531 
1532 	if (!try_module_get(transport->owner))
1533 		return -EINVAL;
1534 
1535 	switch (nlh->nlmsg_type) {
1536 	case ISCSI_UEVENT_CREATE_SESSION:
1537 		err = iscsi_if_create_session(priv, ep, ev,
1538 					      ev->u.c_session.initial_cmdsn,
1539 					      ev->u.c_session.cmds_max,
1540 					      ev->u.c_session.queue_depth);
1541 		break;
1542 	case ISCSI_UEVENT_CREATE_BOUND_SESSION:
1543 		ep = iscsi_lookup_endpoint(ev->u.c_bound_session.ep_handle);
1544 		if (!ep) {
1545 			err = -EINVAL;
1546 			break;
1547 		}
1548 
1549 		err = iscsi_if_create_session(priv, ep, ev,
1550 					ev->u.c_bound_session.initial_cmdsn,
1551 					ev->u.c_bound_session.cmds_max,
1552 					ev->u.c_bound_session.queue_depth);
1553 		break;
1554 	case ISCSI_UEVENT_DESTROY_SESSION:
1555 		session = iscsi_session_lookup(ev->u.d_session.sid);
1556 		if (session)
1557 			transport->destroy_session(session);
1558 		else
1559 			err = -EINVAL;
1560 		break;
1561 	case ISCSI_UEVENT_UNBIND_SESSION:
1562 		session = iscsi_session_lookup(ev->u.d_session.sid);
1563 		if (session)
1564 			scsi_queue_work(iscsi_session_to_shost(session),
1565 					&session->unbind_work);
1566 		else
1567 			err = -EINVAL;
1568 		break;
1569 	case ISCSI_UEVENT_CREATE_CONN:
1570 		err = iscsi_if_create_conn(transport, ev);
1571 		break;
1572 	case ISCSI_UEVENT_DESTROY_CONN:
1573 		err = iscsi_if_destroy_conn(transport, ev);
1574 		break;
1575 	case ISCSI_UEVENT_BIND_CONN:
1576 		session = iscsi_session_lookup(ev->u.b_conn.sid);
1577 		conn = iscsi_conn_lookup(ev->u.b_conn.sid, ev->u.b_conn.cid);
1578 
1579 		if (session && conn)
1580 			ev->r.retcode =	transport->bind_conn(session, conn,
1581 					ev->u.b_conn.transport_eph,
1582 					ev->u.b_conn.is_leading);
1583 		else
1584 			err = -EINVAL;
1585 		break;
1586 	case ISCSI_UEVENT_SET_PARAM:
1587 		err = iscsi_set_param(transport, ev);
1588 		break;
1589 	case ISCSI_UEVENT_START_CONN:
1590 		conn = iscsi_conn_lookup(ev->u.start_conn.sid, ev->u.start_conn.cid);
1591 		if (conn)
1592 			ev->r.retcode = transport->start_conn(conn);
1593 		else
1594 			err = -EINVAL;
1595 		break;
1596 	case ISCSI_UEVENT_STOP_CONN:
1597 		conn = iscsi_conn_lookup(ev->u.stop_conn.sid, ev->u.stop_conn.cid);
1598 		if (conn)
1599 			transport->stop_conn(conn, ev->u.stop_conn.flag);
1600 		else
1601 			err = -EINVAL;
1602 		break;
1603 	case ISCSI_UEVENT_SEND_PDU:
1604 		conn = iscsi_conn_lookup(ev->u.send_pdu.sid, ev->u.send_pdu.cid);
1605 		if (conn)
1606 			ev->r.retcode =	transport->send_pdu(conn,
1607 				(struct iscsi_hdr*)((char*)ev + sizeof(*ev)),
1608 				(char*)ev + sizeof(*ev) + ev->u.send_pdu.hdr_size,
1609 				ev->u.send_pdu.data_size);
1610 		else
1611 			err = -EINVAL;
1612 		break;
1613 	case ISCSI_UEVENT_GET_STATS:
1614 		err = iscsi_if_get_stats(transport, nlh);
1615 		break;
1616 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1617 	case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1618 	case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1619 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST:
1620 		err = iscsi_if_transport_ep(transport, ev, nlh->nlmsg_type);
1621 		break;
1622 	case ISCSI_UEVENT_TGT_DSCVR:
1623 		err = iscsi_tgt_dscvr(transport, ev);
1624 		break;
1625 	case ISCSI_UEVENT_SET_HOST_PARAM:
1626 		err = iscsi_set_host_param(transport, ev);
1627 		break;
1628 	case ISCSI_UEVENT_PATH_UPDATE:
1629 		err = iscsi_set_path(transport, ev);
1630 		break;
1631 	default:
1632 		err = -ENOSYS;
1633 		break;
1634 	}
1635 
1636 	module_put(transport->owner);
1637 	return err;
1638 }
1639 
1640 /*
1641  * Get message from skb.  Each message is processed by iscsi_if_recv_msg.
