1 /*******************************************************************************
2  * This file contains the iSCSI Target specific utility functions.
3  *
4  * (c) Copyright 2007-2013 Datera, Inc.
5  *
6  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  ******************************************************************************/
18 
19 #include <linux/list.h>
20 #include <linux/sched/signal.h>
21 #include <net/ipv6.h>         /* ipv6_addr_equal() */
22 #include <scsi/scsi_tcq.h>
23 #include <scsi/iscsi_proto.h>
24 #include <target/target_core_base.h>
25 #include <target/target_core_fabric.h>
26 #include <target/iscsi/iscsi_transport.h>
27 
28 #include <target/iscsi/iscsi_target_core.h>
29 #include "iscsi_target_parameters.h"
30 #include "iscsi_target_seq_pdu_list.h"
31 #include "iscsi_target_datain_values.h"
32 #include "iscsi_target_erl0.h"
33 #include "iscsi_target_erl1.h"
34 #include "iscsi_target_erl2.h"
35 #include "iscsi_target_tpg.h"
36 #include "iscsi_target_util.h"
37 #include "iscsi_target.h"
38 
39 #define PRINT_BUFF(buff, len)					\
40 {								\
41 	int zzz;						\
42 								\
43 	pr_debug("%d:\n", __LINE__);				\
44 	for (zzz = 0; zzz < len; zzz++) {			\
45 		if (zzz % 16 == 0) {				\
46 			if (zzz)				\
47 				pr_debug("\n");			\
48 			pr_debug("%4i: ", zzz);			\
49 		}						\
50 		pr_debug("%02x ", (unsigned char) (buff)[zzz]);	\
51 	}							\
52 	if ((len + 1) % 16)					\
53 		pr_debug("\n");					\
54 }
55 
56 extern struct list_head g_tiqn_list;
57 extern spinlock_t tiqn_lock;
58 
59 /*
60  *	Called with cmd->r2t_lock held.
61  */
62 int iscsit_add_r2t_to_list(
63 	struct iscsi_cmd *cmd,
64 	u32 offset,
65 	u32 xfer_len,
66 	int recovery,
67 	u32 r2t_sn)
68 {
69 	struct iscsi_r2t *r2t;
70 
71 	r2t = kmem_cache_zalloc(lio_r2t_cache, GFP_ATOMIC);
72 	if (!r2t) {
73 		pr_err("Unable to allocate memory for struct iscsi_r2t.\n");
74 		return -1;
75 	}
76 	INIT_LIST_HEAD(&r2t->r2t_list);
77 
78 	r2t->recovery_r2t = recovery;
79 	r2t->r2t_sn = (!r2t_sn) ? cmd->r2t_sn++ : r2t_sn;
80 	r2t->offset = offset;
81 	r2t->xfer_len = xfer_len;
82 	list_add_tail(&r2t->r2t_list, &cmd->cmd_r2t_list);
83 	spin_unlock_bh(&cmd->r2t_lock);
84 
85 	iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
86 
87 	spin_lock_bh(&cmd->r2t_lock);
88 	return 0;
89 }
90 
91 struct iscsi_r2t *iscsit_get_r2t_for_eos(
92 	struct iscsi_cmd *cmd,
93 	u32 offset,
94 	u32 length)
95 {
96 	struct iscsi_r2t *r2t;
97 
98 	spin_lock_bh(&cmd->r2t_lock);
99 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
100 		if ((r2t->offset <= offset) &&
101 		    (r2t->offset + r2t->xfer_len) >= (offset + length)) {
102 			spin_unlock_bh(&cmd->r2t_lock);
103 			return r2t;
104 		}
105 	}
106 	spin_unlock_bh(&cmd->r2t_lock);
107 
108 	pr_err("Unable to locate R2T for Offset: %u, Length:"
109 			" %u\n", offset, length);
110 	return NULL;
111 }
112 
113 struct iscsi_r2t *iscsit_get_r2t_from_list(struct iscsi_cmd *cmd)
114 {
115 	struct iscsi_r2t *r2t;
116 
117 	spin_lock_bh(&cmd->r2t_lock);
118 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
119 		if (!r2t->sent_r2t) {
120 			spin_unlock_bh(&cmd->r2t_lock);
121 			return r2t;
122 		}
123 	}
124 	spin_unlock_bh(&cmd->r2t_lock);
125 
126 	pr_err("Unable to locate next R2T to send for ITT:"
127 			" 0x%08x.\n", cmd->init_task_tag);
128 	return NULL;
129 }
130 
131 /*
132  *	Called with cmd->r2t_lock held.
133  */
134 void iscsit_free_r2t(struct iscsi_r2t *r2t, struct iscsi_cmd *cmd)
135 {
136 	list_del(&r2t->r2t_list);
137 	kmem_cache_free(lio_r2t_cache, r2t);
138 }
139 
140 void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd)
141 {
142 	struct iscsi_r2t *r2t, *r2t_tmp;
143 
144 	spin_lock_bh(&cmd->r2t_lock);
145 	list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list)
146 		iscsit_free_r2t(r2t, cmd);
147 	spin_unlock_bh(&cmd->r2t_lock);
148 }
149 
150 static int iscsit_wait_for_tag(struct se_session *se_sess, int state, int *cpup)
151 {
152 	int tag = -1;
153 	DEFINE_WAIT(wait);
154 	struct sbq_wait_state *ws;
155 
156 	if (state == TASK_RUNNING)
157 		return tag;
158 
159 	ws = &se_sess->sess_tag_pool.ws[0];
160 	for (;;) {
161 		prepare_to_wait_exclusive(&ws->wait, &wait, state);
162 		if (signal_pending_state(state, current))
163 			break;
164 		tag = sbitmap_queue_get(&se_sess->sess_tag_pool, cpup);
165 		if (tag >= 0)
166 			break;
167 		schedule();
168 	}
169 
170 	finish_wait(&ws->wait, &wait);
171 	return tag;
172 }
173 
174 /*
175  * May be called from software interrupt (timer) context for allocating
176  * iSCSI NopINs.
