1 /*******************************************************************************
2  * This file contains main functions related to the iSCSI Target Core Driver.
3  *
4  * (c) Copyright 2007-2013 Datera, Inc.
5  *
6  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  ******************************************************************************/
18 
19 #include <crypto/hash.h>
20 #include <linux/string.h>
21 #include <linux/kthread.h>
22 #include <linux/completion.h>
23 #include <linux/module.h>
24 #include <linux/vmalloc.h>
25 #include <linux/idr.h>
26 #include <linux/delay.h>
27 #include <linux/sched/signal.h>
28 #include <asm/unaligned.h>
29 #include <net/ipv6.h>
30 #include <scsi/scsi_proto.h>
31 #include <scsi/iscsi_proto.h>
32 #include <scsi/scsi_tcq.h>
33 #include <target/target_core_base.h>
34 #include <target/target_core_fabric.h>
35 
36 #include <target/iscsi/iscsi_target_core.h>
37 #include "iscsi_target_parameters.h"
38 #include "iscsi_target_seq_pdu_list.h"
39 #include "iscsi_target_datain_values.h"
40 #include "iscsi_target_erl0.h"
41 #include "iscsi_target_erl1.h"
42 #include "iscsi_target_erl2.h"
43 #include "iscsi_target_login.h"
44 #include "iscsi_target_tmr.h"
45 #include "iscsi_target_tpg.h"
46 #include "iscsi_target_util.h"
47 #include "iscsi_target.h"
48 #include "iscsi_target_device.h"
49 #include <target/iscsi/iscsi_target_stat.h>
50 
51 #include <target/iscsi/iscsi_transport.h>
52 
53 static LIST_HEAD(g_tiqn_list);
54 static LIST_HEAD(g_np_list);
55 static DEFINE_SPINLOCK(tiqn_lock);
56 static DEFINE_MUTEX(np_lock);
57 
58 static struct idr tiqn_idr;
59 struct idr sess_idr;
60 struct mutex auth_id_lock;
61 spinlock_t sess_idr_lock;
62 
63 struct iscsit_global *iscsit_global;
64 
65 struct kmem_cache *lio_qr_cache;
66 struct kmem_cache *lio_dr_cache;
67 struct kmem_cache *lio_ooo_cache;
68 struct kmem_cache *lio_r2t_cache;
69 
70 static int iscsit_handle_immediate_data(struct iscsi_cmd *,
71 			struct iscsi_scsi_req *, u32);
72 
73 struct iscsi_tiqn *iscsit_get_tiqn_for_login(unsigned char *buf)
74 {
75 	struct iscsi_tiqn *tiqn = NULL;
76 
77 	spin_lock(&tiqn_lock);
78 	list_for_each_entry(tiqn, &g_tiqn_list, tiqn_list) {
79 		if (!strcmp(tiqn->tiqn, buf)) {
80 
81 			spin_lock(&tiqn->tiqn_state_lock);
82 			if (tiqn->tiqn_state == TIQN_STATE_ACTIVE) {
83 				tiqn->tiqn_access_count++;
84 				spin_unlock(&tiqn->tiqn_state_lock);
85 				spin_unlock(&tiqn_lock);
86 				return tiqn;
87 			}
88 			spin_unlock(&tiqn->tiqn_state_lock);
89 		}
90 	}
91 	spin_unlock(&tiqn_lock);
92 
93 	return NULL;
94 }
95 
96 static int iscsit_set_tiqn_shutdown(struct iscsi_tiqn *tiqn)
97 {
98 	spin_lock(&tiqn->tiqn_state_lock);
99 	if (tiqn->tiqn_state == TIQN_STATE_ACTIVE) {
100 		tiqn->tiqn_state = TIQN_STATE_SHUTDOWN;
101 		spin_unlock(&tiqn->tiqn_state_lock);
102 		return 0;
103 	}
104 	spin_unlock(&tiqn->tiqn_state_lock);
105 
106 	return -1;
107 }
108 
109 void iscsit_put_tiqn_for_login(struct iscsi_tiqn *tiqn)
110 {
111 	spin_lock(&tiqn->tiqn_state_lock);
112 	tiqn->tiqn_access_count--;
113 	spin_unlock(&tiqn->tiqn_state_lock);
114 }
115 
116 /*
117  * Note that IQN formatting is expected to be done in userspace, and
118  * no explict IQN format checks are done here.
119  */
120 struct iscsi_tiqn *iscsit_add_tiqn(unsigned char *buf)
121 {
122 	struct iscsi_tiqn *tiqn = NULL;
123 	int ret;
124 
125 	if (strlen(buf) >= ISCSI_IQN_LEN) {
126 		pr_err("Target IQN exceeds %d bytes\n",
127 				ISCSI_IQN_LEN);
128 		return ERR_PTR(-EINVAL);
129 	}
130 
131 	tiqn = kzalloc(sizeof(*tiqn), GFP_KERNEL);
132 	if (!tiqn)
133 		return ERR_PTR(-ENOMEM);
134 
135 	sprintf(tiqn->tiqn, "%s", buf);
136 	INIT_LIST_HEAD(&tiqn->tiqn_list);
137 	INIT_LIST_HEAD(&tiqn->tiqn_tpg_list);
138 	spin_lock_init(&tiqn->tiqn_state_lock);
139 	spin_lock_init(&tiqn->tiqn_tpg_lock);
140 	spin_lock_init(&tiqn->sess_err_stats.lock);
141 	spin_lock_init(&tiqn->login_stats.lock);
142 	spin_lock_init(&tiqn->logout_stats.lock);
143 
144 	tiqn->tiqn_state = TIQN_STATE_ACTIVE;
145 
146 	idr_preload(GFP_KERNEL);
147 	spin_lock(&tiqn_lock);
148 
149 	ret = idr_alloc(&tiqn_idr, NULL, 0, 0, GFP_NOWAIT);
150 	if (ret < 0) {
151 		pr_err("idr_alloc() failed for tiqn->tiqn_index\n");
152 		spin_unlock(&tiqn_lock);
153 		idr_preload_end();
154 		kfree(tiqn);
155 		return ERR_PTR(ret);
156 	}
157 	tiqn->tiqn_index = ret;
158 	list_add_tail(&tiqn->tiqn_list, &g_tiqn_list);
159 
160 	spin_unlock(&tiqn_lock);
161 	idr_preload_end();
162 
163 	pr_debug("CORE[0] - Added iSCSI Target IQN: %s\n", tiqn->tiqn);
164 
165 	return tiqn;
166 
167 }
168 
169 static void iscsit_wait_for_tiqn(struct iscsi_tiqn *tiqn)
170 {
171 	/*
172 	 * Wait for accesses to said struct iscsi_tiqn to end.
173 	 */
174 	spin_lock(&tiqn->tiqn_state_lock);
175 	while (tiqn->tiqn_access_count != 0) {
176 		spin_unlock(&tiqn->tiqn_state_lock);
177 		msleep(10);
178 		spin_lock(&tiqn->tiqn_state_lock);
179 	}
180 	spin_unlock(&tiqn->tiqn_state_lock);
181 }
182 
183 void iscsit_del_tiqn(struct iscsi_tiqn *tiqn)
184 {
185 	/*
186 	 * iscsit_set_tiqn_shutdown sets tiqn->tiqn_state = TIQN_STATE_SHUTDOWN
187 	 * while holding tiqn->tiqn_state_lock.  This means that all subsequent
188 	 * attempts to access this struct iscsi_tiqn will fail from both transport
189 	 * fabric and control code paths.
190 	 */
191 	if (iscsit_set_tiqn_shutdown(tiqn) < 0) {
192 		pr_err("iscsit_set_tiqn_shutdown() failed\n");
193 		return;
194 	}
195 
196 	iscsit_wait_for_tiqn(tiqn);
197 
198 	spin_lock(&tiqn_lock);
199 	list_del(&tiqn->tiqn_list);
200 	idr_remove(&tiqn_idr, tiqn->tiqn_index);
201 	spin_unlock(&tiqn_lock);
202 
203 	pr_debug("CORE[0] - Deleted iSCSI Target IQN: %s\n",
204 			tiqn->tiqn);
205 	kfree(tiqn);
206 }
207 
208 int iscsit_access_np(struct iscsi_np *np, struct iscsi_portal_group *tpg)
209 {
210 	int ret;
211 	/*
212 	 * Determine if the network portal is accepting storage traffic.
213 	 */
214 	spin_lock_bh(&np->np_thread_lock);
215 	if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
216 		spin_unlock_bh(&np->np_thread_lock);
217 		return -1;
218 	}
219 	spin_unlock_bh(&np->np_thread_lock);
220 	/*
221 	 * Determine if the portal group is accepting storage traffic.
222 	 */
223 	spin_lock_bh(&tpg->tpg_state_lock);
224 	if (tpg->tpg_state != TPG_STATE_ACTIVE) {
225 		spin_unlock_bh(&tpg->tpg_state_lock);
226 		return -1;
227 	}
228 	spin_unlock_bh(&tpg->tpg_state_lock);
229 
230 	/*
231 	 * Here we serialize access across the TIQN+TPG Tuple.
232 	 */
233 	ret = down_interruptible(&tpg->np_login_sem);
234 	if (ret != 0)
235 		return -1;
236 
237 	spin_lock_bh(&tpg->tpg_state_lock);
238 	if (tpg->tpg_state != TPG_STATE_ACTIVE) {
239 		spin_unlock_bh(&tpg->tpg_state_lock);
240 		up(&tpg->np_login_sem);
241 		return -1;
242 	}
243 	spin_unlock_bh(&tpg->tpg_state_lock);
244 
245 	return 0;
246 }
247 
248 void iscsit_login_kref_put(struct kref *kref)
249 {
250 	struct iscsi_tpg_np *tpg_np = container_of(kref,
251 				struct iscsi_tpg_np, tpg_np_kref);
252 
253 	complete(&tpg_np->tpg_np_comp);
254 }
255 
256 int iscsit_deaccess_np(struct iscsi_np *np, struct iscsi_portal_group *tpg,
257 		       struct iscsi_tpg_np *tpg_np)
258 {
259 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
260 
261 	up(&tpg->np_login_sem);
262 
263 	if (tpg_np)
264 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
265 
266 	if (tiqn)
267 		iscsit_put_tiqn_for_login(tiqn);
268 
269 	return 0;
270 }
271 
272 bool iscsit_check_np_match(
273 	struct sockaddr_storage *sockaddr,
274 	struct iscsi_np *np,
275 	int network_transport)
276 {
277 	struct sockaddr_in *sock_in, *sock_in_e;
278 	struct sockaddr_in6 *sock_in6, *sock_in6_e;
279 	bool ip_match = false;
280 	u16 port, port_e;
281 
282 	if (sockaddr->ss_family == AF_INET6) {
283 		sock_in6 = (struct sockaddr_in6 *)sockaddr;
284 		sock_in6_e = (struct sockaddr_in6 *)&np->np_sockaddr;
285 
286 		if (!memcmp(&sock_in6->sin6_addr.in6_u,
287 			    &sock_in6_e->sin6_addr.in6_u,
288 			    sizeof(struct in6_addr)))
289 			ip_match = true;
290 
291 		port = ntohs(sock_in6->sin6_port);
292 		port_e = ntohs(sock_in6_e->sin6_port);
293 	} else {
294 		sock_in = (struct sockaddr_in *)sockaddr;
295 		sock_in_e = (struct sockaddr_in *)&np->np_sockaddr;
296 
297 		if (sock_in->sin_addr.s_addr == sock_in_e->sin_addr.s_addr)
298 			ip_match = true;
299 
300 		port = ntohs(sock_in->sin_port);
301 		port_e = ntohs(sock_in_e->sin_port);
302 	}
303 
304 	if (ip_match && (port_e == port) &&
305 	    (np->np_network_transport == network_transport))
306 		return true;
307 
308 	return false;
309 }
310 
311 /*
312  * Called with mutex np_lock held
313  */
314 static struct iscsi_np *iscsit_get_np(
315 	struct sockaddr_storage *sockaddr,
316 	int network_transport)
317 {
318 	struct iscsi_np *np;
319 	bool match;
320 
321 	list_for_each_entry(np, &g_np_list, np_list) {
322 		spin_lock_bh(&np->np_thread_lock);
323 		if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
324 			spin_unlock_bh(&np->np_thread_lock);
325 			continue;
326 		}
327 
328 		match = iscsit_check_np_match(sockaddr, np, network_transport);
329 		if (match) {
330 			/*
331 			 * Increment the np_exports reference count now to
332 			 * prevent iscsit_del_np() below from being called
333 			 * while iscsi_tpg_add_network_portal() is called.
334 			 */
335 			np->np_exports++;
336 			spin_unlock_bh(&np->np_thread_lock);
337 			return np;
338 		}
339 		spin_unlock_bh(&np->np_thread_lock);
340 	}
341 
342 	return NULL;
343 }
344 
345 struct iscsi_np *iscsit_add_np(
346 	struct sockaddr_storage *sockaddr,
347 	int network_transport)
348 {
349 	struct iscsi_np *np;
350 	int ret;
351 
352 	mutex_lock(&np_lock);
353 
354 	/*
355 	 * Locate the existing struct iscsi_np if already active..
356 	 */
357 	np = iscsit_get_np(sockaddr, network_transport);
358 	if (np) {
359 		mutex_unlock(&np_lock);
360 		return np;
361 	}
362 
363 	np = kzalloc(sizeof(*np), GFP_KERNEL);
364 	if (!np) {
365 		mutex_unlock(&np_lock);
366 		return ERR_PTR(-ENOMEM);
367 	}
368 
369 	np->np_flags |= NPF_IP_NETWORK;
370 	np->np_network_transport = network_transport;
371 	spin_lock_init(&np->np_thread_lock);
372 	init_completion(&np->np_restart_comp);
373 	INIT_LIST_HEAD(&np->np_list);
374 
375 	ret = iscsi_target_setup_login_socket(np, sockaddr);
376 	if (ret != 0) {
377 		kfree(np);
378 		mutex_unlock(&np_lock);
379 		return ERR_PTR(ret);
380 	}
381 
382 	np->np_thread = kthread_run(iscsi_target_login_thread, np, "iscsi_np");
383 	if (IS_ERR(np->np_thread)) {
384 		pr_err("Unable to create kthread: iscsi_np\n");
385 		ret = PTR_ERR(np->np_thread);
386 		kfree(np);
387 		mutex_unlock(&np_lock);
388 		return ERR_PTR(ret);
389 	}
390 	/*
391 	 * Increment the np_exports reference count now to prevent
392 	 * iscsit_del_np() below from being run while a new call to
393 	 * iscsi_tpg_add_network_portal() for a matching iscsi_np is
394 	 * active.  We don't need to hold np->np_thread_lock at this
395 	 * point because iscsi_np has not been added to g_np_list yet.
396 	 */
397 	np->np_exports = 1;
398 	np->np_thread_state = ISCSI_NP_THREAD_ACTIVE;
399 
400 	list_add_tail(&np->np_list, &g_np_list);
401 	mutex_unlock(&np_lock);
402 
403 	pr_debug("CORE[0] - Added Network Portal: %pISpc on %s\n",
404 		&np->np_sockaddr, np->np_transport->name);
405 
406 	return np;
407 }
408 
409 int iscsit_reset_np_thread(
410 	struct iscsi_np *np,
411 	struct iscsi_tpg_np *tpg_np,
412 	struct iscsi_portal_group *tpg,
413 	bool shutdown)
414 {
415 	spin_lock_bh(&np->np_thread_lock);
416 	if (np->np_thread_state == ISCSI_NP_THREAD_INACTIVE) {
417 		spin_unlock_bh(&np->np_thread_lock);
418 		return 0;
419 	}
420 	np->np_thread_state = ISCSI_NP_THREAD_RESET;
421 
422 	if (np->np_thread) {
423 		spin_unlock_bh(&np->np_thread_lock);
424 		send_sig(SIGINT, np->np_thread, 1);
425 		wait_for_completion(&np->np_restart_comp);
426 		spin_lock_bh(&np->np_thread_lock);
427 	}
428 	spin_unlock_bh(&np->np_thread_lock);
429 
430 	if (tpg_np && shutdown) {
431 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
432 
433 		wait_for_completion(&tpg_np->tpg_np_comp);
434 	}
435 
436 	return 0;
437 }
438 
439 static void iscsit_free_np(struct iscsi_np *np)
440 {
441 	if (np->np_socket)
442 		sock_release(np->np_socket);
443 }
444 
445 int iscsit_del_np(struct iscsi_np *np)
446 {
447 	spin_lock_bh(&np->np_thread_lock);
448 	np->np_exports--;
449 	if (np->np_exports) {
450 		np->enabled = true;
451 		spin_unlock_bh(&np->np_thread_lock);
452 		return 0;
453 	}
454 	np->np_thread_state = ISCSI_NP_THREAD_SHUTDOWN;
455 	spin_unlock_bh(&np->np_thread_lock);
456 
457 	if (np->np_thread) {
458 		/*
459 		 * We need to send the signal to wakeup Linux/Net
460 		 * which may be sleeping in sock_accept()..
