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 <trace/events/sock.h>
17 #include <scsi/iscsi_proto.h>
18 #include <target/target_core_base.h>
19 #include <target/target_core_fabric.h>
20 #include <target/iscsi/iscsi_transport.h>
21 
22 #include <target/iscsi/iscsi_target_core.h>
23 #include "iscsi_target_parameters.h"
24 #include "iscsi_target_login.h"
25 #include "iscsi_target_nego.h"
26 #include "iscsi_target_tpg.h"
27 #include "iscsi_target_util.h"
28 #include "iscsi_target.h"
29 #include "iscsi_target_auth.h"
30 
31 #define MAX_LOGIN_PDUS  7
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 -EINVAL;
67 
68 	ptr = strstr(in_buf, pattern);
69 	if (!ptr)
70 		return -ENOENT;
71 
72 	ptr = strstr(ptr, "=");
73 	if (!ptr)
74 		return -EINVAL;
75 
76 	ptr += 1;
77 	if (*ptr == '0' && (*(ptr+1) == 'x' || *(ptr+1) == 'X')) {
78 		ptr += 2; /* skip 0x */
79 		*type = HEX;
80 	} else if (*ptr == '0' && (*(ptr+1) == 'b' || *(ptr+1) == 'B')) {
81 		ptr += 2; /* skip 0b */
82 		*type = BASE64;
83 	} else
84 		*type = DECIMAL;
85 
86 	len = strlen_semi(ptr);
87 	if (len < 0)
88 		return -EINVAL;
89 
90 	if (len >= max_length) {
91 		pr_err("Length of input: %d exceeds max_length:"
92 			" %d\n", len, max_length);
93 		return -EINVAL;
94 	}
95 	memcpy(out_buf, ptr, len);
96 	out_buf[len] = '\0';
97 
98 	return 0;
99 }
100 
101 static struct iscsi_node_auth *iscsi_get_node_auth(struct iscsit_conn *conn)
102 {
103 	struct iscsi_portal_group *tpg;
104 	struct iscsi_node_acl *nacl;
105 	struct se_node_acl *se_nacl;
106 
107 	if (conn->sess->sess_ops->SessionType)
108 		return &iscsit_global->discovery_acl.node_auth;
109 
110 	se_nacl = conn->sess->se_sess->se_node_acl;
111 	if (!se_nacl) {
112 		pr_err("Unable to locate struct se_node_acl for CHAP auth\n");
113 		return NULL;
114 	}
115 
116 	if (se_nacl->dynamic_node_acl) {
117 		tpg = to_iscsi_tpg(se_nacl->se_tpg);
118 		return &tpg->tpg_demo_auth;
119 	}
120 
121 	nacl = to_iscsi_nacl(se_nacl);
122 
123 	return &nacl->node_auth;
124 }
125 
126 static u32 iscsi_handle_authentication(
127 	struct iscsit_conn *conn,
128 	char *in_buf,
129 	char *out_buf,
130 	int in_length,
131 	int *out_length,
132 	unsigned char *authtype)
133 {
134 	struct iscsi_node_auth *auth;
135 
136 	auth = iscsi_get_node_auth(conn);
137 	if (!auth)
138 		return -1;
139 
140 	if (strstr("CHAP", authtype))
141 		strcpy(conn->sess->auth_type, "CHAP");
142 	else
143 		strcpy(conn->sess->auth_type, NONE);
144 
145 	if (strstr("None", authtype))
146 		return 1;
147 	else if (strstr("CHAP", authtype))
148 		return chap_main_loop(conn, auth, in_buf, out_buf,
149 				&in_length, out_length);
150 	/* SRP, SPKM1, SPKM2 and KRB5 are unsupported */
151 	return 2;
152 }
153 
154 static void iscsi_remove_failed_auth_entry(struct iscsit_conn *conn)
155 {
156 	kfree(conn->auth_protocol);
157 }
158 
159 int iscsi_target_check_login_request(
160 	struct iscsit_conn *conn,
161 	struct iscsi_login *login)
162 {
163 	int req_csg, req_nsg;
164 	u32 payload_length;
165 	struct iscsi_login_req *login_req;
166 
167 	login_req = (struct iscsi_login_req *) login->req;
168 	payload_length = ntoh24(login_req->dlength);
169 
170 	switch (login_req->opcode & ISCSI_OPCODE_MASK) {
171 	case ISCSI_OP_LOGIN:
172 		break;
173 	default:
174 		pr_err("Received unknown opcode 0x%02x.\n",
175 				login_req->opcode & ISCSI_OPCODE_MASK);
176 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
177 				ISCSI_LOGIN_STATUS_INIT_ERR);
178 		return -1;
179 	}
180 
181 	if ((login_req->flags & ISCSI_FLAG_LOGIN_CONTINUE) &&
182 	    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
183 		pr_err("Login request has both ISCSI_FLAG_LOGIN_CONTINUE"
184 			" and ISCSI_FLAG_LOGIN_TRANSIT set, protocol error.\n");
185 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
186 				ISCSI_LOGIN_STATUS_INIT_ERR);
187 		return -1;
188 	}
189 
190 	req_csg = ISCSI_LOGIN_CURRENT_STAGE(login_req->flags);
191 	req_nsg = ISCSI_LOGIN_NEXT_STAGE(login_req->flags);
192 
193 	if (req_csg != login->current_stage) {
194 		pr_err("Initiator unexpectedly changed login stage"
195 			" from %d to %d, login failed.\n", login->current_stage,
196 			req_csg);
197 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
198 				ISCSI_LOGIN_STATUS_INIT_ERR);
199 		return -1;
200 	}
201 
202 	if ((req_nsg == 2) || (req_csg >= 2) ||
203 	   ((login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT) &&
204 	    (req_nsg <= req_csg))) {
205 		pr_err("Illegal login_req->flags Combination, CSG: %d,"
206 			" NSG: %d, ISCSI_FLAG_LOGIN_TRANSIT: %d.\n", req_csg,
207 			req_nsg, (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT));
208 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