1642  * Malformed skbs with wrong lengths or invalid creds are not processed.
1643  */
1644 static void
1645 iscsi_if_rx(struct sk_buff *skb)
1646 {
1647 	mutex_lock(&rx_queue_mutex);
1648 	while (skb->len >= NLMSG_SPACE(0)) {
1649 		int err;
1650 		uint32_t rlen;
1651 		struct nlmsghdr	*nlh;
1652 		struct iscsi_uevent *ev;
1653 		uint32_t group;
1654 
1655 		nlh = nlmsg_hdr(skb);
1656 		if (nlh->nlmsg_len < sizeof(*nlh) ||
1657 		    skb->len < nlh->nlmsg_len) {
1658 			break;
1659 		}
1660 
1661 		ev = NLMSG_DATA(nlh);
1662 		rlen = NLMSG_ALIGN(nlh->nlmsg_len);
1663 		if (rlen > skb->len)
1664 			rlen = skb->len;
1665 
1666 		err = iscsi_if_recv_msg(skb, nlh, &group);
1667 		if (err) {
1668 			ev->type = ISCSI_KEVENT_IF_ERROR;
1669 			ev->iferror = err;
1670 		}
1671 		do {
1672 			/*
1673 			 * special case for GET_STATS:
1674 			 * on success - sending reply and stats from
1675 			 * inside of if_recv_msg(),
1676 			 * on error - fall through.
1677 			 */
1678 			if (ev->type == ISCSI_UEVENT_GET_STATS && !err)
1679 				break;
1680 			err = iscsi_if_send_reply(group, nlh->nlmsg_seq,
1681 				nlh->nlmsg_type, 0, 0, ev, sizeof(*ev));
1682 		} while (err < 0 && err != -ECONNREFUSED);
1683 		skb_pull(skb, rlen);
1684 	}
1685 	mutex_unlock(&rx_queue_mutex);
1686 }
1687 
1688 #define ISCSI_CLASS_ATTR(_prefix,_name,_mode,_show,_store)		\
1689 struct device_attribute dev_attr_##_prefix##_##_name =	\
1690 	__ATTR(_name,_mode,_show,_store)
1691 
1692 /*
1693  * iSCSI connection attrs
1694  */
1695 #define iscsi_conn_attr_show(param)					\
1696 static ssize_t								\
1697 show_conn_param_##param(struct device *dev, 				\
1698 			struct device_attribute *attr, char *buf)	\
1699 {									\
1700 	struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev->parent);	\
1701 	struct iscsi_transport *t = conn->transport;			\
1702 	return t->get_conn_param(conn, param, buf);			\
1703 }
1704 
1705 #define iscsi_conn_attr(field, param)					\
1706 	iscsi_conn_attr_show(param)					\
1707 static ISCSI_CLASS_ATTR(conn, field, S_IRUGO, show_conn_param_##param,	\
1708 			NULL);
1709 
1710 iscsi_conn_attr(max_recv_dlength, ISCSI_PARAM_MAX_RECV_DLENGTH);
1711 iscsi_conn_attr(max_xmit_dlength, ISCSI_PARAM_MAX_XMIT_DLENGTH);
1712 iscsi_conn_attr(header_digest, ISCSI_PARAM_HDRDGST_EN);
1713 iscsi_conn_attr(data_digest, ISCSI_PARAM_DATADGST_EN);
1714 iscsi_conn_attr(ifmarker, ISCSI_PARAM_IFMARKER_EN);
1715 iscsi_conn_attr(ofmarker, ISCSI_PARAM_OFMARKER_EN);
1716 iscsi_conn_attr(persistent_port, ISCSI_PARAM_PERSISTENT_PORT);
1717 iscsi_conn_attr(port, ISCSI_PARAM_CONN_PORT);
1718 iscsi_conn_attr(exp_statsn, ISCSI_PARAM_EXP_STATSN);
1719 iscsi_conn_attr(persistent_address, ISCSI_PARAM_PERSISTENT_ADDRESS);
1720 iscsi_conn_attr(address, ISCSI_PARAM_CONN_ADDRESS);
1721 iscsi_conn_attr(ping_tmo, ISCSI_PARAM_PING_TMO);
1722 iscsi_conn_attr(recv_tmo, ISCSI_PARAM_RECV_TMO);
1723 
1724 /*
1725  * iSCSI session attrs
1726  */
1727 #define iscsi_session_attr_show(param, perm)				\