461 		 */
462 		send_sig(SIGINT, np->np_thread, 1);
463 		kthread_stop(np->np_thread);
464 		np->np_thread = NULL;
465 	}
466 
467 	np->np_transport->iscsit_free_np(np);
468 
469 	mutex_lock(&np_lock);
470 	list_del(&np->np_list);
471 	mutex_unlock(&np_lock);
472 
473 	pr_debug("CORE[0] - Removed Network Portal: %pISpc on %s\n",
474 		&np->np_sockaddr, np->np_transport->name);
475 
476 	iscsit_put_transport(np->np_transport);
477 	kfree(np);
478 	return 0;
479 }
480 
481 static void iscsit_get_rx_pdu(struct iscsi_conn *);
482 
483 int iscsit_queue_rsp(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
484 {
485 	return iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
486 }
487 EXPORT_SYMBOL(iscsit_queue_rsp);
488 
489 void iscsit_aborted_task(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
490 {
491 	spin_lock_bh(&conn->cmd_lock);
492 	if (!list_empty(&cmd->i_conn_node) &&
493 	    !(cmd->se_cmd.transport_state & CMD_T_FABRIC_STOP))
494 		list_del_init(&cmd->i_conn_node);
495 	spin_unlock_bh(&conn->cmd_lock);
496 
497 	__iscsit_free_cmd(cmd, true);
498 }
499 EXPORT_SYMBOL(iscsit_aborted_task);
500 
501 static void iscsit_do_crypto_hash_buf(struct ahash_request *, const void *,
502 				      u32, u32, u8 *, u8 *);
503 static void iscsit_tx_thread_wait_for_tcp(struct iscsi_conn *);
504 
505 static int
506 iscsit_xmit_nondatain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
507 			  const void *data_buf, u32 data_buf_len)
508 {
509 	struct iscsi_hdr *hdr = (struct iscsi_hdr *)cmd->pdu;
510 	struct kvec *iov;
511 	u32 niov = 0, tx_size = ISCSI_HDR_LEN;
512 	int ret;
513 
514 	iov = &cmd->iov_misc[0];
515 	iov[niov].iov_base	= cmd->pdu;
516 	iov[niov++].iov_len	= ISCSI_HDR_LEN;
517 
518 	if (conn->conn_ops->HeaderDigest) {
519 		u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];
520 
521 		iscsit_do_crypto_hash_buf(conn->conn_tx_hash, hdr,
522 					  ISCSI_HDR_LEN, 0, NULL,
523 					  (u8 *)header_digest);
524 
525 		iov[0].iov_len += ISCSI_CRC_LEN;
526 		tx_size += ISCSI_CRC_LEN;
527 		pr_debug("Attaching CRC32C HeaderDigest"
528 			 " to opcode 0x%x 0x%08x\n",
529 			 hdr->opcode, *header_digest);
530 	}
531 
532 	if (data_buf_len) {
533 		u32 padding = ((-data_buf_len) & 3);
534 
535 		iov[niov].iov_base	= (void *)data_buf;
536 		iov[niov++].iov_len	= data_buf_len;
537 		tx_size += data_buf_len;
538 
539 		if (padding != 0) {
540 			iov[niov].iov_base = &cmd->pad_bytes;
541 			iov[niov++].iov_len = padding;
542 			tx_size += padding;
543 			pr_debug("Attaching %u additional"
544 				 " padding bytes.\n", padding);
545 		}
546 
547 		if (conn->conn_ops->DataDigest) {
548 			iscsit_do_crypto_hash_buf(conn->conn_tx_hash,
549 						  data_buf, data_buf_len,
550 						  padding,
551 						  (u8 *)&cmd->pad_bytes,
552 						  (u8 *)&cmd->data_crc);
553 
554 			iov[niov].iov_base = &cmd->data_crc;
555 			iov[niov++].iov_len = ISCSI_CRC_LEN;
556 			tx_size += ISCSI_CRC_LEN;
557 			pr_debug("Attached DataDigest for %u"
558 				 " bytes opcode 0x%x, CRC 0x%08x\n",
559 				 data_buf_len, hdr->opcode, cmd->data_crc);
560 		}
561 	}
562 
563 	cmd->iov_misc_count = niov;
564 	cmd->tx_size = tx_size;
565 
566 	ret = iscsit_send_tx_data(cmd, conn, 1);
567 	if (ret < 0) {
568 		iscsit_tx_thread_wait_for_tcp(conn);
569 		return ret;
570 	}
571 
572 	return 0;
573 }
574 
575 static int iscsit_map_iovec(struct iscsi_cmd *, struct kvec *, u32, u32);
576 static void iscsit_unmap_iovec(struct iscsi_cmd *);
577 static u32 iscsit_do_crypto_hash_sg(struct ahash_request *, struct iscsi_cmd *,
578 				    u32, u32, u32, u8 *);
579 static int
580 iscsit_xmit_datain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
581 		       const struct iscsi_datain *datain)
582 {
583 	struct kvec *iov;
584 	u32 iov_count = 0, tx_size = 0;
585 	int ret, iov_ret;
586 
587 	iov = &cmd->iov_data[0];
588 	iov[iov_count].iov_base	= cmd->pdu;
589 	iov[iov_count++].iov_len = ISCSI_HDR_LEN;
590 	tx_size += ISCSI_HDR_LEN;
591 
592 	if (conn->conn_ops->HeaderDigest) {
593 		u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];
594 
595 		iscsit_do_crypto_hash_buf(conn->conn_tx_hash, cmd->pdu,
596 					  ISCSI_HDR_LEN, 0, NULL,
597 					  (u8 *)header_digest);
598 
599 		iov[0].iov_len += ISCSI_CRC_LEN;
600 		tx_size += ISCSI_CRC_LEN;
601 
602 		pr_debug("Attaching CRC32 HeaderDigest for DataIN PDU 0x%08x\n",
603 			 *header_digest);
604 	}
605 
606 	iov_ret = iscsit_map_iovec(cmd, &cmd->iov_data[1],
607 				   datain->offset, datain->length);
608 	if (iov_ret < 0)
609 		return -1;
610 
611 	iov_count += iov_ret;
612 	tx_size += datain->length;
613 
614 	cmd->padding = ((-datain->length) & 3);
615 	if (cmd->padding) {
616 		iov[iov_count].iov_base		= cmd->pad_bytes;
617 		iov[iov_count++].iov_len	= cmd->padding;
618 		tx_size += cmd->padding;
619 
620 		pr_debug("Attaching %u padding bytes\n", cmd->padding);
621 	}
622 
623 	if (conn->conn_ops->DataDigest) {
624 		cmd->data_crc = iscsit_do_crypto_hash_sg(conn->conn_tx_hash,
625 							 cmd, datain->offset,
626 							 datain->length,
627 							 cmd->padding,
628 							 cmd->pad_bytes);
629 
630 		iov[iov_count].iov_base	= &cmd->data_crc;
631 		iov[iov_count++].iov_len = ISCSI_CRC_LEN;
632 		tx_size += ISCSI_CRC_LEN;
633 
634 		pr_debug("Attached CRC32C DataDigest %d bytes, crc 0x%08x\n",
635 			 datain->length + cmd->padding, cmd->data_crc);
636 	}
637 
638 	cmd->iov_data_count = iov_count;
639 	cmd->tx_size = tx_size;
640 
641 	ret = iscsit_fe_sendpage_sg(cmd, conn);
642 
643 	iscsit_unmap_iovec(cmd);
644 
645 	if (ret < 0) {
646 		iscsit_tx_thread_wait_for_tcp(conn);
647 		return ret;
648 	}
649 
650 	return 0;
651 }
652 
653 static int iscsit_xmit_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
654 			   struct iscsi_datain_req *dr, const void *buf,
655 			   u32 buf_len)
656 {
657 	if (dr)
658 		return iscsit_xmit_datain_pdu(conn, cmd, buf);
659 	else
660 		return iscsit_xmit_nondatain_pdu(conn, cmd, buf, buf_len);
661 }
662 
663 static enum target_prot_op iscsit_get_sup_prot_ops(struct iscsi_conn *conn)
664 {
665 	return TARGET_PROT_NORMAL;
666 }
667 
668 static struct iscsit_transport iscsi_target_transport = {
669 	.name			= "iSCSI/TCP",
670 	.transport_type		= ISCSI_TCP,
671 	.rdma_shutdown		= false,
672 	.owner			= NULL,
673 	.iscsit_setup_np	= iscsit_setup_np,
674 	.iscsit_accept_np	= iscsit_accept_np,
675 	.iscsit_free_np		= iscsit_free_np,
676 	.iscsit_get_login_rx	= iscsit_get_login_rx,
677 	.iscsit_put_login_tx	= iscsit_put_login_tx,
678 	.iscsit_get_dataout	= iscsit_build_r2ts_for_cmd,
679 	.iscsit_immediate_queue	= iscsit_immediate_queue,
680 	.iscsit_response_queue	= iscsit_response_queue,
681 	.iscsit_queue_data_in	= iscsit_queue_rsp,
682 	.iscsit_queue_status	= iscsit_queue_rsp,
683 	.iscsit_aborted_task	= iscsit_aborted_task,
684 	.iscsit_xmit_pdu	= iscsit_xmit_pdu,
685 	.iscsit_get_rx_pdu	= iscsit_get_rx_pdu,
686 	.iscsit_get_sup_prot_ops = iscsit_get_sup_prot_ops,
687 };
688 
689 static int __init iscsi_target_init_module(void)
690 {
691 	int ret = 0, size;
692 
693 	pr_debug("iSCSI-Target "ISCSIT_VERSION"\n");
694 	iscsit_global = kzalloc(sizeof(*iscsit_global), GFP_KERNEL);
695 	if (!iscsit_global)
696 		return -1;
697 
698 	spin_lock_init(&iscsit_global->ts_bitmap_lock);
699 	mutex_init(&auth_id_lock);
700 	spin_lock_init(&sess_idr_lock);
701 	idr_init(&tiqn_idr);
702 	idr_init(&sess_idr);
703 
704 	ret = target_register_template(&iscsi_ops);
705 	if (ret)
706 		goto out;
707 
708 	size = BITS_TO_LONGS(ISCSIT_BITMAP_BITS) * sizeof(long);
709 	iscsit_global->ts_bitmap = vzalloc(size);
710 	if (!iscsit_global->ts_bitmap)
711 		goto configfs_out;
712 
713 	lio_qr_cache = kmem_cache_create("lio_qr_cache",
714 			sizeof(struct iscsi_queue_req),
715 			__alignof__(struct iscsi_queue_req), 0, NULL);
716 	if (!lio_qr_cache) {
717 		pr_err("nable to kmem_cache_create() for"
718 				" lio_qr_cache\n");
719 		goto bitmap_out;
720 	}
721 
722 	lio_dr_cache = kmem_cache_create("lio_dr_cache",
723 			sizeof(struct iscsi_datain_req),
724 			__alignof__(struct iscsi_datain_req), 0, NULL);
725 	if (!lio_dr_cache) {
726 		pr_err("Unable to kmem_cache_create() for"
727 				" lio_dr_cache\n");
728 		goto qr_out;
729 	}
730 
731 	lio_ooo_cache = kmem_cache_create("lio_ooo_cache",
732 			sizeof(struct iscsi_ooo_cmdsn),
733 			__alignof__(struct iscsi_ooo_cmdsn), 0, NULL);
734 	if (!lio_ooo_cache) {
735 		pr_err("Unable to kmem_cache_create() for"
736 				" lio_ooo_cache\n");
737 		goto dr_out;
738 	}
739 
740 	lio_r2t_cache = kmem_cache_create("lio_r2t_cache",
741 			sizeof(struct iscsi_r2t), __alignof__(struct iscsi_r2t),
742 			0, NULL);
743 	if (!lio_r2t_cache) {
744 		pr_err("Unable to kmem_cache_create() for"
745 				" lio_r2t_cache\n");
746 		goto ooo_out;
747 	}
748 
749 	iscsit_register_transport(&iscsi_target_transport);
750 
751 	if (iscsit_load_discovery_tpg() < 0)
752 		goto r2t_out;
753 
754 	return ret;
755 r2t_out:
756 	iscsit_unregister_transport(&iscsi_target_transport);
757 	kmem_cache_destroy(lio_r2t_cache);
758 ooo_out:
759 	kmem_cache_destroy(lio_ooo_cache);
760 dr_out:
761 	kmem_cache_destroy(lio_dr_cache);
762 qr_out:
763 	kmem_cache_destroy(lio_qr_cache);
764 bitmap_out:
765 	vfree(iscsit_global->ts_bitmap);
766 configfs_out:
767 	/* XXX: this probably wants it to be it's own unwind step.. */
768 	if (iscsit_global->discovery_tpg)
769 		iscsit_tpg_disable_portal_group(iscsit_global->discovery_tpg, 1);
770 	target_unregister_template(&iscsi_ops);
771 out:
772 	kfree(iscsit_global);
773 	return -ENOMEM;
774 }
775 
776 static void __exit iscsi_target_cleanup_module(void)
777 {
778 	iscsit_release_discovery_tpg();
779 	iscsit_unregister_transport(&iscsi_target_transport);
780 	kmem_cache_destroy(lio_qr_cache);
781 	kmem_cache_destroy(lio_dr_cache);
782 	kmem_cache_destroy(lio_ooo_cache);
783 	kmem_cache_destroy(lio_r2t_cache);
784 
785 	/*
786 	 * Shutdown discovery sessions and disable discovery TPG
787 	 */
788 	if (iscsit_global->discovery_tpg)
789 		iscsit_tpg_disable_portal_group(iscsit_global->discovery_tpg, 1);
790 
791 	target_unregister_template(&iscsi_ops);
792 
793 	vfree(iscsit_global->ts_bitmap);
794 	kfree(iscsit_global);
795 }
796 
797 int iscsit_add_reject(
798 	struct iscsi_conn *conn,
799 	u8 reason,
800 	unsigned char *buf)
801 {
802 	struct iscsi_cmd *cmd;
803 
804 	cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
805 	if (!cmd)
806 		return -1;
807 
808 	cmd->iscsi_opcode = ISCSI_OP_REJECT;
809 	cmd->reject_reason = reason;
810 
811 	cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL);
812 	if (!cmd->buf_ptr) {
813 		pr_err("Unable to allocate memory for cmd->buf_ptr\n");
814 		iscsit_free_cmd(cmd, false);
815 		return -1;
816 	}
817 
818 	spin_lock_bh(&conn->cmd_lock);
819 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
820 	spin_unlock_bh(&conn->cmd_lock);
821 
822 	cmd->i_state = ISTATE_SEND_REJECT;
823 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
824 
825 	return -1;
826 }
827 EXPORT_SYMBOL(iscsit_add_reject);
828 
829 static int iscsit_add_reject_from_cmd(
830 	struct iscsi_cmd *cmd,
831 	u8 reason,
832 	bool add_to_conn,
833 	unsigned char *buf)
834 {
835 	struct iscsi_conn *conn;
836 
837 	if (!cmd->conn) {
838 		pr_err("cmd->conn is NULL for ITT: 0x%08x\n",
839 				cmd->init_task_tag);
840 		return -1;
841 	}
842 	conn = cmd->conn;
843 
844 	cmd->iscsi_opcode = ISCSI_OP_REJECT;
845 	cmd->reject_reason = reason;
846 
847 	cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL);
848 	if (!cmd->buf_ptr) {
849 		pr_err("Unable to allocate memory for cmd->buf_ptr\n");
850 		iscsit_free_cmd(cmd, false);
851 		return -1;
852 	}
853 
854 	if (add_to_conn) {
855 		spin_lock_bh(&conn->cmd_lock);
856 		list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
857 		spin_unlock_bh(&conn->cmd_lock);
858 	}
859 
860 	cmd->i_state = ISTATE_SEND_REJECT;
861 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
862 	/*
863 	 * Perform the kref_put now if se_cmd has already been setup by
864 	 * scsit_setup_scsi_cmd()
865 	 */
866 	if (cmd->se_cmd.se_tfo != NULL) {
867 		pr_debug("iscsi reject: calling target_put_sess_cmd >>>>>>\n");
868 		target_put_sess_cmd(&cmd->se_cmd);
869 	}
870 	return -1;
871 }
872 
873 static int iscsit_add_reject_cmd(struct iscsi_cmd *cmd, u8 reason,
874 				 unsigned char *buf)
875 {
876 	return iscsit_add_reject_from_cmd(cmd, reason, true, buf);
877 }
878 
879 int iscsit_reject_cmd(struct iscsi_cmd *cmd, u8 reason, unsigned char *buf)
880 {
881 	return iscsit_add_reject_from_cmd(cmd, reason, false, buf);
882 }
883 EXPORT_SYMBOL(iscsit_reject_cmd);
884 
885 /*
886  * Map some portion of the allocated scatterlist to an iovec, suitable for
887  * kernel sockets to copy data in/out.
888  */
889 static int iscsit_map_iovec(
890 	struct iscsi_cmd *cmd,
891 	struct kvec *iov,
892 	u32 data_offset,
893 	u32 data_length)
894 {
895 	u32 i = 0;
896 	struct scatterlist *sg;
897 	unsigned int page_off;
898 
899 	/*
900 	 * We know each entry in t_data_sg contains a page.
901 	 */
902 	u32 ent = data_offset / PAGE_SIZE;
903 
904 	if (ent >= cmd->se_cmd.t_data_nents) {
905 		pr_err("Initial page entry out-of-bounds\n");
906 		return -1;
907 	}
908 
909 	sg = &cmd->se_cmd.t_data_sg[ent];
910 	page_off = (data_offset % PAGE_SIZE);
911 
912 	cmd->first_data_sg = sg;
913 	cmd->first_data_sg_off = page_off;
914 
915 	while (data_length) {
916 		u32 cur_len = min_t(u32, data_length, sg->length - page_off);
917 
918 		iov[i].iov_base = kmap(sg_page(sg)) + sg->offset + page_off;
919 		iov[i].iov_len = cur_len;
920 
921 		data_length -= cur_len;
922 		page_off = 0;
923 		sg = sg_next(sg);
924 		i++;
925 	}
926 
927 	cmd->kmapped_nents = i;
928 
929 	return i;
930 }
931 
932 static void iscsit_unmap_iovec(struct iscsi_cmd *cmd)
933 {
934 	u32 i;
935 	struct scatterlist *sg;
936 
937 	sg = cmd->first_data_sg;
938 
939 	for (i = 0; i < cmd->kmapped_nents; i++)
940 		kunmap(sg_page(&sg[i]));
941 }
942 
943 static void iscsit_ack_from_expstatsn(struct iscsi_conn *conn, u32 exp_statsn)
944 {
945 	LIST_HEAD(ack_list);
946 	struct iscsi_cmd *cmd, *cmd_p;
947 
948 	conn->exp_statsn = exp_statsn;
949 
950 	if (conn->sess->sess_ops->RDMAExtensions)
951 		return;
952 
953 	spin_lock_bh(&conn->cmd_lock);
954 	list_for_each_entry_safe(cmd, cmd_p, &conn->conn_cmd_list, i_conn_node) {
955 		spin_lock(&cmd->istate_lock);
956 		if ((cmd->i_state == ISTATE_SENT_STATUS) &&
957 		    iscsi_sna_lt(cmd->stat_sn, exp_statsn)) {
958 			cmd->i_state = ISTATE_REMOVE;
959 			spin_unlock(&cmd->istate_lock);
960 			list_move_tail(&cmd->i_conn_node, &ack_list);
961 			continue;
962 		}
963 		spin_unlock(&cmd->istate_lock);
964 	}
965 	spin_unlock_bh(&conn->cmd_lock);
966 
967 	list_for_each_entry_safe(cmd, cmd_p, &ack_list, i_conn_node) {
968 		list_del_init(&cmd->i_conn_node);
969 		iscsit_free_cmd(cmd, false);
970 	}
971 }
972 
973 static int iscsit_allocate_iovecs(struct iscsi_cmd *cmd)
974 {
975 	u32 iov_count = max(1UL, DIV_ROUND_UP(cmd->se_cmd.data_length, PAGE_SIZE));
976 
977 	iov_count += ISCSI_IOV_DATA_BUFFER;
978 	cmd->iov_data = kcalloc(iov_count, sizeof(*cmd->iov_data), GFP_KERNEL);
979 	if (!cmd->iov_data)
980 		return -ENOMEM;
981 
982 	cmd->orig_iov_data_count = iov_count;
983 	return 0;
984 }
985 
986 int iscsit_setup_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
987 			  unsigned char *buf)
988 {
989 	int data_direction, payload_length;
990 	struct iscsi_scsi_req *hdr;
991 	int iscsi_task_attr;
992 	int sam_task_attr;
993 
994 	atomic_long_inc(&conn->sess->cmd_pdus);
995 
996 	hdr			= (struct iscsi_scsi_req *) buf;
997 	payload_length		= ntoh24(hdr->dlength);
998 
999 	/* FIXME; Add checks for AdditionalHeaderSegment */
1000 
1001 	if (!(hdr->flags & ISCSI_FLAG_CMD_WRITE) &&
1002 	    !(hdr->flags & ISCSI_FLAG_CMD_FINAL)) {
1003 		pr_err("ISCSI_FLAG_CMD_WRITE & ISCSI_FLAG_CMD_FINAL"
1004 				" not set. Bad iSCSI Initiator.\n");
1005 		return iscsit_add_reject_cmd(cmd,
1006 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1007 	}
1008 
1009 	if (((hdr->flags & ISCSI_FLAG_CMD_READ) ||
1010 	     (hdr->flags & ISCSI_FLAG_CMD_WRITE)) && !hdr->data_length) {
1011 		/*
1012 		 * From RFC-3720 Section 10.3.1:
1013 		 *
1014 		 * "Either or both of R and W MAY be 1 when either the
1015 		 *  Expected Data Transfer Length and/or Bidirectional Read
1016 		 *  Expected Data Transfer Length are 0"
1017 		 *
1018 		 * For this case, go ahead and clear the unnecssary bits
1019 		 * to avoid any confusion with ->data_direction.
1020 		 */
1021 		hdr->flags &= ~ISCSI_FLAG_CMD_READ;
1022 		hdr->flags &= ~ISCSI_FLAG_CMD_WRITE;
1023 
1024 		pr_warn("ISCSI_FLAG_CMD_READ or ISCSI_FLAG_CMD_WRITE"
1025 			" set when Expected Data Transfer Length is 0 for"
1026 			" CDB: 0x%02x, Fixing up flags\n", hdr->cdb[0]);
1027 	}
1028 
1029 	if (!(hdr->flags & ISCSI_FLAG_CMD_READ) &&
1030 	    !(hdr->flags & ISCSI_FLAG_CMD_WRITE) && (hdr->data_length != 0)) {
1031 		pr_err("ISCSI_FLAG_CMD_READ and/or ISCSI_FLAG_CMD_WRITE"
1032 			" MUST be set if Expected Data Transfer Length is not 0."
1033 			" Bad iSCSI Initiator\n");
1034 		return iscsit_add_reject_cmd(cmd,
1035 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1036 	}
1037 
1038 	if ((hdr->flags & ISCSI_FLAG_CMD_READ) &&
1039 	    (hdr->flags & ISCSI_FLAG_CMD_WRITE)) {
1040 		pr_err("Bidirectional operations not supported!\n");
1041 		return iscsit_add_reject_cmd(cmd,
1042 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1043 	}
1044 
1045 	if (hdr->opcode & ISCSI_OP_IMMEDIATE) {
1046 		pr_err("Illegally set Immediate Bit in iSCSI Initiator"
1047 				" Scsi Command PDU.\n");
1048 		return iscsit_add_reject_cmd(cmd,
1049 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1050 	}
1051 
1052 	if (payload_length && !conn->sess->sess_ops->ImmediateData) {
1053 		pr_err("ImmediateData=No but DataSegmentLength=%u,"
1054 			" protocol error.\n", payload_length);
1055 		return iscsit_add_reject_cmd(cmd,
1056 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1057 	}
1058 
1059 	if ((be32_to_cpu(hdr->data_length) == payload_length) &&
1060 	    (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))) {
1061 		pr_err("Expected Data Transfer Length and Length of"
1062 			" Immediate Data are the same, but ISCSI_FLAG_CMD_FINAL"
1063 			" bit is not set protocol error\n");
1064 		return iscsit_add_reject_cmd(cmd,
1065 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1066 	}
1067 
1068 	if (payload_length > be32_to_cpu(hdr->data_length)) {
1069 		pr_err("DataSegmentLength: %u is greater than"
1070 			" EDTL: %u, protocol error.\n", payload_length,
1071 				hdr->data_length);
1072 		return iscsit_add_reject_cmd(cmd,
1073 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1074 	}
1075 
1076 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1077 		pr_err("DataSegmentLength: %u is greater than"
1078 			" MaxXmitDataSegmentLength: %u, protocol error.\n",
1079 			payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
1080 		return iscsit_add_reject_cmd(cmd,
1081 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1082 	}
1083 
1084 	if (payload_length > conn->sess->sess_ops->FirstBurstLength) {
1085 		pr_err("DataSegmentLength: %u is greater than"
1086 			" FirstBurstLength: %u, protocol error.\n",
1087 			payload_length, conn->sess->sess_ops->FirstBurstLength);
1088 		return iscsit_add_reject_cmd(cmd,
1089 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1090 	}
1091 
1092 	data_direction = (hdr->flags & ISCSI_FLAG_CMD_WRITE) ? DMA_TO_DEVICE :
1093 			 (hdr->flags & ISCSI_FLAG_CMD_READ) ? DMA_FROM_DEVICE :
1094 			  DMA_NONE;
1095 
1096 	cmd->data_direction = data_direction;
1097 	iscsi_task_attr = hdr->flags & ISCSI_FLAG_CMD_ATTR_MASK;
1098 	/*
1099 	 * Figure out the SAM Task Attribute for the incoming SCSI CDB
1100 	 */
1101 	if ((iscsi_task_attr == ISCSI_ATTR_UNTAGGED) ||
1102 	    (iscsi_task_attr == ISCSI_ATTR_SIMPLE))
1103 		sam_task_attr = TCM_SIMPLE_TAG;
1104 	else if (iscsi_task_attr == ISCSI_ATTR_ORDERED)
1105 		sam_task_attr = TCM_ORDERED_TAG;
1106 	else if (iscsi_task_attr == ISCSI_ATTR_HEAD_OF_QUEUE)
1107 		sam_task_attr = TCM_HEAD_TAG;
1108 	else if (iscsi_task_attr == ISCSI_ATTR_ACA)
1109 		sam_task_attr = TCM_ACA_TAG;
1110 	else {
1111 		pr_debug("Unknown iSCSI Task Attribute: 0x%02x, using"
1112 			" TCM_SIMPLE_TAG\n", iscsi_task_attr);
1113 		sam_task_attr = TCM_SIMPLE_TAG;
1114 	}
1115 
1116 	cmd->iscsi_opcode	= ISCSI_OP_SCSI_CMD;
1117 	cmd->i_state		= ISTATE_NEW_CMD;
1118 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
1119 	cmd->immediate_data	= (payload_length) ? 1 : 0;
1120 	cmd->unsolicited_data	= ((!(hdr->flags & ISCSI_FLAG_CMD_FINAL) &&
1121 				     (hdr->flags & ISCSI_FLAG_CMD_WRITE)) ? 1 : 0);
1122 	if (cmd->unsolicited_data)
1123 		cmd->cmd_flags |= ICF_NON_IMMEDIATE_UNSOLICITED_DATA;
1124 
1125 	conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
1126 	if (hdr->flags & ISCSI_FLAG_CMD_READ)
1127 		cmd->targ_xfer_tag = session_get_next_ttt(conn->sess);
1128 	else
1129 		cmd->targ_xfer_tag = 0xFFFFFFFF;
1130 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
1131 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
1132 	cmd->first_burst_len	= payload_length;
1133 
1134 	if (!conn->sess->sess_ops->RDMAExtensions &&
1135 	     cmd->data_direction == DMA_FROM_DEVICE) {
1136 		struct iscsi_datain_req *dr;
1137 
1138 		dr = iscsit_allocate_datain_req();
1139 		if (!dr)
1140 			return iscsit_add_reject_cmd(cmd,
1141 					ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1142 
1143 		iscsit_attach_datain_req(cmd, dr);
1144 	}
1145 
1146 	/*
1147 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
1148 	 */
1149 	transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops,
1150 			conn->sess->se_sess, be32_to_cpu(hdr->data_length),
1151 			cmd->data_direction, sam_task_attr,
1152 			cmd->sense_buffer + 2);
1153 
1154 	pr_debug("Got SCSI Command, ITT: 0x%08x, CmdSN: 0x%08x,"
1155 		" ExpXferLen: %u, Length: %u, CID: %hu\n", hdr->itt,
1156 		hdr->cmdsn, be32_to_cpu(hdr->data_length), payload_length,
1157 		conn->cid);
1158 
1159 	target_get_sess_cmd(&cmd->se_cmd, true);
1160 
1161 	cmd->sense_reason = transport_lookup_cmd_lun(&cmd->se_cmd,
1162 						     scsilun_to_int(&hdr->lun));
1163 	if (cmd->sense_reason)
1164 		goto attach_cmd;
1165 
1166 	/* only used for printks or comparing with ->ref_task_tag */
1167 	cmd->se_cmd.tag = (__force u32)cmd->init_task_tag;
1168 	cmd->sense_reason = target_setup_cmd_from_cdb(&cmd->se_cmd, hdr->cdb);
1169 	if (cmd->sense_reason) {
1170 		if (cmd->sense_reason == TCM_OUT_OF_RESOURCES) {
1171 			return iscsit_add_reject_cmd(cmd,
1172 					ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1173 		}
1174 
1175 		goto attach_cmd;
1176 	}
1177 
1178 	if (iscsit_build_pdu_and_seq_lists(cmd, payload_length) < 0) {
1179 		return iscsit_add_reject_cmd(cmd,
1180 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1181 	}
1182 
1183 attach_cmd:
1184 	spin_lock_bh(&conn->cmd_lock);
1185 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
1186 	spin_unlock_bh(&conn->cmd_lock);
1187 	/*
1188 	 * Check if we need to delay processing because of ALUA
1189 	 * Active/NonOptimized primary access state..
