xref: /linux/drivers/target/iscsi/iscsi_target_nego.c (revision b8d312aa075f33282565467662c4628dae0a2aff)
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 FALSE\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 	rc = iscsi_target_do_login(conn, login);
629 	if (rc < 0) {
630 		goto err;
631 	} else if (!rc) {
632 		if (iscsi_target_sk_check_and_clear(conn, LOGIN_FLAGS_READ_ACTIVE))
633 			goto err;
634 	} else if (rc == 1) {
635 		iscsi_target_nego_release(conn);
636 		iscsi_post_login_handler(np, conn, zero_tsih);
637 		iscsit_deaccess_np(np, tpg, tpg_np);
638 	}
639 	return;
640 
641 err:
642 	iscsi_target_restore_sock_callbacks(conn);
643 	iscsi_target_login_drop(conn, login);
644 	iscsit_deaccess_np(np, tpg, tpg_np);
645 }
646 
647 static void iscsi_target_sk_state_change(struct sock *sk)
648 {
649 	struct iscsi_conn *conn;
650 	void (*orig_state_change)(struct sock *);
651 	bool state;
652 
653 	pr_debug("Entering iscsi_target_sk_state_change\n");
654 
655 	write_lock_bh(&sk->sk_callback_lock);
656 	conn = sk->sk_user_data;
657 	if (!conn) {
658 		write_unlock_bh(&sk->sk_callback_lock);
659 		return;
660 	}
661 	orig_state_change = conn->orig_state_change;
662 
663 	if (!test_bit(LOGIN_FLAGS_READY, &conn->login_flags)) {
664 		pr_debug("Got LOGIN_FLAGS_READY=0 sk_state_change conn: %p\n",
665 			 conn);
666 		write_unlock_bh(&sk->sk_callback_lock);
667 		orig_state_change(sk);
668 		return;
669 	}
670 	state = __iscsi_target_sk_check_close(sk);
671 	pr_debug("__iscsi_target_sk_close_change: state: %d\n", state);
672 
673 	if (test_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags)) {
674 		pr_debug("Got LOGIN_FLAGS_READ_ACTIVE=1 sk_state_change"
675 			 " conn: %p\n", conn);
676 		if (state)
677 			set_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags);
678 		write_unlock_bh(&sk->sk_callback_lock);
679 		orig_state_change(sk);
680 		return;
681 	}
682 	if (test_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags)) {
683 		pr_debug("Got LOGIN_FLAGS_CLOSED=1 sk_state_change conn: %p\n",
684 			 conn);
685 		write_unlock_bh(&sk->sk_callback_lock);
686 		orig_state_change(sk);
687 		return;
688 	}
689 	/*
690 	 * If the TCP connection has dropped, go ahead and set LOGIN_FLAGS_CLOSED,
691 	 * but only queue conn->login_work -> iscsi_target_do_login_rx()
692 	 * processing if LOGIN_FLAGS_INITIAL_PDU has already been cleared.
693 	 *
694 	 * When iscsi_target_do_login_rx() runs, iscsi_target_sk_check_close()
695 	 * will detect the dropped TCP connection from delayed workqueue context.
696 	 *
697 	 * If LOGIN_FLAGS_INITIAL_PDU is still set, which means the initial
698 	 * iscsi_target_start_negotiation() is running, iscsi_target_do_login()
699 	 * via iscsi_target_sk_check_close() or iscsi_target_start_negotiation()
700 	 * via iscsi_target_sk_check_and_clear() is responsible for detecting the
701 	 * dropped TCP connection in iscsi_np process context, and cleaning up
702 	 * the remaining iscsi connection resources.
703 	 */
704 	if (state) {
705 		pr_debug("iscsi_target_sk_state_change got failed state\n");
706 		set_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags);
707 		state = test_bit(LOGIN_FLAGS_INITIAL_PDU, &conn->login_flags);
708 		write_unlock_bh(&sk->sk_callback_lock);
709 
710 		orig_state_change(sk);
711 
712 		if (!state)
713 			schedule_delayed_work(&conn->login_work, 0);
714 		return;
715 	}
716 	write_unlock_bh(&sk->sk_callback_lock);
717 
718 	orig_state_change(sk);
719 }
720 
721 /*
722  *	NOTE: We check for existing sessions or connections AFTER the initiator
723  *	has been successfully authenticated in order to protect against faked
724  *	ISID/TSIH combinations.
