1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3  * This file contains main functions related to iSCSI Parameter negotiation.
4  *
5  * (c) Copyright 2007-2013 Datera, Inc.
6  *
7  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
8  *
9  ******************************************************************************/
10 
11 #include <linux/ctype.h>
12 #include <linux/kthread.h>
13 #include <linux/slab.h>
14 #include <linux/sched/signal.h>
15 #include <net/sock.h>
16 #include <scsi/iscsi_proto.h>
17 #include <target/target_core_base.h>
18 #include <target/target_core_fabric.h>
19 #include <target/iscsi/iscsi_transport.h>
20 
21 #include <target/iscsi/iscsi_target_core.h>
22 #include "iscsi_target_parameters.h"
23 #include "iscsi_target_login.h"
24 #include "iscsi_target_nego.h"
25 #include "iscsi_target_tpg.h"
26 #include "iscsi_target_util.h"
27 #include "iscsi_target.h"
28 #include "iscsi_target_auth.h"
29 
30 #define MAX_LOGIN_PDUS  7
31 #define TEXT_LEN	4096
32 
33 void convert_null_to_semi(char *buf, int len)
34 {
35 	int i;
36 
37 	for (i = 0; i < len; i++)
38 		if (buf[i] == '\0')
39 			buf[i] = ';';
40 }
41 
42 static int strlen_semi(char *buf)
43 {
44 	int i = 0;
45 
46 	while (buf[i] != '\0') {
47 		if (buf[i] == ';')
48 			return i;
49 		i++;
50 	}
51 
52 	return -1;
53 }
54 
55 int extract_param(
56 	const char *in_buf,
57 	const char *pattern,
58 	unsigned int max_length,
59 	char *out_buf,
60 	unsigned char *type)
61 {
62 	char *ptr;
63 	int len;
64 
65 	if (!in_buf || !pattern || !out_buf || !type)
66 		return -1;
67 
68 	ptr = strstr(in_buf, pattern);
69 	if (!ptr)
70 		return -1;
71 
72 	ptr = strstr(ptr, "=");
73 	if (!ptr)
74 		return -1;
75 
76 	ptr += 1;
77 	if (*ptr == '0' && (*(ptr+1) == 'x' || *(ptr+1) == 'X')) {
78 		ptr += 2; /* skip 0x */
79 		*type = HEX;
80 	} else
81 		*type = DECIMAL;
82 
83 	len = strlen_semi(ptr);
84 	if (len < 0)
85 		return -1;
86 
87 	if (len >= max_length) {
88 		pr_err("Length of input: %d exceeds max_length:"
89 			" %d\n", len, max_length);
90 		return -1;
91 	}
92 	memcpy(out_buf, ptr, len);
93 	out_buf[len] = '\0';
94 
95 	return 0;
96 }
97 
98 static u32 iscsi_handle_authentication(
99 	struct iscsi_conn *conn,
100 	char *in_buf,
101 	char *out_buf,
102 	int in_length,
103 	int *out_length,
104 	unsigned char *authtype)
105 {
106 	struct iscsi_session *sess = conn->sess;
107 	struct iscsi_node_auth *auth;
108 	struct iscsi_node_acl *iscsi_nacl;
109 	struct iscsi_portal_group *iscsi_tpg;
110 	struct se_node_acl *se_nacl;
111 
112 	if (!sess->sess_ops->SessionType) {
113 		/*
114 		 * For SessionType=Normal
115 		 */
116 		se_nacl = conn->sess->se_sess->se_node_acl;
117 		if (!se_nacl) {
118 			pr_err("Unable to locate struct se_node_acl for"
119 					" CHAP auth\n");
120 			return -1;
121 		}
122 		iscsi_nacl = container_of(se_nacl, struct iscsi_node_acl,
123 				se_node_acl);
124 		if (!iscsi_nacl) {
125 			pr_err("Unable to locate struct iscsi_node_acl for"
126 					" CHAP auth\n");
127 			return -1;
128 		}
129 
130 		if (se_nacl->dynamic_node_acl) {
131 			iscsi_tpg = container_of(se_nacl->se_tpg,
132 					struct iscsi_portal_group, tpg_se_tpg);
133 
134 			auth = &iscsi_tpg->tpg_demo_auth;
135 		} else {
136 			iscsi_nacl = container_of(se_nacl, struct iscsi_node_acl,
137 						  se_node_acl);
138 
139 			auth = &iscsi_nacl->node_auth;
140 		}
141 	} else {
142 		/*
143 		 * For SessionType=Discovery
144 		 */
145 		auth = &iscsit_global->discovery_acl.node_auth;
146 	}
147 
148 	if (strstr("CHAP", authtype))
149 		strcpy(conn->sess->auth_type, "CHAP");
150 	else
151 		strcpy(conn->sess->auth_type, NONE);
152 
153 	if (strstr("None", authtype))
154 		return 1;
155 	else if (strstr("CHAP", authtype))
156 		return chap_main_loop(conn, auth, in_buf, out_buf,
157 				&in_length, out_length);
158 	/* SRP, SPKM1, SPKM2 and KRB5 are unsupported */
159 	return 2;
160 }
161 
162 static void iscsi_remove_failed_auth_entry(struct iscsi_conn *conn)
163 {
164 	kfree(conn->auth_protocol);
165 }
166 
167 int iscsi_target_check_login_request(
168 	struct iscsi_conn *conn,
169 	struct iscsi_login *login)
170 {
171 	int req_csg, req_nsg;
172 	u32 payload_length;
173 	struct iscsi_login_req *login_req;
174 
175 	login_req = (struct iscsi_login_req *) login->req;
176 	payload_length = ntoh24(login_req->dlength);
177 
178 	switch (login_req->opcode & ISCSI_OPCODE_MASK) {
179 	case ISCSI_OP_LOGIN:
180 		break;
181 	default:
182 		pr_err("Received unknown opcode 0x%02x.\n",
183 				login_req->opcode & ISCSI_OPCODE_MASK);
184 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
185 				ISCSI_LOGIN_STATUS_INIT_ERR);
186 		return -1;
187 	}
188 
189 	if ((login_req->flags & ISCSI_FLAG_LOGIN_CONTINUE) &&
190 	    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
191 		pr_err("Login request has both ISCSI_FLAG_LOGIN_CONTINUE"
192 			" and ISCSI_FLAG_LOGIN_TRANSIT set, protocol error.\n");
193 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
194 				ISCSI_LOGIN_STATUS_INIT_ERR);
195 		return -1;
196 	}
197 
198 	req_csg = ISCSI_LOGIN_CURRENT_STAGE(login_req->flags);
199 	req_nsg = ISCSI_LOGIN_NEXT_STAGE(login_req->flags);
200 
201 	if (req_csg != login->current_stage) {
202 		pr_err("Initiator unexpectedly changed login stage"
