xref: /linux/drivers/scsi/scsi_transport_iscsi.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
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 <linux/slab.h>
26 #include <linux/bsg-lib.h>
27 #include <linux/idr.h>
28 #include <net/tcp.h>
29 #include <scsi/scsi.h>
30 #include <scsi/scsi_host.h>
31 #include <scsi/scsi_device.h>
32 #include <scsi/scsi_transport.h>
33 #include <scsi/scsi_transport_iscsi.h>
34 #include <scsi/iscsi_if.h>
35 #include <scsi/scsi_cmnd.h>
36 #include <scsi/scsi_bsg_iscsi.h>
37 
38 #define ISCSI_TRANSPORT_VERSION "2.0-870"
39 
40 static int dbg_session;
41 module_param_named(debug_session, dbg_session, int,
42 		   S_IRUGO | S_IWUSR);
43 MODULE_PARM_DESC(debug_session,
44 		 "Turn on debugging for sessions in scsi_transport_iscsi "
45 		 "module. Set to 1 to turn on, and zero to turn off. Default "
46 		 "is off.");
47 
48 static int dbg_conn;
49 module_param_named(debug_conn, dbg_conn, int,
50 		   S_IRUGO | S_IWUSR);
51 MODULE_PARM_DESC(debug_conn,
52 		 "Turn on debugging for connections in scsi_transport_iscsi "
53 		 "module. Set to 1 to turn on, and zero to turn off. Default "
54 		 "is off.");
55 
56 #define ISCSI_DBG_TRANS_SESSION(_session, dbg_fmt, arg...)		\
57 	do {								\
58 		if (dbg_session)					\
59 			iscsi_cls_session_printk(KERN_INFO, _session,	\
60 						 "%s: " dbg_fmt,	\
61 						 __func__, ##arg);	\
62 	} while (0);
63 
64 #define ISCSI_DBG_TRANS_CONN(_conn, dbg_fmt, arg...)			\
65 	do {								\
66 		if (dbg_conn)						\
67 			iscsi_cls_conn_printk(KERN_INFO, _conn,		\
68 					      "%s: " dbg_fmt,		\
69 					      __func__, ##arg);	\
70 	} while (0);
71 
72 struct iscsi_internal {
73 	struct scsi_transport_template t;
74 	struct iscsi_transport *iscsi_transport;
75 	struct list_head list;
76 	struct device dev;
77 
78 	struct transport_container conn_cont;
79 	struct transport_container session_cont;
80 };
81 
82 static atomic_t iscsi_session_nr; /* sysfs session id for next new session */
83 static struct workqueue_struct *iscsi_eh_timer_workq;
84 
85 static DEFINE_IDA(iscsi_sess_ida);
86 /*
87  * list of registered transports and lock that must
88  * be held while accessing list. The iscsi_transport_lock must
89  * be acquired after the rx_queue_mutex.
90  */
91 static LIST_HEAD(iscsi_transports);
92 static DEFINE_SPINLOCK(iscsi_transport_lock);
93 
94 #define to_iscsi_internal(tmpl) \
95 	container_of(tmpl, struct iscsi_internal, t)
96 
97 #define dev_to_iscsi_internal(_dev) \
98 	container_of(_dev, struct iscsi_internal, dev)
99 
100 static void iscsi_transport_release(struct device *dev)
101 {
102 	struct iscsi_internal *priv = dev_to_iscsi_internal(dev);
103 	kfree(priv);
104 }
105 
106 /*
107  * iscsi_transport_class represents the iscsi_transports that are
108  * registered.
109  */
110 static struct class iscsi_transport_class = {
111 	.name = "iscsi_transport",
112 	.dev_release = iscsi_transport_release,
113 };
114 
115 static ssize_t
116 show_transport_handle(struct device *dev, struct device_attribute *attr,
117 		      char *buf)
118 {
119 	struct iscsi_internal *priv = dev_to_iscsi_internal(dev);
120 	return sprintf(buf, "%llu\n", (unsigned long long)iscsi_handle(priv->iscsi_transport));
121 }
122 static DEVICE_ATTR(handle, S_IRUGO, show_transport_handle, NULL);
123 
124 #define show_transport_attr(name, format)				\
125 static ssize_t								\
126 show_transport_##name(struct device *dev, 				\
127 		      struct device_attribute *attr,char *buf)		\
128 {									\
129 	struct iscsi_internal *priv = dev_to_iscsi_internal(dev);	\
130 	return sprintf(buf, format"\n", priv->iscsi_transport->name);	\
131 }									\
132 static DEVICE_ATTR(name, S_IRUGO, show_transport_##name, NULL);
133 
134 show_transport_attr(caps, "0x%x");
135 
136 static struct attribute *iscsi_transport_attrs[] = {
137 	&dev_attr_handle.attr,
138 	&dev_attr_caps.attr,
139 	NULL,
140 };
141 
142 static struct attribute_group iscsi_transport_group = {
143 	.attrs = iscsi_transport_attrs,
144 };
145 
146 /*
147  * iSCSI endpoint attrs
148  */
149 #define iscsi_dev_to_endpoint(_dev) \
150 	container_of(_dev, struct iscsi_endpoint, dev)
151 
152 #define ISCSI_ATTR(_prefix,_name,_mode,_show,_store)	\
153 struct device_attribute dev_attr_##_prefix##_##_name =	\
154         __ATTR(_name,_mode,_show,_store)
155 
156 static void iscsi_endpoint_release(struct device *dev)
157 {
158 	struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
159 	kfree(ep);
160 }
161 
162 static struct class iscsi_endpoint_class = {
163 	.name = "iscsi_endpoint",
164 	.dev_release = iscsi_endpoint_release,
165 };
166 
167 static ssize_t
168 show_ep_handle(struct device *dev, struct device_attribute *attr, char *buf)
169 {
170 	struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
171 	return sprintf(buf, "%llu\n", (unsigned long long) ep->id);
172 }
173 static ISCSI_ATTR(ep, handle, S_IRUGO, show_ep_handle, NULL);
174 
175 static struct attribute *iscsi_endpoint_attrs[] = {
176 	&dev_attr_ep_handle.attr,
177 	NULL,
178 };
179 
180 static struct attribute_group iscsi_endpoint_group = {
181 	.attrs = iscsi_endpoint_attrs,
182 };
183 
184 #define ISCSI_MAX_EPID -1
185 
186 static int iscsi_match_epid(struct device *dev, void *data)
187 {
188 	struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
189 	uint64_t *epid = (uint64_t *) data;
190 
191 	return *epid == ep->id;
192 }
193 
194 struct iscsi_endpoint *
195 iscsi_create_endpoint(int dd_size)
196 {
197 	struct device *dev;
198 	struct iscsi_endpoint *ep;
199 	uint64_t id;
200 	int err;
201 
202 	for (id = 1; id < ISCSI_MAX_EPID; id++) {
203 		dev = class_find_device(&iscsi_endpoint_class, NULL, &id,
204 					iscsi_match_epid);
205 		if (!dev)
206 			break;
207 	}
208 	if (id == ISCSI_MAX_EPID) {
209 		printk(KERN_ERR "Too many connections. Max supported %u\n",
210 		       ISCSI_MAX_EPID - 1);
211 		return NULL;
212 	}
213 
214 	ep = kzalloc(sizeof(*ep) + dd_size, GFP_KERNEL);
215 	if (!ep)
216 		return NULL;
217 
218 	ep->id = id;
219 	ep->dev.class = &iscsi_endpoint_class;
220 	dev_set_name(&ep->dev, "ep-%llu", (unsigned long long) id);
221 	err = device_register(&ep->dev);
222         if (err)
223                 goto free_ep;
224 
225 	err = sysfs_create_group(&ep->dev.kobj, &iscsi_endpoint_group);
226 	if (err)
227 		goto unregister_dev;
228 
229 	if (dd_size)
230 		ep->dd_data = &ep[1];
231 	return ep;
232 
233 unregister_dev:
234 	device_unregister(&ep->dev);
235 	return NULL;
236 
237 free_ep:
238 	kfree(ep);
239 	return NULL;
240 }
241 EXPORT_SYMBOL_GPL(iscsi_create_endpoint);
242 
243 void iscsi_destroy_endpoint(struct iscsi_endpoint *ep)
244 {
245 	sysfs_remove_group(&ep->dev.kobj, &iscsi_endpoint_group);
246 	device_unregister(&ep->dev);
247 }
248 EXPORT_SYMBOL_GPL(iscsi_destroy_endpoint);
249 
250 struct iscsi_endpoint *iscsi_lookup_endpoint(u64 handle)
251 {
252 	struct iscsi_endpoint *ep;
253 	struct device *dev;
254 
255 	dev = class_find_device(&iscsi_endpoint_class, NULL, &handle,
256 				iscsi_match_epid);
257 	if (!dev)
258 		return NULL;
259 
260 	ep = iscsi_dev_to_endpoint(dev);
261 	/*
262 	 * we can drop this now because the interface will prevent
263 	 * removals and lookups from racing.
264 	 */
265 	put_device(dev);
266 	return ep;
267 }
268 EXPORT_SYMBOL_GPL(iscsi_lookup_endpoint);
269 
270 /*
271  * Interface to display network param to sysfs
272  */
273 
274 static void iscsi_iface_release(struct device *dev)
275 {
276 	struct iscsi_iface *iface = iscsi_dev_to_iface(dev);
277 	struct device *parent = iface->dev.parent;
278 
279 	kfree(iface);
280 	put_device(parent);
281 }
282 
283 
284 static struct class iscsi_iface_class = {
285 	.name = "iscsi_iface",
286 	.dev_release = iscsi_iface_release,
287 };
288 
289 #define ISCSI_IFACE_ATTR(_prefix, _name, _mode, _show, _store)	\
290 struct device_attribute dev_attr_##_prefix##_##_name =		\
291 	__ATTR(_name, _mode, _show, _store)
292 
293 /* iface attrs show */
294 #define iscsi_iface_attr_show(type, name, param_type, param)		\
295 static ssize_t								\
296 show_##type##_##name(struct device *dev, struct device_attribute *attr,	\
297 		     char *buf)						\
298 {									\
299 	struct iscsi_iface *iface = iscsi_dev_to_iface(dev);		\
300 	struct iscsi_transport *t = iface->transport;			\
301 	return t->get_iface_param(iface, param_type, param, buf);	\
302 }									\
303 
304 #define iscsi_iface_net_attr(type, name, param)				\
305 	iscsi_iface_attr_show(type, name, ISCSI_NET_PARAM, param)	\
306 static ISCSI_IFACE_ATTR(type, name, S_IRUGO, show_##type##_##name, NULL);
307 
308 /* generic read only ipvi4 attribute */
309 iscsi_iface_net_attr(ipv4_iface, ipaddress, ISCSI_NET_PARAM_IPV4_ADDR);
310 iscsi_iface_net_attr(ipv4_iface, gateway, ISCSI_NET_PARAM_IPV4_GW);
311 iscsi_iface_net_attr(ipv4_iface, subnet, ISCSI_NET_PARAM_IPV4_SUBNET);
312 iscsi_iface_net_attr(ipv4_iface, bootproto, ISCSI_NET_PARAM_IPV4_BOOTPROTO);
313 
314 /* generic read only ipv6 attribute */
315 iscsi_iface_net_attr(ipv6_iface, ipaddress, ISCSI_NET_PARAM_IPV6_ADDR);
316 iscsi_iface_net_attr(ipv6_iface, link_local_addr, ISCSI_NET_PARAM_IPV6_LINKLOCAL);
317 iscsi_iface_net_attr(ipv6_iface, router_addr, ISCSI_NET_PARAM_IPV6_ROUTER);
318 iscsi_iface_net_attr(ipv6_iface, ipaddr_autocfg,
319 		     ISCSI_NET_PARAM_IPV6_ADDR_AUTOCFG);
320 iscsi_iface_net_attr(ipv6_iface, link_local_autocfg,
321 		     ISCSI_NET_PARAM_IPV6_LINKLOCAL_AUTOCFG);
322 
323 /* common read only iface attribute */
324 iscsi_iface_net_attr(iface, enabled, ISCSI_NET_PARAM_IFACE_ENABLE);
325 iscsi_iface_net_attr(iface, vlan_id, ISCSI_NET_PARAM_VLAN_ID);
326 iscsi_iface_net_attr(iface, vlan_priority, ISCSI_NET_PARAM_VLAN_PRIORITY);
327 iscsi_iface_net_attr(iface, vlan_enabled, ISCSI_NET_PARAM_VLAN_ENABLED);
328 iscsi_iface_net_attr(iface, mtu, ISCSI_NET_PARAM_MTU);
329 iscsi_iface_net_attr(iface, port, ISCSI_NET_PARAM_PORT);
330 
331 static mode_t iscsi_iface_attr_is_visible(struct kobject *kobj,
332 					  struct attribute *attr, int i)
333 {
334 	struct device *dev = container_of(kobj, struct device, kobj);
335 	struct iscsi_iface *iface = iscsi_dev_to_iface(dev);
336 	struct iscsi_transport *t = iface->transport;
337 	int param;
338 
339 	if (attr == &dev_attr_iface_enabled.attr)
340 		param = ISCSI_NET_PARAM_IFACE_ENABLE;
341 	else if (attr == &dev_attr_iface_vlan_id.attr)
342 		param = ISCSI_NET_PARAM_VLAN_ID;
343 	else if (attr == &dev_attr_iface_vlan_priority.attr)
344 		param = ISCSI_NET_PARAM_VLAN_PRIORITY;
345 	else if (attr == &dev_attr_iface_vlan_enabled.attr)
346 		param = ISCSI_NET_PARAM_VLAN_ENABLED;
347 	else if (attr == &dev_attr_iface_mtu.attr)
348 		param = ISCSI_NET_PARAM_MTU;
349 	else if (attr == &dev_attr_iface_port.attr)
350 		param = ISCSI_NET_PARAM_PORT;
351 	else if (iface->iface_type == ISCSI_IFACE_TYPE_IPV4) {
352 		if (attr == &dev_attr_ipv4_iface_ipaddress.attr)
353 			param = ISCSI_NET_PARAM_IPV4_ADDR;
354 		else if (attr == &dev_attr_ipv4_iface_gateway.attr)
355 			param = ISCSI_NET_PARAM_IPV4_GW;
356 		else if (attr == &dev_attr_ipv4_iface_subnet.attr)
357 			param = ISCSI_NET_PARAM_IPV4_SUBNET;
358 		else if (attr == &dev_attr_ipv4_iface_bootproto.attr)
359 			param = ISCSI_NET_PARAM_IPV4_BOOTPROTO;
360 		else
361 			return 0;
362 	} else if (iface->iface_type == ISCSI_IFACE_TYPE_IPV6) {
363 		if (attr == &dev_attr_ipv6_iface_ipaddress.attr)
364 			param = ISCSI_NET_PARAM_IPV6_ADDR;
365 		else if (attr == &dev_attr_ipv6_iface_link_local_addr.attr)
