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 struct conn_timeout {
539 	struct timer_list timer;
540 	struct iscsit_conn *conn;
541 };
542 
543 static void iscsi_target_login_timeout(struct timer_list *t)
544 {
545 	struct conn_timeout *timeout = from_timer(timeout, t, timer);
546 	struct iscsit_conn *conn = timeout->conn;
547 
548 	pr_debug("Entering iscsi_target_login_timeout >>>>>>>>>>>>>>>>>>>\n");
549 
550 	if (conn->login_kworker) {
551 		pr_debug("Sending SIGINT to conn->login_kworker %s/%d\n",
552 			 conn->login_kworker->comm, conn->login_kworker->pid);
553 		send_sig(SIGINT, conn->login_kworker, 1);
554 	}
555 }
556 
557 static void iscsi_target_do_login_rx(struct work_struct *work)
558 {
559 	struct iscsit_conn *conn = container_of(work,
560 				struct iscsit_conn, login_work.work);
561 	struct iscsi_login *login = conn->login;
562 	struct iscsi_np *np = login->np;
563 	struct iscsi_portal_group *tpg = conn->tpg;
564 	struct iscsi_tpg_np *tpg_np = conn->tpg_np;
565 	struct conn_timeout timeout;
566 	int rc, zero_tsih = login->zero_tsih;
567 	bool state;
568 
569 	pr_debug("entering iscsi_target_do_login_rx, conn: %p, %s:%d\n",
570 			conn, current->comm, current->pid);
571 	/*
572 	 * If iscsi_target_do_login_rx() has been invoked by ->sk_data_ready()
573 	 * before initial PDU processing in iscsi_target_start_negotiation()
574 	 * has completed, go ahead and retry until it's cleared.
575 	 *
576 	 * Otherwise if the TCP connection drops while this is occuring,
577 	 * iscsi_target_start_negotiation() will detect the failure, call
578 	 * cancel_delayed_work_sync(&conn->login_work), and cleanup the
579 	 * remaining iscsi connection resources from iscsi_np process context.
580 	 */
581 	if (iscsi_target_sk_check_flag(conn, LOGIN_FLAGS_INITIAL_PDU)) {
582 		schedule_delayed_work(&conn->login_work, msecs_to_jiffies(10));
583 		return;
584 	}
585 
586 	spin_lock(&tpg->tpg_state_lock);
587 	state = (tpg->tpg_state == TPG_STATE_ACTIVE);
588 	spin_unlock(&tpg->tpg_state_lock);
589 
590 	if (!state) {
591 		pr_debug("iscsi_target_do_login_rx: tpg_state != TPG_STATE_ACTIVE\n");
592 		goto err;
593 	}
594 
595 	if (iscsi_target_sk_check_close(conn)) {
596 		pr_debug("iscsi_target_do_login_rx, TCP state CLOSE\n");
597 		goto err;
598 	}
599 
600 	conn->login_kworker = current;
601 	allow_signal(SIGINT);
602 
603 	timeout.conn = conn;
604 	timer_setup_on_stack(&timeout.timer, iscsi_target_login_timeout, 0);
605 	mod_timer(&timeout.timer, jiffies + TA_LOGIN_TIMEOUT * HZ);
606 	pr_debug("Starting login timer for %s/%d\n", current->comm, current->pid);
607 
608 	rc = conn->conn_transport->iscsit_get_login_rx(conn, login);
609 	del_timer_sync(&timeout.timer);
610 	destroy_timer_on_stack(&timeout.timer);
611 	flush_signals(current);
612 	conn->login_kworker = NULL;
613 
614 	if (rc < 0)
615 		goto err;
616 
617 	pr_debug("iscsi_target_do_login_rx after rx_login_io, %p, %s:%d\n",
618 			conn, current->comm, current->pid);
619 
620 	/*
621 	 * LOGIN_FLAGS_READ_ACTIVE is cleared so that sk_data_ready
622 	 * could be triggered again after this.