203 			" from %d to %d, login failed.\n", login->current_stage,
204 			req_csg);
205 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
206 				ISCSI_LOGIN_STATUS_INIT_ERR);
207 		return -1;
208 	}
209 
210 	if ((req_nsg == 2) || (req_csg >= 2) ||
211 	   ((login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT) &&
212 	    (req_nsg <= req_csg))) {
213 		pr_err("Illegal login_req->flags Combination, CSG: %d,"
214 			" NSG: %d, ISCSI_FLAG_LOGIN_TRANSIT: %d.\n", req_csg,
215 			req_nsg, (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT));
216 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
217 				ISCSI_LOGIN_STATUS_INIT_ERR);
218 		return -1;
219 	}
220 
221 	if ((login_req->max_version != login->version_max) ||
222 	    (login_req->min_version != login->version_min)) {
223 		pr_err("Login request changed Version Max/Nin"
224 			" unexpectedly to 0x%02x/0x%02x, protocol error\n",
225 			login_req->max_version, login_req->min_version);
226 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
227 				ISCSI_LOGIN_STATUS_INIT_ERR);
228 		return -1;
229 	}
230 
231 	if (memcmp(login_req->isid, login->isid, 6) != 0) {
232 		pr_err("Login request changed ISID unexpectedly,"
233 				" protocol error.\n");
234 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
235 				ISCSI_LOGIN_STATUS_INIT_ERR);
236 		return -1;
237 	}
238 
239 	if (login_req->itt != login->init_task_tag) {
240 		pr_err("Login request changed ITT unexpectedly to"
241 			" 0x%08x, protocol error.\n", login_req->itt);
242 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
243 				ISCSI_LOGIN_STATUS_INIT_ERR);
244 		return -1;
245 	}
246 
247 	if (payload_length > MAX_KEY_VALUE_PAIRS) {
248 		pr_err("Login request payload exceeds default"
249 			" MaxRecvDataSegmentLength: %u, protocol error.\n",
250 				MAX_KEY_VALUE_PAIRS);
251 		return -1;
252 	}
253 
254 	return 0;
255 }
256 EXPORT_SYMBOL(iscsi_target_check_login_request);
257 
258 static int iscsi_target_check_first_request(
259 	struct iscsi_conn *conn,
260 	struct iscsi_login *login)
261 {
262 	struct iscsi_param *param = NULL;
263 	struct se_node_acl *se_nacl;
264 
265 	login->first_request = 0;
266 
267 	list_for_each_entry(param, &conn->param_list->param_list, p_list) {
268 		if (!strncmp(param->name, SESSIONTYPE, 11)) {
269 			if (!IS_PSTATE_ACCEPTOR(param)) {
270 				pr_err("SessionType key not received"
271 					" in first login request.\n");
272 				iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
273 					ISCSI_LOGIN_STATUS_MISSING_FIELDS);
274 				return -1;
275 			}
276 			if (!strncmp(param->value, DISCOVERY, 9))
277 				return 0;
278 		}
279 
280 		if (!strncmp(param->name, INITIATORNAME, 13)) {
281 			if (!IS_PSTATE_ACCEPTOR(param)) {
282 				if (!login->leading_connection)
283 					continue;
284 
285 				pr_err("InitiatorName key not received"
286 					" in first login request.\n");
287 				iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
288 					ISCSI_LOGIN_STATUS_MISSING_FIELDS);
289 				return -1;
290 			}
291 
292 			/*
293 			 * For non-leading connections, double check that the
294 			 * received InitiatorName matches the existing session's
295 			 * struct iscsi_node_acl.
296 			 */
297 			if (!login->leading_connection) {
298 				se_nacl = conn->sess->se_sess->se_node_acl;
299 				if (!se_nacl) {
300 					pr_err("Unable to locate"
301 						" struct se_node_acl\n");
302 					iscsit_tx_login_rsp(conn,
303 							ISCSI_STATUS_CLS_INITIATOR_ERR,
304 							ISCSI_LOGIN_STATUS_TGT_NOT_FOUND);
305 					return -1;
306 				}
307 
308 				if (strcmp(param->value,
309 						se_nacl->initiatorname)) {
310 					pr_err("Incorrect"
311 						" InitiatorName: %s for this"
312 						" iSCSI Initiator Node.\n",
313 						param->value);
314 					iscsit_tx_login_rsp(conn,
315 							ISCSI_STATUS_CLS_INITIATOR_ERR,
316 							ISCSI_LOGIN_STATUS_TGT_NOT_FOUND);
317 					return -1;
318 				}
319 			}
320 		}
321 	}
322 
323 	return 0;
324 }
325 
326 static int iscsi_target_do_tx_login_io(struct iscsi_conn *conn, struct iscsi_login *login)
327 {
328 	u32 padding = 0;
329 	struct iscsi_login_rsp *login_rsp;
330 
331 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
332 
333 	login_rsp->opcode		= ISCSI_OP_LOGIN_RSP;
334 	hton24(login_rsp->dlength, login->rsp_length);
335 	memcpy(login_rsp->isid, login->isid, 6);
336 	login_rsp->tsih			= cpu_to_be16(login->tsih);
337 	login_rsp->itt			= login->init_task_tag;
338 	login_rsp->statsn		= cpu_to_be32(conn->stat_sn++);
339 	login_rsp->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
340 	login_rsp->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
341 
342 	pr_debug("Sending Login Response, Flags: 0x%02x, ITT: 0x%08x,"
343 		" ExpCmdSN; 0x%08x, MaxCmdSN: 0x%08x, StatSN: 0x%08x, Length:"
344 		" %u\n", login_rsp->flags, (__force u32)login_rsp->itt,
345 		ntohl(login_rsp->exp_cmdsn), ntohl(login_rsp->max_cmdsn),
346 		ntohl(login_rsp->statsn), login->rsp_length);
347 
348 	padding = ((-login->rsp_length) & 3);
349 	/*
350 	 * Before sending the last login response containing the transition
351 	 * bit for full-feature-phase, go ahead and start up TX/RX threads
352 	 * now to avoid potential resource allocation failures after the
353 	 * final login response has been sent.