1728 static ssize_t								\
1729 show_session_param_##param(struct device *dev,				\
1730 			   struct device_attribute *attr, char *buf)	\
1731 {									\
1732 	struct iscsi_cls_session *session = 				\
1733 		iscsi_dev_to_session(dev->parent);			\
1734 	struct iscsi_transport *t = session->transport;			\
1735 									\
1736 	if (perm && !capable(CAP_SYS_ADMIN))				\
1737 		return -EACCES;						\
1738 	return t->get_session_param(session, param, buf);		\
1739 }
1740 
1741 #define iscsi_session_attr(field, param, perm)				\
1742 	iscsi_session_attr_show(param, perm)				\
1743 static ISCSI_CLASS_ATTR(sess, field, S_IRUGO, show_session_param_##param, \
1744 			NULL);
1745 
1746 iscsi_session_attr(targetname, ISCSI_PARAM_TARGET_NAME, 0);
1747 iscsi_session_attr(initial_r2t, ISCSI_PARAM_INITIAL_R2T_EN, 0);
1748 iscsi_session_attr(max_outstanding_r2t, ISCSI_PARAM_MAX_R2T, 0);
1749 iscsi_session_attr(immediate_data, ISCSI_PARAM_IMM_DATA_EN, 0);
1750 iscsi_session_attr(first_burst_len, ISCSI_PARAM_FIRST_BURST, 0);
1751 iscsi_session_attr(max_burst_len, ISCSI_PARAM_MAX_BURST, 0);
1752 iscsi_session_attr(data_pdu_in_order, ISCSI_PARAM_PDU_INORDER_EN, 0);
1753 iscsi_session_attr(data_seq_in_order, ISCSI_PARAM_DATASEQ_INORDER_EN, 0);
1754 iscsi_session_attr(erl, ISCSI_PARAM_ERL, 0);
1755 iscsi_session_attr(tpgt, ISCSI_PARAM_TPGT, 0);
1756 iscsi_session_attr(username, ISCSI_PARAM_USERNAME, 1);
1757 iscsi_session_attr(username_in, ISCSI_PARAM_USERNAME_IN, 1);
1758 iscsi_session_attr(password, ISCSI_PARAM_PASSWORD, 1);
1759 iscsi_session_attr(password_in, ISCSI_PARAM_PASSWORD_IN, 1);
1760 iscsi_session_attr(fast_abort, ISCSI_PARAM_FAST_ABORT, 0);
1761 iscsi_session_attr(abort_tmo, ISCSI_PARAM_ABORT_TMO, 0);
1762 iscsi_session_attr(lu_reset_tmo, ISCSI_PARAM_LU_RESET_TMO, 0);
1763 iscsi_session_attr(tgt_reset_tmo, ISCSI_PARAM_TGT_RESET_TMO, 0);
1764 iscsi_session_attr(ifacename, ISCSI_PARAM_IFACE_NAME, 0);
1765 iscsi_session_attr(initiatorname, ISCSI_PARAM_INITIATOR_NAME, 0)
1766 
1767 static ssize_t
1768 show_priv_session_state(struct device *dev, struct device_attribute *attr,
1769 			char *buf)
1770 {
1771 	struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
1772 	return sprintf(buf, "%s\n", iscsi_session_state_name(session->state));
1773 }
1774 static ISCSI_CLASS_ATTR(priv_sess, state, S_IRUGO, show_priv_session_state,
1775 			NULL);
1776 
1777 #define iscsi_priv_session_attr_show(field, format)			\
1778 static ssize_t								\
1779 show_priv_session_##field(struct device *dev, 				\
1780 			  struct device_attribute *attr, char *buf)	\
1781 {									\
1782 	struct iscsi_cls_session *session = 				\
1783 			iscsi_dev_to_session(dev->parent);		\
1784 	return sprintf(buf, format"\n", session->field);		\
1785 }
1786 
1787 #define iscsi_priv_session_attr(field, format)				\
1788 	iscsi_priv_session_attr_show(field, format)			\
1789 static ISCSI_CLASS_ATTR(priv_sess, field, S_IRUGO, show_priv_session_##field, \