209 				ISCSI_LOGIN_STATUS_INIT_ERR);
210 		return -1;
211 	}
212 
213 	if ((login_req->max_version != login->version_max) ||
214 	    (login_req->min_version != login->version_min)) {
215 		pr_err("Login request changed Version Max/Nin"
216 			" unexpectedly to 0x%02x/0x%02x, protocol error\n",
217 			login_req->max_version, login_req->min_version);
218 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
219 				ISCSI_LOGIN_STATUS_INIT_ERR);
220 		return -1;
221 	}
222 
223 	if (memcmp(login_req->isid, login->isid, 6) != 0) {
224 		pr_err("Login request changed ISID unexpectedly,"
225 				" protocol error.\n");
226 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
227 				ISCSI_LOGIN_STATUS_INIT_ERR);
228 		return -1;
229 	}
230 
231 	if (login_req->itt != login->init_task_tag) {
232 		pr_err("Login request changed ITT unexpectedly to"
233 			" 0x%08x, protocol error.\n", login_req->itt);
234 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
235 				ISCSI_LOGIN_STATUS_INIT_ERR);
236 		return -1;
237 	}
238 
239 	if (payload_length > MAX_KEY_VALUE_PAIRS) {
240 		pr_err("Login request payload exceeds default"
241 			" MaxRecvDataSegmentLength: %u, protocol error.\n",
242 				MAX_KEY_VALUE_PAIRS);
243 		return -1;
244 	}
245 
246 	return 0;
247 }
248 EXPORT_SYMBOL(iscsi_target_check_login_request);
249 
250 static int iscsi_target_check_first_request(
251 	struct iscsit_conn *conn,
252 	struct iscsi_login *login)
253 {
254 	struct iscsi_param *param = NULL;
255 	struct se_node_acl *se_nacl;
256 
257 	login->first_request = 0;
258 
259 	list_for_each_entry(param, &conn->param_list->param_list, p_list) {
260 		if (!strncmp(param->name, SESSIONTYPE, 11)) {
261 			if (!IS_PSTATE_ACCEPTOR(param)) {
262 				pr_err("SessionType key not received"
263 					" in first login request.\n");
264 				iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
265 					ISCSI_LOGIN_STATUS_MISSING_FIELDS);
266 				return -1;
267 			}
268 			if (!strncmp(param->value, DISCOVERY, 9))
269 				return 0;
270 		}
271 
272 		if (!strncmp(param->name, INITIATORNAME, 13)) {
273 			if (!IS_PSTATE_ACCEPTOR(param)) {
274 				if (!login->leading_connection)
275 					continue;
276 
277 				pr_err("InitiatorName key not received"
278 					" in first login request.\n");
279 				iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
280 					ISCSI_LOGIN_STATUS_MISSING_FIELDS);
281 				return -1;
282 			}
283 
284 			/*
285 			 * For non-leading connections, double check that the
286 			 * received InitiatorName matches the existing session's
287 			 * struct iscsi_node_acl.
288 			 */
289 			if (!login->leading_connection) {
290 				se_nacl = conn->sess->se_sess->se_node_acl;
291 				if (!se_nacl) {
292 					pr_err("Unable to locate"
293 						" struct se_node_acl\n");
294 					iscsit_tx_login_rsp(conn,
295 							ISCSI_STATUS_CLS_INITIATOR_ERR,
296 							ISCSI_LOGIN_STATUS_TGT_NOT_FOUND);
297 					return -1;
298 				}
299 
300 				if (strcmp(param->value,
301 						se_nacl->initiatorname)) {
302 					pr_err("Incorrect"
303 						" InitiatorName: %s for this"
304 						" iSCSI Initiator Node.\n",
305 						param->value);
306 					iscsit_tx_login_rsp(conn,
307 							ISCSI_STATUS_CLS_INITIATOR_ERR,
308 							ISCSI_LOGIN_STATUS_TGT_NOT_FOUND);
309 					return -1;
310 				}
311 			}
312 		}
313 	}
314 
315 	return 0;
316 }
317 
318 static int iscsi_target_do_tx_login_io(struct iscsit_conn *conn, struct iscsi_login *login)
319 {
320 	u32 padding = 0;
321 	struct iscsi_login_rsp *login_rsp;
322 
323 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
324 
325 	login_rsp->opcode		= ISCSI_OP_LOGIN_RSP;
326 	hton24(login_rsp->dlength, login->rsp_length);
327 	memcpy(login_rsp->isid, login->isid, 6);
328 	login_rsp->tsih			= cpu_to_be16(login->tsih);
329 	login_rsp->itt			= login->init_task_tag;
330 	login_rsp->statsn		= cpu_to_be32(conn->stat_sn++);
331 	login_rsp->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
332 	login_rsp->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
333 
334 	pr_debug("Sending Login Response, Flags: 0x%02x, ITT: 0x%08x,"
335 		" ExpCmdSN; 0x%08x, MaxCmdSN: 0x%08x, StatSN: 0x%08x, Length:"
336 		" %u\n", login_rsp->flags, (__force u32)login_rsp->itt,
337 		ntohl(login_rsp->exp_cmdsn), ntohl(login_rsp->max_cmdsn),
338 		ntohl(login_rsp->statsn), login->rsp_length);
339 
340 	padding = ((-login->rsp_length) & 3);
341 	/*
342 	 * Before sending the last login response containing the transition
343 	 * bit for full-feature-phase, go ahead and start up TX/RX threads
344 	 * now to avoid potential resource allocation failures after the
345 	 * final login response has been sent.