354 	 */
355 	if (login->login_complete) {
356 		int rc = iscsit_start_kthreads(conn);
357 		if (rc) {
358 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
359 					    ISCSI_LOGIN_STATUS_NO_RESOURCES);
360 			return -1;
361 		}
362 	}
363 
364 	if (conn->conn_transport->iscsit_put_login_tx(conn, login,
365 					login->rsp_length + padding) < 0)
366 		goto err;
367 
368 	login->rsp_length		= 0;
369 
370 	return 0;
371 
372 err:
373 	if (login->login_complete) {
374 		if (conn->rx_thread && conn->rx_thread_active) {
375 			send_sig(SIGINT, conn->rx_thread, 1);
376 			complete(&conn->rx_login_comp);
377 			kthread_stop(conn->rx_thread);
378 		}
379 		if (conn->tx_thread && conn->tx_thread_active) {
380 			send_sig(SIGINT, conn->tx_thread, 1);
381 			kthread_stop(conn->tx_thread);
382 		}
383 		spin_lock(&iscsit_global->ts_bitmap_lock);
384 		bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
385 				      get_order(1));
386 		spin_unlock(&iscsit_global->ts_bitmap_lock);
387 	}
388 	return -1;
389 }
390 
391 static void iscsi_target_sk_data_ready(struct sock *sk)
392 {
393 	struct iscsi_conn *conn = sk->sk_user_data;
394 	bool rc;
395 
396 	pr_debug("Entering iscsi_target_sk_data_ready: conn: %p\n", conn);
397 
398 	write_lock_bh(&sk->sk_callback_lock);
399 	if (!sk->sk_user_data) {
400 		write_unlock_bh(&sk->sk_callback_lock);
401 		return;
402 	}
403 	if (!test_bit(LOGIN_FLAGS_READY, &conn->login_flags)) {
404 		write_unlock_bh(&sk->sk_callback_lock);
405 		pr_debug("Got LOGIN_FLAGS_READY=0, conn: %p >>>>\n", conn);
406 		return;
407 	}
408 	if (test_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags)) {
409 		write_unlock_bh(&sk->sk_callback_lock);
410 		pr_debug("Got LOGIN_FLAGS_CLOSED=1, conn: %p >>>>\n", conn);
411 		return;
412 	}
413 	if (test_and_set_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags)) {
414 		write_unlock_bh(&sk->sk_callback_lock);
415 		pr_debug("Got LOGIN_FLAGS_READ_ACTIVE=1, conn: %p >>>>\n", conn);
416 		if (iscsi_target_sk_data_ready == conn->orig_data_ready)
417 			return;
418 		conn->orig_data_ready(sk);
419 		return;
420 	}
421 
422 	rc = schedule_delayed_work(&conn->login_work, 0);
423 	if (!rc) {
424 		pr_debug("iscsi_target_sk_data_ready, schedule_delayed_work"
425 			 " got false\n");
426 	}
427 	write_unlock_bh(&sk->sk_callback_lock);
428 }
429 
430 static void iscsi_target_sk_state_change(struct sock *);
431 
432 static void iscsi_target_set_sock_callbacks(struct iscsi_conn *conn)
433 {
434 	struct sock *sk;
435 
436 	if (!conn->sock)
437 		return;
438 
439 	sk = conn->sock->sk;
440 	pr_debug("Entering iscsi_target_set_sock_callbacks: conn: %p\n", conn);
441 
442 	write_lock_bh(&sk->sk_callback_lock);
443 	sk->sk_user_data = conn;
444 	conn->orig_data_ready = sk->sk_data_ready;
445 	conn->orig_state_change = sk->sk_state_change;
446 	sk->sk_data_ready = iscsi_target_sk_data_ready;
447 	sk->sk_state_change = iscsi_target_sk_state_change;
448 	write_unlock_bh(&sk->sk_callback_lock);
449 
450 	sk->sk_sndtimeo = TA_LOGIN_TIMEOUT * HZ;
451 	sk->sk_rcvtimeo = TA_LOGIN_TIMEOUT * HZ;
452 }
453 
454 static void iscsi_target_restore_sock_callbacks(struct iscsi_conn *conn)
455 {
456 	struct sock *sk;
457 
458 	if (!conn->sock)
459 		return;
460 
461 	sk = conn->sock->sk;
462 	pr_debug("Entering iscsi_target_restore_sock_callbacks: conn: %p\n", conn);
463 
464 	write_lock_bh(&sk->sk_callback_lock);
465 	if (!sk->sk_user_data) {
466 		write_unlock_bh(&sk->sk_callback_lock);
467 		return;
468 	}
469 	sk->sk_user_data = NULL;
470 	sk->sk_data_ready = conn->orig_data_ready;
471 	sk->sk_state_change = conn->orig_state_change;
472 	write_unlock_bh(&sk->sk_callback_lock);
473 
474 	sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
475 	sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;
476 }
477 
478 static int iscsi_target_do_login(struct iscsi_conn *, struct iscsi_login *);
479 
480 static bool __iscsi_target_sk_check_close(struct sock *sk)
481 {
482 	if (sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) {
483 		pr_debug("__iscsi_target_sk_check_close: TCP_CLOSE_WAIT|TCP_CLOSE,"
484 			"returning TRUE\n");
485 		return true;
486 	}
487 	return false;
488 }
489 
490 static bool iscsi_target_sk_check_close(struct iscsi_conn *conn)
491 {
492 	bool state = false;
493 
494 	if (conn->sock) {
495 		struct sock *sk = conn->sock->sk;
496 
497 		read_lock_bh(&sk->sk_callback_lock);
498 		state = (__iscsi_target_sk_check_close(sk) ||
499 			 test_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags));
500 		read_unlock_bh(&sk->sk_callback_lock);
501 	}
502 	return state;
503 }
504 