366 			param = ISCSI_NET_PARAM_IPV6_LINKLOCAL;
367 		else if (attr == &dev_attr_ipv6_iface_router_addr.attr)
368 			param = ISCSI_NET_PARAM_IPV6_ROUTER;
369 		else if (attr == &dev_attr_ipv6_iface_ipaddr_autocfg.attr)
370 			param = ISCSI_NET_PARAM_IPV6_ADDR_AUTOCFG;
371 		else if (attr == &dev_attr_ipv6_iface_link_local_autocfg.attr)
372 			param = ISCSI_NET_PARAM_IPV6_LINKLOCAL_AUTOCFG;
373 		else
374 			return 0;
375 	} else {
376 		WARN_ONCE(1, "Invalid iface attr");
377 		return 0;
378 	}
379 
380 	return t->attr_is_visible(ISCSI_NET_PARAM, param);
381 }
382 
383 static struct attribute *iscsi_iface_attrs[] = {
384 	&dev_attr_iface_enabled.attr,
385 	&dev_attr_iface_vlan_id.attr,
386 	&dev_attr_iface_vlan_priority.attr,
387 	&dev_attr_iface_vlan_enabled.attr,
388 	&dev_attr_ipv4_iface_ipaddress.attr,
389 	&dev_attr_ipv4_iface_gateway.attr,
390 	&dev_attr_ipv4_iface_subnet.attr,
391 	&dev_attr_ipv4_iface_bootproto.attr,
392 	&dev_attr_ipv6_iface_ipaddress.attr,
393 	&dev_attr_ipv6_iface_link_local_addr.attr,
394 	&dev_attr_ipv6_iface_router_addr.attr,
395 	&dev_attr_ipv6_iface_ipaddr_autocfg.attr,
396 	&dev_attr_ipv6_iface_link_local_autocfg.attr,
397 	&dev_attr_iface_mtu.attr,
398 	&dev_attr_iface_port.attr,
399 	NULL,
400 };
401 
402 static struct attribute_group iscsi_iface_group = {
403 	.attrs = iscsi_iface_attrs,
404 	.is_visible = iscsi_iface_attr_is_visible,
405 };
406 
407 struct iscsi_iface *
408 iscsi_create_iface(struct Scsi_Host *shost, struct iscsi_transport *transport,
409 		   uint32_t iface_type, uint32_t iface_num, int dd_size)
410 {
411 	struct iscsi_iface *iface;
412 	int err;
413 
414 	iface = kzalloc(sizeof(*iface) + dd_size, GFP_KERNEL);
415 	if (!iface)
416 		return NULL;
417 
418 	iface->transport = transport;
419 	iface->iface_type = iface_type;
420 	iface->iface_num = iface_num;
421 	iface->dev.release = iscsi_iface_release;
422 	iface->dev.class = &iscsi_iface_class;
423 	/* parent reference released in iscsi_iface_release */
424 	iface->dev.parent = get_device(&shost->shost_gendev);
425 	if (iface_type == ISCSI_IFACE_TYPE_IPV4)
426 		dev_set_name(&iface->dev, "ipv4-iface-%u-%u", shost->host_no,
427 			     iface_num);
428 	else
429 		dev_set_name(&iface->dev, "ipv6-iface-%u-%u", shost->host_no,
430 			     iface_num);
431 
432 	err = device_register(&iface->dev);
433 	if (err)
434 		goto free_iface;
435 
436 	err = sysfs_create_group(&iface->dev.kobj, &iscsi_iface_group);
437 	if (err)
438 		goto unreg_iface;
439 
440 	if (dd_size)
441 		iface->dd_data = &iface[1];
442 	return iface;
443 
444 unreg_iface:
445 	device_unregister(&iface->dev);
446 	return NULL;
447 
448 free_iface:
449 	put_device(iface->dev.parent);
450 	kfree(iface);
451 	return NULL;
452 }
453 EXPORT_SYMBOL_GPL(iscsi_create_iface);
454 
455 void iscsi_destroy_iface(struct iscsi_iface *iface)
456 {
457 	sysfs_remove_group(&iface->dev.kobj, &iscsi_iface_group);
458 	device_unregister(&iface->dev);
459 }
460 EXPORT_SYMBOL_GPL(iscsi_destroy_iface);
461 
462 /*
463  * BSG support
464  */
465 /**
466  * iscsi_bsg_host_dispatch - Dispatch command to LLD.
467  * @job: bsg job to be processed
468  */
469 static int iscsi_bsg_host_dispatch(struct bsg_job *job)
470 {
471 	struct Scsi_Host *shost = iscsi_job_to_shost(job);
472 	struct iscsi_bsg_request *req = job->request;
473 	struct iscsi_bsg_reply *reply = job->reply;
474 	struct iscsi_internal *i = to_iscsi_internal(shost->transportt);
475 	int cmdlen = sizeof(uint32_t);	/* start with length of msgcode */
476 	int ret;
477 
478 	/* check if we have the msgcode value at least */
479 	if (job->request_len < sizeof(uint32_t)) {
480 		ret = -ENOMSG;
481 		goto fail_host_msg;
482 	}
483 
484 	/* Validate the host command */
485 	switch (req->msgcode) {
486 	case ISCSI_BSG_HST_VENDOR:
487 		cmdlen += sizeof(struct iscsi_bsg_host_vendor);
488 		if ((shost->hostt->vendor_id == 0L) ||
489 		    (req->rqst_data.h_vendor.vendor_id !=
490 			shost->hostt->vendor_id)) {
491 			ret = -ESRCH;
492 			goto fail_host_msg;
493 		}
494 		break;
495 	default:
496 		ret = -EBADR;
497 		goto fail_host_msg;
498 	}
499 
500 	/* check if we really have all the request data needed */
501 	if (job->request_len < cmdlen) {
502 		ret = -ENOMSG;
503 		goto fail_host_msg;
504 	}
505 
506 	ret = i->iscsi_transport->bsg_request(job);
507 	if (!ret)
508 		return 0;
509 
510 fail_host_msg:
511 	/* return the errno failure code as the only status */
512 	BUG_ON(job->reply_len < sizeof(uint32_t));
513 	reply->reply_payload_rcv_len = 0;
514 	reply->result = ret;
515 	job->reply_len = sizeof(uint32_t);
516 	bsg_job_done(job, ret, 0);
517 	return 0;
518 }
519 
520 /**
521  * iscsi_bsg_host_add - Create and add the bsg hooks to receive requests
522  * @shost: shost for iscsi_host
523  * @ihost: iscsi_cls_host adding the structures to
524  */
525 static int
526 iscsi_bsg_host_add(struct Scsi_Host *shost, struct iscsi_cls_host *ihost)
527 {
528 	struct device *dev = &shost->shost_gendev;
529 	struct iscsi_internal *i = to_iscsi_internal(shost->transportt);
530 	struct request_queue *q;
531 	char bsg_name[20];
532 	int ret;
533 
534 	if (!i->iscsi_transport->bsg_request)
535 		return -ENOTSUPP;
536 
537 	snprintf(bsg_name, sizeof(bsg_name), "iscsi_host%d", shost->host_no);
538 
539 	q = __scsi_alloc_queue(shost, bsg_request_fn);
540 	if (!q)
541 		return -ENOMEM;
542 
543 	ret = bsg_setup_queue(dev, q, bsg_name, iscsi_bsg_host_dispatch, 0);
544 	if (ret) {
545 		shost_printk(KERN_ERR, shost, "bsg interface failed to "
546 			     "initialize - no request queue\n");
547 		blk_cleanup_queue(q);
548 		return ret;
549 	}
550 
551 	ihost->bsg_q = q;
552 	return 0;
553 }
554 
555 static int iscsi_setup_host(struct transport_container *tc, struct device *dev,
556 			    struct device *cdev)
557 {
558 	struct Scsi_Host *shost = dev_to_shost(dev);
559 	struct iscsi_cls_host *ihost = shost->shost_data;
560 
561 	memset(ihost, 0, sizeof(*ihost));
562 	atomic_set(&ihost->nr_scans, 0);
563 	mutex_init(&ihost->mutex);
564 
565 	iscsi_bsg_host_add(shost, ihost);
566 	/* ignore any bsg add error - we just can't do sgio */
567 
568 	return 0;
569 }
570 
571 static int iscsi_remove_host(struct transport_container *tc,
572 			     struct device *dev, struct device *cdev)
573 {
574 	struct Scsi_Host *shost = dev_to_shost(dev);
575 	struct iscsi_cls_host *ihost = shost->shost_data;
576 
577 	if (ihost->bsg_q) {
578 		bsg_remove_queue(ihost->bsg_q);
579 		blk_cleanup_queue(ihost->bsg_q);
580 	}
581 	return 0;
582 }
583 
584 static DECLARE_TRANSPORT_CLASS(iscsi_host_class,
585 			       "iscsi_host",
586 			       iscsi_setup_host,
587 			       iscsi_remove_host,
588 			       NULL);
589 
590 static DECLARE_TRANSPORT_CLASS(iscsi_session_class,
591 			       "iscsi_session",
592 			       NULL,
593 			       NULL,
594 			       NULL);
595 
596 static DECLARE_TRANSPORT_CLASS(iscsi_connection_class,
597 			       "iscsi_connection",
598 			       NULL,
599 			       NULL,
600 			       NULL);
601 
602 static struct sock *nls;
603 static DEFINE_MUTEX(rx_queue_mutex);
604 
605 static LIST_HEAD(sesslist);
606 static DEFINE_SPINLOCK(sesslock);
607 static LIST_HEAD(connlist);
608 static DEFINE_SPINLOCK(connlock);
609 
610 static uint32_t iscsi_conn_get_sid(struct iscsi_cls_conn *conn)
611 {
612 	struct iscsi_cls_session *sess = iscsi_dev_to_session(conn->dev.parent);
613 	return sess->sid;
614 }
615 
616 /*
617  * Returns the matching session to a given sid
618  */
619 static struct iscsi_cls_session *iscsi_session_lookup(uint32_t sid)
620 {
621 	unsigned long flags;
622 	struct iscsi_cls_session *sess;
623 
624 	spin_lock_irqsave(&sesslock, flags);
625 	list_for_each_entry(sess, &sesslist, sess_list) {
626 		if (sess->sid == sid) {
627 			spin_unlock_irqrestore(&sesslock, flags);
628 			return sess;
629 		}
630 	}
631 	spin_unlock_irqrestore(&sesslock, flags);
632 	return NULL;
633 }
634 
635 /*
636  * Returns the matching connection to a given sid / cid tuple
637  */
638 static struct iscsi_cls_conn *iscsi_conn_lookup(uint32_t sid, uint32_t cid)
639 {
640 	unsigned long flags;
641 	struct iscsi_cls_conn *conn;
642 
643 	spin_lock_irqsave(&connlock, flags);
644 	list_for_each_entry(conn, &connlist, conn_list) {
645 		if ((conn->cid == cid) && (iscsi_conn_get_sid(conn) == sid)) {
646 			spin_unlock_irqrestore(&connlock, flags);
647 			return conn;
648 		}
649 	}
650 	spin_unlock_irqrestore(&connlock, flags);
651 	return NULL;
652 }
653 
654 /*
655  * The following functions can be used by LLDs that allocate
656  * their own scsi_hosts or by software iscsi LLDs
657  */
658 static struct {
659 	int value;
660 	char *name;
661 } iscsi_session_state_names[] = {
662 	{ ISCSI_SESSION_LOGGED_IN,	"LOGGED_IN" },
663 	{ ISCSI_SESSION_FAILED,		"FAILED" },
664 	{ ISCSI_SESSION_FREE,		"FREE" },
665 };
666 
667 static const char *iscsi_session_state_name(int state)
668 {
669 	int i;
670 	char *name = NULL;
671 
672 	for (i = 0; i < ARRAY_SIZE(iscsi_session_state_names); i++) {
673 		if (iscsi_session_state_names[i].value == state) {
674 			name = iscsi_session_state_names[i].name;
675 			break;
676 		}
677 	}
678 	return name;
679 }
680 
681 int iscsi_session_chkready(struct iscsi_cls_session *session)
682 {
683 	unsigned long flags;
684 	int err;
685 
686 	spin_lock_irqsave(&session->lock, flags);
687 	switch (session->state) {
688 	case ISCSI_SESSION_LOGGED_IN:
689 		err = 0;
690 		break;
691 	case ISCSI_SESSION_FAILED:
692 		err = DID_IMM_RETRY << 16;
693 		break;
694 	case ISCSI_SESSION_FREE:
695 		err = DID_TRANSPORT_FAILFAST << 16;
696 		break;
697 	default:
698 		err = DID_NO_CONNECT << 16;
699 		break;
700 	}
701 	spin_unlock_irqrestore(&session->lock, flags);
702 	return err;
703 }
704 EXPORT_SYMBOL_GPL(iscsi_session_chkready);
705 
706 int iscsi_is_session_online(struct iscsi_cls_session *session)
707 {
708 	unsigned long flags;
709 	int ret = 0;
710 
711 	spin_lock_irqsave(&session->lock, flags);
712 	if (session->state == ISCSI_SESSION_LOGGED_IN)
713 		ret = 1;
714 	spin_unlock_irqrestore(&session->lock, flags);
715 	return ret;
716 }
717 EXPORT_SYMBOL_GPL(iscsi_is_session_online);
718 
719 static void iscsi_session_release(struct device *dev)
720 {
721 	struct iscsi_cls_session *session = iscsi_dev_to_session(dev);
722 	struct Scsi_Host *shost;
723 
724 	shost = iscsi_session_to_shost(session);
725 	scsi_host_put(shost);
726 	ISCSI_DBG_TRANS_SESSION(session, "Completing session release\n");
727 	kfree(session);
728 }
729 
730 static int iscsi_is_session_dev(const struct device *dev)
731 {
732 	return dev->release == iscsi_session_release;
733 }
734 
735 static int iscsi_iter_session_fn(struct device *dev, void *data)
736 {
737 	void (* fn) (struct iscsi_cls_session *) = data;
738 
739 	if (!iscsi_is_session_dev(dev))
740 		return 0;
741 	fn(iscsi_dev_to_session(dev));
742 	return 0;
743 }
744 
745 void iscsi_host_for_each_session(struct Scsi_Host *shost,
746 				 void (*fn)(struct iscsi_cls_session *))
747 {
748 	device_for_each_child(&shost->shost_gendev, fn,
749 			      iscsi_iter_session_fn);
750 }
751 EXPORT_SYMBOL_GPL(iscsi_host_for_each_session);
752 
753 /**
754  * iscsi_scan_finished - helper to report when running scans are done
755  * @shost: scsi host
756  * @time: scan run time
757  *
758  * This function can be used by drives like qla4xxx to report to the scsi
759  * layer when the scans it kicked off at module load time are done.
