1 /*******************************************************************************
2  * This file contains main functions related to iSCSI Parameter negotiation.
3  *
4  * \u00a9 Copyright 2007-2011 RisingTide Systems LLC.
5  *
6  * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
7  *
8  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  ******************************************************************************/
20 
21 #include <linux/ctype.h>
22 #include <scsi/iscsi_proto.h>
23 #include <target/target_core_base.h>
24 #include <target/target_core_tpg.h>
25 
26 #include "iscsi_target_core.h"
27 #include "iscsi_target_parameters.h"
28 #include "iscsi_target_login.h"
29 #include "iscsi_target_nego.h"
30 #include "iscsi_target_tpg.h"
31 #include "iscsi_target_util.h"
32 #include "iscsi_target.h"
33 #include "iscsi_target_auth.h"
34 
35 #define MAX_LOGIN_PDUS  7
36 #define TEXT_LEN	4096
37 
38 void convert_null_to_semi(char *buf, int len)
39 {
40 	int i;
41 
42 	for (i = 0; i < len; i++)
43 		if (buf[i] == '\0')
44 			buf[i] = ';';
45 }
46 
47 int strlen_semi(char *buf)
48 {
49 	int i = 0;
50 
51 	while (buf[i] != '\0') {
52 		if (buf[i] == ';')
53 			return i;
54 		i++;
55 	}
56 
57 	return -1;
58 }
59 
60 int extract_param(
61 	const char *in_buf,
62 	const char *pattern,
63 	unsigned int max_length,
64 	char *out_buf,
65 	unsigned char *type)
66 {
67 	char *ptr;
68 	int len;
69 
70 	if (!in_buf || !pattern || !out_buf || !type)
71 		return -1;
72 
73 	ptr = strstr(in_buf, pattern);
74 	if (!ptr)
75 		return -1;
76 
77 	ptr = strstr(ptr, "=");
78 	if (!ptr)
79 		return -1;
80 
81 	ptr += 1;
82 	if (*ptr == '0' && (*(ptr+1) == 'x' || *(ptr+1) == 'X')) {
83 		ptr += 2; /* skip 0x */
84 		*type = HEX;
85 	} else
86 		*type = DECIMAL;
87 
88 	len = strlen_semi(ptr);
89 	if (len < 0)
90 		return -1;
91 
92 	if (len > max_length) {
93 		pr_err("Length of input: %d exeeds max_length:"
94 			" %d\n", len, max_length);
95 		return -1;
96 	}
97 	memcpy(out_buf, ptr, len);
98 	out_buf[len] = '\0';
99 
100 	return 0;
101 }
102 
103 static u32 iscsi_handle_authentication(
104 	struct iscsi_conn *conn,
105 	char *in_buf,
106 	char *out_buf,
107 	int in_length,
108 	int *out_length,
109 	unsigned char *authtype)
110 {
111 	struct iscsi_session *sess = conn->sess;
112 	struct iscsi_node_auth *auth;
113 	struct iscsi_node_acl *iscsi_nacl;
114 	struct se_node_acl *se_nacl;
115 
116 	if (!sess->sess_ops->SessionType) {
117 		/*
118 		 * For SessionType=Normal
119 		 */
120 		se_nacl = conn->sess->se_sess->se_node_acl;
121 		if (!se_nacl) {
122 			pr_err("Unable to locate struct se_node_acl for"
123 					" CHAP auth\n");
124 			return -1;
125 		}
126 		iscsi_nacl = container_of(se_nacl, struct iscsi_node_acl,
127 				se_node_acl);
128 		if (!iscsi_nacl) {
129 			pr_err("Unable to locate struct iscsi_node_acl for"
130 					" CHAP auth\n");
131 			return -1;
132 		}
133 
134 		auth = ISCSI_NODE_AUTH(iscsi_nacl);
135 	} else {
136 		/*
137 		 * For SessionType=Discovery
138 		 */
139 		auth = &iscsit_global->discovery_acl.node_auth;
140 	}
141 
142 	if (strstr("CHAP", authtype))
143 		strcpy(conn->sess->auth_type, "CHAP");
144 	else
145 		strcpy(conn->sess->auth_type, NONE);
146 
147 	if (strstr("None", authtype))
148 		return 1;
149 #ifdef CANSRP
150 	else if (strstr("SRP", authtype))
151 		return srp_main_loop(conn, auth, in_buf, out_buf,
152 				&in_length, out_length);
153 #endif
154 	else if (strstr("CHAP", authtype))
155 		return chap_main_loop(conn, auth, in_buf, out_buf,
156 				&in_length, out_length);
157 	else if (strstr("SPKM1", authtype))
158 		return 2;
159 	else if (strstr("SPKM2", authtype))
160 		return 2;
161 	else if (strstr("KRB5", authtype))
162 		return 2;
163 	else
164 		return 2;
165 }
166 
167 static void iscsi_remove_failed_auth_entry(struct iscsi_conn *conn)
168 {
169 	kfree(conn->auth_protocol);
170 }
171 
172 static int iscsi_target_check_login_request(
173 	struct iscsi_conn *conn,
174 	struct iscsi_login *login)
175 {
176 	int req_csg, req_nsg, rsp_csg, rsp_nsg;
177 	u32 payload_length;
178 	struct iscsi_login_req *login_req;
179 	struct iscsi_login_rsp *login_rsp;
180 
181 	login_req = (struct iscsi_login_req *) login->req;
182 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
183 	payload_length = ntoh24(login_req->dlength);
