xref: /linux/drivers/scsi/scsi_transport_iscsi.c (revision b43ab901d671e3e3cad425ea5e9a3c74e266dcdd)
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 umode_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->creator = -1;
1034 	session->recovery_tmo = 120;
1035 	session->state = ISCSI_SESSION_FREE;
1036 	INIT_DELAYED_WORK(&session->recovery_work, session_recovery_timedout);
1037 	INIT_LIST_HEAD(&session->sess_list);
1038 	INIT_WORK(&session->unblock_work, __iscsi_unblock_session);
1039 	INIT_WORK(&session->block_work, __iscsi_block_session);
1040 	INIT_WORK(&session->unbind_work, __iscsi_unbind_session);
1041 	INIT_WORK(&session->scan_work, iscsi_scan_session);
1042 	spin_lock_init(&session->lock);
1043 
1044 	/* this is released in the dev's release function */
1045 	scsi_host_get(shost);
1046 	session->dev.parent = &shost->shost_gendev;
1047 	session->dev.release = iscsi_session_release;
1048 	device_initialize(&session->dev);
1049 	if (dd_size)
1050 		session->dd_data = &session[1];
1051 
1052 	ISCSI_DBG_TRANS_SESSION(session, "Completed session allocation\n");
1053 	return session;
1054 }
1055 EXPORT_SYMBOL_GPL(iscsi_alloc_session);
1056 
1057 int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
1058 {
1059 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
1060 	struct iscsi_cls_host *ihost;
1061 	unsigned long flags;
1062 	int id = 0;
1063 	int err;
1064 
1065 	ihost = shost->shost_data;
1066 	session->sid = atomic_add_return(1, &iscsi_session_nr);
1067 
1068 	if (target_id == ISCSI_MAX_TARGET) {
1069 		id = ida_simple_get(&iscsi_sess_ida, 0, 0, GFP_KERNEL);
1070 
1071 		if (id < 0) {
1072 			iscsi_cls_session_printk(KERN_ERR, session,
1073 					"Failure in Target ID Allocation\n");
1074 			return id;
1075 		}
1076 		session->target_id = (unsigned int)id;
1077 		session->ida_used = true;
1078 	} else
1079 		session->target_id = target_id;
1080 
1081 	dev_set_name(&session->dev, "session%u", session->sid);
1082 	err = device_add(&session->dev);
1083 	if (err) {
1084 		iscsi_cls_session_printk(KERN_ERR, session,
1085 					 "could not register session's dev\n");
1086 		goto release_ida;
1087 	}
1088 	transport_register_device(&session->dev);
1089 
1090 	spin_lock_irqsave(&sesslock, flags);
1091 	list_add(&session->sess_list, &sesslist);
1092 	spin_unlock_irqrestore(&sesslock, flags);
1093 
1094 	iscsi_session_event(session, ISCSI_KEVENT_CREATE_SESSION);
1095 	ISCSI_DBG_TRANS_SESSION(session, "Completed session adding\n");
1096 	return 0;
1097 
1098 release_ida:
1099 	if (session->ida_used)
1100 		ida_simple_remove(&iscsi_sess_ida, session->target_id);
1101 
1102 	return err;
1103 }
1104 EXPORT_SYMBOL_GPL(iscsi_add_session);
1105 
1106 /**
1107  * iscsi_create_session - create iscsi class session
1108  * @shost: scsi host
1109  * @transport: iscsi transport
1110  * @dd_size: private driver data size
1111  * @target_id: which target
1112  *
1113  * This can be called from a LLD or iscsi_transport.
1114  */
1115 struct iscsi_cls_session *
1116 iscsi_create_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
1117 		     int dd_size, unsigned int target_id)
1118 {
1119 	struct iscsi_cls_session *session;
1120 
1121 	session = iscsi_alloc_session(shost, transport, dd_size);
1122 	if (!session)
1123 		return NULL;
1124 
1125 	if (iscsi_add_session(session, target_id)) {
1126 		iscsi_free_session(session);
1127 		return NULL;
1128 	}
1129 	return session;
1130 }
1131 EXPORT_SYMBOL_GPL(iscsi_create_session);
1132 
1133 static void iscsi_conn_release(struct device *dev)
1134 {
1135 	struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev);
1136 	struct device *parent = conn->dev.parent;
1137 
1138 	ISCSI_DBG_TRANS_CONN(conn, "Releasing conn\n");
1139 	kfree(conn);
1140 	put_device(parent);
1141 }
1142 
1143 static int iscsi_is_conn_dev(const struct device *dev)
1144 {
1145 	return dev->release == iscsi_conn_release;
1146 }
1147 
1148 static int iscsi_iter_destroy_conn_fn(struct device *dev, void *data)
1149 {
1150 	if (!iscsi_is_conn_dev(dev))
1151 		return 0;
1152 	return iscsi_destroy_conn(iscsi_dev_to_conn(dev));
1153 }
1154 
1155 void iscsi_remove_session(struct iscsi_cls_session *session)
1156 {
1157 	struct Scsi_Host *shost = iscsi_session_to_shost(session);
1158 	unsigned long flags;
1159 	int err;
1160 
1161 	ISCSI_DBG_TRANS_SESSION(session, "Removing session\n");
1162 
1163 	spin_lock_irqsave(&sesslock, flags);
1164 	list_del(&session->sess_list);
1165 	spin_unlock_irqrestore(&sesslock, flags);
1166 
1167 	/* make sure there are no blocks/unblocks queued */
1168 	flush_workqueue(iscsi_eh_timer_workq);
1169 	/* make sure the timedout callout is not running */
1170 	if (!cancel_delayed_work(&session->recovery_work))
1171 		flush_workqueue(iscsi_eh_timer_workq);
1172 	/*
1173 	 * If we are blocked let commands flow again. The lld or iscsi
1174 	 * layer should set up the queuecommand to fail commands.
1175 	 * We assume that LLD will not be calling block/unblock while
1176 	 * removing the session.
1177 	 */
1178 	spin_lock_irqsave(&session->lock, flags);
1179 	session->state = ISCSI_SESSION_FREE;
1180 	spin_unlock_irqrestore(&session->lock, flags);
1181 
1182 	scsi_target_unblock(&session->dev);
1183 	/* flush running scans then delete devices */
1184 	scsi_flush_work(shost);
1185 	__iscsi_unbind_session(&session->unbind_work);
1186 
1187 	/* hw iscsi may not have removed all connections from session */
1188 	err = device_for_each_child(&session->dev, NULL,
1189 				    iscsi_iter_destroy_conn_fn);
1190 	if (err)
1191 		iscsi_cls_session_printk(KERN_ERR, session,
1192 					 "Could not delete all connections "
1193 					 "for session. Error %d.\n", err);
1194 
1195 	transport_unregister_device(&session->dev);
1196 
1197 	ISCSI_DBG_TRANS_SESSION(session, "Completing session removal\n");
1198 	device_del(&session->dev);
1199 }
1200 EXPORT_SYMBOL_GPL(iscsi_remove_session);
1201 
1202 void iscsi_free_session(struct iscsi_cls_session *session)
1203 {
1204 	ISCSI_DBG_TRANS_SESSION(session, "Freeing session\n");
1205 	iscsi_session_event(session, ISCSI_KEVENT_DESTROY_SESSION);
1206 	put_device(&session->dev);
1207 }
1208 EXPORT_SYMBOL_GPL(iscsi_free_session);
1209 
1210 /**
1211  * iscsi_destroy_session - destroy iscsi session
1212  * @session: iscsi_session
1213  *
1214  * Can be called by a LLD or iscsi_transport. There must not be
1215  * any running connections.
1216  */
1217 int iscsi_destroy_session(struct iscsi_cls_session *session)
1218 {
1219 	iscsi_remove_session(session);
1220 	ISCSI_DBG_TRANS_SESSION(session, "Completing session destruction\n");
1221 	iscsi_free_session(session);
1222 	return 0;
1223 }
1224 EXPORT_SYMBOL_GPL(iscsi_destroy_session);
1225 
1226 /**
1227  * iscsi_create_conn - create iscsi class connection
1228  * @session: iscsi cls session
1229  * @dd_size: private driver data size
1230  * @cid: connection id
1231  *
1232  * This can be called from a LLD or iscsi_transport. The connection
1233  * is child of the session so cid must be unique for all connections
1234  * on the session.
1235  *
1236  * Since we do not support MCS, cid will normally be zero. In some cases
1237  * for software iscsi we could be trying to preallocate a connection struct
1238  * in which case there could be two connection structs and cid would be
1239  * non-zero.
