1/*-
2 * Copyright (c) 2012 The FreeBSD Foundation
3 * All rights reserved.
4 *
5 * This software was developed by Edward Tomasz Napierala under sponsorship
6 * from the FreeBSD Foundation.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: stable/10/usr.sbin/ctld/login.c 276613 2015-01-03 13:08:08Z mav $");
33
34#include <assert.h>
35#include <stdbool.h>
36#include <stdint.h>
37#include <stdio.h>
38#include <stdlib.h>
39#include <string.h>
40#include <unistd.h>
41#include <netinet/in.h>
42
43#include "ctld.h"
44#include "iscsi_proto.h"
45
46static void login_send_error(struct pdu *request,
47 char class, char detail);
48
49static void
50login_set_nsg(struct pdu *response, int nsg)
51{
52 struct iscsi_bhs_login_response *bhslr;
53
54 assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
55 nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
56 nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
57
58 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
59
60 bhslr->bhslr_flags &= 0xFC;
61 bhslr->bhslr_flags |= nsg;
62}
63
64static int
65login_csg(const struct pdu *request)
66{
67 struct iscsi_bhs_login_request *bhslr;
68
69 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
70
71 return ((bhslr->bhslr_flags & 0x0C) >> 2);
72}
73
74static void
75login_set_csg(struct pdu *response, int csg)
76{
77 struct iscsi_bhs_login_response *bhslr;
78
79 assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
80 csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
81 csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
82
83 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
84
85 bhslr->bhslr_flags &= 0xF3;
86 bhslr->bhslr_flags |= csg << 2;
87}
88
89static struct pdu *
90login_receive(struct connection *conn, bool initial)
91{
92 struct pdu *request;
93 struct iscsi_bhs_login_request *bhslr;
94
95 request = pdu_new(conn);
96 pdu_receive(request);
97 if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) !=
98 ISCSI_BHS_OPCODE_LOGIN_REQUEST) {
99 /*
100 * The first PDU in session is special - if we receive any PDU
101 * different than login request, we have to drop the connection
102 * without sending response ("A target receiving any PDU
103 * except a Login request before the Login Phase is started MUST
104 * immediately terminate the connection on which the PDU
105 * was received.")
106 */
107 if (initial == false)
108 login_send_error(request, 0x02, 0x0b);
109 log_errx(1, "protocol error: received invalid opcode 0x%x",
110 request->pdu_bhs->bhs_opcode);
111 }
112 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
113 /*
114 * XXX: Implement the C flag some day.
115 */
116 if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0) {
117 login_send_error(request, 0x03, 0x00);
118 log_errx(1, "received Login PDU with unsupported \"C\" flag");
119 }
120 if (bhslr->bhslr_version_max != 0x00) {
121 login_send_error(request, 0x02, 0x05);
122 log_errx(1, "received Login PDU with unsupported "
123 "Version-max 0x%x", bhslr->bhslr_version_max);
124 }
125 if (bhslr->bhslr_version_min != 0x00) {
126 login_send_error(request, 0x02, 0x05);
127 log_errx(1, "received Login PDU with unsupported "
128 "Version-min 0x%x", bhslr->bhslr_version_min);
129 }
130 if (ISCSI_SNLT(ntohl(bhslr->bhslr_cmdsn), conn->conn_cmdsn)) {
131 login_send_error(request, 0x02, 0x05);
132 log_errx(1, "received Login PDU with decreasing CmdSN: "
133 "was %u, is %u", conn->conn_cmdsn,
134 ntohl(bhslr->bhslr_cmdsn));
135 }
136 if (initial == false &&
137 ntohl(bhslr->bhslr_expstatsn) != conn->conn_statsn) {
138 login_send_error(request, 0x02, 0x05);
139 log_errx(1, "received Login PDU with wrong ExpStatSN: "
140 "is %u, should be %u", ntohl(bhslr->bhslr_expstatsn),
141 conn->conn_statsn);
142 }
143 conn->conn_cmdsn = ntohl(bhslr->bhslr_cmdsn);
144
145 return (request);
146}
147
148static struct pdu *
149login_new_response(struct pdu *request)
150{
151 struct pdu *response;
152 struct connection *conn;
153 struct iscsi_bhs_login_request *bhslr;
154 struct iscsi_bhs_login_response *bhslr2;
155
156 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
157 conn = request->pdu_connection;
158
159 response = pdu_new_response(request);
160 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
161 bhslr2->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_RESPONSE;
162 login_set_csg(response, BHSLR_STAGE_SECURITY_NEGOTIATION);
163 memcpy(bhslr2->bhslr_isid,
164 bhslr->bhslr_isid, sizeof(bhslr2->bhslr_isid));
165 bhslr2->bhslr_initiator_task_tag = bhslr->bhslr_initiator_task_tag;
166 bhslr2->bhslr_statsn = htonl(conn->conn_statsn++);
167 bhslr2->bhslr_expcmdsn = htonl(conn->conn_cmdsn);
168 bhslr2->bhslr_maxcmdsn = htonl(conn->conn_cmdsn);
169
170 return (response);
171}
172
173static void
174login_send_error(struct pdu *request, char class, char detail)
175{
176 struct pdu *response;
177 struct iscsi_bhs_login_response *bhslr2;
178
179 log_debugx("sending Login Response PDU with failure class 0x%x/0x%x; "
180 "see next line for reason", class, detail);
181 response = login_new_response(request);
182 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
183 bhslr2->bhslr_status_class = class;
184 bhslr2->bhslr_status_detail = detail;
185
186 pdu_send(response);
187 pdu_delete(response);
188}
189
190static int
191login_list_contains(const char *list, const char *what)
192{
193 char *tofree, *str, *token;
194
195 tofree = str = checked_strdup(list);
196
197 while ((token = strsep(&str, ",")) != NULL) {
198 if (strcmp(token, what) == 0) {
199 free(tofree);
200 return (1);
201 }
202 }
203 free(tofree);
204 return (0);
205}
206
207static int
208login_list_prefers(const char *list,
209 const char *choice1, const char *choice2)
210{
211 char *tofree, *str, *token;
212
213 tofree = str = checked_strdup(list);
214
215 while ((token = strsep(&str, ",")) != NULL) {
216 if (strcmp(token, choice1) == 0) {
217 free(tofree);
218 return (1);
219 }
220 if (strcmp(token, choice2) == 0) {
221 free(tofree);
222 return (2);
223 }
224 }
225 free(tofree);
226 return (-1);
227}
228
229static struct pdu *
230login_receive_chap_a(struct connection *conn)
231{
232 struct pdu *request;
233 struct keys *request_keys;
234 const char *chap_a;
235
236 request = login_receive(conn, false);
237 request_keys = keys_new();
238 keys_load(request_keys, request);
239
240 chap_a = keys_find(request_keys, "CHAP_A");
241 if (chap_a == NULL) {
242 login_send_error(request, 0x02, 0x07);
243 log_errx(1, "received CHAP Login PDU without CHAP_A");
244 }
245 if (login_list_contains(chap_a, "5") == 0) {
246 login_send_error(request, 0x02, 0x01);
247 log_errx(1, "received CHAP Login PDU with unsupported CHAP_A "
248 "\"%s\"", chap_a);
249 }
250 keys_delete(request_keys);
251
252 return (request);
253}
254
255static void
256login_send_chap_c(struct pdu *request, struct chap *chap)
257{
258 struct pdu *response;
259 struct keys *response_keys;
260 char *chap_c, *chap_i;
261
262 chap_c = chap_get_challenge(chap);
263 chap_i = chap_get_id(chap);
264
265 response = login_new_response(request);
266 response_keys = keys_new();
267 keys_add(response_keys, "CHAP_A", "5");
268 keys_add(response_keys, "CHAP_I", chap_i);
269 keys_add(response_keys, "CHAP_C", chap_c);
270 free(chap_i);
271 free(chap_c);
272 keys_save(response_keys, response);
273 pdu_send(response);
274 pdu_delete(response);
275 keys_delete(response_keys);
276}
277
278static struct pdu *
279login_receive_chap_r(struct connection *conn, struct auth_group *ag,
280 struct chap *chap, const struct auth **authp)
281{
282 struct pdu *request;
283 struct keys *request_keys;
284 const char *chap_n, *chap_r;
285 const struct auth *auth;
286 int error;
287
288 request = login_receive(conn, false);
289 request_keys = keys_new();
290 keys_load(request_keys, request);
291
292 chap_n = keys_find(request_keys, "CHAP_N");
293 if (chap_n == NULL) {
294 login_send_error(request, 0x02, 0x07);
295 log_errx(1, "received CHAP Login PDU without CHAP_N");
296 }
297 chap_r = keys_find(request_keys, "CHAP_R");
298 if (chap_r == NULL) {
299 login_send_error(request, 0x02, 0x07);
300 log_errx(1, "received CHAP Login PDU without CHAP_R");
301 }
302 error = chap_receive(chap, chap_r);
303 if (error != 0) {
304 login_send_error(request, 0x02, 0x07);
305 log_errx(1, "received CHAP Login PDU with malformed CHAP_R");
306 }
307
308 /*
309 * Verify the response.
