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 18
34 #define ISCSI_CONN_ATTRS 11
35 #define ISCSI_HOST_ATTRS 4
36 #define ISCSI_TRANSPORT_VERSION "2.0-867"
37 
38 struct iscsi_internal {
39 	int daemon_pid;
40 	struct scsi_transport_template t;
41 	struct iscsi_transport *iscsi_transport;
42 	struct list_head list;
43 	struct class_device cdev;
44 
45 	struct class_device_attribute *host_attrs[ISCSI_HOST_ATTRS + 1];
46 	struct transport_container conn_cont;
47 	struct class_device_attribute *conn_attrs[ISCSI_CONN_ATTRS + 1];
48 	struct transport_container session_cont;
49 	struct class_device_attribute *session_attrs[ISCSI_SESSION_ATTRS + 1];
50 };
51 
52 static atomic_t iscsi_session_nr; /* sysfs session id for next new session */
53 static struct workqueue_struct *iscsi_eh_timer_workq;
54 
55 /*
56  * list of registered transports and lock that must
57  * be held while accessing list. The iscsi_transport_lock must
58  * be acquired after the rx_queue_mutex.
59  */
60 static LIST_HEAD(iscsi_transports);
61 static DEFINE_SPINLOCK(iscsi_transport_lock);
62 
63 #define to_iscsi_internal(tmpl) \
64 	container_of(tmpl, struct iscsi_internal, t)
65 
66 #define cdev_to_iscsi_internal(_cdev) \
67 	container_of(_cdev, struct iscsi_internal, cdev)
68 
69 static void iscsi_transport_release(struct class_device *cdev)
70 {
71 	struct iscsi_internal *priv = cdev_to_iscsi_internal(cdev);
72 	kfree(priv);
73 }
74 
75 /*
76  * iscsi_transport_class represents the iscsi_transports that are
77  * registered.
78  */
79 static struct class iscsi_transport_class = {
80 	.name = "iscsi_transport",
81 	.release = iscsi_transport_release,
82 };
83 
84 static ssize_t
85 show_transport_handle(struct class_device *cdev, char *buf)
86 {
87 	struct iscsi_internal *priv = cdev_to_iscsi_internal(cdev);
88 	return sprintf(buf, "%llu\n", (unsigned long long)iscsi_handle(priv->iscsi_transport));
89 }
90 static CLASS_DEVICE_ATTR(handle, S_IRUGO, show_transport_handle, NULL);
91 
92 #define show_transport_attr(name, format)				\
93 static ssize_t								\
94 show_transport_##name(struct class_device *cdev, char *buf)		\
95 {									\
96 	struct iscsi_internal *priv = cdev_to_iscsi_internal(cdev);	\
97 	return sprintf(buf, format"\n", priv->iscsi_transport->name);	\
98 }									\
99 static CLASS_DEVICE_ATTR(name, S_IRUGO, show_transport_##name, NULL);
100 
101 show_transport_attr(caps, "0x%x");
102 show_transport_attr(max_lun, "%d");
103 show_transport_attr(max_conn, "%d");
104 show_transport_attr(max_cmd_len, "%d");
105 
106 static struct attribute *iscsi_transport_attrs[] = {
107 	&class_device_attr_handle.attr,
108 	&class_device_attr_caps.attr,
109 	&class_device_attr_max_lun.attr,
110 	&class_device_attr_max_conn.attr,
111 	&class_device_attr_max_cmd_len.attr,
112 	NULL,
113 };
114 
115 static struct attribute_group iscsi_transport_group = {
116 	.attrs = iscsi_transport_attrs,
117 };
118 
119 
120 
121 static int iscsi_setup_host(struct transport_container *tc, struct device *dev,
122 			    struct class_device *cdev)
123 {
124 	struct Scsi_Host *shost = dev_to_shost(dev);
125 	struct iscsi_host *ihost = shost->shost_data;
126 
127 	memset(ihost, 0, sizeof(*ihost));
128 	INIT_LIST_HEAD(&ihost->sessions);
129 	mutex_init(&ihost->mutex);
130 
131 	snprintf(ihost->unbind_workq_name, KOBJ_NAME_LEN, "iscsi_unbind_%d",
132 		shost->host_no);
133 	ihost->unbind_workq = create_singlethread_workqueue(
134 						ihost->unbind_workq_name);
135 	if (!ihost->unbind_workq)
136 		return -ENOMEM;
137 	return 0;
138 }
139 
140 static int iscsi_remove_host(struct transport_container *tc, struct device *dev,
141 			     struct class_device *cdev)
142 {
143 	struct Scsi_Host *shost = dev_to_shost(dev);
144 	struct iscsi_host *ihost = shost->shost_data;
145 
146 	destroy_workqueue(ihost->unbind_workq);
147 	return 0;
148 }
149 
150 static DECLARE_TRANSPORT_CLASS(iscsi_host_class,
151 			       "iscsi_host",
152 			       iscsi_setup_host,
153 			       iscsi_remove_host,
154 			       NULL);
155 
156 static DECLARE_TRANSPORT_CLASS(iscsi_session_class,
157 			       "iscsi_session",
158 			       NULL,
159 			       NULL,
160 			       NULL);
161 
162 static DECLARE_TRANSPORT_CLASS(iscsi_connection_class,
163 			       "iscsi_connection",
164 			       NULL,
165 			       NULL,
166 			       NULL);
167 
168 static struct sock *nls;
169 static DEFINE_MUTEX(rx_queue_mutex);
170 
171 static LIST_HEAD(sesslist);
172 static DEFINE_SPINLOCK(sesslock);
173 static LIST_HEAD(connlist);
174 static DEFINE_SPINLOCK(connlock);
175 
176 static uint32_t iscsi_conn_get_sid(struct iscsi_cls_conn *conn)
177 {
178 	struct iscsi_cls_session *sess = iscsi_dev_to_session(conn->dev.parent);
179 	return sess->sid;
180 }
181 
182 /*
183  * Returns the matching session to a given sid
184  */
185 static struct iscsi_cls_session *iscsi_session_lookup(uint32_t sid)
186 {
187 	unsigned long flags;
188 	struct iscsi_cls_session *sess;
189 
190 	spin_lock_irqsave(&sesslock, flags);
191 	list_for_each_entry(sess, &sesslist, sess_list) {
192 		if (sess->sid == sid) {
193 			spin_unlock_irqrestore(&sesslock, flags);
194 			return sess;
195 		}
196 	}
197 	spin_unlock_irqrestore(&sesslock, flags);
198 	return NULL;
199 }
200 
201 /*
202  * Returns the matching connection to a given sid / cid tuple
203  */
204 static struct iscsi_cls_conn *iscsi_conn_lookup(uint32_t sid, uint32_t cid)
205 {
206 	unsigned long flags;
207 	struct iscsi_cls_conn *conn;
208 
209 	spin_lock_irqsave(&connlock, flags);
210 	list_for_each_entry(conn, &connlist, conn_list) {
211 		if ((conn->cid == cid) && (iscsi_conn_get_sid(conn) == sid)) {
212 			spin_unlock_irqrestore(&connlock, flags);
213 			return conn;
214 		}
215 	}
216 	spin_unlock_irqrestore(&connlock, flags);
217 	return NULL;
218 }
219 
220 /*
221  * The following functions can be used by LLDs that allocate
222  * their own scsi_hosts or by software iscsi LLDs
223  */
224 static void iscsi_session_release(struct device *dev)
225 {
226 	struct iscsi_cls_session *session = iscsi_dev_to_session(dev);
227 	struct Scsi_Host *shost;
228 
229 	shost = iscsi_session_to_shost(session);
230 	scsi_host_put(shost);
231 	kfree(session);
232 }
233 
234 static int iscsi_is_session_dev(const struct device *dev)
235 {
236 	return dev->release == iscsi_session_release;
237 }
238 
239 static int iscsi_user_scan(struct Scsi_Host *shost, uint channel,
240 			   uint id, uint lun)
241 {
242 	struct iscsi_host *ihost = shost->shost_data;
243 	struct iscsi_cls_session *session;
244 
245 	mutex_lock(&ihost->mutex);
246 	list_for_each_entry(session, &ihost->sessions, host_list) {
247 		if ((channel == SCAN_WILD_CARD || channel == 0) &&
248 		    (id == SCAN_WILD_CARD || id == session->target_id))
249 			scsi_scan_target(&session->dev, 0,
250 					 session->target_id, lun, 1);
251 	}
252 	mutex_unlock(&ihost->mutex);
253 
254 	return 0;
255 }
256 
257 static void session_recovery_timedout(struct work_struct *work)
258 {
259 	struct iscsi_cls_session *session =