177  */
178 struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, int state)
179 {
180 	struct iscsi_cmd *cmd;
181 	struct se_session *se_sess = conn->sess->se_sess;
182 	int size, tag, cpu;
183 
184 	tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
185 	if (tag < 0)
186 		tag = iscsit_wait_for_tag(se_sess, state, &cpu);
187 	if (tag < 0)
188 		return NULL;
189 
190 	size = sizeof(struct iscsi_cmd) + conn->conn_transport->priv_size;
191 	cmd = (struct iscsi_cmd *)(se_sess->sess_cmd_map + (tag * size));
192 	memset(cmd, 0, size);
193 
194 	cmd->se_cmd.map_tag = tag;
195 	cmd->se_cmd.map_cpu = cpu;
196 	cmd->conn = conn;
197 	cmd->data_direction = DMA_NONE;
198 	INIT_LIST_HEAD(&cmd->i_conn_node);
199 	INIT_LIST_HEAD(&cmd->datain_list);
200 	INIT_LIST_HEAD(&cmd->cmd_r2t_list);
201 	spin_lock_init(&cmd->datain_lock);
202 	spin_lock_init(&cmd->dataout_timeout_lock);
203 	spin_lock_init(&cmd->istate_lock);
204 	spin_lock_init(&cmd->error_lock);
205 	spin_lock_init(&cmd->r2t_lock);
206 	timer_setup(&cmd->dataout_timer, iscsit_handle_dataout_timeout, 0);
207 
208 	return cmd;
209 }
210 EXPORT_SYMBOL(iscsit_allocate_cmd);
211 
212 struct iscsi_seq *iscsit_get_seq_holder_for_datain(
213 	struct iscsi_cmd *cmd,
214 	u32 seq_send_order)
215 {
216 	u32 i;
217 
218 	for (i = 0; i < cmd->seq_count; i++)
219 		if (cmd->seq_list[i].seq_send_order == seq_send_order)
220 			return &cmd->seq_list[i];
221 
222 	return NULL;
223 }
224 
225 struct iscsi_seq *iscsit_get_seq_holder_for_r2t(struct iscsi_cmd *cmd)
226 {
227 	u32 i;
228 
229 	if (!cmd->seq_list) {
230 		pr_err("struct iscsi_cmd->seq_list is NULL!\n");
231 		return NULL;
232 	}
233 
234 	for (i = 0; i < cmd->seq_count; i++) {
235 		if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
236 			continue;
237 		if (cmd->seq_list[i].seq_send_order == cmd->seq_send_order) {
238 			cmd->seq_send_order++;
239 			return &cmd->seq_list[i];
240 		}
241 	}
242 
243 	return NULL;
244 }
245 
246 struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
247 	struct iscsi_cmd *cmd,
248 	u32 r2t_sn)
249 {
250 	struct iscsi_r2t *r2t;
251 
252 	spin_lock_bh(&cmd->r2t_lock);
253 	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
254 		if (r2t->r2t_sn == r2t_sn) {
255 			spin_unlock_bh(&cmd->r2t_lock);
256 			return r2t;
257 		}
258 	}
259 	spin_unlock_bh(&cmd->r2t_lock);
260 
261 	return NULL;
262 }
263 
264 static inline int iscsit_check_received_cmdsn(struct iscsi_session *sess, u32 cmdsn)
265 {
266 	u32 max_cmdsn;
267 	int ret;
268 
269 	/*
270 	 * This is the proper method of checking received CmdSN against
271 	 * ExpCmdSN and MaxCmdSN values, as well as accounting for out
272 	 * or order CmdSNs due to multiple connection sessions and/or
273 	 * CRC failures.
274 	 */
275 	max_cmdsn = atomic_read(&sess->max_cmd_sn);
276 	if (iscsi_sna_gt(cmdsn, max_cmdsn)) {
277 		pr_err("Received CmdSN: 0x%08x is greater than"
278 		       " MaxCmdSN: 0x%08x, ignoring.\n", cmdsn, max_cmdsn);
279 		ret = CMDSN_MAXCMDSN_OVERRUN;
280 
281 	} else if (cmdsn == sess->exp_cmd_sn) {
282 		sess->exp_cmd_sn++;
283 		pr_debug("Received CmdSN matches ExpCmdSN,"
284 		      " incremented ExpCmdSN to: 0x%08x\n",
285 		      sess->exp_cmd_sn);
286 		ret = CMDSN_NORMAL_OPERATION;
287 
288 	} else if (iscsi_sna_gt(cmdsn, sess->exp_cmd_sn)) {
289 		pr_debug("Received CmdSN: 0x%08x is greater"
290 		      " than ExpCmdSN: 0x%08x, not acknowledging.\n",
291 		      cmdsn, sess->exp_cmd_sn);
292 		ret = CMDSN_HIGHER_THAN_EXP;
293 
294 	} else {
295 		pr_err("Received CmdSN: 0x%08x is less than"
296 		       " ExpCmdSN: 0x%08x, ignoring.\n", cmdsn,
297 		       sess->exp_cmd_sn);
298 		ret = CMDSN_LOWER_THAN_EXP;
299 	}
300 
301 	return ret;
302 }
303 
304 /*
305  * Commands may be received out of order if MC/S is in use.
306  * Ensure they are executed in CmdSN order.
307  */
308 int iscsit_sequence_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
309 			unsigned char *buf, __be32 cmdsn)
310 {
311 	int ret, cmdsn_ret;
312 	bool reject = false;
313 	u8 reason = ISCSI_REASON_BOOKMARK_NO_RESOURCES;
314 
315 	mutex_lock(&conn->sess->cmdsn_mutex);
316 
317 	cmdsn_ret = iscsit_check_received_cmdsn(conn->sess, be32_to_cpu(cmdsn));
318 	switch (cmdsn_ret) {
319 	case CMDSN_NORMAL_OPERATION:
320 		ret = iscsit_execute_cmd(cmd, 0);
321 		if ((ret >= 0) && !list_empty(&conn->sess->sess_ooo_cmdsn_list))
322 			iscsit_execute_ooo_cmdsns(conn->sess);
323 		else if (ret < 0) {
324 			reject = true;
325 			ret = CMDSN_ERROR_CANNOT_RECOVER;
326 		}
327 		break;
328 	case CMDSN_HIGHER_THAN_EXP:
329 		ret = iscsit_handle_ooo_cmdsn(conn->sess, cmd, be32_to_cpu(cmdsn));
330 		if (ret < 0) {
331 			reject = true;
332 			ret = CMDSN_ERROR_CANNOT_RECOVER;
333 			break;
334 		}
335 		ret = CMDSN_HIGHER_THAN_EXP;
336 		break;
337 	case CMDSN_LOWER_THAN_EXP:
338 	case CMDSN_MAXCMDSN_OVERRUN:
339 	default:
340 		cmd->i_state = ISTATE_REMOVE;
341 		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
342 		/*
343 		 * Existing callers for iscsit_sequence_cmd() will silently
344 		 * ignore commands with CMDSN_LOWER_THAN_EXP, so force this
345 		 * return for CMDSN_MAXCMDSN_OVERRUN as well..
