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 <assert.h> 34 #include <stdbool.h> 35 #include <stdlib.h> 36 #include <string.h> 37 #include <unistd.h> 38 #include <netinet/in.h> 39 40 #include "ctld.h" 41 #include "iscsi_proto.h" 42 43 static void login_send_error(struct pdu *request, 44 char class, char detail); 45 46 static void 47 login_set_nsg(struct pdu *response, int nsg) 48 { 49 struct iscsi_bhs_login_response *bhslr; 50 51 assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION || 52 nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION || 53 nsg == BHSLR_STAGE_FULL_FEATURE_PHASE); 54 55 bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs; 56 57 bhslr->bhslr_flags &= 0xFC; 58 bhslr->bhslr_flags |= nsg; 59 bhslr->bhslr_flags |= BHSLR_FLAGS_TRANSIT; 60 } 61 62 static int 63 login_csg(const struct pdu *request) 64 { 65 struct iscsi_bhs_login_request *bhslr; 66 67 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs; 68 69 return ((bhslr->bhslr_flags & 0x0C) >> 2); 70 } 71 72 static void 73 login_set_csg(struct pdu *response, int csg) 74 { 75 struct iscsi_bhs_login_response *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_response *)response->pdu_bhs; 82 83 bhslr->bhslr_flags &= 0xF3; 84 bhslr->bhslr_flags |= csg << 2; 85 } 86 87 static struct pdu * 88 login_receive(struct connection *conn, bool initial) 89 { 90 struct pdu *request; 91 struct iscsi_bhs_login_request *bhslr; 92 93 request = pdu_new(conn); 94 pdu_receive(request); 95 if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) != 96 ISCSI_BHS_OPCODE_LOGIN_REQUEST) { 97 /* 98 * The first PDU in session is special - if we receive any PDU 99 * different than login request, we have to drop the connection 100 * without sending response ("A target receiving any PDU 101 * except a Login request before the Login Phase is started MUST 102 * immediately terminate the connection on which the PDU 103 * was received.") 104 */ 105 if (initial == false) 106 login_send_error(request, 0x02, 0x0b); 107 log_errx(1, "protocol error: received invalid opcode 0x%x", 108 request->pdu_bhs->bhs_opcode); 109 } 110 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs; 111 /* 112 * XXX: Implement the C flag some day. 113 */ 114 if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0) { 115 login_send_error(request, 0x03, 0x00); 116 log_errx(1, "received Login PDU with unsupported \"C\" flag"); 117 } 118 if (bhslr->bhslr_version_max != 0x00) { 119 login_send_error(request, 0x02, 0x05); 120 log_errx(1, "received Login PDU with unsupported " 121 "Version-max 0x%x", bhslr->bhslr_version_max); 122 } 123 if (bhslr->bhslr_version_min != 0x00) { 124 login_send_error(request, 0x02, 0x05); 125 log_errx(1, "received Login PDU with unsupported " 126 "Version-min 0x%x", bhslr->bhslr_version_min); 127 } 128 if (initial == false && 129 ISCSI_SNLT(ntohl(bhslr->bhslr_cmdsn), conn->conn_cmdsn)) { 130 login_send_error(request, 0x02, 0x00); 131 log_errx(1, "received Login PDU with decreasing CmdSN: " 132 "was %u, is %u", conn->conn_cmdsn, 133 ntohl(bhslr->bhslr_cmdsn)); 134 } 135 if (initial == false && 136 ntohl(bhslr->bhslr_expstatsn) != conn->conn_statsn) { 137 login_send_error(request, 0x02, 0x00); 138 log_errx(1, "received Login PDU with wrong ExpStatSN: " 139 "is %u, should be %u", ntohl(bhslr->bhslr_expstatsn), 140 conn->conn_statsn); 141 } 142 conn->conn_cmdsn = ntohl(bhslr->bhslr_cmdsn); 143 144 return (request); 145 } 146 147 static struct pdu * 148 login_new_response(struct pdu *request) 149 { 150 struct pdu *response; 151 struct connection *conn; 152 struct iscsi_bhs_login_request *bhslr; 153 struct iscsi_bhs_login_response *bhslr2; 154 155 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs; 156 conn = request->pdu_connection; 157 158 response = pdu_new_response(request); 159 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs; 160 bhslr2->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_RESPONSE; 161 login_set_csg(response, BHSLR_STAGE_SECURITY_NEGOTIATION); 162 