310 */
311 assert(ag->ag_type == AG_TYPE_CHAP ||
312 ag->ag_type == AG_TYPE_CHAP_MUTUAL);
313 auth = auth_find(ag, chap_n);
314 if (auth == NULL) {
315 login_send_error(request, 0x02, 0x01);
316 log_errx(1, "received CHAP Login with invalid user \"%s\"",
317 chap_n);
318 }
319
320 assert(auth->a_secret != NULL);
321 assert(strlen(auth->a_secret) > 0);
322
323 error = chap_authenticate(chap, auth->a_secret);
324 if (error != 0) {
325 login_send_error(request, 0x02, 0x01);
326 log_errx(1, "CHAP authentication failed for user \"%s\"",
327 auth->a_user);
328 }
329
330 keys_delete(request_keys);
331
332 *authp = auth;
333 return (request);
334}
335
336static void
337login_send_chap_success(struct pdu *request,
338 const struct auth *auth)
339{
340 struct pdu *response;
341 struct keys *request_keys, *response_keys;
342 struct iscsi_bhs_login_response *bhslr2;
343 struct rchap *rchap;
344 const char *chap_i, *chap_c;
345 char *chap_r;
346 int error;
347
348 response = login_new_response(request);
349 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
350 bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
351 login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
352
353 /*
354 * Actually, one more thing: mutual authentication.
355 */
356 request_keys = keys_new();
357 keys_load(request_keys, request);
358 chap_i = keys_find(request_keys, "CHAP_I");
359 chap_c = keys_find(request_keys, "CHAP_C");
360 if (chap_i != NULL || chap_c != NULL) {
361 if (chap_i == NULL) {
362 login_send_error(request, 0x02, 0x07);
363 log_errx(1, "initiator requested target "
364 "authentication, but didn't send CHAP_I");
365 }
366 if (chap_c == NULL) {
367 login_send_error(request, 0x02, 0x07);
368 log_errx(1, "initiator requested target "
369 "authentication, but didn't send CHAP_C");
370 }
371 if (auth->a_auth_group->ag_type != AG_TYPE_CHAP_MUTUAL) {
372 login_send_error(request, 0x02, 0x01);
373 log_errx(1, "initiator requests target authentication "
374 "for user \"%s\", but mutual user/secret "
375 "is not set", auth->a_user);
376 }
377
378 log_debugx("performing mutual authentication as user \"%s\"",
379 auth->a_mutual_user);
380
381 rchap = rchap_new(auth->a_mutual_secret);
382 error = rchap_receive(rchap, chap_i, chap_c);
383 if (error != 0) {
384 login_send_error(request, 0x02, 0x07);
385 log_errx(1, "received CHAP Login PDU with malformed "
386 "CHAP_I or CHAP_C");
387 }
388 chap_r = rchap_get_response(rchap);
389 rchap_delete(rchap);
390 response_keys = keys_new();
391 keys_add(response_keys, "CHAP_N", auth->a_mutual_user);
392 keys_add(response_keys, "CHAP_R", chap_r);
393 free(chap_r);
394 keys_save(response_keys, response);
395 keys_delete(response_keys);
396 } else {
397 log_debugx("initiator did not request target authentication");
398 }
399
400 keys_delete(request_keys);
401 pdu_send(response);
402 pdu_delete(response);
403}
404
405static void
406login_chap(struct connection *conn, struct auth_group *ag)
407{
408 const struct auth *auth;
409 struct chap *chap;
410 struct pdu *request;
411
412 /*
413 * Receive CHAP_A PDU.
414 */
415 log_debugx("beginning CHAP authentication; waiting for CHAP_A");
416 request = login_receive_chap_a(conn);
417
418 /*
419 * Generate the challenge.
420 */
421 chap = chap_new();
422
423 /*
424 * Send the challenge.
425 */
426 log_debugx("sending CHAP_C, binary challenge size is %zd bytes",
427 sizeof(chap->chap_challenge));
428 login_send_chap_c(request, chap);
429 pdu_delete(request);
430
431 /*
432 * Receive CHAP_N/CHAP_R PDU and authenticate.
433 */
434 log_debugx("waiting for CHAP_N/CHAP_R");
435 request = login_receive_chap_r(conn, ag, chap, &auth);
436
437 /*
438 * Yay, authentication succeeded!
439 */
440 log_debugx("authentication succeeded for user \"%s\"; "
441 "transitioning to Negotiation Phase", auth->a_user);
442 login_send_chap_success(request, auth);
443 pdu_delete(request);
444
445 /*
446 * Leave username and CHAP information for discovery().
447 */
448 conn->conn_user = auth->a_user;
449 conn->conn_chap = chap;
450}
451
452static void
453login_negotiate_key(struct pdu *request, const char *name,
454 const char *value, bool skipped_security, struct keys *response_keys)
455{
456 int which, tmp;
457 struct connection *conn;
458
459 conn = request->pdu_connection;
460
461 if (strcmp(name, "InitiatorName") == 0) {
462 if (!skipped_security)
463 log_errx(1, "initiator resent InitiatorName");
464 } else if (strcmp(name, "SessionType") == 0) {
465 if (!skipped_security)
466 log_errx(1, "initiator resent SessionType");
467 } else if (strcmp(name, "TargetName") == 0) {
468 if (!skipped_security)
469 log_errx(1, "initiator resent TargetName");
470 } else if (strcmp(name, "InitiatorAlias") == 0) {
471 if (conn->conn_initiator_alias != NULL)
472 free(conn->conn_initiator_alias);
473 conn->conn_initiator_alias = checked_strdup(value);
474 } else if (strcmp(value, "Irrelevant") == 0) {
475 /* Ignore. */
476 } else if (strcmp(name, "HeaderDigest") == 0) {
477 /*
478 * We don't handle digests for discovery sessions.