346 		 */
347 		ret = CMDSN_LOWER_THAN_EXP;
348 		break;
349 	}
350 	mutex_unlock(&conn->sess->cmdsn_mutex);
351 
352 	if (reject)
353 		iscsit_reject_cmd(cmd, reason, buf);
354 
355 	return ret;
356 }
357 EXPORT_SYMBOL(iscsit_sequence_cmd);
358 
359 int iscsit_check_unsolicited_dataout(struct iscsi_cmd *cmd, unsigned char *buf)
360 {
361 	struct iscsi_conn *conn = cmd->conn;
362 	struct se_cmd *se_cmd = &cmd->se_cmd;
363 	struct iscsi_data *hdr = (struct iscsi_data *) buf;
364 	u32 payload_length = ntoh24(hdr->dlength);
365 
366 	if (conn->sess->sess_ops->InitialR2T) {
367 		pr_err("Received unexpected unsolicited data"
368 			" while InitialR2T=Yes, protocol error.\n");
369 		transport_send_check_condition_and_sense(se_cmd,
370 				TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
371 		return -1;
372 	}
373 
374 	if ((cmd->first_burst_len + payload_length) >
375 	     conn->sess->sess_ops->FirstBurstLength) {
376 		pr_err("Total %u bytes exceeds FirstBurstLength: %u"
377 			" for this Unsolicited DataOut Burst.\n",
378 			(cmd->first_burst_len + payload_length),
379 				conn->sess->sess_ops->FirstBurstLength);
380 		transport_send_check_condition_and_sense(se_cmd,
381 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
382 		return -1;
383 	}
384 
385 	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))
386 		return 0;
387 
388 	if (((cmd->first_burst_len + payload_length) != cmd->se_cmd.data_length) &&
389 	    ((cmd->first_burst_len + payload_length) !=
390 	      conn->sess->sess_ops->FirstBurstLength)) {
391 		pr_err("Unsolicited non-immediate data received %u"
392 			" does not equal FirstBurstLength: %u, and does"
393 			" not equal ExpXferLen %u.\n",
394 			(cmd->first_burst_len + payload_length),
395 			conn->sess->sess_ops->FirstBurstLength, cmd->se_cmd.data_length);
396 		transport_send_check_condition_and_sense(se_cmd,
397 				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
398 		return -1;
399 	}
400 	return 0;
401 }
402 
403 struct iscsi_cmd *iscsit_find_cmd_from_itt(
404 	struct iscsi_conn *conn,
405 	itt_t init_task_tag)
406 {
407 	struct iscsi_cmd *cmd;
408 
409 	spin_lock_bh(&conn->cmd_lock);
410 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
411 		if (cmd->init_task_tag == init_task_tag) {
412 			spin_unlock_bh(&conn->cmd_lock);
413 			return cmd;
414 		}
415 	}
416 	spin_unlock_bh(&conn->cmd_lock);
417 
418 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu",
419 			init_task_tag, conn->cid);
420 	return NULL;
421 }
422 EXPORT_SYMBOL(iscsit_find_cmd_from_itt);
423 
424 struct iscsi_cmd *iscsit_find_cmd_from_itt_or_dump(
425 	struct iscsi_conn *conn,
426 	itt_t init_task_tag,
427 	u32 length)
428 {
429 	struct iscsi_cmd *cmd;
430 
431 	spin_lock_bh(&conn->cmd_lock);
432 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
433 		if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT)
434 			continue;
435 		if (cmd->init_task_tag == init_task_tag) {
436 			spin_unlock_bh(&conn->cmd_lock);
437 			return cmd;
438 		}
439 	}
440 	spin_unlock_bh(&conn->cmd_lock);
441 
442 	pr_err("Unable to locate ITT: 0x%08x on CID: %hu,"
443 			" dumping payload\n", init_task_tag, conn->cid);
444 	if (length)
445 		iscsit_dump_data_payload(conn, length, 1);
446 
447 	return NULL;
448 }
449 EXPORT_SYMBOL(iscsit_find_cmd_from_itt_or_dump);
450 
451 struct iscsi_cmd *iscsit_find_cmd_from_ttt(
452 	struct iscsi_conn *conn,
453 	u32 targ_xfer_tag)
454 {
455 	struct iscsi_cmd *cmd = NULL;
456 
457 	spin_lock_bh(&conn->cmd_lock);
458 	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
459 		if (cmd->targ_xfer_tag == targ_xfer_tag) {
460 			spin_unlock_bh(&conn->cmd_lock);
461 			return cmd;
462 		}
463 	}
464 	spin_unlock_bh(&conn->cmd_lock);
465 
466 	pr_err("Unable to locate TTT: 0x%08x on CID: %hu\n",
467 			targ_xfer_tag, conn->cid);
468 	return NULL;
469 }
470 
471 int iscsit_find_cmd_for_recovery(
472 	struct iscsi_session *sess,
473 	struct iscsi_cmd **cmd_ptr,
474 	struct iscsi_conn_recovery **cr_ptr,
475 	itt_t init_task_tag)
476 {
477 	struct iscsi_cmd *cmd = NULL;
478 	struct iscsi_conn_recovery *cr;
479 	/*
480 	 * Scan through the inactive connection recovery list's command list.
481 	 * If init_task_tag matches the command is still alligent.
482 	 */
483 	spin_lock(&sess->cr_i_lock);
484 	list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
485 		spin_lock(&cr->conn_recovery_cmd_lock);
486 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
487 			if (cmd->init_task_tag == init_task_tag) {
488 				spin_unlock(&cr->conn_recovery_cmd_lock);
489 				spin_unlock(&sess->cr_i_lock);
490 
491 				*cr_ptr = cr;
492 				*cmd_ptr = cmd;
493 				return -2;
494 			}
495 		}
496 		spin_unlock(&cr->conn_recovery_cmd_lock);
497 	}
498 	spin_unlock(&sess->cr_i_lock);
499 	/*
500 	 * Scan through the active connection recovery list's command list.
501 	 * If init_task_tag matches the command is ready to be reassigned.