184 
185 	switch (login_req->opcode & ISCSI_OPCODE_MASK) {
186 	case ISCSI_OP_LOGIN:
187 		break;
188 	default:
189 		pr_err("Received unknown opcode 0x%02x.\n",
190 				login_req->opcode & ISCSI_OPCODE_MASK);
191 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
192 				ISCSI_LOGIN_STATUS_INIT_ERR);
193 		return -1;
194 	}
195 
196 	if ((login_req->flags & ISCSI_FLAG_LOGIN_CONTINUE) &&
197 	    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
198 		pr_err("Login request has both ISCSI_FLAG_LOGIN_CONTINUE"
199 			" and ISCSI_FLAG_LOGIN_TRANSIT set, protocol error.\n");
200 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
201 				ISCSI_LOGIN_STATUS_INIT_ERR);
202 		return -1;
203 	}
204 
205 	req_csg = (login_req->flags & ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK) >> 2;
206 	rsp_csg = (login_rsp->flags & ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK) >> 2;
207 	req_nsg = (login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK);
208 	rsp_nsg = (login_rsp->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK);
209 
210 	if (req_csg != login->current_stage) {
211 		pr_err("Initiator unexpectedly changed login stage"
212 			" from %d to %d, login failed.\n", login->current_stage,
213 			req_csg);
214 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
215 				ISCSI_LOGIN_STATUS_INIT_ERR);
216 		return -1;
217 	}
218 
219 	if ((req_nsg == 2) || (req_csg >= 2) ||
220 	   ((login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT) &&
221 	    (req_nsg <= req_csg))) {
222 		pr_err("Illegal login_req->flags Combination, CSG: %d,"
223 			" NSG: %d, ISCSI_FLAG_LOGIN_TRANSIT: %d.\n", req_csg,
224 			req_nsg, (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT));
225 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
226 				ISCSI_LOGIN_STATUS_INIT_ERR);
227 		return -1;
228 	}
229 
230 	if ((login_req->max_version != login->version_max) ||
231 	    (login_req->min_version != login->version_min)) {
232 		pr_err("Login request changed Version Max/Nin"
233 			" unexpectedly to 0x%02x/0x%02x, protocol error\n",
234 			login_req->max_version, login_req->min_version);
235 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
236 				ISCSI_LOGIN_STATUS_INIT_ERR);
237 		return -1;
238 	}
239 
240 	if (memcmp(login_req->isid, login->isid, 6) != 0) {
241 		pr_err("Login request changed ISID unexpectedly,"
242 				" protocol error.\n");
243 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
244 				ISCSI_LOGIN_STATUS_INIT_ERR);
245 		return -1;
246 	}
247 
248 	if (login_req->itt != login->init_task_tag) {
249 		pr_err("Login request changed ITT unexpectedly to"
250 			" 0x%08x, protocol error.\n", login_req->itt);
251 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
252 				ISCSI_LOGIN_STATUS_INIT_ERR);
253 		return -1;
254 	}
255 
256 	if (payload_length > MAX_KEY_VALUE_PAIRS) {
257 		pr_err("Login request payload exceeds default"
258 			" MaxRecvDataSegmentLength: %u, protocol error.\n",
259 				MAX_KEY_VALUE_PAIRS);
260 		return -1;
261 	}
262 
263 	return 0;
264 }
265 
266 static int iscsi_target_check_first_request(
267 	struct iscsi_conn *conn,
268 	struct iscsi_login *login)
269 {
270 	struct iscsi_param *param = NULL;
271 	struct se_node_acl *se_nacl;
272 
273 	login->first_request = 0;
274 
275 	list_for_each_entry(param, &conn->param_list->param_list, p_list) {
276 		if (!strncmp(param->name, SESSIONTYPE, 11)) {
277 			if (!IS_PSTATE_ACCEPTOR(param)) {
278 				pr_err("SessionType key not received"
279 					" in first login request.\n");
280 				iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
281 					ISCSI_LOGIN_STATUS_MISSING_FIELDS);
282 				return -1;
283 			}
284 			if (!strncmp(param->value, DISCOVERY, 9))
285 				return 0;
286 		}
287 
288 		if (!strncmp(param->name, INITIATORNAME, 13)) {
289 			if (!IS_PSTATE_ACCEPTOR(param)) {
290 				if (!login->leading_connection)
291 					continue;
292 
293 				pr_err("InitiatorName key not received"
294 					" in first login request.\n");
295 				iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
296 					ISCSI_LOGIN_STATUS_MISSING_FIELDS);
297 				return -1;
298 			}
299 
300 			/*
301 			 * For non-leading connections, double check that the
302 			 * received InitiatorName matches the existing session's
303 			 * struct iscsi_node_acl.