260 		container_of(work, struct iscsi_cls_session,
261 			     recovery_work.work);
262 
263 	dev_printk(KERN_INFO, &session->dev, "iscsi: session recovery timed "
264 		  "out after %d secs\n", session->recovery_tmo);
265 
266 	if (session->transport->session_recovery_timedout)
267 		session->transport->session_recovery_timedout(session);
268 
269 	scsi_target_unblock(&session->dev);
270 }
271 
272 void iscsi_unblock_session(struct iscsi_cls_session *session)
273 {
274 	if (!cancel_delayed_work(&session->recovery_work))
275 		flush_workqueue(iscsi_eh_timer_workq);
276 	scsi_target_unblock(&session->dev);
277 }
278 EXPORT_SYMBOL_GPL(iscsi_unblock_session);
279 
280 void iscsi_block_session(struct iscsi_cls_session *session)
281 {
282 	scsi_target_block(&session->dev);
283 	queue_delayed_work(iscsi_eh_timer_workq, &session->recovery_work,
284 			   session->recovery_tmo * HZ);
285 }
286 EXPORT_SYMBOL_GPL(iscsi_block_session);
287 
288 static void __iscsi_unbind_session(struct work_struct *work)
289 {
290 	struct iscsi_cls_session *session =
291 			container_of(work, struct iscsi_cls_session,
292 				     unbind_work);
293 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
294 	struct iscsi_host *ihost = shost->shost_data;
295 
296 	/* Prevent new scans and make sure scanning is not in progress */
297 	mutex_lock(&ihost->mutex);
298 	if (list_empty(&session->host_list)) {
299 		mutex_unlock(&ihost->mutex);
300 		return;
301 	}
302 	list_del_init(&session->host_list);
303 	mutex_unlock(&ihost->mutex);
304 
305 	scsi_remove_target(&session->dev);
306 	iscsi_session_event(session, ISCSI_KEVENT_UNBIND_SESSION);
307 }
308 
309 static int iscsi_unbind_session(struct iscsi_cls_session *session)
310 {
311 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
312 	struct iscsi_host *ihost = shost->shost_data;
313 
314 	return queue_work(ihost->unbind_workq, &session->unbind_work);
315 }
316 
317 struct iscsi_cls_session *
318 iscsi_alloc_session(struct Scsi_Host *shost,
319 		    struct iscsi_transport *transport)
320 {
321 	struct iscsi_cls_session *session;
322 
323 	session = kzalloc(sizeof(*session) + transport->sessiondata_size,
324 			  GFP_KERNEL);
325 	if (!session)
326 		return NULL;
327 
328 	session->transport = transport;
329 	session->recovery_tmo = 120;
330 	INIT_DELAYED_WORK(&session->recovery_work, session_recovery_timedout);
331 	INIT_LIST_HEAD(&session->host_list);
332 	INIT_LIST_HEAD(&session->sess_list);
333 	INIT_WORK(&session->unbind_work, __iscsi_unbind_session);
334 
335 	/* this is released in the dev's release function */
336 	scsi_host_get(shost);
337 	session->dev.parent = &shost->shost_gendev;
338 	session->dev.release = iscsi_session_release;
339 	device_initialize(&session->dev);
340 	if (transport->sessiondata_size)
341 		session->dd_data = &session[1];
342 	return session;
343 }
344 EXPORT_SYMBOL_GPL(iscsi_alloc_session);
345 
346 int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
347 {
348 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
349 	struct iscsi_host *ihost;
350 	unsigned long flags;
351 	int err;
352 
353 	ihost = shost->shost_data;
354 	session->sid = atomic_add_return(1, &iscsi_session_nr);
355 	session->target_id = target_id;
356 
357 	snprintf(session->dev.bus_id, BUS_ID_SIZE, "session%u",
358 		 session->sid);
359 	err = device_add(&session->dev);
360 	if (err) {
361 		dev_printk(KERN_ERR, &session->dev, "iscsi: could not "
362 			   "register session's dev\n");
363 		goto release_host;
364 	}
365 	transport_register_device(&session->dev);
366 
367 	spin_lock_irqsave(&sesslock, flags);
368 	list_add(&session->sess_list, &sesslist);
369 	spin_unlock_irqrestore(&sesslock, flags);
370 
371 	mutex_lock(&ihost->mutex);
372 	list_add(&session->host_list, &ihost->sessions);
373 	mutex_unlock(&ihost->mutex);
374 
375 	iscsi_session_event(session, ISCSI_KEVENT_CREATE_SESSION);
376 	return 0;
377 
378 release_host:
379 	scsi_host_put(shost);
380 	return err;
381 }
382 EXPORT_SYMBOL_GPL(iscsi_add_session);
383 
384 /**
385  * iscsi_create_session - create iscsi class session
386  * @shost: scsi host
387  * @transport: iscsi transport
388  * @target_id: which target
389  *
390  * This can be called from a LLD or iscsi_transport.
391  */
392 struct iscsi_cls_session *
393 iscsi_create_session(struct Scsi_Host *shost,
394 		     struct iscsi_transport *transport,
395 		     unsigned int target_id)
396 {
397 	struct iscsi_cls_session *session;
398 
399 	session = iscsi_alloc_session(shost, transport);
400 	if (!session)
401 		return NULL;
402 
403 	if (iscsi_add_session(session, target_id)) {
404 		iscsi_free_session(session);
405 		return NULL;
406 	}
407 	return session;
408 }
409 EXPORT_SYMBOL_GPL(iscsi_create_session);
410 
411 static void iscsi_conn_release(struct device *dev)
412 {
413 	struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev);
414 	struct device *parent = conn->dev.parent;
415 
416 	kfree(conn);
417 	put_device(parent);
418 }
419 
420 static int iscsi_is_conn_dev(const struct device *dev)
421 {
422 	return dev->release == iscsi_conn_release;
423 }
424 
425 static int iscsi_iter_destroy_conn_fn(struct device *dev, void *data)
426 {
427 	if (!iscsi_is_conn_dev(dev))
428 		return 0;
429 	return iscsi_destroy_conn(iscsi_dev_to_conn(dev));
430 }
431 
432 void iscsi_remove_session(struct iscsi_cls_session *session)
433 {
434 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
435 	struct iscsi_host *ihost = shost->shost_data;
436 	unsigned long flags;
437 	int err;
438 
439 	spin_lock_irqsave(&sesslock, flags);
440 	list_del(&session->sess_list);
441 	spin_unlock_irqrestore(&sesslock, flags);
442 
443 	/*
444 	 * If we are blocked let commands flow again. The lld or iscsi
445 	 * layer should set up the queuecommand to fail commands.
446 	 */
447 	iscsi_unblock_session(session);
448 	iscsi_unbind_session(session);
449 	/*
450 	 * If the session dropped while removing devices then we need to make
451 	 * sure it is not blocked
452 	 */
453 	if (!cancel_delayed_work(&session->recovery_work))
454 		flush_workqueue(iscsi_eh_timer_workq);
455 	flush_workqueue(ihost->unbind_workq);
456 
457 	/* hw iscsi may not have removed all connections from session */
458 	err = device_for_each_child(&session->dev, NULL,
459 				    iscsi_iter_destroy_conn_fn);
460 	if (err)
461 		dev_printk(KERN_ERR, &session->dev, "iscsi: Could not delete "
462 			   "all connections for session. Error %d.\n", err);
463 
464 	transport_unregister_device(&session->dev);
465 	device_del(&session->dev);
466 }
467 EXPORT_SYMBOL_GPL(iscsi_remove_session);
468 
469 void iscsi_free_session(struct iscsi_cls_session *session)
470 {
471 	iscsi_session_event(session, ISCSI_KEVENT_DESTROY_SESSION);
472 	put_device(&session->dev);
473 }
474 EXPORT_SYMBOL_GPL(iscsi_free_session);
475 
476 /**
477  * iscsi_destroy_session - destroy iscsi session
478  * @session: iscsi_session
479  *
480  * Can be called by a LLD or iscsi_transport. There must not be
481  * any running connections.