760  */
761 int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time)
762 {
763 	struct iscsi_cls_host *ihost = shost->shost_data;
764 	/*
765 	 * qla4xxx will have kicked off some session unblocks before calling
766 	 * scsi_scan_host, so just wait for them to complete.
767 	 */
768 	return !atomic_read(&ihost->nr_scans);
769 }
770 EXPORT_SYMBOL_GPL(iscsi_scan_finished);
771 
772 struct iscsi_scan_data {
773 	unsigned int channel;
774 	unsigned int id;
775 	unsigned int lun;
776 };
777 
778 static int iscsi_user_scan_session(struct device *dev, void *data)
779 {
780 	struct iscsi_scan_data *scan_data = data;
781 	struct iscsi_cls_session *session;
782 	struct Scsi_Host *shost;
783 	struct iscsi_cls_host *ihost;
784 	unsigned long flags;
785 	unsigned int id;
786 
787 	if (!iscsi_is_session_dev(dev))
788 		return 0;
789 
790 	session = iscsi_dev_to_session(dev);
791 
792 	ISCSI_DBG_TRANS_SESSION(session, "Scanning session\n");
793 
794 	shost = iscsi_session_to_shost(session);
795 	ihost = shost->shost_data;
796 
797 	mutex_lock(&ihost->mutex);
798 	spin_lock_irqsave(&session->lock, flags);
799 	if (session->state != ISCSI_SESSION_LOGGED_IN) {
800 		spin_unlock_irqrestore(&session->lock, flags);
801 		goto user_scan_exit;
802 	}
803 	id = session->target_id;
804 	spin_unlock_irqrestore(&session->lock, flags);
805 
806 	if (id != ISCSI_MAX_TARGET) {
807 		if ((scan_data->channel == SCAN_WILD_CARD ||
808 		     scan_data->channel == 0) &&
809 		    (scan_data->id == SCAN_WILD_CARD ||
810 		     scan_data->id == id))
811 			scsi_scan_target(&session->dev, 0, id,
812 					 scan_data->lun, 1);
813 	}
814 
815 user_scan_exit:
816 	mutex_unlock(&ihost->mutex);
817 	ISCSI_DBG_TRANS_SESSION(session, "Completed session scan\n");
818 	return 0;
819 }
820 
821 static int iscsi_user_scan(struct Scsi_Host *shost, uint channel,
822 			   uint id, uint lun)
823 {
824 	struct iscsi_scan_data scan_data;
825 
826 	scan_data.channel = channel;
827 	scan_data.id = id;
828 	scan_data.lun = lun;
829 
830 	return device_for_each_child(&shost->shost_gendev, &scan_data,
831 				     iscsi_user_scan_session);
832 }
833 
834 static void iscsi_scan_session(struct work_struct *work)
835 {
836 	struct iscsi_cls_session *session =
837 			container_of(work, struct iscsi_cls_session, scan_work);
838 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
839 	struct iscsi_cls_host *ihost = shost->shost_data;
840 	struct iscsi_scan_data scan_data;
841 
842 	scan_data.channel = 0;
843 	scan_data.id = SCAN_WILD_CARD;
844 	scan_data.lun = SCAN_WILD_CARD;
845 
846 	iscsi_user_scan_session(&session->dev, &scan_data);
847 	atomic_dec(&ihost->nr_scans);
848 }
849 
850 /**
851  * iscsi_block_scsi_eh - block scsi eh until session state has transistioned
852  * @cmd: scsi cmd passed to scsi eh handler
853  *
854  * If the session is down this function will wait for the recovery
855  * timer to fire or for the session to be logged back in. If the
856  * recovery timer fires then FAST_IO_FAIL is returned. The caller
857  * should pass this error value to the scsi eh.
858  */
859 int iscsi_block_scsi_eh(struct scsi_cmnd *cmd)
860 {
861 	struct iscsi_cls_session *session =
862 			starget_to_session(scsi_target(cmd->device));
863 	unsigned long flags;
864 	int ret = 0;
865 
866 	spin_lock_irqsave(&session->lock, flags);
867 	while (session->state != ISCSI_SESSION_LOGGED_IN) {
868 		if (session->state == ISCSI_SESSION_FREE) {
869 			ret = FAST_IO_FAIL;
870 			break;
871 		}
872 		spin_unlock_irqrestore(&session->lock, flags);
873 		msleep(1000);
874 		spin_lock_irqsave(&session->lock, flags);
875 	}
876 	spin_unlock_irqrestore(&session->lock, flags);
877 	return ret;
878 }
879 EXPORT_SYMBOL_GPL(iscsi_block_scsi_eh);
880 
881 static void session_recovery_timedout(struct work_struct *work)
882 {
883 	struct iscsi_cls_session *session =
884 		container_of(work, struct iscsi_cls_session,
885 			     recovery_work.work);
886 	unsigned long flags;
887 
888 	iscsi_cls_session_printk(KERN_INFO, session,
889 				 "session recovery timed out after %d secs\n",
890 				 session->recovery_tmo);
891 
892 	spin_lock_irqsave(&session->lock, flags);
893 	switch (session->state) {
894 	case ISCSI_SESSION_FAILED:
895 		session->state = ISCSI_SESSION_FREE;
896 		break;
897 	case ISCSI_SESSION_LOGGED_IN:
898 	case ISCSI_SESSION_FREE:
899 		/* we raced with the unblock's flush */
900 		spin_unlock_irqrestore(&session->lock, flags);
901 		return;
902 	}
903 	spin_unlock_irqrestore(&session->lock, flags);
904 
905 	if (session->transport->session_recovery_timedout)
906 		session->transport->session_recovery_timedout(session);
907 
908 	ISCSI_DBG_TRANS_SESSION(session, "Unblocking SCSI target\n");
909 	scsi_target_unblock(&session->dev);
910 	ISCSI_DBG_TRANS_SESSION(session, "Completed unblocking SCSI target\n");
911 }
912 
913 static void __iscsi_unblock_session(struct work_struct *work)
914 {
915 	struct iscsi_cls_session *session =
916 			container_of(work, struct iscsi_cls_session,
917 				     unblock_work);
918 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
919 	struct iscsi_cls_host *ihost = shost->shost_data;
920 	unsigned long flags;
921 
922 	ISCSI_DBG_TRANS_SESSION(session, "Unblocking session\n");
923 	/*
924 	 * The recovery and unblock work get run from the same workqueue,
925 	 * so try to cancel it if it was going to run after this unblock.
926 	 */
927 	cancel_delayed_work(&session->recovery_work);
928 	spin_lock_irqsave(&session->lock, flags);
929 	session->state = ISCSI_SESSION_LOGGED_IN;
930 	spin_unlock_irqrestore(&session->lock, flags);
931 	/* start IO */
932 	scsi_target_unblock(&session->dev);
933 	/*
934 	 * Only do kernel scanning if the driver is properly hooked into
935 	 * the async scanning code (drivers like iscsi_tcp do login and
936 	 * scanning from userspace).
937 	 */
938 	if (shost->hostt->scan_finished) {
939 		if (scsi_queue_work(shost, &session->scan_work))
940 			atomic_inc(&ihost->nr_scans);
941 	}
942 	ISCSI_DBG_TRANS_SESSION(session, "Completed unblocking session\n");
943 }
944 
945 /**
946  * iscsi_unblock_session - set a session as logged in and start IO.
947  * @session: iscsi session
948  *
949  * Mark a session as ready to accept IO.
950  */
951 void iscsi_unblock_session(struct iscsi_cls_session *session)
952 {
953 	queue_work(iscsi_eh_timer_workq, &session->unblock_work);
954 	/*
955 	 * make sure all the events have completed before tell the driver
956 	 * it is safe
957 	 */
958 	flush_workqueue(iscsi_eh_timer_workq);
959 }
960 EXPORT_SYMBOL_GPL(iscsi_unblock_session);
961 
962 static void __iscsi_block_session(struct work_struct *work)
963 {
964 	struct iscsi_cls_session *session =
965 			container_of(work, struct iscsi_cls_session,
966 				     block_work);
967 	unsigned long flags;
968 
969 	ISCSI_DBG_TRANS_SESSION(session, "Blocking session\n");
970 	spin_lock_irqsave(&session->lock, flags);
971 	session->state = ISCSI_SESSION_FAILED;
972 	spin_unlock_irqrestore(&session->lock, flags);
973 	scsi_target_block(&session->dev);
974 	ISCSI_DBG_TRANS_SESSION(session, "Completed SCSI target blocking\n");
975 	if (session->recovery_tmo >= 0)
976 		queue_delayed_work(iscsi_eh_timer_workq,
977 				   &session->recovery_work,
978 				   session->recovery_tmo * HZ);
979 }
980 
981 void iscsi_block_session(struct iscsi_cls_session *session)
982 {
983 	queue_work(iscsi_eh_timer_workq, &session->block_work);
984 }
985 EXPORT_SYMBOL_GPL(iscsi_block_session);
986 
987 static void __iscsi_unbind_session(struct work_struct *work)
988 {
989 	struct iscsi_cls_session *session =
990 			container_of(work, struct iscsi_cls_session,
991 				     unbind_work);
992 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
993 	struct iscsi_cls_host *ihost = shost->shost_data;
994 	unsigned long flags;
995 	unsigned int target_id;
996 
997 	ISCSI_DBG_TRANS_SESSION(session, "Unbinding session\n");
998 
999 	/* Prevent new scans and make sure scanning is not in progress */
1000 	mutex_lock(&ihost->mutex);
1001 	spin_lock_irqsave(&session->lock, flags);
1002 	if (session->target_id == ISCSI_MAX_TARGET) {
1003 		spin_unlock_irqrestore(&session->lock, flags);
1004 		mutex_unlock(&ihost->mutex);
1005 		return;
1006 	}
1007 
1008 	target_id = session->target_id;
1009 	session->target_id = ISCSI_MAX_TARGET;
1010 	spin_unlock_irqrestore(&session->lock, flags);
1011 	mutex_unlock(&ihost->mutex);
1012 
1013 	if (session->ida_used)
1014 		ida_simple_remove(&iscsi_sess_ida, target_id);
1015 
1016 	scsi_remove_target(&session->dev);
1017 	iscsi_session_event(session, ISCSI_KEVENT_UNBIND_SESSION);
1018 	ISCSI_DBG_TRANS_SESSION(session, "Completed target removal\n");
1019 }
1020 
1021 struct iscsi_cls_session *
1022 iscsi_alloc_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
1023 		    int dd_size)
1024 {
1025 	struct iscsi_cls_session *session;
1026 
1027 	session = kzalloc(sizeof(*session) + dd_size,
1028 			  GFP_KERNEL);
1029 	if (!session)
1030 		return NULL;
1031 
1032 	session->transport = transport;
1033 	session->recovery_tmo = 120;
1034 	session->state = ISCSI_SESSION_FREE;
1035 	INIT_DELAYED_WORK(&session->recovery_work, session_recovery_timedout);
1036 	INIT_LIST_HEAD(&session->sess_list);
1037 	INIT_WORK(&session->unblock_work, __iscsi_unblock_session);
1038 	INIT_WORK(&session->block_work, __iscsi_block_session);
1039 	INIT_WORK(&session->unbind_work, __iscsi_unbind_session);
1040 	INIT_WORK(&session->scan_work, iscsi_scan_session);
1041 	spin_lock_init(&session->lock);
1042 
1043 	/* this is released in the dev's release function */
1044 	scsi_host_get(shost);
1045 	session->dev.parent = &shost->shost_gendev;
1046 	session->dev.release = iscsi_session_release;
1047 	device_initialize(&session->dev);
1048 	if (dd_size)
1049 		session->dd_data = &session[1];
1050 
1051 	ISCSI_DBG_TRANS_SESSION(session, "Completed session allocation\n");
1052 	return session;
1053 }
1054 EXPORT_SYMBOL_GPL(iscsi_alloc_session);
1055 
1056 int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
1057 {
1058 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
1059 	struct iscsi_cls_host *ihost;
1060 	unsigned long flags;
1061 	int id = 0;
1062 	int err;
1063 
1064 	ihost = shost->shost_data;
1065 	session->sid = atomic_add_return(1, &iscsi_session_nr);
1066 
1067 	if (target_id == ISCSI_MAX_TARGET) {
1068 		id = ida_simple_get(&iscsi_sess_ida, 0, 0, GFP_KERNEL);
1069 
1070 		if (id < 0) {
1071 			iscsi_cls_session_printk(KERN_ERR, session,
1072 					"Failure in Target ID Allocation\n");
1073 			return id;
1074 		}
1075 		session->target_id = (unsigned int)id;
1076 		session->ida_used = true;
1077 	} else
1078 		session->target_id = target_id;
1079 
1080 	dev_set_name(&session->dev, "session%u", session->sid);
1081 	err = device_add(&session->dev);
1082 	if (err) {
1083 		iscsi_cls_session_printk(KERN_ERR, session,
1084 					 "could not register session's dev\n");
1085 		goto release_ida;
1086 	}
1087 	transport_register_device(&session->dev);
1088 
1089 	spin_lock_irqsave(&sesslock, flags);
1090 	list_add(&session->sess_list, &sesslist);
1091 	spin_unlock_irqrestore(&sesslock, flags);
1092 
1093 	iscsi_session_event(session, ISCSI_KEVENT_CREATE_SESSION);
1094 	ISCSI_DBG_TRANS_SESSION(session, "Completed session adding\n");
1095 	return 0;
1096 
1097 release_ida:
1098 	if (session->ida_used)
1099 		ida_simple_remove(&iscsi_sess_ida, session->target_id);
1100 
1101 	return err;
1102 }
1103 EXPORT_SYMBOL_GPL(iscsi_add_session);
1104 
1105 /**
1106  * iscsi_create_session - create iscsi class session
1107  * @shost: scsi host
1108  * @transport: iscsi transport
1109  * @dd_size: private driver data size
1110  * @target_id: which target
1111  *
1112  * This can be called from a LLD or iscsi_transport.
