1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
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 #include <sys/types.h>
34 #include <sys/ioctl.h>
35 #include <assert.h>
36 #include <stdbool.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <netinet/in.h>
41
42 #include "iscsid.h"
43 #include "iscsi_proto.h"
44
45 static int
login_nsg(const struct pdu * response)46 login_nsg(const struct pdu *response)
47 {
48 struct iscsi_bhs_login_response *bhslr;
49
50 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
51
52 return (bhslr->bhslr_flags & 0x03);
53 }
54
55 static void
login_set_nsg(struct pdu * request,int nsg)56 login_set_nsg(struct pdu *request, int nsg)
57 {
58 struct iscsi_bhs_login_request *bhslr;
59
60 assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
61 nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
62 nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
63
64 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
65
66 bhslr->bhslr_flags &= 0xFC;
67 bhslr->bhslr_flags |= nsg;
68 }
69
70 static void
login_set_csg(struct pdu * request,int csg)71 login_set_csg(struct pdu *request, int csg)
72 {
73 struct iscsi_bhs_login_request *bhslr;
74
75 assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
76 csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
77 csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
78
79 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
80
81 bhslr->bhslr_flags &= 0xF3;
82 bhslr->bhslr_flags |= csg << 2;
83 }
84
85 static const char *
login_target_error_str(int class,int detail)86 login_target_error_str(int class, int detail)
87 {
88 static char msg[128];
89
90 /*
91 * RFC 3270, 10.13.5. Status-Class and Status-Detail
92 */
93 switch (class) {
94 case 0x01:
95 switch (detail) {
96 case 0x01:
97 return ("Target moved temporarily");
98 case 0x02:
99 return ("Target moved permanently");
100 default:
101 snprintf(msg, sizeof(msg), "unknown redirection; "
102 "Status-Class 0x%x, Status-Detail 0x%x",
103 class, detail);
104 return (msg);
105 }
106 case 0x02:
107 switch (detail) {
108 case 0x00:
109 return ("Initiator error");
110 case 0x01:
111 return ("Authentication failure");
112 case 0x02:
113 return ("Authorization failure");
114 case 0x03:
115 return ("Not found");
116 case 0x04:
117 return ("Target removed");
118 case 0x05:
119 return ("Unsupported version");
120 case 0x06:
121 return ("Too many connections");
122 case 0x07:
123 return ("Missing parameter");
124 case 0x08:
125 return ("Can't include in session");
126 case 0x09:
127 return ("Session type not supported");
128 case 0x0a:
129 return ("Session does not exist");
130 case 0x0b:
131 return ("Invalid during login");
132 default:
133 snprintf(msg, sizeof(msg), "unknown initiator error; "
134 "Status-Class 0x%x, Status-Detail 0x%x",
135 class, detail);
136 return (msg);
137 }
138 case 0x03:
139 switch (detail) {
140 case 0x00:
141 return ("Target error");
142 case 0x01:
143 return ("Service unavailable");
144 case 0x02:
145 return ("Out of resources");
146 default:
147 snprintf(msg, sizeof(msg), "unknown target error; "
148 "Status-Class 0x%x, Status-Detail 0x%x",
149 class, detail);
150 return (msg);
151 }
152 default:
153 snprintf(msg, sizeof(msg), "unknown error; "
154 "Status-Class 0x%x, Status-Detail 0x%x",
155 class, detail);
156 return (msg);
157 }
158 }
159
160 static void
kernel_modify(const struct iscsid_connection * conn,const char * target_address)161 kernel_modify(const struct iscsid_connection *conn, const char *target_address)
162 {
163 struct iscsi_session_modify ism;
164 int error;
165
166 memset(&ism, 0, sizeof(ism));
167 ism.ism_session_id = conn->conn_session_id;
168 memcpy(&ism.ism_conf, &conn->conn_conf, sizeof(ism.ism_conf));
169 strlcpy(ism.ism_conf.isc_target_addr, target_address,
170 sizeof(ism.ism_conf.isc_target_addr));
171 error = ioctl(conn->conn_iscsi_fd, ISCSISMODIFY, &ism);
172 if (error != 0) {
173 log_err(1, "failed to redirect to %s: ISCSISMODIFY",
174 target_address);
175 }
176 }
177
178 /*
179 * XXX: The way it works is suboptimal; what should happen is described
180 * in draft-gilligan-iscsi-fault-tolerance-00. That, however, would
181 * be much more complicated: we would need to keep "dependencies"
182 * for sessions, so that, in case described in draft and using draft
183 * terminology, we would have three sessions: one for discovery,
184 * one for initial target portal, and one for redirect portal.
