xref: /linux/drivers/target/iscsi/iscsi_target.c (revision a1c3be890440a1769ed6f822376a3e3ab0d42994)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3  * This file contains main functions related to the iSCSI Target Core Driver.
4  *
5  * (c) Copyright 2007-2013 Datera, Inc.
6  *
7  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
8  *
9  ******************************************************************************/
10 
11 #include <crypto/hash.h>
12 #include <linux/string.h>
13 #include <linux/kthread.h>
14 #include <linux/completion.h>
15 #include <linux/module.h>
16 #include <linux/vmalloc.h>
17 #include <linux/idr.h>
18 #include <linux/delay.h>
19 #include <linux/sched/signal.h>
20 #include <asm/unaligned.h>
21 #include <linux/inet.h>
22 #include <net/ipv6.h>
23 #include <scsi/scsi_proto.h>
24 #include <scsi/iscsi_proto.h>
25 #include <scsi/scsi_tcq.h>
26 #include <target/target_core_base.h>
27 #include <target/target_core_fabric.h>
28 
29 #include <target/iscsi/iscsi_target_core.h>
30 #include "iscsi_target_parameters.h"
31 #include "iscsi_target_seq_pdu_list.h"
32 #include "iscsi_target_datain_values.h"
33 #include "iscsi_target_erl0.h"
34 #include "iscsi_target_erl1.h"
35 #include "iscsi_target_erl2.h"
36 #include "iscsi_target_login.h"
37 #include "iscsi_target_tmr.h"
38 #include "iscsi_target_tpg.h"
39 #include "iscsi_target_util.h"
40 #include "iscsi_target.h"
41 #include "iscsi_target_device.h"
42 #include <target/iscsi/iscsi_target_stat.h>
43 
44 #include <target/iscsi/iscsi_transport.h>
45 
46 static LIST_HEAD(g_tiqn_list);
47 static LIST_HEAD(g_np_list);
48 static DEFINE_SPINLOCK(tiqn_lock);
49 static DEFINE_MUTEX(np_lock);
50 
51 static struct idr tiqn_idr;
52 DEFINE_IDA(sess_ida);
53 struct mutex auth_id_lock;
54 
55 struct iscsit_global *iscsit_global;
56 
57 struct kmem_cache *lio_qr_cache;
58 struct kmem_cache *lio_dr_cache;
59 struct kmem_cache *lio_ooo_cache;
60 struct kmem_cache *lio_r2t_cache;
61 
62 static int iscsit_handle_immediate_data(struct iscsi_cmd *,
63 			struct iscsi_scsi_req *, u32);
64 
65 struct iscsi_tiqn *iscsit_get_tiqn_for_login(unsigned char *buf)
66 {
67 	struct iscsi_tiqn *tiqn = NULL;
68 
69 	spin_lock(&tiqn_lock);
70 	list_for_each_entry(tiqn, &g_tiqn_list, tiqn_list) {
71 		if (!strcmp(tiqn->tiqn, buf)) {
72 
73 			spin_lock(&tiqn->tiqn_state_lock);
74 			if (tiqn->tiqn_state == TIQN_STATE_ACTIVE) {
75 				tiqn->tiqn_access_count++;
76 				spin_unlock(&tiqn->tiqn_state_lock);
77 				spin_unlock(&tiqn_lock);
78 				return tiqn;
79 			}
80 			spin_unlock(&tiqn->tiqn_state_lock);
81 		}
82 	}
83 	spin_unlock(&tiqn_lock);
84 
85 	return NULL;
86 }
87 
88 static int iscsit_set_tiqn_shutdown(struct iscsi_tiqn *tiqn)
89 {
90 	spin_lock(&tiqn->tiqn_state_lock);
91 	if (tiqn->tiqn_state == TIQN_STATE_ACTIVE) {
92 		tiqn->tiqn_state = TIQN_STATE_SHUTDOWN;
93 		spin_unlock(&tiqn->tiqn_state_lock);
94 		return 0;
95 	}
96 	spin_unlock(&tiqn->tiqn_state_lock);
97 
98 	return -1;
99 }
100 
101 void iscsit_put_tiqn_for_login(struct iscsi_tiqn *tiqn)
102 {
103 	spin_lock(&tiqn->tiqn_state_lock);
104 	tiqn->tiqn_access_count--;
105 	spin_unlock(&tiqn->tiqn_state_lock);
106 }
107 
108 /*
109  * Note that IQN formatting is expected to be done in userspace, and
110  * no explict IQN format checks are done here.
111  */
112 struct iscsi_tiqn *iscsit_add_tiqn(unsigned char *buf)
113 {
114 	struct iscsi_tiqn *tiqn = NULL;
115 	int ret;
116 
117 	if (strlen(buf) >= ISCSI_IQN_LEN) {
118 		pr_err("Target IQN exceeds %d bytes\n",
119 				ISCSI_IQN_LEN);
120 		return ERR_PTR(-EINVAL);
121 	}
122 
123 	tiqn = kzalloc(sizeof(*tiqn), GFP_KERNEL);
124 	if (!tiqn)
125 		return ERR_PTR(-ENOMEM);
126 
127 	sprintf(tiqn->tiqn, "%s", buf);
128 	INIT_LIST_HEAD(&tiqn->tiqn_list);
129 	INIT_LIST_HEAD(&tiqn->tiqn_tpg_list);
130 	spin_lock_init(&tiqn->tiqn_state_lock);
131 	spin_lock_init(&tiqn->tiqn_tpg_lock);
132 	spin_lock_init(&tiqn->sess_err_stats.lock);
133 	spin_lock_init(&tiqn->login_stats.lock);
134 	spin_lock_init(&tiqn->logout_stats.lock);
135 
136 	tiqn->tiqn_state = TIQN_STATE_ACTIVE;
137 
138 	idr_preload(GFP_KERNEL);
139 	spin_lock(&tiqn_lock);
140 
141 	ret = idr_alloc(&tiqn_idr, NULL, 0, 0, GFP_NOWAIT);
142 	if (ret < 0) {
143 		pr_err("idr_alloc() failed for tiqn->tiqn_index\n");
144 		spin_unlock(&tiqn_lock);
145 		idr_preload_end();
146 		kfree(tiqn);
147 		return ERR_PTR(ret);
148 	}
149 	tiqn->tiqn_index = ret;
150 	list_add_tail(&tiqn->tiqn_list, &g_tiqn_list);
151 
152 	spin_unlock(&tiqn_lock);
153 	idr_preload_end();
154 
155 	pr_debug("CORE[0] - Added iSCSI Target IQN: %s\n", tiqn->tiqn);
156 
157 	return tiqn;
158 
159 }
160 
161 static void iscsit_wait_for_tiqn(struct iscsi_tiqn *tiqn)
162 {
163 	/*
164 	 * Wait for accesses to said struct iscsi_tiqn to end.
165 	 */
166 	spin_lock(&tiqn->tiqn_state_lock);
167 	while (tiqn->tiqn_access_count != 0) {
168 		spin_unlock(&tiqn->tiqn_state_lock);
169 		msleep(10);
170 		spin_lock(&tiqn->tiqn_state_lock);
171 	}
172 	spin_unlock(&tiqn->tiqn_state_lock);
173 }
174 
175 void iscsit_del_tiqn(struct iscsi_tiqn *tiqn)
176 {
177 	/*
178 	 * iscsit_set_tiqn_shutdown sets tiqn->tiqn_state = TIQN_STATE_SHUTDOWN
179 	 * while holding tiqn->tiqn_state_lock.  This means that all subsequent
180 	 * attempts to access this struct iscsi_tiqn will fail from both transport
181 	 * fabric and control code paths.
182 	 */
183 	if (iscsit_set_tiqn_shutdown(tiqn) < 0) {
184 		pr_err("iscsit_set_tiqn_shutdown() failed\n");
185 		return;
186 	}
187 
188 	iscsit_wait_for_tiqn(tiqn);
189 
190 	spin_lock(&tiqn_lock);
191 	list_del(&tiqn->tiqn_list);
192 	idr_remove(&tiqn_idr, tiqn->tiqn_index);
193 	spin_unlock(&tiqn_lock);
194 
195 	pr_debug("CORE[0] - Deleted iSCSI Target IQN: %s\n",
196 			tiqn->tiqn);
197 	kfree(tiqn);
198 }
199 
200 int iscsit_access_np(struct iscsi_np *np, struct iscsi_portal_group *tpg)
201 {
202 	int ret;
203 	/*
204 	 * Determine if the network portal is accepting storage traffic.
205 	 */
206 	spin_lock_bh(&np->np_thread_lock);
207 	if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
208 		spin_unlock_bh(&np->np_thread_lock);
209 		return -1;
210 	}
211 	spin_unlock_bh(&np->np_thread_lock);
212 	/*
213 	 * Determine if the portal group is accepting storage traffic.
214 	 */
215 	spin_lock_bh(&tpg->tpg_state_lock);
216 	if (tpg->tpg_state != TPG_STATE_ACTIVE) {
217 		spin_unlock_bh(&tpg->tpg_state_lock);
218 		return -1;
219 	}
220 	spin_unlock_bh(&tpg->tpg_state_lock);
221 
222 	/*
223 	 * Here we serialize access across the TIQN+TPG Tuple.
224 	 */
225 	ret = down_interruptible(&tpg->np_login_sem);
226 	if (ret != 0)
227 		return -1;
228 
229 	spin_lock_bh(&tpg->tpg_state_lock);
230 	if (tpg->tpg_state != TPG_STATE_ACTIVE) {
231 		spin_unlock_bh(&tpg->tpg_state_lock);
232 		up(&tpg->np_login_sem);
233 		return -1;
234 	}
235 	spin_unlock_bh(&tpg->tpg_state_lock);
236 
237 	return 0;
238 }
239 
240 void iscsit_login_kref_put(struct kref *kref)
241 {
242 	struct iscsi_tpg_np *tpg_np = container_of(kref,
243 				struct iscsi_tpg_np, tpg_np_kref);
244 
245 	complete(&tpg_np->tpg_np_comp);
246 }
247 
248 int iscsit_deaccess_np(struct iscsi_np *np, struct iscsi_portal_group *tpg,
249 		       struct iscsi_tpg_np *tpg_np)
250 {
251 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
252 
253 	up(&tpg->np_login_sem);
254 
255 	if (tpg_np)
256 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
257 
258 	if (tiqn)
259 		iscsit_put_tiqn_for_login(tiqn);
260 
261 	return 0;
262 }
263 
264 bool iscsit_check_np_match(
265 	struct sockaddr_storage *sockaddr,
266 	struct iscsi_np *np,
267 	int network_transport)
268 {
269 	struct sockaddr_in *sock_in, *sock_in_e;
270 	struct sockaddr_in6 *sock_in6, *sock_in6_e;
271 	bool ip_match = false;
272 	u16 port, port_e;
273 
274 	if (sockaddr->ss_family == AF_INET6) {
275 		sock_in6 = (struct sockaddr_in6 *)sockaddr;
276 		sock_in6_e = (struct sockaddr_in6 *)&np->np_sockaddr;
277 
278 		if (!memcmp(&sock_in6->sin6_addr.in6_u,
279 			    &sock_in6_e->sin6_addr.in6_u,
280 			    sizeof(struct in6_addr)))
281 			ip_match = true;
282 
283 		port = ntohs(sock_in6->sin6_port);
284 		port_e = ntohs(sock_in6_e->sin6_port);
285 	} else {
286 		sock_in = (struct sockaddr_in *)sockaddr;
287 		sock_in_e = (struct sockaddr_in *)&np->np_sockaddr;
288 
289 		if (sock_in->sin_addr.s_addr == sock_in_e->sin_addr.s_addr)
290 			ip_match = true;
291 
292 		port = ntohs(sock_in->sin_port);
293 		port_e = ntohs(sock_in_e->sin_port);
294 	}
295 
296 	if (ip_match && (port_e == port) &&
297 	    (np->np_network_transport == network_transport))
298 		return true;
299 
300 	return false;
301 }
302 
303 static struct iscsi_np *iscsit_get_np(
304 	struct sockaddr_storage *sockaddr,
305 	int network_transport)
306 {
307 	struct iscsi_np *np;
308 	bool match;
309 
310 	lockdep_assert_held(&np_lock);
311 
312 	list_for_each_entry(np, &g_np_list, np_list) {
313 		spin_lock_bh(&np->np_thread_lock);
314 		if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
315 			spin_unlock_bh(&np->np_thread_lock);
316 			continue;
317 		}
318 
319 		match = iscsit_check_np_match(sockaddr, np, network_transport);
320 		if (match) {
321 			/*
322 			 * Increment the np_exports reference count now to
323 			 * prevent iscsit_del_np() below from being called
324 			 * while iscsi_tpg_add_network_portal() is called.
325 			 */
326 			np->np_exports++;
327 			spin_unlock_bh(&np->np_thread_lock);
328 			return np;
329 		}
330 		spin_unlock_bh(&np->np_thread_lock);
331 	}
332 
333 	return NULL;
334 }
335 
336 struct iscsi_np *iscsit_add_np(
337 	struct sockaddr_storage *sockaddr,
338 	int network_transport)
339 {
340 	struct iscsi_np *np;
341 	int ret;
342 
343 	mutex_lock(&np_lock);
344 
345 	/*
346 	 * Locate the existing struct iscsi_np if already active..
347 	 */
348 	np = iscsit_get_np(sockaddr, network_transport);
349 	if (np) {
350 		mutex_unlock(&np_lock);
351 		return np;
352 	}
353 
354 	np = kzalloc(sizeof(*np), GFP_KERNEL);
355 	if (!np) {
356 		mutex_unlock(&np_lock);
357 		return ERR_PTR(-ENOMEM);
358 	}
359 
360 	np->np_flags |= NPF_IP_NETWORK;
361 	np->np_network_transport = network_transport;
362 	spin_lock_init(&np->np_thread_lock);
363 	init_completion(&np->np_restart_comp);
364 	INIT_LIST_HEAD(&np->np_list);
365 
366 	timer_setup(&np->np_login_timer, iscsi_handle_login_thread_timeout, 0);
367 
368 	ret = iscsi_target_setup_login_socket(np, sockaddr);
369 	if (ret != 0) {
370 		kfree(np);
371 		mutex_unlock(&np_lock);
372 		return ERR_PTR(ret);
373 	}
374 
375 	np->np_thread = kthread_run(iscsi_target_login_thread, np, "iscsi_np");
376 	if (IS_ERR(np->np_thread)) {
377 		pr_err("Unable to create kthread: iscsi_np\n");
378 		ret = PTR_ERR(np->np_thread);
379 		kfree(np);
380 		mutex_unlock(&np_lock);
381 		return ERR_PTR(ret);
382 	}
383 	/*
384 	 * Increment the np_exports reference count now to prevent
385 	 * iscsit_del_np() below from being run while a new call to
386 	 * iscsi_tpg_add_network_portal() for a matching iscsi_np is
387 	 * active.  We don't need to hold np->np_thread_lock at this
388 	 * point because iscsi_np has not been added to g_np_list yet.
389 	 */
390 	np->np_exports = 1;
391 	np->np_thread_state = ISCSI_NP_THREAD_ACTIVE;
392 
393 	list_add_tail(&np->np_list, &g_np_list);
394 	mutex_unlock(&np_lock);
395 
396 	pr_debug("CORE[0] - Added Network Portal: %pISpc on %s\n",
397 		&np->np_sockaddr, np->np_transport->name);
398 
399 	return np;
400 }
401 
402 int iscsit_reset_np_thread(
403 	struct iscsi_np *np,
404 	struct iscsi_tpg_np *tpg_np,
405 	struct iscsi_portal_group *tpg,
406 	bool shutdown)
407 {
408 	spin_lock_bh(&np->np_thread_lock);
409 	if (np->np_thread_state == ISCSI_NP_THREAD_INACTIVE) {
410 		spin_unlock_bh(&np->np_thread_lock);
411 		return 0;
412 	}
413 	np->np_thread_state = ISCSI_NP_THREAD_RESET;
414 	atomic_inc(&np->np_reset_count);
415 
416 	if (np->np_thread) {
417 		spin_unlock_bh(&np->np_thread_lock);
418 		send_sig(SIGINT, np->np_thread, 1);
419 		wait_for_completion(&np->np_restart_comp);
420 		spin_lock_bh(&np->np_thread_lock);
421 	}
422 	spin_unlock_bh(&np->np_thread_lock);
423 
424 	if (tpg_np && shutdown) {
425 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
426 
427 		wait_for_completion(&tpg_np->tpg_np_comp);
428 	}
429 
430 	return 0;
431 }
432 
433 static void iscsit_free_np(struct iscsi_np *np)
434 {
435 	if (np->np_socket)
436 		sock_release(np->np_socket);
437 }
438 
439 int iscsit_del_np(struct iscsi_np *np)
440 {
441 	spin_lock_bh(&np->np_thread_lock);
442 	np->np_exports--;
443 	if (np->np_exports) {
444 		np->enabled = true;
445 		spin_unlock_bh(&np->np_thread_lock);
446 		return 0;
447 	}
448 	np->np_thread_state = ISCSI_NP_THREAD_SHUTDOWN;
449 	spin_unlock_bh(&np->np_thread_lock);
450 
451 	if (np->np_thread) {
452 		/*
453 		 * We need to send the signal to wakeup Linux/Net
454 		 * which may be sleeping in sock_accept()..