1113  */
1114 struct iscsi_cls_session *
1115 iscsi_create_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
1116 		     int dd_size, unsigned int target_id)
1117 {
1118 	struct iscsi_cls_session *session;
1119 
1120 	session = iscsi_alloc_session(shost, transport, dd_size);
1121 	if (!session)
1122 		return NULL;
1123 
1124 	if (iscsi_add_session(session, target_id)) {
1125 		iscsi_free_session(session);
1126 		return NULL;
1127 	}
1128 	return session;
1129 }
1130 EXPORT_SYMBOL_GPL(iscsi_create_session);
1131 
1132 static void iscsi_conn_release(struct device *dev)
1133 {
1134 	struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev);
1135 	struct device *parent = conn->dev.parent;
1136 
1137 	ISCSI_DBG_TRANS_CONN(conn, "Releasing conn\n");
1138 	kfree(conn);
1139 	put_device(parent);
1140 }
1141 
1142 static int iscsi_is_conn_dev(const struct device *dev)
1143 {
1144 	return dev->release == iscsi_conn_release;
1145 }
1146 
1147 static int iscsi_iter_destroy_conn_fn(struct device *dev, void *data)
1148 {
1149 	if (!iscsi_is_conn_dev(dev))
1150 		return 0;
1151 	return iscsi_destroy_conn(iscsi_dev_to_conn(dev));
1152 }
1153 
1154 void iscsi_remove_session(struct iscsi_cls_session *session)
1155 {
1156 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
1157 	unsigned long flags;
1158 	int err;
1159 
1160 	ISCSI_DBG_TRANS_SESSION(session, "Removing session\n");
1161 
1162 	spin_lock_irqsave(&sesslock, flags);
1163 	list_del(&session->sess_list);
1164 	spin_unlock_irqrestore(&sesslock, flags);
1165 
1166 	/* make sure there are no blocks/unblocks queued */
1167 	flush_workqueue(iscsi_eh_timer_workq);
1168 	/* make sure the timedout callout is not running */
1169 	if (!cancel_delayed_work(&session->recovery_work))
1170 		flush_workqueue(iscsi_eh_timer_workq);
1171 	/*
1172 	 * If we are blocked let commands flow again. The lld or iscsi
1173 	 * layer should set up the queuecommand to fail commands.
1174 	 * We assume that LLD will not be calling block/unblock while
1175 	 * removing the session.
1176 	 */
1177 	spin_lock_irqsave(&session->lock, flags);
1178 	session->state = ISCSI_SESSION_FREE;
1179 	spin_unlock_irqrestore(&session->lock, flags);
1180 
1181 	scsi_target_unblock(&session->dev);
1182 	/* flush running scans then delete devices */
1183 	scsi_flush_work(shost);
1184 	__iscsi_unbind_session(&session->unbind_work);
1185 
1186 	/* hw iscsi may not have removed all connections from session */
1187 	err = device_for_each_child(&session->dev, NULL,
1188 				    iscsi_iter_destroy_conn_fn);
1189 	if (err)
1190 		iscsi_cls_session_printk(KERN_ERR, session,
1191 					 "Could not delete all connections "
1192 					 "for session. Error %d.\n", err);
1193 
1194 	transport_unregister_device(&session->dev);
1195 
1196 	ISCSI_DBG_TRANS_SESSION(session, "Completing session removal\n");
1197 	device_del(&session->dev);
1198 }
1199 EXPORT_SYMBOL_GPL(iscsi_remove_session);
1200 
1201 void iscsi_free_session(struct iscsi_cls_session *session)
1202 {
1203 	ISCSI_DBG_TRANS_SESSION(session, "Freeing session\n");
1204 	iscsi_session_event(session, ISCSI_KEVENT_DESTROY_SESSION);
1205 	put_device(&session->dev);
1206 }
1207 EXPORT_SYMBOL_GPL(iscsi_free_session);
1208 
1209 /**
1210  * iscsi_destroy_session - destroy iscsi session
1211  * @session: iscsi_session
1212  *
1213  * Can be called by a LLD or iscsi_transport. There must not be
1214  * any running connections.
1215  */
1216 int iscsi_destroy_session(struct iscsi_cls_session *session)
1217 {
1218 	iscsi_remove_session(session);
1219 	ISCSI_DBG_TRANS_SESSION(session, "Completing session destruction\n");
1220 	iscsi_free_session(session);
1221 	return 0;
1222 }
1223 EXPORT_SYMBOL_GPL(iscsi_destroy_session);
1224 
1225 /**
1226  * iscsi_create_conn - create iscsi class connection
1227  * @session: iscsi cls session
1228  * @dd_size: private driver data size
1229  * @cid: connection id
1230  *
1231  * This can be called from a LLD or iscsi_transport. The connection
1232  * is child of the session so cid must be unique for all connections
1233  * on the session.
1234  *
1235  * Since we do not support MCS, cid will normally be zero. In some cases
1236  * for software iscsi we could be trying to preallocate a connection struct
1237  * in which case there could be two connection structs and cid would be
1238  * non-zero.
1239  */
1240 struct iscsi_cls_conn *
1241 iscsi_create_conn(struct iscsi_cls_session *session, int dd_size, uint32_t cid)
1242 {
1243 	struct iscsi_transport *transport = session->transport;
1244 	struct iscsi_cls_conn *conn;
1245 	unsigned long flags;
1246 	int err;
1247 
1248 	conn = kzalloc(sizeof(*conn) + dd_size, GFP_KERNEL);
1249 	if (!conn)
1250 		return NULL;
1251 	if (dd_size)
1252 		conn->dd_data = &conn[1];
1253 
1254 	mutex_init(&conn->ep_mutex);
1255 	INIT_LIST_HEAD(&conn->conn_list);
1256 	conn->transport = transport;
1257 	conn->cid = cid;
1258 
1259 	/* this is released in the dev's release function */
1260 	if (!get_device(&session->dev))
1261 		goto free_conn;
1262 
1263 	dev_set_name(&conn->dev, "connection%d:%u", session->sid, cid);
1264 	conn->dev.parent = &session->dev;
1265 	conn->dev.release = iscsi_conn_release;
1266 	err = device_register(&conn->dev);
1267 	if (err) {
1268 		iscsi_cls_session_printk(KERN_ERR, session, "could not "
1269 					 "register connection's dev\n");
1270 		goto release_parent_ref;
1271 	}
1272 	transport_register_device(&conn->dev);
1273 
1274 	spin_lock_irqsave(&connlock, flags);
1275 	list_add(&conn->conn_list, &connlist);
1276 	spin_unlock_irqrestore(&connlock, flags);
1277 
1278 	ISCSI_DBG_TRANS_CONN(conn, "Completed conn creation\n");
1279 	return conn;
1280 
1281 release_parent_ref:
1282 	put_device(&session->dev);
1283 free_conn:
1284 	kfree(conn);
1285 	return NULL;
1286 }
1287 
1288 EXPORT_SYMBOL_GPL(iscsi_create_conn);
1289 
1290 /**
1291  * iscsi_destroy_conn - destroy iscsi class connection
1292  * @conn: iscsi cls session
1293  *
1294  * This can be called from a LLD or iscsi_transport.
1295  */
1296 int iscsi_destroy_conn(struct iscsi_cls_conn *conn)
1297 {
1298 	unsigned long flags;
1299 
1300 	spin_lock_irqsave(&connlock, flags);
1301 	list_del(&conn->conn_list);
1302 	spin_unlock_irqrestore(&connlock, flags);
1303 
1304 	transport_unregister_device(&conn->dev);
1305 	ISCSI_DBG_TRANS_CONN(conn, "Completing conn destruction\n");
1306 	device_unregister(&conn->dev);
1307 	return 0;
1308 }
1309 EXPORT_SYMBOL_GPL(iscsi_destroy_conn);
1310 
1311 /*
1312  * iscsi interface functions
1313  */
1314 static struct iscsi_internal *
1315 iscsi_if_transport_lookup(struct iscsi_transport *tt)
1316 {
1317 	struct iscsi_internal *priv;
1318 	unsigned long flags;
1319 
1320 	spin_lock_irqsave(&iscsi_transport_lock, flags);
1321 	list_for_each_entry(priv, &iscsi_transports, list) {
1322 		if (tt == priv->iscsi_transport) {
1323 			spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1324 			return priv;
1325 		}
1326 	}
1327 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1328 	return NULL;
1329 }
1330 
1331 static int
1332 iscsi_multicast_skb(struct sk_buff *skb, uint32_t group, gfp_t gfp)
1333 {
1334 	return nlmsg_multicast(nls, skb, 0, group, gfp);
1335 }
1336 
1337 int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
1338 		   char *data, uint32_t data_size)
1339 {
1340 	struct nlmsghdr	*nlh;
1341 	struct sk_buff *skb;
1342 	struct iscsi_uevent *ev;
1343 	char *pdu;
1344 	struct iscsi_internal *priv;
1345 	int len = NLMSG_SPACE(sizeof(*ev) + sizeof(struct iscsi_hdr) +
1346 			      data_size);
1347 
1348 	priv = iscsi_if_transport_lookup(conn->transport);
1349 	if (!priv)
1350 		return -EINVAL;
1351 
1352 	skb = alloc_skb(len, GFP_ATOMIC);
1353 	if (!skb) {
1354 		iscsi_conn_error_event(conn, ISCSI_ERR_CONN_FAILED);
1355 		iscsi_cls_conn_printk(KERN_ERR, conn, "can not deliver "
1356 				      "control PDU: OOM\n");
1357 		return -ENOMEM;
1358 	}
1359 
1360 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1361 	ev = NLMSG_DATA(nlh);
1362 	memset(ev, 0, sizeof(*ev));
1363 	ev->transport_handle = iscsi_handle(conn->transport);
1364 	ev->type = ISCSI_KEVENT_RECV_PDU;
1365 	ev->r.recv_req.cid = conn->cid;
1366 	ev->r.recv_req.sid = iscsi_conn_get_sid(conn);
1367 	pdu = (char*)ev + sizeof(*ev);
1368 	memcpy(pdu, hdr, sizeof(struct iscsi_hdr));
1369 	memcpy(pdu + sizeof(struct iscsi_hdr), data, data_size);
1370 
1371 	return iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);
1372 }
1373 EXPORT_SYMBOL_GPL(iscsi_recv_pdu);
1374 
1375 int iscsi_offload_mesg(struct Scsi_Host *shost,
1376 		       struct iscsi_transport *transport, uint32_t type,
1377 		       char *data, uint16_t data_size)
1378 {
1379 	struct nlmsghdr	*nlh;
1380 	struct sk_buff *skb;
1381 	struct iscsi_uevent *ev;
1382 	int len = NLMSG_SPACE(sizeof(*ev) + data_size);
1383 
1384 	skb = alloc_skb(len, GFP_ATOMIC);
1385 	if (!skb) {
1386 		printk(KERN_ERR "can not deliver iscsi offload message:OOM\n");
1387 		return -ENOMEM;
1388 	}
1389 
1390 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1391 	ev = NLMSG_DATA(nlh);
1392 	memset(ev, 0, sizeof(*ev));
1393 	ev->type = type;
1394 	ev->transport_handle = iscsi_handle(transport);
1395 	switch (type) {
1396 	case ISCSI_KEVENT_PATH_REQ:
1397 		ev->r.req_path.host_no = shost->host_no;
1398 		break;
1399 	case ISCSI_KEVENT_IF_DOWN:
1400 		ev->r.notify_if_down.host_no = shost->host_no;
1401 		break;
1402 	}
1403 
1404 	memcpy((char *)ev + sizeof(*ev), data, data_size);
1405 
1406 	return iscsi_multicast_skb(skb, ISCSI_NL_GRP_UIP, GFP_ATOMIC);
1407 }
1408 EXPORT_SYMBOL_GPL(iscsi_offload_mesg);
1409 
1410 void iscsi_conn_error_event(struct iscsi_cls_conn *conn, enum iscsi_err error)
1411 {
1412 	struct nlmsghdr	*nlh;
1413 	struct sk_buff	*skb;
1414 	struct iscsi_uevent *ev;
1415 	struct iscsi_internal *priv;
1416 	int len = NLMSG_SPACE(sizeof(*ev));
1417 
1418 	priv = iscsi_if_transport_lookup(conn->transport);
1419 	if (!priv)
1420 		return;
1421 
1422 	skb = alloc_skb(len, GFP_ATOMIC);
1423 	if (!skb) {
1424 		iscsi_cls_conn_printk(KERN_ERR, conn, "gracefully ignored "
1425 				      "conn error (%d)\n", error);
1426 		return;
1427 	}
1428 
1429 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1430 	ev = NLMSG_DATA(nlh);
1431 	ev->transport_handle = iscsi_handle(conn->transport);
1432 	ev->type = ISCSI_KEVENT_CONN_ERROR;