479 */
480 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
481 log_debugx("discovery session; digests disabled");
482 keys_add(response_keys, name, "None");
483 return;
484 }
485
486 which = login_list_prefers(value, "CRC32C", "None");
487 switch (which) {
488 case 1:
489 log_debugx("initiator prefers CRC32C "
490 "for header digest; we'll use it");
491 conn->conn_header_digest = CONN_DIGEST_CRC32C;
492 keys_add(response_keys, name, "CRC32C");
493 break;
494 case 2:
495 log_debugx("initiator prefers not to do "
496 "header digest; we'll comply");
497 keys_add(response_keys, name, "None");
498 break;
499 default:
500 log_warnx("initiator sent unrecognized "
501 "HeaderDigest value \"%s\"; will use None", value);
502 keys_add(response_keys, name, "None");
503 break;
504 }
505 } else if (strcmp(name, "DataDigest") == 0) {
506 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
507 log_debugx("discovery session; digests disabled");
508 keys_add(response_keys, name, "None");
509 return;
510 }
511
512 which = login_list_prefers(value, "CRC32C", "None");
513 switch (which) {
514 case 1:
515 log_debugx("initiator prefers CRC32C "
516 "for data digest; we'll use it");
517 conn->conn_data_digest = CONN_DIGEST_CRC32C;
518 keys_add(response_keys, name, "CRC32C");
519 break;
520 case 2:
521 log_debugx("initiator prefers not to do "
522 "data digest; we'll comply");
523 keys_add(response_keys, name, "None");
524 break;
525 default:
526 log_warnx("initiator sent unrecognized "
527 "DataDigest value \"%s\"; will use None", value);
528 keys_add(response_keys, name, "None");
529 break;
530 }
531 } else if (strcmp(name, "MaxConnections") == 0) {
532 keys_add(response_keys, name, "1");
533 } else if (strcmp(name, "InitialR2T") == 0) {
534 keys_add(response_keys, name, "Yes");
535 } else if (strcmp(name, "ImmediateData") == 0) {
536 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
537 log_debugx("discovery session; ImmediateData irrelevant");
538 keys_add(response_keys, name, "Irrelevant");
539 } else {
540 if (strcmp(value, "Yes") == 0) {
541 conn->conn_immediate_data = true;
542 keys_add(response_keys, name, "Yes");
543 } else {
544 conn->conn_immediate_data = false;
545 keys_add(response_keys, name, "No");
546 }
547 }
548 } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
549 tmp = strtoul(value, NULL, 10);
550 if (tmp <= 0) {
551 login_send_error(request, 0x02, 0x00);
552 log_errx(1, "received invalid "
553 "MaxRecvDataSegmentLength");
554 }
555 if (tmp > MAX_DATA_SEGMENT_LENGTH) {
556 log_debugx("capping MaxRecvDataSegmentLength "
557 "from %d to %d", tmp, MAX_DATA_SEGMENT_LENGTH);
558 tmp = MAX_DATA_SEGMENT_LENGTH;
559 }
560 conn->conn_max_data_segment_length = tmp;
561 keys_add_int(response_keys, name, MAX_DATA_SEGMENT_LENGTH);
562 } else if (strcmp(name, "MaxBurstLength") == 0) {
563 tmp = strtoul(value, NULL, 10);
564 if (tmp <= 0) {
565 login_send_error(request, 0x02, 0x00);
566 log_errx(1, "received invalid MaxBurstLength");
567 }
568 if (tmp > MAX_BURST_LENGTH) {
569 log_debugx("capping MaxBurstLength from %d to %d",
570 tmp, MAX_BURST_LENGTH);
571 tmp = MAX_BURST_LENGTH;
572 }
573 conn->conn_max_burst_length = tmp;
574 keys_add(response_keys, name, value);
575 } else if (strcmp(name, "FirstBurstLength") == 0) {
576 tmp = strtoul(value, NULL, 10);
577 if (tmp <= 0) {
578 login_send_error(request, 0x02, 0x00);
579 log_errx(1, "received invalid "
580 "FirstBurstLength");
581 }
582 if (tmp > MAX_DATA_SEGMENT_LENGTH) {
583 log_debugx("capping FirstBurstLength from %d to %d",
584 tmp, MAX_DATA_SEGMENT_LENGTH);
585 tmp = MAX_DATA_SEGMENT_LENGTH;
586 }
587 /*
588 * We don't pass the value to the kernel; it only enforces
589 * hardcoded limit anyway.
590 */
591 keys_add_int(response_keys, name, tmp);
592 } else if (strcmp(name, "DefaultTime2Wait") == 0) {
593 keys_add(response_keys, name, value);
594 } else if (strcmp(name, "DefaultTime2Retain") == 0) {
595 keys_add(response_keys, name, "0");
596 } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
597 keys_add(response_keys, name, "1");
598 } else if (strcmp(name, "DataPDUInOrder") == 0) {
599 keys_add(response_keys, name, "Yes");
600 } else if (strcmp(name, "DataSequenceInOrder") == 0) {
601 keys_add(response_keys, name, "Yes");
602 } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
603 keys_add(response_keys, name, "0");
604 } else if (strcmp(name, "OFMarker") == 0) {
605 keys_add(response_keys, name, "No");
606 } else if (strcmp(name, "IFMarker") == 0) {
607 keys_add(response_keys, name, "No");
608 } else {
609 log_debugx("unknown key \"%s\"; responding "
610 "with NotUnderstood", name);
611 keys_add(response_keys, name, "NotUnderstood");
612 }
613}
614
615static void
616login_redirect(struct pdu *request, const char *target_address)
617{
618 struct pdu *response;
619 struct iscsi_bhs_login_response *bhslr2;
620 struct keys *response_keys;
621
622 response = login_new_response(request);
623 login_set_csg(response, login_csg(request));
624 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
625 bhslr2->bhslr_status_class = 0x01;
626 bhslr2->bhslr_status_detail = 0x01;
627
628 response_keys = keys_new();
629 keys_add(response_keys, "TargetAddress", target_address);
630
631 keys_save(response_keys, response);
632 pdu_send(response);
633 pdu_delete(response);
634 keys_delete(response_keys);
635}
636
637static bool
638login_portal_redirect(struct connection *conn, struct pdu *request)
639{
640 const struct portal_group *pg;
641
642 pg = conn->conn_portal->p_portal_group;
643 if (pg->pg_redirection == NULL)
644 return (false);
645
646 log_debugx("portal-group \"%s\" configured to redirect to %s",
647 pg->pg_name, pg->pg_redirection);
648 login_redirect(request, pg->pg_redirection);
649
650 return (true);
651}
652
653static bool
654login_target_redirect(struct connection *conn, struct pdu *request)
655{
656 const char *target_address;
657
658 assert(conn->conn_portal->p_portal_group->pg_redirection == NULL);
659
660 if (conn->conn_target == NULL)
661 return (false);
662
663 target_address = conn->conn_target->t_redirection;
664 if (target_address == NULL)
665 return (false);
666
667 log_debugx("target \"%s\" configured to redirect to %s",
668 conn->conn_target->t_name, target_address);
669 login_redirect(request, target_address);
670
671 return (true);
672}
673
674static void
675login_negotiate(struct connection *conn, struct pdu *request)
676{
677 struct pdu *response;
678 struct iscsi_bhs_login_response *bhslr2;
679 struct keys *request_keys, *response_keys;
680 int i;
681 bool redirected, skipped_security;
682
683 if (request == NULL) {
684 log_debugx("beginning operational parameter negotiation; "
685 "waiting for Login PDU");
686 request = login_receive(conn, false);
687 skipped_security = false;
688 } else
689 skipped_security = true;
690
691 /*
692 * RFC 3720, 10.13.5. Status-Class and Status-Detail, says
693 * the redirection SHOULD be accepted by the initiator before
694 * authentication, but MUST be be accepted afterwards; that's
695 * why we're doing it here and not earlier.
696 */
697 redirected = login_target_redirect(conn, request);
698 if (redirected) {
699 log_debugx("initiator redirected; exiting");
700 exit(0);
701 }
702
703 request_keys = keys_new();
704 keys_load(request_keys, request);
705
706 response = login_new_response(request);
707 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
708 bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
709 bhslr2->bhslr_tsih = htons(0xbadd);
710 login_set_csg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
711 login_set_nsg(response, BHSLR_STAGE_FULL_FEATURE_PHASE);
712 response_keys = keys_new();
713
714 if (skipped_security &&
715 conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
716 if (conn->conn_target->t_alias != NULL)
717 keys_add(response_keys,
718 "TargetAlias", conn->conn_target->t_alias);
719 keys_add_int(response_keys, "TargetPortalGroupTag",
720 conn->conn_portal->p_portal_group->pg_tag);
721 }
722
723 for (i = 0; i < KEYS_MAX; i++) {
724 if (request_keys->keys_names[i] == NULL)
725 break;
726
727 login_negotiate_key(request, request_keys->keys_names[i],
728 request_keys->keys_values[i], skipped_security,
729 response_keys);
730 }
731
732 log_debugx("operational parameter negotiation done; "
733 "transitioning to Full Feature Phase");
734
735 keys_save(response_keys, response);
736 pdu_send(response);
737 pdu_delete(response);
738 keys_delete(response_keys);
739 pdu_delete(request);
740 keys_delete(request_keys);
741}
742
743void
744login(struct connection *conn)
745{
746 struct pdu *request, *response;
747 struct iscsi_bhs_login_request *bhslr;
748 struct iscsi_bhs_login_response *bhslr2;
749 struct keys *request_keys, *response_keys;
750 struct auth_group *ag;
751 struct portal_group *pg;
752 const char *initiator_name, *initiator_alias, *session_type,
753 *target_name, *auth_method;
754 bool redirected;
755
756 /*
757 * Handle the initial Login Request - figure out required authentication
758 * method and either transition to the next phase, if no authentication
759 * is required, or call appropriate authentication code.