1240  */
1241 struct iscsi_cls_conn *
1242 iscsi_create_conn(struct iscsi_cls_session *session, int dd_size, uint32_t cid)
1243 {
1244 	struct iscsi_transport *transport = session->transport;
1245 	struct iscsi_cls_conn *conn;
1246 	unsigned long flags;
1247 	int err;
1248 
1249 	conn = kzalloc(sizeof(*conn) + dd_size, GFP_KERNEL);
1250 	if (!conn)
1251 		return NULL;
1252 	if (dd_size)
1253 		conn->dd_data = &conn[1];
1254 
1255 	mutex_init(&conn->ep_mutex);
1256 	INIT_LIST_HEAD(&conn->conn_list);
1257 	conn->transport = transport;
1258 	conn->cid = cid;
1259 
1260 	/* this is released in the dev's release function */
1261 	if (!get_device(&session->dev))
1262 		goto free_conn;
1263 
1264 	dev_set_name(&conn->dev, "connection%d:%u", session->sid, cid);
1265 	conn->dev.parent = &session->dev;
1266 	conn->dev.release = iscsi_conn_release;
1267 	err = device_register(&conn->dev);
1268 	if (err) {
1269 		iscsi_cls_session_printk(KERN_ERR, session, "could not "
1270 					 "register connection's dev\n");
1271 		goto release_parent_ref;
1272 	}
1273 	transport_register_device(&conn->dev);
1274 
1275 	spin_lock_irqsave(&connlock, flags);
1276 	list_add(&conn->conn_list, &connlist);
1277 	spin_unlock_irqrestore(&connlock, flags);
1278 
1279 	ISCSI_DBG_TRANS_CONN(conn, "Completed conn creation\n");
1280 	return conn;
1281 
1282 release_parent_ref:
1283 	put_device(&session->dev);
1284 free_conn:
1285 	kfree(conn);
1286 	return NULL;
1287 }
1288 
1289 EXPORT_SYMBOL_GPL(iscsi_create_conn);
1290 
1291 /**
1292  * iscsi_destroy_conn - destroy iscsi class connection
1293  * @conn: iscsi cls session
1294  *
1295  * This can be called from a LLD or iscsi_transport.
1296  */
1297 int iscsi_destroy_conn(struct iscsi_cls_conn *conn)
1298 {
1299 	unsigned long flags;
1300 
1301 	spin_lock_irqsave(&connlock, flags);
1302 	list_del(&conn->conn_list);
1303 	spin_unlock_irqrestore(&connlock, flags);
1304 
1305 	transport_unregister_device(&conn->dev);
1306 	ISCSI_DBG_TRANS_CONN(conn, "Completing conn destruction\n");
1307 	device_unregister(&conn->dev);
1308 	return 0;
1309 }
1310 EXPORT_SYMBOL_GPL(iscsi_destroy_conn);
1311 
1312 /*
1313  * iscsi interface functions
1314  */
1315 static struct iscsi_internal *
1316 iscsi_if_transport_lookup(struct iscsi_transport *tt)
1317 {
1318 	struct iscsi_internal *priv;
1319 	unsigned long flags;
1320 
1321 	spin_lock_irqsave(&iscsi_transport_lock, flags);
1322 	list_for_each_entry(priv, &iscsi_transports, list) {
1323 		if (tt == priv->iscsi_transport) {
1324 			spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1325 			return priv;
1326 		}
1327 	}
1328 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
1329 	return NULL;
1330 }
1331 
1332 static int
1333 iscsi_multicast_skb(struct sk_buff *skb, uint32_t group, gfp_t gfp)
1334 {
1335 	return nlmsg_multicast(nls, skb, 0, group, gfp);
1336 }
1337 
1338 int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
1339 		   char *data, uint32_t data_size)
1340 {
1341 	struct nlmsghdr	*nlh;
1342 	struct sk_buff *skb;
1343 	struct iscsi_uevent *ev;
1344 	char *pdu;
1345 	struct iscsi_internal *priv;
1346 	int len = NLMSG_SPACE(sizeof(*ev) + sizeof(struct iscsi_hdr) +
1347 			      data_size);
1348 
1349 	priv = iscsi_if_transport_lookup(conn->transport);
1350 	if (!priv)
1351 		return -EINVAL;
1352 
1353 	skb = alloc_skb(len, GFP_ATOMIC);
1354 	if (!skb) {
1355 		iscsi_conn_error_event(conn, ISCSI_ERR_CONN_FAILED);
1356 		iscsi_cls_conn_printk(KERN_ERR, conn, "can not deliver "
1357 				      "control PDU: OOM\n");
1358 		return -ENOMEM;
1359 	}
1360 
1361 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1362 	ev = NLMSG_DATA(nlh);
1363 	memset(ev, 0, sizeof(*ev));
1364 	ev->transport_handle = iscsi_handle(conn->transport);
1365 	ev->type = ISCSI_KEVENT_RECV_PDU;
1366 	ev->r.recv_req.cid = conn->cid;
1367 	ev->r.recv_req.sid = iscsi_conn_get_sid(conn);
1368 	pdu = (char*)ev + sizeof(*ev);
1369 	memcpy(pdu, hdr, sizeof(struct iscsi_hdr));
1370 	memcpy(pdu + sizeof(struct iscsi_hdr), data, data_size);
1371 
1372 	return iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);
1373 }
1374 EXPORT_SYMBOL_GPL(iscsi_recv_pdu);
1375 
1376 int iscsi_offload_mesg(struct Scsi_Host *shost,
1377 		       struct iscsi_transport *transport, uint32_t type,
1378 		       char *data, uint16_t data_size)
1379 {
1380 	struct nlmsghdr	*nlh;
1381 	struct sk_buff *skb;
1382 	struct iscsi_uevent *ev;
1383 	int len = NLMSG_SPACE(sizeof(*ev) + data_size);
1384 
1385 	skb = alloc_skb(len, GFP_ATOMIC);
1386 	if (!skb) {
1387 		printk(KERN_ERR "can not deliver iscsi offload message:OOM\n");
1388 		return -ENOMEM;
1389 	}
1390 
1391 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1392 	ev = NLMSG_DATA(nlh);
1393 	memset(ev, 0, sizeof(*ev));
1394 	ev->type = type;
1395 	ev->transport_handle = iscsi_handle(transport);
1396 	switch (type) {
1397 	case ISCSI_KEVENT_PATH_REQ:
1398 		ev->r.req_path.host_no = shost->host_no;
1399 		break;
1400 	case ISCSI_KEVENT_IF_DOWN:
1401 		ev->r.notify_if_down.host_no = shost->host_no;
1402 		break;
1403 	}
1404 
1405 	memcpy((char *)ev + sizeof(*ev), data, data_size);
1406 
1407 	return iscsi_multicast_skb(skb, ISCSI_NL_GRP_UIP, GFP_ATOMIC);
1408 }
1409 EXPORT_SYMBOL_GPL(iscsi_offload_mesg);
1410 
1411 void iscsi_conn_error_event(struct iscsi_cls_conn *conn, enum iscsi_err error)
1412 {
1413 	struct nlmsghdr	*nlh;
1414 	struct sk_buff	*skb;
1415 	struct iscsi_uevent *ev;
1416 	struct iscsi_internal *priv;
1417 	int len = NLMSG_SPACE(sizeof(*ev));
1418 
1419 	priv = iscsi_if_transport_lookup(conn->transport);
1420 	if (!priv)
1421 		return;
1422 
1423 	skb = alloc_skb(len, GFP_ATOMIC);
1424 	if (!skb) {
1425 		iscsi_cls_conn_printk(KERN_ERR, conn, "gracefully ignored "
1426 				      "conn error (%d)\n", error);
1427 		return;
1428 	}
1429 
1430 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1431 	ev = NLMSG_DATA(nlh);
1432 	ev->transport_handle = iscsi_handle(conn->transport);
1433 	ev->type = ISCSI_KEVENT_CONN_ERROR;
1434 	ev->r.connerror.error = error;
1435 	ev->r.connerror.cid = conn->cid;
1436 	ev->r.connerror.sid = iscsi_conn_get_sid(conn);
1437 
1438 	iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);
1439 
1440 	iscsi_cls_conn_printk(KERN_INFO, conn, "detected conn error (%d)\n",
1441 			      error);
1442 }
1443 EXPORT_SYMBOL_GPL(iscsi_conn_error_event);
1444 
1445 void iscsi_conn_login_event(struct iscsi_cls_conn *conn,
1446 			    enum iscsi_conn_state state)
1447 {
1448 	struct nlmsghdr *nlh;
1449 	struct sk_buff  *skb;
1450 	struct iscsi_uevent *ev;
1451 	struct iscsi_internal *priv;
1452 	int len = NLMSG_SPACE(sizeof(*ev));
1453 
1454 	priv = iscsi_if_transport_lookup(conn->transport);
1455 	if (!priv)
1456 		return;
1457 
1458 	skb = alloc_skb(len, GFP_ATOMIC);
1459 	if (!skb) {
1460 		iscsi_cls_conn_printk(KERN_ERR, conn, "gracefully ignored "
1461 				      "conn login (%d)\n", state);
1462 		return;
1463 	}
1464 
1465 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1466 	ev = NLMSG_DATA(nlh);
1467 	ev->transport_handle = iscsi_handle(conn->transport);
1468 	ev->type = ISCSI_KEVENT_CONN_LOGIN_STATE;
1469 	ev->r.conn_login.state = state;
1470 	ev->r.conn_login.cid = conn->cid;
1471 	ev->r.conn_login.sid = iscsi_conn_get_sid(conn);