455 		 */
456 		send_sig(SIGINT, np->np_thread, 1);
457 		kthread_stop(np->np_thread);
458 		np->np_thread = NULL;
459 	}
460 
461 	np->np_transport->iscsit_free_np(np);
462 
463 	mutex_lock(&np_lock);
464 	list_del(&np->np_list);
465 	mutex_unlock(&np_lock);
466 
467 	pr_debug("CORE[0] - Removed Network Portal: %pISpc on %s\n",
468 		&np->np_sockaddr, np->np_transport->name);
469 
470 	iscsit_put_transport(np->np_transport);
471 	kfree(np);
472 	return 0;
473 }
474 
475 static void iscsit_get_rx_pdu(struct iscsi_conn *);
476 
477 int iscsit_queue_rsp(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
478 {
479 	return iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
480 }
481 EXPORT_SYMBOL(iscsit_queue_rsp);
482 
483 void iscsit_aborted_task(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
484 {
485 	spin_lock_bh(&conn->cmd_lock);
486 	if (!list_empty(&cmd->i_conn_node))
487 		list_del_init(&cmd->i_conn_node);
488 	spin_unlock_bh(&conn->cmd_lock);
489 
490 	__iscsit_free_cmd(cmd, true);
491 }
492 EXPORT_SYMBOL(iscsit_aborted_task);
493 
494 static void iscsit_do_crypto_hash_buf(struct ahash_request *, const void *,
495 				      u32, u32, const void *, void *);
496 static void iscsit_tx_thread_wait_for_tcp(struct iscsi_conn *);
497 
498 static int
499 iscsit_xmit_nondatain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
500 			  const void *data_buf, u32 data_buf_len)
501 {
502 	struct iscsi_hdr *hdr = (struct iscsi_hdr *)cmd->pdu;
503 	struct kvec *iov;
504 	u32 niov = 0, tx_size = ISCSI_HDR_LEN;
505 	int ret;
506 
507 	iov = &cmd->iov_misc[0];
508 	iov[niov].iov_base	= cmd->pdu;
509 	iov[niov++].iov_len	= ISCSI_HDR_LEN;
510 
511 	if (conn->conn_ops->HeaderDigest) {
512 		u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];
513 
514 		iscsit_do_crypto_hash_buf(conn->conn_tx_hash, hdr,
515 					  ISCSI_HDR_LEN, 0, NULL,
516 					  header_digest);
517 
518 		iov[0].iov_len += ISCSI_CRC_LEN;
519 		tx_size += ISCSI_CRC_LEN;
520 		pr_debug("Attaching CRC32C HeaderDigest"
521 			 " to opcode 0x%x 0x%08x\n",
522 			 hdr->opcode, *header_digest);
523 	}
524 
525 	if (data_buf_len) {
526 		u32 padding = ((-data_buf_len) & 3);
527 
528 		iov[niov].iov_base	= (void *)data_buf;
529 		iov[niov++].iov_len	= data_buf_len;
530 		tx_size += data_buf_len;
531 
532 		if (padding != 0) {
533 			iov[niov].iov_base = &cmd->pad_bytes;
534 			iov[niov++].iov_len = padding;
535 			tx_size += padding;
536 			pr_debug("Attaching %u additional"
537 				 " padding bytes.\n", padding);
538 		}
539 
540 		if (conn->conn_ops->DataDigest) {
541 			iscsit_do_crypto_hash_buf(conn->conn_tx_hash,
542 						  data_buf, data_buf_len,
543 						  padding, &cmd->pad_bytes,
544 						  &cmd->data_crc);
545 
546 			iov[niov].iov_base = &cmd->data_crc;
547 			iov[niov++].iov_len = ISCSI_CRC_LEN;
548 			tx_size += ISCSI_CRC_LEN;
549 			pr_debug("Attached DataDigest for %u"
550 				 " bytes opcode 0x%x, CRC 0x%08x\n",
551 				 data_buf_len, hdr->opcode, cmd->data_crc);
552 		}
553 	}
554 
555 	cmd->iov_misc_count = niov;
556 	cmd->tx_size = tx_size;
557 
558 	ret = iscsit_send_tx_data(cmd, conn, 1);
559 	if (ret < 0) {
560 		iscsit_tx_thread_wait_for_tcp(conn);
561 		return ret;
562 	}
563 
564 	return 0;
565 }
566 
567 static int iscsit_map_iovec(struct iscsi_cmd *cmd, struct kvec *iov, int nvec,
568 			    u32 data_offset, u32 data_length);
569 static void iscsit_unmap_iovec(struct iscsi_cmd *);
570 static u32 iscsit_do_crypto_hash_sg(struct ahash_request *, struct iscsi_cmd *,
571 				    u32, u32, u32, u8 *);
572 static int
573 iscsit_xmit_datain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
574 		       const struct iscsi_datain *datain)
575 {
576 	struct kvec *iov;
577 	u32 iov_count = 0, tx_size = 0;
578 	int ret, iov_ret;
579 
580 	iov = &cmd->iov_data[0];
581 	iov[iov_count].iov_base	= cmd->pdu;
582 	iov[iov_count++].iov_len = ISCSI_HDR_LEN;
583 	tx_size += ISCSI_HDR_LEN;
584 
585 	if (conn->conn_ops->HeaderDigest) {
586 		u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];
587 
588 		iscsit_do_crypto_hash_buf(conn->conn_tx_hash, cmd->pdu,
589 					  ISCSI_HDR_LEN, 0, NULL,
590 					  header_digest);
591 
592 		iov[0].iov_len += ISCSI_CRC_LEN;
593 		tx_size += ISCSI_CRC_LEN;
594 
595 		pr_debug("Attaching CRC32 HeaderDigest for DataIN PDU 0x%08x\n",
596 			 *header_digest);
597 	}
598 
599 	iov_ret = iscsit_map_iovec(cmd, &cmd->iov_data[iov_count],
600 				   cmd->orig_iov_data_count - (iov_count + 2),
601 				   datain->offset, datain->length);
602 	if (iov_ret < 0)
603 		return -1;
604 
605 	iov_count += iov_ret;
606 	tx_size += datain->length;
607 
608 	cmd->padding = ((-datain->length) & 3);
609 	if (cmd->padding) {
610 		iov[iov_count].iov_base		= cmd->pad_bytes;
611 		iov[iov_count++].iov_len	= cmd->padding;
612 		tx_size += cmd->padding;
613 
614 		pr_debug("Attaching %u padding bytes\n", cmd->padding);
615 	}
616 
617 	if (conn->conn_ops->DataDigest) {
618 		cmd->data_crc = iscsit_do_crypto_hash_sg(conn->conn_tx_hash,
619 							 cmd, datain->offset,
620 							 datain->length,
621 							 cmd->padding,
622 							 cmd->pad_bytes);
623 
624 		iov[iov_count].iov_base	= &cmd->data_crc;
625 		iov[iov_count++].iov_len = ISCSI_CRC_LEN;
626 		tx_size += ISCSI_CRC_LEN;
627 
628 		pr_debug("Attached CRC32C DataDigest %d bytes, crc 0x%08x\n",
629 			 datain->length + cmd->padding, cmd->data_crc);
630 	}
631 
632 	cmd->iov_data_count = iov_count;
633 	cmd->tx_size = tx_size;
634 
635 	ret = iscsit_fe_sendpage_sg(cmd, conn);
636 
637 	iscsit_unmap_iovec(cmd);
638 
639 	if (ret < 0) {
640 		iscsit_tx_thread_wait_for_tcp(conn);
641 		return ret;
642 	}
643 
644 	return 0;
645 }
646 
647 static int iscsit_xmit_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
648 			   struct iscsi_datain_req *dr, const void *buf,
649 			   u32 buf_len)
650 {
651 	if (dr)
652 		return iscsit_xmit_datain_pdu(conn, cmd, buf);
653 	else
654 		return iscsit_xmit_nondatain_pdu(conn, cmd, buf, buf_len);
655 }
656 
657 static enum target_prot_op iscsit_get_sup_prot_ops(struct iscsi_conn *conn)
658 {
659 	return TARGET_PROT_NORMAL;
660 }
661 
662 static struct iscsit_transport iscsi_target_transport = {
663 	.name			= "iSCSI/TCP",
664 	.transport_type		= ISCSI_TCP,
665 	.rdma_shutdown		= false,
666 	.owner			= NULL,
667 	.iscsit_setup_np	= iscsit_setup_np,
668 	.iscsit_accept_np	= iscsit_accept_np,
669 	.iscsit_free_np		= iscsit_free_np,
670 	.iscsit_get_login_rx	= iscsit_get_login_rx,
671 	.iscsit_put_login_tx	= iscsit_put_login_tx,
672 	.iscsit_get_dataout	= iscsit_build_r2ts_for_cmd,
673 	.iscsit_immediate_queue	= iscsit_immediate_queue,
674 	.iscsit_response_queue	= iscsit_response_queue,
675 	.iscsit_queue_data_in	= iscsit_queue_rsp,
676 	.iscsit_queue_status	= iscsit_queue_rsp,
677 	.iscsit_aborted_task	= iscsit_aborted_task,
678 	.iscsit_xmit_pdu	= iscsit_xmit_pdu,
679 	.iscsit_get_rx_pdu	= iscsit_get_rx_pdu,
680 	.iscsit_get_sup_prot_ops = iscsit_get_sup_prot_ops,
681 };
682 
683 static int __init iscsi_target_init_module(void)
684 {
685 	int ret = 0, size;
686 
687 	pr_debug("iSCSI-Target "ISCSIT_VERSION"\n");
688 	iscsit_global = kzalloc(sizeof(*iscsit_global), GFP_KERNEL);
689 	if (!iscsit_global)
690 		return -1;
691 
692 	spin_lock_init(&iscsit_global->ts_bitmap_lock);
693 	mutex_init(&auth_id_lock);
694 	idr_init(&tiqn_idr);
695 
696 	ret = target_register_template(&iscsi_ops);
697 	if (ret)
698 		goto out;
699 
700 	size = BITS_TO_LONGS(ISCSIT_BITMAP_BITS) * sizeof(long);
701 	iscsit_global->ts_bitmap = vzalloc(size);
702 	if (!iscsit_global->ts_bitmap)
703 		goto configfs_out;
704 
705 	lio_qr_cache = kmem_cache_create("lio_qr_cache",
706 			sizeof(struct iscsi_queue_req),
707 			__alignof__(struct iscsi_queue_req), 0, NULL);
708 	if (!lio_qr_cache) {
709 		pr_err("Unable to kmem_cache_create() for"
710 				" lio_qr_cache\n");
711 		goto bitmap_out;
712 	}
713 
714 	lio_dr_cache = kmem_cache_create("lio_dr_cache",
715 			sizeof(struct iscsi_datain_req),
716 			__alignof__(struct iscsi_datain_req), 0, NULL);
717 	if (!lio_dr_cache) {
718 		pr_err("Unable to kmem_cache_create() for"
719 				" lio_dr_cache\n");
720 		goto qr_out;
721 	}
722 
723 	lio_ooo_cache = kmem_cache_create("lio_ooo_cache",
724 			sizeof(struct iscsi_ooo_cmdsn),
725 			__alignof__(struct iscsi_ooo_cmdsn), 0, NULL);
726 	if (!lio_ooo_cache) {
727 		pr_err("Unable to kmem_cache_create() for"
728 				" lio_ooo_cache\n");
729 		goto dr_out;
730 	}
731 
732 	lio_r2t_cache = kmem_cache_create("lio_r2t_cache",
733 			sizeof(struct iscsi_r2t), __alignof__(struct iscsi_r2t),
734 			0, NULL);
735 	if (!lio_r2t_cache) {
736 		pr_err("Unable to kmem_cache_create() for"
737 				" lio_r2t_cache\n");
738 		goto ooo_out;
739 	}
740 
741 	iscsit_register_transport(&iscsi_target_transport);
742 
743 	if (iscsit_load_discovery_tpg() < 0)
744 		goto r2t_out;
745 
746 	return ret;
747 r2t_out:
748 	iscsit_unregister_transport(&iscsi_target_transport);
749 	kmem_cache_destroy(lio_r2t_cache);
750 ooo_out:
751 	kmem_cache_destroy(lio_ooo_cache);
752 dr_out:
753 	kmem_cache_destroy(lio_dr_cache);
754 qr_out:
755 	kmem_cache_destroy(lio_qr_cache);
756 bitmap_out:
757 	vfree(iscsit_global->ts_bitmap);
758 configfs_out:
759 	/* XXX: this probably wants it to be it's own unwind step.. */
760 	if (iscsit_global->discovery_tpg)
761 		iscsit_tpg_disable_portal_group(iscsit_global->discovery_tpg, 1);
762 	target_unregister_template(&iscsi_ops);
763 out:
764 	kfree(iscsit_global);
765 	return -ENOMEM;
766 }
767 
768 static void __exit iscsi_target_cleanup_module(void)
769 {
770 	iscsit_release_discovery_tpg();
771 	iscsit_unregister_transport(&iscsi_target_transport);
772 	kmem_cache_destroy(lio_qr_cache);
773 	kmem_cache_destroy(lio_dr_cache);
774 	kmem_cache_destroy(lio_ooo_cache);
775 	kmem_cache_destroy(lio_r2t_cache);
776 
777 	/*
778 	 * Shutdown discovery sessions and disable discovery TPG
779 	 */
780 	if (iscsit_global->discovery_tpg)
781 		iscsit_tpg_disable_portal_group(iscsit_global->discovery_tpg, 1);
782 
783 	target_unregister_template(&iscsi_ops);
784 
785 	vfree(iscsit_global->ts_bitmap);
786 	kfree(iscsit_global);
787 }
788 
789 int iscsit_add_reject(
790 	struct iscsi_conn *conn,
791 	u8 reason,
792 	unsigned char *buf)
793 {
794 	struct iscsi_cmd *cmd;
795 
796 	cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
797 	if (!cmd)
798 		return -1;
799 
800 	cmd->iscsi_opcode = ISCSI_OP_REJECT;
801 	cmd->reject_reason = reason;
802 
803 	cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL);
804 	if (!cmd->buf_ptr) {
805 		pr_err("Unable to allocate memory for cmd->buf_ptr\n");
806 		iscsit_free_cmd(cmd, false);
807 		return -1;
808 	}
809 
810 	spin_lock_bh(&conn->cmd_lock);
811 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
812 	spin_unlock_bh(&conn->cmd_lock);
813 
814 	cmd->i_state = ISTATE_SEND_REJECT;
815 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
816 
817 	return -1;
818 }
819 EXPORT_SYMBOL(iscsit_add_reject);
820 
821 static int iscsit_add_reject_from_cmd(
822 	struct iscsi_cmd *cmd,
823 	u8 reason,
824 	bool add_to_conn,
825 	unsigned char *buf)
826 {
827 	struct iscsi_conn *conn;
828 	const bool do_put = cmd->se_cmd.se_tfo != NULL;
829 
830 	if (!cmd->conn) {
831 		pr_err("cmd->conn is NULL for ITT: 0x%08x\n",
832 				cmd->init_task_tag);
833 		return -1;
834 	}
835 	conn = cmd->conn;
836 
837 	cmd->iscsi_opcode = ISCSI_OP_REJECT;
838 	cmd->reject_reason = reason;
839 
840 	cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL);
841 	if (!cmd->buf_ptr) {
842 		pr_err("Unable to allocate memory for cmd->buf_ptr\n");
843 		iscsit_free_cmd(cmd, false);
844 		return -1;
845 	}
846 
847 	if (add_to_conn) {
848 		spin_lock_bh(&conn->cmd_lock);
849 		list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
850 		spin_unlock_bh(&conn->cmd_lock);
851 	}
852 
853 	cmd->i_state = ISTATE_SEND_REJECT;
854 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
855 	/*
856 	 * Perform the kref_put now if se_cmd has already been setup by
857 	 * scsit_setup_scsi_cmd()
858 	 */
859 	if (do_put) {
860 		pr_debug("iscsi reject: calling target_put_sess_cmd >>>>>>\n");
861 		target_put_sess_cmd(&cmd->se_cmd);
862 	}
863 	return -1;
864 }
865 
866 static int iscsit_add_reject_cmd(struct iscsi_cmd *cmd, u8 reason,
867 				 unsigned char *buf)
868 {
869 	return iscsit_add_reject_from_cmd(cmd, reason, true, buf);
870 }
871 
872 int iscsit_reject_cmd(struct iscsi_cmd *cmd, u8 reason, unsigned char *buf)
873 {
874 	return iscsit_add_reject_from_cmd(cmd, reason, false, buf);
875 }
876 EXPORT_SYMBOL(iscsit_reject_cmd);
877 
878 /*
879  * Map some portion of the allocated scatterlist to an iovec, suitable for
880  * kernel sockets to copy data in/out.
881  */
882 static int iscsit_map_iovec(struct iscsi_cmd *cmd, struct kvec *iov, int nvec,
883 			    u32 data_offset, u32 data_length)
884 {
885 	u32 i = 0, orig_data_length = data_length;
886 	struct scatterlist *sg;
887 	unsigned int page_off;
888 
889 	/*
890 	 * We know each entry in t_data_sg contains a page.
891 	 */
892 	u32 ent = data_offset / PAGE_SIZE;
893 
894 	if (!data_length)
895 		return 0;
896 
897 	if (ent >= cmd->se_cmd.t_data_nents) {
898 		pr_err("Initial page entry out-of-bounds\n");
899 		goto overflow;
900 	}
901 
902 	sg = &cmd->se_cmd.t_data_sg[ent];
903 	page_off = (data_offset % PAGE_SIZE);
904 
905 	cmd->first_data_sg = sg;
906 	cmd->first_data_sg_off = page_off;
907 
908 	while (data_length) {
909 		u32 cur_len;
910 
911 		if (WARN_ON_ONCE(!sg || i >= nvec))
912 			goto overflow;
913 
914 		cur_len = min_t(u32, data_length, sg->length - page_off);
915 
916 		iov[i].iov_base = kmap(sg_page(sg)) + sg->offset + page_off;
917 		iov[i].iov_len = cur_len;
918 
919 		data_length -= cur_len;
920 		page_off = 0;
921 		sg = sg_next(sg);
922 		i++;
923 	}
924 
925 	cmd->kmapped_nents = i;
926 
927 	return i;
928 
929 overflow:
930 	pr_err("offset %d + length %d overflow; %d/%d; sg-list:\n",
931 	       data_offset, orig_data_length, i, nvec);
932 	for_each_sg(cmd->se_cmd.t_data_sg, sg,
933 		    cmd->se_cmd.t_data_nents, i) {
934 		pr_err("[%d] off %d len %d\n",
935 		       i, sg->offset, sg->length);
936 	}
937 	return -1;
938 }
939 
940 static void iscsit_unmap_iovec(struct iscsi_cmd *cmd)
941 {
942 	u32 i;
943 	struct scatterlist *sg;
944 
945 	sg = cmd->first_data_sg;
946 
947 	for (i = 0; i < cmd->kmapped_nents; i++)
948 		kunmap(sg_page(&sg[i]));
949 }
950 
951 static void iscsit_ack_from_expstatsn(struct iscsi_conn *conn, u32 exp_statsn)
952 {
953 	LIST_HEAD(ack_list);
954 	struct iscsi_cmd *cmd, *cmd_p;
955 
956 	conn->exp_statsn = exp_statsn;
957 
958 	if (conn->sess->sess_ops->RDMAExtensions)
959 		return;
960 
961 	spin_lock_bh(&conn->cmd_lock);
962 	list_for_each_entry_safe(cmd, cmd_p, &conn->conn_cmd_list, i_conn_node) {
963 		spin_lock(&cmd->istate_lock);
964 		if ((cmd->i_state == ISTATE_SENT_STATUS) &&
965 		    iscsi_sna_lt(cmd->stat_sn, exp_statsn)) {
966 			cmd->i_state = ISTATE_REMOVE;
967 			spin_unlock(&cmd->istate_lock);
968 			list_move_tail(&cmd->i_conn_node, &ack_list);
969 			continue;
970 		}
971 		spin_unlock(&cmd->istate_lock);
972 	}
973 	spin_unlock_bh(&conn->cmd_lock);
974 
975 	list_for_each_entry_safe(cmd, cmd_p, &ack_list, i_conn_node) {
976 		list_del_init(&cmd->i_conn_node);
977 		iscsit_free_cmd(cmd, false);
978 	}
979 }
980 
981 static int iscsit_allocate_iovecs(struct iscsi_cmd *cmd)
982 {
983 	u32 iov_count = max(1UL, DIV_ROUND_UP(cmd->se_cmd.data_length, PAGE_SIZE));
984 
985 	iov_count += ISCSI_IOV_DATA_BUFFER;
986 	cmd->iov_data = kcalloc(iov_count, sizeof(*cmd->iov_data), GFP_KERNEL);
987 	if (!cmd->iov_data)
988 		return -ENOMEM;
989 
990 	cmd->orig_iov_data_count = iov_count;
991 	return 0;
992 }
993 
994 int iscsit_setup_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
995 			  unsigned char *buf)
996 {
997 	int data_direction, payload_length;
998 	struct iscsi_scsi_req *hdr;
999 	int iscsi_task_attr;
1000 	int sam_task_attr;
1001 
1002 	atomic_long_inc(&conn->sess->cmd_pdus);
1003 
1004 	hdr			= (struct iscsi_scsi_req *) buf;
1005 	payload_length		= ntoh24(hdr->dlength);
1006 
1007 	/* FIXME; Add checks for AdditionalHeaderSegment */
1008 
1009 	if (!(hdr->flags & ISCSI_FLAG_CMD_WRITE) &&
1010 	    !(hdr->flags & ISCSI_FLAG_CMD_FINAL)) {
1011 		pr_err("ISCSI_FLAG_CMD_WRITE & ISCSI_FLAG_CMD_FINAL"
1012 				" not set. Bad iSCSI Initiator.\n");
1013 		return iscsit_add_reject_cmd(cmd,
1014 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1015 	}
1016 
1017 	if (((hdr->flags & ISCSI_FLAG_CMD_READ) ||
1018 	     (hdr->flags & ISCSI_FLAG_CMD_WRITE)) && !hdr->data_length) {
1019 		/*
1020 		 * From RFC-3720 Section 10.3.1:
1021 		 *
1022 		 * "Either or both of R and W MAY be 1 when either the
1023 		 *  Expected Data Transfer Length and/or Bidirectional Read
1024 		 *  Expected Data Transfer Length are 0"
1025 		 *
1026 		 * For this case, go ahead and clear the unnecssary bits
1027 		 * to avoid any confusion with ->data_direction.
1028 		 */
1029 		hdr->flags &= ~ISCSI_FLAG_CMD_READ;
1030 		hdr->flags &= ~ISCSI_FLAG_CMD_WRITE;
1031 
1032 		pr_warn("ISCSI_FLAG_CMD_READ or ISCSI_FLAG_CMD_WRITE"
1033 			" set when Expected Data Transfer Length is 0 for"
1034 			" CDB: 0x%02x, Fixing up flags\n", hdr->cdb[0]);
1035 	}
1036 
1037 	if (!(hdr->flags & ISCSI_FLAG_CMD_READ) &&
1038 	    !(hdr->flags & ISCSI_FLAG_CMD_WRITE) && (hdr->data_length != 0)) {
1039 		pr_err("ISCSI_FLAG_CMD_READ and/or ISCSI_FLAG_CMD_WRITE"
1040 			" MUST be set if Expected Data Transfer Length is not 0."
1041 			" Bad iSCSI Initiator\n");
1042 		return iscsit_add_reject_cmd(cmd,
1043 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1044 	}
1045 
1046 	if ((hdr->flags & ISCSI_FLAG_CMD_READ) &&
1047 	    (hdr->flags & ISCSI_FLAG_CMD_WRITE)) {
1048 		pr_err("Bidirectional operations not supported!\n");
1049 		return iscsit_add_reject_cmd(cmd,
1050 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1051 	}
1052 
1053 	if (hdr->opcode & ISCSI_OP_IMMEDIATE) {
1054 		pr_err("Illegally set Immediate Bit in iSCSI Initiator"
1055 				" Scsi Command PDU.\n");
1056 		return iscsit_add_reject_cmd(cmd,
1057 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1058 	}
1059 
1060 	if (payload_length && !conn->sess->sess_ops->ImmediateData) {
1061 		pr_err("ImmediateData=No but DataSegmentLength=%u,"
1062 			" protocol error.\n", payload_length);
1063 		return iscsit_add_reject_cmd(cmd,
1064 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1065 	}
1066 
1067 	if ((be32_to_cpu(hdr->data_length) == payload_length) &&
1068 	    (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))) {
1069 		pr_err("Expected Data Transfer Length and Length of"
1070 			" Immediate Data are the same, but ISCSI_FLAG_CMD_FINAL"
1071 			" bit is not set protocol error\n");
1072 		return iscsit_add_reject_cmd(cmd,
1073 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1074 	}
1075 
1076 	if (payload_length > be32_to_cpu(hdr->data_length)) {
1077 		pr_err("DataSegmentLength: %u is greater than"
1078 			" EDTL: %u, protocol error.\n", payload_length,
1079 				hdr->data_length);
1080 		return iscsit_add_reject_cmd(cmd,
1081 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1082 	}
1083 
1084 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1085 		pr_err("DataSegmentLength: %u is greater than"
1086 			" MaxXmitDataSegmentLength: %u, protocol error.\n",
1087 			payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
1088 		return iscsit_add_reject_cmd(cmd,
1089 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
1090 	}
1091 
1092 	if (payload_length > conn->sess->sess_ops->FirstBurstLength) {
1093 		pr_err("DataSegmentLength: %u is greater than"
1094 			" FirstBurstLength: %u, protocol error.\n",
1095 			payload_length, conn->sess->sess_ops->FirstBurstLength);
1096 		return iscsit_add_reject_cmd(cmd,
1097 					     ISCSI_REASON_BOOKMARK_INVALID, buf);
1098 	}
1099 
1100 	data_direction = (hdr->flags & ISCSI_FLAG_CMD_WRITE) ? DMA_TO_DEVICE :
1101 			 (hdr->flags & ISCSI_FLAG_CMD_READ) ? DMA_FROM_DEVICE :
1102 			  DMA_NONE;
1103 
1104 	cmd->data_direction = data_direction;
1105 	iscsi_task_attr = hdr->flags & ISCSI_FLAG_CMD_ATTR_MASK;
1106 	/*
1107 	 * Figure out the SAM Task Attribute for the incoming SCSI CDB
1108 	 */
1109 	if ((iscsi_task_attr == ISCSI_ATTR_UNTAGGED) ||
1110 	    (iscsi_task_attr == ISCSI_ATTR_SIMPLE))
1111 		sam_task_attr = TCM_SIMPLE_TAG;
1112 	else if (iscsi_task_attr == ISCSI_ATTR_ORDERED)
1113 		sam_task_attr = TCM_ORDERED_TAG;
1114 	else if (iscsi_task_attr == ISCSI_ATTR_HEAD_OF_QUEUE)
1115 		sam_task_attr = TCM_HEAD_TAG;
1116 	else if (iscsi_task_attr == ISCSI_ATTR_ACA)
1117 		sam_task_attr = TCM_ACA_TAG;
1118 	else {
1119 		pr_debug("Unknown iSCSI Task Attribute: 0x%02x, using"
1120 			" TCM_SIMPLE_TAG\n", iscsi_task_attr);
1121 		sam_task_attr = TCM_SIMPLE_TAG;
1122 	}
1123 
1124 	cmd->iscsi_opcode	= ISCSI_OP_SCSI_CMD;
1125 	cmd->i_state		= ISTATE_NEW_CMD;
1126 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
1127 	cmd->immediate_data	= (payload_length) ? 1 : 0;
1128 	cmd->unsolicited_data	= ((!(hdr->flags & ISCSI_FLAG_CMD_FINAL) &&
1129 				     (hdr->flags & ISCSI_FLAG_CMD_WRITE)) ? 1 : 0);
1130 	if (cmd->unsolicited_data)
1131 		cmd->cmd_flags |= ICF_NON_IMMEDIATE_UNSOLICITED_DATA;
1132 
1133 	conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
1134 	if (hdr->flags & ISCSI_FLAG_CMD_READ)
1135 		cmd->targ_xfer_tag = session_get_next_ttt(conn->sess);
1136 	else
1137 		cmd->targ_xfer_tag = 0xFFFFFFFF;
1138 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
1139 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
1140 	cmd->first_burst_len	= payload_length;
1141 
1142 	if (!conn->sess->sess_ops->RDMAExtensions &&
1143 	     cmd->data_direction == DMA_FROM_DEVICE) {
1144 		struct iscsi_datain_req *dr;
1145 
1146 		dr = iscsit_allocate_datain_req();
1147 		if (!dr)
1148 			return iscsit_add_reject_cmd(cmd,
1149 					ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1150 
1151 		iscsit_attach_datain_req(cmd, dr);
1152 	}
1153 
1154 	/*
1155 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
1156 	 */
1157 	transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops,
1158 			conn->sess->se_sess, be32_to_cpu(hdr->data_length),
1159 			cmd->data_direction, sam_task_attr,
1160 			cmd->sense_buffer + 2, scsilun_to_int(&hdr->lun));
1161 
1162 	pr_debug("Got SCSI Command, ITT: 0x%08x, CmdSN: 0x%08x,"
1163 		" ExpXferLen: %u, Length: %u, CID: %hu\n", hdr->itt,
1164 		hdr->cmdsn, be32_to_cpu(hdr->data_length), payload_length,
1165 		conn->cid);
1166 
1167 	target_get_sess_cmd(&cmd->se_cmd, true);
1168 
1169 	cmd->sense_reason = target_cmd_init_cdb(&cmd->se_cmd, hdr->cdb);
1170 	if (cmd->sense_reason) {
1171 		if (cmd->sense_reason == TCM_OUT_OF_RESOURCES) {
1172 			return iscsit_add_reject_cmd(cmd,
1173 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1174 		}
1175 
1176 		goto attach_cmd;
1177 	}
1178 
1179 	cmd->sense_reason = transport_lookup_cmd_lun(&cmd->se_cmd);
1180 	if (cmd->sense_reason)
1181 		goto attach_cmd;
1182 
1183 	/* only used for printks or comparing with ->ref_task_tag */
1184 	cmd->se_cmd.tag = (__force u32)cmd->init_task_tag;
1185 	cmd->sense_reason = target_cmd_parse_cdb(&cmd->se_cmd);
1186 	if (cmd->sense_reason)
1187 		goto attach_cmd;
1188 
1189 	if (iscsit_build_pdu_and_seq_lists(cmd, payload_length) < 0) {
1190 		return iscsit_add_reject_cmd(cmd,
1191 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1192 	}
1193 
1194 attach_cmd:
1195 	spin_lock_bh(&conn->cmd_lock);
1196 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
1197 	spin_unlock_bh(&conn->cmd_lock);
1198 	/*
1199 	 * Check if we need to delay processing because of ALUA
1200 	 * Active/NonOptimized primary access state..