memcpy(bhslr2->bhslr_isid, 163 bhslr->bhslr_isid, sizeof(bhslr2->bhslr_isid)); 164 bhslr2->bhslr_initiator_task_tag = bhslr->bhslr_initiator_task_tag; 165 bhslr2->bhslr_statsn = htonl(conn->conn_statsn++); 166 bhslr2->bhslr_expcmdsn = htonl(conn->conn_cmdsn); 167 bhslr2->bhslr_maxcmdsn = htonl(conn->conn_cmdsn); 168 169 return (response); 170 } 171 172 static void 173 login_send_error(struct pdu *request, char class, char detail) 174 { 175 struct pdu *response; 176 struct iscsi_bhs_login_response *bhslr2; 177 178 log_debugx("sending Login Response PDU with failure class 0x%x/0x%x; " 179 "see next line for reason", class, detail); 180 response = login_new_response(request); 181 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs; 182 bhslr2->bhslr_status_class = class; 183 bhslr2->bhslr_status_detail = detail; 184 185 pdu_send(response); 186 pdu_delete(response); 187 } 188 189 static int 190 login_list_contains(const char *list, const char *what) 191 { 192 char *tofree, *str, *token; 193 194 tofree = str = checked_strdup(list); 195 196 while ((token = strsep(&str, ",")) != NULL) { 197 if (strcmp(token, what) == 0) { 198 free(tofree); 199 return (1); 200 } 201 } 202 free(tofree); 203 return (0); 204 } 205 206 static int 207 login_list_prefers(const char *list, 208 const char *choice1, const char *choice2) 209 { 210 char *tofree, *str, *token; 211 212 tofree = str = checked_strdup(list); 213 214 while ((token = strsep(&str, ",")) != NULL) { 215 if (strcmp(token, choice1) == 0) { 216 free(tofree); 217 return (1); 218 } 219 if (strcmp(token, choice2) == 0) { 220 free(tofree); 221 return (2); 222 } 223 } 224 free(tofree); 225 return (-1); 226 } 227 228 static struct pdu * 229 login_receive_chap_a(struct connection *conn) 230 { 231 struct pdu *request; 232 struct keys *request_keys; 233 const char *chap_a; 234 235 request = login_receive(conn, false); 236 request_keys = keys_new(); 237 keys_load_pdu(request_keys, request); 238 239 chap_a = keys_find(request_keys, "CHAP_A"); 240 if (chap_a == NULL) { 241 login_send_error(request, 0x02, 0x07); 242 log_errx(1, "received CHAP Login PDU without CHAP_A"); 243 } 244 if (login_list_contains(chap_a, "5") == 0) { 245 login_send_error(request, 0x02, 0x01); 246 log_errx(1, "received CHAP Login PDU with unsupported CHAP_A " 247 "\"%s\"", chap_a); 248 } 249 keys_delete(request_keys); 250 251 return (request); 252 } 253 254 static void 255 login_send_chap_c(struct pdu *request, struct chap *chap) 256 { 257 struct pdu *response; 258 struct keys *response_keys; 259 char *chap_c, *chap_i; 260 261 chap_c = chap_get_challenge(chap); 262 chap_i = chap_get_id(chap); 263 264 response = login_new_response(request); 265 response_keys = keys_new(); 266 keys_add(response_keys, "CHAP_A", "5"); 267 keys_add(response_keys, "CHAP_I", chap_i); 268 keys_add(response_keys, "CHAP_C", chap_c); 269 free(chap_i); 270 free(chap_c); 271 keys_save_pdu(response_keys, response); 272 pdu_send(response); 273 pdu_delete(response); 274 keys_delete(response_keys); 275 } 276 277 static struct pdu * 278 login_receive_chap_r(struct connection *conn, struct auth_group *ag, 279 struct chap *chap, const struct auth **authp) 280 { 281 struct pdu *request; 282 struct keys *request_keys; 283 const char *chap_n, *chap_r; 284 const struct auth *auth; 285 int error; 286 287 request = login_receive(conn, false); 288 request_keys = keys_new(); 289 keys_load_pdu(request_keys, request); 290 291 chap_n = keys_find(request_keys, "CHAP_N"); 292 if (chap_n == NULL) { 293 login_send_error(request, 0x02, 0x07); 294 log_errx(1, "received CHAP Login PDU without CHAP_N"); 295 } 296 chap_r = keys_find(request_keys, "CHAP_R"); 297 if (chap_r == NULL) { 298 login_send_error(request, 0x02, 0x07); 299 log_errx(1, "received CHAP Login PDU without CHAP_R"); 300 } 301 error = chap_receive(chap, chap_r); 302 if (error != 0) { 303 login_send_error(request, 0x02, 0x07); 304 log_errx(1, "received CHAP Login PDU with malformed CHAP_R"); 305 } 306 307 /* 308 * Verify the response. 