1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3  * This file contains main functions related to the iSCSI Target Core Driver.
4  *
5  * (c) Copyright 2007-2013 Datera, Inc.
6  *
7  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
8  *
9  ******************************************************************************/
10 
11 #include <crypto/hash.h>
12 #include <linux/string.h>
13 #include <linux/kthread.h>
14 #include <linux/completion.h>
15 #include <linux/module.h>
16 #include <linux/vmalloc.h>
17 #include <linux/idr.h>
18 #include <linux/delay.h>
19 #include <linux/sched/signal.h>
20 #include <asm/unaligned.h>
21 #include <linux/inet.h>
22 #include <net/ipv6.h>
23 #include <scsi/scsi_proto.h>
24 #include <scsi/iscsi_proto.h>
25 #include <scsi/scsi_tcq.h>
26 #include <target/target_core_base.h>
27 #include <target/target_core_fabric.h>
28 
29 #include <target/iscsi/iscsi_target_core.h>
30 #include "iscsi_target_parameters.h"
31 #include "iscsi_target_seq_pdu_list.h"
32 #include "iscsi_target_datain_values.h"
33 #include "iscsi_target_erl0.h"
34 #include "iscsi_target_erl1.h"
35 #include "iscsi_target_erl2.h"
36 #include "iscsi_target_login.h"
37 #include "iscsi_target_tmr.h"
38 #include "iscsi_target_tpg.h"
39 #include "iscsi_target_util.h"
40 #include "iscsi_target.h"
41 #include "iscsi_target_device.h"
42 #include <target/iscsi/iscsi_target_stat.h>
43 
44 #include <target/iscsi/iscsi_transport.h>
45 
46 static LIST_HEAD(g_tiqn_list);
47 static LIST_HEAD(g_np_list);
48 static DEFINE_SPINLOCK(tiqn_lock);
49 static DEFINE_MUTEX(np_lock);
50 
51 static struct idr tiqn_idr;
52 DEFINE_IDA(sess_ida);
53 struct mutex auth_id_lock;
54 
55 struct iscsit_global *iscsit_global;
56 
57 struct kmem_cache *lio_qr_cache;
58 struct kmem_cache *lio_dr_cache;
59 struct kmem_cache *lio_ooo_cache;
60 struct kmem_cache *lio_r2t_cache;
61 
62 static int iscsit_handle_immediate_data(struct iscsi_cmd *,
63 			struct iscsi_scsi_req *, u32);
64 
65 struct iscsi_tiqn *iscsit_get_tiqn_for_login(unsigned char *buf)
66 {
67 	struct iscsi_tiqn *tiqn = NULL;
68 
69 	spin_lock(&tiqn_lock);
70 	list_for_each_entry(tiqn, &g_tiqn_list, tiqn_list) {
71 		if (!strcmp(tiqn->tiqn, buf)) {
72 
73 			spin_lock(&tiqn->tiqn_state_lock);
74 			if (tiqn->tiqn_state == TIQN_STATE_ACTIVE) {
75 				tiqn->tiqn_access_count++;
76 				spin_unlock(&tiqn->tiqn_state_lock);
77 				spin_unlock(&tiqn_lock);
78 				return tiqn;
79 			}
80 			spin_unlock(&tiqn->tiqn_state_lock);
81 		}
82 	}
83 	spin_unlock(&tiqn_lock);
84 
85 	return NULL;
86 }
87 
88 static int iscsit_set_tiqn_shutdown(struct iscsi_tiqn *tiqn)
89 {
90 	spin_lock(&tiqn->tiqn_state_lock);
91 	if (tiqn->tiqn_state == TIQN_STATE_ACTIVE) {
92 		tiqn->tiqn_state = TIQN_STATE_SHUTDOWN;
93 		spin_unlock(&tiqn->tiqn_state_lock);
94 		return 0;
95 	}
96 	spin_unlock(&tiqn->tiqn_state_lock);
97 
98 	return -1;
99 }
100 
101 void iscsit_put_tiqn_for_login(struct iscsi_tiqn *tiqn)
102 {
103 	spin_lock(&tiqn->tiqn_state_lock);
104 	tiqn->tiqn_access_count--;
105 	spin_unlock(&tiqn->tiqn_state_lock);
106 }
107 
108 /*
109  * Note that IQN formatting is expected to be done in userspace, and
110  * no explict IQN format checks are done here.
111  */
112 struct iscsi_tiqn *iscsit_add_tiqn(unsigned char *buf)
113 {
114 	struct iscsi_tiqn *tiqn = NULL;
115 	int ret;
116 
117 	if (strlen(buf) >= ISCSI_IQN_LEN) {
118 		pr_err("Target IQN exceeds %d bytes\n",
119 				ISCSI_IQN_LEN);
120 		return ERR_PTR(-EINVAL);
121 	}
122 
123 	tiqn = kzalloc(sizeof(*tiqn), GFP_KERNEL);
124 	if (!tiqn)
125 		return ERR_PTR(-ENOMEM);
126 
127 	sprintf(tiqn->tiqn, "%s", buf);
128 	INIT_LIST_HEAD(&tiqn->tiqn_list);
129 	INIT_LIST_HEAD(&tiqn->tiqn_tpg_list);
130 	spin_lock_init(&tiqn->tiqn_state_lock);
131 	spin_lock_init(&tiqn->tiqn_tpg_lock);
132 	spin_lock_init(&tiqn->sess_err_stats.lock);
133 	spin_lock_init(&tiqn->login_stats.lock);
134 	spin_lock_init(&tiqn->logout_stats.lock);
135 
136 	tiqn->tiqn_state = TIQN_STATE_ACTIVE;
137 
138 	idr_preload(GFP_KERNEL);
139 	spin_lock(&tiqn_lock);
140 
141 	ret = idr_alloc(&tiqn_idr, NULL, 0, 0, GFP_NOWAIT);
142 	if (ret < 0) {
143 		pr_err("idr_alloc() failed for tiqn->tiqn_index\n");
144 		spin_unlock(&tiqn_lock);
145 		idr_preload_end();
146 		kfree(tiqn);
147 		return ERR_PTR(ret);
148 	}
149 	tiqn->tiqn_index = ret;
150 	list_add_tail(&tiqn->tiqn_list, &g_tiqn_list);
151 
152 	spin_unlock(&tiqn_lock);
153 	idr_preload_end();
154 
155 	pr_debug("CORE[0] - Added iSCSI Target IQN: %s\n", tiqn->tiqn);
156 
157 	return tiqn;
158 
159 }
160 
161 static void iscsit_wait_for_tiqn(struct iscsi_tiqn *tiqn)
162 {
163 	/*
164 	 * Wait for accesses to said struct iscsi_tiqn to end.
165 	 */
166 	spin_lock(&tiqn->tiqn_state_lock);
167 	while (tiqn->tiqn_access_count != 0) {
168 		spin_unlock(&tiqn->tiqn_state_lock);
169 		msleep(10);
170 		spin_lock(&tiqn->tiqn_state_lock);
171 	}
172 	spin_unlock(&tiqn->tiqn_state_lock);
173 }
174 
175 void iscsit_del_tiqn(struct iscsi_tiqn *tiqn)
176 {
177 	/*
178 	 * iscsit_set_tiqn_shutdown sets tiqn->tiqn_state = TIQN_STATE_SHUTDOWN
179 	 * while holding tiqn->tiqn_state_lock.  This means that all subsequent
180 	 * attempts to access this struct iscsi_tiqn will fail from both transport
181 	 * fabric and control code paths.
182 	 */
183 	if (iscsit_set_tiqn_shutdown(tiqn) < 0) {
184 		pr_err("iscsit_set_tiqn_shutdown() failed\n");
185 		return;
186 	}
187 
188 	iscsit_wait_for_tiqn(tiqn);
189 
190 	spin_lock(&tiqn_lock);
191 	list_del(&tiqn->tiqn_list);
192 	idr_remove(&tiqn_idr, tiqn->tiqn_index);
193 	spin_unlock(&tiqn_lock);
194 
195 	pr_debug("CORE[0] - Deleted iSCSI Target IQN: %s\n",
196 			tiqn->tiqn);
197 	kfree(tiqn);
198 }
199 
200 int iscsit_access_np(struct iscsi_np *np, struct iscsi_portal_group *tpg)
201 {
202 	int ret;
203 	/*
204 	 * Determine if the network portal is accepting storage traffic.
205 	 */
206 	spin_lock_bh(&np->np_thread_lock);
207 	if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
208 		spin_unlock_bh(&np->np_thread_lock);
209 		return -1;
210 	}
211 	spin_unlock_bh(&np->np_thread_lock);
212 	/*
213 	 * Determine if the portal group is accepting storage traffic.
214 	 */
215 	spin_lock_bh(&tpg->tpg_state_lock);
216 	if (tpg->tpg_state != TPG_STATE_ACTIVE) {
217 		spin_unlock_bh(&tpg->tpg_state_lock);
218 		return -1;
219 	}
220 	spin_unlock_bh(&tpg->tpg_state_lock);
221 
222 	/*
223 	 * Here we serialize access across the TIQN+TPG Tuple.
224 	 */
225 	ret = down_interruptible(&tpg->np_login_sem);
226 	if (ret != 0)
227 		return -1;
228 
229 	spin_lock_bh(&tpg->tpg_state_lock);
230 	if (tpg->tpg_state != TPG_STATE_ACTIVE) {
231 		spin_unlock_bh(&tpg->tpg_state_lock);
232 		up(&tpg->np_login_sem);
233 		return -1;
234 	}
235 	spin_unlock_bh(&tpg->tpg_state_lock);
236 
237 	return 0;
238 }
239 
240 void iscsit_login_kref_put(struct kref *kref)
241 {
242 	struct iscsi_tpg_np *tpg_np = container_of(kref,
243 				struct iscsi_tpg_np, tpg_np_kref);
244 
245 	complete(&tpg_np->tpg_np_comp);
246 }
247 
248 int iscsit_deaccess_np(struct iscsi_np *np, struct iscsi_portal_group *tpg,
249 		       struct iscsi_tpg_np *tpg_np)
250 {
251 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
252 
253 	up(&tpg->np_login_sem);
254 
255 	if (tpg_np)
256 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
257 
258 	if (tiqn)
259 		iscsit_put_tiqn_for_login(tiqn);
260 
261 	return 0;
262 }
263 
264 bool iscsit_check_np_match(
265 	struct sockaddr_storage *sockaddr,
266 	struct iscsi_np *np,
267 	int network_transport)
268 {
269 	struct sockaddr_in *sock_in, *sock_in_e;
270 	struct sockaddr_in6 *sock_in6, *sock_in6_e;
271 	bool ip_match = false;
272 	u16 port, port_e;
273 
274 	if (sockaddr->ss_family == AF_INET6) {
275 		sock_in6 = (struct sockaddr_in6 *)sockaddr;
276 		sock_in6_e = (struct sockaddr_in6 *)&np->np_sockaddr;
277 
278 		if (!memcmp(&sock_in6->sin6_addr.in6_u,
279 			    &sock_in6_e->sin6_addr.in6_u,
280 			    sizeof(struct in6_addr)))
281 			ip_match = true;
282 
283 		port = ntohs(sock_in6->sin6_port);
284 		port_e = ntohs(sock_in6_e->sin6_port);
285 	} else {
286 		sock_in = (struct sockaddr_in *)sockaddr;
287 		sock_in_e = (struct sockaddr_in *)&np->np_sockaddr;
288 
289 		if (sock_in->sin_addr.s_addr == sock_in_e->sin_addr.s_addr)
290 			ip_match = true;
291 
292 		port = ntohs(sock_in->sin_port);
293 		port_e = ntohs(sock_in_e->sin_port);
294 	}
295 
296 	if (ip_match && (port_e == port) &&
297 	    (np->np_network_transport == network_transport))
298 		return true;
299 
300 	return false;
301 }
302 
303 static struct iscsi_np *iscsit_get_np(
304 	struct sockaddr_storage *sockaddr,
305 	int network_transport)
306 {
307 	struct iscsi_np *np;
308 	bool match;
309 
310 	lockdep_assert_held(&np_lock);
311 
312 	list_for_each_entry(np, &g_np_list, np_list) {
313 		spin_lock_bh(&np->np_thread_lock);
314 		if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
315 			spin_unlock_bh(&np->np_thread_lock);
316 			continue;
317 		}
318 
319 		match = iscsit_check_np_match(sockaddr, np, network_transport);
320 		if (match) {
321 			/*
322 			 * Increment the np_exports reference count now to
323 			 * prevent iscsit_del_np() below from being called
324 			 * while iscsi_tpg_add_network_portal() is called.
325 			 */
326 			np->np_exports++;
327 			spin_unlock_bh(&np->np_thread_lock);
328 			return np;
329 		}
330 		spin_unlock_bh(&np->np_thread_lock);
331 	}
332 
333 	return NULL;
334 }
335 
336 struct iscsi_np *iscsit_add_np(
337 	struct sockaddr_storage *sockaddr,
338 	int network_transport)
339 {
340 	struct iscsi_np *np;
341 	int ret;
342 
343 	mutex_lock(&np_lock);
344 
345 	/*
346 	 * Locate the existing struct iscsi_np if already active..
347 	 */
348 	np = iscsit_get_np(sockaddr, network_transport);
349 	if (np) {
350 		mutex_unlock(&np_lock);
351 		return np;
352 	}
353 
354 	np = kzalloc(sizeof(*np), GFP_KERNEL);
355 	if (!np) {
356 		mutex_unlock(&np_lock);
357 		return ERR_PTR(-ENOMEM);
358 	}
359 
360 	np->np_flags |= NPF_IP_NETWORK;
361 	np->np_network_transport = network_transport;
362 	spin_lock_init(&np->np_thread_lock);
363 	init_completion(&np->np_restart_comp);
364 	INIT_LIST_HEAD(&np->np_list);
365 
366 	timer_setup(&np->np_login_timer, iscsi_handle_login_thread_timeout, 0);
367 
368 	ret = iscsi_target_setup_login_socket(np, sockaddr);
369 	if (ret != 0) {
370 		kfree(np);
371 		mutex_unlock(&np_lock);
372 		return ERR_PTR(ret);
373 	}
374 
375 	np->np_thread = kthread_run(iscsi_target_login_thread, np, "iscsi_np");
376 	if (IS_ERR(np->np_thread)) {
377 		pr_err("Unable to create kthread: iscsi_np\n");
378 		ret = PTR_ERR(np->np_thread);
379 		kfree(np);
380 		mutex_unlock(&np_lock);
381 		return ERR_PTR(ret);
382 	}
383 	/*
384 	 * Increment the np_exports reference count now to prevent
385 	 * iscsit_del_np() below from being run while a new call to
386 	 * iscsi_tpg_add_network_portal() for a matching iscsi_np is
387 	 * active.  We don't need to hold np->np_thread_lock at this
388 	 * point because iscsi_np has not been added to g_np_list yet.
389 	 */
390 	np->np_exports = 1;
391 	np->np_thread_state = ISCSI_NP_THREAD_ACTIVE;
392 
393 	list_add_tail(&np->np_list, &g_np_list);
394 	mutex_unlock(&np_lock);
395 
396 	pr_debug("CORE[0] - Added Network Portal: %pISpc on %s\n",
397 		&np->np_sockaddr, np->np_transport->name);
398 
399 	return np;
400 }
401 
402 int iscsit_reset_np_thread(
403 	struct iscsi_np *np,
404 	struct iscsi_tpg_np *tpg_np,
405 	struct iscsi_portal_group *tpg,
406 	bool shutdown)
407 {
408 	spin_lock_bh(&np->np_thread_lock);
409 	if (np->np_thread_state == ISCSI_NP_THREAD_INACTIVE) {
410 		spin_unlock_bh(&np->np_thread_lock);
411 		return 0;
412 	}
413 	np->np_thread_state = ISCSI_NP_THREAD_RESET;
414 	atomic_inc(&np->np_reset_count);
415 
416 	if (np->np_thread) {
417 		spin_unlock_bh(&np->np_thread_lock);
418 		send_sig(SIGINT, np->np_thread, 1);
419 		wait_for_completion(&np->np_restart_comp);
420 		spin_lock_bh(&np->np_thread_lock);
421 	}
422 	spin_unlock_bh(&np->np_thread_lock);
423 
424 	if (tpg_np && shutdown) {
425 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
426 
427 		wait_for_completion(&tpg_np->tpg_np_comp);
428 	}
429 
430 	return 0;
431 }
432 
433 static void iscsit_free_np(struct iscsi_np *np)
434 {
435 	if (np->np_socket)
436 		sock_release(np->np_socket);
437 }
438 
439 int iscsit_del_np(struct iscsi_np *np)
440 {
441 	spin_lock_bh(&np->np_thread_lock);
442 	np->np_exports--;
443 	if (np->np_exports) {
444 		np->enabled = true;
445 		spin_unlock_bh(&np->np_thread_lock);
446 		return 0;
447 	}
448 	np->np_thread_state = ISCSI_NP_THREAD_SHUTDOWN;
449 	spin_unlock_bh(&np->np_thread_lock);
450 
451 	if (np->np_thread) {
452 		/*
453 		 * We need to send the signal to wakeup Linux/Net
454 		 * which may be sleeping in sock_accept()..