1472 	iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);
1473 
1474 	iscsi_cls_conn_printk(KERN_INFO, conn, "detected conn login (%d)\n",
1475 			      state);
1476 }
1477 EXPORT_SYMBOL_GPL(iscsi_conn_login_event);
1478 
1479 static int
1480 iscsi_if_send_reply(uint32_t group, int seq, int type, int done, int multi,
1481 		    void *payload, int size)
1482 {
1483 	struct sk_buff	*skb;
1484 	struct nlmsghdr	*nlh;
1485 	int len = NLMSG_SPACE(size);
1486 	int flags = multi ? NLM_F_MULTI : 0;
1487 	int t = done ? NLMSG_DONE : type;
1488 
1489 	skb = alloc_skb(len, GFP_ATOMIC);
1490 	if (!skb) {
1491 		printk(KERN_ERR "Could not allocate skb to send reply.\n");
1492 		return -ENOMEM;
1493 	}
1494 
1495 	nlh = __nlmsg_put(skb, 0, 0, t, (len - sizeof(*nlh)), 0);
1496 	nlh->nlmsg_flags = flags;
1497 	memcpy(NLMSG_DATA(nlh), payload, size);
1498 	return iscsi_multicast_skb(skb, group, GFP_ATOMIC);
1499 }
1500 
1501 static int
1502 iscsi_if_get_stats(struct iscsi_transport *transport, struct nlmsghdr *nlh)
1503 {
1504 	struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1505 	struct iscsi_stats *stats;
1506 	struct sk_buff *skbstat;
1507 	struct iscsi_cls_conn *conn;
1508 	struct nlmsghdr	*nlhstat;
1509 	struct iscsi_uevent *evstat;
1510 	struct iscsi_internal *priv;
1511 	int len = NLMSG_SPACE(sizeof(*ev) +
1512 			      sizeof(struct iscsi_stats) +
1513 			      sizeof(struct iscsi_stats_custom) *
1514 			      ISCSI_STATS_CUSTOM_MAX);
1515 	int err = 0;
1516 
1517 	priv = iscsi_if_transport_lookup(transport);
1518 	if (!priv)
1519 		return -EINVAL;
1520 
1521 	conn = iscsi_conn_lookup(ev->u.get_stats.sid, ev->u.get_stats.cid);
1522 	if (!conn)
1523 		return -EEXIST;
1524 
1525 	do {
1526 		int actual_size;
1527 
1528 		skbstat = alloc_skb(len, GFP_ATOMIC);
1529 		if (!skbstat) {
1530 			iscsi_cls_conn_printk(KERN_ERR, conn, "can not "
1531 					      "deliver stats: OOM\n");
1532 			return -ENOMEM;
1533 		}
1534 
1535 		nlhstat = __nlmsg_put(skbstat, 0, 0, 0,
1536 				      (len - sizeof(*nlhstat)), 0);
1537 		evstat = NLMSG_DATA(nlhstat);
1538 		memset(evstat, 0, sizeof(*evstat));
1539 		evstat->transport_handle = iscsi_handle(conn->transport);
1540 		evstat->type = nlh->nlmsg_type;
1541 		evstat->u.get_stats.cid =
1542 			ev->u.get_stats.cid;
1543 		evstat->u.get_stats.sid =
1544 			ev->u.get_stats.sid;
1545 		stats = (struct iscsi_stats *)
1546 			((char*)evstat + sizeof(*evstat));
1547 		memset(stats, 0, sizeof(*stats));
1548 
1549 		transport->get_stats(conn, stats);
1550 		actual_size = NLMSG_SPACE(sizeof(struct iscsi_uevent) +
1551 					  sizeof(struct iscsi_stats) +
1552 					  sizeof(struct iscsi_stats_custom) *
1553 					  stats->custom_length);
1554 		actual_size -= sizeof(*nlhstat);
1555 		actual_size = NLMSG_LENGTH(actual_size);
1556 		skb_trim(skbstat, NLMSG_ALIGN(actual_size));
1557 		nlhstat->nlmsg_len = actual_size;
1558 
1559 		err = iscsi_multicast_skb(skbstat, ISCSI_NL_GRP_ISCSID,
1560 					  GFP_ATOMIC);
1561 	} while (err < 0 && err != -ECONNREFUSED);
1562 
1563 	return err;
1564 }
1565 
1566 /**
1567  * iscsi_session_event - send session destr. completion event
1568  * @session: iscsi class session
1569  * @event: type of event
1570  */
1571 int iscsi_session_event(struct iscsi_cls_session *session,
1572 			enum iscsi_uevent_e event)
1573 {
1574 	struct iscsi_internal *priv;
1575 	struct Scsi_Host *shost;
1576 	struct iscsi_uevent *ev;
1577 	struct sk_buff  *skb;
1578 	struct nlmsghdr *nlh;
1579 	int rc, len = NLMSG_SPACE(sizeof(*ev));
1580 
1581 	priv = iscsi_if_transport_lookup(session->transport);
1582 	if (!priv)
1583 		return -EINVAL;
1584 	shost = iscsi_session_to_shost(session);
1585 
1586 	skb = alloc_skb(len, GFP_KERNEL);
1587 	if (!skb) {
1588 		iscsi_cls_session_printk(KERN_ERR, session,
1589 					 "Cannot notify userspace of session "
1590 					 "event %u\n", event);
1591 		return -ENOMEM;
1592 	}
1593 
1594 	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
1595 	ev = NLMSG_DATA(nlh);
1596 	ev->transport_handle = iscsi_handle(session->transport);
1597 
1598 	ev->type = event;
1599 	switch (event) {
1600 	case ISCSI_KEVENT_DESTROY_SESSION:
1601 		ev->r.d_session.host_no = shost->host_no;
1602 		ev->r.d_session.sid = session->sid;
1603 		break;
1604 	case ISCSI_KEVENT_CREATE_SESSION:
1605 		ev->r.c_session_ret.host_no = shost->host_no;
1606 		ev->r.c_session_ret.sid = session->sid;
1607 		break;
1608 	case ISCSI_KEVENT_UNBIND_SESSION:
1609 		ev->r.unbind_session.host_no = shost->host_no;
1610 		ev->r.unbind_session.sid = session->sid;
1611 		break;
1612 	default:
1613 		iscsi_cls_session_printk(KERN_ERR, session, "Invalid event "
1614 					 "%u.\n", event);
1615 		kfree_skb(skb);
1616 		return -EINVAL;
1617 	}
1618 
1619 	/*
1620 	 * this will occur if the daemon is not up, so we just warn
1621 	 * the user and when the daemon is restarted it will handle it
1622 	 */
1623 	rc = iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_KERNEL);
1624 	if (rc == -ESRCH)
1625 		iscsi_cls_session_printk(KERN_ERR, session,
1626 					 "Cannot notify userspace of session "
1627 					 "event %u. Check iscsi daemon\n",
1628 					 event);
1629 
1630 	ISCSI_DBG_TRANS_SESSION(session, "Completed handling event %d rc %d\n",
1631 				event, rc);
1632 	return rc;
1633 }
1634 EXPORT_SYMBOL_GPL(iscsi_session_event);
1635 
1636 static int
1637 iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_endpoint *ep,
1638 			struct iscsi_uevent *ev, pid_t pid,
1639 			uint32_t initial_cmdsn,	uint16_t cmds_max,
1640 			uint16_t queue_depth)
1641 {
1642 	struct iscsi_transport *transport = priv->iscsi_transport;
1643 	struct iscsi_cls_session *session;
1644 	struct Scsi_Host *shost;
1645 
1646 	session = transport->create_session(ep, cmds_max, queue_depth,
1647 					    initial_cmdsn);
1648 	if (!session)
1649 		return -ENOMEM;
1650 
1651 	session->creator = pid;
1652 	shost = iscsi_session_to_shost(session);
1653 	ev->r.c_session_ret.host_no = shost->host_no;
1654 	ev->r.c_session_ret.sid = session->sid;
1655 	ISCSI_DBG_TRANS_SESSION(session,
1656 				"Completed creating transport session\n");
1657 	return 0;
1658 }
1659 
1660 static int
1661 iscsi_if_create_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1662 {
1663 	struct iscsi_cls_conn *conn;
1664 	struct iscsi_cls_session *session;
1665 
1666 	session = iscsi_session_lookup(ev->u.c_conn.sid);
1667 	if (!session) {
1668 		printk(KERN_ERR "iscsi: invalid session %d.\n",
1669 		       ev->u.c_conn.sid);
1670 		return -EINVAL;
1671 	}
1672 
1673 	conn = transport->create_conn(session, ev->u.c_conn.cid);
1674 	if (!conn) {
1675 		iscsi_cls_session_printk(KERN_ERR, session,
1676 					 "couldn't create a new connection.");
1677 		return -ENOMEM;
1678 	}
1679 
1680 	ev->r.c_conn_ret.sid = session->sid;
1681 	ev->r.c_conn_ret.cid = conn->cid;
1682 
1683 	ISCSI_DBG_TRANS_CONN(conn, "Completed creating transport conn\n");
1684 	return 0;
1685 }
1686 
1687 static int
1688 iscsi_if_destroy_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1689 {
1690 	struct iscsi_cls_conn *conn;
1691 
1692 	conn = iscsi_conn_lookup(ev->u.d_conn.sid, ev->u.d_conn.cid);
1693 	if (!conn)
1694 		return -EINVAL;
1695 
1696 	ISCSI_DBG_TRANS_CONN(conn, "Destroying transport conn\n");