304 			 */
305 			if (!login->leading_connection) {
306 				se_nacl = conn->sess->se_sess->se_node_acl;
307 				if (!se_nacl) {
308 					pr_err("Unable to locate"
309 						" struct se_node_acl\n");
310 					iscsit_tx_login_rsp(conn,
311 							ISCSI_STATUS_CLS_INITIATOR_ERR,
312 							ISCSI_LOGIN_STATUS_TGT_NOT_FOUND);
313 					return -1;
314 				}
315 
316 				if (strcmp(param->value,
317 						se_nacl->initiatorname)) {
318 					pr_err("Incorrect"
319 						" InitiatorName: %s for this"
320 						" iSCSI Initiator Node.\n",
321 						param->value);
322 					iscsit_tx_login_rsp(conn,
323 							ISCSI_STATUS_CLS_INITIATOR_ERR,
324 							ISCSI_LOGIN_STATUS_TGT_NOT_FOUND);
325 					return -1;
326 				}
327 			}
328 		}
329 	}
330 
331 	return 0;
332 }
333 
334 static int iscsi_target_do_tx_login_io(struct iscsi_conn *conn, struct iscsi_login *login)
335 {
336 	u32 padding = 0;
337 	struct iscsi_session *sess = conn->sess;
338 	struct iscsi_login_rsp *login_rsp;
339 
340 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
341 
342 	login_rsp->opcode		= ISCSI_OP_LOGIN_RSP;
343 	hton24(login_rsp->dlength, login->rsp_length);
344 	memcpy(login_rsp->isid, login->isid, 6);
345 	login_rsp->tsih			= cpu_to_be16(login->tsih);
346 	login_rsp->itt			= cpu_to_be32(login->init_task_tag);
347 	login_rsp->statsn		= cpu_to_be32(conn->stat_sn++);
348 	login_rsp->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
349 	login_rsp->max_cmdsn		= cpu_to_be32(conn->sess->max_cmd_sn);
350 
351 	pr_debug("Sending Login Response, Flags: 0x%02x, ITT: 0x%08x,"
352 		" ExpCmdSN; 0x%08x, MaxCmdSN: 0x%08x, StatSN: 0x%08x, Length:"
353 		" %u\n", login_rsp->flags, ntohl(login_rsp->itt),
354 		ntohl(login_rsp->exp_cmdsn), ntohl(login_rsp->max_cmdsn),
355 		ntohl(login_rsp->statsn), login->rsp_length);
356 
357 	padding = ((-login->rsp_length) & 3);
358 
359 	if (iscsi_login_tx_data(
360 			conn,
361 			login->rsp,
362 			login->rsp_buf,
363 			login->rsp_length + padding) < 0)
364 		return -1;
365 
366 	login->rsp_length		= 0;
367 	login_rsp->tsih			= be16_to_cpu(login_rsp->tsih);
368 	login_rsp->itt			= be32_to_cpu(login_rsp->itt);
369 	login_rsp->statsn		= be32_to_cpu(login_rsp->statsn);
370 	mutex_lock(&sess->cmdsn_mutex);
371 	login_rsp->exp_cmdsn		= be32_to_cpu(sess->exp_cmd_sn);
372 	login_rsp->max_cmdsn		= be32_to_cpu(sess->max_cmd_sn);
373 	mutex_unlock(&sess->cmdsn_mutex);
374 
375 	return 0;
376 }
377 
378 static int iscsi_target_do_rx_login_io(struct iscsi_conn *conn, struct iscsi_login *login)
379 {
380 	u32 padding = 0, payload_length;
381 	struct iscsi_login_req *login_req;
382 
383 	if (iscsi_login_rx_data(conn, login->req, ISCSI_HDR_LEN) < 0)
384 		return -1;
385 
386 	login_req = (struct iscsi_login_req *) login->req;
387 	payload_length			= ntoh24(login_req->dlength);
388 	login_req->tsih			= be16_to_cpu(login_req->tsih);
389 	login_req->itt			= be32_to_cpu(login_req->itt);
390 	login_req->cid			= be16_to_cpu(login_req->cid);
391 	login_req->cmdsn		= be32_to_cpu(login_req->cmdsn);
392 	login_req->exp_statsn		= be32_to_cpu(login_req->exp_statsn);
393 
394 	pr_debug("Got Login Command, Flags 0x%02x, ITT: 0x%08x,"
395 		" CmdSN: 0x%08x, ExpStatSN: 0x%08x, CID: %hu, Length: %u\n",
396 		 login_req->flags, login_req->itt, login_req->cmdsn,
397 		 login_req->exp_statsn, login_req->cid, payload_length);
398 
399 	if (iscsi_target_check_login_request(conn, login) < 0)
400 		return -1;
401 
402 	padding = ((-payload_length) & 3);
403 	memset(login->req_buf, 0, MAX_KEY_VALUE_PAIRS);
404 
405 	if (iscsi_login_rx_data(
406 			conn,
407 			login->req_buf,
408 			payload_length + padding) < 0)
409 		return -1;
410 
411 	return 0;
412 }
413 
414 static int iscsi_target_do_login_io(struct iscsi_conn *conn, struct iscsi_login *login)
415 {
416 	if (iscsi_target_do_tx_login_io(conn, login) < 0)