455 		 */
456 		send_sig(SIGINT, np->np_thread, 1);
457 		kthread_stop(np->np_thread);
458 		np->np_thread = NULL;
459 	}
460 
461 	np->np_transport->iscsit_free_np(np);
462 
463 	mutex_lock(&np_lock);
464 	list_del(&np->np_list);
465 	mutex_unlock(&np_lock);
466 
467 	pr_debug("CORE[0] - Removed Network Portal: %pISpc on %s\n",
468 		&np->np_sockaddr, np->np_transport->name);
469 
470 	iscsit_put_transport(np->np_transport);
471 	kfree(np);
472 	return 0;
473 }
474 
475 static void iscsit_get_rx_pdu(struct iscsi_conn *);
476 
477 int iscsit_queue_rsp(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
478 {
479 	return iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
480 }
481 EXPORT_SYMBOL(iscsit_queue_rsp);
482 
483 void iscsit_aborted_task(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
484 {
485 	spin_lock_bh(&conn->cmd_lock);
486 	if (!list_empty(&cmd->i_conn_node) &&
487 	    !(cmd->se_cmd.transport_state & CMD_T_FABRIC_STOP))
488 		list_del_init(&cmd->i_conn_node);
489 	spin_unlock_bh(&conn->cmd_lock);
490 
491 	__iscsit_free_cmd(cmd, true);
492 }
493 EXPORT_SYMBOL(iscsit_aborted_task);
494 
495 static void iscsit_do_crypto_hash_buf(struct ahash_request *, const void *,
496 				      u32, u32, const void *, void *);
497 static void iscsit_tx_thread_wait_for_tcp(struct iscsi_conn *);
498 
499 static int
500 iscsit_xmit_nondatain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
501 			  const void *data_buf, u32 data_buf_len)
502 {
503 	struct iscsi_hdr *hdr = (struct iscsi_hdr *)cmd->pdu;
504 	struct kvec *iov;
505 	u32 niov = 0, tx_size = ISCSI_HDR_LEN;
506 	int ret;
507 
508 	iov = &cmd->iov_misc[0];
509 	iov[niov].iov_base	= cmd->pdu;
510 	iov[niov++].iov_len	= ISCSI_HDR_LEN;
511 
512 	if (conn->conn_ops->HeaderDigest) {
513 		u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];
514 
515 		iscsit_do_crypto_hash_buf(conn->conn_tx_hash, hdr,
516 					  ISCSI_HDR_LEN, 0, NULL,
517 					  header_digest);
518 
519 		iov[0].iov_len += ISCSI_CRC_LEN;
520 		tx_size += ISCSI_CRC_LEN;
521 		pr_debug("Attaching CRC32C HeaderDigest"
522 			 " to opcode 0x%x 0x%08x\n",
523 			 hdr->opcode, *header_digest);
524 	}
525 
526 	if (data_buf_len) {
527 		u32 padding = ((-data_buf_len) & 3);
528 
529 		iov[niov].iov_base	= (void *)data_buf;
530 		iov[niov++].iov_len	= data_buf_len;
531 		tx_size += data_buf_len;
532 
533 		if (padding != 0) {
534 			iov[niov].iov_base = &cmd->pad_bytes;
535 			iov[niov++].iov_len = padding;
536 			tx_size += padding;
537 			pr_debug("Attaching %u additional"
538 				 " padding bytes.\n", padding);
539 		}
540 
541 		if (conn->conn_ops->DataDigest) {
542 			iscsit_do_crypto_hash_buf(conn->conn_tx_hash,
543 						  data_buf, data_buf_len,
544 						  padding, &cmd->pad_bytes,
545 						  &cmd->data_crc);
546 
547 			iov[niov].iov_base = &cmd->data_crc;
548 			iov[niov++].iov_len = ISCSI_CRC_LEN;
549 			tx_size += ISCSI_CRC_LEN;
550 			pr_debug("Attached DataDigest for %u"
551 				 " bytes opcode 0x%x, CRC 0x%08x\n",
552 				 data_buf_len, hdr->opcode, cmd->data_crc);
553 		}
554 	}
555 
556 	cmd->iov_misc_count = niov;
557 	cmd->tx_size = tx_size;
558 
559 	ret = iscsit_send_tx_data(cmd, conn, 1);
560 	if (ret < 0) {
561 		iscsit_tx_thread_wait_for_tcp(conn);
562 		return ret;
563 	}
564 
565 	return 0;
566 }
567 
568 static int iscsit_map_iovec(struct iscsi_cmd *cmd, struct kvec *iov, int nvec,
569 			    u32 data_offset, u32 data_length);
570 static void iscsit_unmap_iovec(struct iscsi_cmd *);
571 static u32 iscsit_do_crypto_hash_sg(struct ahash_request *, struct iscsi_cmd *,
572 				    u32, u32, u32, u8 *);
573 static int
574 iscsit_xmit_datain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
575 		       const struct iscsi_datain *datain)
576 {
577 	struct kvec *iov;
578 	u32 iov_count = 0, tx_size = 0;
579 	int ret, iov_ret;
580 
581 	iov = &cmd->iov_data[0];
582 	iov[iov_count].iov_base	= cmd->pdu;
583 	iov[iov_count++].iov_len = ISCSI_HDR_LEN;
584 	tx_size += ISCSI_HDR_LEN;
585 
586 	if (conn->conn_ops->HeaderDigest) {
587 		u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];
588 
589 		iscsit_do_crypto_hash_buf(conn->conn_tx_hash, cmd->pdu,
590 					  ISCSI_HDR_LEN, 0, NULL,
591 					  header_digest);
592 
593 		iov[0].iov_len += ISCSI_CRC_LEN;
594 		tx_size += ISCSI_CRC_LEN;
595 
596 		pr_debug("Attaching CRC32 HeaderDigest for DataIN PDU 0x%08x\n",
597 			 *header_digest);
598 	}
599 
600 	iov_ret = iscsit_map_iovec(cmd, &cmd->iov_data[iov_count],
601 				   cmd->orig_iov_data_count - (iov_count + 2),
602 				   datain->offset, datain->length);
603 	if (iov_ret < 0)
604 		return -1;
605 
606 	iov_count += iov_ret;
607 	tx_size += datain->length;
608 
609 	cmd->padding = ((-datain->length) & 3);
610 	if (cmd->padding) {
611 		iov[iov_count].iov_base		= cmd->pad_bytes;
612 		iov[iov_count++].iov_len	= cmd->padding;
613 		tx_size += cmd->padding;
614 
615 		pr_debug("Attaching %u padding bytes\n", cmd->padding);
616 	}
617 
618 	if (conn->conn_ops->DataDigest) {
619 		cmd->data_crc = iscsit_do_crypto_hash_sg(conn->conn_tx_hash,
620 							 cmd, datain->offset,
621 							 datain->length,
622 							 cmd->padding,
623 							 cmd->pad_bytes);
624 
625 		iov[iov_count].iov_base	= &cmd->data_crc;
626 		iov[iov_count++].iov_len = ISCSI_CRC_LEN;
627 		tx_size += ISCSI_CRC_LEN;
628 
629 		pr_debug("Attached CRC32C DataDigest %d bytes, crc 0x%08x\n",
630 			 datain->length + cmd->padding, cmd->data_crc);
631 	}
632 
633 	cmd->iov_data_count = iov_count;
634 	cmd->tx_size = tx_size;
635 
636 	ret = iscsit_fe_sendpage_sg(cmd, conn);
637 
638 	iscsit_unmap_iovec(cmd);
639 
640 	if (ret < 0) {
641 		iscsit_tx_thread_wait_for_tcp(conn);
642 		return ret;
643 	}
644 
645 	return 0;
646 }
647 
648 static int iscsit_xmit_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
649 			   struct iscsi_datain_req *dr, const void *buf,
650 			   u32 buf_len)
651 {
652 	if (dr)
653 		return iscsit_xmit_datain_pdu(conn, cmd, buf);
654 	else
655 		return iscsit_xmit_nondatain_pdu(conn, cmd, buf, buf_len);
656 }
657 
658 static enum target_prot_op iscsit_get_sup_prot_ops(struct iscsi_conn *conn)
659 {
660 	return TARGET_PROT_NORMAL;
661 }
662 
663 static struct iscsit_transport iscsi_target_transport = {
664 	.name			= "iSCSI/TCP",
665 	.transport_type		= ISCSI_TCP,
666 	.rdma_shutdown		= false,
667 	.owner			= NULL,
668 	.iscsit_setup_np	= iscsit_setup_np,
669 	.iscsit_accept_np	= iscsit_accept_np,
670 	.iscsit_free_np		= iscsit_free_np,
671 	.iscsit_get_login_rx	= iscsit_get_login_rx,
672 	.iscsit_put_login_tx	= iscsit_put_login_tx,
673 	.iscsit_get_dataout	= iscsit_build_r2ts_for_cmd,
674 	.iscsit_immediate_queue	= iscsit_immediate_queue,
675 	.iscsit_response_queue	= iscsit_response_queue,
676 	.iscsit_queue_data_in	= iscsit_queue_rsp,
677 	.iscsit_queue_status	= iscsit_queue_rsp,
678 	.iscsit_aborted_task	= iscsit_aborted_task,
679 	.iscsit_xmit_pdu	= iscsit_xmit_pdu,
680 	.iscsit_get_rx_pdu	= iscsit_get_rx_pdu,
681 	.iscsit_get_sup_prot_ops = iscsit_get_sup_prot_ops,
682 };
683 
684 static int __init iscsi_target_init_module(void)
685 {
686 	int ret = 0, size;
687 
688 	pr_debug("iSCSI-Target "ISCSIT_VERSION"\n");
689 	iscsit_global = kzalloc(sizeof(*iscsit_global), GFP_KERNEL);
690 	if (!iscsit_global)
691 		return -1;
692 
693 	spin_lock_init(&iscsit_global->ts_bitmap_lock);
694 	mutex_init(&auth_id_lock);
695 	idr_init(&tiqn_idr);
696 
697 	ret = target_register_template(&iscsi_ops);
698 	if (ret)
699 		goto out;
700 
701 	size = BITS_TO_LONGS(ISCSIT_BITMAP_BITS) * sizeof(long);
702 	iscsit_global->ts_bitmap = vzalloc(size);
703 	if (!iscsit_global->ts_bitmap)
704 		goto configfs_out;
705 
706 	lio_qr_cache = kmem_cache_create("lio_qr_cache",
707 			sizeof(struct iscsi_queue_req),
708 			__alignof__(struct iscsi_queue_req), 0, NULL);
709 	if (!lio_qr_cache) {
710 		pr_err("Unable to kmem_cache_create() for"
711 				" lio_qr_cache\n");
712 		goto bitmap_out;
713 	}
714 
715 	lio_dr_cache = kmem_cache_create("lio_dr_cache",
716 			sizeof(struct iscsi_datain_req),
717 			__alignof__(struct iscsi_datain_req), 0, NULL);
718 	if (!lio_dr_cache) {
719 		pr_err("Unable to kmem_cache_create() for"
720 				" lio_dr_cache\n");
721 		goto qr_out;
722 	}
723 
724 	lio_ooo_cache = kmem_cache_create("lio_ooo_cache",
725 			sizeof(struct iscsi_ooo_cmdsn),
726 			__alignof__(struct iscsi_ooo_cmdsn), 0, NULL);
727 	if (!lio_ooo_cache) {
728 		pr_err("Unable to kmem_cache_create() for"
729 				" lio_ooo_cache\n");
730 		goto dr_out;
731 	}
732 
733 	lio_r2t_cache = kmem_cache_create("lio_r2t_cache",
734 			sizeof(struct iscsi_r2t), __alignof__(struct iscsi_r2t),
735 			0, NULL);
736 	if (!lio_r2t_cache) {
737 		pr_err("Unable to kmem_cache_create() for"
738 				" lio_r2t_cache\n");
739 		goto ooo_out;
740 	}
741 
742 	iscsit_register_transport(&iscsi_target_transport);
743 
744 	if (iscsit_load_discovery_tpg() < 0)
745 		goto r2t_out;
746 
747 	return ret;
748 r2t_out:
749 	iscsit_unregister_transport(&iscsi_target_transport);
750 	kmem_cache_destroy(lio_r2t_cache);
751 ooo_out:
752 	kmem_cache_destroy(lio_ooo_cache);
753 dr_out:
754 	kmem_cache_destroy(lio_dr_cache);
755 qr_out:
756 	kmem_cache_destroy(lio_qr_cache);
757 bitmap_out:
758 	vfree(iscsit_global->ts_bitmap);
759 configfs_out:
760 	/* XXX: this probably wants it to be it's own unwind step.. */
761 	if (iscsit_global->discovery_tpg)
762 		iscsit_tpg_disable_portal_group(iscsit_global->discovery_tpg, 1);
763 	target_unregister_template(&iscsi_ops);
764 out:
765 	kfree(iscsit_global);
766 	return -ENOMEM;
767 }
768 
769 static void __exit iscsi_target_cleanup_module(void)
770 {
771 	iscsit_release_discovery_tpg();
772 	iscsit_unregister_transport(&iscsi_target_transport);
773 	kmem_cache_destroy(lio_qr_cache);
774 	kmem_cache_destroy(lio_dr_cache);
775 	kmem_cache_destroy(lio_ooo_cache);
776 	kmem_cache_destroy(lio_r2t_cache);
777 
778 	/*
779 	 * Shutdown discovery sessions and disable discovery TPG
780 	 */
781 	if (iscsit_global->discovery_tpg)
782 		iscsit_tpg_disable_portal_group(iscsit_global->discovery_tpg, 1);
783 
784 	target_unregister_template(&iscsi_ops);
785 
786 	vfree(iscsit_global->ts_bitmap);
787 	kfree(iscsit_global);
788 }
789 
790 int iscsit_add_reject(
791 	struct iscsi_conn *conn,
792 	u8 reason,
793 	unsigned char *buf)
794 {
795 	struct iscsi_cmd *cmd;
796 
797 	cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
798 	if (!cmd)
799 		return -1;
800 
801 	cmd->iscsi_opcode = ISCSI_OP_REJECT;
802 	cmd->reject_reason = reason;
803 
804 	cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL);
805 	if (!cmd->buf_ptr) {
806 		pr_err("Unable to allocate memory for cmd->buf_ptr\n");
807 		iscsit_free_cmd(cmd, false);
808 		return -1;
809 	}
810 
811 	spin_lock_bh(&conn->cmd_lock);
812 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
813 	spin_unlock_bh(&conn->cmd_lock);
814 
815 	cmd->i_state = ISTATE_SEND_REJECT;
816 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
817 
818 	return -1;
819 }
820 EXPORT_SYMBOL(iscsit_add_reject);
821 
822 static int iscsit_add_reject_from_cmd(
823 	struct iscsi_cmd *cmd,
824 	u8 reason,
825 	bool add_to_conn,
826 	unsigned char *buf)
827 {
828 	struct iscsi_conn *conn;
829 	const bool do_put = cmd->se_cmd.se_tfo != NULL;
830 
831 	if (!cmd->conn) {
832 		pr_err("cmd->conn is NULL for ITT: 0x%08x\n",
833 				cmd->init_task_tag);
834 		return -1;
835 	}
836 	conn = cmd->conn;
837 
838 	cmd->iscsi_opcode = ISCSI_OP_REJECT;
839 	cmd->reject_reason = reason;
840 
841 	cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL);
842 	if (!cmd->buf_ptr) {
843 		pr_err("Unable to allocate memory for cmd->buf_ptr\n");
844 		iscsit_free_cmd(cmd, false);
845 		return -1;
846 	}
847 
848 	if (add_to_conn) {
849 		spin_lock_bh(&conn->cmd_lock);
850 		list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
851 		spin_unlock_bh(&conn->cmd_lock);
852 	}
853 
854 	cmd->i_state = ISTATE_SEND_REJECT;
855 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
856 	/*
857 	 * Perform the kref_put now if se_cmd has already been setup by
858 	 * scsit_setup_scsi_cmd()
859 	 */
860 	if (do_put) {
861 		pr_debug("iscsi reject: calling target_put_sess_cmd >>>>>>\n");
862 		target_put_sess_cmd(&cmd->se_cmd);
863 	}
864 	return -1;
865 }
866 
867 static int iscsit_add_reject_cmd(struct iscsi_cmd *cmd, u8 reason,
868 				 unsigned char *buf)
869 {
870 	return iscsit_add_reject_from_cmd(cmd, reason, true, buf);
871 }
872 
873 int iscsit_reject_cmd(struct iscsi_cmd *cmd, u8 reason, unsigned char *buf)
874 {
875 	return iscsit_add_reject_from_cmd(cmd, reason, false, buf);
876 }
877 EXPORT_SYMBOL(iscsit_reject_cmd);
878 
879 /*
880  * Map some portion of the allocated scatterlist to an iovec, suitable for
881  * kernel sockets to copy data in/out.
882  */
883 static int iscsit_map_iovec(struct iscsi_cmd *cmd, struct kvec *iov, int nvec,
884 			    u32 data_offset, u32 data_length)
885 {
886 	u32 i = 0, orig_data_length = data_length;
887 	struct scatterlist *sg;
888 	unsigned int page_off;
889 
890 	/*
891 	 * We know each entry in t_data_sg contains a page.
892 	 */
893 	u32 ent = data_offset / PAGE_SIZE;
894 
895 	if (!data_length)
896 		return 0;
897 
898 	if (ent >= cmd->se_cmd.t_data_nents) {
899 		pr_err("Initial page entry out-of-bounds\n");
900 		goto overflow;
901 	}
902 
903 	sg = &cmd->se_cmd.t_data_sg[ent];
904 	page_off = (data_offset % PAGE_SIZE);
905 
906 	cmd->first_data_sg = sg;
907 	cmd->first_data_sg_off = page_off;
908 
909 	while (data_length) {
910 		u32 cur_len;
911 
912 		if (WARN_ON_ONCE(!sg || i >= nvec))
913 			goto overflow;
914 
915 		cur_len = min_t(u32, data_length, sg->length - page_off);
916 
917 		iov[i].iov_base = kmap(sg_page(sg)) + sg->offset + page_off;
918 		iov[i].iov_len = cur_len;
919 
920 		data_length -= cur_len;
921 		page_off = 0;
922 		sg = sg_next(sg);
923 		i++;
924 	}
925 
926 	cmd->kmapped_nents = i;
927 
928 	return i;
929 
930 overflow:
931 	pr_err("offset %d + length %d overflow; %d/%d; sg-list:\n",
932 	       data_offset, orig_data_length, i, nvec);
933 	for_each_sg(cmd->se_cmd.t_data_sg, sg,
934 		    cmd->se_cmd.t_data_nents, i) {
935 		pr_err("[%d] off %d len %d\n",
936 		       i, sg->offset, sg->length);
937 	}
938 	return -1;
939 }
940 
941 static void iscsit_unmap_iovec(struct iscsi_cmd *cmd)
942 {
943 	u32 i;
944 	struct scatterlist *sg;
945 
946 	sg = cmd->first_data_sg;
947 
948 	for (i = 0; i < cmd->kmapped_nents; i++)
949 		kunmap(sg_page(&sg[i]));
950 }
951 
952 static void iscsit_ack_from_expstatsn(struct iscsi_conn *conn, u32 exp_statsn)
953 {
954 	LIST_HEAD(ack_list);
955 	struct iscsi_cmd *cmd, *cmd_p;
956 
957 	conn->exp_statsn = exp_statsn;
958 
959 	if (conn->sess->sess_ops->RDMAExtensions)
960 		return;
961 
962 	spin_lock_bh(&conn->cmd_lock);
963 	list_for_each_entry_safe(cmd, cmd_p, &conn->conn_cmd_list, i_conn_node) {
964 		spin_lock(&cmd->istate_lock);
965 		if ((cmd->i_state == ISTATE_SENT_STATUS) &&
966 		    iscsi_sna_lt(cmd->stat_sn, exp_statsn)) {
967 			cmd->i_state = ISTATE_REMOVE;
968 			spin_unlock(&cmd->istate_lock);
969 			list_move_tail(&cmd->i_conn_node, &ack_list);
970 			continue;
971 		}
972 		spin_unlock(&cmd->istate_lock);
973 	}
974 	spin_unlock_bh(&conn->cmd_lock);
975 
976 	list_for_each_entry_safe(cmd, cmd_p, &ack_list, i_conn_node) {
977 		list_del_init(&cmd->i_conn_node);
978 		iscsit_free_cmd(cmd, false);
979 	}
980 }
981 
982 static int iscsit_allocate_iovecs(struct iscsi_cmd *cmd)
983 {
984 	u32 iov_count = max(1UL, DIV_ROUND_UP(cmd->se_cmd.data_length, PAGE_SIZE));
985 
986 	iov_count += ISCSI_IOV_DATA_BUFFER;
987 	cmd->iov_data = kcalloc(iov_count, sizeof(*cmd->iov_data), GFP_KERNEL);
988 	if (!cmd->iov_data)
989 		return -ENOMEM;
990 
991 	cmd->orig_iov_data_count = iov_count;
992 	return 0;
993 }
994 
995 int iscsit_setup_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
996 			  unsigned char *buf)
997 {
998 	int data_direction, payload_length;
999 	struct iscsi_scsi_req *hdr;
1000 	int iscsi_task_attr;
1001 	int sam_task_attr;
1002 
1003 	atomic_long_inc(&conn->sess->cmd_pdus);
1004 
1005 	hdr			= (struct iscsi_scsi_req *) buf;
1006 	payload_length		= ntoh24(hdr->dlength);
1007 
1008 	/* FIXME; Add checks for AdditionalHeaderSegment */
1009 
1010 	if (!(hdr->flags & ISCSI_FLAG_CMD_WRITE) &&
1011 	    !(hdr->flags & ISCSI_FLAG_CMD_FINAL)) {
1012 		pr_err("ISCSI_FLAG_CMD_WRITE & ISCSI_FLAG_CMD_FINAL"
1013 				" not set. Bad iSCSI Initiator.\n");
1014 		return iscsit_add_reject_cmd(cmd,
1015 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1016 	}
1017 
1018 	if (((hdr->flags & ISCSI_FLAG_CMD_READ) ||
1019 	     (hdr->flags & ISCSI_FLAG_CMD_WRITE)) && !hdr->data_length) {
1020 		/*
1021 		 * From RFC-3720 Section 10.3.1:
1022 		 *
1023 		 * "Either or both of R and W MAY be 1 when either the
1024 		 *  Expected Data Transfer Length and/or Bidirectional Read
1025 		 *  Expected Data Transfer Length are 0"
1026 		 *
1027 		 * For this case, go ahead and clear the unnecssary bits
1028 		 * to avoid any confusion with ->data_direction.
1029 		 */
1030 		hdr->flags &= ~ISCSI_FLAG_CMD_READ;
1031 		hdr->flags &= ~ISCSI_FLAG_CMD_WRITE;
1032 
1033 		pr_warn("ISCSI_FLAG_CMD_READ or ISCSI_FLAG_CMD_WRITE"
1034 			" set when Expected Data Transfer Length is 0 for"
1035 			" CDB: 0x%02x, Fixing up flags\n", hdr->cdb[0]);
1036 	}
1037 
1038 	if (!(hdr->flags & ISCSI_FLAG_CMD_READ) &&
1039 	    !(hdr->flags & ISCSI_FLAG_CMD_WRITE) && (hdr->data_length != 0)) {
1040 		pr_err("ISCSI_FLAG_CMD_READ and/or ISCSI_FLAG_CMD_WRITE"
1041 			" MUST be set if Expected Data Transfer Length is not 0."
1042 			" Bad iSCSI Initiator\n");
1043 		return iscsit_add_reject_cmd(cmd,
1044 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1045 	}
1046 
1047 	if ((hdr->flags & ISCSI_FLAG_CMD_READ) &&
1048 	    (hdr->flags & ISCSI_FLAG_CMD_WRITE)) {
1049 		pr_err("Bidirectional operations not supported!\n");
1050 		return iscsit_add_reject_cmd(cmd,
1051 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1052 	}
1053 
1054 	if (hdr->opcode & ISCSI_OP_IMMEDIATE) {
1055 		pr_err("Illegally set Immediate Bit in iSCSI Initiator"
1056 				" Scsi Command PDU.\n");
1057 		return iscsit_add_reject_cmd(cmd,
1058 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1059 	}
1060 
1061 	if (payload_length && !conn->sess->sess_ops->ImmediateData) {
1062 		pr_err("ImmediateData=No but DataSegmentLength=%u,"
1063 			" protocol error.\n", payload_length);
1064 		return iscsit_add_reject_cmd(cmd,
1065 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1066 	}
1067 
1068 	if ((be32_to_cpu(hdr->data_length) == payload_length) &&
1069 	    (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))) {
1070 		pr_err("Expected Data Transfer Length and Length of"
1071 			" Immediate Data are the same, but ISCSI_FLAG_CMD_FINAL"
1072 			" bit is not set protocol error\n");
1073 		return iscsit_add_reject_cmd(cmd,
1074 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1075 	}
1076 
1077 	if (payload_length > be32_to_cpu(hdr->data_length)) {
1078 		pr_err("DataSegmentLength: %u is greater than"
1079 			" EDTL: %u, protocol error.\n", payload_length,
1080 				hdr->data_length);
1081 		return iscsit_add_reject_cmd(cmd,
1082 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1083 	}
1084 
1085 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1086 		pr_err("DataSegmentLength: %u is greater than"
1087 			" MaxXmitDataSegmentLength: %u, protocol error.\n",
1088 			payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
1089 		return iscsit_add_reject_cmd(cmd,
1090 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1091 	}
1092 
1093 	if (payload_length > conn->sess->sess_ops->FirstBurstLength) {
1094 		pr_err("DataSegmentLength: %u is greater than"
1095 			" FirstBurstLength: %u, protocol error.\n",
1096 			payload_length, conn->sess->sess_ops->FirstBurstLength);
1097 		return iscsit_add_reject_cmd(cmd,
1098 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1099 	}
1100 
1101 	data_direction = (hdr->flags & ISCSI_FLAG_CMD_WRITE) ? DMA_TO_DEVICE :
1102 			 (hdr->flags & ISCSI_FLAG_CMD_READ) ? DMA_FROM_DEVICE :
1103 			  DMA_NONE;
1104 
1105 	cmd->data_direction = data_direction;
1106 	iscsi_task_attr = hdr->flags & ISCSI_FLAG_CMD_ATTR_MASK;
1107 	/*
1108 	 * Figure out the SAM Task Attribute for the incoming SCSI CDB
1109 	 */
1110 	if ((iscsi_task_attr == ISCSI_ATTR_UNTAGGED) ||
1111 	    (iscsi_task_attr == ISCSI_ATTR_SIMPLE))
1112 		sam_task_attr = TCM_SIMPLE_TAG;
1113 	else if (iscsi_task_attr == ISCSI_ATTR_ORDERED)
1114 		sam_task_attr = TCM_ORDERED_TAG;
1115 	else if (iscsi_task_attr == ISCSI_ATTR_HEAD_OF_QUEUE)
1116 		sam_task_attr = TCM_HEAD_TAG;
1117 	else if (iscsi_task_attr == ISCSI_ATTR_ACA)
1118 		sam_task_attr = TCM_ACA_TAG;
1119 	else {
1120 		pr_debug("Unknown iSCSI Task Attribute: 0x%02x, using"
1121 			" TCM_SIMPLE_TAG\n", iscsi_task_attr);
1122 		sam_task_attr = TCM_SIMPLE_TAG;
1123 	}
1124 
1125 	cmd->iscsi_opcode	= ISCSI_OP_SCSI_CMD;
1126 	cmd->i_state		= ISTATE_NEW_CMD;
1127 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
1128 	cmd->immediate_data	= (payload_length) ? 1 : 0;
1129 	cmd->unsolicited_data	= ((!(hdr->flags & ISCSI_FLAG_CMD_FINAL) &&
1130 				     (hdr->flags & ISCSI_FLAG_CMD_WRITE)) ? 1 : 0);
1131 	if (cmd->unsolicited_data)
1132 		cmd->cmd_flags |= ICF_NON_IMMEDIATE_UNSOLICITED_DATA;
1133 
1134 	conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
1135 	if (hdr->flags & ISCSI_FLAG_CMD_READ)
1136 		cmd->targ_xfer_tag = session_get_next_ttt(conn->sess);
1137 	else
1138 		cmd->targ_xfer_tag = 0xFFFFFFFF;
1139 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
1140 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
1141 	cmd->first_burst_len	= payload_length;
1142 
1143 	if (!conn->sess->sess_ops->RDMAExtensions &&
1144 	     cmd->data_direction == DMA_FROM_DEVICE) {
1145 		struct iscsi_datain_req *dr;
1146 
1147 		dr = iscsit_allocate_datain_req();
1148 		if (!dr)
1149 			return iscsit_add_reject_cmd(cmd,
1150 					ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1151 
1152 		iscsit_attach_datain_req(cmd, dr);
1153 	}
1154 
1155 	/*
1156 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
1157 	 */
1158 	transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops,
1159 			conn->sess->se_sess, be32_to_cpu(hdr->data_length),
1160 			cmd->data_direction, sam_task_attr,
1161 			cmd->sense_buffer + 2);
1162 
1163 	pr_debug("Got SCSI Command, ITT: 0x%08x, CmdSN: 0x%08x,"
1164 		" ExpXferLen: %u, Length: %u, CID: %hu\n", hdr->itt,
1165 		hdr->cmdsn, be32_to_cpu(hdr->data_length), payload_length,
1166 		conn->cid);
1167 
1168 	target_get_sess_cmd(&cmd->se_cmd, true);
1169 
1170 	cmd->sense_reason = transport_lookup_cmd_lun(&cmd->se_cmd,
1171 						     scsilun_to_int(&hdr->lun));
1172 	if (cmd->sense_reason)
1173 		goto attach_cmd;
1174 
1175 	/* only used for printks or comparing with ->ref_task_tag */
1176 	cmd->se_cmd.tag = (__force u32)cmd->init_task_tag;
1177 	cmd->sense_reason = target_setup_cmd_from_cdb(&cmd->se_cmd, hdr->cdb);
1178 	if (cmd->sense_reason) {
1179 		if (cmd->sense_reason == TCM_OUT_OF_RESOURCES) {
1180 			return iscsit_add_reject_cmd(cmd,
1181 					ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1182 		}
1183 
1184 		goto attach_cmd;
1185 	}
1186 
1187 	if (iscsit_build_pdu_and_seq_lists(cmd, payload_length) < 0) {
1188 		return iscsit_add_reject_cmd(cmd,
1189 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1190 	}
1191 
1192 attach_cmd:
1193 	spin_lock_bh(&conn->cmd_lock);
1194 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
1195 	spin_unlock_bh(&conn->cmd_lock);
1196 	/*
1197 	 * Check if we need to delay processing because of ALUA
1198 	 * Active/NonOptimized primary access state..