1433 	ev->r.connerror.error = error;
1434 	ev->r.connerror.cid = conn->cid;
1435 	ev->r.connerror.sid = iscsi_conn_get_sid(conn);
1436 
1437 	iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);
1438 
1439 	iscsi_cls_conn_printk(KERN_INFO, conn, "detected conn error (%d)\n",
1440 			      error);
1441 }
1442 EXPORT_SYMBOL_GPL(iscsi_conn_error_event);
1443 
1444 void iscsi_conn_login_event(struct iscsi_cls_conn *conn,
1445 			    enum iscsi_conn_state state)
1446 {
1447 	struct nlmsghdr *nlh;
1448 	struct sk_buff  *skb;
1449 	struct iscsi_uevent *ev;
1450 	struct iscsi_internal *priv;
1451 	int len = NLMSG_SPACE(sizeof(*ev));
1452 
1453 	priv = iscsi_if_transport_lookup(conn->transport);
1454 	if (!priv)
1455 		return;
1456 
1457 	skb = alloc_skb(len, GFP_ATOMIC);
1458 	if (!skb) {
1459 		iscsi_cls_conn_printk(KERN_ERR, conn, "gracefully ignored "
1460 				      "conn login (%d)\n", state);
1461 		return;
1462 	}
1463 
1464 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1465 	ev = NLMSG_DATA(nlh);
1466 	ev->transport_handle = iscsi_handle(conn->transport);
1467 	ev->type = ISCSI_KEVENT_CONN_LOGIN_STATE;
1468 	ev->r.conn_login.state = state;
1469 	ev->r.conn_login.cid = conn->cid;
1470 	ev->r.conn_login.sid = iscsi_conn_get_sid(conn);
1471 	iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);
1472 
1473 	iscsi_cls_conn_printk(KERN_INFO, conn, "detected conn login (%d)\n",
1474 			      state);
1475 }
1476 EXPORT_SYMBOL_GPL(iscsi_conn_login_event);
1477 
1478 static int
1479 iscsi_if_send_reply(uint32_t group, int seq, int type, int done, int multi,
1480 		    void *payload, int size)
1481 {
1482 	struct sk_buff	*skb;
1483 	struct nlmsghdr	*nlh;
1484 	int len = NLMSG_SPACE(size);
1485 	int flags = multi ? NLM_F_MULTI : 0;
1486 	int t = done ? NLMSG_DONE : type;
1487 
1488 	skb = alloc_skb(len, GFP_ATOMIC);
1489 	if (!skb) {
1490 		printk(KERN_ERR "Could not allocate skb to send reply.\n");
1491 		return -ENOMEM;
1492 	}
1493 
1494 	nlh = __nlmsg_put(skb, 0, 0, t, (len - sizeof(*nlh)), 0);
1495 	nlh->nlmsg_flags = flags;
1496 	memcpy(NLMSG_DATA(nlh), payload, size);
1497 	return iscsi_multicast_skb(skb, group, GFP_ATOMIC);
1498 }
1499 
1500 static int
1501 iscsi_if_get_stats(struct iscsi_transport *transport, struct nlmsghdr *nlh)
1502 {
1503 	struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1504 	struct iscsi_stats *stats;
1505 	struct sk_buff *skbstat;
1506 	struct iscsi_cls_conn *conn;
1507 	struct nlmsghdr	*nlhstat;
1508 	struct iscsi_uevent *evstat;
1509 	struct iscsi_internal *priv;
1510 	int len = NLMSG_SPACE(sizeof(*ev) +
1511 			      sizeof(struct iscsi_stats) +
1512 			      sizeof(struct iscsi_stats_custom) *
1513 			      ISCSI_STATS_CUSTOM_MAX);
1514 	int err = 0;
1515 
1516 	priv = iscsi_if_transport_lookup(transport);
1517 	if (!priv)
1518 		return -EINVAL;
1519 
1520 	conn = iscsi_conn_lookup(ev->u.get_stats.sid, ev->u.get_stats.cid);
1521 	if (!conn)
1522 		return -EEXIST;
1523 
1524 	do {
1525 		int actual_size;
1526 
1527 		skbstat = alloc_skb(len, GFP_ATOMIC);
1528 		if (!skbstat) {
1529 			iscsi_cls_conn_printk(KERN_ERR, conn, "can not "
1530 					      "deliver stats: OOM\n");
1531 			return -ENOMEM;
1532 		}
1533 
1534 		nlhstat = __nlmsg_put(skbstat, 0, 0, 0,
1535 				      (len - sizeof(*nlhstat)), 0);
1536 		evstat = NLMSG_DATA(nlhstat);
1537 		memset(evstat, 0, sizeof(*evstat));
1538 		evstat->transport_handle = iscsi_handle(conn->transport);
1539 		evstat->type = nlh->nlmsg_type;
1540 		evstat->u.get_stats.cid =
1541 			ev->u.get_stats.cid;
1542 		evstat->u.get_stats.sid =
1543 			ev->u.get_stats.sid;
1544 		stats = (struct iscsi_stats *)
1545 			((char*)evstat + sizeof(*evstat));
1546 		memset(stats, 0, sizeof(*stats));
1547 
1548 		transport->get_stats(conn, stats);
1549 		actual_size = NLMSG_SPACE(sizeof(struct iscsi_uevent) +
1550 					  sizeof(struct iscsi_stats) +
1551 					  sizeof(struct iscsi_stats_custom) *
1552 					  stats->custom_length);
1553 		actual_size -= sizeof(*nlhstat);
1554 		actual_size = NLMSG_LENGTH(actual_size);
1555 		skb_trim(skbstat, NLMSG_ALIGN(actual_size));
1556 		nlhstat->nlmsg_len = actual_size;
1557 
1558 		err = iscsi_multicast_skb(skbstat, ISCSI_NL_GRP_ISCSID,
1559 					  GFP_ATOMIC);
1560 	} while (err < 0 && err != -ECONNREFUSED);
1561 
1562 	return err;
1563 }
1564 
1565 /**
1566  * iscsi_session_event - send session destr. completion event
1567  * @session: iscsi class session
1568  * @event: type of event
1569  */
1570 int iscsi_session_event(struct iscsi_cls_session *session,
1571 			enum iscsi_uevent_e event)
1572 {
1573 	struct iscsi_internal *priv;
1574 	struct Scsi_Host *shost;
1575 	struct iscsi_uevent *ev;
1576 	struct sk_buff  *skb;
1577 	struct nlmsghdr *nlh;
1578 	int rc, len = NLMSG_SPACE(sizeof(*ev));
1579 
1580 	priv = iscsi_if_transport_lookup(session->transport);
1581 	if (!priv)
1582 		return -EINVAL;
1583 	shost = iscsi_session_to_shost(session);
1584 
1585 	skb = alloc_skb(len, GFP_KERNEL);
1586 	if (!skb) {
1587 		iscsi_cls_session_printk(KERN_ERR, session,
1588 					 "Cannot notify userspace of session "
1589 					 "event %u\n", event);
1590 		return -ENOMEM;
1591 	}
1592 
1593 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1594 	ev = NLMSG_DATA(nlh);
1595 	ev->transport_handle = iscsi_handle(session->transport);
1596 
1597 	ev->type = event;
1598 	switch (event) {
1599 	case ISCSI_KEVENT_DESTROY_SESSION:
1600 		ev->r.d_session.host_no = shost->host_no;
1601 		ev->r.d_session.sid = session->sid;
1602 		break;
1603 	case ISCSI_KEVENT_CREATE_SESSION:
1604 		ev->r.c_session_ret.host_no = shost->host_no;
1605 		ev->r.c_session_ret.sid = session->sid;
1606 		break;
1607 	case ISCSI_KEVENT_UNBIND_SESSION:
1608 		ev->r.unbind_session.host_no = shost->host_no;
1609 		ev->r.unbind_session.sid = session->sid;
1610 		break;
1611 	default:
1612 		iscsi_cls_session_printk(KERN_ERR, session, "Invalid event "
1613 					 "%u.\n", event);
1614 		kfree_skb(skb);
1615 		return -EINVAL;
1616 	}
1617 
1618 	/*
1619 	 * this will occur if the daemon is not up, so we just warn
1620 	 * the user and when the daemon is restarted it will handle it
1621 	 */
1622 	rc = iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_KERNEL);
1623 	if (rc == -ESRCH)
1624 		iscsi_cls_session_printk(KERN_ERR, session,
1625 					 "Cannot notify userspace of session "
1626 					 "event %u. Check iscsi daemon\n",
1627 					 event);
1628 
1629 	ISCSI_DBG_TRANS_SESSION(session, "Completed handling event %d rc %d\n",
1630 				event, rc);
1631 	return rc;
1632 }
1633 EXPORT_SYMBOL_GPL(iscsi_session_event);
1634 
1635 static int
1636 iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_endpoint *ep,
1637 			struct iscsi_uevent *ev, uint32_t initial_cmdsn,
1638 			uint16_t cmds_max, uint16_t queue_depth)
1639 {
1640 	struct iscsi_transport *transport = priv->iscsi_transport;
1641 	struct iscsi_cls_session *session;
1642 	struct Scsi_Host *shost;
1643 
1644 	session = transport->create_session(ep, cmds_max, queue_depth,
1645 					    initial_cmdsn);
1646 	if (!session)
1647 		return -ENOMEM;
1648 
1649 	shost = iscsi_session_to_shost(session);
1650 	ev->r.c_session_ret.host_no = shost->host_no;
1651 	ev->r.c_session_ret.sid = session->sid;
1652 	ISCSI_DBG_TRANS_SESSION(session,
1653 				"Completed creating transport session\n");
1654 	return 0;
1655 }
1656 
1657 static int
1658 iscsi_if_create_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1659 {
1660 	struct iscsi_cls_conn *conn;
1661 	struct iscsi_cls_session *session;
1662 
1663 	session = iscsi_session_lookup(ev->u.c_conn.sid);
1664 	if (!session) {
1665 		printk(KERN_ERR "iscsi: invalid session %d.\n",
1666 		       ev->u.c_conn.sid);
1667 		return -EINVAL;
1668 	}
1669 
1670 	conn = transport->create_conn(session, ev->u.c_conn.cid);
1671 	if (!conn) {
1672 		iscsi_cls_session_printk(KERN_ERR, session,
1673 					 "couldn't create a new connection.");
1674 		return -ENOMEM;
1675 	}
1676 
1677 	ev->r.c_conn_ret.sid = session->sid;
1678 	ev->r.c_conn_ret.cid = conn->cid;
1679 
1680 	ISCSI_DBG_TRANS_CONN(conn, "Completed creating transport conn\n");
1681 	return 0;
1682 }
1683 
1684 static int
1685 iscsi_if_destroy_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1686 {
1687 	struct iscsi_cls_conn *conn;
1688 
1689 	conn = iscsi_conn_lookup(ev->u.d_conn.sid, ev->u.d_conn.cid);
1690 	if (!conn)
1691 		return -EINVAL;
1692 
1693 	ISCSI_DBG_TRANS_CONN(conn, "Destroying transport conn\n");
1694 	if (transport->destroy_conn)
1695 		transport->destroy_conn(conn);
1696 
1697 	return 0;
1698 }
1699 
1700 static int
1701 iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1702 {
1703 	char *data = (char*)ev + sizeof(*ev);
1704 	struct iscsi_cls_conn *conn;
1705 	struct iscsi_cls_session *session;
1706 	int err = 0, value = 0;
1707 
1708 	session = iscsi_session_lookup(ev->u.set_param.sid);
1709 	conn = iscsi_conn_lookup(ev->u.set_param.sid, ev->u.set_param.cid);
1710 	if (!conn || !session)
1711 		return -EINVAL;
1712 
1713 	switch (ev->u.set_param.param) {
1714 	case ISCSI_PARAM_SESS_RECOVERY_TMO:
1715 		sscanf(data, "%d", &value);
1716 		session->recovery_tmo = value;
1717 		break;
1718 	default:
1719 		err = transport->set_param(conn, ev->u.set_param.param,
1720 					   data, ev->u.set_param.len);
1721 	}
1722 
1723 	return err;
1724 }
1725 
1726 static int iscsi_if_ep_connect(struct iscsi_transport *transport,
1727 			       struct iscsi_uevent *ev, int msg_type)
1728 {
1729 	struct iscsi_endpoint *ep;
1730 	struct sockaddr *dst_addr;
1731 	struct Scsi_Host *shost = NULL;
1732 	int non_blocking, err = 0;
1733 
1734 	if (!transport->ep_connect)
1735 		return -EINVAL;
1736 
1737 	if (msg_type == ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST) {
1738 		shost = scsi_host_lookup(ev->u.ep_connect_through_host.host_no);
1739 		if (!shost) {
1740 			printk(KERN_ERR "ep connect failed. Could not find "
1741 			       "host no %u\n",
1742 			       ev->u.ep_connect_through_host.host_no);
1743 			return -ENODEV;
1744 		}
1745 		non_blocking = ev->u.ep_connect_through_host.non_blocking;
1746 	} else
1747 		non_blocking = ev->u.ep_connect.non_blocking;
1748 
1749 	dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1750 	ep = transport->ep_connect(shost, dst_addr, non_blocking);
1751 	if (IS_ERR(ep)) {
1752 		err = PTR_ERR(ep);