482  */
483 int iscsi_destroy_session(struct iscsi_cls_session *session)
484 {
485 	iscsi_remove_session(session);
486 	iscsi_free_session(session);
487 	return 0;
488 }
489 EXPORT_SYMBOL_GPL(iscsi_destroy_session);
490 
491 /**
492  * iscsi_create_conn - create iscsi class connection
493  * @session: iscsi cls session
494  * @cid: connection id
495  *
496  * This can be called from a LLD or iscsi_transport. The connection
497  * is child of the session so cid must be unique for all connections
498  * on the session.
499  *
500  * Since we do not support MCS, cid will normally be zero. In some cases
501  * for software iscsi we could be trying to preallocate a connection struct
502  * in which case there could be two connection structs and cid would be
503  * non-zero.
504  */
505 struct iscsi_cls_conn *
506 iscsi_create_conn(struct iscsi_cls_session *session, uint32_t cid)
507 {
508 	struct iscsi_transport *transport = session->transport;
509 	struct iscsi_cls_conn *conn;
510 	unsigned long flags;
511 	int err;
512 
513 	conn = kzalloc(sizeof(*conn) + transport->conndata_size, GFP_KERNEL);
514 	if (!conn)
515 		return NULL;
516 
517 	if (transport->conndata_size)
518 		conn->dd_data = &conn[1];
519 
520 	INIT_LIST_HEAD(&conn->conn_list);
521 	conn->transport = transport;
522 	conn->cid = cid;
523 
524 	/* this is released in the dev's release function */
525 	if (!get_device(&session->dev))
526 		goto free_conn;
527 
528 	snprintf(conn->dev.bus_id, BUS_ID_SIZE, "connection%d:%u",
529 		 session->sid, cid);
530 	conn->dev.parent = &session->dev;
531 	conn->dev.release = iscsi_conn_release;
532 	err = device_register(&conn->dev);
533 	if (err) {
534 		dev_printk(KERN_ERR, &conn->dev, "iscsi: could not register "
535 			   "connection's dev\n");
536 		goto release_parent_ref;
537 	}
538 	transport_register_device(&conn->dev);
539 
540 	spin_lock_irqsave(&connlock, flags);
541 	list_add(&conn->conn_list, &connlist);
542 	conn->active = 1;
543 	spin_unlock_irqrestore(&connlock, flags);
544 	return conn;
545 
546 release_parent_ref:
547 	put_device(&session->dev);
548 free_conn:
549 	kfree(conn);
550 	return NULL;
551 }
552 
553 EXPORT_SYMBOL_GPL(iscsi_create_conn);
554 
555 /**
556  * iscsi_destroy_conn - destroy iscsi class connection
557  * @conn: iscsi cls session
558  *
559  * This can be called from a LLD or iscsi_transport.
560  */
561 int iscsi_destroy_conn(struct iscsi_cls_conn *conn)
562 {
563 	unsigned long flags;
564 
565 	spin_lock_irqsave(&connlock, flags);
566 	conn->active = 0;
567 	list_del(&conn->conn_list);
568 	spin_unlock_irqrestore(&connlock, flags);
569 
570 	transport_unregister_device(&conn->dev);
571 	device_unregister(&conn->dev);
572 	return 0;
573 }
574 EXPORT_SYMBOL_GPL(iscsi_destroy_conn);
575 
576 /*
577  * iscsi interface functions
578  */
579 static struct iscsi_internal *
580 iscsi_if_transport_lookup(struct iscsi_transport *tt)
581 {
582 	struct iscsi_internal *priv;
583 	unsigned long flags;
584 
585 	spin_lock_irqsave(&iscsi_transport_lock, flags);
586 	list_for_each_entry(priv, &iscsi_transports, list) {
587 		if (tt == priv->iscsi_transport) {
588 			spin_unlock_irqrestore(&iscsi_transport_lock, flags);
589 			return priv;
590 		}
591 	}
592 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
593 	return NULL;
594 }
595 
596 static int
597 iscsi_broadcast_skb(struct sk_buff *skb, gfp_t gfp)
598 {
599 	int rc;
600 
601 	rc = netlink_broadcast(nls, skb, 0, 1, gfp);
602 	if (rc < 0) {
603 		printk(KERN_ERR "iscsi: can not broadcast skb (%d)\n", rc);
604 		return rc;
605 	}
606 
607 	return 0;
608 }
609 
610 static int
611 iscsi_unicast_skb(struct sk_buff *skb, int pid)
612 {
613 	int rc;
614 
615 	rc = netlink_unicast(nls, skb, pid, MSG_DONTWAIT);
616 	if (rc < 0) {
617 		printk(KERN_ERR "iscsi: can not unicast skb (%d)\n", rc);
618 		return rc;
619 	}
620 
621 	return 0;
622 }
623 
624 int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
625 		   char *data, uint32_t data_size)
626 {
627 	struct nlmsghdr	*nlh;
628 	struct sk_buff *skb;
629 	struct iscsi_uevent *ev;
630 	char *pdu;
631 	struct iscsi_internal *priv;
632 	int len = NLMSG_SPACE(sizeof(*ev) + sizeof(struct iscsi_hdr) +
633 			      data_size);
634 
635 	priv = iscsi_if_transport_lookup(conn->transport);
636 	if (!priv)
637 		return -EINVAL;
638 
639 	skb = alloc_skb(len, GFP_ATOMIC);
640 	if (!skb) {
641 		iscsi_conn_error(conn, ISCSI_ERR_CONN_FAILED);
642 		dev_printk(KERN_ERR, &conn->dev, "iscsi: can not deliver "
643 			   "control PDU: OOM\n");
644 		return -ENOMEM;
645 	}
646 
647 	nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
648 	ev = NLMSG_DATA(nlh);
649 	memset(ev, 0, sizeof(*ev));
650 	ev->transport_handle = iscsi_handle(conn->transport);
651 	ev->type = ISCSI_KEVENT_RECV_PDU;
652 	ev->r.recv_req.cid = conn->cid;
653 	ev->r.recv_req.sid = iscsi_conn_get_sid(conn);
654 	pdu = (char*)ev + sizeof(*ev);
655 	memcpy(pdu, hdr, sizeof(struct iscsi_hdr));
656 	memcpy(pdu + sizeof(struct iscsi_hdr), data, data_size);
657 
658 	return iscsi_unicast_skb(skb, priv->daemon_pid);
659 }
660 EXPORT_SYMBOL_GPL(iscsi_recv_pdu);
661 
662 void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error)
663 {
664 	struct nlmsghdr	*nlh;
665 	struct sk_buff	*skb;
666 	struct iscsi_uevent *ev;
667 	struct iscsi_internal *priv;
668 	int len = NLMSG_SPACE(sizeof(*ev));
669 
670 	priv = iscsi_if_transport_lookup(conn->transport);
671 	if (!priv)
672 		return;
673 
674 	skb = alloc_skb(len, GFP_ATOMIC);
675 	if (!skb) {
676 		dev_printk(KERN_ERR, &conn->dev, "iscsi: gracefully ignored "
677 			  "conn error (%d)\n", error);
678 		return;
679 	}
680 
681 	nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
682 	ev = NLMSG_DATA(nlh);
683 	ev->transport_handle = iscsi_handle(conn->transport);
684 	ev->type = ISCSI_KEVENT_CONN_ERROR;
685 	ev->r.connerror.error = error;
686 	ev->r.connerror.cid = conn->cid;
687 	ev->r.connerror.sid = iscsi_conn_get_sid(conn);
688 
689 	iscsi_broadcast_skb(skb, GFP_ATOMIC);
690 
691 	dev_printk(KERN_INFO, &conn->dev, "iscsi: detected conn error (%d)\n",
692 		   error);
693 }
694 EXPORT_SYMBOL_GPL(iscsi_conn_error);
695 
696 static int
697 iscsi_if_send_reply(int pid, int seq, int type, int done, int multi,
698 		      void *payload, int size)
699 {
700 	struct sk_buff	*skb;
701 	struct nlmsghdr	*nlh;
702 	int len = NLMSG_SPACE(size);
