1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2012 The FreeBSD Foundation
5 *
6 * This software was developed by Edward Tomasz Napierala under sponsorship
7 * from the FreeBSD Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34
35 #include <sys/types.h>
36 #include <sys/ioctl.h>
37 #include <assert.h>
38 #include <stdbool.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <netinet/in.h>
43
44 #include "iscsid.h"
45 #include "iscsi_proto.h"
46
47 static int
login_nsg(const struct pdu * response)48 login_nsg(const struct pdu *response)
49 {
50 struct iscsi_bhs_login_response *bhslr;
51
52 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
53
54 return (bhslr->bhslr_flags & 0x03);
55 }
56
57 static void
login_set_nsg(struct pdu * request,int nsg)58 login_set_nsg(struct pdu *request, int nsg)
59 {
60 struct iscsi_bhs_login_request *bhslr;
61
62 assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
63 nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
64 nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
65
66 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
67
68 bhslr->bhslr_flags &= 0xFC;
69 bhslr->bhslr_flags |= nsg;
70 }
71
72 static void
login_set_csg(struct pdu * request,int csg)73 login_set_csg(struct pdu *request, int csg)
74 {
75 struct iscsi_bhs_login_request *bhslr;
76
77 assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
78 csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
79 csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
80
81 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
82
83 bhslr->bhslr_flags &= 0xF3;
84 bhslr->bhslr_flags |= csg << 2;
85 }
86
87 static const char *
login_target_error_str(int class,int detail)88 login_target_error_str(int class, int detail)
89 {
90 static char msg[128];
91
92 /*
93 * RFC 3270, 10.13.5. Status-Class and Status-Detail
94 */
95 switch (class) {
96 case 0x01:
97 switch (detail) {
98 case 0x01:
99 return ("Target moved temporarily");
100 case 0x02:
101 return ("Target moved permanently");
102 default:
103 snprintf(msg, sizeof(msg), "unknown redirection; "
104 "Status-Class 0x%x, Status-Detail 0x%x",
105 class, detail);
106 return (msg);
107 }
108 case 0x02:
109 switch (detail) {
110 case 0x00:
111 return ("Initiator error");
112 case 0x01:
113 return ("Authentication failure");
114 case 0x02:
115 return ("Authorization failure");
116 case 0x03:
117 return ("Not found");
118 case 0x04:
119 return ("Target removed");
120 case 0x05:
121 return ("Unsupported version");
122 case 0x06:
123 return ("Too many connections");
124 case 0x07:
125 return ("Missing parameter");
126 case 0x08:
127 return ("Can't include in session");
128 case 0x09:
129 return ("Session type not supported");
130 case 0x0a:
131 return ("Session does not exist");
132 case 0x0b:
133 return ("Invalid during login");
134 default:
135 snprintf(msg, sizeof(msg), "unknown initiator error; "
136 "Status-Class 0x%x, Status-Detail 0x%x",
137 class, detail);
138 return (msg);
139 }
140 case 0x03:
141 switch (detail) {
142 case 0x00:
143 return ("Target error");
144 case 0x01:
145 return ("Service unavailable");
146 case 0x02:
147 return ("Out of resources");
148 default:
149 snprintf(msg, sizeof(msg), "unknown target error; "
150 "Status-Class 0x%x, Status-Detail 0x%x",
151 class, detail);
152 return (msg);
153 }
154 default:
155 snprintf(msg, sizeof(msg), "unknown error; "
156 "Status-Class 0x%x, Status-Detail 0x%x",
157 class, detail);
158 return (msg);
159 }
160 }
161
162 static void
kernel_modify(const struct connection * conn,const char * target_address)163 kernel_modify(const struct connection *conn, const char *target_address)
164 {
165 struct iscsi_session_modify ism;
166 int error;
167
168 memset(&ism, 0, sizeof(ism));
169 ism.ism_session_id = conn->conn_session_id;
170 memcpy(&ism.ism_conf, &conn->conn_conf, sizeof(ism.ism_conf));
171 strlcpy(ism.ism_conf.isc_target_addr, target_address,
172 sizeof(ism.ism_conf.isc_target_addr));
173 error = ioctl(conn->conn_iscsi_fd, ISCSISMODIFY, &ism);
174 if (error != 0) {
175 log_err(1, "failed to redirect to %s: ISCSISMODIFY",
176 target_address);
177 }
178 }
179
180 /*
181 * XXX: The way it works is suboptimal; what should happen is described
182 * in draft-gilligan-iscsi-fault-tolerance-00. That, however, would
183 * be much more complicated: we would need to keep "dependencies"
184 * for sessions, so that, in case described in draft and using draft
185 * terminology, we would have three sessions: one for discovery,
186 * one for initial target portal, and one for redirect portal.