417 		return -1;
418 
419 	if (iscsi_target_do_rx_login_io(conn, login) < 0)
420 		return -1;
421 
422 	return 0;
423 }
424 
425 static int iscsi_target_get_initial_payload(
426 	struct iscsi_conn *conn,
427 	struct iscsi_login *login)
428 {
429 	u32 padding = 0, payload_length;
430 	struct iscsi_login_req *login_req;
431 
432 	login_req = (struct iscsi_login_req *) login->req;
433 	payload_length = ntoh24(login_req->dlength);
434 
435 	pr_debug("Got Login Command, Flags 0x%02x, ITT: 0x%08x,"
436 		" CmdSN: 0x%08x, ExpStatSN: 0x%08x, Length: %u\n",
437 		login_req->flags, login_req->itt, login_req->cmdsn,
438 		login_req->exp_statsn, payload_length);
439 
440 	if (iscsi_target_check_login_request(conn, login) < 0)
441 		return -1;
442 
443 	padding = ((-payload_length) & 3);
444 
445 	if (iscsi_login_rx_data(
446 			conn,
447 			login->req_buf,
448 			payload_length + padding) < 0)
449 		return -1;
450 
451 	return 0;
452 }
453 
454 /*
455  *	NOTE: We check for existing sessions or connections AFTER the initiator
456  *	has been successfully authenticated in order to protect against faked
457  *	ISID/TSIH combinations.
458  */
459 static int iscsi_target_check_for_existing_instances(
460 	struct iscsi_conn *conn,
461 	struct iscsi_login *login)
462 {
463 	if (login->checked_for_existing)
464 		return 0;
465 
466 	login->checked_for_existing = 1;
467 
468 	if (!login->tsih)
469 		return iscsi_check_for_session_reinstatement(conn);
470 	else
471 		return iscsi_login_post_auth_non_zero_tsih(conn, login->cid,
472 				login->initial_exp_statsn);
473 }
474 
475 static int iscsi_target_do_authentication(
476 	struct iscsi_conn *conn,
477 	struct iscsi_login *login)
478 {
479 	int authret;
480 	u32 payload_length;
481 	struct iscsi_param *param;
482 	struct iscsi_login_req *login_req;
483 	struct iscsi_login_rsp *login_rsp;
484 
485 	login_req = (struct iscsi_login_req *) login->req;
486 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
487 	payload_length = ntoh24(login_req->dlength);
488 
489 	param = iscsi_find_param_from_key(AUTHMETHOD, conn->param_list);
490 	if (!param)
491 		return -1;
492 
493 	authret = iscsi_handle_authentication(
494 			conn,
495 			login->req_buf,
496 			login->rsp_buf,
497 			payload_length,
498 			&login->rsp_length,
499 			param->value);
500 	switch (authret) {
501 	case 0:
502 		pr_debug("Received OK response"
503 		" from LIO Authentication, continuing.\n");
504 		break;
505 	case 1:
506 		pr_debug("iSCSI security negotiation"
507 			" completed successfully.\n");
508 		login->auth_complete = 1;
509 		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE1) &&
510 		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
511 			login_rsp->flags |= (ISCSI_FLAG_LOGIN_NEXT_STAGE1 |
512 					     ISCSI_FLAG_LOGIN_TRANSIT);
513 			login->current_stage = 1;
514 		}
515 		return iscsi_target_check_for_existing_instances(
516 				conn, login);
517 	case 2:
518 		pr_err("Security negotiation"
519 			" failed.\n");
520 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
521 				ISCSI_LOGIN_STATUS_AUTH_FAILED);
522 		return -1;
523 	default:
524 		pr_err("Received unknown error %d from LIO"
525 				" Authentication\n", authret);
526 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
527 				ISCSI_LOGIN_STATUS_TARGET_ERROR);
528 		return -1;
529 	}
530 
531 	return 0;
532 }
533 
534 static int iscsi_target_handle_csg_zero(
535 	struct iscsi_conn *conn,
536 	struct iscsi_login *login)
537 {
538 	int ret;
539 	u32 payload_length;
540 	struct iscsi_param *param;
541 	struct iscsi_login_req *login_req;
542 	struct iscsi_login_rsp *login_rsp;
543 
544 	login_req = (struct iscsi_login_req *) login->req;
545 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
546 	payload_length = ntoh24(login_req->dlength);
547 