1697 	if (transport->destroy_conn)
1698 		transport->destroy_conn(conn);
1699 
1700 	return 0;
1701 }
1702 
1703 static int
1704 iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1705 {
1706 	char *data = (char*)ev + sizeof(*ev);
1707 	struct iscsi_cls_conn *conn;
1708 	struct iscsi_cls_session *session;
1709 	int err = 0, value = 0;
1710 
1711 	session = iscsi_session_lookup(ev->u.set_param.sid);
1712 	conn = iscsi_conn_lookup(ev->u.set_param.sid, ev->u.set_param.cid);
1713 	if (!conn || !session)
1714 		return -EINVAL;
1715 
1716 	switch (ev->u.set_param.param) {
1717 	case ISCSI_PARAM_SESS_RECOVERY_TMO:
1718 		sscanf(data, "%d", &value);
1719 		session->recovery_tmo = value;
1720 		break;
1721 	default:
1722 		err = transport->set_param(conn, ev->u.set_param.param,
1723 					   data, ev->u.set_param.len);
1724 	}
1725 
1726 	return err;
1727 }
1728 
1729 static int iscsi_if_ep_connect(struct iscsi_transport *transport,
1730 			       struct iscsi_uevent *ev, int msg_type)
1731 {
1732 	struct iscsi_endpoint *ep;
1733 	struct sockaddr *dst_addr;
1734 	struct Scsi_Host *shost = NULL;
1735 	int non_blocking, err = 0;
1736 
1737 	if (!transport->ep_connect)
1738 		return -EINVAL;
1739 
1740 	if (msg_type == ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST) {
1741 		shost = scsi_host_lookup(ev->u.ep_connect_through_host.host_no);
1742 		if (!shost) {
1743 			printk(KERN_ERR "ep connect failed. Could not find "
1744 			       "host no %u\n",
1745 			       ev->u.ep_connect_through_host.host_no);
1746 			return -ENODEV;
1747 		}
1748 		non_blocking = ev->u.ep_connect_through_host.non_blocking;
1749 	} else
1750 		non_blocking = ev->u.ep_connect.non_blocking;
1751 
1752 	dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1753 	ep = transport->ep_connect(shost, dst_addr, non_blocking);
1754 	if (IS_ERR(ep)) {
1755 		err = PTR_ERR(ep);
1756 		goto release_host;
1757 	}
1758 
1759 	ev->r.ep_connect_ret.handle = ep->id;
1760 release_host:
1761 	if (shost)
1762 		scsi_host_put(shost);
1763 	return err;
1764 }
1765 
1766 static int iscsi_if_ep_disconnect(struct iscsi_transport *transport,
1767 				  u64 ep_handle)
1768 {
1769 	struct iscsi_cls_conn *conn;
1770 	struct iscsi_endpoint *ep;
1771 
1772 	if (!transport->ep_disconnect)
1773 		return -EINVAL;
1774 
1775 	ep = iscsi_lookup_endpoint(ep_handle);
1776 	if (!ep)
1777 		return -EINVAL;
1778 	conn = ep->conn;
1779 	if (conn) {
1780 		mutex_lock(&conn->ep_mutex);
1781 		conn->ep = NULL;
1782 		mutex_unlock(&conn->ep_mutex);
1783 	}
1784 
1785 	transport->ep_disconnect(ep);
1786 	return 0;
1787 }
1788 
1789 static int
1790 iscsi_if_transport_ep(struct iscsi_transport *transport,
1791 		      struct iscsi_uevent *ev, int msg_type)
1792 {
1793 	struct iscsi_endpoint *ep;
1794 	int rc = 0;
1795 
1796 	switch (msg_type) {
1797 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST:
1798 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
1799 		rc = iscsi_if_ep_connect(transport, ev, msg_type);
1800 		break;
1801 	case ISCSI_UEVENT_TRANSPORT_EP_POLL:
1802 		if (!transport->ep_poll)
1803 			return -EINVAL;
1804 
1805 		ep = iscsi_lookup_endpoint(ev->u.ep_poll.ep_handle);
1806 		if (!ep)
1807 			return -EINVAL;
1808 
1809 		ev->r.retcode = transport->ep_poll(ep,
1810 						   ev->u.ep_poll.timeout_ms);
1811 		break;
1812 	case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
1813 		rc = iscsi_if_ep_disconnect(transport,
1814 					    ev->u.ep_disconnect.ep_handle);
1815 		break;
1816 	}
1817 	return rc;
1818 }
1819 
1820 static int
1821 iscsi_tgt_dscvr(struct iscsi_transport *transport,
1822 		struct iscsi_uevent *ev)
1823 {
1824 	struct Scsi_Host *shost;
1825 	struct sockaddr *dst_addr;
1826 	int err;
1827 
1828 	if (!transport->tgt_dscvr)
1829 		return -EINVAL;
1830 
1831 	shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);
1832 	if (!shost) {
1833 		printk(KERN_ERR "target discovery could not find host no %u\n",
1834 		       ev->u.tgt_dscvr.host_no);
1835 		return -ENODEV;
1836 	}
1837 
1838 
1839 	dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
1840 	err = transport->tgt_dscvr(shost, ev->u.tgt_dscvr.type,
1841 				   ev->u.tgt_dscvr.enable, dst_addr);
1842 	scsi_host_put(shost);
1843 	return err;
1844 }
1845 
1846 static int
1847 iscsi_set_host_param(struct iscsi_transport *transport,
1848 		     struct iscsi_uevent *ev)
1849 {
1850 	char *data = (char*)ev + sizeof(*ev);
1851 	struct Scsi_Host *shost;
1852 	int err;
1853 
1854 	if (!transport->set_host_param)
1855 		return -ENOSYS;
1856 
1857 	shost = scsi_host_lookup(ev->u.set_host_param.host_no);
1858 	if (!shost) {
1859 		printk(KERN_ERR "set_host_param could not find host no %u\n",
1860 		       ev->u.set_host_param.host_no);
1861 		return -ENODEV;
1862 	}
1863 
1864 	err = transport->set_host_param(shost, ev->u.set_host_param.param,
1865 					data, ev->u.set_host_param.len);
1866 	scsi_host_put(shost);
1867 	return err;
1868 }
1869 
1870 static int
1871 iscsi_set_path(struct iscsi_transport *transport, struct iscsi_uevent *ev)
1872 {
1873 	struct Scsi_Host *shost;
1874 	struct iscsi_path *params;
1875 	int err;
1876 
1877 	if (!transport->set_path)
1878 		return -ENOSYS;
1879 
1880 	shost = scsi_host_lookup(ev->u.set_path.host_no);
1881 	if (!shost) {
1882 		printk(KERN_ERR "set path could not find host no %u\n",
1883 		       ev->u.set_path.host_no);
1884 		return -ENODEV;
1885 	}
1886 
1887 	params = (struct iscsi_path *)((char *)ev + sizeof(*ev));
1888 	err = transport->set_path(shost, params);
1889 
1890 	scsi_host_put(shost);
1891 	return err;
1892 }
1893 
1894 static int
1895 iscsi_set_iface_params(struct iscsi_transport *transport,
1896 		       struct iscsi_uevent *ev, uint32_t len)
1897 {
1898 	char *data = (char *)ev + sizeof(*ev);
1899 	struct Scsi_Host *shost;
1900 	int err;
1901 
1902 	if (!transport->set_iface_param)
1903 		return -ENOSYS;
1904 
1905 	shost = scsi_host_lookup(ev->u.set_iface_params.host_no);
1906 	if (!shost) {
1907 		printk(KERN_ERR "set_iface_params could not find host no %u\n",
1908 		       ev->u.set_iface_params.host_no);
1909 		return -ENODEV;
1910 	}
1911 
1912 	err = transport->set_iface_param(shost, data, len);
1913 	scsi_host_put(shost);
1914 	return err;
1915 }
1916 
1917 static int
1918 iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
1919 {
1920 	int err = 0;
1921 	struct iscsi_uevent *ev = NLMSG_DATA(nlh);
1922 	struct iscsi_transport *transport = NULL;
1923 	struct iscsi_internal *priv;
1924 	struct iscsi_cls_session *session;
1925 	struct iscsi_cls_conn *conn;
1926 	struct iscsi_endpoint *ep = NULL;
1927 
1928 	if (nlh->nlmsg_type == ISCSI_UEVENT_PATH_UPDATE)
1929 		*group = ISCSI_NL_GRP_UIP;
1930 	else
1931 		*group = ISCSI_NL_GRP_ISCSID;
1932 
1933 	priv = iscsi_if_transport_lookup(iscsi_ptr(ev->transport_handle));
1934 	if (!priv)
1935 		return -EINVAL;
1936 	transport = priv->iscsi_transport;
1937 
1938 	if (!try_module_get(transport->owner))
1939 		return -EINVAL;
1940 
1941 	switch (nlh->nlmsg_type) {
1942 	case ISCSI_UEVENT_CREATE_SESSION:
1943 		err = iscsi_if_create_session(priv, ep, ev,
1944 					      NETLINK_CREDS(skb)->pid,
1945 					      ev->u.c_session.initial_cmdsn,
1946 					      ev->u.c_session.cmds_max,