309 */ 310 assert(ag->ag_type == AG_TYPE_CHAP || 311 ag->ag_type == AG_TYPE_CHAP_MUTUAL); 312 auth = auth_find(ag, chap_n); 313 if (auth == NULL) { 314 login_send_error(request, 0x02, 0x01); 315 log_errx(1, "received CHAP Login with invalid user \"%s\"", 316 chap_n); 317 } 318 319 assert(auth->a_secret != NULL); 320 assert(strlen(auth->a_secret) > 0); 321 322 error = chap_authenticate(chap, auth->a_secret); 323 if (error != 0) { 324 login_send_error(request, 0x02, 0x01); 325 log_errx(1, "CHAP authentication failed for user \"%s\"", 326 auth->a_user); 327 } 328 329 keys_delete(request_keys); 330 331 *authp = auth; 332 return (request); 333 } 334 335 static void 336 login_send_chap_success(struct pdu *request, 337 const struct auth *auth) 338 { 339 struct pdu *response; 340 struct keys *request_keys, *response_keys; 341 struct rchap *rchap; 342 const char *chap_i, *chap_c; 343 char *chap_r; 344 int error; 345 346 response = login_new_response(request); 347 login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION); 348 349 /* 350 * Actually, one more thing: mutual authentication. 351 */ 352 request_keys = keys_new(); 353 keys_load_pdu(request_keys, request); 354 chap_i = keys_find(request_keys, "CHAP_I"); 355 chap_c = keys_find(request_keys, "CHAP_C"); 356 if (chap_i != NULL || chap_c != NULL) { 357 if (chap_i == NULL) { 358 login_send_error(request, 0x02, 0x07); 359 log_errx(1, "initiator requested target " 360 "authentication, but didn't send CHAP_I"); 361 } 362 if (chap_c == NULL) { 363 login_send_error(request, 0x02, 0x07); 364 log_errx(1, "initiator requested target " 365 "authentication, but didn't send CHAP_C"); 366 } 367 if (auth->a_auth_group->ag_type != AG_TYPE_CHAP_MUTUAL) { 368 login_send_error(request, 0x02, 0x01); 369 log_errx(1, "initiator requests target authentication " 370 "for user \"%s\", but mutual user/secret " 371 "is not set", auth->a_user); 372 } 373 374 log_debugx("performing mutual authentication as user \"%s\"", 375 auth->a_mutual_user); 376 377 rchap = rchap_new(auth->a_mutual_secret); 378 error = rchap_receive(rchap, chap_i, chap_c); 379 if (error != 0) { 380 login_send_error(request, 0x02, 0x07); 381 log_errx(1, "received CHAP Login PDU with malformed " 382 "CHAP_I or CHAP_C"); 383 } 384 chap_r = rchap_get_response(rchap); 385 rchap_delete(rchap); 386 response_keys = keys_new(); 387 keys_add(response_keys, "CHAP_N", auth->a_mutual_user); 388 keys_add(response_keys, "CHAP_R", chap_r); 389 free(chap_r); 390 keys_save_pdu(response_keys, response); 391 keys_delete(response_keys); 392 } else { 393 log_debugx("initiator did not request target authentication"); 394 } 395 396 keys_delete(request_keys); 397 pdu_send(response); 398 pdu_delete(response); 399 } 400 401 static void 402 login_chap(struct ctld_connection *conn, struct auth_group *ag) 403 { 404 const struct auth *auth; 405 struct chap *chap; 406 struct pdu *request; 407 408 /* 409 * Receive CHAP_A PDU. 410 */ 411 log_debugx("beginning CHAP authentication; waiting for CHAP_A"); 412 request = login_receive_chap_a(&conn->conn); 413 414 /* 415 * Generate the challenge. 416 */ 417 chap = chap_new(); 418 419 /* 420 * Send the challenge. 421 */ 422 log_debugx("sending CHAP_C, binary challenge size is %zd bytes", 423 sizeof(chap->chap_challenge)); 424 login_send_chap_c(request, chap); 425 pdu_delete(request); 426 427 /* 428 * Receive CHAP_N/CHAP_R PDU and authenticate. 429 */ 430 log_debugx("waiting for CHAP_N/CHAP_R"); 431 request = login_receive_chap_r(&conn->conn, ag, chap, &auth); 432 433 /* 434 * Yay, authentication succeeded! 435 */ 436 log_debugx("authentication succeeded for user \"%s\"; " 437 "transitioning to operational parameter negotiation", auth->a_user); 438 login_send_chap_success(request, auth); 439 pdu_delete(request); 440 441 /* 442 * Leave username and CHAP information for discovery(). 