346 	 */
347 	if (login->login_complete) {
348 		int rc = iscsit_start_kthreads(conn);
349 		if (rc) {
350 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
351 					    ISCSI_LOGIN_STATUS_NO_RESOURCES);
352 			return -1;
353 		}
354 	}
355 
356 	if (conn->conn_transport->iscsit_put_login_tx(conn, login,
357 					login->rsp_length + padding) < 0)
358 		goto err;
359 
360 	login->rsp_length		= 0;
361 
362 	return 0;
363 
364 err:
365 	if (login->login_complete) {
366 		if (conn->rx_thread && conn->rx_thread_active) {
367 			send_sig(SIGINT, conn->rx_thread, 1);
368 			complete(&conn->rx_login_comp);
369 			kthread_stop(conn->rx_thread);
370 		}
371 		if (conn->tx_thread && conn->tx_thread_active) {
372 			send_sig(SIGINT, conn->tx_thread, 1);
373 			kthread_stop(conn->tx_thread);
374 		}
375 		spin_lock(&iscsit_global->ts_bitmap_lock);
376 		bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
377 				      get_order(1));
378 		spin_unlock(&iscsit_global->ts_bitmap_lock);
379 	}
380 	return -1;
381 }
382 
383 static void iscsi_target_sk_data_ready(struct sock *sk)
384 {
385 	struct iscsit_conn *conn = sk->sk_user_data;
386 	bool rc;
387 
388 	trace_sk_data_ready(sk);
389 	pr_debug("Entering iscsi_target_sk_data_ready: conn: %p\n", conn);
390 
391 	write_lock_bh(&sk->sk_callback_lock);
392 	if (!sk->sk_user_data) {
393 		write_unlock_bh(&sk->sk_callback_lock);
394 		return;
395 	}
396 	if (!test_bit(LOGIN_FLAGS_READY, &conn->login_flags)) {
397 		write_unlock_bh(&sk->sk_callback_lock);
398 		pr_debug("Got LOGIN_FLAGS_READY=0, conn: %p >>>>\n", conn);
399 		return;
400 	}
401 	if (test_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags)) {
402 		write_unlock_bh(&sk->sk_callback_lock);
403 		pr_debug("Got LOGIN_FLAGS_CLOSED=1, conn: %p >>>>\n", conn);
404 		return;
405 	}
406 	if (test_and_set_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags)) {
407 		write_unlock_bh(&sk->sk_callback_lock);
408 		pr_debug("Got LOGIN_FLAGS_READ_ACTIVE=1, conn: %p >>>>\n", conn);
409 		if (iscsi_target_sk_data_ready == conn->orig_data_ready)
410 			return;
411 		conn->orig_data_ready(sk);
412 		return;
413 	}
414 
415 	rc = schedule_delayed_work(&conn->login_work, 0);
416 	if (!rc) {
417 		pr_debug("iscsi_target_sk_data_ready, schedule_delayed_work"
418 			 " got false\n");
419 	}
420 	write_unlock_bh(&sk->sk_callback_lock);
421 }
422 
423 static void iscsi_target_sk_state_change(struct sock *);
424 
425 static void iscsi_target_set_sock_callbacks(struct iscsit_conn *conn)
426 {
427 	struct sock *sk;
428 
429 	if (!conn->sock)
430 		return;
431 
432 	sk = conn->sock->sk;
433 	pr_debug("Entering iscsi_target_set_sock_callbacks: conn: %p\n", conn);
434 
435 	write_lock_bh(&sk->sk_callback_lock);
436 	sk->sk_user_data = conn;
437 	conn->orig_data_ready = sk->sk_data_ready;
438 	conn->orig_state_change = sk->sk_state_change;
439 	sk->sk_data_ready = iscsi_target_sk_data_ready;
440 	sk->sk_state_change = iscsi_target_sk_state_change;
441 	write_unlock_bh(&sk->sk_callback_lock);
442 
443 	sk->sk_sndtimeo = TA_LOGIN_TIMEOUT * HZ;
444 	sk->sk_rcvtimeo = TA_LOGIN_TIMEOUT * HZ;
445 }
446 
447 static void iscsi_target_restore_sock_callbacks(struct iscsit_conn *conn)
448 {
449 	struct sock *sk;
450 
451 	if (!conn->sock)
452 		return;
453 
454 	sk = conn->sock->sk;
455 	pr_debug("Entering iscsi_target_restore_sock_callbacks: conn: %p\n", conn);
456 
457 	write_lock_bh(&sk->sk_callback_lock);
458 	if (!sk->sk_user_data) {
459 		write_unlock_bh(&sk->sk_callback_lock);
460 		return;
461 	}
462 	sk->sk_user_data = NULL;
463 	sk->sk_data_ready = conn->orig_data_ready;
464 	sk->sk_state_change = conn->orig_state_change;
465 	write_unlock_bh(&sk->sk_callback_lock);
466 
467 	sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
468 	sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;
469 }
470 
471 static int iscsi_target_do_login(struct iscsit_conn *, struct iscsi_login *);
472 
473 static bool __iscsi_target_sk_check_close(struct sock *sk)
474 {
475 	if (sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) {
476 		pr_debug("__iscsi_target_sk_check_close: TCP_CLOSE_WAIT|TCP_CLOSE,"
477 			"returning TRUE\n");
478 		return true;
479 	}
480 	return false;
481 }
482 
483 static bool iscsi_target_sk_check_close(struct iscsit_conn *conn)
484 {
485 	bool state = false;
486 
487 	if (conn->sock) {
488 		struct sock *sk = conn->sock->sk;
489 
490 		read_lock_bh(&sk->sk_callback_lock);
491 		state = (__iscsi_target_sk_check_close(sk) ||
492 			 test_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags));
493 		read_unlock_bh(&sk->sk_callback_lock);
494 	}
495 	return state;
496 }
497 
498 static bool iscsi_target_sk_check_flag(struct iscsit_conn *conn, unsigned int flag)
499 {
500 	bool state = false;
501 
502 	if (conn->sock) {
503 		struct sock *sk = conn->sock->sk;
504 
505 		read_lock_bh(&sk->sk_callback_lock);
506 		state = test_bit(flag, &conn->login_flags);
507 		read_unlock_bh(&sk->sk_callback_lock);
508 	}
509 	return state;
510 }
511 
512 static bool iscsi_target_sk_check_and_clear(struct iscsit_conn *conn, unsigned int flag)
513 {
514 	bool state = false;
515 
516 	if (conn->sock) {
517 		struct sock *sk = conn->sock->sk;
518 
519 		write_lock_bh(&sk->sk_callback_lock);
520 		state = (__iscsi_target_sk_check_close(sk) ||
521 			 test_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags));
522 		if (!state)
523 			clear_bit(flag, &conn->login_flags);
524 		write_unlock_bh(&sk->sk_callback_lock);
525 	}
526 	return state;
527 }
528 
529 static void iscsi_target_login_drop(struct iscsit_conn *conn, struct iscsi_login *login)
530 {
531 	bool zero_tsih = login->zero_tsih;
532 
533 	iscsi_remove_failed_auth_entry(conn);
534 	iscsi_target_nego_release(conn);
535 	iscsi_target_login_sess_out(conn, zero_tsih, true);
536 }
537 
538 static void iscsi_target_do_login_rx(struct work_struct *work)
539 {
540 	struct iscsit_conn *conn = container_of(work,
541 				struct iscsit_conn, login_work.work);
542 	struct iscsi_login *login = conn->login;
543 	struct iscsi_np *np = login->np;
544 	struct iscsi_portal_group *tpg = conn->tpg;
545 	struct iscsi_tpg_np *tpg_np = conn->tpg_np;
546 	int rc, zero_tsih = login->zero_tsih;
547 	bool state;
548 
549 	pr_debug("entering iscsi_target_do_login_rx, conn: %p, %s:%d\n",
550 			conn, current->comm, current->pid);
551 
552 	spin_lock(&conn->login_worker_lock);
553 	set_bit(LOGIN_FLAGS_WORKER_RUNNING, &conn->login_flags);
554 	spin_unlock(&conn->login_worker_lock);
555 	/*
556 	 * If iscsi_target_do_login_rx() has been invoked by ->sk_data_ready()
557 	 * before initial PDU processing in iscsi_target_start_negotiation()
558 	 * has completed, go ahead and retry until it's cleared.