1199 	 */
1200 	core_alua_check_nonop_delay(&cmd->se_cmd);
1201 
1202 	return 0;
1203 }
1204 EXPORT_SYMBOL(iscsit_setup_scsi_cmd);
1205 
1206 void iscsit_set_unsolicited_dataout(struct iscsi_cmd *cmd)
1207 {
1208 	iscsit_set_dataout_sequence_values(cmd);
1209 
1210 	spin_lock_bh(&cmd->dataout_timeout_lock);
1211 	iscsit_start_dataout_timer(cmd, cmd->conn);
1212 	spin_unlock_bh(&cmd->dataout_timeout_lock);
1213 }
1214 EXPORT_SYMBOL(iscsit_set_unsolicited_dataout);
1215 
1216 int iscsit_process_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1217 			    struct iscsi_scsi_req *hdr)
1218 {
1219 	int cmdsn_ret = 0;
1220 	/*
1221 	 * Check the CmdSN against ExpCmdSN/MaxCmdSN here if
1222 	 * the Immediate Bit is not set, and no Immediate
1223 	 * Data is attached.
1224 	 *
1225 	 * A PDU/CmdSN carrying Immediate Data can only
1226 	 * be processed after the DataCRC has passed.
1227 	 * If the DataCRC fails, the CmdSN MUST NOT
1228 	 * be acknowledged. (See below)
1229 	 */
1230 	if (!cmd->immediate_data) {
1231 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
1232 					(unsigned char *)hdr, hdr->cmdsn);
1233 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1234 			return -1;
1235 		else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
1236 			target_put_sess_cmd(&cmd->se_cmd);
1237 			return 0;
1238 		}
1239 	}
1240 
1241 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
1242 
1243 	/*
1244 	 * If no Immediate Data is attached, it's OK to return now.
1245 	 */
1246 	if (!cmd->immediate_data) {
1247 		if (!cmd->sense_reason && cmd->unsolicited_data)
1248 			iscsit_set_unsolicited_dataout(cmd);
1249 		if (!cmd->sense_reason)
1250 			return 0;
1251 
1252 		target_put_sess_cmd(&cmd->se_cmd);
1253 		return 0;
1254 	}
1255 
1256 	/*
1257 	 * Early CHECK_CONDITIONs with ImmediateData never make it to command
1258 	 * execution.  These exceptions are processed in CmdSN order using
1259 	 * iscsit_check_received_cmdsn() in iscsit_get_immediate_data() below.
1260 	 */
1261 	if (cmd->sense_reason)
1262 		return 1;
1263 	/*
1264 	 * Call directly into transport_generic_new_cmd() to perform
1265 	 * the backend memory allocation.
1266 	 */
1267 	cmd->sense_reason = transport_generic_new_cmd(&cmd->se_cmd);
1268 	if (cmd->sense_reason)
1269 		return 1;
1270 
1271 	return 0;
1272 }
1273 EXPORT_SYMBOL(iscsit_process_scsi_cmd);
1274 
1275 static int
1276 iscsit_get_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
1277 			  bool dump_payload)
1278 {
1279 	int cmdsn_ret = 0, immed_ret = IMMEDIATE_DATA_NORMAL_OPERATION;
1280 	int rc;
1281 
1282 	/*
1283 	 * Special case for Unsupported SAM WRITE Opcodes and ImmediateData=Yes.
1284 	 */
1285 	if (dump_payload) {
1286 		u32 length = min(cmd->se_cmd.data_length - cmd->write_data_done,
1287 				 cmd->first_burst_len);
1288 
1289 		pr_debug("Dumping min(%d - %d, %d) = %d bytes of immediate data\n",
1290 			 cmd->se_cmd.data_length, cmd->write_data_done,
1291 			 cmd->first_burst_len, length);
1292 		rc = iscsit_dump_data_payload(cmd->conn, length, 1);
1293 		pr_debug("Finished dumping immediate data\n");
1294 		if (rc < 0)
1295 			immed_ret = IMMEDIATE_DATA_CANNOT_RECOVER;
1296 	} else {
1297 		immed_ret = iscsit_handle_immediate_data(cmd, hdr,
1298 							 cmd->first_burst_len);
1299 	}
1300 
1301 	if (immed_ret == IMMEDIATE_DATA_NORMAL_OPERATION) {
1302 		/*
1303 		 * A PDU/CmdSN carrying Immediate Data passed
1304 		 * DataCRC, check against ExpCmdSN/MaxCmdSN if
1305 		 * Immediate Bit is not set.
1306 		 */
1307 		cmdsn_ret = iscsit_sequence_cmd(cmd->conn, cmd,
1308 					(unsigned char *)hdr, hdr->cmdsn);
1309 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1310 			return -1;
1311 
1312 		if (cmd->sense_reason || cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
1313 			target_put_sess_cmd(&cmd->se_cmd);
1314 
1315 			return 0;
1316 		} else if (cmd->unsolicited_data)
1317 			iscsit_set_unsolicited_dataout(cmd);
1318 
1319 	} else if (immed_ret == IMMEDIATE_DATA_ERL1_CRC_FAILURE) {
1320 		/*
1321 		 * Immediate Data failed DataCRC and ERL>=1,
1322 		 * silently drop this PDU and let the initiator
1323 		 * plug the CmdSN gap.
1324 		 *
1325 		 * FIXME: Send Unsolicited NOPIN with reserved
1326 		 * TTT here to help the initiator figure out
1327 		 * the missing CmdSN, although they should be
1328 		 * intelligent enough to determine the missing
1329 		 * CmdSN and issue a retry to plug the sequence.
1330 		 */
1331 		cmd->i_state = ISTATE_REMOVE;
1332 		iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, cmd->i_state);
1333 	} else /* immed_ret == IMMEDIATE_DATA_CANNOT_RECOVER */
1334 		return -1;
1335 
1336 	return 0;
1337 }
1338 
1339 static int
1340 iscsit_handle_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1341 			   unsigned char *buf)
1342 {
1343 	struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)buf;
1344 	int rc, immed_data;
1345 	bool dump_payload = false;
1346 
1347 	rc = iscsit_setup_scsi_cmd(conn, cmd, buf);
1348 	if (rc < 0)
1349 		return 0;
1350 	/*
1351 	 * Allocation iovecs needed for struct socket operations for
1352 	 * traditional iSCSI block I/O.
1353 	 */
1354 	if (iscsit_allocate_iovecs(cmd) < 0) {
1355 		return iscsit_reject_cmd(cmd,
1356 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1357 	}
1358 	immed_data = cmd->immediate_data;
1359 
1360 	rc = iscsit_process_scsi_cmd(conn, cmd, hdr);
1361 	if (rc < 0)
1362 		return rc;
1363 	else if (rc > 0)
1364 		dump_payload = true;
1365 
1366 	if (!immed_data)
1367 		return 0;
1368 
1369 	return iscsit_get_immediate_data(cmd, hdr, dump_payload);
1370 }
1371 
1372 static u32 iscsit_do_crypto_hash_sg(
1373 	struct ahash_request *hash,
1374 	struct iscsi_cmd *cmd,
1375 	u32 data_offset,
1376 	u32 data_length,
1377 	u32 padding,
1378 	u8 *pad_bytes)
1379 {
1380 	u32 data_crc;
1381 	struct scatterlist *sg;
1382 	unsigned int page_off;
1383 
1384 	crypto_ahash_init(hash);
1385 
1386 	sg = cmd->first_data_sg;
1387 	page_off = cmd->first_data_sg_off;
1388 
1389 	while (data_length) {
1390 		u32 cur_len = min_t(u32, data_length, (sg->length - page_off));
1391 
1392 		ahash_request_set_crypt(hash, sg, NULL, cur_len);
1393 		crypto_ahash_update(hash);
1394 
1395 		data_length -= cur_len;
1396 		page_off = 0;
1397 		/* iscsit_map_iovec has already checked for invalid sg pointers */
1398 		sg = sg_next(sg);
1399 	}
1400 
1401 	if (padding) {
1402 		struct scatterlist pad_sg;
1403 
1404 		sg_init_one(&pad_sg, pad_bytes, padding);
1405 		ahash_request_set_crypt(hash, &pad_sg, (u8 *)&data_crc,
1406 					padding);
1407 		crypto_ahash_finup(hash);
1408 	} else {
1409 		ahash_request_set_crypt(hash, NULL, (u8 *)&data_crc, 0);
1410 		crypto_ahash_final(hash);
1411 	}
1412 
1413 	return data_crc;
1414 }
1415 
1416 static void iscsit_do_crypto_hash_buf(struct ahash_request *hash,
1417 	const void *buf, u32 payload_length, u32 padding,
1418 	const void *pad_bytes, void *data_crc)
1419 {
1420 	struct scatterlist sg[2];
1421 
1422 	sg_init_table(sg, ARRAY_SIZE(sg));
1423 	sg_set_buf(sg, buf, payload_length);
1424 	if (padding)
1425 		sg_set_buf(sg + 1, pad_bytes, padding);
1426 
1427 	ahash_request_set_crypt(hash, sg, data_crc, payload_length + padding);
1428 
1429 	crypto_ahash_digest(hash);
1430 }
1431 
1432 int
1433 __iscsit_check_dataout_hdr(struct iscsi_conn *conn, void *buf,
1434 			   struct iscsi_cmd *cmd, u32 payload_length,
1435 			   bool *success)
1436 {
1437 	struct iscsi_data *hdr = buf;
1438 	struct se_cmd *se_cmd;
1439 	int rc;
1440 
1441 	/* iSCSI write */
1442 	atomic_long_add(payload_length, &conn->sess->rx_data_octets);
1443 
1444 	pr_debug("Got DataOut ITT: 0x%08x, TTT: 0x%08x,"
1445 		" DataSN: 0x%08x, Offset: %u, Length: %u, CID: %hu\n",
1446 		hdr->itt, hdr->ttt, hdr->datasn, ntohl(hdr->offset),
1447 		payload_length, conn->cid);
1448 
1449 	if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
1450 		pr_err("Command ITT: 0x%08x received DataOUT after"
1451 			" last DataOUT received, dumping payload\n",
1452 			cmd->init_task_tag);
1453 		return iscsit_dump_data_payload(conn, payload_length, 1);
1454 	}
1455 
1456 	if (cmd->data_direction != DMA_TO_DEVICE) {
1457 		pr_err("Command ITT: 0x%08x received DataOUT for a"
1458 			" NON-WRITE command.\n", cmd->init_task_tag);
1459 		return iscsit_dump_data_payload(conn, payload_length, 1);
1460 	}
1461 	se_cmd = &cmd->se_cmd;
1462 	iscsit_mod_dataout_timer(cmd);
1463 
1464 	if ((be32_to_cpu(hdr->offset) + payload_length) > cmd->se_cmd.data_length) {
1465 		pr_err("DataOut Offset: %u, Length %u greater than iSCSI Command EDTL %u, protocol error.\n",
1466 		       be32_to_cpu(hdr->offset), payload_length,
1467 		       cmd->se_cmd.data_length);
1468 		return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_INVALID, buf);
1469 	}
1470 
1471 	if (cmd->unsolicited_data) {
1472 		int dump_unsolicited_data = 0;
1473 
1474 		if (conn->sess->sess_ops->InitialR2T) {
1475 			pr_err("Received unexpected unsolicited data"
1476 				" while InitialR2T=Yes, protocol error.\n");
1477 			transport_send_check_condition_and_sense(&cmd->se_cmd,
1478 					TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
1479 			return -1;
1480 		}
1481 		/*
1482 		 * Special case for dealing with Unsolicited DataOUT
1483 		 * and Unsupported SAM WRITE Opcodes and SE resource allocation
1484 		 * failures;
1485 		 */
1486 
1487 		/* Something's amiss if we're not in WRITE_PENDING state... */
1488 		WARN_ON(se_cmd->t_state != TRANSPORT_WRITE_PENDING);
1489 		if (!(se_cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE))
1490 			dump_unsolicited_data = 1;
1491 
1492 		if (dump_unsolicited_data) {
1493 			/*
1494 			 * Check if a delayed TASK_ABORTED status needs to
1495 			 * be sent now if the ISCSI_FLAG_CMD_FINAL has been
1496 			 * received with the unsolicited data out.
1497 			 */
1498 			if (hdr->flags & ISCSI_FLAG_CMD_FINAL)
1499 				iscsit_stop_dataout_timer(cmd);
1500 
1501 			return iscsit_dump_data_payload(conn, payload_length, 1);
1502 		}
1503 	} else {
1504 		/*
1505 		 * For the normal solicited data path:
1506 		 *
1507 		 * Check for a delayed TASK_ABORTED status and dump any
1508 		 * incoming data out payload if one exists.  Also, when the
1509 		 * ISCSI_FLAG_CMD_FINAL is set to denote the end of the current
1510 		 * data out sequence, we decrement outstanding_r2ts.  Once
1511 		 * outstanding_r2ts reaches zero, go ahead and send the delayed
1512 		 * TASK_ABORTED status.
1513 		 */
1514 		if (se_cmd->transport_state & CMD_T_ABORTED) {
1515 			if (hdr->flags & ISCSI_FLAG_CMD_FINAL &&
1516 			    --cmd->outstanding_r2ts < 1)
1517 				iscsit_stop_dataout_timer(cmd);
1518 
1519 			return iscsit_dump_data_payload(conn, payload_length, 1);
1520 		}
1521 	}
1522 	/*
1523 	 * Perform DataSN, DataSequenceInOrder, DataPDUInOrder, and
1524 	 * within-command recovery checks before receiving the payload.
1525 	 */
1526 	rc = iscsit_check_pre_dataout(cmd, buf);
1527 	if (rc == DATAOUT_WITHIN_COMMAND_RECOVERY)
1528 		return 0;
1529 	else if (rc == DATAOUT_CANNOT_RECOVER)
1530 		return -1;
1531 	*success = true;
1532 	return 0;
1533 }
1534 EXPORT_SYMBOL(__iscsit_check_dataout_hdr);
1535 
1536 int
1537 iscsit_check_dataout_hdr(struct iscsi_conn *conn, void *buf,
1538 			 struct iscsi_cmd **out_cmd)
1539 {
1540 	struct iscsi_data *hdr = buf;
1541 	struct iscsi_cmd *cmd;
1542 	u32 payload_length = ntoh24(hdr->dlength);
1543 	int rc;
1544 	bool success = false;
1545 
1546 	if (!payload_length) {
1547 		pr_warn_ratelimited("DataOUT payload is ZERO, ignoring.\n");
1548 		return 0;
1549 	}
1550 
1551 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1552 		pr_err_ratelimited("DataSegmentLength: %u is greater than"
1553 			" MaxXmitDataSegmentLength: %u\n", payload_length,
1554 			conn->conn_ops->MaxXmitDataSegmentLength);
1555 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR, buf);
1556 	}
1557 
1558 	cmd = iscsit_find_cmd_from_itt_or_dump(conn, hdr->itt, payload_length);
1559 	if (!cmd)
1560 		return 0;
1561 
1562 	rc = __iscsit_check_dataout_hdr(conn, buf, cmd, payload_length, &success);
1563 
1564 	if (success)
1565 		*out_cmd = cmd;
1566 
1567 	return rc;
1568 }
1569 EXPORT_SYMBOL(iscsit_check_dataout_hdr);
1570 
1571 static int
1572 iscsit_get_dataout(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1573 		   struct iscsi_data *hdr)
1574 {
1575 	struct kvec *iov;
1576 	u32 checksum, iov_count = 0, padding = 0, rx_got = 0, rx_size = 0;
1577 	u32 payload_length;
1578 	int iov_ret, data_crc_failed = 0;
1579 
1580 	payload_length = min_t(u32, cmd->se_cmd.data_length,
1581 			       ntoh24(hdr->dlength));
1582 	rx_size += payload_length;
1583 	iov = &cmd->iov_data[0];
1584 
1585 	iov_ret = iscsit_map_iovec(cmd, iov, cmd->orig_iov_data_count - 2,
1586 				   be32_to_cpu(hdr->offset), payload_length);
1587 	if (iov_ret < 0)
1588 		return -1;
1589 
1590 	iov_count += iov_ret;
1591 
1592 	padding = ((-payload_length) & 3);
1593 	if (padding != 0) {
1594 		iov[iov_count].iov_base	= cmd->pad_bytes;
1595 		iov[iov_count++].iov_len = padding;
1596 		rx_size += padding;
1597 		pr_debug("Receiving %u padding bytes.\n", padding);
1598 	}
1599 
1600 	if (conn->conn_ops->DataDigest) {
1601 		iov[iov_count].iov_base = &checksum;
1602 		iov[iov_count++].iov_len = ISCSI_CRC_LEN;
1603 		rx_size += ISCSI_CRC_LEN;
1604 	}
1605 
1606 	WARN_ON_ONCE(iov_count > cmd->orig_iov_data_count);
1607 	rx_got = rx_data(conn, &cmd->iov_data[0], iov_count, rx_size);
1608 
1609 	iscsit_unmap_iovec(cmd);
1610 
1611 	if (rx_got != rx_size)
1612 		return -1;
1613 
1614 	if (conn->conn_ops->DataDigest) {
1615 		u32 data_crc;
1616 
1617 		data_crc = iscsit_do_crypto_hash_sg(conn->conn_rx_hash, cmd,
1618 						    be32_to_cpu(hdr->offset),
1619 						    payload_length, padding,
1620 						    cmd->pad_bytes);
1621 
1622 		if (checksum != data_crc) {
1623 			pr_err("ITT: 0x%08x, Offset: %u, Length: %u,"
1624 				" DataSN: 0x%08x, CRC32C DataDigest 0x%08x"
1625 				" does not match computed 0x%08x\n",
1626 				hdr->itt, hdr->offset, payload_length,
1627 				hdr->datasn, checksum, data_crc);
1628 			data_crc_failed = 1;
1629 		} else {
1630 			pr_debug("Got CRC32C DataDigest 0x%08x for"
1631 				" %u bytes of Data Out\n", checksum,
1632 				payload_length);
1633 		}
1634 	}
1635 
1636 	return data_crc_failed;
1637 }
1638 
1639 int
1640 iscsit_check_dataout_payload(struct iscsi_cmd *cmd, struct iscsi_data *hdr,
1641 			     bool data_crc_failed)
1642 {
1643 	struct iscsi_conn *conn = cmd->conn;
1644 	int rc, ooo_cmdsn;
1645 	/*
1646 	 * Increment post receive data and CRC values or perform
1647 	 * within-command recovery.
1648 	 */
1649 	rc = iscsit_check_post_dataout(cmd, (unsigned char *)hdr, data_crc_failed);
1650 	if ((rc == DATAOUT_NORMAL) || (rc == DATAOUT_WITHIN_COMMAND_RECOVERY))
1651 		return 0;
1652 	else if (rc == DATAOUT_SEND_R2T) {
1653 		iscsit_set_dataout_sequence_values(cmd);
1654 		conn->conn_transport->iscsit_get_dataout(conn, cmd, false);
1655 	} else if (rc == DATAOUT_SEND_TO_TRANSPORT) {
1656 		/*
1657 		 * Handle extra special case for out of order
1658 		 * Unsolicited Data Out.
1659 		 */
1660 		spin_lock_bh(&cmd->istate_lock);
1661 		ooo_cmdsn = (cmd->cmd_flags & ICF_OOO_CMDSN);
1662 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
1663 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
1664 		spin_unlock_bh(&cmd->istate_lock);
1665 
1666 		iscsit_stop_dataout_timer(cmd);
1667 		if (ooo_cmdsn)
1668 			return 0;
1669 		target_execute_cmd(&cmd->se_cmd);
1670 		return 0;
1671 	} else /* DATAOUT_CANNOT_RECOVER */
1672 		return -1;
1673 
1674 	return 0;
1675 }
1676 EXPORT_SYMBOL(iscsit_check_dataout_payload);
1677 
1678 static int iscsit_handle_data_out(struct iscsi_conn *conn, unsigned char *buf)
1679 {
1680 	struct iscsi_cmd *cmd = NULL;
1681 	struct iscsi_data *hdr = (struct iscsi_data *)buf;
1682 	int rc;
1683 	bool data_crc_failed = false;
1684 
1685 	rc = iscsit_check_dataout_hdr(conn, buf, &cmd);
1686 	if (rc < 0)
1687 		return 0;
1688 	else if (!cmd)
1689 		return 0;
1690 
1691 	rc = iscsit_get_dataout(conn, cmd, hdr);
1692 	if (rc < 0)
1693 		return rc;
1694 	else if (rc > 0)
1695 		data_crc_failed = true;
1696 
1697 	return iscsit_check_dataout_payload(cmd, hdr, data_crc_failed);
1698 }
1699 
1700 int iscsit_setup_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1701 			 struct iscsi_nopout *hdr)
1702 {
1703 	u32 payload_length = ntoh24(hdr->dlength);
1704 
1705 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL)) {
1706 		pr_err("NopOUT Flag's, Left Most Bit not set, protocol error.\n");
1707 		if (!cmd)
1708 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1709 						 (unsigned char *)hdr);
1710 
1711 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1712 					 (unsigned char *)hdr);
1713 	}
1714 
1715 	if (hdr->itt == RESERVED_ITT && !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
1716 		pr_err("NOPOUT ITT is reserved, but Immediate Bit is"
1717 			" not set, protocol error.\n");
1718 		if (!cmd)
1719 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1720 						 (unsigned char *)hdr);
1721 
1722 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1723 					 (unsigned char *)hdr);
1724 	}
1725 
1726 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1727 		pr_err("NOPOUT Ping Data DataSegmentLength: %u is"
1728 			" greater than MaxXmitDataSegmentLength: %u, protocol"
1729 			" error.\n", payload_length,
1730 			conn->conn_ops->MaxXmitDataSegmentLength);
1731 		if (!cmd)
1732 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1733 						 (unsigned char *)hdr);
1734 
1735 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1736 					 (unsigned char *)hdr);
1737 	}
1738 
1739 	pr_debug("Got NOPOUT Ping %s ITT: 0x%08x, TTT: 0x%08x,"
1740 		" CmdSN: 0x%08x, ExpStatSN: 0x%08x, Length: %u\n",
1741 		hdr->itt == RESERVED_ITT ? "Response" : "Request",
1742 		hdr->itt, hdr->ttt, hdr->cmdsn, hdr->exp_statsn,
1743 		payload_length);
1744 	/*
1745 	 * This is not a response to a Unsolicited NopIN, which means
1746 	 * it can either be a NOPOUT ping request (with a valid ITT),
1747 	 * or a NOPOUT not requesting a NOPIN (with a reserved ITT).
1748 	 * Either way, make sure we allocate an struct iscsi_cmd, as both
1749 	 * can contain ping data.
1750 	 */
1751 	if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1752 		cmd->iscsi_opcode	= ISCSI_OP_NOOP_OUT;
1753 		cmd->i_state		= ISTATE_SEND_NOPIN;
1754 		cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ?
1755 						1 : 0);
1756 		conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
1757 		cmd->targ_xfer_tag	= 0xFFFFFFFF;
1758 		cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
1759 		cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
1760 		cmd->data_direction	= DMA_NONE;
1761 	}
1762 
1763 	return 0;
1764 }
1765 EXPORT_SYMBOL(iscsit_setup_nop_out);
1766 
1767 int iscsit_process_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1768 			   struct iscsi_nopout *hdr)
1769 {
1770 	struct iscsi_cmd *cmd_p = NULL;
1771 	int cmdsn_ret = 0;
1772 	/*
1773 	 * Initiator is expecting a NopIN ping reply..
1774 	 */
1775 	if (hdr->itt != RESERVED_ITT) {
1776 		if (!cmd)
1777 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1778 						(unsigned char *)hdr);
1779 
1780 		spin_lock_bh(&conn->cmd_lock);
1781 		list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
1782 		spin_unlock_bh(&conn->cmd_lock);
1783 
1784 		iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
1785 
1786 		if (hdr->opcode & ISCSI_OP_IMMEDIATE) {
1787 			iscsit_add_cmd_to_response_queue(cmd, conn,
1788 							 cmd->i_state);
1789 			return 0;
1790 		}
1791 
1792 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
1793 				(unsigned char *)hdr, hdr->cmdsn);
1794                 if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
1795 			return 0;
1796 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1797 			return -1;
1798 
1799 		return 0;
1800 	}
1801 	/*
1802 	 * This was a response to a unsolicited NOPIN ping.