725  */
726 static int iscsi_target_check_for_existing_instances(
727 	struct iscsi_conn *conn,
728 	struct iscsi_login *login)
729 {
730 	if (login->checked_for_existing)
731 		return 0;
732 
733 	login->checked_for_existing = 1;
734 
735 	if (!login->tsih)
736 		return iscsi_check_for_session_reinstatement(conn);
737 	else
738 		return iscsi_login_post_auth_non_zero_tsih(conn, login->cid,
739 				login->initial_exp_statsn);
740 }
741 
742 static int iscsi_target_do_authentication(
743 	struct iscsi_conn *conn,
744 	struct iscsi_login *login)
745 {
746 	int authret;
747 	u32 payload_length;
748 	struct iscsi_param *param;
749 	struct iscsi_login_req *login_req;
750 	struct iscsi_login_rsp *login_rsp;
751 
752 	login_req = (struct iscsi_login_req *) login->req;
753 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
754 	payload_length = ntoh24(login_req->dlength);
755 
756 	param = iscsi_find_param_from_key(AUTHMETHOD, conn->param_list);
757 	if (!param)
758 		return -1;
759 
760 	authret = iscsi_handle_authentication(
761 			conn,
762 			login->req_buf,
763 			login->rsp_buf,
764 			payload_length,
765 			&login->rsp_length,
766 			param->value);
767 	switch (authret) {
768 	case 0:
769 		pr_debug("Received OK response"
770 		" from LIO Authentication, continuing.\n");
771 		break;
772 	case 1:
773 		pr_debug("iSCSI security negotiation"
774 			" completed successfully.\n");
775 		login->auth_complete = 1;
776 		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE1) &&
777 		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
778 			login_rsp->flags |= (ISCSI_FLAG_LOGIN_NEXT_STAGE1 |
779 					     ISCSI_FLAG_LOGIN_TRANSIT);
780 			login->current_stage = 1;
781 		}
782 		return iscsi_target_check_for_existing_instances(
783 				conn, login);
784 	case 2:
785 		pr_err("Security negotiation"
786 			" failed.\n");
787 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
788 				ISCSI_LOGIN_STATUS_AUTH_FAILED);
789 		return -1;
790 	default:
791 		pr_err("Received unknown error %d from LIO"
792 				" Authentication\n", authret);
793 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
794 				ISCSI_LOGIN_STATUS_TARGET_ERROR);
795 		return -1;
796 	}
797 
798 	return 0;
799 }
800 
801 static int iscsi_target_handle_csg_zero(
802 	struct iscsi_conn *conn,
803 	struct iscsi_login *login)
804 {
805 	int ret;
806 	u32 payload_length;
807 	struct iscsi_param *param;
808 	struct iscsi_login_req *login_req;
809 	struct iscsi_login_rsp *login_rsp;
810 
811 	login_req = (struct iscsi_login_req *) login->req;
812 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
813 	payload_length = ntoh24(login_req->dlength);
814 
815 	param = iscsi_find_param_from_key(AUTHMETHOD, conn->param_list);
816 	if (!param)
817 		return -1;
818 
819 	ret = iscsi_decode_text_input(
820 			PHASE_SECURITY|PHASE_DECLARATIVE,
821 			SENDER_INITIATOR|SENDER_RECEIVER,
822 			login->req_buf,
823 			payload_length,
824 			conn);
825 	if (ret < 0)
826 		return -1;
827 
828 	if (ret > 0) {
829 		if (login->auth_complete) {
830 			pr_err("Initiator has already been"
831 				" successfully authenticated, but is still"
832 				" sending %s keys.\n", param->value);
833 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
834 					ISCSI_LOGIN_STATUS_INIT_ERR);
835 			return -1;
836 		}
837 
838 		goto do_auth;
839 	} else if (!payload_length) {
840 		pr_err("Initiator sent zero length security payload,"
841 		       " login failed\n");
842 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
843 				    ISCSI_LOGIN_STATUS_AUTH_FAILED);
844 		return -1;
845 	}
846 
847 	if (login->first_request)
848 		if (iscsi_target_check_first_request(conn, login) < 0)
849 			return -1;
850 
851 	ret = iscsi_encode_text_output(
852 			PHASE_SECURITY|PHASE_DECLARATIVE,
853 			SENDER_TARGET,
854 			login->rsp_buf,
855 			&login->rsp_length,
856 			conn->param_list,
857 			conn->tpg->tpg_attrib.login_keys_workaround);
858 	if (ret < 0)
859 		return -1;
860 
861 	if (!iscsi_check_negotiated_keys(conn->param_list)) {
862 		if (conn->tpg->tpg_attrib.authentication &&