443 */ 444 conn->conn_user = auth->a_user; 445 conn->conn_chap = chap; 446 } 447 448 static void 449 login_negotiate_key(struct pdu *request, const char *name, 450 const char *value, bool skipped_security, struct keys *response_keys) 451 { 452 int which; 453 size_t tmp; 454 struct ctld_connection *conn; 455 456 conn = (struct ctld_connection *)request->pdu_connection; 457 458 if (strcmp(name, "InitiatorName") == 0) { 459 if (!skipped_security) 460 log_errx(1, "initiator resent InitiatorName"); 461 } else if (strcmp(name, "SessionType") == 0) { 462 if (!skipped_security) 463 log_errx(1, "initiator resent SessionType"); 464 } else if (strcmp(name, "TargetName") == 0) { 465 if (!skipped_security) 466 log_errx(1, "initiator resent TargetName"); 467 } else if (strcmp(name, "InitiatorAlias") == 0) { 468 if (conn->conn_initiator_alias != NULL) 469 free(conn->conn_initiator_alias); 470 conn->conn_initiator_alias = checked_strdup(value); 471 } else if (strcmp(value, "Irrelevant") == 0) { 472 /* Ignore. */ 473 } else if (strcmp(name, "HeaderDigest") == 0) { 474 /* 475 * We don't handle digests for discovery sessions. 476 */ 477 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) { 478 log_debugx("discovery session; digests disabled"); 479 keys_add(response_keys, name, "None"); 480 return; 481 } 482 483 which = login_list_prefers(value, "CRC32C", "None"); 484 switch (which) { 485 case 1: 486 log_debugx("initiator prefers CRC32C " 487 "for header digest; we'll use it"); 488 conn->conn.conn_header_digest = CONN_DIGEST_CRC32C; 489 keys_add(response_keys, name, "CRC32C"); 490 break; 491 case 2: 492 log_debugx("initiator prefers not to do " 493 "header digest; we'll comply"); 494 keys_add(response_keys, name, "None"); 495 break; 496 default: 497 log_warnx("initiator sent unrecognized " 498 "HeaderDigest value \"%s\"; will use None", value); 499 keys_add(response_keys, name, "None"); 500 break; 501 } 502 } else if (strcmp(name, "DataDigest") == 0) { 503 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) { 504 log_debugx("discovery session; digests disabled"); 505 keys_add(response_keys, name, "None"); 506 return; 507 } 508 509 which = login_list_prefers(value, "CRC32C", "None"); 510 switch (which) { 511 case 1: 512 log_debugx("initiator prefers CRC32C " 513 "for data digest; we'll use it"); 514 conn->conn.conn_data_digest = CONN_DIGEST_CRC32C; 515 keys_add(response_keys, name, "CRC32C"); 516 break; 517 case 2: 518 log_debugx("initiator prefers not to do " 519 "data digest; we'll comply"); 520 keys_add(response_keys, name, "None"); 521 break; 522 default: 523 log_warnx("initiator sent unrecognized " 524 "DataDigest value \"%s\"; will use None", value); 525 keys_add(response_keys, name, "None"); 526 break; 527 } 528 } else if (strcmp(name, "MaxConnections") == 0) { 529 keys_add(response_keys, name, "1"); 530 } else if (strcmp(name, "InitialR2T") == 0) { 531 keys_add(response_keys, name, "Yes"); 532 } else if (strcmp(name, "ImmediateData") == 0) { 533 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) { 534 log_debugx("discovery session; ImmediateData irrelevant"); 535 keys_add(response_keys, name, "Irrelevant"); 536 } else { 537 if (strcmp(value, "Yes") == 0) { 538 conn->conn.conn_immediate_data = true; 539 keys_add(response_keys, name, "Yes"); 540 } else { 541 conn->conn.conn_immediate_data = false; 542 keys_add(response_keys, name, "No"); 543 } 544 } 545 } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) { 546 tmp = strtoul(value, NULL, 10); 547 if (tmp <= 0) { 548 login_send_error(request, 0x02, 0x00); 549 log_errx(1, "received invalid " 550 "MaxRecvDataSegmentLength"); 551 } 552 553 /* 554 * MaxRecvDataSegmentLength is a direction-specific parameter. 