505 static bool iscsi_target_sk_check_flag(struct iscsi_conn *conn, unsigned int flag)
506 {
507 	bool state = false;
508 
509 	if (conn->sock) {
510 		struct sock *sk = conn->sock->sk;
511 
512 		read_lock_bh(&sk->sk_callback_lock);
513 		state = test_bit(flag, &conn->login_flags);
514 		read_unlock_bh(&sk->sk_callback_lock);
515 	}
516 	return state;
517 }
518 
519 static bool iscsi_target_sk_check_and_clear(struct iscsi_conn *conn, unsigned int flag)
520 {
521 	bool state = false;
522 
523 	if (conn->sock) {
524 		struct sock *sk = conn->sock->sk;
525 
526 		write_lock_bh(&sk->sk_callback_lock);
527 		state = (__iscsi_target_sk_check_close(sk) ||
528 			 test_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags));
529 		if (!state)
530 			clear_bit(flag, &conn->login_flags);
531 		write_unlock_bh(&sk->sk_callback_lock);
532 	}
533 	return state;
534 }
535 
536 static void iscsi_target_login_drop(struct iscsi_conn *conn, struct iscsi_login *login)
537 {
538 	struct iscsi_np *np = login->np;
539 	bool zero_tsih = login->zero_tsih;
540 
541 	iscsi_remove_failed_auth_entry(conn);
542 	iscsi_target_nego_release(conn);
543 	iscsi_target_login_sess_out(conn, np, zero_tsih, true);
544 }
545 
546 struct conn_timeout {
547 	struct timer_list timer;
548 	struct iscsi_conn *conn;
549 };
550 
551 static void iscsi_target_login_timeout(struct timer_list *t)
552 {
553 	struct conn_timeout *timeout = from_timer(timeout, t, timer);
554 	struct iscsi_conn *conn = timeout->conn;
555 
556 	pr_debug("Entering iscsi_target_login_timeout >>>>>>>>>>>>>>>>>>>\n");
557 
558 	if (conn->login_kworker) {
559 		pr_debug("Sending SIGINT to conn->login_kworker %s/%d\n",
560 			 conn->login_kworker->comm, conn->login_kworker->pid);
561 		send_sig(SIGINT, conn->login_kworker, 1);
562 	}
563 }
564 
565 static void iscsi_target_do_login_rx(struct work_struct *work)
566 {
567 	struct iscsi_conn *conn = container_of(work,
568 				struct iscsi_conn, login_work.work);
569 	struct iscsi_login *login = conn->login;
570 	struct iscsi_np *np = login->np;
571 	struct iscsi_portal_group *tpg = conn->tpg;
572 	struct iscsi_tpg_np *tpg_np = conn->tpg_np;
573 	struct conn_timeout timeout;
574 	int rc, zero_tsih = login->zero_tsih;
575 	bool state;
576 
577 	pr_debug("entering iscsi_target_do_login_rx, conn: %p, %s:%d\n",
578 			conn, current->comm, current->pid);
579 	/*
580 	 * If iscsi_target_do_login_rx() has been invoked by ->sk_data_ready()
581 	 * before initial PDU processing in iscsi_target_start_negotiation()
582 	 * has completed, go ahead and retry until it's cleared.
583 	 *
584 	 * Otherwise if the TCP connection drops while this is occuring,
585 	 * iscsi_target_start_negotiation() will detect the failure, call
586 	 * cancel_delayed_work_sync(&conn->login_work), and cleanup the
587 	 * remaining iscsi connection resources from iscsi_np process context.
588 	 */
589 	if (iscsi_target_sk_check_flag(conn, LOGIN_FLAGS_INITIAL_PDU)) {
590 		schedule_delayed_work(&conn->login_work, msecs_to_jiffies(10));
591 		return;
592 	}
593 
594 	spin_lock(&tpg->tpg_state_lock);
595 	state = (tpg->tpg_state == TPG_STATE_ACTIVE);
596 	spin_unlock(&tpg->tpg_state_lock);
597 
598 	if (!state) {
599 		pr_debug("iscsi_target_do_login_rx: tpg_state != TPG_STATE_ACTIVE\n");
600 		goto err;
601 	}
602 
603 	if (iscsi_target_sk_check_close(conn)) {
604 		pr_debug("iscsi_target_do_login_rx, TCP state CLOSE\n");
605 		goto err;
606 	}
607 
608 	conn->login_kworker = current;
609 	allow_signal(SIGINT);
610 
611 	timeout.conn = conn;
612 	timer_setup_on_stack(&timeout.timer, iscsi_target_login_timeout, 0);
613 	mod_timer(&timeout.timer, jiffies + TA_LOGIN_TIMEOUT * HZ);
614 	pr_debug("Starting login timer for %s/%d\n", current->comm, current->pid);
615 
616 	rc = conn->conn_transport->iscsit_get_login_rx(conn, login);
617 	del_timer_sync(&timeout.timer);
618 	destroy_timer_on_stack(&timeout.timer);
619 	flush_signals(current);
620 	conn->login_kworker = NULL;
621 
622 	if (rc < 0)
623 		goto err;
624 
625 	pr_debug("iscsi_target_do_login_rx after rx_login_io, %p, %s:%d\n",
626 			conn, current->comm, current->pid);
627 
628 	/*
629 	 * LOGIN_FLAGS_READ_ACTIVE is cleared so that sk_data_ready
630 	 * could be triggered again after this.
631 	 *
632 	 * LOGIN_FLAGS_WRITE_ACTIVE is cleared after we successfully
633 	 * process a login PDU, so that sk_state_chage can do login
634 	 * cleanup as needed if the socket is closed. If a delayed work is
635 	 * ongoing (LOGIN_FLAGS_WRITE_ACTIVE or LOGIN_FLAGS_READ_ACTIVE),
636 	 * sk_state_change will leave the cleanup to the delayed work or
637 	 * it will schedule a delayed work to do cleanup.