1190 	 */
1191 	core_alua_check_nonop_delay(&cmd->se_cmd);
1192 
1193 	return 0;
1194 }
1195 EXPORT_SYMBOL(iscsit_setup_scsi_cmd);
1196 
1197 void iscsit_set_unsoliticed_dataout(struct iscsi_cmd *cmd)
1198 {
1199 	iscsit_set_dataout_sequence_values(cmd);
1200 
1201 	spin_lock_bh(&cmd->dataout_timeout_lock);
1202 	iscsit_start_dataout_timer(cmd, cmd->conn);
1203 	spin_unlock_bh(&cmd->dataout_timeout_lock);
1204 }
1205 EXPORT_SYMBOL(iscsit_set_unsoliticed_dataout);
1206 
1207 int iscsit_process_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1208 			    struct iscsi_scsi_req *hdr)
1209 {
1210 	int cmdsn_ret = 0;
1211 	/*
1212 	 * Check the CmdSN against ExpCmdSN/MaxCmdSN here if
1213 	 * the Immediate Bit is not set, and no Immediate
1214 	 * Data is attached.
1215 	 *
1216 	 * A PDU/CmdSN carrying Immediate Data can only
1217 	 * be processed after the DataCRC has passed.
1218 	 * If the DataCRC fails, the CmdSN MUST NOT
1219 	 * be acknowledged. (See below)
1220 	 */
1221 	if (!cmd->immediate_data) {
1222 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
1223 					(unsigned char *)hdr, hdr->cmdsn);
1224 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1225 			return -1;
1226 		else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
1227 			target_put_sess_cmd(&cmd->se_cmd);
1228 			return 0;
1229 		}
1230 	}
1231 
1232 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
1233 
1234 	/*
1235 	 * If no Immediate Data is attached, it's OK to return now.
1236 	 */
1237 	if (!cmd->immediate_data) {
1238 		if (!cmd->sense_reason && cmd->unsolicited_data)
1239 			iscsit_set_unsoliticed_dataout(cmd);
1240 		if (!cmd->sense_reason)
1241 			return 0;
1242 
1243 		target_put_sess_cmd(&cmd->se_cmd);
1244 		return 0;
1245 	}
1246 
1247 	/*
1248 	 * Early CHECK_CONDITIONs with ImmediateData never make it to command
1249 	 * execution.  These exceptions are processed in CmdSN order using
1250 	 * iscsit_check_received_cmdsn() in iscsit_get_immediate_data() below.
1251 	 */
1252 	if (cmd->sense_reason)
1253 		return 1;
1254 	/*
1255 	 * Call directly into transport_generic_new_cmd() to perform
1256 	 * the backend memory allocation.
1257 	 */
1258 	cmd->sense_reason = transport_generic_new_cmd(&cmd->se_cmd);
1259 	if (cmd->sense_reason)
1260 		return 1;
1261 
1262 	return 0;
1263 }
1264 EXPORT_SYMBOL(iscsit_process_scsi_cmd);
1265 
1266 static int
1267 iscsit_get_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
1268 			  bool dump_payload)
1269 {
1270 	int cmdsn_ret = 0, immed_ret = IMMEDIATE_DATA_NORMAL_OPERATION;
1271 	/*
1272 	 * Special case for Unsupported SAM WRITE Opcodes and ImmediateData=Yes.
1273 	 */
1274 	if (dump_payload)
1275 		goto after_immediate_data;
1276 	/*
1277 	 * Check for underflow case where both EDTL and immediate data payload
1278 	 * exceeds what is presented by CDB's TRANSFER LENGTH, and what has
1279 	 * already been set in target_cmd_size_check() as se_cmd->data_length.
1280 	 *
1281 	 * For this special case, fail the command and dump the immediate data
1282 	 * payload.
1283 	 */
1284 	if (cmd->first_burst_len > cmd->se_cmd.data_length) {
1285 		cmd->sense_reason = TCM_INVALID_CDB_FIELD;
1286 		goto after_immediate_data;
1287 	}
1288 
1289 	immed_ret = iscsit_handle_immediate_data(cmd, hdr,
1290 					cmd->first_burst_len);
1291 after_immediate_data:
1292 	if (immed_ret == IMMEDIATE_DATA_NORMAL_OPERATION) {
1293 		/*
1294 		 * A PDU/CmdSN carrying Immediate Data passed
1295 		 * DataCRC, check against ExpCmdSN/MaxCmdSN if
1296 		 * Immediate Bit is not set.
1297 		 */
1298 		cmdsn_ret = iscsit_sequence_cmd(cmd->conn, cmd,
1299 					(unsigned char *)hdr, hdr->cmdsn);
1300 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1301 			return -1;
1302 
1303 		if (cmd->sense_reason || cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
1304 			int rc;
1305 
1306 			rc = iscsit_dump_data_payload(cmd->conn,
1307 						      cmd->first_burst_len, 1);
1308 			target_put_sess_cmd(&cmd->se_cmd);
1309 			return rc;
1310 		} else if (cmd->unsolicited_data)
1311 			iscsit_set_unsoliticed_dataout(cmd);
1312 
1313 	} else if (immed_ret == IMMEDIATE_DATA_ERL1_CRC_FAILURE) {
1314 		/*
1315 		 * Immediate Data failed DataCRC and ERL>=1,
1316 		 * silently drop this PDU and let the initiator
1317 		 * plug the CmdSN gap.
1318 		 *
1319 		 * FIXME: Send Unsolicited NOPIN with reserved
1320 		 * TTT here to help the initiator figure out
1321 		 * the missing CmdSN, although they should be
1322 		 * intelligent enough to determine the missing
1323 		 * CmdSN and issue a retry to plug the sequence.
1324 		 */
1325 		cmd->i_state = ISTATE_REMOVE;
1326 		iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, cmd->i_state);
1327 	} else /* immed_ret == IMMEDIATE_DATA_CANNOT_RECOVER */
1328 		return -1;
1329 
1330 	return 0;
1331 }
1332 
1333 static int
1334 iscsit_handle_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1335 			   unsigned char *buf)
1336 {
1337 	struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)buf;
1338 	int rc, immed_data;
1339 	bool dump_payload = false;
1340 
1341 	rc = iscsit_setup_scsi_cmd(conn, cmd, buf);
1342 	if (rc < 0)
1343 		return 0;
1344 	/*
1345 	 * Allocation iovecs needed for struct socket operations for
1346 	 * traditional iSCSI block I/O.
1347 	 */
1348 	if (iscsit_allocate_iovecs(cmd) < 0) {
1349 		return iscsit_reject_cmd(cmd,
1350 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1351 	}
1352 	immed_data = cmd->immediate_data;
1353 
1354 	rc = iscsit_process_scsi_cmd(conn, cmd, hdr);
1355 	if (rc < 0)
1356 		return rc;
1357 	else if (rc > 0)
1358 		dump_payload = true;
1359 
1360 	if (!immed_data)
1361 		return 0;
1362 
1363 	return iscsit_get_immediate_data(cmd, hdr, dump_payload);
1364 }
1365 
1366 static u32 iscsit_do_crypto_hash_sg(
1367 	struct ahash_request *hash,
1368 	struct iscsi_cmd *cmd,
1369 	u32 data_offset,
1370 	u32 data_length,
1371 	u32 padding,
1372 	u8 *pad_bytes)
1373 {
1374 	u32 data_crc;
1375 	struct scatterlist *sg;
1376 	unsigned int page_off;
1377 
1378 	crypto_ahash_init(hash);
1379 
1380 	sg = cmd->first_data_sg;
1381 	page_off = cmd->first_data_sg_off;
1382 
1383 	while (data_length) {
1384 		u32 cur_len = min_t(u32, data_length, (sg->length - page_off));
1385 
1386 		ahash_request_set_crypt(hash, sg, NULL, cur_len);
1387 		crypto_ahash_update(hash);
1388 
1389 		data_length -= cur_len;
1390 		page_off = 0;
1391 		/* iscsit_map_iovec has already checked for invalid sg pointers */
1392 		sg = sg_next(sg);
1393 	}
1394 
1395 	if (padding) {
1396 		struct scatterlist pad_sg;
1397 
1398 		sg_init_one(&pad_sg, pad_bytes, padding);
1399 		ahash_request_set_crypt(hash, &pad_sg, (u8 *)&data_crc,
1400 					padding);
1401 		crypto_ahash_finup(hash);
1402 	} else {
1403 		ahash_request_set_crypt(hash, NULL, (u8 *)&data_crc, 0);
1404 		crypto_ahash_final(hash);
1405 	}
1406 
1407 	return data_crc;
1408 }
1409 
1410 static void iscsit_do_crypto_hash_buf(
1411 	struct ahash_request *hash,
1412 	const void *buf,
1413 	u32 payload_length,
1414 	u32 padding,
1415 	u8 *pad_bytes,
1416 	u8 *data_crc)
1417 {
1418 	struct scatterlist sg[2];
1419 
1420 	sg_init_table(sg, ARRAY_SIZE(sg));
1421 	sg_set_buf(sg, buf, payload_length);
1422 	sg_set_buf(sg + 1, pad_bytes, padding);
1423 
1424 	ahash_request_set_crypt(hash, sg, data_crc, payload_length + padding);
1425 
1426 	crypto_ahash_digest(hash);
1427 }
1428 
1429 int
1430 __iscsit_check_dataout_hdr(struct iscsi_conn *conn, void *buf,
1431 			   struct iscsi_cmd *cmd, u32 payload_length,
1432 			   bool *success)
1433 {
1434 	struct iscsi_data *hdr = buf;
1435 	struct se_cmd *se_cmd;
1436 	int rc;
1437 
1438 	/* iSCSI write */
1439 	atomic_long_add(payload_length, &conn->sess->rx_data_octets);
1440 
1441 	pr_debug("Got DataOut ITT: 0x%08x, TTT: 0x%08x,"
1442 		" DataSN: 0x%08x, Offset: %u, Length: %u, CID: %hu\n",
1443 		hdr->itt, hdr->ttt, hdr->datasn, ntohl(hdr->offset),
1444 		payload_length, conn->cid);
1445 
1446 	if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
1447 		pr_err("Command ITT: 0x%08x received DataOUT after"
1448 			" last DataOUT received, dumping payload\n",
1449 			cmd->init_task_tag);
1450 		return iscsit_dump_data_payload(conn, payload_length, 1);
1451 	}
1452 
1453 	if (cmd->data_direction != DMA_TO_DEVICE) {
1454 		pr_err("Command ITT: 0x%08x received DataOUT for a"
1455 			" NON-WRITE command.\n", cmd->init_task_tag);
1456 		return iscsit_dump_data_payload(conn, payload_length, 1);
1457 	}
1458 	se_cmd = &cmd->se_cmd;
1459 	iscsit_mod_dataout_timer(cmd);
1460 
1461 	if ((be32_to_cpu(hdr->offset) + payload_length) > cmd->se_cmd.data_length) {
1462 		pr_err("DataOut Offset: %u, Length %u greater than"
1463 			" iSCSI Command EDTL %u, protocol error.\n",
1464 			hdr->offset, payload_length, cmd->se_cmd.data_length);
1465 		return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_INVALID, buf);
1466 	}
1467 
1468 	if (cmd->unsolicited_data) {
1469 		int dump_unsolicited_data = 0;
1470 
1471 		if (conn->sess->sess_ops->InitialR2T) {
1472 			pr_err("Received unexpected unsolicited data"
1473 				" while InitialR2T=Yes, protocol error.\n");
1474 			transport_send_check_condition_and_sense(&cmd->se_cmd,
1475 					TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
1476 			return -1;
1477 		}
1478 		/*
1479 		 * Special case for dealing with Unsolicited DataOUT
1480 		 * and Unsupported SAM WRITE Opcodes and SE resource allocation
1481 		 * failures;
1482 		 */
1483 
1484 		/* Something's amiss if we're not in WRITE_PENDING state... */
1485 		WARN_ON(se_cmd->t_state != TRANSPORT_WRITE_PENDING);
1486 		if (!(se_cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE))
1487 			dump_unsolicited_data = 1;
1488 
1489 		if (dump_unsolicited_data) {
1490 			/*
1491 			 * Check if a delayed TASK_ABORTED status needs to
1492 			 * be sent now if the ISCSI_FLAG_CMD_FINAL has been
1493 			 * received with the unsolicited data out.
1494 			 */
1495 			if (hdr->flags & ISCSI_FLAG_CMD_FINAL)
1496 				iscsit_stop_dataout_timer(cmd);
1497 
1498 			transport_check_aborted_status(se_cmd,
1499 					(hdr->flags & ISCSI_FLAG_CMD_FINAL));
1500 			return iscsit_dump_data_payload(conn, payload_length, 1);
1501 		}
1502 	} else {
1503 		/*
1504 		 * For the normal solicited data path:
1505 		 *
1506 		 * Check for a delayed TASK_ABORTED status and dump any
1507 		 * incoming data out payload if one exists.  Also, when the
1508 		 * ISCSI_FLAG_CMD_FINAL is set to denote the end of the current
1509 		 * data out sequence, we decrement outstanding_r2ts.  Once
1510 		 * outstanding_r2ts reaches zero, go ahead and send the delayed
1511 		 * TASK_ABORTED status.
1512 		 */
1513 		if (se_cmd->transport_state & CMD_T_ABORTED) {
1514 			if (hdr->flags & ISCSI_FLAG_CMD_FINAL)
1515 				if (--cmd->outstanding_r2ts < 1) {
1516 					iscsit_stop_dataout_timer(cmd);
1517 					transport_check_aborted_status(
1518 							se_cmd, 1);
1519 				}
1520 
1521 			return iscsit_dump_data_payload(conn, payload_length, 1);
1522 		}
1523 	}
1524 	/*
1525 	 * Perform DataSN, DataSequenceInOrder, DataPDUInOrder, and
1526 	 * within-command recovery checks before receiving the payload.
1527 	 */
1528 	rc = iscsit_check_pre_dataout(cmd, buf);
1529 	if (rc == DATAOUT_WITHIN_COMMAND_RECOVERY)
1530 		return 0;
1531 	else if (rc == DATAOUT_CANNOT_RECOVER)
1532 		return -1;
1533 	*success = true;
1534 	return 0;
1535 }
1536 EXPORT_SYMBOL(__iscsit_check_dataout_hdr);
1537 
1538 int
1539 iscsit_check_dataout_hdr(struct iscsi_conn *conn, void *buf,
1540 			 struct iscsi_cmd **out_cmd)
1541 {
1542 	struct iscsi_data *hdr = buf;
1543 	struct iscsi_cmd *cmd;
1544 	u32 payload_length = ntoh24(hdr->dlength);
1545 	int rc;
1546 	bool success = false;
1547 
1548 	if (!payload_length) {
1549 		pr_warn_ratelimited("DataOUT payload is ZERO, ignoring.\n");
1550 		return 0;
1551 	}
1552 
1553 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1554 		pr_err_ratelimited("DataSegmentLength: %u is greater than"
1555 			" MaxXmitDataSegmentLength: %u\n", payload_length,
1556 			conn->conn_ops->MaxXmitDataSegmentLength);
1557 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR, buf);
1558 	}
1559 
1560 	cmd = iscsit_find_cmd_from_itt_or_dump(conn, hdr->itt, payload_length);
1561 	if (!cmd)
1562 		return 0;
1563 
1564 	rc = __iscsit_check_dataout_hdr(conn, buf, cmd, payload_length, &success);
1565 
1566 	if (success)
1567 		*out_cmd = cmd;
1568 
1569 	return rc;
1570 }
1571 EXPORT_SYMBOL(iscsit_check_dataout_hdr);
1572 
1573 static int
1574 iscsit_get_dataout(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1575 		   struct iscsi_data *hdr)
1576 {
1577 	struct kvec *iov;
1578 	u32 checksum, iov_count = 0, padding = 0, rx_got = 0, rx_size = 0;
1579 	u32 payload_length = ntoh24(hdr->dlength);
1580 	int iov_ret, data_crc_failed = 0;
1581 
1582 	rx_size += payload_length;
1583 	iov = &cmd->iov_data[0];
1584 
1585 	iov_ret = iscsit_map_iovec(cmd, iov, be32_to_cpu(hdr->offset),
1586 				   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 	rx_got = rx_data(conn, &cmd->iov_data[0], iov_count, rx_size);
1607 
1608 	iscsit_unmap_iovec(cmd);
1609 
1610 	if (rx_got != rx_size)
1611 		return -1;
1612 
1613 	if (conn->conn_ops->DataDigest) {
1614 		u32 data_crc;
1615 
1616 		data_crc = iscsit_do_crypto_hash_sg(conn->conn_rx_hash, cmd,
1617 						    be32_to_cpu(hdr->offset),
1618 						    payload_length, padding,
1619 						    cmd->pad_bytes);
1620 
1621 		if (checksum != data_crc) {
1622 			pr_err("ITT: 0x%08x, Offset: %u, Length: %u,"
1623 				" DataSN: 0x%08x, CRC32C DataDigest 0x%08x"
1624 				" does not match computed 0x%08x\n",
1625 				hdr->itt, hdr->offset, payload_length,
1626 				hdr->datasn, checksum, data_crc);
1627 			data_crc_failed = 1;
1628 		} else {
1629 			pr_debug("Got CRC32C DataDigest 0x%08x for"
1630 				" %u bytes of Data Out\n", checksum,
1631 				payload_length);
1632 		}
1633 	}
1634 
1635 	return data_crc_failed;
1636 }
1637 
1638 int
1639 iscsit_check_dataout_payload(struct iscsi_cmd *cmd, struct iscsi_data *hdr,
1640 			     bool data_crc_failed)
1641 {
1642 	struct iscsi_conn *conn = cmd->conn;
1643 	int rc, ooo_cmdsn;
1644 	/*
1645 	 * Increment post receive data and CRC values or perform
1646 	 * within-command recovery.
1647 	 */
1648 	rc = iscsit_check_post_dataout(cmd, (unsigned char *)hdr, data_crc_failed);
1649 	if ((rc == DATAOUT_NORMAL) || (rc == DATAOUT_WITHIN_COMMAND_RECOVERY))
1650 		return 0;
1651 	else if (rc == DATAOUT_SEND_R2T) {
1652 		iscsit_set_dataout_sequence_values(cmd);
1653 		conn->conn_transport->iscsit_get_dataout(conn, cmd, false);
1654 	} else if (rc == DATAOUT_SEND_TO_TRANSPORT) {
1655 		/*
1656 		 * Handle extra special case for out of order
1657 		 * Unsolicited Data Out.
1658 		 */
1659 		spin_lock_bh(&cmd->istate_lock);
1660 		ooo_cmdsn = (cmd->cmd_flags & ICF_OOO_CMDSN);
1661 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
1662 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
1663 		spin_unlock_bh(&cmd->istate_lock);
1664 
1665 		iscsit_stop_dataout_timer(cmd);
1666 		if (ooo_cmdsn)
1667 			return 0;
1668 		target_execute_cmd(&cmd->se_cmd);
1669 		return 0;
1670 	} else /* DATAOUT_CANNOT_RECOVER */
1671 		return -1;
1672 
1673 	return 0;
1674 }
1675 EXPORT_SYMBOL(iscsit_check_dataout_payload);
1676 
1677 static int iscsit_handle_data_out(struct iscsi_conn *conn, unsigned char *buf)
1678 {
1679 	struct iscsi_cmd *cmd = NULL;
1680 	struct iscsi_data *hdr = (struct iscsi_data *)buf;
1681 	int rc;
1682 	bool data_crc_failed = false;
1683 
1684 	rc = iscsit_check_dataout_hdr(conn, buf, &cmd);
1685 	if (rc < 0)
1686 		return 0;
1687 	else if (!cmd)
1688 		return 0;
1689 
1690 	rc = iscsit_get_dataout(conn, cmd, hdr);
1691 	if (rc < 0)
1692 		return rc;
1693 	else if (rc > 0)
1694 		data_crc_failed = true;
1695 
1696 	return iscsit_check_dataout_payload(cmd, hdr, data_crc_failed);
1697 }
1698 
1699 int iscsit_setup_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1700 			 struct iscsi_nopout *hdr)
1701 {
1702 	u32 payload_length = ntoh24(hdr->dlength);
1703 
1704 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL)) {
1705 		pr_err("NopOUT Flag's, Left Most Bit not set, protocol error.\n");
1706 		if (!cmd)
1707 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1708 						 (unsigned char *)hdr);
1709 
1710 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1711 					 (unsigned char *)hdr);
1712 	}
1713 
1714 	if (hdr->itt == RESERVED_ITT && !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
1715 		pr_err("NOPOUT ITT is reserved, but Immediate Bit is"
1716 			" not set, protocol error.\n");
1717 		if (!cmd)
1718 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1719 						 (unsigned char *)hdr);
1720 
1721 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1722 					 (unsigned char *)hdr);
1723 	}
1724 
1725 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1726 		pr_err("NOPOUT Ping Data DataSegmentLength: %u is"
1727 			" greater than MaxXmitDataSegmentLength: %u, protocol"
1728 			" error.\n", payload_length,
1729 			conn->conn_ops->MaxXmitDataSegmentLength);
1730 		if (!cmd)
1731 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1732 						 (unsigned char *)hdr);
1733 
1734 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1735 					 (unsigned char *)hdr);
1736 	}
1737 
1738 	pr_debug("Got NOPOUT Ping %s ITT: 0x%08x, TTT: 0x%08x,"
1739 		" CmdSN: 0x%08x, ExpStatSN: 0x%08x, Length: %u\n",
1740 		hdr->itt == RESERVED_ITT ? "Response" : "Request",
1741 		hdr->itt, hdr->ttt, hdr->cmdsn, hdr->exp_statsn,
1742 		payload_length);
1743 	/*
1744 	 * This is not a response to a Unsolicited NopIN, which means
1745 	 * it can either be a NOPOUT ping request (with a valid ITT),
1746 	 * or a NOPOUT not requesting a NOPIN (with a reserved ITT).
1747 	 * Either way, make sure we allocate an struct iscsi_cmd, as both
1748 	 * can contain ping data.
1749 	 */
1750 	if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1751 		cmd->iscsi_opcode	= ISCSI_OP_NOOP_OUT;
1752 		cmd->i_state		= ISTATE_SEND_NOPIN;
1753 		cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ?
1754 						1 : 0);
1755 		conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
1756 		cmd->targ_xfer_tag	= 0xFFFFFFFF;
1757 		cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
1758 		cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
1759 		cmd->data_direction	= DMA_NONE;
1760 	}
1761 
1762 	return 0;
1763 }
1764 EXPORT_SYMBOL(iscsit_setup_nop_out);
1765 
1766 int iscsit_process_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1767 			   struct iscsi_nopout *hdr)
1768 {
1769 	struct iscsi_cmd *cmd_p = NULL;
1770 	int cmdsn_ret = 0;
1771 	/*
1772 	 * Initiator is expecting a NopIN ping reply..