185 * This would allow us to "backtrack" on connection failure,
186 * as described in draft.
187 */
188 static void
login_handle_redirection(struct iscsid_connection * conn,struct pdu * response)189 login_handle_redirection(struct iscsid_connection *conn, struct pdu *response)
190 {
191 struct iscsi_bhs_login_response *bhslr;
192 struct keys *response_keys;
193 const char *target_address;
194
195 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
196 assert (bhslr->bhslr_status_class == 1);
197
198 response_keys = keys_new();
199 keys_load_pdu(response_keys, response);
200
201 target_address = keys_find(response_keys, "TargetAddress");
202 if (target_address == NULL)
203 log_errx(1, "received redirection without TargetAddress");
204 if (target_address[0] == '\0')
205 log_errx(1, "received redirection with empty TargetAddress");
206 if (strlen(target_address) >=
207 sizeof(conn->conn_conf.isc_target_addr) - 1)
208 log_errx(1, "received TargetAddress is too long");
209
210 log_debugx("received redirection to \"%s\"", target_address);
211 kernel_modify(conn, target_address);
212 keys_delete(response_keys);
213 }
214
215 static struct pdu *
login_receive(struct connection * conn)216 login_receive(struct connection *conn)
217 {
218 struct pdu *response;
219 struct iscsi_bhs_login_response *bhslr;
220 const char *errorstr;
221 static bool initial = true;
222
223 response = pdu_new(conn);
224 pdu_receive(response);
225 if (response->pdu_bhs->bhs_opcode != ISCSI_BHS_OPCODE_LOGIN_RESPONSE) {
226 log_errx(1, "protocol error: received invalid opcode 0x%x",
227 response->pdu_bhs->bhs_opcode);
228 }
229 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
230 /*
231 * XXX: Implement the C flag some day.
232 */
233 if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0)
234 log_errx(1, "received Login PDU with unsupported \"C\" flag");
235 if (bhslr->bhslr_version_max != 0x00)
236 log_errx(1, "received Login PDU with unsupported "
237 "Version-max 0x%x", bhslr->bhslr_version_max);
238 if (bhslr->bhslr_version_active != 0x00)
239 log_errx(1, "received Login PDU with unsupported "
240 "Version-active 0x%x", bhslr->bhslr_version_active);
241 if (bhslr->bhslr_status_class == 1) {
242 login_handle_redirection((struct iscsid_connection *)conn,
243 response);
244 log_debugx("redirection handled; exiting");
245 exit(0);
246 }
247 if (bhslr->bhslr_status_class != 0) {
248 errorstr = login_target_error_str(bhslr->bhslr_status_class,
249 bhslr->bhslr_status_detail);
250 fail(conn, errorstr);
251 log_errx(1, "target returned error: %s", errorstr);
252 }
253 if (initial == false &&
254 ntohl(bhslr->bhslr_statsn) != conn->conn_statsn + 1) {
255 /*
256 * It's a warning, not an error, to work around what seems
257 * to be bug in NetBSD iSCSI target.