638 	 */
639 	if (conn->sock) {
640 		struct sock *sk = conn->sock->sk;
641 
642 		write_lock_bh(&sk->sk_callback_lock);
643 		if (!test_bit(LOGIN_FLAGS_INITIAL_PDU, &conn->login_flags)) {
644 			clear_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags);
645 			set_bit(LOGIN_FLAGS_WRITE_ACTIVE, &conn->login_flags);
646 		}
647 		write_unlock_bh(&sk->sk_callback_lock);
648 	}
649 
650 	rc = iscsi_target_do_login(conn, login);
651 	if (rc < 0) {
652 		goto err;
653 	} else if (!rc) {
654 		if (iscsi_target_sk_check_and_clear(conn,
655 						    LOGIN_FLAGS_WRITE_ACTIVE))
656 			goto err;
657 	} else if (rc == 1) {
658 		cancel_delayed_work(&conn->login_work);
659 		iscsi_target_nego_release(conn);
660 		iscsi_post_login_handler(np, conn, zero_tsih);
661 		iscsit_deaccess_np(np, tpg, tpg_np);
662 	}
663 	return;
664 
665 err:
666 	iscsi_target_restore_sock_callbacks(conn);
667 	cancel_delayed_work(&conn->login_work);
668 	iscsi_target_login_drop(conn, login);
669 	iscsit_deaccess_np(np, tpg, tpg_np);
670 }
671 
672 static void iscsi_target_sk_state_change(struct sock *sk)
673 {
674 	struct iscsi_conn *conn;
675 	void (*orig_state_change)(struct sock *);
676 	bool state;
677 
678 	pr_debug("Entering iscsi_target_sk_state_change\n");
679 
680 	write_lock_bh(&sk->sk_callback_lock);
681 	conn = sk->sk_user_data;
682 	if (!conn) {
683 		write_unlock_bh(&sk->sk_callback_lock);
684 		return;
685 	}
686 	orig_state_change = conn->orig_state_change;
687 
688 	if (!test_bit(LOGIN_FLAGS_READY, &conn->login_flags)) {
689 		pr_debug("Got LOGIN_FLAGS_READY=0 sk_state_change conn: %p\n",
690 			 conn);
691 		write_unlock_bh(&sk->sk_callback_lock);
692 		orig_state_change(sk);
693 		return;
694 	}
695 	state = __iscsi_target_sk_check_close(sk);
696 	pr_debug("__iscsi_target_sk_close_change: state: %d\n", state);
697 
698 	if (test_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags) ||
699 	    test_bit(LOGIN_FLAGS_WRITE_ACTIVE, &conn->login_flags)) {
700 		pr_debug("Got LOGIN_FLAGS_{READ|WRITE}_ACTIVE=1"
701 			 " sk_state_change conn: %p\n", conn);
702 		if (state)
703 			set_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags);
704 		write_unlock_bh(&sk->sk_callback_lock);
705 		orig_state_change(sk);
706 		return;
707 	}
708 	if (test_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags)) {
709 		pr_debug("Got LOGIN_FLAGS_CLOSED=1 sk_state_change conn: %p\n",
710 			 conn);
711 		write_unlock_bh(&sk->sk_callback_lock);
712 		orig_state_change(sk);
713 		return;
714 	}
715 	/*
716 	 * If the TCP connection has dropped, go ahead and set LOGIN_FLAGS_CLOSED,
717 	 * but only queue conn->login_work -> iscsi_target_do_login_rx()
718 	 * processing if LOGIN_FLAGS_INITIAL_PDU has already been cleared.
719 	 *
720 	 * When iscsi_target_do_login_rx() runs, iscsi_target_sk_check_close()
721 	 * will detect the dropped TCP connection from delayed workqueue context.
722 	 *
723 	 * If LOGIN_FLAGS_INITIAL_PDU is still set, which means the initial
724 	 * iscsi_target_start_negotiation() is running, iscsi_target_do_login()
725 	 * via iscsi_target_sk_check_close() or iscsi_target_start_negotiation()
726 	 * via iscsi_target_sk_check_and_clear() is responsible for detecting the
727 	 * dropped TCP connection in iscsi_np process context, and cleaning up
728 	 * the remaining iscsi connection resources.
729 	 */
730 	if (state) {
731 		pr_debug("iscsi_target_sk_state_change got failed state\n");
732 		set_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags);
733 		state = test_bit(LOGIN_FLAGS_INITIAL_PDU, &conn->login_flags);
734 		write_unlock_bh(&sk->sk_callback_lock);
735 
736 		orig_state_change(sk);
737 
738 		if (!state)
739 			schedule_delayed_work(&conn->login_work, 0);
740 		return;
741 	}
742 	write_unlock_bh(&sk->sk_callback_lock);
743 
744 	orig_state_change(sk);
745 }
746 
747 /*
748  *	NOTE: We check for existing sessions or connections AFTER the initiator
749  *	has been successfully authenticated in order to protect against faked
750  *	ISID/TSIH combinations.
751  */
752 static int iscsi_target_check_for_existing_instances(
753 	struct iscsi_conn *conn,
754 	struct iscsi_login *login)
755 {
756 	if (login->checked_for_existing)
757 		return 0;
758 
759 	login->checked_for_existing = 1;
760 
761 	if (!login->tsih)
762 		return iscsi_check_for_session_reinstatement(conn);
763 	else
764 		return iscsi_login_post_auth_non_zero_tsih(conn, login->cid,
765 				login->initial_exp_statsn);
766 }
767 
768 static int iscsi_target_do_authentication(
769 	struct iscsi_conn *conn,
770 	struct iscsi_login *login)
771 {
772 	int authret;
773 	u32 payload_length;
774 	struct iscsi_param *param;
775 	struct iscsi_login_req *login_req;
776 	struct iscsi_login_rsp *login_rsp;
777 
778 	login_req = (struct iscsi_login_req *) login->req;
779 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
780 	payload_length = ntoh24(login_req->dlength);
781 
782 	param = iscsi_find_param_from_key(AUTHMETHOD, conn->param_list);
783 	if (!param)
784 		return -1;
785 
786 	authret = iscsi_handle_authentication(
787 			conn,
788 			login->req_buf,
789 			login->rsp_buf,
790 			payload_length,
791 			&login->rsp_length,
792 			param->value);
793 	switch (authret) {
794 	case 0:
795 		pr_debug("Received OK response"
796 		" from LIO Authentication, continuing.\n");
797 		break;
798 	case 1:
799 		pr_debug("iSCSI security negotiation"
800 			" completed successfully.\n");
801 		login->auth_complete = 1;
802 		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE1) &&
803 		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
804 			login_rsp->flags |= (ISCSI_FLAG_LOGIN_NEXT_STAGE1 |
805 					     ISCSI_FLAG_LOGIN_TRANSIT);
806 			login->current_stage = 1;
807 		}
808 		return iscsi_target_check_for_existing_instances(
809 				conn, login);
810 	case 2:
811 		pr_err("Security negotiation"
812 			" failed.\n");
813 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
814 				ISCSI_LOGIN_STATUS_AUTH_FAILED);
815 		return -1;
816 	default:
817 		pr_err("Received unknown error %d from LIO"
818 				" Authentication\n", authret);