548 	param = iscsi_find_param_from_key(AUTHMETHOD, conn->param_list);
549 	if (!param)
550 		return -1;
551 
552 	ret = iscsi_decode_text_input(
553 			PHASE_SECURITY|PHASE_DECLARATIVE,
554 			SENDER_INITIATOR|SENDER_RECEIVER,
555 			login->req_buf,
556 			payload_length,
557 			conn->param_list);
558 	if (ret < 0)
559 		return -1;
560 
561 	if (ret > 0) {
562 		if (login->auth_complete) {
563 			pr_err("Initiator has already been"
564 				" successfully authenticated, but is still"
565 				" sending %s keys.\n", param->value);
566 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
567 					ISCSI_LOGIN_STATUS_INIT_ERR);
568 			return -1;
569 		}
570 
571 		goto do_auth;
572 	}
573 
574 	if (login->first_request)
575 		if (iscsi_target_check_first_request(conn, login) < 0)
576 			return -1;
577 
578 	ret = iscsi_encode_text_output(
579 			PHASE_SECURITY|PHASE_DECLARATIVE,
580 			SENDER_TARGET,
581 			login->rsp_buf,
582 			&login->rsp_length,
583 			conn->param_list);
584 	if (ret < 0)
585 		return -1;
586 
587 	if (!iscsi_check_negotiated_keys(conn->param_list)) {
588 		if (ISCSI_TPG_ATTRIB(ISCSI_TPG_C(conn))->authentication &&
589 		    !strncmp(param->value, NONE, 4)) {
590 			pr_err("Initiator sent AuthMethod=None but"
591 				" Target is enforcing iSCSI Authentication,"
592 					" login failed.\n");
593 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
594 					ISCSI_LOGIN_STATUS_AUTH_FAILED);
595 			return -1;
596 		}
597 
598 		if (ISCSI_TPG_ATTRIB(ISCSI_TPG_C(conn))->authentication &&
599 		    !login->auth_complete)
600 			return 0;
601 
602 		if (strncmp(param->value, NONE, 4) && !login->auth_complete)
603 			return 0;
604 
605 		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE1) &&
606 		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
607 			login_rsp->flags |= ISCSI_FLAG_LOGIN_NEXT_STAGE1 |
608 					    ISCSI_FLAG_LOGIN_TRANSIT;
609 			login->current_stage = 1;
610 		}
611 	}
612 
613 	return 0;
614 do_auth:
615 	return iscsi_target_do_authentication(conn, login);
616 }
617 
618 static int iscsi_target_handle_csg_one(struct iscsi_conn *conn, struct iscsi_login *login)
619 {
620 	int ret;
621 	u32 payload_length;
622 	struct iscsi_login_req *login_req;
623 	struct iscsi_login_rsp *login_rsp;
624 
625 	login_req = (struct iscsi_login_req *) login->req;
626 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
627 	payload_length = ntoh24(login_req->dlength);
628 
629 	ret = iscsi_decode_text_input(
630 			PHASE_OPERATIONAL|PHASE_DECLARATIVE,
631 			SENDER_INITIATOR|SENDER_RECEIVER,
632 			login->req_buf,
633 			payload_length,
634 			conn->param_list);
635 	if (ret < 0)
636 		return -1;
637 
638 	if (login->first_request)
639 		if (iscsi_target_check_first_request(conn, login) < 0)
640 			return -1;
641 
642 	if (iscsi_target_check_for_existing_instances(conn, login) < 0)
643 		return -1;
644 
645 	ret = iscsi_encode_text_output(
646 			PHASE_OPERATIONAL|PHASE_DECLARATIVE,
647 			SENDER_TARGET,
648 			login->rsp_buf,
649 			&login->rsp_length,
650 			conn->param_list);
651 	if (ret < 0)
652 		return -1;
653 
654 	if (!login->auth_complete &&
655 	     ISCSI_TPG_ATTRIB(ISCSI_TPG_C(conn))->authentication) {
656 		pr_err("Initiator is requesting CSG: 1, has not been"
657 			 " successfully authenticated, and the Target is"
658 			" enforcing iSCSI Authentication, login failed.\n");
659 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
660 				ISCSI_LOGIN_STATUS_AUTH_FAILED);
661 		return -1;
662 	}
663 
664 	if (!iscsi_check_negotiated_keys(conn->param_list))
665 		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE3) &&
666 		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT))
667 			login_rsp->flags |= ISCSI_FLAG_LOGIN_NEXT_STAGE3 |
668 					    ISCSI_FLAG_LOGIN_TRANSIT;
669 
670 	return 0;
671 }
672 
673 static int iscsi_target_do_login(struct iscsi_conn *conn, struct iscsi_login *login)