258 */
259 log_warnx("received Login PDU with wrong StatSN: "
260 "is %u, should be %u", ntohl(bhslr->bhslr_statsn),
261 conn->conn_statsn + 1);
262 }
263 conn->conn_tsih = ntohs(bhslr->bhslr_tsih);
264 conn->conn_statsn = ntohl(bhslr->bhslr_statsn);
265
266 initial = false;
267
268 return (response);
269 }
270
271 static struct pdu *
login_new_request(struct connection * conn,int csg)272 login_new_request(struct connection *conn, int csg)
273 {
274 struct pdu *request;
275 struct iscsi_bhs_login_request *bhslr;
276 int nsg;
277
278 request = pdu_new(conn);
279 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
280 bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_REQUEST |
281 ISCSI_BHS_OPCODE_IMMEDIATE;
282
283 bhslr->bhslr_flags = BHSLR_FLAGS_TRANSIT;
284 switch (csg) {
285 case BHSLR_STAGE_SECURITY_NEGOTIATION:
286 nsg = BHSLR_STAGE_OPERATIONAL_NEGOTIATION;
287 break;
288 case BHSLR_STAGE_OPERATIONAL_NEGOTIATION:
289 nsg = BHSLR_STAGE_FULL_FEATURE_PHASE;
290 break;
291 default:
292 assert(!"invalid csg");
293 log_errx(1, "invalid csg %d", csg);
294 }
295 login_set_csg(request, csg);
296 login_set_nsg(request, nsg);
297
298 memcpy(bhslr->bhslr_isid, &conn->conn_isid, sizeof(bhslr->bhslr_isid));
299 bhslr->bhslr_tsih = htons(conn->conn_tsih);
300 bhslr->bhslr_initiator_task_tag = 0;
301 bhslr->bhslr_cmdsn = 0;
302 bhslr->bhslr_expstatsn = htonl(conn->conn_statsn + 1);
303
304 return (request);
305 }
306
307 static int
login_list_prefers(const char * list,const char * choice1,const char * choice2)308 login_list_prefers(const char *list,
309 const char *choice1, const char *choice2)
310 {
311 char *tofree, *str, *token;
312
313 tofree = str = checked_strdup(list);
314
315 while ((token = strsep(&str, ",")) != NULL) {
316 if (strcmp(token, choice1) == 0) {
317 free(tofree);
318 return (1);
319 }
320 if (strcmp(token, choice2) == 0) {
321 free(tofree);
322 return (2);
323 }
324 }
325 free(tofree);
326 return (-1);
327 }
328
329 static void
login_negotiate_key(struct iscsid_connection * conn,const char * name,const char * value)330 login_negotiate_key(struct iscsid_connection *conn, const char *name,
331 const char *value)
332 {
333 struct iscsi_session_limits *isl;
334 int which, tmp;
335
336 isl = &conn->conn_limits;
337 if (strcmp(name, "TargetAlias") == 0) {
338 strlcpy(conn->conn_target_alias, value,
339 sizeof(conn->conn_target_alias));
340 } else if (strcmp(value, "Irrelevant") == 0) {
341 /* Ignore. */
342 } else if (strcmp(name, "iSCSIProtocolLevel") == 0) {
343 tmp = strtoul(value, NULL, 10);
344 if (tmp < 0 || tmp > 31)
345 log_errx(1, "received invalid iSCSIProtocolLevel");
346 conn->conn_protocol_level = tmp;
347 } else if (strcmp(name, "HeaderDigest") == 0) {
348 which = login_list_prefers(value, "CRC32C", "None");
349 switch (which) {
350 case 1:
351 log_debugx("target prefers CRC32C "
352 "for header digest; we'll use it");
353 conn->conn.conn_header_digest = CONN_DIGEST_CRC32C;
354 break;
355 case 2:
356 log_debugx("target prefers not to do "
357 "header digest; we'll comply");
358 break;
359 default:
360 log_warnx("target sent unrecognized "
361 "HeaderDigest value \"%s\"; will use None", value);
362 break;
363 }
364 } else if (strcmp(name, "DataDigest") == 0) {
365 which = login_list_prefers(value, "CRC32C", "None");
366 switch (which) {
367 case 1:
368 log_debugx("target prefers CRC32C "
369 "for data digest; we'll use it");
370 conn->conn.conn_data_digest = CONN_DIGEST_CRC32C;
371 break;
372 case 2:
373 log_debugx("target prefers not to do "
374 "data digest; we'll comply");
375 break;
376 default:
377 log_warnx("target sent unrecognized "
378 "DataDigest value \"%s\"; will use None", value);
379 break;
380 }
381 } else if (strcmp(name, "MaxConnections") == 0) {
382 /* Ignore. */
383 } else if (strcmp(name, "InitialR2T") == 0) {
384 if (strcmp(value, "Yes") == 0)
385 conn->conn_initial_r2t = true;
386 else
387 conn->conn_initial_r2t = false;
388 } else if (strcmp(name, "ImmediateData") == 0) {
389 if (strcmp(value, "Yes") == 0)
390 conn->conn.conn_immediate_data = true;
391 else
392 conn->conn.conn_immediate_data = false;
393 } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
394 tmp = strtoul(value, NULL, 10);
395 if (tmp <= 0)
396 log_errx(1, "received invalid "
397 "MaxRecvDataSegmentLength");
398 if (tmp > isl->isl_max_send_data_segment_length) {
399 log_debugx("capping max_send_data_segment_length "