863 		    !strncmp(param->value, NONE, 4)) {
864 			pr_err("Initiator sent AuthMethod=None but"
865 				" Target is enforcing iSCSI Authentication,"
866 					" login failed.\n");
867 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
868 					ISCSI_LOGIN_STATUS_AUTH_FAILED);
869 			return -1;
870 		}
871 
872 		if (conn->tpg->tpg_attrib.authentication &&
873 		    !login->auth_complete)
874 			return 0;
875 
876 		if (strncmp(param->value, NONE, 4) && !login->auth_complete)
877 			return 0;
878 
879 		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE1) &&
880 		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
881 			login_rsp->flags |= ISCSI_FLAG_LOGIN_NEXT_STAGE1 |
882 					    ISCSI_FLAG_LOGIN_TRANSIT;
883 			login->current_stage = 1;
884 		}
885 	}
886 
887 	return 0;
888 do_auth:
889 	return iscsi_target_do_authentication(conn, login);
890 }
891 
892 static int iscsi_target_handle_csg_one(struct iscsi_conn *conn, struct iscsi_login *login)
893 {
894 	int ret;
895 	u32 payload_length;
896 	struct iscsi_login_req *login_req;
897 	struct iscsi_login_rsp *login_rsp;
898 
899 	login_req = (struct iscsi_login_req *) login->req;
900 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
901 	payload_length = ntoh24(login_req->dlength);
902 
903 	ret = iscsi_decode_text_input(
904 			PHASE_OPERATIONAL|PHASE_DECLARATIVE,
905 			SENDER_INITIATOR|SENDER_RECEIVER,
906 			login->req_buf,
907 			payload_length,
908 			conn);
909 	if (ret < 0) {
910 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
911 				ISCSI_LOGIN_STATUS_INIT_ERR);
912 		return -1;
913 	}
914 
915 	if (login->first_request)
916 		if (iscsi_target_check_first_request(conn, login) < 0)
917 			return -1;
918 
919 	if (iscsi_target_check_for_existing_instances(conn, login) < 0)
920 		return -1;
921 
922 	ret = iscsi_encode_text_output(
923 			PHASE_OPERATIONAL|PHASE_DECLARATIVE,
924 			SENDER_TARGET,
925 			login->rsp_buf,
926 			&login->rsp_length,
927 			conn->param_list,
928 			conn->tpg->tpg_attrib.login_keys_workaround);
929 	if (ret < 0) {
930 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
931 				ISCSI_LOGIN_STATUS_INIT_ERR);
932 		return -1;
933 	}
934 
935 	if (!login->auth_complete &&
936 	     conn->tpg->tpg_attrib.authentication) {
937 		pr_err("Initiator is requesting CSG: 1, has not been"
938 			 " successfully authenticated, and the Target is"
939 			" enforcing iSCSI Authentication, login failed.\n");
940 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
941 				ISCSI_LOGIN_STATUS_AUTH_FAILED);
942 		return -1;
943 	}
944 
945 	if (!iscsi_check_negotiated_keys(conn->param_list))
946 		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE3) &&
947 		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT))
948 			login_rsp->flags |= ISCSI_FLAG_LOGIN_NEXT_STAGE3 |
949 					    ISCSI_FLAG_LOGIN_TRANSIT;
950 
951 	return 0;
952 }
953 
954 static int iscsi_target_do_login(struct iscsi_conn *conn, struct iscsi_login *login)
955 {
956 	int pdu_count = 0;
957 	struct iscsi_login_req *login_req;
958 	struct iscsi_login_rsp *login_rsp;
959 
960 	login_req = (struct iscsi_login_req *) login->req;
961 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
962 
963 	while (1) {
964 		if (++pdu_count > MAX_LOGIN_PDUS) {
965 			pr_err("MAX_LOGIN_PDUS count reached.\n");
966 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
967 					ISCSI_LOGIN_STATUS_TARGET_ERROR);
968 			return -1;
969 		}
970 
971 		switch (ISCSI_LOGIN_CURRENT_STAGE(login_req->flags)) {
972 		case 0:
973 			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK;
974 			if (iscsi_target_handle_csg_zero(conn, login) < 0)
975 				return -1;
976 			break;
977 		case 1:
978 			login_rsp->flags |= ISCSI_FLAG_LOGIN_CURRENT_STAGE1;
979 			if (iscsi_target_handle_csg_one(conn, login) < 0)
980 				return -1;
981 			if (login_rsp->flags & ISCSI_FLAG_LOGIN_TRANSIT) {
982 				/*
983 				 * Check to make sure the TCP connection has not
984 				 * dropped asynchronously while session reinstatement
985 				 * was occuring in this kthread context, before
986 				 * transitioning to full feature phase operation.