674 {
675 	int pdu_count = 0;
676 	struct iscsi_login_req *login_req;
677 	struct iscsi_login_rsp *login_rsp;
678 
679 	login_req = (struct iscsi_login_req *) login->req;
680 	login_rsp = (struct iscsi_login_rsp *) login->rsp;
681 
682 	while (1) {
683 		if (++pdu_count > MAX_LOGIN_PDUS) {
684 			pr_err("MAX_LOGIN_PDUS count reached.\n");
685 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
686 					ISCSI_LOGIN_STATUS_TARGET_ERROR);
687 			return -1;
688 		}
689 
690 		switch ((login_req->flags & ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK) >> 2) {
691 		case 0:
692 			login_rsp->flags |= (0 & ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK);
693 			if (iscsi_target_handle_csg_zero(conn, login) < 0)
694 				return -1;
695 			break;
696 		case 1:
697 			login_rsp->flags |= ISCSI_FLAG_LOGIN_CURRENT_STAGE1;
698 			if (iscsi_target_handle_csg_one(conn, login) < 0)
699 				return -1;
700 			if (login_rsp->flags & ISCSI_FLAG_LOGIN_TRANSIT) {
701 				login->tsih = conn->sess->tsih;
702 				if (iscsi_target_do_tx_login_io(conn,
703 						login) < 0)
704 					return -1;
705 				return 0;
706 			}
707 			break;
708 		default:
709 			pr_err("Illegal CSG: %d received from"
710 				" Initiator, protocol error.\n",
711 				(login_req->flags & ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK)
712 				>> 2);
713 			break;
714 		}
715 
716 		if (iscsi_target_do_login_io(conn, login) < 0)
717 			return -1;
718 
719 		if (login_rsp->flags & ISCSI_FLAG_LOGIN_TRANSIT) {
720 			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_TRANSIT;
721 			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK;
722 		}
723 	}
724 
725 	return 0;
726 }
727 
728 static void iscsi_initiatorname_tolower(
729 	char *param_buf)
730 {
731 	char *c;
732 	u32 iqn_size = strlen(param_buf), i;
733 
734 	for (i = 0; i < iqn_size; i++) {
735 		c = (char *)&param_buf[i];
736 		if (!isupper(*c))
737 			continue;
738 
739 		*c = tolower(*c);
740 	}
741 }
742 
743 /*
744  * Processes the first Login Request..
745  */
746 static int iscsi_target_locate_portal(
747 	struct iscsi_np *np,
748 	struct iscsi_conn *conn,
749 	struct iscsi_login *login)
750 {
751 	char *i_buf = NULL, *s_buf = NULL, *t_buf = NULL;
752 	char *tmpbuf, *start = NULL, *end = NULL, *key, *value;
753 	struct iscsi_session *sess = conn->sess;
754 	struct iscsi_tiqn *tiqn;
755 	struct iscsi_login_req *login_req;
756 	struct iscsi_targ_login_rsp *login_rsp;
757 	u32 payload_length;
758 	int sessiontype = 0, ret = 0;
759 
760 	login_req = (struct iscsi_login_req *) login->req;
761 	login_rsp = (struct iscsi_targ_login_rsp *) login->rsp;
762 	payload_length = ntoh24(login_req->dlength);
763 
764 	login->first_request	= 1;
765 	login->leading_connection = (!login_req->tsih) ? 1 : 0;
766 	login->current_stage	=
767 		(login_req->flags & ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK) >> 2;
768 	login->version_min	= login_req->min_version;
769 	login->version_max	= login_req->max_version;
770 	memcpy(login->isid, login_req->isid, 6);
771 	login->cmd_sn		= login_req->cmdsn;
772 	login->init_task_tag	= login_req->itt;
773 	login->initial_exp_statsn = login_req->exp_statsn;
774 	login->cid		= login_req->cid;
775 	login->tsih		= login_req->tsih;
776 
777 	if (iscsi_target_get_initial_payload(conn, login) < 0)
778 		return -1;
779 
780 	tmpbuf = kzalloc(payload_length + 1, GFP_KERNEL);
781 	if (!tmpbuf) {
782 		pr_err("Unable to allocate memory for tmpbuf.\n");
783 		return -1;
784 	}
785 
786 	memcpy(tmpbuf, login->req_buf, payload_length);
787 	tmpbuf[payload_length] = '\0';
788 	start = tmpbuf;
789 	end = (start + payload_length);
790 
791 	/*
792 	 * Locate the initial keys expected from the Initiator node in
793 	 * the first login request in order to progress with the login phase.