559 	 *
560 	 * Otherwise if the TCP connection drops while this is occuring,
561 	 * iscsi_target_start_negotiation() will detect the failure, call
562 	 * cancel_delayed_work_sync(&conn->login_work), and cleanup the
563 	 * remaining iscsi connection resources from iscsi_np process context.
564 	 */
565 	if (iscsi_target_sk_check_flag(conn, LOGIN_FLAGS_INITIAL_PDU)) {
566 		schedule_delayed_work(&conn->login_work, msecs_to_jiffies(10));
567 		return;
568 	}
569 
570 	spin_lock(&tpg->tpg_state_lock);
571 	state = (tpg->tpg_state == TPG_STATE_ACTIVE);
572 	spin_unlock(&tpg->tpg_state_lock);
573 
574 	if (!state) {
575 		pr_debug("iscsi_target_do_login_rx: tpg_state != TPG_STATE_ACTIVE\n");
576 		goto err;
577 	}
578 
579 	if (iscsi_target_sk_check_close(conn)) {
580 		pr_debug("iscsi_target_do_login_rx, TCP state CLOSE\n");
581 		goto err;
582 	}
583 
584 	allow_signal(SIGINT);
585 	rc = iscsit_set_login_timer_kworker(conn, current);
586 	if (rc < 0) {
587 		/* The login timer has already expired */
588 		pr_debug("iscsi_target_do_login_rx, login failed\n");
589 		goto err;
590 	}
591 
592 	rc = conn->conn_transport->iscsit_get_login_rx(conn, login);
593 	flush_signals(current);
594 
595 	if (rc < 0)
596 		goto err;
597 
598 	pr_debug("iscsi_target_do_login_rx after rx_login_io, %p, %s:%d\n",
599 			conn, current->comm, current->pid);
600 
601 	/*
602 	 * LOGIN_FLAGS_READ_ACTIVE is cleared so that sk_data_ready
603 	 * could be triggered again after this.
604 	 *
605 	 * LOGIN_FLAGS_WRITE_ACTIVE is cleared after we successfully
606 	 * process a login PDU, so that sk_state_chage can do login
607 	 * cleanup as needed if the socket is closed. If a delayed work is
608 	 * ongoing (LOGIN_FLAGS_WRITE_ACTIVE or LOGIN_FLAGS_READ_ACTIVE),
609 	 * sk_state_change will leave the cleanup to the delayed work or
610 	 * it will schedule a delayed work to do cleanup.
611 	 */
612 	if (conn->sock) {
613 		struct sock *sk = conn->sock->sk;
614 
615 		write_lock_bh(&sk->sk_callback_lock);
616 		if (!test_bit(LOGIN_FLAGS_INITIAL_PDU, &conn->login_flags)) {
617 			clear_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags);
618 			set_bit(LOGIN_FLAGS_WRITE_ACTIVE, &conn->login_flags);
619 		}
620 		write_unlock_bh(&sk->sk_callback_lock);
621 	}
622 
623 	rc = iscsi_target_do_login(conn, login);
624 	if (rc < 0) {
625 		goto err;
626 	} else if (!rc) {
627 		if (iscsi_target_sk_check_and_clear(conn,
628 						    LOGIN_FLAGS_WRITE_ACTIVE))
629 			goto err;
630 
631 		/*
632 		 * Set the login timer thread pointer to NULL to prevent the
633 		 * login process from getting stuck if the initiator
634 		 * stops sending data.
635 		 */
636 		rc = iscsit_set_login_timer_kworker(conn, NULL);
637 		if (rc < 0)
638 			goto err;
639 	} else if (rc == 1) {
640 		iscsit_stop_login_timer(conn);
641 		cancel_delayed_work(&conn->login_work);
642 		iscsi_target_nego_release(conn);
643 		iscsi_post_login_handler(np, conn, zero_tsih);
644 		iscsit_deaccess_np(np, tpg, tpg_np);
645 	}
646 	return;
647 
648 err:
649 	iscsi_target_restore_sock_callbacks(conn);
650 	iscsit_stop_login_timer(conn);
651 	cancel_delayed_work(&conn->login_work);
652 	iscsi_target_login_drop(conn, login);
653 	iscsit_deaccess_np(np, tpg, tpg_np);
654 }
655 
656 static void iscsi_target_sk_state_change(struct sock *sk)
657 {
658 	struct iscsit_conn *conn;
659 	void (*orig_state_change)(struct sock *);
660 	bool state;
661 
662 	pr_debug("Entering iscsi_target_sk_state_change\n");
663 
664 	write_lock_bh(&sk->sk_callback_lock);
665 	conn = sk->sk_user_data;
666 	if (!conn) {
667 		write_unlock_bh(&sk->sk_callback_lock);
668 		return;
669 	}
670 	orig_state_change = conn->orig_state_change;
671 
672 	if (!test_bit(LOGIN_FLAGS_READY, &conn->login_flags)) {
673 		pr_debug("Got LOGIN_FLAGS_READY=0 sk_state_change conn: %p\n",
674 			 conn);
675 		write_unlock_bh(&sk->sk_callback_lock);
676 		orig_state_change(sk);
677 		return;
678 	}
679 	state = __iscsi_target_sk_check_close(sk);
680 	pr_debug("__iscsi_target_sk_close_change: state: %d\n", state);
681 
682 	if (test_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags) ||
683 	    test_bit(LOGIN_FLAGS_WRITE_ACTIVE, &conn->login_flags)) {
684 		pr_debug("Got LOGIN_FLAGS_{READ|WRITE}_ACTIVE=1"
685 			 " sk_state_change conn: %p\n", conn);
686 		if (state)
687 			set_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags);
688 		write_unlock_bh(&sk->sk_callback_lock);
689 		orig_state_change(sk);
690 		return;
691 	}
692 	if (test_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags)) {
693 		pr_debug("Got LOGIN_FLAGS_CLOSED=1 sk_state_change conn: %p\n",
694 			 conn);
695 		write_unlock_bh(&sk->sk_callback_lock);
696 		orig_state_change(sk);
697 		return;
698 	}
699 	/*
700 	 * If the TCP connection has dropped, go ahead and set LOGIN_FLAGS_CLOSED,
701 	 * but only queue conn->login_work -> iscsi_target_do_login_rx()
702 	 * processing if LOGIN_FLAGS_INITIAL_PDU has already been cleared.