502 	 */
503 	spin_lock(&sess->cr_a_lock);
504 	list_for_each_entry(cr, &sess->cr_active_list, cr_list) {
505 		spin_lock(&cr->conn_recovery_cmd_lock);
506 		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_conn_node) {
507 			if (cmd->init_task_tag == init_task_tag) {
508 				spin_unlock(&cr->conn_recovery_cmd_lock);
509 				spin_unlock(&sess->cr_a_lock);
510 
511 				*cr_ptr = cr;
512 				*cmd_ptr = cmd;
513 				return 0;
514 			}
515 		}
516 		spin_unlock(&cr->conn_recovery_cmd_lock);
517 	}
518 	spin_unlock(&sess->cr_a_lock);
519 
520 	return -1;
521 }
522 
523 void iscsit_add_cmd_to_immediate_queue(
524 	struct iscsi_cmd *cmd,
525 	struct iscsi_conn *conn,
526 	u8 state)
527 {
528 	struct iscsi_queue_req *qr;
529 
530 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
531 	if (!qr) {
532 		pr_err("Unable to allocate memory for"
533 				" struct iscsi_queue_req\n");
534 		return;
535 	}
536 	INIT_LIST_HEAD(&qr->qr_list);
537 	qr->cmd = cmd;
538 	qr->state = state;
539 
540 	spin_lock_bh(&conn->immed_queue_lock);
541 	list_add_tail(&qr->qr_list, &conn->immed_queue_list);
542 	atomic_inc(&cmd->immed_queue_count);
543 	atomic_set(&conn->check_immediate_queue, 1);
544 	spin_unlock_bh(&conn->immed_queue_lock);
545 
546 	wake_up(&conn->queues_wq);
547 }
548 EXPORT_SYMBOL(iscsit_add_cmd_to_immediate_queue);
549 
550 struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsi_conn *conn)
551 {
552 	struct iscsi_queue_req *qr;
553 
554 	spin_lock_bh(&conn->immed_queue_lock);
555 	if (list_empty(&conn->immed_queue_list)) {
556 		spin_unlock_bh(&conn->immed_queue_lock);
557 		return NULL;
558 	}
559 	qr = list_first_entry(&conn->immed_queue_list,
560 			      struct iscsi_queue_req, qr_list);
561 
562 	list_del(&qr->qr_list);
563 	if (qr->cmd)
564 		atomic_dec(&qr->cmd->immed_queue_count);
565 	spin_unlock_bh(&conn->immed_queue_lock);
566 
567 	return qr;
568 }
569 
570 static void iscsit_remove_cmd_from_immediate_queue(
571 	struct iscsi_cmd *cmd,
572 	struct iscsi_conn *conn)
573 {
574 	struct iscsi_queue_req *qr, *qr_tmp;
575 
576 	spin_lock_bh(&conn->immed_queue_lock);
577 	if (!atomic_read(&cmd->immed_queue_count)) {
578 		spin_unlock_bh(&conn->immed_queue_lock);
579 		return;
580 	}
581 
582 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
583 		if (qr->cmd != cmd)
584 			continue;
585 
586 		atomic_dec(&qr->cmd->immed_queue_count);
587 		list_del(&qr->qr_list);
588 		kmem_cache_free(lio_qr_cache, qr);
589 	}
590 	spin_unlock_bh(&conn->immed_queue_lock);
591 
592 	if (atomic_read(&cmd->immed_queue_count)) {
593 		pr_err("ITT: 0x%08x immed_queue_count: %d\n",
594 			cmd->init_task_tag,
595 			atomic_read(&cmd->immed_queue_count));
596 	}
597 }
598 
599 int iscsit_add_cmd_to_response_queue(
600 	struct iscsi_cmd *cmd,
601 	struct iscsi_conn *conn,
602 	u8 state)
603 {
604 	struct iscsi_queue_req *qr;
605 
606 	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
607 	if (!qr) {
608 		pr_err("Unable to allocate memory for"
609 			" struct iscsi_queue_req\n");
610 		return -ENOMEM;
611 	}
612 	INIT_LIST_HEAD(&qr->qr_list);
613 	qr->cmd = cmd;
614 	qr->state = state;
615 
616 	spin_lock_bh(&conn->response_queue_lock);
617 	list_add_tail(&qr->qr_list, &conn->response_queue_list);
618 	atomic_inc(&cmd->response_queue_count);
619 	spin_unlock_bh(&conn->response_queue_lock);
620 
621 	wake_up(&conn->queues_wq);
622 	return 0;
623 }
624 
625 struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsi_conn *conn)
626 {
627 	struct iscsi_queue_req *qr;
628 
629 	spin_lock_bh(&conn->response_queue_lock);
630 	if (list_empty(&conn->response_queue_list)) {
631 		spin_unlock_bh(&conn->response_queue_lock);
632 		return NULL;
633 	}
634 
635 	qr = list_first_entry(&conn->response_queue_list,
636 			      struct iscsi_queue_req, qr_list);
637 
638 	list_del(&qr->qr_list);
639 	if (qr->cmd)
640 		atomic_dec(&qr->cmd->response_queue_count);
641 	spin_unlock_bh(&conn->response_queue_lock);
642 
643 	return qr;
644 }
645 
646 static void iscsit_remove_cmd_from_response_queue(
647 	struct iscsi_cmd *cmd,
648 	struct iscsi_conn *conn)
649 {
650 	struct iscsi_queue_req *qr, *qr_tmp;
651 
652 	spin_lock_bh(&conn->response_queue_lock);
653 	if (!atomic_read(&cmd->response_queue_count)) {
654 		spin_unlock_bh(&conn->response_queue_lock);
655 		return;
656 	}
657 
658 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
659 				qr_list) {
660 		if (qr->cmd != cmd)
661 			continue;
662 
663 		atomic_dec(&qr->cmd->response_queue_count);
664 		list_del(&qr->qr_list);
665 		kmem_cache_free(lio_qr_cache, qr);
666 	}
667 	spin_unlock_bh(&conn->response_queue_lock);
668 
669 	if (atomic_read(&cmd->response_queue_count)) {
670 		pr_err("ITT: 0x%08x response_queue_count: %d\n",
671 			cmd->init_task_tag,
672 			atomic_read(&cmd->response_queue_count));
673 	}
674 }
675 
676 bool iscsit_conn_all_queues_empty(struct iscsi_conn *conn)
677 {
678 	bool empty;
679 
680 	spin_lock_bh(&conn->immed_queue_lock);
681 	empty = list_empty(&conn->immed_queue_list);
682 	spin_unlock_bh(&conn->immed_queue_lock);
683 
684 	if (!empty)
685 		return empty;
686 
687 	spin_lock_bh(&conn->response_queue_lock);
688 	empty = list_empty(&conn->response_queue_list);
689 	spin_unlock_bh(&conn->response_queue_lock);
690 
691 	return empty;
692 }
693 
694 void iscsit_free_queue_reqs_for_conn(struct iscsi_conn *conn)
695 {
696 	struct iscsi_queue_req *qr, *qr_tmp;
697 
698 	spin_lock_bh(&conn->immed_queue_lock);
699 	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
700 		list_del(&qr->qr_list);
701 		if (qr->cmd)
702 			atomic_dec(&qr->cmd->immed_queue_count);
703 
704 		kmem_cache_free(lio_qr_cache, qr);