1773 	 */
1774 	if (hdr->itt != RESERVED_ITT) {
1775 		if (!cmd)
1776 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1777 						(unsigned char *)hdr);
1778 
1779 		spin_lock_bh(&conn->cmd_lock);
1780 		list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
1781 		spin_unlock_bh(&conn->cmd_lock);
1782 
1783 		iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
1784 
1785 		if (hdr->opcode & ISCSI_OP_IMMEDIATE) {
1786 			iscsit_add_cmd_to_response_queue(cmd, conn,
1787 							 cmd->i_state);
1788 			return 0;
1789 		}
1790 
1791 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
1792 				(unsigned char *)hdr, hdr->cmdsn);
1793                 if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
1794 			return 0;
1795 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1796 			return -1;
1797 
1798 		return 0;
1799 	}
1800 	/*
1801 	 * This was a response to a unsolicited NOPIN ping.
1802 	 */
1803 	if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
1804 		cmd_p = iscsit_find_cmd_from_ttt(conn, be32_to_cpu(hdr->ttt));
1805 		if (!cmd_p)
1806 			return -EINVAL;
1807 
1808 		iscsit_stop_nopin_response_timer(conn);
1809 
1810 		cmd_p->i_state = ISTATE_REMOVE;
1811 		iscsit_add_cmd_to_immediate_queue(cmd_p, conn, cmd_p->i_state);
1812 
1813 		iscsit_start_nopin_timer(conn);
1814 		return 0;
1815 	}
1816 	/*
1817 	 * Otherwise, initiator is not expecting a NOPIN is response.
1818 	 * Just ignore for now.
1819 	 */
1820 
1821 	if (cmd)
1822 		iscsit_free_cmd(cmd, false);
1823 
1824         return 0;
1825 }
1826 EXPORT_SYMBOL(iscsit_process_nop_out);
1827 
1828 static int iscsit_handle_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1829 				 unsigned char *buf)
1830 {
1831 	unsigned char *ping_data = NULL;
1832 	struct iscsi_nopout *hdr = (struct iscsi_nopout *)buf;
1833 	struct kvec *iov = NULL;
1834 	u32 payload_length = ntoh24(hdr->dlength);
1835 	int ret;
1836 
1837 	ret = iscsit_setup_nop_out(conn, cmd, hdr);
1838 	if (ret < 0)
1839 		return 0;
1840 	/*
1841 	 * Handle NOP-OUT payload for traditional iSCSI sockets
1842 	 */
1843 	if (payload_length && hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1844 		u32 checksum, data_crc, padding = 0;
1845 		int niov = 0, rx_got, rx_size = payload_length;
1846 
1847 		ping_data = kzalloc(payload_length + 1, GFP_KERNEL);
1848 		if (!ping_data) {
1849 			ret = -1;
1850 			goto out;
1851 		}
1852 
1853 		iov = &cmd->iov_misc[0];
1854 		iov[niov].iov_base	= ping_data;
1855 		iov[niov++].iov_len	= payload_length;
1856 
1857 		padding = ((-payload_length) & 3);
1858 		if (padding != 0) {
1859 			pr_debug("Receiving %u additional bytes"
1860 				" for padding.\n", padding);
1861 			iov[niov].iov_base	= &cmd->pad_bytes;
1862 			iov[niov++].iov_len	= padding;
1863 			rx_size += padding;
1864 		}
1865 		if (conn->conn_ops->DataDigest) {
1866 			iov[niov].iov_base	= &checksum;
1867 			iov[niov++].iov_len	= ISCSI_CRC_LEN;
1868 			rx_size += ISCSI_CRC_LEN;
1869 		}
1870 
1871 		rx_got = rx_data(conn, &cmd->iov_misc[0], niov, rx_size);
1872 		if (rx_got != rx_size) {
1873 			ret = -1;
1874 			goto out;
1875 		}
1876 
1877 		if (conn->conn_ops->DataDigest) {
1878 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash,
1879 					ping_data, payload_length,
1880 					padding, cmd->pad_bytes,
1881 					(u8 *)&data_crc);
1882 
1883 			if (checksum != data_crc) {
1884 				pr_err("Ping data CRC32C DataDigest"
1885 				" 0x%08x does not match computed 0x%08x\n",
1886 					checksum, data_crc);
1887 				if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
1888 					pr_err("Unable to recover from"
1889 					" NOPOUT Ping DataCRC failure while in"
1890 						" ERL=0.\n");
1891 					ret = -1;
1892 					goto out;
1893 				} else {
1894 					/*
1895 					 * Silently drop this PDU and let the
1896 					 * initiator plug the CmdSN gap.
1897 					 */
1898 					pr_debug("Dropping NOPOUT"
1899 					" Command CmdSN: 0x%08x due to"
1900 					" DataCRC error.\n", hdr->cmdsn);
1901 					ret = 0;
1902 					goto out;
1903 				}
1904 			} else {
1905 				pr_debug("Got CRC32C DataDigest"
1906 				" 0x%08x for %u bytes of ping data.\n",
1907 					checksum, payload_length);
1908 			}
1909 		}
1910 
1911 		ping_data[payload_length] = '\0';
1912 		/*
1913 		 * Attach ping data to struct iscsi_cmd->buf_ptr.
1914 		 */
1915 		cmd->buf_ptr = ping_data;
1916 		cmd->buf_ptr_size = payload_length;
1917 
1918 		pr_debug("Got %u bytes of NOPOUT ping"
1919 			" data.\n", payload_length);
1920 		pr_debug("Ping Data: \"%s\"\n", ping_data);
1921 	}
1922 
1923 	return iscsit_process_nop_out(conn, cmd, hdr);
1924 out:
1925 	if (cmd)
1926 		iscsit_free_cmd(cmd, false);
1927 
1928 	kfree(ping_data);
1929 	return ret;
1930 }
1931 
1932 static enum tcm_tmreq_table iscsit_convert_tmf(u8 iscsi_tmf)
1933 {
1934 	switch (iscsi_tmf) {
1935 	case ISCSI_TM_FUNC_ABORT_TASK:
1936 		return TMR_ABORT_TASK;
1937 	case ISCSI_TM_FUNC_ABORT_TASK_SET:
1938 		return TMR_ABORT_TASK_SET;
1939 	case ISCSI_TM_FUNC_CLEAR_ACA:
1940 		return TMR_CLEAR_ACA;
1941 	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
1942 		return TMR_CLEAR_TASK_SET;
1943 	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
1944 		return TMR_LUN_RESET;
1945 	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
1946 		return TMR_TARGET_WARM_RESET;
1947 	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
1948 		return TMR_TARGET_COLD_RESET;
1949 	default:
1950 		return TMR_UNKNOWN;
1951 	}
1952 }
1953 
1954 int
1955 iscsit_handle_task_mgt_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1956 			   unsigned char *buf)
1957 {
1958 	struct se_tmr_req *se_tmr;
1959 	struct iscsi_tmr_req *tmr_req;
1960 	struct iscsi_tm *hdr;
1961 	int out_of_order_cmdsn = 0, ret;
1962 	bool sess_ref = false;
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 	 * TASK_REASSIGN for ERL=2 / connection stays inside of
2002 	 * LIO-Target $FABRIC_MOD
2003 	 */
2004 	if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {
2005 		transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops,
2006 				      conn->sess->se_sess, 0, DMA_NONE,
2007 				      TCM_SIMPLE_TAG, cmd->sense_buffer + 2);
2008 
2009 		target_get_sess_cmd(&cmd->se_cmd, true);
2010 		sess_ref = true;
2011 		tcm_function = iscsit_convert_tmf(function);
2012 		if (tcm_function == TMR_UNKNOWN) {
2013 			pr_err("Unknown iSCSI TMR Function:"
2014 			       " 0x%02x\n", function);
2015 			return iscsit_add_reject_cmd(cmd,
2016 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
2017 		}
2018 	}
2019 	ret = core_tmr_alloc_req(&cmd->se_cmd, cmd->tmr_req, tcm_function,
2020 				 GFP_KERNEL);
2021 	if (ret < 0)
2022 		return iscsit_add_reject_cmd(cmd,
2023 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
2024 
2025 	cmd->tmr_req->se_tmr_req = cmd->se_cmd.se_tmr_req;
2026 
2027 	cmd->iscsi_opcode	= ISCSI_OP_SCSI_TMFUNC;
2028 	cmd->i_state		= ISTATE_SEND_TASKMGTRSP;
2029 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2030 	cmd->init_task_tag	= hdr->itt;
2031 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2032 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
2033 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
2034 	se_tmr			= cmd->se_cmd.se_tmr_req;
2035 	tmr_req			= cmd->tmr_req;
2036 	/*
2037 	 * Locate the struct se_lun for all TMRs not related to ERL=2 TASK_REASSIGN
2038 	 */
2039 	if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {
2040 		ret = transport_lookup_tmr_lun(&cmd->se_cmd,
2041 					       scsilun_to_int(&hdr->lun));
2042 		if (ret < 0) {
2043 			se_tmr->response = ISCSI_TMF_RSP_NO_LUN;
2044 			goto attach;
2045 		}
2046 	}
2047 
2048 	switch (function) {
2049 	case ISCSI_TM_FUNC_ABORT_TASK:
2050 		se_tmr->response = iscsit_tmr_abort_task(cmd, buf);
2051 		if (se_tmr->response)
2052 			goto attach;
2053 		break;
2054 	case ISCSI_TM_FUNC_ABORT_TASK_SET:
2055 	case ISCSI_TM_FUNC_CLEAR_ACA:
2056 	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
2057 	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
2058 		break;
2059 	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
2060 		if (iscsit_tmr_task_warm_reset(conn, tmr_req, buf) < 0) {
2061 			se_tmr->response = ISCSI_TMF_RSP_AUTH_FAILED;
2062 			goto attach;
2063 		}
2064 		break;
2065 	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
2066 		if (iscsit_tmr_task_cold_reset(conn, tmr_req, buf) < 0) {
2067 			se_tmr->response = ISCSI_TMF_RSP_AUTH_FAILED;
2068 			goto attach;
2069 		}
2070 		break;
2071 	case ISCSI_TM_FUNC_TASK_REASSIGN:
2072 		se_tmr->response = iscsit_tmr_task_reassign(cmd, buf);
2073 		/*
2074 		 * Perform sanity checks on the ExpDataSN only if the
2075 		 * TASK_REASSIGN was successful.
2076 		 */
2077 		if (se_tmr->response)
2078 			break;
2079 
2080 		if (iscsit_check_task_reassign_expdatasn(tmr_req, conn) < 0)
2081 			return iscsit_add_reject_cmd(cmd,
2082 					ISCSI_REASON_BOOKMARK_INVALID, buf);
2083 		break;
2084 	default:
2085 		pr_err("Unknown TMR function: 0x%02x, protocol"
2086 			" error.\n", function);
2087 		se_tmr->response = ISCSI_TMF_RSP_NOT_SUPPORTED;
2088 		goto attach;
2089 	}
2090 
2091 	if ((function != ISCSI_TM_FUNC_TASK_REASSIGN) &&
2092 	    (se_tmr->response == ISCSI_TMF_RSP_COMPLETE))
2093 		se_tmr->call_transport = 1;
2094 attach:
2095 	spin_lock_bh(&conn->cmd_lock);
2096 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2097 	spin_unlock_bh(&conn->cmd_lock);
2098 
2099 	if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
2100 		int cmdsn_ret = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);
2101 		if (cmdsn_ret == CMDSN_HIGHER_THAN_EXP)
2102 			out_of_order_cmdsn = 1;
2103 		else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
2104 			return 0;
2105 		else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
2106 			return -1;
2107 	}
2108 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2109 
2110 	if (out_of_order_cmdsn || !(hdr->opcode & ISCSI_OP_IMMEDIATE))
2111 		return 0;
2112 	/*
2113 	 * Found the referenced task, send to transport for processing.
2114 	 */
2115 	if (se_tmr->call_transport)
2116 		return transport_generic_handle_tmr(&cmd->se_cmd);
2117 
2118 	/*
2119 	 * Could not find the referenced LUN, task, or Task Management
2120 	 * command not authorized or supported.  Change state and
2121 	 * let the tx_thread send the response.
2122 	 *
2123 	 * For connection recovery, this is also the default action for
2124 	 * TMR TASK_REASSIGN.
2125 	 */
2126 	if (sess_ref) {
2127 		pr_debug("Handle TMR, using sess_ref=true check\n");
2128 		target_put_sess_cmd(&cmd->se_cmd);
2129 	}
2130 
2131 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2132 	return 0;
2133 }
2134 EXPORT_SYMBOL(iscsit_handle_task_mgt_cmd);
2135 
2136 /* #warning FIXME: Support Text Command parameters besides SendTargets */
2137 int
2138 iscsit_setup_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2139 		      struct iscsi_text *hdr)
2140 {
2141 	u32 payload_length = ntoh24(hdr->dlength);
2142 
2143 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
2144 		pr_err("Unable to accept text parameter length: %u"
2145 			"greater than MaxXmitDataSegmentLength %u.\n",
2146 		       payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
2147 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
2148 					 (unsigned char *)hdr);
2149 	}
2150 
2151 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL) ||
2152 	     (hdr->flags & ISCSI_FLAG_TEXT_CONTINUE)) {
2153 		pr_err("Multi sequence text commands currently not supported\n");
2154 		return iscsit_reject_cmd(cmd, ISCSI_REASON_CMD_NOT_SUPPORTED,
2155 					(unsigned char *)hdr);
2156 	}
2157 
2158 	pr_debug("Got Text Request: ITT: 0x%08x, CmdSN: 0x%08x,"
2159 		" ExpStatSN: 0x%08x, Length: %u\n", hdr->itt, hdr->cmdsn,
2160 		hdr->exp_statsn, payload_length);
2161 
2162 	cmd->iscsi_opcode	= ISCSI_OP_TEXT;
2163 	cmd->i_state		= ISTATE_SEND_TEXTRSP;
2164 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2165 	conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
2166 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2167 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
2168 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
2169 	cmd->data_direction	= DMA_NONE;
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, 11) != 0) {
2193 		pr_err("Received Text Data that is not"
2194 			" SendTargets, cannot continue.\n");
2195 		goto reject;
2196 	}
2197 	text_ptr = strchr(text_in, '=');
2198 	if (!text_ptr) {
2199 		pr_err("No \"=\" separator found in Text Data,"
2200 			"  cannot continue.\n");
2201 		goto reject;
2202 	}
2203 	if (!strncmp("=All", text_ptr, 4)) {
2204 		cmd->cmd_flags |= ICF_SENDTARGETS_ALL;
2205 	} else if (!strncmp("=iqn.", text_ptr, 5) ||
2206 		   !strncmp("=eui.", text_ptr, 5)) {
2207 		cmd->cmd_flags |= ICF_SENDTARGETS_SINGLE;
2208 	} else {
2209 		pr_err("Unable to locate valid SendTargets=%s value\n", text_ptr);
2210 		goto reject;
2211 	}
2212 
2213 	spin_lock_bh(&conn->cmd_lock);
2214 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2215 	spin_unlock_bh(&conn->cmd_lock);
2216 
2217 empty_sendtargets:
2218 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2219 
2220 	if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
2221 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
2222 				(unsigned char *)hdr, hdr->cmdsn);
2223 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
2224 			return -1;
2225 
2226 		return 0;
2227 	}
2228 
2229 	return iscsit_execute_cmd(cmd, 0);
2230 
2231 reject:
2232 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
2233 				 (unsigned char *)hdr);
2234 }
2235 EXPORT_SYMBOL(iscsit_process_text_cmd);
2236 
2237 static int
2238 iscsit_handle_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2239 		       unsigned char *buf)
2240 {
2241 	struct iscsi_text *hdr = (struct iscsi_text *)buf;
2242 	char *text_in = NULL;
2243 	u32 payload_length = ntoh24(hdr->dlength);
2244 	int rx_size, rc;
2245 
2246 	rc = iscsit_setup_text_cmd(conn, cmd, hdr);
2247 	if (rc < 0)
2248 		return 0;
2249 
2250 	rx_size = payload_length;
2251 	if (payload_length) {
2252 		u32 checksum = 0, data_crc = 0;
2253 		u32 padding = 0, pad_bytes = 0;
2254 		int niov = 0, rx_got;
2255 		struct kvec iov[3];
2256 
2257 		text_in = kzalloc(payload_length, GFP_KERNEL);
2258 		if (!text_in)
2259 			goto reject;
2260 
2261 		cmd->text_in_ptr = text_in;
2262 
2263 		memset(iov, 0, 3 * sizeof(struct kvec));
2264 		iov[niov].iov_base	= text_in;
2265 		iov[niov++].iov_len	= payload_length;
2266 
2267 		padding = ((-payload_length) & 3);
2268 		if (padding != 0) {
2269 			iov[niov].iov_base = &pad_bytes;
2270 			iov[niov++].iov_len  = padding;
2271 			rx_size += padding;
2272 			pr_debug("Receiving %u additional bytes"
2273 					" for padding.\n", padding);
2274 		}
2275 		if (conn->conn_ops->DataDigest) {
2276 			iov[niov].iov_base	= &checksum;
2277 			iov[niov++].iov_len	= ISCSI_CRC_LEN;
2278 			rx_size += ISCSI_CRC_LEN;
2279 		}
2280 
2281 		rx_got = rx_data(conn, &iov[0], niov, rx_size);
2282 		if (rx_got != rx_size)
2283 			goto reject;
2284 
2285 		if (conn->conn_ops->DataDigest) {
2286 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash,
2287 					text_in, payload_length,
2288 					padding, (u8 *)&pad_bytes,
2289 					(u8 *)&data_crc);
2290 
2291 			if (checksum != data_crc) {
2292 				pr_err("Text data CRC32C DataDigest"
2293 					" 0x%08x does not match computed"
2294 					" 0x%08x\n", checksum, data_crc);
2295 				if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2296 					pr_err("Unable to recover from"
2297 					" Text Data digest failure while in"
2298 						" ERL=0.\n");
2299 					goto reject;
2300 				} else {
2301 					/*
2302 					 * Silently drop this PDU and let the
2303 					 * initiator plug the CmdSN gap.
2304 					 */
2305 					pr_debug("Dropping Text"
2306 					" Command CmdSN: 0x%08x due to"
2307 					" DataCRC error.\n", hdr->cmdsn);
2308 					kfree(text_in);
2309 					return 0;
2310 				}
2311 			} else {
2312 				pr_debug("Got CRC32C DataDigest"
2313 					" 0x%08x for %u bytes of text data.\n",
2314 						checksum, payload_length);
2315 			}
2316 		}
2317 		text_in[payload_length - 1] = '\0';
2318 		pr_debug("Successfully read %d bytes of text"
2319 				" data.\n", payload_length);
2320 	}
2321 
2322 	return iscsit_process_text_cmd(conn, cmd, hdr);
2323 
2324 reject:
2325 	kfree(cmd->text_in_ptr);
2326 	cmd->text_in_ptr = NULL;
2327 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);
2328 }
2329 
2330 int iscsit_logout_closesession(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2331 {
2332 	struct iscsi_conn *conn_p;
2333 	struct iscsi_session *sess = conn->sess;
2334 
2335 	pr_debug("Received logout request CLOSESESSION on CID: %hu"
2336 		" for SID: %u.\n", conn->cid, conn->sess->sid);
2337 
2338 	atomic_set(&sess->session_logout, 1);
2339 	atomic_set(&conn->conn_logout_remove, 1);
2340 	conn->conn_logout_reason = ISCSI_LOGOUT_REASON_CLOSE_SESSION;
2341 
2342 	iscsit_inc_conn_usage_count(conn);
2343 	iscsit_inc_session_usage_count(sess);
2344 
2345 	spin_lock_bh(&sess->conn_lock);
2346 	list_for_each_entry(conn_p, &sess->sess_conn_list, conn_list) {
2347 		if (conn_p->conn_state != TARG_CONN_STATE_LOGGED_IN)
2348 			continue;
2349 
2350 		pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
2351 		conn_p->conn_state = TARG_CONN_STATE_IN_LOGOUT;
2352 	}
2353 	spin_unlock_bh(&sess->conn_lock);
2354 
2355 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2356 
2357 	return 0;
2358 }
2359 
2360 int iscsit_logout_closeconnection(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2361 {
2362 	struct iscsi_conn *l_conn;
2363 	struct iscsi_session *sess = conn->sess;
2364 
2365 	pr_debug("Received logout request CLOSECONNECTION for CID:"
2366 		" %hu on CID: %hu.\n", cmd->logout_cid, conn->cid);
2367 
2368 	/*
2369 	 * A Logout Request with a CLOSECONNECTION reason code for a CID
2370 	 * can arrive on a connection with a differing CID.
2371 	 */
2372 	if (conn->cid == cmd->logout_cid) {
2373 		spin_lock_bh(&conn->state_lock);
2374 		pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
2375 		conn->conn_state = TARG_CONN_STATE_IN_LOGOUT;
2376 
2377 		atomic_set(&conn->conn_logout_remove, 1);
2378 		conn->conn_logout_reason = ISCSI_LOGOUT_REASON_CLOSE_CONNECTION;
2379 		iscsit_inc_conn_usage_count(conn);
2380 
2381 		spin_unlock_bh(&conn->state_lock);
2382 	} else {
2383 		/*
2384 		 * Handle all different cid CLOSECONNECTION requests in
2385 		 * iscsit_logout_post_handler_diffcid() as to give enough
2386 		 * time for any non immediate command's CmdSN to be
2387 		 * acknowledged on the connection in question.
2388 		 *
2389 		 * Here we simply make sure the CID is still around.
2390 		 */
2391 		l_conn = iscsit_get_conn_from_cid(sess,
2392 				cmd->logout_cid);
2393 		if (!l_conn) {
2394 			cmd->logout_response = ISCSI_LOGOUT_CID_NOT_FOUND;
2395 			iscsit_add_cmd_to_response_queue(cmd, conn,
2396 					cmd->i_state);
2397 			return 0;
2398 		}
2399 
2400 		iscsit_dec_conn_usage_count(l_conn);
2401 	}
2402 
2403 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2404 
2405 	return 0;
2406 }
2407 
2408 int iscsit_logout_removeconnforrecovery(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2409 {
2410 	struct iscsi_session *sess = conn->sess;
2411 
2412 	pr_debug("Received explicit REMOVECONNFORRECOVERY logout for"
2413 		" CID: %hu on CID: %hu.\n", cmd->logout_cid, conn->cid);
2414 
2415 	if (sess->sess_ops->ErrorRecoveryLevel != 2) {
2416 		pr_err("Received Logout Request REMOVECONNFORRECOVERY"
2417 			" while ERL!=2.\n");
2418 		cmd->logout_response = ISCSI_LOGOUT_RECOVERY_UNSUPPORTED;
2419 		iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2420 		return 0;
2421 	}
2422 
2423 	if (conn->cid == cmd->logout_cid) {
2424 		pr_err("Received Logout Request REMOVECONNFORRECOVERY"
2425 			" with CID: %hu on CID: %hu, implementation error.\n",
2426 				cmd->logout_cid, conn->cid);
2427 		cmd->logout_response = ISCSI_LOGOUT_CLEANUP_FAILED;
2428 		iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2429 		return 0;
2430 	}
2431 
2432 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2433 
2434 	return 0;
2435 }
2436 
2437 int
2438 iscsit_handle_logout_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2439 			unsigned char *buf)
2440 {
2441 	int cmdsn_ret, logout_remove = 0;
2442 	u8 reason_code = 0;
2443 	struct iscsi_logout *hdr;
2444 	struct iscsi_tiqn *tiqn = iscsit_snmp_get_tiqn(conn);
2445 
2446 	hdr			= (struct iscsi_logout *) buf;
2447 	reason_code		= (hdr->flags & 0x7f);
2448 
2449 	if (tiqn) {
2450 		spin_lock(&tiqn->logout_stats.lock);
2451 		if (reason_code == ISCSI_LOGOUT_REASON_CLOSE_SESSION)
2452 			tiqn->logout_stats.normal_logouts++;
2453 		else
2454 			tiqn->logout_stats.abnormal_logouts++;
2455 		spin_unlock(&tiqn->logout_stats.lock);
2456 	}
2457 
2458 	pr_debug("Got Logout Request ITT: 0x%08x CmdSN: 0x%08x"
2459 		" ExpStatSN: 0x%08x Reason: 0x%02x CID: %hu on CID: %hu\n",
2460 		hdr->itt, hdr->cmdsn, hdr->exp_statsn, reason_code,
2461 		hdr->cid, conn->cid);
2462 
2463 	if (conn->conn_state != TARG_CONN_STATE_LOGGED_IN) {
2464 		pr_err("Received logout request on connection that"
2465 			" is not in logged in state, ignoring request.\n");
2466 		iscsit_free_cmd(cmd, false);
2467 		return 0;
2468 	}
2469 
2470 	cmd->iscsi_opcode       = ISCSI_OP_LOGOUT;
2471 	cmd->i_state            = ISTATE_SEND_LOGOUTRSP;
2472 	cmd->immediate_cmd      = ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2473 	conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
2474 	cmd->targ_xfer_tag      = 0xFFFFFFFF;
2475 	cmd->cmd_sn             = be32_to_cpu(hdr->cmdsn);
2476 	cmd->exp_stat_sn        = be32_to_cpu(hdr->exp_statsn);
2477 	cmd->logout_cid         = be16_to_cpu(hdr->cid);
2478 	cmd->logout_reason      = reason_code;
2479 	cmd->data_direction     = DMA_NONE;
2480 
2481 	/*
2482 	 * We need to sleep in these cases (by returning 1) until the Logout
2483 	 * Response gets sent in the tx thread.