703 	 *
704 	 * When iscsi_target_do_login_rx() runs, iscsi_target_sk_check_close()
705 	 * will detect the dropped TCP connection from delayed workqueue context.
706 	 *
707 	 * If LOGIN_FLAGS_INITIAL_PDU is still set, which means the initial
708 	 * iscsi_target_start_negotiation() is running, iscsi_target_do_login()
709 	 * via iscsi_target_sk_check_close() or iscsi_target_start_negotiation()
710 	 * via iscsi_target_sk_check_and_clear() is responsible for detecting the
711 	 * dropped TCP connection in iscsi_np process context, and cleaning up
712 	 * the remaining iscsi connection resources.
713 	 */
714 	if (state) {
715 		pr_debug("iscsi_target_sk_state_change got failed state\n");
716 		set_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags);
717 		state = test_bit(LOGIN_FLAGS_INITIAL_PDU, &conn->login_flags);
718 		write_unlock_bh(&sk->sk_callback_lock);
719 
720 		orig_state_change(sk);
721 
722 		if (!state)
723 			schedule_delayed_work(&conn->login_work, 0);
724 		return;
725 	}
726 	write_unlock_bh(&sk->sk_callback_lock);
727 
728 	orig_state_change(sk);
729 }
730 
731 /*
732  *	NOTE: We check for existing sessions or connections AFTER the initiator
733  *	has been successfully authenticated in order to protect against faked
734  *	ISID/TSIH combinations.
735  */
736 static int iscsi_target_check_for_existing_instances(
737 	struct iscsit_conn *conn,
738 	struct iscsi_login *login)
739 {
740 	if (login->checked_for_existing)
741 		return 0;
742 
743 	login->checked_for_existing = 1;
744 
745 	if (!login->tsih)
746 		return iscsi_check_for_session_reinstatement(conn);
747 	else
748 		return iscsi_login_post_auth_non_zero_tsih(conn, login->cid,
749 				login->initial_exp_statsn);
750 }
751 
752 static int iscsi_target_do_authentication(
753 	struct iscsit_conn *conn,
754 	struct iscsi_login *login)
755 {
756 	int authret;
757 	u32 payload_length;
758 	struct iscsi_param *param;
759 	struct iscsi_login_req *login_req;
760 	struct iscsi_login_rsp *login_rsp;
761 
762 	login_req = (struct iscsi_login_req *) login->req;
763 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
764 	payload_length = ntoh24(login_req->dlength);
765 
766 	param = iscsi_find_param_from_key(AUTHMETHOD, conn->param_list);
767 	if (!param)
768 		return -1;
769 
770 	authret = iscsi_handle_authentication(
771 			conn,
772 			login->req_buf,
773 			login->rsp_buf,
774 			payload_length,
775 			&login->rsp_length,
776 			param->value);
777 	switch (authret) {
778 	case 0:
779 		pr_debug("Received OK response"
780 		" from LIO Authentication, continuing.\n");
781 		break;
782 	case 1:
783 		pr_debug("iSCSI security negotiation"
784 			" completed successfully.\n");
785 		login->auth_complete = 1;
786 		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE1) &&
787 		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
788 			login_rsp->flags |= (ISCSI_FLAG_LOGIN_NEXT_STAGE1 |
789 					     ISCSI_FLAG_LOGIN_TRANSIT);
790 			login->current_stage = 1;
791 		}
792 		return iscsi_target_check_for_existing_instances(
793 				conn, login);
794 	case 2:
795 		pr_err("Security negotiation"
796 			" failed.\n");
797 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
798 				ISCSI_LOGIN_STATUS_AUTH_FAILED);
799 		return -1;
800 	default:
801 		pr_err("Received unknown error %d from LIO"
802 				" Authentication\n", authret);
803 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
804 				ISCSI_LOGIN_STATUS_TARGET_ERROR);
805 		return -1;
806 	}
807 
808 	return 0;
809 }
810 
811 bool iscsi_conn_auth_required(struct iscsit_conn *conn)
812 {
813 	struct iscsi_node_acl *nacl;
814 	struct se_node_acl *se_nacl;
815 
816 	if (conn->sess->sess_ops->SessionType) {
817 		/*
818 		 * For SessionType=Discovery
819 		 */
820 		return conn->tpg->tpg_attrib.authentication;
821 	}
822 	/*
823 	 * For SessionType=Normal
824 	 */
825 	se_nacl = conn->sess->se_sess->se_node_acl;
826 	if (!se_nacl) {
827 		pr_debug("Unknown ACL is trying to connect\n");
828 		return true;
829 	}
830 
831 	if (se_nacl->dynamic_node_acl) {
832 		pr_debug("Dynamic ACL %s is trying to connect\n",
833 			 se_nacl->initiatorname);
834 		return conn->tpg->tpg_attrib.authentication;
835 	}
836 
837 	pr_debug("Known ACL %s is trying to connect\n",
838 		 se_nacl->initiatorname);
839 
840 	nacl = to_iscsi_nacl(se_nacl);
841 	if (nacl->node_attrib.authentication == NA_AUTHENTICATION_INHERITED)
842 		return conn->tpg->tpg_attrib.authentication;
843 
844 	return nacl->node_attrib.authentication;
845 }
846 
847 static int iscsi_target_handle_csg_zero(
848 	struct iscsit_conn *conn,
849 	struct iscsi_login *login)
850 {
851 	int ret;
852 	u32 payload_length;
853 	struct iscsi_param *param;
854 	struct iscsi_login_req *login_req;
855 	struct iscsi_login_rsp *login_rsp;
856 
857 	login_req = (struct iscsi_login_req *) login->req;
858 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
859 	payload_length = ntoh24(login_req->dlength);
860 
861 	param = iscsi_find_param_from_key(AUTHMETHOD, conn->param_list);
862 	if (!param)
863 		return -1;
864 
865 	ret = iscsi_decode_text_input(
866 			PHASE_SECURITY|PHASE_DECLARATIVE,
867 			SENDER_INITIATOR|SENDER_RECEIVER,
868 			login->req_buf,
869 			payload_length,
870 			conn);
871 	if (ret < 0)
872 		return -1;
873 
874 	if (ret > 0) {
875 		if (login->auth_complete) {
876 			pr_err("Initiator has already been"
877 				" successfully authenticated, but is still"
878 				" sending %s keys.\n", param->value);