760 */
761 log_debugx("beginning Login Phase; waiting for Login PDU");
762 request = login_receive(conn, true);
763 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
764 if (bhslr->bhslr_tsih != 0) {
765 login_send_error(request, 0x02, 0x0a);
766 log_errx(1, "received Login PDU with non-zero TSIH");
767 }
768
769 pg = conn->conn_portal->p_portal_group;
770
771 memcpy(conn->conn_initiator_isid, bhslr->bhslr_isid,
772 sizeof(conn->conn_initiator_isid));
773
774 /*
775 * XXX: Implement the C flag some day.
776 */
777 request_keys = keys_new();
778 keys_load(request_keys, request);
779
780 assert(conn->conn_initiator_name == NULL);
781 initiator_name = keys_find(request_keys, "InitiatorName");
782 if (initiator_name == NULL) {
783 login_send_error(request, 0x02, 0x07);
784 log_errx(1, "received Login PDU without InitiatorName");
785 }
786 if (valid_iscsi_name(initiator_name) == false) {
787 login_send_error(request, 0x02, 0x00);
788 log_errx(1, "received Login PDU with invalid InitiatorName");
789 }
790 conn->conn_initiator_name = checked_strdup(initiator_name);
791 log_set_peer_name(conn->conn_initiator_name);
792 /*
793 * XXX: This doesn't work (does nothing) because of Capsicum.
794 */
795 setproctitle("%s (%s)", conn->conn_initiator_addr, conn->conn_initiator_name);
796
797 redirected = login_portal_redirect(conn, request);
798 if (redirected) {
799 log_debugx("initiator redirected; exiting");
800 exit(0);
801 }
802
803 initiator_alias = keys_find(request_keys, "InitiatorAlias");
804 if (initiator_alias != NULL)
805 conn->conn_initiator_alias = checked_strdup(initiator_alias);
806
807 assert(conn->conn_session_type == CONN_SESSION_TYPE_NONE);
808 session_type = keys_find(request_keys, "SessionType");
809 if (session_type != NULL) {
810 if (strcmp(session_type, "Normal") == 0) {
811 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
812 } else if (strcmp(session_type, "Discovery") == 0) {
813 conn->conn_session_type = CONN_SESSION_TYPE_DISCOVERY;
814 } else {
815 login_send_error(request, 0x02, 0x00);
816 log_errx(1, "received Login PDU with invalid "
817 "SessionType \"%s\"", session_type);
818 }
819 } else
820 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
821
822 assert(conn->conn_target == NULL);
823 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
824 target_name = keys_find(request_keys, "TargetName");
825 if (target_name == NULL) {
826 login_send_error(request, 0x02, 0x07);
827 log_errx(1, "received Login PDU without TargetName");
828 }
829
830 conn->conn_target = target_find(pg->pg_conf, target_name);
831 if (conn->conn_target == NULL) {
832 login_send_error(request, 0x02, 0x03);
833 log_errx(1, "requested target \"%s\" not found",
834 target_name);
835 }
836 }
837
838 /*
839 * At this point we know what kind of authentication we need.
840 */
841 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
842 ag = conn->conn_target->t_auth_group;
843 if (ag->ag_name != NULL) {
844 log_debugx("initiator requests to connect "
845 "to target \"%s\"; auth-group \"%s\"",
846 conn->conn_target->t_name,
847 ag->ag_name);
848 } else {
849 log_debugx("initiator requests to connect "
850 "to target \"%s\"", conn->conn_target->t_name);
851 }
852 } else {
853 assert(conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY);
854 ag = pg->pg_discovery_auth_group;
855 if (ag->ag_name != NULL) {
856 log_debugx("initiator requests "
857 "discovery session; auth-group \"%s\"", ag->ag_name);
858 } else {
859 log_debugx("initiator requests discovery session");
860 }
861 }
862
863 /*
864 * Enforce initiator-name and initiator-portal.
865 */
866 if (auth_name_check(ag, initiator_name) != 0) {
867 login_send_error(request, 0x02, 0x02);
868 log_errx(1, "initiator does not match allowed initiator names");
869 }
870
871 if (auth_portal_check(ag, &conn->conn_initiator_sa) != 0) {
872 login_send_error(request, 0x02, 0x02);
873 log_errx(1, "initiator does not match allowed "
874 "initiator portals");
875 }
876
877 /*
878 * Let's see if the initiator intends to do any kind of authentication
879 * at all.
880 */
881 if (login_csg(request) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
882 if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
883 login_send_error(request, 0x02, 0x01);
884 log_errx(1, "initiator skipped the authentication, "
885 "but authentication is required");
886 }
887
888 keys_delete(request_keys);
889
890 log_debugx("initiator skipped the authentication, "
891 "and we don't need it; proceeding with negotiation");
892 login_negotiate(conn, request);
893 return;
894 }
895
896 if (ag->ag_type == AG_TYPE_NO_AUTHENTICATION) {
897 /*
898 * Initiator might want to to authenticate,
899 * but we don't need it.
900 */
901 log_debugx("authentication not required; "
902 "transitioning to operational parameter negotiation");
903
904 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0)
905 log_warnx("initiator did not set the \"T\" flag; "
906 "transitioning anyway");
907
908 response = login_new_response(request);
909 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
910 bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
911 login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
912 response_keys = keys_new();
913 /*
914 * Required by Linux initiator.
915 */
916 auth_method = keys_find(request_keys, "AuthMethod");
917 if (auth_method != NULL &&
918 login_list_contains(auth_method, "None"))
919 keys_add(response_keys, "AuthMethod", "None");
920
921 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
922 if (conn->conn_target->t_alias != NULL)
923 keys_add(response_keys,
924 "TargetAlias", conn->conn_target->t_alias);
925 keys_add_int(response_keys,
926 "TargetPortalGroupTag", pg->pg_tag);
927 }
928 keys_save(response_keys, response);
929 pdu_send(response);
930 pdu_delete(response);
931 keys_delete(response_keys);
932 pdu_delete(request);
933 keys_delete(request_keys);
934
935 login_negotiate(conn, NULL);
936 return;
937 }
938
939 if (ag->ag_type == AG_TYPE_DENY) {
940 login_send_error(request, 0x02, 0x01);
941 log_errx(1, "auth-type is \"deny\"");
942 }
943
944 if (ag->ag_type == AG_TYPE_UNKNOWN) {
945 /*
946 * This can happen with empty auth-group.
947 */
948 login_send_error(request, 0x02, 0x01);
949 log_errx(1, "auth-type not set, denying access");
950 }
951
952 log_debugx("CHAP authentication required");
953
954 auth_method = keys_find(request_keys, "AuthMethod");
955 if (auth_method == NULL) {
956 login_send_error(request, 0x02, 0x07);
957 log_errx(1, "received Login PDU without AuthMethod");
958 }
959 /*
960 * XXX: This should be Reject, not just a login failure (5.3.2).
961 */
962 if (login_list_contains(auth_method, "CHAP") == 0) {
963 login_send_error(request, 0x02, 0x01);
964 log_errx(1, "initiator requests unsupported AuthMethod \"%s\" "
965 "instead of \"CHAP\"", auth_method);
966 }
967
968 response = login_new_response(request);
969
970 response_keys = keys_new();
971 keys_add(response_keys, "AuthMethod", "CHAP");
972 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
973 if (conn->conn_target->t_alias != NULL)
974 keys_add(response_keys,
975 "TargetAlias", conn->conn_target->t_alias);
976 keys_add_int(response_keys,
977 "TargetPortalGroupTag", pg->pg_tag);
978 }
979 keys_save(response_keys, response);
980
981 pdu_send(response);
982 pdu_delete(response);
983 keys_delete(response_keys);
984 pdu_delete(request);
985 keys_delete(request_keys);
986
987 login_chap(conn, ag);
988
989 login_negotiate(conn, NULL);
990}
2 * Copyright (c) 2012 The FreeBSD Foundation
3 * All rights reserved.