794 	 */
795 	while (start < end) {
796 		if (iscsi_extract_key_value(start, &key, &value) < 0) {
797 			ret = -1;
798 			goto out;
799 		}
800 
801 		if (!strncmp(key, "InitiatorName", 13))
802 			i_buf = value;
803 		else if (!strncmp(key, "SessionType", 11))
804 			s_buf = value;
805 		else if (!strncmp(key, "TargetName", 10))
806 			t_buf = value;
807 
808 		start += strlen(key) + strlen(value) + 2;
809 	}
810 
811 	/*
812 	 * See 5.3.  Login Phase.
813 	 */
814 	if (!i_buf) {
815 		pr_err("InitiatorName key not received"
816 			" in first login request.\n");
817 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
818 			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
819 		ret = -1;
820 		goto out;
821 	}
822 	/*
823 	 * Convert the incoming InitiatorName to lowercase following
824 	 * RFC-3720 3.2.6.1. section c) that says that iSCSI IQNs
825 	 * are NOT case sensitive.
826 	 */
827 	iscsi_initiatorname_tolower(i_buf);
828 
829 	if (!s_buf) {
830 		if (!login->leading_connection)
831 			goto get_target;
832 
833 		pr_err("SessionType key not received"
834 			" in first login request.\n");
835 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
836 			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
837 		ret = -1;
838 		goto out;
839 	}
840 
841 	/*
842 	 * Use default portal group for discovery sessions.
843 	 */
844 	sessiontype = strncmp(s_buf, DISCOVERY, 9);
845 	if (!sessiontype) {
846 		conn->tpg = iscsit_global->discovery_tpg;
847 		if (!login->leading_connection)
848 			goto get_target;
849 
850 		sess->sess_ops->SessionType = 1;
851 		/*
852 		 * Setup crc32c modules from libcrypto
853 		 */
854 		if (iscsi_login_setup_crypto(conn) < 0) {
855 			pr_err("iscsi_login_setup_crypto() failed\n");
856 			ret = -1;
857 			goto out;
858 		}
859 		/*
860 		 * Serialize access across the discovery struct iscsi_portal_group to
861 		 * process login attempt.
862 		 */
863 		if (iscsit_access_np(np, conn->tpg) < 0) {
864 			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
865 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
866 			ret = -1;
867 			goto out;
868 		}
869 		ret = 0;
870 		goto out;
871 	}
872 
873 get_target:
874 	if (!t_buf) {
875 		pr_err("TargetName key not received"
876 			" in first login request while"
877 			" SessionType=Normal.\n");
878 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
879 			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
880 		ret = -1;
881 		goto out;
882 	}
883 
884 	/*
885 	 * Locate Target IQN from Storage Node.
886 	 */
887 	tiqn = iscsit_get_tiqn_for_login(t_buf);
888 	if (!tiqn) {
889 		pr_err("Unable to locate Target IQN: %s in"
890 			" Storage Node\n", t_buf);
891 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
892 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
893 		ret = -1;
894 		goto out;
895 	}
896 	pr_debug("Located Storage Object: %s\n", tiqn->tiqn);
897 
898 	/*
899 	 * Locate Target Portal Group from Storage Node.
900 	 */
901 	conn->tpg = iscsit_get_tpg_from_np(tiqn, np);
902 	if (!conn->tpg) {
903 		pr_err("Unable to locate Target Portal Group"
904 				" on %s\n", tiqn->tiqn);
905 		iscsit_put_tiqn_for_login(tiqn);
906 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
907 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
908 		ret = -1;
909 		goto out;
910 	}
911 	pr_debug("Located Portal Group Object: %hu\n", conn->tpg->tpgt);
912 	/*
913 	 * Setup crc32c modules from libcrypto
914 	 */
915 	if (iscsi_login_setup_crypto(conn) < 0) {
916 		pr_err("iscsi_login_setup_crypto() failed\n");
917 		ret = -1;
918 		goto out;
919 	}
920 	/*
921 	 * Serialize access across the struct iscsi_portal_group to
922 	 * process login attempt.
923 	 */
924 	if (iscsit_access_np(np, conn->tpg) < 0) {
925 		iscsit_put_tiqn_for_login(tiqn);
926 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
927 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
928 		ret = -1;
929 		conn->tpg = NULL;
930 		goto out;
931 	}
932 
933 	/*
934 	 * conn->sess->node_acl will be set when the referenced
935 	 * struct iscsi_session is located from received ISID+TSIH in
936 	 * iscsi_login_non_zero_tsih_s2().