819 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
820 				ISCSI_LOGIN_STATUS_TARGET_ERROR);
821 		return -1;
822 	}
823 
824 	return 0;
825 }
826 
827 static int iscsi_target_handle_csg_zero(
828 	struct iscsi_conn *conn,
829 	struct iscsi_login *login)
830 {
831 	int ret;
832 	u32 payload_length;
833 	struct iscsi_param *param;
834 	struct iscsi_login_req *login_req;
835 	struct iscsi_login_rsp *login_rsp;
836 
837 	login_req = (struct iscsi_login_req *) login->req;
838 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
839 	payload_length = ntoh24(login_req->dlength);
840 
841 	param = iscsi_find_param_from_key(AUTHMETHOD, conn->param_list);
842 	if (!param)
843 		return -1;
844 
845 	ret = iscsi_decode_text_input(
846 			PHASE_SECURITY|PHASE_DECLARATIVE,
847 			SENDER_INITIATOR|SENDER_RECEIVER,
848 			login->req_buf,
849 			payload_length,
850 			conn);
851 	if (ret < 0)
852 		return -1;
853 
854 	if (ret > 0) {
855 		if (login->auth_complete) {
856 			pr_err("Initiator has already been"
857 				" successfully authenticated, but is still"
858 				" sending %s keys.\n", param->value);
859 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
860 					ISCSI_LOGIN_STATUS_INIT_ERR);
861 			return -1;
862 		}
863 
864 		goto do_auth;
865 	} else if (!payload_length) {
866 		pr_err("Initiator sent zero length security payload,"
867 		       " login failed\n");
868 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
869 				    ISCSI_LOGIN_STATUS_AUTH_FAILED);
870 		return -1;
871 	}
872 
873 	if (login->first_request)
874 		if (iscsi_target_check_first_request(conn, login) < 0)
875 			return -1;
876 
877 	ret = iscsi_encode_text_output(
878 			PHASE_SECURITY|PHASE_DECLARATIVE,
879 			SENDER_TARGET,
880 			login->rsp_buf,
881 			&login->rsp_length,
882 			conn->param_list,
883 			conn->tpg->tpg_attrib.login_keys_workaround);
884 	if (ret < 0)
885 		return -1;
886 
887 	if (!iscsi_check_negotiated_keys(conn->param_list)) {
888 		if (conn->tpg->tpg_attrib.authentication &&
889 		    !strncmp(param->value, NONE, 4)) {
890 			pr_err("Initiator sent AuthMethod=None but"
891 				" Target is enforcing iSCSI Authentication,"
892 					" login failed.\n");
893 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
894 					ISCSI_LOGIN_STATUS_AUTH_FAILED);
895 			return -1;
896 		}
897 
898 		if (conn->tpg->tpg_attrib.authentication &&
899 		    !login->auth_complete)
900 			return 0;
901 
902 		if (strncmp(param->value, NONE, 4) && !login->auth_complete)
903 			return 0;
904 
905 		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE1) &&
906 		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
907 			login_rsp->flags |= ISCSI_FLAG_LOGIN_NEXT_STAGE1 |
908 					    ISCSI_FLAG_LOGIN_TRANSIT;
909 			login->current_stage = 1;
910 		}
911 	}
912 
913 	return 0;
914 do_auth:
915 	return iscsi_target_do_authentication(conn, login);
916 }
917 
918 static int iscsi_target_handle_csg_one(struct iscsi_conn *conn, struct iscsi_login *login)
919 {
920 	int ret;
921 	u32 payload_length;
922 	struct iscsi_login_req *login_req;
923 	struct iscsi_login_rsp *login_rsp;
924 
925 	login_req = (struct iscsi_login_req *) login->req;
926 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
927 	payload_length = ntoh24(login_req->dlength);
928 
929 	ret = iscsi_decode_text_input(
930 			PHASE_OPERATIONAL|PHASE_DECLARATIVE,
931 			SENDER_INITIATOR|SENDER_RECEIVER,
932 			login->req_buf,
933 			payload_length,
934 			conn);
935 	if (ret < 0) {
936 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
937 				ISCSI_LOGIN_STATUS_INIT_ERR);
938 		return -1;
939 	}
940 
941 	if (login->first_request)
942 		if (iscsi_target_check_first_request(conn, login) < 0)
943 			return -1;
944 
945 	if (iscsi_target_check_for_existing_instances(conn, login) < 0)
946 		return -1;
947 
948 	ret = iscsi_encode_text_output(
949 			PHASE_OPERATIONAL|PHASE_DECLARATIVE,
950 			SENDER_TARGET,
951 			login->rsp_buf,
952 			&login->rsp_length,
953 			conn->param_list,
954 			conn->tpg->tpg_attrib.login_keys_workaround);
955 	if (ret < 0) {
956 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
957 				ISCSI_LOGIN_STATUS_INIT_ERR);
958 		return -1;
959 	}
960 
961 	if (!login->auth_complete &&
962 	     conn->tpg->tpg_attrib.authentication) {
963 		pr_err("Initiator is requesting CSG: 1, has not been"
964 			 " successfully authenticated, and the Target is"
965 			" enforcing iSCSI Authentication, login failed.\n");
966 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
967 				ISCSI_LOGIN_STATUS_AUTH_FAILED);
968 		return -1;
969 	}
970 
971 	if (!iscsi_check_negotiated_keys(conn->param_list))
972 		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE3) &&
973 		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT))
974 			login_rsp->flags |= ISCSI_FLAG_LOGIN_NEXT_STAGE3 |
975 					    ISCSI_FLAG_LOGIN_TRANSIT;
976 
977 	return 0;
978 }
979 
980 static int iscsi_target_do_login(struct iscsi_conn *conn, struct iscsi_login *login)
981 {
982 	int pdu_count = 0;
983 	struct iscsi_login_req *login_req;
984 	struct iscsi_login_rsp *login_rsp;
985 
986 	login_req = (struct iscsi_login_req *) login->req;
987 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
988 
989 	while (1) {
990 		if (++pdu_count > MAX_LOGIN_PDUS) {
991 			pr_err("MAX_LOGIN_PDUS count reached.\n");
992 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
993 					ISCSI_LOGIN_STATUS_TARGET_ERROR);
994 			return -1;
995 		}
996 
997 		switch (ISCSI_LOGIN_CURRENT_STAGE(login_req->flags)) {
998 		case 0:
999 			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK;
1000 			if (iscsi_target_handle_csg_zero(conn, login) < 0)
1001 				return -1;
1002 			break;
1003 		case 1:
1004 			login_rsp->flags |= ISCSI_FLAG_LOGIN_CURRENT_STAGE1;
1005 			if (iscsi_target_handle_csg_one(conn, login) < 0)
1006 				return -1;
1007 			if (login_rsp->flags & ISCSI_FLAG_LOGIN_TRANSIT) {
1008 				/*
1009 				 * Check to make sure the TCP connection has not
1010 				 * dropped asynchronously while session reinstatement
1011 				 * was occuring in this kthread context, before
1012 				 * transitioning to full feature phase operation.