1803 	 */
1804 	if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
1805 		cmd_p = iscsit_find_cmd_from_ttt(conn, be32_to_cpu(hdr->ttt));
1806 		if (!cmd_p)
1807 			return -EINVAL;
1808 
1809 		iscsit_stop_nopin_response_timer(conn);
1810 
1811 		cmd_p->i_state = ISTATE_REMOVE;
1812 		iscsit_add_cmd_to_immediate_queue(cmd_p, conn, cmd_p->i_state);
1813 
1814 		iscsit_start_nopin_timer(conn);
1815 		return 0;
1816 	}
1817 	/*
1818 	 * Otherwise, initiator is not expecting a NOPIN is response.
1819 	 * Just ignore for now.
1820 	 */
1821 
1822 	if (cmd)
1823 		iscsit_free_cmd(cmd, false);
1824 
1825         return 0;
1826 }
1827 EXPORT_SYMBOL(iscsit_process_nop_out);
1828 
1829 static int iscsit_handle_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1830 				 unsigned char *buf)
1831 {
1832 	unsigned char *ping_data = NULL;
1833 	struct iscsi_nopout *hdr = (struct iscsi_nopout *)buf;
1834 	struct kvec *iov = NULL;
1835 	u32 payload_length = ntoh24(hdr->dlength);
1836 	int ret;
1837 
1838 	ret = iscsit_setup_nop_out(conn, cmd, hdr);
1839 	if (ret < 0)
1840 		return 0;
1841 	/*
1842 	 * Handle NOP-OUT payload for traditional iSCSI sockets
1843 	 */
1844 	if (payload_length && hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1845 		u32 checksum, data_crc, padding = 0;
1846 		int niov = 0, rx_got, rx_size = payload_length;
1847 
1848 		ping_data = kzalloc(payload_length + 1, GFP_KERNEL);
1849 		if (!ping_data) {
1850 			ret = -1;
1851 			goto out;
1852 		}
1853 
1854 		iov = &cmd->iov_misc[0];
1855 		iov[niov].iov_base	= ping_data;
1856 		iov[niov++].iov_len	= payload_length;
1857 
1858 		padding = ((-payload_length) & 3);
1859 		if (padding != 0) {
1860 			pr_debug("Receiving %u additional bytes"
1861 				" for padding.\n", padding);
1862 			iov[niov].iov_base	= &cmd->pad_bytes;
1863 			iov[niov++].iov_len	= padding;
1864 			rx_size += padding;
1865 		}
1866 		if (conn->conn_ops->DataDigest) {
1867 			iov[niov].iov_base	= &checksum;
1868 			iov[niov++].iov_len	= ISCSI_CRC_LEN;
1869 			rx_size += ISCSI_CRC_LEN;
1870 		}
1871 
1872 		WARN_ON_ONCE(niov > ARRAY_SIZE(cmd->iov_misc));
1873 		rx_got = rx_data(conn, &cmd->iov_misc[0], niov, rx_size);
1874 		if (rx_got != rx_size) {
1875 			ret = -1;
1876 			goto out;
1877 		}
1878 
1879 		if (conn->conn_ops->DataDigest) {
1880 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash, ping_data,
1881 						  payload_length, padding,
1882 						  cmd->pad_bytes, &data_crc);
1883 
1884 			if (checksum != data_crc) {
1885 				pr_err("Ping data CRC32C DataDigest"
1886 				" 0x%08x does not match computed 0x%08x\n",
1887 					checksum, data_crc);
1888 				if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
1889 					pr_err("Unable to recover from"
1890 					" NOPOUT Ping DataCRC failure while in"
1891 						" ERL=0.\n");
1892 					ret = -1;
1893 					goto out;
1894 				} else {
1895 					/*
1896 					 * Silently drop this PDU and let the
1897 					 * initiator plug the CmdSN gap.
1898 					 */
1899 					pr_debug("Dropping NOPOUT"
1900 					" Command CmdSN: 0x%08x due to"
1901 					" DataCRC error.\n", hdr->cmdsn);
1902 					ret = 0;
1903 					goto out;
1904 				}
1905 			} else {
1906 				pr_debug("Got CRC32C DataDigest"
1907 				" 0x%08x for %u bytes of ping data.\n",
1908 					checksum, payload_length);
1909 			}
1910 		}
1911 
1912 		ping_data[payload_length] = '\0';
1913 		/*
1914 		 * Attach ping data to struct iscsi_cmd->buf_ptr.
1915 		 */
1916 		cmd->buf_ptr = ping_data;
1917 		cmd->buf_ptr_size = payload_length;
1918 
1919 		pr_debug("Got %u bytes of NOPOUT ping"
1920 			" data.\n", payload_length);
1921 		pr_debug("Ping Data: \"%s\"\n", ping_data);
1922 	}
1923 
1924 	return iscsit_process_nop_out(conn, cmd, hdr);
1925 out:
1926 	if (cmd)
1927 		iscsit_free_cmd(cmd, false);
1928 
1929 	kfree(ping_data);
1930 	return ret;
1931 }
1932 
1933 static enum tcm_tmreq_table iscsit_convert_tmf(u8 iscsi_tmf)
1934 {
1935 	switch (iscsi_tmf) {
1936 	case ISCSI_TM_FUNC_ABORT_TASK:
1937 		return TMR_ABORT_TASK;
1938 	case ISCSI_TM_FUNC_ABORT_TASK_SET:
1939 		return TMR_ABORT_TASK_SET;
1940 	case ISCSI_TM_FUNC_CLEAR_ACA:
1941 		return TMR_CLEAR_ACA;
1942 	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
1943 		return TMR_CLEAR_TASK_SET;
1944 	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
1945 		return TMR_LUN_RESET;
1946 	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
1947 		return TMR_TARGET_WARM_RESET;
1948 	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
1949 		return TMR_TARGET_COLD_RESET;
1950 	default:
1951 		return TMR_UNKNOWN;
1952 	}
1953 }
1954 
1955 int
1956 iscsit_handle_task_mgt_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1957 			   unsigned char *buf)
1958 {
1959 	struct se_tmr_req *se_tmr;
1960 	struct iscsi_tmr_req *tmr_req;
1961 	struct iscsi_tm *hdr;
1962 	int out_of_order_cmdsn = 0, ret;
1963 	u8 function, tcm_function = TMR_UNKNOWN;
1964 
1965 	hdr			= (struct iscsi_tm *) buf;
1966 	hdr->flags &= ~ISCSI_FLAG_CMD_FINAL;
1967 	function = hdr->flags;
1968 
1969 	pr_debug("Got Task Management Request ITT: 0x%08x, CmdSN:"
1970 		" 0x%08x, Function: 0x%02x, RefTaskTag: 0x%08x, RefCmdSN:"
1971 		" 0x%08x, CID: %hu\n", hdr->itt, hdr->cmdsn, function,
1972 		hdr->rtt, hdr->refcmdsn, conn->cid);
1973 
1974 	if ((function != ISCSI_TM_FUNC_ABORT_TASK) &&
1975 	    ((function != ISCSI_TM_FUNC_TASK_REASSIGN) &&
1976 	     hdr->rtt != RESERVED_ITT)) {
1977 		pr_err("RefTaskTag should be set to 0xFFFFFFFF.\n");
1978 		hdr->rtt = RESERVED_ITT;
1979 	}
1980 
1981 	if ((function == ISCSI_TM_FUNC_TASK_REASSIGN) &&
1982 			!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
1983 		pr_err("Task Management Request TASK_REASSIGN not"
1984 			" issued as immediate command, bad iSCSI Initiator"
1985 				"implementation\n");
1986 		return iscsit_add_reject_cmd(cmd,
1987 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1988 	}
1989 	if ((function != ISCSI_TM_FUNC_ABORT_TASK) &&
1990 	    be32_to_cpu(hdr->refcmdsn) != ISCSI_RESERVED_TAG)
1991 		hdr->refcmdsn = cpu_to_be32(ISCSI_RESERVED_TAG);
1992 
1993 	cmd->data_direction = DMA_NONE;
1994 	cmd->tmr_req = kzalloc(sizeof(*cmd->tmr_req), GFP_KERNEL);
1995 	if (!cmd->tmr_req) {
1996 		return iscsit_add_reject_cmd(cmd,
1997 					     ISCSI_REASON_BOOKMARK_NO_RESOURCES,
1998 					     buf);
1999 	}
2000 
2001 	transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops,
2002 			      conn->sess->se_sess, 0, DMA_NONE,
2003 			      TCM_SIMPLE_TAG, cmd->sense_buffer + 2);
2004 
2005 	target_get_sess_cmd(&cmd->se_cmd, true);
2006 
2007 	/*
2008 	 * TASK_REASSIGN for ERL=2 / connection stays inside of
2009 	 * LIO-Target $FABRIC_MOD
2010 	 */
2011 	if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {
2012 		tcm_function = iscsit_convert_tmf(function);
2013 		if (tcm_function == TMR_UNKNOWN) {
2014 			pr_err("Unknown iSCSI TMR Function:"
2015 			       " 0x%02x\n", function);
2016 			return iscsit_add_reject_cmd(cmd,
2017 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
2018 		}
2019 	}
2020 	ret = core_tmr_alloc_req(&cmd->se_cmd, cmd->tmr_req, tcm_function,
2021 				 GFP_KERNEL);
2022 	if (ret < 0)
2023 		return iscsit_add_reject_cmd(cmd,
2024 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
2025 
2026 	cmd->tmr_req->se_tmr_req = cmd->se_cmd.se_tmr_req;
2027 
2028 	cmd->iscsi_opcode	= ISCSI_OP_SCSI_TMFUNC;
2029 	cmd->i_state		= ISTATE_SEND_TASKMGTRSP;
2030 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2031 	cmd->init_task_tag	= hdr->itt;
2032 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2033 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
2034 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
2035 	se_tmr			= cmd->se_cmd.se_tmr_req;
2036 	tmr_req			= cmd->tmr_req;
2037 	/*
2038 	 * Locate the struct se_lun for all TMRs not related to ERL=2 TASK_REASSIGN
2039 	 */
2040 	if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {
2041 		ret = transport_lookup_tmr_lun(&cmd->se_cmd,
2042 					       scsilun_to_int(&hdr->lun));
2043 		if (ret < 0) {
2044 			se_tmr->response = ISCSI_TMF_RSP_NO_LUN;
2045 			goto attach;
2046 		}
2047 	}
2048 
2049 	switch (function) {
2050 	case ISCSI_TM_FUNC_ABORT_TASK:
2051 		se_tmr->response = iscsit_tmr_abort_task(cmd, buf);
2052 		if (se_tmr->response)
2053 			goto attach;
2054 		break;
2055 	case ISCSI_TM_FUNC_ABORT_TASK_SET:
2056 	case ISCSI_TM_FUNC_CLEAR_ACA:
2057 	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
2058 	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
2059 		break;
2060 	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
2061 		if (iscsit_tmr_task_warm_reset(conn, tmr_req, buf) < 0) {
2062 			se_tmr->response = ISCSI_TMF_RSP_AUTH_FAILED;
2063 			goto attach;
2064 		}
2065 		break;
2066 	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
2067 		if (iscsit_tmr_task_cold_reset(conn, tmr_req, buf) < 0) {
2068 			se_tmr->response = ISCSI_TMF_RSP_AUTH_FAILED;
2069 			goto attach;
2070 		}
2071 		break;
2072 	case ISCSI_TM_FUNC_TASK_REASSIGN:
2073 		se_tmr->response = iscsit_tmr_task_reassign(cmd, buf);
2074 		/*
2075 		 * Perform sanity checks on the ExpDataSN only if the
2076 		 * TASK_REASSIGN was successful.
2077 		 */
2078 		if (se_tmr->response)
2079 			break;
2080 
2081 		if (iscsit_check_task_reassign_expdatasn(tmr_req, conn) < 0)
2082 			return iscsit_add_reject_cmd(cmd,
2083 					ISCSI_REASON_BOOKMARK_INVALID, buf);
2084 		break;
2085 	default:
2086 		pr_err("Unknown TMR function: 0x%02x, protocol"
2087 			" error.\n", function);
2088 		se_tmr->response = ISCSI_TMF_RSP_NOT_SUPPORTED;
2089 		goto attach;
2090 	}
2091 
2092 	if ((function != ISCSI_TM_FUNC_TASK_REASSIGN) &&
2093 	    (se_tmr->response == ISCSI_TMF_RSP_COMPLETE))
2094 		se_tmr->call_transport = 1;
2095 attach:
2096 	spin_lock_bh(&conn->cmd_lock);
2097 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2098 	spin_unlock_bh(&conn->cmd_lock);
2099 
2100 	if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
2101 		int cmdsn_ret = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);
2102 		if (cmdsn_ret == CMDSN_HIGHER_THAN_EXP) {
2103 			out_of_order_cmdsn = 1;
2104 		} else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
2105 			target_put_sess_cmd(&cmd->se_cmd);
2106 			return 0;
2107 		} else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER) {
2108 			return -1;
2109 		}
2110 	}
2111 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2112 
2113 	if (out_of_order_cmdsn || !(hdr->opcode & ISCSI_OP_IMMEDIATE))
2114 		return 0;
2115 	/*
2116 	 * Found the referenced task, send to transport for processing.
2117 	 */
2118 	if (se_tmr->call_transport)
2119 		return transport_generic_handle_tmr(&cmd->se_cmd);
2120 
2121 	/*
2122 	 * Could not find the referenced LUN, task, or Task Management
2123 	 * command not authorized or supported.  Change state and
2124 	 * let the tx_thread send the response.
2125 	 *
2126 	 * For connection recovery, this is also the default action for
2127 	 * TMR TASK_REASSIGN.
2128 	 */
2129 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2130 	target_put_sess_cmd(&cmd->se_cmd);
2131 	return 0;
2132 }
2133 EXPORT_SYMBOL(iscsit_handle_task_mgt_cmd);
2134 
2135 /* #warning FIXME: Support Text Command parameters besides SendTargets */
2136 int
2137 iscsit_setup_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2138 		      struct iscsi_text *hdr)
2139 {
2140 	u32 payload_length = ntoh24(hdr->dlength);
2141 
2142 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
2143 		pr_err("Unable to accept text parameter length: %u"
2144 			"greater than MaxXmitDataSegmentLength %u.\n",
2145 		       payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
2146 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
2147 					 (unsigned char *)hdr);
2148 	}
2149 
2150 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL) ||
2151 	     (hdr->flags & ISCSI_FLAG_TEXT_CONTINUE)) {
2152 		pr_err("Multi sequence text commands currently not supported\n");
2153 		return iscsit_reject_cmd(cmd, ISCSI_REASON_CMD_NOT_SUPPORTED,
2154 					(unsigned char *)hdr);
2155 	}
2156 
2157 	pr_debug("Got Text Request: ITT: 0x%08x, CmdSN: 0x%08x,"
2158 		" ExpStatSN: 0x%08x, Length: %u\n", hdr->itt, hdr->cmdsn,
2159 		hdr->exp_statsn, payload_length);
2160 
2161 	cmd->iscsi_opcode	= ISCSI_OP_TEXT;
2162 	cmd->i_state		= ISTATE_SEND_TEXTRSP;
2163 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2164 	conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
2165 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2166 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
2167 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
2168 	cmd->data_direction	= DMA_NONE;
2169 	kfree(cmd->text_in_ptr);
2170 	cmd->text_in_ptr	= NULL;
2171 
2172 	return 0;
2173 }
2174 EXPORT_SYMBOL(iscsit_setup_text_cmd);
2175 
2176 int
2177 iscsit_process_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2178 			struct iscsi_text *hdr)
2179 {
2180 	unsigned char *text_in = cmd->text_in_ptr, *text_ptr;
2181 	int cmdsn_ret;
2182 
2183 	if (!text_in) {
2184 		cmd->targ_xfer_tag = be32_to_cpu(hdr->ttt);
2185 		if (cmd->targ_xfer_tag == 0xFFFFFFFF) {
2186 			pr_err("Unable to locate text_in buffer for sendtargets"
2187 			       " discovery\n");
2188 			goto reject;
2189 		}
2190 		goto empty_sendtargets;
2191 	}
2192 	if (strncmp("SendTargets=", text_in, 12) != 0) {
2193 		pr_err("Received Text Data that is not"
2194 			" SendTargets, cannot continue.\n");
2195 		goto reject;
2196 	}
2197 	/* '=' confirmed in strncmp */
2198 	text_ptr = strchr(text_in, '=');
2199 	BUG_ON(!text_ptr);
2200 	if (!strncmp("=All", text_ptr, 5)) {
2201 		cmd->cmd_flags |= ICF_SENDTARGETS_ALL;
2202 	} else if (!strncmp("=iqn.", text_ptr, 5) ||
2203 		   !strncmp("=eui.", text_ptr, 5)) {
2204 		cmd->cmd_flags |= ICF_SENDTARGETS_SINGLE;
2205 	} else {
2206 		pr_err("Unable to locate valid SendTargets%s value\n",
2207 		       text_ptr);
2208 		goto reject;
2209 	}
2210 
2211 	spin_lock_bh(&conn->cmd_lock);
2212 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2213 	spin_unlock_bh(&conn->cmd_lock);
2214 
2215 empty_sendtargets:
2216 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2217 
2218 	if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
2219 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
2220 				(unsigned char *)hdr, hdr->cmdsn);
2221 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
2222 			return -1;
2223 
2224 		return 0;
2225 	}
2226 
2227 	return iscsit_execute_cmd(cmd, 0);
2228 
2229 reject:
2230 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
2231 				 (unsigned char *)hdr);
2232 }
2233 EXPORT_SYMBOL(iscsit_process_text_cmd);
2234 
2235 static int
2236 iscsit_handle_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2237 		       unsigned char *buf)
2238 {
2239 	struct iscsi_text *hdr = (struct iscsi_text *)buf;
2240 	char *text_in = NULL;
2241 	u32 payload_length = ntoh24(hdr->dlength);
2242 	int rx_size, rc;
2243 
2244 	rc = iscsit_setup_text_cmd(conn, cmd, hdr);
2245 	if (rc < 0)
2246 		return 0;
2247 
2248 	rx_size = payload_length;
2249 	if (payload_length) {
2250 		u32 checksum = 0, data_crc = 0;
2251 		u32 padding = 0;
2252 		int niov = 0, rx_got;
2253 		struct kvec iov[2];
2254 
2255 		rx_size = ALIGN(payload_length, 4);
2256 		text_in = kzalloc(rx_size, GFP_KERNEL);
2257 		if (!text_in)
2258 			goto reject;
2259 
2260 		cmd->text_in_ptr = text_in;
2261 
2262 		memset(iov, 0, sizeof(iov));
2263 		iov[niov].iov_base	= text_in;
2264 		iov[niov++].iov_len	= rx_size;
2265 
2266 		padding = rx_size - payload_length;
2267 		if (padding)
2268 			pr_debug("Receiving %u additional bytes"
2269 					" for padding.\n", padding);
2270 		if (conn->conn_ops->DataDigest) {
2271 			iov[niov].iov_base	= &checksum;
2272 			iov[niov++].iov_len	= ISCSI_CRC_LEN;
2273 			rx_size += ISCSI_CRC_LEN;
2274 		}
2275 
2276 		WARN_ON_ONCE(niov > ARRAY_SIZE(iov));
2277 		rx_got = rx_data(conn, &iov[0], niov, rx_size);
2278 		if (rx_got != rx_size)
2279 			goto reject;
2280 
2281 		if (conn->conn_ops->DataDigest) {
2282 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash,
2283 						  text_in, rx_size, 0, NULL,
2284 						  &data_crc);
2285 
2286 			if (checksum != data_crc) {
2287 				pr_err("Text data CRC32C DataDigest"
2288 					" 0x%08x does not match computed"
2289 					" 0x%08x\n", checksum, data_crc);
2290 				if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2291 					pr_err("Unable to recover from"
2292 					" Text Data digest failure while in"
2293 						" ERL=0.\n");
2294 					goto reject;
2295 				} else {
2296 					/*
2297 					 * Silently drop this PDU and let the
2298 					 * initiator plug the CmdSN gap.
2299 					 */
2300 					pr_debug("Dropping Text"
2301 					" Command CmdSN: 0x%08x due to"
2302 					" DataCRC error.\n", hdr->cmdsn);
2303 					kfree(text_in);
2304 					return 0;
2305 				}
2306 			} else {
2307 				pr_debug("Got CRC32C DataDigest"
2308 					" 0x%08x for %u bytes of text data.\n",
2309 						checksum, payload_length);
2310 			}
2311 		}
2312 		text_in[payload_length - 1] = '\0';
2313 		pr_debug("Successfully read %d bytes of text"
2314 				" data.\n", payload_length);
2315 	}
2316 
2317 	return iscsit_process_text_cmd(conn, cmd, hdr);
2318 
2319 reject:
2320 	kfree(cmd->text_in_ptr);
2321 	cmd->text_in_ptr = NULL;
2322 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);
2323 }
2324 
2325 int iscsit_logout_closesession(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2326 {
2327 	struct iscsi_conn *conn_p;
2328 	struct iscsi_session *sess = conn->sess;
2329 
2330 	pr_debug("Received logout request CLOSESESSION on CID: %hu"
2331 		" for SID: %u.\n", conn->cid, conn->sess->sid);
2332 
2333 	atomic_set(&sess->session_logout, 1);
2334 	atomic_set(&conn->conn_logout_remove, 1);
2335 	conn->conn_logout_reason = ISCSI_LOGOUT_REASON_CLOSE_SESSION;
2336 
2337 	iscsit_inc_conn_usage_count(conn);
2338 	iscsit_inc_session_usage_count(sess);
2339 
2340 	spin_lock_bh(&sess->conn_lock);
2341 	list_for_each_entry(conn_p, &sess->sess_conn_list, conn_list) {
2342 		if (conn_p->conn_state != TARG_CONN_STATE_LOGGED_IN)
2343 			continue;
2344 
2345 		pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
2346 		conn_p->conn_state = TARG_CONN_STATE_IN_LOGOUT;
2347 	}
2348 	spin_unlock_bh(&sess->conn_lock);
2349 
2350 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2351 
2352 	return 0;
2353 }
2354 
2355 int iscsit_logout_closeconnection(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2356 {
2357 	struct iscsi_conn *l_conn;
2358 	struct iscsi_session *sess = conn->sess;
2359 
2360 	pr_debug("Received logout request CLOSECONNECTION for CID:"
2361 		" %hu on CID: %hu.\n", cmd->logout_cid, conn->cid);
2362 
2363 	/*
2364 	 * A Logout Request with a CLOSECONNECTION reason code for a CID
2365 	 * can arrive on a connection with a differing CID.
2366 	 */
2367 	if (conn->cid == cmd->logout_cid) {
2368 		spin_lock_bh(&conn->state_lock);
2369 		pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
2370 		conn->conn_state = TARG_CONN_STATE_IN_LOGOUT;
2371 
2372 		atomic_set(&conn->conn_logout_remove, 1);
2373 		conn->conn_logout_reason = ISCSI_LOGOUT_REASON_CLOSE_CONNECTION;
2374 		iscsit_inc_conn_usage_count(conn);
2375 
2376 		spin_unlock_bh(&conn->state_lock);
2377 	} else {
2378 		/*
2379 		 * Handle all different cid CLOSECONNECTION requests in
2380 		 * iscsit_logout_post_handler_diffcid() as to give enough
2381 		 * time for any non immediate command's CmdSN to be
2382 		 * acknowledged on the connection in question.
2383 		 *
2384 		 * Here we simply make sure the CID is still around.