1201 	 */
1202 	core_alua_check_nonop_delay(&cmd->se_cmd);
1203 
1204 	return 0;
1205 }
1206 EXPORT_SYMBOL(iscsit_setup_scsi_cmd);
1207 
1208 void iscsit_set_unsolicited_dataout(struct iscsi_cmd *cmd)
1209 {
1210 	iscsit_set_dataout_sequence_values(cmd);
1211 
1212 	spin_lock_bh(&cmd->dataout_timeout_lock);
1213 	iscsit_start_dataout_timer(cmd, cmd->conn);
1214 	spin_unlock_bh(&cmd->dataout_timeout_lock);
1215 }
1216 EXPORT_SYMBOL(iscsit_set_unsolicited_dataout);
1217 
1218 int iscsit_process_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1219 			    struct iscsi_scsi_req *hdr)
1220 {
1221 	int cmdsn_ret = 0;
1222 	/*
1223 	 * Check the CmdSN against ExpCmdSN/MaxCmdSN here if
1224 	 * the Immediate Bit is not set, and no Immediate
1225 	 * Data is attached.
1226 	 *
1227 	 * A PDU/CmdSN carrying Immediate Data can only
1228 	 * be processed after the DataCRC has passed.
1229 	 * If the DataCRC fails, the CmdSN MUST NOT
1230 	 * be acknowledged. (See below)
1231 	 */
1232 	if (!cmd->immediate_data) {
1233 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
1234 					(unsigned char *)hdr, hdr->cmdsn);
1235 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1236 			return -1;
1237 		else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
1238 			target_put_sess_cmd(&cmd->se_cmd);
1239 			return 0;
1240 		}
1241 	}
1242 
1243 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
1244 
1245 	/*
1246 	 * If no Immediate Data is attached, it's OK to return now.
1247 	 */
1248 	if (!cmd->immediate_data) {
1249 		if (!cmd->sense_reason && cmd->unsolicited_data)
1250 			iscsit_set_unsolicited_dataout(cmd);
1251 		if (!cmd->sense_reason)
1252 			return 0;
1253 
1254 		target_put_sess_cmd(&cmd->se_cmd);
1255 		return 0;
1256 	}
1257 
1258 	/*
1259 	 * Early CHECK_CONDITIONs with ImmediateData never make it to command
1260 	 * execution.  These exceptions are processed in CmdSN order using
1261 	 * iscsit_check_received_cmdsn() in iscsit_get_immediate_data() below.
1262 	 */
1263 	if (cmd->sense_reason)
1264 		return 1;
1265 	/*
1266 	 * Call directly into transport_generic_new_cmd() to perform
1267 	 * the backend memory allocation.
1268 	 */
1269 	cmd->sense_reason = transport_generic_new_cmd(&cmd->se_cmd);
1270 	if (cmd->sense_reason)
1271 		return 1;
1272 
1273 	return 0;
1274 }
1275 EXPORT_SYMBOL(iscsit_process_scsi_cmd);
1276 
1277 static int
1278 iscsit_get_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
1279 			  bool dump_payload)
1280 {
1281 	int cmdsn_ret = 0, immed_ret = IMMEDIATE_DATA_NORMAL_OPERATION;
1282 	int rc;
1283 
1284 	/*
1285 	 * Special case for Unsupported SAM WRITE Opcodes and ImmediateData=Yes.
1286 	 */
1287 	if (dump_payload) {
1288 		u32 length = min(cmd->se_cmd.data_length - cmd->write_data_done,
1289 				 cmd->first_burst_len);
1290 
1291 		pr_debug("Dumping min(%d - %d, %d) = %d bytes of immediate data\n",
1292 			 cmd->se_cmd.data_length, cmd->write_data_done,
1293 			 cmd->first_burst_len, length);
1294 		rc = iscsit_dump_data_payload(cmd->conn, length, 1);
1295 		pr_debug("Finished dumping immediate data\n");
1296 		if (rc < 0)
1297 			immed_ret = IMMEDIATE_DATA_CANNOT_RECOVER;
1298 	} else {
1299 		immed_ret = iscsit_handle_immediate_data(cmd, hdr,
1300 							 cmd->first_burst_len);
1301 	}
1302 
1303 	if (immed_ret == IMMEDIATE_DATA_NORMAL_OPERATION) {
1304 		/*
1305 		 * A PDU/CmdSN carrying Immediate Data passed
1306 		 * DataCRC, check against ExpCmdSN/MaxCmdSN if
1307 		 * Immediate Bit is not set.
1308 		 */
1309 		cmdsn_ret = iscsit_sequence_cmd(cmd->conn, cmd,
1310 					(unsigned char *)hdr, hdr->cmdsn);
1311 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1312 			return -1;
1313 
1314 		if (cmd->sense_reason || cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
1315 			target_put_sess_cmd(&cmd->se_cmd);
1316 
1317 			return 0;
1318 		} else if (cmd->unsolicited_data)
1319 			iscsit_set_unsolicited_dataout(cmd);
1320 
1321 	} else if (immed_ret == IMMEDIATE_DATA_ERL1_CRC_FAILURE) {
1322 		/*
1323 		 * Immediate Data failed DataCRC and ERL>=1,
1324 		 * silently drop this PDU and let the initiator
1325 		 * plug the CmdSN gap.
1326 		 *
1327 		 * FIXME: Send Unsolicited NOPIN with reserved
1328 		 * TTT here to help the initiator figure out
1329 		 * the missing CmdSN, although they should be
1330 		 * intelligent enough to determine the missing
1331 		 * CmdSN and issue a retry to plug the sequence.
1332 		 */
1333 		cmd->i_state = ISTATE_REMOVE;
1334 		iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, cmd->i_state);
1335 	} else /* immed_ret == IMMEDIATE_DATA_CANNOT_RECOVER */
1336 		return -1;
1337 
1338 	return 0;
1339 }
1340 
1341 static int
1342 iscsit_handle_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1343 			   unsigned char *buf)
1344 {
1345 	struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)buf;
1346 	int rc, immed_data;
1347 	bool dump_payload = false;
1348 
1349 	rc = iscsit_setup_scsi_cmd(conn, cmd, buf);
1350 	if (rc < 0)
1351 		return 0;
1352 	/*
1353 	 * Allocation iovecs needed for struct socket operations for
1354 	 * traditional iSCSI block I/O.
1355 	 */
1356 	if (iscsit_allocate_iovecs(cmd) < 0) {
1357 		return iscsit_reject_cmd(cmd,
1358 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
1359 	}
1360 	immed_data = cmd->immediate_data;
1361 
1362 	rc = iscsit_process_scsi_cmd(conn, cmd, hdr);
1363 	if (rc < 0)
1364 		return rc;
1365 	else if (rc > 0)
1366 		dump_payload = true;
1367 
1368 	if (!immed_data)
1369 		return 0;
1370 
1371 	return iscsit_get_immediate_data(cmd, hdr, dump_payload);
1372 }
1373 
1374 static u32 iscsit_do_crypto_hash_sg(
1375 	struct ahash_request *hash,
1376 	struct iscsi_cmd *cmd,
1377 	u32 data_offset,
1378 	u32 data_length,
1379 	u32 padding,
1380 	u8 *pad_bytes)
1381 {
1382 	u32 data_crc;
1383 	struct scatterlist *sg;
1384 	unsigned int page_off;
1385 
1386 	crypto_ahash_init(hash);
1387 
1388 	sg = cmd->first_data_sg;
1389 	page_off = cmd->first_data_sg_off;
1390 
1391 	if (data_length && page_off) {
1392 		struct scatterlist first_sg;
1393 		u32 len = min_t(u32, data_length, sg->length - page_off);
1394 
1395 		sg_init_table(&first_sg, 1);
1396 		sg_set_page(&first_sg, sg_page(sg), len, sg->offset + page_off);
1397 
1398 		ahash_request_set_crypt(hash, &first_sg, NULL, len);
1399 		crypto_ahash_update(hash);
1400 
1401 		data_length -= len;
1402 		sg = sg_next(sg);
1403 	}
1404 
1405 	while (data_length) {
1406 		u32 cur_len = min_t(u32, data_length, sg->length);
1407 
1408 		ahash_request_set_crypt(hash, sg, NULL, cur_len);
1409 		crypto_ahash_update(hash);
1410 
1411 		data_length -= cur_len;
1412 		/* iscsit_map_iovec has already checked for invalid sg pointers */
1413 		sg = sg_next(sg);
1414 	}
1415 
1416 	if (padding) {
1417 		struct scatterlist pad_sg;
1418 
1419 		sg_init_one(&pad_sg, pad_bytes, padding);
1420 		ahash_request_set_crypt(hash, &pad_sg, (u8 *)&data_crc,
1421 					padding);
1422 		crypto_ahash_finup(hash);
1423 	} else {
1424 		ahash_request_set_crypt(hash, NULL, (u8 *)&data_crc, 0);
1425 		crypto_ahash_final(hash);
1426 	}
1427 
1428 	return data_crc;
1429 }
1430 
1431 static void iscsit_do_crypto_hash_buf(struct ahash_request *hash,
1432 	const void *buf, u32 payload_length, u32 padding,
1433 	const void *pad_bytes, void *data_crc)
1434 {
1435 	struct scatterlist sg[2];
1436 
1437 	sg_init_table(sg, ARRAY_SIZE(sg));
1438 	sg_set_buf(sg, buf, payload_length);
1439 	if (padding)
1440 		sg_set_buf(sg + 1, pad_bytes, padding);
1441 
1442 	ahash_request_set_crypt(hash, sg, data_crc, payload_length + padding);
1443 
1444 	crypto_ahash_digest(hash);
1445 }
1446 
1447 int
1448 __iscsit_check_dataout_hdr(struct iscsi_conn *conn, void *buf,
1449 			   struct iscsi_cmd *cmd, u32 payload_length,
1450 			   bool *success)
1451 {
1452 	struct iscsi_data *hdr = buf;
1453 	struct se_cmd *se_cmd;
1454 	int rc;
1455 
1456 	/* iSCSI write */
1457 	atomic_long_add(payload_length, &conn->sess->rx_data_octets);
1458 
1459 	pr_debug("Got DataOut ITT: 0x%08x, TTT: 0x%08x,"
1460 		" DataSN: 0x%08x, Offset: %u, Length: %u, CID: %hu\n",
1461 		hdr->itt, hdr->ttt, hdr->datasn, ntohl(hdr->offset),
1462 		payload_length, conn->cid);
1463 
1464 	if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
1465 		pr_err("Command ITT: 0x%08x received DataOUT after"
1466 			" last DataOUT received, dumping payload\n",
1467 			cmd->init_task_tag);
1468 		return iscsit_dump_data_payload(conn, payload_length, 1);
1469 	}
1470 
1471 	if (cmd->data_direction != DMA_TO_DEVICE) {
1472 		pr_err("Command ITT: 0x%08x received DataOUT for a"
1473 			" NON-WRITE command.\n", cmd->init_task_tag);
1474 		return iscsit_dump_data_payload(conn, payload_length, 1);
1475 	}
1476 	se_cmd = &cmd->se_cmd;
1477 	iscsit_mod_dataout_timer(cmd);
1478 
1479 	if ((be32_to_cpu(hdr->offset) + payload_length) > cmd->se_cmd.data_length) {
1480 		pr_err("DataOut Offset: %u, Length %u greater than iSCSI Command EDTL %u, protocol error.\n",
1481 		       be32_to_cpu(hdr->offset), payload_length,
1482 		       cmd->se_cmd.data_length);
1483 		return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_INVALID, buf);
1484 	}
1485 
1486 	if (cmd->unsolicited_data) {
1487 		int dump_unsolicited_data = 0;
1488 
1489 		if (conn->sess->sess_ops->InitialR2T) {
1490 			pr_err("Received unexpected unsolicited data"
1491 				" while InitialR2T=Yes, protocol error.\n");
1492 			transport_send_check_condition_and_sense(&cmd->se_cmd,
1493 					TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
1494 			return -1;
1495 		}
1496 		/*
1497 		 * Special case for dealing with Unsolicited DataOUT
1498 		 * and Unsupported SAM WRITE Opcodes and SE resource allocation
1499 		 * failures;
1500 		 */
1501 
1502 		/* Something's amiss if we're not in WRITE_PENDING state... */
1503 		WARN_ON(se_cmd->t_state != TRANSPORT_WRITE_PENDING);
1504 		if (!(se_cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE))
1505 			dump_unsolicited_data = 1;
1506 
1507 		if (dump_unsolicited_data) {
1508 			/*
1509 			 * Check if a delayed TASK_ABORTED status needs to
1510 			 * be sent now if the ISCSI_FLAG_CMD_FINAL has been
1511 			 * received with the unsolicited data out.
1512 			 */
1513 			if (hdr->flags & ISCSI_FLAG_CMD_FINAL)
1514 				iscsit_stop_dataout_timer(cmd);
1515 
1516 			return iscsit_dump_data_payload(conn, payload_length, 1);
1517 		}
1518 	} else {
1519 		/*
1520 		 * For the normal solicited data path:
1521 		 *
1522 		 * Check for a delayed TASK_ABORTED status and dump any
1523 		 * incoming data out payload if one exists.  Also, when the
1524 		 * ISCSI_FLAG_CMD_FINAL is set to denote the end of the current
1525 		 * data out sequence, we decrement outstanding_r2ts.  Once
1526 		 * outstanding_r2ts reaches zero, go ahead and send the delayed
1527 		 * TASK_ABORTED status.
1528 		 */
1529 		if (se_cmd->transport_state & CMD_T_ABORTED) {
1530 			if (hdr->flags & ISCSI_FLAG_CMD_FINAL &&
1531 			    --cmd->outstanding_r2ts < 1)
1532 				iscsit_stop_dataout_timer(cmd);
1533 
1534 			return iscsit_dump_data_payload(conn, payload_length, 1);
1535 		}
1536 	}
1537 	/*
1538 	 * Perform DataSN, DataSequenceInOrder, DataPDUInOrder, and
1539 	 * within-command recovery checks before receiving the payload.
1540 	 */
1541 	rc = iscsit_check_pre_dataout(cmd, buf);
1542 	if (rc == DATAOUT_WITHIN_COMMAND_RECOVERY)
1543 		return 0;
1544 	else if (rc == DATAOUT_CANNOT_RECOVER)
1545 		return -1;
1546 	*success = true;
1547 	return 0;
1548 }
1549 EXPORT_SYMBOL(__iscsit_check_dataout_hdr);
1550 
1551 int
1552 iscsit_check_dataout_hdr(struct iscsi_conn *conn, void *buf,
1553 			 struct iscsi_cmd **out_cmd)
1554 {
1555 	struct iscsi_data *hdr = buf;
1556 	struct iscsi_cmd *cmd;
1557 	u32 payload_length = ntoh24(hdr->dlength);
1558 	int rc;
1559 	bool success = false;
1560 
1561 	if (!payload_length) {
1562 		pr_warn_ratelimited("DataOUT payload is ZERO, ignoring.\n");
1563 		return 0;
1564 	}
1565 
1566 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1567 		pr_err_ratelimited("DataSegmentLength: %u is greater than"
1568 			" MaxXmitDataSegmentLength: %u\n", payload_length,
1569 			conn->conn_ops->MaxXmitDataSegmentLength);
1570 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR, buf);
1571 	}
1572 
1573 	cmd = iscsit_find_cmd_from_itt_or_dump(conn, hdr->itt, payload_length);
1574 	if (!cmd)
1575 		return 0;
1576 
1577 	rc = __iscsit_check_dataout_hdr(conn, buf, cmd, payload_length, &success);
1578 
1579 	if (success)
1580 		*out_cmd = cmd;
1581 
1582 	return rc;
1583 }
1584 EXPORT_SYMBOL(iscsit_check_dataout_hdr);
1585 
1586 static int
1587 iscsit_get_dataout(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1588 		   struct iscsi_data *hdr)
1589 {
1590 	struct kvec *iov;
1591 	u32 checksum, iov_count = 0, padding = 0, rx_got = 0, rx_size = 0;
1592 	u32 payload_length;
1593 	int iov_ret, data_crc_failed = 0;
1594 
1595 	payload_length = min_t(u32, cmd->se_cmd.data_length,
1596 			       ntoh24(hdr->dlength));
1597 	rx_size += payload_length;
1598 	iov = &cmd->iov_data[0];
1599 
1600 	iov_ret = iscsit_map_iovec(cmd, iov, cmd->orig_iov_data_count - 2,
1601 				   be32_to_cpu(hdr->offset), payload_length);
1602 	if (iov_ret < 0)
1603 		return -1;
1604 
1605 	iov_count += iov_ret;
1606 
1607 	padding = ((-payload_length) & 3);
1608 	if (padding != 0) {
1609 		iov[iov_count].iov_base	= cmd->pad_bytes;
1610 		iov[iov_count++].iov_len = padding;
1611 		rx_size += padding;
1612 		pr_debug("Receiving %u padding bytes.\n", padding);
1613 	}
1614 
1615 	if (conn->conn_ops->DataDigest) {
1616 		iov[iov_count].iov_base = &checksum;
1617 		iov[iov_count++].iov_len = ISCSI_CRC_LEN;
1618 		rx_size += ISCSI_CRC_LEN;
1619 	}
1620 
1621 	WARN_ON_ONCE(iov_count > cmd->orig_iov_data_count);
1622 	rx_got = rx_data(conn, &cmd->iov_data[0], iov_count, rx_size);
1623 
1624 	iscsit_unmap_iovec(cmd);
1625 
1626 	if (rx_got != rx_size)
1627 		return -1;
1628 
1629 	if (conn->conn_ops->DataDigest) {
1630 		u32 data_crc;
1631 
1632 		data_crc = iscsit_do_crypto_hash_sg(conn->conn_rx_hash, cmd,
1633 						    be32_to_cpu(hdr->offset),
1634 						    payload_length, padding,
1635 						    cmd->pad_bytes);
1636 
1637 		if (checksum != data_crc) {
1638 			pr_err("ITT: 0x%08x, Offset: %u, Length: %u,"
1639 				" DataSN: 0x%08x, CRC32C DataDigest 0x%08x"
1640 				" does not match computed 0x%08x\n",
1641 				hdr->itt, hdr->offset, payload_length,
1642 				hdr->datasn, checksum, data_crc);
1643 			data_crc_failed = 1;
1644 		} else {
1645 			pr_debug("Got CRC32C DataDigest 0x%08x for"
1646 				" %u bytes of Data Out\n", checksum,
1647 				payload_length);
1648 		}
1649 	}
1650 
1651 	return data_crc_failed;
1652 }
1653 
1654 int
1655 iscsit_check_dataout_payload(struct iscsi_cmd *cmd, struct iscsi_data *hdr,
1656 			     bool data_crc_failed)
1657 {
1658 	struct iscsi_conn *conn = cmd->conn;
1659 	int rc, ooo_cmdsn;
1660 	/*
1661 	 * Increment post receive data and CRC values or perform
1662 	 * within-command recovery.
1663 	 */
1664 	rc = iscsit_check_post_dataout(cmd, (unsigned char *)hdr, data_crc_failed);
1665 	if ((rc == DATAOUT_NORMAL) || (rc == DATAOUT_WITHIN_COMMAND_RECOVERY))
1666 		return 0;
1667 	else if (rc == DATAOUT_SEND_R2T) {
1668 		iscsit_set_dataout_sequence_values(cmd);
1669 		conn->conn_transport->iscsit_get_dataout(conn, cmd, false);
1670 	} else if (rc == DATAOUT_SEND_TO_TRANSPORT) {
1671 		/*
1672 		 * Handle extra special case for out of order
1673 		 * Unsolicited Data Out.
1674 		 */
1675 		spin_lock_bh(&cmd->istate_lock);
1676 		ooo_cmdsn = (cmd->cmd_flags & ICF_OOO_CMDSN);
1677 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
1678 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
1679 		spin_unlock_bh(&cmd->istate_lock);
1680 
1681 		iscsit_stop_dataout_timer(cmd);
1682 		if (ooo_cmdsn)
1683 			return 0;
1684 		target_execute_cmd(&cmd->se_cmd);
1685 		return 0;
1686 	} else /* DATAOUT_CANNOT_RECOVER */
1687 		return -1;
1688 
1689 	return 0;
1690 }
1691 EXPORT_SYMBOL(iscsit_check_dataout_payload);
1692 
1693 static int iscsit_handle_data_out(struct iscsi_conn *conn, unsigned char *buf)
1694 {
1695 	struct iscsi_cmd *cmd = NULL;
1696 	struct iscsi_data *hdr = (struct iscsi_data *)buf;
1697 	int rc;
1698 	bool data_crc_failed = false;
1699 
1700 	rc = iscsit_check_dataout_hdr(conn, buf, &cmd);
1701 	if (rc < 0)
1702 		return 0;
1703 	else if (!cmd)
1704 		return 0;
1705 
1706 	rc = iscsit_get_dataout(conn, cmd, hdr);
1707 	if (rc < 0)
1708 		return rc;
1709 	else if (rc > 0)
1710 		data_crc_failed = true;
1711 
1712 	return iscsit_check_dataout_payload(cmd, hdr, data_crc_failed);
1713 }
1714 
1715 int iscsit_setup_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1716 			 struct iscsi_nopout *hdr)
1717 {
1718 	u32 payload_length = ntoh24(hdr->dlength);
1719 
1720 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL)) {
1721 		pr_err("NopOUT Flag's, Left Most Bit not set, protocol error.\n");
1722 		if (!cmd)
1723 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1724 						 (unsigned char *)hdr);
1725 
1726 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1727 					 (unsigned char *)hdr);
1728 	}
1729 
1730 	if (hdr->itt == RESERVED_ITT && !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
1731 		pr_err("NOPOUT ITT is reserved, but Immediate Bit is"
1732 			" not set, protocol error.\n");
1733 		if (!cmd)
1734 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1735 						 (unsigned char *)hdr);
1736 
1737 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1738 					 (unsigned char *)hdr);
1739 	}
1740 
1741 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
1742 		pr_err("NOPOUT Ping Data DataSegmentLength: %u is"
1743 			" greater than MaxXmitDataSegmentLength: %u, protocol"
1744 			" error.\n", payload_length,
1745 			conn->conn_ops->MaxXmitDataSegmentLength);
1746 		if (!cmd)
1747 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1748 						 (unsigned char *)hdr);
1749 
1750 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
1751 					 (unsigned char *)hdr);
1752 	}
1753 
1754 	pr_debug("Got NOPOUT Ping %s ITT: 0x%08x, TTT: 0x%08x,"
1755 		" CmdSN: 0x%08x, ExpStatSN: 0x%08x, Length: %u\n",
1756 		hdr->itt == RESERVED_ITT ? "Response" : "Request",
1757 		hdr->itt, hdr->ttt, hdr->cmdsn, hdr->exp_statsn,
1758 		payload_length);
1759 	/*
1760 	 * This is not a response to a Unsolicited NopIN, which means
1761 	 * it can either be a NOPOUT ping request (with a valid ITT),
1762 	 * or a NOPOUT not requesting a NOPIN (with a reserved ITT).
1763 	 * Either way, make sure we allocate an struct iscsi_cmd, as both
1764 	 * can contain ping data.
1765 	 */
1766 	if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1767 		cmd->iscsi_opcode	= ISCSI_OP_NOOP_OUT;
1768 		cmd->i_state		= ISTATE_SEND_NOPIN;
1769 		cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ?
1770 						1 : 0);
1771 		conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
1772 		cmd->targ_xfer_tag	= 0xFFFFFFFF;
1773 		cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
1774 		cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
1775 		cmd->data_direction	= DMA_NONE;
1776 	}
1777 
1778 	return 0;
1779 }
1780 EXPORT_SYMBOL(iscsit_setup_nop_out);
1781 
1782 int iscsit_process_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1783 			   struct iscsi_nopout *hdr)
1784 {
1785 	struct iscsi_cmd *cmd_p = NULL;
1786 	int cmdsn_ret = 0;
1787 	/*
1788 	 * Initiator is expecting a NopIN ping reply..