1947 					      ev->u.c_session.queue_depth);
1948 		break;
1949 	case ISCSI_UEVENT_CREATE_BOUND_SESSION:
1950 		ep = iscsi_lookup_endpoint(ev->u.c_bound_session.ep_handle);
1951 		if (!ep) {
1952 			err = -EINVAL;
1953 			break;
1954 		}
1955 
1956 		err = iscsi_if_create_session(priv, ep, ev,
1957 					NETLINK_CREDS(skb)->pid,
1958 					ev->u.c_bound_session.initial_cmdsn,
1959 					ev->u.c_bound_session.cmds_max,
1960 					ev->u.c_bound_session.queue_depth);
1961 		break;
1962 	case ISCSI_UEVENT_DESTROY_SESSION:
1963 		session = iscsi_session_lookup(ev->u.d_session.sid);
1964 		if (session)
1965 			transport->destroy_session(session);
1966 		else
1967 			err = -EINVAL;
1968 		break;
1969 	case ISCSI_UEVENT_UNBIND_SESSION:
1970 		session = iscsi_session_lookup(ev->u.d_session.sid);
1971 		if (session)
1972 			scsi_queue_work(iscsi_session_to_shost(session),
1973 					&session->unbind_work);
1974 		else
1975 			err = -EINVAL;
1976 		break;
1977 	case ISCSI_UEVENT_CREATE_CONN:
1978 		err = iscsi_if_create_conn(transport, ev);
1979 		break;
1980 	case ISCSI_UEVENT_DESTROY_CONN:
1981 		err = iscsi_if_destroy_conn(transport, ev);
1982 		break;
1983 	case ISCSI_UEVENT_BIND_CONN:
1984 		session = iscsi_session_lookup(ev->u.b_conn.sid);
1985 		conn = iscsi_conn_lookup(ev->u.b_conn.sid, ev->u.b_conn.cid);
1986 
1987 		if (conn && conn->ep)
1988 			iscsi_if_ep_disconnect(transport, conn->ep->id);
1989 
1990 		if (!session || !conn) {
1991 			err = -EINVAL;
1992 			break;
1993 		}
1994 
1995 		ev->r.retcode =	transport->bind_conn(session, conn,
1996 						ev->u.b_conn.transport_eph,
1997 						ev->u.b_conn.is_leading);
1998 		if (ev->r.retcode || !transport->ep_connect)
1999 			break;
2000 
2001 		ep = iscsi_lookup_endpoint(ev->u.b_conn.transport_eph);
2002 		if (ep) {
2003 			ep->conn = conn;
2004 
2005 			mutex_lock(&conn->ep_mutex);
2006 			conn->ep = ep;
2007 			mutex_unlock(&conn->ep_mutex);
2008 		} else
2009 			iscsi_cls_conn_printk(KERN_ERR, conn,
2010 					      "Could not set ep conn "
2011 					      "binding\n");
2012 		break;
2013 	case ISCSI_UEVENT_SET_PARAM:
2014 		err = iscsi_set_param(transport, ev);
2015 		break;
2016 	case ISCSI_UEVENT_START_CONN:
2017 		conn = iscsi_conn_lookup(ev->u.start_conn.sid, ev->u.start_conn.cid);
2018 		if (conn)
2019 			ev->r.retcode = transport->start_conn(conn);
2020 		else
2021 			err = -EINVAL;
2022 		break;
2023 	case ISCSI_UEVENT_STOP_CONN:
2024 		conn = iscsi_conn_lookup(ev->u.stop_conn.sid, ev->u.stop_conn.cid);
2025 		if (conn)
2026 			transport->stop_conn(conn, ev->u.stop_conn.flag);
2027 		else
2028 			err = -EINVAL;
2029 		break;
2030 	case ISCSI_UEVENT_SEND_PDU:
2031 		conn = iscsi_conn_lookup(ev->u.send_pdu.sid, ev->u.send_pdu.cid);
2032 		if (conn)
2033 			ev->r.retcode =	transport->send_pdu(conn,
2034 				(struct iscsi_hdr*)((char*)ev + sizeof(*ev)),
2035 				(char*)ev + sizeof(*ev) + ev->u.send_pdu.hdr_size,
2036 				ev->u.send_pdu.data_size);
2037 		else
2038 			err = -EINVAL;
2039 		break;
2040 	case ISCSI_UEVENT_GET_STATS:
2041 		err = iscsi_if_get_stats(transport, nlh);
2042 		break;
2043 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
2044 	case ISCSI_UEVENT_TRANSPORT_EP_POLL:
2045 	case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
2046 	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST:
2047 		err = iscsi_if_transport_ep(transport, ev, nlh->nlmsg_type);
2048 		break;
2049 	case ISCSI_UEVENT_TGT_DSCVR:
2050 		err = iscsi_tgt_dscvr(transport, ev);
2051 		break;
2052 	case ISCSI_UEVENT_SET_HOST_PARAM:
2053 		err = iscsi_set_host_param(transport, ev);
2054 		break;
2055 	case ISCSI_UEVENT_PATH_UPDATE:
2056 		err = iscsi_set_path(transport, ev);
2057 		break;
2058 	case ISCSI_UEVENT_SET_IFACE_PARAMS:
2059 		err = iscsi_set_iface_params(transport, ev,
2060 					     nlmsg_attrlen(nlh, sizeof(*ev)));
2061 		break;
2062 	default:
2063 		err = -ENOSYS;
2064 		break;
2065 	}
2066 
2067 	module_put(transport->owner);
2068 	return err;
2069 }
2070 
2071 /*
2072  * Get message from skb.  Each message is processed by iscsi_if_recv_msg.
2073  * Malformed skbs with wrong lengths or invalid creds are not processed.
2074  */
2075 static void
2076 iscsi_if_rx(struct sk_buff *skb)
2077 {
2078 	mutex_lock(&rx_queue_mutex);
2079 	while (skb->len >= NLMSG_SPACE(0)) {
2080 		int err;
2081 		uint32_t rlen;
2082 		struct nlmsghdr	*nlh;
2083 		struct iscsi_uevent *ev;
2084 		uint32_t group;
2085 
2086 		nlh = nlmsg_hdr(skb);
2087 		if (nlh->nlmsg_len < sizeof(*nlh) ||
2088 		    skb->len < nlh->nlmsg_len) {
2089 			break;
2090 		}
2091 
2092 		ev = NLMSG_DATA(nlh);
2093 		rlen = NLMSG_ALIGN(nlh->nlmsg_len);
2094 		if (rlen > skb->len)
2095 			rlen = skb->len;
2096 
2097 		err = iscsi_if_recv_msg(skb, nlh, &group);
2098 		if (err) {
2099 			ev->type = ISCSI_KEVENT_IF_ERROR;
2100 			ev->iferror = err;
2101 		}
2102 		do {
2103 			/*
2104 			 * special case for GET_STATS:
2105 			 * on success - sending reply and stats from
2106 			 * inside of if_recv_msg(),
2107 			 * on error - fall through.
2108 			 */
2109 			if (ev->type == ISCSI_UEVENT_GET_STATS && !err)
2110 				break;
2111 			err = iscsi_if_send_reply(group, nlh->nlmsg_seq,
2112 				nlh->nlmsg_type, 0, 0, ev, sizeof(*ev));
2113 		} while (err < 0 && err != -ECONNREFUSED);
2114 		skb_pull(skb, rlen);
2115 	}
2116 	mutex_unlock(&rx_queue_mutex);
2117 }
2118 
2119 #define ISCSI_CLASS_ATTR(_prefix,_name,_mode,_show,_store)		\
2120 struct device_attribute dev_attr_##_prefix##_##_name =	\
2121 	__ATTR(_name,_mode,_show,_store)
2122 
2123 /*
2124  * iSCSI connection attrs
2125  */
2126 #define iscsi_conn_attr_show(param)					\
2127 static ssize_t								\
2128 show_conn_param_##param(struct device *dev, 				\
2129 			struct device_attribute *attr, char *buf)	\
2130 {									\
2131 	struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev->parent);	\
2132 	struct iscsi_transport *t = conn->transport;			\
2133 	return t->get_conn_param(conn, param, buf);			\
2134 }
2135 
2136 #define iscsi_conn_attr(field, param)					\
2137 	iscsi_conn_attr_show(param)					\
2138 static ISCSI_CLASS_ATTR(conn, field, S_IRUGO, show_conn_param_##param,	\
2139 			NULL);
2140 
2141 iscsi_conn_attr(max_recv_dlength, ISCSI_PARAM_MAX_RECV_DLENGTH);
2142 iscsi_conn_attr(max_xmit_dlength, ISCSI_PARAM_MAX_XMIT_DLENGTH);
2143 iscsi_conn_attr(header_digest, ISCSI_PARAM_HDRDGST_EN);
2144 iscsi_conn_attr(data_digest, ISCSI_PARAM_DATADGST_EN);
2145 iscsi_conn_attr(ifmarker, ISCSI_PARAM_IFMARKER_EN);
2146 iscsi_conn_attr(ofmarker, ISCSI_PARAM_OFMARKER_EN);
2147 iscsi_conn_attr(persistent_port, ISCSI_PARAM_PERSISTENT_PORT);
2148 iscsi_conn_attr(exp_statsn, ISCSI_PARAM_EXP_STATSN);
2149 iscsi_conn_attr(persistent_address, ISCSI_PARAM_PERSISTENT_ADDRESS);
2150 iscsi_conn_attr(ping_tmo, ISCSI_PARAM_PING_TMO);
2151 iscsi_conn_attr(recv_tmo, ISCSI_PARAM_RECV_TMO);
2152 
2153 #define iscsi_conn_ep_attr_show(param)					\
2154 static ssize_t show_conn_ep_param_##param(struct device *dev,		\
2155 					  struct device_attribute *attr,\
2156 					  char *buf)			\
2157 {									\
2158 	struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev->parent);	\
2159 	struct iscsi_transport *t = conn->transport;			\
2160 	struct iscsi_endpoint *ep;					\