555 * We'll limit our _send_ to what the initiator can handle but 556 * our MaxRecvDataSegmentLength is not influenced by the 557 * initiator in any way. 558 */ 559 if ((int)tmp > conn->conn_max_send_data_segment_limit) { 560 log_debugx("capping MaxRecvDataSegmentLength " 561 "from %zd to %d", tmp, 562 conn->conn_max_send_data_segment_limit); 563 tmp = conn->conn_max_send_data_segment_limit; 564 } 565 conn->conn.conn_max_send_data_segment_length = tmp; 566 } else if (strcmp(name, "MaxBurstLength") == 0) { 567 tmp = strtoul(value, NULL, 10); 568 if (tmp <= 0) { 569 login_send_error(request, 0x02, 0x00); 570 log_errx(1, "received invalid MaxBurstLength"); 571 } 572 if ((int)tmp > conn->conn_max_burst_limit) { 573 log_debugx("capping MaxBurstLength from %zd to %d", 574 tmp, conn->conn_max_burst_limit); 575 tmp = conn->conn_max_burst_limit; 576 } 577 conn->conn.conn_max_burst_length = tmp; 578 keys_add_int(response_keys, name, tmp); 579 } else if (strcmp(name, "FirstBurstLength") == 0) { 580 tmp = strtoul(value, NULL, 10); 581 if (tmp <= 0) { 582 login_send_error(request, 0x02, 0x00); 583 log_errx(1, "received invalid FirstBurstLength"); 584 } 585 if ((int)tmp > conn->conn_first_burst_limit) { 586 log_debugx("capping FirstBurstLength from %zd to %d", 587 tmp, conn->conn_first_burst_limit); 588 tmp = conn->conn_first_burst_limit; 589 } 590 conn->conn.conn_first_burst_length = tmp; 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 if (strcmp(name, "iSCSIProtocolLevel") == 0) { 609 tmp = strtoul(value, NULL, 10); 610 if (tmp > 2) 611 tmp = 2; 612 keys_add_int(response_keys, name, tmp); 613 } else { 614 log_debugx("unknown key \"%s\"; responding " 615 "with NotUnderstood", name); 616 keys_add(response_keys, name, "NotUnderstood"); 617 } 618 } 619 620 static void 621 login_redirect(struct pdu *request, const char *target_address) 622 { 623 struct pdu *response; 624 struct iscsi_bhs_login_response *bhslr2; 625 struct keys *response_keys; 626 627 response = login_new_response(request); 628 login_set_csg(response, login_csg(request)); 629 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs; 630 bhslr2->bhslr_status_class = 0x01; 631 bhslr2->bhslr_status_detail = 0x01; 632 633 response_keys = keys_new(); 634 keys_add(response_keys, "TargetAddress", target_address); 635 636 keys_save_pdu(response_keys, response); 637 pdu_send(response); 638 pdu_delete(response); 639 keys_delete(response_keys); 640 } 641 642 static bool 643 login_portal_redirect(struct ctld_connection *conn, struct pdu *request) 644 { 645 const struct portal_group *pg; 646 647 pg = conn->conn_portal->p_portal_group; 648 if (pg->pg_redirection == NULL) 649 return (false); 650 651 log_debugx("portal-group \"%s\" configured to redirect to %s", 652 pg->pg_name, pg->pg_redirection); 653 login_redirect(request, pg->pg_redirection); 654 655 return (true); 656 } 657 658 static bool 659 login_target_redirect(struct ctld_connection *conn, struct pdu *request) 660 { 661 const char *target_address; 662 663 assert(conn->conn_portal->p_portal_group->pg_redirection == NULL); 664 665 if (conn->conn_target == NULL) 666 return (false); 667 668 target_address = conn->conn_target->t_redirection; 669 if (target_address == NULL) 670 return (false); 671 672 log_debugx("target \"%s\" configured to redirect to %s", 673 conn->conn_target->t_name, target_address); 674 login_redirect(request, target_address); 675 676 return (true); 677 } 678 679 static void 680 login_negotiate(struct ctld_connection *conn, struct pdu *request) 681 { 682 struct pdu *response; 683 struct iscsi_bhs_login_response *bhslr2; 684 struct keys *request_keys, *response_keys; 685 int i; 686 bool redirected, skipped_security; 687 688 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) { 689 /* 690 * Query the kernel for various size limits. In case of 691 * offload, it depends on hardware capabilities. 692 */ 693 assert(conn->conn_target != NULL); 694 conn->conn_max_recv_data_segment_limit = (1 << 24) - 1; 695 conn->conn_max_send_data_segment_limit = (1 << 24) - 1; 696 conn->conn_max_burst_limit = (1 << 24) - 1; 697 conn->conn_first_burst_limit = (1 << 24) - 1; 698 kernel_limits(conn->conn_portal->p_portal_group->pg_offload, 699 conn->conn.conn_socket, 700 &conn->conn_max_recv_data_segment_limit, 701 &conn->conn_max_send_data_segment_limit, 702 &conn->conn_max_burst_limit, 703 &conn->conn_first_burst_limit); 704 705 /* We expect legal, usable values at this point. */ 706 assert(conn->conn_max_recv_data_segment_limit >= 512); 707 assert(conn->conn_max_recv_data_segment_limit < (1 << 24)); 708 assert(conn->conn_max_send_data_segment_limit >= 512); 709 assert(conn->conn_max_send_data_segment_limit < (1 << 24)); 710 assert(conn->conn_max_burst_limit >= 512); 711 assert(conn->conn_max_burst_limit < (1 << 24)); 712 assert(conn->conn_first_burst_limit >= 512); 713 assert(conn->conn_first_burst_limit < (1 << 24)); 714 assert(conn->conn_first_burst_limit <= 715 conn->conn_max_burst_limit); 716 717 /* 718 * Limit default send length in case it won't be negotiated. 