1789 	 */
1790 	if (hdr->itt != RESERVED_ITT) {
1791 		if (!cmd)
1792 			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
1793 						(unsigned char *)hdr);
1794 
1795 		spin_lock_bh(&conn->cmd_lock);
1796 		list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
1797 		spin_unlock_bh(&conn->cmd_lock);
1798 
1799 		iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
1800 
1801 		if (hdr->opcode & ISCSI_OP_IMMEDIATE) {
1802 			iscsit_add_cmd_to_response_queue(cmd, conn,
1803 							 cmd->i_state);
1804 			return 0;
1805 		}
1806 
1807 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
1808 				(unsigned char *)hdr, hdr->cmdsn);
1809                 if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
1810 			return 0;
1811 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
1812 			return -1;
1813 
1814 		return 0;
1815 	}
1816 	/*
1817 	 * This was a response to a unsolicited NOPIN ping.
1818 	 */
1819 	if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
1820 		cmd_p = iscsit_find_cmd_from_ttt(conn, be32_to_cpu(hdr->ttt));
1821 		if (!cmd_p)
1822 			return -EINVAL;
1823 
1824 		iscsit_stop_nopin_response_timer(conn);
1825 
1826 		cmd_p->i_state = ISTATE_REMOVE;
1827 		iscsit_add_cmd_to_immediate_queue(cmd_p, conn, cmd_p->i_state);
1828 
1829 		iscsit_start_nopin_timer(conn);
1830 		return 0;
1831 	}
1832 	/*
1833 	 * Otherwise, initiator is not expecting a NOPIN is response.
1834 	 * Just ignore for now.
1835 	 */
1836 
1837 	if (cmd)
1838 		iscsit_free_cmd(cmd, false);
1839 
1840         return 0;
1841 }
1842 EXPORT_SYMBOL(iscsit_process_nop_out);
1843 
1844 static int iscsit_handle_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1845 				 unsigned char *buf)
1846 {
1847 	unsigned char *ping_data = NULL;
1848 	struct iscsi_nopout *hdr = (struct iscsi_nopout *)buf;
1849 	struct kvec *iov = NULL;
1850 	u32 payload_length = ntoh24(hdr->dlength);
1851 	int ret;
1852 
1853 	ret = iscsit_setup_nop_out(conn, cmd, hdr);
1854 	if (ret < 0)
1855 		return 0;
1856 	/*
1857 	 * Handle NOP-OUT payload for traditional iSCSI sockets
1858 	 */
1859 	if (payload_length && hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
1860 		u32 checksum, data_crc, padding = 0;
1861 		int niov = 0, rx_got, rx_size = payload_length;
1862 
1863 		ping_data = kzalloc(payload_length + 1, GFP_KERNEL);
1864 		if (!ping_data) {
1865 			ret = -1;
1866 			goto out;
1867 		}
1868 
1869 		iov = &cmd->iov_misc[0];
1870 		iov[niov].iov_base	= ping_data;
1871 		iov[niov++].iov_len	= payload_length;
1872 
1873 		padding = ((-payload_length) & 3);
1874 		if (padding != 0) {
1875 			pr_debug("Receiving %u additional bytes"
1876 				" for padding.\n", padding);
1877 			iov[niov].iov_base	= &cmd->pad_bytes;
1878 			iov[niov++].iov_len	= padding;
1879 			rx_size += padding;
1880 		}
1881 		if (conn->conn_ops->DataDigest) {
1882 			iov[niov].iov_base	= &checksum;
1883 			iov[niov++].iov_len	= ISCSI_CRC_LEN;
1884 			rx_size += ISCSI_CRC_LEN;
1885 		}
1886 
1887 		WARN_ON_ONCE(niov > ARRAY_SIZE(cmd->iov_misc));
1888 		rx_got = rx_data(conn, &cmd->iov_misc[0], niov, rx_size);
1889 		if (rx_got != rx_size) {
1890 			ret = -1;
1891 			goto out;
1892 		}
1893 
1894 		if (conn->conn_ops->DataDigest) {
1895 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash, ping_data,
1896 						  payload_length, padding,
1897 						  cmd->pad_bytes, &data_crc);
1898 
1899 			if (checksum != data_crc) {
1900 				pr_err("Ping data CRC32C DataDigest"
1901 				" 0x%08x does not match computed 0x%08x\n",
1902 					checksum, data_crc);
1903 				if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
1904 					pr_err("Unable to recover from"
1905 					" NOPOUT Ping DataCRC failure while in"
1906 						" ERL=0.\n");
1907 					ret = -1;
1908 					goto out;
1909 				} else {
1910 					/*
1911 					 * Silently drop this PDU and let the
1912 					 * initiator plug the CmdSN gap.
1913 					 */
1914 					pr_debug("Dropping NOPOUT"
1915 					" Command CmdSN: 0x%08x due to"
1916 					" DataCRC error.\n", hdr->cmdsn);
1917 					ret = 0;
1918 					goto out;
1919 				}
1920 			} else {
1921 				pr_debug("Got CRC32C DataDigest"
1922 				" 0x%08x for %u bytes of ping data.\n",
1923 					checksum, payload_length);
1924 			}
1925 		}
1926 
1927 		ping_data[payload_length] = '\0';
1928 		/*
1929 		 * Attach ping data to struct iscsi_cmd->buf_ptr.
1930 		 */
1931 		cmd->buf_ptr = ping_data;
1932 		cmd->buf_ptr_size = payload_length;
1933 
1934 		pr_debug("Got %u bytes of NOPOUT ping"
1935 			" data.\n", payload_length);
1936 		pr_debug("Ping Data: \"%s\"\n", ping_data);
1937 	}
1938 
1939 	return iscsit_process_nop_out(conn, cmd, hdr);
1940 out:
1941 	if (cmd)
1942 		iscsit_free_cmd(cmd, false);
1943 
1944 	kfree(ping_data);
1945 	return ret;
1946 }
1947 
1948 static enum tcm_tmreq_table iscsit_convert_tmf(u8 iscsi_tmf)
1949 {
1950 	switch (iscsi_tmf) {
1951 	case ISCSI_TM_FUNC_ABORT_TASK:
1952 		return TMR_ABORT_TASK;
1953 	case ISCSI_TM_FUNC_ABORT_TASK_SET:
1954 		return TMR_ABORT_TASK_SET;
1955 	case ISCSI_TM_FUNC_CLEAR_ACA:
1956 		return TMR_CLEAR_ACA;
1957 	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
1958 		return TMR_CLEAR_TASK_SET;
1959 	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
1960 		return TMR_LUN_RESET;
1961 	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
1962 		return TMR_TARGET_WARM_RESET;
1963 	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
1964 		return TMR_TARGET_COLD_RESET;
1965 	default:
1966 		return TMR_UNKNOWN;
1967 	}
1968 }
1969 
1970 int
1971 iscsit_handle_task_mgt_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
1972 			   unsigned char *buf)
1973 {
1974 	struct se_tmr_req *se_tmr;
1975 	struct iscsi_tmr_req *tmr_req;
1976 	struct iscsi_tm *hdr;
1977 	int out_of_order_cmdsn = 0, ret;
1978 	u8 function, tcm_function = TMR_UNKNOWN;
1979 
1980 	hdr			= (struct iscsi_tm *) buf;
1981 	hdr->flags &= ~ISCSI_FLAG_CMD_FINAL;
1982 	function = hdr->flags;
1983 
1984 	pr_debug("Got Task Management Request ITT: 0x%08x, CmdSN:"
1985 		" 0x%08x, Function: 0x%02x, RefTaskTag: 0x%08x, RefCmdSN:"
1986 		" 0x%08x, CID: %hu\n", hdr->itt, hdr->cmdsn, function,
1987 		hdr->rtt, hdr->refcmdsn, conn->cid);
1988 
1989 	if ((function != ISCSI_TM_FUNC_ABORT_TASK) &&
1990 	    ((function != ISCSI_TM_FUNC_TASK_REASSIGN) &&
1991 	     hdr->rtt != RESERVED_ITT)) {
1992 		pr_err("RefTaskTag should be set to 0xFFFFFFFF.\n");
1993 		hdr->rtt = RESERVED_ITT;
1994 	}
1995 
1996 	if ((function == ISCSI_TM_FUNC_TASK_REASSIGN) &&
1997 			!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
1998 		pr_err("Task Management Request TASK_REASSIGN not"
1999 			" issued as immediate command, bad iSCSI Initiator"
2000 				"implementation\n");
2001 		return iscsit_add_reject_cmd(cmd,
2002 					     ISCSI_REASON_PROTOCOL_ERROR, buf);
2003 	}
2004 	if ((function != ISCSI_TM_FUNC_ABORT_TASK) &&
2005 	    be32_to_cpu(hdr->refcmdsn) != ISCSI_RESERVED_TAG)
2006 		hdr->refcmdsn = cpu_to_be32(ISCSI_RESERVED_TAG);
2007 
2008 	cmd->data_direction = DMA_NONE;
2009 	cmd->tmr_req = kzalloc(sizeof(*cmd->tmr_req), GFP_KERNEL);
2010 	if (!cmd->tmr_req) {
2011 		return iscsit_add_reject_cmd(cmd,
2012 					     ISCSI_REASON_BOOKMARK_NO_RESOURCES,
2013 					     buf);
2014 	}
2015 
2016 	transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops,
2017 			      conn->sess->se_sess, 0, DMA_NONE,
2018 			      TCM_SIMPLE_TAG, cmd->sense_buffer + 2,
2019 			      scsilun_to_int(&hdr->lun));
2020 
2021 	target_get_sess_cmd(&cmd->se_cmd, true);
2022 
2023 	/*
2024 	 * TASK_REASSIGN for ERL=2 / connection stays inside of
2025 	 * LIO-Target $FABRIC_MOD
2026 	 */
2027 	if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {
2028 		tcm_function = iscsit_convert_tmf(function);
2029 		if (tcm_function == TMR_UNKNOWN) {
2030 			pr_err("Unknown iSCSI TMR Function:"
2031 			       " 0x%02x\n", function);
2032 			return iscsit_add_reject_cmd(cmd,
2033 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
2034 		}
2035 	}
2036 	ret = core_tmr_alloc_req(&cmd->se_cmd, cmd->tmr_req, tcm_function,
2037 				 GFP_KERNEL);
2038 	if (ret < 0)
2039 		return iscsit_add_reject_cmd(cmd,
2040 				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
2041 
2042 	cmd->tmr_req->se_tmr_req = cmd->se_cmd.se_tmr_req;
2043 
2044 	cmd->iscsi_opcode	= ISCSI_OP_SCSI_TMFUNC;
2045 	cmd->i_state		= ISTATE_SEND_TASKMGTRSP;
2046 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2047 	cmd->init_task_tag	= hdr->itt;
2048 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2049 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
2050 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
2051 	se_tmr			= cmd->se_cmd.se_tmr_req;
2052 	tmr_req			= cmd->tmr_req;
2053 	/*
2054 	 * Locate the struct se_lun for all TMRs not related to ERL=2 TASK_REASSIGN
2055 	 */
2056 	if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {
2057 		ret = transport_lookup_tmr_lun(&cmd->se_cmd);
2058 		if (ret < 0) {
2059 			se_tmr->response = ISCSI_TMF_RSP_NO_LUN;
2060 			goto attach;
2061 		}
2062 	}
2063 
2064 	switch (function) {
2065 	case ISCSI_TM_FUNC_ABORT_TASK:
2066 		se_tmr->response = iscsit_tmr_abort_task(cmd, buf);
2067 		if (se_tmr->response)
2068 			goto attach;
2069 		break;
2070 	case ISCSI_TM_FUNC_ABORT_TASK_SET:
2071 	case ISCSI_TM_FUNC_CLEAR_ACA:
2072 	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
2073 	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
2074 		break;
2075 	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
2076 		if (iscsit_tmr_task_warm_reset(conn, tmr_req, buf) < 0) {
2077 			se_tmr->response = ISCSI_TMF_RSP_AUTH_FAILED;
2078 			goto attach;
2079 		}
2080 		break;
2081 	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
2082 		if (iscsit_tmr_task_cold_reset(conn, tmr_req, buf) < 0) {
2083 			se_tmr->response = ISCSI_TMF_RSP_AUTH_FAILED;
2084 			goto attach;
2085 		}
2086 		break;
2087 	case ISCSI_TM_FUNC_TASK_REASSIGN:
2088 		se_tmr->response = iscsit_tmr_task_reassign(cmd, buf);
2089 		/*
2090 		 * Perform sanity checks on the ExpDataSN only if the
2091 		 * TASK_REASSIGN was successful.
2092 		 */
2093 		if (se_tmr->response)
2094 			break;
2095 
2096 		if (iscsit_check_task_reassign_expdatasn(tmr_req, conn) < 0)
2097 			return iscsit_add_reject_cmd(cmd,
2098 					ISCSI_REASON_BOOKMARK_INVALID, buf);
2099 		break;
2100 	default:
2101 		pr_err("Unknown TMR function: 0x%02x, protocol"
2102 			" error.\n", function);
2103 		se_tmr->response = ISCSI_TMF_RSP_NOT_SUPPORTED;
2104 		goto attach;
2105 	}
2106 
2107 	if ((function != ISCSI_TM_FUNC_TASK_REASSIGN) &&
2108 	    (se_tmr->response == ISCSI_TMF_RSP_COMPLETE))
2109 		se_tmr->call_transport = 1;
2110 attach:
2111 	spin_lock_bh(&conn->cmd_lock);
2112 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2113 	spin_unlock_bh(&conn->cmd_lock);
2114 
2115 	if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
2116 		int cmdsn_ret = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);
2117 		if (cmdsn_ret == CMDSN_HIGHER_THAN_EXP) {
2118 			out_of_order_cmdsn = 1;
2119 		} else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
2120 			target_put_sess_cmd(&cmd->se_cmd);
2121 			return 0;
2122 		} else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER) {
2123 			return -1;
2124 		}
2125 	}
2126 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2127 
2128 	if (out_of_order_cmdsn || !(hdr->opcode & ISCSI_OP_IMMEDIATE))
2129 		return 0;
2130 	/*
2131 	 * Found the referenced task, send to transport for processing.
2132 	 */
2133 	if (se_tmr->call_transport)
2134 		return transport_generic_handle_tmr(&cmd->se_cmd);
2135 
2136 	/*
2137 	 * Could not find the referenced LUN, task, or Task Management
2138 	 * command not authorized or supported.  Change state and
2139 	 * let the tx_thread send the response.
2140 	 *
2141 	 * For connection recovery, this is also the default action for
2142 	 * TMR TASK_REASSIGN.
2143 	 */
2144 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2145 	target_put_sess_cmd(&cmd->se_cmd);
2146 	return 0;
2147 }
2148 EXPORT_SYMBOL(iscsit_handle_task_mgt_cmd);
2149 
2150 /* #warning FIXME: Support Text Command parameters besides SendTargets */
2151 int
2152 iscsit_setup_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2153 		      struct iscsi_text *hdr)
2154 {
2155 	u32 payload_length = ntoh24(hdr->dlength);
2156 
2157 	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
2158 		pr_err("Unable to accept text parameter length: %u"
2159 			"greater than MaxXmitDataSegmentLength %u.\n",
2160 		       payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
2161 		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
2162 					 (unsigned char *)hdr);
2163 	}
2164 
2165 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL) ||
2166 	     (hdr->flags & ISCSI_FLAG_TEXT_CONTINUE)) {
2167 		pr_err("Multi sequence text commands currently not supported\n");
2168 		return iscsit_reject_cmd(cmd, ISCSI_REASON_CMD_NOT_SUPPORTED,
2169 					(unsigned char *)hdr);
2170 	}
2171 
2172 	pr_debug("Got Text Request: ITT: 0x%08x, CmdSN: 0x%08x,"
2173 		" ExpStatSN: 0x%08x, Length: %u\n", hdr->itt, hdr->cmdsn,
2174 		hdr->exp_statsn, payload_length);
2175 
2176 	cmd->iscsi_opcode	= ISCSI_OP_TEXT;
2177 	cmd->i_state		= ISTATE_SEND_TEXTRSP;
2178 	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2179 	conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
2180 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2181 	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
2182 	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
2183 	cmd->data_direction	= DMA_NONE;
2184 	kfree(cmd->text_in_ptr);
2185 	cmd->text_in_ptr	= NULL;
2186 
2187 	return 0;
2188 }
2189 EXPORT_SYMBOL(iscsit_setup_text_cmd);
2190 
2191 int
2192 iscsit_process_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2193 			struct iscsi_text *hdr)
2194 {
2195 	unsigned char *text_in = cmd->text_in_ptr, *text_ptr;
2196 	int cmdsn_ret;
2197 
2198 	if (!text_in) {
2199 		cmd->targ_xfer_tag = be32_to_cpu(hdr->ttt);
2200 		if (cmd->targ_xfer_tag == 0xFFFFFFFF) {
2201 			pr_err("Unable to locate text_in buffer for sendtargets"
2202 			       " discovery\n");
2203 			goto reject;
2204 		}
2205 		goto empty_sendtargets;
2206 	}
2207 	if (strncmp("SendTargets=", text_in, 12) != 0) {
2208 		pr_err("Received Text Data that is not"
2209 			" SendTargets, cannot continue.\n");
2210 		goto reject;
2211 	}
2212 	/* '=' confirmed in strncmp */
2213 	text_ptr = strchr(text_in, '=');
2214 	BUG_ON(!text_ptr);
2215 	if (!strncmp("=All", text_ptr, 5)) {
2216 		cmd->cmd_flags |= ICF_SENDTARGETS_ALL;
2217 	} else if (!strncmp("=iqn.", text_ptr, 5) ||
2218 		   !strncmp("=eui.", text_ptr, 5)) {
2219 		cmd->cmd_flags |= ICF_SENDTARGETS_SINGLE;
2220 	} else {
2221 		pr_err("Unable to locate valid SendTargets%s value\n",
2222 		       text_ptr);
2223 		goto reject;
2224 	}
2225 
2226 	spin_lock_bh(&conn->cmd_lock);
2227 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2228 	spin_unlock_bh(&conn->cmd_lock);
2229 
2230 empty_sendtargets:
2231 	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2232 
2233 	if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
2234 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
2235 				(unsigned char *)hdr, hdr->cmdsn);
2236 		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
2237 			return -1;
2238 
2239 		return 0;
2240 	}
2241 
2242 	return iscsit_execute_cmd(cmd, 0);
2243 
2244 reject:
2245 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
2246 				 (unsigned char *)hdr);
2247 }
2248 EXPORT_SYMBOL(iscsit_process_text_cmd);
2249 
2250 static int
2251 iscsit_handle_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2252 		       unsigned char *buf)
2253 {
2254 	struct iscsi_text *hdr = (struct iscsi_text *)buf;
2255 	char *text_in = NULL;
2256 	u32 payload_length = ntoh24(hdr->dlength);
2257 	int rx_size, rc;
2258 
2259 	rc = iscsit_setup_text_cmd(conn, cmd, hdr);
2260 	if (rc < 0)
2261 		return 0;
2262 
2263 	rx_size = payload_length;
2264 	if (payload_length) {
2265 		u32 checksum = 0, data_crc = 0;
2266 		u32 padding = 0;
2267 		int niov = 0, rx_got;
2268 		struct kvec iov[2];
2269 
2270 		rx_size = ALIGN(payload_length, 4);
2271 		text_in = kzalloc(rx_size, GFP_KERNEL);
2272 		if (!text_in)
2273 			goto reject;
2274 
2275 		cmd->text_in_ptr = text_in;
2276 
2277 		memset(iov, 0, sizeof(iov));
2278 		iov[niov].iov_base	= text_in;
2279 		iov[niov++].iov_len	= rx_size;
2280 
2281 		padding = rx_size - payload_length;
2282 		if (padding)
2283 			pr_debug("Receiving %u additional bytes"
2284 					" for padding.\n", padding);
2285 		if (conn->conn_ops->DataDigest) {
2286 			iov[niov].iov_base	= &checksum;
2287 			iov[niov++].iov_len	= ISCSI_CRC_LEN;
2288 			rx_size += ISCSI_CRC_LEN;
2289 		}
2290 
2291 		WARN_ON_ONCE(niov > ARRAY_SIZE(iov));
2292 		rx_got = rx_data(conn, &iov[0], niov, rx_size);
2293 		if (rx_got != rx_size)
2294 			goto reject;
2295 
2296 		if (conn->conn_ops->DataDigest) {
2297 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash,
2298 						  text_in, rx_size, 0, NULL,
2299 						  &data_crc);
2300 
2301 			if (checksum != data_crc) {
2302 				pr_err("Text data CRC32C DataDigest"
2303 					" 0x%08x does not match computed"
2304 					" 0x%08x\n", checksum, data_crc);
2305 				if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2306 					pr_err("Unable to recover from"
2307 					" Text Data digest failure while in"
2308 						" ERL=0.\n");
2309 					goto reject;
2310 				} else {
2311 					/*
2312 					 * Silently drop this PDU and let the
2313 					 * initiator plug the CmdSN gap.
2314 					 */
2315 					pr_debug("Dropping Text"
2316 					" Command CmdSN: 0x%08x due to"
2317 					" DataCRC error.\n", hdr->cmdsn);
2318 					kfree(text_in);
2319 					return 0;
2320 				}
2321 			} else {
2322 				pr_debug("Got CRC32C DataDigest"
2323 					" 0x%08x for %u bytes of text data.\n",
2324 						checksum, payload_length);
2325 			}
2326 		}
2327 		text_in[payload_length - 1] = '\0';
2328 		pr_debug("Successfully read %d bytes of text"
2329 				" data.\n", payload_length);
2330 	}
2331 
2332 	return iscsit_process_text_cmd(conn, cmd, hdr);
2333 
2334 reject:
2335 	kfree(cmd->text_in_ptr);
2336 	cmd->text_in_ptr = NULL;
2337 	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);
2338 }
2339 
2340 int iscsit_logout_closesession(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2341 {
2342 	struct iscsi_conn *conn_p;
2343 	struct iscsi_session *sess = conn->sess;
2344 
2345 	pr_debug("Received logout request CLOSESESSION on CID: %hu"
2346 		" for SID: %u.\n", conn->cid, conn->sess->sid);
2347 
2348 	atomic_set(&sess->session_logout, 1);
2349 	atomic_set(&conn->conn_logout_remove, 1);
2350 	conn->conn_logout_reason = ISCSI_LOGOUT_REASON_CLOSE_SESSION;
2351 
2352 	iscsit_inc_conn_usage_count(conn);
2353 	iscsit_inc_session_usage_count(sess);
2354 
2355 	spin_lock_bh(&sess->conn_lock);
2356 	list_for_each_entry(conn_p, &sess->sess_conn_list, conn_list) {
2357 		if (conn_p->conn_state != TARG_CONN_STATE_LOGGED_IN)
2358 			continue;
2359 
2360 		pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
2361 		conn_p->conn_state = TARG_CONN_STATE_IN_LOGOUT;
2362 	}
2363 	spin_unlock_bh(&sess->conn_lock);
2364 
2365 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2366 
2367 	return 0;
2368 }
2369 
2370 int iscsit_logout_closeconnection(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2371 {
2372 	struct iscsi_conn *l_conn;
2373 	struct iscsi_session *sess = conn->sess;
2374 
2375 	pr_debug("Received logout request CLOSECONNECTION for CID:"
2376 		" %hu on CID: %hu.\n", cmd->logout_cid, conn->cid);
2377 
2378 	/*
2379 	 * A Logout Request with a CLOSECONNECTION reason code for a CID
2380 	 * can arrive on a connection with a differing CID.