1013 				 */
1014 				if (iscsi_target_sk_check_close(conn))
1015 					return -1;
1016 
1017 				login->tsih = conn->sess->tsih;
1018 				login->login_complete = 1;
1019 				iscsi_target_restore_sock_callbacks(conn);
1020 				if (iscsi_target_do_tx_login_io(conn,
1021 						login) < 0)
1022 					return -1;
1023 				return 1;
1024 			}
1025 			break;
1026 		default:
1027 			pr_err("Illegal CSG: %d received from"
1028 				" Initiator, protocol error.\n",
1029 				ISCSI_LOGIN_CURRENT_STAGE(login_req->flags));
1030 			break;
1031 		}
1032 
1033 		if (iscsi_target_do_tx_login_io(conn, login) < 0)
1034 			return -1;
1035 
1036 		if (login_rsp->flags & ISCSI_FLAG_LOGIN_TRANSIT) {
1037 			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_TRANSIT;
1038 			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK;
1039 		}
1040 		break;
1041 	}
1042 
1043 	return 0;
1044 }
1045 
1046 static void iscsi_initiatorname_tolower(
1047 	char *param_buf)
1048 {
1049 	char *c;
1050 	u32 iqn_size = strlen(param_buf), i;
1051 
1052 	for (i = 0; i < iqn_size; i++) {
1053 		c = &param_buf[i];
1054 		if (!isupper(*c))
1055 			continue;
1056 
1057 		*c = tolower(*c);
1058 	}
1059 }
1060 
1061 /*
1062  * Processes the first Login Request..
1063  */
1064 int iscsi_target_locate_portal(
1065 	struct iscsi_np *np,
1066 	struct iscsi_conn *conn,
1067 	struct iscsi_login *login)
1068 {
1069 	char *i_buf = NULL, *s_buf = NULL, *t_buf = NULL;
1070 	char *tmpbuf, *start = NULL, *end = NULL, *key, *value;
1071 	struct iscsi_session *sess = conn->sess;
1072 	struct iscsi_tiqn *tiqn;
1073 	struct iscsi_tpg_np *tpg_np = NULL;
1074 	struct iscsi_login_req *login_req;
1075 	struct se_node_acl *se_nacl;
1076 	u32 payload_length, queue_depth = 0;
1077 	int sessiontype = 0, ret = 0, tag_num, tag_size;
1078 
1079 	INIT_DELAYED_WORK(&conn->login_work, iscsi_target_do_login_rx);
1080 	iscsi_target_set_sock_callbacks(conn);
1081 
1082 	login->np = np;
1083 
1084 	login_req = (struct iscsi_login_req *) login->req;
1085 	payload_length = ntoh24(login_req->dlength);
1086 
1087 	tmpbuf = kzalloc(payload_length + 1, GFP_KERNEL);
1088 	if (!tmpbuf) {
1089 		pr_err("Unable to allocate memory for tmpbuf.\n");
1090 		return -1;
1091 	}
1092 
1093 	memcpy(tmpbuf, login->req_buf, payload_length);
1094 	tmpbuf[payload_length] = '\0';
1095 	start = tmpbuf;
1096 	end = (start + payload_length);
1097 
1098 	/*
1099 	 * Locate the initial keys expected from the Initiator node in
1100 	 * the first login request in order to progress with the login phase.
1101 	 */
1102 	while (start < end) {
1103 		if (iscsi_extract_key_value(start, &key, &value) < 0) {
1104 			ret = -1;
1105 			goto out;
1106 		}
1107 
1108 		if (!strncmp(key, "InitiatorName", 13))
1109 			i_buf = value;
1110 		else if (!strncmp(key, "SessionType", 11))
1111 			s_buf = value;
1112 		else if (!strncmp(key, "TargetName", 10))
1113 			t_buf = value;
1114 
1115 		start += strlen(key) + strlen(value) + 2;
1116 	}
1117 	/*
1118 	 * See 5.3.  Login Phase.
1119 	 */
1120 	if (!i_buf) {
1121 		pr_err("InitiatorName key not received"
1122 			" in first login request.\n");
1123 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1124 			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
1125 		ret = -1;
1126 		goto out;
1127 	}
1128 	/*
1129 	 * Convert the incoming InitiatorName to lowercase following
1130 	 * RFC-3720 3.2.6.1. section c) that says that iSCSI IQNs
1131 	 * are NOT case sensitive.
1132 	 */
1133 	iscsi_initiatorname_tolower(i_buf);
1134 
1135 	if (!s_buf) {
1136 		if (!login->leading_connection)
1137 			goto get_target;
1138 
1139 		pr_err("SessionType key not received"
1140 			" in first login request.\n");
1141 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1142 			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
1143 		ret = -1;
1144 		goto out;
1145 	}
1146 
1147 	/*
1148 	 * Use default portal group for discovery sessions.
1149 	 */
1150 	sessiontype = strncmp(s_buf, DISCOVERY, 9);
1151 	if (!sessiontype) {
1152 		conn->tpg = iscsit_global->discovery_tpg;
1153 		if (!login->leading_connection)
1154 			goto get_target;
1155 
1156 		sess->sess_ops->SessionType = 1;
1157 		/*
1158 		 * Setup crc32c modules from libcrypto
1159 		 */
1160 		if (iscsi_login_setup_crypto(conn) < 0) {
1161 			pr_err("iscsi_login_setup_crypto() failed\n");
1162 			ret = -1;
1163 			goto out;
1164 		}
1165 		/*
1166 		 * Serialize access across the discovery struct iscsi_portal_group to
1167 		 * process login attempt.
1168 		 */
1169 		if (iscsit_access_np(np, conn->tpg) < 0) {
1170 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1171 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
1172 			ret = -1;
1173 			goto out;
1174 		}
1175 		ret = 0;
1176 		goto alloc_tags;
1177 	}
1178 
1179 get_target:
1180 	if (!t_buf) {
1181 		pr_err("TargetName key not received"
1182 			" in first login request while"
1183 			" SessionType=Normal.\n");
1184 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1185 			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
1186 		ret = -1;
1187 		goto out;
1188 	}
1189 
1190 	/*
1191 	 * Locate Target IQN from Storage Node.