703 	int flags = multi ? NLM_F_MULTI : 0;
704 	int t = done ? NLMSG_DONE : type;
705 
706 	skb = alloc_skb(len, GFP_ATOMIC);
707 	if (!skb) {
708 		printk(KERN_ERR "Could not allocate skb to send reply.\n");
709 		return -ENOMEM;
710 	}
711 
712 	nlh = __nlmsg_put(skb, pid, seq, t, (len - sizeof(*nlh)), 0);
713 	nlh->nlmsg_flags = flags;
714 	memcpy(NLMSG_DATA(nlh), payload, size);
715 	return iscsi_unicast_skb(skb, pid);
716 }
717 
718 static int
719 iscsi_if_get_stats(struct iscsi_transport *transport, struct nlmsghdr *nlh)
720 {
721 	struct iscsi_uevent *ev = NLMSG_DATA(nlh);
722 	struct iscsi_stats *stats;
723 	struct sk_buff *skbstat;
724 	struct iscsi_cls_conn *conn;
725 	struct nlmsghdr	*nlhstat;
726 	struct iscsi_uevent *evstat;
727 	struct iscsi_internal *priv;
728 	int len = NLMSG_SPACE(sizeof(*ev) +
729 			      sizeof(struct iscsi_stats) +
730 			      sizeof(struct iscsi_stats_custom) *
731 			      ISCSI_STATS_CUSTOM_MAX);
732 	int err = 0;
733 
734 	priv = iscsi_if_transport_lookup(transport);
735 	if (!priv)
736 		return -EINVAL;
737 
738 	conn = iscsi_conn_lookup(ev->u.get_stats.sid, ev->u.get_stats.cid);
739 	if (!conn)
740 		return -EEXIST;
741 
742 	do {
743 		int actual_size;
744 
745 		skbstat = alloc_skb(len, GFP_ATOMIC);
746 		if (!skbstat) {
747 			dev_printk(KERN_ERR, &conn->dev, "iscsi: can not "
748 				   "deliver stats: OOM\n");
749 			return -ENOMEM;
750 		}
751 
752 		nlhstat = __nlmsg_put(skbstat, priv->daemon_pid, 0, 0,
753 				      (len - sizeof(*nlhstat)), 0);
754 		evstat = NLMSG_DATA(nlhstat);
755 		memset(evstat, 0, sizeof(*evstat));
756 		evstat->transport_handle = iscsi_handle(conn->transport);
757 		evstat->type = nlh->nlmsg_type;
758 		evstat->u.get_stats.cid =
759 			ev->u.get_stats.cid;
760 		evstat->u.get_stats.sid =
761 			ev->u.get_stats.sid;
762 		stats = (struct iscsi_stats *)
763 			((char*)evstat + sizeof(*evstat));
764 		memset(stats, 0, sizeof(*stats));
765 
766 		transport->get_stats(conn, stats);
767 		actual_size = NLMSG_SPACE(sizeof(struct iscsi_uevent) +
768 					  sizeof(struct iscsi_stats) +
769 					  sizeof(struct iscsi_stats_custom) *
770 					  stats->custom_length);
771 		actual_size -= sizeof(*nlhstat);
772 		actual_size = NLMSG_LENGTH(actual_size);
773 		skb_trim(skbstat, NLMSG_ALIGN(actual_size));
774 		nlhstat->nlmsg_len = actual_size;
775 
776 		err = iscsi_unicast_skb(skbstat, priv->daemon_pid);
777 	} while (err < 0 && err != -ECONNREFUSED);
778 
779 	return err;
780 }
781 
782 /**
783  * iscsi_session_event - send session destr. completion event
784  * @session: iscsi class session
785  * @event: type of event
786  */
787 int iscsi_session_event(struct iscsi_cls_session *session,
788 			enum iscsi_uevent_e event)
789 {
790 	struct iscsi_internal *priv;
791 	struct Scsi_Host *shost;
792 	struct iscsi_uevent *ev;
793 	struct sk_buff  *skb;
794 	struct nlmsghdr *nlh;
795 	int rc, len = NLMSG_SPACE(sizeof(*ev));
796 
797 	priv = iscsi_if_transport_lookup(session->transport);
798 	if (!priv)
799 		return -EINVAL;
800 	shost = iscsi_session_to_shost(session);
801 
802 	skb = alloc_skb(len, GFP_KERNEL);
803 	if (!skb) {
804 		dev_printk(KERN_ERR, &session->dev, "Cannot notify userspace "
805 			  "of session event %u\n", event);
806 		return -ENOMEM;
807 	}
808 
809 	nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
810 	ev = NLMSG_DATA(nlh);
811 	ev->transport_handle = iscsi_handle(session->transport);
812 
813 	ev->type = event;
814 	switch (event) {
815 	case ISCSI_KEVENT_DESTROY_SESSION:
816 		ev->r.d_session.host_no = shost->host_no;
817 		ev->r.d_session.sid = session->sid;
818 		break;
819 	case ISCSI_KEVENT_CREATE_SESSION:
820 		ev->r.c_session_ret.host_no = shost->host_no;
821 		ev->r.c_session_ret.sid = session->sid;
822 		break;
823 	case ISCSI_KEVENT_UNBIND_SESSION:
824 		ev->r.unbind_session.host_no = shost->host_no;
825 		ev->r.unbind_session.sid = session->sid;
826 		break;
827 	default:
828 		dev_printk(KERN_ERR, &session->dev, "Invalid event %u.\n",
829 			   event);
830 		kfree_skb(skb);
831 		return -EINVAL;
832 	}
833 
834 	/*
835 	 * this will occur if the daemon is not up, so we just warn
836 	 * the user and when the daemon is restarted it will handle it
837 	 */
838 	rc = iscsi_broadcast_skb(skb, GFP_KERNEL);
839 	if (rc < 0)
840 		dev_printk(KERN_ERR, &session->dev, "Cannot notify userspace "
841 			  "of session event %u. Check iscsi daemon\n", event);
842 	return rc;
843 }
844 EXPORT_SYMBOL_GPL(iscsi_session_event);
845 
846 static int
847 iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_uevent *ev)
848 {
849 	struct iscsi_transport *transport = priv->iscsi_transport;
850 	struct iscsi_cls_session *session;
851 	uint32_t hostno;
852 
853 	session = transport->create_session(transport, &priv->t,
854 					    ev->u.c_session.cmds_max,
855 					    ev->u.c_session.queue_depth,
856 					    ev->u.c_session.initial_cmdsn,
857 					    &hostno);
858 	if (!session)
859 		return -ENOMEM;
860 
861 	ev->r.c_session_ret.host_no = hostno;
862 	ev->r.c_session_ret.sid = session->sid;
863 	return 0;
864 }
865 
866 static int
867 iscsi_if_create_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
868 {
869 	struct iscsi_cls_conn *conn;
870 	struct iscsi_cls_session *session;
871 
872 	session = iscsi_session_lookup(ev->u.c_conn.sid);
873 	if (!session) {
874 		printk(KERN_ERR "iscsi: invalid session %d\n",
875 		       ev->u.c_conn.sid);
876 		return -EINVAL;
877 	}
878 
879 	conn = transport->create_conn(session, ev->u.c_conn.cid);
880 	if (!conn) {
881 		printk(KERN_ERR "iscsi: couldn't create a new "
882 			   "connection for session %d\n",
883 			   session->sid);
884 		return -ENOMEM;
885 	}
886 
887 	ev->r.c_conn_ret.sid = session->sid;
888 	ev->r.c_conn_ret.cid = conn->cid;
889 	return 0;
890 }
891 
892 static int
893 iscsi_if_destroy_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
894 {
895 	struct iscsi_cls_conn *conn;
896 
897 	conn = iscsi_conn_lookup(ev->u.d_conn.sid, ev->u.d_conn.cid);
898 	if (!conn)
899 		return -EINVAL;
900 
901 	if (transport->destroy_conn)
902 		transport->destroy_conn(conn);
903 	return 0;
904 }
905 
906 static int
907 iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
908 {
909 	char *data = (char*)ev + sizeof(*ev);
910 	struct iscsi_cls_conn *conn;
911 	struct iscsi_cls_session *session;
912 	int err = 0, value = 0;
913 