623 	 *
624 	 * LOGIN_FLAGS_WRITE_ACTIVE is cleared after we successfully
625 	 * process a login PDU, so that sk_state_chage can do login
626 	 * cleanup as needed if the socket is closed. If a delayed work is
627 	 * ongoing (LOGIN_FLAGS_WRITE_ACTIVE or LOGIN_FLAGS_READ_ACTIVE),
628 	 * sk_state_change will leave the cleanup to the delayed work or
629 	 * it will schedule a delayed work to do cleanup.
630 	 */
631 	if (conn->sock) {
632 		struct sock *sk = conn->sock->sk;
633 
634 		write_lock_bh(&sk->sk_callback_lock);
635 		if (!test_bit(LOGIN_FLAGS_INITIAL_PDU, &conn->login_flags)) {
636 			clear_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags);
637 			set_bit(LOGIN_FLAGS_WRITE_ACTIVE, &conn->login_flags);
638 		}
639 		write_unlock_bh(&sk->sk_callback_lock);
640 	}
641 
642 	rc = iscsi_target_do_login(conn, login);
643 	if (rc < 0) {
644 		goto err;
645 	} else if (!rc) {
646 		if (iscsi_target_sk_check_and_clear(conn,
647 						    LOGIN_FLAGS_WRITE_ACTIVE))
648 			goto err;
649 	} else if (rc == 1) {
650 		cancel_delayed_work(&conn->login_work);
651 		iscsi_target_nego_release(conn);
652 		iscsi_post_login_handler(np, conn, zero_tsih);
653 		iscsit_deaccess_np(np, tpg, tpg_np);
654 	}
655 	return;
656 
657 err:
658 	iscsi_target_restore_sock_callbacks(conn);
659 	cancel_delayed_work(&conn->login_work);
660 	iscsi_target_login_drop(conn, login);
661 	iscsit_deaccess_np(np, tpg, tpg_np);
662 }
663 
664 static void iscsi_target_sk_state_change(struct sock *sk)
665 {
666 	struct iscsit_conn *conn;
667 	void (*orig_state_change)(struct sock *);
668 	bool state;
669 
670 	pr_debug("Entering iscsi_target_sk_state_change\n");
671 
672 	write_lock_bh(&sk->sk_callback_lock);
673 	conn = sk->sk_user_data;
674 	if (!conn) {
675 		write_unlock_bh(&sk->sk_callback_lock);
676 		return;
677 	}
678 	orig_state_change = conn->orig_state_change;
679 
680 	if (!test_bit(LOGIN_FLAGS_READY, &conn->login_flags)) {
681 		pr_debug("Got LOGIN_FLAGS_READY=0 sk_state_change conn: %p\n",
682 			 conn);
683 		write_unlock_bh(&sk->sk_callback_lock);
684 		orig_state_change(sk);
685 		return;
686 	}
687 	state = __iscsi_target_sk_check_close(sk);
688 	pr_debug("__iscsi_target_sk_close_change: state: %d\n", state);
689 
690 	if (test_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags) ||
691 	    test_bit(LOGIN_FLAGS_WRITE_ACTIVE, &conn->login_flags)) {
692 		pr_debug("Got LOGIN_FLAGS_{READ|WRITE}_ACTIVE=1"
693 			 " sk_state_change conn: %p\n", conn);
694 		if (state)
695 			set_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags);
696 		write_unlock_bh(&sk->sk_callback_lock);
697 		orig_state_change(sk);
698 		return;
699 	}
700 	if (test_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags)) {
701 		pr_debug("Got LOGIN_FLAGS_CLOSED=1 sk_state_change conn: %p\n",
702 			 conn);
703 		write_unlock_bh(&sk->sk_callback_lock);
704 		orig_state_change(sk);
705 		return;
706 	}
707 	/*
708 	 * If the TCP connection has dropped, go ahead and set LOGIN_FLAGS_CLOSED,
709 	 * but only queue conn->login_work -> iscsi_target_do_login_rx()
710 	 * processing if LOGIN_FLAGS_INITIAL_PDU has already been cleared.
711 	 *
712 	 * When iscsi_target_do_login_rx() runs, iscsi_target_sk_check_close()
713 	 * will detect the dropped TCP connection from delayed workqueue context.