1192 	 */
1193 	tiqn = iscsit_get_tiqn_for_login(t_buf);
1194 	if (!tiqn) {
1195 		pr_err("Unable to locate Target IQN: %s in"
1196 			" Storage Node\n", t_buf);
1197 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1198 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
1199 		ret = -1;
1200 		goto out;
1201 	}
1202 	pr_debug("Located Storage Object: %s\n", tiqn->tiqn);
1203 
1204 	/*
1205 	 * Locate Target Portal Group from Storage Node.
1206 	 */
1207 	conn->tpg = iscsit_get_tpg_from_np(tiqn, np, &tpg_np);
1208 	if (!conn->tpg) {
1209 		pr_err("Unable to locate Target Portal Group"
1210 				" on %s\n", tiqn->tiqn);
1211 		iscsit_put_tiqn_for_login(tiqn);
1212 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1213 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
1214 		ret = -1;
1215 		goto out;
1216 	}
1217 	conn->tpg_np = tpg_np;
1218 	pr_debug("Located Portal Group Object: %hu\n", conn->tpg->tpgt);
1219 	/*
1220 	 * Setup crc32c modules from libcrypto
1221 	 */
1222 	if (iscsi_login_setup_crypto(conn) < 0) {
1223 		pr_err("iscsi_login_setup_crypto() failed\n");
1224 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
1225 		iscsit_put_tiqn_for_login(tiqn);
1226 		conn->tpg = NULL;
1227 		ret = -1;
1228 		goto out;
1229 	}
1230 	/*
1231 	 * Serialize access across the struct iscsi_portal_group to
1232 	 * process login attempt.
1233 	 */
1234 	if (iscsit_access_np(np, conn->tpg) < 0) {
1235 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
1236 		iscsit_put_tiqn_for_login(tiqn);
1237 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1238 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
1239 		conn->tpg = NULL;
1240 		ret = -1;
1241 		goto out;
1242 	}
1243 
1244 	/*
1245 	 * conn->sess->node_acl will be set when the referenced
1246 	 * struct iscsi_session is located from received ISID+TSIH in
1247 	 * iscsi_login_non_zero_tsih_s2().
1248 	 */
1249 	if (!login->leading_connection) {
1250 		ret = 0;
1251 		goto out;
1252 	}
1253 
1254 	/*
1255 	 * This value is required in iscsi_login_zero_tsih_s2()
1256 	 */
1257 	sess->sess_ops->SessionType = 0;
1258 
1259 	/*
1260 	 * Locate incoming Initiator IQN reference from Storage Node.
1261 	 */
1262 	sess->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1263 			&conn->tpg->tpg_se_tpg, i_buf);
1264 	if (!sess->se_sess->se_node_acl) {
1265 		pr_err("iSCSI Initiator Node: %s is not authorized to"
1266 			" access iSCSI target portal group: %hu.\n",
1267 				i_buf, conn->tpg->tpgt);
1268 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1269 				ISCSI_LOGIN_STATUS_TGT_FORBIDDEN);
1270 		ret = -1;
1271 		goto out;
1272 	}
1273 	se_nacl = sess->se_sess->se_node_acl;
1274 	queue_depth = se_nacl->queue_depth;
1275 	/*
1276 	 * Setup pre-allocated tags based upon allowed per NodeACL CmdSN
1277 	 * depth for non immediate commands, plus extra tags for immediate
1278 	 * commands.
1279 	 *
1280 	 * Also enforce a ISCSIT_MIN_TAGS to prevent unnecessary contention
1281 	 * in per-cpu-ida tag allocation logic + small queue_depth.
1282 	 */
1283 alloc_tags:
1284 	tag_num = max_t(u32, ISCSIT_MIN_TAGS, queue_depth);
1285 	tag_num = (tag_num * 2) + ISCSIT_EXTRA_TAGS;
1286 	tag_size = sizeof(struct iscsi_cmd) + conn->conn_transport->priv_size;
1287 
1288 	ret = transport_alloc_session_tags(sess->se_sess, tag_num, tag_size);
1289 	if (ret < 0) {
1290 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1291 				    ISCSI_LOGIN_STATUS_NO_RESOURCES);
1292 		ret = -1;
1293 	}
1294 out:
1295 	kfree(tmpbuf);
1296 	return ret;
1297 }
1298 
1299 int iscsi_target_start_negotiation(
1300 	struct iscsi_login *login,
1301 	struct iscsi_conn *conn)
1302 {
1303 	int ret;
1304 
1305 	if (conn->sock) {
1306 		struct sock *sk = conn->sock->sk;
1307 
1308 		write_lock_bh(&sk->sk_callback_lock);
1309 		set_bit(LOGIN_FLAGS_READY, &conn->login_flags);
1310 		set_bit(LOGIN_FLAGS_INITIAL_PDU, &conn->login_flags);
1311 		write_unlock_bh(&sk->sk_callback_lock);
1312 	}
1313 	/*
1314 	 * If iscsi_target_do_login returns zero to signal more PDU
1315 	 * exchanges are required to complete the login, go ahead and
1316 	 * clear LOGIN_FLAGS_INITIAL_PDU but only if the TCP connection
1317 	 * is still active.
1318 	 *
1319 	 * Otherwise if TCP connection dropped asynchronously, go ahead
1320 	 * and perform connection cleanup now.
1321 	 */
1322 	ret = iscsi_target_do_login(conn, login);
1323 	if (!ret && iscsi_target_sk_check_and_clear(conn, LOGIN_FLAGS_INITIAL_PDU))
1324 		ret = -1;
1325 
1326 	if (ret < 0) {
1327 		cancel_delayed_work_sync(&conn->login_work);
1328 		iscsi_target_restore_sock_callbacks(conn);
1329 		iscsi_remove_failed_auth_entry(conn);
1330 	}
1331 	if (ret != 0)
1332 		iscsi_target_nego_release(conn);
1333 
1334 	return ret;
1335 }
1336 
1337 void iscsi_target_nego_release(struct iscsi_conn *conn)
1338 {
1339 	struct iscsi_login *login = conn->conn_login;
1340 
1341 	if (!login)
1342 		return;
1343 
1344 	kfree(login->req_buf);
1345 	kfree(login->rsp_buf);
1346 	kfree(login);
1347 
1348 	conn->conn_login = NULL;
1349 }
1350