2385 		 */
2386 		l_conn = iscsit_get_conn_from_cid(sess,
2387 				cmd->logout_cid);
2388 		if (!l_conn) {
2389 			cmd->logout_response = ISCSI_LOGOUT_CID_NOT_FOUND;
2390 			iscsit_add_cmd_to_response_queue(cmd, conn,
2391 					cmd->i_state);
2392 			return 0;
2393 		}
2394 
2395 		iscsit_dec_conn_usage_count(l_conn);
2396 	}
2397 
2398 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2399 
2400 	return 0;
2401 }
2402 
2403 int iscsit_logout_removeconnforrecovery(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2404 {
2405 	struct iscsi_session *sess = conn->sess;
2406 
2407 	pr_debug("Received explicit REMOVECONNFORRECOVERY logout for"
2408 		" CID: %hu on CID: %hu.\n", cmd->logout_cid, conn->cid);
2409 
2410 	if (sess->sess_ops->ErrorRecoveryLevel != 2) {
2411 		pr_err("Received Logout Request REMOVECONNFORRECOVERY"
2412 			" while ERL!=2.\n");
2413 		cmd->logout_response = ISCSI_LOGOUT_RECOVERY_UNSUPPORTED;
2414 		iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2415 		return 0;
2416 	}
2417 
2418 	if (conn->cid == cmd->logout_cid) {
2419 		pr_err("Received Logout Request REMOVECONNFORRECOVERY"
2420 			" with CID: %hu on CID: %hu, implementation error.\n",
2421 				cmd->logout_cid, conn->cid);
2422 		cmd->logout_response = ISCSI_LOGOUT_CLEANUP_FAILED;
2423 		iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2424 		return 0;
2425 	}
2426 
2427 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2428 
2429 	return 0;
2430 }
2431 
2432 int
2433 iscsit_handle_logout_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2434 			unsigned char *buf)
2435 {
2436 	int cmdsn_ret, logout_remove = 0;
2437 	u8 reason_code = 0;
2438 	struct iscsi_logout *hdr;
2439 	struct iscsi_tiqn *tiqn = iscsit_snmp_get_tiqn(conn);
2440 
2441 	hdr			= (struct iscsi_logout *) buf;
2442 	reason_code		= (hdr->flags & 0x7f);
2443 
2444 	if (tiqn) {
2445 		spin_lock(&tiqn->logout_stats.lock);
2446 		if (reason_code == ISCSI_LOGOUT_REASON_CLOSE_SESSION)
2447 			tiqn->logout_stats.normal_logouts++;
2448 		else
2449 			tiqn->logout_stats.abnormal_logouts++;
2450 		spin_unlock(&tiqn->logout_stats.lock);
2451 	}
2452 
2453 	pr_debug("Got Logout Request ITT: 0x%08x CmdSN: 0x%08x"
2454 		" ExpStatSN: 0x%08x Reason: 0x%02x CID: %hu on CID: %hu\n",
2455 		hdr->itt, hdr->cmdsn, hdr->exp_statsn, reason_code,
2456 		hdr->cid, conn->cid);
2457 
2458 	if (conn->conn_state != TARG_CONN_STATE_LOGGED_IN) {
2459 		pr_err("Received logout request on connection that"
2460 			" is not in logged in state, ignoring request.\n");
2461 		iscsit_free_cmd(cmd, false);
2462 		return 0;
2463 	}
2464 
2465 	cmd->iscsi_opcode       = ISCSI_OP_LOGOUT;
2466 	cmd->i_state            = ISTATE_SEND_LOGOUTRSP;
2467 	cmd->immediate_cmd      = ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2468 	conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
2469 	cmd->targ_xfer_tag      = 0xFFFFFFFF;
2470 	cmd->cmd_sn             = be32_to_cpu(hdr->cmdsn);
2471 	cmd->exp_stat_sn        = be32_to_cpu(hdr->exp_statsn);
2472 	cmd->logout_cid         = be16_to_cpu(hdr->cid);
2473 	cmd->logout_reason      = reason_code;
2474 	cmd->data_direction     = DMA_NONE;
2475 
2476 	/*
2477 	 * We need to sleep in these cases (by returning 1) until the Logout
2478 	 * Response gets sent in the tx thread.
2479 	 */
2480 	if ((reason_code == ISCSI_LOGOUT_REASON_CLOSE_SESSION) ||
2481 	   ((reason_code == ISCSI_LOGOUT_REASON_CLOSE_CONNECTION) &&
2482 	    be16_to_cpu(hdr->cid) == conn->cid))
2483 		logout_remove = 1;
2484 
2485 	spin_lock_bh(&conn->cmd_lock);
2486 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2487 	spin_unlock_bh(&conn->cmd_lock);
2488 
2489 	if (reason_code != ISCSI_LOGOUT_REASON_RECOVERY)
2490 		iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2491 
2492 	/*
2493 	 * Immediate commands are executed, well, immediately.
2494 	 * Non-Immediate Logout Commands are executed in CmdSN order.
2495 	 */
2496 	if (cmd->immediate_cmd) {
2497 		int ret = iscsit_execute_cmd(cmd, 0);
2498 
2499 		if (ret < 0)
2500 			return ret;
2501 	} else {
2502 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);
2503 		if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
2504 			logout_remove = 0;
2505 		else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
2506 			return -1;
2507 	}
2508 
2509 	return logout_remove;
2510 }
2511 EXPORT_SYMBOL(iscsit_handle_logout_cmd);
2512 
2513 int iscsit_handle_snack(
2514 	struct iscsi_conn *conn,
2515 	unsigned char *buf)
2516 {
2517 	struct iscsi_snack *hdr;
2518 
2519 	hdr			= (struct iscsi_snack *) buf;
2520 	hdr->flags		&= ~ISCSI_FLAG_CMD_FINAL;
2521 
2522 	pr_debug("Got ISCSI_INIT_SNACK, ITT: 0x%08x, ExpStatSN:"
2523 		" 0x%08x, Type: 0x%02x, BegRun: 0x%08x, RunLength: 0x%08x,"
2524 		" CID: %hu\n", hdr->itt, hdr->exp_statsn, hdr->flags,
2525 			hdr->begrun, hdr->runlength, conn->cid);
2526 
2527 	if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2528 		pr_err("Initiator sent SNACK request while in"
2529 			" ErrorRecoveryLevel=0.\n");
2530 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2531 					 buf);
2532 	}
2533 	/*
2534 	 * SNACK_DATA and SNACK_R2T are both 0,  so check which function to
2535 	 * call from inside iscsi_send_recovery_datain_or_r2t().
2536 	 */
2537 	switch (hdr->flags & ISCSI_FLAG_SNACK_TYPE_MASK) {
2538 	case 0:
2539 		return iscsit_handle_recovery_datain_or_r2t(conn, buf,
2540 			hdr->itt,
2541 			be32_to_cpu(hdr->ttt),
2542 			be32_to_cpu(hdr->begrun),
2543 			be32_to_cpu(hdr->runlength));
2544 	case ISCSI_FLAG_SNACK_TYPE_STATUS:
2545 		return iscsit_handle_status_snack(conn, hdr->itt,
2546 			be32_to_cpu(hdr->ttt),
2547 			be32_to_cpu(hdr->begrun), be32_to_cpu(hdr->runlength));
2548 	case ISCSI_FLAG_SNACK_TYPE_DATA_ACK:
2549 		return iscsit_handle_data_ack(conn, be32_to_cpu(hdr->ttt),
2550 			be32_to_cpu(hdr->begrun),
2551 			be32_to_cpu(hdr->runlength));
2552 	case ISCSI_FLAG_SNACK_TYPE_RDATA:
2553 		/* FIXME: Support R-Data SNACK */
2554 		pr_err("R-Data SNACK Not Supported.\n");
2555 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2556 					 buf);
2557 	default:
2558 		pr_err("Unknown SNACK type 0x%02x, protocol"
2559 			" error.\n", hdr->flags & 0x0f);
2560 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2561 					 buf);
2562 	}
2563 
2564 	return 0;
2565 }
2566 EXPORT_SYMBOL(iscsit_handle_snack);
2567 
2568 static void iscsit_rx_thread_wait_for_tcp(struct iscsi_conn *conn)
2569 {
2570 	if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) ||
2571 	    (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) {
2572 		wait_for_completion_interruptible_timeout(
2573 					&conn->rx_half_close_comp,
2574 					ISCSI_RX_THREAD_TCP_TIMEOUT * HZ);
2575 	}
2576 }
2577 
2578 static int iscsit_handle_immediate_data(
2579 	struct iscsi_cmd *cmd,
2580 	struct iscsi_scsi_req *hdr,
2581 	u32 length)
2582 {
2583 	int iov_ret, rx_got = 0, rx_size = 0;
2584 	u32 checksum, iov_count = 0, padding = 0;
2585 	struct iscsi_conn *conn = cmd->conn;
2586 	struct kvec *iov;
2587 	void *overflow_buf = NULL;
2588 
2589 	BUG_ON(cmd->write_data_done > cmd->se_cmd.data_length);
2590 	rx_size = min(cmd->se_cmd.data_length - cmd->write_data_done, length);
2591 	iov_ret = iscsit_map_iovec(cmd, cmd->iov_data,
2592 				   cmd->orig_iov_data_count - 2,
2593 				   cmd->write_data_done, rx_size);
2594 	if (iov_ret < 0)
2595 		return IMMEDIATE_DATA_CANNOT_RECOVER;
2596 
2597 	iov_count = iov_ret;
2598 	iov = &cmd->iov_data[0];
2599 	if (rx_size < length) {
2600 		/*
2601 		 * Special case: length of immediate data exceeds the data
2602 		 * buffer size derived from the CDB.
2603 		 */
2604 		overflow_buf = kmalloc(length - rx_size, GFP_KERNEL);
2605 		if (!overflow_buf) {
2606 			iscsit_unmap_iovec(cmd);
2607 			return IMMEDIATE_DATA_CANNOT_RECOVER;
2608 		}
2609 		cmd->overflow_buf = overflow_buf;
2610 		iov[iov_count].iov_base = overflow_buf;
2611 		iov[iov_count].iov_len = length - rx_size;
2612 		iov_count++;
2613 		rx_size = length;
2614 	}
2615 
2616 	padding = ((-length) & 3);
2617 	if (padding != 0) {
2618 		iov[iov_count].iov_base	= cmd->pad_bytes;
2619 		iov[iov_count++].iov_len = padding;
2620 		rx_size += padding;
2621 	}
2622 
2623 	if (conn->conn_ops->DataDigest) {
2624 		iov[iov_count].iov_base		= &checksum;
2625 		iov[iov_count++].iov_len	= ISCSI_CRC_LEN;
2626 		rx_size += ISCSI_CRC_LEN;
2627 	}
2628 
2629 	WARN_ON_ONCE(iov_count > cmd->orig_iov_data_count);
2630 	rx_got = rx_data(conn, &cmd->iov_data[0], iov_count, rx_size);
2631 
2632 	iscsit_unmap_iovec(cmd);
2633 
2634 	if (rx_got != rx_size) {
2635 		iscsit_rx_thread_wait_for_tcp(conn);
2636 		return IMMEDIATE_DATA_CANNOT_RECOVER;
2637 	}
2638 
2639 	if (conn->conn_ops->DataDigest) {
2640 		u32 data_crc;
2641 
2642 		data_crc = iscsit_do_crypto_hash_sg(conn->conn_rx_hash, cmd,
2643 						    cmd->write_data_done, length, padding,
2644 						    cmd->pad_bytes);
2645 
2646 		if (checksum != data_crc) {
2647 			pr_err("ImmediateData CRC32C DataDigest 0x%08x"
2648 				" does not match computed 0x%08x\n", checksum,
2649 				data_crc);
2650 
2651 			if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2652 				pr_err("Unable to recover from"
2653 					" Immediate Data digest failure while"
2654 					" in ERL=0.\n");
2655 				iscsit_reject_cmd(cmd,
2656 						ISCSI_REASON_DATA_DIGEST_ERROR,
2657 						(unsigned char *)hdr);
2658 				return IMMEDIATE_DATA_CANNOT_RECOVER;
2659 			} else {
2660 				iscsit_reject_cmd(cmd,
2661 						ISCSI_REASON_DATA_DIGEST_ERROR,
2662 						(unsigned char *)hdr);
2663 				return IMMEDIATE_DATA_ERL1_CRC_FAILURE;
2664 			}
2665 		} else {
2666 			pr_debug("Got CRC32C DataDigest 0x%08x for"
2667 				" %u bytes of Immediate Data\n", checksum,
2668 				length);
2669 		}
2670 	}
2671 
2672 	cmd->write_data_done += length;
2673 
2674 	if (cmd->write_data_done == cmd->se_cmd.data_length) {
2675 		spin_lock_bh(&cmd->istate_lock);
2676 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
2677 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
2678 		spin_unlock_bh(&cmd->istate_lock);
2679 	}
2680 
2681 	return IMMEDIATE_DATA_NORMAL_OPERATION;
2682 }
2683 
2684 /* #warning iscsi_build_conn_drop_async_message() only sends out on connections
2685 	with active network interface */
2686 static void iscsit_build_conn_drop_async_message(struct iscsi_conn *conn)
2687 {
2688 	struct iscsi_cmd *cmd;
2689 	struct iscsi_conn *conn_p;
2690 	bool found = false;
2691 
2692 	lockdep_assert_held(&conn->sess->conn_lock);
2693 
2694 	/*
2695 	 * Only send a Asynchronous Message on connections whos network
2696 	 * interface is still functional.
2697 	 */
2698 	list_for_each_entry(conn_p, &conn->sess->sess_conn_list, conn_list) {
2699 		if (conn_p->conn_state == TARG_CONN_STATE_LOGGED_IN) {
2700 			iscsit_inc_conn_usage_count(conn_p);
2701 			found = true;
2702 			break;
2703 		}
2704 	}
2705 
2706 	if (!found)
2707 		return;
2708 
2709 	cmd = iscsit_allocate_cmd(conn_p, TASK_RUNNING);
2710 	if (!cmd) {
2711 		iscsit_dec_conn_usage_count(conn_p);
2712 		return;
2713 	}
2714 
2715 	cmd->logout_cid = conn->cid;
2716 	cmd->iscsi_opcode = ISCSI_OP_ASYNC_EVENT;
2717 	cmd->i_state = ISTATE_SEND_ASYNCMSG;
2718 
2719 	spin_lock_bh(&conn_p->cmd_lock);
2720 	list_add_tail(&cmd->i_conn_node, &conn_p->conn_cmd_list);
2721 	spin_unlock_bh(&conn_p->cmd_lock);
2722 
2723 	iscsit_add_cmd_to_response_queue(cmd, conn_p, cmd->i_state);
2724 	iscsit_dec_conn_usage_count(conn_p);
2725 }
2726 
2727 static int iscsit_send_conn_drop_async_message(
2728 	struct iscsi_cmd *cmd,
2729 	struct iscsi_conn *conn)
2730 {
2731 	struct iscsi_async *hdr;
2732 
2733 	cmd->iscsi_opcode = ISCSI_OP_ASYNC_EVENT;
2734 
2735 	hdr			= (struct iscsi_async *) cmd->pdu;
2736 	hdr->opcode		= ISCSI_OP_ASYNC_EVENT;
2737 	hdr->flags		= ISCSI_FLAG_CMD_FINAL;
2738 	cmd->init_task_tag	= RESERVED_ITT;
2739 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2740 	put_unaligned_be64(0xFFFFFFFFFFFFFFFFULL, &hdr->rsvd4[0]);
2741 	cmd->stat_sn		= conn->stat_sn++;
2742 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2743 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2744 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2745 	hdr->async_event	= ISCSI_ASYNC_MSG_DROPPING_CONNECTION;
2746 	hdr->param1		= cpu_to_be16(cmd->logout_cid);
2747 	hdr->param2		= cpu_to_be16(conn->sess->sess_ops->DefaultTime2Wait);
2748 	hdr->param3		= cpu_to_be16(conn->sess->sess_ops->DefaultTime2Retain);
2749 
2750 	pr_debug("Sending Connection Dropped Async Message StatSN:"
2751 		" 0x%08x, for CID: %hu on CID: %hu\n", cmd->stat_sn,
2752 			cmd->logout_cid, conn->cid);
2753 
2754 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
2755 }
2756 
2757 static void iscsit_tx_thread_wait_for_tcp(struct iscsi_conn *conn)
2758 {
2759 	if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) ||
2760 	    (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) {
2761 		wait_for_completion_interruptible_timeout(
2762 					&conn->tx_half_close_comp,
2763 					ISCSI_TX_THREAD_TCP_TIMEOUT * HZ);
2764 	}
2765 }
2766 
2767 void
2768 iscsit_build_datain_pdu(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2769 			struct iscsi_datain *datain, struct iscsi_data_rsp *hdr,
2770 			bool set_statsn)
2771 {
2772 	hdr->opcode		= ISCSI_OP_SCSI_DATA_IN;
2773 	hdr->flags		= datain->flags;
2774 	if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
2775 		if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
2776 			hdr->flags |= ISCSI_FLAG_DATA_OVERFLOW;
2777 			hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
2778 		} else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
2779 			hdr->flags |= ISCSI_FLAG_DATA_UNDERFLOW;
2780 			hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
2781 		}
2782 	}
2783 	hton24(hdr->dlength, datain->length);
2784 	if (hdr->flags & ISCSI_FLAG_DATA_ACK)
2785 		int_to_scsilun(cmd->se_cmd.orig_fe_lun,
2786 				(struct scsi_lun *)&hdr->lun);
2787 	else
2788 		put_unaligned_le64(0xFFFFFFFFFFFFFFFFULL, &hdr->lun);
2789 
2790 	hdr->itt		= cmd->init_task_tag;
2791 
2792 	if (hdr->flags & ISCSI_FLAG_DATA_ACK)
2793 		hdr->ttt		= cpu_to_be32(cmd->targ_xfer_tag);
2794 	else
2795 		hdr->ttt		= cpu_to_be32(0xFFFFFFFF);
2796 	if (set_statsn)
2797 		hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2798 	else
2799 		hdr->statsn		= cpu_to_be32(0xFFFFFFFF);
2800 
2801 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2802 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2803 	hdr->datasn		= cpu_to_be32(datain->data_sn);
2804 	hdr->offset		= cpu_to_be32(datain->offset);
2805 
2806 	pr_debug("Built DataIN ITT: 0x%08x, StatSN: 0x%08x,"
2807 		" DataSN: 0x%08x, Offset: %u, Length: %u, CID: %hu\n",
2808 		cmd->init_task_tag, ntohl(hdr->statsn), ntohl(hdr->datasn),
2809 		ntohl(hdr->offset), datain->length, conn->cid);
2810 }
2811 EXPORT_SYMBOL(iscsit_build_datain_pdu);
2812 
2813 static int iscsit_send_datain(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2814 {
2815 	struct iscsi_data_rsp *hdr = (struct iscsi_data_rsp *)&cmd->pdu[0];
2816 	struct iscsi_datain datain;
2817 	struct iscsi_datain_req *dr;
2818 	int eodr = 0, ret;
2819 	bool set_statsn = false;
2820 
2821 	memset(&datain, 0, sizeof(struct iscsi_datain));
2822 	dr = iscsit_get_datain_values(cmd, &datain);
2823 	if (!dr) {
2824 		pr_err("iscsit_get_datain_values failed for ITT: 0x%08x\n",
2825 				cmd->init_task_tag);
2826 		return -1;
2827 	}
2828 	/*
2829 	 * Be paranoid and double check the logic for now.
2830 	 */
2831 	if ((datain.offset + datain.length) > cmd->se_cmd.data_length) {
2832 		pr_err("Command ITT: 0x%08x, datain.offset: %u and"
2833 			" datain.length: %u exceeds cmd->data_length: %u\n",
2834 			cmd->init_task_tag, datain.offset, datain.length,
2835 			cmd->se_cmd.data_length);
2836 		return -1;
2837 	}
2838 
2839 	atomic_long_add(datain.length, &conn->sess->tx_data_octets);
2840 	/*
2841 	 * Special case for successfully execution w/ both DATAIN
2842 	 * and Sense Data.
2843 	 */
2844 	if ((datain.flags & ISCSI_FLAG_DATA_STATUS) &&
2845 	    (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE))
2846 		datain.flags &= ~ISCSI_FLAG_DATA_STATUS;
2847 	else {
2848 		if ((dr->dr_complete == DATAIN_COMPLETE_NORMAL) ||
2849 		    (dr->dr_complete == DATAIN_COMPLETE_CONNECTION_RECOVERY)) {
2850 			iscsit_increment_maxcmdsn(cmd, conn->sess);
2851 			cmd->stat_sn = conn->stat_sn++;
2852 			set_statsn = true;
2853 		} else if (dr->dr_complete ==
2854 			   DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY)
2855 			set_statsn = true;
2856 	}
2857 
2858 	iscsit_build_datain_pdu(cmd, conn, &datain, hdr, set_statsn);
2859 
2860 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, dr, &datain, 0);
2861 	if (ret < 0)
2862 		return ret;
2863 
2864 	if (dr->dr_complete) {
2865 		eodr = (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ?
2866 				2 : 1;
2867 		iscsit_free_datain_req(cmd, dr);
2868 	}
2869 
2870 	return eodr;
2871 }
2872 
2873 int
2874 iscsit_build_logout_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2875 			struct iscsi_logout_rsp *hdr)
2876 {
2877 	struct iscsi_conn *logout_conn = NULL;
2878 	struct iscsi_conn_recovery *cr = NULL;
2879 	struct iscsi_session *sess = conn->sess;
2880 	/*
2881 	 * The actual shutting down of Sessions and/or Connections
2882 	 * for CLOSESESSION and CLOSECONNECTION Logout Requests
2883 	 * is done in scsi_logout_post_handler().
2884 	 */
2885 	switch (cmd->logout_reason) {
2886 	case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
2887 		pr_debug("iSCSI session logout successful, setting"
2888 			" logout response to ISCSI_LOGOUT_SUCCESS.\n");
2889 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2890 		break;
2891 	case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
2892 		if (cmd->logout_response == ISCSI_LOGOUT_CID_NOT_FOUND)
2893 			break;
2894 		/*
2895 		 * For CLOSECONNECTION logout requests carrying
2896 		 * a matching logout CID -> local CID, the reference
2897 		 * for the local CID will have been incremented in
2898 		 * iscsi_logout_closeconnection().
2899 		 *
2900 		 * For CLOSECONNECTION logout requests carrying
2901 		 * a different CID than the connection it arrived
2902 		 * on, the connection responding to cmd->logout_cid
2903 		 * is stopped in iscsit_logout_post_handler_diffcid().
2904 		 */
2905 
2906 		pr_debug("iSCSI CID: %hu logout on CID: %hu"
2907 			" successful.\n", cmd->logout_cid, conn->cid);
2908 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2909 		break;
2910 	case ISCSI_LOGOUT_REASON_RECOVERY:
2911 		if ((cmd->logout_response == ISCSI_LOGOUT_RECOVERY_UNSUPPORTED) ||
2912 		    (cmd->logout_response == ISCSI_LOGOUT_CLEANUP_FAILED))
2913 			break;
2914 		/*
2915 		 * If the connection is still active from our point of view
2916 		 * force connection recovery to occur.