705 	}
706 	spin_unlock_bh(&conn->immed_queue_lock);
707 
708 	spin_lock_bh(&conn->response_queue_lock);
709 	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
710 			qr_list) {
711 		list_del(&qr->qr_list);
712 		if (qr->cmd)
713 			atomic_dec(&qr->cmd->response_queue_count);
714 
715 		kmem_cache_free(lio_qr_cache, qr);
716 	}
717 	spin_unlock_bh(&conn->response_queue_lock);
718 }
719 
720 void iscsit_release_cmd(struct iscsi_cmd *cmd)
721 {
722 	struct iscsi_session *sess;
723 	struct se_cmd *se_cmd = &cmd->se_cmd;
724 
725 	WARN_ON(!list_empty(&cmd->i_conn_node));
726 
727 	if (cmd->conn)
728 		sess = cmd->conn->sess;
729 	else
730 		sess = cmd->sess;
731 
732 	BUG_ON(!sess || !sess->se_sess);
733 
734 	kfree(cmd->buf_ptr);
735 	kfree(cmd->pdu_list);
736 	kfree(cmd->seq_list);
737 	kfree(cmd->tmr_req);
738 	kfree(cmd->iov_data);
739 	kfree(cmd->text_in_ptr);
740 
741 	target_free_tag(sess->se_sess, se_cmd);
742 }
743 EXPORT_SYMBOL(iscsit_release_cmd);
744 
745 void __iscsit_free_cmd(struct iscsi_cmd *cmd, bool check_queues)
746 {
747 	struct iscsi_conn *conn = cmd->conn;
748 
749 	WARN_ON(!list_empty(&cmd->i_conn_node));
750 
751 	if (cmd->data_direction == DMA_TO_DEVICE) {
752 		iscsit_stop_dataout_timer(cmd);
753 		iscsit_free_r2ts_from_list(cmd);
754 	}
755 	if (cmd->data_direction == DMA_FROM_DEVICE)
756 		iscsit_free_all_datain_reqs(cmd);
757 
758 	if (conn && check_queues) {
759 		iscsit_remove_cmd_from_immediate_queue(cmd, conn);
760 		iscsit_remove_cmd_from_response_queue(cmd, conn);
761 	}
762 
763 	if (conn && conn->conn_transport->iscsit_release_cmd)
764 		conn->conn_transport->iscsit_release_cmd(conn, cmd);
765 }
766 
767 void iscsit_free_cmd(struct iscsi_cmd *cmd, bool shutdown)
768 {
769 	struct se_cmd *se_cmd = cmd->se_cmd.se_tfo ? &cmd->se_cmd : NULL;
770 	int rc;
771 
772 	__iscsit_free_cmd(cmd, shutdown);
773 	if (se_cmd) {
774 		rc = transport_generic_free_cmd(se_cmd, shutdown);
775 		if (!rc && shutdown && se_cmd->se_sess) {
776 			__iscsit_free_cmd(cmd, shutdown);
777 			target_put_sess_cmd(se_cmd);
778 		}
779 	} else {
780 		iscsit_release_cmd(cmd);
781 	}
782 }
783 EXPORT_SYMBOL(iscsit_free_cmd);
784 
785 int iscsit_check_session_usage_count(struct iscsi_session *sess)
786 {
787 	spin_lock_bh(&sess->session_usage_lock);
788 	if (sess->session_usage_count != 0) {
789 		sess->session_waiting_on_uc = 1;
790 		spin_unlock_bh(&sess->session_usage_lock);
791 		if (in_interrupt())
792 			return 2;
793 
794 		wait_for_completion(&sess->session_waiting_on_uc_comp);
795 		return 1;
796 	}
797 	spin_unlock_bh(&sess->session_usage_lock);
798 
799 	return 0;
800 }
801 
802 void iscsit_dec_session_usage_count(struct iscsi_session *sess)
803 {
804 	spin_lock_bh(&sess->session_usage_lock);
805 	sess->session_usage_count--;
806 
807 	if (!sess->session_usage_count && sess->session_waiting_on_uc)
808 		complete(&sess->session_waiting_on_uc_comp);
809 
810 	spin_unlock_bh(&sess->session_usage_lock);
811 }
812 
813 void iscsit_inc_session_usage_count(struct iscsi_session *sess)
814 {
815 	spin_lock_bh(&sess->session_usage_lock);
816 	sess->session_usage_count++;
817 	spin_unlock_bh(&sess->session_usage_lock);
818 }
819 
820 struct iscsi_conn *iscsit_get_conn_from_cid(struct iscsi_session *sess, u16 cid)
821 {
822 	struct iscsi_conn *conn;
823 
824 	spin_lock_bh(&sess->conn_lock);
825 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
826 		if ((conn->cid == cid) &&
827 		    (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
828 			iscsit_inc_conn_usage_count(conn);
829 			spin_unlock_bh(&sess->conn_lock);
830 			return conn;
831 		}
832 	}
833 	spin_unlock_bh(&sess->conn_lock);
834 
835 	return NULL;
836 }
837 
838 struct iscsi_conn *iscsit_get_conn_from_cid_rcfr(struct iscsi_session *sess, u16 cid)
839 {
840 	struct iscsi_conn *conn;
841 
842 	spin_lock_bh(&sess->conn_lock);
843 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
844 		if (conn->cid == cid) {
845 			iscsit_inc_conn_usage_count(conn);
846 			spin_lock(&conn->state_lock);
847 			atomic_set(&conn->connection_wait_rcfr, 1);
848 			spin_unlock(&conn->state_lock);
849 			spin_unlock_bh(&sess->conn_lock);
850 			return conn;
851 		}
852 	}
853 	spin_unlock_bh(&sess->conn_lock);
854 
855 	return NULL;
856 }
857 
858 void iscsit_check_conn_usage_count(struct iscsi_conn *conn)
859 {
860 	spin_lock_bh(&conn->conn_usage_lock);
861 	if (conn->conn_usage_count != 0) {
862 		conn->conn_waiting_on_uc = 1;
863 		spin_unlock_bh(&conn->conn_usage_lock);
864 
865 		wait_for_completion(&conn->conn_waiting_on_uc_comp);
866 		return;
867 	}
868 	spin_unlock_bh(&conn->conn_usage_lock);
869 }
870 
871 void iscsit_dec_conn_usage_count(struct iscsi_conn *conn)
872 {
873 	spin_lock_bh(&conn->conn_usage_lock);
874 	conn->conn_usage_count--;
875 
876 	if (!conn->conn_usage_count && conn->conn_waiting_on_uc)
877 		complete(&conn->conn_waiting_on_uc_comp);
878 
879 	spin_unlock_bh(&conn->conn_usage_lock);
880 }
881 
882 void iscsit_inc_conn_usage_count(struct iscsi_conn *conn)
883 {
884 	spin_lock_bh(&conn->conn_usage_lock);
885 	conn->conn_usage_count++;
886 	spin_unlock_bh(&conn->conn_usage_lock);
887 }
888 
889 static int iscsit_add_nopin(struct iscsi_conn *conn, int want_response)
890 {
891 	u8 state;
892 	struct iscsi_cmd *cmd;
893 
894 	cmd = iscsit_allocate_cmd(conn, TASK_RUNNING);
895 	if (!cmd)
896 		return -1;
897 
898 	cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
899 	state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
900 				ISTATE_SEND_NOPIN_NO_RESPONSE;
901 	cmd->init_task_tag = RESERVED_ITT;
902 	cmd->targ_xfer_tag = (want_response) ?