1753 		goto release_host;
1754 	}
1755 
1756 	ev->r.ep_connect_ret.handle = ep->id;
1757 release_host:
1758 	if (shost)
1759 		scsi_host_put(shost);
1760 	return err;
1761 }
1762 
1763 static int iscsi_if_ep_disconnect(struct iscsi_transport *transport,
1764 				  u64 ep_handle)
1765 {
1766 	struct iscsi_cls_conn *conn;
1767 	struct iscsi_endpoint *ep;
1768 
1769 	if (!transport->ep_disconnect)
1770 		return -EINVAL;
1771 
1772 	ep = iscsi_lookup_endpoint(ep_handle);
1773 	if (!ep)
1774 		return -EINVAL;
1775 	conn = ep->conn;
1776 	if (conn) {
1777 		mutex_lock(&conn->ep_mutex);
1778 		conn->ep = NULL;
1779 		mutex_unlock(&conn->ep_mutex);
1780 	}
1781 
1782 	transport->ep_disconnect(ep);
1783 	return 0;
1784 }
1785 
1786 static int
1787 iscsi_if_transport_ep(struct iscsi_transport *transport,
1788 		      struct iscsi_uevent *ev, int msg_type)
1789 {
1790 	struct iscsi_endpoint *ep;
1791 	int rc = 0;
1792 
1793 	switch (msg_type) {
1794 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST:
1795 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1796 		rc = iscsi_if_ep_connect(transport, ev, msg_type);
1797 		break;
1798 	case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1799 		if (!transport->ep_poll)
1800 			return -EINVAL;
1801 
1802 		ep = iscsi_lookup_endpoint(ev->u.ep_poll.ep_handle);
1803 		if (!ep)
1804 			return -EINVAL;
1805 
1806 		ev->r.retcode = transport->ep_poll(ep,
1807 						   ev->u.ep_poll.timeout_ms);
1808 		break;
1809 	case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1810 		rc = iscsi_if_ep_disconnect(transport,
1811 					    ev->u.ep_disconnect.ep_handle);
1812 		break;
1813 	}
1814 	return rc;
1815 }
1816 
1817 static int
1818 iscsi_tgt_dscvr(struct iscsi_transport *transport,
1819 		struct iscsi_uevent *ev)
1820 {
1821 	struct Scsi_Host *shost;
1822 	struct sockaddr *dst_addr;
1823 	int err;
1824 
1825 	if (!transport->tgt_dscvr)
1826 		return -EINVAL;
1827 
1828 	shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);
1829 	if (!shost) {
1830 		printk(KERN_ERR "target discovery could not find host no %u\n",
1831 		       ev->u.tgt_dscvr.host_no);
1832 		return -ENODEV;
1833 	}
1834 
1835 
1836 	dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1837 	err = transport->tgt_dscvr(shost, ev->u.tgt_dscvr.type,
1838 				   ev->u.tgt_dscvr.enable, dst_addr);
1839 	scsi_host_put(shost);
1840 	return err;
1841 }
1842 
1843 static int
1844 iscsi_set_host_param(struct iscsi_transport *transport,
1845 		     struct iscsi_uevent *ev)
1846 {
1847 	char *data = (char*)ev + sizeof(*ev);
1848 	struct Scsi_Host *shost;
1849 	int err;
1850 
1851 	if (!transport->set_host_param)
1852 		return -ENOSYS;
1853 
1854 	shost = scsi_host_lookup(ev->u.set_host_param.host_no);
1855 	if (!shost) {
1856 		printk(KERN_ERR "set_host_param could not find host no %u\n",
1857 		       ev->u.set_host_param.host_no);
1858 		return -ENODEV;
1859 	}
1860 
1861 	err = transport->set_host_param(shost, ev->u.set_host_param.param,
1862 					data, ev->u.set_host_param.len);
1863 	scsi_host_put(shost);
1864 	return err;
1865 }
1866 
1867 static int
1868 iscsi_set_path(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1869 {
1870 	struct Scsi_Host *shost;
1871 	struct iscsi_path *params;
1872 	int err;
1873 
1874 	if (!transport->set_path)
1875 		return -ENOSYS;
1876 
1877 	shost = scsi_host_lookup(ev->u.set_path.host_no);
1878 	if (!shost) {
1879 		printk(KERN_ERR "set path could not find host no %u\n",
1880 		       ev->u.set_path.host_no);
1881 		return -ENODEV;
1882 	}
1883 
1884 	params = (struct iscsi_path *)((char *)ev + sizeof(*ev));
1885 	err = transport->set_path(shost, params);
1886 
1887 	scsi_host_put(shost);
1888 	return err;
1889 }
1890 
1891 static int
1892 iscsi_set_iface_params(struct iscsi_transport *transport,
1893 		       struct iscsi_uevent *ev, uint32_t len)
1894 {
1895 	char *data = (char *)ev + sizeof(*ev);
1896 	struct Scsi_Host *shost;
1897 	int err;
1898 
1899 	if (!transport->set_iface_param)
1900 		return -ENOSYS;
1901 
1902 	shost = scsi_host_lookup(ev->u.set_iface_params.host_no);
1903 	if (!shost) {
1904 		printk(KERN_ERR "set_iface_params could not find host no %u\n",
1905 		       ev->u.set_iface_params.host_no);
1906 		return -ENODEV;
1907 	}
1908 
1909 	err = transport->set_iface_param(shost, data, len);
1910 	scsi_host_put(shost);
1911 	return err;
1912 }
1913 
1914 static int
1915 iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
1916 {
1917 	int err = 0;
1918 	struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1919 	struct iscsi_transport *transport = NULL;
1920 	struct iscsi_internal *priv;
1921 	struct iscsi_cls_session *session;
1922 	struct iscsi_cls_conn *conn;
1923 	struct iscsi_endpoint *ep = NULL;
1924 
1925 	if (nlh->nlmsg_type == ISCSI_UEVENT_PATH_UPDATE)
1926 		*group = ISCSI_NL_GRP_UIP;
1927 	else
1928 		*group = ISCSI_NL_GRP_ISCSID;
1929 
1930 	priv = iscsi_if_transport_lookup(iscsi_ptr(ev->transport_handle));
1931 	if (!priv)
1932 		return -EINVAL;
1933 	transport = priv->iscsi_transport;
1934 
1935 	if (!try_module_get(transport->owner))
1936 		return -EINVAL;
1937 
1938 	switch (nlh->nlmsg_type) {
1939 	case ISCSI_UEVENT_CREATE_SESSION:
1940 		err = iscsi_if_create_session(priv, ep, ev,
1941 					      ev->u.c_session.initial_cmdsn,
1942 					      ev->u.c_session.cmds_max,
1943 					      ev->u.c_session.queue_depth);
1944 		break;
1945 	case ISCSI_UEVENT_CREATE_BOUND_SESSION:
1946 		ep = iscsi_lookup_endpoint(ev->u.c_bound_session.ep_handle);
1947 		if (!ep) {
1948 			err = -EINVAL;
1949 			break;
1950 		}
1951 
1952 		err = iscsi_if_create_session(priv, ep, ev,
1953 					ev->u.c_bound_session.initial_cmdsn,
1954 					ev->u.c_bound_session.cmds_max,
1955 					ev->u.c_bound_session.queue_depth);
1956 		break;
1957 	case ISCSI_UEVENT_DESTROY_SESSION:
1958 		session = iscsi_session_lookup(ev->u.d_session.sid);
1959 		if (session)
1960 			transport->destroy_session(session);
1961 		else
1962 			err = -EINVAL;
1963 		break;
1964 	case ISCSI_UEVENT_UNBIND_SESSION:
1965 		session = iscsi_session_lookup(ev->u.d_session.sid);
1966 		if (session)
1967 			scsi_queue_work(iscsi_session_to_shost(session),
1968 					&session->unbind_work);
1969 		else
1970 			err = -EINVAL;
1971 		break;
1972 	case ISCSI_UEVENT_CREATE_CONN:
1973 		err = iscsi_if_create_conn(transport, ev);
1974 		break;
1975 	case ISCSI_UEVENT_DESTROY_CONN:
1976 		err = iscsi_if_destroy_conn(transport, ev);
1977 		break;
1978 	case ISCSI_UEVENT_BIND_CONN:
1979 		session = iscsi_session_lookup(ev->u.b_conn.sid);
1980 		conn = iscsi_conn_lookup(ev->u.b_conn.sid, ev->u.b_conn.cid);
1981 
1982 		if (conn && conn->ep)
1983 			iscsi_if_ep_disconnect(transport, conn->ep->id);
1984 
1985 		if (!session || !conn) {
1986 			err = -EINVAL;
1987 			break;
1988 		}
1989 
1990 		ev->r.retcode =	transport->bind_conn(session, conn,
1991 						ev->u.b_conn.transport_eph,
1992 						ev->u.b_conn.is_leading);
1993 		if (ev->r.retcode || !transport->ep_connect)
1994 			break;
1995 
1996 		ep = iscsi_lookup_endpoint(ev->u.b_conn.transport_eph);
1997 		if (ep) {
1998 			ep->conn = conn;
1999 
2000 			mutex_lock(&conn->ep_mutex);
2001 			conn->ep = ep;
2002 			mutex_unlock(&conn->ep_mutex);
2003 		} else
2004 			iscsi_cls_conn_printk(KERN_ERR, conn,
2005 					      "Could not set ep conn "
2006 					      "binding\n");
2007 		break;
2008 	case ISCSI_UEVENT_SET_PARAM:
2009 		err = iscsi_set_param(transport, ev);
2010 		break;
2011 	case ISCSI_UEVENT_START_CONN:
2012 		conn = iscsi_conn_lookup(ev->u.start_conn.sid, ev->u.start_conn.cid);
2013 		if (conn)
2014 			ev->r.retcode = transport->start_conn(conn);
2015 		else
2016 			err = -EINVAL;
2017 		break;
2018 	case ISCSI_UEVENT_STOP_CONN:
2019 		conn = iscsi_conn_lookup(ev->u.stop_conn.sid, ev->u.stop_conn.cid);
2020 		if (conn)
2021 			transport->stop_conn(conn, ev->u.stop_conn.flag);
2022 		else
2023 			err = -EINVAL;
2024 		break;
2025 	case ISCSI_UEVENT_SEND_PDU:
2026 		conn = iscsi_conn_lookup(ev->u.send_pdu.sid, ev->u.send_pdu.cid);
2027 		if (conn)
2028 			ev->r.retcode =	transport->send_pdu(conn,
2029 				(struct iscsi_hdr*)((char*)ev + sizeof(*ev)),
2030 				(char*)ev + sizeof(*ev) + ev->u.send_pdu.hdr_size,
2031 				ev->u.send_pdu.data_size);
2032 		else
2033 			err = -EINVAL;
2034 		break;
2035 	case ISCSI_UEVENT_GET_STATS:
2036 		err = iscsi_if_get_stats(transport, nlh);
2037 		break;
2038 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
2039 	case ISCSI_UEVENT_TRANSPORT_EP_POLL:
2040 	case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
2041 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST:
2042 		err = iscsi_if_transport_ep(transport, ev, nlh->nlmsg_type);
2043 		break;
2044 	case ISCSI_UEVENT_TGT_DSCVR:
2045 		err = iscsi_tgt_dscvr(transport, ev);
2046 		break;
2047 	case ISCSI_UEVENT_SET_HOST_PARAM:
2048 		err = iscsi_set_host_param(transport, ev);
2049 		break;
2050 	case ISCSI_UEVENT_PATH_UPDATE:
2051 		err = iscsi_set_path(transport, ev);
2052 		break;
2053 	case ISCSI_UEVENT_SET_IFACE_PARAMS:
2054 		err = iscsi_set_iface_params(transport, ev,
2055 					     nlmsg_attrlen(nlh, sizeof(*ev)));
2056 		break;
2057 	default:
2058 		err = -ENOSYS;
2059 		break;
2060 	}
2061 
2062 	module_put(transport->owner);
2063 	return err;
2064 }
2065 
2066 /*
2067  * Get message from skb.  Each message is processed by iscsi_if_recv_msg.
2068  * Malformed skbs with wrong lengths or invalid creds are not processed.
2069  */
2070 static void
2071 iscsi_if_rx(struct sk_buff *skb)
2072 {
2073 	mutex_lock(&rx_queue_mutex);
2074 	while (skb->len >= NLMSG_SPACE(0)) {
2075 		int err;
2076 		uint32_t rlen;
2077 		struct nlmsghdr	*nlh;
2078 		struct iscsi_uevent *ev;
2079 		uint32_t group;
2080 
2081 		nlh = nlmsg_hdr(skb);
2082 		if (nlh->nlmsg_len < sizeof(*nlh) ||
2083 		    skb->len < nlh->nlmsg_len) {
2084 			break;
2085 		}
2086 
2087 		ev = NLMSG_DATA(nlh);
2088 		rlen = NLMSG_ALIGN(nlh->nlmsg_len);
2089 		if (rlen > skb->len)
2090 			rlen = skb->len;
2091 
2092 		err = iscsi_if_recv_msg(skb, nlh, &group);
2093 		if (err) {
2094 			ev->type = ISCSI_KEVENT_IF_ERROR;
2095 			ev->iferror = err;
2096 		}
2097 		do {
2098 			/*
2099 			 * special case for GET_STATS:
2100 			 * on success - sending reply and stats from
2101 			 * inside of if_recv_msg(),
2102 			 * on error - fall through.