1790 			NULL)
1791 iscsi_priv_session_attr(recovery_tmo, "%d");
1792 
1793 /*
1794  * iSCSI host attrs
1795  */
1796 #define iscsi_host_attr_show(param)					\
1797 static ssize_t								\
1798 show_host_param_##param(struct device *dev, 				\
1799 			struct device_attribute *attr, char *buf)	\
1800 {									\
1801 	struct Scsi_Host *shost = transport_class_to_shost(dev);	\
1802 	struct iscsi_internal *priv = to_iscsi_internal(shost->transportt); \
1803 	return priv->iscsi_transport->get_host_param(shost, param, buf); \
1804 }
1805 
1806 #define iscsi_host_attr(field, param)					\
1807 	iscsi_host_attr_show(param)					\
1808 static ISCSI_CLASS_ATTR(host, field, S_IRUGO, show_host_param_##param,	\
1809 			NULL);
1810 
1811 iscsi_host_attr(netdev, ISCSI_HOST_PARAM_NETDEV_NAME);
1812 iscsi_host_attr(hwaddress, ISCSI_HOST_PARAM_HWADDRESS);
1813 iscsi_host_attr(ipaddress, ISCSI_HOST_PARAM_IPADDRESS);
1814 iscsi_host_attr(initiatorname, ISCSI_HOST_PARAM_INITIATOR_NAME);
1815 
1816 #define SETUP_PRIV_SESSION_RD_ATTR(field)				\
1817 do {									\
1818 	priv->session_attrs[count] = &dev_attr_priv_sess_##field; \
1819 	count++;							\
1820 } while (0)
1821 
1822 
1823 #define SETUP_SESSION_RD_ATTR(field, param_flag)			\
1824 do {									\
1825 	if (tt->param_mask & param_flag) {				\
1826 		priv->session_attrs[count] = &dev_attr_sess_##field; \
1827 		count++;						\
1828 	}								\
1829 } while (0)
1830 
1831 #define SETUP_CONN_RD_ATTR(field, param_flag)				\
1832 do {									\
1833 	if (tt->param_mask & param_flag) {				\
1834 		priv->conn_attrs[count] = &dev_attr_conn_##field; \
1835 		count++;						\
1836 	}								\
1837 } while (0)
1838 
1839 #define SETUP_HOST_RD_ATTR(field, param_flag)				\
1840 do {									\
1841 	if (tt->host_param_mask & param_flag) {				\
1842 		priv->host_attrs[count] = &dev_attr_host_##field; \
1843 		count++;						\
1844 	}								\
1845 } while (0)
1846 
1847 static int iscsi_session_match(struct attribute_container *cont,
1848 			   struct device *dev)
1849 {
1850 	struct iscsi_cls_session *session;
1851 	struct Scsi_Host *shost;
1852 	struct iscsi_internal *priv;
1853 
1854 	if (!iscsi_is_session_dev(dev))
1855 		return 0;
1856 
1857 	session = iscsi_dev_to_session(dev);
1858 	shost = iscsi_session_to_shost(session);
1859 	if (!shost->transportt)
1860 		return 0;
1861 
1862 	priv = to_iscsi_internal(shost->transportt);
1863 	if (priv->session_cont.ac.class != &iscsi_session_class.class)
1864 		return 0;
1865 
1866 	return &priv->session_cont.ac == cont;
1867 }
1868 
1869 static int iscsi_conn_match(struct attribute_container *cont,
1870 			   struct device *dev)
1871 {
1872 	struct iscsi_cls_session *session;
1873 	struct iscsi_cls_conn *conn;
1874 	struct Scsi_Host *shost;
1875 	struct iscsi_internal *priv;
1876 
1877 	if (!iscsi_is_conn_dev(dev))
1878 		return 0;
1879 
1880 	conn = iscsi_dev_to_conn(dev);
1881 	session = iscsi_dev_to_session(conn->dev.parent);