2917 		 */
2918 		logout_conn = iscsit_get_conn_from_cid_rcfr(sess,
2919 				cmd->logout_cid);
2920 		if (logout_conn) {
2921 			iscsit_connection_reinstatement_rcfr(logout_conn);
2922 			iscsit_dec_conn_usage_count(logout_conn);
2923 		}
2924 
2925 		cr = iscsit_get_inactive_connection_recovery_entry(
2926 				conn->sess, cmd->logout_cid);
2927 		if (!cr) {
2928 			pr_err("Unable to locate CID: %hu for"
2929 			" REMOVECONNFORRECOVERY Logout Request.\n",
2930 				cmd->logout_cid);
2931 			cmd->logout_response = ISCSI_LOGOUT_CID_NOT_FOUND;
2932 			break;
2933 		}
2934 
2935 		iscsit_discard_cr_cmds_by_expstatsn(cr, cmd->exp_stat_sn);
2936 
2937 		pr_debug("iSCSI REMOVECONNFORRECOVERY logout"
2938 			" for recovery for CID: %hu on CID: %hu successful.\n",
2939 				cmd->logout_cid, conn->cid);
2940 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2941 		break;
2942 	default:
2943 		pr_err("Unknown cmd->logout_reason: 0x%02x\n",
2944 				cmd->logout_reason);
2945 		return -1;
2946 	}
2947 
2948 	hdr->opcode		= ISCSI_OP_LOGOUT_RSP;
2949 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
2950 	hdr->response		= cmd->logout_response;
2951 	hdr->itt		= cmd->init_task_tag;
2952 	cmd->stat_sn		= conn->stat_sn++;
2953 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2954 
2955 	iscsit_increment_maxcmdsn(cmd, conn->sess);
2956 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2957 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2958 
2959 	pr_debug("Built Logout Response ITT: 0x%08x StatSN:"
2960 		" 0x%08x Response: 0x%02x CID: %hu on CID: %hu\n",
2961 		cmd->init_task_tag, cmd->stat_sn, hdr->response,
2962 		cmd->logout_cid, conn->cid);
2963 
2964 	return 0;
2965 }
2966 EXPORT_SYMBOL(iscsit_build_logout_rsp);
2967 
2968 static int
2969 iscsit_send_logout(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2970 {
2971 	int rc;
2972 
2973 	rc = iscsit_build_logout_rsp(cmd, conn,
2974 			(struct iscsi_logout_rsp *)&cmd->pdu[0]);
2975 	if (rc < 0)
2976 		return rc;
2977 
2978 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
2979 }
2980 
2981 void
2982 iscsit_build_nopin_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2983 		       struct iscsi_nopin *hdr, bool nopout_response)
2984 {
2985 	hdr->opcode		= ISCSI_OP_NOOP_IN;
2986 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
2987         hton24(hdr->dlength, cmd->buf_ptr_size);
2988 	if (nopout_response)
2989 		put_unaligned_le64(0xFFFFFFFFFFFFFFFFULL, &hdr->lun);
2990 	hdr->itt		= cmd->init_task_tag;
2991 	hdr->ttt		= cpu_to_be32(cmd->targ_xfer_tag);
2992 	cmd->stat_sn		= (nopout_response) ? conn->stat_sn++ :
2993 				  conn->stat_sn;
2994 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2995 
2996 	if (nopout_response)
2997 		iscsit_increment_maxcmdsn(cmd, conn->sess);
2998 
2999 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3000 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3001 
3002 	pr_debug("Built NOPIN %s Response ITT: 0x%08x, TTT: 0x%08x,"
3003 		" StatSN: 0x%08x, Length %u\n", (nopout_response) ?
3004 		"Solicited" : "Unsolicited", cmd->init_task_tag,
3005 		cmd->targ_xfer_tag, cmd->stat_sn, cmd->buf_ptr_size);
3006 }
3007 EXPORT_SYMBOL(iscsit_build_nopin_rsp);
3008 
3009 /*
3010  *	Unsolicited NOPIN, either requesting a response or not.
3011  */
3012 static int iscsit_send_unsolicited_nopin(
3013 	struct iscsi_cmd *cmd,
3014 	struct iscsi_conn *conn,
3015 	int want_response)
3016 {
3017 	struct iscsi_nopin *hdr = (struct iscsi_nopin *)&cmd->pdu[0];
3018 	int ret;
3019 
3020 	iscsit_build_nopin_rsp(cmd, conn, hdr, false);
3021 
3022 	pr_debug("Sending Unsolicited NOPIN TTT: 0x%08x StatSN:"
3023 		" 0x%08x CID: %hu\n", hdr->ttt, cmd->stat_sn, conn->cid);
3024 
3025 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3026 	if (ret < 0)
3027 		return ret;
3028 
3029 	spin_lock_bh(&cmd->istate_lock);
3030 	cmd->i_state = want_response ?
3031 		ISTATE_SENT_NOPIN_WANT_RESPONSE : ISTATE_SENT_STATUS;
3032 	spin_unlock_bh(&cmd->istate_lock);
3033 
3034 	return 0;
3035 }
3036 
3037 static int
3038 iscsit_send_nopin(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3039 {
3040 	struct iscsi_nopin *hdr = (struct iscsi_nopin *)&cmd->pdu[0];
3041 
3042 	iscsit_build_nopin_rsp(cmd, conn, hdr, true);
3043 
3044 	/*
3045 	 * NOPOUT Ping Data is attached to struct iscsi_cmd->buf_ptr.
3046 	 * NOPOUT DataSegmentLength is at struct iscsi_cmd->buf_ptr_size.
3047 	 */
3048 	pr_debug("Echoing back %u bytes of ping data.\n", cmd->buf_ptr_size);
3049 
3050 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3051 						     cmd->buf_ptr,
3052 						     cmd->buf_ptr_size);
3053 }
3054 
3055 static int iscsit_send_r2t(
3056 	struct iscsi_cmd *cmd,
3057 	struct iscsi_conn *conn)
3058 {
3059 	struct iscsi_r2t *r2t;
3060 	struct iscsi_r2t_rsp *hdr;
3061 	int ret;
3062 
3063 	r2t = iscsit_get_r2t_from_list(cmd);
3064 	if (!r2t)
3065 		return -1;
3066 
3067 	hdr			= (struct iscsi_r2t_rsp *) cmd->pdu;
3068 	memset(hdr, 0, ISCSI_HDR_LEN);
3069 	hdr->opcode		= ISCSI_OP_R2T;
3070 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3071 	int_to_scsilun(cmd->se_cmd.orig_fe_lun,
3072 			(struct scsi_lun *)&hdr->lun);
3073 	hdr->itt		= cmd->init_task_tag;
3074 	if (conn->conn_transport->iscsit_get_r2t_ttt)
3075 		conn->conn_transport->iscsit_get_r2t_ttt(conn, cmd, r2t);
3076 	else
3077 		r2t->targ_xfer_tag = session_get_next_ttt(conn->sess);
3078 	hdr->ttt		= cpu_to_be32(r2t->targ_xfer_tag);
3079 	hdr->statsn		= cpu_to_be32(conn->stat_sn);
3080 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3081 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3082 	hdr->r2tsn		= cpu_to_be32(r2t->r2t_sn);
3083 	hdr->data_offset	= cpu_to_be32(r2t->offset);
3084 	hdr->data_length	= cpu_to_be32(r2t->xfer_len);
3085 
3086 	pr_debug("Built %sR2T, ITT: 0x%08x, TTT: 0x%08x, StatSN:"
3087 		" 0x%08x, R2TSN: 0x%08x, Offset: %u, DDTL: %u, CID: %hu\n",
3088 		(!r2t->recovery_r2t) ? "" : "Recovery ", cmd->init_task_tag,
3089 		r2t->targ_xfer_tag, ntohl(hdr->statsn), r2t->r2t_sn,
3090 			r2t->offset, r2t->xfer_len, conn->cid);
3091 
3092 	spin_lock_bh(&cmd->r2t_lock);
3093 	r2t->sent_r2t = 1;
3094 	spin_unlock_bh(&cmd->r2t_lock);
3095 
3096 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3097 	if (ret < 0) {
3098 		return ret;
3099 	}
3100 
3101 	spin_lock_bh(&cmd->dataout_timeout_lock);
3102 	iscsit_start_dataout_timer(cmd, conn);
3103 	spin_unlock_bh(&cmd->dataout_timeout_lock);
3104 
3105 	return 0;
3106 }
3107 
3108 /*
3109  *	@recovery: If called from iscsi_task_reassign_complete_write() for
3110  *		connection recovery.
3111  */
3112 int iscsit_build_r2ts_for_cmd(
3113 	struct iscsi_conn *conn,
3114 	struct iscsi_cmd *cmd,
3115 	bool recovery)
3116 {
3117 	int first_r2t = 1;
3118 	u32 offset = 0, xfer_len = 0;
3119 
3120 	spin_lock_bh(&cmd->r2t_lock);
3121 	if (cmd->cmd_flags & ICF_SENT_LAST_R2T) {
3122 		spin_unlock_bh(&cmd->r2t_lock);
3123 		return 0;
3124 	}
3125 
3126 	if (conn->sess->sess_ops->DataSequenceInOrder &&
3127 	    !recovery)
3128 		cmd->r2t_offset = max(cmd->r2t_offset, cmd->write_data_done);
3129 
3130 	while (cmd->outstanding_r2ts < conn->sess->sess_ops->MaxOutstandingR2T) {
3131 		if (conn->sess->sess_ops->DataSequenceInOrder) {
3132 			offset = cmd->r2t_offset;
3133 
3134 			if (first_r2t && recovery) {
3135 				int new_data_end = offset +
3136 					conn->sess->sess_ops->MaxBurstLength -
3137 					cmd->next_burst_len;
3138 
3139 				if (new_data_end > cmd->se_cmd.data_length)
3140 					xfer_len = cmd->se_cmd.data_length - offset;
3141 				else
3142 					xfer_len =
3143 						conn->sess->sess_ops->MaxBurstLength -
3144 						cmd->next_burst_len;
3145 			} else {
3146 				int new_data_end = offset +
3147 					conn->sess->sess_ops->MaxBurstLength;
3148 
3149 				if (new_data_end > cmd->se_cmd.data_length)
3150 					xfer_len = cmd->se_cmd.data_length - offset;
3151 				else
3152 					xfer_len = conn->sess->sess_ops->MaxBurstLength;
3153 			}
3154 
3155 			if ((s32)xfer_len < 0) {
3156 				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
3157 				break;
3158 			}
3159 
3160 			cmd->r2t_offset += xfer_len;
3161 
3162 			if (cmd->r2t_offset == cmd->se_cmd.data_length)
3163 				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
3164 		} else {
3165 			struct iscsi_seq *seq;
3166 
3167 			seq = iscsit_get_seq_holder_for_r2t(cmd);
3168 			if (!seq) {
3169 				spin_unlock_bh(&cmd->r2t_lock);
3170 				return -1;
3171 			}
3172 
3173 			offset = seq->offset;
3174 			xfer_len = seq->xfer_len;
3175 
3176 			if (cmd->seq_send_order == cmd->seq_count)
3177 				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
3178 		}
3179 		cmd->outstanding_r2ts++;
3180 		first_r2t = 0;
3181 
3182 		if (iscsit_add_r2t_to_list(cmd, offset, xfer_len, 0, 0) < 0) {
3183 			spin_unlock_bh(&cmd->r2t_lock);
3184 			return -1;
3185 		}
3186 
3187 		if (cmd->cmd_flags & ICF_SENT_LAST_R2T)
3188 			break;
3189 	}
3190 	spin_unlock_bh(&cmd->r2t_lock);
3191 
3192 	return 0;
3193 }
3194 EXPORT_SYMBOL(iscsit_build_r2ts_for_cmd);
3195 
3196 void iscsit_build_rsp_pdu(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3197 			bool inc_stat_sn, struct iscsi_scsi_rsp *hdr)
3198 {
3199 	if (inc_stat_sn)
3200 		cmd->stat_sn = conn->stat_sn++;
3201 
3202 	atomic_long_inc(&conn->sess->rsp_pdus);
3203 
3204 	memset(hdr, 0, ISCSI_HDR_LEN);
3205 	hdr->opcode		= ISCSI_OP_SCSI_CMD_RSP;
3206 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3207 	if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
3208 		hdr->flags |= ISCSI_FLAG_CMD_OVERFLOW;
3209 		hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
3210 	} else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
3211 		hdr->flags |= ISCSI_FLAG_CMD_UNDERFLOW;
3212 		hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
3213 	}
3214 	hdr->response		= cmd->iscsi_response;
3215 	hdr->cmd_status		= cmd->se_cmd.scsi_status;
3216 	hdr->itt		= cmd->init_task_tag;
3217 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3218 
3219 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3220 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3221 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3222 
3223 	pr_debug("Built SCSI Response, ITT: 0x%08x, StatSN: 0x%08x,"
3224 		" Response: 0x%02x, SAM Status: 0x%02x, CID: %hu\n",
3225 		cmd->init_task_tag, cmd->stat_sn, cmd->se_cmd.scsi_status,
3226 		cmd->se_cmd.scsi_status, conn->cid);
3227 }
3228 EXPORT_SYMBOL(iscsit_build_rsp_pdu);
3229 
3230 static int iscsit_send_response(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3231 {
3232 	struct iscsi_scsi_rsp *hdr = (struct iscsi_scsi_rsp *)&cmd->pdu[0];
3233 	bool inc_stat_sn = (cmd->i_state == ISTATE_SEND_STATUS);
3234 	void *data_buf = NULL;
3235 	u32 padding = 0, data_buf_len = 0;
3236 
3237 	iscsit_build_rsp_pdu(cmd, conn, inc_stat_sn, hdr);
3238 
3239 	/*
3240 	 * Attach SENSE DATA payload to iSCSI Response PDU
3241 	 */
3242 	if (cmd->se_cmd.sense_buffer &&
3243 	   ((cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
3244 	    (cmd->se_cmd.se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
3245 		put_unaligned_be16(cmd->se_cmd.scsi_sense_length, cmd->sense_buffer);
3246 		cmd->se_cmd.scsi_sense_length += sizeof (__be16);
3247 
3248 		padding		= -(cmd->se_cmd.scsi_sense_length) & 3;
3249 		hton24(hdr->dlength, (u32)cmd->se_cmd.scsi_sense_length);
3250 		data_buf = cmd->sense_buffer;
3251 		data_buf_len = cmd->se_cmd.scsi_sense_length + padding;
3252 
3253 		if (padding) {
3254 			memset(cmd->sense_buffer +
3255 				cmd->se_cmd.scsi_sense_length, 0, padding);
3256 			pr_debug("Adding %u bytes of padding to"
3257 				" SENSE.\n", padding);
3258 		}
3259 
3260 		pr_debug("Attaching SENSE DATA: %u bytes to iSCSI"
3261 				" Response PDU\n",
3262 				cmd->se_cmd.scsi_sense_length);
3263 	}
3264 
3265 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, data_buf,
3266 						     data_buf_len);
3267 }
3268 
3269 static u8 iscsit_convert_tcm_tmr_rsp(struct se_tmr_req *se_tmr)
3270 {
3271 	switch (se_tmr->response) {
3272 	case TMR_FUNCTION_COMPLETE:
3273 		return ISCSI_TMF_RSP_COMPLETE;
3274 	case TMR_TASK_DOES_NOT_EXIST:
3275 		return ISCSI_TMF_RSP_NO_TASK;
3276 	case TMR_LUN_DOES_NOT_EXIST:
3277 		return ISCSI_TMF_RSP_NO_LUN;
3278 	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
3279 		return ISCSI_TMF_RSP_NOT_SUPPORTED;
3280 	case TMR_FUNCTION_REJECTED:
3281 	default:
3282 		return ISCSI_TMF_RSP_REJECTED;
3283 	}
3284 }
3285 
3286 void
3287 iscsit_build_task_mgt_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3288 			  struct iscsi_tm_rsp *hdr)
3289 {
3290 	struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req;
3291 
3292 	hdr->opcode		= ISCSI_OP_SCSI_TMFUNC_RSP;
3293 	hdr->flags		= ISCSI_FLAG_CMD_FINAL;
3294 	hdr->response		= iscsit_convert_tcm_tmr_rsp(se_tmr);
3295 	hdr->itt		= cmd->init_task_tag;
3296 	cmd->stat_sn		= conn->stat_sn++;
3297 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3298 
3299 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3300 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3301 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3302 
3303 	pr_debug("Built Task Management Response ITT: 0x%08x,"
3304 		" StatSN: 0x%08x, Response: 0x%02x, CID: %hu\n",
3305 		cmd->init_task_tag, cmd->stat_sn, hdr->response, conn->cid);
3306 }
3307 EXPORT_SYMBOL(iscsit_build_task_mgt_rsp);
3308 
3309 static int
3310 iscsit_send_task_mgt_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3311 {
3312 	struct iscsi_tm_rsp *hdr = (struct iscsi_tm_rsp *)&cmd->pdu[0];
3313 
3314 	iscsit_build_task_mgt_rsp(cmd, conn, hdr);
3315 
3316 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3317 }
3318 
3319 #define SENDTARGETS_BUF_LIMIT 32768U
3320 
3321 static int
3322 iscsit_build_sendtargets_response(struct iscsi_cmd *cmd,
3323 				  enum iscsit_transport_type network_transport,
3324 				  int skip_bytes, bool *completed)
3325 {
3326 	char *payload = NULL;
3327 	struct iscsi_conn *conn = cmd->conn;
3328 	struct iscsi_portal_group *tpg;
3329 	struct iscsi_tiqn *tiqn;
3330 	struct iscsi_tpg_np *tpg_np;
3331 	int buffer_len, end_of_buf = 0, len = 0, payload_len = 0;
3332 	int target_name_printed;
3333 	unsigned char buf[ISCSI_IQN_LEN+12]; /* iqn + "TargetName=" + \0 */
3334 	unsigned char *text_in = cmd->text_in_ptr, *text_ptr = NULL;
3335 	bool active;
3336 
3337 	buffer_len = min(conn->conn_ops->MaxRecvDataSegmentLength,
3338 			 SENDTARGETS_BUF_LIMIT);
3339 
3340 	payload = kzalloc(buffer_len, GFP_KERNEL);
3341 	if (!payload)
3342 		return -ENOMEM;
3343 
3344 	/*
3345 	 * Locate pointer to iqn./eui. string for ICF_SENDTARGETS_SINGLE
3346 	 * explicit case..
3347 	 */
3348 	if (cmd->cmd_flags & ICF_SENDTARGETS_SINGLE) {
3349 		text_ptr = strchr(text_in, '=');
3350 		if (!text_ptr) {
3351 			pr_err("Unable to locate '=' string in text_in:"
3352 			       " %s\n", text_in);
3353 			kfree(payload);
3354 			return -EINVAL;
3355 		}
3356 		/*
3357 		 * Skip over '=' character..
3358 		 */
3359 		text_ptr += 1;
3360 	}
3361 
3362 	spin_lock(&tiqn_lock);
3363 	list_for_each_entry(tiqn, &g_tiqn_list, tiqn_list) {
3364 		if ((cmd->cmd_flags & ICF_SENDTARGETS_SINGLE) &&
3365 		     strcmp(tiqn->tiqn, text_ptr)) {
3366 			continue;
3367 		}
3368 
3369 		target_name_printed = 0;
3370 
3371 		spin_lock(&tiqn->tiqn_tpg_lock);
3372 		list_for_each_entry(tpg, &tiqn->tiqn_tpg_list, tpg_list) {
3373 
3374 			/* If demo_mode_discovery=0 and generate_node_acls=0
3375 			 * (demo mode dislabed) do not return
3376 			 * TargetName+TargetAddress unless a NodeACL exists.
3377 			 */
3378 
3379 			if ((tpg->tpg_attrib.generate_node_acls == 0) &&
3380 			    (tpg->tpg_attrib.demo_mode_discovery == 0) &&
3381 			    (!target_tpg_has_node_acl(&tpg->tpg_se_tpg,
3382 				cmd->conn->sess->sess_ops->InitiatorName))) {
3383 				continue;
3384 			}
3385 
3386 			spin_lock(&tpg->tpg_state_lock);
3387 			active = (tpg->tpg_state == TPG_STATE_ACTIVE);
3388 			spin_unlock(&tpg->tpg_state_lock);
3389 
3390 			if (!active && tpg->tpg_attrib.tpg_enabled_sendtargets)
3391 				continue;
3392 
3393 			spin_lock(&tpg->tpg_np_lock);
3394 			list_for_each_entry(tpg_np, &tpg->tpg_gnp_list,
3395 						tpg_np_list) {
3396 				struct iscsi_np *np = tpg_np->tpg_np;
3397 				struct sockaddr_storage *sockaddr;
3398 
3399 				if (np->np_network_transport != network_transport)
3400 					continue;
3401 
3402 				if (!target_name_printed) {
3403 					len = sprintf(buf, "TargetName=%s",
3404 						      tiqn->tiqn);
3405 					len += 1;
3406 
3407 					if ((len + payload_len) > buffer_len) {
3408 						spin_unlock(&tpg->tpg_np_lock);
3409 						spin_unlock(&tiqn->tiqn_tpg_lock);
3410 						end_of_buf = 1;
3411 						goto eob;
3412 					}
3413 
3414 					if (skip_bytes && len <= skip_bytes) {
3415 						skip_bytes -= len;
3416 					} else {
3417 						memcpy(payload + payload_len, buf, len);
3418 						payload_len += len;
3419 						target_name_printed = 1;
3420 						if (len > skip_bytes)
3421 							skip_bytes = 0;
3422 					}
3423 				}
3424 
3425 				if (inet_addr_is_any((struct sockaddr *)&np->np_sockaddr))
3426 					sockaddr = &conn->local_sockaddr;
3427 				else
3428 					sockaddr = &np->np_sockaddr;
3429 
3430 				len = sprintf(buf, "TargetAddress="
3431 					      "%pISpc,%hu",
3432 					      sockaddr,
3433 					      tpg->tpgt);
3434 				len += 1;
3435 
3436 				if ((len + payload_len) > buffer_len) {
3437 					spin_unlock(&tpg->tpg_np_lock);
3438 					spin_unlock(&tiqn->tiqn_tpg_lock);
3439 					end_of_buf = 1;
3440 					goto eob;
3441 				}
3442 
3443 				if (skip_bytes && len <= skip_bytes) {
3444 					skip_bytes -= len;
3445 				} else {
3446 					memcpy(payload + payload_len, buf, len);
3447 					payload_len += len;
3448 					if (len > skip_bytes)
3449 						skip_bytes = 0;
3450 				}
3451 			}
3452 			spin_unlock(&tpg->tpg_np_lock);
3453 		}
3454 		spin_unlock(&tiqn->tiqn_tpg_lock);
3455 eob:
3456 		if (end_of_buf) {
3457 			*completed = false;
3458 			break;
3459 		}
3460 
3461 		if (cmd->cmd_flags & ICF_SENDTARGETS_SINGLE)
3462 			break;
3463 	}
3464 	spin_unlock(&tiqn_lock);
3465 
3466 	cmd->buf_ptr = payload;
3467 
3468 	return payload_len;
3469 }
3470 
3471 int
3472 iscsit_build_text_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3473 		      struct iscsi_text_rsp *hdr,
3474 		      enum iscsit_transport_type network_transport)
3475 {
3476 	int text_length, padding;
3477 	bool completed = true;
3478 
3479 	text_length = iscsit_build_sendtargets_response(cmd, network_transport,
3480 							cmd->read_data_done,
3481 							&completed);
3482 	if (text_length < 0)
3483 		return text_length;
3484 
3485 	if (completed) {
3486 		hdr->flags = ISCSI_FLAG_CMD_FINAL;
3487 	} else {
3488 		hdr->flags = ISCSI_FLAG_TEXT_CONTINUE;
3489 		cmd->read_data_done += text_length;
3490 		if (cmd->targ_xfer_tag == 0xFFFFFFFF)
3491 			cmd->targ_xfer_tag = session_get_next_ttt(conn->sess);
3492 	}
3493 	hdr->opcode = ISCSI_OP_TEXT_RSP;
3494 	padding = ((-text_length) & 3);
3495 	hton24(hdr->dlength, text_length);
3496 	hdr->itt = cmd->init_task_tag;
3497 	hdr->ttt = cpu_to_be32(cmd->targ_xfer_tag);
3498 	cmd->stat_sn = conn->stat_sn++;
3499 	hdr->statsn = cpu_to_be32(cmd->stat_sn);
3500 
3501 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3502 	/*
3503 	 * Reset maxcmdsn_inc in multi-part text payload exchanges to
3504 	 * correctly increment MaxCmdSN for each response answering a
3505 	 * non immediate text request with a valid CmdSN.