2103 			 */
2104 			if (ev->type == ISCSI_UEVENT_GET_STATS && !err)
2105 				break;
2106 			err = iscsi_if_send_reply(group, nlh->nlmsg_seq,
2107 				nlh->nlmsg_type, 0, 0, ev, sizeof(*ev));
2108 		} while (err < 0 && err != -ECONNREFUSED);
2109 		skb_pull(skb, rlen);
2110 	}
2111 	mutex_unlock(&rx_queue_mutex);
2112 }
2113 
2114 #define ISCSI_CLASS_ATTR(_prefix,_name,_mode,_show,_store)		\
2115 struct device_attribute dev_attr_##_prefix##_##_name =	\
2116 	__ATTR(_name,_mode,_show,_store)
2117 
2118 /*
2119  * iSCSI connection attrs
2120  */
2121 #define iscsi_conn_attr_show(param)					\
2122 static ssize_t								\
2123 show_conn_param_##param(struct device *dev, 				\
2124 			struct device_attribute *attr, char *buf)	\
2125 {									\
2126 	struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev->parent);	\
2127 	struct iscsi_transport *t = conn->transport;			\
2128 	return t->get_conn_param(conn, param, buf);			\
2129 }
2130 
2131 #define iscsi_conn_attr(field, param)					\
2132 	iscsi_conn_attr_show(param)					\
2133 static ISCSI_CLASS_ATTR(conn, field, S_IRUGO, show_conn_param_##param,	\
2134 			NULL);
2135 
2136 iscsi_conn_attr(max_recv_dlength, ISCSI_PARAM_MAX_RECV_DLENGTH);
2137 iscsi_conn_attr(max_xmit_dlength, ISCSI_PARAM_MAX_XMIT_DLENGTH);
2138 iscsi_conn_attr(header_digest, ISCSI_PARAM_HDRDGST_EN);
2139 iscsi_conn_attr(data_digest, ISCSI_PARAM_DATADGST_EN);
2140 iscsi_conn_attr(ifmarker, ISCSI_PARAM_IFMARKER_EN);
2141 iscsi_conn_attr(ofmarker, ISCSI_PARAM_OFMARKER_EN);
2142 iscsi_conn_attr(persistent_port, ISCSI_PARAM_PERSISTENT_PORT);
2143 iscsi_conn_attr(exp_statsn, ISCSI_PARAM_EXP_STATSN);
2144 iscsi_conn_attr(persistent_address, ISCSI_PARAM_PERSISTENT_ADDRESS);
2145 iscsi_conn_attr(ping_tmo, ISCSI_PARAM_PING_TMO);
2146 iscsi_conn_attr(recv_tmo, ISCSI_PARAM_RECV_TMO);
2147 
2148 #define iscsi_conn_ep_attr_show(param)					\
2149 static ssize_t show_conn_ep_param_##param(struct device *dev,		\
2150 					  struct device_attribute *attr,\
2151 					  char *buf)			\
2152 {									\
2153 	struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev->parent);	\
2154 	struct iscsi_transport *t = conn->transport;			\
2155 	struct iscsi_endpoint *ep;					\
2156 	ssize_t rc;							\
2157 									\
2158 	/*								\
2159 	 * Need to make sure ep_disconnect does not free the LLD's	\
2160 	 * interconnect resources while we are trying to read them.	\
2161 	 */								\
2162 	mutex_lock(&conn->ep_mutex);					\
2163 	ep = conn->ep;							\
2164 	if (!ep && t->ep_connect) {					\
2165 		mutex_unlock(&conn->ep_mutex);				\
2166 		return -ENOTCONN;					\
2167 	}								\
2168 									\
2169 	if (ep)								\
2170 		rc = t->get_ep_param(ep, param, buf);			\
2171 	else								\
2172 		rc = t->get_conn_param(conn, param, buf);		\
2173 	mutex_unlock(&conn->ep_mutex);					\
2174 	return rc;							\
2175 }
2176 
2177 #define iscsi_conn_ep_attr(field, param)				\
2178 	iscsi_conn_ep_attr_show(param)					\
2179 static ISCSI_CLASS_ATTR(conn, field, S_IRUGO,				\
2180 			show_conn_ep_param_##param, NULL);
2181 
2182 iscsi_conn_ep_attr(address, ISCSI_PARAM_CONN_ADDRESS);
2183 iscsi_conn_ep_attr(port, ISCSI_PARAM_CONN_PORT);
2184 
2185 static struct attribute *iscsi_conn_attrs[] = {
2186 	&dev_attr_conn_max_recv_dlength.attr,
2187 	&dev_attr_conn_max_xmit_dlength.attr,
2188 	&dev_attr_conn_header_digest.attr,
2189 	&dev_attr_conn_data_digest.attr,
2190 	&dev_attr_conn_ifmarker.attr,
2191 	&dev_attr_conn_ofmarker.attr,
2192 	&dev_attr_conn_address.attr,
2193 	&dev_attr_conn_port.attr,
2194 	&dev_attr_conn_exp_statsn.attr,
2195 	&dev_attr_conn_persistent_address.attr,
2196 	&dev_attr_conn_persistent_port.attr,
2197 	&dev_attr_conn_ping_tmo.attr,
2198 	&dev_attr_conn_recv_tmo.attr,
2199 	NULL,
2200 };
2201 
2202 static mode_t iscsi_conn_attr_is_visible(struct kobject *kobj,
2203 					 struct attribute *attr, int i)
2204 {
2205 	struct device *cdev = container_of(kobj, struct device, kobj);
2206 	struct iscsi_cls_conn *conn = transport_class_to_conn(cdev);
2207 	struct iscsi_transport *t = conn->transport;
2208 	int param;
2209 
2210 	if (attr == &dev_attr_conn_max_recv_dlength.attr)
2211 		param = ISCSI_PARAM_MAX_RECV_DLENGTH;
2212 	else if (attr == &dev_attr_conn_max_xmit_dlength.attr)
2213 		param = ISCSI_PARAM_MAX_XMIT_DLENGTH;
2214 	else if (attr == &dev_attr_conn_header_digest.attr)
2215 		param = ISCSI_PARAM_HDRDGST_EN;
2216 	else if (attr == &dev_attr_conn_data_digest.attr)
2217 		param = ISCSI_PARAM_DATADGST_EN;
2218 	else if (attr == &dev_attr_conn_ifmarker.attr)
2219 		param = ISCSI_PARAM_IFMARKER_EN;
2220 	else if (attr == &dev_attr_conn_ofmarker.attr)
2221 		param = ISCSI_PARAM_OFMARKER_EN;
2222 	else if (attr == &dev_attr_conn_address.attr)
2223 		param = ISCSI_PARAM_CONN_ADDRESS;
2224 	else if (attr == &dev_attr_conn_port.attr)
2225 		param = ISCSI_PARAM_CONN_PORT;
2226 	else if (attr == &dev_attr_conn_exp_statsn.attr)
2227 		param = ISCSI_PARAM_EXP_STATSN;
2228 	else if (attr == &dev_attr_conn_persistent_address.attr)
2229 		param = ISCSI_PARAM_PERSISTENT_ADDRESS;
2230 	else if (attr == &dev_attr_conn_persistent_port.attr)
2231 		param = ISCSI_PARAM_PERSISTENT_PORT;
2232 	else if (attr == &dev_attr_conn_ping_tmo.attr)
2233 		param = ISCSI_PARAM_PING_TMO;
2234 	else if (attr == &dev_attr_conn_recv_tmo.attr)
2235 		param = ISCSI_PARAM_RECV_TMO;
2236 	else {
2237 		WARN_ONCE(1, "Invalid conn attr");
2238 		return 0;
2239 	}
2240 
2241 	return t->attr_is_visible(ISCSI_PARAM, param);
2242 }
2243 
2244 static struct attribute_group iscsi_conn_group = {
2245 	.attrs = iscsi_conn_attrs,
2246 	.is_visible = iscsi_conn_attr_is_visible,
2247 };
2248 
2249 /*
2250  * iSCSI session attrs
2251  */
2252 #define iscsi_session_attr_show(param, perm)				\
2253 static ssize_t								\
2254 show_session_param_##param(struct device *dev,				\
2255 			   struct device_attribute *attr, char *buf)	\
2256 {									\
2257 	struct iscsi_cls_session *session = 				\
2258 		iscsi_dev_to_session(dev->parent);			\
2259 	struct iscsi_transport *t = session->transport;			\
2260 									\
2261 	if (perm && !capable(CAP_SYS_ADMIN))				\
2262 		return -EACCES;						\
2263 	return t->get_session_param(session, param, buf);		\
2264 }
2265 
2266 #define iscsi_session_attr(field, param, perm)				\
2267 	iscsi_session_attr_show(param, perm)				\
2268 static ISCSI_CLASS_ATTR(sess, field, S_IRUGO, show_session_param_##param, \
2269 			NULL);
2270 iscsi_session_attr(targetname, ISCSI_PARAM_TARGET_NAME, 0);
2271 iscsi_session_attr(initial_r2t, ISCSI_PARAM_INITIAL_R2T_EN, 0);
2272 iscsi_session_attr(max_outstanding_r2t, ISCSI_PARAM_MAX_R2T, 0);
2273 iscsi_session_attr(immediate_data, ISCSI_PARAM_IMM_DATA_EN, 0);
2274 iscsi_session_attr(first_burst_len, ISCSI_PARAM_FIRST_BURST, 0);
2275 iscsi_session_attr(max_burst_len, ISCSI_PARAM_MAX_BURST, 0);
2276 iscsi_session_attr(data_pdu_in_order, ISCSI_PARAM_PDU_INORDER_EN, 0);
2277 iscsi_session_attr(data_seq_in_order, ISCSI_PARAM_DATASEQ_INORDER_EN, 0);
2278 iscsi_session_attr(erl, ISCSI_PARAM_ERL, 0);
2279 iscsi_session_attr(tpgt, ISCSI_PARAM_TPGT, 0);
2280 iscsi_session_attr(username, ISCSI_PARAM_USERNAME, 1);
2281 iscsi_session_attr(username_in, ISCSI_PARAM_USERNAME_IN, 1);
2282 iscsi_session_attr(password, ISCSI_PARAM_PASSWORD, 1);
2283 iscsi_session_attr(password_in, ISCSI_PARAM_PASSWORD_IN, 1);
2284 iscsi_session_attr(fast_abort, ISCSI_PARAM_FAST_ABORT, 0);
2285 iscsi_session_attr(abort_tmo, ISCSI_PARAM_ABORT_TMO, 0);
2286 iscsi_session_attr(lu_reset_tmo, ISCSI_PARAM_LU_RESET_TMO, 0);
2287 iscsi_session_attr(tgt_reset_tmo, ISCSI_PARAM_TGT_RESET_TMO, 0);
2288 iscsi_session_attr(ifacename, ISCSI_PARAM_IFACE_NAME, 0);
2289 iscsi_session_attr(initiatorname, ISCSI_PARAM_INITIATOR_NAME, 0);
2290 iscsi_session_attr(targetalias, ISCSI_PARAM_TARGET_ALIAS, 0);
2291 
2292 static ssize_t
2293 show_priv_session_state(struct device *dev, struct device_attribute *attr,
2294 			char *buf)
2295 {
2296 	struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
2297 	return sprintf(buf, "%s\n", iscsi_session_state_name(session->state));
2298 }
2299 static ISCSI_CLASS_ATTR(priv_sess, state, S_IRUGO, show_priv_session_state,
2300 			NULL);
2301 
2302 #define iscsi_priv_session_attr_show(field, format)			\
2303 static ssize_t								\
2304 show_priv_session_##field(struct device *dev, 				\
2305 			  struct device_attribute *attr, char *buf)	\
2306 {									\
2307 	struct iscsi_cls_session *session = 				\
2308 			iscsi_dev_to_session(dev->parent);		\
2309 	if (session->field == -1)					\
2310 		return sprintf(buf, "off\n");				\
2311 	return sprintf(buf, format"\n", session->field);		\
2312 }
2313 
2314 #define iscsi_priv_session_attr_store(field)				\
2315 static ssize_t								\
2316 store_priv_session_##field(struct device *dev,				\
2317 			   struct device_attribute *attr,		\
2318 			   const char *buf, size_t count)		\
2319 {									\
2320 	int val;							\
2321 	char *cp;							\
2322 	struct iscsi_cls_session *session =				\
2323 		iscsi_dev_to_session(dev->parent);			\
2324 	if ((session->state == ISCSI_SESSION_FREE) ||			\
2325 	    (session->state == ISCSI_SESSION_FAILED))			\
2326 		return -EBUSY;						\
2327 	if (strncmp(buf, "off", 3) == 0)				\
2328 		session->field = -1;					\
2329 	else {								\
2330 		val = simple_strtoul(buf, &cp, 0);			\
2331 		if (*cp != '\0' && *cp != '\n')				\
2332 			return -EINVAL;					\
2333 		session->field = val;					\
2334 	}								\
2335 	return count;							\
2336 }
2337 
2338 #define iscsi_priv_session_rw_attr(field, format)			\
2339 	iscsi_priv_session_attr_show(field, format)			\
2340 	iscsi_priv_session_attr_store(field)				\
2341 static ISCSI_CLASS_ATTR(priv_sess, field, S_IRUGO | S_IWUSR,		\
2342 			show_priv_session_##field,			\
2343 			store_priv_session_##field)
2344 iscsi_priv_session_rw_attr(recovery_tmo, "%d");
2345 
2346 static struct attribute *iscsi_session_attrs[] = {
2347 	&dev_attr_sess_initial_r2t.attr,
2348 	&dev_attr_sess_max_outstanding_r2t.attr,
2349 	&dev_attr_sess_immediate_data.attr,
2350 	&dev_attr_sess_first_burst_len.attr,
2351 	&dev_attr_sess_max_burst_len.attr,
2352 	&dev_attr_sess_data_pdu_in_order.attr,
2353 	&dev_attr_sess_data_seq_in_order.attr,
2354 	&dev_attr_sess_erl.attr,
2355 	&dev_attr_sess_targetname.attr,
2356 	&dev_attr_sess_tpgt.attr,
2357 	&dev_attr_sess_password.attr,
2358 	&dev_attr_sess_password_in.attr,
2359 	&dev_attr_sess_username.attr,
2360 	&dev_attr_sess_username_in.attr,
2361 	&dev_attr_sess_fast_abort.attr,
2362 	&dev_attr_sess_abort_tmo.attr,
2363 	&dev_attr_sess_lu_reset_tmo.attr,
2364 	&dev_attr_sess_tgt_reset_tmo.attr,
2365 	&dev_attr_sess_ifacename.attr,
2366 	&dev_attr_sess_initiatorname.attr,
2367 	&dev_attr_sess_targetalias.attr,
2368 	&dev_attr_priv_sess_recovery_tmo.attr,
2369 	&dev_attr_priv_sess_state.attr,
2370 	NULL,
2371 };
2372 
2373 static mode_t iscsi_session_attr_is_visible(struct kobject *kobj,
2374 					    struct attribute *attr, int i)
2375 {
2376 	struct device *cdev = container_of(kobj, struct device, kobj);
2377 	struct iscsi_cls_session *session = transport_class_to_session(cdev);
2378 	struct iscsi_transport *t = session->transport;
2379 	int param;
2380 
2381 	if (attr == &dev_attr_sess_initial_r2t.attr)
2382 		param = ISCSI_PARAM_INITIAL_R2T_EN;
2383 	else if (attr == &dev_attr_sess_max_outstanding_r2t.attr)
2384 		param = ISCSI_PARAM_MAX_R2T;
2385 	else if (attr == &dev_attr_sess_immediate_data.attr)
2386 		param = ISCSI_PARAM_IMM_DATA_EN;
2387 	else if (attr == &dev_attr_sess_first_burst_len.attr)
2388 		param = ISCSI_PARAM_FIRST_BURST;
2389 	else if (attr == &dev_attr_sess_max_burst_len.attr)
2390 		param = ISCSI_PARAM_MAX_BURST;
2391 	else if (attr == &dev_attr_sess_data_pdu_in_order.attr)