914 	session = iscsi_session_lookup(ev->u.set_param.sid);
915 	conn = iscsi_conn_lookup(ev->u.set_param.sid, ev->u.set_param.cid);
916 	if (!conn || !session)
917 		return -EINVAL;
918 
919 	switch (ev->u.set_param.param) {
920 	case ISCSI_PARAM_SESS_RECOVERY_TMO:
921 		sscanf(data, "%d", &value);
922 		if (value != 0)
923 			session->recovery_tmo = value;
924 		break;
925 	default:
926 		err = transport->set_param(conn, ev->u.set_param.param,
927 					   data, ev->u.set_param.len);
928 	}
929 
930 	return err;
931 }
932 
933 static int
934 iscsi_if_transport_ep(struct iscsi_transport *transport,
935 		      struct iscsi_uevent *ev, int msg_type)
936 {
937 	struct sockaddr *dst_addr;
938 	int rc = 0;
939 
940 	switch (msg_type) {
941 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
942 		if (!transport->ep_connect)
943 			return -EINVAL;
944 
945 		dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
946 		rc = transport->ep_connect(dst_addr,
947 					   ev->u.ep_connect.non_blocking,
948 					   &ev->r.ep_connect_ret.handle);
949 		break;
950 	case ISCSI_UEVENT_TRANSPORT_EP_POLL:
951 		if (!transport->ep_poll)
952 			return -EINVAL;
953 
954 		ev->r.retcode = transport->ep_poll(ev->u.ep_poll.ep_handle,
955 						   ev->u.ep_poll.timeout_ms);
956 		break;
957 	case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
958 		if (!transport->ep_disconnect)
959 			return -EINVAL;
960 
961 		transport->ep_disconnect(ev->u.ep_disconnect.ep_handle);
962 		break;
963 	}
964 	return rc;
965 }
966 
967 static int
968 iscsi_tgt_dscvr(struct iscsi_transport *transport,
969 		struct iscsi_uevent *ev)
970 {
971 	struct Scsi_Host *shost;
972 	struct sockaddr *dst_addr;
973 	int err;
974 
975 	if (!transport->tgt_dscvr)
976 		return -EINVAL;
977 
978 	shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);
979 	if (IS_ERR(shost)) {
980 		printk(KERN_ERR "target discovery could not find host no %u\n",
981 		       ev->u.tgt_dscvr.host_no);
982 		return -ENODEV;
983 	}
984 
985 
986 	dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
987 	err = transport->tgt_dscvr(shost, ev->u.tgt_dscvr.type,
988 				   ev->u.tgt_dscvr.enable, dst_addr);
989 	scsi_host_put(shost);
990 	return err;
991 }
992 
993 static int
994 iscsi_set_host_param(struct iscsi_transport *transport,
995 		     struct iscsi_uevent *ev)
996 {
997 	char *data = (char*)ev + sizeof(*ev);
998 	struct Scsi_Host *shost;
999 	int err;
1000 
1001 	if (!transport->set_host_param)
1002 		return -ENOSYS;
1003 
1004 	shost = scsi_host_lookup(ev->u.set_host_param.host_no);
1005 	if (IS_ERR(shost)) {
1006 		printk(KERN_ERR "set_host_param could not find host no %u\n",
1007 		       ev->u.set_host_param.host_no);
1008 		return -ENODEV;
1009 	}
1010 
1011 	err = transport->set_host_param(shost, ev->u.set_host_param.param,
1012 					data, ev->u.set_host_param.len);
1013 	scsi_host_put(shost);
1014 	return err;
1015 }
1016 
1017 static int
1018 iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
1019 {
1020 	int err = 0;
1021 	struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1022 	struct iscsi_transport *transport = NULL;
1023 	struct iscsi_internal *priv;
1024 	struct iscsi_cls_session *session;
1025 	struct iscsi_cls_conn *conn;
1026 
1027 	priv = iscsi_if_transport_lookup(iscsi_ptr(ev->transport_handle));
1028 	if (!priv)
1029 		return -EINVAL;
1030 	transport = priv->iscsi_transport;
1031 
1032 	if (!try_module_get(transport->owner))
1033 		return -EINVAL;
1034 
1035 	priv->daemon_pid = NETLINK_CREDS(skb)->pid;
1036 
1037 	switch (nlh->nlmsg_type) {
1038 	case ISCSI_UEVENT_CREATE_SESSION:
1039 		err = iscsi_if_create_session(priv, ev);
1040 		break;
1041 	case ISCSI_UEVENT_DESTROY_SESSION:
1042 		session = iscsi_session_lookup(ev->u.d_session.sid);
1043 		if (session)
1044 			transport->destroy_session(session);
1045 		else
1046 			err = -EINVAL;
1047 		break;
1048 	case ISCSI_UEVENT_UNBIND_SESSION:
1049 		session = iscsi_session_lookup(ev->u.d_session.sid);
1050 		if (session)
1051 			iscsi_unbind_session(session);
1052 		else
1053 			err = -EINVAL;
1054 		break;
1055 	case ISCSI_UEVENT_CREATE_CONN:
1056 		err = iscsi_if_create_conn(transport, ev);
1057 		break;
1058 	case ISCSI_UEVENT_DESTROY_CONN:
1059 		err = iscsi_if_destroy_conn(transport, ev);
1060 		break;
1061 	case ISCSI_UEVENT_BIND_CONN:
1062 		session = iscsi_session_lookup(ev->u.b_conn.sid);
1063 		conn = iscsi_conn_lookup(ev->u.b_conn.sid, ev->u.b_conn.cid);
1064 
1065 		if (session && conn)
1066 			ev->r.retcode =	transport->bind_conn(session, conn,
1067 					ev->u.b_conn.transport_eph,
1068 					ev->u.b_conn.is_leading);
1069 		else
1070 			err = -EINVAL;
1071 		break;
1072 	case ISCSI_UEVENT_SET_PARAM:
1073 		err = iscsi_set_param(transport, ev);
1074 		break;
1075 	case ISCSI_UEVENT_START_CONN:
1076 		conn = iscsi_conn_lookup(ev->u.start_conn.sid, ev->u.start_conn.cid);
1077 		if (conn)
1078 			ev->r.retcode = transport->start_conn(conn);
1079 		else
1080 			err = -EINVAL;
1081 		break;
1082 	case ISCSI_UEVENT_STOP_CONN:
1083 		conn = iscsi_conn_lookup(ev->u.stop_conn.sid, ev->u.stop_conn.cid);
1084 		if (conn)
1085 			transport->stop_conn(conn, ev->u.stop_conn.flag);
1086 		else
1087 			err = -EINVAL;
1088 		break;
1089 	case ISCSI_UEVENT_SEND_PDU:
1090 		conn = iscsi_conn_lookup(ev->u.send_pdu.sid, ev->u.send_pdu.cid);
1091 		if (conn)
1092 			ev->r.retcode =	transport->send_pdu(conn,
1093 				(struct iscsi_hdr*)((char*)ev + sizeof(*ev)),
1094 				(char*)ev + sizeof(*ev) + ev->u.send_pdu.hdr_size,
1095 				ev->u.send_pdu.data_size);
1096 		else
1097 			err = -EINVAL;
1098 		break;
1099 	case ISCSI_UEVENT_GET_STATS:
1100 		err = iscsi_if_get_stats(transport, nlh);
1101 		break;
1102 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1103 	case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1104 	case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1105 		err = iscsi_if_transport_ep(transport, ev, nlh->nlmsg_type);
1106 		break;
1107 	case ISCSI_UEVENT_TGT_DSCVR:
1108 		err = iscsi_tgt_dscvr(transport, ev);
1109 		break;
1110 	case ISCSI_UEVENT_SET_HOST_PARAM:
1111 		err = iscsi_set_host_param(transport, ev);
1112 		break;
1113 	default:
1114 		err = -ENOSYS;
1115 		break;
1116 	}
1117 
1118 	module_put(transport->owner);
1119 	return err;
1120 }
1121 
1122 /*
1123  * Get message from skb.  Each message is processed by iscsi_if_recv_msg.