2161 	ssize_t rc;							\
2162 									\
2163 	/*								\
2164 	 * Need to make sure ep_disconnect does not free the LLD's	\
2165 	 * interconnect resources while we are trying to read them.	\
2166 	 */								\
2167 	mutex_lock(&conn->ep_mutex);					\
2168 	ep = conn->ep;							\
2169 	if (!ep && t->ep_connect) {					\
2170 		mutex_unlock(&conn->ep_mutex);				\
2171 		return -ENOTCONN;					\
2172 	}								\
2173 									\
2174 	if (ep)								\
2175 		rc = t->get_ep_param(ep, param, buf);			\
2176 	else								\
2177 		rc = t->get_conn_param(conn, param, buf);		\
2178 	mutex_unlock(&conn->ep_mutex);					\
2179 	return rc;							\
2180 }
2181 
2182 #define iscsi_conn_ep_attr(field, param)				\
2183 	iscsi_conn_ep_attr_show(param)					\
2184 static ISCSI_CLASS_ATTR(conn, field, S_IRUGO,				\
2185 			show_conn_ep_param_##param, NULL);
2186 
2187 iscsi_conn_ep_attr(address, ISCSI_PARAM_CONN_ADDRESS);
2188 iscsi_conn_ep_attr(port, ISCSI_PARAM_CONN_PORT);
2189 
2190 static struct attribute *iscsi_conn_attrs[] = {
2191 	&dev_attr_conn_max_recv_dlength.attr,
2192 	&dev_attr_conn_max_xmit_dlength.attr,
2193 	&dev_attr_conn_header_digest.attr,
2194 	&dev_attr_conn_data_digest.attr,
2195 	&dev_attr_conn_ifmarker.attr,
2196 	&dev_attr_conn_ofmarker.attr,
2197 	&dev_attr_conn_address.attr,
2198 	&dev_attr_conn_port.attr,
2199 	&dev_attr_conn_exp_statsn.attr,
2200 	&dev_attr_conn_persistent_address.attr,
2201 	&dev_attr_conn_persistent_port.attr,
2202 	&dev_attr_conn_ping_tmo.attr,
2203 	&dev_attr_conn_recv_tmo.attr,
2204 	NULL,
2205 };
2206 
2207 static umode_t iscsi_conn_attr_is_visible(struct kobject *kobj,
2208 					 struct attribute *attr, int i)
2209 {
2210 	struct device *cdev = container_of(kobj, struct device, kobj);
2211 	struct iscsi_cls_conn *conn = transport_class_to_conn(cdev);
2212 	struct iscsi_transport *t = conn->transport;
2213 	int param;
2214 
2215 	if (attr == &dev_attr_conn_max_recv_dlength.attr)
2216 		param = ISCSI_PARAM_MAX_RECV_DLENGTH;
2217 	else if (attr == &dev_attr_conn_max_xmit_dlength.attr)
2218 		param = ISCSI_PARAM_MAX_XMIT_DLENGTH;
2219 	else if (attr == &dev_attr_conn_header_digest.attr)
2220 		param = ISCSI_PARAM_HDRDGST_EN;
2221 	else if (attr == &dev_attr_conn_data_digest.attr)
2222 		param = ISCSI_PARAM_DATADGST_EN;
2223 	else if (attr == &dev_attr_conn_ifmarker.attr)
2224 		param = ISCSI_PARAM_IFMARKER_EN;
2225 	else if (attr == &dev_attr_conn_ofmarker.attr)
2226 		param = ISCSI_PARAM_OFMARKER_EN;
2227 	else if (attr == &dev_attr_conn_address.attr)
2228 		param = ISCSI_PARAM_CONN_ADDRESS;
2229 	else if (attr == &dev_attr_conn_port.attr)
2230 		param = ISCSI_PARAM_CONN_PORT;
2231 	else if (attr == &dev_attr_conn_exp_statsn.attr)
2232 		param = ISCSI_PARAM_EXP_STATSN;
2233 	else if (attr == &dev_attr_conn_persistent_address.attr)
2234 		param = ISCSI_PARAM_PERSISTENT_ADDRESS;
2235 	else if (attr == &dev_attr_conn_persistent_port.attr)
2236 		param = ISCSI_PARAM_PERSISTENT_PORT;
2237 	else if (attr == &dev_attr_conn_ping_tmo.attr)
2238 		param = ISCSI_PARAM_PING_TMO;
2239 	else if (attr == &dev_attr_conn_recv_tmo.attr)
2240 		param = ISCSI_PARAM_RECV_TMO;
2241 	else {
2242 		WARN_ONCE(1, "Invalid conn attr");
2243 		return 0;
2244 	}
2245 
2246 	return t->attr_is_visible(ISCSI_PARAM, param);
2247 }
2248 
2249 static struct attribute_group iscsi_conn_group = {
2250 	.attrs = iscsi_conn_attrs,
2251 	.is_visible = iscsi_conn_attr_is_visible,
2252 };
2253 
2254 /*
2255  * iSCSI session attrs
2256  */
2257 #define iscsi_session_attr_show(param, perm)				\
2258 static ssize_t								\
2259 show_session_param_##param(struct device *dev,				\
2260 			   struct device_attribute *attr, char *buf)	\
2261 {									\
2262 	struct iscsi_cls_session *session = 				\
2263 		iscsi_dev_to_session(dev->parent);			\
2264 	struct iscsi_transport *t = session->transport;			\
2265 									\
2266 	if (perm && !capable(CAP_SYS_ADMIN))				\
2267 		return -EACCES;						\
2268 	return t->get_session_param(session, param, buf);		\
2269 }
2270 
2271 #define iscsi_session_attr(field, param, perm)				\
2272 	iscsi_session_attr_show(param, perm)				\
2273 static ISCSI_CLASS_ATTR(sess, field, S_IRUGO, show_session_param_##param, \
2274 			NULL);
2275 iscsi_session_attr(targetname, ISCSI_PARAM_TARGET_NAME, 0);
2276 iscsi_session_attr(initial_r2t, ISCSI_PARAM_INITIAL_R2T_EN, 0);
2277 iscsi_session_attr(max_outstanding_r2t, ISCSI_PARAM_MAX_R2T, 0);
2278 iscsi_session_attr(immediate_data, ISCSI_PARAM_IMM_DATA_EN, 0);
2279 iscsi_session_attr(first_burst_len, ISCSI_PARAM_FIRST_BURST, 0);
2280 iscsi_session_attr(max_burst_len, ISCSI_PARAM_MAX_BURST, 0);
2281 iscsi_session_attr(data_pdu_in_order, ISCSI_PARAM_PDU_INORDER_EN, 0);
2282 iscsi_session_attr(data_seq_in_order, ISCSI_PARAM_DATASEQ_INORDER_EN, 0);
2283 iscsi_session_attr(erl, ISCSI_PARAM_ERL, 0);
2284 iscsi_session_attr(tpgt, ISCSI_PARAM_TPGT, 0);
2285 iscsi_session_attr(username, ISCSI_PARAM_USERNAME, 1);
2286 iscsi_session_attr(username_in, ISCSI_PARAM_USERNAME_IN, 1);
2287 iscsi_session_attr(password, ISCSI_PARAM_PASSWORD, 1);
2288 iscsi_session_attr(password_in, ISCSI_PARAM_PASSWORD_IN, 1);
2289 iscsi_session_attr(fast_abort, ISCSI_PARAM_FAST_ABORT, 0);
2290 iscsi_session_attr(abort_tmo, ISCSI_PARAM_ABORT_TMO, 0);
2291 iscsi_session_attr(lu_reset_tmo, ISCSI_PARAM_LU_RESET_TMO, 0);
2292 iscsi_session_attr(tgt_reset_tmo, ISCSI_PARAM_TGT_RESET_TMO, 0);
2293 iscsi_session_attr(ifacename, ISCSI_PARAM_IFACE_NAME, 0);
2294 iscsi_session_attr(initiatorname, ISCSI_PARAM_INITIATOR_NAME, 0);
2295 iscsi_session_attr(targetalias, ISCSI_PARAM_TARGET_ALIAS, 0);
2296 
2297 static ssize_t
2298 show_priv_session_state(struct device *dev, struct device_attribute *attr,
2299 			char *buf)
2300 {
2301 	struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
2302 	return sprintf(buf, "%s\n", iscsi_session_state_name(session->state));
2303 }
2304 static ISCSI_CLASS_ATTR(priv_sess, state, S_IRUGO, show_priv_session_state,
2305 			NULL);
2306 static ssize_t
2307 show_priv_session_creator(struct device *dev, struct device_attribute *attr,
2308 			char *buf)
2309 {
2310 	struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
2311 	return sprintf(buf, "%d\n", session->creator);
2312 }
2313 static ISCSI_CLASS_ATTR(priv_sess, creator, S_IRUGO, show_priv_session_creator,
2314 			NULL);
2315 
2316 #define iscsi_priv_session_attr_show(field, format)			\
2317 static ssize_t								\
2318 show_priv_session_##field(struct device *dev, 				\
2319 			  struct device_attribute *attr, char *buf)	\
2320 {									\
2321 	struct iscsi_cls_session *session = 				\
2322 			iscsi_dev_to_session(dev->parent);		\
2323 	if (session->field == -1)					\
2324 		return sprintf(buf, "off\n");				\
2325 	return sprintf(buf, format"\n", session->field);		\
2326 }
2327 
2328 #define iscsi_priv_session_attr_store(field)				\
2329 static ssize_t								\
2330 store_priv_session_##field(struct device *dev,				\
2331 			   struct device_attribute *attr,		\
2332 			   const char *buf, size_t count)		\
2333 {									\
2334 	int val;							\
2335 	char *cp;							\
2336 	struct iscsi_cls_session *session =				\
2337 		iscsi_dev_to_session(dev->parent);			\
2338 	if ((session->state == ISCSI_SESSION_FREE) ||			\