1882 	shost = iscsi_session_to_shost(session);
1883 
1884 	if (!shost->transportt)
1885 		return 0;
1886 
1887 	priv = to_iscsi_internal(shost->transportt);
1888 	if (priv->conn_cont.ac.class != &iscsi_connection_class.class)
1889 		return 0;
1890 
1891 	return &priv->conn_cont.ac == cont;
1892 }
1893 
1894 static int iscsi_host_match(struct attribute_container *cont,
1895 			    struct device *dev)
1896 {
1897 	struct Scsi_Host *shost;
1898 	struct iscsi_internal *priv;
1899 
1900 	if (!scsi_is_host_device(dev))
1901 		return 0;
1902 
1903 	shost = dev_to_shost(dev);
1904 	if (!shost->transportt  ||
1905 	    shost->transportt->host_attrs.ac.class != &iscsi_host_class.class)
1906 		return 0;
1907 
1908         priv = to_iscsi_internal(shost->transportt);
1909         return &priv->t.host_attrs.ac == cont;
1910 }
1911 
1912 struct scsi_transport_template *
1913 iscsi_register_transport(struct iscsi_transport *tt)
1914 {
1915 	struct iscsi_internal *priv;
1916 	unsigned long flags;
1917 	int count = 0, err;
1918 
1919 	BUG_ON(!tt);
1920 
1921 	priv = iscsi_if_transport_lookup(tt);
1922 	if (priv)
1923 		return NULL;
1924 
1925 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1926 	if (!priv)
1927 		return NULL;
1928 	INIT_LIST_HEAD(&priv->list);
1929 	priv->iscsi_transport = tt;
1930 	priv->t.user_scan = iscsi_user_scan;
1931 	priv->t.create_work_queue = 1;
1932 
1933 	priv->dev.class = &iscsi_transport_class;
1934 	dev_set_name(&priv->dev, "%s", tt->name);
1935 	err = device_register(&priv->dev);
1936 	if (err)
1937 		goto free_priv;
1938 
1939 	err = sysfs_create_group(&priv->dev.kobj, &iscsi_transport_group);
1940 	if (err)
1941 		goto unregister_dev;
1942 
1943 	/* host parameters */
1944 	priv->t.host_attrs.ac.attrs = &priv->host_attrs[0];
1945 	priv->t.host_attrs.ac.class = &iscsi_host_class.class;
1946 	priv->t.host_attrs.ac.match = iscsi_host_match;
1947 	priv->t.host_size = sizeof(struct iscsi_cls_host);
1948 	transport_container_register(&priv->t.host_attrs);
1949 
1950 	SETUP_HOST_RD_ATTR(netdev, ISCSI_HOST_NETDEV_NAME);
1951 	SETUP_HOST_RD_ATTR(ipaddress, ISCSI_HOST_IPADDRESS);
1952 	SETUP_HOST_RD_ATTR(hwaddress, ISCSI_HOST_HWADDRESS);
1953 	SETUP_HOST_RD_ATTR(initiatorname, ISCSI_HOST_INITIATOR_NAME);
1954 	BUG_ON(count > ISCSI_HOST_ATTRS);
1955 	priv->host_attrs[count] = NULL;
1956 	count = 0;
1957 
1958 	/* connection parameters */
1959 	priv->conn_cont.ac.attrs = &priv->conn_attrs[0];
1960 	priv->conn_cont.ac.class = &iscsi_connection_class.class;
1961 	priv->conn_cont.ac.match = iscsi_conn_match;
1962 	transport_container_register(&priv->conn_cont);
1963 
1964 	SETUP_CONN_RD_ATTR(max_recv_dlength, ISCSI_MAX_RECV_DLENGTH);
1965 	SETUP_CONN_RD_ATTR(max_xmit_dlength, ISCSI_MAX_XMIT_DLENGTH);
1966 	SETUP_CONN_RD_ATTR(header_digest, ISCSI_HDRDGST_EN);
1967 	SETUP_CONN_RD_ATTR(data_digest, ISCSI_DATADGST_EN);
1968 	SETUP_CONN_RD_ATTR(ifmarker, ISCSI_IFMARKER_EN);
1969 	SETUP_CONN_RD_ATTR(ofmarker, ISCSI_OFMARKER_EN);