400 "from %d to %d", tmp,
401 isl->isl_max_send_data_segment_length);
402 tmp = isl->isl_max_send_data_segment_length;
403 }
404 conn->conn.conn_max_send_data_segment_length = tmp;
405 } else if (strcmp(name, "MaxBurstLength") == 0) {
406 tmp = strtoul(value, NULL, 10);
407 if (tmp <= 0)
408 log_errx(1, "received invalid MaxBurstLength");
409 if (tmp > isl->isl_max_burst_length) {
410 log_debugx("capping MaxBurstLength "
411 "from %d to %d", tmp, isl->isl_max_burst_length);
412 tmp = isl->isl_max_burst_length;
413 }
414 conn->conn.conn_max_burst_length = tmp;
415 } else if (strcmp(name, "FirstBurstLength") == 0) {
416 tmp = strtoul(value, NULL, 10);
417 if (tmp <= 0)
418 log_errx(1, "received invalid FirstBurstLength");
419 if (tmp > isl->isl_first_burst_length) {
420 log_debugx("capping FirstBurstLength "
421 "from %d to %d", tmp, isl->isl_first_burst_length);
422 tmp = isl->isl_first_burst_length;
423 }
424 conn->conn.conn_first_burst_length = tmp;
425 } else if (strcmp(name, "DefaultTime2Wait") == 0) {
426 /* Ignore */
427 } else if (strcmp(name, "DefaultTime2Retain") == 0) {
428 /* Ignore */
429 } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
430 /* Ignore */
431 } else if (strcmp(name, "DataPDUInOrder") == 0) {
432 /* Ignore */
433 } else if (strcmp(name, "DataSequenceInOrder") == 0) {
434 /* Ignore */
435 } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
436 /* Ignore */
437 } else if (strcmp(name, "OFMarker") == 0) {
438 /* Ignore */
439 } else if (strcmp(name, "IFMarker") == 0) {
440 /* Ignore */
441 } else if (strcmp(name, "RDMAExtensions") == 0) {
442 if (conn->conn_conf.isc_iser == 1 &&
443 strcmp(value, "Yes") != 0) {
444 log_errx(1, "received unsupported RDMAExtensions");
445 }
446 } else if (strcmp(name, "InitiatorRecvDataSegmentLength") == 0) {
447 tmp = strtoul(value, NULL, 10);
448 if (tmp <= 0)
449 log_errx(1, "received invalid "
450 "InitiatorRecvDataSegmentLength");
451 if ((int)tmp > isl->isl_max_recv_data_segment_length) {
452 log_debugx("capping InitiatorRecvDataSegmentLength "
453 "from %d to %d", tmp,
454 isl->isl_max_recv_data_segment_length);
455 tmp = isl->isl_max_recv_data_segment_length;
456 }
457 conn->conn.conn_max_recv_data_segment_length = tmp;
458 } else if (strcmp(name, "TargetPortalGroupTag") == 0) {
459 /* Ignore */
460 } else if (strcmp(name, "TargetRecvDataSegmentLength") == 0) {
461 tmp = strtoul(value, NULL, 10);
462 if (tmp <= 0) {
463 log_errx(1,
464 "received invalid TargetRecvDataSegmentLength");
465 }
466 if (tmp > isl->isl_max_send_data_segment_length) {
467 log_debugx("capping TargetRecvDataSegmentLength "
468 "from %d to %d", tmp,
469 isl->isl_max_send_data_segment_length);
470 tmp = isl->isl_max_send_data_segment_length;
471 }
472 conn->conn.conn_max_send_data_segment_length = tmp;
473 } else {
474 log_debugx("unknown key \"%s\"; ignoring", name);
475 }
476 }
477
478 static void
login_negotiate(struct iscsid_connection * conn)479 login_negotiate(struct iscsid_connection *conn)
480 {
481 struct pdu *request, *response;
482 struct keys *request_keys, *response_keys;
483 struct iscsi_bhs_login_response *bhslr;
484 int i, nrequests = 0;
485 struct iscsi_session_limits *isl;
486
487 log_debugx("beginning operational parameter negotiation");
488 request = login_new_request(&conn->conn,
489 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.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_pdu(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->conn);
552 response_keys = keys_new();
553 keys_load_pdu(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->conn,
583 BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
584 pdu_send(request);
585 pdu_delete(request);
586
587 response = login_receive(&conn->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_pdu(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 iscsid_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 = (struct iscsid_connection *)response->pdu_connection;
635
636 response_keys = keys_new();
637 keys_load_pdu(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->conn,
669 BHSLR_STAGE_SECURITY_NEGOTIATION);
670 request_keys = keys_new();
671 keys_add(request_keys, "CHAP_N", conn->conn_conf.isc_user);
672 keys_add(request_keys, "CHAP_R", chap_r);
673 free(chap_r);
674
675 /*
676 * If we want mutual authentication, we're expected to send
677 * our CHAP_I/CHAP_C now.