187 * This would allow us to "backtrack" on connection failure,
188 * as described in draft.
189 */
190 static void
login_handle_redirection(struct connection * conn,struct pdu * response)191 login_handle_redirection(struct connection *conn, struct pdu *response)
192 {
193 struct iscsi_bhs_login_response *bhslr;
194 struct keys *response_keys;
195 const char *target_address;
196
197 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
198 assert (bhslr->bhslr_status_class == 1);
199
200 response_keys = keys_new();
201 keys_load(response_keys, response);
202
203 target_address = keys_find(response_keys, "TargetAddress");
204 if (target_address == NULL)
205 log_errx(1, "received redirection without TargetAddress");
206 if (target_address[0] == '\0')
207 log_errx(1, "received redirection with empty TargetAddress");
208 if (strlen(target_address) >=
209 sizeof(conn->conn_conf.isc_target_addr) - 1)
210 log_errx(1, "received TargetAddress is too long");
211
212 log_debugx("received redirection to \"%s\"", target_address);
213 kernel_modify(conn, target_address);
214 keys_delete(response_keys);
215 }
216
217 static struct pdu *
login_receive(struct connection * conn)218 login_receive(struct connection *conn)
219 {
220 struct pdu *response;
221 struct iscsi_bhs_login_response *bhslr;
222 const char *errorstr;
223 static bool initial = true;
224
225 response = pdu_new(conn);
226 pdu_receive(response);
227 if (response->pdu_bhs->bhs_opcode != ISCSI_BHS_OPCODE_LOGIN_RESPONSE) {
228 log_errx(1, "protocol error: received invalid opcode 0x%x",
229 response->pdu_bhs->bhs_opcode);
230 }
231 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
232 /*
233 * XXX: Implement the C flag some day.
234 */
235 if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0)
236 log_errx(1, "received Login PDU with unsupported \"C\" flag");
237 if (bhslr->bhslr_version_max != 0x00)
238 log_errx(1, "received Login PDU with unsupported "
239 "Version-max 0x%x", bhslr->bhslr_version_max);
240 if (bhslr->bhslr_version_active != 0x00)
241 log_errx(1, "received Login PDU with unsupported "
242 "Version-active 0x%x", bhslr->bhslr_version_active);
243 if (bhslr->bhslr_status_class == 1) {
244 login_handle_redirection(conn, response);
245 log_debugx("redirection handled; exiting");
246 exit(0);
247 }
248 if (bhslr->bhslr_status_class != 0) {
249 errorstr = login_target_error_str(bhslr->bhslr_status_class,
250 bhslr->bhslr_status_detail);
251 fail(conn, errorstr);
252 log_errx(1, "target returned error: %s", errorstr);
253 }
254 if (initial == false &&
255 ntohl(bhslr->bhslr_statsn) != conn->conn_statsn + 1) {
256 /*
257 * It's a warning, not an error, to work around what seems
258 * to be bug in NetBSD iSCSI target.