879 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
880 					ISCSI_LOGIN_STATUS_INIT_ERR);
881 			return -1;
882 		}
883 
884 		goto do_auth;
885 	} else if (!payload_length) {
886 		pr_err("Initiator sent zero length security payload,"
887 		       " login failed\n");
888 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
889 				    ISCSI_LOGIN_STATUS_AUTH_FAILED);
890 		return -1;
891 	}
892 
893 	if (login->first_request)
894 		if (iscsi_target_check_first_request(conn, login) < 0)
895 			return -1;
896 
897 	ret = iscsi_encode_text_output(
898 			PHASE_SECURITY|PHASE_DECLARATIVE,
899 			SENDER_TARGET,
900 			login->rsp_buf,
901 			&login->rsp_length,
902 			conn->param_list,
903 			conn->tpg->tpg_attrib.login_keys_workaround);
904 	if (ret < 0)
905 		return -1;
906 
907 	if (!iscsi_check_negotiated_keys(conn->param_list)) {
908 		bool auth_required = iscsi_conn_auth_required(conn);
909 
910 		if (auth_required) {
911 			if (!strncmp(param->value, NONE, 4)) {
912 				pr_err("Initiator sent AuthMethod=None but"
913 				       " Target is enforcing iSCSI Authentication,"
914 				       " login failed.\n");
915 				iscsit_tx_login_rsp(conn,
916 						ISCSI_STATUS_CLS_INITIATOR_ERR,
917 						ISCSI_LOGIN_STATUS_AUTH_FAILED);
918 				return -1;
919 			}
920 
921 			if (!login->auth_complete)
922 				return 0;
923 
924 			if (strncmp(param->value, NONE, 4) &&
925 			    !login->auth_complete)
926 				return 0;
927 		}
928 
929 		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE1) &&
930 		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
931 			login_rsp->flags |= ISCSI_FLAG_LOGIN_NEXT_STAGE1 |
932 					    ISCSI_FLAG_LOGIN_TRANSIT;
933 			login->current_stage = 1;
934 		}
935 	}
936 
937 	return 0;
938 do_auth:
939 	return iscsi_target_do_authentication(conn, login);
940 }
941 
942 static bool iscsi_conn_authenticated(struct iscsit_conn *conn,
943 				     struct iscsi_login *login)
944 {
945 	if (!iscsi_conn_auth_required(conn))
946 		return true;
947 
948 	if (login->auth_complete)
949 		return true;
950 
951 	return false;
952 }
953 
954 static int iscsi_target_handle_csg_one(struct iscsit_conn *conn, struct iscsi_login *login)
955 {
956 	int ret;
957 	u32 payload_length;
958 	struct iscsi_login_req *login_req;
959 	struct iscsi_login_rsp *login_rsp;
960 
961 	login_req = (struct iscsi_login_req *) login->req;
962 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
963 	payload_length = ntoh24(login_req->dlength);
964 
965 	ret = iscsi_decode_text_input(
966 			PHASE_OPERATIONAL|PHASE_DECLARATIVE,
967 			SENDER_INITIATOR|SENDER_RECEIVER,
968 			login->req_buf,
969 			payload_length,
970 			conn);
971 	if (ret < 0) {
972 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
973 				ISCSI_LOGIN_STATUS_INIT_ERR);
974 		return -1;
975 	}
976 
977 	if (login->first_request)
978 		if (iscsi_target_check_first_request(conn, login) < 0)
979 			return -1;
980 
981 	if (iscsi_target_check_for_existing_instances(conn, login) < 0)
982 		return -1;
983 
984 	ret = iscsi_encode_text_output(
985 			PHASE_OPERATIONAL|PHASE_DECLARATIVE,
986 			SENDER_TARGET,
987 			login->rsp_buf,
988 			&login->rsp_length,
989 			conn->param_list,
990 			conn->tpg->tpg_attrib.login_keys_workaround);
991 	if (ret < 0) {
992 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
993 				ISCSI_LOGIN_STATUS_INIT_ERR);
994 		return -1;
995 	}
996 
997 	if (!iscsi_conn_authenticated(conn, login)) {
998 		pr_err("Initiator is requesting CSG: 1, has not been"
999 		       " successfully authenticated, and the Target is"
1000 		       " enforcing iSCSI Authentication, login failed.\n");
1001 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1002 				ISCSI_LOGIN_STATUS_AUTH_FAILED);
1003 		return -1;
1004 	}
1005 
1006 	if (!iscsi_check_negotiated_keys(conn->param_list))
1007 		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE3) &&
1008 		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT))
1009 			login_rsp->flags |= ISCSI_FLAG_LOGIN_NEXT_STAGE3 |
1010 					    ISCSI_FLAG_LOGIN_TRANSIT;
1011 
1012 	return 0;
1013 }
1014 
1015 /*
1016  * RETURN VALUE:
1017  *
1018  *  1 = Login successful
1019  * -1 = Login failed
1020  *  0 = More PDU exchanges required
1021  */
1022 static int iscsi_target_do_login(struct iscsit_conn *conn, struct iscsi_login *login)
1023 {
1024 	int pdu_count = 0;
1025 	struct iscsi_login_req *login_req;
1026 	struct iscsi_login_rsp *login_rsp;
1027 
1028 	login_req = (struct iscsi_login_req *) login->req;
1029 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
1030 
1031 	while (1) {
1032 		if (++pdu_count > MAX_LOGIN_PDUS) {
1033 			pr_err("MAX_LOGIN_PDUS count reached.\n");
1034 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1035 					ISCSI_LOGIN_STATUS_TARGET_ERROR);
1036 			return -1;
1037 		}
1038 
1039 		switch (ISCSI_LOGIN_CURRENT_STAGE(login_req->flags)) {
1040 		case 0:
1041 			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK;
1042 			if (iscsi_target_handle_csg_zero(conn, login) < 0)
1043 				return -1;
1044 			break;
1045 		case 1:
1046 			login_rsp->flags |= ISCSI_FLAG_LOGIN_CURRENT_STAGE1;
1047 			if (iscsi_target_handle_csg_one(conn, login) < 0)
1048 				return -1;
1049 			if (login_rsp->flags & ISCSI_FLAG_LOGIN_TRANSIT) {
1050 				/*
1051 				 * Check to make sure the TCP connection has not
1052 				 * dropped asynchronously while session reinstatement
1053 				 * was occuring in this kthread context, before
1054 				 * transitioning to full feature phase operation.