714 	 *
715 	 * If LOGIN_FLAGS_INITIAL_PDU is still set, which means the initial
716 	 * iscsi_target_start_negotiation() is running, iscsi_target_do_login()
717 	 * via iscsi_target_sk_check_close() or iscsi_target_start_negotiation()
718 	 * via iscsi_target_sk_check_and_clear() is responsible for detecting the
719 	 * dropped TCP connection in iscsi_np process context, and cleaning up
720 	 * the remaining iscsi connection resources.
721 	 */
722 	if (state) {
723 		pr_debug("iscsi_target_sk_state_change got failed state\n");
724 		set_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags);
725 		state = test_bit(LOGIN_FLAGS_INITIAL_PDU, &conn->login_flags);
726 		write_unlock_bh(&sk->sk_callback_lock);
727 
728 		orig_state_change(sk);
729 
730 		if (!state)
731 			schedule_delayed_work(&conn->login_work, 0);
732 		return;
733 	}
734 	write_unlock_bh(&sk->sk_callback_lock);
735 
736 	orig_state_change(sk);
737 }
738 
739 /*
740  *	NOTE: We check for existing sessions or connections AFTER the initiator
741  *	has been successfully authenticated in order to protect against faked
742  *	ISID/TSIH combinations.
743  */
744 static int iscsi_target_check_for_existing_instances(
745 	struct iscsit_conn *conn,
746 	struct iscsi_login *login)
747 {
748 	if (login->checked_for_existing)
749 		return 0;
750 
751 	login->checked_for_existing = 1;
752 
753 	if (!login->tsih)
754 		return iscsi_check_for_session_reinstatement(conn);
755 	else
756 		return iscsi_login_post_auth_non_zero_tsih(conn, login->cid,
757 				login->initial_exp_statsn);
758 }
759 
760 static int iscsi_target_do_authentication(
761 	struct iscsit_conn *conn,
762 	struct iscsi_login *login)
763 {
764 	int authret;
765 	u32 payload_length;
766 	struct iscsi_param *param;
767 	struct iscsi_login_req *login_req;
768 	struct iscsi_login_rsp *login_rsp;
769 
770 	login_req = (struct iscsi_login_req *) login->req;
771 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
772 	payload_length = ntoh24(login_req->dlength);
773 
774 	param = iscsi_find_param_from_key(AUTHMETHOD, conn->param_list);
775 	if (!param)
776 		return -1;
777 
778 	authret = iscsi_handle_authentication(
779 			conn,
780 			login->req_buf,
781 			login->rsp_buf,
782 			payload_length,
783 			&login->rsp_length,
784 			param->value);
785 	switch (authret) {
786 	case 0:
787 		pr_debug("Received OK response"
788 		" from LIO Authentication, continuing.\n");
789 		break;
790 	case 1:
791 		pr_debug("iSCSI security negotiation"
792 			" completed successfully.\n");
793 		login->auth_complete = 1;
794 		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE1) &&
795 		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
796 			login_rsp->flags |= (ISCSI_FLAG_LOGIN_NEXT_STAGE1 |
797 					     ISCSI_FLAG_LOGIN_TRANSIT);
798 			login->current_stage = 1;
799 		}
800 		return iscsi_target_check_for_existing_instances(
801 				conn, login);
802 	case 2:
803 		pr_err("Security negotiation"
804 			" failed.\n");
805 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
806 				ISCSI_LOGIN_STATUS_AUTH_FAILED);
807 		return -1;
808 	default:
809 		pr_err("Received unknown error %d from LIO"
810 				" Authentication\n", authret);
811 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
812 				ISCSI_LOGIN_STATUS_TARGET_ERROR);
813 		return -1;
814 	}
815 
816 	return 0;
817 }
818 
819 bool iscsi_conn_auth_required(struct iscsit_conn *conn)
820 {
821 	struct iscsi_node_acl *nacl;
822 	struct se_node_acl *se_nacl;
823 
824 	if (conn->sess->sess_ops->SessionType) {
825 		/*
826 		 * For SessionType=Discovery
827 		 */