719 * We can't do it for other limits, since they may affect both 720 * sender and receiver operation, and we must obey defaults. 721 */ 722 if (conn->conn_max_send_data_segment_limit < 723 conn->conn.conn_max_send_data_segment_length) { 724 conn->conn.conn_max_send_data_segment_length = 725 conn->conn_max_send_data_segment_limit; 726 } 727 } else { 728 conn->conn_max_recv_data_segment_limit = 729 MAX_DATA_SEGMENT_LENGTH; 730 conn->conn_max_send_data_segment_limit = 731 MAX_DATA_SEGMENT_LENGTH; 732 } 733 734 if (request == NULL) { 735 log_debugx("beginning operational parameter negotiation; " 736 "waiting for Login PDU"); 737 request = login_receive(&conn->conn, false); 738 skipped_security = false; 739 } else 740 skipped_security = true; 741 742 /* 743 * RFC 3720, 10.13.5. Status-Class and Status-Detail, says 744 * the redirection SHOULD be accepted by the initiator before 745 * authentication, but MUST be accepted afterwards; that's 746 * why we're doing it here and not earlier. 747 */ 748 redirected = login_target_redirect(conn, request); 749 if (redirected) { 750 log_debugx("initiator redirected; exiting"); 751 exit(0); 752 } 753 754 request_keys = keys_new(); 755 keys_load_pdu(request_keys, request); 756 757 response = login_new_response(request); 758 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs; 759 bhslr2->bhslr_tsih = htons(0xbadd); 760 login_set_csg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION); 761 login_set_nsg(response, BHSLR_STAGE_FULL_FEATURE_PHASE); 762 response_keys = keys_new(); 763 764 if (skipped_security && 765 conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) { 766 if (conn->conn_target->t_alias != NULL) 767 keys_add(response_keys, 768 "TargetAlias", conn->conn_target->t_alias); 769 keys_add_int(response_keys, "TargetPortalGroupTag", 770 conn->conn_portal->p_portal_group->pg_tag); 771 } 772 773 for (i = 0; i < KEYS_MAX; i++) { 774 if (request_keys->keys_names[i] == NULL) 775 break; 776 777 login_negotiate_key(request, request_keys->keys_names[i], 778 request_keys->keys_values[i], skipped_security, 779 response_keys); 780 } 781 782 /* 783 * We'd started with usable values at our end. But a bad initiator 784 * could have presented a large FirstBurstLength and then a smaller 785 * MaxBurstLength (in that order) and because we process the key/value 786 * pairs in the order they are in the request we might have ended up 787 * with illegal values here. 788 */ 789 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL && 790 conn->conn.conn_first_burst_length > 791 conn->conn.conn_max_burst_length) { 792 log_errx(1, "initiator sent FirstBurstLength > MaxBurstLength"); 793 } 794 795 conn->conn.conn_max_recv_data_segment_length = 796 conn->conn_max_recv_data_segment_limit; 797 keys_add_int(response_keys, "MaxRecvDataSegmentLength", 798 conn->conn.conn_max_recv_data_segment_length); 799 800 log_debugx("operational parameter negotiation done; " 801 "transitioning to Full Feature Phase"); 802 803 keys_save_pdu(response_keys, response); 804 pdu_send(response); 805 pdu_delete(response); 806 keys_delete(response_keys); 807 pdu_delete(request); 808 keys_delete(request_keys); 809 } 810 811 static void 812 login_wait_transition(struct ctld_connection *conn) 813 { 814 struct pdu *request, *response; 815 struct iscsi_bhs_login_request *bhslr; 816 817 log_debugx("waiting for state transition request"); 818 request = login_receive(&conn->conn, false); 