1055 				 */
1056 				if (iscsi_target_sk_check_close(conn))
1057 					return -1;
1058 
1059 				login->tsih = conn->sess->tsih;
1060 				login->login_complete = 1;
1061 				iscsi_target_restore_sock_callbacks(conn);
1062 				if (iscsi_target_do_tx_login_io(conn,
1063 						login) < 0)
1064 					return -1;
1065 				return 1;
1066 			}
1067 			break;
1068 		default:
1069 			pr_err("Illegal CSG: %d received from"
1070 				" Initiator, protocol error.\n",
1071 				ISCSI_LOGIN_CURRENT_STAGE(login_req->flags));
1072 			break;
1073 		}
1074 
1075 		if (iscsi_target_do_tx_login_io(conn, login) < 0)
1076 			return -1;
1077 
1078 		if (login_rsp->flags & ISCSI_FLAG_LOGIN_TRANSIT) {
1079 			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_TRANSIT;
1080 			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK;
1081 		}
1082 		break;
1083 	}
1084 
1085 	return 0;
1086 }
1087 
1088 static void iscsi_initiatorname_tolower(
1089 	char *param_buf)
1090 {
1091 	char *c;
1092 	u32 iqn_size = strlen(param_buf), i;
1093 
1094 	for (i = 0; i < iqn_size; i++) {
1095 		c = &param_buf[i];
1096 		if (!isupper(*c))
1097 			continue;
1098 
1099 		*c = tolower(*c);
1100 	}
1101 }
1102 
1103 /*
1104  * Processes the first Login Request..
1105  */
1106 int iscsi_target_locate_portal(
1107 	struct iscsi_np *np,
1108 	struct iscsit_conn *conn,
1109 	struct iscsi_login *login)
1110 {
1111 	char *i_buf = NULL, *s_buf = NULL, *t_buf = NULL;
1112 	char *tmpbuf, *start = NULL, *end = NULL, *key, *value;
1113 	struct iscsit_session *sess = conn->sess;
1114 	struct iscsi_tiqn *tiqn;
1115 	struct iscsi_tpg_np *tpg_np = NULL;
1116 	struct iscsi_login_req *login_req;
1117 	struct se_node_acl *se_nacl;
1118 	u32 payload_length, queue_depth = 0;
1119 	int sessiontype = 0, ret = 0, tag_num, tag_size;
1120 
1121 	INIT_DELAYED_WORK(&conn->login_work, iscsi_target_do_login_rx);
1122 	iscsi_target_set_sock_callbacks(conn);
1123 
1124 	login->np = np;
1125 	conn->tpg = NULL;
1126 
1127 	login_req = (struct iscsi_login_req *) login->req;
1128 	payload_length = ntoh24(login_req->dlength);
1129 
1130 	tmpbuf = kmemdup_nul(login->req_buf, payload_length, GFP_KERNEL);
1131 	if (!tmpbuf) {
1132 		pr_err("Unable to allocate memory for tmpbuf.\n");
1133 		return -1;
1134 	}
1135 
1136 	start = tmpbuf;
1137 	end = (start + payload_length);
1138 
1139 	/*
1140 	 * Locate the initial keys expected from the Initiator node in
1141 	 * the first login request in order to progress with the login phase.
1142 	 */
1143 	while (start < end) {
1144 		if (iscsi_extract_key_value(start, &key, &value) < 0) {
1145 			ret = -1;
1146 			goto out;
1147 		}
1148 
1149 		if (!strncmp(key, "InitiatorName", 13))
1150 			i_buf = value;
1151 		else if (!strncmp(key, "SessionType", 11))
1152 			s_buf = value;
1153 		else if (!strncmp(key, "TargetName", 10))
1154 			t_buf = value;
1155 
1156 		start += strlen(key) + strlen(value) + 2;
1157 	}
1158 	/*
1159 	 * See 5.3.  Login Phase.
1160 	 */
1161 	if (!i_buf) {
1162 		pr_err("InitiatorName key not received"
1163 			" in first login request.\n");
1164 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1165 			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
1166 		ret = -1;
1167 		goto out;
1168 	}
1169 	/*
1170 	 * Convert the incoming InitiatorName to lowercase following
1171 	 * RFC-3720 3.2.6.1. section c) that says that iSCSI IQNs
1172 	 * are NOT case sensitive.
1173 	 */
1174 	iscsi_initiatorname_tolower(i_buf);
1175 
1176 	if (!s_buf) {
1177 		if (!login->leading_connection)
1178 			goto get_target;
1179 
1180 		pr_err("SessionType key not received"
1181 			" in first login request.\n");
1182 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1183 			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
1184 		ret = -1;
1185 		goto out;
1186 	}
1187 
1188 	/*
1189 	 * Use default portal group for discovery sessions.
1190 	 */
1191 	sessiontype = strncmp(s_buf, DISCOVERY, 9);
1192 	if (!sessiontype) {
1193 		if (!login->leading_connection)
1194 			goto get_target;
1195 
1196 		sess->sess_ops->SessionType = 1;
1197 		/*
1198 		 * Setup crc32c modules from libcrypto
1199 		 */
1200 		if (iscsi_login_setup_crypto(conn) < 0) {
1201 			pr_err("iscsi_login_setup_crypto() failed\n");
1202 			ret = -1;
1203 			goto out;
1204 		}
1205 		/*
1206 		 * Serialize access across the discovery struct iscsi_portal_group to
1207 		 * process login attempt.
1208 		 */
1209 		conn->tpg = iscsit_global->discovery_tpg;
1210 		if (iscsit_access_np(np, conn->tpg) < 0) {
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 		ret = 0;
1218 		goto alloc_tags;
1219 	}
1220 
1221 get_target:
1222 	if (!t_buf) {
1223 		pr_err("TargetName key not received"
1224 			" in first login request while"
1225 			" SessionType=Normal.\n");
1226 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1227 			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
1228 		ret = -1;
1229 		goto out;
1230 	}
1231 
1232 	/*
1233 	 * Locate Target IQN from Storage Node.
1234 	 */
1235 	tiqn = iscsit_get_tiqn_for_login(t_buf);
1236 	if (!tiqn) {
1237 		pr_err("Unable to locate Target IQN: %s in"
1238 			" Storage Node\n", t_buf);
1239 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1240 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
1241 		ret = -1;
1242 		goto out;
1243 	}
1244 	pr_debug("Located Storage Object: %s\n", tiqn->tiqn);
1245 
1246 	/*
1247 	 * Locate Target Portal Group from Storage Node.