828 		return conn->tpg->tpg_attrib.authentication;
829 	}
830 	/*
831 	 * For SessionType=Normal
832 	 */
833 	se_nacl = conn->sess->se_sess->se_node_acl;
834 	if (!se_nacl) {
835 		pr_debug("Unknown ACL is trying to connect\n");
836 		return true;
837 	}
838 
839 	if (se_nacl->dynamic_node_acl) {
840 		pr_debug("Dynamic ACL %s is trying to connect\n",
841 			 se_nacl->initiatorname);
842 		return conn->tpg->tpg_attrib.authentication;
843 	}
844 
845 	pr_debug("Known ACL %s is trying to connect\n",
846 		 se_nacl->initiatorname);
847 
848 	nacl = to_iscsi_nacl(se_nacl);
849 	if (nacl->node_attrib.authentication == NA_AUTHENTICATION_INHERITED)
850 		return conn->tpg->tpg_attrib.authentication;
851 
852 	return nacl->node_attrib.authentication;
853 }
854 
855 static int iscsi_target_handle_csg_zero(
856 	struct iscsit_conn *conn,
857 	struct iscsi_login *login)
858 {
859 	int ret;
860 	u32 payload_length;
861 	struct iscsi_param *param;
862 	struct iscsi_login_req *login_req;
863 	struct iscsi_login_rsp *login_rsp;
864 
865 	login_req = (struct iscsi_login_req *) login->req;
866 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
867 	payload_length = ntoh24(login_req->dlength);
868 
869 	param = iscsi_find_param_from_key(AUTHMETHOD, conn->param_list);
870 	if (!param)
871 		return -1;
872 
873 	ret = iscsi_decode_text_input(
874 			PHASE_SECURITY|PHASE_DECLARATIVE,
875 			SENDER_INITIATOR|SENDER_RECEIVER,
876 			login->req_buf,
877 			payload_length,
878 			conn);
879 	if (ret < 0)
880 		return -1;
881 
882 	if (ret > 0) {
883 		if (login->auth_complete) {
884 			pr_err("Initiator has already been"
885 				" successfully authenticated, but is still"
886 				" sending %s keys.\n", param->value);
887 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
888 					ISCSI_LOGIN_STATUS_INIT_ERR);
889 			return -1;
890 		}
891 
892 		goto do_auth;
893 	} else if (!payload_length) {
894 		pr_err("Initiator sent zero length security payload,"
895 		       " login failed\n");
896 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
897 				    ISCSI_LOGIN_STATUS_AUTH_FAILED);
898 		return -1;
899 	}
900 
901 	if (login->first_request)
902 		if (iscsi_target_check_first_request(conn, login) < 0)
903 			return -1;
904 
905 	ret = iscsi_encode_text_output(
906 			PHASE_SECURITY|PHASE_DECLARATIVE,
907 			SENDER_TARGET,
908 			login->rsp_buf,
909 			&login->rsp_length,
910 			conn->param_list,
911 			conn->tpg->tpg_attrib.login_keys_workaround);
912 	if (ret < 0)
913 		return -1;
914 
915 	if (!iscsi_check_negotiated_keys(conn->param_list)) {
916 		bool auth_required = iscsi_conn_auth_required(conn);
917 
918 		if (auth_required) {
919 			if (!strncmp(param->value, NONE, 4)) {
920 				pr_err("Initiator sent AuthMethod=None but"
921 				       " Target is enforcing iSCSI Authentication,"
922 				       " login failed.\n");
923 				iscsit_tx_login_rsp(conn,
924 						ISCSI_STATUS_CLS_INITIATOR_ERR,
925 						ISCSI_LOGIN_STATUS_AUTH_FAILED);
926 				return -1;
927 			}
928 
929 			if (!login->auth_complete)
930 				return 0;
931 
932 			if (strncmp(param->value, NONE, 4) &&
933 			    !login->auth_complete)
934 				return 0;
935 		}
936 
937 		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE1) &&
938 		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
939 			login_rsp->flags |= ISCSI_FLAG_LOGIN_NEXT_STAGE1 |
940 					    ISCSI_FLAG_LOGIN_TRANSIT;
941 			login->current_stage = 1;
942 		}
943 	}
944 
945 	return 0;
946 do_auth:
947 	return iscsi_target_do_authentication(conn, login);
948 }
949 
950 static bool iscsi_conn_authenticated(struct iscsit_conn *conn,