4 *
5 * This software was developed by Edward Tomasz Napierala under sponsorship
6 * from the FreeBSD Foundation.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: stable/10/usr.sbin/ctld/login.c 276613 2015-01-03 13:08:08Z mav $");
33
34#include <assert.h>
35#include <stdbool.h>
36#include <stdint.h>
37#include <stdio.h>
38#include <stdlib.h>
39#include <string.h>
40#include <unistd.h>
41#include <netinet/in.h>
42
43#include "ctld.h"
44#include "iscsi_proto.h"
45
46static void login_send_error(struct pdu *request,
47 char class, char detail);
48
49static void
50login_set_nsg(struct pdu *response, int nsg)
51{
52 struct iscsi_bhs_login_response *bhslr;
53
54 assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
55 nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
56 nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
57
58 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
59
60 bhslr->bhslr_flags &= 0xFC;
61 bhslr->bhslr_flags |= nsg;
62}
63
64static int
65login_csg(const struct pdu *request)
66{
67 struct iscsi_bhs_login_request *bhslr;
68
69 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
70
71 return ((bhslr->bhslr_flags & 0x0C) >> 2);
72}
73
74static void
75login_set_csg(struct pdu *response, int csg)
76{
77 struct iscsi_bhs_login_response *bhslr;
78
79 assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
80 csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
81 csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
82
83 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
84
85 bhslr->bhslr_flags &= 0xF3;
86 bhslr->bhslr_flags |= csg << 2;
87}
88
89static struct pdu *
90login_receive(struct connection *conn, bool initial)
91{
92 struct pdu *request;
93 struct iscsi_bhs_login_request *bhslr;
94
95 request = pdu_new(conn);
96 pdu_receive(request);
97 if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) !=
98 ISCSI_BHS_OPCODE_LOGIN_REQUEST) {
99 /*
100 * The first PDU in session is special - if we receive any PDU
101 * different than login request, we have to drop the connection
102 * without sending response ("A target receiving any PDU
103 * except a Login request before the Login Phase is started MUST
104 * immediately terminate the connection on which the PDU
105 * was received.")
106 */
107 if (initial == false)
108 login_send_error(request, 0x02, 0x0b);
109 log_errx(1, "protocol error: received invalid opcode 0x%x",
110 request->pdu_bhs->bhs_opcode);
111 }
112 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
113 /*
114 * XXX: Implement the C flag some day.
115 */
116 if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0) {
117 login_send_error(request, 0x03, 0x00);
118 log_errx(1, "received Login PDU with unsupported \"C\" flag");
119 }
120 if (bhslr->bhslr_version_max != 0x00) {
121 login_send_error(request, 0x02, 0x05);
122 log_errx(1, "received Login PDU with unsupported "
123 "Version-max 0x%x", bhslr->bhslr_version_max);
124 }
125 if (bhslr->bhslr_version_min != 0x00) {
126 login_send_error(request, 0x02, 0x05);
127 log_errx(1, "received Login PDU with unsupported "
128 "Version-min 0x%x", bhslr->bhslr_version_min);
129 }
130 if (ISCSI_SNLT(ntohl(bhslr->bhslr_cmdsn), conn->conn_cmdsn)) {
131 login_send_error(request, 0x02, 0x05);
132 log_errx(1, "received Login PDU with decreasing CmdSN: "
133 "was %u, is %u", conn->conn_cmdsn,
134 ntohl(bhslr->bhslr_cmdsn));
135 }
136 if (initial == false &&
137 ntohl(bhslr->bhslr_expstatsn) != conn->conn_statsn) {
138 login_send_error(request, 0x02, 0x05);
139 log_errx(1, "received Login PDU with wrong ExpStatSN: "
140 "is %u, should be %u", ntohl(bhslr->bhslr_expstatsn),
141 conn->conn_statsn);
142 }
143 conn->conn_cmdsn = ntohl(bhslr->bhslr_cmdsn);
144
145 return (request);
146}
147
148static struct pdu *
149login_new_response(struct pdu *request)
150{
151 struct pdu *response;
152 struct connection *conn;
153 struct iscsi_bhs_login_request *bhslr;
154 struct iscsi_bhs_login_response *bhslr2;
155
156 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
157 conn = request->pdu_connection;
158
159 response = pdu_new_response(request);
160 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
161 bhslr2->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_RESPONSE;
162 login_set_csg(response, BHSLR_STAGE_SECURITY_NEGOTIATION);
163 memcpy(bhslr2->bhslr_isid,
164 bhslr->bhslr_isid, sizeof(bhslr2->bhslr_isid));
165 bhslr2->bhslr_initiator_task_tag = bhslr->bhslr_initiator_task_tag;
166 bhslr2->bhslr_statsn = htonl(conn->conn_statsn++);
167 bhslr2->bhslr_expcmdsn = htonl(conn->conn_cmdsn);
168 bhslr2->bhslr_maxcmdsn = htonl(conn->conn_cmdsn);
169
170 return (response);
171}
172
173static void
174login_send_error(struct pdu *request, char class, char detail)
175{
176 struct pdu *response;
177 struct iscsi_bhs_login_response *bhslr2;
178
179 log_debugx("sending Login Response PDU with failure class 0x%x/0x%x; "
180 "see next line for reason", class, detail);
181 response = login_new_response(request);
182 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
183 bhslr2->bhslr_status_class = class;
184 bhslr2->bhslr_status_detail = detail;
185
186 pdu_send(response);
187 pdu_delete(response);
188}
189
190static int
191login_list_contains(const char *list, const char *what)
192{
193 char *tofree, *str, *token;
194
195 tofree = str = checked_strdup(list);
196
197 while ((token = strsep(&str, ",")) != NULL) {
198 if (strcmp(token, what) == 0) {
199 free(tofree);
200 return (1);
201 }
202 }
203 free(tofree);
204 return (0);
205}
206
207static int
208login_list_prefers(const char *list,
209 const char *choice1, const char *choice2)
210{
211 char *tofree, *str, *token;
212
213 tofree = str = checked_strdup(list);
214
215 while ((token = strsep(&str, ",")) != NULL) {
216 if (strcmp(token, choice1) == 0) {
217 free(tofree);
218 return (1);
219 }
220 if (strcmp(token, choice2) == 0) {
221 free(tofree);
222 return (2);
223 }
224 }
225 free(tofree);
226 return (-1);
227}
228
229static struct pdu *
230login_receive_chap_a(struct connection *conn)
231{
232 struct pdu *request;
233 struct keys *request_keys;
234 const char *chap_a;
235
236 request = login_receive(conn, false);
237 request_keys = keys_new();
238 keys_load(request_keys, request);
239
240 chap_a = keys_find(request_keys, "CHAP_A");
241 if (chap_a == NULL) {
242 login_send_error(request, 0x02, 0x07);
243 log_errx(1, "received CHAP Login PDU without CHAP_A");
244 }
245 if (login_list_contains(chap_a, "5") == 0) {
246 login_send_error(request, 0x02, 0x01);
247 log_errx(1, "received CHAP Login PDU with unsupported CHAP_A "
248 "\"%s\"", chap_a);
249 }
250 keys_delete(request_keys);
251
252 return (request);
253}
254
255static void
256login_send_chap_c(struct pdu *request, struct chap *chap)
257{
258 struct pdu *response;
259 struct keys *response_keys;
260 char *chap_c, *chap_i;
261
262 chap_c = chap_get_challenge(chap);
263 chap_i = chap_get_id(chap);
264
265 response = login_new_response(request);
266 response_keys = keys_new();
267 keys_add(response_keys, "CHAP_A", "5");
268 keys_add(response_keys, "CHAP_I", chap_i);
269 keys_add(response_keys, "CHAP_C", chap_c);
270 free(chap_i);
271 free(chap_c);
272 keys_save(response_keys, response);
273 pdu_send(response);
274 pdu_delete(response);
275 keys_delete(response_keys);
276}
277
278static struct pdu *
279login_receive_chap_r(struct connection *conn, struct auth_group *ag,
280 struct chap *chap, const struct auth **authp)
281{
282 struct pdu *request;
283 struct keys *request_keys;
284 const char *chap_n, *chap_r;
285 const struct auth *auth;
286 int error;
287
288 request = login_receive(conn, false);
289 request_keys = keys_new();
290 keys_load(request_keys, request);
291
292 chap_n = keys_find(request_keys, "CHAP_N");
293 if (chap_n == NULL) {
294 login_send_error(request, 0x02, 0x07);
295 log_errx(1, "received CHAP Login PDU without CHAP_N");
296 }
297 chap_r = keys_find(request_keys, "CHAP_R");
298 if (chap_r == NULL) {
299 login_send_error(request, 0x02, 0x07);
300 log_errx(1, "received CHAP Login PDU without CHAP_R");
301 }
302 error = chap_receive(chap, chap_r);
303 if (error != 0) {
304 login_send_error(request, 0x02, 0x07);
305 log_errx(1, "received CHAP Login PDU with malformed CHAP_R");
306 }
307
308 /*
309 * Verify the response.