2484 	 */
2485 	if ((reason_code == ISCSI_LOGOUT_REASON_CLOSE_SESSION) ||
2486 	   ((reason_code == ISCSI_LOGOUT_REASON_CLOSE_CONNECTION) &&
2487 	    be16_to_cpu(hdr->cid) == conn->cid))
2488 		logout_remove = 1;
2489 
2490 	spin_lock_bh(&conn->cmd_lock);
2491 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2492 	spin_unlock_bh(&conn->cmd_lock);
2493 
2494 	if (reason_code != ISCSI_LOGOUT_REASON_RECOVERY)
2495 		iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2496 
2497 	/*
2498 	 * Immediate commands are executed, well, immediately.
2499 	 * Non-Immediate Logout Commands are executed in CmdSN order.
2500 	 */
2501 	if (cmd->immediate_cmd) {
2502 		int ret = iscsit_execute_cmd(cmd, 0);
2503 
2504 		if (ret < 0)
2505 			return ret;
2506 	} else {
2507 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);
2508 		if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
2509 			logout_remove = 0;
2510 		else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
2511 			return -1;
2512 	}
2513 
2514 	return logout_remove;
2515 }
2516 EXPORT_SYMBOL(iscsit_handle_logout_cmd);
2517 
2518 int iscsit_handle_snack(
2519 	struct iscsi_conn *conn,
2520 	unsigned char *buf)
2521 {
2522 	struct iscsi_snack *hdr;
2523 
2524 	hdr			= (struct iscsi_snack *) buf;
2525 	hdr->flags		&= ~ISCSI_FLAG_CMD_FINAL;
2526 
2527 	pr_debug("Got ISCSI_INIT_SNACK, ITT: 0x%08x, ExpStatSN:"
2528 		" 0x%08x, Type: 0x%02x, BegRun: 0x%08x, RunLength: 0x%08x,"
2529 		" CID: %hu\n", hdr->itt, hdr->exp_statsn, hdr->flags,
2530 			hdr->begrun, hdr->runlength, conn->cid);
2531 
2532 	if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2533 		pr_err("Initiator sent SNACK request while in"
2534 			" ErrorRecoveryLevel=0.\n");
2535 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2536 					 buf);
2537 	}
2538 	/*
2539 	 * SNACK_DATA and SNACK_R2T are both 0,  so check which function to
2540 	 * call from inside iscsi_send_recovery_datain_or_r2t().
2541 	 */
2542 	switch (hdr->flags & ISCSI_FLAG_SNACK_TYPE_MASK) {
2543 	case 0:
2544 		return iscsit_handle_recovery_datain_or_r2t(conn, buf,
2545 			hdr->itt,
2546 			be32_to_cpu(hdr->ttt),
2547 			be32_to_cpu(hdr->begrun),
2548 			be32_to_cpu(hdr->runlength));
2549 	case ISCSI_FLAG_SNACK_TYPE_STATUS:
2550 		return iscsit_handle_status_snack(conn, hdr->itt,
2551 			be32_to_cpu(hdr->ttt),
2552 			be32_to_cpu(hdr->begrun), be32_to_cpu(hdr->runlength));
2553 	case ISCSI_FLAG_SNACK_TYPE_DATA_ACK:
2554 		return iscsit_handle_data_ack(conn, be32_to_cpu(hdr->ttt),
2555 			be32_to_cpu(hdr->begrun),
2556 			be32_to_cpu(hdr->runlength));
2557 	case ISCSI_FLAG_SNACK_TYPE_RDATA:
2558 		/* FIXME: Support R-Data SNACK */
2559 		pr_err("R-Data SNACK Not Supported.\n");
2560 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2561 					 buf);
2562 	default:
2563 		pr_err("Unknown SNACK type 0x%02x, protocol"
2564 			" error.\n", hdr->flags & 0x0f);
2565 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2566 					 buf);
2567 	}
2568 
2569 	return 0;
2570 }
2571 EXPORT_SYMBOL(iscsit_handle_snack);
2572 
2573 static void iscsit_rx_thread_wait_for_tcp(struct iscsi_conn *conn)
2574 {
2575 	if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) ||
2576 	    (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) {
2577 		wait_for_completion_interruptible_timeout(
2578 					&conn->rx_half_close_comp,
2579 					ISCSI_RX_THREAD_TCP_TIMEOUT * HZ);
2580 	}
2581 }
2582 
2583 static int iscsit_handle_immediate_data(
2584 	struct iscsi_cmd *cmd,
2585 	struct iscsi_scsi_req *hdr,
2586 	u32 length)
2587 {
2588 	int iov_ret, rx_got = 0, rx_size = 0;
2589 	u32 checksum, iov_count = 0, padding = 0;
2590 	struct iscsi_conn *conn = cmd->conn;
2591 	struct kvec *iov;
2592 
2593 	iov_ret = iscsit_map_iovec(cmd, cmd->iov_data, cmd->write_data_done, length);
2594 	if (iov_ret < 0)
2595 		return IMMEDIATE_DATA_CANNOT_RECOVER;
2596 
2597 	rx_size = length;
2598 	iov_count = iov_ret;
2599 	iov = &cmd->iov_data[0];
2600 
2601 	padding = ((-length) & 3);
2602 	if (padding != 0) {
2603 		iov[iov_count].iov_base	= cmd->pad_bytes;
2604 		iov[iov_count++].iov_len = padding;
2605 		rx_size += padding;
2606 	}
2607 
2608 	if (conn->conn_ops->DataDigest) {
2609 		iov[iov_count].iov_base		= &checksum;
2610 		iov[iov_count++].iov_len	= ISCSI_CRC_LEN;
2611 		rx_size += ISCSI_CRC_LEN;
2612 	}
2613 
2614 	rx_got = rx_data(conn, &cmd->iov_data[0], iov_count, rx_size);
2615 
2616 	iscsit_unmap_iovec(cmd);
2617 
2618 	if (rx_got != rx_size) {
2619 		iscsit_rx_thread_wait_for_tcp(conn);
2620 		return IMMEDIATE_DATA_CANNOT_RECOVER;
2621 	}
2622 
2623 	if (conn->conn_ops->DataDigest) {
2624 		u32 data_crc;
2625 
2626 		data_crc = iscsit_do_crypto_hash_sg(conn->conn_rx_hash, cmd,
2627 						    cmd->write_data_done, length, padding,
2628 						    cmd->pad_bytes);
2629 
2630 		if (checksum != data_crc) {
2631 			pr_err("ImmediateData CRC32C DataDigest 0x%08x"
2632 				" does not match computed 0x%08x\n", checksum,
2633 				data_crc);
2634 
2635 			if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2636 				pr_err("Unable to recover from"
2637 					" Immediate Data digest failure while"
2638 					" in ERL=0.\n");
2639 				iscsit_reject_cmd(cmd,
2640 						ISCSI_REASON_DATA_DIGEST_ERROR,
2641 						(unsigned char *)hdr);
2642 				return IMMEDIATE_DATA_CANNOT_RECOVER;
2643 			} else {
2644 				iscsit_reject_cmd(cmd,
2645 						ISCSI_REASON_DATA_DIGEST_ERROR,
2646 						(unsigned char *)hdr);
2647 				return IMMEDIATE_DATA_ERL1_CRC_FAILURE;
2648 			}
2649 		} else {
2650 			pr_debug("Got CRC32C DataDigest 0x%08x for"
2651 				" %u bytes of Immediate Data\n", checksum,
2652 				length);
2653 		}
2654 	}
2655 
2656 	cmd->write_data_done += length;
2657 
2658 	if (cmd->write_data_done == cmd->se_cmd.data_length) {
2659 		spin_lock_bh(&cmd->istate_lock);
2660 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
2661 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
2662 		spin_unlock_bh(&cmd->istate_lock);
2663 	}
2664 
2665 	return IMMEDIATE_DATA_NORMAL_OPERATION;
2666 }
2667 
2668 /*
2669  *	Called with sess->conn_lock held.
2670  */
2671 /* #warning iscsi_build_conn_drop_async_message() only sends out on connections
2672 	with active network interface */
2673 static void iscsit_build_conn_drop_async_message(struct iscsi_conn *conn)
2674 {
2675 	struct iscsi_cmd *cmd;
2676 	struct iscsi_conn *conn_p;
2677 	bool found = false;
2678 
2679 	/*
2680 	 * Only send a Asynchronous Message on connections whos network
2681 	 * interface is still functional.
2682 	 */
2683 	list_for_each_entry(conn_p, &conn->sess->sess_conn_list, conn_list) {
2684 		if (conn_p->conn_state == TARG_CONN_STATE_LOGGED_IN) {
2685 			iscsit_inc_conn_usage_count(conn_p);
2686 			found = true;
2687 			break;
2688 		}
2689 	}
2690 
2691 	if (!found)
2692 		return;
2693 
2694 	cmd = iscsit_allocate_cmd(conn_p, TASK_RUNNING);
2695 	if (!cmd) {
2696 		iscsit_dec_conn_usage_count(conn_p);
2697 		return;
2698 	}
2699 
2700 	cmd->logout_cid = conn->cid;
2701 	cmd->iscsi_opcode = ISCSI_OP_ASYNC_EVENT;
2702 	cmd->i_state = ISTATE_SEND_ASYNCMSG;
2703 
2704 	spin_lock_bh(&conn_p->cmd_lock);
2705 	list_add_tail(&cmd->i_conn_node, &conn_p->conn_cmd_list);
2706 	spin_unlock_bh(&conn_p->cmd_lock);
2707 
2708 	iscsit_add_cmd_to_response_queue(cmd, conn_p, cmd->i_state);
2709 	iscsit_dec_conn_usage_count(conn_p);
2710 }
2711 
2712 static int iscsit_send_conn_drop_async_message(
2713 	struct iscsi_cmd *cmd,
2714 	struct iscsi_conn *conn)
2715 {
2716 	struct iscsi_async *hdr;
2717 
2718 	cmd->iscsi_opcode = ISCSI_OP_ASYNC_EVENT;
2719 
2720 	hdr			= (struct iscsi_async *) cmd->pdu;
2721 	hdr->opcode		= ISCSI_OP_ASYNC_EVENT;
2722 	hdr->flags		= ISCSI_FLAG_CMD_FINAL;
2723 	cmd->init_task_tag	= RESERVED_ITT;
2724 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2725 	put_unaligned_be64(0xFFFFFFFFFFFFFFFFULL, &hdr->rsvd4[0]);
2726 	cmd->stat_sn		= conn->stat_sn++;
2727 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2728 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2729 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2730 	hdr->async_event	= ISCSI_ASYNC_MSG_DROPPING_CONNECTION;
2731 	hdr->param1		= cpu_to_be16(cmd->logout_cid);
2732 	hdr->param2		= cpu_to_be16(conn->sess->sess_ops->DefaultTime2Wait);
2733 	hdr->param3		= cpu_to_be16(conn->sess->sess_ops->DefaultTime2Retain);
2734 
2735 	pr_debug("Sending Connection Dropped Async Message StatSN:"
2736 		" 0x%08x, for CID: %hu on CID: %hu\n", cmd->stat_sn,
2737 			cmd->logout_cid, conn->cid);
2738 
2739 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
2740 }
2741 
2742 static void iscsit_tx_thread_wait_for_tcp(struct iscsi_conn *conn)
2743 {
2744 	if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) ||
2745 	    (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) {
2746 		wait_for_completion_interruptible_timeout(
2747 					&conn->tx_half_close_comp,
2748 					ISCSI_TX_THREAD_TCP_TIMEOUT * HZ);
2749 	}
2750 }
2751 
2752 void
2753 iscsit_build_datain_pdu(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2754 			struct iscsi_datain *datain, struct iscsi_data_rsp *hdr,
2755 			bool set_statsn)
2756 {
2757 	hdr->opcode		= ISCSI_OP_SCSI_DATA_IN;
2758 	hdr->flags		= datain->flags;
2759 	if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
2760 		if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
2761 			hdr->flags |= ISCSI_FLAG_DATA_OVERFLOW;
2762 			hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
2763 		} else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
2764 			hdr->flags |= ISCSI_FLAG_DATA_UNDERFLOW;
2765 			hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
2766 		}
2767 	}
2768 	hton24(hdr->dlength, datain->length);
2769 	if (hdr->flags & ISCSI_FLAG_DATA_ACK)
2770 		int_to_scsilun(cmd->se_cmd.orig_fe_lun,
2771 				(struct scsi_lun *)&hdr->lun);
2772 	else
2773 		put_unaligned_le64(0xFFFFFFFFFFFFFFFFULL, &hdr->lun);
2774 
2775 	hdr->itt		= cmd->init_task_tag;
2776 
2777 	if (hdr->flags & ISCSI_FLAG_DATA_ACK)
2778 		hdr->ttt		= cpu_to_be32(cmd->targ_xfer_tag);
2779 	else
2780 		hdr->ttt		= cpu_to_be32(0xFFFFFFFF);
2781 	if (set_statsn)
2782 		hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2783 	else
2784 		hdr->statsn		= cpu_to_be32(0xFFFFFFFF);
2785 
2786 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2787 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2788 	hdr->datasn		= cpu_to_be32(datain->data_sn);
2789 	hdr->offset		= cpu_to_be32(datain->offset);
2790 
2791 	pr_debug("Built DataIN ITT: 0x%08x, StatSN: 0x%08x,"
2792 		" DataSN: 0x%08x, Offset: %u, Length: %u, CID: %hu\n",
2793 		cmd->init_task_tag, ntohl(hdr->statsn), ntohl(hdr->datasn),
2794 		ntohl(hdr->offset), datain->length, conn->cid);
2795 }
2796 EXPORT_SYMBOL(iscsit_build_datain_pdu);
2797 
2798 static int iscsit_send_datain(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2799 {
2800 	struct iscsi_data_rsp *hdr = (struct iscsi_data_rsp *)&cmd->pdu[0];
2801 	struct iscsi_datain datain;
2802 	struct iscsi_datain_req *dr;
2803 	int eodr = 0, ret;
2804 	bool set_statsn = false;
2805 
2806 	memset(&datain, 0, sizeof(struct iscsi_datain));
2807 	dr = iscsit_get_datain_values(cmd, &datain);
2808 	if (!dr) {
2809 		pr_err("iscsit_get_datain_values failed for ITT: 0x%08x\n",
2810 				cmd->init_task_tag);
2811 		return -1;
2812 	}
2813 	/*
2814 	 * Be paranoid and double check the logic for now.
2815 	 */
2816 	if ((datain.offset + datain.length) > cmd->se_cmd.data_length) {
2817 		pr_err("Command ITT: 0x%08x, datain.offset: %u and"
2818 			" datain.length: %u exceeds cmd->data_length: %u\n",
2819 			cmd->init_task_tag, datain.offset, datain.length,
2820 			cmd->se_cmd.data_length);
2821 		return -1;
2822 	}
2823 
2824 	atomic_long_add(datain.length, &conn->sess->tx_data_octets);
2825 	/*
2826 	 * Special case for successfully execution w/ both DATAIN
2827 	 * and Sense Data.
2828 	 */
2829 	if ((datain.flags & ISCSI_FLAG_DATA_STATUS) &&
2830 	    (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE))
2831 		datain.flags &= ~ISCSI_FLAG_DATA_STATUS;
2832 	else {
2833 		if ((dr->dr_complete == DATAIN_COMPLETE_NORMAL) ||
2834 		    (dr->dr_complete == DATAIN_COMPLETE_CONNECTION_RECOVERY)) {
2835 			iscsit_increment_maxcmdsn(cmd, conn->sess);
2836 			cmd->stat_sn = conn->stat_sn++;
2837 			set_statsn = true;
2838 		} else if (dr->dr_complete ==
2839 			   DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY)
2840 			set_statsn = true;
2841 	}
2842 
2843 	iscsit_build_datain_pdu(cmd, conn, &datain, hdr, set_statsn);
2844 
2845 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, dr, &datain, 0);
2846 	if (ret < 0)
2847 		return ret;
2848 
2849 	if (dr->dr_complete) {
2850 		eodr = (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ?
2851 				2 : 1;
2852 		iscsit_free_datain_req(cmd, dr);
2853 	}
2854 
2855 	return eodr;
2856 }
2857 
2858 int
2859 iscsit_build_logout_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2860 			struct iscsi_logout_rsp *hdr)
2861 {
2862 	struct iscsi_conn *logout_conn = NULL;
2863 	struct iscsi_conn_recovery *cr = NULL;
2864 	struct iscsi_session *sess = conn->sess;
2865 	/*
2866 	 * The actual shutting down of Sessions and/or Connections
2867 	 * for CLOSESESSION and CLOSECONNECTION Logout Requests
2868 	 * is done in scsi_logout_post_handler().
2869 	 */
2870 	switch (cmd->logout_reason) {
2871 	case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
2872 		pr_debug("iSCSI session logout successful, setting"
2873 			" logout response to ISCSI_LOGOUT_SUCCESS.\n");
2874 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2875 		break;
2876 	case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
2877 		if (cmd->logout_response == ISCSI_LOGOUT_CID_NOT_FOUND)
2878 			break;
2879 		/*
2880 		 * For CLOSECONNECTION logout requests carrying
2881 		 * a matching logout CID -> local CID, the reference
2882 		 * for the local CID will have been incremented in
2883 		 * iscsi_logout_closeconnection().
2884 		 *
2885 		 * For CLOSECONNECTION logout requests carrying
2886 		 * a different CID than the connection it arrived
2887 		 * on, the connection responding to cmd->logout_cid
2888 		 * is stopped in iscsit_logout_post_handler_diffcid().
2889 		 */
2890 
2891 		pr_debug("iSCSI CID: %hu logout on CID: %hu"
2892 			" successful.\n", cmd->logout_cid, conn->cid);
2893 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2894 		break;
2895 	case ISCSI_LOGOUT_REASON_RECOVERY:
2896 		if ((cmd->logout_response == ISCSI_LOGOUT_RECOVERY_UNSUPPORTED) ||
2897 		    (cmd->logout_response == ISCSI_LOGOUT_CLEANUP_FAILED))
2898 			break;
2899 		/*
2900 		 * If the connection is still active from our point of view
2901 		 * force connection recovery to occur.
2902 		 */
2903 		logout_conn = iscsit_get_conn_from_cid_rcfr(sess,
2904 				cmd->logout_cid);
2905 		if (logout_conn) {
2906 			iscsit_connection_reinstatement_rcfr(logout_conn);
2907 			iscsit_dec_conn_usage_count(logout_conn);
2908 		}
2909 
2910 		cr = iscsit_get_inactive_connection_recovery_entry(
2911 				conn->sess, cmd->logout_cid);
2912 		if (!cr) {
2913 			pr_err("Unable to locate CID: %hu for"
2914 			" REMOVECONNFORRECOVERY Logout Request.\n",
2915 				cmd->logout_cid);
2916 			cmd->logout_response = ISCSI_LOGOUT_CID_NOT_FOUND;
2917 			break;
2918 		}
2919 
2920 		iscsit_discard_cr_cmds_by_expstatsn(cr, cmd->exp_stat_sn);
2921 
2922 		pr_debug("iSCSI REMOVECONNFORRECOVERY logout"
2923 			" for recovery for CID: %hu on CID: %hu successful.\n",
2924 				cmd->logout_cid, conn->cid);
2925 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2926 		break;
2927 	default:
2928 		pr_err("Unknown cmd->logout_reason: 0x%02x\n",
2929 				cmd->logout_reason);
2930 		return -1;
2931 	}
2932 
2933 	hdr->opcode		= ISCSI_OP_LOGOUT_RSP;
2934 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
2935 	hdr->response		= cmd->logout_response;
2936 	hdr->itt		= cmd->init_task_tag;
2937 	cmd->stat_sn		= conn->stat_sn++;
2938 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2939 
2940 	iscsit_increment_maxcmdsn(cmd, conn->sess);
2941 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2942 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2943 
2944 	pr_debug("Built Logout Response ITT: 0x%08x StatSN:"
2945 		" 0x%08x Response: 0x%02x CID: %hu on CID: %hu\n",
2946 		cmd->init_task_tag, cmd->stat_sn, hdr->response,
2947 		cmd->logout_cid, conn->cid);
2948 
2949 	return 0;
2950 }
2951 EXPORT_SYMBOL(iscsit_build_logout_rsp);
2952 
2953 static int
2954 iscsit_send_logout(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2955 {
2956 	int rc;
2957 
2958 	rc = iscsit_build_logout_rsp(cmd, conn,
2959 			(struct iscsi_logout_rsp *)&cmd->pdu[0]);
2960 	if (rc < 0)
2961 		return rc;
2962 
2963 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
2964 }
2965 
2966 void
2967 iscsit_build_nopin_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2968 		       struct iscsi_nopin *hdr, bool nopout_response)
2969 {
2970 	hdr->opcode		= ISCSI_OP_NOOP_IN;
2971 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
2972         hton24(hdr->dlength, cmd->buf_ptr_size);
2973 	if (nopout_response)
2974 		put_unaligned_le64(0xFFFFFFFFFFFFFFFFULL, &hdr->lun);
2975 	hdr->itt		= cmd->init_task_tag;
2976 	hdr->ttt		= cpu_to_be32(cmd->targ_xfer_tag);
2977 	cmd->stat_sn		= (nopout_response) ? conn->stat_sn++ :
2978 				  conn->stat_sn;
2979 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2980 
2981 	if (nopout_response)
2982 		iscsit_increment_maxcmdsn(cmd, conn->sess);
2983 
2984 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2985 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2986 
2987 	pr_debug("Built NOPIN %s Response ITT: 0x%08x, TTT: 0x%08x,"
2988 		" StatSN: 0x%08x, Length %u\n", (nopout_response) ?