259 */
260 log_warnx("received Login PDU with wrong StatSN: "
261 "is %u, should be %u", ntohl(bhslr->bhslr_statsn),
262 conn->conn_statsn + 1);
263 }
264 conn->conn_tsih = ntohs(bhslr->bhslr_tsih);
265 conn->conn_statsn = ntohl(bhslr->bhslr_statsn);
266
267 initial = false;
268
269 return (response);
270 }
271
272 static struct pdu *
login_new_request(struct connection * conn,int csg)273 login_new_request(struct connection *conn, int csg)
274 {
275 struct pdu *request;
276 struct iscsi_bhs_login_request *bhslr;
277 int nsg;
278
279 request = pdu_new(conn);
280 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
281 bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_REQUEST |
282 ISCSI_BHS_OPCODE_IMMEDIATE;
283
284 bhslr->bhslr_flags = BHSLR_FLAGS_TRANSIT;
285 switch (csg) {
286 case BHSLR_STAGE_SECURITY_NEGOTIATION:
287 nsg = BHSLR_STAGE_OPERATIONAL_NEGOTIATION;
288 break;
289 case BHSLR_STAGE_OPERATIONAL_NEGOTIATION:
290 nsg = BHSLR_STAGE_FULL_FEATURE_PHASE;
291 break;
292 default:
293 assert(!"invalid csg");
294 log_errx(1, "invalid csg %d", csg);
295 }
296 login_set_csg(request, csg);
297 login_set_nsg(request, nsg);
298
299 memcpy(bhslr->bhslr_isid, &conn->conn_isid, sizeof(bhslr->bhslr_isid));
300 bhslr->bhslr_tsih = htons(conn->conn_tsih);
301 bhslr->bhslr_initiator_task_tag = 0;
302 bhslr->bhslr_cmdsn = 0;
303 bhslr->bhslr_expstatsn = htonl(conn->conn_statsn + 1);
304
305 return (request);
306 }
307
308 static int
login_list_prefers(const char * list,const char * choice1,const char * choice2)309 login_list_prefers(const char *list,
310 const char *choice1, const char *choice2)
311 {
312 char *tofree, *str, *token;
313
314 tofree = str = checked_strdup(list);
315
316 while ((token = strsep(&str, ",")) != NULL) {
317 if (strcmp(token, choice1) == 0) {
318 free(tofree);
319 return (1);
320 }
321 if (strcmp(token, choice2) == 0) {
322 free(tofree);
323 return (2);
324 }
325 }
326 free(tofree);
327 return (-1);
328 }
329
330 static void
login_negotiate_key(struct connection * conn,const char * name,const char * value)331 login_negotiate_key(struct connection *conn, const char *name,
332 const char *value)
333 {
334 struct iscsi_session_limits *isl;
335 int which, tmp;
336
337 isl = &conn->conn_limits;
338 if (strcmp(name, "TargetAlias") == 0) {
339 strlcpy(conn->conn_target_alias, value,
340 sizeof(conn->conn_target_alias));
341 } else if (strcmp(value, "Irrelevant") == 0) {
342 /* Ignore. */
343 } else if (strcmp(name, "iSCSIProtocolLevel") == 0) {
344 tmp = strtoul(value, NULL, 10);
345 if (tmp < 0 || tmp > 31)
346 log_errx(1, "received invalid iSCSIProtocolLevel");
347 conn->conn_protocol_level = tmp;
348 } else if (strcmp(name, "HeaderDigest") == 0) {
349 which = login_list_prefers(value, "CRC32C", "None");
350 switch (which) {
351 case 1:
352 log_debugx("target prefers CRC32C "
353 "for header digest; we'll use it");
354 conn->conn_header_digest = CONN_DIGEST_CRC32C;
355 break;
356 case 2:
357 log_debugx("target prefers not to do "
358 "header digest; we'll comply");
359 break;
360 default:
361 log_warnx("target sent unrecognized "
362 "HeaderDigest value \"%s\"; will use None", value);
363 break;
364 }
365 } else if (strcmp(name, "DataDigest") == 0) {
366 which = login_list_prefers(value, "CRC32C", "None");
367 switch (which) {
368 case 1:
369 log_debugx("target prefers CRC32C "
370 "for data digest; we'll use it");
371 conn->conn_data_digest = CONN_DIGEST_CRC32C;