903 			     session_get_next_ttt(conn->sess) : 0xFFFFFFFF;
904 	spin_lock_bh(&conn->cmd_lock);
905 	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
906 	spin_unlock_bh(&conn->cmd_lock);
907 
908 	if (want_response)
909 		iscsit_start_nopin_response_timer(conn);
910 	iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
911 
912 	return 0;
913 }
914 
915 void iscsit_handle_nopin_response_timeout(struct timer_list *t)
916 {
917 	struct iscsi_conn *conn = from_timer(conn, t, nopin_response_timer);
918 
919 	iscsit_inc_conn_usage_count(conn);
920 
921 	spin_lock_bh(&conn->nopin_timer_lock);
922 	if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
923 		spin_unlock_bh(&conn->nopin_timer_lock);
924 		iscsit_dec_conn_usage_count(conn);
925 		return;
926 	}
927 
928 	pr_debug("Did not receive response to NOPIN on CID: %hu on"
929 		" SID: %u, failing connection.\n", conn->cid,
930 			conn->sess->sid);
931 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
932 	spin_unlock_bh(&conn->nopin_timer_lock);
933 
934 	{
935 	struct iscsi_portal_group *tpg = conn->sess->tpg;
936 	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
937 
938 	if (tiqn) {
939 		spin_lock_bh(&tiqn->sess_err_stats.lock);
940 		strcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
941 				conn->sess->sess_ops->InitiatorName);
942 		tiqn->sess_err_stats.last_sess_failure_type =
943 				ISCSI_SESS_ERR_CXN_TIMEOUT;
944 		tiqn->sess_err_stats.cxn_timeout_errors++;
945 		atomic_long_inc(&conn->sess->conn_timeout_errors);
946 		spin_unlock_bh(&tiqn->sess_err_stats.lock);
947 	}
948 	}
949 
950 	iscsit_cause_connection_reinstatement(conn, 0);
951 	iscsit_dec_conn_usage_count(conn);
952 }
953 
954 void iscsit_mod_nopin_response_timer(struct iscsi_conn *conn)
955 {
956 	struct iscsi_session *sess = conn->sess;
957 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
958 
959 	spin_lock_bh(&conn->nopin_timer_lock);
960 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
961 		spin_unlock_bh(&conn->nopin_timer_lock);
962 		return;
963 	}
964 
965 	mod_timer(&conn->nopin_response_timer,
966 		(get_jiffies_64() + na->nopin_response_timeout * HZ));
967 	spin_unlock_bh(&conn->nopin_timer_lock);
968 }
969 
970 /*
971  *	Called with conn->nopin_timer_lock held.
972  */
973 void iscsit_start_nopin_response_timer(struct iscsi_conn *conn)
974 {
975 	struct iscsi_session *sess = conn->sess;
976 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
977 
978 	spin_lock_bh(&conn->nopin_timer_lock);
979 	if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
980 		spin_unlock_bh(&conn->nopin_timer_lock);
981 		return;
982 	}
983 
984 	conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
985 	conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
986 	mod_timer(&conn->nopin_response_timer,
987 		  jiffies + na->nopin_response_timeout * HZ);
988 
989 	pr_debug("Started NOPIN Response Timer on CID: %d to %u"
990 		" seconds\n", conn->cid, na->nopin_response_timeout);
991 	spin_unlock_bh(&conn->nopin_timer_lock);
992 }
993 
994 void iscsit_stop_nopin_response_timer(struct iscsi_conn *conn)
995 {
996 	spin_lock_bh(&conn->nopin_timer_lock);
997 	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
998 		spin_unlock_bh(&conn->nopin_timer_lock);
999 		return;
1000 	}
1001 	conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
1002 	spin_unlock_bh(&conn->nopin_timer_lock);
1003 
1004 	del_timer_sync(&conn->nopin_response_timer);
1005 
1006 	spin_lock_bh(&conn->nopin_timer_lock);
1007 	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
1008 	spin_unlock_bh(&conn->nopin_timer_lock);
1009 }
1010 
1011 void iscsit_handle_nopin_timeout(struct timer_list *t)
1012 {
1013 	struct iscsi_conn *conn = from_timer(conn, t, nopin_timer);
1014 
1015 	iscsit_inc_conn_usage_count(conn);
1016 
1017 	spin_lock_bh(&conn->nopin_timer_lock);
1018 	if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
1019 		spin_unlock_bh(&conn->nopin_timer_lock);
1020 		iscsit_dec_conn_usage_count(conn);
1021 		return;
1022 	}
1023 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1024 	spin_unlock_bh(&conn->nopin_timer_lock);
1025 
1026 	iscsit_add_nopin(conn, 1);
1027 	iscsit_dec_conn_usage_count(conn);
1028 }
1029 
1030 /*
1031  * Called with conn->nopin_timer_lock held.
1032  */
1033 void __iscsit_start_nopin_timer(struct iscsi_conn *conn)
1034 {
1035 	struct iscsi_session *sess = conn->sess;
1036 	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1037 	/*
1038 	* NOPIN timeout is disabled.