3506 	 */
3507 	cmd->maxcmdsn_inc = 0;
3508 	hdr->exp_cmdsn = cpu_to_be32(conn->sess->exp_cmd_sn);
3509 	hdr->max_cmdsn = cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3510 
3511 	pr_debug("Built Text Response: ITT: 0x%08x, TTT: 0x%08x, StatSN: 0x%08x,"
3512 		" Length: %u, CID: %hu F: %d C: %d\n", cmd->init_task_tag,
3513 		cmd->targ_xfer_tag, cmd->stat_sn, text_length, conn->cid,
3514 		!!(hdr->flags & ISCSI_FLAG_CMD_FINAL),
3515 		!!(hdr->flags & ISCSI_FLAG_TEXT_CONTINUE));
3516 
3517 	return text_length + padding;
3518 }
3519 EXPORT_SYMBOL(iscsit_build_text_rsp);
3520 
3521 static int iscsit_send_text_rsp(
3522 	struct iscsi_cmd *cmd,
3523 	struct iscsi_conn *conn)
3524 {
3525 	struct iscsi_text_rsp *hdr = (struct iscsi_text_rsp *)cmd->pdu;
3526 	int text_length;
3527 
3528 	text_length = iscsit_build_text_rsp(cmd, conn, hdr,
3529 				conn->conn_transport->transport_type);
3530 	if (text_length < 0)
3531 		return text_length;
3532 
3533 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3534 						     cmd->buf_ptr,
3535 						     text_length);
3536 }
3537 
3538 void
3539 iscsit_build_reject(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3540 		    struct iscsi_reject *hdr)
3541 {
3542 	hdr->opcode		= ISCSI_OP_REJECT;
3543 	hdr->reason		= cmd->reject_reason;
3544 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3545 	hton24(hdr->dlength, ISCSI_HDR_LEN);
3546 	hdr->ffffffff		= cpu_to_be32(0xffffffff);
3547 	cmd->stat_sn		= conn->stat_sn++;
3548 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3549 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3550 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3551 
3552 }
3553 EXPORT_SYMBOL(iscsit_build_reject);
3554 
3555 static int iscsit_send_reject(
3556 	struct iscsi_cmd *cmd,
3557 	struct iscsi_conn *conn)
3558 {
3559 	struct iscsi_reject *hdr = (struct iscsi_reject *)&cmd->pdu[0];
3560 
3561 	iscsit_build_reject(cmd, conn, hdr);
3562 
3563 	pr_debug("Built Reject PDU StatSN: 0x%08x, Reason: 0x%02x,"
3564 		" CID: %hu\n", ntohl(hdr->statsn), hdr->reason, conn->cid);
3565 
3566 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3567 						     cmd->buf_ptr,
3568 						     ISCSI_HDR_LEN);
3569 }
3570 
3571 void iscsit_thread_get_cpumask(struct iscsi_conn *conn)
3572 {
3573 	int ord, cpu;
3574 	/*
3575 	 * bitmap_id is assigned from iscsit_global->ts_bitmap from
3576 	 * within iscsit_start_kthreads()
3577 	 *
3578 	 * Here we use bitmap_id to determine which CPU that this
3579 	 * iSCSI connection's RX/TX threads will be scheduled to
3580 	 * execute upon.
3581 	 */
3582 	ord = conn->bitmap_id % cpumask_weight(cpu_online_mask);
3583 	for_each_online_cpu(cpu) {
3584 		if (ord-- == 0) {
3585 			cpumask_set_cpu(cpu, conn->conn_cpumask);
3586 			return;
3587 		}
3588 	}
3589 	/*
3590 	 * This should never be reached..
3591 	 */
3592 	dump_stack();
3593 	cpumask_setall(conn->conn_cpumask);
3594 }
3595 
3596 int
3597 iscsit_immediate_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
3598 {
3599 	int ret;
3600 
3601 	switch (state) {
3602 	case ISTATE_SEND_R2T:
3603 		ret = iscsit_send_r2t(cmd, conn);
3604 		if (ret < 0)
3605 			goto err;
3606 		break;
3607 	case ISTATE_REMOVE:
3608 		spin_lock_bh(&conn->cmd_lock);
3609 		list_del_init(&cmd->i_conn_node);
3610 		spin_unlock_bh(&conn->cmd_lock);
3611 
3612 		iscsit_free_cmd(cmd, false);
3613 		break;
3614 	case ISTATE_SEND_NOPIN_WANT_RESPONSE:
3615 		iscsit_mod_nopin_response_timer(conn);
3616 		ret = iscsit_send_unsolicited_nopin(cmd, conn, 1);
3617 		if (ret < 0)
3618 			goto err;
3619 		break;
3620 	case ISTATE_SEND_NOPIN_NO_RESPONSE:
3621 		ret = iscsit_send_unsolicited_nopin(cmd, conn, 0);
3622 		if (ret < 0)
3623 			goto err;
3624 		break;
3625 	default:
3626 		pr_err("Unknown Opcode: 0x%02x ITT:"
3627 		       " 0x%08x, i_state: %d on CID: %hu\n",
3628 		       cmd->iscsi_opcode, cmd->init_task_tag, state,
3629 		       conn->cid);
3630 		goto err;
3631 	}
3632 
3633 	return 0;
3634 
3635 err:
3636 	return -1;
3637 }
3638 EXPORT_SYMBOL(iscsit_immediate_queue);
3639 
3640 static int
3641 iscsit_handle_immediate_queue(struct iscsi_conn *conn)
3642 {
3643 	struct iscsit_transport *t = conn->conn_transport;
3644 	struct iscsi_queue_req *qr;
3645 	struct iscsi_cmd *cmd;
3646 	u8 state;
3647 	int ret;
3648 
3649 	while ((qr = iscsit_get_cmd_from_immediate_queue(conn))) {
3650 		atomic_set(&conn->check_immediate_queue, 0);
3651 		cmd = qr->cmd;
3652 		state = qr->state;
3653 		kmem_cache_free(lio_qr_cache, qr);
3654 
3655 		ret = t->iscsit_immediate_queue(conn, cmd, state);
3656 		if (ret < 0)
3657 			return ret;
3658 	}
3659 
3660 	return 0;
3661 }
3662 
3663 int
3664 iscsit_response_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
3665 {
3666 	int ret;
3667 
3668 check_rsp_state:
3669 	switch (state) {
3670 	case ISTATE_SEND_DATAIN:
3671 		ret = iscsit_send_datain(cmd, conn);
3672 		if (ret < 0)
3673 			goto err;
3674 		else if (!ret)
3675 			/* more drs */
3676 			goto check_rsp_state;
3677 		else if (ret == 1) {
3678 			/* all done */
3679 			spin_lock_bh(&cmd->istate_lock);
3680 			cmd->i_state = ISTATE_SENT_STATUS;
3681 			spin_unlock_bh(&cmd->istate_lock);
3682 
3683 			if (atomic_read(&conn->check_immediate_queue))
3684 				return 1;
3685 
3686 			return 0;
3687 		} else if (ret == 2) {
3688 			/* Still must send status,
3689 			   SCF_TRANSPORT_TASK_SENSE was set */
3690 			spin_lock_bh(&cmd->istate_lock);
3691 			cmd->i_state = ISTATE_SEND_STATUS;
3692 			spin_unlock_bh(&cmd->istate_lock);
3693 			state = ISTATE_SEND_STATUS;
3694 			goto check_rsp_state;
3695 		}
3696 
3697 		break;
3698 	case ISTATE_SEND_STATUS:
3699 	case ISTATE_SEND_STATUS_RECOVERY:
3700 		ret = iscsit_send_response(cmd, conn);
3701 		break;
3702 	case ISTATE_SEND_LOGOUTRSP:
3703 		ret = iscsit_send_logout(cmd, conn);
3704 		break;
3705 	case ISTATE_SEND_ASYNCMSG:
3706 		ret = iscsit_send_conn_drop_async_message(
3707 			cmd, conn);
3708 		break;
3709 	case ISTATE_SEND_NOPIN:
3710 		ret = iscsit_send_nopin(cmd, conn);
3711 		break;
3712 	case ISTATE_SEND_REJECT:
3713 		ret = iscsit_send_reject(cmd, conn);
3714 		break;
3715 	case ISTATE_SEND_TASKMGTRSP:
3716 		ret = iscsit_send_task_mgt_rsp(cmd, conn);
3717 		if (ret != 0)
3718 			break;
3719 		ret = iscsit_tmr_post_handler(cmd, conn);
3720 		if (ret != 0)
3721 			iscsit_fall_back_to_erl0(conn->sess);
3722 		break;
3723 	case ISTATE_SEND_TEXTRSP:
3724 		ret = iscsit_send_text_rsp(cmd, conn);
3725 		break;
3726 	default:
3727 		pr_err("Unknown Opcode: 0x%02x ITT:"
3728 		       " 0x%08x, i_state: %d on CID: %hu\n",
3729 		       cmd->iscsi_opcode, cmd->init_task_tag,
3730 		       state, conn->cid);
3731 		goto err;
3732 	}
3733 	if (ret < 0)
3734 		goto err;
3735 
3736 	switch (state) {
3737 	case ISTATE_SEND_LOGOUTRSP:
3738 		if (!iscsit_logout_post_handler(cmd, conn))
3739 			return -ECONNRESET;
3740 		/* fall through */
3741 	case ISTATE_SEND_STATUS:
3742 	case ISTATE_SEND_ASYNCMSG:
3743 	case ISTATE_SEND_NOPIN:
3744 	case ISTATE_SEND_STATUS_RECOVERY:
3745 	case ISTATE_SEND_TEXTRSP:
3746 	case ISTATE_SEND_TASKMGTRSP:
3747 	case ISTATE_SEND_REJECT:
3748 		spin_lock_bh(&cmd->istate_lock);
3749 		cmd->i_state = ISTATE_SENT_STATUS;
3750 		spin_unlock_bh(&cmd->istate_lock);
3751 		break;
3752 	default:
3753 		pr_err("Unknown Opcode: 0x%02x ITT:"
3754 		       " 0x%08x, i_state: %d on CID: %hu\n",
3755 		       cmd->iscsi_opcode, cmd->init_task_tag,
3756 		       cmd->i_state, conn->cid);
3757 		goto err;
3758 	}
3759 
3760 	if (atomic_read(&conn->check_immediate_queue))
3761 		return 1;
3762 
3763 	return 0;
3764 
3765 err:
3766 	return -1;
3767 }
3768 EXPORT_SYMBOL(iscsit_response_queue);
3769 
3770 static int iscsit_handle_response_queue(struct iscsi_conn *conn)
3771 {
3772 	struct iscsit_transport *t = conn->conn_transport;
3773 	struct iscsi_queue_req *qr;
3774 	struct iscsi_cmd *cmd;
3775 	u8 state;
3776 	int ret;
3777 
3778 	while ((qr = iscsit_get_cmd_from_response_queue(conn))) {
3779 		cmd = qr->cmd;
3780 		state = qr->state;
3781 		kmem_cache_free(lio_qr_cache, qr);
3782 
3783 		ret = t->iscsit_response_queue(conn, cmd, state);
3784 		if (ret == 1 || ret < 0)
3785 			return ret;
3786 	}
3787 
3788 	return 0;
3789 }
3790 
3791 int iscsi_target_tx_thread(void *arg)
3792 {
3793 	int ret = 0;
3794 	struct iscsi_conn *conn = arg;
3795 	bool conn_freed = false;
3796 
3797 	/*
3798 	 * Allow ourselves to be interrupted by SIGINT so that a
3799 	 * connection recovery / failure event can be triggered externally.
3800 	 */
3801 	allow_signal(SIGINT);
3802 
3803 	while (!kthread_should_stop()) {
3804 		/*
3805 		 * Ensure that both TX and RX per connection kthreads
3806 		 * are scheduled to run on the same CPU.
3807 		 */
3808 		iscsit_thread_check_cpumask(conn, current, 1);
3809 
3810 		wait_event_interruptible(conn->queues_wq,
3811 					 !iscsit_conn_all_queues_empty(conn));
3812 
3813 		if (signal_pending(current))
3814 			goto transport_err;
3815 
3816 get_immediate:
3817 		ret = iscsit_handle_immediate_queue(conn);
3818 		if (ret < 0)
3819 			goto transport_err;
3820 
3821 		ret = iscsit_handle_response_queue(conn);
3822 		if (ret == 1) {
3823 			goto get_immediate;
3824 		} else if (ret == -ECONNRESET) {
3825 			conn_freed = true;
3826 			goto out;
3827 		} else if (ret < 0) {
3828 			goto transport_err;
3829 		}
3830 	}
3831 
3832 transport_err:
3833 	/*
3834 	 * Avoid the normal connection failure code-path if this connection
3835 	 * is still within LOGIN mode, and iscsi_np process context is
3836 	 * responsible for cleaning up the early connection failure.
3837 	 */
3838 	if (conn->conn_state != TARG_CONN_STATE_IN_LOGIN)
3839 		iscsit_take_action_for_connection_exit(conn, &conn_freed);
3840 out:
3841 	if (!conn_freed) {
3842 		while (!kthread_should_stop()) {
3843 			msleep(100);
3844 		}
3845 	}
3846 	return 0;
3847 }
3848 
3849 static int iscsi_target_rx_opcode(struct iscsi_conn *conn, unsigned char *buf)
3850 {
3851 	struct iscsi_hdr *hdr = (struct iscsi_hdr *)buf;
3852 	struct iscsi_cmd *cmd;
3853 	int ret = 0;
3854 
3855 	switch (hdr->opcode & ISCSI_OPCODE_MASK) {
3856 	case ISCSI_OP_SCSI_CMD:
3857 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3858 		if (!cmd)
3859 			goto reject;
3860 
3861 		ret = iscsit_handle_scsi_cmd(conn, cmd, buf);
3862 		break;
3863 	case ISCSI_OP_SCSI_DATA_OUT:
3864 		ret = iscsit_handle_data_out(conn, buf);
3865 		break;
3866 	case ISCSI_OP_NOOP_OUT:
3867 		cmd = NULL;
3868 		if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
3869 			cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3870 			if (!cmd)
3871 				goto reject;
3872 		}
3873 		ret = iscsit_handle_nop_out(conn, cmd, buf);
3874 		break;
3875 	case ISCSI_OP_SCSI_TMFUNC:
3876 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3877 		if (!cmd)
3878 			goto reject;
3879 
3880 		ret = iscsit_handle_task_mgt_cmd(conn, cmd, buf);
3881 		break;
3882 	case ISCSI_OP_TEXT:
3883 		if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
3884 			cmd = iscsit_find_cmd_from_itt(conn, hdr->itt);
3885 			if (!cmd)
3886 				goto reject;
3887 		} else {
3888 			cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3889 			if (!cmd)
3890 				goto reject;
3891 		}
3892 
3893 		ret = iscsit_handle_text_cmd(conn, cmd, buf);
3894 		break;
3895 	case ISCSI_OP_LOGOUT:
3896 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3897 		if (!cmd)
3898 			goto reject;
3899 
3900 		ret = iscsit_handle_logout_cmd(conn, cmd, buf);
3901 		if (ret > 0)
3902 			wait_for_completion_timeout(&conn->conn_logout_comp,
3903 					SECONDS_FOR_LOGOUT_COMP * HZ);
3904 		break;
3905 	case ISCSI_OP_SNACK:
3906 		ret = iscsit_handle_snack(conn, buf);
3907 		break;
3908 	default:
3909 		pr_err("Got unknown iSCSI OpCode: 0x%02x\n", hdr->opcode);
3910 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
3911 			pr_err("Cannot recover from unknown"
3912 			" opcode while ERL=0, closing iSCSI connection.\n");
3913 			return -1;
3914 		}
3915 		pr_err("Unable to recover from unknown opcode while OFMarker=No,"
3916 		       " closing iSCSI connection.\n");
3917 		ret = -1;
3918 		break;
3919 	}
3920 
3921 	return ret;
3922 reject:
3923 	return iscsit_add_reject(conn, ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
3924 }
3925 
3926 static bool iscsi_target_check_conn_state(struct iscsi_conn *conn)
3927 {
3928 	bool ret;
3929 
3930 	spin_lock_bh(&conn->state_lock);
3931 	ret = (conn->conn_state != TARG_CONN_STATE_LOGGED_IN);
3932 	spin_unlock_bh(&conn->state_lock);
3933 
3934 	return ret;
3935 }
3936 
3937 static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
3938 {
3939 	int ret;
3940 	u8 *buffer, opcode;
3941 	u32 checksum = 0, digest = 0;
3942 	struct kvec iov;
3943 
3944 	buffer = kcalloc(ISCSI_HDR_LEN, sizeof(*buffer), GFP_KERNEL);
3945 	if (!buffer)
3946 		return;
3947 
3948 	while (!kthread_should_stop()) {
3949 		/*
3950 		 * Ensure that both TX and RX per connection kthreads
3951 		 * are scheduled to run on the same CPU.
3952 		 */
3953 		iscsit_thread_check_cpumask(conn, current, 0);
3954 
3955 		memset(&iov, 0, sizeof(struct kvec));
3956 
3957 		iov.iov_base	= buffer;
3958 		iov.iov_len	= ISCSI_HDR_LEN;
3959 
3960 		ret = rx_data(conn, &iov, 1, ISCSI_HDR_LEN);
3961 		if (ret != ISCSI_HDR_LEN) {
3962 			iscsit_rx_thread_wait_for_tcp(conn);
3963 			break;
3964 		}
3965 
3966 		if (conn->conn_ops->HeaderDigest) {
3967 			iov.iov_base	= &digest;
3968 			iov.iov_len	= ISCSI_CRC_LEN;
3969 
3970 			ret = rx_data(conn, &iov, 1, ISCSI_CRC_LEN);
3971 			if (ret != ISCSI_CRC_LEN) {
3972 				iscsit_rx_thread_wait_for_tcp(conn);
3973 				break;
3974 			}
3975 
3976 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash, buffer,
3977 						  ISCSI_HDR_LEN, 0, NULL,
3978 						  &checksum);
3979 
3980 			if (digest != checksum) {
3981 				pr_err("HeaderDigest CRC32C failed,"
3982 					" received 0x%08x, computed 0x%08x\n",
3983 					digest, checksum);
3984 				/*
3985 				 * Set the PDU to 0xff so it will intentionally
3986 				 * hit default in the switch below.
3987 				 */
3988 				memset(buffer, 0xff, ISCSI_HDR_LEN);
3989 				atomic_long_inc(&conn->sess->conn_digest_errors);
3990 			} else {
3991 				pr_debug("Got HeaderDigest CRC32C"
3992 						" 0x%08x\n", checksum);
3993 			}
3994 		}
3995 
3996 		if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT)
3997 			break;
3998 
3999 		opcode = buffer[0] & ISCSI_OPCODE_MASK;
4000 
4001 		if (conn->sess->sess_ops->SessionType &&
4002 		   ((!(opcode & ISCSI_OP_TEXT)) ||
4003 		    (!(opcode & ISCSI_OP_LOGOUT)))) {
4004 			pr_err("Received illegal iSCSI Opcode: 0x%02x"
4005 			" while in Discovery Session, rejecting.\n", opcode);
4006 			iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
4007 					  buffer);
4008 			break;
4009 		}
4010 
4011 		ret = iscsi_target_rx_opcode(conn, buffer);
4012 		if (ret < 0)
4013 			break;
4014 	}
4015 
4016 	kfree(buffer);
4017 }
4018 
4019 int iscsi_target_rx_thread(void *arg)
4020 {
4021 	int rc;
4022 	struct iscsi_conn *conn = arg;
4023 	bool conn_freed = false;
4024 
4025 	/*
4026 	 * Allow ourselves to be interrupted by SIGINT so that a
4027 	 * connection recovery / failure event can be triggered externally.
4028 	 */
4029 	allow_signal(SIGINT);
4030 	/*
4031 	 * Wait for iscsi_post_login_handler() to complete before allowing
4032 	 * incoming iscsi/tcp socket I/O, and/or failing the connection.
4033 	 */
4034 	rc = wait_for_completion_interruptible(&conn->rx_login_comp);
4035 	if (rc < 0 || iscsi_target_check_conn_state(conn))
4036 		goto out;
4037 
4038 	if (!conn->conn_transport->iscsit_get_rx_pdu)
4039 		return 0;
4040 
4041 	conn->conn_transport->iscsit_get_rx_pdu(conn);
4042 
4043 	if (!signal_pending(current))
4044 		atomic_set(&conn->transport_failed, 1);
4045 	iscsit_take_action_for_connection_exit(conn, &conn_freed);
4046 
4047 out:
4048 	if (!conn_freed) {
4049 		while (!kthread_should_stop()) {
4050 			msleep(100);
4051 		}
4052 	}
4053 
4054 	return 0;
4055 }
4056 
4057 static void iscsit_release_commands_from_conn(struct iscsi_conn *conn)
4058 {
4059 	LIST_HEAD(tmp_list);
4060 	struct iscsi_cmd *cmd = NULL, *cmd_tmp = NULL;
4061 	struct iscsi_session *sess = conn->sess;
4062 	/*
4063 	 * We expect this function to only ever be called from either RX or TX
4064 	 * thread context via iscsit_close_connection() once the other context
4065 	 * has been reset -> returned sleeping pre-handler state.
4066 	 */
4067 	spin_lock_bh(&conn->cmd_lock);
4068 	list_splice_init(&conn->conn_cmd_list, &tmp_list);
4069 
4070 	list_for_each_entry(cmd, &tmp_list, i_conn_node) {
4071 		struct se_cmd *se_cmd = &cmd->se_cmd;
4072 
4073 		if (se_cmd->se_tfo != NULL) {
4074 			spin_lock_irq(&se_cmd->t_state_lock);
4075 			se_cmd->transport_state |= CMD_T_FABRIC_STOP;
4076 			spin_unlock_irq(&se_cmd->t_state_lock);
4077 		}
4078 	}
4079 	spin_unlock_bh(&conn->cmd_lock);
4080 
4081 	list_for_each_entry_safe(cmd, cmd_tmp, &tmp_list, i_conn_node) {
4082 		list_del_init(&cmd->i_conn_node);
4083 
4084 		iscsit_increment_maxcmdsn(cmd, sess);
4085 		iscsit_free_cmd(cmd, true);
4086 
4087 	}
4088 }
4089 
4090 static void iscsit_stop_timers_for_cmds(
4091 	struct iscsi_conn *conn)
4092 {
4093 	struct iscsi_cmd *cmd;
4094 
4095 	spin_lock_bh(&conn->cmd_lock);
4096 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
4097 		if (cmd->data_direction == DMA_TO_DEVICE)
4098 			iscsit_stop_dataout_timer(cmd);
4099 	}
4100 	spin_unlock_bh(&conn->cmd_lock);
4101 }
4102 
4103 int iscsit_close_connection(
4104 	struct iscsi_conn *conn)
4105 {
4106 	int conn_logout = (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT);
4107 	struct iscsi_session	*sess = conn->sess;
4108 
4109 	pr_debug("Closing iSCSI connection CID %hu on SID:"
4110 		" %u\n", conn->cid, sess->sid);
4111 	/*
4112 	 * Always up conn_logout_comp for the traditional TCP and HW_OFFLOAD
4113 	 * case just in case the RX Thread in iscsi_target_rx_opcode() is
4114 	 * sleeping and the logout response never got sent because the
4115 	 * connection failed.
4116 	 *
4117 	 * However for iser-target, isert_wait4logout() is using conn_logout_comp
4118 	 * to signal logout response TX interrupt completion.  Go ahead and skip
4119 	 * this for iser since isert_rx_opcode() does not wait on logout failure,
4120 	 * and to avoid iscsi_conn pointer dereference in iser-target code.