372 break;
373 case 2:
374 log_debugx("target prefers not to do "
375 "data digest; we'll comply");
376 break;
377 default:
378 log_warnx("target sent unrecognized "
379 "DataDigest value \"%s\"; will use None", value);
380 break;
381 }
382 } else if (strcmp(name, "MaxConnections") == 0) {
383 /* Ignore. */
384 } else if (strcmp(name, "InitialR2T") == 0) {
385 if (strcmp(value, "Yes") == 0)
386 conn->conn_initial_r2t = true;
387 else
388 conn->conn_initial_r2t = false;
389 } else if (strcmp(name, "ImmediateData") == 0) {
390 if (strcmp(value, "Yes") == 0)
391 conn->conn_immediate_data = true;
392 else
393 conn->conn_immediate_data = false;
394 } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
395 tmp = strtoul(value, NULL, 10);
396 if (tmp <= 0)
397 log_errx(1, "received invalid "
398 "MaxRecvDataSegmentLength");
399 if (tmp > isl->isl_max_send_data_segment_length) {
400 log_debugx("capping max_send_data_segment_length "
401 "from %d to %d", tmp,
402 isl->isl_max_send_data_segment_length);
403 tmp = isl->isl_max_send_data_segment_length;
404 }
405 conn->conn_max_send_data_segment_length = tmp;
406 } else if (strcmp(name, "MaxBurstLength") == 0) {
407 tmp = strtoul(value, NULL, 10);
408 if (tmp <= 0)
409 log_errx(1, "received invalid MaxBurstLength");
410 if (tmp > isl->isl_max_burst_length) {
411 log_debugx("capping MaxBurstLength "
412 "from %d to %d", tmp, isl->isl_max_burst_length);
413 tmp = isl->isl_max_burst_length;
414 }
415 conn->conn_max_burst_length = tmp;
416 } else if (strcmp(name, "FirstBurstLength") == 0) {
417 tmp = strtoul(value, NULL, 10);
418 if (tmp <= 0)
419 log_errx(1, "received invalid FirstBurstLength");
420 if (tmp > isl->isl_first_burst_length) {
421 log_debugx("capping FirstBurstLength "
422 "from %d to %d", tmp, isl->isl_first_burst_length);
423 tmp = isl->isl_first_burst_length;
424 }
425 conn->conn_first_burst_length = tmp;
426 } else if (strcmp(name, "DefaultTime2Wait") == 0) {
427 /* Ignore */
428 } else if (strcmp(name, "DefaultTime2Retain") == 0) {
429 /* Ignore */
430 } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
431 /* Ignore */
432 } else if (strcmp(name, "DataPDUInOrder") == 0) {
433 /* Ignore */
434 } else if (strcmp(name, "DataSequenceInOrder") == 0) {
435 /* Ignore */
436 } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
437 /* Ignore */
438 } else if (strcmp(name, "OFMarker") == 0) {
439 /* Ignore */
440 } else if (strcmp(name, "IFMarker") == 0) {
441 /* Ignore */
442 } else if (strcmp(name, "RDMAExtensions") == 0) {
443 if (conn->conn_conf.isc_iser == 1 &&
444 strcmp(value, "Yes") != 0) {
445 log_errx(1, "received unsupported RDMAExtensions");
446 }
447 } else if (strcmp(name, "InitiatorRecvDataSegmentLength") == 0) {
448 tmp = strtoul(value, NULL, 10);
449 if (tmp <= 0)
450 log_errx(1, "received invalid "
451 "InitiatorRecvDataSegmentLength");
452 if ((int)tmp > isl->isl_max_recv_data_segment_length) {
453 log_debugx("capping InitiatorRecvDataSegmentLength "
454 "from %d to %d", tmp,
455 isl->isl_max_recv_data_segment_length);
456 tmp = isl->isl_max_recv_data_segment_length;
457 }
458 conn->conn_max_recv_data_segment_length = tmp;
459 } else if (strcmp(name, "TargetPortalGroupTag") == 0) {
460 /* Ignore */
461 } else if (strcmp(name, "TargetRecvDataSegmentLength") == 0) {
462 tmp = strtoul(value, NULL, 10);
463 if (tmp <= 0) {
464 log_errx(1,
465 "received invalid TargetRecvDataSegmentLength");