2989 		"Solicited" : "Unsolicited", cmd->init_task_tag,
2990 		cmd->targ_xfer_tag, cmd->stat_sn, cmd->buf_ptr_size);
2991 }
2992 EXPORT_SYMBOL(iscsit_build_nopin_rsp);
2993 
2994 /*
2995  *	Unsolicited NOPIN, either requesting a response or not.
2996  */
2997 static int iscsit_send_unsolicited_nopin(
2998 	struct iscsi_cmd *cmd,
2999 	struct iscsi_conn *conn,
3000 	int want_response)
3001 {
3002 	struct iscsi_nopin *hdr = (struct iscsi_nopin *)&cmd->pdu[0];
3003 	int ret;
3004 
3005 	iscsit_build_nopin_rsp(cmd, conn, hdr, false);
3006 
3007 	pr_debug("Sending Unsolicited NOPIN TTT: 0x%08x StatSN:"
3008 		" 0x%08x CID: %hu\n", hdr->ttt, cmd->stat_sn, conn->cid);
3009 
3010 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3011 	if (ret < 0)
3012 		return ret;
3013 
3014 	spin_lock_bh(&cmd->istate_lock);
3015 	cmd->i_state = want_response ?
3016 		ISTATE_SENT_NOPIN_WANT_RESPONSE : ISTATE_SENT_STATUS;
3017 	spin_unlock_bh(&cmd->istate_lock);
3018 
3019 	return 0;
3020 }
3021 
3022 static int
3023 iscsit_send_nopin(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3024 {
3025 	struct iscsi_nopin *hdr = (struct iscsi_nopin *)&cmd->pdu[0];
3026 
3027 	iscsit_build_nopin_rsp(cmd, conn, hdr, true);
3028 
3029 	/*
3030 	 * NOPOUT Ping Data is attached to struct iscsi_cmd->buf_ptr.
3031 	 * NOPOUT DataSegmentLength is at struct iscsi_cmd->buf_ptr_size.
3032 	 */
3033 	pr_debug("Echoing back %u bytes of ping data.\n", cmd->buf_ptr_size);
3034 
3035 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3036 						     cmd->buf_ptr,
3037 						     cmd->buf_ptr_size);
3038 }
3039 
3040 static int iscsit_send_r2t(
3041 	struct iscsi_cmd *cmd,
3042 	struct iscsi_conn *conn)
3043 {
3044 	struct iscsi_r2t *r2t;
3045 	struct iscsi_r2t_rsp *hdr;
3046 	int ret;
3047 
3048 	r2t = iscsit_get_r2t_from_list(cmd);
3049 	if (!r2t)
3050 		return -1;
3051 
3052 	hdr			= (struct iscsi_r2t_rsp *) cmd->pdu;
3053 	memset(hdr, 0, ISCSI_HDR_LEN);
3054 	hdr->opcode		= ISCSI_OP_R2T;
3055 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3056 	int_to_scsilun(cmd->se_cmd.orig_fe_lun,
3057 			(struct scsi_lun *)&hdr->lun);
3058 	hdr->itt		= cmd->init_task_tag;
3059 	if (conn->conn_transport->iscsit_get_r2t_ttt)
3060 		conn->conn_transport->iscsit_get_r2t_ttt(conn, cmd, r2t);
3061 	else
3062 		r2t->targ_xfer_tag = session_get_next_ttt(conn->sess);
3063 	hdr->ttt		= cpu_to_be32(r2t->targ_xfer_tag);
3064 	hdr->statsn		= cpu_to_be32(conn->stat_sn);
3065 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3066 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3067 	hdr->r2tsn		= cpu_to_be32(r2t->r2t_sn);
3068 	hdr->data_offset	= cpu_to_be32(r2t->offset);
3069 	hdr->data_length	= cpu_to_be32(r2t->xfer_len);
3070 
3071 	pr_debug("Built %sR2T, ITT: 0x%08x, TTT: 0x%08x, StatSN:"
3072 		" 0x%08x, R2TSN: 0x%08x, Offset: %u, DDTL: %u, CID: %hu\n",
3073 		(!r2t->recovery_r2t) ? "" : "Recovery ", cmd->init_task_tag,
3074 		r2t->targ_xfer_tag, ntohl(hdr->statsn), r2t->r2t_sn,
3075 			r2t->offset, r2t->xfer_len, conn->cid);
3076 
3077 	spin_lock_bh(&cmd->r2t_lock);
3078 	r2t->sent_r2t = 1;
3079 	spin_unlock_bh(&cmd->r2t_lock);
3080 
3081 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3082 	if (ret < 0) {
3083 		return ret;
3084 	}
3085 
3086 	spin_lock_bh(&cmd->dataout_timeout_lock);
3087 	iscsit_start_dataout_timer(cmd, conn);
3088 	spin_unlock_bh(&cmd->dataout_timeout_lock);
3089 
3090 	return 0;
3091 }
3092 
3093 /*
3094  *	@recovery: If called from iscsi_task_reassign_complete_write() for
3095  *		connection recovery.
3096  */
3097 int iscsit_build_r2ts_for_cmd(
3098 	struct iscsi_conn *conn,
3099 	struct iscsi_cmd *cmd,
3100 	bool recovery)
3101 {
3102 	int first_r2t = 1;
3103 	u32 offset = 0, xfer_len = 0;
3104 
3105 	spin_lock_bh(&cmd->r2t_lock);
3106 	if (cmd->cmd_flags & ICF_SENT_LAST_R2T) {
3107 		spin_unlock_bh(&cmd->r2t_lock);
3108 		return 0;
3109 	}
3110 
3111 	if (conn->sess->sess_ops->DataSequenceInOrder &&
3112 	    !recovery)
3113 		cmd->r2t_offset = max(cmd->r2t_offset, cmd->write_data_done);
3114 
3115 	while (cmd->outstanding_r2ts < conn->sess->sess_ops->MaxOutstandingR2T) {
3116 		if (conn->sess->sess_ops->DataSequenceInOrder) {
3117 			offset = cmd->r2t_offset;
3118 
3119 			if (first_r2t && recovery) {
3120 				int new_data_end = offset +
3121 					conn->sess->sess_ops->MaxBurstLength -
3122 					cmd->next_burst_len;
3123 
3124 				if (new_data_end > cmd->se_cmd.data_length)
3125 					xfer_len = cmd->se_cmd.data_length - offset;
3126 				else
3127 					xfer_len =
3128 						conn->sess->sess_ops->MaxBurstLength -
3129 						cmd->next_burst_len;
3130 			} else {
3131 				int new_data_end = offset +
3132 					conn->sess->sess_ops->MaxBurstLength;
3133 
3134 				if (new_data_end > cmd->se_cmd.data_length)
3135 					xfer_len = cmd->se_cmd.data_length - offset;
3136 				else
3137 					xfer_len = conn->sess->sess_ops->MaxBurstLength;
3138 			}
3139 			cmd->r2t_offset += xfer_len;
3140 
3141 			if (cmd->r2t_offset == cmd->se_cmd.data_length)
3142 				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
3143 		} else {
3144 			struct iscsi_seq *seq;
3145 
3146 			seq = iscsit_get_seq_holder_for_r2t(cmd);
3147 			if (!seq) {
3148 				spin_unlock_bh(&cmd->r2t_lock);
3149 				return -1;
3150 			}
3151 
3152 			offset = seq->offset;
3153 			xfer_len = seq->xfer_len;
3154 
3155 			if (cmd->seq_send_order == cmd->seq_count)
3156 				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
3157 		}
3158 		cmd->outstanding_r2ts++;
3159 		first_r2t = 0;
3160 
3161 		if (iscsit_add_r2t_to_list(cmd, offset, xfer_len, 0, 0) < 0) {
3162 			spin_unlock_bh(&cmd->r2t_lock);
3163 			return -1;
3164 		}
3165 
3166 		if (cmd->cmd_flags & ICF_SENT_LAST_R2T)
3167 			break;
3168 	}
3169 	spin_unlock_bh(&cmd->r2t_lock);
3170 
3171 	return 0;
3172 }
3173 EXPORT_SYMBOL(iscsit_build_r2ts_for_cmd);
3174 
3175 void iscsit_build_rsp_pdu(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3176 			bool inc_stat_sn, struct iscsi_scsi_rsp *hdr)
3177 {
3178 	if (inc_stat_sn)
3179 		cmd->stat_sn = conn->stat_sn++;
3180 
3181 	atomic_long_inc(&conn->sess->rsp_pdus);
3182 
3183 	memset(hdr, 0, ISCSI_HDR_LEN);
3184 	hdr->opcode		= ISCSI_OP_SCSI_CMD_RSP;
3185 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3186 	if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
3187 		hdr->flags |= ISCSI_FLAG_CMD_OVERFLOW;
3188 		hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
3189 	} else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
3190 		hdr->flags |= ISCSI_FLAG_CMD_UNDERFLOW;
3191 		hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
3192 	}
3193 	hdr->response		= cmd->iscsi_response;
3194 	hdr->cmd_status		= cmd->se_cmd.scsi_status;
3195 	hdr->itt		= cmd->init_task_tag;
3196 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3197 
3198 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3199 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3200 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3201 
3202 	pr_debug("Built SCSI Response, ITT: 0x%08x, StatSN: 0x%08x,"
3203 		" Response: 0x%02x, SAM Status: 0x%02x, CID: %hu\n",
3204 		cmd->init_task_tag, cmd->stat_sn, cmd->se_cmd.scsi_status,
3205 		cmd->se_cmd.scsi_status, conn->cid);
3206 }
3207 EXPORT_SYMBOL(iscsit_build_rsp_pdu);
3208 
3209 static int iscsit_send_response(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3210 {
3211 	struct iscsi_scsi_rsp *hdr = (struct iscsi_scsi_rsp *)&cmd->pdu[0];
3212 	bool inc_stat_sn = (cmd->i_state == ISTATE_SEND_STATUS);
3213 	void *data_buf = NULL;
3214 	u32 padding = 0, data_buf_len = 0;
3215 
3216 	iscsit_build_rsp_pdu(cmd, conn, inc_stat_sn, hdr);
3217 
3218 	/*
3219 	 * Attach SENSE DATA payload to iSCSI Response PDU
3220 	 */
3221 	if (cmd->se_cmd.sense_buffer &&
3222 	   ((cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
3223 	    (cmd->se_cmd.se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
3224 		put_unaligned_be16(cmd->se_cmd.scsi_sense_length, cmd->sense_buffer);
3225 		cmd->se_cmd.scsi_sense_length += sizeof (__be16);
3226 
3227 		padding		= -(cmd->se_cmd.scsi_sense_length) & 3;
3228 		hton24(hdr->dlength, (u32)cmd->se_cmd.scsi_sense_length);
3229 		data_buf = cmd->sense_buffer;
3230 		data_buf_len = cmd->se_cmd.scsi_sense_length + padding;
3231 
3232 		if (padding) {
3233 			memset(cmd->sense_buffer +
3234 				cmd->se_cmd.scsi_sense_length, 0, padding);
3235 			pr_debug("Adding %u bytes of padding to"
3236 				" SENSE.\n", padding);
3237 		}
3238 
3239 		pr_debug("Attaching SENSE DATA: %u bytes to iSCSI"
3240 				" Response PDU\n",
3241 				cmd->se_cmd.scsi_sense_length);
3242 	}
3243 
3244 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, data_buf,
3245 						     data_buf_len);
3246 }
3247 
3248 static u8 iscsit_convert_tcm_tmr_rsp(struct se_tmr_req *se_tmr)
3249 {
3250 	switch (se_tmr->response) {
3251 	case TMR_FUNCTION_COMPLETE:
3252 		return ISCSI_TMF_RSP_COMPLETE;
3253 	case TMR_TASK_DOES_NOT_EXIST:
3254 		return ISCSI_TMF_RSP_NO_TASK;
3255 	case TMR_LUN_DOES_NOT_EXIST:
3256 		return ISCSI_TMF_RSP_NO_LUN;
3257 	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
3258 		return ISCSI_TMF_RSP_NOT_SUPPORTED;
3259 	case TMR_FUNCTION_REJECTED:
3260 	default:
3261 		return ISCSI_TMF_RSP_REJECTED;
3262 	}
3263 }
3264 
3265 void
3266 iscsit_build_task_mgt_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3267 			  struct iscsi_tm_rsp *hdr)
3268 {
3269 	struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req;
3270 
3271 	hdr->opcode		= ISCSI_OP_SCSI_TMFUNC_RSP;
3272 	hdr->flags		= ISCSI_FLAG_CMD_FINAL;
3273 	hdr->response		= iscsit_convert_tcm_tmr_rsp(se_tmr);
3274 	hdr->itt		= cmd->init_task_tag;
3275 	cmd->stat_sn		= conn->stat_sn++;
3276 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3277 
3278 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3279 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3280 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3281 
3282 	pr_debug("Built Task Management Response ITT: 0x%08x,"
3283 		" StatSN: 0x%08x, Response: 0x%02x, CID: %hu\n",
3284 		cmd->init_task_tag, cmd->stat_sn, hdr->response, conn->cid);
3285 }
3286 EXPORT_SYMBOL(iscsit_build_task_mgt_rsp);
3287 
3288 static int
3289 iscsit_send_task_mgt_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3290 {
3291 	struct iscsi_tm_rsp *hdr = (struct iscsi_tm_rsp *)&cmd->pdu[0];
3292 
3293 	iscsit_build_task_mgt_rsp(cmd, conn, hdr);
3294 
3295 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3296 }
3297 
3298 static bool iscsit_check_inaddr_any(struct iscsi_np *np)
3299 {
3300 	bool ret = false;
3301 
3302 	if (np->np_sockaddr.ss_family == AF_INET6) {
3303 		const struct sockaddr_in6 sin6 = {
3304 			.sin6_addr = IN6ADDR_ANY_INIT };
3305 		struct sockaddr_in6 *sock_in6 =
3306 			 (struct sockaddr_in6 *)&np->np_sockaddr;
3307 
3308 		if (!memcmp(sock_in6->sin6_addr.s6_addr,
3309 				sin6.sin6_addr.s6_addr, 16))
3310 			ret = true;
3311 	} else {
3312 		struct sockaddr_in * sock_in =
3313 			(struct sockaddr_in *)&np->np_sockaddr;
3314 
3315 		if (sock_in->sin_addr.s_addr == htonl(INADDR_ANY))
3316 			ret = true;
3317 	}
3318 
3319 	return ret;
3320 }
3321 
3322 #define SENDTARGETS_BUF_LIMIT 32768U
3323 
3324 static int
3325 iscsit_build_sendtargets_response(struct iscsi_cmd *cmd,
3326 				  enum iscsit_transport_type network_transport,
3327 				  int skip_bytes, bool *completed)
3328 {
3329 	char *payload = NULL;
3330 	struct iscsi_conn *conn = cmd->conn;
3331 	struct iscsi_portal_group *tpg;
3332 	struct iscsi_tiqn *tiqn;
3333 	struct iscsi_tpg_np *tpg_np;
3334 	int buffer_len, end_of_buf = 0, len = 0, payload_len = 0;
3335 	int target_name_printed;
3336 	unsigned char buf[ISCSI_IQN_LEN+12]; /* iqn + "TargetName=" + \0 */
3337 	unsigned char *text_in = cmd->text_in_ptr, *text_ptr = NULL;
3338 	bool active;
3339 
3340 	buffer_len = min(conn->conn_ops->MaxRecvDataSegmentLength,
3341 			 SENDTARGETS_BUF_LIMIT);
3342 
3343 	payload = kzalloc(buffer_len, GFP_KERNEL);
3344 	if (!payload)
3345 		return -ENOMEM;
3346 
3347 	/*
3348 	 * Locate pointer to iqn./eui. string for ICF_SENDTARGETS_SINGLE
3349 	 * explicit case..
3350 	 */
3351 	if (cmd->cmd_flags & ICF_SENDTARGETS_SINGLE) {
3352 		text_ptr = strchr(text_in, '=');
3353 		if (!text_ptr) {
3354 			pr_err("Unable to locate '=' string in text_in:"
3355 			       " %s\n", text_in);
3356 			kfree(payload);
3357 			return -EINVAL;
3358 		}
3359 		/*
3360 		 * Skip over '=' character..
3361 		 */
3362 		text_ptr += 1;
3363 	}
3364 
3365 	spin_lock(&tiqn_lock);
3366 	list_for_each_entry(tiqn, &g_tiqn_list, tiqn_list) {
3367 		if ((cmd->cmd_flags & ICF_SENDTARGETS_SINGLE) &&
3368 		     strcmp(tiqn->tiqn, text_ptr)) {
3369 			continue;
3370 		}
3371 
3372 		target_name_printed = 0;
3373 
3374 		spin_lock(&tiqn->tiqn_tpg_lock);
3375 		list_for_each_entry(tpg, &tiqn->tiqn_tpg_list, tpg_list) {
3376 
3377 			/* If demo_mode_discovery=0 and generate_node_acls=0
3378 			 * (demo mode dislabed) do not return
3379 			 * TargetName+TargetAddress unless a NodeACL exists.
3380 			 */
3381 
3382 			if ((tpg->tpg_attrib.generate_node_acls == 0) &&
3383 			    (tpg->tpg_attrib.demo_mode_discovery == 0) &&
3384 			    (!target_tpg_has_node_acl(&tpg->tpg_se_tpg,
3385 				cmd->conn->sess->sess_ops->InitiatorName))) {
3386 				continue;
3387 			}
3388 
3389 			spin_lock(&tpg->tpg_state_lock);
3390 			active = (tpg->tpg_state == TPG_STATE_ACTIVE);
3391 			spin_unlock(&tpg->tpg_state_lock);
3392 
3393 			if (!active && tpg->tpg_attrib.tpg_enabled_sendtargets)
3394 				continue;
3395 
3396 			spin_lock(&tpg->tpg_np_lock);
3397 			list_for_each_entry(tpg_np, &tpg->tpg_gnp_list,
3398 						tpg_np_list) {
3399 				struct iscsi_np *np = tpg_np->tpg_np;
3400 				bool inaddr_any = iscsit_check_inaddr_any(np);
3401 				struct sockaddr_storage *sockaddr;
3402 
3403 				if (np->np_network_transport != network_transport)
3404 					continue;
3405 
3406 				if (!target_name_printed) {
3407 					len = sprintf(buf, "TargetName=%s",
3408 						      tiqn->tiqn);
3409 					len += 1;
3410 
3411 					if ((len + payload_len) > buffer_len) {
3412 						spin_unlock(&tpg->tpg_np_lock);
3413 						spin_unlock(&tiqn->tiqn_tpg_lock);
3414 						end_of_buf = 1;
3415 						goto eob;
3416 					}
3417 
3418 					if (skip_bytes && len <= skip_bytes) {
3419 						skip_bytes -= len;
3420 					} else {
3421 						memcpy(payload + payload_len, buf, len);
3422 						payload_len += len;
3423 						target_name_printed = 1;
3424 						if (len > skip_bytes)
3425 							skip_bytes = 0;
3426 					}
3427 				}
3428 
3429 				if (inaddr_any)
3430 					sockaddr = &conn->local_sockaddr;
3431 				else
3432 					sockaddr = &np->np_sockaddr;
3433 
3434 				len = sprintf(buf, "TargetAddress="
3435 					      "%pISpc,%hu",
3436 					      sockaddr,
3437 					      tpg->tpgt);
3438 				len += 1;
3439 
3440 				if ((len + payload_len) > buffer_len) {
3441 					spin_unlock(&tpg->tpg_np_lock);
3442 					spin_unlock(&tiqn->tiqn_tpg_lock);
3443 					end_of_buf = 1;
3444 					goto eob;
3445 				}
3446 
3447 				if (skip_bytes && len <= skip_bytes) {
3448 					skip_bytes -= len;
3449 				} else {
3450 					memcpy(payload + payload_len, buf, len);
3451 					payload_len += len;
3452 					if (len > skip_bytes)
3453 						skip_bytes = 0;
3454 				}
3455 			}
3456 			spin_unlock(&tpg->tpg_np_lock);
3457 		}
3458 		spin_unlock(&tiqn->tiqn_tpg_lock);
3459 eob:
3460 		if (end_of_buf) {
3461 			*completed = false;
3462 			break;
3463 		}
3464 
3465 		if (cmd->cmd_flags & ICF_SENDTARGETS_SINGLE)
3466 			break;
3467 	}
3468 	spin_unlock(&tiqn_lock);
3469 
3470 	cmd->buf_ptr = payload;
3471 
3472 	return payload_len;
3473 }
3474 
3475 int
3476 iscsit_build_text_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3477 		      struct iscsi_text_rsp *hdr,
3478 		      enum iscsit_transport_type network_transport)
3479 {
3480 	int text_length, padding;
3481 	bool completed = true;
3482 
3483 	text_length = iscsit_build_sendtargets_response(cmd, network_transport,
3484 							cmd->read_data_done,
3485 							&completed);
3486 	if (text_length < 0)
3487 		return text_length;
3488 
3489 	if (completed) {
3490 		hdr->flags |= ISCSI_FLAG_CMD_FINAL;
3491 	} else {
3492 		hdr->flags |= ISCSI_FLAG_TEXT_CONTINUE;
3493 		cmd->read_data_done += text_length;
3494 		if (cmd->targ_xfer_tag == 0xFFFFFFFF)
3495 			cmd->targ_xfer_tag = session_get_next_ttt(conn->sess);
3496 	}
3497 	hdr->opcode = ISCSI_OP_TEXT_RSP;
3498 	padding = ((-text_length) & 3);
3499 	hton24(hdr->dlength, text_length);
3500 	hdr->itt = cmd->init_task_tag;
3501 	hdr->ttt = cpu_to_be32(cmd->targ_xfer_tag);
3502 	cmd->stat_sn = conn->stat_sn++;
3503 	hdr->statsn = cpu_to_be32(cmd->stat_sn);
3504 
3505 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3506 	/*
3507 	 * Reset maxcmdsn_inc in multi-part text payload exchanges to
3508 	 * correctly increment MaxCmdSN for each response answering a
3509 	 * non immediate text request with a valid CmdSN.