2381 	 */
2382 	if (conn->cid == cmd->logout_cid) {
2383 		spin_lock_bh(&conn->state_lock);
2384 		pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
2385 		conn->conn_state = TARG_CONN_STATE_IN_LOGOUT;
2386 
2387 		atomic_set(&conn->conn_logout_remove, 1);
2388 		conn->conn_logout_reason = ISCSI_LOGOUT_REASON_CLOSE_CONNECTION;
2389 		iscsit_inc_conn_usage_count(conn);
2390 
2391 		spin_unlock_bh(&conn->state_lock);
2392 	} else {
2393 		/*
2394 		 * Handle all different cid CLOSECONNECTION requests in
2395 		 * iscsit_logout_post_handler_diffcid() as to give enough
2396 		 * time for any non immediate command's CmdSN to be
2397 		 * acknowledged on the connection in question.
2398 		 *
2399 		 * Here we simply make sure the CID is still around.
2400 		 */
2401 		l_conn = iscsit_get_conn_from_cid(sess,
2402 				cmd->logout_cid);
2403 		if (!l_conn) {
2404 			cmd->logout_response = ISCSI_LOGOUT_CID_NOT_FOUND;
2405 			iscsit_add_cmd_to_response_queue(cmd, conn,
2406 					cmd->i_state);
2407 			return 0;
2408 		}
2409 
2410 		iscsit_dec_conn_usage_count(l_conn);
2411 	}
2412 
2413 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2414 
2415 	return 0;
2416 }
2417 
2418 int iscsit_logout_removeconnforrecovery(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2419 {
2420 	struct iscsi_session *sess = conn->sess;
2421 
2422 	pr_debug("Received explicit REMOVECONNFORRECOVERY logout for"
2423 		" CID: %hu on CID: %hu.\n", cmd->logout_cid, conn->cid);
2424 
2425 	if (sess->sess_ops->ErrorRecoveryLevel != 2) {
2426 		pr_err("Received Logout Request REMOVECONNFORRECOVERY"
2427 			" while ERL!=2.\n");
2428 		cmd->logout_response = ISCSI_LOGOUT_RECOVERY_UNSUPPORTED;
2429 		iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2430 		return 0;
2431 	}
2432 
2433 	if (conn->cid == cmd->logout_cid) {
2434 		pr_err("Received Logout Request REMOVECONNFORRECOVERY"
2435 			" with CID: %hu on CID: %hu, implementation error.\n",
2436 				cmd->logout_cid, conn->cid);
2437 		cmd->logout_response = ISCSI_LOGOUT_CLEANUP_FAILED;
2438 		iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2439 		return 0;
2440 	}
2441 
2442 	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
2443 
2444 	return 0;
2445 }
2446 
2447 int
2448 iscsit_handle_logout_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
2449 			unsigned char *buf)
2450 {
2451 	int cmdsn_ret, logout_remove = 0;
2452 	u8 reason_code = 0;
2453 	struct iscsi_logout *hdr;
2454 	struct iscsi_tiqn *tiqn = iscsit_snmp_get_tiqn(conn);
2455 
2456 	hdr			= (struct iscsi_logout *) buf;
2457 	reason_code		= (hdr->flags & 0x7f);
2458 
2459 	if (tiqn) {
2460 		spin_lock(&tiqn->logout_stats.lock);
2461 		if (reason_code == ISCSI_LOGOUT_REASON_CLOSE_SESSION)
2462 			tiqn->logout_stats.normal_logouts++;
2463 		else
2464 			tiqn->logout_stats.abnormal_logouts++;
2465 		spin_unlock(&tiqn->logout_stats.lock);
2466 	}
2467 
2468 	pr_debug("Got Logout Request ITT: 0x%08x CmdSN: 0x%08x"
2469 		" ExpStatSN: 0x%08x Reason: 0x%02x CID: %hu on CID: %hu\n",
2470 		hdr->itt, hdr->cmdsn, hdr->exp_statsn, reason_code,
2471 		hdr->cid, conn->cid);
2472 
2473 	if (conn->conn_state != TARG_CONN_STATE_LOGGED_IN) {
2474 		pr_err("Received logout request on connection that"
2475 			" is not in logged in state, ignoring request.\n");
2476 		iscsit_free_cmd(cmd, false);
2477 		return 0;
2478 	}
2479 
2480 	cmd->iscsi_opcode       = ISCSI_OP_LOGOUT;
2481 	cmd->i_state            = ISTATE_SEND_LOGOUTRSP;
2482 	cmd->immediate_cmd      = ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
2483 	conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
2484 	cmd->targ_xfer_tag      = 0xFFFFFFFF;
2485 	cmd->cmd_sn             = be32_to_cpu(hdr->cmdsn);
2486 	cmd->exp_stat_sn        = be32_to_cpu(hdr->exp_statsn);
2487 	cmd->logout_cid         = be16_to_cpu(hdr->cid);
2488 	cmd->logout_reason      = reason_code;
2489 	cmd->data_direction     = DMA_NONE;
2490 
2491 	/*
2492 	 * We need to sleep in these cases (by returning 1) until the Logout
2493 	 * Response gets sent in the tx thread.
2494 	 */
2495 	if ((reason_code == ISCSI_LOGOUT_REASON_CLOSE_SESSION) ||
2496 	   ((reason_code == ISCSI_LOGOUT_REASON_CLOSE_CONNECTION) &&
2497 	    be16_to_cpu(hdr->cid) == conn->cid))
2498 		logout_remove = 1;
2499 
2500 	spin_lock_bh(&conn->cmd_lock);
2501 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
2502 	spin_unlock_bh(&conn->cmd_lock);
2503 
2504 	if (reason_code != ISCSI_LOGOUT_REASON_RECOVERY)
2505 		iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
2506 
2507 	/*
2508 	 * Immediate commands are executed, well, immediately.
2509 	 * Non-Immediate Logout Commands are executed in CmdSN order.
2510 	 */
2511 	if (cmd->immediate_cmd) {
2512 		int ret = iscsit_execute_cmd(cmd, 0);
2513 
2514 		if (ret < 0)
2515 			return ret;
2516 	} else {
2517 		cmdsn_ret = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);
2518 		if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
2519 			logout_remove = 0;
2520 		else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
2521 			return -1;
2522 	}
2523 
2524 	return logout_remove;
2525 }
2526 EXPORT_SYMBOL(iscsit_handle_logout_cmd);
2527 
2528 int iscsit_handle_snack(
2529 	struct iscsi_conn *conn,
2530 	unsigned char *buf)
2531 {
2532 	struct iscsi_snack *hdr;
2533 
2534 	hdr			= (struct iscsi_snack *) buf;
2535 	hdr->flags		&= ~ISCSI_FLAG_CMD_FINAL;
2536 
2537 	pr_debug("Got ISCSI_INIT_SNACK, ITT: 0x%08x, ExpStatSN:"
2538 		" 0x%08x, Type: 0x%02x, BegRun: 0x%08x, RunLength: 0x%08x,"
2539 		" CID: %hu\n", hdr->itt, hdr->exp_statsn, hdr->flags,
2540 			hdr->begrun, hdr->runlength, conn->cid);
2541 
2542 	if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2543 		pr_err("Initiator sent SNACK request while in"
2544 			" ErrorRecoveryLevel=0.\n");
2545 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2546 					 buf);
2547 	}
2548 	/*
2549 	 * SNACK_DATA and SNACK_R2T are both 0,  so check which function to
2550 	 * call from inside iscsi_send_recovery_datain_or_r2t().
2551 	 */
2552 	switch (hdr->flags & ISCSI_FLAG_SNACK_TYPE_MASK) {
2553 	case 0:
2554 		return iscsit_handle_recovery_datain_or_r2t(conn, buf,
2555 			hdr->itt,
2556 			be32_to_cpu(hdr->ttt),
2557 			be32_to_cpu(hdr->begrun),
2558 			be32_to_cpu(hdr->runlength));
2559 	case ISCSI_FLAG_SNACK_TYPE_STATUS:
2560 		return iscsit_handle_status_snack(conn, hdr->itt,
2561 			be32_to_cpu(hdr->ttt),
2562 			be32_to_cpu(hdr->begrun), be32_to_cpu(hdr->runlength));
2563 	case ISCSI_FLAG_SNACK_TYPE_DATA_ACK:
2564 		return iscsit_handle_data_ack(conn, be32_to_cpu(hdr->ttt),
2565 			be32_to_cpu(hdr->begrun),
2566 			be32_to_cpu(hdr->runlength));
2567 	case ISCSI_FLAG_SNACK_TYPE_RDATA:
2568 		/* FIXME: Support R-Data SNACK */
2569 		pr_err("R-Data SNACK Not Supported.\n");
2570 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2571 					 buf);
2572 	default:
2573 		pr_err("Unknown SNACK type 0x%02x, protocol"
2574 			" error.\n", hdr->flags & 0x0f);
2575 		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
2576 					 buf);
2577 	}
2578 
2579 	return 0;
2580 }
2581 EXPORT_SYMBOL(iscsit_handle_snack);
2582 
2583 static void iscsit_rx_thread_wait_for_tcp(struct iscsi_conn *conn)
2584 {
2585 	if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) ||
2586 	    (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) {
2587 		wait_for_completion_interruptible_timeout(
2588 					&conn->rx_half_close_comp,
2589 					ISCSI_RX_THREAD_TCP_TIMEOUT * HZ);
2590 	}
2591 }
2592 
2593 static int iscsit_handle_immediate_data(
2594 	struct iscsi_cmd *cmd,
2595 	struct iscsi_scsi_req *hdr,
2596 	u32 length)
2597 {
2598 	int iov_ret, rx_got = 0, rx_size = 0;
2599 	u32 checksum, iov_count = 0, padding = 0;
2600 	struct iscsi_conn *conn = cmd->conn;
2601 	struct kvec *iov;
2602 	void *overflow_buf = NULL;
2603 
2604 	BUG_ON(cmd->write_data_done > cmd->se_cmd.data_length);
2605 	rx_size = min(cmd->se_cmd.data_length - cmd->write_data_done, length);
2606 	iov_ret = iscsit_map_iovec(cmd, cmd->iov_data,
2607 				   cmd->orig_iov_data_count - 2,
2608 				   cmd->write_data_done, rx_size);
2609 	if (iov_ret < 0)
2610 		return IMMEDIATE_DATA_CANNOT_RECOVER;
2611 
2612 	iov_count = iov_ret;
2613 	iov = &cmd->iov_data[0];
2614 	if (rx_size < length) {
2615 		/*
2616 		 * Special case: length of immediate data exceeds the data
2617 		 * buffer size derived from the CDB.
2618 		 */
2619 		overflow_buf = kmalloc(length - rx_size, GFP_KERNEL);
2620 		if (!overflow_buf) {
2621 			iscsit_unmap_iovec(cmd);
2622 			return IMMEDIATE_DATA_CANNOT_RECOVER;
2623 		}
2624 		cmd->overflow_buf = overflow_buf;
2625 		iov[iov_count].iov_base = overflow_buf;
2626 		iov[iov_count].iov_len = length - rx_size;
2627 		iov_count++;
2628 		rx_size = length;
2629 	}
2630 
2631 	padding = ((-length) & 3);
2632 	if (padding != 0) {
2633 		iov[iov_count].iov_base	= cmd->pad_bytes;
2634 		iov[iov_count++].iov_len = padding;
2635 		rx_size += padding;
2636 	}
2637 
2638 	if (conn->conn_ops->DataDigest) {
2639 		iov[iov_count].iov_base		= &checksum;
2640 		iov[iov_count++].iov_len	= ISCSI_CRC_LEN;
2641 		rx_size += ISCSI_CRC_LEN;
2642 	}
2643 
2644 	WARN_ON_ONCE(iov_count > cmd->orig_iov_data_count);
2645 	rx_got = rx_data(conn, &cmd->iov_data[0], iov_count, rx_size);
2646 
2647 	iscsit_unmap_iovec(cmd);
2648 
2649 	if (rx_got != rx_size) {
2650 		iscsit_rx_thread_wait_for_tcp(conn);
2651 		return IMMEDIATE_DATA_CANNOT_RECOVER;
2652 	}
2653 
2654 	if (conn->conn_ops->DataDigest) {
2655 		u32 data_crc;
2656 
2657 		data_crc = iscsit_do_crypto_hash_sg(conn->conn_rx_hash, cmd,
2658 						    cmd->write_data_done, length, padding,
2659 						    cmd->pad_bytes);
2660 
2661 		if (checksum != data_crc) {
2662 			pr_err("ImmediateData CRC32C DataDigest 0x%08x"
2663 				" does not match computed 0x%08x\n", checksum,
2664 				data_crc);
2665 
2666 			if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
2667 				pr_err("Unable to recover from"
2668 					" Immediate Data digest failure while"
2669 					" in ERL=0.\n");
2670 				iscsit_reject_cmd(cmd,
2671 						ISCSI_REASON_DATA_DIGEST_ERROR,
2672 						(unsigned char *)hdr);
2673 				return IMMEDIATE_DATA_CANNOT_RECOVER;
2674 			} else {
2675 				iscsit_reject_cmd(cmd,
2676 						ISCSI_REASON_DATA_DIGEST_ERROR,
2677 						(unsigned char *)hdr);
2678 				return IMMEDIATE_DATA_ERL1_CRC_FAILURE;
2679 			}
2680 		} else {
2681 			pr_debug("Got CRC32C DataDigest 0x%08x for"
2682 				" %u bytes of Immediate Data\n", checksum,
2683 				length);
2684 		}
2685 	}
2686 
2687 	cmd->write_data_done += length;
2688 
2689 	if (cmd->write_data_done == cmd->se_cmd.data_length) {
2690 		spin_lock_bh(&cmd->istate_lock);
2691 		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
2692 		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
2693 		spin_unlock_bh(&cmd->istate_lock);
2694 	}
2695 
2696 	return IMMEDIATE_DATA_NORMAL_OPERATION;
2697 }
2698 
2699 /* #warning iscsi_build_conn_drop_async_message() only sends out on connections
2700 	with active network interface */
2701 static void iscsit_build_conn_drop_async_message(struct iscsi_conn *conn)
2702 {
2703 	struct iscsi_cmd *cmd;
2704 	struct iscsi_conn *conn_p;
2705 	bool found = false;
2706 
2707 	lockdep_assert_held(&conn->sess->conn_lock);
2708 
2709 	/*
2710 	 * Only send a Asynchronous Message on connections whos network
2711 	 * interface is still functional.
2712 	 */
2713 	list_for_each_entry(conn_p, &conn->sess->sess_conn_list, conn_list) {
2714 		if (conn_p->conn_state == TARG_CONN_STATE_LOGGED_IN) {
2715 			iscsit_inc_conn_usage_count(conn_p);
2716 			found = true;
2717 			break;
2718 		}
2719 	}
2720 
2721 	if (!found)
2722 		return;
2723 
2724 	cmd = iscsit_allocate_cmd(conn_p, TASK_RUNNING);
2725 	if (!cmd) {
2726 		iscsit_dec_conn_usage_count(conn_p);
2727 		return;
2728 	}
2729 
2730 	cmd->logout_cid = conn->cid;
2731 	cmd->iscsi_opcode = ISCSI_OP_ASYNC_EVENT;
2732 	cmd->i_state = ISTATE_SEND_ASYNCMSG;
2733 
2734 	spin_lock_bh(&conn_p->cmd_lock);
2735 	list_add_tail(&cmd->i_conn_node, &conn_p->conn_cmd_list);
2736 	spin_unlock_bh(&conn_p->cmd_lock);
2737 
2738 	iscsit_add_cmd_to_response_queue(cmd, conn_p, cmd->i_state);
2739 	iscsit_dec_conn_usage_count(conn_p);
2740 }
2741 
2742 static int iscsit_send_conn_drop_async_message(
2743 	struct iscsi_cmd *cmd,
2744 	struct iscsi_conn *conn)
2745 {
2746 	struct iscsi_async *hdr;
2747 
2748 	cmd->iscsi_opcode = ISCSI_OP_ASYNC_EVENT;
2749 
2750 	hdr			= (struct iscsi_async *) cmd->pdu;
2751 	hdr->opcode		= ISCSI_OP_ASYNC_EVENT;
2752 	hdr->flags		= ISCSI_FLAG_CMD_FINAL;
2753 	cmd->init_task_tag	= RESERVED_ITT;
2754 	cmd->targ_xfer_tag	= 0xFFFFFFFF;
2755 	put_unaligned_be64(0xFFFFFFFFFFFFFFFFULL, &hdr->rsvd4[0]);
2756 	cmd->stat_sn		= conn->stat_sn++;
2757 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2758 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2759 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2760 	hdr->async_event	= ISCSI_ASYNC_MSG_DROPPING_CONNECTION;
2761 	hdr->param1		= cpu_to_be16(cmd->logout_cid);
2762 	hdr->param2		= cpu_to_be16(conn->sess->sess_ops->DefaultTime2Wait);
2763 	hdr->param3		= cpu_to_be16(conn->sess->sess_ops->DefaultTime2Retain);
2764 
2765 	pr_debug("Sending Connection Dropped Async Message StatSN:"
2766 		" 0x%08x, for CID: %hu on CID: %hu\n", cmd->stat_sn,
2767 			cmd->logout_cid, conn->cid);
2768 
2769 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
2770 }
2771 
2772 static void iscsit_tx_thread_wait_for_tcp(struct iscsi_conn *conn)
2773 {
2774 	if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) ||
2775 	    (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) {
2776 		wait_for_completion_interruptible_timeout(
2777 					&conn->tx_half_close_comp,
2778 					ISCSI_TX_THREAD_TCP_TIMEOUT * HZ);
2779 	}
2780 }
2781 
2782 void
2783 iscsit_build_datain_pdu(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2784 			struct iscsi_datain *datain, struct iscsi_data_rsp *hdr,
2785 			bool set_statsn)
2786 {
2787 	hdr->opcode		= ISCSI_OP_SCSI_DATA_IN;
2788 	hdr->flags		= datain->flags;
2789 	if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
2790 		if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
2791 			hdr->flags |= ISCSI_FLAG_DATA_OVERFLOW;
2792 			hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
2793 		} else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
2794 			hdr->flags |= ISCSI_FLAG_DATA_UNDERFLOW;
2795 			hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
2796 		}
2797 	}
2798 	hton24(hdr->dlength, datain->length);
2799 	if (hdr->flags & ISCSI_FLAG_DATA_ACK)
2800 		int_to_scsilun(cmd->se_cmd.orig_fe_lun,
2801 				(struct scsi_lun *)&hdr->lun);
2802 	else
2803 		put_unaligned_le64(0xFFFFFFFFFFFFFFFFULL, &hdr->lun);
2804 
2805 	hdr->itt		= cmd->init_task_tag;
2806 
2807 	if (hdr->flags & ISCSI_FLAG_DATA_ACK)
2808 		hdr->ttt		= cpu_to_be32(cmd->targ_xfer_tag);
2809 	else
2810 		hdr->ttt		= cpu_to_be32(0xFFFFFFFF);
2811 	if (set_statsn)
2812 		hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2813 	else
2814 		hdr->statsn		= cpu_to_be32(0xFFFFFFFF);
2815 
2816 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2817 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2818 	hdr->datasn		= cpu_to_be32(datain->data_sn);
2819 	hdr->offset		= cpu_to_be32(datain->offset);
2820 
2821 	pr_debug("Built DataIN ITT: 0x%08x, StatSN: 0x%08x,"
2822 		" DataSN: 0x%08x, Offset: %u, Length: %u, CID: %hu\n",
2823 		cmd->init_task_tag, ntohl(hdr->statsn), ntohl(hdr->datasn),
2824 		ntohl(hdr->offset), datain->length, conn->cid);
2825 }
2826 EXPORT_SYMBOL(iscsit_build_datain_pdu);
2827 
2828 static int iscsit_send_datain(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2829 {
2830 	struct iscsi_data_rsp *hdr = (struct iscsi_data_rsp *)&cmd->pdu[0];
2831 	struct iscsi_datain datain;
2832 	struct iscsi_datain_req *dr;
2833 	int eodr = 0, ret;
2834 	bool set_statsn = false;
2835 
2836 	memset(&datain, 0, sizeof(struct iscsi_datain));
2837 	dr = iscsit_get_datain_values(cmd, &datain);
2838 	if (!dr) {
2839 		pr_err("iscsit_get_datain_values failed for ITT: 0x%08x\n",
2840 				cmd->init_task_tag);
2841 		return -1;
2842 	}
2843 	/*
2844 	 * Be paranoid and double check the logic for now.
2845 	 */
2846 	if ((datain.offset + datain.length) > cmd->se_cmd.data_length) {
2847 		pr_err("Command ITT: 0x%08x, datain.offset: %u and"
2848 			" datain.length: %u exceeds cmd->data_length: %u\n",
2849 			cmd->init_task_tag, datain.offset, datain.length,
2850 			cmd->se_cmd.data_length);
2851 		return -1;
2852 	}
2853 
2854 	atomic_long_add(datain.length, &conn->sess->tx_data_octets);
2855 	/*
2856 	 * Special case for successfully execution w/ both DATAIN
2857 	 * and Sense Data.
2858 	 */
2859 	if ((datain.flags & ISCSI_FLAG_DATA_STATUS) &&
2860 	    (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE))
2861 		datain.flags &= ~ISCSI_FLAG_DATA_STATUS;
2862 	else {
2863 		if ((dr->dr_complete == DATAIN_COMPLETE_NORMAL) ||
2864 		    (dr->dr_complete == DATAIN_COMPLETE_CONNECTION_RECOVERY)) {
2865 			iscsit_increment_maxcmdsn(cmd, conn->sess);
2866 			cmd->stat_sn = conn->stat_sn++;
2867 			set_statsn = true;
2868 		} else if (dr->dr_complete ==
2869 			   DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY)
2870 			set_statsn = true;
2871 	}
2872 
2873 	iscsit_build_datain_pdu(cmd, conn, &datain, hdr, set_statsn);
2874 
2875 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, dr, &datain, 0);
2876 	if (ret < 0)
2877 		return ret;
2878 
2879 	if (dr->dr_complete) {
2880 		eodr = (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ?
2881 				2 : 1;
2882 		iscsit_free_datain_req(cmd, dr);
2883 	}
2884 
2885 	return eodr;
2886 }
2887 
2888 int
2889 iscsit_build_logout_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2890 			struct iscsi_logout_rsp *hdr)
2891 {
2892 	struct iscsi_conn *logout_conn = NULL;
2893 	struct iscsi_conn_recovery *cr = NULL;
2894 	struct iscsi_session *sess = conn->sess;
2895 	/*
2896 	 * The actual shutting down of Sessions and/or Connections
2897 	 * for CLOSESESSION and CLOSECONNECTION Logout Requests
2898 	 * is done in scsi_logout_post_handler().
2899 	 */
2900 	switch (cmd->logout_reason) {
2901 	case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
2902 		pr_debug("iSCSI session logout successful, setting"
2903 			" logout response to ISCSI_LOGOUT_SUCCESS.\n");
2904 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2905 		break;
2906 	case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
2907 		if (cmd->logout_response == ISCSI_LOGOUT_CID_NOT_FOUND)
2908 			break;
2909 		/*
2910 		 * For CLOSECONNECTION logout requests carrying
2911 		 * a matching logout CID -> local CID, the reference
2912 		 * for the local CID will have been incremented in
2913 		 * iscsi_logout_closeconnection().
2914 		 *
2915 		 * For CLOSECONNECTION logout requests carrying
2916 		 * a different CID than the connection it arrived
2917 		 * on, the connection responding to cmd->logout_cid
2918 		 * is stopped in iscsit_logout_post_handler_diffcid().
2919 		 */
2920 
2921 		pr_debug("iSCSI CID: %hu logout on CID: %hu"
2922 			" successful.\n", cmd->logout_cid, conn->cid);
2923 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2924 		break;
2925 	case ISCSI_LOGOUT_REASON_RECOVERY:
2926 		if ((cmd->logout_response == ISCSI_LOGOUT_RECOVERY_UNSUPPORTED) ||
2927 		    (cmd->logout_response == ISCSI_LOGOUT_CLEANUP_FAILED))
2928 			break;
2929 		/*
2930 		 * If the connection is still active from our point of view
2931 		 * force connection recovery to occur.