1124  * Malformed skbs with wrong lengths or invalid creds are not processed.
1125  */
1126 static void
1127 iscsi_if_rx(struct sk_buff *skb)
1128 {
1129 	mutex_lock(&rx_queue_mutex);
1130 	while (skb->len >= NLMSG_SPACE(0)) {
1131 		int err;
1132 		uint32_t rlen;
1133 		struct nlmsghdr	*nlh;
1134 		struct iscsi_uevent *ev;
1135 
1136 		nlh = nlmsg_hdr(skb);
1137 		if (nlh->nlmsg_len < sizeof(*nlh) ||
1138 		    skb->len < nlh->nlmsg_len) {
1139 			break;
1140 		}
1141 
1142 		ev = NLMSG_DATA(nlh);
1143 		rlen = NLMSG_ALIGN(nlh->nlmsg_len);
1144 		if (rlen > skb->len)
1145 			rlen = skb->len;
1146 
1147 		err = iscsi_if_recv_msg(skb, nlh);
1148 		if (err) {
1149 			ev->type = ISCSI_KEVENT_IF_ERROR;
1150 			ev->iferror = err;
1151 		}
1152 		do {
1153 			/*
1154 			 * special case for GET_STATS:
1155 			 * on success - sending reply and stats from
1156 			 * inside of if_recv_msg(),
1157 			 * on error - fall through.
1158 			 */
1159 			if (ev->type == ISCSI_UEVENT_GET_STATS && !err)
1160 				break;
1161 			err = iscsi_if_send_reply(
1162 				NETLINK_CREDS(skb)->pid, nlh->nlmsg_seq,
1163 				nlh->nlmsg_type, 0, 0, ev, sizeof(*ev));
1164 		} while (err < 0 && err != -ECONNREFUSED);
1165 		skb_pull(skb, rlen);
1166 	}
1167 	mutex_unlock(&rx_queue_mutex);
1168 }
1169 
1170 #define iscsi_cdev_to_conn(_cdev) \
1171 	iscsi_dev_to_conn(_cdev->dev)
1172 
1173 #define ISCSI_CLASS_ATTR(_prefix,_name,_mode,_show,_store)		\
1174 struct class_device_attribute class_device_attr_##_prefix##_##_name =	\
1175 	__ATTR(_name,_mode,_show,_store)
1176 
1177 /*
1178  * iSCSI connection attrs
1179  */
1180 #define iscsi_conn_attr_show(param)					\
1181 static ssize_t								\
1182 show_conn_param_##param(struct class_device *cdev, char *buf)		\
1183 {									\
1184 	struct iscsi_cls_conn *conn = iscsi_cdev_to_conn(cdev);		\
1185 	struct iscsi_transport *t = conn->transport;			\
1186 	return t->get_conn_param(conn, param, buf);			\
1187 }
1188 
1189 #define iscsi_conn_attr(field, param)					\
1190 	iscsi_conn_attr_show(param)					\
1191 static ISCSI_CLASS_ATTR(conn, field, S_IRUGO, show_conn_param_##param,	\
1192 			NULL);
1193 
1194 iscsi_conn_attr(max_recv_dlength, ISCSI_PARAM_MAX_RECV_DLENGTH);
1195 iscsi_conn_attr(max_xmit_dlength, ISCSI_PARAM_MAX_XMIT_DLENGTH);
1196 iscsi_conn_attr(header_digest, ISCSI_PARAM_HDRDGST_EN);
1197 iscsi_conn_attr(data_digest, ISCSI_PARAM_DATADGST_EN);
1198 iscsi_conn_attr(ifmarker, ISCSI_PARAM_IFMARKER_EN);
1199 iscsi_conn_attr(ofmarker, ISCSI_PARAM_OFMARKER_EN);
1200 iscsi_conn_attr(persistent_port, ISCSI_PARAM_PERSISTENT_PORT);
1201 iscsi_conn_attr(port, ISCSI_PARAM_CONN_PORT);
1202 iscsi_conn_attr(exp_statsn, ISCSI_PARAM_EXP_STATSN);
1203 iscsi_conn_attr(persistent_address, ISCSI_PARAM_PERSISTENT_ADDRESS);
1204 iscsi_conn_attr(address, ISCSI_PARAM_CONN_ADDRESS);
1205 iscsi_conn_attr(ping_tmo, ISCSI_PARAM_PING_TMO);
1206 iscsi_conn_attr(recv_tmo, ISCSI_PARAM_RECV_TMO);
1207 
1208 #define iscsi_cdev_to_session(_cdev) \
1209 	iscsi_dev_to_session(_cdev->dev)
1210 
1211 /*
1212  * iSCSI session attrs
1213  */
1214 #define iscsi_session_attr_show(param, perm)				\
1215 static ssize_t								\
1216 show_session_param_##param(struct class_device *cdev, char *buf)	\
1217 {									\
1218 	struct iscsi_cls_session *session = iscsi_cdev_to_session(cdev); \
1219 	struct iscsi_transport *t = session->transport;			\
1220 									\
1221 	if (perm && !capable(CAP_SYS_ADMIN))				\
1222 		return -EACCES;						\
1223 	return t->get_session_param(session, param, buf);		\
1224 }
1225 
1226 #define iscsi_session_attr(field, param, perm)				\
1227 	iscsi_session_attr_show(param, perm)				\
1228 static ISCSI_CLASS_ATTR(sess, field, S_IRUGO, show_session_param_##param, \
1229 			NULL);
1230 
1231 iscsi_session_attr(targetname, ISCSI_PARAM_TARGET_NAME, 0);
1232 iscsi_session_attr(initial_r2t, ISCSI_PARAM_INITIAL_R2T_EN, 0);
1233 iscsi_session_attr(max_outstanding_r2t, ISCSI_PARAM_MAX_R2T, 0);
1234 iscsi_session_attr(immediate_data, ISCSI_PARAM_IMM_DATA_EN, 0);
1235 iscsi_session_attr(first_burst_len, ISCSI_PARAM_FIRST_BURST, 0);
1236 iscsi_session_attr(max_burst_len, ISCSI_PARAM_MAX_BURST, 0);
1237 iscsi_session_attr(data_pdu_in_order, ISCSI_PARAM_PDU_INORDER_EN, 0);
1238 iscsi_session_attr(data_seq_in_order, ISCSI_PARAM_DATASEQ_INORDER_EN, 0);
1239 iscsi_session_attr(erl, ISCSI_PARAM_ERL, 0);
1240 iscsi_session_attr(tpgt, ISCSI_PARAM_TPGT, 0);
1241 iscsi_session_attr(username, ISCSI_PARAM_USERNAME, 1);
1242 iscsi_session_attr(username_in, ISCSI_PARAM_USERNAME_IN, 1);
1243 iscsi_session_attr(password, ISCSI_PARAM_PASSWORD, 1);
1244 iscsi_session_attr(password_in, ISCSI_PARAM_PASSWORD_IN, 1);
1245 iscsi_session_attr(fast_abort, ISCSI_PARAM_FAST_ABORT, 0);
1246 iscsi_session_attr(abort_tmo, ISCSI_PARAM_ABORT_TMO, 0);
1247 iscsi_session_attr(lu_reset_tmo, ISCSI_PARAM_LU_RESET_TMO, 0);
1248 
1249 #define iscsi_priv_session_attr_show(field, format)			\
1250 static ssize_t								\
1251 show_priv_session_##field(struct class_device *cdev, char *buf)		\
1252 {									\
1253 	struct iscsi_cls_session *session = iscsi_cdev_to_session(cdev);\
1254 	return sprintf(buf, format"\n", session->field);		\
1255 }
1256 
1257 #define iscsi_priv_session_attr(field, format)				\
1258 	iscsi_priv_session_attr_show(field, format)			\
1259 static ISCSI_CLASS_ATTR(priv_sess, field, S_IRUGO, show_priv_session_##field, \
1260 			NULL)
1261 iscsi_priv_session_attr(recovery_tmo, "%d");
1262 
1263 /*
1264  * iSCSI host attrs
1265  */
1266 #define iscsi_host_attr_show(param)					\
1267 static ssize_t								\