678 */
679 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
680 log_debugx("requesting mutual authentication; "
681 "binary challenge size is %zd bytes",
682 sizeof(conn->conn_mutual_chap->chap_challenge));
683
684 assert(conn->conn_mutual_chap == NULL);
685 conn->conn_mutual_chap = chap_new();
686 mutual_chap_i = chap_get_id(conn->conn_mutual_chap);
687 mutual_chap_c = chap_get_challenge(conn->conn_mutual_chap);
688 keys_add(request_keys, "CHAP_I", mutual_chap_i);
689 keys_add(request_keys, "CHAP_C", mutual_chap_c);
690 free(mutual_chap_i);
691 free(mutual_chap_c);
692 }
693
694 keys_save_pdu(request_keys, request);
695 keys_delete(request_keys);
696 pdu_send(request);
697 pdu_delete(request);
698 }
699
700 static void
login_verify_mutual(const struct pdu * response)701 login_verify_mutual(const struct pdu *response)
702 {
703 struct iscsid_connection *conn;
704 struct keys *response_keys;
705 const char *chap_n, *chap_r;
706 int error;
707
708 conn = (struct iscsid_connection *)response->pdu_connection;
709
710 response_keys = keys_new();
711 keys_load_pdu(response_keys, response);
712
713 chap_n = keys_find(response_keys, "CHAP_N");
714 if (chap_n == NULL)
715 log_errx(1, "received CHAP Response PDU without CHAP_N");
716 chap_r = keys_find(response_keys, "CHAP_R");
717 if (chap_r == NULL)
718 log_errx(1, "received CHAP Response PDU without CHAP_R");
719
720 error = chap_receive(conn->conn_mutual_chap, chap_r);
721 if (error != 0)
722 log_errx(1, "received CHAP Response PDU with invalid CHAP_R");
723
724 if (strcmp(chap_n, conn->conn_conf.isc_mutual_user) != 0) {
725 fail(&conn->conn, "Mutual CHAP failed");
726 log_errx(1, "mutual CHAP authentication failed: wrong user");
727 }
728
729 error = chap_authenticate(conn->conn_mutual_chap,
730 conn->conn_conf.isc_mutual_secret);
731 if (error != 0) {
732 fail(&conn->conn, "Mutual CHAP failed");
733 log_errx(1, "mutual CHAP authentication failed: wrong secret");
734 }
735
736 keys_delete(response_keys);
737 chap_delete(conn->conn_mutual_chap);
738 conn->conn_mutual_chap = NULL;
739
740 log_debugx("mutual CHAP authentication succeeded");
741 }
742
743 static void
login_chap(struct iscsid_connection * conn)744 login_chap(struct iscsid_connection *conn)
745 {
746 struct pdu *response;
747
748 log_debugx("beginning CHAP authentication; sending CHAP_A");
749 login_send_chap_a(&conn->conn);
750
751 log_debugx("waiting for CHAP_A/CHAP_C/CHAP_I");
752 response = login_receive(&conn->conn);
753
754 log_debugx("sending CHAP_N/CHAP_R");
755 login_send_chap_r(response);
756 pdu_delete(response);
757
758 /*
759 * XXX: Make sure this is not susceptible to MITM.