466 }
467 if (tmp > isl->isl_max_send_data_segment_length) {
468 log_debugx("capping TargetRecvDataSegmentLength "
469 "from %d to %d", tmp,
470 isl->isl_max_send_data_segment_length);
471 tmp = isl->isl_max_send_data_segment_length;
472 }
473 conn->conn_max_send_data_segment_length = tmp;
474 } else {
475 log_debugx("unknown key \"%s\"; ignoring", name);
476 }
477 }
478
479 static void
login_negotiate(struct connection * conn)480 login_negotiate(struct connection *conn)
481 {
482 struct pdu *request, *response;
483 struct keys *request_keys, *response_keys;
484 struct iscsi_bhs_login_response *bhslr;
485 int i, nrequests = 0;
486 struct iscsi_session_limits *isl;
487
488 log_debugx("beginning operational parameter negotiation");
489 request = login_new_request(conn, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
490 request_keys = keys_new();
491
492 isl = &conn->conn_limits;
493 log_debugx("Limits for offload \"%s\" are "
494 "MaxRecvDataSegment=%d, max_send_dsl=%d, "
495 "MaxBurstLength=%d, FirstBurstLength=%d",
496 conn->conn_conf.isc_offload, isl->isl_max_recv_data_segment_length,
497 isl->isl_max_send_data_segment_length, isl->isl_max_burst_length,
498 isl->isl_first_burst_length);
499
500 /*
501 * The following keys are irrelevant for discovery sessions.
502 */
503 if (conn->conn_conf.isc_discovery == 0) {
504 keys_add(request_keys, "iSCSIProtocolLevel", "2");
505 if (conn->conn_conf.isc_header_digest != 0)
506 keys_add(request_keys, "HeaderDigest", "CRC32C");
507 else
508 keys_add(request_keys, "HeaderDigest", "None");
509 if (conn->conn_conf.isc_data_digest != 0)
510 keys_add(request_keys, "DataDigest", "CRC32C");
511 else
512 keys_add(request_keys, "DataDigest", "None");
513
514 keys_add(request_keys, "ImmediateData", "Yes");
515 keys_add_int(request_keys, "MaxBurstLength",
516 isl->isl_max_burst_length);
517 keys_add_int(request_keys, "FirstBurstLength",
518 isl->isl_first_burst_length);
519 keys_add(request_keys, "InitialR2T", "Yes");
520 keys_add(request_keys, "MaxOutstandingR2T", "1");
521 if (conn->conn_conf.isc_iser == 1) {
522 keys_add_int(request_keys, "InitiatorRecvDataSegmentLength",
523 isl->isl_max_recv_data_segment_length);
524 keys_add_int(request_keys, "TargetRecvDataSegmentLength",
525 isl->isl_max_send_data_segment_length);
526 keys_add(request_keys, "RDMAExtensions", "Yes");
527 } else {
528 keys_add_int(request_keys, "MaxRecvDataSegmentLength",
529 isl->isl_max_recv_data_segment_length);
530 }
531 } else {
532 keys_add(request_keys, "HeaderDigest", "None");
533 keys_add(request_keys, "DataDigest", "None");
534 keys_add_int(request_keys, "MaxRecvDataSegmentLength",
535 isl->isl_max_recv_data_segment_length);
536 }
537
538 conn->conn_max_recv_data_segment_length =
539 isl->isl_max_recv_data_segment_length;
540
541 keys_add(request_keys, "DefaultTime2Wait", "0");
542 keys_add(request_keys, "DefaultTime2Retain", "0");
543 keys_add(request_keys, "ErrorRecoveryLevel", "0");
544 keys_save(request_keys, request);
545 keys_delete(request_keys);
546 request_keys = NULL;
547 pdu_send(request);
548 pdu_delete(request);
549 request = NULL;
550
551 response = login_receive(conn);
552 response_keys = keys_new();
553 keys_load(response_keys, response);
554 for (i = 0; i < KEYS_MAX; i++) {
555 if (response_keys->keys_names[i] == NULL)
556 break;
557
558 login_negotiate_key(conn,
559 response_keys->keys_names[i], response_keys->keys_values[i]);