1039 	 */
1040 	if (!na->nopin_timeout)
1041 		return;
1042 
1043 	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
1044 		return;
1045 
1046 	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
1047 	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
1048 	mod_timer(&conn->nopin_timer, jiffies + na->nopin_timeout * HZ);
1049 
1050 	pr_debug("Started NOPIN Timer on CID: %d at %u second"
1051 		" interval\n", conn->cid, na->nopin_timeout);
1052 }
1053 
1054 void iscsit_start_nopin_timer(struct iscsi_conn *conn)
1055 {
1056 	spin_lock_bh(&conn->nopin_timer_lock);
1057 	__iscsit_start_nopin_timer(conn);
1058 	spin_unlock_bh(&conn->nopin_timer_lock);
1059 }
1060 
1061 void iscsit_stop_nopin_timer(struct iscsi_conn *conn)
1062 {
1063 	spin_lock_bh(&conn->nopin_timer_lock);
1064 	if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
1065 		spin_unlock_bh(&conn->nopin_timer_lock);
1066 		return;
1067 	}
1068 	conn->nopin_timer_flags |= ISCSI_TF_STOP;
1069 	spin_unlock_bh(&conn->nopin_timer_lock);
1070 
1071 	del_timer_sync(&conn->nopin_timer);
1072 
1073 	spin_lock_bh(&conn->nopin_timer_lock);
1074 	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
1075 	spin_unlock_bh(&conn->nopin_timer_lock);
1076 }
1077 
1078 int iscsit_send_tx_data(
1079 	struct iscsi_cmd *cmd,
1080 	struct iscsi_conn *conn,
1081 	int use_misc)
1082 {
1083 	int tx_sent, tx_size;
1084 	u32 iov_count;
1085 	struct kvec *iov;
1086 
1087 send_data:
1088 	tx_size = cmd->tx_size;
1089 
1090 	if (!use_misc) {
1091 		iov = &cmd->iov_data[0];
1092 		iov_count = cmd->iov_data_count;
1093 	} else {
1094 		iov = &cmd->iov_misc[0];
1095 		iov_count = cmd->iov_misc_count;
1096 	}
1097 
1098 	tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
1099 	if (tx_size != tx_sent) {
1100 		if (tx_sent == -EAGAIN) {
1101 			pr_err("tx_data() returned -EAGAIN\n");
1102 			goto send_data;
1103 		} else
1104 			return -1;
1105 	}
1106 	cmd->tx_size = 0;
1107 
1108 	return 0;
1109 }
1110 
1111 int iscsit_fe_sendpage_sg(
1112 	struct iscsi_cmd *cmd,
1113 	struct iscsi_conn *conn)
1114 {
1115 	struct scatterlist *sg = cmd->first_data_sg;
1116 	struct kvec iov;
1117 	u32 tx_hdr_size, data_len;
1118 	u32 offset = cmd->first_data_sg_off;
1119 	int tx_sent, iov_off;
1120 
1121 send_hdr:
1122 	tx_hdr_size = ISCSI_HDR_LEN;
1123 	if (conn->conn_ops->HeaderDigest)
1124 		tx_hdr_size += ISCSI_CRC_LEN;
1125 
1126 	iov.iov_base = cmd->pdu;
1127 	iov.iov_len = tx_hdr_size;
1128 
1129 	tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
1130 	if (tx_hdr_size != tx_sent) {
1131 		if (tx_sent == -EAGAIN) {
1132 			pr_err("tx_data() returned -EAGAIN\n");
1133 			goto send_hdr;
1134 		}
1135 		return -1;
1136 	}
1137 
1138 	data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
1139 	/*
1140 	 * Set iov_off used by padding and data digest tx_data() calls below
1141 	 * in order to determine proper offset into cmd->iov_data[]
1142 	 */
1143 	if (conn->conn_ops->DataDigest) {
1144 		data_len -= ISCSI_CRC_LEN;
1145 		if (cmd->padding)
1146 			iov_off = (cmd->iov_data_count - 2);
1147 		else
1148 			iov_off = (cmd->iov_data_count - 1);
1149 	} else {
1150 		iov_off = (cmd->iov_data_count - 1);
1151 	}
1152 	/*
1153 	 * Perform sendpage() for each page in the scatterlist
1154 	 */
1155 	while (data_len) {
1156 		u32 space = (sg->length - offset);
1157 		u32 sub_len = min_t(u32, data_len, space);
1158 send_pg:
1159 		tx_sent = conn->sock->ops->sendpage(conn->sock,
1160 					sg_page(sg), sg->offset + offset, sub_len, 0);
1161 		if (tx_sent != sub_len) {
1162 			if (tx_sent == -EAGAIN) {
1163 				pr_err("tcp_sendpage() returned"
1164 						" -EAGAIN\n");
1165 				goto send_pg;
1166 			}
1167 
1168 			pr_err("tcp_sendpage() failure: %d\n",
1169 					tx_sent);
1170 			return -1;
1171 		}
1172 
1173 		data_len -= sub_len;
1174 		offset = 0;
1175 		sg = sg_next(sg);
1176 	}
1177 
1178 send_padding:
1179 	if (cmd->padding) {
1180 		struct kvec *iov_p = &cmd->iov_data[iov_off++];
1181 
1182 		tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
1183 		if (cmd->padding != tx_sent) {
1184 			if (tx_sent == -EAGAIN) {
1185 				pr_err("tx_data() returned -EAGAIN\n");
1186 				goto send_padding;
1187 			}
1188 			return -1;
1189 		}
1190 	}
1191 
1192 send_datacrc:
1193 	if (conn->conn_ops->DataDigest) {
1194 		struct kvec *iov_d = &cmd->iov_data[iov_off];
1195 
1196 		tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
1197 		if (ISCSI_CRC_LEN != tx_sent) {
1198 			if (tx_sent == -EAGAIN) {
1199 				pr_err("tx_data() returned -EAGAIN\n");
1200 				goto send_datacrc;
1201 			}
1202 			return -1;
1203 		}
1204 	}
1205 
1206 	return 0;
1207 }
1208 
1209 /*
1210  *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
1211  *      back to the Initiator when an expection condition occurs with the
1212  *      errors set in status_class and status_detail.
1213  *
1214  *      Parameters:     iSCSI Connection, Status Class, Status Detail.
1215  *      Returns:        0 on success, -1 on error.