310 */
311 assert(ag->ag_type == AG_TYPE_CHAP ||
312 ag->ag_type == AG_TYPE_CHAP_MUTUAL);
313 auth = auth_find(ag, chap_n);
314 if (auth == NULL) {
315 login_send_error(request, 0x02, 0x01);
316 log_errx(1, "received CHAP Login with invalid user \"%s\"",
317 chap_n);
318 }
319
320 assert(auth->a_secret != NULL);
321 assert(strlen(auth->a_secret) > 0);
322
323 error = chap_authenticate(chap, auth->a_secret);
324 if (error != 0) {
325 login_send_error(request, 0x02, 0x01);
326 log_errx(1, "CHAP authentication failed for user \"%s\"",
327 auth->a_user);
328 }
329
330 keys_delete(request_keys);
331
332 *authp = auth;
333 return (request);
334}
335
336static void
337login_send_chap_success(struct pdu *request,
338 const struct auth *auth)
339{
340 struct pdu *response;
341 struct keys *request_keys, *response_keys;
342 struct iscsi_bhs_login_response *bhslr2;
343 struct rchap *rchap;
344 const char *chap_i, *chap_c;
345 char *chap_r;
346 int error;
347
348 response = login_new_response(request);
349 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
350 bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
351 login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
352
353 /*
354 * Actually, one more thing: mutual authentication.
355 */
356 request_keys = keys_new();
357 keys_load(request_keys, request);
358 chap_i = keys_find(request_keys, "CHAP_I");
359 chap_c = keys_find(request_keys, "CHAP_C");
360 if (chap_i != NULL || chap_c != NULL) {
361 if (chap_i == NULL) {
362 login_send_error(request, 0x02, 0x07);
363 log_errx(1, "initiator requested target "
364 "authentication, but didn't send CHAP_I");
365 }
366 if (chap_c == NULL) {
367 login_send_error(request, 0x02, 0x07);
368 log_errx(1, "initiator requested target "
369 "authentication, but didn't send CHAP_C");
370 }
371 if (auth->a_auth_group->ag_type != AG_TYPE_CHAP_MUTUAL) {
372 login_send_error(request, 0x02, 0x01);
373 log_errx(1, "initiator requests target authentication "
374 "for user \"%s\", but mutual user/secret "
375 "is not set", auth->a_user);
376 }
377
378 log_debugx("performing mutual authentication as user \"%s\"",
379 auth->a_mutual_user);
380
381 rchap = rchap_new(auth->a_mutual_secret);
382 error = rchap_receive(rchap, chap_i, chap_c);
383 if (error != 0) {
384 login_send_error(request, 0x02, 0x07);
385 log_errx(1, "received CHAP Login PDU with malformed "
386 "CHAP_I or CHAP_C");
387 }
388 chap_r = rchap_get_response(rchap);
389 rchap_delete(rchap);
390 response_keys = keys_new();
391 keys_add(response_keys, "CHAP_N", auth->a_mutual_user);
392 keys_add(response_keys, "CHAP_R", chap_r);
393 free(chap_r);
394 keys_save(response_keys, response);
395 keys_delete(response_keys);
396 } else {
397 log_debugx("initiator did not request target authentication");
398 }
399
400 keys_delete(request_keys);
401 pdu_send(response);
402 pdu_delete(response);
403}
404
405static void
406login_chap(struct connection *conn, struct auth_group *ag)
407{
408 const struct auth *auth;
409 struct chap *chap;
410 struct pdu *request;
411
412 /*
413 * Receive CHAP_A PDU.
414 */
415 log_debugx("beginning CHAP authentication; waiting for CHAP_A");
416 request = login_receive_chap_a(conn);
417
418 /*
419 * Generate the challenge.
420 */
421 chap = chap_new();
422
423 /*
424 * Send the challenge.
425 */
426 log_debugx("sending CHAP_C, binary challenge size is %zd bytes",
427 sizeof(chap->chap_challenge));
428 login_send_chap_c(request, chap);
429 pdu_delete(request);
430
431 /*
432 * Receive CHAP_N/CHAP_R PDU and authenticate.
433 */
434 log_debugx("waiting for CHAP_N/CHAP_R");
435 request = login_receive_chap_r(conn, ag, chap, &auth);
436
437 /*
438 * Yay, authentication succeeded!
439 */
440 log_debugx("authentication succeeded for user \"%s\"; "
441 "transitioning to Negotiation Phase", auth->a_user);
442 login_send_chap_success(request, auth);
443 pdu_delete(request);
444
445 /*
446 * Leave username and CHAP information for discovery().
447 */
448 conn->conn_user = auth->a_user;
449 conn->conn_chap = chap;
450}
451
452static void
453login_negotiate_key(struct pdu *request, const char *name,
454 const char *value, bool skipped_security, struct keys *response_keys)
455{
456 int which, tmp;
457 struct connection *conn;
458
459 conn = request->pdu_connection;
460
461 if (strcmp(name, "InitiatorName") == 0) {
462 if (!skipped_security)
463 log_errx(1, "initiator resent InitiatorName");
464 } else if (strcmp(name, "SessionType") == 0) {
465 if (!skipped_security)
466 log_errx(1, "initiator resent SessionType");
467 } else if (strcmp(name, "TargetName") == 0) {
468 if (!skipped_security)
469 log_errx(1, "initiator resent TargetName");
470 } else if (strcmp(name, "InitiatorAlias") == 0) {
471 if (conn->conn_initiator_alias != NULL)
472 free(conn->conn_initiator_alias);
473 conn->conn_initiator_alias = checked_strdup(value);
474 } else if (strcmp(value, "Irrelevant") == 0) {
475 /* Ignore. */
476 } else if (strcmp(name, "HeaderDigest") == 0) {
477 /*
478 * We don't handle digests for discovery sessions.