2339 	    (session->state == ISCSI_SESSION_FAILED))			\
2340 		return -EBUSY;						\
2341 	if (strncmp(buf, "off", 3) == 0)				\
2342 		session->field = -1;					\
2343 	else {								\
2344 		val = simple_strtoul(buf, &cp, 0);			\
2345 		if (*cp != '\0' && *cp != '\n')				\
2346 			return -EINVAL;					\
2347 		session->field = val;					\
2348 	}								\
2349 	return count;							\
2350 }
2351 
2352 #define iscsi_priv_session_rw_attr(field, format)			\
2353 	iscsi_priv_session_attr_show(field, format)			\
2354 	iscsi_priv_session_attr_store(field)				\
2355 static ISCSI_CLASS_ATTR(priv_sess, field, S_IRUGO | S_IWUSR,		\
2356 			show_priv_session_##field,			\
2357 			store_priv_session_##field)
2358 iscsi_priv_session_rw_attr(recovery_tmo, "%d");
2359 
2360 static struct attribute *iscsi_session_attrs[] = {
2361 	&dev_attr_sess_initial_r2t.attr,
2362 	&dev_attr_sess_max_outstanding_r2t.attr,
2363 	&dev_attr_sess_immediate_data.attr,
2364 	&dev_attr_sess_first_burst_len.attr,
2365 	&dev_attr_sess_max_burst_len.attr,
2366 	&dev_attr_sess_data_pdu_in_order.attr,
2367 	&dev_attr_sess_data_seq_in_order.attr,
2368 	&dev_attr_sess_erl.attr,
2369 	&dev_attr_sess_targetname.attr,
2370 	&dev_attr_sess_tpgt.attr,
2371 	&dev_attr_sess_password.attr,
2372 	&dev_attr_sess_password_in.attr,
2373 	&dev_attr_sess_username.attr,
2374 	&dev_attr_sess_username_in.attr,
2375 	&dev_attr_sess_fast_abort.attr,
2376 	&dev_attr_sess_abort_tmo.attr,
2377 	&dev_attr_sess_lu_reset_tmo.attr,
2378 	&dev_attr_sess_tgt_reset_tmo.attr,
2379 	&dev_attr_sess_ifacename.attr,
2380 	&dev_attr_sess_initiatorname.attr,
2381 	&dev_attr_sess_targetalias.attr,
2382 	&dev_attr_priv_sess_recovery_tmo.attr,
2383 	&dev_attr_priv_sess_state.attr,
2384 	&dev_attr_priv_sess_creator.attr,
2385 	NULL,
2386 };
2387 
2388 static umode_t iscsi_session_attr_is_visible(struct kobject *kobj,
2389 					    struct attribute *attr, int i)
2390 {
2391 	struct device *cdev = container_of(kobj, struct device, kobj);
2392 	struct iscsi_cls_session *session = transport_class_to_session(cdev);
2393 	struct iscsi_transport *t = session->transport;
2394 	int param;
2395 
2396 	if (attr == &dev_attr_sess_initial_r2t.attr)
2397 		param = ISCSI_PARAM_INITIAL_R2T_EN;
2398 	else if (attr == &dev_attr_sess_max_outstanding_r2t.attr)
2399 		param = ISCSI_PARAM_MAX_R2T;
2400 	else if (attr == &dev_attr_sess_immediate_data.attr)
2401 		param = ISCSI_PARAM_IMM_DATA_EN;
2402 	else if (attr == &dev_attr_sess_first_burst_len.attr)
2403 		param = ISCSI_PARAM_FIRST_BURST;
2404 	else if (attr == &dev_attr_sess_max_burst_len.attr)
2405 		param = ISCSI_PARAM_MAX_BURST;
2406 	else if (attr == &dev_attr_sess_data_pdu_in_order.attr)
2407 		param = ISCSI_PARAM_PDU_INORDER_EN;
2408 	else if (attr == &dev_attr_sess_data_seq_in_order.attr)
2409 		param = ISCSI_PARAM_DATASEQ_INORDER_EN;
2410 	else if (attr == &dev_attr_sess_erl.attr)
2411 		param = ISCSI_PARAM_ERL;
2412 	else if (attr == &dev_attr_sess_targetname.attr)
2413 		param = ISCSI_PARAM_TARGET_NAME;
2414 	else if (attr == &dev_attr_sess_tpgt.attr)
2415 		param = ISCSI_PARAM_TPGT;
2416 	else if (attr == &dev_attr_sess_password.attr)
2417 		param = ISCSI_PARAM_USERNAME;
2418 	else if (attr == &dev_attr_sess_password_in.attr)
2419 		param = ISCSI_PARAM_USERNAME_IN;
2420 	else if (attr == &dev_attr_sess_username.attr)
2421 		param = ISCSI_PARAM_PASSWORD;
2422 	else if (attr == &dev_attr_sess_username_in.attr)
2423 		param = ISCSI_PARAM_PASSWORD_IN;
2424 	else if (attr == &dev_attr_sess_fast_abort.attr)
2425 		param = ISCSI_PARAM_FAST_ABORT;
2426 	else if (attr == &dev_attr_sess_abort_tmo.attr)
2427 		param = ISCSI_PARAM_ABORT_TMO;
2428 	else if (attr == &dev_attr_sess_lu_reset_tmo.attr)
2429 		param = ISCSI_PARAM_LU_RESET_TMO;
2430 	else if (attr == &dev_attr_sess_tgt_reset_tmo.attr)
2431 		param = ISCSI_PARAM_TGT_RESET_TMO;
2432 	else if (attr == &dev_attr_sess_ifacename.attr)
2433 		param = ISCSI_PARAM_IFACE_NAME;
2434 	else if (attr == &dev_attr_sess_initiatorname.attr)
2435 		param = ISCSI_PARAM_INITIATOR_NAME;
2436 	else if (attr == &dev_attr_sess_targetalias.attr)
2437 		param = ISCSI_PARAM_TARGET_ALIAS;
2438 	else if (attr == &dev_attr_priv_sess_recovery_tmo.attr)
2439 		return S_IRUGO | S_IWUSR;
2440 	else if (attr == &dev_attr_priv_sess_state.attr)
2441 		return S_IRUGO;
2442 	else if (attr == &dev_attr_priv_sess_creator.attr)
2443 		return S_IRUGO;
2444 	else {
2445 		WARN_ONCE(1, "Invalid session attr");
2446 		return 0;
2447 	}
2448 
2449 	return t->attr_is_visible(ISCSI_PARAM, param);
2450 }
2451 
2452 static struct attribute_group iscsi_session_group = {
2453 	.attrs = iscsi_session_attrs,
2454 	.is_visible = iscsi_session_attr_is_visible,
2455 };
2456 
2457 /*
2458  * iSCSI host attrs
2459  */
2460 #define iscsi_host_attr_show(param)					\
2461 static ssize_t								\
2462 show_host_param_##param(struct device *dev, 				\
2463 			struct device_attribute *attr, char *buf)	\
2464 {									\
2465 	struct Scsi_Host *shost = transport_class_to_shost(dev);	\
2466 	struct iscsi_internal *priv = to_iscsi_internal(shost->transportt); \
2467 	return priv->iscsi_transport->get_host_param(shost, param, buf); \
2468 }
2469 
2470 #define iscsi_host_attr(field, param)					\
2471 	iscsi_host_attr_show(param)					\
2472 static ISCSI_CLASS_ATTR(host, field, S_IRUGO, show_host_param_##param,	\
2473 			NULL);
2474 
2475 iscsi_host_attr(netdev, ISCSI_HOST_PARAM_NETDEV_NAME);
2476 iscsi_host_attr(hwaddress, ISCSI_HOST_PARAM_HWADDRESS);
2477 iscsi_host_attr(ipaddress, ISCSI_HOST_PARAM_IPADDRESS);
2478 iscsi_host_attr(initiatorname, ISCSI_HOST_PARAM_INITIATOR_NAME);
2479 
2480 static struct attribute *iscsi_host_attrs[] = {
2481 	&dev_attr_host_netdev.attr,
2482 	&dev_attr_host_hwaddress.attr,
2483 	&dev_attr_host_ipaddress.attr,
2484 	&dev_attr_host_initiatorname.attr,
2485 	NULL,
2486 };
2487 
2488 static umode_t iscsi_host_attr_is_visible(struct kobject *kobj,
2489 					 struct attribute *attr, int i)
2490 {
2491 	struct device *cdev = container_of(kobj, struct device, kobj);
2492 	struct Scsi_Host *shost = transport_class_to_shost(cdev);
2493 	struct iscsi_internal *priv = to_iscsi_internal(shost->transportt);
2494 	int param;
2495 
2496 	if (attr == &dev_attr_host_netdev.attr)
2497 		param = ISCSI_HOST_PARAM_NETDEV_NAME;
2498 	else if (attr == &dev_attr_host_hwaddress.attr)
2499 		param = ISCSI_HOST_PARAM_HWADDRESS;
2500 	else if (attr == &dev_attr_host_ipaddress.attr)
2501 		param = ISCSI_HOST_PARAM_IPADDRESS;
2502 	else if (attr == &dev_attr_host_initiatorname.attr)
2503 		param = ISCSI_HOST_PARAM_INITIATOR_NAME;
2504 	else {
2505 		WARN_ONCE(1, "Invalid host attr");
2506 		return 0;
2507 	}
2508 
2509 	return priv->iscsi_transport->attr_is_visible(ISCSI_HOST_PARAM, param);
2510 }
2511 
2512 static struct attribute_group iscsi_host_group = {
2513 	.attrs = iscsi_host_attrs,
2514 	.is_visible = iscsi_host_attr_is_visible,
2515 };
2516 
2517 static int iscsi_session_match(struct attribute_container *cont,
2518 			   struct device *dev)
2519 {
2520 	struct iscsi_cls_session *session;
2521 	struct Scsi_Host *shost;
2522 	struct iscsi_internal *priv;
2523 
2524 	if (!iscsi_is_session_dev(dev))
2525 		return 0;
2526 
2527 	session = iscsi_dev_to_session(dev);