951 				     struct iscsi_login *login)
952 {
953 	if (!iscsi_conn_auth_required(conn))
954 		return true;
955 
956 	if (login->auth_complete)
957 		return true;
958 
959 	return false;
960 }
961 
962 static int iscsi_target_handle_csg_one(struct iscsit_conn *conn, struct iscsi_login *login)
963 {
964 	int ret;
965 	u32 payload_length;
966 	struct iscsi_login_req *login_req;
967 	struct iscsi_login_rsp *login_rsp;
968 
969 	login_req = (struct iscsi_login_req *) login->req;
970 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
971 	payload_length = ntoh24(login_req->dlength);
972 
973 	ret = iscsi_decode_text_input(
974 			PHASE_OPERATIONAL|PHASE_DECLARATIVE,
975 			SENDER_INITIATOR|SENDER_RECEIVER,
976 			login->req_buf,
977 			payload_length,
978 			conn);
979 	if (ret < 0) {
980 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
981 				ISCSI_LOGIN_STATUS_INIT_ERR);
982 		return -1;
983 	}
984 
985 	if (login->first_request)
986 		if (iscsi_target_check_first_request(conn, login) < 0)
987 			return -1;
988 
989 	if (iscsi_target_check_for_existing_instances(conn, login) < 0)
990 		return -1;
991 
992 	ret = iscsi_encode_text_output(
993 			PHASE_OPERATIONAL|PHASE_DECLARATIVE,
994 			SENDER_TARGET,
995 			login->rsp_buf,
996 			&login->rsp_length,
997 			conn->param_list,
998 			conn->tpg->tpg_attrib.login_keys_workaround);
999 	if (ret < 0) {
1000 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1001 				ISCSI_LOGIN_STATUS_INIT_ERR);
1002 		return -1;
1003 	}
1004 
1005 	if (!iscsi_conn_authenticated(conn, login)) {
1006 		pr_err("Initiator is requesting CSG: 1, has not been"
1007 		       " successfully authenticated, and the Target is"
1008 		       " enforcing iSCSI Authentication, login failed.\n");
1009 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1010 				ISCSI_LOGIN_STATUS_AUTH_FAILED);
1011 		return -1;
1012 	}
1013 
1014 	if (!iscsi_check_negotiated_keys(conn->param_list))
1015 		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE3) &&
1016 		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT))
1017 			login_rsp->flags |= ISCSI_FLAG_LOGIN_NEXT_STAGE3 |
1018 					    ISCSI_FLAG_LOGIN_TRANSIT;
1019 
1020 	return 0;
1021 }
1022 
1023 /*
1024  * RETURN VALUE:
1025  *
1026  *  1 = Login successful
1027  * -1 = Login failed
1028  *  0 = More PDU exchanges required
1029  */
1030 static int iscsi_target_do_login(struct iscsit_conn *conn, struct iscsi_login *login)
1031 {
1032 	int pdu_count = 0;
1033 	struct iscsi_login_req *login_req;
1034 	struct iscsi_login_rsp *login_rsp;
1035 
1036 	login_req = (struct iscsi_login_req *) login->req;
1037 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
1038 
1039 	while (1) {
1040 		if (++pdu_count > MAX_LOGIN_PDUS) {
1041 			pr_err("MAX_LOGIN_PDUS count reached.\n");
1042 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1043 					ISCSI_LOGIN_STATUS_TARGET_ERROR);
1044 			return -1;
1045 		}
1046 
1047 		switch (ISCSI_LOGIN_CURRENT_STAGE(login_req->flags)) {
1048 		case 0:
1049 			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK;
1050 			if (iscsi_target_handle_csg_zero(conn, login) < 0)
1051 				return -1;
1052 			break;
1053 		case 1:
1054 			login_rsp->flags |= ISCSI_FLAG_LOGIN_CURRENT_STAGE1;
1055 			if (iscsi_target_handle_csg_one(conn, login) < 0)
1056 				return -1;
1057 			if (login_rsp->flags & ISCSI_FLAG_LOGIN_TRANSIT) {
1058 				/*
1059 				 * Check to make sure the TCP connection has not
1060 				 * dropped asynchronously while session reinstatement
1061 				 * was occuring in this kthread context, before
1062 				 * transitioning to full feature phase operation.