3510 	 */
3511 	cmd->maxcmdsn_inc = 0;
3512 	hdr->exp_cmdsn = cpu_to_be32(conn->sess->exp_cmd_sn);
3513 	hdr->max_cmdsn = cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3514 
3515 	pr_debug("Built Text Response: ITT: 0x%08x, TTT: 0x%08x, StatSN: 0x%08x,"
3516 		" Length: %u, CID: %hu F: %d C: %d\n", cmd->init_task_tag,
3517 		cmd->targ_xfer_tag, cmd->stat_sn, text_length, conn->cid,
3518 		!!(hdr->flags & ISCSI_FLAG_CMD_FINAL),
3519 		!!(hdr->flags & ISCSI_FLAG_TEXT_CONTINUE));
3520 
3521 	return text_length + padding;
3522 }
3523 EXPORT_SYMBOL(iscsit_build_text_rsp);
3524 
3525 static int iscsit_send_text_rsp(
3526 	struct iscsi_cmd *cmd,
3527 	struct iscsi_conn *conn)
3528 {
3529 	struct iscsi_text_rsp *hdr = (struct iscsi_text_rsp *)cmd->pdu;
3530 	int text_length;
3531 
3532 	text_length = iscsit_build_text_rsp(cmd, conn, hdr,
3533 				conn->conn_transport->transport_type);
3534 	if (text_length < 0)
3535 		return text_length;
3536 
3537 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3538 						     cmd->buf_ptr,
3539 						     text_length);
3540 }
3541 
3542 void
3543 iscsit_build_reject(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3544 		    struct iscsi_reject *hdr)
3545 {
3546 	hdr->opcode		= ISCSI_OP_REJECT;
3547 	hdr->reason		= cmd->reject_reason;
3548 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3549 	hton24(hdr->dlength, ISCSI_HDR_LEN);
3550 	hdr->ffffffff		= cpu_to_be32(0xffffffff);
3551 	cmd->stat_sn		= conn->stat_sn++;
3552 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3553 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3554 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3555 
3556 }
3557 EXPORT_SYMBOL(iscsit_build_reject);
3558 
3559 static int iscsit_send_reject(
3560 	struct iscsi_cmd *cmd,
3561 	struct iscsi_conn *conn)
3562 {
3563 	struct iscsi_reject *hdr = (struct iscsi_reject *)&cmd->pdu[0];
3564 
3565 	iscsit_build_reject(cmd, conn, hdr);
3566 
3567 	pr_debug("Built Reject PDU StatSN: 0x%08x, Reason: 0x%02x,"
3568 		" CID: %hu\n", ntohl(hdr->statsn), hdr->reason, conn->cid);
3569 
3570 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3571 						     cmd->buf_ptr,
3572 						     ISCSI_HDR_LEN);
3573 }
3574 
3575 void iscsit_thread_get_cpumask(struct iscsi_conn *conn)
3576 {
3577 	int ord, cpu;
3578 	/*
3579 	 * bitmap_id is assigned from iscsit_global->ts_bitmap from
3580 	 * within iscsit_start_kthreads()
3581 	 *
3582 	 * Here we use bitmap_id to determine which CPU that this
3583 	 * iSCSI connection's RX/TX threads will be scheduled to
3584 	 * execute upon.
3585 	 */
3586 	ord = conn->bitmap_id % cpumask_weight(cpu_online_mask);
3587 	for_each_online_cpu(cpu) {
3588 		if (ord-- == 0) {
3589 			cpumask_set_cpu(cpu, conn->conn_cpumask);
3590 			return;
3591 		}
3592 	}
3593 	/*
3594 	 * This should never be reached..
3595 	 */
3596 	dump_stack();
3597 	cpumask_setall(conn->conn_cpumask);
3598 }
3599 
3600 int
3601 iscsit_immediate_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
3602 {
3603 	int ret;
3604 
3605 	switch (state) {
3606 	case ISTATE_SEND_R2T:
3607 		ret = iscsit_send_r2t(cmd, conn);
3608 		if (ret < 0)
3609 			goto err;
3610 		break;
3611 	case ISTATE_REMOVE:
3612 		spin_lock_bh(&conn->cmd_lock);
3613 		list_del_init(&cmd->i_conn_node);
3614 		spin_unlock_bh(&conn->cmd_lock);
3615 
3616 		iscsit_free_cmd(cmd, false);
3617 		break;
3618 	case ISTATE_SEND_NOPIN_WANT_RESPONSE:
3619 		iscsit_mod_nopin_response_timer(conn);
3620 		ret = iscsit_send_unsolicited_nopin(cmd, conn, 1);
3621 		if (ret < 0)
3622 			goto err;
3623 		break;
3624 	case ISTATE_SEND_NOPIN_NO_RESPONSE:
3625 		ret = iscsit_send_unsolicited_nopin(cmd, conn, 0);
3626 		if (ret < 0)
3627 			goto err;
3628 		break;
3629 	default:
3630 		pr_err("Unknown Opcode: 0x%02x ITT:"
3631 		       " 0x%08x, i_state: %d on CID: %hu\n",
3632 		       cmd->iscsi_opcode, cmd->init_task_tag, state,
3633 		       conn->cid);
3634 		goto err;
3635 	}
3636 
3637 	return 0;
3638 
3639 err:
3640 	return -1;
3641 }
3642 EXPORT_SYMBOL(iscsit_immediate_queue);
3643 
3644 static int
3645 iscsit_handle_immediate_queue(struct iscsi_conn *conn)
3646 {
3647 	struct iscsit_transport *t = conn->conn_transport;
3648 	struct iscsi_queue_req *qr;
3649 	struct iscsi_cmd *cmd;
3650 	u8 state;
3651 	int ret;
3652 
3653 	while ((qr = iscsit_get_cmd_from_immediate_queue(conn))) {
3654 		atomic_set(&conn->check_immediate_queue, 0);
3655 		cmd = qr->cmd;
3656 		state = qr->state;
3657 		kmem_cache_free(lio_qr_cache, qr);
3658 
3659 		ret = t->iscsit_immediate_queue(conn, cmd, state);
3660 		if (ret < 0)
3661 			return ret;
3662 	}
3663 
3664 	return 0;
3665 }
3666 
3667 int
3668 iscsit_response_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
3669 {
3670 	int ret;
3671 
3672 check_rsp_state:
3673 	switch (state) {
3674 	case ISTATE_SEND_DATAIN:
3675 		ret = iscsit_send_datain(cmd, conn);
3676 		if (ret < 0)
3677 			goto err;
3678 		else if (!ret)
3679 			/* more drs */
3680 			goto check_rsp_state;
3681 		else if (ret == 1) {
3682 			/* all done */
3683 			spin_lock_bh(&cmd->istate_lock);
3684 			cmd->i_state = ISTATE_SENT_STATUS;
3685 			spin_unlock_bh(&cmd->istate_lock);
3686 
3687 			if (atomic_read(&conn->check_immediate_queue))
3688 				return 1;
3689 
3690 			return 0;
3691 		} else if (ret == 2) {
3692 			/* Still must send status,
3693 			   SCF_TRANSPORT_TASK_SENSE was set */
3694 			spin_lock_bh(&cmd->istate_lock);
3695 			cmd->i_state = ISTATE_SEND_STATUS;
3696 			spin_unlock_bh(&cmd->istate_lock);
3697 			state = ISTATE_SEND_STATUS;
3698 			goto check_rsp_state;
3699 		}
3700 
3701 		break;
3702 	case ISTATE_SEND_STATUS:
3703 	case ISTATE_SEND_STATUS_RECOVERY:
3704 		ret = iscsit_send_response(cmd, conn);
3705 		break;
3706 	case ISTATE_SEND_LOGOUTRSP:
3707 		ret = iscsit_send_logout(cmd, conn);
3708 		break;
3709 	case ISTATE_SEND_ASYNCMSG:
3710 		ret = iscsit_send_conn_drop_async_message(
3711 			cmd, conn);
3712 		break;
3713 	case ISTATE_SEND_NOPIN:
3714 		ret = iscsit_send_nopin(cmd, conn);
3715 		break;
3716 	case ISTATE_SEND_REJECT:
3717 		ret = iscsit_send_reject(cmd, conn);
3718 		break;
3719 	case ISTATE_SEND_TASKMGTRSP:
3720 		ret = iscsit_send_task_mgt_rsp(cmd, conn);
3721 		if (ret != 0)
3722 			break;
3723 		ret = iscsit_tmr_post_handler(cmd, conn);
3724 		if (ret != 0)
3725 			iscsit_fall_back_to_erl0(conn->sess);
3726 		break;
3727 	case ISTATE_SEND_TEXTRSP:
3728 		ret = iscsit_send_text_rsp(cmd, conn);
3729 		break;
3730 	default:
3731 		pr_err("Unknown Opcode: 0x%02x ITT:"
3732 		       " 0x%08x, i_state: %d on CID: %hu\n",
3733 		       cmd->iscsi_opcode, cmd->init_task_tag,
3734 		       state, conn->cid);
3735 		goto err;
3736 	}
3737 	if (ret < 0)
3738 		goto err;
3739 
3740 	switch (state) {
3741 	case ISTATE_SEND_LOGOUTRSP:
3742 		if (!iscsit_logout_post_handler(cmd, conn))
3743 			return -ECONNRESET;
3744 		/* fall through */
3745 	case ISTATE_SEND_STATUS:
3746 	case ISTATE_SEND_ASYNCMSG:
3747 	case ISTATE_SEND_NOPIN:
3748 	case ISTATE_SEND_STATUS_RECOVERY:
3749 	case ISTATE_SEND_TEXTRSP:
3750 	case ISTATE_SEND_TASKMGTRSP:
3751 	case ISTATE_SEND_REJECT:
3752 		spin_lock_bh(&cmd->istate_lock);
3753 		cmd->i_state = ISTATE_SENT_STATUS;
3754 		spin_unlock_bh(&cmd->istate_lock);
3755 		break;
3756 	default:
3757 		pr_err("Unknown Opcode: 0x%02x ITT:"
3758 		       " 0x%08x, i_state: %d on CID: %hu\n",
3759 		       cmd->iscsi_opcode, cmd->init_task_tag,
3760 		       cmd->i_state, conn->cid);
3761 		goto err;
3762 	}
3763 
3764 	if (atomic_read(&conn->check_immediate_queue))
3765 		return 1;
3766 
3767 	return 0;
3768 
3769 err:
3770 	return -1;
3771 }
3772 EXPORT_SYMBOL(iscsit_response_queue);
3773 
3774 static int iscsit_handle_response_queue(struct iscsi_conn *conn)
3775 {
3776 	struct iscsit_transport *t = conn->conn_transport;
3777 	struct iscsi_queue_req *qr;
3778 	struct iscsi_cmd *cmd;
3779 	u8 state;
3780 	int ret;
3781 
3782 	while ((qr = iscsit_get_cmd_from_response_queue(conn))) {
3783 		cmd = qr->cmd;
3784 		state = qr->state;
3785 		kmem_cache_free(lio_qr_cache, qr);
3786 
3787 		ret = t->iscsit_response_queue(conn, cmd, state);
3788 		if (ret == 1 || ret < 0)
3789 			return ret;
3790 	}
3791 
3792 	return 0;
3793 }
3794 
3795 int iscsi_target_tx_thread(void *arg)
3796 {
3797 	int ret = 0;
3798 	struct iscsi_conn *conn = arg;
3799 	bool conn_freed = false;
3800 
3801 	/*
3802 	 * Allow ourselves to be interrupted by SIGINT so that a
3803 	 * connection recovery / failure event can be triggered externally.
3804 	 */
3805 	allow_signal(SIGINT);
3806 
3807 	while (!kthread_should_stop()) {
3808 		/*
3809 		 * Ensure that both TX and RX per connection kthreads
3810 		 * are scheduled to run on the same CPU.
3811 		 */
3812 		iscsit_thread_check_cpumask(conn, current, 1);
3813 
3814 		wait_event_interruptible(conn->queues_wq,
3815 					 !iscsit_conn_all_queues_empty(conn));
3816 
3817 		if (signal_pending(current))
3818 			goto transport_err;
3819 
3820 get_immediate:
3821 		ret = iscsit_handle_immediate_queue(conn);
3822 		if (ret < 0)
3823 			goto transport_err;
3824 
3825 		ret = iscsit_handle_response_queue(conn);
3826 		if (ret == 1) {
3827 			goto get_immediate;
3828 		} else if (ret == -ECONNRESET) {
3829 			conn_freed = true;
3830 			goto out;
3831 		} else if (ret < 0) {
3832 			goto transport_err;
3833 		}
3834 	}
3835 
3836 transport_err:
3837 	/*
3838 	 * Avoid the normal connection failure code-path if this connection
3839 	 * is still within LOGIN mode, and iscsi_np process context is
3840 	 * responsible for cleaning up the early connection failure.
3841 	 */
3842 	if (conn->conn_state != TARG_CONN_STATE_IN_LOGIN)
3843 		iscsit_take_action_for_connection_exit(conn, &conn_freed);
3844 out:
3845 	if (!conn_freed) {
3846 		while (!kthread_should_stop()) {
3847 			msleep(100);
3848 		}
3849 	}
3850 	return 0;
3851 }
3852 
3853 static int iscsi_target_rx_opcode(struct iscsi_conn *conn, unsigned char *buf)
3854 {
3855 	struct iscsi_hdr *hdr = (struct iscsi_hdr *)buf;
3856 	struct iscsi_cmd *cmd;
3857 	int ret = 0;
3858 
3859 	switch (hdr->opcode & ISCSI_OPCODE_MASK) {
3860 	case ISCSI_OP_SCSI_CMD:
3861 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3862 		if (!cmd)
3863 			goto reject;
3864 
3865 		ret = iscsit_handle_scsi_cmd(conn, cmd, buf);
3866 		break;
3867 	case ISCSI_OP_SCSI_DATA_OUT:
3868 		ret = iscsit_handle_data_out(conn, buf);
3869 		break;
3870 	case ISCSI_OP_NOOP_OUT:
3871 		cmd = NULL;
3872 		if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
3873 			cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3874 			if (!cmd)
3875 				goto reject;
3876 		}
3877 		ret = iscsit_handle_nop_out(conn, cmd, buf);
3878 		break;
3879 	case ISCSI_OP_SCSI_TMFUNC:
3880 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3881 		if (!cmd)
3882 			goto reject;
3883 
3884 		ret = iscsit_handle_task_mgt_cmd(conn, cmd, buf);
3885 		break;
3886 	case ISCSI_OP_TEXT:
3887 		if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
3888 			cmd = iscsit_find_cmd_from_itt(conn, hdr->itt);
3889 			if (!cmd)
3890 				goto reject;
3891 		} else {
3892 			cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3893 			if (!cmd)
3894 				goto reject;
3895 		}
3896 
3897 		ret = iscsit_handle_text_cmd(conn, cmd, buf);
3898 		break;
3899 	case ISCSI_OP_LOGOUT:
3900 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3901 		if (!cmd)
3902 			goto reject;
3903 
3904 		ret = iscsit_handle_logout_cmd(conn, cmd, buf);
3905 		if (ret > 0)
3906 			wait_for_completion_timeout(&conn->conn_logout_comp,
3907 					SECONDS_FOR_LOGOUT_COMP * HZ);
3908 		break;
3909 	case ISCSI_OP_SNACK:
3910 		ret = iscsit_handle_snack(conn, buf);
3911 		break;
3912 	default:
3913 		pr_err("Got unknown iSCSI OpCode: 0x%02x\n", hdr->opcode);
3914 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
3915 			pr_err("Cannot recover from unknown"
3916 			" opcode while ERL=0, closing iSCSI connection.\n");
3917 			return -1;
3918 		}
3919 		pr_err("Unable to recover from unknown opcode while OFMarker=No,"
3920 		       " closing iSCSI connection.\n");
3921 		ret = -1;
3922 		break;
3923 	}
3924 
3925 	return ret;
3926 reject:
3927 	return iscsit_add_reject(conn, ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
3928 }
3929 
3930 static bool iscsi_target_check_conn_state(struct iscsi_conn *conn)
3931 {
3932 	bool ret;
3933 
3934 	spin_lock_bh(&conn->state_lock);
3935 	ret = (conn->conn_state != TARG_CONN_STATE_LOGGED_IN);
3936 	spin_unlock_bh(&conn->state_lock);
3937 
3938 	return ret;
3939 }
3940 
3941 static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
3942 {
3943 	int ret;
3944 	u8 buffer[ISCSI_HDR_LEN], opcode;
3945 	u32 checksum = 0, digest = 0;
3946 	struct kvec iov;
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(buffer, 0, ISCSI_HDR_LEN);
3956 		memset(&iov, 0, sizeof(struct kvec));
3957 
3958 		iov.iov_base	= buffer;
3959 		iov.iov_len	= ISCSI_HDR_LEN;
3960 
3961 		ret = rx_data(conn, &iov, 1, ISCSI_HDR_LEN);
3962 		if (ret != ISCSI_HDR_LEN) {
3963 			iscsit_rx_thread_wait_for_tcp(conn);
3964 			return;
3965 		}
3966 
3967 		if (conn->conn_ops->HeaderDigest) {
3968 			iov.iov_base	= &digest;
3969 			iov.iov_len	= ISCSI_CRC_LEN;
3970 
3971 			ret = rx_data(conn, &iov, 1, ISCSI_CRC_LEN);
3972 			if (ret != ISCSI_CRC_LEN) {
3973 				iscsit_rx_thread_wait_for_tcp(conn);
3974 				return;
3975 			}
3976 
3977 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash,
3978 					buffer, ISCSI_HDR_LEN,
3979 					0, NULL, (u8 *)&checksum);
3980 
3981 			if (digest != checksum) {
3982 				pr_err("HeaderDigest CRC32C failed,"
3983 					" received 0x%08x, computed 0x%08x\n",
3984 					digest, checksum);
3985 				/*
3986 				 * Set the PDU to 0xff so it will intentionally
3987 				 * hit default in the switch below.
3988 				 */
3989 				memset(buffer, 0xff, ISCSI_HDR_LEN);
3990 				atomic_long_inc(&conn->sess->conn_digest_errors);
3991 			} else {
3992 				pr_debug("Got HeaderDigest CRC32C"
3993 						" 0x%08x\n", checksum);
3994 			}
3995 		}
3996 
3997 		if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT)
3998 			return;
3999 
4000 		opcode = buffer[0] & ISCSI_OPCODE_MASK;
4001 
4002 		if (conn->sess->sess_ops->SessionType &&
4003 		   ((!(opcode & ISCSI_OP_TEXT)) ||
4004 		    (!(opcode & ISCSI_OP_LOGOUT)))) {
4005 			pr_err("Received illegal iSCSI Opcode: 0x%02x"
4006 			" while in Discovery Session, rejecting.\n", opcode);
4007 			iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
4008 					  buffer);
4009 			return;
4010 		}
4011 
4012 		ret = iscsi_target_rx_opcode(conn, buffer);
4013 		if (ret < 0)
4014 			return;
4015 	}
4016 }
4017 
4018 int iscsi_target_rx_thread(void *arg)
4019 {
4020 	int rc;
4021 	struct iscsi_conn *conn = arg;
4022 	bool conn_freed = false;
4023 
4024 	/*
4025 	 * Allow ourselves to be interrupted by SIGINT so that a
4026 	 * connection recovery / failure event can be triggered externally.
4027 	 */
4028 	allow_signal(SIGINT);
4029 	/*
4030 	 * Wait for iscsi_post_login_handler() to complete before allowing
4031 	 * incoming iscsi/tcp socket I/O, and/or failing the connection.
4032 	 */
4033 	rc = wait_for_completion_interruptible(&conn->rx_login_comp);
4034 	if (rc < 0 || iscsi_target_check_conn_state(conn))
4035 		goto out;
4036 
4037 	if (!conn->conn_transport->iscsit_get_rx_pdu)
4038 		return 0;
4039 
4040 	conn->conn_transport->iscsit_get_rx_pdu(conn);
4041 
4042 	if (!signal_pending(current))
4043 		atomic_set(&conn->transport_failed, 1);
4044 	iscsit_take_action_for_connection_exit(conn, &conn_freed);
4045 
4046 out:
4047 	if (!conn_freed) {
4048 		while (!kthread_should_stop()) {
4049 			msleep(100);
4050 		}
4051 	}
4052 
4053 	return 0;
4054 }
4055 
4056 static void iscsit_release_commands_from_conn(struct iscsi_conn *conn)
4057 {
4058 	LIST_HEAD(tmp_list);
4059 	struct iscsi_cmd *cmd = NULL, *cmd_tmp = NULL;
4060 	struct iscsi_session *sess = conn->sess;
4061 	/*
4062 	 * We expect this function to only ever be called from either RX or TX
4063 	 * thread context via iscsit_close_connection() once the other context
4064 	 * has been reset -> returned sleeping pre-handler state.
4065 	 */
4066 	spin_lock_bh(&conn->cmd_lock);
4067 	list_splice_init(&conn->conn_cmd_list, &tmp_list);
4068 
4069 	list_for_each_entry(cmd, &tmp_list, i_conn_node) {
4070 		struct se_cmd *se_cmd = &cmd->se_cmd;
4071 
4072 		if (se_cmd->se_tfo != NULL) {
4073 			spin_lock(&se_cmd->t_state_lock);
4074 			se_cmd->transport_state |= CMD_T_FABRIC_STOP;
4075 			spin_unlock(&se_cmd->t_state_lock);
4076 		}
4077 	}
4078 	spin_unlock_bh(&conn->cmd_lock);
4079 
4080 	list_for_each_entry_safe(cmd, cmd_tmp, &tmp_list, i_conn_node) {
4081 		list_del_init(&cmd->i_conn_node);
4082 
4083 		iscsit_increment_maxcmdsn(cmd, sess);
4084 		iscsit_free_cmd(cmd, true);
4085 
4086 	}
4087 }
4088 
4089 static void iscsit_stop_timers_for_cmds(
4090 	struct iscsi_conn *conn)
4091 {
4092 	struct iscsi_cmd *cmd;
4093 
4094 	spin_lock_bh(&conn->cmd_lock);
4095 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
4096 		if (cmd->data_direction == DMA_TO_DEVICE)
4097 			iscsit_stop_dataout_timer(cmd);
4098 	}
4099 	spin_unlock_bh(&conn->cmd_lock);
4100 }
4101 
4102 int iscsit_close_connection(
4103 	struct iscsi_conn *conn)
4104 {
4105 	int conn_logout = (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT);
4106 	struct iscsi_session	*sess = conn->sess;
4107 
4108 	pr_debug("Closing iSCSI connection CID %hu on SID:"
4109 		" %u\n", conn->cid, sess->sid);
4110 	/*
4111 	 * Always up conn_logout_comp for the traditional TCP and HW_OFFLOAD
4112 	 * case just in case the RX Thread in iscsi_target_rx_opcode() is
4113 	 * sleeping and the logout response never got sent because the
4114 	 * connection failed.
4115 	 *
4116 	 * However for iser-target, isert_wait4logout() is using conn_logout_comp
4117 	 * to signal logout response TX interrupt completion.  Go ahead and skip
4118 	 * this for iser since isert_rx_opcode() does not wait on logout failure,
4119 	 * and to avoid iscsi_conn pointer dereference in iser-target code.
4120 	 */
4121 	if (!conn->conn_transport->rdma_shutdown)
4122 		complete(&conn->conn_logout_comp);
4123 
4124 	if (!strcmp(current->comm, ISCSI_RX_THREAD_NAME)) {
4125 		if (conn->tx_thread &&
4126 		    cmpxchg(&conn->tx_thread_active, true, false)) {
4127 			send_sig(SIGINT, conn->tx_thread, 1);
4128 			kthread_stop(conn->tx_thread);
4129 		}
4130 	} else if (!strcmp(current->comm, ISCSI_TX_THREAD_NAME)) {
4131 		if (conn->rx_thread &&
4132 		    cmpxchg(&conn->rx_thread_active, true, false)) {
4133 			send_sig(SIGINT, conn->rx_thread, 1);
4134 			kthread_stop(conn->rx_thread);
4135 		}
4136 	}
4137 
4138 	spin_lock(&iscsit_global->ts_bitmap_lock);
4139 	bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
4140 			      get_order(1));
4141 	spin_unlock(&iscsit_global->ts_bitmap_lock);
4142 
4143 	iscsit_stop_timers_for_cmds(conn);
4144 	iscsit_stop_nopin_response_timer(conn);
4145 	iscsit_stop_nopin_timer(conn);
4146 
4147 	if (conn->conn_transport->iscsit_wait_conn)
4148 		conn->conn_transport->iscsit_wait_conn(conn);
4149 
4150 	/*
4151 	 * During Connection recovery drop unacknowledged out of order
4152 	 * commands for this connection, and prepare the other commands
4153 	 * for reallegiance.