479 */
480 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
481 log_debugx("discovery session; digests disabled");
482 keys_add(response_keys, name, "None");
483 return;
484 }
485
486 which = login_list_prefers(value, "CRC32C", "None");
487 switch (which) {
488 case 1:
489 log_debugx("initiator prefers CRC32C "
490 "for header digest; we'll use it");
491 conn->conn_header_digest = CONN_DIGEST_CRC32C;
492 keys_add(response_keys, name, "CRC32C");
493 break;
494 case 2:
495 log_debugx("initiator prefers not to do "
496 "header digest; we'll comply");
497 keys_add(response_keys, name, "None");
498 break;
499 default:
500 log_warnx("initiator sent unrecognized "
501 "HeaderDigest value \"%s\"; will use None", value);
502 keys_add(response_keys, name, "None");
503 break;
504 }
505 } else if (strcmp(name, "DataDigest") == 0) {
506 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
507 log_debugx("discovery session; digests disabled");
508 keys_add(response_keys, name, "None");
509 return;
510 }
511
512 which = login_list_prefers(value, "CRC32C", "None");
513 switch (which) {
514 case 1:
515 log_debugx("initiator prefers CRC32C "
516 "for data digest; we'll use it");
517 conn->conn_data_digest = CONN_DIGEST_CRC32C;
518 keys_add(response_keys, name, "CRC32C");
519 break;
520 case 2:
521 log_debugx("initiator prefers not to do "
522 "data digest; we'll comply");
523 keys_add(response_keys, name, "None");
524 break;
525 default:
526 log_warnx("initiator sent unrecognized "
527 "DataDigest value \"%s\"; will use None", value);
528 keys_add(response_keys, name, "None");
529 break;
530 }
531 } else if (strcmp(name, "MaxConnections") == 0) {
532 keys_add(response_keys, name, "1");
533 } else if (strcmp(name, "InitialR2T") == 0) {
534 keys_add(response_keys, name, "Yes");
535 } else if (strcmp(name, "ImmediateData") == 0) {
536 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
537 log_debugx("discovery session; ImmediateData irrelevant");
538 keys_add(response_keys, name, "Irrelevant");
539 } else {
540 if (strcmp(value, "Yes") == 0) {
541 conn->conn_immediate_data = true;
542 keys_add(response_keys, name, "Yes");
543 } else {
544 conn->conn_immediate_data = false;
545 keys_add(response_keys, name, "No");
546 }
547 }
548 } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
549 tmp = strtoul(value, NULL, 10);
550 if (tmp <= 0) {
551 login_send_error(request, 0x02, 0x00);
552 log_errx(1, "received invalid "
553 "MaxRecvDataSegmentLength");
554 }
555 if (tmp > MAX_DATA_SEGMENT_LENGTH) {
556 log_debugx("capping MaxRecvDataSegmentLength "
557 "from %d to %d", tmp, MAX_DATA_SEGMENT_LENGTH);
558 tmp = MAX_DATA_SEGMENT_LENGTH;
559 }
560 conn->conn_max_data_segment_length = tmp;
561 keys_add_int(response_keys, name, MAX_DATA_SEGMENT_LENGTH);
562 } else if (strcmp(name, "MaxBurstLength") == 0) {
563 tmp = strtoul(value, NULL, 10);
564 if (tmp <= 0) {
565 login_send_error(request, 0x02, 0x00);
566 log_errx(1, "received invalid MaxBurstLength");
567 }
568 if (tmp > MAX_BURST_LENGTH) {
569 log_debugx("capping MaxBurstLength from %d to %d",
570 tmp, MAX_BURST_LENGTH);
571 tmp = MAX_BURST_LENGTH;
572 }
573 conn->conn_max_burst_length = tmp;
574 keys_add(response_keys, name, value);
575 } else if (strcmp(name, "FirstBurstLength") == 0) {
576 tmp = strtoul(value, NULL, 10);
577 if (tmp <= 0) {
578 login_send_error(request, 0x02, 0x00);
579 log_errx(1, "received invalid "
580 "FirstBurstLength");
581 }
582 if (tmp > MAX_DATA_SEGMENT_LENGTH) {
583 log_debugx("capping FirstBurstLength from %d to %d",
584 tmp, MAX_DATA_SEGMENT_LENGTH);
585 tmp = MAX_DATA_SEGMENT_LENGTH;
586 }
587 /*
588 * We don't pass the value to the kernel; it only enforces
589 * hardcoded limit anyway.
590 */
591 keys_add_int(response_keys, name, tmp);
592 } else if (strcmp(name, "DefaultTime2Wait") == 0) {
593 keys_add(response_keys, name, value);
594 } else if (strcmp(name, "DefaultTime2Retain") == 0) {
595 keys_add(response_keys, name, "0");
596 } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
597 keys_add(response_keys, name, "1");
598 } else if (strcmp(name, "DataPDUInOrder") == 0) {
599 keys_add(response_keys, name, "Yes");
600 } else if (strcmp(name, "DataSequenceInOrder") == 0) {
601 keys_add(response_keys, name, "Yes");
602 } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
603 keys_add(response_keys, name, "0");
604 } else if (strcmp(name, "OFMarker") == 0) {
605 keys_add(response_keys, name, "No");
606 } else if (strcmp(name, "IFMarker") == 0) {
607 keys_add(response_keys, name, "No");
608 } else {
609 log_debugx("unknown key \"%s\"; responding "
610 "with NotUnderstood", name);
611 keys_add(response_keys, name, "NotUnderstood");
612 }
613}
614
615static void
616login_redirect(struct pdu *request, const char *target_address)
617{
618 struct pdu *response;
619 struct iscsi_bhs_login_response *bhslr2;
620 struct keys *response_keys;
621
622 response = login_new_response(request);
623 login_set_csg(response, login_csg(request));
624 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
625 bhslr2->bhslr_status_class = 0x01;
626 bhslr2->bhslr_status_detail = 0x01;
627
628 response_keys = keys_new();
629 keys_add(response_keys, "TargetAddress", target_address);
630
631 keys_save(response_keys, response);
632 pdu_send(response);
633 pdu_delete(response);
634 keys_delete(response_keys);
635}
636
637static bool
638login_portal_redirect(struct connection *conn, struct pdu *request)
639{
640 const struct portal_group *pg;
641
642 pg = conn->conn_portal->p_portal_group;
643 if (pg->pg_redirection == NULL)
644 return (false);
645
646 log_debugx("portal-group \"%s\" configured to redirect to %s",
647 pg->pg_name, pg->pg_redirection);
648 login_redirect(request, pg->pg_redirection);
649
650 return (true);
651}
652
653static bool
654login_target_redirect(struct connection *conn, struct pdu *request)
655{
656 const char *target_address;
657
658 assert(conn->conn_portal->p_portal_group->pg_redirection == NULL);
659
660 if (conn->conn_target == NULL)
661 return (false);
662
663 target_address = conn->conn_target->t_redirection;
664 if (target_address == NULL)
665 return (false);
666
667 log_debugx("target \"%s\" configured to redirect to %s",
668 conn->conn_target->t_name, target_address);
669 login_redirect(request, target_address);
670
671 return (true);
672}
673
674static void
675login_negotiate(struct connection *conn, struct pdu *request)
676{
677 struct pdu *response;
678 struct iscsi_bhs_login_response *bhslr2;
679 struct keys *request_keys, *response_keys;
680 int i;
681 bool redirected, skipped_security;
682
683 if (request == NULL) {
684 log_debugx("beginning operational parameter negotiation; "
685 "waiting for Login PDU");
686 request = login_receive(conn, false);
687 skipped_security = false;
688 } else
689 skipped_security = true;
690
691 /*
692 * RFC 3720, 10.13.5. Status-Class and Status-Detail, says
693 * the redirection SHOULD be accepted by the initiator before
694 * authentication, but MUST be be accepted afterwards; that's
695 * why we're doing it here and not earlier.
696 */
697 redirected = login_target_redirect(conn, request);
698 if (redirected) {
699 log_debugx("initiator redirected; exiting");
700 exit(0);
701 }
702
703 request_keys = keys_new();
704 keys_load(request_keys, request);
705
706 response = login_new_response(request);
707 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
708 bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
709 bhslr2->bhslr_tsih = htons(0xbadd);
710 login_set_csg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
711 login_set_nsg(response, BHSLR_STAGE_FULL_FEATURE_PHASE);
712 response_keys = keys_new();
713
714 if (skipped_security &&
715 conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
716 if (conn->conn_target->t_alias != NULL)
717 keys_add(response_keys,
718 "TargetAlias", conn->conn_target->t_alias);
719 keys_add_int(response_keys, "TargetPortalGroupTag",
720 conn->conn_portal->p_portal_group->pg_tag);
721 }
722
723 for (i = 0; i < KEYS_MAX; i++) {
724 if (request_keys->keys_names[i] == NULL)
725 break;
726
727 login_negotiate_key(request, request_keys->keys_names[i],
728 request_keys->keys_values[i], skipped_security,
729 response_keys);
730 }
731
732 log_debugx("operational parameter negotiation done; "
733 "transitioning to Full Feature Phase");
734
735 keys_save(response_keys, response);
736 pdu_send(response);
737 pdu_delete(response);
738 keys_delete(response_keys);
739 pdu_delete(request);
740 keys_delete(request_keys);
741}
742
743void
744login(struct connection *conn)
745{
746 struct pdu *request, *response;
747 struct iscsi_bhs_login_request *bhslr;
748 struct iscsi_bhs_login_response *bhslr2;
749 struct keys *request_keys, *response_keys;
750 struct auth_group *ag;
751 struct portal_group *pg;
752 const char *initiator_name, *initiator_alias, *session_type,
753 *target_name, *auth_method;
754 bool redirected;
755
756 /*
757 * Handle the initial Login Request - figure out required authentication
758 * method and either transition to the next phase, if no authentication
759 * is required, or call appropriate authentication code.