1063 				 */
1064 				if (iscsi_target_sk_check_close(conn))
1065 					return -1;
1066 
1067 				login->tsih = conn->sess->tsih;
1068 				login->login_complete = 1;
1069 				iscsi_target_restore_sock_callbacks(conn);
1070 				if (iscsi_target_do_tx_login_io(conn,
1071 						login) < 0)
1072 					return -1;
1073 				return 1;
1074 			}
1075 			break;
1076 		default:
1077 			pr_err("Illegal CSG: %d received from"
1078 				" Initiator, protocol error.\n",
1079 				ISCSI_LOGIN_CURRENT_STAGE(login_req->flags));
1080 			break;
1081 		}
1082 
1083 		if (iscsi_target_do_tx_login_io(conn, login) < 0)
1084 			return -1;
1085 
1086 		if (login_rsp->flags & ISCSI_FLAG_LOGIN_TRANSIT) {
1087 			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_TRANSIT;
1088 			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK;
1089 		}
1090 		break;
1091 	}
1092 
1093 	return 0;
1094 }
1095 
1096 static void iscsi_initiatorname_tolower(
1097 	char *param_buf)
1098 {
1099 	char *c;
1100 	u32 iqn_size = strlen(param_buf), i;
1101 
1102 	for (i = 0; i < iqn_size; i++) {
1103 		c = &param_buf[i];
1104 		if (!isupper(*c))
1105 			continue;
1106 
1107 		*c = tolower(*c);
1108 	}
1109 }
1110 
1111 /*
1112  * Processes the first Login Request..
1113  */
1114 int iscsi_target_locate_portal(
1115 	struct iscsi_np *np,
1116 	struct iscsit_conn *conn,
1117 	struct iscsi_login *login)
1118 {
1119 	char *i_buf = NULL, *s_buf = NULL, *t_buf = NULL;
1120 	char *tmpbuf, *start = NULL, *end = NULL, *key, *value;
1121 	struct iscsit_session *sess = conn->sess;
1122 	struct iscsi_tiqn *tiqn;
1123 	struct iscsi_tpg_np *tpg_np = NULL;
1124 	struct iscsi_login_req *login_req;
1125 	struct se_node_acl *se_nacl;
1126 	u32 payload_length, queue_depth = 0;
1127 	int sessiontype = 0, ret = 0, tag_num, tag_size;
1128 
1129 	INIT_DELAYED_WORK(&conn->login_work, iscsi_target_do_login_rx);
1130 	iscsi_target_set_sock_callbacks(conn);
1131 
1132 	login->np = np;
1133 
1134 	login_req = (struct iscsi_login_req *) login->req;
1135 	payload_length = ntoh24(login_req->dlength);
1136 
1137 	tmpbuf = kmemdup_nul(login->req_buf, payload_length, GFP_KERNEL);
1138 	if (!tmpbuf) {
1139 		pr_err("Unable to allocate memory for tmpbuf.\n");
1140 		return -1;
1141 	}
1142 
1143 	start = tmpbuf;
1144 	end = (start + payload_length);
1145 
1146 	/*
1147 	 * Locate the initial keys expected from the Initiator node in
1148 	 * the first login request in order to progress with the login phase.
1149 	 */
1150 	while (start < end) {
1151 		if (iscsi_extract_key_value(start, &key, &value) < 0) {
1152 			ret = -1;
1153 			goto out;
1154 		}
1155 
1156 		if (!strncmp(key, "InitiatorName", 13))
1157 			i_buf = value;
1158 		else if (!strncmp(key, "SessionType", 11))
1159 			s_buf = value;
1160 		else if (!strncmp(key, "TargetName", 10))
1161 			t_buf = value;
1162 
1163 		start += strlen(key) + strlen(value) + 2;
1164 	}
1165 	/*
1166 	 * See 5.3.  Login Phase.
1167 	 */
1168 	if (!i_buf) {
1169 		pr_err("InitiatorName key not received"
1170 			" in first login request.\n");
1171 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1172 			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
1173 		ret = -1;
1174 		goto out;
1175 	}
1176 	/*
1177 	 * Convert the incoming InitiatorName to lowercase following
1178 	 * RFC-3720 3.2.6.1. section c) that says that iSCSI IQNs
1179 	 * are NOT case sensitive.