1216  */
1217 int iscsit_tx_login_rsp(struct iscsi_conn *conn, u8 status_class, u8 status_detail)
1218 {
1219 	struct iscsi_login_rsp *hdr;
1220 	struct iscsi_login *login = conn->conn_login;
1221 
1222 	login->login_failed = 1;
1223 	iscsit_collect_login_stats(conn, status_class, status_detail);
1224 
1225 	memset(&login->rsp[0], 0, ISCSI_HDR_LEN);
1226 
1227 	hdr	= (struct iscsi_login_rsp *)&login->rsp[0];
1228 	hdr->opcode		= ISCSI_OP_LOGIN_RSP;
1229 	hdr->status_class	= status_class;
1230 	hdr->status_detail	= status_detail;
1231 	hdr->itt		= conn->login_itt;
1232 
1233 	return conn->conn_transport->iscsit_put_login_tx(conn, login, 0);
1234 }
1235 
1236 void iscsit_print_session_params(struct iscsi_session *sess)
1237 {
1238 	struct iscsi_conn *conn;
1239 
1240 	pr_debug("-----------------------------[Session Params for"
1241 		" SID: %u]-----------------------------\n", sess->sid);
1242 	spin_lock_bh(&sess->conn_lock);
1243 	list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
1244 		iscsi_dump_conn_ops(conn->conn_ops);
1245 	spin_unlock_bh(&sess->conn_lock);
1246 
1247 	iscsi_dump_sess_ops(sess->sess_ops);
1248 }
1249 
1250 static int iscsit_do_rx_data(
1251 	struct iscsi_conn *conn,
1252 	struct iscsi_data_count *count)
1253 {
1254 	int data = count->data_length, rx_loop = 0, total_rx = 0;
1255 	struct msghdr msg;
1256 
1257 	if (!conn || !conn->sock || !conn->conn_ops)
1258 		return -1;
1259 
1260 	memset(&msg, 0, sizeof(struct msghdr));
1261 	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC,
1262 		      count->iov, count->iov_count, data);
1263 
1264 	while (msg_data_left(&msg)) {
1265 		rx_loop = sock_recvmsg(conn->sock, &msg, MSG_WAITALL);
1266 		if (rx_loop <= 0) {
1267 			pr_debug("rx_loop: %d total_rx: %d\n",
1268 				rx_loop, total_rx);
1269 			return rx_loop;
1270 		}
1271 		total_rx += rx_loop;
1272 		pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
1273 				rx_loop, total_rx, data);
1274 	}
1275 
1276 	return total_rx;
1277 }
1278 
1279 int rx_data(
1280 	struct iscsi_conn *conn,
1281 	struct kvec *iov,
1282 	int iov_count,
1283 	int data)
1284 {
1285 	struct iscsi_data_count c;
1286 
1287 	if (!conn || !conn->sock || !conn->conn_ops)
1288 		return -1;
1289 
1290 	memset(&c, 0, sizeof(struct iscsi_data_count));
1291 	c.iov = iov;
1292 	c.iov_count = iov_count;
1293 	c.data_length = data;
1294 	c.type = ISCSI_RX_DATA;
1295 
1296 	return iscsit_do_rx_data(conn, &c);
1297 }
1298 
1299 int tx_data(
1300 	struct iscsi_conn *conn,
1301 	struct kvec *iov,
1302 	int iov_count,
1303 	int data)
1304 {
1305 	struct msghdr msg;
1306 	int total_tx = 0;
1307 
1308 	if (!conn || !conn->sock || !conn->conn_ops)
1309 		return -1;
1310 
1311 	if (data <= 0) {
1312 		pr_err("Data length is: %d\n", data);
1313 		return -1;
1314 	}
1315 
1316 	memset(&msg, 0, sizeof(struct msghdr));
1317 
1318 	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC,
1319 		      iov, iov_count, data);
1320 
1321 	while (msg_data_left(&msg)) {
1322 		int tx_loop = sock_sendmsg(conn->sock, &msg);
1323 		if (tx_loop <= 0) {
1324 			pr_debug("tx_loop: %d total_tx %d\n",
1325 				tx_loop, total_tx);
1326 			return tx_loop;
1327 		}
1328 		total_tx += tx_loop;
1329 		pr_debug("tx_loop: %d, total_tx: %d, data: %d\n",
1330 					tx_loop, total_tx, data);
1331 	}
1332 
1333 	return total_tx;
1334 }
1335 
1336 void iscsit_collect_login_stats(
1337 	struct iscsi_conn *conn,
1338 	u8 status_class,
1339 	u8 status_detail)
1340 {
1341 	struct iscsi_param *intrname = NULL;
1342 	struct iscsi_tiqn *tiqn;
1343 	struct iscsi_login_stats *ls;
1344 
1345 	tiqn = iscsit_snmp_get_tiqn(conn);
1346 	if (!tiqn)
1347 		return;
1348 
1349 	ls = &tiqn->login_stats;
1350 
1351 	spin_lock(&ls->lock);
1352 	if (status_class == ISCSI_STATUS_CLS_SUCCESS)
1353 		ls->accepts++;
1354 	else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
1355 		ls->redirects++;
1356 		ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
1357 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1358 		 (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
1359 		ls->authenticate_fails++;
1360 		ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
1361 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
1362 		 (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
1363 		ls->authorize_fails++;
1364 		ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
1365 	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
1366 		 (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
1367 		ls->negotiate_fails++;
1368 		ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
1369 	} else {
1370 		ls->other_fails++;
1371 		ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
1372 	}
1373 
1374 	/* Save initiator name, ip address and time, if it is a failed login */
1375 	if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
1376 		if (conn->param_list)
1377 			intrname = iscsi_find_param_from_key(INITIATORNAME,
1378 							     conn->param_list);
1379 		strlcpy(ls->last_intr_fail_name,
1380 		       (intrname ? intrname->value : "Unknown"),
1381 		       sizeof(ls->last_intr_fail_name));
1382 
1383 		ls->last_intr_fail_ip_family = conn->login_family;
1384 
1385 		ls->last_intr_fail_sockaddr = conn->login_sockaddr;
1386 		ls->last_fail_time = get_jiffies_64();
1387 	}
1388 
1389 	spin_unlock(&ls->lock);
1390 }
1391 
1392 struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsi_conn *conn)
1393 {
1394 	struct iscsi_portal_group *tpg;
1395 
1396 	if (!conn)
1397 		return NULL;
1398 
1399 	tpg = conn->tpg;
1400 	if (!tpg)
1401 		return NULL;
1402 
1403 	if (!tpg->tpg_tiqn)
1404 		return NULL;
1405 
1406 	return tpg->tpg_tiqn;
1407 }
1408