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