2932 		 */
2933 		logout_conn = iscsit_get_conn_from_cid_rcfr(sess,
2934 				cmd->logout_cid);
2935 		if (logout_conn) {
2936 			iscsit_connection_reinstatement_rcfr(logout_conn);
2937 			iscsit_dec_conn_usage_count(logout_conn);
2938 		}
2939 
2940 		cr = iscsit_get_inactive_connection_recovery_entry(
2941 				conn->sess, cmd->logout_cid);
2942 		if (!cr) {
2943 			pr_err("Unable to locate CID: %hu for"
2944 			" REMOVECONNFORRECOVERY Logout Request.\n",
2945 				cmd->logout_cid);
2946 			cmd->logout_response = ISCSI_LOGOUT_CID_NOT_FOUND;
2947 			break;
2948 		}
2949 
2950 		iscsit_discard_cr_cmds_by_expstatsn(cr, cmd->exp_stat_sn);
2951 
2952 		pr_debug("iSCSI REMOVECONNFORRECOVERY logout"
2953 			" for recovery for CID: %hu on CID: %hu successful.\n",
2954 				cmd->logout_cid, conn->cid);
2955 		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
2956 		break;
2957 	default:
2958 		pr_err("Unknown cmd->logout_reason: 0x%02x\n",
2959 				cmd->logout_reason);
2960 		return -1;
2961 	}
2962 
2963 	hdr->opcode		= ISCSI_OP_LOGOUT_RSP;
2964 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
2965 	hdr->response		= cmd->logout_response;
2966 	hdr->itt		= cmd->init_task_tag;
2967 	cmd->stat_sn		= conn->stat_sn++;
2968 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
2969 
2970 	iscsit_increment_maxcmdsn(cmd, conn->sess);
2971 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
2972 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
2973 
2974 	pr_debug("Built Logout Response ITT: 0x%08x StatSN:"
2975 		" 0x%08x Response: 0x%02x CID: %hu on CID: %hu\n",
2976 		cmd->init_task_tag, cmd->stat_sn, hdr->response,
2977 		cmd->logout_cid, conn->cid);
2978 
2979 	return 0;
2980 }
2981 EXPORT_SYMBOL(iscsit_build_logout_rsp);
2982 
2983 static int
2984 iscsit_send_logout(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
2985 {
2986 	int rc;
2987 
2988 	rc = iscsit_build_logout_rsp(cmd, conn,
2989 			(struct iscsi_logout_rsp *)&cmd->pdu[0]);
2990 	if (rc < 0)
2991 		return rc;
2992 
2993 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
2994 }
2995 
2996 void
2997 iscsit_build_nopin_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
2998 		       struct iscsi_nopin *hdr, bool nopout_response)
2999 {
3000 	hdr->opcode		= ISCSI_OP_NOOP_IN;
3001 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3002         hton24(hdr->dlength, cmd->buf_ptr_size);
3003 	if (nopout_response)
3004 		put_unaligned_le64(0xFFFFFFFFFFFFFFFFULL, &hdr->lun);
3005 	hdr->itt		= cmd->init_task_tag;
3006 	hdr->ttt		= cpu_to_be32(cmd->targ_xfer_tag);
3007 	cmd->stat_sn		= (nopout_response) ? conn->stat_sn++ :
3008 				  conn->stat_sn;
3009 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3010 
3011 	if (nopout_response)
3012 		iscsit_increment_maxcmdsn(cmd, conn->sess);
3013 
3014 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3015 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3016 
3017 	pr_debug("Built NOPIN %s Response ITT: 0x%08x, TTT: 0x%08x,"
3018 		" StatSN: 0x%08x, Length %u\n", (nopout_response) ?
3019 		"Solicited" : "Unsolicited", cmd->init_task_tag,
3020 		cmd->targ_xfer_tag, cmd->stat_sn, cmd->buf_ptr_size);
3021 }
3022 EXPORT_SYMBOL(iscsit_build_nopin_rsp);
3023 
3024 /*
3025  *	Unsolicited NOPIN, either requesting a response or not.
3026  */
3027 static int iscsit_send_unsolicited_nopin(
3028 	struct iscsi_cmd *cmd,
3029 	struct iscsi_conn *conn,
3030 	int want_response)
3031 {
3032 	struct iscsi_nopin *hdr = (struct iscsi_nopin *)&cmd->pdu[0];
3033 	int ret;
3034 
3035 	iscsit_build_nopin_rsp(cmd, conn, hdr, false);
3036 
3037 	pr_debug("Sending Unsolicited NOPIN TTT: 0x%08x StatSN:"
3038 		" 0x%08x CID: %hu\n", hdr->ttt, cmd->stat_sn, conn->cid);
3039 
3040 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3041 	if (ret < 0)
3042 		return ret;
3043 
3044 	spin_lock_bh(&cmd->istate_lock);
3045 	cmd->i_state = want_response ?
3046 		ISTATE_SENT_NOPIN_WANT_RESPONSE : ISTATE_SENT_STATUS;
3047 	spin_unlock_bh(&cmd->istate_lock);
3048 
3049 	return 0;
3050 }
3051 
3052 static int
3053 iscsit_send_nopin(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3054 {
3055 	struct iscsi_nopin *hdr = (struct iscsi_nopin *)&cmd->pdu[0];
3056 
3057 	iscsit_build_nopin_rsp(cmd, conn, hdr, true);
3058 
3059 	/*
3060 	 * NOPOUT Ping Data is attached to struct iscsi_cmd->buf_ptr.
3061 	 * NOPOUT DataSegmentLength is at struct iscsi_cmd->buf_ptr_size.
3062 	 */
3063 	pr_debug("Echoing back %u bytes of ping data.\n", cmd->buf_ptr_size);
3064 
3065 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3066 						     cmd->buf_ptr,
3067 						     cmd->buf_ptr_size);
3068 }
3069 
3070 static int iscsit_send_r2t(
3071 	struct iscsi_cmd *cmd,
3072 	struct iscsi_conn *conn)
3073 {
3074 	struct iscsi_r2t *r2t;
3075 	struct iscsi_r2t_rsp *hdr;
3076 	int ret;
3077 
3078 	r2t = iscsit_get_r2t_from_list(cmd);
3079 	if (!r2t)
3080 		return -1;
3081 
3082 	hdr			= (struct iscsi_r2t_rsp *) cmd->pdu;
3083 	memset(hdr, 0, ISCSI_HDR_LEN);
3084 	hdr->opcode		= ISCSI_OP_R2T;
3085 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3086 	int_to_scsilun(cmd->se_cmd.orig_fe_lun,
3087 			(struct scsi_lun *)&hdr->lun);
3088 	hdr->itt		= cmd->init_task_tag;
3089 	if (conn->conn_transport->iscsit_get_r2t_ttt)
3090 		conn->conn_transport->iscsit_get_r2t_ttt(conn, cmd, r2t);
3091 	else
3092 		r2t->targ_xfer_tag = session_get_next_ttt(conn->sess);
3093 	hdr->ttt		= cpu_to_be32(r2t->targ_xfer_tag);
3094 	hdr->statsn		= cpu_to_be32(conn->stat_sn);
3095 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3096 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3097 	hdr->r2tsn		= cpu_to_be32(r2t->r2t_sn);
3098 	hdr->data_offset	= cpu_to_be32(r2t->offset);
3099 	hdr->data_length	= cpu_to_be32(r2t->xfer_len);
3100 
3101 	pr_debug("Built %sR2T, ITT: 0x%08x, TTT: 0x%08x, StatSN:"
3102 		" 0x%08x, R2TSN: 0x%08x, Offset: %u, DDTL: %u, CID: %hu\n",
3103 		(!r2t->recovery_r2t) ? "" : "Recovery ", cmd->init_task_tag,
3104 		r2t->targ_xfer_tag, ntohl(hdr->statsn), r2t->r2t_sn,
3105 			r2t->offset, r2t->xfer_len, conn->cid);
3106 
3107 	spin_lock_bh(&cmd->r2t_lock);
3108 	r2t->sent_r2t = 1;
3109 	spin_unlock_bh(&cmd->r2t_lock);
3110 
3111 	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3112 	if (ret < 0) {
3113 		return ret;
3114 	}
3115 
3116 	spin_lock_bh(&cmd->dataout_timeout_lock);
3117 	iscsit_start_dataout_timer(cmd, conn);
3118 	spin_unlock_bh(&cmd->dataout_timeout_lock);
3119 
3120 	return 0;
3121 }
3122 
3123 /*
3124  *	@recovery: If called from iscsi_task_reassign_complete_write() for
3125  *		connection recovery.
3126  */
3127 int iscsit_build_r2ts_for_cmd(
3128 	struct iscsi_conn *conn,
3129 	struct iscsi_cmd *cmd,
3130 	bool recovery)
3131 {
3132 	int first_r2t = 1;
3133 	u32 offset = 0, xfer_len = 0;
3134 
3135 	spin_lock_bh(&cmd->r2t_lock);
3136 	if (cmd->cmd_flags & ICF_SENT_LAST_R2T) {
3137 		spin_unlock_bh(&cmd->r2t_lock);
3138 		return 0;
3139 	}
3140 
3141 	if (conn->sess->sess_ops->DataSequenceInOrder &&
3142 	    !recovery)
3143 		cmd->r2t_offset = max(cmd->r2t_offset, cmd->write_data_done);
3144 
3145 	while (cmd->outstanding_r2ts < conn->sess->sess_ops->MaxOutstandingR2T) {
3146 		if (conn->sess->sess_ops->DataSequenceInOrder) {
3147 			offset = cmd->r2t_offset;
3148 
3149 			if (first_r2t && recovery) {
3150 				int new_data_end = offset +
3151 					conn->sess->sess_ops->MaxBurstLength -
3152 					cmd->next_burst_len;
3153 
3154 				if (new_data_end > cmd->se_cmd.data_length)
3155 					xfer_len = cmd->se_cmd.data_length - offset;
3156 				else
3157 					xfer_len =
3158 						conn->sess->sess_ops->MaxBurstLength -
3159 						cmd->next_burst_len;
3160 			} else {
3161 				int new_data_end = offset +
3162 					conn->sess->sess_ops->MaxBurstLength;
3163 
3164 				if (new_data_end > cmd->se_cmd.data_length)
3165 					xfer_len = cmd->se_cmd.data_length - offset;
3166 				else
3167 					xfer_len = conn->sess->sess_ops->MaxBurstLength;
3168 			}
3169 
3170 			if ((s32)xfer_len < 0) {
3171 				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
3172 				break;
3173 			}
3174 
3175 			cmd->r2t_offset += xfer_len;
3176 
3177 			if (cmd->r2t_offset == cmd->se_cmd.data_length)
3178 				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
3179 		} else {
3180 			struct iscsi_seq *seq;
3181 
3182 			seq = iscsit_get_seq_holder_for_r2t(cmd);
3183 			if (!seq) {
3184 				spin_unlock_bh(&cmd->r2t_lock);
3185 				return -1;
3186 			}
3187 
3188 			offset = seq->offset;
3189 			xfer_len = seq->xfer_len;
3190 
3191 			if (cmd->seq_send_order == cmd->seq_count)
3192 				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
3193 		}
3194 		cmd->outstanding_r2ts++;
3195 		first_r2t = 0;
3196 
3197 		if (iscsit_add_r2t_to_list(cmd, offset, xfer_len, 0, 0) < 0) {
3198 			spin_unlock_bh(&cmd->r2t_lock);
3199 			return -1;
3200 		}
3201 
3202 		if (cmd->cmd_flags & ICF_SENT_LAST_R2T)
3203 			break;
3204 	}
3205 	spin_unlock_bh(&cmd->r2t_lock);
3206 
3207 	return 0;
3208 }
3209 EXPORT_SYMBOL(iscsit_build_r2ts_for_cmd);
3210 
3211 void iscsit_build_rsp_pdu(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3212 			bool inc_stat_sn, struct iscsi_scsi_rsp *hdr)
3213 {
3214 	if (inc_stat_sn)
3215 		cmd->stat_sn = conn->stat_sn++;
3216 
3217 	atomic_long_inc(&conn->sess->rsp_pdus);
3218 
3219 	memset(hdr, 0, ISCSI_HDR_LEN);
3220 	hdr->opcode		= ISCSI_OP_SCSI_CMD_RSP;
3221 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3222 	if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
3223 		hdr->flags |= ISCSI_FLAG_CMD_OVERFLOW;
3224 		hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
3225 	} else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
3226 		hdr->flags |= ISCSI_FLAG_CMD_UNDERFLOW;
3227 		hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
3228 	}
3229 	hdr->response		= cmd->iscsi_response;
3230 	hdr->cmd_status		= cmd->se_cmd.scsi_status;
3231 	hdr->itt		= cmd->init_task_tag;
3232 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3233 
3234 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3235 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3236 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3237 
3238 	pr_debug("Built SCSI Response, ITT: 0x%08x, StatSN: 0x%08x,"
3239 		" Response: 0x%02x, SAM Status: 0x%02x, CID: %hu\n",
3240 		cmd->init_task_tag, cmd->stat_sn, cmd->se_cmd.scsi_status,
3241 		cmd->se_cmd.scsi_status, conn->cid);
3242 }
3243 EXPORT_SYMBOL(iscsit_build_rsp_pdu);
3244 
3245 static int iscsit_send_response(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3246 {
3247 	struct iscsi_scsi_rsp *hdr = (struct iscsi_scsi_rsp *)&cmd->pdu[0];
3248 	bool inc_stat_sn = (cmd->i_state == ISTATE_SEND_STATUS);
3249 	void *data_buf = NULL;
3250 	u32 padding = 0, data_buf_len = 0;
3251 
3252 	iscsit_build_rsp_pdu(cmd, conn, inc_stat_sn, hdr);
3253 
3254 	/*
3255 	 * Attach SENSE DATA payload to iSCSI Response PDU
3256 	 */
3257 	if (cmd->se_cmd.sense_buffer &&
3258 	   ((cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
3259 	    (cmd->se_cmd.se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
3260 		put_unaligned_be16(cmd->se_cmd.scsi_sense_length, cmd->sense_buffer);
3261 		cmd->se_cmd.scsi_sense_length += sizeof (__be16);
3262 
3263 		padding		= -(cmd->se_cmd.scsi_sense_length) & 3;
3264 		hton24(hdr->dlength, (u32)cmd->se_cmd.scsi_sense_length);
3265 		data_buf = cmd->sense_buffer;
3266 		data_buf_len = cmd->se_cmd.scsi_sense_length + padding;
3267 
3268 		if (padding) {
3269 			memset(cmd->sense_buffer +
3270 				cmd->se_cmd.scsi_sense_length, 0, padding);
3271 			pr_debug("Adding %u bytes of padding to"
3272 				" SENSE.\n", padding);
3273 		}
3274 
3275 		pr_debug("Attaching SENSE DATA: %u bytes to iSCSI"
3276 				" Response PDU\n",
3277 				cmd->se_cmd.scsi_sense_length);
3278 	}
3279 
3280 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, data_buf,
3281 						     data_buf_len);
3282 }
3283 
3284 static u8 iscsit_convert_tcm_tmr_rsp(struct se_tmr_req *se_tmr)
3285 {
3286 	switch (se_tmr->response) {
3287 	case TMR_FUNCTION_COMPLETE:
3288 		return ISCSI_TMF_RSP_COMPLETE;
3289 	case TMR_TASK_DOES_NOT_EXIST:
3290 		return ISCSI_TMF_RSP_NO_TASK;
3291 	case TMR_LUN_DOES_NOT_EXIST:
3292 		return ISCSI_TMF_RSP_NO_LUN;
3293 	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
3294 		return ISCSI_TMF_RSP_NOT_SUPPORTED;
3295 	case TMR_FUNCTION_REJECTED:
3296 	default:
3297 		return ISCSI_TMF_RSP_REJECTED;
3298 	}
3299 }
3300 
3301 void
3302 iscsit_build_task_mgt_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3303 			  struct iscsi_tm_rsp *hdr)
3304 {
3305 	struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req;
3306 
3307 	hdr->opcode		= ISCSI_OP_SCSI_TMFUNC_RSP;
3308 	hdr->flags		= ISCSI_FLAG_CMD_FINAL;
3309 	hdr->response		= iscsit_convert_tcm_tmr_rsp(se_tmr);
3310 	hdr->itt		= cmd->init_task_tag;
3311 	cmd->stat_sn		= conn->stat_sn++;
3312 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3313 
3314 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3315 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3316 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3317 
3318 	pr_debug("Built Task Management Response ITT: 0x%08x,"
3319 		" StatSN: 0x%08x, Response: 0x%02x, CID: %hu\n",
3320 		cmd->init_task_tag, cmd->stat_sn, hdr->response, conn->cid);
3321 }
3322 EXPORT_SYMBOL(iscsit_build_task_mgt_rsp);
3323 
3324 static int
3325 iscsit_send_task_mgt_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
3326 {
3327 	struct iscsi_tm_rsp *hdr = (struct iscsi_tm_rsp *)&cmd->pdu[0];
3328 
3329 	iscsit_build_task_mgt_rsp(cmd, conn, hdr);
3330 
3331 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
3332 }
3333 
3334 #define SENDTARGETS_BUF_LIMIT 32768U
3335 
3336 static int
3337 iscsit_build_sendtargets_response(struct iscsi_cmd *cmd,
3338 				  enum iscsit_transport_type network_transport,
3339 				  int skip_bytes, bool *completed)
3340 {
3341 	char *payload = NULL;
3342 	struct iscsi_conn *conn = cmd->conn;
3343 	struct iscsi_portal_group *tpg;
3344 	struct iscsi_tiqn *tiqn;
3345 	struct iscsi_tpg_np *tpg_np;
3346 	int buffer_len, end_of_buf = 0, len = 0, payload_len = 0;
3347 	int target_name_printed;
3348 	unsigned char buf[ISCSI_IQN_LEN+12]; /* iqn + "TargetName=" + \0 */
3349 	unsigned char *text_in = cmd->text_in_ptr, *text_ptr = NULL;
3350 	bool active;
3351 
3352 	buffer_len = min(conn->conn_ops->MaxRecvDataSegmentLength,
3353 			 SENDTARGETS_BUF_LIMIT);
3354 
3355 	payload = kzalloc(buffer_len, GFP_KERNEL);
3356 	if (!payload)
3357 		return -ENOMEM;
3358 
3359 	/*
3360 	 * Locate pointer to iqn./eui. string for ICF_SENDTARGETS_SINGLE
3361 	 * explicit case..
3362 	 */
3363 	if (cmd->cmd_flags & ICF_SENDTARGETS_SINGLE) {
3364 		text_ptr = strchr(text_in, '=');
3365 		if (!text_ptr) {
3366 			pr_err("Unable to locate '=' string in text_in:"
3367 			       " %s\n", text_in);
3368 			kfree(payload);
3369 			return -EINVAL;
3370 		}
3371 		/*
3372 		 * Skip over '=' character..
3373 		 */
3374 		text_ptr += 1;
3375 	}
3376 
3377 	spin_lock(&tiqn_lock);
3378 	list_for_each_entry(tiqn, &g_tiqn_list, tiqn_list) {
3379 		if ((cmd->cmd_flags & ICF_SENDTARGETS_SINGLE) &&
3380 		     strcmp(tiqn->tiqn, text_ptr)) {
3381 			continue;
3382 		}
3383 
3384 		target_name_printed = 0;
3385 
3386 		spin_lock(&tiqn->tiqn_tpg_lock);
3387 		list_for_each_entry(tpg, &tiqn->tiqn_tpg_list, tpg_list) {
3388 
3389 			/* If demo_mode_discovery=0 and generate_node_acls=0
3390 			 * (demo mode dislabed) do not return
3391 			 * TargetName+TargetAddress unless a NodeACL exists.
3392 			 */
3393 
3394 			if ((tpg->tpg_attrib.generate_node_acls == 0) &&
3395 			    (tpg->tpg_attrib.demo_mode_discovery == 0) &&
3396 			    (!target_tpg_has_node_acl(&tpg->tpg_se_tpg,
3397 				cmd->conn->sess->sess_ops->InitiatorName))) {
3398 				continue;
3399 			}
3400 
3401 			spin_lock(&tpg->tpg_state_lock);
3402 			active = (tpg->tpg_state == TPG_STATE_ACTIVE);
3403 			spin_unlock(&tpg->tpg_state_lock);
3404 
3405 			if (!active && tpg->tpg_attrib.tpg_enabled_sendtargets)
3406 				continue;
3407 
3408 			spin_lock(&tpg->tpg_np_lock);
3409 			list_for_each_entry(tpg_np, &tpg->tpg_gnp_list,
3410 						tpg_np_list) {
3411 				struct iscsi_np *np = tpg_np->tpg_np;
3412 				struct sockaddr_storage *sockaddr;
3413 
3414 				if (np->np_network_transport != network_transport)
3415 					continue;
3416 
3417 				if (!target_name_printed) {
3418 					len = sprintf(buf, "TargetName=%s",
3419 						      tiqn->tiqn);
3420 					len += 1;
3421 
3422 					if ((len + payload_len) > buffer_len) {
3423 						spin_unlock(&tpg->tpg_np_lock);
3424 						spin_unlock(&tiqn->tiqn_tpg_lock);
3425 						end_of_buf = 1;
3426 						goto eob;
3427 					}
3428 
3429 					if (skip_bytes && len <= skip_bytes) {
3430 						skip_bytes -= len;
3431 					} else {
3432 						memcpy(payload + payload_len, buf, len);
3433 						payload_len += len;
3434 						target_name_printed = 1;
3435 						if (len > skip_bytes)
3436 							skip_bytes = 0;
3437 					}
3438 				}
3439 
3440 				if (inet_addr_is_any((struct sockaddr *)&np->np_sockaddr))
3441 					sockaddr = &conn->local_sockaddr;
3442 				else
3443 					sockaddr = &np->np_sockaddr;
3444 
3445 				len = sprintf(buf, "TargetAddress="
3446 					      "%pISpc,%hu",
3447 					      sockaddr,
3448 					      tpg->tpgt);
3449 				len += 1;
3450 
3451 				if ((len + payload_len) > buffer_len) {
3452 					spin_unlock(&tpg->tpg_np_lock);
3453 					spin_unlock(&tiqn->tiqn_tpg_lock);
3454 					end_of_buf = 1;
3455 					goto eob;
3456 				}
3457 
3458 				if (skip_bytes && len <= skip_bytes) {
3459 					skip_bytes -= len;
3460 				} else {
3461 					memcpy(payload + payload_len, buf, len);
3462 					payload_len += len;
3463 					if (len > skip_bytes)
3464 						skip_bytes = 0;
3465 				}
3466 			}
3467 			spin_unlock(&tpg->tpg_np_lock);
3468 		}
3469 		spin_unlock(&tiqn->tiqn_tpg_lock);
3470 eob:
3471 		if (end_of_buf) {
3472 			*completed = false;
3473 			break;
3474 		}
3475 
3476 		if (cmd->cmd_flags & ICF_SENDTARGETS_SINGLE)
3477 			break;
3478 	}
3479 	spin_unlock(&tiqn_lock);
3480 
3481 	cmd->buf_ptr = payload;
3482 
3483 	return payload_len;
3484 }
3485 
3486 int
3487 iscsit_build_text_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3488 		      struct iscsi_text_rsp *hdr,
3489 		      enum iscsit_transport_type network_transport)
3490 {
3491 	int text_length, padding;
3492 	bool completed = true;
3493 
3494 	text_length = iscsit_build_sendtargets_response(cmd, network_transport,
3495 							cmd->read_data_done,
3496 							&completed);
3497 	if (text_length < 0)
3498 		return text_length;
3499 
3500 	if (completed) {
3501 		hdr->flags = ISCSI_FLAG_CMD_FINAL;
3502 	} else {
3503 		hdr->flags = ISCSI_FLAG_TEXT_CONTINUE;
3504 		cmd->read_data_done += text_length;
3505 		if (cmd->targ_xfer_tag == 0xFFFFFFFF)
3506 			cmd->targ_xfer_tag = session_get_next_ttt(conn->sess);
3507 	}
3508 	hdr->opcode = ISCSI_OP_TEXT_RSP;
3509 	padding = ((-text_length) & 3);
3510 	hton24(hdr->dlength, text_length);
3511 	hdr->itt = cmd->init_task_tag;
3512 	hdr->ttt = cpu_to_be32(cmd->targ_xfer_tag);
3513 	cmd->stat_sn = conn->stat_sn++;
3514 	hdr->statsn = cpu_to_be32(cmd->stat_sn);
3515 
3516 	iscsit_increment_maxcmdsn(cmd, conn->sess);
3517 	/*
3518 	 * Reset maxcmdsn_inc in multi-part text payload exchanges to
3519 	 * correctly increment MaxCmdSN for each response answering a
3520 	 * non immediate text request with a valid CmdSN.