2392 		param = ISCSI_PARAM_PDU_INORDER_EN;
2393 	else if (attr == &dev_attr_sess_data_seq_in_order.attr)
2394 		param = ISCSI_PARAM_DATASEQ_INORDER_EN;
2395 	else if (attr == &dev_attr_sess_erl.attr)
2396 		param = ISCSI_PARAM_ERL;
2397 	else if (attr == &dev_attr_sess_targetname.attr)
2398 		param = ISCSI_PARAM_TARGET_NAME;
2399 	else if (attr == &dev_attr_sess_tpgt.attr)
2400 		param = ISCSI_PARAM_TPGT;
2401 	else if (attr == &dev_attr_sess_password.attr)
2402 		param = ISCSI_PARAM_USERNAME;
2403 	else if (attr == &dev_attr_sess_password_in.attr)
2404 		param = ISCSI_PARAM_USERNAME_IN;
2405 	else if (attr == &dev_attr_sess_username.attr)
2406 		param = ISCSI_PARAM_PASSWORD;
2407 	else if (attr == &dev_attr_sess_username_in.attr)
2408 		param = ISCSI_PARAM_PASSWORD_IN;
2409 	else if (attr == &dev_attr_sess_fast_abort.attr)
2410 		param = ISCSI_PARAM_FAST_ABORT;
2411 	else if (attr == &dev_attr_sess_abort_tmo.attr)
2412 		param = ISCSI_PARAM_ABORT_TMO;
2413 	else if (attr == &dev_attr_sess_lu_reset_tmo.attr)
2414 		param = ISCSI_PARAM_LU_RESET_TMO;
2415 	else if (attr == &dev_attr_sess_tgt_reset_tmo.attr)
2416 		param = ISCSI_PARAM_TGT_RESET_TMO;
2417 	else if (attr == &dev_attr_sess_ifacename.attr)
2418 		param = ISCSI_PARAM_IFACE_NAME;
2419 	else if (attr == &dev_attr_sess_initiatorname.attr)
2420 		param = ISCSI_PARAM_INITIATOR_NAME;
2421 	else if (attr == &dev_attr_sess_targetalias.attr)
2422 		param = ISCSI_PARAM_TARGET_ALIAS;
2423 	else if (attr == &dev_attr_priv_sess_recovery_tmo.attr)
2424 		return S_IRUGO | S_IWUSR;
2425 	else if (attr == &dev_attr_priv_sess_state.attr)
2426 		return S_IRUGO;
2427 	else {
2428 		WARN_ONCE(1, "Invalid session attr");
2429 		return 0;
2430 	}
2431 
2432 	return t->attr_is_visible(ISCSI_PARAM, param);
2433 }
2434 
2435 static struct attribute_group iscsi_session_group = {
2436 	.attrs = iscsi_session_attrs,
2437 	.is_visible = iscsi_session_attr_is_visible,
2438 };
2439 
2440 /*
2441  * iSCSI host attrs
2442  */
2443 #define iscsi_host_attr_show(param)					\
2444 static ssize_t								\
2445 show_host_param_##param(struct device *dev, 				\
2446 			struct device_attribute *attr, char *buf)	\
2447 {									\
2448 	struct Scsi_Host *shost = transport_class_to_shost(dev);	\
2449 	struct iscsi_internal *priv = to_iscsi_internal(shost->transportt); \
2450 	return priv->iscsi_transport->get_host_param(shost, param, buf); \
2451 }
2452 
2453 #define iscsi_host_attr(field, param)					\
2454 	iscsi_host_attr_show(param)					\
2455 static ISCSI_CLASS_ATTR(host, field, S_IRUGO, show_host_param_##param,	\
2456 			NULL);
2457 
2458 iscsi_host_attr(netdev, ISCSI_HOST_PARAM_NETDEV_NAME);
2459 iscsi_host_attr(hwaddress, ISCSI_HOST_PARAM_HWADDRESS);
2460 iscsi_host_attr(ipaddress, ISCSI_HOST_PARAM_IPADDRESS);
2461 iscsi_host_attr(initiatorname, ISCSI_HOST_PARAM_INITIATOR_NAME);
2462 
2463 static struct attribute *iscsi_host_attrs[] = {
2464 	&dev_attr_host_netdev.attr,
2465 	&dev_attr_host_hwaddress.attr,
2466 	&dev_attr_host_ipaddress.attr,
2467 	&dev_attr_host_initiatorname.attr,
2468 	NULL,
2469 };
2470 
2471 static mode_t iscsi_host_attr_is_visible(struct kobject *kobj,
2472 					 struct attribute *attr, int i)
2473 {
2474 	struct device *cdev = container_of(kobj, struct device, kobj);
2475 	struct Scsi_Host *shost = transport_class_to_shost(cdev);
2476 	struct iscsi_internal *priv = to_iscsi_internal(shost->transportt);
2477 	int param;
2478 
2479 	if (attr == &dev_attr_host_netdev.attr)
2480 		param = ISCSI_HOST_PARAM_NETDEV_NAME;
2481 	else if (attr == &dev_attr_host_hwaddress.attr)
2482 		param = ISCSI_HOST_PARAM_HWADDRESS;
2483 	else if (attr == &dev_attr_host_ipaddress.attr)
2484 		param = ISCSI_HOST_PARAM_IPADDRESS;
2485 	else if (attr == &dev_attr_host_initiatorname.attr)
2486 		param = ISCSI_HOST_PARAM_INITIATOR_NAME;
2487 	else {
2488 		WARN_ONCE(1, "Invalid host attr");
2489 		return 0;
2490 	}
2491 
2492 	return priv->iscsi_transport->attr_is_visible(ISCSI_HOST_PARAM, param);
2493 }
2494 
2495 static struct attribute_group iscsi_host_group = {
2496 	.attrs = iscsi_host_attrs,
2497 	.is_visible = iscsi_host_attr_is_visible,
2498 };
2499 
2500 static int iscsi_session_match(struct attribute_container *cont,
2501 			   struct device *dev)
2502 {
2503 	struct iscsi_cls_session *session;
2504 	struct Scsi_Host *shost;
2505 	struct iscsi_internal *priv;
2506 
2507 	if (!iscsi_is_session_dev(dev))
2508 		return 0;
2509 
2510 	session = iscsi_dev_to_session(dev);
2511 	shost = iscsi_session_to_shost(session);
2512 	if (!shost->transportt)
2513 		return 0;
2514 
2515 	priv = to_iscsi_internal(shost->transportt);
2516 	if (priv->session_cont.ac.class != &iscsi_session_class.class)
2517 		return 0;
2518 
2519 	return &priv->session_cont.ac == cont;
2520 }
2521 
2522 static int iscsi_conn_match(struct attribute_container *cont,
2523 			   struct device *dev)
2524 {
2525 	struct iscsi_cls_session *session;
2526 	struct iscsi_cls_conn *conn;
2527 	struct Scsi_Host *shost;
2528 	struct iscsi_internal *priv;
2529 
2530 	if (!iscsi_is_conn_dev(dev))
2531 		return 0;
2532 
2533 	conn = iscsi_dev_to_conn(dev);
2534 	session = iscsi_dev_to_session(conn->dev.parent);
2535 	shost = iscsi_session_to_shost(session);
2536 
2537 	if (!shost->transportt)
2538 		return 0;
2539 
2540 	priv = to_iscsi_internal(shost->transportt);
2541 	if (priv->conn_cont.ac.class != &iscsi_connection_class.class)
2542 		return 0;
2543 
2544 	return &priv->conn_cont.ac == cont;
2545 }
2546 
2547 static int iscsi_host_match(struct attribute_container *cont,
2548 			    struct device *dev)
2549 {
2550 	struct Scsi_Host *shost;
2551 	struct iscsi_internal *priv;
2552 
2553 	if (!scsi_is_host_device(dev))
2554 		return 0;
2555 
2556 	shost = dev_to_shost(dev);
2557 	if (!shost->transportt  ||
2558 	    shost->transportt->host_attrs.ac.class != &iscsi_host_class.class)
2559 		return 0;
2560 
2561         priv = to_iscsi_internal(shost->transportt);
2562         return &priv->t.host_attrs.ac == cont;
2563 }
2564 
2565 struct scsi_transport_template *
2566 iscsi_register_transport(struct iscsi_transport *tt)
2567 {
2568 	struct iscsi_internal *priv;
2569 	unsigned long flags;
2570 	int err;
2571 
2572 	BUG_ON(!tt);
2573 
2574 	priv = iscsi_if_transport_lookup(tt);
2575 	if (priv)
2576 		return NULL;
2577 
2578 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
2579 	if (!priv)
2580 		return NULL;
2581 	INIT_LIST_HEAD(&priv->list);
2582 	priv->iscsi_transport = tt;
2583 	priv->t.user_scan = iscsi_user_scan;
2584 	priv->t.create_work_queue = 1;
2585 
2586 	priv->dev.class = &iscsi_transport_class;
2587 	dev_set_name(&priv->dev, "%s", tt->name);
2588 	err = device_register(&priv->dev);
2589 	if (err)
2590 		goto free_priv;
2591 
2592 	err = sysfs_create_group(&priv->dev.kobj, &iscsi_transport_group);
2593 	if (err)
2594 		goto unregister_dev;
2595 
2596 	/* host parameters */
2597 	priv->t.host_attrs.ac.class = &iscsi_host_class.class;
2598 	priv->t.host_attrs.ac.match = iscsi_host_match;
2599 	priv->t.host_attrs.ac.grp = &iscsi_host_group;
2600 	priv->t.host_size = sizeof(struct iscsi_cls_host);
2601 	transport_container_register(&priv->t.host_attrs);
2602 
2603 	/* connection parameters */
2604 	priv->conn_cont.ac.class = &iscsi_connection_class.class;
2605 	priv->conn_cont.ac.match = iscsi_conn_match;
2606 	priv->conn_cont.ac.grp = &iscsi_conn_group;
2607 	transport_container_register(&priv->conn_cont);
2608 
2609 	/* session parameters */
2610 	priv->session_cont.ac.class = &iscsi_session_class.class;
2611 	priv->session_cont.ac.match = iscsi_session_match;
2612 	priv->session_cont.ac.grp = &iscsi_session_group;
2613 	transport_container_register(&priv->session_cont);
2614 
2615 	spin_lock_irqsave(&iscsi_transport_lock, flags);
2616 	list_add(&priv->list, &iscsi_transports);
2617 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
2618 
2619 	printk(KERN_NOTICE "iscsi: registered transport (%s)\n", tt->name);
2620 	return &priv->t;
2621 
2622 unregister_dev:
2623 	device_unregister(&priv->dev);
2624 	return NULL;
2625 free_priv:
2626 	kfree(priv);
2627 	return NULL;
2628 }
2629 EXPORT_SYMBOL_GPL(iscsi_register_transport);
2630 
2631 int iscsi_unregister_transport(struct iscsi_transport *tt)
2632 {
2633 	struct iscsi_internal *priv;
2634 	unsigned long flags;
2635 
2636 	BUG_ON(!tt);
2637 
2638 	mutex_lock(&rx_queue_mutex);
2639 
2640 	priv = iscsi_if_transport_lookup(tt);
2641 	BUG_ON (!priv);
2642 
2643 	spin_lock_irqsave(&iscsi_transport_lock, flags);
2644 	list_del(&priv->list);
2645 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
2646 
2647 	transport_container_unregister(&priv->conn_cont);
2648 	transport_container_unregister(&priv->session_cont);
2649 	transport_container_unregister(&priv->t.host_attrs);
2650 
2651 	sysfs_remove_group(&priv->dev.kobj, &iscsi_transport_group);
2652 	device_unregister(&priv->dev);
2653 	mutex_unlock(&rx_queue_mutex);
2654 
2655 	return 0;
2656 }
2657 EXPORT_SYMBOL_GPL(iscsi_unregister_transport);
2658 
2659 static __init int iscsi_transport_init(void)
2660 {
2661 	int err;
2662 
2663 	printk(KERN_INFO "Loading iSCSI transport class v%s.\n",
2664 		ISCSI_TRANSPORT_VERSION);
2665 
2666 	atomic_set(&iscsi_session_nr, 0);
2667 
2668 	err = class_register(&iscsi_transport_class);
2669 	if (err)
2670 		return err;
2671 
2672 	err = class_register(&iscsi_endpoint_class);
2673 	if (err)
2674 		goto unregister_transport_class;
2675 
2676 	err = class_register(&iscsi_iface_class);
2677 	if (err)
2678 		goto unregister_endpoint_class;
2679 
2680 	err = transport_class_register(&iscsi_host_class);
2681 	if (err)
2682 		goto unregister_iface_class;
2683 
2684 	err = transport_class_register(&iscsi_connection_class);
2685 	if (err)
2686 		goto unregister_host_class;
2687 
2688 	err = transport_class_register(&iscsi_session_class);
2689 	if (err)
2690 		goto unregister_conn_class;
2691 
2692 	nls = netlink_kernel_create(&init_net, NETLINK_ISCSI, 1, iscsi_if_rx,
2693 				    NULL, THIS_MODULE);
2694 	if (!nls) {
2695 		err = -ENOBUFS;
2696 		goto unregister_session_class;
2697 	}
2698 
2699 	iscsi_eh_timer_workq = create_singlethread_workqueue("iscsi_eh");
2700 	if (!iscsi_eh_timer_workq)
2701 		goto release_nls;
2702 
2703 	return 0;
2704 
2705 release_nls:
2706 	netlink_kernel_release(nls);
2707 unregister_session_class:
2708 	transport_class_unregister(&iscsi_session_class);
2709 unregister_conn_class:
2710 	transport_class_unregister(&iscsi_connection_class);
2711 unregister_host_class:
2712 	transport_class_unregister(&iscsi_host_class);
2713 unregister_iface_class:
2714 	class_unregister(&iscsi_iface_class);
2715 unregister_endpoint_class:
2716 	class_unregister(&iscsi_endpoint_class);
2717 unregister_transport_class:
2718 	class_unregister(&iscsi_transport_class);
2719 	return err;
2720 }
2721 
2722 static void __exit iscsi_transport_exit(void)
2723 {
2724 	destroy_workqueue(iscsi_eh_timer_workq);
2725 	netlink_kernel_release(nls);
2726 	transport_class_unregister(&iscsi_connection_class);
2727 	transport_class_unregister(&iscsi_session_class);
2728 	transport_class_unregister(&iscsi_host_class);
2729 	class_unregister(&iscsi_endpoint_class);
2730 	class_unregister(&iscsi_iface_class);
2731 	class_unregister(&iscsi_transport_class);
2732 }
2733 
2734 module_init(iscsi_transport_init);
2735 module_exit(iscsi_transport_exit);
2736 
2737 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
2738 	      "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
2739 	      "Alex Aizman <itn780@yahoo.com>");
2740 MODULE_DESCRIPTION("iSCSI Transport Interface");
2741 MODULE_LICENSE("GPL");
2742 MODULE_VERSION(ISCSI_TRANSPORT_VERSION);
2743 MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_ISCSI);
2744