760 */
761
762 log_debugx("waiting for CHAP result");
763 response = login_receive(&conn->conn);
764 if (conn->conn_conf.isc_mutual_user[0] != '\0')
765 login_verify_mutual(response);
766 pdu_delete(response);
767
768 log_debugx("CHAP authentication done");
769 }
770
771 void
login(struct iscsid_connection * conn)772 login(struct iscsid_connection *conn)
773 {
774 struct pdu *request, *response;
775 struct keys *request_keys, *response_keys;
776 struct iscsi_bhs_login_response *bhslr2;
777 const char *auth_method;
778 int i;
779
780 log_debugx("beginning Login phase; sending Login PDU");
781 request = login_new_request(&conn->conn,
782 BHSLR_STAGE_SECURITY_NEGOTIATION);
783 request_keys = keys_new();
784 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
785 keys_add(request_keys, "AuthMethod", "CHAP");
786 } else if (conn->conn_conf.isc_user[0] != '\0') {
787 /*
788 * Give target a chance to skip authentication if it
789 * doesn't feel like it.
790 *
791 * None is first, CHAP second; this is to work around
792 * what seems to be LIO (Linux target) bug: otherwise,
793 * if target is configured with no authentication,
794 * and we are configured to authenticate, the target
795 * will erroneously respond with AuthMethod=CHAP
796 * instead of AuthMethod=None, and will subsequently
797 * fail the connection. This usually happens with
798 * Discovery sessions, which default to no authentication.
799 */
800 keys_add(request_keys, "AuthMethod", "None,CHAP");
801 } else {
802 keys_add(request_keys, "AuthMethod", "None");
803 }
804 keys_add(request_keys, "InitiatorName",
805 conn->conn_conf.isc_initiator);
806 if (conn->conn_conf.isc_initiator_alias[0] != '\0') {
807 keys_add(request_keys, "InitiatorAlias",
808 conn->conn_conf.isc_initiator_alias);
809 }
810 if (conn->conn_conf.isc_discovery == 0) {
811 keys_add(request_keys, "SessionType", "Normal");
812 keys_add(request_keys,
813 "TargetName", conn->conn_conf.isc_target);
814 } else {
815 keys_add(request_keys, "SessionType", "Discovery");
816 }
817 keys_save_pdu(request_keys, request);
818 keys_delete(request_keys);
819 pdu_send(request);
820 pdu_delete(request);
821
822 response = login_receive(&conn->conn);
823
824 response_keys = keys_new();
825 keys_load_pdu(response_keys, response);
826
827 for (i = 0; i < KEYS_MAX; i++) {
828 if (response_keys->keys_names[i] == NULL)
829 break;
830
831 /*
832 * Not interested in AuthMethod at this point; we only need
833 * to parse things such as TargetAlias.
834 *
835 * XXX: This is somewhat ugly. We should have a way to apply
836 * all the keys to the session and use that by default
837 * instead of discarding them.
838 */
839 if (strcmp(response_keys->keys_names[i], "AuthMethod") == 0)
840 continue;
841
842 login_negotiate_key(conn,
843 response_keys->keys_names[i], response_keys->keys_values[i]);
844 }
845
846 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
847 if ((bhslr2->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0 &&
848 login_nsg(response) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
849 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
850 log_errx(1, "target requested transition "
851 "to operational parameter negotiation, "
852 "but we require mutual CHAP");
853 }
854
855 log_debugx("target requested transition "
856 "to operational parameter negotiation");
857 keys_delete(response_keys);
858 pdu_delete(response);
859 login_negotiate(conn);
860 return;
861 }
862
863 auth_method = keys_find(response_keys, "AuthMethod");
864 if (auth_method == NULL)
865 log_errx(1, "received response without AuthMethod");
866 if (strcmp(auth_method, "None") == 0) {
867 if (conn->conn_conf.isc_mutual_user[0] != '\0') {
868 log_errx(1, "target does not require authantication, "
869 "but we require mutual CHAP");
870 }
871
872 log_debugx("target does not require authentication");
873 keys_delete(response_keys);
874 pdu_delete(response);
875 login_negotiate(conn);
876 return;
877 }
878
879 if (strcmp(auth_method, "CHAP") != 0) {
880 fail(&conn->conn, "Unsupported AuthMethod");
881 log_errx(1, "received response "
882 "with unsupported AuthMethod \"%s\"", auth_method);
883 }
884
885 if (conn->conn_conf.isc_user[0] == '\0' ||
886 conn->conn_conf.isc_secret[0] == '\0') {
887 fail(&conn->conn, "Authentication required");
888 log_errx(1, "target requests CHAP authentication, but we don't "
889 "have user and secret");
890 }
891
892 keys_delete(response_keys);
893 response_keys = NULL;
894 pdu_delete(response);
895 response = NULL;
896
897 login_chap(conn);
898 login_negotiate(conn);
899 }
900