1180 	 */
1181 	iscsi_initiatorname_tolower(i_buf);
1182 
1183 	if (!s_buf) {
1184 		if (!login->leading_connection)
1185 			goto get_target;
1186 
1187 		pr_err("SessionType key not received"
1188 			" in first login request.\n");
1189 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1190 			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
1191 		ret = -1;
1192 		goto out;
1193 	}
1194 
1195 	/*
1196 	 * Use default portal group for discovery sessions.
1197 	 */
1198 	sessiontype = strncmp(s_buf, DISCOVERY, 9);
1199 	if (!sessiontype) {
1200 		conn->tpg = iscsit_global->discovery_tpg;
1201 		if (!login->leading_connection)
1202 			goto get_target;
1203 
1204 		sess->sess_ops->SessionType = 1;
1205 		/*
1206 		 * Setup crc32c modules from libcrypto
1207 		 */
1208 		if (iscsi_login_setup_crypto(conn) < 0) {
1209 			pr_err("iscsi_login_setup_crypto() failed\n");
1210 			ret = -1;
1211 			goto out;
1212 		}
1213 		/*
1214 		 * Serialize access across the discovery struct iscsi_portal_group to
1215 		 * process login attempt.
1216 		 */
1217 		if (iscsit_access_np(np, conn->tpg) < 0) {
1218 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1219 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
1220 			ret = -1;
1221 			goto out;
1222 		}
1223 		ret = 0;
1224 		goto alloc_tags;
1225 	}
1226 
1227 get_target:
1228 	if (!t_buf) {
1229 		pr_err("TargetName key not received"
1230 			" in first login request while"
1231 			" SessionType=Normal.\n");
1232 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1233 			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
1234 		ret = -1;
1235 		goto out;
1236 	}
1237 
1238 	/*
1239 	 * Locate Target IQN from Storage Node.
1240 	 */
1241 	tiqn = iscsit_get_tiqn_for_login(t_buf);
1242 	if (!tiqn) {
1243 		pr_err("Unable to locate Target IQN: %s in"
1244 			" Storage Node\n", t_buf);
1245 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1246 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
1247 		ret = -1;
1248 		goto out;
1249 	}
1250 	pr_debug("Located Storage Object: %s\n", tiqn->tiqn);
1251 
1252 	/*
1253 	 * Locate Target Portal Group from Storage Node.
1254 	 */
1255 	conn->tpg = iscsit_get_tpg_from_np(tiqn, np, &tpg_np);
1256 	if (!conn->tpg) {
1257 		pr_err("Unable to locate Target Portal Group"
1258 				" on %s\n", tiqn->tiqn);
1259 		iscsit_put_tiqn_for_login(tiqn);
1260 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1261 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
1262 		ret = -1;
1263 		goto out;
1264 	}
1265 	conn->tpg_np = tpg_np;
1266 	pr_debug("Located Portal Group Object: %hu\n", conn->tpg->tpgt);
1267 	/*
1268 	 * Setup crc32c modules from libcrypto
1269 	 */
1270 	if (iscsi_login_setup_crypto(conn) < 0) {
1271 		pr_err("iscsi_login_setup_crypto() failed\n");
1272 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
1273 		iscsit_put_tiqn_for_login(tiqn);
1274 		conn->tpg = NULL;
1275 		ret = -1;
1276 		goto out;
1277 	}
1278 	/*
1279 	 * Serialize access across the struct iscsi_portal_group to
1280 	 * process login attempt.
1281 	 */
1282 	if (iscsit_access_np(np, conn->tpg) < 0) {
1283 		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
1284 		iscsit_put_tiqn_for_login(tiqn);
1285 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1286 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
1287 		conn->tpg = NULL;
1288 		ret = -1;
1289 		goto out;
1290 	}
1291 
1292 	/*
1293 	 * conn->sess->node_acl will be set when the referenced
1294 	 * struct iscsit_session is located from received ISID+TSIH in
1295 	 * iscsi_login_non_zero_tsih_s2().