987 				 */
988 				if (iscsi_target_sk_check_close(conn))
989 					return -1;
990 
991 				login->tsih = conn->sess->tsih;
992 				login->login_complete = 1;
993 				iscsi_target_restore_sock_callbacks(conn);
994 				if (iscsi_target_do_tx_login_io(conn,
995 						login) < 0)
996 					return -1;
997 				return 1;
998 			}
999 			break;
1000 		default:
1001 			pr_err("Illegal CSG: %d received from"
1002 				" Initiator, protocol error.\n",
1003 				ISCSI_LOGIN_CURRENT_STAGE(login_req->flags));
1004 			break;
1005 		}
1006 
1007 		if (iscsi_target_do_tx_login_io(conn, login) < 0)
1008 			return -1;
1009 
1010 		if (login_rsp->flags & ISCSI_FLAG_LOGIN_TRANSIT) {
1011 			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_TRANSIT;
1012 			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK;
1013 		}
1014 		break;
1015 	}
1016 
1017 	return 0;
1018 }
1019 
1020 static void iscsi_initiatorname_tolower(
1021 	char *param_buf)
1022 {
1023 	char *c;
1024 	u32 iqn_size = strlen(param_buf), i;
1025 
1026 	for (i = 0; i < iqn_size; i++) {
1027 		c = &param_buf[i];
1028 		if (!isupper(*c))
1029 			continue;
1030 
1031 		*c = tolower(*c);
1032 	}
1033 }
1034 
1035 /*
1036  * Processes the first Login Request..
1037  */
1038 int iscsi_target_locate_portal(
1039 	struct iscsi_np *np,
1040 	struct iscsi_conn *conn,
1041 	struct iscsi_login *login)
1042 {
1043 	char *i_buf = NULL, *s_buf = NULL, *t_buf = NULL;
1044 	char *tmpbuf, *start = NULL, *end = NULL, *key, *value;
1045 	struct iscsi_session *sess = conn->sess;
1046 	struct iscsi_tiqn *tiqn;
1047 	struct iscsi_tpg_np *tpg_np = NULL;
1048 	struct iscsi_login_req *login_req;
1049 	struct se_node_acl *se_nacl;
1050 	u32 payload_length, queue_depth = 0;
1051 	int sessiontype = 0, ret = 0, tag_num, tag_size;
1052 
1053 	INIT_DELAYED_WORK(&conn->login_work, iscsi_target_do_login_rx);
1054 	iscsi_target_set_sock_callbacks(conn);
1055 
1056 	login->np = np;
1057 
1058 	login_req = (struct iscsi_login_req *) login->req;
1059 	payload_length = ntoh24(login_req->dlength);
1060 
1061 	tmpbuf = kzalloc(payload_length + 1, GFP_KERNEL);
1062 	if (!tmpbuf) {
1063 		pr_err("Unable to allocate memory for tmpbuf.\n");
1064 		return -1;
1065 	}
1066 
1067 	memcpy(tmpbuf, login->req_buf, payload_length);
1068 	tmpbuf[payload_length] = '\0';
1069 	start = tmpbuf;
1070 	end = (start + payload_length);
1071 
1072 	/*
1073 	 * Locate the initial keys expected from the Initiator node in
1074 	 * the first login request in order to progress with the login phase.
1075 	 */
1076 	while (start < end) {
1077 		if (iscsi_extract_key_value(start, &key, &value) < 0) {
1078 			ret = -1;
1079 			goto out;
1080 		}
1081 
1082 		if (!strncmp(key, "InitiatorName", 13))
1083 			i_buf = value;
1084 		else if (!strncmp(key, "SessionType", 11))
1085 			s_buf = value;
1086 		else if (!strncmp(key, "TargetName", 10))
1087 			t_buf = value;
1088 
1089 		start += strlen(key) + strlen(value) + 2;
1090 	}
1091 	/*
1092 	 * See 5.3.  Login Phase.