560 }
561
562 keys_delete(response_keys);
563 response_keys = NULL;
564
565 for (;;) {
566 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
567 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0)
568 break;
569
570 nrequests++;
571 if (nrequests > 5) {
572 log_warnx("received login response "
573 "without the \"T\" flag too many times; giving up");
574 break;
575 }
576
577 log_debugx("received login response "
578 "without the \"T\" flag; sending another request");
579
580 pdu_delete(response);
581
582 request = login_new_request(conn,
583 BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
584 pdu_send(request);
585 pdu_delete(request);
586
587 response = login_receive(conn);
588 }
589
590 if (login_nsg(response) != BHSLR_STAGE_FULL_FEATURE_PHASE)
591 log_warnx("received final login response with wrong NSG 0x%x",
592 login_nsg(response));
593 pdu_delete(response);
594
595 log_debugx("operational parameter negotiation done; "
596 "transitioning to Full Feature phase");
597 }
598
599 static void
login_send_chap_a(struct connection * conn)600 login_send_chap_a(struct connection *conn)
601 {
602 struct pdu *request;
603 struct keys *request_keys;
604
605 request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
606 request_keys = keys_new();
607 keys_add(request_keys, "CHAP_A", "5");
608 keys_save(request_keys, request);
609 keys_delete(request_keys);
610 pdu_send(request);
611 pdu_delete(request);
612 }
613
614 static void
login_send_chap_r(struct pdu * response)615 login_send_chap_r(struct pdu *response)
616 {
617 struct connection *conn;
618 struct pdu *request;
619 struct keys *request_keys, *response_keys;
620 struct rchap *rchap;
621 const char *chap_a, *chap_c, *chap_i;
622 char *chap_r;
623 int error;
624 char *mutual_chap_c, *mutual_chap_i;
625
626 /*
627 * As in the rest of the initiator, 'request' means
628 * 'initiator -> target', and 'response' means 'target -> initiator',
629 *
630 * So, here the 'response' from the target is the packet that contains
631 * CHAP challenge; our CHAP response goes into 'request'.
632 */
633
634 conn = response->pdu_connection;
635
636 response_keys = keys_new();
637 keys_load(response_keys, response);
638
639 /*
640 * First, compute the response.
641 */
642 chap_a = keys_find(response_keys, "CHAP_A");
643 if (chap_a == NULL)
644 log_errx(1, "received CHAP packet without CHAP_A");
645 chap_c = keys_find(response_keys, "CHAP_C");
646 if (chap_c == NULL)
647 log_errx(1, "received CHAP packet without CHAP_C");
648 chap_i = keys_find(response_keys, "CHAP_I");
649 if (chap_i == NULL)
650 log_errx(1, "received CHAP packet without CHAP_I");
651
652 if (strcmp(chap_a, "5") != 0) {
653 log_errx(1, "received CHAP packet "
654 "with unsupported CHAP_A \"%s\"", chap_a);
655 }
656
657 rchap = rchap_new(conn->conn_conf.isc_secret);
658 error = rchap_receive(rchap, chap_i, chap_c);
659 if (error != 0) {
660 log_errx(1, "received CHAP packet "
661 "with malformed CHAP_I or CHAP_C");
662 }
663 chap_r = rchap_get_response(rchap);
664 rchap_delete(rchap);
665
666 keys_delete(response_keys);
667
668 request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
669 request_keys = keys_new();
670 keys_add(request_keys, "CHAP_N", conn->conn_conf.isc_user);
671 keys_add(request_keys, "CHAP_R", chap_r);
672 free(chap_r);
673
674 /*
675 * If we want mutual authentication, we're expected to send
676 * our CHAP_I/CHAP_C now.
