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