1093 	 */
1094 	if (!i_buf) {
1095 		pr_err("InitiatorName key not received"
1096 			" in first login request.\n");
1097 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1098 			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
1099 		ret = -1;
1100 		goto out;
1101 	}
1102 	/*
1103 	 * Convert the incoming InitiatorName to lowercase following
1104 	 * RFC-3720 3.2.6.1. section c) that says that iSCSI IQNs
1105 	 * are NOT case sensitive.
1106 	 */
1107 	iscsi_initiatorname_tolower(i_buf);
1108 
1109 	if (!s_buf) {
1110 		if (!login->leading_connection)
1111 			goto get_target;
1112 
1113 		pr_err("SessionType key not received"
1114 			" in first login request.\n");
1115 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1116 			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
1117 		ret = -1;
1118 		goto out;
1119 	}
1120 
1121 	/*
1122 	 * Use default portal group for discovery sessions.
1123 	 */
1124 	sessiontype = strncmp(s_buf, DISCOVERY, 9);
1125 	if (!sessiontype) {
1126 		conn->tpg = iscsit_global->discovery_tpg;
1127 		if (!login->leading_connection)
1128 			goto get_target;
1129 
1130 		sess->sess_ops->SessionType = 1;
1131 		/*
1132 		 * Setup crc32c modules from libcrypto
1133 		 */
1134 		if (iscsi_login_setup_crypto(conn) < 0) {
1135 			pr_err("iscsi_login_setup_crypto() failed\n");
1136 			ret = -1;
1137 			goto out;
1138 		}
1139 		/*
1140 		 * Serialize access across the discovery struct iscsi_portal_group to
1141 		 * process login attempt.
1142 		 */
1143 		if (iscsit_access_np(np, conn->tpg) < 0) {
1144 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1145 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
1146 			ret = -1;
1147 			goto out;
1148 		}
1149 		ret = 0;
1150 		goto alloc_tags;
1151 	}
1152 
1153 get_target:
1154 	if (!t_buf) {
1155 		pr_err("TargetName key not received"
1156 			" in first login request while"
1157 			" SessionType=Normal.\n");
1158 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1159 			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
1160 		ret = -1;
1161 		goto out;
1162 	}
1163 
1164 	/*
1165 	 * Locate Target IQN from Storage Node.
1166 	 */
1167 	tiqn = iscsit_get_tiqn_for_login(t_buf);
1168 	if (!tiqn) {
1169 		pr_err("Unable to locate Target IQN: %s in"
1170 			" Storage Node\n", t_buf);
1171 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1172 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
1173 		ret = -1;
1174 		goto out;
1175 	}
1176 	pr_debug("Located Storage Object: %s\n", tiqn->tiqn);
1177 
1178 	/*
1179 	 * Locate Target Portal Group from Storage Node.
1180 	 */
1181 	conn->tpg = iscsit_get_tpg_from_np(tiqn, np, &tpg_np);
1182 	if (!conn->tpg) {
1183 		pr_err("Unable to locate Target Portal Group"
1184 				" on %s\n", tiqn->tiqn);
1185 		iscsit_put_tiqn_for_login(tiqn);
1186 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1187 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
1188 		ret = -1;
1189 		goto out;
1190 	}
1191 	conn->tpg_np = tpg_np;
1192 	pr_debug("Located Portal Group Object: %hu\n", conn->tpg->tpgt);
1193 	/*
1194 	 * Setup crc32c modules from libcrypto
1195 	 */
1196 	if (iscsi_login_setup_crypto(conn) < 0) {
1197 		pr_err("iscsi_login_setup_crypto() failed\n");
1198 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
1199 		iscsit_put_tiqn_for_login(tiqn);
1200 		conn->tpg = NULL;
1201 		ret = -1;
1202 		goto out;
1203 	}
1204 	/*
1205 	 * Serialize access across the struct iscsi_portal_group to
1206 	 * process login attempt.
1207 	 */
1208 	if (iscsit_access_np(np, conn->tpg) < 0) {
1209 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
1210 		iscsit_put_tiqn_for_login(tiqn);
1211 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1212 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
1213 		conn->tpg = NULL;
1214 		ret = -1;
1215 		goto out;
1216 	}
1217 
1218 	/*
1219 	 * conn->sess->node_acl will be set when the referenced
1220 	 * struct iscsi_session is located from received ISID+TSIH in
1221 	 * iscsi_login_non_zero_tsih_s2().