819 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs; 820 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0) { 821 login_send_error(request, 0x02, 0x00); 822 log_errx(1, "got no \"T\" flag after answering AuthMethod"); 823 } 824 825 log_debugx("got state transition request"); 826 response = login_new_response(request); 827 pdu_delete(request); 828 login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION); 829 pdu_send(response); 830 pdu_delete(response); 831 832 login_negotiate(conn, NULL); 833 } 834 835 void 836 login(struct ctld_connection *conn) 837 { 838 struct pdu *request, *response; 839 struct iscsi_bhs_login_request *bhslr; 840 struct keys *request_keys, *response_keys; 841 struct auth_group *ag; 842 struct portal_group *pg; 843 const char *initiator_name, *initiator_alias, *session_type, 844 *target_name, *auth_method; 845 bool redirected, fail, trans; 846 847 /* 848 * Handle the initial Login Request - figure out required authentication 849 * method and either transition to the next phase, if no authentication 850 * is required, or call appropriate authentication code. 851 */ 852 log_debugx("beginning Login Phase; waiting for Login PDU"); 853 request = login_receive(&conn->conn, true); 854 bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs; 855 if (bhslr->bhslr_tsih != 0) { 856 login_send_error(request, 0x02, 0x0a); 857 log_errx(1, "received Login PDU with non-zero TSIH"); 858 } 859 860 pg = conn->conn_portal->p_portal_group; 861 862 memcpy(conn->conn_initiator_isid, bhslr->bhslr_isid, 863 sizeof(conn->conn_initiator_isid)); 864 865 /* 866 * XXX: Implement the C flag some day. 867 */ 868 request_keys = keys_new(); 869 keys_load_pdu(request_keys, request); 870 871 assert(conn->conn_initiator_name == NULL); 872 initiator_name = keys_find(request_keys, "InitiatorName"); 873 if (initiator_name == NULL) { 874 login_send_error(request, 0x02, 0x07); 875 log_errx(1, "received Login PDU without InitiatorName"); 876 } 877 if (valid_iscsi_name(initiator_name) == false) { 878 login_send_error(request, 0x02, 0x00); 879 log_errx(1, "received Login PDU with invalid InitiatorName"); 880 } 881 conn->conn_initiator_name = checked_strdup(initiator_name); 882 log_set_peer_name(conn->conn_initiator_name); 883 setproctitle("%s (%s)", conn->conn_initiator_addr, conn->conn_initiator_name); 884 885 redirected = login_portal_redirect(conn, request); 886 if (redirected) { 887 log_debugx("initiator redirected; exiting"); 888 exit(0); 889 } 890 891 initiator_alias = keys_find(request_keys, "InitiatorAlias"); 892 if (initiator_alias != NULL) 893 conn->conn_initiator_alias = checked_strdup(initiator_alias); 894 895 assert(conn->conn_session_type == CONN_SESSION_TYPE_NONE); 896 session_type = keys_find(request_keys, "SessionType"); 897 if (session_type != NULL) { 898 if (strcmp(session_type, "Normal") == 0) { 899 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL; 900 } else if (strcmp(session_type, "Discovery") == 0) { 901 conn->conn_session_type = CONN_SESSION_TYPE_DISCOVERY; 902 } else { 903 login_send_error(request, 0x02, 0x00); 904 log_errx(1, "received Login PDU with invalid " 905 "SessionType \"%s\"", session_type); 906 } 907 } else 908 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL; 909 910 assert(conn->conn_target == NULL); 911 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) { 912 target_name = keys_find(request_keys, "TargetName"); 913 if (target_name == NULL) { 914 login_send_error(request, 0x02, 0x07); 915 log_errx(1, "received Login PDU without TargetName"); 916 } 917 918 conn->conn_port = port_find_in_pg(pg, target_name); 919 if (conn->conn_port == NULL) { 920 login_send_error(request, 0x02, 0x03); 921 log_errx(1, "requested target \"%s\" not found", 922 target_name); 923 } 924 conn->conn_target = conn->conn_port->p_target; 925 } 926 927 /* 928 * At this point we know what kind of authentication we need. 929 */ 930 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) { 931 ag = conn->conn_port->p_auth_group; 