3521 	 */
3522 	cmd->maxcmdsn_inc = 0;
3523 	hdr->exp_cmdsn = cpu_to_be32(conn->sess->exp_cmd_sn);
3524 	hdr->max_cmdsn = cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3525 
3526 	pr_debug("Built Text Response: ITT: 0x%08x, TTT: 0x%08x, StatSN: 0x%08x,"
3527 		" Length: %u, CID: %hu F: %d C: %d\n", cmd->init_task_tag,
3528 		cmd->targ_xfer_tag, cmd->stat_sn, text_length, conn->cid,
3529 		!!(hdr->flags & ISCSI_FLAG_CMD_FINAL),
3530 		!!(hdr->flags & ISCSI_FLAG_TEXT_CONTINUE));
3531 
3532 	return text_length + padding;
3533 }
3534 EXPORT_SYMBOL(iscsit_build_text_rsp);
3535 
3536 static int iscsit_send_text_rsp(
3537 	struct iscsi_cmd *cmd,
3538 	struct iscsi_conn *conn)
3539 {
3540 	struct iscsi_text_rsp *hdr = (struct iscsi_text_rsp *)cmd->pdu;
3541 	int text_length;
3542 
3543 	text_length = iscsit_build_text_rsp(cmd, conn, hdr,
3544 				conn->conn_transport->transport_type);
3545 	if (text_length < 0)
3546 		return text_length;
3547 
3548 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3549 						     cmd->buf_ptr,
3550 						     text_length);
3551 }
3552 
3553 void
3554 iscsit_build_reject(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
3555 		    struct iscsi_reject *hdr)
3556 {
3557 	hdr->opcode		= ISCSI_OP_REJECT;
3558 	hdr->reason		= cmd->reject_reason;
3559 	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
3560 	hton24(hdr->dlength, ISCSI_HDR_LEN);
3561 	hdr->ffffffff		= cpu_to_be32(0xffffffff);
3562 	cmd->stat_sn		= conn->stat_sn++;
3563 	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
3564 	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
3565 	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
3566 
3567 }
3568 EXPORT_SYMBOL(iscsit_build_reject);
3569 
3570 static int iscsit_send_reject(
3571 	struct iscsi_cmd *cmd,
3572 	struct iscsi_conn *conn)
3573 {
3574 	struct iscsi_reject *hdr = (struct iscsi_reject *)&cmd->pdu[0];
3575 
3576 	iscsit_build_reject(cmd, conn, hdr);
3577 
3578 	pr_debug("Built Reject PDU StatSN: 0x%08x, Reason: 0x%02x,"
3579 		" CID: %hu\n", ntohl(hdr->statsn), hdr->reason, conn->cid);
3580 
3581 	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
3582 						     cmd->buf_ptr,
3583 						     ISCSI_HDR_LEN);
3584 }
3585 
3586 void iscsit_thread_get_cpumask(struct iscsi_conn *conn)
3587 {
3588 	int ord, cpu;
3589 	/*
3590 	 * bitmap_id is assigned from iscsit_global->ts_bitmap from
3591 	 * within iscsit_start_kthreads()
3592 	 *
3593 	 * Here we use bitmap_id to determine which CPU that this
3594 	 * iSCSI connection's RX/TX threads will be scheduled to
3595 	 * execute upon.
3596 	 */
3597 	ord = conn->bitmap_id % cpumask_weight(cpu_online_mask);
3598 	for_each_online_cpu(cpu) {
3599 		if (ord-- == 0) {
3600 			cpumask_set_cpu(cpu, conn->conn_cpumask);
3601 			return;
3602 		}
3603 	}
3604 	/*
3605 	 * This should never be reached..
3606 	 */
3607 	dump_stack();
3608 	cpumask_setall(conn->conn_cpumask);
3609 }
3610 
3611 int
3612 iscsit_immediate_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
3613 {
3614 	int ret;
3615 
3616 	switch (state) {
3617 	case ISTATE_SEND_R2T:
3618 		ret = iscsit_send_r2t(cmd, conn);
3619 		if (ret < 0)
3620 			goto err;
3621 		break;
3622 	case ISTATE_REMOVE:
3623 		spin_lock_bh(&conn->cmd_lock);
3624 		list_del_init(&cmd->i_conn_node);
3625 		spin_unlock_bh(&conn->cmd_lock);
3626 
3627 		iscsit_free_cmd(cmd, false);
3628 		break;
3629 	case ISTATE_SEND_NOPIN_WANT_RESPONSE:
3630 		iscsit_mod_nopin_response_timer(conn);
3631 		ret = iscsit_send_unsolicited_nopin(cmd, conn, 1);
3632 		if (ret < 0)
3633 			goto err;
3634 		break;
3635 	case ISTATE_SEND_NOPIN_NO_RESPONSE:
3636 		ret = iscsit_send_unsolicited_nopin(cmd, conn, 0);
3637 		if (ret < 0)
3638 			goto err;
3639 		break;
3640 	default:
3641 		pr_err("Unknown Opcode: 0x%02x ITT:"
3642 		       " 0x%08x, i_state: %d on CID: %hu\n",
3643 		       cmd->iscsi_opcode, cmd->init_task_tag, state,
3644 		       conn->cid);
3645 		goto err;
3646 	}
3647 
3648 	return 0;
3649 
3650 err:
3651 	return -1;
3652 }
3653 EXPORT_SYMBOL(iscsit_immediate_queue);
3654 
3655 static int
3656 iscsit_handle_immediate_queue(struct iscsi_conn *conn)
3657 {
3658 	struct iscsit_transport *t = conn->conn_transport;
3659 	struct iscsi_queue_req *qr;
3660 	struct iscsi_cmd *cmd;
3661 	u8 state;
3662 	int ret;
3663 
3664 	while ((qr = iscsit_get_cmd_from_immediate_queue(conn))) {
3665 		atomic_set(&conn->check_immediate_queue, 0);
3666 		cmd = qr->cmd;
3667 		state = qr->state;
3668 		kmem_cache_free(lio_qr_cache, qr);
3669 
3670 		ret = t->iscsit_immediate_queue(conn, cmd, state);
3671 		if (ret < 0)
3672 			return ret;
3673 	}
3674 
3675 	return 0;
3676 }
3677 
3678 int
3679 iscsit_response_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
3680 {
3681 	int ret;
3682 
3683 check_rsp_state:
3684 	switch (state) {
3685 	case ISTATE_SEND_DATAIN:
3686 		ret = iscsit_send_datain(cmd, conn);
3687 		if (ret < 0)
3688 			goto err;
3689 		else if (!ret)
3690 			/* more drs */
3691 			goto check_rsp_state;
3692 		else if (ret == 1) {
3693 			/* all done */
3694 			spin_lock_bh(&cmd->istate_lock);
3695 			cmd->i_state = ISTATE_SENT_STATUS;
3696 			spin_unlock_bh(&cmd->istate_lock);
3697 
3698 			if (atomic_read(&conn->check_immediate_queue))
3699 				return 1;
3700 
3701 			return 0;
3702 		} else if (ret == 2) {
3703 			/* Still must send status,
3704 			   SCF_TRANSPORT_TASK_SENSE was set */
3705 			spin_lock_bh(&cmd->istate_lock);
3706 			cmd->i_state = ISTATE_SEND_STATUS;
3707 			spin_unlock_bh(&cmd->istate_lock);
3708 			state = ISTATE_SEND_STATUS;
3709 			goto check_rsp_state;
3710 		}
3711 
3712 		break;
3713 	case ISTATE_SEND_STATUS:
3714 	case ISTATE_SEND_STATUS_RECOVERY:
3715 		ret = iscsit_send_response(cmd, conn);
3716 		break;
3717 	case ISTATE_SEND_LOGOUTRSP:
3718 		ret = iscsit_send_logout(cmd, conn);
3719 		break;
3720 	case ISTATE_SEND_ASYNCMSG:
3721 		ret = iscsit_send_conn_drop_async_message(
3722 			cmd, conn);
3723 		break;
3724 	case ISTATE_SEND_NOPIN:
3725 		ret = iscsit_send_nopin(cmd, conn);
3726 		break;
3727 	case ISTATE_SEND_REJECT:
3728 		ret = iscsit_send_reject(cmd, conn);
3729 		break;
3730 	case ISTATE_SEND_TASKMGTRSP:
3731 		ret = iscsit_send_task_mgt_rsp(cmd, conn);
3732 		if (ret != 0)
3733 			break;
3734 		ret = iscsit_tmr_post_handler(cmd, conn);
3735 		if (ret != 0)
3736 			iscsit_fall_back_to_erl0(conn->sess);
3737 		break;
3738 	case ISTATE_SEND_TEXTRSP:
3739 		ret = iscsit_send_text_rsp(cmd, conn);
3740 		break;
3741 	default:
3742 		pr_err("Unknown Opcode: 0x%02x ITT:"
3743 		       " 0x%08x, i_state: %d on CID: %hu\n",
3744 		       cmd->iscsi_opcode, cmd->init_task_tag,
3745 		       state, conn->cid);
3746 		goto err;
3747 	}
3748 	if (ret < 0)
3749 		goto err;
3750 
3751 	switch (state) {
3752 	case ISTATE_SEND_LOGOUTRSP:
3753 		if (!iscsit_logout_post_handler(cmd, conn))
3754 			return -ECONNRESET;
3755 		fallthrough;
3756 	case ISTATE_SEND_STATUS:
3757 	case ISTATE_SEND_ASYNCMSG:
3758 	case ISTATE_SEND_NOPIN:
3759 	case ISTATE_SEND_STATUS_RECOVERY:
3760 	case ISTATE_SEND_TEXTRSP:
3761 	case ISTATE_SEND_TASKMGTRSP:
3762 	case ISTATE_SEND_REJECT:
3763 		spin_lock_bh(&cmd->istate_lock);
3764 		cmd->i_state = ISTATE_SENT_STATUS;
3765 		spin_unlock_bh(&cmd->istate_lock);
3766 		break;
3767 	default:
3768 		pr_err("Unknown Opcode: 0x%02x ITT:"
3769 		       " 0x%08x, i_state: %d on CID: %hu\n",
3770 		       cmd->iscsi_opcode, cmd->init_task_tag,
3771 		       cmd->i_state, conn->cid);
3772 		goto err;
3773 	}
3774 
3775 	if (atomic_read(&conn->check_immediate_queue))
3776 		return 1;
3777 
3778 	return 0;
3779 
3780 err:
3781 	return -1;
3782 }
3783 EXPORT_SYMBOL(iscsit_response_queue);
3784 
3785 static int iscsit_handle_response_queue(struct iscsi_conn *conn)
3786 {
3787 	struct iscsit_transport *t = conn->conn_transport;
3788 	struct iscsi_queue_req *qr;
3789 	struct iscsi_cmd *cmd;
3790 	u8 state;
3791 	int ret;
3792 
3793 	while ((qr = iscsit_get_cmd_from_response_queue(conn))) {
3794 		cmd = qr->cmd;
3795 		state = qr->state;
3796 		kmem_cache_free(lio_qr_cache, qr);
3797 
3798 		ret = t->iscsit_response_queue(conn, cmd, state);
3799 		if (ret == 1 || ret < 0)
3800 			return ret;
3801 	}
3802 
3803 	return 0;
3804 }
3805 
3806 int iscsi_target_tx_thread(void *arg)
3807 {
3808 	int ret = 0;
3809 	struct iscsi_conn *conn = arg;
3810 	bool conn_freed = false;
3811 
3812 	/*
3813 	 * Allow ourselves to be interrupted by SIGINT so that a
3814 	 * connection recovery / failure event can be triggered externally.
3815 	 */
3816 	allow_signal(SIGINT);
3817 
3818 	while (!kthread_should_stop()) {
3819 		/*
3820 		 * Ensure that both TX and RX per connection kthreads
3821 		 * are scheduled to run on the same CPU.
3822 		 */
3823 		iscsit_thread_check_cpumask(conn, current, 1);
3824 
3825 		wait_event_interruptible(conn->queues_wq,
3826 					 !iscsit_conn_all_queues_empty(conn));
3827 
3828 		if (signal_pending(current))
3829 			goto transport_err;
3830 
3831 get_immediate:
3832 		ret = iscsit_handle_immediate_queue(conn);
3833 		if (ret < 0)
3834 			goto transport_err;
3835 
3836 		ret = iscsit_handle_response_queue(conn);
3837 		if (ret == 1) {
3838 			goto get_immediate;
3839 		} else if (ret == -ECONNRESET) {
3840 			conn_freed = true;
3841 			goto out;
3842 		} else if (ret < 0) {
3843 			goto transport_err;
3844 		}
3845 	}
3846 
3847 transport_err:
3848 	/*
3849 	 * Avoid the normal connection failure code-path if this connection
3850 	 * is still within LOGIN mode, and iscsi_np process context is
3851 	 * responsible for cleaning up the early connection failure.
3852 	 */
3853 	if (conn->conn_state != TARG_CONN_STATE_IN_LOGIN)
3854 		iscsit_take_action_for_connection_exit(conn, &conn_freed);
3855 out:
3856 	if (!conn_freed) {
3857 		while (!kthread_should_stop()) {
3858 			msleep(100);
3859 		}
3860 	}
3861 	return 0;
3862 }
3863 
3864 static int iscsi_target_rx_opcode(struct iscsi_conn *conn, unsigned char *buf)
3865 {
3866 	struct iscsi_hdr *hdr = (struct iscsi_hdr *)buf;
3867 	struct iscsi_cmd *cmd;
3868 	int ret = 0;
3869 
3870 	switch (hdr->opcode & ISCSI_OPCODE_MASK) {
3871 	case ISCSI_OP_SCSI_CMD:
3872 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3873 		if (!cmd)
3874 			goto reject;
3875 
3876 		ret = iscsit_handle_scsi_cmd(conn, cmd, buf);
3877 		break;
3878 	case ISCSI_OP_SCSI_DATA_OUT:
3879 		ret = iscsit_handle_data_out(conn, buf);
3880 		break;
3881 	case ISCSI_OP_NOOP_OUT:
3882 		cmd = NULL;
3883 		if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
3884 			cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3885 			if (!cmd)
3886 				goto reject;
3887 		}
3888 		ret = iscsit_handle_nop_out(conn, cmd, buf);
3889 		break;
3890 	case ISCSI_OP_SCSI_TMFUNC:
3891 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3892 		if (!cmd)
3893 			goto reject;
3894 
3895 		ret = iscsit_handle_task_mgt_cmd(conn, cmd, buf);
3896 		break;
3897 	case ISCSI_OP_TEXT:
3898 		if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
3899 			cmd = iscsit_find_cmd_from_itt(conn, hdr->itt);
3900 			if (!cmd)
3901 				goto reject;
3902 		} else {
3903 			cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3904 			if (!cmd)
3905 				goto reject;
3906 		}
3907 
3908 		ret = iscsit_handle_text_cmd(conn, cmd, buf);
3909 		break;
3910 	case ISCSI_OP_LOGOUT:
3911 		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
3912 		if (!cmd)
3913 			goto reject;
3914 
3915 		ret = iscsit_handle_logout_cmd(conn, cmd, buf);
3916 		if (ret > 0)
3917 			wait_for_completion_timeout(&conn->conn_logout_comp,
3918 					SECONDS_FOR_LOGOUT_COMP * HZ);
3919 		break;
3920 	case ISCSI_OP_SNACK:
3921 		ret = iscsit_handle_snack(conn, buf);
3922 		break;
3923 	default:
3924 		pr_err("Got unknown iSCSI OpCode: 0x%02x\n", hdr->opcode);
3925 		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
3926 			pr_err("Cannot recover from unknown"
3927 			" opcode while ERL=0, closing iSCSI connection.\n");
3928 			return -1;
3929 		}
3930 		pr_err("Unable to recover from unknown opcode while OFMarker=No,"
3931 		       " closing iSCSI connection.\n");
3932 		ret = -1;
3933 		break;
3934 	}
3935 
3936 	return ret;
3937 reject:
3938 	return iscsit_add_reject(conn, ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
3939 }
3940 
3941 static bool iscsi_target_check_conn_state(struct iscsi_conn *conn)
3942 {
3943 	bool ret;
3944 
3945 	spin_lock_bh(&conn->state_lock);
3946 	ret = (conn->conn_state != TARG_CONN_STATE_LOGGED_IN);
3947 	spin_unlock_bh(&conn->state_lock);
3948 
3949 	return ret;
3950 }
3951 
3952 static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
3953 {
3954 	int ret;
3955 	u8 *buffer, opcode;
3956 	u32 checksum = 0, digest = 0;
3957 	struct kvec iov;
3958 
3959 	buffer = kcalloc(ISCSI_HDR_LEN, sizeof(*buffer), GFP_KERNEL);
3960 	if (!buffer)
3961 		return;
3962 
3963 	while (!kthread_should_stop()) {
3964 		/*
3965 		 * Ensure that both TX and RX per connection kthreads
3966 		 * are scheduled to run on the same CPU.
3967 		 */
3968 		iscsit_thread_check_cpumask(conn, current, 0);
3969 
3970 		memset(&iov, 0, sizeof(struct kvec));
3971 
3972 		iov.iov_base	= buffer;
3973 		iov.iov_len	= ISCSI_HDR_LEN;
3974 
3975 		ret = rx_data(conn, &iov, 1, ISCSI_HDR_LEN);
3976 		if (ret != ISCSI_HDR_LEN) {
3977 			iscsit_rx_thread_wait_for_tcp(conn);
3978 			break;
3979 		}
3980 
3981 		if (conn->conn_ops->HeaderDigest) {
3982 			iov.iov_base	= &digest;
3983 			iov.iov_len	= ISCSI_CRC_LEN;
3984 
3985 			ret = rx_data(conn, &iov, 1, ISCSI_CRC_LEN);
3986 			if (ret != ISCSI_CRC_LEN) {
3987 				iscsit_rx_thread_wait_for_tcp(conn);
3988 				break;
3989 			}
3990 
3991 			iscsit_do_crypto_hash_buf(conn->conn_rx_hash, buffer,
3992 						  ISCSI_HDR_LEN, 0, NULL,
3993 						  &checksum);
3994 
3995 			if (digest != checksum) {
3996 				pr_err("HeaderDigest CRC32C failed,"
3997 					" received 0x%08x, computed 0x%08x\n",
3998 					digest, checksum);
3999 				/*
4000 				 * Set the PDU to 0xff so it will intentionally
4001 				 * hit default in the switch below.
4002 				 */
4003 				memset(buffer, 0xff, ISCSI_HDR_LEN);
4004 				atomic_long_inc(&conn->sess->conn_digest_errors);
4005 			} else {
4006 				pr_debug("Got HeaderDigest CRC32C"
4007 						" 0x%08x\n", checksum);
4008 			}
4009 		}
4010 
4011 		if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT)
4012 			break;
4013 
4014 		opcode = buffer[0] & ISCSI_OPCODE_MASK;
4015 
4016 		if (conn->sess->sess_ops->SessionType &&
4017 		   ((!(opcode & ISCSI_OP_TEXT)) ||
4018 		    (!(opcode & ISCSI_OP_LOGOUT)))) {
4019 			pr_err("Received illegal iSCSI Opcode: 0x%02x"
4020 			" while in Discovery Session, rejecting.\n", opcode);
4021 			iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
4022 					  buffer);
4023 			break;
4024 		}
4025 
4026 		ret = iscsi_target_rx_opcode(conn, buffer);
4027 		if (ret < 0)
4028 			break;
4029 	}
4030 
4031 	kfree(buffer);
4032 }
4033 
4034 int iscsi_target_rx_thread(void *arg)
4035 {
4036 	int rc;
4037 	struct iscsi_conn *conn = arg;
4038 	bool conn_freed = false;
4039 
4040 	/*
4041 	 * Allow ourselves to be interrupted by SIGINT so that a
4042 	 * connection recovery / failure event can be triggered externally.
4043 	 */
4044 	allow_signal(SIGINT);
4045 	/*
4046 	 * Wait for iscsi_post_login_handler() to complete before allowing
4047 	 * incoming iscsi/tcp socket I/O, and/or failing the connection.
4048 	 */
4049 	rc = wait_for_completion_interruptible(&conn->rx_login_comp);
4050 	if (rc < 0 || iscsi_target_check_conn_state(conn))
4051 		goto out;
4052 
4053 	if (!conn->conn_transport->iscsit_get_rx_pdu)
4054 		return 0;
4055 
4056 	conn->conn_transport->iscsit_get_rx_pdu(conn);
4057 
4058 	if (!signal_pending(current))
4059 		atomic_set(&conn->transport_failed, 1);
4060 	iscsit_take_action_for_connection_exit(conn, &conn_freed);
4061 
4062 out:
4063 	if (!conn_freed) {
4064 		while (!kthread_should_stop()) {
4065 			msleep(100);
4066 		}
4067 	}
4068 
4069 	return 0;
4070 }
4071 
4072 static void iscsit_release_commands_from_conn(struct iscsi_conn *conn)
4073 {
4074 	LIST_HEAD(tmp_list);
4075 	struct iscsi_cmd *cmd = NULL, *cmd_tmp = NULL;
4076 	struct iscsi_session *sess = conn->sess;
4077 	/*
4078 	 * We expect this function to only ever be called from either RX or TX
4079 	 * thread context via iscsit_close_connection() once the other context
4080 	 * has been reset -> returned sleeping pre-handler state.
4081 	 */
4082 	spin_lock_bh(&conn->cmd_lock);
4083 	list_splice_init(&conn->conn_cmd_list, &tmp_list);
4084 
4085 	list_for_each_entry_safe(cmd, cmd_tmp, &tmp_list, i_conn_node) {
4086 		struct se_cmd *se_cmd = &cmd->se_cmd;
4087 
4088 		if (se_cmd->se_tfo != NULL) {
4089 			spin_lock_irq(&se_cmd->t_state_lock);
4090 			if (se_cmd->transport_state & CMD_T_ABORTED) {
4091 				/*
4092 				 * LIO's abort path owns the cleanup for this,
4093 				 * so put it back on the list and let
4094 				 * aborted_task handle it.
4095 				 */
4096 				list_move_tail(&cmd->i_conn_node,
4097 					       &conn->conn_cmd_list);
4098 			} else {
4099 				se_cmd->transport_state |= CMD_T_FABRIC_STOP;
4100 			}
4101 			spin_unlock_irq(&se_cmd->t_state_lock);
4102 		}
4103 	}
4104 	spin_unlock_bh(&conn->cmd_lock);
4105 
4106 	list_for_each_entry_safe(cmd, cmd_tmp, &tmp_list, i_conn_node) {
4107 		list_del_init(&cmd->i_conn_node);
4108 
4109 		iscsit_increment_maxcmdsn(cmd, sess);
4110 		iscsit_free_cmd(cmd, true);
4111 
4112 	}
4113 }
4114 
4115 static void iscsit_stop_timers_for_cmds(
4116 	struct iscsi_conn *conn)
4117 {
4118 	struct iscsi_cmd *cmd;
4119 
4120 	spin_lock_bh(&conn->cmd_lock);
4121 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
4122 		if (cmd->data_direction == DMA_TO_DEVICE)
4123 			iscsit_stop_dataout_timer(cmd);
4124 	}
4125 	spin_unlock_bh(&conn->cmd_lock);
4126 }
4127 
4128 int iscsit_close_connection(
4129 	struct iscsi_conn *conn)
4130 {
4131 	int conn_logout = (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT);
4132 	struct iscsi_session	*sess = conn->sess;
4133 
4134 	pr_debug("Closing iSCSI connection CID %hu on SID:"
4135 		" %u\n", conn->cid, sess->sid);
4136 	/*
4137 	 * Always up conn_logout_comp for the traditional TCP and HW_OFFLOAD
4138 	 * case just in case the RX Thread in iscsi_target_rx_opcode() is
4139 	 * sleeping and the logout response never got sent because the
4140 	 * connection failed.