1296 	 */
1297 	if (!login->leading_connection) {
1298 		ret = 0;
1299 		goto out;
1300 	}
1301 
1302 	/*
1303 	 * This value is required in iscsi_login_zero_tsih_s2()
1304 	 */
1305 	sess->sess_ops->SessionType = 0;
1306 
1307 	/*
1308 	 * Locate incoming Initiator IQN reference from Storage Node.
1309 	 */
1310 	sess->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1311 			&conn->tpg->tpg_se_tpg, i_buf);
1312 	if (!sess->se_sess->se_node_acl) {
1313 		pr_err("iSCSI Initiator Node: %s is not authorized to"
1314 			" access iSCSI target portal group: %hu.\n",
1315 				i_buf, conn->tpg->tpgt);
1316 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
1317 				ISCSI_LOGIN_STATUS_TGT_FORBIDDEN);
1318 		ret = -1;
1319 		goto out;
1320 	}
1321 	se_nacl = sess->se_sess->se_node_acl;
1322 	queue_depth = se_nacl->queue_depth;
1323 	/*
1324 	 * Setup pre-allocated tags based upon allowed per NodeACL CmdSN
1325 	 * depth for non immediate commands, plus extra tags for immediate
1326 	 * commands.
1327 	 *
1328 	 * Also enforce a ISCSIT_MIN_TAGS to prevent unnecessary contention
1329 	 * in per-cpu-ida tag allocation logic + small queue_depth.
1330 	 */
1331 alloc_tags:
1332 	tag_num = max_t(u32, ISCSIT_MIN_TAGS, queue_depth);
1333 	tag_num = (tag_num * 2) + ISCSIT_EXTRA_TAGS;
1334 	tag_size = sizeof(struct iscsit_cmd) + conn->conn_transport->priv_size;
1335 
1336 	ret = transport_alloc_session_tags(sess->se_sess, tag_num, tag_size);
1337 	if (ret < 0) {
1338 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1339 				    ISCSI_LOGIN_STATUS_NO_RESOURCES);
1340 		ret = -1;
1341 	}
1342 out:
1343 	kfree(tmpbuf);
1344 	return ret;
1345 }
1346 
1347 int iscsi_target_start_negotiation(
1348 	struct iscsi_login *login,
1349 	struct iscsit_conn *conn)
1350 {
1351 	int ret;
1352 
1353 	if (conn->sock) {
1354 		struct sock *sk = conn->sock->sk;
1355 
1356 		write_lock_bh(&sk->sk_callback_lock);
1357 		set_bit(LOGIN_FLAGS_READY, &conn->login_flags);
1358 		set_bit(LOGIN_FLAGS_INITIAL_PDU, &conn->login_flags);
1359 		write_unlock_bh(&sk->sk_callback_lock);
1360 	}
1361 	/*
1362 	 * If iscsi_target_do_login returns zero to signal more PDU
1363 	 * exchanges are required to complete the login, go ahead and
1364 	 * clear LOGIN_FLAGS_INITIAL_PDU but only if the TCP connection
1365 	 * is still active.
1366 	 *
1367 	 * Otherwise if TCP connection dropped asynchronously, go ahead
1368 	 * and perform connection cleanup now.
1369 	 */
1370 	ret = iscsi_target_do_login(conn, login);
1371 	if (!ret && iscsi_target_sk_check_and_clear(conn, LOGIN_FLAGS_INITIAL_PDU))
1372 		ret = -1;
1373 
1374 	if (ret < 0) {
1375 		iscsi_target_restore_sock_callbacks(conn);
1376 		iscsi_remove_failed_auth_entry(conn);
1377 	}
1378 	if (ret != 0) {
1379 		cancel_delayed_work_sync(&conn->login_work);
1380 		iscsi_target_nego_release(conn);
1381 	}
1382 
1383 	return ret;
1384 }
1385 
1386 void iscsi_target_nego_release(struct iscsit_conn *conn)
1387 {
1388 	struct iscsi_login *login = conn->conn_login;
1389 
1390 	if (!login)
1391 		return;
1392 
1393 	kfree(login->req_buf);
1394 	kfree(login->rsp_buf);
1395 	kfree(login);
1396 
1397 	conn->conn_login = NULL;
1398 }
1399