4154 	 *
4155 	 * During normal operation clear the out of order commands (but
4156 	 * do not free the struct iscsi_ooo_cmdsn's) and release all
4157 	 * struct iscsi_cmds.
4158 	 */
4159 	if (atomic_read(&conn->connection_recovery)) {
4160 		iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(conn);
4161 		iscsit_prepare_cmds_for_reallegiance(conn);
4162 	} else {
4163 		iscsit_clear_ooo_cmdsns_for_conn(conn);
4164 		iscsit_release_commands_from_conn(conn);
4165 	}
4166 	iscsit_free_queue_reqs_for_conn(conn);
4167 
4168 	/*
4169 	 * Handle decrementing session or connection usage count if
4170 	 * a logout response was not able to be sent because the
4171 	 * connection failed.  Fall back to Session Recovery here.
4172 	 */
4173 	if (atomic_read(&conn->conn_logout_remove)) {
4174 		if (conn->conn_logout_reason == ISCSI_LOGOUT_REASON_CLOSE_SESSION) {
4175 			iscsit_dec_conn_usage_count(conn);
4176 			iscsit_dec_session_usage_count(sess);
4177 		}
4178 		if (conn->conn_logout_reason == ISCSI_LOGOUT_REASON_CLOSE_CONNECTION)
4179 			iscsit_dec_conn_usage_count(conn);
4180 
4181 		atomic_set(&conn->conn_logout_remove, 0);
4182 		atomic_set(&sess->session_reinstatement, 0);
4183 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4184 	}
4185 
4186 	spin_lock_bh(&sess->conn_lock);
4187 	list_del(&conn->conn_list);
4188 
4189 	/*
4190 	 * Attempt to let the Initiator know this connection failed by
4191 	 * sending an Connection Dropped Async Message on another
4192 	 * active connection.
4193 	 */
4194 	if (atomic_read(&conn->connection_recovery))
4195 		iscsit_build_conn_drop_async_message(conn);
4196 
4197 	spin_unlock_bh(&sess->conn_lock);
4198 
4199 	/*
4200 	 * If connection reinstatement is being performed on this connection,
4201 	 * up the connection reinstatement semaphore that is being blocked on
4202 	 * in iscsit_cause_connection_reinstatement().
4203 	 */
4204 	spin_lock_bh(&conn->state_lock);
4205 	if (atomic_read(&conn->sleep_on_conn_wait_comp)) {
4206 		spin_unlock_bh(&conn->state_lock);
4207 		complete(&conn->conn_wait_comp);
4208 		wait_for_completion(&conn->conn_post_wait_comp);
4209 		spin_lock_bh(&conn->state_lock);
4210 	}
4211 
4212 	/*
4213 	 * If connection reinstatement is being performed on this connection
4214 	 * by receiving a REMOVECONNFORRECOVERY logout request, up the
4215 	 * connection wait rcfr semaphore that is being blocked on
4216 	 * an iscsit_connection_reinstatement_rcfr().
4217 	 */
4218 	if (atomic_read(&conn->connection_wait_rcfr)) {
4219 		spin_unlock_bh(&conn->state_lock);
4220 		complete(&conn->conn_wait_rcfr_comp);
4221 		wait_for_completion(&conn->conn_post_wait_comp);
4222 		spin_lock_bh(&conn->state_lock);
4223 	}
4224 	atomic_set(&conn->connection_reinstatement, 1);
4225 	spin_unlock_bh(&conn->state_lock);
4226 
4227 	/*
4228 	 * If any other processes are accessing this connection pointer we
4229 	 * must wait until they have completed.
4230 	 */
4231 	iscsit_check_conn_usage_count(conn);
4232 
4233 	ahash_request_free(conn->conn_tx_hash);
4234 	if (conn->conn_rx_hash) {
4235 		struct crypto_ahash *tfm;
4236 
4237 		tfm = crypto_ahash_reqtfm(conn->conn_rx_hash);
4238 		ahash_request_free(conn->conn_rx_hash);
4239 		crypto_free_ahash(tfm);
4240 	}
4241 
4242 	free_cpumask_var(conn->conn_cpumask);
4243 
4244 	kfree(conn->conn_ops);
4245 	conn->conn_ops = NULL;
4246 
4247 	if (conn->sock)
4248 		sock_release(conn->sock);
4249 
4250 	if (conn->conn_transport->iscsit_free_conn)
4251 		conn->conn_transport->iscsit_free_conn(conn);
4252 
4253 	iscsit_put_transport(conn->conn_transport);
4254 
4255 	pr_debug("Moving to TARG_CONN_STATE_FREE.\n");
4256 	conn->conn_state = TARG_CONN_STATE_FREE;
4257 	kfree(conn);
4258 
4259 	spin_lock_bh(&sess->conn_lock);
4260 	atomic_dec(&sess->nconn);
4261 	pr_debug("Decremented iSCSI connection count to %hu from node:"
4262 		" %s\n", atomic_read(&sess->nconn),
4263 		sess->sess_ops->InitiatorName);
4264 	/*
4265 	 * Make sure that if one connection fails in an non ERL=2 iSCSI
4266 	 * Session that they all fail.
4267 	 */
4268 	if ((sess->sess_ops->ErrorRecoveryLevel != 2) && !conn_logout &&
4269 	     !atomic_read(&sess->session_logout))
4270 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4271 
4272 	/*
4273 	 * If this was not the last connection in the session, and we are
4274 	 * performing session reinstatement or falling back to ERL=0, call
4275 	 * iscsit_stop_session() without sleeping to shutdown the other
4276 	 * active connections.
4277 	 */
4278 	if (atomic_read(&sess->nconn)) {
4279 		if (!atomic_read(&sess->session_reinstatement) &&
4280 		    !atomic_read(&sess->session_fall_back_to_erl0)) {
4281 			spin_unlock_bh(&sess->conn_lock);
4282 			return 0;
4283 		}
4284 		if (!atomic_read(&sess->session_stop_active)) {
4285 			atomic_set(&sess->session_stop_active, 1);
4286 			spin_unlock_bh(&sess->conn_lock);
4287 			iscsit_stop_session(sess, 0, 0);
4288 			return 0;
4289 		}
4290 		spin_unlock_bh(&sess->conn_lock);
4291 		return 0;
4292 	}
4293 
4294 	/*
4295 	 * If this was the last connection in the session and one of the
4296 	 * following is occurring:
4297 	 *
4298 	 * Session Reinstatement is not being performed, and are falling back
4299 	 * to ERL=0 call iscsit_close_session().
4300 	 *
4301 	 * Session Logout was requested.  iscsit_close_session() will be called
4302 	 * elsewhere.
4303 	 *
4304 	 * Session Continuation is not being performed, start the Time2Retain
4305 	 * handler and check if sleep_on_sess_wait_sem is active.
4306 	 */
4307 	if (!atomic_read(&sess->session_reinstatement) &&
4308 	     atomic_read(&sess->session_fall_back_to_erl0)) {
4309 		spin_unlock_bh(&sess->conn_lock);
4310 		iscsit_close_session(sess);
4311 
4312 		return 0;
4313 	} else if (atomic_read(&sess->session_logout)) {
4314 		pr_debug("Moving to TARG_SESS_STATE_FREE.\n");
4315 		sess->session_state = TARG_SESS_STATE_FREE;
4316 		spin_unlock_bh(&sess->conn_lock);
4317 
4318 		if (atomic_read(&sess->sleep_on_sess_wait_comp))
4319 			complete(&sess->session_wait_comp);
4320 
4321 		return 0;
4322 	} else {
4323 		pr_debug("Moving to TARG_SESS_STATE_FAILED.\n");
4324 		sess->session_state = TARG_SESS_STATE_FAILED;
4325 
4326 		if (!atomic_read(&sess->session_continuation)) {
4327 			spin_unlock_bh(&sess->conn_lock);
4328 			iscsit_start_time2retain_handler(sess);
4329 		} else
4330 			spin_unlock_bh(&sess->conn_lock);
4331 
4332 		if (atomic_read(&sess->sleep_on_sess_wait_comp))
4333 			complete(&sess->session_wait_comp);
4334 
4335 		return 0;
4336 	}
4337 }
4338 
4339 /*
4340  * If the iSCSI Session for the iSCSI Initiator Node exists,
4341  * forcefully shutdown the iSCSI NEXUS.
4342  */
4343 int iscsit_close_session(struct iscsi_session *sess)
4344 {
4345 	struct iscsi_portal_group *tpg = sess->tpg;
4346 	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
4347 
4348 	if (atomic_read(&sess->nconn)) {
4349 		pr_err("%d connection(s) still exist for iSCSI session"
4350 			" to %s\n", atomic_read(&sess->nconn),
4351 			sess->sess_ops->InitiatorName);
4352 		BUG();
4353 	}
4354 
4355 	spin_lock_bh(&se_tpg->session_lock);
4356 	atomic_set(&sess->session_logout, 1);
4357 	atomic_set(&sess->session_reinstatement, 1);
4358 	iscsit_stop_time2retain_timer(sess);
4359 	spin_unlock_bh(&se_tpg->session_lock);
4360 
4361 	/*
4362 	 * transport_deregister_session_configfs() will clear the
4363 	 * struct se_node_acl->nacl_sess pointer now as a iscsi_np process context
4364 	 * can be setting it again with __transport_register_session() in
4365 	 * iscsi_post_login_handler() again after the iscsit_stop_session()
4366 	 * completes in iscsi_np context.
4367 	 */
4368 	transport_deregister_session_configfs(sess->se_sess);
4369 
4370 	/*
4371 	 * If any other processes are accessing this session pointer we must
4372 	 * wait until they have completed.  If we are in an interrupt (the
4373 	 * time2retain handler) and contain and active session usage count we
4374 	 * restart the timer and exit.
4375 	 */
4376 	if (!in_interrupt()) {
4377 		if (iscsit_check_session_usage_count(sess) == 1)
4378 			iscsit_stop_session(sess, 1, 1);
4379 	} else {
4380 		if (iscsit_check_session_usage_count(sess) == 2) {
4381 			atomic_set(&sess->session_logout, 0);
4382 			iscsit_start_time2retain_handler(sess);
4383 			return 0;
4384 		}
4385 	}
4386 
4387 	transport_deregister_session(sess->se_sess);
4388 
4389 	if (sess->sess_ops->ErrorRecoveryLevel == 2)
4390 		iscsit_free_connection_recovery_entires(sess);
4391 
4392 	iscsit_free_all_ooo_cmdsns(sess);
4393 
4394 	spin_lock_bh(&se_tpg->session_lock);
4395 	pr_debug("Moving to TARG_SESS_STATE_FREE.\n");
4396 	sess->session_state = TARG_SESS_STATE_FREE;
4397 	pr_debug("Released iSCSI session from node: %s\n",
4398 			sess->sess_ops->InitiatorName);
4399 	tpg->nsessions--;
4400 	if (tpg->tpg_tiqn)
4401 		tpg->tpg_tiqn->tiqn_nsessions--;
4402 
4403 	pr_debug("Decremented number of active iSCSI Sessions on"
4404 		" iSCSI TPG: %hu to %u\n", tpg->tpgt, tpg->nsessions);
4405 
4406 	spin_lock(&sess_idr_lock);
4407 	idr_remove(&sess_idr, sess->session_index);
4408 	spin_unlock(&sess_idr_lock);
4409 
4410 	kfree(sess->sess_ops);
4411 	sess->sess_ops = NULL;
4412 	spin_unlock_bh(&se_tpg->session_lock);
4413 
4414 	kfree(sess);
4415 	return 0;
4416 }
4417 
4418 static void iscsit_logout_post_handler_closesession(
4419 	struct iscsi_conn *conn)
4420 {
4421 	struct iscsi_session *sess = conn->sess;
4422 	int sleep = 1;
4423 	/*
4424 	 * Traditional iscsi/tcp will invoke this logic from TX thread
4425 	 * context during session logout, so clear tx_thread_active and
4426 	 * sleep if iscsit_close_connection() has not already occured.
4427 	 *
4428 	 * Since iser-target invokes this logic from it's own workqueue,
4429 	 * always sleep waiting for RX/TX thread shutdown to complete
4430 	 * within iscsit_close_connection().
4431 	 */
4432 	if (!conn->conn_transport->rdma_shutdown) {
4433 		sleep = cmpxchg(&conn->tx_thread_active, true, false);
4434 		if (!sleep)
4435 			return;
4436 	}
4437 
4438 	atomic_set(&conn->conn_logout_remove, 0);
4439 	complete(&conn->conn_logout_comp);
4440 
4441 	iscsit_dec_conn_usage_count(conn);
4442 	iscsit_stop_session(sess, sleep, sleep);
4443 	iscsit_dec_session_usage_count(sess);
4444 	iscsit_close_session(sess);
4445 }
4446 
4447 static void iscsit_logout_post_handler_samecid(
4448 	struct iscsi_conn *conn)
4449 {
4450 	int sleep = 1;
4451 
4452 	if (!conn->conn_transport->rdma_shutdown) {
4453 		sleep = cmpxchg(&conn->tx_thread_active, true, false);
4454 		if (!sleep)
4455 			return;
4456 	}
4457 
4458 	atomic_set(&conn->conn_logout_remove, 0);
4459 	complete(&conn->conn_logout_comp);
4460 
4461 	iscsit_cause_connection_reinstatement(conn, sleep);
4462 	iscsit_dec_conn_usage_count(conn);
4463 }
4464 
4465 static void iscsit_logout_post_handler_diffcid(
4466 	struct iscsi_conn *conn,
4467 	u16 cid)
4468 {
4469 	struct iscsi_conn *l_conn;
4470 	struct iscsi_session *sess = conn->sess;
4471 	bool conn_found = false;
4472 
4473 	if (!sess)
4474 		return;
4475 
4476 	spin_lock_bh(&sess->conn_lock);
4477 	list_for_each_entry(l_conn, &sess->sess_conn_list, conn_list) {
4478 		if (l_conn->cid == cid) {
4479 			iscsit_inc_conn_usage_count(l_conn);
4480 			conn_found = true;
4481 			break;
4482 		}
4483 	}
4484 	spin_unlock_bh(&sess->conn_lock);
4485 
4486 	if (!conn_found)
4487 		return;
4488 
4489 	if (l_conn->sock)
4490 		l_conn->sock->ops->shutdown(l_conn->sock, RCV_SHUTDOWN);
4491 
4492 	spin_lock_bh(&l_conn->state_lock);
4493 	pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
4494 	l_conn->conn_state = TARG_CONN_STATE_IN_LOGOUT;
4495 	spin_unlock_bh(&l_conn->state_lock);
4496 
4497 	iscsit_cause_connection_reinstatement(l_conn, 1);
4498 	iscsit_dec_conn_usage_count(l_conn);
4499 }
4500 
4501 /*
4502  *	Return of 0 causes the TX thread to restart.
4503  */
4504 int iscsit_logout_post_handler(
4505 	struct iscsi_cmd *cmd,
4506 	struct iscsi_conn *conn)
4507 {
4508 	int ret = 0;
4509 
4510 	switch (cmd->logout_reason) {
4511 	case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
4512 		switch (cmd->logout_response) {
4513 		case ISCSI_LOGOUT_SUCCESS:
4514 		case ISCSI_LOGOUT_CLEANUP_FAILED:
4515 		default:
4516 			iscsit_logout_post_handler_closesession(conn);
4517 			break;
4518 		}
4519 		ret = 0;
4520 		break;
4521 	case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
4522 		if (conn->cid == cmd->logout_cid) {
4523 			switch (cmd->logout_response) {
4524 			case ISCSI_LOGOUT_SUCCESS:
4525 			case ISCSI_LOGOUT_CLEANUP_FAILED:
4526 			default:
4527 				iscsit_logout_post_handler_samecid(conn);
4528 				break;
4529 			}
4530 			ret = 0;
4531 		} else {
4532 			switch (cmd->logout_response) {
4533 			case ISCSI_LOGOUT_SUCCESS:
4534 				iscsit_logout_post_handler_diffcid(conn,
4535 					cmd->logout_cid);
4536 				break;
4537 			case ISCSI_LOGOUT_CID_NOT_FOUND:
4538 			case ISCSI_LOGOUT_CLEANUP_FAILED:
4539 			default:
4540 				break;
4541 			}
4542 			ret = 1;
4543 		}
4544 		break;
4545 	case ISCSI_LOGOUT_REASON_RECOVERY:
4546 		switch (cmd->logout_response) {
4547 		case ISCSI_LOGOUT_SUCCESS:
4548 		case ISCSI_LOGOUT_CID_NOT_FOUND:
4549 		case ISCSI_LOGOUT_RECOVERY_UNSUPPORTED:
4550 		case ISCSI_LOGOUT_CLEANUP_FAILED:
4551 		default:
4552 			break;
4553 		}
4554 		ret = 1;
4555 		break;
4556 	default:
4557 		break;
4558 
4559 	}
4560 	return ret;
4561 }
4562 EXPORT_SYMBOL(iscsit_logout_post_handler);
4563 
4564 void iscsit_fail_session(struct iscsi_session *sess)
4565 {
4566 	struct iscsi_conn *conn;
4567 
4568 	spin_lock_bh(&sess->conn_lock);
4569 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
4570 		pr_debug("Moving to TARG_CONN_STATE_CLEANUP_WAIT.\n");
4571 		conn->conn_state = TARG_CONN_STATE_CLEANUP_WAIT;
4572 	}
4573 	spin_unlock_bh(&sess->conn_lock);
4574 
4575 	pr_debug("Moving to TARG_SESS_STATE_FAILED.\n");
4576 	sess->session_state = TARG_SESS_STATE_FAILED;
4577 }
4578 
4579 int iscsit_free_session(struct iscsi_session *sess)
4580 {
4581 	u16 conn_count = atomic_read(&sess->nconn);
4582 	struct iscsi_conn *conn, *conn_tmp = NULL;
4583 	int is_last;
4584 
4585 	spin_lock_bh(&sess->conn_lock);
4586 	atomic_set(&sess->sleep_on_sess_wait_comp, 1);
4587 
4588 	list_for_each_entry_safe(conn, conn_tmp, &sess->sess_conn_list,
4589 			conn_list) {
4590 		if (conn_count == 0)
4591 			break;
4592 
4593 		if (list_is_last(&conn->conn_list, &sess->sess_conn_list)) {
4594 			is_last = 1;
4595 		} else {
4596 			iscsit_inc_conn_usage_count(conn_tmp);
4597 			is_last = 0;
4598 		}
4599 		iscsit_inc_conn_usage_count(conn);
4600 
4601 		spin_unlock_bh(&sess->conn_lock);
4602 		iscsit_cause_connection_reinstatement(conn, 1);
4603 		spin_lock_bh(&sess->conn_lock);
4604 
4605 		iscsit_dec_conn_usage_count(conn);
4606 		if (is_last == 0)
4607 			iscsit_dec_conn_usage_count(conn_tmp);
4608 
4609 		conn_count--;
4610 	}
4611 
4612 	if (atomic_read(&sess->nconn)) {
4613 		spin_unlock_bh(&sess->conn_lock);
4614 		wait_for_completion(&sess->session_wait_comp);
4615 	} else
4616 		spin_unlock_bh(&sess->conn_lock);
4617 
4618 	iscsit_close_session(sess);
4619 	return 0;
4620 }
4621 
4622 void iscsit_stop_session(
4623 	struct iscsi_session *sess,
4624 	int session_sleep,
4625 	int connection_sleep)
4626 {
4627 	u16 conn_count = atomic_read(&sess->nconn);
4628 	struct iscsi_conn *conn, *conn_tmp = NULL;
4629 	int is_last;
4630 
4631 	spin_lock_bh(&sess->conn_lock);
4632 	if (session_sleep)
4633 		atomic_set(&sess->sleep_on_sess_wait_comp, 1);
4634 
4635 	if (connection_sleep) {
4636 		list_for_each_entry_safe(conn, conn_tmp, &sess->sess_conn_list,
4637 				conn_list) {
4638 			if (conn_count == 0)
4639 				break;
4640 
4641 			if (list_is_last(&conn->conn_list, &sess->sess_conn_list)) {
4642 				is_last = 1;
4643 			} else {
4644 				iscsit_inc_conn_usage_count(conn_tmp);
4645 				is_last = 0;
4646 			}
4647 			iscsit_inc_conn_usage_count(conn);
4648 
4649 			spin_unlock_bh(&sess->conn_lock);
4650 			iscsit_cause_connection_reinstatement(conn, 1);
4651 			spin_lock_bh(&sess->conn_lock);
4652 
4653 			iscsit_dec_conn_usage_count(conn);
4654 			if (is_last == 0)
4655 				iscsit_dec_conn_usage_count(conn_tmp);
4656 			conn_count--;
4657 		}
4658 	} else {
4659 		list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
4660 			iscsit_cause_connection_reinstatement(conn, 0);
4661 	}
4662 
4663 	if (session_sleep && atomic_read(&sess->nconn)) {
4664 		spin_unlock_bh(&sess->conn_lock);
4665 		wait_for_completion(&sess->session_wait_comp);
4666 	} else
4667 		spin_unlock_bh(&sess->conn_lock);
4668 }
4669 
4670 int iscsit_release_sessions_for_tpg(struct iscsi_portal_group *tpg, int force)
4671 {
4672 	struct iscsi_session *sess;
4673 	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
4674 	struct se_session *se_sess, *se_sess_tmp;
4675 	LIST_HEAD(free_list);
4676 	int session_count = 0;
4677 
4678 	spin_lock_bh(&se_tpg->session_lock);
4679 	if (tpg->nsessions && !force) {
4680 		spin_unlock_bh(&se_tpg->session_lock);
4681 		return -1;
4682 	}
4683 
4684 	list_for_each_entry_safe(se_sess, se_sess_tmp, &se_tpg->tpg_sess_list,
4685 			sess_list) {
4686 		sess = (struct iscsi_session *)se_sess->fabric_sess_ptr;
4687 
4688 		spin_lock(&sess->conn_lock);
4689 		if (atomic_read(&sess->session_fall_back_to_erl0) ||
4690 		    atomic_read(&sess->session_logout) ||
4691 		    (sess->time2retain_timer_flags & ISCSI_TF_EXPIRED)) {
4692 			spin_unlock(&sess->conn_lock);
4693 			continue;
4694 		}
4695 		atomic_set(&sess->session_reinstatement, 1);
4696 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4697 		spin_unlock(&sess->conn_lock);
4698 
4699 		list_move_tail(&se_sess->sess_list, &free_list);
4700 	}
4701 	spin_unlock_bh(&se_tpg->session_lock);
4702 
4703 	list_for_each_entry_safe(se_sess, se_sess_tmp, &free_list, sess_list) {
4704 		sess = (struct iscsi_session *)se_sess->fabric_sess_ptr;
4705 
4706 		iscsit_free_session(sess);
4707 		session_count++;
4708 	}
4709 
4710 	pr_debug("Released %d iSCSI Session(s) from Target Portal"
4711 			" Group: %hu\n", session_count, tpg->tpgt);
4712 	return 0;
4713 }
4714 
4715 MODULE_DESCRIPTION("iSCSI-Target Driver for mainline target infrastructure");
4716 MODULE_VERSION("4.1.x");
4717 MODULE_AUTHOR("nab@Linux-iSCSI.org");
4718 MODULE_LICENSE("GPL");
4719 
4720 module_init(iscsi_target_init_module);
4721 module_exit(iscsi_target_cleanup_module);
4722