932 if (ag == NULL) 933 ag = conn->conn_target->t_auth_group; 934 if (ag->ag_name != NULL) { 935 log_debugx("initiator requests to connect " 936 "to target \"%s\"; auth-group \"%s\"", 937 conn->conn_target->t_name, 938 ag->ag_name); 939 } else { 940 log_debugx("initiator requests to connect " 941 "to target \"%s\"", conn->conn_target->t_name); 942 } 943 } else { 944 assert(conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY); 945 ag = pg->pg_discovery_auth_group; 946 if (ag->ag_name != NULL) { 947 log_debugx("initiator requests " 948 "discovery session; auth-group \"%s\"", ag->ag_name); 949 } else { 950 log_debugx("initiator requests discovery session"); 951 } 952 } 953 954 if (ag->ag_type == AG_TYPE_DENY) { 955 login_send_error(request, 0x02, 0x01); 956 log_errx(1, "auth-type is \"deny\""); 957 } 958 959 if (ag->ag_type == AG_TYPE_UNKNOWN) { 960 /* 961 * This can happen with empty auth-group. 962 */ 963 login_send_error(request, 0x02, 0x01); 964 log_errx(1, "auth-type not set, denying access"); 965 } 966 967 /* 968 * Enforce initiator-name and initiator-portal. 969 */ 970 if (auth_name_check(ag, initiator_name) != 0) { 971 login_send_error(request, 0x02, 0x02); 972 log_errx(1, "initiator does not match allowed initiator names"); 973 } 974 975 if (auth_portal_check(ag, &conn->conn_initiator_sa) != 0) { 976 login_send_error(request, 0x02, 0x02); 977 log_errx(1, "initiator does not match allowed " 978 "initiator portals"); 979 } 980 981 /* 982 * Let's see if the initiator intends to do any kind of authentication 983 * at all. 984 */ 985 if (login_csg(request) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) { 986 if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) { 987 login_send_error(request, 0x02, 0x01); 988 log_errx(1, "initiator skipped the authentication, " 989 "but authentication is required"); 990 } 991 992 keys_delete(request_keys); 993 994 log_debugx("initiator skipped the authentication, " 995 "and we don't need it; proceeding with negotiation"); 996 login_negotiate(conn, request); 997 return; 998 } 999 1000 fail = false; 1001 response = login_new_response(request); 1002 response_keys = keys_new(); 1003 trans = (bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0; 1004 auth_method = keys_find(request_keys, "AuthMethod"); 1005 if (ag->ag_type == AG_TYPE_NO_AUTHENTICATION) { 1006 log_debugx("authentication not required"); 1007 if (auth_method == NULL || 1008 login_list_contains(auth_method, "None")) { 1009 keys_add(response_keys, "AuthMethod", "None"); 1010 } else { 1011 log_warnx("initiator requests " 1012 "AuthMethod \"%s\" instead of \"None\"", 1013 auth_method); 1014 keys_add(response_keys, "AuthMethod", "Reject"); 1015 } 1016 if (trans) 1017 login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION); 1018 } else { 1019 log_debugx("CHAP authentication required"); 1020 if (auth_method == NULL || 1021 login_list_contains(auth_method, "CHAP")) { 1022 keys_add(response_keys, "AuthMethod", "CHAP"); 1023 } else { 1024 log_warnx("initiator requests unsupported " 1025 "AuthMethod \"%s\" instead of \"CHAP\"", 1026 auth_method); 1027 keys_add(response_keys, "AuthMethod", "Reject"); 1028 fail = true; 1029 } 1030 } 1031 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) { 1032 if (conn->conn_target->t_alias != NULL) 1033 keys_add(response_keys, 1034 "TargetAlias", conn->conn_target->t_alias); 1035 keys_add_int(response_keys, 1036 "TargetPortalGroupTag", pg->pg_tag); 1037 } 1038 keys_save_pdu(response_keys, response); 1039 1040 pdu_send(response); 1041 pdu_delete(response); 1042 keys_delete(response_keys); 1043 pdu_delete(request); 1044 keys_delete(request_keys); 1045 1046 if (fail) { 1047 log_debugx("sent reject for AuthMethod; exiting"); 1048 exit(1); 1049 } 1050 1051 if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) { 1052 login_chap(conn, ag); 1053 login_negotiate(conn, NULL); 1054 } else if (trans) { 1055 login_negotiate(conn, NULL); 1056 } else { 1057 login_wait_transition(conn); 1058 } 1059 } 1060