760 */
761 log_debugx("beginning Login Phase; waiting for Login PDU");
762 request = login_receive(conn, true);
763 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
764 if (bhslr->bhslr_tsih != 0) {
765 login_send_error(request, 0x02, 0x0a);
766 log_errx(1, "received Login PDU with non-zero TSIH");
767 }
768
769 pg = conn->conn_portal->p_portal_group;
770
771 memcpy(conn->conn_initiator_isid, bhslr->bhslr_isid,
772 sizeof(conn->conn_initiator_isid));
773
774 /*
775 * XXX: Implement the C flag some day.
776 */
777 request_keys = keys_new();
778 keys_load(request_keys, request);
779
780 assert(conn->conn_initiator_name == NULL);
781 initiator_name = keys_find(request_keys, "InitiatorName");
782 if (initiator_name == NULL) {
783 login_send_error(request, 0x02, 0x07);
784 log_errx(1, "received Login PDU without InitiatorName");
785 }
786 if (valid_iscsi_name(initiator_name) == false) {
787 login_send_error(request, 0x02, 0x00);
788 log_errx(1, "received Login PDU with invalid InitiatorName");
789 }
790 conn->conn_initiator_name = checked_strdup(initiator_name);
791 log_set_peer_name(conn->conn_initiator_name);
792 /*
793 * XXX: This doesn't work (does nothing) because of Capsicum.
794 */
795 setproctitle("%s (%s)", conn->conn_initiator_addr, conn->conn_initiator_name);
796
797 redirected = login_portal_redirect(conn, request);
798 if (redirected) {
799 log_debugx("initiator redirected; exiting");
800 exit(0);
801 }
802
803 initiator_alias = keys_find(request_keys, "InitiatorAlias");
804 if (initiator_alias != NULL)
805 conn->conn_initiator_alias = checked_strdup(initiator_alias);
806
807 assert(conn->conn_session_type == CONN_SESSION_TYPE_NONE);
808 session_type = keys_find(request_keys, "SessionType");
809 if (session_type != NULL) {
810 if (strcmp(session_type, "Normal") == 0) {
811 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
812 } else if (strcmp(session_type, "Discovery") == 0) {
813 conn->conn_session_type = CONN_SESSION_TYPE_DISCOVERY;
814 } else {
815 login_send_error(request, 0x02, 0x00);
816 log_errx(1, "received Login PDU with invalid "
817 "SessionType \"%s\"", session_type);
818 }
819 } else
820 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
821
822 assert(conn->conn_target == NULL);
823 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
824 target_name = keys_find(request_keys, "TargetName");
825 if (target_name == NULL) {
826 login_send_error(request, 0x02, 0x07);
827 log_errx(1, "received Login PDU without TargetName");
828 }
829
830 conn->conn_target = target_find(pg->pg_conf, target_name);
831 if (conn->conn_target == NULL) {
832 login_send_error(request, 0x02, 0x03);
833 log_errx(1, "requested target \"%s\" not found",
834 target_name);
835 }
836 }
837
838 /*
839 * At this point we know what kind of authentication we need.
840 */
841 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
842 ag = conn->conn_target->t_auth_group;
843 if (ag->ag_name != NULL) {
844 log_debugx("initiator requests to connect "
845 "to target \"%s\"; auth-group \"%s\"",
846 conn->conn_target->t_name,
847 ag->ag_name);
848 } else {
849 log_debugx("initiator requests to connect "
850 "to target \"%s\"", conn->conn_target->t_name);
851 }
852 } else {
853 assert(conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY);
854 ag = pg->pg_discovery_auth_group;
855 if (ag->ag_name != NULL) {
856 log_debugx("initiator requests "
857 "discovery session; auth-group \"%s\"", ag->ag_name);
858 } else {
859 log_debugx("initiator requests discovery session");
860 }
861 }
862
863 /*
864 * Enforce initiator-name and initiator-portal.
865 */
866 if (auth_name_check(ag, initiator_name) != 0) {
867 login_send_error(request, 0x02, 0x02);
868 log_errx(1, "initiator does not match allowed initiator names");
869 }
870
871 if (auth_portal_check(ag, &conn->conn_initiator_sa) != 0) {
872 login_send_error(request, 0x02, 0x02);
873 log_errx(1, "initiator does not match allowed "
874 "initiator portals");
875 }
876
877 /*
878 * Let's see if the initiator intends to do any kind of authentication
879 * at all.
880 */
881 if (login_csg(request) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
882 if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
883 login_send_error(request, 0x02, 0x01);
884 log_errx(1, "initiator skipped the authentication, "
885 "but authentication is required");
886 }
887
888 keys_delete(request_keys);
889
890 log_debugx("initiator skipped the authentication, "
891 "and we don't need it; proceeding with negotiation");
892 login_negotiate(conn, request);
893 return;
894 }
895
896 if (ag->ag_type == AG_TYPE_NO_AUTHENTICATION) {
897 /*
898 * Initiator might want to to authenticate,
899 * but we don't need it.
900 */
901 log_debugx("authentication not required; "
902 "transitioning to operational parameter negotiation");
903
904 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0)
905 log_warnx("initiator did not set the \"T\" flag; "
906 "transitioning anyway");
907
908 response = login_new_response(request);
909 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
910 bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
911 login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
912 response_keys = keys_new();
913 /*
914 * Required by Linux initiator.
915 */
916 auth_method = keys_find(request_keys, "AuthMethod");
917 if (auth_method != NULL &&
918 login_list_contains(auth_method, "None"))
919 keys_add(response_keys, "AuthMethod", "None");
920
921 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
922 if (conn->conn_target->t_alias != NULL)
923 keys_add(response_keys,
924 "TargetAlias", conn->conn_target->t_alias);
925 keys_add_int(response_keys,
926 "TargetPortalGroupTag", pg->pg_tag);
927 }
928 keys_save(response_keys, response);
929 pdu_send(response);
930 pdu_delete(response);
931 keys_delete(response_keys);
932 pdu_delete(request);
933 keys_delete(request_keys);
934
935 login_negotiate(conn, NULL);
936 return;
937 }
938
939 if (ag->ag_type == AG_TYPE_DENY) {
940 login_send_error(request, 0x02, 0x01);
941 log_errx(1, "auth-type is \"deny\"");
942 }
943
944 if (ag->ag_type == AG_TYPE_UNKNOWN) {
945 /*
946 * This can happen with empty auth-group.
947 */
948 login_send_error(request, 0x02, 0x01);
949 log_errx(1, "auth-type not set, denying access");
950 }
951
952 log_debugx("CHAP authentication required");
953
954 auth_method = keys_find(request_keys, "AuthMethod");
955 if (auth_method == NULL) {
956 login_send_error(request, 0x02, 0x07);
957 log_errx(1, "received Login PDU without AuthMethod");
958 }
959 /*
960 * XXX: This should be Reject, not just a login failure (5.3.2).
961 */
962 if (login_list_contains(auth_method, "CHAP") == 0) {
963 login_send_error(request, 0x02, 0x01);
964 log_errx(1, "initiator requests unsupported AuthMethod \"%s\" "
965 "instead of \"CHAP\"", auth_method);
966 }
967
968 response = login_new_response(request);
969
970 response_keys = keys_new();
971 keys_add(response_keys, "AuthMethod", "CHAP");
972 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
973 if (conn->conn_target->t_alias != NULL)
974 keys_add(response_keys,
975 "TargetAlias", conn->conn_target->t_alias);
976 keys_add_int(response_keys,
977 "TargetPortalGroupTag", pg->pg_tag);
978 }
979 keys_save(response_keys, response);
980
981 pdu_send(response);
982 pdu_delete(response);
983 keys_delete(response_keys);
984 pdu_delete(request);
985 keys_delete(request_keys);
986
987 login_chap(conn, ag);
988
989 login_negotiate(conn, NULL);
990}