4141 	 *
4142 	 * However for iser-target, isert_wait4logout() is using conn_logout_comp
4143 	 * to signal logout response TX interrupt completion.  Go ahead and skip
4144 	 * this for iser since isert_rx_opcode() does not wait on logout failure,
4145 	 * and to avoid iscsi_conn pointer dereference in iser-target code.
4146 	 */
4147 	if (!conn->conn_transport->rdma_shutdown)
4148 		complete(&conn->conn_logout_comp);
4149 
4150 	if (!strcmp(current->comm, ISCSI_RX_THREAD_NAME)) {
4151 		if (conn->tx_thread &&
4152 		    cmpxchg(&conn->tx_thread_active, true, false)) {
4153 			send_sig(SIGINT, conn->tx_thread, 1);
4154 			kthread_stop(conn->tx_thread);
4155 		}
4156 	} else if (!strcmp(current->comm, ISCSI_TX_THREAD_NAME)) {
4157 		if (conn->rx_thread &&
4158 		    cmpxchg(&conn->rx_thread_active, true, false)) {
4159 			send_sig(SIGINT, conn->rx_thread, 1);
4160 			kthread_stop(conn->rx_thread);
4161 		}
4162 	}
4163 
4164 	spin_lock(&iscsit_global->ts_bitmap_lock);
4165 	bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
4166 			      get_order(1));
4167 	spin_unlock(&iscsit_global->ts_bitmap_lock);
4168 
4169 	iscsit_stop_timers_for_cmds(conn);
4170 	iscsit_stop_nopin_response_timer(conn);
4171 	iscsit_stop_nopin_timer(conn);
4172 
4173 	if (conn->conn_transport->iscsit_wait_conn)
4174 		conn->conn_transport->iscsit_wait_conn(conn);
4175 
4176 	/*
4177 	 * During Connection recovery drop unacknowledged out of order
4178 	 * commands for this connection, and prepare the other commands
4179 	 * for reallegiance.
4180 	 *
4181 	 * During normal operation clear the out of order commands (but
4182 	 * do not free the struct iscsi_ooo_cmdsn's) and release all
4183 	 * struct iscsi_cmds.
4184 	 */
4185 	if (atomic_read(&conn->connection_recovery)) {
4186 		iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(conn);
4187 		iscsit_prepare_cmds_for_reallegiance(conn);
4188 	} else {
4189 		iscsit_clear_ooo_cmdsns_for_conn(conn);
4190 		iscsit_release_commands_from_conn(conn);
4191 	}
4192 	iscsit_free_queue_reqs_for_conn(conn);
4193 
4194 	/*
4195 	 * Handle decrementing session or connection usage count if
4196 	 * a logout response was not able to be sent because the
4197 	 * connection failed.  Fall back to Session Recovery here.
4198 	 */
4199 	if (atomic_read(&conn->conn_logout_remove)) {
4200 		if (conn->conn_logout_reason == ISCSI_LOGOUT_REASON_CLOSE_SESSION) {
4201 			iscsit_dec_conn_usage_count(conn);
4202 			iscsit_dec_session_usage_count(sess);
4203 		}
4204 		if (conn->conn_logout_reason == ISCSI_LOGOUT_REASON_CLOSE_CONNECTION)
4205 			iscsit_dec_conn_usage_count(conn);
4206 
4207 		atomic_set(&conn->conn_logout_remove, 0);
4208 		atomic_set(&sess->session_reinstatement, 0);
4209 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4210 	}
4211 
4212 	spin_lock_bh(&sess->conn_lock);
4213 	list_del(&conn->conn_list);
4214 
4215 	/*
4216 	 * Attempt to let the Initiator know this connection failed by
4217 	 * sending an Connection Dropped Async Message on another
4218 	 * active connection.
4219 	 */
4220 	if (atomic_read(&conn->connection_recovery))
4221 		iscsit_build_conn_drop_async_message(conn);
4222 
4223 	spin_unlock_bh(&sess->conn_lock);
4224 
4225 	/*
4226 	 * If connection reinstatement is being performed on this connection,
4227 	 * up the connection reinstatement semaphore that is being blocked on
4228 	 * in iscsit_cause_connection_reinstatement().
4229 	 */
4230 	spin_lock_bh(&conn->state_lock);
4231 	if (atomic_read(&conn->sleep_on_conn_wait_comp)) {
4232 		spin_unlock_bh(&conn->state_lock);
4233 		complete(&conn->conn_wait_comp);
4234 		wait_for_completion(&conn->conn_post_wait_comp);
4235 		spin_lock_bh(&conn->state_lock);
4236 	}
4237 
4238 	/*
4239 	 * If connection reinstatement is being performed on this connection
4240 	 * by receiving a REMOVECONNFORRECOVERY logout request, up the
4241 	 * connection wait rcfr semaphore that is being blocked on
4242 	 * an iscsit_connection_reinstatement_rcfr().
4243 	 */
4244 	if (atomic_read(&conn->connection_wait_rcfr)) {
4245 		spin_unlock_bh(&conn->state_lock);
4246 		complete(&conn->conn_wait_rcfr_comp);
4247 		wait_for_completion(&conn->conn_post_wait_comp);
4248 		spin_lock_bh(&conn->state_lock);
4249 	}
4250 	atomic_set(&conn->connection_reinstatement, 1);
4251 	spin_unlock_bh(&conn->state_lock);
4252 
4253 	/*
4254 	 * If any other processes are accessing this connection pointer we
4255 	 * must wait until they have completed.
4256 	 */
4257 	iscsit_check_conn_usage_count(conn);
4258 
4259 	ahash_request_free(conn->conn_tx_hash);
4260 	if (conn->conn_rx_hash) {
4261 		struct crypto_ahash *tfm;
4262 
4263 		tfm = crypto_ahash_reqtfm(conn->conn_rx_hash);
4264 		ahash_request_free(conn->conn_rx_hash);
4265 		crypto_free_ahash(tfm);
4266 	}
4267 
4268 	if (conn->sock)
4269 		sock_release(conn->sock);
4270 
4271 	if (conn->conn_transport->iscsit_free_conn)
4272 		conn->conn_transport->iscsit_free_conn(conn);
4273 
4274 	pr_debug("Moving to TARG_CONN_STATE_FREE.\n");
4275 	conn->conn_state = TARG_CONN_STATE_FREE;
4276 	iscsit_free_conn(conn);
4277 
4278 	spin_lock_bh(&sess->conn_lock);
4279 	atomic_dec(&sess->nconn);
4280 	pr_debug("Decremented iSCSI connection count to %hu from node:"
4281 		" %s\n", atomic_read(&sess->nconn),
4282 		sess->sess_ops->InitiatorName);
4283 	/*
4284 	 * Make sure that if one connection fails in an non ERL=2 iSCSI
4285 	 * Session that they all fail.
4286 	 */
4287 	if ((sess->sess_ops->ErrorRecoveryLevel != 2) && !conn_logout &&
4288 	     !atomic_read(&sess->session_logout))
4289 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4290 
4291 	/*
4292 	 * If this was not the last connection in the session, and we are
4293 	 * performing session reinstatement or falling back to ERL=0, call
4294 	 * iscsit_stop_session() without sleeping to shutdown the other
4295 	 * active connections.
4296 	 */
4297 	if (atomic_read(&sess->nconn)) {
4298 		if (!atomic_read(&sess->session_reinstatement) &&
4299 		    !atomic_read(&sess->session_fall_back_to_erl0)) {
4300 			spin_unlock_bh(&sess->conn_lock);
4301 			return 0;
4302 		}
4303 		if (!atomic_read(&sess->session_stop_active)) {
4304 			atomic_set(&sess->session_stop_active, 1);
4305 			spin_unlock_bh(&sess->conn_lock);
4306 			iscsit_stop_session(sess, 0, 0);
4307 			return 0;
4308 		}
4309 		spin_unlock_bh(&sess->conn_lock);
4310 		return 0;
4311 	}
4312 
4313 	/*
4314 	 * If this was the last connection in the session and one of the
4315 	 * following is occurring:
4316 	 *
4317 	 * Session Reinstatement is not being performed, and are falling back
4318 	 * to ERL=0 call iscsit_close_session().
4319 	 *
4320 	 * Session Logout was requested.  iscsit_close_session() will be called
4321 	 * elsewhere.
4322 	 *
4323 	 * Session Continuation is not being performed, start the Time2Retain
4324 	 * handler and check if sleep_on_sess_wait_sem is active.
4325 	 */
4326 	if (!atomic_read(&sess->session_reinstatement) &&
4327 	     atomic_read(&sess->session_fall_back_to_erl0)) {
4328 		spin_unlock_bh(&sess->conn_lock);
4329 		complete_all(&sess->session_wait_comp);
4330 		iscsit_close_session(sess, true);
4331 
4332 		return 0;
4333 	} else if (atomic_read(&sess->session_logout)) {
4334 		pr_debug("Moving to TARG_SESS_STATE_FREE.\n");
4335 		sess->session_state = TARG_SESS_STATE_FREE;
4336 
4337 		if (atomic_read(&sess->session_close)) {
4338 			spin_unlock_bh(&sess->conn_lock);
4339 			complete_all(&sess->session_wait_comp);
4340 			iscsit_close_session(sess, true);
4341 		} else {
4342 			spin_unlock_bh(&sess->conn_lock);
4343 		}
4344 
4345 		return 0;
4346 	} else {
4347 		pr_debug("Moving to TARG_SESS_STATE_FAILED.\n");
4348 		sess->session_state = TARG_SESS_STATE_FAILED;
4349 
4350 		if (!atomic_read(&sess->session_continuation))
4351 			iscsit_start_time2retain_handler(sess);
4352 
4353 		if (atomic_read(&sess->session_close)) {
4354 			spin_unlock_bh(&sess->conn_lock);
4355 			complete_all(&sess->session_wait_comp);
4356 			iscsit_close_session(sess, true);
4357 		} else {
4358 			spin_unlock_bh(&sess->conn_lock);
4359 		}
4360 
4361 		return 0;
4362 	}
4363 }
4364 
4365 /*
4366  * If the iSCSI Session for the iSCSI Initiator Node exists,
4367  * forcefully shutdown the iSCSI NEXUS.
4368  */
4369 int iscsit_close_session(struct iscsi_session *sess, bool can_sleep)
4370 {
4371 	struct iscsi_portal_group *tpg = sess->tpg;
4372 	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
4373 
4374 	if (atomic_read(&sess->nconn)) {
4375 		pr_err("%d connection(s) still exist for iSCSI session"
4376 			" to %s\n", atomic_read(&sess->nconn),
4377 			sess->sess_ops->InitiatorName);
4378 		BUG();
4379 	}
4380 
4381 	spin_lock_bh(&se_tpg->session_lock);
4382 	atomic_set(&sess->session_logout, 1);
4383 	atomic_set(&sess->session_reinstatement, 1);
4384 	iscsit_stop_time2retain_timer(sess);
4385 	spin_unlock_bh(&se_tpg->session_lock);
4386 
4387 	/*
4388 	 * transport_deregister_session_configfs() will clear the
4389 	 * struct se_node_acl->nacl_sess pointer now as a iscsi_np process context
4390 	 * can be setting it again with __transport_register_session() in
4391 	 * iscsi_post_login_handler() again after the iscsit_stop_session()
4392 	 * completes in iscsi_np context.
4393 	 */
4394 	transport_deregister_session_configfs(sess->se_sess);
4395 
4396 	/*
4397 	 * If any other processes are accessing this session pointer we must
4398 	 * wait until they have completed.  If we are in an interrupt (the
4399 	 * time2retain handler) and contain and active session usage count we
4400 	 * restart the timer and exit.
4401 	 */
4402 	if (iscsit_check_session_usage_count(sess, can_sleep)) {
4403 		atomic_set(&sess->session_logout, 0);
4404 		iscsit_start_time2retain_handler(sess);
4405 		return 0;
4406 	}
4407 
4408 	transport_deregister_session(sess->se_sess);
4409 
4410 	if (sess->sess_ops->ErrorRecoveryLevel == 2)
4411 		iscsit_free_connection_recovery_entries(sess);
4412 
4413 	iscsit_free_all_ooo_cmdsns(sess);
4414 
4415 	spin_lock_bh(&se_tpg->session_lock);
4416 	pr_debug("Moving to TARG_SESS_STATE_FREE.\n");
4417 	sess->session_state = TARG_SESS_STATE_FREE;
4418 	pr_debug("Released iSCSI session from node: %s\n",
4419 			sess->sess_ops->InitiatorName);
4420 	tpg->nsessions--;
4421 	if (tpg->tpg_tiqn)
4422 		tpg->tpg_tiqn->tiqn_nsessions--;
4423 
4424 	pr_debug("Decremented number of active iSCSI Sessions on"
4425 		" iSCSI TPG: %hu to %u\n", tpg->tpgt, tpg->nsessions);
4426 
4427 	ida_free(&sess_ida, sess->session_index);
4428 	kfree(sess->sess_ops);
4429 	sess->sess_ops = NULL;
4430 	spin_unlock_bh(&se_tpg->session_lock);
4431 
4432 	kfree(sess);
4433 	return 0;
4434 }
4435 
4436 static void iscsit_logout_post_handler_closesession(
4437 	struct iscsi_conn *conn)
4438 {
4439 	struct iscsi_session *sess = conn->sess;
4440 	int sleep = 1;
4441 	/*
4442 	 * Traditional iscsi/tcp will invoke this logic from TX thread
4443 	 * context during session logout, so clear tx_thread_active and
4444 	 * sleep if iscsit_close_connection() has not already occured.
4445 	 *
4446 	 * Since iser-target invokes this logic from it's own workqueue,
4447 	 * always sleep waiting for RX/TX thread shutdown to complete
4448 	 * within iscsit_close_connection().
4449 	 */
4450 	if (!conn->conn_transport->rdma_shutdown) {
4451 		sleep = cmpxchg(&conn->tx_thread_active, true, false);
4452 		if (!sleep)
4453 			return;
4454 	}
4455 
4456 	atomic_set(&conn->conn_logout_remove, 0);
4457 	complete(&conn->conn_logout_comp);
4458 
4459 	iscsit_dec_conn_usage_count(conn);
4460 	atomic_set(&sess->session_close, 1);
4461 	iscsit_stop_session(sess, sleep, sleep);
4462 	iscsit_dec_session_usage_count(sess);
4463 }
4464 
4465 static void iscsit_logout_post_handler_samecid(
4466 	struct iscsi_conn *conn)
4467 {
4468 	int sleep = 1;
4469 
4470 	if (!conn->conn_transport->rdma_shutdown) {
4471 		sleep = cmpxchg(&conn->tx_thread_active, true, false);
4472 		if (!sleep)
4473 			return;
4474 	}
4475 
4476 	atomic_set(&conn->conn_logout_remove, 0);
4477 	complete(&conn->conn_logout_comp);
4478 
4479 	iscsit_cause_connection_reinstatement(conn, sleep);
4480 	iscsit_dec_conn_usage_count(conn);
4481 }
4482 
4483 static void iscsit_logout_post_handler_diffcid(
4484 	struct iscsi_conn *conn,
4485 	u16 cid)
4486 {
4487 	struct iscsi_conn *l_conn;
4488 	struct iscsi_session *sess = conn->sess;
4489 	bool conn_found = false;
4490 
4491 	if (!sess)
4492 		return;
4493 
4494 	spin_lock_bh(&sess->conn_lock);
4495 	list_for_each_entry(l_conn, &sess->sess_conn_list, conn_list) {
4496 		if (l_conn->cid == cid) {
4497 			iscsit_inc_conn_usage_count(l_conn);
4498 			conn_found = true;
4499 			break;
4500 		}
4501 	}
4502 	spin_unlock_bh(&sess->conn_lock);
4503 
4504 	if (!conn_found)
4505 		return;
4506 
4507 	if (l_conn->sock)
4508 		l_conn->sock->ops->shutdown(l_conn->sock, RCV_SHUTDOWN);
4509 
4510 	spin_lock_bh(&l_conn->state_lock);
4511 	pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
4512 	l_conn->conn_state = TARG_CONN_STATE_IN_LOGOUT;
4513 	spin_unlock_bh(&l_conn->state_lock);
4514 
4515 	iscsit_cause_connection_reinstatement(l_conn, 1);
4516 	iscsit_dec_conn_usage_count(l_conn);
4517 }
4518 
4519 /*
4520  *	Return of 0 causes the TX thread to restart.
4521  */
4522 int iscsit_logout_post_handler(
4523 	struct iscsi_cmd *cmd,
4524 	struct iscsi_conn *conn)
4525 {
4526 	int ret = 0;
4527 
4528 	switch (cmd->logout_reason) {
4529 	case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
4530 		switch (cmd->logout_response) {
4531 		case ISCSI_LOGOUT_SUCCESS:
4532 		case ISCSI_LOGOUT_CLEANUP_FAILED:
4533 		default:
4534 			iscsit_logout_post_handler_closesession(conn);
4535 			break;
4536 		}
4537 		break;
4538 	case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
4539 		if (conn->cid == cmd->logout_cid) {
4540 			switch (cmd->logout_response) {
4541 			case ISCSI_LOGOUT_SUCCESS:
4542 			case ISCSI_LOGOUT_CLEANUP_FAILED:
4543 			default:
4544 				iscsit_logout_post_handler_samecid(conn);
4545 				break;
4546 			}
4547 		} else {
4548 			switch (cmd->logout_response) {
4549 			case ISCSI_LOGOUT_SUCCESS:
4550 				iscsit_logout_post_handler_diffcid(conn,
4551 					cmd->logout_cid);
4552 				break;
4553 			case ISCSI_LOGOUT_CID_NOT_FOUND:
4554 			case ISCSI_LOGOUT_CLEANUP_FAILED:
4555 			default:
4556 				break;
4557 			}
4558 			ret = 1;
4559 		}
4560 		break;
4561 	case ISCSI_LOGOUT_REASON_RECOVERY:
4562 		switch (cmd->logout_response) {
4563 		case ISCSI_LOGOUT_SUCCESS:
4564 		case ISCSI_LOGOUT_CID_NOT_FOUND:
4565 		case ISCSI_LOGOUT_RECOVERY_UNSUPPORTED:
4566 		case ISCSI_LOGOUT_CLEANUP_FAILED:
4567 		default:
4568 			break;
4569 		}
4570 		ret = 1;
4571 		break;
4572 	default:
4573 		break;
4574 
4575 	}
4576 	return ret;
4577 }
4578 EXPORT_SYMBOL(iscsit_logout_post_handler);
4579 
4580 void iscsit_fail_session(struct iscsi_session *sess)
4581 {
4582 	struct iscsi_conn *conn;
4583 
4584 	spin_lock_bh(&sess->conn_lock);
4585 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
4586 		pr_debug("Moving to TARG_CONN_STATE_CLEANUP_WAIT.\n");
4587 		conn->conn_state = TARG_CONN_STATE_CLEANUP_WAIT;
4588 	}
4589 	spin_unlock_bh(&sess->conn_lock);
4590 
4591 	pr_debug("Moving to TARG_SESS_STATE_FAILED.\n");
4592 	sess->session_state = TARG_SESS_STATE_FAILED;
4593 }
4594 
4595 void iscsit_stop_session(
4596 	struct iscsi_session *sess,
4597 	int session_sleep,
4598 	int connection_sleep)
4599 {
4600 	u16 conn_count = atomic_read(&sess->nconn);
4601 	struct iscsi_conn *conn, *conn_tmp = NULL;
4602 	int is_last;
4603 
4604 	spin_lock_bh(&sess->conn_lock);
4605 
4606 	if (connection_sleep) {
4607 		list_for_each_entry_safe(conn, conn_tmp, &sess->sess_conn_list,
4608 				conn_list) {
4609 			if (conn_count == 0)
4610 				break;
4611 
4612 			if (list_is_last(&conn->conn_list, &sess->sess_conn_list)) {
4613 				is_last = 1;
4614 			} else {
4615 				iscsit_inc_conn_usage_count(conn_tmp);
4616 				is_last = 0;
4617 			}
4618 			iscsit_inc_conn_usage_count(conn);
4619 
4620 			spin_unlock_bh(&sess->conn_lock);
4621 			iscsit_cause_connection_reinstatement(conn, 1);
4622 			spin_lock_bh(&sess->conn_lock);
4623 
4624 			iscsit_dec_conn_usage_count(conn);
4625 			if (is_last == 0)
4626 				iscsit_dec_conn_usage_count(conn_tmp);
4627 			conn_count--;
4628 		}
4629 	} else {
4630 		list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
4631 			iscsit_cause_connection_reinstatement(conn, 0);
4632 	}
4633 
4634 	if (session_sleep && atomic_read(&sess->nconn)) {
4635 		spin_unlock_bh(&sess->conn_lock);
4636 		wait_for_completion(&sess->session_wait_comp);
4637 	} else
4638 		spin_unlock_bh(&sess->conn_lock);
4639 }
4640 
4641 int iscsit_release_sessions_for_tpg(struct iscsi_portal_group *tpg, int force)
4642 {
4643 	struct iscsi_session *sess;
4644 	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
4645 	struct se_session *se_sess, *se_sess_tmp;
4646 	LIST_HEAD(free_list);
4647 	int session_count = 0;
4648 
4649 	spin_lock_bh(&se_tpg->session_lock);
4650 	if (tpg->nsessions && !force) {
4651 		spin_unlock_bh(&se_tpg->session_lock);
4652 		return -1;
4653 	}
4654 
4655 	list_for_each_entry_safe(se_sess, se_sess_tmp, &se_tpg->tpg_sess_list,
4656 			sess_list) {
4657 		sess = (struct iscsi_session *)se_sess->fabric_sess_ptr;
4658 
4659 		spin_lock(&sess->conn_lock);
4660 		if (atomic_read(&sess->session_fall_back_to_erl0) ||
4661 		    atomic_read(&sess->session_logout) ||
4662 		    atomic_read(&sess->session_close) ||
4663 		    (sess->time2retain_timer_flags & ISCSI_TF_EXPIRED)) {
4664 			spin_unlock(&sess->conn_lock);
4665 			continue;
4666 		}
4667 		iscsit_inc_session_usage_count(sess);
4668 		atomic_set(&sess->session_reinstatement, 1);
4669 		atomic_set(&sess->session_fall_back_to_erl0, 1);
4670 		atomic_set(&sess->session_close, 1);
4671 		spin_unlock(&sess->conn_lock);
4672 
4673 		list_move_tail(&se_sess->sess_list, &free_list);
4674 	}
4675 	spin_unlock_bh(&se_tpg->session_lock);
4676 
4677 	list_for_each_entry_safe(se_sess, se_sess_tmp, &free_list, sess_list) {
4678 		sess = (struct iscsi_session *)se_sess->fabric_sess_ptr;
4679 
4680 		list_del_init(&se_sess->sess_list);
4681 		iscsit_stop_session(sess, 1, 1);
4682 		iscsit_dec_session_usage_count(sess);
4683 		session_count++;
4684 	}
4685 
4686 	pr_debug("Released %d iSCSI Session(s) from Target Portal"
4687 			" Group: %hu\n", session_count, tpg->tpgt);
4688 	return 0;
4689 }
4690 
4691 MODULE_DESCRIPTION("iSCSI-Target Driver for mainline target infrastructure");
4692 MODULE_VERSION("4.1.x");
4693 MODULE_AUTHOR("nab@Linux-iSCSI.org");
4694 MODULE_LICENSE("GPL");
4695 
4696 module_init(iscsi_target_init_module);
4697 module_exit(iscsi_target_cleanup_module);
4698