1222 	 */
1223 	if (!login->leading_connection) {
1224 		ret = 0;
1225 		goto out;
1226 	}
1227 
1228 	/*
1229 	 * This value is required in iscsi_login_zero_tsih_s2()
1230 	 */
1231 	sess->sess_ops->SessionType = 0;
1232 
1233 	/*
1234 	 * Locate incoming Initiator IQN reference from Storage Node.
1235 	 */
1236 	sess->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1237 			&conn->tpg->tpg_se_tpg, i_buf);
1238 	if (!sess->se_sess->se_node_acl) {
1239 		pr_err("iSCSI Initiator Node: %s is not authorized to"
1240 			" access iSCSI target portal group: %hu.\n",
1241 				i_buf, conn->tpg->tpgt);
1242 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1243 				ISCSI_LOGIN_STATUS_TGT_FORBIDDEN);
1244 		ret = -1;
1245 		goto out;
1246 	}
1247 	se_nacl = sess->se_sess->se_node_acl;
1248 	queue_depth = se_nacl->queue_depth;
1249 	/*
1250 	 * Setup pre-allocated tags based upon allowed per NodeACL CmdSN
1251 	 * depth for non immediate commands, plus extra tags for immediate
1252 	 * commands.
1253 	 *
1254 	 * Also enforce a ISCSIT_MIN_TAGS to prevent unnecessary contention
1255 	 * in per-cpu-ida tag allocation logic + small queue_depth.
1256 	 */
1257 alloc_tags:
1258 	tag_num = max_t(u32, ISCSIT_MIN_TAGS, queue_depth);
1259 	tag_num = (tag_num * 2) + ISCSIT_EXTRA_TAGS;
1260 	tag_size = sizeof(struct iscsi_cmd) + conn->conn_transport->priv_size;
1261 
1262 	ret = transport_alloc_session_tags(sess->se_sess, tag_num, tag_size);
1263 	if (ret < 0) {
1264 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1265 				    ISCSI_LOGIN_STATUS_NO_RESOURCES);
1266 		ret = -1;
1267 	}
1268 out:
1269 	kfree(tmpbuf);
1270 	return ret;
1271 }
1272 
1273 int iscsi_target_start_negotiation(
1274 	struct iscsi_login *login,
1275 	struct iscsi_conn *conn)
1276 {
1277 	int ret;
1278 
1279 	if (conn->sock) {
1280 		struct sock *sk = conn->sock->sk;
1281 
1282 		write_lock_bh(&sk->sk_callback_lock);
1283 		set_bit(LOGIN_FLAGS_READY, &conn->login_flags);
1284 		set_bit(LOGIN_FLAGS_INITIAL_PDU, &conn->login_flags);
1285 		write_unlock_bh(&sk->sk_callback_lock);
1286 	}
1287 	/*
1288 	 * If iscsi_target_do_login returns zero to signal more PDU
1289 	 * exchanges are required to complete the login, go ahead and
1290 	 * clear LOGIN_FLAGS_INITIAL_PDU but only if the TCP connection
1291 	 * is still active.
1292 	 *
1293 	 * Otherwise if TCP connection dropped asynchronously, go ahead
1294 	 * and perform connection cleanup now.
1295 	 */
1296 	ret = iscsi_target_do_login(conn, login);
1297 	if (!ret && iscsi_target_sk_check_and_clear(conn, LOGIN_FLAGS_INITIAL_PDU))
1298 		ret = -1;
1299 
1300 	if (ret < 0) {
1301 		cancel_delayed_work_sync(&conn->login_work);
1302 		iscsi_target_restore_sock_callbacks(conn);
1303 		iscsi_remove_failed_auth_entry(conn);
1304 	}
1305 	if (ret != 0)
1306 		iscsi_target_nego_release(conn);
1307 
1308 	return ret;
1309 }
1310 
1311 void iscsi_target_nego_release(struct iscsi_conn *conn)
1312 {
1313 	struct iscsi_login *login = conn->conn_login;
1314 
1315 	if (!login)
1316 		return;
1317 
1318 	kfree(login->req_buf);
1319 	kfree(login->rsp_buf);
1320 	kfree(login);
1321 
1322 	conn->conn_login = NULL;
1323 }
1324