2528 	shost = iscsi_session_to_shost(session);
2529 	if (!shost->transportt)
2530 		return 0;
2531 
2532 	priv = to_iscsi_internal(shost->transportt);
2533 	if (priv->session_cont.ac.class != &iscsi_session_class.class)
2534 		return 0;
2535 
2536 	return &priv->session_cont.ac == cont;
2537 }
2538 
2539 static int iscsi_conn_match(struct attribute_container *cont,
2540 			   struct device *dev)
2541 {
2542 	struct iscsi_cls_session *session;
2543 	struct iscsi_cls_conn *conn;
2544 	struct Scsi_Host *shost;
2545 	struct iscsi_internal *priv;
2546 
2547 	if (!iscsi_is_conn_dev(dev))
2548 		return 0;
2549 
2550 	conn = iscsi_dev_to_conn(dev);
2551 	session = iscsi_dev_to_session(conn->dev.parent);
2552 	shost = iscsi_session_to_shost(session);
2553 
2554 	if (!shost->transportt)
2555 		return 0;
2556 
2557 	priv = to_iscsi_internal(shost->transportt);
2558 	if (priv->conn_cont.ac.class != &iscsi_connection_class.class)
2559 		return 0;
2560 
2561 	return &priv->conn_cont.ac == cont;
2562 }
2563 
2564 static int iscsi_host_match(struct attribute_container *cont,
2565 			    struct device *dev)
2566 {
2567 	struct Scsi_Host *shost;
2568 	struct iscsi_internal *priv;
2569 
2570 	if (!scsi_is_host_device(dev))
2571 		return 0;
2572 
2573 	shost = dev_to_shost(dev);
2574 	if (!shost->transportt  ||
2575 	    shost->transportt->host_attrs.ac.class != &iscsi_host_class.class)
2576 		return 0;
2577 
2578         priv = to_iscsi_internal(shost->transportt);
2579         return &priv->t.host_attrs.ac == cont;
2580 }
2581 
2582 struct scsi_transport_template *
2583 iscsi_register_transport(struct iscsi_transport *tt)
2584 {
2585 	struct iscsi_internal *priv;
2586 	unsigned long flags;
2587 	int err;
2588 
2589 	BUG_ON(!tt);
2590 
2591 	priv = iscsi_if_transport_lookup(tt);
2592 	if (priv)
2593 		return NULL;
2594 
2595 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
2596 	if (!priv)
2597 		return NULL;
2598 	INIT_LIST_HEAD(&priv->list);
2599 	priv->iscsi_transport = tt;
2600 	priv->t.user_scan = iscsi_user_scan;
2601 	priv->t.create_work_queue = 1;
2602 
2603 	priv->dev.class = &iscsi_transport_class;
2604 	dev_set_name(&priv->dev, "%s", tt->name);
2605 	err = device_register(&priv->dev);
2606 	if (err)
2607 		goto free_priv;
2608 
2609 	err = sysfs_create_group(&priv->dev.kobj, &iscsi_transport_group);
2610 	if (err)
2611 		goto unregister_dev;
2612 
2613 	/* host parameters */
2614 	priv->t.host_attrs.ac.class = &iscsi_host_class.class;
2615 	priv->t.host_attrs.ac.match = iscsi_host_match;
2616 	priv->t.host_attrs.ac.grp = &iscsi_host_group;
2617 	priv->t.host_size = sizeof(struct iscsi_cls_host);
2618 	transport_container_register(&priv->t.host_attrs);
2619 
2620 	/* connection parameters */
2621 	priv->conn_cont.ac.class = &iscsi_connection_class.class;
2622 	priv->conn_cont.ac.match = iscsi_conn_match;
2623 	priv->conn_cont.ac.grp = &iscsi_conn_group;
2624 	transport_container_register(&priv->conn_cont);
2625 
2626 	/* session parameters */
2627 	priv->session_cont.ac.class = &iscsi_session_class.class;
2628 	priv->session_cont.ac.match = iscsi_session_match;
2629 	priv->session_cont.ac.grp = &iscsi_session_group;
2630 	transport_container_register(&priv->session_cont);
2631 
2632 	spin_lock_irqsave(&iscsi_transport_lock, flags);
2633 	list_add(&priv->list, &iscsi_transports);
2634 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
2635 
2636 	printk(KERN_NOTICE "iscsi: registered transport (%s)\n", tt->name);
2637 	return &priv->t;
2638 
2639 unregister_dev:
2640 	device_unregister(&priv->dev);
2641 	return NULL;
2642 free_priv:
2643 	kfree(priv);
2644 	return NULL;
2645 }
2646 EXPORT_SYMBOL_GPL(iscsi_register_transport);
2647 
2648 int iscsi_unregister_transport(struct iscsi_transport *tt)
2649 {
2650 	struct iscsi_internal *priv;
2651 	unsigned long flags;
2652 
2653 	BUG_ON(!tt);
2654 
2655 	mutex_lock(&rx_queue_mutex);
2656 
2657 	priv = iscsi_if_transport_lookup(tt);
2658 	BUG_ON (!priv);
2659 
2660 	spin_lock_irqsave(&iscsi_transport_lock, flags);
2661 	list_del(&priv->list);
2662 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);
2663 
2664 	transport_container_unregister(&priv->conn_cont);
2665 	transport_container_unregister(&priv->session_cont);
2666 	transport_container_unregister(&priv->t.host_attrs);
2667 
2668 	sysfs_remove_group(&priv->dev.kobj, &iscsi_transport_group);
2669 	device_unregister(&priv->dev);
2670 	mutex_unlock(&rx_queue_mutex);
2671 
2672 	return 0;
2673 }
2674 EXPORT_SYMBOL_GPL(iscsi_unregister_transport);
2675 
2676 static __init int iscsi_transport_init(void)
2677 {
2678 	int err;
2679 
2680 	printk(KERN_INFO "Loading iSCSI transport class v%s.\n",
2681 		ISCSI_TRANSPORT_VERSION);
2682 
2683 	atomic_set(&iscsi_session_nr, 0);
2684 
2685 	err = class_register(&iscsi_transport_class);
2686 	if (err)
2687 		return err;
2688 
2689 	err = class_register(&iscsi_endpoint_class);
2690 	if (err)
2691 		goto unregister_transport_class;
2692 
2693 	err = class_register(&iscsi_iface_class);
2694 	if (err)
2695 		goto unregister_endpoint_class;
2696 
2697 	err = transport_class_register(&iscsi_host_class);
2698 	if (err)
2699 		goto unregister_iface_class;
2700 
2701 	err = transport_class_register(&iscsi_connection_class);
2702 	if (err)
2703 		goto unregister_host_class;
2704 
2705 	err = transport_class_register(&iscsi_session_class);
2706 	if (err)
2707 		goto unregister_conn_class;
2708 
2709 	nls = netlink_kernel_create(&init_net, NETLINK_ISCSI, 1, iscsi_if_rx,
2710 				    NULL, THIS_MODULE);
2711 	if (!nls) {
2712 		err = -ENOBUFS;
2713 		goto unregister_session_class;
2714 	}
2715 
2716 	iscsi_eh_timer_workq = create_singlethread_workqueue("iscsi_eh");
2717 	if (!iscsi_eh_timer_workq)
2718 		goto release_nls;
2719 
2720 	return 0;
2721 
2722 release_nls:
2723 	netlink_kernel_release(nls);
2724 unregister_session_class:
2725 	transport_class_unregister(&iscsi_session_class);
2726 unregister_conn_class:
2727 	transport_class_unregister(&iscsi_connection_class);
2728 unregister_host_class:
2729 	transport_class_unregister(&iscsi_host_class);
2730 unregister_iface_class:
2731 	class_unregister(&iscsi_iface_class);
2732 unregister_endpoint_class:
2733 	class_unregister(&iscsi_endpoint_class);
2734 unregister_transport_class:
2735 	class_unregister(&iscsi_transport_class);
2736 	return err;
2737 }
2738 
2739 static void __exit iscsi_transport_exit(void)
2740 {
2741 	destroy_workqueue(iscsi_eh_timer_workq);
2742 	netlink_kernel_release(nls);
2743 	transport_class_unregister(&iscsi_connection_class);
2744 	transport_class_unregister(&iscsi_session_class);
2745 	transport_class_unregister(&iscsi_host_class);
2746 	class_unregister(&iscsi_endpoint_class);
2747 	class_unregister(&iscsi_iface_class);
2748 	class_unregister(&iscsi_transport_class);
2749 }
2750 
2751 module_init(iscsi_transport_init);
2752 module_exit(iscsi_transport_exit);
2753 
2754 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, "
2755 	      "Dmitry Yusupov <dmitry_yus@yahoo.com>, "
2756 	      "Alex Aizman <itn780@yahoo.com>");
2757 MODULE_DESCRIPTION("iSCSI Transport Interface");
2758 MODULE_LICENSE("GPL");
2759 MODULE_VERSION(ISCSI_TRANSPORT_VERSION);
2760 MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_ISCSI);
2761