937 	 */
938 	if (!login->leading_connection) {
939 		ret = 0;
940 		goto out;
941 	}
942 
943 	/*
944 	 * This value is required in iscsi_login_zero_tsih_s2()
945 	 */
946 	sess->sess_ops->SessionType = 0;
947 
948 	/*
949 	 * Locate incoming Initiator IQN reference from Storage Node.
950 	 */
951 	sess->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
952 			&conn->tpg->tpg_se_tpg, i_buf);
953 	if (!sess->se_sess->se_node_acl) {
954 		pr_err("iSCSI Initiator Node: %s is not authorized to"
955 			" access iSCSI target portal group: %hu.\n",
956 				i_buf, conn->tpg->tpgt);
957 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
958 				ISCSI_LOGIN_STATUS_TGT_FORBIDDEN);
959 		ret = -1;
960 		goto out;
961 	}
962 
963 	ret = 0;
964 out:
965 	kfree(tmpbuf);
966 	return ret;
967 }
968 
969 struct iscsi_login *iscsi_target_init_negotiation(
970 	struct iscsi_np *np,
971 	struct iscsi_conn *conn,
972 	char *login_pdu)
973 {
974 	struct iscsi_login *login;
975 
976 	login = kzalloc(sizeof(struct iscsi_login), GFP_KERNEL);
977 	if (!login) {
978 		pr_err("Unable to allocate memory for struct iscsi_login.\n");
979 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
980 				ISCSI_LOGIN_STATUS_NO_RESOURCES);
981 		return NULL;
982 	}
983 
984 	login->req = kzalloc(ISCSI_HDR_LEN, GFP_KERNEL);
985 	if (!login->req) {
986 		pr_err("Unable to allocate memory for Login Request.\n");
987 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
988 				ISCSI_LOGIN_STATUS_NO_RESOURCES);
989 		goto out;
990 	}
991 	memcpy(login->req, login_pdu, ISCSI_HDR_LEN);
992 
993 	login->req_buf = kzalloc(MAX_KEY_VALUE_PAIRS, GFP_KERNEL);
994 	if (!login->req_buf) {
995 		pr_err("Unable to allocate memory for response buffer.\n");
996 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
997 				ISCSI_LOGIN_STATUS_NO_RESOURCES);
998 		goto out;
999 	}
1000 	/*
1001 	 * SessionType: Discovery
1002 	 *
1003 	 *	Locates Default Portal
1004 	 *
1005 	 * SessionType: Normal
1006 	 *
1007 	 *	Locates Target Portal from NP -> Target IQN
1008 	 */
1009 	if (iscsi_target_locate_portal(np, conn, login) < 0) {
1010 		pr_err("iSCSI Login negotiation failed.\n");
1011 		goto out;
1012 	}
1013 
1014 	return login;
1015 out:
1016 	kfree(login->req);
1017 	kfree(login->req_buf);
1018 	kfree(login);
1019 
1020 	return NULL;
1021 }
1022 
1023 int iscsi_target_start_negotiation(
1024 	struct iscsi_login *login,
1025 	struct iscsi_conn *conn)
1026 {
1027 	int ret = -1;
1028 
1029 	login->rsp = kzalloc(ISCSI_HDR_LEN, GFP_KERNEL);
1030 	if (!login->rsp) {
1031 		pr_err("Unable to allocate memory for"
1032 				" Login Response.\n");
1033 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1034 				ISCSI_LOGIN_STATUS_NO_RESOURCES);
1035 		ret = -1;
1036 		goto out;
1037 	}
1038 
1039 	login->rsp_buf = kzalloc(MAX_KEY_VALUE_PAIRS, GFP_KERNEL);
1040 	if (!login->rsp_buf) {
1041 		pr_err("Unable to allocate memory for"
1042 			" request buffer.\n");
1043 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
1044 				ISCSI_LOGIN_STATUS_NO_RESOURCES);
1045 		ret = -1;
1046 		goto out;
1047 	}
1048 
1049 	ret = iscsi_target_do_login(conn, login);
1050 out:
1051 	if (ret != 0)
1052 		iscsi_remove_failed_auth_entry(conn);
1053 
1054 	iscsi_target_nego_release(login, conn);
1055 	return ret;
1056 }
1057 
1058 void iscsi_target_nego_release(
1059 	struct iscsi_login *login,
1060 	struct iscsi_conn *conn)
1061 {
1062 	kfree(login->req);
1063 	kfree(login->rsp);
1064 	kfree(login->req_buf);
1065 	kfree(login->rsp_buf);
1066 	kfree(login);
1067 }
1068