1970 	SETUP_CONN_RD_ATTR(address, ISCSI_CONN_ADDRESS);
1971 	SETUP_CONN_RD_ATTR(port, ISCSI_CONN_PORT);
1972 	SETUP_CONN_RD_ATTR(exp_statsn, ISCSI_EXP_STATSN);
1973 	SETUP_CONN_RD_ATTR(persistent_address, ISCSI_PERSISTENT_ADDRESS);
1974 	SETUP_CONN_RD_ATTR(persistent_port, ISCSI_PERSISTENT_PORT);
1975 	SETUP_CONN_RD_ATTR(ping_tmo, ISCSI_PING_TMO);
1976 	SETUP_CONN_RD_ATTR(recv_tmo, ISCSI_RECV_TMO);
1977 
1978 	BUG_ON(count > ISCSI_CONN_ATTRS);
1979 	priv->conn_attrs[count] = NULL;
1980 	count = 0;
1981 
1982 	/* session parameters */
1983 	priv->session_cont.ac.attrs = &priv->session_attrs[0];
1984 	priv->session_cont.ac.class = &iscsi_session_class.class;
1985 	priv->session_cont.ac.match = iscsi_session_match;
1986 	transport_container_register(&priv->session_cont);
1987 
1988 	SETUP_SESSION_RD_ATTR(initial_r2t, ISCSI_INITIAL_R2T_EN);
1989 	SETUP_SESSION_RD_ATTR(max_outstanding_r2t, ISCSI_MAX_R2T);
1990 	SETUP_SESSION_RD_ATTR(immediate_data, ISCSI_IMM_DATA_EN);
1991 	SETUP_SESSION_RD_ATTR(first_burst_len, ISCSI_FIRST_BURST);
1992 	SETUP_SESSION_RD_ATTR(max_burst_len, ISCSI_MAX_BURST);
1993 	SETUP_SESSION_RD_ATTR(data_pdu_in_order, ISCSI_PDU_INORDER_EN);
1994 	SETUP_SESSION_RD_ATTR(data_seq_in_order, ISCSI_DATASEQ_INORDER_EN);
1995 	SETUP_SESSION_RD_ATTR(erl, ISCSI_ERL);
1996 	SETUP_SESSION_RD_ATTR(targetname, ISCSI_TARGET_NAME);
1997 	SETUP_SESSION_RD_ATTR(tpgt, ISCSI_TPGT);
1998 	SETUP_SESSION_RD_ATTR(password, ISCSI_USERNAME);
1999 	SETUP_SESSION_RD_ATTR(password_in, ISCSI_USERNAME_IN);
2000 	SETUP_SESSION_RD_ATTR(username, ISCSI_PASSWORD);
2001 	SETUP_SESSION_RD_ATTR(username_in, ISCSI_PASSWORD_IN);
2002 	SETUP_SESSION_RD_ATTR(fast_abort, ISCSI_FAST_ABORT);
2003 	SETUP_SESSION_RD_ATTR(abort_tmo, ISCSI_ABORT_TMO);
2004 	SETUP_SESSION_RD_ATTR(lu_reset_tmo,ISCSI_LU_RESET_TMO);
2005 	SETUP_SESSION_RD_ATTR(tgt_reset_tmo,ISCSI_TGT_RESET_TMO);
2006 	SETUP_SESSION_RD_ATTR(ifacename, ISCSI_IFACE_NAME);
2007 	SETUP_SESSION_RD_ATTR(initiatorname, ISCSI_INITIATOR_NAME);
2008 	SETUP_PRIV_SESSION_RD_ATTR(recovery_tmo);
2009 	SETUP_PRIV_SESSION_RD_ATTR(state);
2010 
2011 	BUG_ON(count > ISCSI_SESSION_ATTRS);
2012 	priv->session_attrs[count] = NULL;
2013 
2014 	spin_lock_irqsave(&iscsi_transport_lock, flags);
2015 	list_add(&priv->list, &iscsi_transports);
2016 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
2017 
2018 	printk(KERN_NOTICE "iscsi: registered transport (%s)\n", tt->name);
2019 	return &priv->t;
2020 
2021 unregister_dev:
2022 	device_unregister(&priv->dev);
2023 	return NULL;
2024 free_priv:
2025 	kfree(priv);
2026 	return NULL;
2027 }
2028 EXPORT_SYMBOL_GPL(iscsi_register_transport);
2029 
2030 int iscsi_unregister_transport(struct iscsi_transport *tt)
2031 {
2032 	struct iscsi_internal *priv;
2033 	unsigned long flags;
2034 
2035 	BUG_ON(!tt);
2036 
2037 	mutex_lock(&rx_queue_mutex);
2038 
2039 	priv = iscsi_if_transport_lookup(tt);
2040 	BUG_ON (!priv);
2041 
2042 	spin_lock_irqsave(&iscsi_transport_lock, flags);