1268 show_host_param_##param(struct class_device *cdev, char *buf)		\
1269 {									\
1270 	struct Scsi_Host *shost = transport_class_to_shost(cdev);	\
1271 	struct iscsi_internal *priv = to_iscsi_internal(shost->transportt); \
1272 	return priv->iscsi_transport->get_host_param(shost, param, buf); \
1273 }
1274 
1275 #define iscsi_host_attr(field, param)					\
1276 	iscsi_host_attr_show(param)					\
1277 static ISCSI_CLASS_ATTR(host, field, S_IRUGO, show_host_param_##param,	\
1278 			NULL);
1279 
1280 iscsi_host_attr(netdev, ISCSI_HOST_PARAM_NETDEV_NAME);
1281 iscsi_host_attr(hwaddress, ISCSI_HOST_PARAM_HWADDRESS);
1282 iscsi_host_attr(ipaddress, ISCSI_HOST_PARAM_IPADDRESS);
1283 iscsi_host_attr(initiatorname, ISCSI_HOST_PARAM_INITIATOR_NAME);
1284 
1285 #define SETUP_PRIV_SESSION_RD_ATTR(field)				\
1286 do {									\
1287 	priv->session_attrs[count] = &class_device_attr_priv_sess_##field; \
1288 	count++;							\
1289 } while (0)
1290 
1291 
1292 #define SETUP_SESSION_RD_ATTR(field, param_flag)			\
1293 do {									\
1294 	if (tt->param_mask & param_flag) {				\
1295 		priv->session_attrs[count] = &class_device_attr_sess_##field; \
1296 		count++;						\
1297 	}								\
1298 } while (0)
1299 
1300 #define SETUP_CONN_RD_ATTR(field, param_flag)				\
1301 do {									\
1302 	if (tt->param_mask & param_flag) {				\
1303 		priv->conn_attrs[count] = &class_device_attr_conn_##field; \
1304 		count++;						\
1305 	}								\
1306 } while (0)
1307 
1308 #define SETUP_HOST_RD_ATTR(field, param_flag)				\
1309 do {									\
1310 	if (tt->host_param_mask & param_flag) {				\
1311 		priv->host_attrs[count] = &class_device_attr_host_##field; \
1312 		count++;						\
1313 	}								\
1314 } while (0)
1315 
1316 static int iscsi_session_match(struct attribute_container *cont,
1317 			   struct device *dev)
1318 {
1319 	struct iscsi_cls_session *session;
1320 	struct Scsi_Host *shost;
1321 	struct iscsi_internal *priv;
1322 
1323 	if (!iscsi_is_session_dev(dev))
1324 		return 0;
1325 
1326 	session = iscsi_dev_to_session(dev);
1327 	shost = iscsi_session_to_shost(session);
1328 	if (!shost->transportt)
1329 		return 0;
1330 
1331 	priv = to_iscsi_internal(shost->transportt);
1332 	if (priv->session_cont.ac.class != &iscsi_session_class.class)
1333 		return 0;
1334 
1335 	return &priv->session_cont.ac == cont;
1336 }
1337 
1338 static int iscsi_conn_match(struct attribute_container *cont,
1339 			   struct device *dev)
1340 {
1341 	struct iscsi_cls_session *session;
1342 	struct iscsi_cls_conn *conn;
1343 	struct Scsi_Host *shost;
1344 	struct iscsi_internal *priv;
1345 
1346 	if (!iscsi_is_conn_dev(dev))
1347 		return 0;
1348 
1349 	conn = iscsi_dev_to_conn(dev);
1350 	session = iscsi_dev_to_session(conn->dev.parent);
1351 	shost = iscsi_session_to_shost(session);
1352 
1353 	if (!shost->transportt)
1354 		return 0;
1355 
1356 	priv = to_iscsi_internal(shost->transportt);
1357 	if (priv->conn_cont.ac.class != &iscsi_connection_class.class)
1358 		return 0;
1359 
1360 	return &priv->conn_cont.ac == cont;
1361 }
1362 
1363 static int iscsi_host_match(struct attribute_container *cont,
1364 			    struct device *dev)
1365 {
1366 	struct Scsi_Host *shost;
1367 	struct iscsi_internal *priv;
1368 
1369 	if (!scsi_is_host_device(dev))
1370 		return 0;
1371 
1372 	shost = dev_to_shost(dev);
1373 	if (!shost->transportt  ||
1374 	    shost->transportt->host_attrs.ac.class != &iscsi_host_class.class)
1375 		return 0;
1376 
1377         priv = to_iscsi_internal(shost->transportt);
1378         return &priv->t.host_attrs.ac == cont;
1379 }
1380 
1381 struct scsi_transport_template *
1382 iscsi_register_transport(struct iscsi_transport *tt)
1383 {
1384 	struct iscsi_internal *priv;
1385 	unsigned long flags;
1386 	int count = 0, err;
1387 
1388 	BUG_ON(!tt);
1389 
1390 	priv = iscsi_if_transport_lookup(tt);
1391 	if (priv)
1392 		return NULL;
1393 
1394 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1395 	if (!priv)
1396 		return NULL;
1397 	INIT_LIST_HEAD(&priv->list);
1398 	priv->daemon_pid = -1;
1399 	priv->iscsi_transport = tt;
1400 	priv->t.user_scan = iscsi_user_scan;
1401 
1402 	priv->cdev.class = &iscsi_transport_class;
1403 	snprintf(priv->cdev.class_id, BUS_ID_SIZE, "%s", tt->name);
1404 	err = class_device_register(&priv->cdev);
1405 	if (err)
1406 		goto free_priv;
1407 
1408 	err = sysfs_create_group(&priv->cdev.kobj, &iscsi_transport_group);
1409 	if (err)
1410 		goto unregister_cdev;
1411 
1412 	/* host parameters */
1413 	priv->t.host_attrs.ac.attrs = &priv->host_attrs[0];
1414 	priv->t.host_attrs.ac.class = &iscsi_host_class.class;
1415 	priv->t.host_attrs.ac.match = iscsi_host_match;
1416 	priv->t.host_size = sizeof(struct iscsi_host);
1417 	transport_container_register(&priv->t.host_attrs);
1418 
1419 	SETUP_HOST_RD_ATTR(netdev, ISCSI_HOST_NETDEV_NAME);
1420 	SETUP_HOST_RD_ATTR(ipaddress, ISCSI_HOST_IPADDRESS);
1421 	SETUP_HOST_RD_ATTR(hwaddress, ISCSI_HOST_HWADDRESS);
1422 	SETUP_HOST_RD_ATTR(initiatorname, ISCSI_HOST_INITIATOR_NAME);
1423 	BUG_ON(count > ISCSI_HOST_ATTRS);
1424 	priv->host_attrs[count] = NULL;
1425 	count = 0;
1426 
1427 	/* connection parameters */
1428 	priv->conn_cont.ac.attrs = &priv->conn_attrs[0];
1429 	priv->conn_cont.ac.class = &iscsi_connection_class.class;
1430 	priv->conn_cont.ac.match = iscsi_conn_match;
1431 	transport_container_register(&priv->conn_cont);
1432 
1433 	SETUP_CONN_RD_ATTR(max_recv_dlength, ISCSI_MAX_RECV_DLENGTH);
1434 	SETUP_CONN_RD_ATTR(max_xmit_dlength, ISCSI_MAX_XMIT_DLENGTH);
1435 	SETUP_CONN_RD_ATTR(header_digest, ISCSI_HDRDGST_EN);