4121 	 */
4122 	if (!conn->conn_transport->rdma_shutdown)
4123 		complete(&conn->conn_logout_comp);
4124 
4125 	if (!strcmp(current->comm, ISCSI_RX_THREAD_NAME)) {
4126 		if (conn->tx_thread &&
4127 		    cmpxchg(&conn->tx_thread_active, true, false)) {
4128 			send_sig(SIGINT, conn->tx_thread, 1);
4129 			kthread_stop(conn->tx_thread);
4130 		}
4131 	} else if (!strcmp(current->comm, ISCSI_TX_THREAD_NAME)) {
4132 		if (conn->rx_thread &&
4133 		    cmpxchg(&conn->rx_thread_active, true, false)) {
4134 			send_sig(SIGINT, conn->rx_thread, 1);
4135 			kthread_stop(conn->rx_thread);
4136 		}
4137 	}
4138 
4139 	spin_lock(&iscsit_global->ts_bitmap_lock);
4140 	bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
4141 			      get_order(1));
4142 	spin_unlock(&iscsit_global->ts_bitmap_lock);
4143 
4144 	iscsit_stop_timers_for_cmds(conn);
4145 	iscsit_stop_nopin_response_timer(conn);
4146 	iscsit_stop_nopin_timer(conn);
4147 
4148 	if (conn->conn_transport->iscsit_wait_conn)
4149 		conn->conn_transport->iscsit_wait_conn(conn);
4150 
4151 	/*
4152 	 * During Connection recovery drop unacknowledged out of order
4153 	 * commands for this connection, and prepare the other commands
4154 	 * for reallegiance.
4155 	 *
4156 	 * During normal operation clear the out of order commands (but
4157 	 * do not free the struct iscsi_ooo_cmdsn's) and release all
4158 	 * struct iscsi_cmds.
4159 	 */
4160 	if (atomic_read(&conn->connection_recovery)) {
4161 		iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(conn);
4162 		iscsit_prepare_cmds_for_reallegiance(conn);
4163 	} else {
4164 		iscsit_clear_ooo_cmdsns_for_conn(conn);
4165 		iscsit_release_commands_from_conn(conn);
4166 	}
4167 	iscsit_free_queue_reqs_for_conn(conn);
4168 
4169 	/*
4170 	 * Handle decrementing session or connection usage count if
4171 	 * a logout response was not able to be sent because the
4172 	 * connection failed.  Fall back to Session Recovery here.
4173 	 */
4174 	if (atomic_read(&conn->conn_logout_remove)) {
4175 		if (conn->conn_logout_reason == ISCSI_LOGOUT_REASON_CLOSE_SESSION) {
4176 			iscsit_dec_conn_usage_count(conn);
4177 			iscsit_dec_session_usage_count(sess);
4178 		}
4179 		if (conn->conn_logout_reason == ISCSI_LOGOUT_REASON_CLOSE_CONNECTION)
4180 			iscsit_dec_conn_usage_count(conn);
4181 
4182 		atomic_set(&conn->conn_logout_remove, 0);
4183 		atomic_set(&sess->session_reinstatement, 0);
4184 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4185 	}
4186 
4187 	spin_lock_bh(&sess->conn_lock);
4188 	list_del(&conn->conn_list);
4189 
4190 	/*
4191 	 * Attempt to let the Initiator know this connection failed by
4192 	 * sending an Connection Dropped Async Message on another
4193 	 * active connection.
4194 	 */
4195 	if (atomic_read(&conn->connection_recovery))
4196 		iscsit_build_conn_drop_async_message(conn);
4197 
4198 	spin_unlock_bh(&sess->conn_lock);
4199 
4200 	/*
4201 	 * If connection reinstatement is being performed on this connection,
4202 	 * up the connection reinstatement semaphore that is being blocked on
4203 	 * in iscsit_cause_connection_reinstatement().
4204 	 */
4205 	spin_lock_bh(&conn->state_lock);
4206 	if (atomic_read(&conn->sleep_on_conn_wait_comp)) {
4207 		spin_unlock_bh(&conn->state_lock);
4208 		complete(&conn->conn_wait_comp);
4209 		wait_for_completion(&conn->conn_post_wait_comp);
4210 		spin_lock_bh(&conn->state_lock);
4211 	}
4212 
4213 	/*
4214 	 * If connection reinstatement is being performed on this connection
4215 	 * by receiving a REMOVECONNFORRECOVERY logout request, up the
4216 	 * connection wait rcfr semaphore that is being blocked on
4217 	 * an iscsit_connection_reinstatement_rcfr().
4218 	 */
4219 	if (atomic_read(&conn->connection_wait_rcfr)) {
4220 		spin_unlock_bh(&conn->state_lock);
4221 		complete(&conn->conn_wait_rcfr_comp);
4222 		wait_for_completion(&conn->conn_post_wait_comp);
4223 		spin_lock_bh(&conn->state_lock);
4224 	}
4225 	atomic_set(&conn->connection_reinstatement, 1);
4226 	spin_unlock_bh(&conn->state_lock);
4227 
4228 	/*
4229 	 * If any other processes are accessing this connection pointer we
4230 	 * must wait until they have completed.
4231 	 */
4232 	iscsit_check_conn_usage_count(conn);
4233 
4234 	ahash_request_free(conn->conn_tx_hash);
4235 	if (conn->conn_rx_hash) {
4236 		struct crypto_ahash *tfm;
4237 
4238 		tfm = crypto_ahash_reqtfm(conn->conn_rx_hash);
4239 		ahash_request_free(conn->conn_rx_hash);
4240 		crypto_free_ahash(tfm);
4241 	}
4242 
4243 	if (conn->sock)
4244 		sock_release(conn->sock);
4245 
4246 	if (conn->conn_transport->iscsit_free_conn)
4247 		conn->conn_transport->iscsit_free_conn(conn);
4248 
4249 	pr_debug("Moving to TARG_CONN_STATE_FREE.\n");
4250 	conn->conn_state = TARG_CONN_STATE_FREE;
4251 	iscsit_free_conn(conn);
4252 
4253 	spin_lock_bh(&sess->conn_lock);
4254 	atomic_dec(&sess->nconn);
4255 	pr_debug("Decremented iSCSI connection count to %hu from node:"
4256 		" %s\n", atomic_read(&sess->nconn),
4257 		sess->sess_ops->InitiatorName);
4258 	/*
4259 	 * Make sure that if one connection fails in an non ERL=2 iSCSI
4260 	 * Session that they all fail.
4261 	 */
4262 	if ((sess->sess_ops->ErrorRecoveryLevel != 2) && !conn_logout &&
4263 	     !atomic_read(&sess->session_logout))
4264 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4265 
4266 	/*
4267 	 * If this was not the last connection in the session, and we are
4268 	 * performing session reinstatement or falling back to ERL=0, call
4269 	 * iscsit_stop_session() without sleeping to shutdown the other
4270 	 * active connections.
4271 	 */
4272 	if (atomic_read(&sess->nconn)) {
4273 		if (!atomic_read(&sess->session_reinstatement) &&
4274 		    !atomic_read(&sess->session_fall_back_to_erl0)) {
4275 			spin_unlock_bh(&sess->conn_lock);
4276 			return 0;
4277 		}
4278 		if (!atomic_read(&sess->session_stop_active)) {
4279 			atomic_set(&sess->session_stop_active, 1);
4280 			spin_unlock_bh(&sess->conn_lock);
4281 			iscsit_stop_session(sess, 0, 0);
4282 			return 0;
4283 		}
4284 		spin_unlock_bh(&sess->conn_lock);
4285 		return 0;
4286 	}
4287 
4288 	/*
4289 	 * If this was the last connection in the session and one of the
4290 	 * following is occurring:
4291 	 *
4292 	 * Session Reinstatement is not being performed, and are falling back
4293 	 * to ERL=0 call iscsit_close_session().
4294 	 *
4295 	 * Session Logout was requested.  iscsit_close_session() will be called
4296 	 * elsewhere.
4297 	 *
4298 	 * Session Continuation is not being performed, start the Time2Retain
4299 	 * handler and check if sleep_on_sess_wait_sem is active.
4300 	 */
4301 	if (!atomic_read(&sess->session_reinstatement) &&
4302 	     atomic_read(&sess->session_fall_back_to_erl0)) {
4303 		spin_unlock_bh(&sess->conn_lock);
4304 		iscsit_close_session(sess);
4305 
4306 		return 0;
4307 	} else if (atomic_read(&sess->session_logout)) {
4308 		pr_debug("Moving to TARG_SESS_STATE_FREE.\n");
4309 		sess->session_state = TARG_SESS_STATE_FREE;
4310 		spin_unlock_bh(&sess->conn_lock);
4311 
4312 		if (atomic_read(&sess->sleep_on_sess_wait_comp))
4313 			complete(&sess->session_wait_comp);
4314 
4315 		return 0;
4316 	} else {
4317 		pr_debug("Moving to TARG_SESS_STATE_FAILED.\n");
4318 		sess->session_state = TARG_SESS_STATE_FAILED;
4319 
4320 		if (!atomic_read(&sess->session_continuation)) {
4321 			spin_unlock_bh(&sess->conn_lock);
4322 			iscsit_start_time2retain_handler(sess);
4323 		} else
4324 			spin_unlock_bh(&sess->conn_lock);
4325 
4326 		if (atomic_read(&sess->sleep_on_sess_wait_comp))
4327 			complete(&sess->session_wait_comp);
4328 
4329 		return 0;
4330 	}
4331 }
4332 
4333 /*
4334  * If the iSCSI Session for the iSCSI Initiator Node exists,
4335  * forcefully shutdown the iSCSI NEXUS.
4336  */
4337 int iscsit_close_session(struct iscsi_session *sess)
4338 {
4339 	struct iscsi_portal_group *tpg = sess->tpg;
4340 	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
4341 
4342 	if (atomic_read(&sess->nconn)) {
4343 		pr_err("%d connection(s) still exist for iSCSI session"
4344 			" to %s\n", atomic_read(&sess->nconn),
4345 			sess->sess_ops->InitiatorName);
4346 		BUG();
4347 	}
4348 
4349 	spin_lock_bh(&se_tpg->session_lock);
4350 	atomic_set(&sess->session_logout, 1);
4351 	atomic_set(&sess->session_reinstatement, 1);
4352 	iscsit_stop_time2retain_timer(sess);
4353 	spin_unlock_bh(&se_tpg->session_lock);
4354 
4355 	/*
4356 	 * transport_deregister_session_configfs() will clear the
4357 	 * struct se_node_acl->nacl_sess pointer now as a iscsi_np process context
4358 	 * can be setting it again with __transport_register_session() in
4359 	 * iscsi_post_login_handler() again after the iscsit_stop_session()
4360 	 * completes in iscsi_np context.
4361 	 */
4362 	transport_deregister_session_configfs(sess->se_sess);
4363 
4364 	/*
4365 	 * If any other processes are accessing this session pointer we must
4366 	 * wait until they have completed.  If we are in an interrupt (the
4367 	 * time2retain handler) and contain and active session usage count we
4368 	 * restart the timer and exit.
4369 	 */
4370 	if (!in_interrupt()) {
4371 		if (iscsit_check_session_usage_count(sess) == 1)
4372 			iscsit_stop_session(sess, 1, 1);
4373 	} else {
4374 		if (iscsit_check_session_usage_count(sess) == 2) {
4375 			atomic_set(&sess->session_logout, 0);
4376 			iscsit_start_time2retain_handler(sess);
4377 			return 0;
4378 		}
4379 	}
4380 
4381 	transport_deregister_session(sess->se_sess);
4382 
4383 	if (sess->sess_ops->ErrorRecoveryLevel == 2)
4384 		iscsit_free_connection_recovery_entries(sess);
4385 
4386 	iscsit_free_all_ooo_cmdsns(sess);
4387 
4388 	spin_lock_bh(&se_tpg->session_lock);
4389 	pr_debug("Moving to TARG_SESS_STATE_FREE.\n");
4390 	sess->session_state = TARG_SESS_STATE_FREE;
4391 	pr_debug("Released iSCSI session from node: %s\n",
4392 			sess->sess_ops->InitiatorName);
4393 	tpg->nsessions--;
4394 	if (tpg->tpg_tiqn)
4395 		tpg->tpg_tiqn->tiqn_nsessions--;
4396 
4397 	pr_debug("Decremented number of active iSCSI Sessions on"
4398 		" iSCSI TPG: %hu to %u\n", tpg->tpgt, tpg->nsessions);
4399 
4400 	ida_free(&sess_ida, sess->session_index);
4401 	kfree(sess->sess_ops);
4402 	sess->sess_ops = NULL;
4403 	spin_unlock_bh(&se_tpg->session_lock);
4404 
4405 	kfree(sess);
4406 	return 0;
4407 }
4408 
4409 static void iscsit_logout_post_handler_closesession(
4410 	struct iscsi_conn *conn)
4411 {
4412 	struct iscsi_session *sess = conn->sess;
4413 	int sleep = 1;
4414 	/*
4415 	 * Traditional iscsi/tcp will invoke this logic from TX thread
4416 	 * context during session logout, so clear tx_thread_active and
4417 	 * sleep if iscsit_close_connection() has not already occured.
4418 	 *
4419 	 * Since iser-target invokes this logic from it's own workqueue,
4420 	 * always sleep waiting for RX/TX thread shutdown to complete
4421 	 * within iscsit_close_connection().
4422 	 */
4423 	if (!conn->conn_transport->rdma_shutdown) {
4424 		sleep = cmpxchg(&conn->tx_thread_active, true, false);
4425 		if (!sleep)
4426 			return;
4427 	}
4428 
4429 	atomic_set(&conn->conn_logout_remove, 0);
4430 	complete(&conn->conn_logout_comp);
4431 
4432 	iscsit_dec_conn_usage_count(conn);
4433 	iscsit_stop_session(sess, sleep, sleep);
4434 	iscsit_dec_session_usage_count(sess);
4435 	iscsit_close_session(sess);
4436 }
4437 
4438 static void iscsit_logout_post_handler_samecid(
4439 	struct iscsi_conn *conn)
4440 {
4441 	int sleep = 1;
4442 
4443 	if (!conn->conn_transport->rdma_shutdown) {
4444 		sleep = cmpxchg(&conn->tx_thread_active, true, false);
4445 		if (!sleep)
4446 			return;
4447 	}
4448 
4449 	atomic_set(&conn->conn_logout_remove, 0);
4450 	complete(&conn->conn_logout_comp);
4451 
4452 	iscsit_cause_connection_reinstatement(conn, sleep);
4453 	iscsit_dec_conn_usage_count(conn);
4454 }
4455 
4456 static void iscsit_logout_post_handler_diffcid(
4457 	struct iscsi_conn *conn,
4458 	u16 cid)
4459 {
4460 	struct iscsi_conn *l_conn;
4461 	struct iscsi_session *sess = conn->sess;
4462 	bool conn_found = false;
4463 
4464 	if (!sess)
4465 		return;
4466 
4467 	spin_lock_bh(&sess->conn_lock);
4468 	list_for_each_entry(l_conn, &sess->sess_conn_list, conn_list) {
4469 		if (l_conn->cid == cid) {
4470 			iscsit_inc_conn_usage_count(l_conn);
4471 			conn_found = true;
4472 			break;
4473 		}
4474 	}
4475 	spin_unlock_bh(&sess->conn_lock);
4476 
4477 	if (!conn_found)
4478 		return;
4479 
4480 	if (l_conn->sock)
4481 		l_conn->sock->ops->shutdown(l_conn->sock, RCV_SHUTDOWN);
4482 
4483 	spin_lock_bh(&l_conn->state_lock);
4484 	pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
4485 	l_conn->conn_state = TARG_CONN_STATE_IN_LOGOUT;
4486 	spin_unlock_bh(&l_conn->state_lock);
4487 
4488 	iscsit_cause_connection_reinstatement(l_conn, 1);
4489 	iscsit_dec_conn_usage_count(l_conn);
4490 }
4491 
4492 /*
4493  *	Return of 0 causes the TX thread to restart.
4494  */
4495 int iscsit_logout_post_handler(
4496 	struct iscsi_cmd *cmd,
4497 	struct iscsi_conn *conn)
4498 {
4499 	int ret = 0;
4500 
4501 	switch (cmd->logout_reason) {
4502 	case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
4503 		switch (cmd->logout_response) {
4504 		case ISCSI_LOGOUT_SUCCESS:
4505 		case ISCSI_LOGOUT_CLEANUP_FAILED:
4506 		default:
4507 			iscsit_logout_post_handler_closesession(conn);
4508 			break;
4509 		}
4510 		ret = 0;
4511 		break;
4512 	case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
4513 		if (conn->cid == cmd->logout_cid) {
4514 			switch (cmd->logout_response) {
4515 			case ISCSI_LOGOUT_SUCCESS:
4516 			case ISCSI_LOGOUT_CLEANUP_FAILED:
4517 			default:
4518 				iscsit_logout_post_handler_samecid(conn);
4519 				break;
4520 			}
4521 			ret = 0;
4522 		} else {
4523 			switch (cmd->logout_response) {
4524 			case ISCSI_LOGOUT_SUCCESS:
4525 				iscsit_logout_post_handler_diffcid(conn,
4526 					cmd->logout_cid);
4527 				break;
4528 			case ISCSI_LOGOUT_CID_NOT_FOUND:
4529 			case ISCSI_LOGOUT_CLEANUP_FAILED:
4530 			default:
4531 				break;
4532 			}
4533 			ret = 1;
4534 		}
4535 		break;
4536 	case ISCSI_LOGOUT_REASON_RECOVERY:
4537 		switch (cmd->logout_response) {
4538 		case ISCSI_LOGOUT_SUCCESS:
4539 		case ISCSI_LOGOUT_CID_NOT_FOUND:
4540 		case ISCSI_LOGOUT_RECOVERY_UNSUPPORTED:
4541 		case ISCSI_LOGOUT_CLEANUP_FAILED:
4542 		default:
4543 			break;
4544 		}
4545 		ret = 1;
4546 		break;
4547 	default:
4548 		break;
4549 
4550 	}
4551 	return ret;
4552 }
4553 EXPORT_SYMBOL(iscsit_logout_post_handler);
4554 
4555 void iscsit_fail_session(struct iscsi_session *sess)
4556 {
4557 	struct iscsi_conn *conn;
4558 
4559 	spin_lock_bh(&sess->conn_lock);
4560 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
4561 		pr_debug("Moving to TARG_CONN_STATE_CLEANUP_WAIT.\n");
4562 		conn->conn_state = TARG_CONN_STATE_CLEANUP_WAIT;
4563 	}
4564 	spin_unlock_bh(&sess->conn_lock);
4565 
4566 	pr_debug("Moving to TARG_SESS_STATE_FAILED.\n");
4567 	sess->session_state = TARG_SESS_STATE_FAILED;
4568 }
4569 
4570 int iscsit_free_session(struct iscsi_session *sess)
4571 {
4572 	u16 conn_count = atomic_read(&sess->nconn);
4573 	struct iscsi_conn *conn, *conn_tmp = NULL;
4574 	int is_last;
4575 
4576 	spin_lock_bh(&sess->conn_lock);
4577 	atomic_set(&sess->sleep_on_sess_wait_comp, 1);
4578 
4579 	list_for_each_entry_safe(conn, conn_tmp, &sess->sess_conn_list,
4580 			conn_list) {
4581 		if (conn_count == 0)
4582 			break;
4583 
4584 		if (list_is_last(&conn->conn_list, &sess->sess_conn_list)) {
4585 			is_last = 1;
4586 		} else {
4587 			iscsit_inc_conn_usage_count(conn_tmp);
4588 			is_last = 0;
4589 		}
4590 		iscsit_inc_conn_usage_count(conn);
4591 
4592 		spin_unlock_bh(&sess->conn_lock);
4593 		iscsit_cause_connection_reinstatement(conn, 1);
4594 		spin_lock_bh(&sess->conn_lock);
4595 
4596 		iscsit_dec_conn_usage_count(conn);
4597 		if (is_last == 0)
4598 			iscsit_dec_conn_usage_count(conn_tmp);
4599 
4600 		conn_count--;
4601 	}
4602 
4603 	if (atomic_read(&sess->nconn)) {
4604 		spin_unlock_bh(&sess->conn_lock);
4605 		wait_for_completion(&sess->session_wait_comp);
4606 	} else
4607 		spin_unlock_bh(&sess->conn_lock);
4608 
4609 	iscsit_close_session(sess);
4610 	return 0;
4611 }
4612 
4613 void iscsit_stop_session(
4614 	struct iscsi_session *sess,
4615 	int session_sleep,
4616 	int connection_sleep)
4617 {
4618 	u16 conn_count = atomic_read(&sess->nconn);
4619 	struct iscsi_conn *conn, *conn_tmp = NULL;
4620 	int is_last;
4621 
4622 	spin_lock_bh(&sess->conn_lock);
4623 	if (session_sleep)
4624 		atomic_set(&sess->sleep_on_sess_wait_comp, 1);
4625 
4626 	if (connection_sleep) {
4627 		list_for_each_entry_safe(conn, conn_tmp, &sess->sess_conn_list,
4628 				conn_list) {
4629 			if (conn_count == 0)
4630 				break;
4631 
4632 			if (list_is_last(&conn->conn_list, &sess->sess_conn_list)) {
4633 				is_last = 1;
4634 			} else {
4635 				iscsit_inc_conn_usage_count(conn_tmp);
4636 				is_last = 0;
4637 			}
4638 			iscsit_inc_conn_usage_count(conn);
4639 
4640 			spin_unlock_bh(&sess->conn_lock);
4641 			iscsit_cause_connection_reinstatement(conn, 1);
4642 			spin_lock_bh(&sess->conn_lock);
4643 
4644 			iscsit_dec_conn_usage_count(conn);
4645 			if (is_last == 0)
4646 				iscsit_dec_conn_usage_count(conn_tmp);
4647 			conn_count--;
4648 		}
4649 	} else {
4650 		list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
4651 			iscsit_cause_connection_reinstatement(conn, 0);
4652 	}
4653 
4654 	if (session_sleep && atomic_read(&sess->nconn)) {
4655 		spin_unlock_bh(&sess->conn_lock);
4656 		wait_for_completion(&sess->session_wait_comp);
4657 	} else
4658 		spin_unlock_bh(&sess->conn_lock);
4659 }
4660 
4661 int iscsit_release_sessions_for_tpg(struct iscsi_portal_group *tpg, int force)
4662 {
4663 	struct iscsi_session *sess;
4664 	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
4665 	struct se_session *se_sess, *se_sess_tmp;
4666 	LIST_HEAD(free_list);
4667 	int session_count = 0;
4668 
4669 	spin_lock_bh(&se_tpg->session_lock);
4670 	if (tpg->nsessions && !force) {
4671 		spin_unlock_bh(&se_tpg->session_lock);
4672 		return -1;
4673 	}
4674 
4675 	list_for_each_entry_safe(se_sess, se_sess_tmp, &se_tpg->tpg_sess_list,
4676 			sess_list) {
4677 		sess = (struct iscsi_session *)se_sess->fabric_sess_ptr;
4678 
4679 		spin_lock(&sess->conn_lock);
4680 		if (atomic_read(&sess->session_fall_back_to_erl0) ||
4681 		    atomic_read(&sess->session_logout) ||
4682 		    (sess->time2retain_timer_flags & ISCSI_TF_EXPIRED)) {
4683 			spin_unlock(&sess->conn_lock);
4684 			continue;
4685 		}
4686 		atomic_set(&sess->session_reinstatement, 1);
4687 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4688 		spin_unlock(&sess->conn_lock);
4689 
4690 		list_move_tail(&se_sess->sess_list, &free_list);
4691 	}
4692 	spin_unlock_bh(&se_tpg->session_lock);
4693 
4694 	list_for_each_entry_safe(se_sess, se_sess_tmp, &free_list, sess_list) {
4695 		sess = (struct iscsi_session *)se_sess->fabric_sess_ptr;
4696 
4697 		iscsit_free_session(sess);
4698 		session_count++;
4699 	}
4700 
4701 	pr_debug("Released %d iSCSI Session(s) from Target Portal"
4702 			" Group: %hu\n", session_count, tpg->tpgt);
4703 	return 0;
4704 }
4705 
4706 MODULE_DESCRIPTION("iSCSI-Target Driver for mainline target infrastructure");
4707 MODULE_VERSION("4.1.x");
4708 MODULE_AUTHOR("nab@Linux-iSCSI.org");
4709 MODULE_LICENSE("GPL");
4710 
4711 module_init(iscsi_target_init_module);
4712 module_exit(iscsi_target_cleanup_module);
4713