2043 	list_del(&priv->list);
2044 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
2045 
2046 	transport_container_unregister(&priv->conn_cont);
2047 	transport_container_unregister(&priv->session_cont);
2048 	transport_container_unregister(&priv->t.host_attrs);
2049 
2050 	sysfs_remove_group(&priv->dev.kobj, &iscsi_transport_group);
2051 	device_unregister(&priv->dev);
2052 	mutex_unlock(&rx_queue_mutex);
2053 
2054 	return 0;
2055 }
2056 EXPORT_SYMBOL_GPL(iscsi_unregister_transport);
2057 
2058 static __init int iscsi_transport_init(void)
2059 {
2060 	int err;
2061 
2062 	printk(KERN_INFO "Loading iSCSI transport class v%s.\n",
2063 		ISCSI_TRANSPORT_VERSION);
2064 
2065 	atomic_set(&iscsi_session_nr, 0);
2066 
2067 	err = class_register(&iscsi_transport_class);
2068 	if (err)
2069 		return err;
2070 
2071 	err = class_register(&iscsi_endpoint_class);
2072 	if (err)
2073 		goto unregister_transport_class;
2074 
2075 	err = transport_class_register(&iscsi_host_class);
2076 	if (err)
2077 		goto unregister_endpoint_class;
2078 
2079 	err = transport_class_register(&iscsi_connection_class);
2080 	if (err)
2081 		goto unregister_host_class;
2082 
2083 	err = transport_class_register(&iscsi_session_class);
2084 	if (err)
2085 		goto unregister_conn_class;
2086 
2087 	nls = netlink_kernel_create(&init_net, NETLINK_ISCSI, 1, iscsi_if_rx,
2088 				    NULL, THIS_MODULE);
2089 	if (!nls) {
2090 		err = -ENOBUFS;
2091 		goto unregister_session_class;
2092 	}
2093 
2094 	iscsi_eh_timer_workq = create_singlethread_workqueue("iscsi_eh");
2095 	if (!iscsi_eh_timer_workq)
2096 		goto release_nls;
2097 
2098 	return 0;
2099 
2100 release_nls:
2101 	netlink_kernel_release(nls);
2102 unregister_session_class:
2103 	transport_class_unregister(&iscsi_session_class);
2104 unregister_conn_class:
2105 	transport_class_unregister(&iscsi_connection_class);
2106 unregister_host_class:
2107 	transport_class_unregister(&iscsi_host_class);
2108 unregister_endpoint_class:
2109 	class_unregister(&iscsi_endpoint_class);
2110 unregister_transport_class:
2111 	class_unregister(&iscsi_transport_class);
2112 	return err;
2113 }
2114 
2115 static void __exit iscsi_transport_exit(void)
2116 {
2117 	destroy_workqueue(iscsi_eh_timer_workq);
2118 	netlink_kernel_release(nls);
2119 	transport_class_unregister(&iscsi_connection_class);
2120 	transport_class_unregister(&iscsi_session_class);
2121 	transport_class_unregister(&iscsi_host_class);
2122 	class_unregister(&iscsi_endpoint_class);
2123 	class_unregister(&iscsi_transport_class);
2124 }
2125 
2126 module_init(iscsi_transport_init);
2127 module_exit(iscsi_transport_exit);
2128 
2129 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
2130 	      "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
2131 	      "Alex Aizman <itn780@yahoo.com>");
2132 MODULE_DESCRIPTION("iSCSI Transport Interface");
2133 MODULE_LICENSE("GPL");
2134 MODULE_VERSION(ISCSI_TRANSPORT_VERSION);
2135