1436 	SETUP_CONN_RD_ATTR(data_digest, ISCSI_DATADGST_EN);
1437 	SETUP_CONN_RD_ATTR(ifmarker, ISCSI_IFMARKER_EN);
1438 	SETUP_CONN_RD_ATTR(ofmarker, ISCSI_OFMARKER_EN);
1439 	SETUP_CONN_RD_ATTR(address, ISCSI_CONN_ADDRESS);
1440 	SETUP_CONN_RD_ATTR(port, ISCSI_CONN_PORT);
1441 	SETUP_CONN_RD_ATTR(exp_statsn, ISCSI_EXP_STATSN);
1442 	SETUP_CONN_RD_ATTR(persistent_address, ISCSI_PERSISTENT_ADDRESS);
1443 	SETUP_CONN_RD_ATTR(persistent_port, ISCSI_PERSISTENT_PORT);
1444 	SETUP_CONN_RD_ATTR(ping_tmo, ISCSI_PING_TMO);
1445 	SETUP_CONN_RD_ATTR(recv_tmo, ISCSI_RECV_TMO);
1446 
1447 	BUG_ON(count > ISCSI_CONN_ATTRS);
1448 	priv->conn_attrs[count] = NULL;
1449 	count = 0;
1450 
1451 	/* session parameters */
1452 	priv->session_cont.ac.attrs = &priv->session_attrs[0];
1453 	priv->session_cont.ac.class = &iscsi_session_class.class;
1454 	priv->session_cont.ac.match = iscsi_session_match;
1455 	transport_container_register(&priv->session_cont);
1456 
1457 	SETUP_SESSION_RD_ATTR(initial_r2t, ISCSI_INITIAL_R2T_EN);
1458 	SETUP_SESSION_RD_ATTR(max_outstanding_r2t, ISCSI_MAX_R2T);
1459 	SETUP_SESSION_RD_ATTR(immediate_data, ISCSI_IMM_DATA_EN);
1460 	SETUP_SESSION_RD_ATTR(first_burst_len, ISCSI_FIRST_BURST);
1461 	SETUP_SESSION_RD_ATTR(max_burst_len, ISCSI_MAX_BURST);
1462 	SETUP_SESSION_RD_ATTR(data_pdu_in_order, ISCSI_PDU_INORDER_EN);
1463 	SETUP_SESSION_RD_ATTR(data_seq_in_order, ISCSI_DATASEQ_INORDER_EN);
1464 	SETUP_SESSION_RD_ATTR(erl, ISCSI_ERL);
1465 	SETUP_SESSION_RD_ATTR(targetname, ISCSI_TARGET_NAME);
1466 	SETUP_SESSION_RD_ATTR(tpgt, ISCSI_TPGT);
1467 	SETUP_SESSION_RD_ATTR(password, ISCSI_USERNAME);
1468 	SETUP_SESSION_RD_ATTR(password_in, ISCSI_USERNAME_IN);
1469 	SETUP_SESSION_RD_ATTR(username, ISCSI_PASSWORD);
1470 	SETUP_SESSION_RD_ATTR(username_in, ISCSI_PASSWORD_IN);
1471 	SETUP_SESSION_RD_ATTR(fast_abort, ISCSI_FAST_ABORT);
1472 	SETUP_SESSION_RD_ATTR(abort_tmo, ISCSI_ABORT_TMO);
1473 	SETUP_SESSION_RD_ATTR(lu_reset_tmo,ISCSI_LU_RESET_TMO);
1474 	SETUP_PRIV_SESSION_RD_ATTR(recovery_tmo);
1475 
1476 	BUG_ON(count > ISCSI_SESSION_ATTRS);
1477 	priv->session_attrs[count] = NULL;
1478 
1479 	spin_lock_irqsave(&iscsi_transport_lock, flags);
1480 	list_add(&priv->list, &iscsi_transports);
1481 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1482 
1483 	printk(KERN_NOTICE "iscsi: registered transport (%s)\n", tt->name);
1484 	return &priv->t;
1485 
1486 unregister_cdev:
1487 	class_device_unregister(&priv->cdev);
1488 free_priv:
1489 	kfree(priv);
1490 	return NULL;
1491 }
1492 EXPORT_SYMBOL_GPL(iscsi_register_transport);
1493 
1494 int iscsi_unregister_transport(struct iscsi_transport *tt)
1495 {
1496 	struct iscsi_internal *priv;
1497 	unsigned long flags;
1498 
1499 	BUG_ON(!tt);
1500 
1501 	mutex_lock(&rx_queue_mutex);
1502 
1503 	priv = iscsi_if_transport_lookup(tt);
1504 	BUG_ON (!priv);
1505 
1506 	spin_lock_irqsave(&iscsi_transport_lock, flags);
1507 	list_del(&priv->list);
1508 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1509 
1510 	transport_container_unregister(&priv->conn_cont);
1511 	transport_container_unregister(&priv->session_cont);
1512 	transport_container_unregister(&priv->t.host_attrs);
1513 
1514 	sysfs_remove_group(&priv->cdev.kobj, &iscsi_transport_group);
1515 	class_device_unregister(&priv->cdev);
1516 	mutex_unlock(&rx_queue_mutex);
1517 
1518 	return 0;
1519 }
1520 EXPORT_SYMBOL_GPL(iscsi_unregister_transport);
1521 
1522 static __init int iscsi_transport_init(void)
1523 {
1524 	int err;
1525 
1526 	printk(KERN_INFO "Loading iSCSI transport class v%s.\n",
1527 		ISCSI_TRANSPORT_VERSION);
1528 
1529 	atomic_set(&iscsi_session_nr, 0);
1530 
1531 	err = class_register(&iscsi_transport_class);
1532 	if (err)
1533 		return err;
1534 
1535 	err = transport_class_register(&iscsi_host_class);
1536 	if (err)
1537 		goto unregister_transport_class;
1538 
1539 	err = transport_class_register(&iscsi_connection_class);
1540 	if (err)
1541 		goto unregister_host_class;
1542 
1543 	err = transport_class_register(&iscsi_session_class);
1544 	if (err)
1545 		goto unregister_conn_class;
1546 
1547 	nls = netlink_kernel_create(&init_net, NETLINK_ISCSI, 1, iscsi_if_rx, NULL,
1548 			THIS_MODULE);
1549 	if (!nls) {
1550 		err = -ENOBUFS;
1551 		goto unregister_session_class;
1552 	}
1553 
1554 	iscsi_eh_timer_workq = create_singlethread_workqueue("iscsi_eh");
1555 	if (!iscsi_eh_timer_workq)
1556 		goto release_nls;
1557 
1558 	return 0;
1559 
1560 release_nls:
1561 	netlink_kernel_release(nls);
1562 unregister_session_class:
1563 	transport_class_unregister(&iscsi_session_class);
1564 unregister_conn_class:
1565 	transport_class_unregister(&iscsi_connection_class);
1566 unregister_host_class:
1567 	transport_class_unregister(&iscsi_host_class);
1568 unregister_transport_class:
1569 	class_unregister(&iscsi_transport_class);
1570 	return err;
1571 }
1572 
1573 static void __exit iscsi_transport_exit(void)
1574 {
1575 	destroy_workqueue(iscsi_eh_timer_workq);
1576 	netlink_kernel_release(nls);
1577 	transport_class_unregister(&iscsi_connection_class);
1578 	transport_class_unregister(&iscsi_session_class);
1579 	transport_class_unregister(&iscsi_host_class);
1580 	class_unregister(&iscsi_transport_class);
1581 }
1582 
1583 module_init(iscsi_transport_init);
1584 module_exit(iscsi_transport_exit);
1585 
1586 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
1587 	      "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
1588 	      "Alex Aizman <itn780@yahoo.com>");
1589 MODULE_DESCRIPTION("iSCSI Transport Interface");
1590 MODULE_LICENSE("GPL");
1591 MODULE_VERSION(ISCSI_TRANSPORT_VERSION);
1592