677 */
678 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
679 log_debugx("requesting mutual authentication; "
680 "binary challenge size is %zd bytes",
681 sizeof(conn->conn_mutual_chap->chap_challenge));
682
683 assert(conn->conn_mutual_chap == NULL);
684 conn->conn_mutual_chap = chap_new();
685 mutual_chap_i = chap_get_id(conn->conn_mutual_chap);
686 mutual_chap_c = chap_get_challenge(conn->conn_mutual_chap);
687 keys_add(request_keys, "CHAP_I", mutual_chap_i);
688 keys_add(request_keys, "CHAP_C", mutual_chap_c);
689 free(mutual_chap_i);
690 free(mutual_chap_c);
691 }
692
693 keys_save(request_keys, request);
694 keys_delete(request_keys);
695 pdu_send(request);
696 pdu_delete(request);
697 }
698
699 static void
login_verify_mutual(const struct pdu * response)700 login_verify_mutual(const struct pdu *response)
701 {
702 struct connection *conn;
703 struct keys *response_keys;
704 const char *chap_n, *chap_r;
705 int error;
706
707 conn = response->pdu_connection;
708
709 response_keys = keys_new();
710 keys_load(response_keys, response);
711
712 chap_n = keys_find(response_keys, "CHAP_N");
713 if (chap_n == NULL)
714 log_errx(1, "received CHAP Response PDU without CHAP_N");
715 chap_r = keys_find(response_keys, "CHAP_R");
716 if (chap_r == NULL)
717 log_errx(1, "received CHAP Response PDU without CHAP_R");
718
719 error = chap_receive(conn->conn_mutual_chap, chap_r);
720 if (error != 0)
721 log_errx(1, "received CHAP Response PDU with invalid CHAP_R");
722
723 if (strcmp(chap_n, conn->conn_conf.isc_mutual_user) != 0) {
724 fail(conn, "Mutual CHAP failed");
725 log_errx(1, "mutual CHAP authentication failed: wrong user");
726 }
727
728 error = chap_authenticate(conn->conn_mutual_chap,
729 conn->conn_conf.isc_mutual_secret);
730 if (error != 0) {
731 fail(conn, "Mutual CHAP failed");
732 log_errx(1, "mutual CHAP authentication failed: wrong secret");
733 }
734
735 keys_delete(response_keys);
736 chap_delete(conn->conn_mutual_chap);
737 conn->conn_mutual_chap = NULL;
738
739 log_debugx("mutual CHAP authentication succeeded");
740 }
741
742 static void
login_chap(struct connection * conn)743 login_chap(struct connection *conn)
744 {
745 struct pdu *response;
746
747 log_debugx("beginning CHAP authentication; sending CHAP_A");
748 login_send_chap_a(conn);
749
750 log_debugx("waiting for CHAP_A/CHAP_C/CHAP_I");
751 response = login_receive(conn);
752
753 log_debugx("sending CHAP_N/CHAP_R");
754 login_send_chap_r(response);
755 pdu_delete(response);
756
757 /*
758 * XXX: Make sure this is not susceptible to MITM.
759 */
760
761 log_debugx("waiting for CHAP result");
762 response = login_receive(conn);
763 if (conn->conn_conf.isc_mutual_user[0] != '\0')
764 login_verify_mutual(response);
765 pdu_delete(response);
766
767 log_debugx("CHAP authentication done");
768 }
769
770 void
login(struct connection * conn)771 login(struct connection *conn)
772 {
773 struct pdu *request, *response;
774 struct keys *request_keys, *response_keys;
775 struct iscsi_bhs_login_response *bhslr2;
776 const char *auth_method;
777 int i;
778
779 log_debugx("beginning Login phase; sending Login PDU");
780 request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
781 request_keys = keys_new();
782 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
783 keys_add(request_keys, "AuthMethod", "CHAP");
784 } else if (conn->conn_conf.isc_user[0] != '\0') {
785 /*
786 * Give target a chance to skip authentication if it
787 * doesn't feel like it.