1248 	 */
1249 	conn->tpg = iscsit_get_tpg_from_np(tiqn, np, &tpg_np);
1250 	if (!conn->tpg) {
1251 		pr_err("Unable to locate Target Portal Group"
1252 				" on %s\n", tiqn->tiqn);
1253 		iscsit_put_tiqn_for_login(tiqn);
1254 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1255 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
1256 		ret = -1;
1257 		goto out;
1258 	}
1259 	conn->tpg_np = tpg_np;
1260 	pr_debug("Located Portal Group Object: %hu\n", conn->tpg->tpgt);
1261 	/*
1262 	 * Setup crc32c modules from libcrypto
1263 	 */
1264 	if (iscsi_login_setup_crypto(conn) < 0) {
1265 		pr_err("iscsi_login_setup_crypto() failed\n");
1266 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
1267 		iscsit_put_tiqn_for_login(tiqn);
1268 		conn->tpg = NULL;
1269 		ret = -1;
1270 		goto out;
1271 	}
1272 	/*
1273 	 * Serialize access across the struct iscsi_portal_group to
1274 	 * process login attempt.
1275 	 */
1276 	if (iscsit_access_np(np, conn->tpg) < 0) {
1277 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
1278 		iscsit_put_tiqn_for_login(tiqn);
1279 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1280 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
1281 		conn->tpg = NULL;
1282 		ret = -1;
1283 		goto out;
1284 	}
1285 
1286 	/*
1287 	 * conn->sess->node_acl will be set when the referenced
1288 	 * struct iscsit_session is located from received ISID+TSIH in
1289 	 * iscsi_login_non_zero_tsih_s2().
1290 	 */
1291 	if (!login->leading_connection) {
1292 		ret = 0;
1293 		goto out;
1294 	}
1295 
1296 	/*
1297 	 * This value is required in iscsi_login_zero_tsih_s2()
1298 	 */
1299 	sess->sess_ops->SessionType = 0;
1300 
1301 	/*
1302 	 * Locate incoming Initiator IQN reference from Storage Node.
1303 	 */
1304 	sess->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1305 			&conn->tpg->tpg_se_tpg, i_buf);
1306 	if (!sess->se_sess->se_node_acl) {
1307 		pr_err("iSCSI Initiator Node: %s is not authorized to"
1308 			" access iSCSI target portal group: %hu.\n",
1309 				i_buf, conn->tpg->tpgt);
1310 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1311 				ISCSI_LOGIN_STATUS_TGT_FORBIDDEN);
1312 		ret = -1;
1313 		goto out;
1314 	}
1315 	se_nacl = sess->se_sess->se_node_acl;
1316 	queue_depth = se_nacl->queue_depth;
1317 	/*
1318 	 * Setup pre-allocated tags based upon allowed per NodeACL CmdSN
1319 	 * depth for non immediate commands, plus extra tags for immediate
1320 	 * commands.
1321 	 *
1322 	 * Also enforce a ISCSIT_MIN_TAGS to prevent unnecessary contention
1323 	 * in per-cpu-ida tag allocation logic + small queue_depth.
1324 	 */
1325 alloc_tags:
1326 	tag_num = max_t(u32, ISCSIT_MIN_TAGS, queue_depth);
1327 	tag_num = (tag_num * 2) + ISCSIT_EXTRA_TAGS;
1328 	tag_size = sizeof(struct iscsit_cmd) + conn->conn_transport->priv_size;
1329 
1330 	ret = transport_alloc_session_tags(sess->se_sess, tag_num, tag_size);
1331 	if (ret < 0) {
1332 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1333 				    ISCSI_LOGIN_STATUS_NO_RESOURCES);
1334 		ret = -1;
1335 	}
1336 out:
1337 	kfree(tmpbuf);
1338 	return ret;
1339 }
1340 
1341 int iscsi_target_start_negotiation(
1342 	struct iscsi_login *login,
1343 	struct iscsit_conn *conn)
1344 {
1345 	int ret;
1346 
1347 	if (conn->sock) {
1348 		struct sock *sk = conn->sock->sk;
1349 
1350 		write_lock_bh(&sk->sk_callback_lock);
1351 		set_bit(LOGIN_FLAGS_READY, &conn->login_flags);
1352 		set_bit(LOGIN_FLAGS_INITIAL_PDU, &conn->login_flags);
1353 		write_unlock_bh(&sk->sk_callback_lock);
1354 	}
1355 	/*
1356 	 * If iscsi_target_do_login returns zero to signal more PDU
1357 	 * exchanges are required to complete the login, go ahead and
1358 	 * clear LOGIN_FLAGS_INITIAL_PDU but only if the TCP connection
1359 	 * is still active.
1360 	 *
1361 	 * Otherwise if TCP connection dropped asynchronously, go ahead
1362 	 * and perform connection cleanup now.
1363 	 */
1364 	ret = iscsi_target_do_login(conn, login);
1365 	if (!ret) {
1366 		spin_lock(&conn->login_worker_lock);
1367 
1368 		if (iscsi_target_sk_check_and_clear(conn, LOGIN_FLAGS_INITIAL_PDU))
1369 			ret = -1;
1370 		else if (!test_bit(LOGIN_FLAGS_WORKER_RUNNING, &conn->login_flags)) {
1371 			if (iscsit_set_login_timer_kworker(conn, NULL) < 0) {
1372 				/*
1373 				 * The timeout has expired already.
1374 				 * Schedule login_work to perform the cleanup.
1375 				 */
1376 				schedule_delayed_work(&conn->login_work, 0);
1377 			}
1378 		}
1379 
1380 		spin_unlock(&conn->login_worker_lock);
1381 	}
1382 
1383 	if (ret < 0) {
1384 		iscsi_target_restore_sock_callbacks(conn);
1385 		iscsi_remove_failed_auth_entry(conn);
1386 	}
1387 	if (ret != 0) {
1388 		iscsit_stop_login_timer(conn);
1389 		cancel_delayed_work_sync(&conn->login_work);
1390 		iscsi_target_nego_release(conn);
1391 	}
1392 
1393 	return ret;
1394 }
1395 
1396 void iscsi_target_nego_release(struct iscsit_conn *conn)
1397 {
1398 	struct iscsi_login *login = conn->conn_login;
1399 
1400 	if (!login)
1401 		return;
1402 
1403 	kfree(login->req_buf);
1404 	kfree(login->rsp_buf);
1405 	kfree(login);
1406 
1407 	conn->conn_login = NULL;
1408 }
1409