788 *
789 * None is first, CHAP second; this is to work around
790 * what seems to be LIO (Linux target) bug: otherwise,
791 * if target is configured with no authentication,
792 * and we are configured to authenticate, the target
793 * will erroneously respond with AuthMethod=CHAP
794 * instead of AuthMethod=None, and will subsequently
795 * fail the connection. This usually happens with
796 * Discovery sessions, which default to no authentication.
797 */
798 keys_add(request_keys, "AuthMethod", "None,CHAP");
799 } else {
800 keys_add(request_keys, "AuthMethod", "None");
801 }
802 keys_add(request_keys, "InitiatorName",
803 conn->conn_conf.isc_initiator);
804 if (conn->conn_conf.isc_initiator_alias[0] != '\0') {
805 keys_add(request_keys, "InitiatorAlias",
806 conn->conn_conf.isc_initiator_alias);
807 }
808 if (conn->conn_conf.isc_discovery == 0) {
809 keys_add(request_keys, "SessionType", "Normal");
810 keys_add(request_keys,
811 "TargetName", conn->conn_conf.isc_target);
812 } else {
813 keys_add(request_keys, "SessionType", "Discovery");
814 }
815 keys_save(request_keys, request);
816 keys_delete(request_keys);
817 pdu_send(request);
818 pdu_delete(request);
819
820 response = login_receive(conn);
821
822 response_keys = keys_new();
823 keys_load(response_keys, response);
824
825 for (i = 0; i < KEYS_MAX; i++) {
826 if (response_keys->keys_names[i] == NULL)
827 break;
828
829 /*
830 * Not interested in AuthMethod at this point; we only need
831 * to parse things such as TargetAlias.
832 *
833 * XXX: This is somewhat ugly. We should have a way to apply
834 * all the keys to the session and use that by default
835 * instead of discarding them.
836 */
837 if (strcmp(response_keys->keys_names[i], "AuthMethod") == 0)
838 continue;
839
840 login_negotiate_key(conn,
841 response_keys->keys_names[i], response_keys->keys_values[i]);
842 }
843
844 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
845 if ((bhslr2->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0 &&
846 login_nsg(response) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
847 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
848 log_errx(1, "target requested transition "
849 "to operational parameter negotiation, "
850 "but we require mutual CHAP");
851 }
852
853 log_debugx("target requested transition "
854 "to operational parameter negotiation");
855 keys_delete(response_keys);
856 pdu_delete(response);
857 login_negotiate(conn);
858 return;
859 }
860
861 auth_method = keys_find(response_keys, "AuthMethod");
862 if (auth_method == NULL)
863 log_errx(1, "received response without AuthMethod");
864 if (strcmp(auth_method, "None") == 0) {
865 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
866 log_errx(1, "target does not require authantication, "
867 "but we require mutual CHAP");
868 }
869
870 log_debugx("target does not require authentication");
871 keys_delete(response_keys);
872 pdu_delete(response);
873 login_negotiate(conn);
874 return;
875 }
876
877 if (strcmp(auth_method, "CHAP") != 0) {
878 fail(conn, "Unsupported AuthMethod");
879 log_errx(1, "received response "
880 "with unsupported AuthMethod \"%s\"", auth_method);
881 }
882
883 if (conn->conn_conf.isc_user[0] == '\0' ||
884 conn->conn_conf.isc_secret[0] == '\0') {
885 fail(conn, "Authentication required");
886 log_errx(1, "target requests CHAP authentication, but we don't "
887 "have user and secret");
888 }
889
890 keys_delete(response_keys);
891 response_keys = NULL;
892 pdu_delete(response);
893 response = NULL;
894
895 login_chap(conn);
896 login_negotiate(conn);
897 }
898